JP2000266388A - Control method and control device for multi-type refrigeration cycle device - Google Patents

Abstract

(57) [Problem] To provide a control method and a control device capable of supplying more capacity to a load side unit having a large load while giving priority to stability of a refrigeration cycle to a plurality of load side units. Further, a control method and a control device capable of stabilizing the refrigeration cycle with good responsiveness when a stop load side unit exists in the heating operation are obtained. SOLUTION: In a refrigeration cycle apparatus having a plurality of load-side units A and B, first, an opening degree of expansion valves 4a and 4b is set at a predetermined refrigerant distribution ratio by a heat source-side control device 13 (ST31, ST32). Thereafter, the opening of each of the expansion valves 4a and 4b is gradually corrected in consideration of the variation in each load (ST41 to ST43). Also, during the heating operation in which the stop load side unit and the operation load side unit coexist, it is determined at regular time intervals whether or not the refrigerant amount during the operation cycle is appropriate, and if inappropriate, the expansion communicating with the stop load side unit is performed. Refrigerant amount optimization control for appropriately correcting the valve opening is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a control method and a control apparatus for a multi-type refrigeration cycle apparatus having a plurality of load-side units.

[0002]

2. Description of the Related Art FIG. 23 shows a refrigerant circuit diagram showing a conventional multi-type refrigeration cycle apparatus as a control method disclosed in Japanese Patent Application Laid-Open No. 4-84061, for example.

In FIG. 23, 1 is a compressor, 2 is a four-way valve, 3 is a heat source side heat exchanger, 4a to 4c are expansion valves, 11a
11a to 11c are room temperature thermistors, 12a to 12c are remote controllers for setting room temperature, 31 is a liquid receiver, 32 is a thin tube,
33 is a suction refrigerant saturation temperature sensor, 34 is a suction pipe temperature sensor, 35 is a refrigerant split flow determination device, 36 is an expansion valve opening degree determination device, and 37 is an inverter unit. A dotted line indicates a signal line, A, B, and C indicate load-side units, X indicates an outdoor unit on the heat source side, and a dashed line indicates a portion included in the outdoor unit X.

[0004] Next, an example of operation of the multi-type refrigeration cycle apparatus configured as described above relating to refrigerant control will be described with reference to FIG. For example, this is a control method in which three load units A, B, and C are installed in a room, respectively, and air conditioning is performed in each room. When a user sends an operation command indoors to the load units A to C by the remote controllers 12a to 12c, the load units A to C are transmitted.
The temperature difference determination device (not shown) in the C is provided between the set temperature of the remote controllers 12a to 12c and the room temperature thermistor 11.
A temperature difference code is determined from the temperature difference from the room temperature detected in a to 11c, and transmitted to the refrigerant distribution determining device 35 via a signal line. When the remote controller 12a to 12c transmits an operation command to the load side units A to C, the capability code determination device (not shown) in each of the load side units A to C A capacity code value is determined based on the capacity, and transmitted to the refrigerant distribution determining device 35 via a signal line.

The refrigerant distribution determining device 35 determines the refrigerant distribution ratio based on the capacity code values of the load units A to C that have issued the respective operation commands, and further determines the refrigerant distribution ratio based on the temperature difference codes transmitted from the load units A to C. The final refrigerant flow ratio is determined by multiplying the refrigerant flow ratio. Thereafter, the expansion valve opening degree determining device 36 detects the intake refrigerant saturation temperature sensor 33.
And the temperature difference detected by the suction pipe temperature sensor 34,
The expansion valves 4 a to 4 d are controlled so that the superheat degree of the suction refrigerant of the compressor 2 is constant and the determined refrigerant distribution ratio is maintained.
The opening of 4c is determined to control the flow rate of the refrigerant to the load units A to C.

In this refrigeration cycle apparatus, when the air conditioning load in a certain room is large, the remote controllers 12a to 12a
Since the temperature difference between the set temperature of the temperature controller 12c and the temperature detected by the room temperature thermistors 11a to 11c becomes large, the value of the temperature difference code by the temperature difference determination device is also changed by the remote controllers 12a to 12c.
The larger the temperature difference between the set temperature of 12c and the detected temperature of the room temperature thermistors 11a to 11c, the larger the temperature difference, and the larger the refrigerant distribution ratio by the refrigerant distribution determining device 35. Therefore,
The flow rate of the refrigerant flowing through the load-side units A to C having a large air-conditioning load increases, and the set room temperature can be quickly reached. At the same time, the capacity code values of the load units A to C are also taken into account by the capacity code determination device. Therefore, a large refrigerant flow rate is secured for the load units A to C having a large capacity even with the same temperature difference code. .

However, in the above-mentioned multi-type refrigeration cycle apparatus, the refrigerant distribution ratio is determined by the capacity code value.
Next, the final refrigerant distribution ratio is determined by multiplying the refrigerant distribution ratio by the temperature difference code.
Control was performed by setting an extreme refrigerant distribution ratio far from the air-side heat exchange performance of C, resulting in an unstable refrigeration cycle state.

For example, in the heating operation, the heating capacity [W] on the air side of the load-side unit is, as shown in equation (1), the area A [m ² ] of the heat exchanger and the heat transmission rate K [W / m]. ² [K] and the temperature code between the refrigerant temperature Tr [K] and the room temperature Tin [K].

On the other hand, the heating capacity [W] on the refrigerant side is determined by the flow rate G of the refrigerant flowing through the heat exchanger as shown in equation (2).
heat exchanger inlet ratio enthalpy of r and refrigerant [kJ / k
g] and the difference between the outlet specific enthalpy hout [kJ / kg].

[0010] Air-side heating capacity of load-side unit = AK x (Tr-Tin) ... (1) Refrigerant-side heating capacity of load-side unit = Gr x (hin-hout) ... (2)

Since there is no decompression device such as an expansion valve in the pipe connecting the discharge port of the compressor 1 and each load side heat exchanger inlet, the refrigerant state at the inlets of the load side units A to C is compressed. It may be considered that there is not much difference from the refrigerant state of the discharge port of the machine 1. Therefore, in a plurality of load-side units, when the specific enthalpy hin at each load-side heat exchanger inlet and the two-phase part refrigerant temperature Tr in the heat exchanger are the same and the room temperature Tin in each room is the same, each load-side unit Is determined by the ratio of the capacity code value AK. On the other hand, when the refrigerant distribution ratio is distributed by the capacity code value AK, the specific enthalpy hout at the heat exchanger outlet becomes the same.

As a specific example of a two-room heating operation, the ratio between the capacity codes of the load units A and B is 2: 1, and the refrigerant temperature is 4
Suppose that the set temperature of the remote controller 12a in the room A is 30 ° C., the room temperature is 20 ° C., the set temperature of the remote controller 12b in the room B is 21 ° C., and the room temperature is 20 ° C. At this time, the ratio of the difference (ΔT) between the refrigerant temperature and the room temperature is (4
0-20): (40-20) = 1: 1. From the formulas (1) and (2), when the refrigerant flow ratio is the ratio of the capacity code values = 2: 1, the outlet ratio enthalpy hout becomes the same, and the operation of the refrigeration cycle apparatus with good heat exchange efficiency can be performed. On the other hand, in the conventional method of controlling the multi-type refrigeration cycle apparatus described above, the ratio of the difference between the set temperature of the remote controller and the room temperature (temperature difference code) is (30-2).
0) :( 21-20) = 10: 1. When the refrigerant distribution ratio is calculated from the ratio between the capacity code value AK and the integrated value of the temperature difference code, the ratio is 20: 1 from Expression (3).

Gr (room A): Gr (room B) = AK (room A) × temperature difference code (room A): AK (room B) × temperature difference code (room B) = 2 × 10: 1 × 1 = 20: 1 ・ ・ (3)

When operated in accordance with this control method, the load-side unit A cannot completely condense the refrigerant due to excessive refrigerant flow, and flows out into the expansion valve in two phases. For this reason, it becomes difficult to control the flow rate of the refrigerant in the expansion valve, and the refrigeration cycle may be destabilized. On the other hand, in the load side unit B, since the refrigerant flow rate is insufficient, the outlet refrigerant condenses to the air temperature. Thus, the efficiency of heat exchange is not good in any of the heat exchangers of the load units A and B.

In the method of controlling refrigerant in a multi-type refrigeration cycle apparatus, a conventional example of a method of controlling excess refrigerant in a heating operation when an arbitrary load-side unit is stopped will be described. For example, FIG. 24 is a refrigerant circuit diagram showing a configuration of a multi-type refrigeration cycle apparatus disclosed in Japanese Patent Application Laid-Open No. 1-217164. The same reference numerals as those in FIG. 23 denote the same or corresponding parts, and a description thereof will be omitted. 5a, 5b, 5
Reference numeral c denotes a load-side heat exchanger, which is composed of three load-side units, as in FIG. 38 is a temperature detector, 39 is a control device, and 40 is a control signal output device.

Hereinafter, an operation example regarding the refrigerant control of the multi-type refrigeration cycle apparatus having the configuration shown in FIG. 24 will be described.
For example, three load-side heat exchangers 5a, 5b, 5c are installed in a room, respectively, and when heating each room, the load-side heat exchangers 5b, 5c are in a stopped state, and the load-side heat exchanger 5a
The method of controlling the refrigerant when the is in the operating state will be described. The four-way valve 2 is connected to the side indicated by the dotted line in the figure to perform a heating operation.
Expansion valves 4b corresponding to the stop load side heat exchangers 5b, 5c,
The opening degree of 4c is set to b pulse as an initial value, a small amount of refrigerant is circulated also to the load side heat exchangers 5b and 5c, and the refrigerant is accumulated in the stop load side heat exchangers 5b and 5c. Preventing. The control of the opening degree of the expansion valves 4b and 4c during operation is performed by detecting the refrigerant subcooling degree f as follows.

The condensing temperature is detected by the temperature detector 38, and the refrigerant temperature at the inlet side of the expansion valve 4a corresponding to the operating load side heat exchanger 5a is detected by the detector 11a. Then, from the difference between the condensing temperature and the refrigerant temperature on the inlet side of the expansion valve 4a, the refrigerant supercooling degree f of the operating refrigeration cycle is calculated. For example, when the refrigerant supercooling degree f calculated at the time d falls below the set value a, the control device 39 transmits a command signal to the control signal output device 40. As a result, the opening degrees of the expansion valves 4b and 4c increase up to the c pulse, and the refrigerant accumulated in the stopped load side heat exchangers 5b and 5c is discharged. Thereafter, data is taken from the temperature detector 38 at a constant sampling interval, and when the refrigerant subcooling degree f returns to the set value a, the expansion valve 4
The opening degrees of b and 4c are returned to b pulses.

By the above-described control, the degree of subcooling of the refrigerant can be maintained at a certain level or more, the amount of circulating refrigerant is kept optimal, and a proper and stable refrigeration cycle can be obtained. However, in the above-described conventional control method, after the control is completed, the expansion valve openings 4b and 4c are returned to the opening before control (b pulse). Therefore, the load-side heat exchanger 5
If the opening degree (b pulse) of the expansion valve corresponding to b and 5c is inappropriate, this control is intermittently repeated, and the refrigeration cycle may fall into an unstable state.
As the value of the refrigerant supercooling degree f as the control start / end condition, the same set value a is used. Therefore, the refrigerant supercooling degree f in the operating load side heat exchanger 5a immediately after the end of the control overshoots and continues to increase without being stabilized. If the expansion valve opening 4a of the operating unit is controlled accordingly, erroneous control may be caused and the refrigeration cycle may become unstable.

[0019]

As described above, the conventional method of controlling a multi-type refrigeration cycle apparatus has the following problems.

A plurality of load-side units are multiplied by a ratio of a capability code value and a ratio of a temperature difference code to determine a refrigerant distribution ratio, which is extremely different from the air-side heat exchange performance of each load-side unit. Control by setting a proper refrigerant distribution ratio, causing insufficient capacity, unstable supply of capacity, and failure of the compressor due to uncontrollability, resulting in an unstable refrigeration cycle state. Was.

Further, when the operation unit and the stop unit are mixed on the load side, the expansion valve opening of the stop unit is returned to the opening before the control after the control is completed. There has been a problem that an unstable refrigeration cycle state occurs when appropriate. In addition,
Since the value of the degree of supercooling of the refrigerant as the termination condition is the same value, there is a problem that the refrigeration cycle becomes unstable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a control method and a control apparatus for a multi-type refrigeration cycle apparatus capable of operating a refrigeration cycle in a stable state. . Therefore, while prioritizing the stabilization of the balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit in the refrigeration cycle, refrigerant distribution that supplies more capacity to the load-side unit with the largest load is realized. The purpose is to do. Another object of the present invention is to stabilize a refrigeration cycle by flowing an appropriate amount of refrigerant to a stopped load side heat exchanger in a heating operation in which an operating unit and a stopping unit are mixed on the load side.

[0023]

According to the present invention, there is provided a method for controlling a multi-type refrigeration cycle apparatus, comprising: a heat source side unit having a compressor and a heat source side heat exchanger; and a plurality of load side units each having a load side heat exchanger. A multi-type refrigeration cycle apparatus comprising: a plurality of units; and a plurality of flow rate adjusting means communicating with a load side heat exchanger of each of the load side units and adjusting a flow rate of a refrigerant flowing through the load side heat exchanger. When operating the side units, first, the flow rate of the refrigerant flowing through the plurality of load side heat exchangers operating by adjusting the respective flow rate adjusting means is set to a predetermined flow dividing ratio. The flow rate adjusting means is finely adjusted in accordance with the size of the load to increase the flow rate of the refrigerant flowing through the load side heat exchanger having a large load.

Further, the control method of the multi-type refrigeration cycle apparatus according to the present invention is characterized in that the refrigeration cycle apparatus is operated when a load fluctuation exceeding a predetermined value occurs in at least one load side unit in the refrigeration cycle apparatus during operation. It is characterized in that the flow rate of the refrigerant flowing through the load-side heat exchanger of the load-side unit is set to a predetermined split ratio.

Further, in the control method of the multi-type refrigeration cycle apparatus according to the present invention, the dividing ratio of the flow rate of the refrigerant flowing through the plurality of operating load-side heat exchangers is changed to the capacity ratio of each of the load-side heat exchangers. It is characterized in that it is set on the basis of this.

Further, a control method of a multi-type refrigeration cycle apparatus according to the present invention includes a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, In the multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means which are connected to the load side heat exchanger of each load side unit and adjust a flow rate of the refrigerant flowing through the load side heat exchanger, the plurality of load side units are operated. In the case of the cooling operation, the respective flow rate adjusting means are adjusted so that the difference between the target degree of superheating and the measured degree of supercooling is eliminated in the cooling operation, and the difference between the target degree of supercooling and the measured degree of supercooling is eliminated in the heating operation. After setting the flow rate of the refrigerant flowing through the side heat exchanger, the flow rate adjusting means is finely adjusted in accordance with the magnitude of the load of each load side unit, so that the flow rate of the refrigerant flowing through the load side heat exchanger with a large load is adjusted. It is characterized in that to increase.

Further, the control method of the multi-type refrigeration cycle apparatus according to the present invention is characterized in that, when a load fluctuation exceeding a predetermined value occurs in at least one or more load-side units in the operating refrigeration cycle apparatus, In the refrigeration cycle, the flow rate adjusting means is adjusted so as to eliminate the difference between the target degree of superheat and the measured degree of supercooling in the case of cooling operation, and to eliminate the difference between the target degree of supercooling and the measured degree of supercooling in the case of heating operation. The flow rate of the refrigerant flowing through the load side heat exchanger of the load side unit is changed.

Further, in the control method of the multi-type refrigeration cycle apparatus according to the present invention, when the refrigerant flow rate is finely adjusted in accordance with the magnitude of the load on each load side unit, the target overheating of the load side heat exchanger having a large load is performed. Degree or the target supercooling degree is changed to a value smaller than the current target value, and the flow rate adjusting means is finely adjusted so as to eliminate the difference between the measured superheat degree or the measured subcooling degree and the changed target value, The present invention is characterized in that the flow rate of refrigerant flowing through a load-side heat exchanger having a large load is increased.

Further, in the control method of the multi-type refrigeration cycle apparatus according to the present invention, when the refrigerant flow rate is finely adjusted according to the magnitude of the load of each load side unit, the change of the refrigerant flow rate in one fine adjustment is performed. The amount is within a predetermined range.

Further, in the control method of the multi-type refrigeration cycle apparatus according to the present invention, when finely adjusting the flow rate of the refrigerant according to the magnitude of the load of each load side unit, the refrigerant flows to the load side heat exchanger having a large load. It is characterized in that the flow rate of the refrigerant is increased by a predetermined amount.

Further, in the control method of the multi-type refrigeration cycle apparatus according to the present invention, when finely adjusting the flow rate of the refrigerant according to the magnitude of the load of each load side unit, the refrigerant flows to the load side heat exchanger having a large load. The refrigerant flow rate is increased, and the refrigerant flow rate flowing through the load-side heat exchanger with a smaller load is reduced so that the total flow rate of the refrigerant flowing through the respective flow rate adjusting means before and after the change becomes equal. It is.

