JP2008157557A - Air conditioner - Google Patents

Abstract

A defrost operation can be performed on an outdoor heat exchanger that has requested defrost even during a heating operation.
A controller (50) switches a first four-way switching valve (26) of only an outdoor unit (20A) for which a defrost request has been made, and the outdoor heat exchange of the outdoor unit (20A) for which the defrost request has been made. The defrosting operation is performed by communicating the compressor (22) and the discharge side of the compressor (21).
[Selection] Figure 4

Description

  The present invention relates to an air conditioner in which a plurality of outdoor units parallel to each other are connected to an indoor unit, and more particularly to a defrost operation of an outdoor heat exchanger.

  In recent years, air conditioning devices have been required to have high air conditioning performance. When the air conditioning load of an indoor unit becomes large, it is difficult to secure a necessary capacity with only one outdoor unit. Here, it is conceivable to increase the size of the heat exchanger or compressor of the outdoor unit according to the air conditioning performance of the indoor unit, but the casing of the outdoor unit becomes large with this, for example, by an elevator up to the installation site There are various problems such as difficulty in carrying in, and inability to transport on an assembly line in a factory, increasing the number of assembly steps.

Therefore, a plurality of outdoor units are connected in parallel to the inter-unit piping extending from the indoor unit, and the operation of the plurality of outdoor units is controlled according to the air conditioning load in the room to increase the capacity of the air conditioner. What was made into is known (for example, refer patent document 1).
Japanese Patent Laid-Open No. 7-225067

  By the way, in the air conditioner as described above, when frost is generated in the heat exchanger of the outdoor unit during the heating operation, the heating cycle is switched to the cooling cycle, and the high-temperature refrigerant discharged from the compressor is transferred to the outdoor heat exchanger. Defrosting (defrosting) by directing to

  However, in the conventional defrost method, there is a problem that, when the heating cycle is returned to the end after the defrosting, the air conditioning load increases, so that the start of the heating operation is delayed and the heating capacity is reduced.

  The present invention has been made in view of the above points, and an object of the present invention is to enable a defrost operation to be performed on an outdoor heat exchanger that has requested defrost even during a heating operation. There is.

The first invention is the compressor (21), the heat source side heat exchanger (22), and one end side of the heat source side heat exchanger (22) is either the suction side or the discharge side of the compressor (21). A plurality of heat source side units (20A, 20B) having a first switching valve (26) and a second switching valve (27) for switching the refrigerant flow path so as to communicate with one side and connected in parallel;
One end is connected to the other end side of the heat source side heat exchanger (22) of each heat source side unit (20A, 20B), and the other end is connected to the compressor (21) via the second switching valve (27). An air conditioner comprising: a use side unit (40) having a use side heat exchanger (41) connected to one of a suction side and a discharge side in a switchable manner;
The first switching valve (26) of only the heat source side unit (20A) requested to defrost is switched to compress the heat source side heat exchanger (22) of the heat source side unit (20A) requested to defrost. The defrosting means (50) for performing the defrost operation by communicating with the discharge side of the machine (21) is provided.

  In the first invention, the first switching valve (26) of only the heat source side unit (20A) requested to defrost is switched by the defrost means (50), and the heat source side unit (20A) requested to defrost. The heat source side heat exchanger (22) and the discharge side of the compressor (21) are communicated with each other to execute the defrost operation.

  For this reason, if there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B) during the heating operation, the entire air conditioner is cooled from the heating operation to the cooling operation. Without switching to, the first switching valve (26) of only the heat source side unit (20A) for which the defrost is requested is switched, and the high temperature refrigerant discharged from the compressor (21) is transferred to the heat source side heat for which the defrost is requested. The defrosting operation can be performed by directly introducing it into the exchanger (22).

  That is, the air conditioning apparatus as a whole can appropriately perform the defrost operation on the heat source side heat exchanger (22) that requires defrost while performing the heating operation, and after completion of the defrost, the heat source side unit (20A ) Is returned to the heating cycle, the rise of the heating operation is accelerated, which is advantageous in suppressing the decrease in the heating capacity of the entire air conditioner.

2nd invention is the air conditioning apparatus of 1st invention,
The utilization side unit (40) includes a utilization side fan (43) disposed in the vicinity of the utilization side heat exchanger (41),
The defrost means (50) reduces the air volume of the use side fan (43) or stops air blowing when the pressure of the high-pressure refrigerant or the equivalent saturation temperature becomes a predetermined value or less during the defrost operation. It is characterized by being comprised.

