JPH09138024A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control surely in accordance with a required load even when the required load is small by a method wherein the capacity of a variable capacity type compressor is controlled in accordance with the required load or the flow rate of heat medium for a refrigerant heater is controlled in accordance with the same. SOLUTION: A control unit 10 detects a load by operating a difference between a temperature detected by an indoor temperature detector 14 and a set temperature in a remote controller or the like. The load, operated by the operation is judged whether it is within the predetermined capacity range of the compressor 1 or not and when the operated load is within the range of capacity of the compressor, the capacity control of the compressor 1 is effected. When the load is out of the range of capacity, the inflow rate of heat medium of hot-water is controlled by the choking means of the heater 5. According to this method, the air conditioner can be controlled surely in accordance with the required load even when the required load is small whereby the improvement of a performance coefficient can be contrived.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner that uses a heater as an external heat source during heating, and more particularly to a heat pump type air conditioner that can perform heating operation and cooling operation.

[0002]

2. Description of the Related Art Generally, a refrigeration cycle of a heat pump type air conditioner is composed of a compressor, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger and a four-way valve. The exchanger acts as a condenser, and during cooling, the flow of the refrigerant can be switched so that the indoor heat exchanger acts as an evaporator.

In this type of heat pump type air conditioner, especially when used in a cold region, it is practically 1-23090.
As disclosed in the publication, in addition to the purpose of removing frost on the outdoor heat exchanger that acts as an evaporator at the time of heating, in order to supplement the output in the heating operation, heating for heating the refrigerant from the external heat source via the heat medium is performed. Is equipped with a vessel.

In such an air conditioner, the required load may fluctuate due to fluctuations in the room temperature to be air-conditioned or fluctuations in the number of operating units out of a plurality of indoor units. To cope with this fluctuation in load, Conventionally, the capacity of the compressor is changed, and the flow rate of the refrigerant and the speed of the blower fan of the indoor unit are adjusted. For example, in the case of heating operation overload, the discharge capacity of the compressor is controlled, the refrigerant circulation amount is reduced by a refrigerant flow rate adjustment valve, etc., the blower fan speed of the indoor unit is reduced to reduce the heat exchange amount and evaporate. You are holding down your ability. Further, Japanese Utility Model Publication No. 61-23228 discloses a configuration in which the direction of the air blown out into the room is changed depending on the temperature of the heating medium of the heater.

[0005]

However, there is a problem that the coefficient of performance (COP) cannot be improved by the above-described load fluctuation coping method. Further, when the heating load request is small, even an inverter compressor (variable capacity compressor) cannot operate effectively at the lower limit, regardless of the upper limit. For example, as shown in FIG. , In a compressor with a capacity of up to 5 horsepower, 2
There is a problem that effective driving control cannot be performed in the range of horsepower driving or less.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and even if the required load is small, the air conditioner can be surely controlled according to the required load and has an excellent coefficient of performance. To provide.

[0007]

In order to achieve the above object, the invention according to claim 1 has a variable capacity compressor and a refrigerant heater for heating a refrigerant using a heat medium. In the air conditioner, the capacity of the compressor is controlled or the heat medium flow rate of the heater is controlled according to the required load.

According to a second aspect of the present invention, in an air conditioner having a variable capacity compressor and a refrigerant heater for heating a refrigerant by using a heat medium, a pipeline for circulating the heat medium is provided. It is characterized in that a flow rate throttling means is provided, and the flow rate of the heat medium is throttled by the throttling means when the capacity of the compressor cannot be fully throttled against the heating load.

According to a third aspect of the present invention, in an air conditioner having a variable capacity compressor and a refrigerant heater for heating a refrigerant using heat source water, a general-purpose boiler is used for the refrigerant heater. The heat source water is supplied by the throttle means for reducing the flow rate of the heat source water when the capacity of the compressor cannot be reduced against the heating load. It is characterized by that.