Further, the control method of the multi-type refrigeration cycle apparatus according to the present invention includes a heat source side unit having a compressor and a heat source side heat exchanger; a plurality of load side units each having a load side heat exchanger; In the multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means which are connected to the load side heat exchanger of each load side unit and adjust a flow rate of the refrigerant flowing through the load side heat exchanger, the plurality of load side units are operated. When performing the cooling operation, the flow rate adjusting means is adjusted so that the difference between the target superheat degree and the measured superheat degree is reduced, and in the case of the heating operation, the difference between the target superheat degree and the measured supercool degree is eliminated. Adjust the flow rate of the refrigerant flowing through the load-side heat exchanger of the load-side unit, and if the difference between the measured value and the target value of the degree of superheating or supercooling at that time exceeds a predetermined value, the difference becomes small. Like After changing the target value, by adjusting the flow rate adjusting means, it is characterized in changing the refrigerant flow rate so that the difference between the target value has been changed and the measurement value is eliminated.

[0033] Also, a method of controlling a multi-type refrigeration cycle apparatus according to the present invention includes a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, In the multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means which are connected to the load side heat exchanger of each load side unit and adjust the flow rate of the refrigerant flowing through the load side heat exchanger, the plurality of load side units are operated. In the case of, the difference between the target superheat degree and the measured superheat degree in the case of the cooling operation by adjusting the flow rate adjusting means, so as to eliminate the difference between the target supercooling degree and the measured supercooling degree in the case of the heating operation, Adjusting the flow rate of the refrigerant flowing through the load-side heat exchanger of each of the load-side units, the maximum refrigerant flow rate and the minimum refrigerant flow rate among the refrigerant flow rates flowing through each of the load-side heat exchangers at that time When exceeds the predetermined range, for the load side unit where the change amount of the refrigerant flow rate in the predetermined time so far was large, after changing the target value, the flow rate adjusting means was adjusted and changed to a measured value. The refrigerant flow rate is changed so that the difference from the target value is eliminated.

Further, the control method of the multi-type refrigeration cycle apparatus according to the present invention includes a heat source side unit having a compressor and a heat source side heat exchanger; a plurality of load side units each having a load side heat exchanger; In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means communicating with each load side unit and adjusting the flow rate of the refrigerant flowing through the load side heat exchanger, when a heating load operation is performed, a stop load side unit is present. When the measured supercooling degree of the operating load side unit is larger or smaller than a predetermined appropriate range,
The flow rate adjusting means communicating with the stop load side heat exchanger is adjusted so that the measured subcooling degree falls within the appropriate range to increase or decrease the refrigerant flow rate. When the flow rate falls within an appropriate range, the flow rate of the refrigerant flowing through the stop load side heat exchanger is maintained in that state.

Further, a method of controlling a multi-type refrigeration cycle apparatus according to the present invention includes a heat source side unit having a compressor and a heat source side heat exchanger; a plurality of load side units each having a load side heat exchanger; In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means communicating with each load side unit and adjusting a flow rate of the refrigerant flowing through the load side heat exchanger, when a heating load operation is performed, a stop load side unit is present. When the flow rate of the refrigerant flowing through the load-side heat exchanger of the operating load-side unit continuously increases or decreases in only one direction within a predetermined period of time, the flow proceeds to the load-side heat exchanger of the stopped load-side unit. The flow rate of the flowing refrigerant is changed in the same direction as the change direction of the flow rate of the refrigerant flowing through the operation load side heat exchanger, and the flow rate of the refrigerant flowing through the operation load side heat exchanger is changed in one direction. It is characterized in maintaining the flow rate of refrigerant flowing into the stop load-side heat exchanger when escaped the state changes continuously in only in that state.

Further, a method of controlling a multi-type refrigeration cycle apparatus according to the present invention includes a heat source side unit having a compressor and a heat source side heat exchanger; a plurality of load side units each having a load side heat exchanger; In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means communicating with each load side unit and adjusting the flow rate of the refrigerant flowing through the load side unit, when the heating load operation is performed, if the stop load side unit is present, start up. At the time, the flow rate of the refrigerant flowing through the load-side heat exchanger of the stop load-side unit is initially set to a predetermined value so that the flow rate of the refrigerant flowing through the operating load-side unit does not become insufficient, and after a predetermined time elapses, the stoppage is performed. The flow rate adjusting means communicating with the load side heat exchanger is adjusted to gradually decrease the flow rate of the refrigerant flowing through the operation load side unit, and the heat source in the heat source side unit When the pipe temperature of the heat exchanger falls below a predetermined value, the flow rate adjusting means communicating with the stopped load side heat exchanger is returned to the state before the pipe temperature drops and maintained in that state. It is assumed that.

Further, the control device of the multi-type refrigeration cycle apparatus according to the present invention comprises: a heat source side unit having a compressor and a heat source side heat exchanger; a plurality of load side units each having a load side heat exchanger; Refrigerant flow distribution means for distributing the refrigerant flow to the load-side heat exchanger based on the capacity of the load-side heat exchanger, and the refrigerant flow to the plurality of load-side heat exchangers by the load-side unit. Refrigerant flow adjusting means for adjusting according to the magnitude of the load, and when a significant load change occurs in at least one or more of the load-side units, the refrigerant flow distribution means controls the plurality of load-side units. It is characterized in that the flow rate of the refrigerant to the heat exchanger is distributed.

Further, the control device of the multi-type refrigeration cycle apparatus according to the present invention includes a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a cooling unit. In the operation, the difference between the target superheat degree and the measured superheat degree, and in the heating operation, the refrigerant flow rate to each of the load-side heat exchangers of the load-side unit so as to eliminate the difference between the target supercooling degree and the measured supercooling degree. Refrigerant flow distribution means for distributing, and refrigerant flow adjustment means for adjusting the refrigerant flow rate to the plurality of load-side heat exchangers according to the magnitude of the load on each of the load-side units, and at least one or more of the When a large load fluctuation occurs on the load side unit,
The refrigerant flow distribution means distributes the refrigerant flow to the plurality of load-side heat exchangers.

Further, in the control device for the multi-type refrigeration cycle apparatus according to the present invention, when the temperature difference between the set temperature of the load-side unit and the measured temperature exceeds a predetermined value, the load-side unit has a large load variation. Is detected.

Further, the control device of the multi-type refrigeration cycle apparatus according to the present invention detects that a significant load change has occurred in the load side unit when the amount of change in the frequency of the compressor exceeds a predetermined value. Things.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a control method and a control device of the multi-type refrigeration cycle device according to the first embodiment of the present invention will be described. FIG. 1 is a refrigerant circuit diagram showing a configuration of a multi-type refrigeration cycle device according to the present embodiment. In the figure, 1 is a compressor, 2 is a flow path switching means, for example, a four-way valve or a cooling / heating switching valve, 3 is a heat source side heat exchanger, and 4a, 4b are means having functions of a pressure reducing means and a flow rate adjusting means, for example, expansion. Valves 5a and 5b are load side heat exchangers,
10 is a heat source side heat exchanger tube temperature sensor, 11a and 11b are room temperature detection sensors, 12a and 12b are remote controllers, 13 is a heat source side control device, 14a and 14b are load side control devices, 20 is a load side control device 14a, 14b is a signal line connecting the heat source side control device 13; 21 is a signal line connecting the heat source side heat exchanger tube temperature sensor 10 and the heat source side control device 13;
2 is a signal line connecting the motor of the compressor 1 and the heat source side control device 13, 23 is a signal line connecting the expansion valves 4a, 4b and the heat source side control device 13, 24a and 24b are room temperature detection sensors 11a and the load side control device 13a. And room temperature detection sensor 11b
X is a heat source side unit, and A and B are load side units. The multi-type refrigeration cycle apparatus has, for example, one heat source unit and two load units A and B.

The operation of refrigerant flow during the cooling operation will be described below. The four-way valve 2 is connected as shown by a solid line. In the case of the two-load-side operation, the high-pressure gas refrigerant compressed by the compressor 1 flows from the discharge port of the compressor 1 to the heat source-side heat exchanger 3 via the four-way valve 2, where heat is released and the refrigerant is discharged. It condenses and flows out as high-pressure liquid refrigerant. Then, the refrigerant is divided into two paths, flows to the expansion valves 4a and 4b, is adiabatically expanded, and becomes a low-pressure two-phase refrigerant. Further, the low-pressure two-phase refrigerant is supplied to the load-side heat exchangers 5a, 5b.
To cool the room by exchanging heat with room air when collecting and evaporating heat. Then, the refrigerant flows out of the load-side heat exchangers 5a and 5b as low-pressure gas refrigerant and returns to the suction port of the compressor 1 via the four-way valve 2.
In the case of one-load-side operation, for example, when stopping the load-side unit B, the refrigerant is circulated only to the load-side unit A. That is, the expansion valve 4b is fully closed, and the high-pressure liquid refrigerant flows only through the expansion valve 4a, where it is adiabatically expanded into a low-pressure two-phase refrigerant and flows to the load-side heat exchanger 5a. The other operations are the same as in the operation on the two-load-side unit, and a description thereof will be omitted.

Next, the operation of refrigerant circulation during the heating operation will be described. The four-way valve 2 switches the refrigerant circuit in the cooling operation and connects as shown by a dotted line. In the case of the two-load-side operation, the high-pressure gas refrigerant compressed by the compressor 1 is divided into two paths from the discharge port of the compressor 1 via the four-way valve 2 and divided into two paths.
a and 5b, and heats the room by exchanging heat with room air when radiating and condensing here. The refrigerant flows out of the load-side heat exchangers 5a and 5b as high-pressure liquid refrigerant, is adiabatically expanded by the expansion valves 4a and 4b, becomes a low-pressure two-phase refrigerant, and flows into the heat source-side heat exchanger 3. Further, the refrigerant collects heat in the heat source side heat exchanger 3 and evaporates, flows out as a low-pressure gas refrigerant, and returns to the suction port of the compressor 1 via the four-way valve 2. In the case of operation on one load side, for example, load unit B
Is stopped, since the expansion valve 4b is not fully closed, the operation is the same as in the case of the operation on the two load side units, and the description is omitted.

Next, the refrigerant control procedure of the load-side controllers 14a and 14b and the heat-source-side controller 13 when operating the plurality of load-side units A and B will be described. FIG. 2 is a flowchart showing this procedure. In the load side units A and B, as shown in ST1a and ST1b,
After the load-side controllers 14a and 14b receive the respective signals from the sensors and then calculate using the received items, the necessary items among the received items and the calculated items are determined by the heat-source-side controller 13a.
Send to The specific contents are shown below. In addition, these start control when the set temperature code is issued from the remote controllers 11a and 11b, and until the stop code is transmitted from the remote controllers 11a and 11b.
It shall be repeated at regular time intervals, for example, every three minutes.

Reception items (1) Set temperature code transmitted from the remote controllers 12a and 12b In a room where the load side units A and B are installed, the set temperature specified by the user is set to a predetermined corresponding code number. What was replaced. The specific set temperature value may be received. (2) Room temperature measured and transmitted by the room temperature sensors 11a and 11b

Calculation Items (1) Set Temperature The received set temperature code is replaced with a specific temperature value. (2) Temperature difference code Calculates the difference between the above set temperature and the received room temperature.
It represents the magnitude of the load on the load-side units A and B. During cooling operation Δroom temperature = room temperature−set temperature During heating operation Δroom temperature = set temperature−room temperature The value of the calculated Δroom temperature is replaced with a predetermined code number.

Transmission items (1) Temperature difference codes Ca, Cb (2) Capacity values qa of load side units stored in advance,
qb

In the heat source side control device 13, ST21
When a signal is transmitted from one or more load-side units,
The control shown in ST22 to ST43 is performed. First, the heat source side control device 13 receives each signal from the sensor, and then uses the received items to make each expansion valve 4a, 4b for proper refrigerant distribution.
After calculating the opening, a signal is transmitted to each of the expansion valves 4a and 4b to set or correct the opening. If no signal is transmitted from one of the load-side units in ST21, the process ends (END). Hereinafter, specific contents in ST22 to ST43 will be described.

Reception items (1) Temperature difference codes Ca, Cb of each operation load side unit (2) Capacity qa, qb of each operation load side unit

Calculation items (1) Reference compressor frequency Hz Each received temperature difference code Ca, Cb and each capacity qa, qb
Then, a value representing the load state of the measurement is calculated by the equation (4) (ST22).

Measured full load state value q (all) = {C _i · q _i / Σ (rated C · q) _i ·· (4) C: temperature difference code q: capacity or capacity code i: operating load side unit Representation (i = 1, 2, 3,...) Rated Cq: Value when the load side unit is operating at rated load

Next, the refrigerant flow rate of the entire refrigeration cycle corresponding to the load condition is estimated, and the compressor frequency is obtained based on the estimated flow rate (ST23). As a specific example, a correspondence table functio in which a compressor frequency for a measured full load state value is predetermined.
Table 1 shows n1. The compressor frequency obtained in this table may be corrected in consideration of the outside air temperature and the state of the refrigeration cycle.

[0053]

[Table 1]

(2) When the control is started for the first time after the control of the reference expansion valve opening S, control corresponding to the cycle is performed in ST31 and ST32. That is, the total refrigerant flow rates estimated above are calculated by the capacities qa, qb of the load side units A, B.
Expansion valves 4a, 4b according to the values distributed at the ratio determined from
Set the opening of. Here, ST31 and ST32 operate as refrigerant flow distribution means for distributing the refrigerant flow based on the capacity of the load-side units A and B. As a specific example,
As shown in Table 2, a correspondence table functio in which the total opening S (all) of each expansion valve with respect to the compressor frequency is determined in advance.
n2 is stored, and based on Table 2, the total opening degree S (al) of each expansion valve is obtained from the compressor frequency obtained in ST23.
1) is determined (ST31).

[0055]

[Table 2]

Next, the respective opening degrees Sa, Sb of the expansion valves 4a, 4b are distributed by the capacity ratio according to the equation (5) (ST32). The opening degree S of each expansion valve 4a, 4b determined in this way.
a and Sb may be corrected in consideration of the refrigeration cycle state.

Sall = Sa + Sb Sa: Sb = qa: qb (5)

Transmission items (1) The compressor frequency is transmitted to the motor drive section of the compressor 1 (2) The opening degrees Sa, Sb of the expansion valves to each of the expansion valves 4a, 4b
With the above, the first control when the operation is requested from the remote controllers 12a and 12b is performed, the frequency of the compressor 1 and the opening of each of the expansion valves 4a and 4b are initialized, and the cooling operation is started. You.

In the cycle corresponding control, the split ratio of the refrigerant circulated to each load side unit is set based on the capacity ratio of the load side units. For this reason, the split ratio is within a predetermined range, and the extreme split ratio unlike the conventional control method is not set. Therefore, the balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit is lost, causing the refrigeration cycle to become unstable, resulting in insufficient capacity, unstable supply of capacity, and failure of the compressor due to loss of control. It is avoided to cause such.

The heat source side control device 13 starts the control and operates at a predetermined control timing, for example, every three minutes. If there is a significant load change in one or more load units A and B, the frequency of the compressor 1 determined from the load state in ST23 may change significantly from the previous time. That is, if the difference between the previous frequency and the new frequency calculated this time becomes larger than bHz, for example, about 10 Hz in ST25, the cycle corresponding control is performed again in ST31 and ST32, and the frequency of the compressor 1 and the expansion valve 4a , 4b are set again. When a large load change occurs in the load-side units A and B, the cycle state changes. Therefore, the cycle-based control is reset in accordance with the load state. The following can be mentioned. 1) When there is a change in the number of operating vehicles, for example, the operation from two vehicles to one vehicle. 2) For example, set the remote controller to 20
When the set temperature is changed by the user, such as a change from 27 ° C to 27 ° C. 3) When the room temperature changes due to a change in the room space state, for example, when the number of people in the room increases or the cloudy state causes the sun to enter the room and the room temperature rises suddenly, or a stove or a fan is turned on. 4) For example, the fan rotation speed is reduced due to foreign matter suction.
When there is a minor abnormality in driving.

As described above, when there is a large load change in the load side unit, this is detected in ST25, and ST22, ST23, ST31, ST31 are detected in accordance with the load.
At 32, the refrigerant flow rate is reset. For this reason, when there is a large load change, the refrigerant can be distributed so as to be able to reach an appropriate refrigerant flow rate quickly in a timely manner, that is, the refrigeration cycle can be stabilized smoothly with good responsiveness. This large load fluctuation can be detected when the amount of change in the frequency of the compressor exceeds a predetermined value. Further, it can also be detected when the temperature difference between the set temperature of the load-side unit and the measured temperature exceeds a predetermined value. This can be detected by the heat-source-side control device 13 by the values of the temperature difference codes Ca and Cb, which are the items received from the load-side control devices 14a and 14b. If so, it can be determined that a significant load change has occurred.