  In the second invention, when the pressure of the high-pressure refrigerant or the equivalent saturation temperature becomes equal to or lower than a predetermined value during the defrost operation by the defrost means (50), the air volume of the use side fan (43) is reduced or the blowing is stopped. Is done.

  Therefore, if there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B) during heating operation, only the heat source side heat exchanger (22) In the defrost operation, the operation of the use side fan (43) is controlled based on the detected value of the pressure of the high pressure refrigerant or the equivalent saturation temperature to maintain the high pressure, so that the use side unit (40) Can be prevented from being blown.

  That is, when only a part of the heat source side heat exchangers (22) are defrosted, the amount of refrigerant circulating in the refrigerant circuit as a whole of the air conditioner is reduced to all the heat source side units (20A, 20B). Will be reduced compared to when operating as a condenser. Therefore, if the use side fan (43) is operated with the same air volume as in the full operation state, the high pressure cannot be maintained, and cold air is blown by the use side unit (40). Therefore, if the air volume of the use side fan (43) is controlled according to the amount of circulating refrigerant, the high pressure can be maintained and the use side unit (40) can be prevented from blowing cold air. This is preferable.

  The predetermined value is a variable value based on the room temperature, the outdoor temperature, the indoor set temperature, the operating status of the indoor unit (40), the operating frequency of the compressor (21), and the like.

3rd invention is the air conditioning apparatus of 1st or 2nd invention,
A heat source side expansion valve (24) which is provided on the other end side of the heat source side heat exchanger (22) of each of the heat source side units (20A, 20B) and adjusts the flow rate of the refrigerant flowing through the heat source side heat exchanger (22). )
The defrosting means (50) adjusts the opening degree of the heat source side expansion valve (24) of the heat source side unit (20A), which requested the defrost during the defrost operation, to adjust the pressure of the high pressure refrigerant or the equivalent saturation temperature. Is controlled to a predetermined value.

  In the third invention, the opening degree of the heat source side expansion valve (24) of the heat source side unit (20A) requested to defrost during the defrost operation is adjusted by the defrost means (50), and the pressure of the high pressure refrigerant or the equivalent saturation is obtained. The temperature is controlled to a predetermined value.

  For this reason, during a heating operation, when there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B), the heat source side unit ( The amount of the high-temperature refrigerant discharged from the compressor (21) can be adjusted by adjusting the opening of the heat source side expansion valve (24) of 20A). In other words, when it is necessary to rapidly defrost, you do not want to fully open the opening of the heat source side expansion valve (24) to increase the amount of refrigerant flow or to reduce the air conditioning capacity of the entire air conditioner. For this purpose, the degree of opening of the heat source side expansion valve (24) may be slightly opened to reduce the refrigerant flow rate to the heat source side heat exchanger (22) that has requested defrost.

  The predetermined value is a variable value based on the room temperature, the outdoor temperature, the indoor set temperature, the operating status of the indoor unit (40), the operating frequency of the compressor (21), and the like.

A fourth aspect of the present invention is the air conditioner according to any one of the first to third aspects,
The defrost means (50) controls the capacity of the compressor (21) of the heat source side unit (20A) that has requested the defrost during the defrost operation, and sets the pressure of the high pressure refrigerant or the equivalent saturation temperature to a predetermined value. It is comprised so that it may control to.

  In the fourth aspect of the invention, the capacity control of the compressor (21) of the heat source side unit (20A) requested to defrost during the defrost operation is performed by the defrost means (50), and the pressure of the high pressure refrigerant or the equivalent saturation temperature is controlled. It is controlled to a predetermined value.

  For this reason, during a heating operation, when there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B), the heat source side unit ( The capacity of the compressor (21) of 20A) can be controlled to adjust the refrigerant amount of the high-temperature refrigerant discharged from the compressor (21). That is, when it is necessary to rapidly defrost, the capacity of the compressor (21) may be increased to increase the refrigerant flow rate.

5th invention is an air conditioning apparatus in any one of 1st thru | or 4th,
The usage side unit (40) includes a usage side expansion valve (42) connected to a liquid side end of the usage side heat exchanger (41),
The defrost means (50) is configured to control the pressure of the high-pressure refrigerant or the equivalent saturation temperature to a predetermined value by adjusting the opening of the use side expansion valve (42) during the defrost operation. It is characterized by.