The invention according to claim 4 is the invention according to claim 2 or 3.
The throttle means comprises a bypass pipe for bypassing the refrigerant heater to flow a heat medium and a control valve connected to the bypass pipe. When the flow rate is throttled by the throttle means, the control valve is switched. According to the above, the flow rate is controlled by causing the heat medium to flow through the bypass pipe.

According to the invention described in claims 1 to 4, the output of the compressor is controlled or the flow rate of the heat medium of the heater is controlled according to the required load. For example, when the required load is large, the operating capacity of the compressor is controlled by keeping the flow rate of the heat medium flowing through the heater at the maximum flow rate. According to this, since the low pressure of the compressor becomes high, the coefficient of performance can be improved.

When the required load is small, the required amount of load is met by changing the heat medium flow rate of the heater while keeping the capacity of the compressor constant. In this way, by controlling the heat medium flow rate of the compressor or heater as needed,
Optimal control can be achieved in terms of the coefficient of performance according to the required load. For example, in a range where the required load is small, only the heat medium flow rate of the heater is changed and the capacity of the compressor is not changed, so that the operation efficiency can be improved and the coefficient of performance is also excellent. In particular, since it is possible to avoid controlling the compressor in a range where the capacity is small, it is possible to control the capacity of the compressor in an effective range and reduce the number of times of starting and stopping the compressor.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a refrigeration cycle of the air conditioner according to the present embodiment, and arrows show the flow of refrigerant gas during heating operation.

As shown in FIG. 1, the refrigeration cycle is provided with a compressor 1, a plurality of indoor heat exchangers 2, an outdoor heat exchanger 3, and a four-way valve 4. The discharge side of the compressor 1 is
It is connected via a four-way valve 4 to the inlet side of the indoor heat exchanger 2 during heating. Further, the outlet side of the indoor heat exchanger 2 is connected to the inlet side of the outdoor heat exchanger 3 during heating via a third opening / closing valve 7 and a second opening / closing valve 9 which are also used as expansion valves. The outlet side of the outdoor heat exchanger 3 is connected to the four-way valve 4, and the four-way valve 4 further includes a suction side (heater 5
Is also the outlet side of the), and a refrigeration cycle is formed.

The heater 5 is connected in parallel to the outdoor heat exchanger 3. In this case, the first opening / closing valve for allowing the refrigerant to flow into the heater 5 is provided on the inlet side of the heater 5. 8 is provided, and its outlet side is also connected to the downstream side of the check valve 6 described above. As a result, during heating operation,
The refrigerant that has passed through the heater 5 is blocked by the check valve 6 to prevent the refrigerant from stagnation in the outdoor heat exchanger 3.

As the compressor 1, a so-called inverter compressor having a variable discharge capacity is used, and the control device 10 is used.
The discharge capacity can be changed according to the control command from. It should be noted that the compressor 1 is not limited to the inverter compressor, and any compressor whose capacity can be changed by so-called power saving can obtain similar effects as long as its discharge capacity can be controlled. An indoor temperature detector 14 for detecting the indoor temperature is arranged in the room where the indoor heat exchanger 2 is arranged, and sends the detected indoor temperature signal to the control device 10.

As shown in FIG. 2, the heater 5 is provided with a pipe line 101 through which a refrigerant flows and a pipe line 102 through which a heat medium (heat source water) flows, and the pipe line 102 has a general-purpose boiler (not shown). Hot water (heat source water) is supplied from the hot water, and the hot water heats the refrigerant flowing through the pipe 101. Further, the pipe 102 is provided with a diaphragm means 103, and the diaphragm means 103
Bypass pipe 104 that bypasses the heater 5 and flows hot water
And a three-way valve (control valve) connected to this bypass pipe 104
And 105. When the flow rate flowing through the pipe 102 is reduced, the three-way valve 105 is switched to cause hot water to flow through the bypass pipe 104 as indicated by an arrow A, thereby reducing the flow rate.

According to this embodiment, the first opening / closing valve 8,
By switching the second on-off valve 9, it is possible to perform the heating operation using either the outdoor heat exchanger 3 using the air heat source or the refrigerant heater 5 (suitable for the cold season).