In the case of the second or subsequent time after starting the control, that is,
If the cycle-adaptive control has already been performed, ST25
If the difference between the previous frequency and the new frequency is equal to or less than bHz, for example, about 10 Hz, it means that the previous operating state and the situation have not changed much. At this time, S
In T41 to ST43, a load response control is performed to supply as much capacity as possible to the load-side unit having a large load without disrupting the state of the refrigeration cycle. In other words, a plurality of load-side heat exchangers are controlled. Refrigerant flow rate adjusting means for adjusting the flow rate of the refrigerant in accordance with the magnitude of the load on each of the load-side units is provided. Operating load side units A and B
In step ST41, the temperature difference code representing the measured load is compared with the temperature difference codes of other load-side units. In this comparison, when the difference between the temperature difference codes is smaller than a predetermined value, for example, 5, the load state of the operation load side unit is regarded as being equal, and the current opening degree of the expansion valve is maintained (S
T42). In the comparison of ST41, when the difference of the temperature difference code is a predetermined value, for example, 5 or more, the opening degree of the expansion valve communicating with the operation load side unit having the large temperature difference code is changed by a pulse, for example, several pulses. (ST4
3) The flow rate of the refrigerant flowing through the load-side unit having a large load is increased.

The adjustment of the opening degree of the expansion valve by the load corresponding control is performed until the difference between the respective temperature difference codes becomes smaller than a predetermined value (for example, 5).
In ST42, the opening degree of the expansion valve at that time is maintained. In this way, by performing the load-corresponding control, the expansion valves 4a and 4b are finely adjusted according to the magnitude of the load on each of the load-side units A and B, and the flow rate of the refrigerant to the load-side unit with a large load is increased. And provide as much capacity as possible.
In particular, the amount of increase of the expansion valves 4a and 4b at the time of this fine adjustment is a predetermined amount, and is set in advance so as not to change the refrigerant flow rate too much. For this reason, the stability of the refrigeration cycle can be reliably maintained.

Next, FIG. 3 is a time chart showing a specific control according to the present embodiment. For example, the load side units A and B are set as follows. Load-side unit A: capacity = 2.0 kW, capacity code 2, temperature difference code 15 (large load) Load-side unit B: capacity = 4.0 kW, capacity code 3, temperature difference code 7 (small load) Temperature used in comparison with ST41 The predetermined value of the difference code is set to 5. When the full load state value measured by the equation (4) is 0.5, the frequency of the compressor 1 is 60 Hz from Table 1, and the full expansion valve opening is 150 pulses from Table 2. By the cycle correspondence control (ST31, ST32), the ratio of the expansion valve opening is obtained from the ratio of the capacity codes based on the equation (5).
The capacity codes used at this time are the load side units A and B.
The actual capacity (2.0 kW; 4.0 kW) is determined in consideration of heat exchange efficiency and the like, and this value determines the refrigerant distribution ratio. That is, the opening degree of the expansion valve 4a: the opening degree of the expansion valve 4b = 2:
3 = 60 pulses: Set to 90 pulses and drive until control timing t1. At t1, the difference between the temperature difference codes is 5 or more, so the expansion valve 4a having the larger temperature difference code is used.
Is opened by a1 pulse, for example, 3 pulses, and the opening of the expansion valve 4a is corrected to 63 pulses (ST43), and the operation is continued until t2. At this time, the opening degree of the expansion valve 4b was set to 90 pulses. At the control timing t2, the difference between the temperature difference codes is 5 or more, so the expansion valve 4a having the larger temperature difference code is used.
Is opened by a2 pulses, for example, one pulse, and the opening of the expansion valve 4a is corrected to 64 pulses (ST43), and the operation is continued until t3. At this time, the increment of the opening degree of the expansion valve 4a is selected according to the difference between the temperature difference codes. Thereafter, the same control is performed at each control timing. At t4 after a certain time, the load side unit A: capacity = 2.0 kW, the capacity code 2, the temperature difference code 12 (large load), and the load side unit B: the capacity = 4.0 kW. , The capacity code 3 and the temperature difference code 9 (small load), the temperature difference code difference becomes smaller than the predetermined value 5, and the current expansion valve opening degree, that is, the expansion valve 4a opening degree becomes 6
The number of pulses is 5 and the opening of the expansion valve 4b is maintained at 90 pulses. The above refrigerant control procedure is the same for the cooling operation and the heating operation when both of the load-side units A and B are operating.

In the present embodiment, a description will be given of a refrigerant control procedure when either of the load side units A and B is stopped. The operation of the load-side controller 14a is the same as described above, and the operation of the load-side controller 14b is such that a stop signal is transmitted to the heat-source-side controller 13. In the operation of the heat source side control device 13, in the cycle corresponding control, the expansion valve communicating with the stopped load side unit is fully closed during the cooling operation so that the refrigerant does not flow through the stopped load side unit, and the stopped load side unit during the heating operation. Is opened to some extent to allow the excess refrigerant to flow to the stopped load side unit.

As a specific example, for example, the load side unit A,
B is set as follows. Load side unit A: During operation, capacity = 2.0 kW, capacity code = 2 Load side unit B: Stopped, capacity = 4.0 kW, capacity code = 3 From the frequency of compressor 1 obtained in ST22, ST23, ST
When it is calculated at 31 that the total expansion valve opening is 150 pulses, the cooling operation: the opening of the expansion valve 4b = 0 pulse The opening of the expansion valve 4a = 150 pulses The heating operation: the opening of the expansion valve 4b = 50 Pulse The degree of opening of the expansion valve 4a = 150-50 = 100 pulses is set. The 50 pulses set as the opening of the expansion valve 4b of the stop load side unit B during the heating operation are initial values of the expansion valve opening previously set for the stop load side unit. If the initial value is too small, the refrigerant is excessively accumulated in the stop-side heat exchanger 5b, and the refrigerant flow rate on the refrigeration cycle side is insufficient. .

In the load corresponding control after the cycle corresponding control, in the specific example described above, the number of the operating load side unit is A and one unit is not performed. However, for example, three load side units are configured. When one of the units is stopped and the other two units are in operation, load corresponding control is performed in ST41 to ST43 based on the temperature difference code in the unit on the operation load side.

When the opening degree of the expansion valve having the larger temperature difference code is increased in the load control in the control procedure shown in FIG. 2, the opening degrees of the other expansion valves are closed by the number of pulses. Control may be performed. FIG. 4 is a flowchart showing the procedure of the load handling control at this time. In ST43, for example, if the expansion valve 4a having the larger temperature difference code is opened by a pulse to increase the opening degree, the expansion valve 4b having the smaller temperature difference code is closed by a pulse in ST44 to decrease the opening degree. . By performing such control, the total opening of all expansion valves before correction and the total opening of all expansion valves after correction are made the same, or the total opening area of all expansion valves before correction and the total opening area after correction are corrected. And the total opening area of all the expansion valves is the same, and the opening area Sall of the entire expansion valve can be kept constant. That is,
Before and after the change in the refrigerant flow rate due to the fine adjustment of the expansion valves 4a and 4b, the total amount of the refrigerant flow flowing through the respective expansion valves 4a and 4b becomes equal, so that the refrigeration cycle state suddenly changes due to the change in the expansion valve opening. And the load side unit has a good balance of air side heat exchange performance and refrigerant side heat exchange performance,
Further, a refrigeration cycle that can operate stably can be realized, and the refrigerant can be distributed so as to supply a capacity corresponding to the load as much as possible. However, even if the opening of the expansion valve 4b having the smaller temperature difference code is to be decreased by closing the pulse a by a pulse, the adjustment width of the opening of the expansion valve is predetermined and becomes smaller than the minimum opening. Only need to be closed as much as possible. At this time, the opening area Sall of the entire expansion valve is
Is not kept constant, the opening area Sall of the entire expansion valve is
This has the effect of mitigating the change in temperature and ensuring the stable operation of the refrigeration cycle to some extent.

As described above, in the control method and control apparatus for the multi-type refrigeration cycle apparatus according to the present embodiment, first, the refrigerant distribution ratio within a predetermined range is set, and the expansion valve opening is set accordingly. After performing the cycle response control,
A load-dependent control for gradually correcting the opening degree of each expansion valve in consideration of the variation in load for each chamber is added. Therefore, unlike the conventional control method, the refrigeration cycle is not set at an extreme shunt ratio, and a well-balanced air-side heat exchange performance and a refrigerant-side heat exchange performance of the load unit and a stable operation of the refrigeration cycle. realizable. Further, it is possible to supply the capacity according to the load of the load side unit by finely adjusting the flow rate of the refrigerant to be distributed.

Embodiment 2 In the present embodiment, another example of a load-corresponding control procedure which is a part of the control in the control method of the multi-type refrigeration cycle apparatus similar to the first embodiment will be described. FIG. 5 is a flowchart showing a load handling control procedure according to the present embodiment. In ST41, the temperature difference code representing the measured load in the operation load side unit is compared with the temperature difference codes of the other operation load side units. As a result of the comparison, when the difference is equal to or more than a predetermined value (for example, 5), the temperature difference code is large, that is, the flow rate of the refrigerant flowing through the operation load side heat exchanger is increased by a predetermined amount. In this setting of the predetermined amount, in order to estimate the capacity value of the operation load side unit having a large temperature difference code in ST45 a little larger, the capacity value at the time of calculating the refrigerant distribution ratio was calculated by integrating the capacity value q and the capacity correction value C. The initial value Ct0 of the capacitance correction value C is set to 1.
Set to 0. Then, as the capacitance correction value C, for example, Ct0 is set to 1.
1, the capacitance correction value Ct1 at the control timing t1 (=
1.1) and calculating the refrigerant distribution ratio using this capacity value Ct1 · q, the capacity value of the load-side unit having a large temperature difference code can be largely estimated, and the opening of the expansion valve communicating therewith can be estimated. The degree can be increased. Further, by using the refrigerant distribution ratio, the opening degree of the expansion valve communicating with the load-side unit having a small temperature difference code can be automatically reduced.

If the difference between the respective temperature difference codes becomes smaller than a predetermined value (for example, 5) after a certain period of time after the opening degree of the expansion valve is changed, the current opening degree is maintained in ST42, and the load corresponding control is performed. To end. If the difference between the temperature difference codes is still a predetermined value (for example, 5) or more in ST41, in ST45,
For example, Ct1 is multiplied by 1.1 as the capacitance correction value C, and the larger capacitance value of the temperature difference code is further estimated as the capacitance correction value Ct2 (= 1.2) at the control timing t2.
Then, using the capacity value Ct2 · q, the refrigerant distribution ratio is calculated to change the opening of the expansion valve. Such load control is repeated until the difference between the temperature difference codes becomes smaller than a predetermined value (for example, 5), and the capacity correction value of the expansion valve communicating with the operation load side unit having the larger temperature difference code is further corrected. . At this time, the capacity correction value of the expansion valve communicating with the operation load side unit having the small temperature difference code is 1.0.

As a specific example, for example, the load side unit A,
For a refrigeration cycle device in which B is set as follows:
FIG. 6 shows a time chart when the load handling control is performed according to the procedure shown in FIG. Load side unit A: Capacity = 2.0 kW, capacity code 2, temperature difference code 15 (large load) Load side unit B: capacity = 4.0 kW, capacity code 3, temperature difference code 7 (small load) Temperature difference code predetermined value = 5. When the total expansion valve opening is 150 pulses, the cycle corresponding control is performed at t0, and the expansion valve opening ratio is obtained from the capacity code ratio. The capacitance correction value C at this time
Is Ct0 = 1.0. Therefore, the opening degree of the expansion valve 4a: the opening degree of the expansion valve 4b = 2: 3 = 60 pulses: 90 pulses, and is set by this opening degree. In the comparison of the difference between the temperature difference codes at the control timing t1 (ST41), since the difference between the temperature difference codes is 5 or more, the capacitance correction value Ct1 of the capacitance value of the load-side unit having the large temperature difference code is Ct0 ×
When the opening of the expansion valves 4a and 4b is calculated by setting 1.1 = 1.1 (ST45), the opening of the expansion valve 4a: the opening of the expansion valve 4b = 2 · C: 3 = 2.
2: 3 = 63 pulses: 87 pulses. Thereafter, after performing the same control for each control timing, at the control timing t4, the load side unit A: capacity = 2.0 kW, the capacity code 2, the temperature difference code 12 (large load) The load side unit B: the capacity = 4.0 kW , Capacity code 3, temperature difference code 9 (small load), the temperature difference code difference is smaller than 5,
Current opening (opening of expansion valve 4a = 66 pulses, expansion valve 4
(the opening degree of b = 84 pulses) is maintained (ST42). Here, ST41 to ST45 constitute a refrigerant flow adjusting means for adjusting the refrigerant flow to the plurality of load-side heat exchangers in accordance with the magnitude of the load on each of the load-side units.

As described above, according to the present embodiment as well, the refrigerant flow is distributed at the refrigerant distribution ratio based on the capacity ratio of the load side unit, and the cycle corresponding control is performed, so that the refrigeration cycle is operated stably first. Thereafter, load-dependent control for gradually correcting the degree of opening of each expansion valve in consideration of the variation in load for each chamber is added. For this reason, the extreme diverting ratio setting causes the balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit to be lost, causing the refrigeration cycle to become unstable, resulting in insufficient capacity and unstable capacity supply. Thus, it is possible to supply as much capacity as possible to a load-side unit having a large load, while giving priority to avoiding a failure of the compressor due to an uncontrollability. In particular, in the load handling control of the present embodiment, the capacity of the load-side unit having a large load is gradually corrected, so that an extreme shunt ratio is not set.

If there are three or more operating load units in the first and second embodiments, ST41 to ST45
May be performed for all of the plurality of load-side units, or may be performed for the load-side unit having the largest temperature difference code and the load-side unit having the smallest temperature difference code. In either case, the load can be corrected in a direction to eliminate the imbalance, and it is possible to supply as much capacity as possible to the load-side unit having a large load while maintaining the refrigeration cycle in a stable state.

Embodiment 3 Hereinafter, a control method and a control device of a multi-type refrigeration cycle apparatus according to Embodiment 3 of the present invention will be described. FIG. 7 is a refrigerant circuit diagram showing a configuration of the multi-type refrigeration cycle device according to the present embodiment. In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. 15a and 15b are load-side heat exchangers 5;
a, the load-side heat exchanger tube temperature sensors installed on the tube wall at positions where the refrigerant flowing through the inside of the tubes is considered to be always in a two-phase state, 16a, 16b are gas tube temperature sensors, 17a, 17
b is a liquid tube temperature sensor, 25a and 25b are load side heat exchanger tube temperature sensors 15a and 15b and a load side control device 14a,
14b, a signal line connecting the gas pipe temperature sensors 16a, 16b and the heat source side controller 13;
27a and 27b are signal lines connecting the liquid tube temperature sensors 17a and 17b and the heat source side controller 13. In this embodiment,
The two-phase refrigerant is detected by the load-side heat exchanger tube temperature sensors 15a and 15b, the gas refrigerant is detected by the gas tube temperature sensors 16a and 16b, and the liquid refrigerant is detected by the liquid tube temperature sensors 17a and 17b. It is characterized in that it is used for controlling the flow of refrigerant.

The operation of the refrigerant flow in the cooling operation and the heating operation is the same as that in the first embodiment, and the description is omitted here.

Hereinafter, a refrigerant control procedure when the cooling operation is performed by the plurality of load-side units A and B will be described. FIG. 8 is a flowchart showing this procedure. In the load side units A and B, as shown in ST1a and ST1b,
After the load-side controllers 14a and 14b receive the respective signals from the sensors and then calculate using the received items, the necessary items among the received items and the calculated items are determined by the heat-source-side controller 13a.
Send to The specific contents are shown below. In addition, these start control when the set temperature code is issued from the remote controllers 11a and 11b, and until the stop code is transmitted from the remote controllers 11a and 11b.
It shall be repeated at regular time intervals, for example, every three minutes.

Reception items (1) Set temperature code transmitted from remote controllers 12a and 12b In a room where load side units A and B are installed, a set temperature designated by a user is set to a predetermined corresponding code number. What was replaced. The specific set temperature value may be received. (2) Room temperature transmitted from room temperature sensors 11a and 11b (3) Tube temperature of load side heat exchanger transmitted from load side heat exchanger tube temperature sensors 15a and 15b

Calculation Items (1) Set Temperature The received set temperature code is replaced with a specific temperature value. (2) Temperature difference code The difference between the above set temperature and the received room temperature is calculated. During cooling operation Δroom temperature = room temperature−set temperature During heating operation Δroom temperature = set temperature−room temperature The value of the calculated Δroom temperature is replaced with a predetermined code number.