  In the fifth invention, the opening degree of the use side expansion valve (42) is adjusted by the defrosting means (50) during the defrosting operation, and the pressure of the high-pressure refrigerant or the equivalent saturation temperature is controlled to a predetermined value.

  For this reason, during the heating operation, when there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B), the opening degree of the use side expansion valve (42) Adjustment can be made to adjust the amount of refrigerant flowing to the use side unit (40) side. That is, when it is necessary to rapidly defrost, the opening degree of the use side expansion valve (42) is slightly opened, and the compressor (21) is moved to the heat source side heat exchanger (22) side where the defrost is requested. If you want to distribute more of the discharged high-temperature refrigerant, or if you do not want to reduce the air conditioning capacity of the entire air conditioner as much as possible, open the use-side expansion valve (42) fully open to meet the defrost requirement. What is necessary is just to make it reduce the refrigerant | coolant distribution amount to the heat source side heat exchanger (22) which existed.

  In the present invention, if there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B) during the heating operation, the entire air conditioner is cooled from the heating operation to the cooling. Without switching to operation, only the first switching valve (26) of the heat source side unit (20A) that requested defrost is switched, and the high-temperature refrigerant discharged from the compressor (21) is transferred to the heat source side that requested defrost. The defrosting operation can be executed by directly introducing it into the heat exchanger (22).

  That is, the air conditioning apparatus as a whole can appropriately perform the defrost operation on the heat source side heat exchanger (22) that requires defrost while performing the heating operation, and after completion of the defrost, the heat source side unit (20A ) Is returned to the heating cycle, the rise of the heating operation is accelerated, which is advantageous in suppressing the decrease in the heating capacity of the entire air conditioner.

  In the second aspect of the present invention, if there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B) during the heating operation, the heat source side heat exchange is performed. Only by defrosting the vessel (22) and maintaining the high pressure by controlling the operation of the user side fan (43) based on the pressure of the high pressure refrigerant or the detected value of the equivalent saturation temperature during the defrost operation. It is possible to prevent the cool air from being blown at (40).

  That is, when only a part of the heat source side heat exchangers (22) are defrosted, the amount of refrigerant circulating in the refrigerant circuit as a whole of the air conditioner is reduced to all the heat source side units (20A, 20B). Will be reduced compared to when operating as a condenser. Therefore, if the use side fan (43) is operated with the same air volume as in the full operation state, the high pressure cannot be maintained, and cold air is blown by the use side unit (40). Therefore, if the air volume of the use side fan (43) is controlled according to the amount of circulating refrigerant, the high pressure can be maintained, and the use side unit (40) can be prevented from blowing cool air. This is preferable.

  In the third invention, if there is a defrost request for any one of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B) during the heating operation, The amount of the high-temperature refrigerant discharged from the compressor (21) can be adjusted by adjusting the opening of the heat source side expansion valve (24) of the heat source side unit (20A). In other words, when it is necessary to rapidly defrost, you do not want to fully open the opening of the heat source side expansion valve (24) to increase the amount of refrigerant flow or to reduce the air conditioning capacity of the entire air conditioner. For this purpose, the degree of opening of the heat source side expansion valve (24) may be slightly opened to reduce the refrigerant flow rate to the heat source side heat exchanger (22) that has requested defrost.

  In the fourth aspect of the invention, if there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B) during the heating operation, The capacity of the compressor (21) of the heat source side unit (20A) can be controlled to adjust the refrigerant amount of the high-temperature refrigerant discharged from the compressor (21). That is, when it is necessary to rapidly defrost, the capacity of the compressor (21) may be increased to increase the refrigerant flow rate.

  In the fifth aspect of the invention, if there is a defrost request for any of the heat source side heat exchangers (22) of the plurality of heat source side units (20A, 20B) during the heating operation, the use side expansion valve ( The amount of refrigerant flowing to the use side unit (40) side can be adjusted by adjusting the opening degree of 42). That is, when it is necessary to rapidly defrost, the opening degree of the use side expansion valve (42) is slightly opened, and the compressor (21) is moved to the heat source side heat exchanger (22) side where the defrost is requested. If you want to distribute more of the discharged high-temperature refrigerant, or if you do not want to reduce the air conditioning capacity of the entire air conditioner as much as possible, open the use-side expansion valve (42) fully open to meet the defrost requirement. What is necessary is just to make it reduce the refrigerant | coolant distribution amount to the heat source side heat exchanger (22) which existed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

<Embodiment 1>
FIG. 1 is a refrigerant circuit diagram illustrating an overall configuration of an air-conditioning apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the air conditioner according to the present invention includes one indoor unit (40) and two outdoor units (20A, 20B) connected in parallel to each other. The refrigerant circuit (R) is configured by being connected by the liquid pipe (15). In the refrigerant circuit (R), a refrigerant is circulated to perform a vapor compression refrigeration cycle, and a cooling operation or a heating operation can be performed.