During the heating operation using the heater 5, FIG.
As shown in, the second on-off valve 9 is closed while the third on-off valve 7 and the first on-off valve 8 are open. The flow of the refrigerant is indicated by an arrow, and the refrigerant discharged from the compressor 1 is
Through the indoor heat exchanger 2 to release heat, and after passing through the third opening / closing valve 7, the first opening / closing valve 8 and the heater 5 to be heated,
It flows through the four-way valve 4 and returns to the suction side of the compressor 1.

According to this embodiment, the control device 10 controls the capacity of the compressor 1 or the flow rate of the heat medium of the heater 5 according to the required load. A simple control method will be described below.

Referring to FIG. 3, first, after the start, the load is detected in step S1. The load is detected by calculating a temperature difference between the temperature detected by the indoor temperature detector 14 and the set temperature set by the remote controller (remote control device). In step S2, it is determined whether or not the load detected by the calculation is within a predetermined capacity range of the compressor 1, and if it is within the capacity range, the process proceeds to step S3 to control the capacity of the compressor 1, and if it is outside the capacity range. For example, the process proceeds to step S4, and the flow rate control of hot water by the throttle means (three-way valve) 103 is performed. The specific capacity range of the compressor 1 is not particularly limited, but is larger than a predetermined value K with respect to the load (required capacity), as shown on the horizontal axis of the graph shown in FIG. 4, for example. If it is larger than K, compressor control is performed, and if it is K or less, flow rate control is performed.

The graph of FIG. 4 shows the relationship between the required load and the capacity, with the horizontal axis representing the load and the vertical axis representing the capacity (temperature or horsepower).

According to this embodiment, this value K is preferably in the range of about 30 to 50% in the inverter compressor, and is, for example, about 2 horsepower in the 5-horsepower compressor 1.
As described above, K is used as a reference because for a load smaller than this, the operation of the compressor 1 is substantially difficult to control due to its capability, and the compressor 1 is frequently started and stopped. This is because it is not preferable in terms of coefficient.

In the compressor control in step S3, as shown in FIG. 4, the hot water flow rate to the heater 5 is maintained at the maximum flow rate, that is, the flow rate that is flown with the throttle means 103 in a non-operating state, and the required load is met. The load is changed in the range of 2 to 5 horsepower. In this embodiment, since a general-purpose boiler is used as the boiler, the hot water supply amount from this general-purpose boiler is always constant. Within this range, control can be performed reliably and easily, and proportional compression functional force control can be performed as shown in the graph of FIG.

After the control of the compressor, it is judged in step S5 whether or not the capacity = load (target capacity) is reached. If the target value is not reached, the process returns to the load detection in step S1 and the above-mentioned is executed. The steps are repeated, and when the target value is reached, the process ends.

The flow rate control in step S4 is shown on the left side of the value K in the graph of FIG. 4, and when the required load is smaller than the value K, the discharge capacity of the compressor 1 is made constant and the flow rate flows to the heater 5. By appropriately adjusting the flow rate through the throttling means 103, control corresponding to the load is performed.
In the case of this flow rate control, the compressor 1 is driven with a minimum capacity and a constant capacity. In response to this low load requirement, the refrigerant is indirectly heated by water or the like having a large heat capacity, so that stable operation can be achieved.

By performing the above-described control, for example, when the required load is large, the operating capacity of the compressor 1 is controlled while maintaining the heat medium flow rate to the heater 5 at the maximum flow rate. According to this, since the low pressure of the compressor 1 becomes high, the coefficient of performance can be improved. When the required load is small, the heat medium flow rate of the heater 5 is changed while keeping the capacity of the compressor 1 constant to cope with the required load. In this way, by controlling the heat medium flow rate of the compressor 1 or the heater 5 as needed, optimum control can be achieved according to the required capacity and economical efficiency.
For example, in a range where the required load is small, the flow rate of the heat medium of the heater is changed and the capacity of the compressor is not changed, so that the operation efficiency can be increased and the coefficient of performance is also excellent. In particular, since the compressor 1 is not controlled in the range of small capacity, the discharge capacity of the compressor 1 can be controlled in an effective range, and the number of times the compressor 1 is started and stopped can be reduced.