Transmission items (1) Temperature difference codes Ca, Cb (2) Capacity value qa of load side unit stored in advance,
qb (3) Load side heat exchanger tube temperature Ta, Tb

In the heat source side control device 13, ST 21
When a signal is transmitted from one or more load-side units,
The control shown in ST22 to ST43 is performed. First, the heat source side control device 13 receives each signal from the sensor, and then uses the received items to make each expansion valve 4a, 4b for proper refrigerant distribution.
After calculating the opening, a signal is transmitted to each of the expansion valves 4a and 4b to set or correct the opening. If no signal is transmitted from one of the load-side units in ST21, the process ends (END). Hereinafter, specific contents in ST22 to ST43 are shown below.

Reception items (1) Temperature difference codes Ca, Cb of each operation load side unit (2) Capacity qa, qb of each operation load side unit (3) Heat exchanger tube temperature Ta of each operation load side unit, Tb (4) Gas pipe temperature transmitted from gas pipe temperature sensors 16a and 16b

Calculation items (1) Reference compressor frequency Hz Each received temperature difference code Ca, Cb and each capacity qa, qb
Then, a value representing the load state of the measurement is calculated by the equation (4) (ST22). Next, the refrigerant flow rate of the entire refrigeration cycle corresponding to the load state is estimated, and the compressor frequency is obtained based on the estimated flow rate (ST23). As a specific example, the compressor frequency is obtained using a correspondence table function1 in which the compressor frequency for the measured full load state value shown in Table 1 is predetermined.
The compressor frequency obtained in this table may be corrected in consideration of the outside air temperature and the state of the refrigeration cycle. (2) Target superheat degree at the load side heat exchanger outlet The target superheat degree is set in ST34 according to the refrigerant flow rate. As a specific example, Table 3 shows a correspondence table function3 in which a target superheat degree corresponding to the compressor frequency is predetermined. Target superheat degree = function3 (compressor frequency).

[0084]

[Table 3]

(3) Measured degree of superheat at the outlet of the load side heat exchanger The received gas pipe temperature from the gas pipe temperature sensors 16a and 16b and the pipe temperature T of the heat exchanger of the operating load side unit.
The measured degree of superheat is calculated from a and Tb (ST35). (4) Each expansion valve opening value In the case of the first time after starting the control, in ST33, the opening of each expansion valve is initialized and the start-up operation is performed for about 2 minutes. In the initial setting at this time, for example, as in the first embodiment, the overall refrigerant flow rate estimated above is set by the capacity ratio of each of the load-side units A and B. The measured superheat degree at the operation load side heat exchanger outlet by this start-up operation is calculated, and in ST36, according to the difference between the measured superheat degree at the operation load side heat exchanger outlet and the target superheat degree, the operation load is set so as to eliminate the difference. The change width of the opening of the expansion valve communicating with the side unit is determined. Here, ST34 to ST36
Constitute the refrigerant flow distribution means. As a specific example of the change width of the opening degree of the expansion valve, a correspondence table function in which the amount of change in the opening degree of the expansion valve is determined in advance from the difference between the measured superheat degree and the target superheat degree.
4 is shown in Table 4.

[0086]

[Table 4]

As a specific example, for example, the load side unit A,
For a refrigeration cycle device in which B is set as follows:
A description will be given of a case where the cycle corresponding control is performed according to the procedure shown in FIG. 8. Load side unit A: capacity = 2.0 kW, capacity code 2, temperature difference code 15 (large load), measured superheat degree 5 [deg] Load side unit B: capacity = 4.0 kW, capacity code 3, temperature difference code 7 (small load), measured superheat degree 8 [deg] Compressor frequency = 60 [Hz] Initially set opening degree of expansion valve 4a is 60 pulses, expansion valve When the opening degree of 4b is 90 pulses, the target superheat degree is 1 [deg] from Table 3, so the Δsuperheat degree of the load side unit A is 8-1 = 7 [deg]. Superheat degree = 5-1 = 4 [deg] excess. Based on Table 4, the opening change amount of the expansion valve 4a = + 5 pulses and the opening change amount of the expansion valve 4b = + 5 pulses. Therefore, the expansion valve 4a opening = 65 pulses, the expansion valve 4b opening = 9
It becomes 5 pulses.

Transmission items (1) New compressor frequency to compressor motor drive unit (2) New opening value of each expansion valve The above is the cycle corresponding control of refrigerant distribution during cooling operation.

In this cycle corresponding control, control is performed by detecting the degree of superheat during operation, and is set to an optimum diversion ratio for the refrigeration cycle, and an extreme diversion ratio is set as in the conventional control method. Never. Therefore, the balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit is lost, causing the refrigeration cycle to become unstable, resulting in insufficient capacity, unstable supply of capacity, and failure of the compressor due to loss of control. It is avoided to cause such.

The heat source side controller 13 starts the control and operates at a predetermined control timing, for example, every three minutes. However, in the case of the second time or later, that is, in the case where the cycle corresponding control has already been performed, the target overheating is performed. Since the degree has already been set, the actual superheat degree of the measurement is calculated in ST26. The difference between the actual superheat degree calculated here and the target superheat degree is D [deg] or more,
For example, when the temperature is 10 ° C. or higher, there may be some cause during operation, for example, a case where sunlight enters the room from a cloudy state and the room temperature suddenly rises. In this state, the cycle corresponding control is performed again in ST34 to ST36, and the frequency of the compressor 1 and the opening degree S of the expansion valves 4a and 4b are set.
Reset a and Sb. That is, when there is a significant load change in at least one or more load-side units, the distribution of the refrigerant flow is re-distributed so as to match the changed load, instead of the current distribution of the refrigerant flow. For this reason, when there is a large load change, the refrigerant can be distributed so as to be able to reach an appropriate refrigerant flow rate quickly in a timely manner, that is, the refrigeration cycle can be stabilized smoothly with good responsiveness.

In the case of the second and subsequent times after starting the control, that is,
In the case where the cycle corresponding control has already been performed, the difference between the target superheat degree and the actual superheat degree is D [deg] or less in the comparison in ST27.
For example, in the case of 10 deg or less, the previous operation state and situation have not changed so much. At this time, in ST41 to ST43, load-dependent control is performed to supply more capacity to the load-side unit having the largest load according to the magnitude of the load on the load-side unit. The temperature difference code representing the measured load in the operating load side units A and B is compared with the temperature difference codes of the other load side units (ST41). In this comparison, when the difference between the temperature difference codes is smaller than a predetermined value, for example, 5, the load state of the operation load side unit is regarded as being equal, and the current opening degree of the expansion valve is maintained (ST42). ). In the comparison of ST41, when the difference of the temperature difference code is a predetermined value, for example, 5 or more, the opening degree of the expansion valve communicating with the operation load side unit having the large temperature difference code is changed by a pulse, for example, several pulses. Open (ST43). Thereafter, in order to keep the opening area of the entire expansion valve constant, control may be performed to close other expansion valve openings by the number of pulses. Here, ST41 to ST43
Constitutes a refrigerant flow rate adjusting means for adjusting the refrigerant flow rate to the operation load side heat exchanger in accordance with the magnitude of the load on each of the load side units.

The adjustment of the opening degree of the expansion valve by the load corresponding control is performed until the difference between the temperature difference codes becomes smaller than a certain predetermined value (for example, 5).
In ST42, the opening degree of the expansion valve at that time is maintained. As described above, by performing the load handling control, the flow rate of the refrigerant can be finely adjusted in accordance with the magnitude of the load on the load-side unit, and more capacity can be supplied to the load-side unit having the largest load.

Next, the refrigerant control procedure during the heating operation will be described. The load-side control device 14 is the same as that in the cooling operation, and thus the description is omitted. In addition, the heat source side control device 13
In the heating operation, the opening degree of the expansion valve is changed by the degree of superheat of the refrigerant at the load side heat exchanger outlet in the heating operation, but in the cooling operation, the expansion valve is changed by the degree of supercooling of the refrigerant at the load side heat exchanger outlet. Except for changing the opening, the operation is the same as the heating operation. That is, the gas pipe temperature sensor 16
Instead of the gas pipe temperatures transmitted from a and 16b, the liquid pipe temperatures transmitted from the liquid pipe temperature sensors 17a and 17b are used. Also, as the calculation items, the target supercooling degree and the measured supercooling degree at the load-side heat exchanger outlet are calculated instead of the target superheat degree and the measured superheat degree at the load-side heat exchanger outlet. The target degree of superheat at the outlet of the load side heat exchanger sets the target degree of supercooling according to the refrigerant flow rate. As a specific example, a correspondence table function5 in which the target degree of supercooling corresponding to the compressor frequency is set in advance.
Are shown in Table 5. The target degree of subcooling is set to function5 (compressor frequency). The measured degree of supercooling at the outlet of the load side heat exchanger is obtained from the liquid temperature transmitted from the received liquid tube sensors 17a and 17b and the measured degree of subcooling from the tube temperatures Ta and Tb of the heat exchanger of the operating load side unit. Is calculated. The opening value of each of the expansion valves 4a and 4b is changed according to the difference between the measured supercooling degree at the outlet of the operating load side heat exchanger and the target supercooling degree. Determine the width.
As a specific example, Table 6 shows a correspondence table function6 in which the amount of change of the expansion valve opening is determined in advance from the difference between the measured degree of supercooling and the target degree of supercooling.

[0094]

[Table 5]

[0095]

[Table 6]

As a specific example, for example, the load side unit A,
For a refrigeration cycle device in which B is set as follows:
A case where the cycle corresponding control is performed according to the procedure shown in FIG. 8 will be described. Load side unit A: capacity = 2.0 kW, capacity code 2, temperature difference code 15 (large load), measured subcooling degree 5 [deg] Load side unit B: capacity = 4.0 kW, capacity code 3, temperature difference code 7 ( (Low load), degree of supercooling 8 [deg] Compressor frequency = 60 [Hz] When the initially set opening degree of the expansion valve 4a is 60 pulses and the opening degree of the expansion valve 4b is 90 pulses, the target is obtained from Table 5. Since the degree of subcooling is 10 [deg], the Δdegree of subcooling of the load side unit A = 8−10 = −2 [de]
g] overpass Δ subcooling degree of the load side unit B = 5-10 = -5 [de
g] excess, and from Table 6, it is assumed that the opening change amount of the expansion valve 4a = -3 pulses and the opening change amount of the expansion valve 4b = -5 pulses. Therefore, the expansion valve 4a opening = 57 pulses, the expansion valve 4b opening 85
It becomes a pulse.

The following values obtained here are transmitted to each device. (1) New compressor frequency to compressor motor drive unit (2) New expansion valve opening value to each expansion valve The above is the cycle corresponding control of refrigerant distribution during heating operation. The same applies to the load response control during the heating operation.
At T27, the difference between the actual supercooling degree and the target supercooling degree is D
In the case of [deg] or less, the temperature difference codes are compared, and if the difference is equal to or more than a predetermined value (for example, 5), fine adjustment is performed by opening the expansion valve having the larger temperature difference code by a pulse (for example, 3 pulses). (ST43).

As described above, if the refrigerant control method of the multi-type refrigeration cycle apparatus according to the present embodiment is applied, the degree of supercooling at the outlet of each load side unit during the cooling operation, and the degree of superheat at the outlet of each load side unit during the heating operation. After performing cycle-compatible control to set each expansion valve opening in a direction that eliminates the difference between the target value and the measured value, gradually expand each expansion valve opening in consideration of the variation in load for each chamber. Load-dependent control to be performed. Therefore, unlike the conventional control method, the refrigeration cycle is not set at an extreme shunt ratio, and a well-balanced air-side heat exchange performance and a refrigerant-side heat exchange performance of the load unit and a stable operation of the refrigeration cycle. realizable. Further, it is possible to supply the capacity according to the load of the load side unit by finely adjusting the flow rate of the refrigerant to be distributed.

In FIG. 7 according to the third embodiment, the gas pipe temperature sensor 16 and the liquid pipe temperature sensor 17 are mounted on the heat source side unit. However, as shown in FIG. The refrigeration cycle device 17 may be mounted on the load side unit. In this case, the detected values of the gas pipe temperature and the liquid pipe temperature are transmitted to the load-side control devices 14a and 14b. During the cooling operation, the degree of superheat at the outlet of the load-side heat exchangers 5a and 5b = gas pipe temperature-load-side heat. Exchanger tube temperature, during heating operation, the degree of supercooling at the outlets of the load-side heat exchangers 5a and 5b = load-side heat exchanger tube temperature-liquid tube temperature is calculated, and the heat source-side controller 13 is calculated.
Send to Other configurations and controls are the same as those of the third embodiment, and thus description thereof is omitted. With this configuration, the gas pipe temperature sensor 16 or the liquid pipe temperature sensor 1
7 is disposed near the outlets of the load-side heat exchangers 5a and 5b, pressure loss in the refrigerant circuit can be reduced, and control reliability can be improved.

Embodiment 4 In the present embodiment, another example of a load-corresponding control procedure which is a part of the control in the control method of the multi-type refrigeration cycle apparatus similar to the third embodiment will be described. FIG. 10 is a flowchart illustrating a load-corresponding control procedure according to the control method of the multi-type refrigeration cycle apparatus according to the present embodiment. In ST41, the temperature difference code representing the load during operation in the operating load side unit is compared with the temperature difference code of another operating load side unit. As a result of the comparison, if the difference is equal to or more than a predetermined value (for example, 5), it means that there is a certain difference in the loads on the plurality of load-side units. Fine-tune. That is, in ST46, the target superheat degree or the target supercool degree at the outlet of the load side heat exchanger of the operation load side unit having a large temperature difference code is reduced by a predetermined value according to a predetermined correspondence table. Then, in ST47, the change amount of the expansion valve is set using Table 4 or Table 6 from the difference between the measured superheat or the measured supercooling and the target superheat or the target supercooling. Here, by reducing the target degree of superheat or the target degree of subcooling by a predetermined value, it becomes possible to cope with a large load. If the difference between the temperature difference codes becomes smaller than a predetermined value (for example, 5) after a certain period of time after changing the target degree of superheat or the target degree of supercooling, the current opening degree is maintained in ST42. If the difference between the temperature difference codes is still a predetermined value (for example, 5) or more in ST41, the load corresponding control is performed, and in ST46, the target superheat degree or the target superheat degree connected to the operation load side unit having the large temperature difference code is performed. Reduce the degree of cooling. Here, the control based on the degree of superheat is for the cooling operation, and the control based on the degree of supercooling is for the heating operation.

As a specific example, for example, the load side unit A,
FIG. 11 is a time chart when load control is performed in the procedure shown in FIG. 10 for the heating operation of the refrigeration cycle apparatus in which B is set as follows. Load side unit A: capacity = 2.0 kW, capacity code 2, temperature difference code 15 (large load), measured subcooling degree 10 [deg] Load side unit B: capacity = 4.0 kW, capacity code 3, temperature difference code 7 ( Load), measured subcooling degree 10 [deg] Predetermined value of temperature difference code = 5, compressor frequency = 60 Hz,
Target degree of subcooling = 10 [deg], expansion valve 4a opening initially set in startup operation = 60 pulses, expansion valve 4b opening = 9
In the case of 0 pulse, the target supercooling degree and the measured subcooling degree are the same at the t1 control timing, so that the refrigeration cycle is operating stably, and the opening / closing of the on-off valve in the cycle corresponding control is increased or decreased. Is not performed. However, in ST41, since the difference between the temperature difference codes is 5 or more, the load corresponding control is performed in this case.

The target supercooling degree of the unit A having a large temperature difference code is reduced, for example, to 10 → 8 [deg].
The degree of subcooling of the load-side unit A exceeds +2 [deg], and from Table 6, the opening of the expansion valve 4a is controlled to open by +3 pulses. That is, the opening degree of the expansion valve 4a is set to 63 pulses, and the opening degree of the expansion valve 4b is set to 90 pulses. At the t2 control timing, the difference between the measured supercooling degree and the target supercooling degree is 1
(Load-side unit A), 2 (Load-side unit B), the difference between the temperature difference codes is 5. Therefore, in ST46, the target degree of superheat is further reduced by 2 deg to 6 [deg], and ST
At 47, a control signal is transmitted such that the opening of the expansion valve 4a is set to +4 pulses from Table 6 and the opening of the expansion valve 4b is set to -2 pulses from Table 6. That is, the opening degree of the expansion valve 4a is set to 67 pulses, and the opening degree of the expansion valve 4b is set to 88 pulses. Further, t
At three control timings, the difference between the measured subcooling degree and the target subcooling degree is 2 (load-side unit A), 0 (load-side unit B), and the difference between the temperature difference codes is 3. Since the difference between the temperature difference codes has become smaller than a predetermined value (for example, 5), it is determined that the fine adjustment of the refrigerant flow rate according to the load during operation has been completed, and the opening degree of the expansion valve 4a is set to 67 pulses, and the expansion is performed. The opening of the valve 4b may be maintained at 88 pulses.