<Configuration of outdoor unit>
The outdoor units (20A, 20B) constitute a heat source side unit, and include a compressor (21), an outdoor heat exchanger (22), an outdoor expansion valve (24), a first four-way switching valve (26), Two-way switching valve (27) and an outdoor fan (25) are provided. The compressor (21) constitutes an inverter compressor having a variable capacity. The outdoor heat exchanger (22) is a cross-fin type fin-and-tube heat exchanger, and constitutes a heat source side heat exchanger of the present invention. The outdoor expansion valve (24) is an electronic expansion valve and constitutes a heat source side expansion valve of the present invention.

  Furthermore, the outdoor units (20A, 20B) are provided with a plurality of pressure sensors (Ps1, Ps2) for detecting the pressure of the refrigerant. Specifically, the high pressure side pressure sensor (Ps1) that detects the pressure of the high pressure refrigerant is detected on the discharge side of the compressor (21), and the pressure of the low pressure refrigerant is detected on the suction side of the compressor (21). A low-pressure sensor (Ps2) is provided.

  An outdoor fan (25) is provided in the vicinity of the outdoor heat exchanger (22). The outdoor heat exchanger (22) is configured so that the refrigerant exchanges heat with the air taken in by the outdoor fan (25).

  The first four-way selector valve (26) and the second four-way selector valve (27) have first to fourth ports. In the first four-way selector valve (26), the first port is connected to the discharge side of the compressor (21), the second port is connected to the outdoor heat exchanger (22), and the third port is connected to the compressor (21). It is connected to the inhalation side. The fourth port of the first four-way selector valve (26) is closed.

  In the second four-way selector valve (27), the first port is connected to the discharge side of the compressor (21), the second port is closed, and the third port is connected to the suction side of the compressor (21). The fourth port is connected to the indoor unit (40) side.

  The first four-way switching valve (26) and the second four-way switching valve (27) are in a first state in which the first port and the fourth port communicate with each other and the second port and the third port communicate with each other (see FIG. 1 and a second state (state indicated by a broken line in FIG. 1) in which the first port and the second port communicate with each other and the third port and the fourth port communicate with each other. It has become. In addition, you may comprise a 1st switching valve (26) and a 2nd switching valve (27) using a three-way switching valve instead of each four-way switching valve (26,27). Moreover, you may comprise a 1st switching valve (26) and a 2nd switching valve (27) using two solenoid valves.

<Configuration of indoor unit>
The indoor unit (40) constitutes a utilization side unit of the present invention, and includes an indoor heat exchanger (41), an indoor expansion valve (42), and an indoor fan (43). The indoor heat exchanger (41) is a cross fin type fin-and-tube heat exchanger, and constitutes a utilization side heat exchanger of the present invention. The indoor expansion valve (42) is an electronic expansion valve and constitutes a utilization side expansion valve of the present invention. An indoor heat exchanger (41) and an indoor expansion valve (42) are provided in this order from the gas side end of the indoor unit (40).

  An indoor fan (43) is provided in the vicinity of the indoor heat exchanger (41). The indoor heat exchanger (41) is configured so that the refrigerant exchanges heat with the air taken in by the indoor fan (43). The indoor fan (43) constitutes the use side fan of the present invention.

  The gas side end of the indoor unit (40) is connected to the fourth port of the second four-way switching valve (27) of each outdoor unit (20A, 20B) via a gas pipe (13). The liquid side end of the indoor unit (40) is connected to the outdoor heat exchanger (22) of each outdoor unit (20A, 20B) via the liquid pipe (15).

<Configuration of controller>
The air conditioner (10) includes first and second four-way switching valves (26, 27), an indoor expansion valve (42), an outdoor expansion valve (24), a compressor (21), and an indoor fan (43). The controller (50) which controls etc. is provided. This controller (50) constitutes defrost means that receives a defrost request signal for requesting defrost operation for the outdoor heat exchanger (22) that requires defrost during heating operation, and executes the defrost operation based on this defrost request is doing.