During the defrosting operation, the third opening / closing valve 7 is closed, the first opening / closing valve 8 and the second opening / closing valve 9 are opened, and the refrigerant heated by the heater 5 is transferred to the compressor 1 and the refrigerant. Directly sent to the frosted outdoor heat exchanger 3. In this case, in the indoor heat exchanger 2, since the third opening / closing valve 7 is closed, the refrigerant is sent and the heat radiation due to evaporation is almost eliminated. Therefore, after the defrosting is completed, the rising when the heating operation is restarted is good. Become.

Further, during the heating operation by the normal air heat source, the first opening / closing valve 7 and the second opening / closing valve 9 are opened and the first opening / closing valve 7 is opened.
The on-off valve 8 is closed and the refrigerant discharged from the compressor 1 is
It flows through the four-way valve 4, the indoor heat exchanger 2, the third opening / closing valve 7, the outdoor heat exchanger 3, the four-way valve 4, and the check valve 6 and returns to the suction side of the compressor 1.

FIG. 5 shows another embodiment. According to this, the throttling means 103 includes the bypass pipe 104 for bypassing the heater 5 and flowing hot water, and the bypass pipe 10.
4 and a two-way valve 107 connected to each other. Pipeline 102
When restricting the flow rate flowing through, the two-way valve 107 is switched to cause hot water to flow through the bypass pipe 104 as indicated by an arrow B, and thus the flow rate may be restricted. This also
The flow rate can be throttled.

[0031]

As is apparent from the above description, according to these inventions, the capacity of the compressor is controlled or the heat medium flow rate of the heater is controlled according to the required load, so that the required load is required. As a result, it is possible to surely control the above and improve the coefficient of performance.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a refrigeration cycle of an air conditioner according to the present invention.

FIG. 2 is a circuit diagram showing an embodiment of diaphragm means.

FIG. 3 is a flowchart showing an embodiment of an air conditioner according to the present invention.

FIG. 4 is a graph showing the relationship between load and capacity control.

FIG. 5 is a circuit diagram showing another embodiment of the diaphragm means.

[Explanation of symbols]

 1 Compressor 2 Indoor heat exchanger 3 Outdoor heat exchanger 4 Four-way valve 5 Heater 10 Control device 103 Throttling means 104 Bypass pipe 105 Control valve

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takao Shiina 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (4)

[Claims] 1. An air conditioner having a variable capacity compressor and a refrigerant heater for heating a refrigerant using a heat medium, wherein the capacity of the compressor is controlled or the heating is performed according to a required load. An air conditioner characterized by controlling the flow rate of a heat medium in a heater. 2. An air conditioner having a variable capacity compressor and a refrigerant heater for heating a refrigerant by using a heat medium, wherein a flow path throttle means is provided in a pipe line for circulating the heat medium, An air conditioner characterized by reducing the flow rate of a heat medium by the expansion means when the capacity of the compressor cannot be fully reduced with respect to a heating load. 3. An air conditioner having a variable capacity compressor and a refrigerant heater that heats a refrigerant using heat source water, wherein the heat source water is supplied to the refrigerant heater by using a general-purpose boiler. An air conditioner characterized in that the pipe for supplying the heat source water is provided with a throttle means for the flow rate, and the flow rate of the heat source water is throttled by the throttle means when the capacity of the compressor cannot be fully throttled against the heating load. Machine. 4. The throttle means comprises a bypass pipe for bypassing the refrigerant heater and flowing a heat medium, and a control valve connected to the bypass pipe. When the flow rate is throttled by the throttle means, the control valve is switched, The air conditioner according to claim 2 or 3, wherein the flow rate is controlled by causing a heat medium to flow through the bypass pipe.