As described above, also in the present embodiment, the refrigerant flow is distributed at the refrigerant distribution ratio based on the capacity ratio of the load-side unit, and the cycle corresponding control is performed, so that the refrigeration cycle is stabilized first. Thereafter, load-dependent control for gradually correcting the degree of opening of each expansion valve in consideration of the variation in load for each chamber is added. For this reason, the extreme diverting ratio setting causes the balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit to be lost, causing the refrigeration cycle to become unstable, resulting in insufficient capacity and unstable capacity supply. Thus, it is possible to supply more capacity to the load-side unit having the largest load as much as possible while giving priority to avoiding failure of the compressor due to uncontrollability. Particularly, when finely adjusting the refrigerant flow rate according to the magnitude of the load of each load side unit, change the target superheat degree or the target supercool degree of the load side heat exchanger having a large load to a value smaller than the current target value. Finely adjusting the flow rate adjusting means so as to eliminate the difference between the measured superheat degree or the measured supercooling degree and the changed target value, so as to increase the flow rate of the refrigerant flowing through the load-side heat exchanger having a large load. Since the refrigerant flow rate of the load-side unit having a large load is gradually corrected, the refrigerant flow rate can be finely adjusted according to the magnitude of the load of the load unit.

In the first and second embodiments,
In the initial setting of the system corresponding control, and in the third and fourth embodiments, at the time of start-up, the flow is distributed to each load-side heat exchanger based on the capacity ratio of the load-side heat exchanger of the operating load-side unit. Although the split ratio of the coolant flow rate is set, the split ratio may be set in advance based on experience. In addition, the flow rate is set at an appropriate predetermined branch ratio, such as roughly 1: 2 or 1: 1, and is controlled while observing the operating condition according to the degree of superheating or supercooling during operation, and gradually the optimum refrigerant flow rate is obtained. It may be made to drive by.

In the load control according to the first to fourth embodiments, the opening degree of the expansion valves 4a and 4b is gradually changed to finely adjust the flow rate of the refrigerant according to the magnitude of the load. However, at this time, the amount of the refrigerant that changes by changing the expansion valves 4a and 4b may be limited to a predetermined range. For example, in terms of the opening degree of the expansion valve, the amount of change at one control timing is ± 8 pulses. Since the amount of change in the refrigerant flow rate is limited by setting the amount of change of the expansion valve in one fine adjustment within a predetermined range in this manner, the operation of the refrigeration cycle is prioritized with emphasis on system-compatible control. This makes it possible to prevent the flow ratio of the refrigerant from becoming extremely high in the load corresponding control. For this reason, it is possible to reliably prevent a sudden change in the flow rate of the refrigerant flowing through each load-side heat exchanger, and to achieve a good balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit so that the refrigeration can be stably operated. Cycles can be realized and refrigerant can be distributed to provide as much load-dependent capacity as possible.

Embodiment 5 FIG. Hereinafter, a control method of the multi-type refrigeration cycle apparatus according to Embodiment 5 of the present invention will be described. FIG. 12 is an explanatory diagram illustrating a difference in the degree of superheat measured according to a difference in the installation position of the sensor. The installation position of the load side heat exchanger tube temperature sensor 15 and the gas tube temperature sensor 16
When the pressure loss of the refrigerant flowing between the refrigerant and the installation position is large, the difference between the measured superheat degree and the true superheat degree becomes large, and the opening of the expansion valve may be erroneously controlled in the opening and closing reverse direction.

For example, if the refrigerant used is R22, the cooling operation is performed, and the refrigerant pressure at the installation position of the load side heat exchanger tube temperature sensor 15 is 0.7 Pa, the refrigerant saturation temperature decreases by about 10 ° C. when the pressure is reduced by 0.2 Pa. I do. As shown in the figure, it is assumed that the tube temperature at the load-side heat exchanger tube temperature sensor 15 is a saturation temperature of 0.7 Pa at 10.3 ° C. Heat exchanger outlet temperature is 1
At 4.3 ° C., the true outlet superheat is 4 deg. On the other hand, the pipe temperature at the gas pipe temperature sensor 16 drops by about 0.2 Pa due to the pressure loss, so that it becomes about 4.3 ° C., and the measured degree of superheat is −6.0 deg.

If the target degree of superheat is set to 0 deg, since the true degree of superheat is greater than the target degree of superheat, the correct control direction is that the expansion valve communicating with this load-side unit is controlled to open. However, since the heat source side control device 13 detects from the value obtained by the gas pipe temperature sensor 16, the measured superheat degree <the target superheat degree, and the control is performed in the direction to close the expansion valve.
As a result, the true degree of superheat further increases, and there is a good possibility that the heat exchange performance of the load-side heat exchanger will decrease, the cooling capacity will decrease, and the reliability of the compressor will also decrease, such as failure. .

On the other hand, if the true degree of superheat is to be set to 4 deg, in this case, the target degree of superheat should be set to -6.0 deg. Therefore, in order to avoid erroneous control of the opening / closing direction of the expansion valve opening degree, the refrigerant pressure loss in the gas pipe connected to each load side unit is estimated, and the target degree of superheat is determined at the installation position of the gas pipe temperature sensor 16. And a control for appropriately setting the target superheat degree corresponding to the pressure loss value is introduced.

When a plurality of load-side units are operated, the difference between the target degree of superheat and the measured degree of supercooling is reduced in the cooling operation, and the difference between the target degree of supercooling and the measured degree of supercooling is reduced in the heating operation. The stability of the refrigeration cycle is maintained by controlling the flow rate of the refrigerant flowing through the load-side heat exchanger of the load-side unit by controlling the opening degree of the expansion valve. Therefore, if the ratio of the opening degrees of the respective expansion valves exceeds a predetermined range, it is determined that there is a load side unit having an inappropriate target superheat degree. It can be determined that the target value of the load-side unit communicating with the expansion valve having the largest change in the change of the opening degree of the expansion valve at a predetermined time, for example, about five control timings, is not appropriate. Therefore, the target value of the load-side unit is changed so that the difference between the target value and the measured value decreases, that is, approaches the measured value. Further, the target value of the refrigeration cycle, in this case, the target superheat degree is prepared in three levels as shown in FIG. Control using the normal degree of superheating or supercooling of the refrigeration cycle is performed using the target value changed in this manner. At this time, the predetermined range of the opening ratio (4b / 4a) of the expansion valve is set to, for example, 1.2 to 1.8.

As a specific example, for example, the load side unit A,
For a refrigeration cycle device in which B is set as follows:
FIG. 1 is a flowchart showing a processing procedure for changing a target value.
It is shown in FIG. This process may be incorporated in the process of the third embodiment shown in FIG. FIG. 15 is a time chart when control corresponding to pressure loss is performed in the procedure according to the present embodiment. Here, one control timing is, for example, two minutes. Load-side unit A: capacity = 2.0 kW, capacity code 2, measured superheat degree-10 [deg] Load-side unit B: capacity = 4.0 kW, capacity code 3, measured superheat degree-2 [deg] Also, expansion valve 4a, Since the initial value of the opening of the expansion valve 4b is set, for example, by the ratio of the capacity codes, the opening of the expansion valve 4a is set to 10
The number of pulses is 0, and the opening degree of the expansion valve 4b is 150 pulses. Also, the compressor frequency set from the load state is 100 Hz,
The target degree of superheat set in accordance with the compressor frequency is 0 [de
g] (level 1). Further, here, the discharge temperature range is set to 65 ° C. to 80 ° C. in order to determine the stability of the refrigeration cycle.
(At 100 Hz). At t1 control timing,
In the load side unit A, measured superheat degree−target superheat degree = −10. In the determination of ST27, the measured superheat degree-the target superheat degree is compared with the predetermined value D, and D = 3 (d
eg), the process of ST28 is performed, and the ratio of the opening degrees of the expansion valves 4a and 4b is calculated to determine whether the ratio is within a predetermined range (1.2 to 1.8 in this case). At t1, the ratio value is 147/95 = 1.55, and the opening of the expansion valve 4a is closed by five pulses from Table 4 by another refrigerant control without changing the target value. On the other hand, in the load side unit B, the measured superheat degree
Since the target degree of superheat is -2, the opening degree of the expansion valve 4a is closed by three pulses from Table 4. The above cycle control is performed while checking the discharge temperature and the opening ratio of the expansion valve.

It is assumed that the state shown below is obtained at the control timing t5. Load side unit A: Measured superheat degree -4 [deg] Load side unit B: Measured superheat degree 0.5 [deg] Expansion valve 4a opening = 80 pulses, opening change amount = 20 pulses
/ 4 times expansion valve 4b opening = 146, opening change amount = 4 pulses / 4 times The opening ratio (146/80 = 1.825) of the expansion valve is within a predetermined range (for example, 1.2 to 1.8). ST
At 29, the target superheat degree is changed. In this case, it is determined that the target degree of superheat of the expansion valve 4a having a large degree of change in the opening degree of the expansion valve, that is, the target superheat degree of the load side unit A is not appropriate, and the target value is changed from level 1 to level 2. That is, the target degree of superheat of the load side unit A is changed from 0 [deg] to -4 [deg].
Change to The opening of the expansion valve 4a is not changed because the difference between the measured superheat at the t5 control timing and the target superheat is 0. Here, that the degree of change in the expansion valve degree is large means that
It is assumed that there is a change amount of 16 pulses or more / 4 times.

The target degree of superheat of the load side unit A is -4 de.
After the change to g, at the t6 control timing, the measured superheat degree−the target superheat degree = 1, so the opening degree of the expansion valve 4a is opened by one pulse from Table 4, and the opening degree ratio of the expansion valve (146 /
81 = 1.80).

The processing procedure for changing the target value in ST28 and ST29 is a processing when the determination in ST27 is NO, that is, when the difference between the target value and the measured value is larger than D (for example, 3 deg). Since the difference between the target value and the measured value is equal to or less than D (for example, 3 deg) after the control timing, another refrigerant control, for example, control for adjusting the opening of the expansion valve based on Table 4 is performed.

As described above, when the ratio of the degree of opening of the expansion valves 4a and 4b does not fall within a predetermined range, for example, 1.2 to 1.8, the degree of change of the degree of opening of the expansion valve is 16 pulses / 4 times or more. It is determined that the target superheat degree of the expansion valve 4a side, that is, the load side unit A is not appropriate, and is changed. that time,
The target superheat degree is changed so that the difference from the measured superheat degree becomes smaller. As a result, a target value that takes into account the pressure loss is set according to the current state of the refrigeration cycle. And reliability can be improved. 3 operating load units
If there are more than one, the determination may be made based on the ratio between the expansion valve having the maximum refrigerant flow rate and the expansion valve having the minimum refrigerant flow rate among the plurality of expansion valves.

In changing the target value according to the present embodiment, three levels of target heating degrees are set in advance using the compressor frequency as a parameter, and any one of the target values is set so that the operating condition becomes appropriate. You have chosen to use. The target value in consideration of the pressure loss in advance is not limited to the three levels as described above, but may be more, or may be two levels. However, by preparing a large number of target values, a stable refrigeration cycle suitable for the operating condition can be realized, but the control procedures are increased and the control becomes complicated.

In the determination in ST28, it is determined whether the ratio of the opening degree of the expansion valve, ie, the ratio of the flow rate of the refrigerant, exceeds a predetermined set range, but it may be determined by another method. For example, when the difference between the measured value of the degree of superheating or the degree of supercooling and the target value is larger than a predetermined value, it may be determined that there is a load-side unit whose target value is not appropriate. However, the predetermined value at this time is set to a value larger than D (for example, 3 deg), for example, 8 deg. If the difference between the measured value and the target value exceeds this predetermined value, the target value for the load side unit becomes You may judge that it is not appropriate. Then, a change is made based on, for example, FIG. 13 so as to reduce the difference between the target value and the measured value, and control using the normal degree of superheating or supercooling of the refrigeration cycle is performed using the changed target value. In this case, for example, in the state of FIG. 15, the difference (10 deg) between the measured value of the load-side unit A and the target value exceeds this predetermined value (for example, 8 deg) at the t1 control timing. This is control for changing the target value.

As described above, in the present embodiment, the target degree of superheat or the target degree of supercooling can be set on the assumption of the influence of the pressure loss. Erroneous control can be prevented, and highly reliable control can be performed.

Embodiment 6 FIG. A control method for a multi-type refrigeration cycle apparatus according to Embodiment 6 of the present invention will be described. FIG. 16 is a refrigerant circuit diagram showing a configuration of the multi-type refrigeration cycle device according to the present embodiment. The gas pipe temperature sensors 16a and 16b and the signal line 26
This is a configuration excluding a and 26b. The present embodiment is a multi-type refrigeration cycle apparatus having a plurality of load-side units, particularly in the heating operation when the stop load-side unit and the operation load-side unit are mixed, whether the refrigerant amount during the operation cycle is appropriate. Judgment is made at regular intervals, and if improper, control for appropriately correcting the degree of opening of the expansion valve communicating with the stopped load side heat exchanger is referred to as refrigerant amount optimization control. Whether the refrigerant flow rate during the operation cycle is appropriate is determined to be appropriate when the degree of supercooling at the condenser outlet of the operation load side unit is within a predetermined appropriate range. If it is larger or smaller than the appropriate range, it is determined that the refrigerant distribution of the entire circuit is inappropriate due to the inappropriate opening of the expansion valve communicating with the stop load side unit, and the stop load side heat exchanger is Increase or decrease the opening of the communicating expansion valve. Now, the load-side units A and B having the configuration shown in FIG.
Is operated, and the load side unit B is stopped.

Hereinafter, the multi-type refrigeration cycle apparatus according to the present embodiment will be described in detail. The refrigerant circulation operation in the heating operation when the stop load side unit is present is the same as in the first embodiment. Then, the description is omitted.

A control procedure of the heating operation when the stop load side unit is present will be described with reference to FIG.
The items to be received, calculated, and transmitted by the operation load side control device 14a are the same as those in the heating operation of the third embodiment as shown in ST1a, but there is no information received from the stop load side control device 14b. In the heat source side control device 13, the operation load side unit A
, The set temperature code Ca, the capacity qa, and the tube temperature Ta.
In the determination of ST51, it is determined whether or not the heating operation is performed and there is a stop load side unit. If there is no cooling operation or stop load side unit, the refrigerant amount optimization control according to the present embodiment is not performed, and another refrigerant control is performed. If it is determined in ST51 that the unit is in the heating operation and there is a stopped load side unit, the load state is calculated from the temperature difference code Ca and the capacity qa by equation (4) (ST52), and the frequency of the compressor corresponding to the load state is calculated. Is set in function 1 of Table 1 (ST53), and the degree of supercooling is calculated from the tube temperature Ta of the operating load side heat exchanger 5a and the tube temperature measured by the liquid tube temperature sensor 17a (ST54).

Further, in ST55, an appropriate range of the degree of supercooling of the operating load side heat exchanger is calculated. The appropriate range of the degree of supercooling is set according to the estimated refrigerant circulation amount and the load state. As a specific example, as shown in Table 7, the appropriate range of the degree of supercooling is stored in the table as function7 corresponding to the frequency of the compressor, and the appropriate range of the degree of supercooling is set based on this correspondence table. I do. The frequency of the compressor used here is S
In T53, the function is changed according to the estimated refrigerant circulation amount and the load state.
ion1 (Table 1).

[0123]

[Table 7]

As specific examples, for example, the load side unit A,
In the refrigeration cycle apparatus in which B is set as follows, the appropriate range of the degree of supercooling is as follows. Load side unit A: Capacity = 2.0 kW, capacity code 2, temperature difference code 15 (large load), degree of supercooling 0 [deg] Load side unit B: Capacity = 4.0 kW, capacity code 3, stop Compressor frequency = 60 Hz Corresponding to the compressor frequency of 60 Hz, the target supercooling degree is set to 10 [deg] from Table 5 and the appropriate range of the supercooling degree is set to 4 to 14 [deg] from Table 7.

Next, it is determined in ST56 whether or not the measured degree of supercooling at the outlet of the operating load side heat exchanger 5a is within an appropriate range.
When the supercooling degree is within the appropriate range, the refrigerant amount optimization control is not performed, and the opening degree of the expansion valve 4b communicating with the current stopped load side unit is maintained without being changed (ST57).
If the measured degree of supercooling at the outlet of the operating load side heat exchanger 5a is larger or smaller than the appropriate range in the determination of ST56, the circuit is not appropriate because the opening of the expansion valve 4b communicating with the stop load side unit B is inappropriate. It is determined that the entire refrigerant distribution is inappropriate. For example, if the degree of subcooling at the outlet of the operating load side heat exchanger 5a is smaller than the appropriate range of the degree of subcooling, the degree of opening of the expansion valve communicating with the stop load side unit B is too small, and the stay at the stop load side unit. It is determined that as a result of the excessive amount of the refrigerant being performed, the amount of the refrigerant during the operation cycle is becoming insufficient. On the other hand, when the degree of subcooling at the outlet of the operating load side heat exchanger becomes larger than the appropriate range, the expansion valve opening degree communicating with the stopped load side unit is too large, and the amount of refrigerant stagnating in the stopped load side unit is small. As a result, it is determined that the refrigerant amount during the operation cycle is becoming excessive. In any case, in order to optimize the refrigerant distribution, the opening degree of the expansion valve communicating with the stop load side unit is changed so that the degree of subcooling at the outlet of the operating load side unit falls within an appropriate range of the degree of supercooling.