  This defrost request signal detects, for example, that the detection value of the temperature sensor for detecting the surface temperature of the outdoor heat exchanger (22) has become a predetermined value or less, and frost is generated in the outdoor heat exchanger (22). It is conceivable to make a timer control that outputs a defrost request signal every time a predetermined time elapses.

-Driving action-
Below, the operation | movement operation | movement of the air conditioning apparatus (10) which concerns on this Embodiment 1 is demonstrated. In the air conditioner (10), whether the cooling operation or the heating operation is performed is determined by the first four-way switching valve (26) and the second four-way switching valve (27) of the outdoor unit (20A, 20B). Adjusted.

  That is, when the first four-way switching valve (26) and the second four-way switching valve (27) are set to the cooling operation state, the cooling operation is performed in the operating indoor unit (40), and the first four When the path switching valve (26) and the second four-way switching valve (27) are set to the heating operation state, the heating operation is performed in the operating indoor unit (40).

<Heating operation>
In the heating operation, as shown in FIG. 2, the first four-way selector valve (26) is set to the first state, and the second four-way selector valve (27) is set to the first state. When the compressor (21) is operated in this state, a vapor compression refrigeration cycle in which the indoor heat exchanger (41) becomes a condenser and the outdoor heat exchanger (22) becomes an evaporator in the refrigerant circuit (R). Done.

  Specifically, in each outdoor unit (20A, 20B), the refrigerant discharged from the compressor (21) flows into the indoor unit (40) and is taken in from the indoor fan (43) by the indoor heat exchanger (41). Heat exchanges with the room air and condenses. The refrigerant condensed in the indoor heat exchanger (41) is distributed to each outdoor unit (20A, 20B), decompressed by the outdoor expansion valve (24), and then from the outdoor fan (25) by the outdoor heat exchanger (22). Evaporates by exchanging heat with the outdoor air taken in. The refrigerant evaporated in the outdoor heat exchanger (22) is sucked into the compressor (21) and compressed.

<Cooling operation>
In the cooling operation, as shown in FIG. 3, the first four-way switching valve (26) is set to the second state, and the second four-way switching valve (27) is set to the second state. When the compressor (21) is operated in this state, a vapor compression refrigeration cycle in which the outdoor heat exchanger (22) serves as a condenser and the indoor heat exchanger (41) serves as an evaporator in the refrigerant circuit (R). Done.

  Specifically, in each outdoor unit (20A, 20B), the refrigerant discharged from the compressor (21) exchanges heat with outdoor air taken in from the outdoor fan (25) by the outdoor heat exchanger (22). Condensate. The refrigerant condensed in each outdoor heat exchanger (22) flows into the indoor unit (40), is decompressed by the indoor expansion valve (42), and is taken in from the indoor fan (43) by the indoor heat exchanger (41). Evaporates by exchanging heat with room air. The refrigerant evaporated in the indoor heat exchanger (41) is distributed to each outdoor unit (20A, 20B), and is sucked into the compressor (21) of each outdoor unit (20A, 20B) and compressed.

<Defrost operation>
Next, when frost is generated in one outdoor heat exchanger (22) of the outdoor units (20A, 20B) during the heating operation, a defrost operation for defrosting while continuing the heating cycle will be described with reference to FIG. Will be described. In the following description, a case where there is a defrost request for the outdoor unit (20A) will be described.

  As shown in FIG. 4, when there is a defrost request to the outdoor heat exchanger (22) of any of the plurality of outdoor units (20A, 20B) during the heating operation, the controller (50) Without switching the entire conditioner (10) from the heating operation to the cooling operation, the first four-way switching valve (26) of only the outdoor unit (20A) for which the defrost is requested is switched, and the outdoor unit for which the defrost is requested. The outdoor heat exchanger (22A) of (20A) is communicated with the discharge side of the compressor (21). Thereby, the high temperature refrigerant | coolant discharged from the compressor (21) is directly introduce | transduced into the outdoor heat exchanger (22) with which the defrost request | requirement was requested | required, and defrost operation can be performed.

  That is, the air conditioner (10) as a whole can be appropriately defrosted with respect to the outdoor heat exchanger (22) that requires defrosting while performing the heating operation, and after the defrosting, the outdoor unit (20A) When the air conditioner is returned to the heating cycle, the start-up of the heating operation is accelerated, which is advantageous in suppressing the deterioration of the heating capacity of the air conditioner (10) as a whole.

  Furthermore, in the air conditioning apparatus according to the first embodiment, the controller (50) reduces the air volume of the indoor fan (43) when the pressure of the high-pressure refrigerant or the equivalent saturation temperature becomes a predetermined value or less during the defrost operation. Or you may control to stop ventilation.

  Thus, when there is a defrost request for any of the outdoor heat exchangers (22) of the plurality of outdoor units (20A, 20B) during the heating operation, only the outdoor heat exchanger (22) is defrosted. During this defrost operation, the pressure of the high-pressure refrigerant or equivalent saturation temperature is detected by a high-pressure side pressure sensor (Ps1) or a temperature sensor (not shown), and the operation of the indoor fan (43) is controlled based on the detected value. By maintaining the high pressure, it is possible to prevent cold air from being blown by the use side unit (40).

  That is, when only some of the outdoor heat exchangers (22) are defrosted, the amount of refrigerant circulating in the refrigerant circuit (R) as a whole of the air conditioner (10) is reduced to all the outdoor units ( 20A, 20B) will be reduced compared to when operating as a condenser. Therefore, if the indoor fan (43) is operated at the same air volume as in the full operation state, the high pressure cannot be maintained, and cold air is blown by the use side unit (40). Therefore, if the air volume of the use side fan (43) is controlled according to the amount of circulating refrigerant, the high pressure can be maintained, and the use side unit (40) can be prevented from blowing cool air. This is preferable.

  The predetermined value is a variable value based on the room temperature, the outdoor temperature, the indoor set temperature, the operating status of the indoor unit (40), the operating frequency of the compressor (21), and the like.

  Furthermore, in the air conditioning apparatus according to the first embodiment, the controller (50) adjusts the opening degree of the outdoor expansion valve (24) of the outdoor unit (20A) that has requested defrost during the defrost operation, and The pressure or the equivalent saturation temperature may be controlled to a predetermined value.

  In this way, when there is a defrost request for any of the outdoor heat exchangers (22) of the plurality of outdoor units (20A, 20B) during the heating operation, the outdoor unit ( The amount of the high-temperature refrigerant discharged from the compressor (21) can be adjusted by adjusting the opening of the outdoor expansion valve (24) of 20A). That is, when it is necessary to rapidly defrost, it is desirable to increase the refrigerant flow rate by fully opening the outdoor expansion valve (24), or to reduce the air conditioning capacity of the air conditioner (10) as a whole. If not, the opening of the outdoor expansion valve (24) may be slightly opened to reduce the refrigerant flow rate to the outdoor heat exchanger (22) that has requested defrost.

  Furthermore, in the air conditioning apparatus according to the first embodiment, the controller (50) controls the capacity of the compressor (21) of the outdoor unit (20A) that has requested defrost during the defrost operation, and the pressure of the high-pressure refrigerant or The equivalent saturation temperature may be controlled to a predetermined value.

  In this way, when there is a defrost request for any of the outdoor heat exchangers (22) of the plurality of outdoor units (20A, 20B) during the heating operation, the outdoor unit ( The capacity of the compressor (21) of 20A) can be controlled to adjust the refrigerant amount of the high-temperature refrigerant discharged from the compressor (21). That is, when it is necessary to rapidly defrost, the capacity of the compressor (21) may be increased to increase the refrigerant flow rate.

<Embodiment 2>
FIG. 5 is a refrigerant circuit diagram illustrating a configuration of the air-conditioning apparatus according to the second embodiment. The difference from the first embodiment is that a BS unit (30A, 30B) is provided for selecting whether to perform a cooling operation or a heating operation for each indoor unit (40A, 40B). The same parts as those in the first embodiment are denoted by the same reference numerals, and only differences will be described.

  As shown in FIG. 5, in the air conditioner (100), a plurality of indoor units (40A, 40B) are connected in parallel to a plurality of outdoor units (20A, 20B), and each indoor unit (40A, 40B) is connected. ) Is provided with a BS unit (30A, 30B). Each BS unit (30A, 30B) constitutes a switching mechanism. As a result, a so-called cooling / heating-free air conditioner (100) that can select whether to perform the cooling operation or the heating operation for each indoor unit (40A, 40B) is configured. In FIG. 5, only two indoor units (40A, 40B) are shown, but the number of indoor units is not limited to this.