After a certain period of time, if the degree of subcooling at the outlet of the operating load side unit falls within an appropriate range, it is determined that the refrigerant distribution of the entire circuit has returned to an appropriate state, and the expansion valve communicating with the stopped load side unit is determined. The opening is maintained (ST57), and the refrigerant amount optimization control ends. On the other hand, if the degree of subcooling at the outlet of the operation load side unit does not fall within the appropriate range, it is determined that the refrigerant distribution in the entire circuit is still inappropriate, and the refrigerant amount optimization control is further continued. At this time, the opening degree of the expansion valve communicating with the stop load side unit is further increased by ST51 to ST6.
Repeat 0.

Conventionally, when refrigerant accumulates in the heat exchanger on the stop load side, the opening of the expansion valve is temporarily increased, and the accumulated refrigerant is returned to the operation cycle side. Has been periodically repeated.
On the other hand, in the present embodiment, even after the refrigerant amount optimization control, the opening of the expansion valve communicating with the stop load side unit is maintained without returning to the opening before the control, and the refrigerant distribution after the correction is changed. Maintain proper condition. For this reason, when the refrigerant distribution of the entire circuit becomes inappropriate due to the inappropriate opening degree of the expansion valve of the stop load side unit, the refrigerant distribution is optimized and at the same time, the expansion valve communicating with the stop load side unit is opened. By performing the refrigerant amount optimization control for correcting the opening degree, the number of times of performing the conventional process of returning the accumulated refrigerant can be reduced, and the refrigeration cycle can be stabilized.

As a specific example, for example, the load side unit A,
In the refrigeration cycle apparatus in which B is set as follows, the refrigerant amount optimization control is as follows, and a time chart thereof is shown in FIG. Here, one control timing is set to about two minutes. Load side unit A: Capacity = 2.0 kW, capacity code 2, measured subcooling degree 0 [deg], expansion valve 4a opening 100 pulses Load side unit B: capacity = 4.0 kW, capacity code 3, stop, expansion valve 4b open Degree 50 pulse Appropriate range of supercooling degree = 4 to 14 deg At the control timing, the measured subcooling degree of the load side unit A is 0 deg, which is outside the appropriate range of the supercooling degree, so that it is communicated with the stopped load side unit B. The opening of the expansion valve 4b is opened by five pulses from the opening at that time. That is, the opening of the expansion valve 4a is kept at 100 pulses, and the opening of the expansion valve 4b is changed from 50 pulses to 55 pulses. After a certain period of time, at the t2 control timing, the measured supercooling degree of the operating load side unit A becomes 4 [deg] and is within the appropriate range of the supercooling degree, so the expansion valve 4b communicating with the stop load side unit B Maintains the state of 55 pulses.

As described above, if the refrigerant control method shown in the present embodiment is applied, during the heating operation in which the stopped load side unit and the operating load side unit coexist, the supercooling of the heat exchanger outlet of the operating load side unit is performed. If the measured supercooling degree is not within the appropriate range of the predetermined supercooling degree,
The degree of opening of the expansion valve is changed so as to fall within the appropriate range of the degree of subcooling, and the flow rate of the refrigerant flowing through the stop load side heat exchanger is controlled. For this reason, the flow rate of the refrigerant flowing through the stop load side heat exchanger can be made appropriate, that is, the flow rate of the refrigerant flowing through the circuit on the operation cycle side can be made appropriate, and stable refrigeration cycle operation is performed. be able to.

Further, even after the refrigerant amount optimization control, the opening degree of the expansion valve communicating with the stopped load side unit is not returned to the opening degree before the control, so that the corrected refrigerant distribution keeps an appropriate state. For this reason, when the refrigerant distribution of the entire circuit becomes inappropriate due to the inappropriate opening degree of the expansion valve of the stop load side unit,
At the same time as optimizing the refrigerant distribution, the opening degree of the expansion valve communicating with the stop load side unit is corrected, and the number of times the refrigerant amount optimizing control is performed can be reduced to stabilize the refrigeration cycle. In particular, it is not necessary to perform a process of returning the refrigerant accumulated in the stopped load side heat exchanger to the operation cycle as in the related art, or it is possible to lengthen the processing interval even if necessary.

Embodiment 7 FIG. A method for controlling a multi-type refrigeration cycle apparatus according to Embodiment 7 of the present invention will be described. FIG. 19 is a flowchart illustrating a control method of the multi-type refrigeration cycle apparatus according to the present embodiment. As in the sixth embodiment, the present embodiment also relates to the refrigerant amount optimization control in the heating operation in the case where the stop load side unit is present. The description is omitted because it is similar.

Hereinafter, the procedure of the refrigerant amount optimization control in the heating operation when the stopped load side unit exists will be described with reference to FIG. In the heating operation in the case where the stop load side unit is present, when the opening degree of the expansion valve is set by the cycle correspondence control, an initial value (for example, 50 pulses) is set as the opening degree of the expansion valve communicating with the stop load side heat exchanger. Then, the operation is started by flowing a predetermined refrigerant flow rate. The refrigerant amount optimization control process according to the present embodiment is performed, for example, by gradually correcting the opening degree of the expansion valve communicating with the operation load side unit while observing the operation state by the load corresponding control in the first embodiment. Is controlled to prevent correction in the wrong direction. The procedure of the refrigerant amount optimization control shown in FIG. 19 is a process performed by the heat source side control device 13,
This is performed after determining the opening to be corrected of the expansion valve. That is, in FIG. 2, the processing is performed after ST32, ST42, and ST43.

In ST61, it is determined whether or not the unit is in the heating operation and there is a stop load side unit. If there is no cooling operation or stop load side unit, the refrigerant amount optimization control according to the present embodiment is not performed, and another refrigerant control is performed. S
If it is determined in T61 that the heating operation is being performed and there is a stopped load side unit, the load state is calculated in ST52,
Table 1 (function 1)
Is calculated using ST52 and ST53 are the same as in the sixth embodiment. Further, in the refrigerant amount optimization control according to the present embodiment, the control is not performed when there is a large load change, but the refrigerant that is further circulated to the stopped load side heat exchanger for the one performing good refrigeration cycle operation. It is intended to optimize the flow rate. Therefore, the difference between the maximum value and the minimum value of the compressor frequency calculated in ST53 at several control timings in ST62 is equal to or more than a predetermined value,
For example, when the frequency is 5 Hz or more, since it is not the control target in the present embodiment, another refrigerant control is performed.

Next, in ST63, it is determined whether or not the opening degree of the expansion valve communicating with the operating load side unit is changed to the opening direction or the closing direction several times, for example, five times, that is, five control timings or more continuously. If one of the opening and closing has not been changed more than a predetermined number of times, the refrigerant amount optimization control is not performed (S
T64). That is, the current opening degree of the expansion valve 4b communicating with the stop load side unit B is maintained at the current opening degree, and the opening degree of the expansion valve 4a communicating with the operating load side unit A is transmitted as in the load correspondence control. . Then, in ST65, the corrected opening / closing direction of the opening degree of the expansion valve 4a communicating with the operation load side unit A is stored and counted up.

If the degree of opening of the expansion valve 4a communicating with the operating load side unit A has been continuously changed to the opening direction by a predetermined number of times or more in the determinations of ST63 and ST66, the communication with the stopped load side unit B is made at ST67. The opening degree of the expansion valve 4b is increased by a pulse, for example, 5 pulses, to increase the opening degree. ST
63, when the opening degree of the expansion valve 4a communicating with the operating load side unit A is continuously changed to the closing direction by a predetermined number of times or more in the determination of ST66, the stop load side unit B is determined in ST68.
The opening degree of the expansion valve 4b communicating with is closed by a pulse, for example, 5 pulses, to reduce the opening degree. After ST67 and ST68, S
At T69, the counter used for the predetermined number of determinations is cleared. This refrigerant amount optimization control is continued until the opening degree of the expansion valve communicating with the operation load side unit is not continuously changed in one of the open and closed directions.

The expansion valve 4 communicating with the operation load side unit A
The phenomenon that “a” is controlled in the opening direction several times in a row is because the amount of refrigerant in the operating refrigerant circuit is insufficient and the discharge temperature of the compressor 1 rises as a result of excessive accumulation of refrigerant in the stop load side unit B. In addition, it is considered that this occurs in an attempt to lower the discharge temperature, and it is necessary to immediately discharge the refrigerant into the operating refrigerant circuit. Based on this concept, when the expansion valve 4b communicating with the stop load side unit B is opened by several pulses, the refrigerant that has accumulated in the stop load side unit B can be discharged into the operating refrigerant circuit, and the amount of refrigerant required for operation can be reduced. It can be optimized.

On the other hand, the phenomenon that the opening degree of the expansion valve 4a communicating with the operating load side unit A is controlled in the closing direction several times in succession is caused by the discharge temperature of the compressor 1 due to an excessive amount of refrigerant in the operating refrigerant circuit. It is thought that this will occur in order to increase the discharge temperature, so that it is necessary to recover the refrigerant to the stop load side unit B immediately. Based on this concept, when the expansion valve 4b communicating with the stop load side unit B is closed by a few pulses, the excess refrigerant in the operating refrigerant circuit is recovered by the stop load side unit B to optimize the amount of refrigerant required for operation. Can be measured.

As a specific example, for example, the load side unit A,
For a refrigeration cycle device in which B is set as follows:
FIG. 20 is a time chart when the refrigerant amount optimization control is performed according to the procedure shown in FIG. Here, one control timing is, for example, two minutes. Load side unit A: Capacity = 2.0 kW, capacity code 2, temperature difference code 15, initial value of opening of expansion valve 4a = 100 pulses Load side unit B: capacity = 4.0 kW, capacity code 3, stop, expansion valve 4b Initial value of opening degree = 50 pulses It is assumed that the opening degree of the expansion valve 4a is changed as follows in the load corresponding control. Number of times corresponding to load control 0 1 2 3 4 5 Opening degree of expansion valve 4a 100 101 102 105 108 111 The expansion valve 4a is continuously changed in the opening direction five times, so the process of ST67 is performed at control timing t6. That is, since the opening of the expansion valve 4b communicating with the stop load side unit B is opened by 5 pulses from the opening at that time, the opening of the expansion valve 4b is changed from 50 pulses to 55 pulses.

Then, it is assumed that the opening degree of the expansion valve 4a is changed as follows. Number of times of load control 0 1 2 3 4 5 Opening degree of expansion valve 4a 111 114 115 116 117 116 Since the opening direction has not been changed 5 times consecutively, the opening degree of the expansion valve communicating with the stopped load side unit is Maintain in state.

If the refrigerant control method according to the present embodiment is applied, during the heating operation in which the stopped load side unit and the operating load side unit coexist, the expansion valve opening communicating with the operating load side unit can be opened within a predetermined time. If it is continuously changing in only one of the opening and closing, because the expansion valve opening communicating with the stopped load side unit is inappropriate, it is trying to continuously increase or decrease the refrigerant flow rate, It is determined that the refrigerant distribution is inappropriate. Then, the opening degree of the expansion valve communicating with the stop load side unit is corrected in the direction in which the expansion valve opening degree of the operating load side unit is changed. After a certain time after correction,
If the change direction of the expansion valve opening of the operation load side unit is reversed, it is determined that the refrigerant distribution of the entire circuit has returned to an appropriate state, and the expansion valve opening communicating with the stop load side unit is set in that state. Then, the refrigerant amount optimization control is terminated. on the other hand,
If the direction of changing the degree of opening of the expansion valve of the operation load side unit has not been reversed after a certain period of time after the correction, it is determined that the refrigerant distribution in the entire circuit is still inappropriate, and Control is continued. At this time, the opening of the expansion valve communicating with the stop load side unit may be further corrected.

Further, even after the refrigerant amount adjustment control, the opening of the expansion valve communicating with the stopped load side unit is not returned to the opening before the control, so that the corrected refrigerant distribution keeps an appropriate state.

As described above, when the refrigerant distribution of the entire circuit becomes inappropriate due to the inappropriate opening degree of the expansion valve of the stopped load side unit, the refrigerant distribution is optimized and at the same time, the refrigerant is communicated with the stopped load side unit. The amount of refrigerant for correcting the opening of the expansion valve can be optimized. For this reason, conventionally, the process of returning the refrigerant accumulated in the stopped load side heat exchanger to the operation side periodically has been performed.However, the number of times of performing the process of returning the refrigerant can be reduced or eliminated, and the refrigeration cycle can be reduced. Stabilization can be achieved.

Embodiment 8 FIG. A control method of the multi-type refrigeration cycle apparatus according to Embodiment 8 of the present invention will be described. FIG. 21 is a flowchart illustrating a control method of the multi-type refrigeration cycle apparatus according to the present embodiment. This embodiment also relates to the control of the refrigerant in the heating operation in the case where the stop load side unit is present. For example, the refrigerant circuit configuration and the operation of the refrigerant circulation of the refrigeration cycle apparatus are the same as those in the first embodiment, and the load side unit A Is operated for heating, and the load side unit B is stopped.

Hereinafter, the procedure of the refrigerant control for the heating operation performed by the heat source side control device 13 when the stop load side unit is present will be described with reference to FIG. In ST71, it is determined whether or not there is a stop load side unit in the heating operation. If there is no cooling operation or stop load side unit, the refrigerant control according to the present embodiment is not performed, and thus another refrigerant control process is performed. If it is determined in ST71 that the heating operation is performed and there is a stop load side unit, the opening degree of the expansion valve 4a communicating with the operation load side unit A is set to, for example, 200 pulses by another process in ST72.
The opening of the expansion valve 4b communicating with the stop load side unit B is initialized to an E pulse having a predetermined opening, for example, 52 pulses (ST72). At the beginning of the refrigerant amount optimization control, first, an expansion valve communicating with the stopped load side unit B so as to reliably prevent the refrigerant amount in the refrigeration cycle from being insufficient without the refrigerant remaining in the stopped load side unit B. 4b
Since it is necessary to set the opening degree to a certain degree, here, for example, 52 pulses are set.

After setting the degree of opening of the expansion valve 4b communicating with the stopped load side heat exchanger 5b in ST72, a starting operation is performed for a fixed time, for example, about 5 minutes in ST73. After a certain period of time has elapsed after the startup, the tube temperature of the heat source side heat exchanger is measured by the heat source side heat exchanger tube temperature sensor 10 (ST74). The tube temperature of the heat source side heat exchanger is equivalent to the evaporation temperature of the refrigerant.
e0. Next, in ST75, the opening degree of the expansion valve 4b communicating with the stop load side unit B is changed to a direction in which the expansion valve 4b is narrowed by a pulse, for example, 5 pulses. Exchanger tube temperature sensor 1
At 0, the tube temperature of the heat source side heat exchanger is measured, and this is set as Te1 (ST77). The evaporation temperature (Te0) before changing the opening of the expansion valve 4b in ST78 and the evaporation temperature (Te1) after the change.
Compare with Degree of change in evaporation temperature (| Te1-T
If e0 |) is equal to or more than G ° C., for example, about 0.5 ° C., it is determined that the refrigerant distribution is inappropriate because the opening degree of the expansion valve 4b communicating with the stop load side unit B is inappropriate. .

In the case where the evaporation temperature is greatly reduced even though there is almost no load fluctuation, the refrigerant is excessively accumulated in the stop load side unit due to the excessive narrowing of the opening degree of the expansion valve 4b communicating with the stop load side unit B. It is determined that the refrigerant amount on the operation cycle side is insufficient, and in ST79, the opening degree of the expansion valve 4b communicating with the stopped load side unit B is corrected to the opening degree before the opening degree change or the opening degree immediately before the opening degree change. I do. Then, in ST80, it is confirmed that the evaporation temperature has returned to the state before the sudden decrease. As a result, the refrigerant that has accumulated too much in the stop load side unit B is discharged into the operating refrigerant circuit, and the amount of refrigerant necessary for operation is optimized. On the other hand, when the degree of change in the heat source side heat exchanger tube temperature, that is, the evaporation temperature before and after the opening degree change does not exceed a predetermined value (for example, 0.5 ° C.), the expansion valve opening degree communicating with the stop load side unit B is opened. It is determined that the refrigerant distribution is appropriate because it is appropriate, and the opening degree is maintained, or ST82
In order to make this the state before the next opening degree change, Te1 is set to T
e0, and store the evaporation temperature and the opening degree in ST76.
And further closes the expansion valve 4b for 5 pulses to close the expansion valve 4b
To reduce the flow rate of the refrigerant. Thereby, the flow rate of the refrigerant flowing in the operation cycle at this time decreases.

As a specific example, for example, the load side unit A,
For a refrigeration cycle device in which B is set as follows:
FIG. 22 shows a time chart when the refrigerant amount optimization control is performed according to the procedure shown in FIG. Load side unit A: Capacity = 2.0 kW, capacity code 2, operation, initial value of opening of expansion valve 4a = 200 pulses Load side unit B: Capacity = 4.0 kW, capacity code 3, stop, opening of expansion valve 4b Initial value = 52 pulses The start-up operation is performed by setting the degree of opening of each of the expansion valves 4a and 4b (ST72, ST73).
The opening degree of the expansion valve 4b is closed by a pulse, for example, 5 pulses (S
T76). That is, the opening degree of the expansion valve 4b is changed from 52 pulses to 4
Change to 7 pulses.

In this operation, it is assumed that the change in the tube temperature measured by the heat source side heat exchanger sensor is as follows, for example. Control timing: t1 t2 t3 t4 t5 t6 Time (min): 0 After 2 minutes After 4 minutes After 6 minutes After 8 minutes After 10 minutes Tube temperature (° C.): 4.5 4.4 4.3 4.2 4.2. 2 4.2 The decrease in tube temperature for 10 minutes is 0.3 ° C.
It is considered that the tube temperature has not dropped extremely, such as at least 10 ° C./10 minutes, and after 10 minutes (control timing = t6), 5
The pulse is closed (ST76). That is, the opening degree of the expansion valve 4b is changed from 47 pulses to 42 pulses.

After the opening of the expansion valve 4b is changed, it is assumed that the change in the tube temperature measured by the heat source side heat exchanger sensor is as follows, for example. Control timing: t6 t7 t8 t9 t10 t11 Time (min): 0 After 2 minutes After 4 minutes After 6 minutes After 8 minutes After 10 minutes Tube temperature (° C.): 4.2 3.8 3.4 3.0 7 2.3 The decrease in the tube temperature for 10 minutes is 1.9 ° C., which is 1 ° C. or more / 10 minutes, which is extremely low. For this reason, it is determined that the amount of refrigerant staying in the stop load side unit B is excessive, and the opening of the expansion valve 4b is returned to the original value of five pulses (ST8).
0). That is, the opening degree of the expansion valve 4b is returned from 42 pulses to 47 pulses, and after the return, the state is observed for a while.

After returning the opening of the expansion valve 4b, it is assumed that the change in the tube temperature measured by the heat source side heat exchanger sensor is as follows, for example. Control timing: t11 t12 t13 t14 t15 t16 Time (min): 0 After 2 minutes After 4 minutes After 6 minutes After 8 minutes After 10 minutes Tube temperature (° C.): 2.3 1.9 2.7 3.6 3.6 1 4. The tube temperature value was stabilized after 8 minutes, and its value (=
Since 4.1) is close to the value (= 4.2) before the extreme decrease starts, the expansion valve 4b communicating with the stop load side unit B
The opening degree (47 pulses) is regarded as appropriate, and this state is maintained.

The relationship between the change in the evaporation temperature and the opening degree of the expansion valve, that is, the flow rate of the refrigerant flowing through the heat exchanger on the stop load side can be determined as follows. After changing the opening degree of the expansion valve 4b, if the degree of change in the evaporation temperature detected from the heat source side heat exchanger tube temperature during a certain period of time is, for example, 0.5 or less, the entire refrigerant circuit of the operation cycle is It is determined that the refrigerant distribution is appropriate. Then, after a certain period of time, the opening degree of the expansion valve is changed to a further closing direction, and a more appropriate state is searched for. On the other hand, when the degree of change in the evaporation temperature is not 0.5 or less and changes rapidly, for example, it is determined that the refrigerant distribution in the entire refrigerant circuit in the operation cycle is inappropriate. At this time, if the evaporation temperature is low, the degree of opening of the expansion valve communicating with the stopped load side unit was too closed, and the amount of refrigerant remaining in the stopped load side heat exchanger was too large, and the amount of refrigerant in the operating unit was reduced. Insufficient refrigerant distribution in the entire circuit. In addition, when the evaporating temperature is rising, the opening amount of the expansion valve communicating with the stopped load side unit was too large, and the amount of refrigerant remaining in the stopped load side unit is too small, and the amount of refrigerant during the operation cycle is large. And the refrigerant distribution throughout the circuit is inappropriate.

Therefore, in the control method according to the present embodiment, first, the expansion valve communicating with the stopped load side unit is set to a large opening in advance, and the operation is performed in a state where the refrigerant amount is prevented from being too small in the operation cycle. View. Then, the opening degree is gradually changed in the closing direction, and the refrigerant gradually accumulates in the stopped load side heat exchanger 5b. At some point, the opening of the expansion valve is too closed, and the refrigerant distribution in the entire circuit becomes inappropriate.
Since the evaporating temperature at this time suddenly drops, when the evaporating temperature drops below a predetermined value (for example, 0.5), this is detected and the opening is returned to the opening before the sudden drop. By this processing, the distribution of the refrigerant in the entire circuit can be optimized. In that case,
The opening degree of the expansion valve communicating with the stop load side unit is corrected to the opening degree one or two before the control timing at which the evaporation temperature sharply decreased. If a certain period of time has passed after the correction and the degree of change in the evaporation temperature falls within the set range, it is determined that the refrigerant distribution of the entire circuit has returned to an appropriate state, and the opening degree of the expansion valve communicating with the stopped load side unit is determined. Is maintained in that state, and the refrigerant amount optimization control ends. On the other hand, if the degree of change in the evaporating temperature does not fall within the set range even after a certain period of time has elapsed after the correction, the opening of the expansion valve communicating with the stop load side unit is further changed to the opening just before the opening change. Return to

As described above, in the present embodiment, in the heating operation, an appropriate amount of the refrigerant is allowed to flow through the stopped load side heat exchanger, so that the refrigerant distribution in the entire circuit can be appropriately set, thereby stabilizing the refrigeration cycle. be able to. In particular, by adjusting the opening degree of the expansion valve communicating with the stop load side unit while detecting the evaporation temperature, the opening degree of the expansion valve communicating with the stop load side unit in the heating operation can be set in accordance with the operation cycle state. Therefore, it is possible to set the refrigerant distribution in the entire circuit to be appropriate,
The refrigeration cycle can be stabilized.

In the first to eighth embodiments, the expansion valve is used as the flow rate adjusting means, and the refrigerant flow rate is adjusted by the opening degree of the expansion valve. In the description, the opening degree of the expansion valve is opened and closed. Opening the expansion valve opening is equivalent to increasing the refrigerant flow rate, and closing the expansion valve opening is equivalent to decreasing the refrigerant flow rate. Further, the flow rate adjusting means may be other than the expansion valve, and may use another means capable of adjusting the flow rate of the refrigerant.

[0155]

As described above, according to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, In a multi-type refrigeration cycle apparatus comprising a plurality of flow rate adjusting means communicating with a load side heat exchanger of a unit and adjusting a flow rate of a refrigerant flowing through the load side heat exchanger,
When operating the plurality of load-side units, first, the flow rate of the refrigerant flowing through the plurality of load-side heat exchangers that are operated by adjusting the respective flow rate adjusting means is set to a predetermined split ratio. By finely adjusting the flow rate adjusting means in accordance with the magnitude of the load on the load side unit and increasing the flow rate of the refrigerant flowing through the load side heat exchanger with a large load, the air side heat exchange performance of the load side unit and A method of controlling a multi-type refrigeration cycle apparatus capable of realizing a refrigeration cycle with a good balance of refrigerant-side heat exchange performance and stable operation and distributing a refrigerant so as to supply a capacity corresponding to a load as much as possible is obtained. .

Further, according to the present invention, when a load fluctuation exceeding a predetermined value occurs in at least one of the load side units in the operating refrigeration cycle apparatus, the load side heat exchange of the operated load side unit is performed. The flow rate of the refrigerant flowing through the vessel is set to a predetermined distribution ratio, so that it can respond to load fluctuations with good responsiveness, and balance the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit. Refrigeration cycle that can be operated stably,
And the control method of the multi-type refrigeration cycle device which can distribute the refrigerant so as to supply the capacity according to the load as much as possible is obtained.

Further, according to the present invention, the load distribution ratio of the refrigerant flowing through the plurality of operating load-side heat exchangers is set based on the capacity ratio of each of the load-side heat exchangers. A multi-type that can achieve a refrigeration cycle that has a good balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the side unit, can operate stably, and distributes the refrigerant so that it can supply the load as much as possible. A method for controlling a refrigeration cycle apparatus is obtained.

Further, according to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a load side heat source of each of the load side units are provided. When operating a plurality of the load-side units in a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means communicating with an exchanger and adjusting a flow rate of a refrigerant flowing through the load-side heat exchanger, a target overheating is performed in a cooling operation. The refrigerant flowing through the load-side heat exchanger by adjusting the respective flow rate adjusting means so as to eliminate the difference between the target degree of supercooling and the measured degree of supercooling in the heating operation. After setting the flow rate, the flow rate adjusting means is finely adjusted according to the magnitude of the load on each load side unit to increase the flow rate of the refrigerant flowing through the load side heat exchanger having a large load, so that the load side unit is increased. A multi-type refrigeration system that has a good balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance, realizes a refrigeration cycle that can operate stably, and distributes refrigerant so that it can supply the capacity according to the load as much as possible. A method of controlling a cycle device is obtained.

Further, according to the present invention, when a load fluctuation exceeding a predetermined value occurs in at least one of the load side units in the refrigeration cycle apparatus during operation, the cooling operation is performed in the refrigeration cycle after the fluctuation. The difference between the target degree of superheating and the measured degree of superheating, in the case of heating operation, the flow rate adjusting means is adjusted so as to eliminate the difference between the target degree of supercooling and the measured degree of supercooling, and the load side of the load side unit to be operated. By changing the flow rate of the refrigerant flowing through the heat exchanger, it is possible to respond to load fluctuations with good responsiveness, and the refrigeration cycle can be operated stably with a good balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit. And a method of controlling a multi-type refrigeration cycle apparatus capable of distributing a refrigerant so as to supply a capacity corresponding to a load as much as possible.

According to the present invention, when the refrigerant flow rate is finely adjusted in accordance with the magnitude of the load on each load side unit, the target degree of superheat or the target degree of supercooling of the load side heat exchanger having a large load is set to the current value. To a value smaller than the target value, and finely adjust the flow rate adjusting means so as to eliminate the difference between the measured degree of superheat or the measured degree of supercooling and the changed target value. By increasing the flow rate of the refrigerant flowing through the refrigeration cycle, the air-side heat exchange performance of the load-side unit and the refrigerant-side heat exchange performance are well-balanced, and a refrigeration cycle that can operate stably can be realized. A method is provided for controlling a multi-type refrigeration cycle apparatus that can distribute refrigerant to provide capacity.

According to the present invention, when the refrigerant flow rate is finely adjusted according to the magnitude of the load on each load side unit, the amount of change in the refrigerant flow rate in one fine adjustment is set within a predetermined range. This ensures that the flow rate of the refrigerant flowing through each load-side heat exchanger can be prevented from suddenly changing, and that the refrigeration cycle can stably operate with a good balance between the air-side heat exchange performance and the refrigerant-side heat exchange performance of the load-side unit. And a method of controlling a multi-type refrigeration cycle apparatus capable of distributing a refrigerant so as to supply a capacity corresponding to a load as much as possible.

Further, according to the present invention, when finely adjusting the refrigerant flow rate according to the magnitude of the load on each load side unit, the flow rate of the refrigerant flowing through the load side heat exchanger having a large load is increased by a predetermined amount. This makes it possible to reliably prevent a sudden change in the flow rate of the refrigerant flowing through each load-side heat exchanger, and to provide a well-balanced air-side heat exchange performance and a refrigerant-side heat exchange performance of the load-side unit, thereby enabling stable operation of the refrigeration unit. A method of controlling a multi-type refrigeration cycle apparatus capable of realizing a cycle and distributing a refrigerant so as to supply a capacity corresponding to a load as much as possible is obtained.

Further, according to the present invention, when finely adjusting the refrigerant flow rate according to the magnitude of the load on each load side unit, the flow rate of the refrigerant flowing through the load side heat exchanger having a large load is increased and changed. By reducing the flow rate of the refrigerant flowing through the load-side heat exchanger with a small load so that the total amount of the refrigerant flow flowing through the respective flow rate adjusting means becomes equal before and after, the flow rate of the refrigerant flowing through each load-side heat exchanger Can be reliably prevented, and a refrigeration cycle can be realized in which the load side unit has a good balance between the air side heat exchange performance and the refrigerant side heat exchange performance, and can operate more stably. A method is provided for controlling a multi-type refrigeration cycle that can distribute refrigerant to provide capacity.

Further, according to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a load side heat exchanger of each of the load side units are provided. In a multi-type refrigeration cycle apparatus comprising a plurality of flow rate adjusting means communicating with an exchanger and adjusting a flow rate of the refrigerant flowing through the load side heat exchanger, when operating a plurality of the load side units, the flow rate adjusting means The load side heat of each of the load side units is adjusted so that the difference between the target degree of superheat and the measured degree of superheat is adjusted in the cooling operation, and the difference between the target degree of supercooling and the measured degree of supercooling in the heating operation. The flow rate of the refrigerant flowing through the exchanger was adjusted, and when the difference between the measured value of the degree of superheating or the degree of supercooling at that time and the target value was larger than a predetermined value, the target value was changed so that the difference became smaller. After that, the flow control By adjusting the means and changing the refrigerant flow rate so that the difference between the measured value and the changed target value is eliminated, even if the measured value does not indicate the actual value due to pressure loss, each load side heat exchange A method of controlling a multi-type refrigeration cycle apparatus capable of appropriately adjusting the flow rate of refrigerant to a vessel is obtained.

According to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a load side heat source of each of the load side units are provided. In a multi-type refrigeration cycle apparatus comprising a plurality of flow rate adjusting means communicating with an exchanger and adjusting a flow rate of the refrigerant flowing through the load side heat exchanger, when operating a plurality of the load side units, the flow rate adjusting means The load side of each of the load side units is adjusted so that the difference between the target superheat degree and the measured superheat degree is adjusted in the case of the cooling operation, and the difference between the target superheat degree and the measured supercooling degree is eliminated in the case of the heating operation. Adjusting the flow rate of the refrigerant flowing through the heat exchanger, the ratio between the maximum refrigerant flow rate and the minimum refrigerant flow rate among the refrigerant flow rates flowing through each of the load-side heat exchangers at that time exceeds a predetermined range. If ever For the load-side unit having a large amount of change in the refrigerant flow rate in a predetermined time, after changing the target value, adjusting the flow rate adjusting means so that the difference between the measured value and the changed target value disappears. A method for controlling a multi-type refrigeration cycle apparatus capable of appropriately adjusting the refrigerant flow rate to each load-side heat exchanger even when the measured value does not indicate an actual value due to pressure loss by changing the refrigerant flow rate Is obtained.

Further, according to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting the flow rate of the refrigerant flowing through the load side heat exchanger, if a stopped load side unit is present when performing a heating operation, the operation load side unit may be over-measured. When the cooling degree becomes larger or smaller than a predetermined appropriate range, the refrigerant flow rate is increased by adjusting the flow rate adjusting means communicating with the stop load side heat exchanger so that the measured subcooling degree falls within the appropriate range. Alternatively, when the measured degree of subcooling of the operation load side unit falls within the appropriate range, the flow rate of the refrigerant flowing to the stop load side heat exchanger is maintained in that state. By, by circulating an appropriate amount of refrigerant to stop the load-side heat exchanger in the heating operation, the refrigerant control method of multi-type refrigeration cycle apparatus capable of stabilizing the refrigerating cycle can be obtained.

Further, according to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting the flow rate of the refrigerant flowing through the load side heat exchanger, if a stop load side unit is present when performing a heating operation, the load side of the operating load side unit When the flow rate of the refrigerant flowing through the heat exchanger continuously changes in only one direction of increase or decrease within a predetermined time, the flow rate of the refrigerant flowing through the load-side heat exchanger of the stop load-side unit is changed by the operation. It is changed in the same direction as the change direction of the refrigerant flow rate flowing through the load side heat exchanger, and the refrigerant flow rate flowing through the operating load side heat exchanger has escaped the state of continuously changing in only one direction. By maintaining the flow rate of the refrigerant flowing through the stop load side heat exchanger in that state, a proper amount of refrigerant can flow through the stop load side heat exchanger during the heating operation, and the refrigerant distribution in the entire circuit can be appropriately set. In addition, a refrigerant control method for a multi-type refrigeration cycle apparatus capable of stabilizing a refrigeration cycle can be obtained.

Further, according to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and communicating with each of the load side units, In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting the flow rate of the refrigerant flowing through the load side unit, if a stop load side unit exists when performing a heating operation, the load of the stop load side unit at the time of startup The flow rate of the refrigerant flowing through the side heat exchanger is initially set to a predetermined value so that the flow rate of the refrigerant flowing through the operation load side unit is not insufficient, and after a predetermined time has elapsed, the refrigerant flow is communicated with the stopped load side heat exchanger. The flow rate adjusting means is adjusted to gradually reduce the flow rate of the refrigerant flowing through the operation load side unit, and the pipe temperature of the heat source side heat exchanger in the heat source side unit drops below a predetermined value. In this case, by returning the flow rate adjusting means communicating with the stop load side heat exchanger before the pipe temperature decreases and maintaining that state, an appropriate amount of heat is supplied to the stop load side heat exchanger in the heating operation. A refrigerant control method for a multi-type refrigeration cycle apparatus can be obtained in which a refrigerant can be circulated to appropriately set the refrigerant distribution in the entire circuit and stabilize the refrigeration cycle.

According to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a plurality of the load side heat exchangers are provided. Refrigerant flow distribution means for distributing the refrigerant flow rate based on the capacity of the load-side heat exchanger, and the refrigerant flow rate to the plurality of load-side heat exchangers in accordance with the load of each of the load-side units. And a refrigerant flow rate adjusting means for adjusting the flow rate of refrigerant to the plurality of load side heat exchangers by the refrigerant flow rate distribution means when a significant load change occurs in at least one or more of the load side units. By distributing, it is possible to realize a refrigeration cycle in which the air-side heat exchange performance of the load-side unit and the refrigerant-side heat exchange performance are well-balanced and can operate stably, and can respond to load fluctuations with good responsiveness. Ri control device for multi-type refrigeration cycle apparatus capable of distributing a refrigerant to obtain to supply capability corresponding to the load.

Further, according to the present invention, a heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a target superheat degree and a measured superheat in a cooling operation. The refrigerant flow distribution means for distributing the refrigerant flow to each of the load-side heat exchangers of the load-side unit so as to eliminate the difference between the target subcooling degree and the measured subcooling degree in the heating operation. Refrigerant flow adjusting means for adjusting the refrigerant flow to the plurality of load-side heat exchangers according to the magnitude of the load of each of the load-side units, wherein at least one or more of the load-side units have a large load variation. Occurs, the refrigerant flow rate distribution means distributes the refrigerant flow rate to the plurality of load side heat exchangers, so that the load side unit has a good balance between the air side heat exchange performance and the refrigerant side heat exchange performance. , Cheap To the refrigeration cycle can be realized which can be operated, with good response can accommodate load variations, and the control device of the multi-type refrigeration cycle apparatus capable of distributing a refrigerant to provide the ability according to the load as possible is obtained.

Further, according to the present invention, it is possible to detect that a significant load change has occurred in the load-side unit when the temperature difference between the set temperature of the load-side unit and the measured temperature exceeds a predetermined value. Accordingly, a control device for a refrigeration cycle device that can respond to load fluctuations with good responsiveness and can operate stably can be obtained.

Further, according to the present invention, by detecting that a large load change has occurred in the load side unit when the amount of change in the frequency of the compressor exceeds a predetermined value, it is possible to respond to the load change. A control device for a refrigeration cycle device that can respond well and can operate stably can be obtained.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram illustrating a configuration of a multi-type refrigeration cycle apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart showing a processing procedure of a control method of the multi-type refrigeration cycle device according to the first embodiment.

FIG. 3 is a time chart of a control method according to the first embodiment.

FIG. 4 is a flowchart showing a process of another control method according to the first embodiment.

FIG. 5 is a refrigerant circuit diagram illustrating a configuration of a multi-type refrigeration cycle apparatus according to Embodiment 2 of the present invention.

FIG. 6 is a flowchart showing a processing procedure of a load response control according to the control method of the multi-type refrigeration cycle apparatus according to the second embodiment.

FIG. 7 is a refrigerant circuit diagram showing a configuration of a multi-type refrigeration cycle apparatus according to Embodiment 3 of the present invention.

FIG. 8 is a flowchart illustrating a processing procedure of a control method of the multi-type refrigeration cycle device according to the third embodiment.

FIG. 9 is a refrigerant circuit diagram showing another configuration of the multi-type refrigeration cycle device according to the third embodiment.

FIG. 10 is a flowchart showing a processing procedure of a load response control according to a control method of the multi-type refrigeration cycle apparatus according to Embodiment 4 of the present invention.

FIG. 11 is a time chart of a control method for a multi-type refrigeration cycle apparatus according to a fourth embodiment.

FIG. 12 is an explanatory diagram showing a difference in superheat measured according to a difference in the installation position of a sensor according to the fifth embodiment of the present invention.

FIG. 13 is a graph showing a change in setting of a target superheat degree with respect to a compressor frequency according to the fifth embodiment.

FIG. 14 is a flowchart showing a procedure for changing a target value in consideration of a pressure loss in a method of controlling a multi-type refrigeration cycle apparatus according to a fifth embodiment.

FIG. 15 is a time chart of the control method according to the fifth embodiment.

FIG. 16 is a refrigerant circuit diagram illustrating a configuration of a multi-type refrigeration cycle apparatus according to Embodiment 6 of the present invention.

FIG. 17 is a flowchart showing a processing procedure of a control method for the multi-type refrigeration cycle apparatus according to the sixth embodiment.

FIG. 18 is a time chart of the control method according to the sixth embodiment.

FIG. 19 is a flowchart illustrating a processing procedure of a control method for the multi-type refrigeration cycle apparatus according to Embodiment 7 of the present invention.

FIG. 20 is a time chart of the control method according to the seventh embodiment.

FIG. 21 is a flowchart illustrating a processing procedure of a control method for the multi-type refrigeration cycle apparatus according to Embodiment 8 of the present invention.

FIG. 22 is a time chart of the control method according to the eighth embodiment.

FIG. 23 is a refrigerant circuit diagram showing a configuration of a conventional multi-type refrigeration cycle device.

FIG. 24 is a refrigerant circuit diagram showing another configuration of a conventional multi-type refrigeration cycle device.

[Explanation of symbols]

1 compressor, 2 channel switching means, 3 heat source side heat exchanger,
4a, 4b Flow rate adjusting means, 5a, 5b Load side heat exchanger, 10 Heat source side heat exchanger tube temperature sensor, 11a, 11
b Room temperature detection sensor, 13 Heat source side control device, 14
a, 14b Load side control device, 20 to 24 control signal lines, X heat source side unit, A, B Load side unit.

Continuing from the front page (72) Takeshi Kuramochi, 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Haruo Nakano 2-3-2, Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Co., Ltd. Company F term (reference) 3L060 AA03 AA06 CC04 CC08 DD02 EE09 3L092 GA01 JA14 KA04 KA06 LA04 LA06

Claims (18)

[Claims] A heat source side unit having a compressor and a heat source side heat exchanger; a plurality of load side units each having a load side heat exchanger; and a load side heat exchanger of each of the load side units. In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting the flow rate of the refrigerant flowing through the load side heat exchanger, when operating a plurality of the load side units, first adjust each of the flow rate adjusting means. After adjusting the flow rate of the refrigerant flowing through the plurality of load-side heat exchangers to be operated to a predetermined split ratio, the flow rate adjusting means is finely adjusted according to the magnitude of the load on each load-side unit, and the load is adjusted. A refrigerant control method for a multi-type refrigeration cycle apparatus, comprising: increasing the flow rate of refrigerant flowing through a load-side heat exchanger having a large flow rate. 2. A flow rate of refrigerant flowing through a load-side heat exchanger of the operated load-side unit when a load fluctuation exceeding a predetermined value occurs in at least one load-side unit in the operating refrigeration cycle apparatus. 2. The refrigerant control method for a multi-type refrigeration cycle apparatus according to claim 1, wherein a predetermined flow ratio is set. 3. The method according to claim 1, wherein a split ratio of a flow rate of the refrigerant flowing through the plurality of load-side heat exchangers to be operated is set based on a capacity ratio of each of the load-side heat exchangers. Item 3. A refrigerant control method for a multi-type refrigeration cycle device according to item 2. 4. A heat source-side unit having a compressor and a heat source-side heat exchanger, a plurality of load-side units each having a load-side heat exchanger, and said load-side heat exchanger being connected to said load-side heat exchanger of each of said load-side units. In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting the flow rate of the refrigerant flowing through the load-side heat exchanger, when operating a plurality of the load-side units, the target superheat degree and the measured superheat degree in the cooling operation. After setting the flow rate of the refrigerant flowing through the load-side heat exchanger by adjusting the respective flow rate adjusting means so as to eliminate the difference between the target subcooling degree and the measured subcooling degree in the heating operation,
The refrigerant of the multi-type refrigeration cycle apparatus characterized by finely adjusting the flow rate adjusting means according to the magnitude of the load on each load side unit to increase the flow rate of the refrigerant flowing through the load side heat exchanger having a large load. Control method. 5. In a refrigeration cycle apparatus during operation, when a load fluctuation exceeding a predetermined value occurs in at least one or more load-side units, in a cooling operation in the refrigeration cycle after the fluctuation, the target degree of superheat and the measured superheat. In the case of the heating operation, the flow rate adjusting means is adjusted so as to eliminate the difference between the target degree of supercooling and the measured degree of supercooling, and the difference is circulated to the load side heat exchanger of the load side unit to be operated. 5. The refrigerant control method for a multi-type refrigeration cycle device according to claim 4, wherein the refrigerant flow rate is changed. 6. When the refrigerant flow rate is finely adjusted according to the magnitude of the load on each load side unit, the target superheat degree or target supercool degree of the load side heat exchanger having a large load is set to a value smaller than the current target value. To finely adjust the flow rate adjusting means so as to eliminate the difference between the measured superheat degree or the measured subcooling degree and the changed target value, to reduce the flow rate of the refrigerant flowing through the load-side heat exchanger having a large load. 5. The method according to claim 4, wherein the number is increased.
6. A refrigerant control method for a multi-type refrigeration cycle apparatus according to claim 5. 7. The method according to claim 1, wherein when the refrigerant flow rate is finely adjusted according to the magnitude of the load of each load-side unit, the amount of change in the refrigerant flow rate in one fine adjustment is within a predetermined range. The refrigerant control method for a multi-type refrigeration cycle apparatus according to any one of claims 1 to 6. 8. The method according to claim 1, wherein when finely adjusting the flow rate of the refrigerant according to the magnitude of the load of each load side unit, the flow rate of the refrigerant flowing through the load side heat exchanger having a large load is increased by a predetermined amount. A refrigerant control method for a multi-type refrigeration cycle apparatus according to any one of claims 1 to 5. 9. When the refrigerant flow rate is finely adjusted according to the magnitude of the load on each load side unit, the flow rate of the refrigerant flowing through the load side heat exchanger having a large load is increased, and the flow rate is adjusted before and after the change. 9. The method according to claim 1, wherein the flow rate of the refrigerant flowing through the load-side heat exchanger having a small load is reduced so that the total flow rate of the refrigerant flowing through the means becomes equal. A refrigerant control method for a multi-type refrigeration cycle device. 10. A heat source-side unit having a compressor and a heat source-side heat exchanger, a plurality of load-side units each having a load-side heat exchanger, and said load-side heat exchanger of each of said load-side units being in communication with said load-side heat exchanger. In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting the flow rate of the refrigerant flowing through the load side heat exchanger, when operating a plurality of the load side units, adjusting the flow rate adjusting means and performing a cooling operation. In the case where the difference between the target degree of superheat and the measured degree of supercooling, and in the case of the heating operation, the refrigerant flowing through the load side heat exchanger of each of the load side units so as to eliminate the difference between the target degree of supercooling and the measured degree of supercooling The flow rate is adjusted, and if the difference between the measured value of the degree of superheating or the degree of supercooling at that time and the target value is larger than a predetermined value, the target value is changed so that the difference becomes smaller. Adjust the total A refrigerant control method for a multi-type refrigeration cycle apparatus, wherein a refrigerant flow rate is changed so that a difference between a measured value and the changed target value is eliminated. 11. A heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and the load side heat exchangers of the respective load side units being in communication with each other. In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting the flow rate of the refrigerant flowing through the load side heat exchanger, when operating a plurality of the load side units, adjusting the flow rate adjusting means and performing a cooling operation. In such a case, the difference between the target superheat degree and the measured superheat degree is eliminated, and in the case of the heating operation, the difference between the target superheat degree and the measured superheat degree is eliminated.
Adjusting the flow rate of the refrigerant flowing through the load-side heat exchanger of each of the load-side units, the maximum refrigerant flow rate and the minimum refrigerant flow rate among the refrigerant flow rates flowing through each of the load-side heat exchangers at that time When the ratio exceeds a predetermined range, the target value is changed for the load side unit in which the amount of change in the refrigerant flow rate during the predetermined time has been large, and the flow rate adjusting means is adjusted to change the measured value to the measured value. A refrigerant control method for a multi-type refrigeration cycle apparatus, wherein the refrigerant flow rate is changed so as to eliminate the difference from the target value. 12. A heat source-side unit having a compressor and a heat source-side heat exchanger, a plurality of load-side units each having a load-side heat exchanger, and a plurality of load-side units connected to the load-side units and connected to the load-side heat exchanger. In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting a flow rate of a flowing refrigerant, when a stop load side unit is present when performing a heating operation, the measured supercooling degree of the operation load side unit is a predetermined appropriate level. When it becomes larger or smaller than the range, the flow rate adjusting means communicating with the stop load side heat exchanger is adjusted so that the measured degree of subcooling falls within the appropriate range to increase or decrease the refrigerant flow rate, and the operation When the measured degree of subcooling of the load side unit falls within the appropriate range, the flow rate of the refrigerant flowing through the stopped load side heat exchanger is maintained in that state. Refrigerant control method for a multi-type refrigeration cycle device. 13. A heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a plurality of load side units connected to the load side units and connected to the load side heat exchanger. In a multi-type refrigeration cycle apparatus including a plurality of flow rate adjusting means for adjusting a flow rate of a flowing refrigerant, when a stop load side unit is present when performing a heating operation, the flow is distributed to a load side heat exchanger of the operation load side unit. When the refrigerant flow rate continuously changes in only one direction of increase or decrease within a predetermined time, the flow rate of the refrigerant flowing through the load side heat exchanger of the stopped load side unit is changed to the operation load side heat exchanger. When the flow rate of the refrigerant flowing through the heat exchanger changes in the same direction as the direction of change in the flow rate of the flowing refrigerant, and the flow rate of the refrigerant flowing through the heat exchanger on the operating load side changes from being continuously changed in only one direction, the heat on the stop load side is changed. A refrigerant control method for a multi-type refrigeration cycle apparatus, wherein a flow rate of a refrigerant flowing through an exchanger is maintained in that state. 14. A heat source-side unit having a compressor and a heat source-side heat exchanger, a plurality of load-side units each having a load-side heat exchanger, and communicating with each of the load-side units and flowing to the load-side unit. In a multi-type refrigeration cycle device including a plurality of flow rate adjusting means for adjusting a refrigerant flow rate, when a stop load-side unit is present when performing a heating operation, it flows to the load-side heat exchanger of the stop load-side unit at startup. The refrigerant flow to be performed is initially set to a predetermined value so that the refrigerant flow flowing to the operation load side unit does not run short, and after a predetermined time has elapsed, the flow rate adjusting means communicating with the stop load side heat exchanger is adjusted. And gradually decreasing the flow rate of the refrigerant flowing through the operation load side unit, and stopping when the pipe temperature of the heat source side heat exchanger in the heat source side unit falls below a predetermined value. A refrigerant control method for a multi-type refrigeration cycle apparatus, characterized in that the flow rate adjusting means communicating with the load side heat exchanger is returned before the pipe temperature decreases and is maintained in that state. 15. A heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a refrigerant flow rate to a plurality of the load side heat exchangers, respectively. Refrigerant flow distribution means for distributing the refrigerant based on the capacity of the load-side heat exchanger, and refrigerant flow adjusting means for adjusting the refrigerant flow to the plurality of load-side heat exchangers in accordance with the load of each of the load-side units When a significant load change occurs in at least one or more of the load-side units, the refrigerant flow distribution means distributes the refrigerant flow to the plurality of load-side heat exchangers. Control system for a multi-type refrigeration cycle device. 16. A heat source side unit having a compressor and a heat source side heat exchanger, a plurality of load side units each having a load side heat exchanger, and a difference between a target superheat degree and a measured superheat degree in the cooling operation. In the heating operation, refrigerant flow distribution means for distributing the refrigerant flow to each of the load-side heat exchangers of the load-side unit so as to eliminate the difference between the target subcooling degree and the measured subcooling degree, and a plurality of the load-side heat exchangers. And refrigerant flow rate adjusting means for adjusting the flow rate of the refrigerant to the exchanger in accordance with the magnitude of the load of each of the load-side units, when a significant load change occurs in at least one or more of the load-side units, A refrigerant control device for a multi-type refrigeration cycle apparatus, wherein the refrigerant flow distribution means distributes a refrigerant flow to the plurality of load-side heat exchangers. 17. The method according to claim 17, wherein a temperature difference between the set temperature of the load-side unit and the measured temperature exceeds a predetermined value, thereby detecting that a significant load change has occurred in the load-side unit. A refrigerant control device for a multi-type refrigeration cycle device according to claim 15 or 16. 18. The method according to claim 15, wherein when a change in the frequency of the compressor exceeds a predetermined value, it is detected that a significant load change has occurred in the load-side unit. Refrigerant control device for multi-type refrigeration cycle device.