<Configuration of BS unit>
The air conditioner (100) includes BS units (30A, 30B) corresponding to the indoor units (40A, 40B) described above. Each BS unit (30A, 30B) has a high-pressure gas pipe (11) and a low-pressure gas pipe (12) branched from each indoor unit (40A, 40B). The high pressure gas pipe (11) is provided with a high pressure side control valve (31) whose opening degree is adjustable, and the low pressure gas pipe (12) is provided with a low pressure side control valve (32) whose degree of opening is adjustable. Yes. Each BS unit (30A, 30B) adjusts the opening of the high-pressure side control valve (31) and the low-pressure side control valve (32) so that the other end side of the corresponding indoor heat exchanger (40A, 40B) The refrigerant flow path can be switched so as to communicate with one of the suction side and the discharge side of the compressor (21).

-Driving action-
The operation of the air conditioner (100) according to Embodiment 2 will be described. In this air conditioner (100), the settings of the first and second four-way selector valves (26, 27), the high pressure side control valve (31) and the low pressure side control valve (32 of each BS unit (30A, 30B)) ), Multiple types of operation are possible. Below, typical operation is illustrated and demonstrated among these driving | operations.

<All heating operation>
The all heating operation is for heating each room by all the indoor units (40A, 40B). As shown in FIG. 6, in this operation, the first and second four-way switching valves (26, 27) are set to communicate with the first port and the fourth port, and the second port and the third port, respectively. Is done. In each BS unit (30A, 30B), the high-pressure side control valve (31) is opened and the low-pressure side control valve (32) is closed.

  In this operation, a refrigeration cycle is performed in which each outdoor heat exchanger (22, 22) is an evaporator and each indoor heat exchanger (41, 41) is a condenser. In this refrigeration cycle, the refrigerant discharged from the compressor (21) passes through the second four-way switching valve (27) and then flows into the high-pressure gas pipe (11) of each BS unit (30A, 30B). The refrigerant that has passed through each BS unit (30A, 30B) flows into the corresponding indoor unit (40A, 40B).

  For example, when the refrigerant flows into the indoor heat exchanger (41) in the indoor unit (40A), the refrigerant dissipates heat to the indoor air and condenses in the indoor heat exchanger (41). As a result, room heating corresponding to the indoor unit (40A) is performed. The refrigerant condensed in the indoor heat exchanger (41) passes through the indoor expansion valve (42). In the indoor unit (40B), the refrigerant flows similarly to the indoor unit (40A), and the corresponding indoor heating is performed.

  The refrigerant that has flowed out of each indoor unit (40A, 40B) flows through the liquid pipe (15) and is divided into each outdoor unit (20A, 20B). When the refrigerant passes through the outdoor expansion valve (24), the refrigerant is depressurized to a low pressure and flows through the outdoor heat exchanger (22). In the outdoor heat exchanger (22), the refrigerant absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (22) passes through the first four-way switching valve (26), and then is sucked into the compressor (21) and compressed again.

<All cooling operation>
The all cooling operation is to cool each room by all the indoor units (40A, 40B). As shown in FIG. 7, in this operation, the first and second four-way selector valves (26, 27) are set to communicate with the first port and the second port, and the third port and the fourth port, respectively. Is done. In each BS unit (30A, 30B), the low pressure side control valve (32) is opened and the high pressure side control valve (31) is closed.

  In this operation, a refrigeration cycle is performed in which each outdoor heat exchanger (22, 22) is a condenser and each indoor heat exchanger (41, 41) is an evaporator. Specifically, the refrigerant discharged from the compressor (21) flows through the outdoor heat exchanger (22) after passing through the first four-way switching valve (26). In the outdoor heat exchanger (22), the refrigerant dissipates heat to the outdoor air and condenses. The refrigerant condensed in the outdoor heat exchanger (22) passes through the outdoor expansion valve (24) set to a fully opened state, flows through the liquid pipe (15), and is divided into each indoor unit (40A, 40B).

  For example, in the indoor unit (40A), when the refrigerant passes through the indoor expansion valve (42), the refrigerant is depressurized to a low pressure and flows through the indoor heat exchanger (41). In the indoor heat exchanger (41), the refrigerant absorbs heat from the indoor air and evaporates. As a result, room cooling corresponding to the indoor unit (40A) is performed. In the indoor unit (40B), the refrigerant flows similarly to the indoor unit (40A), and the corresponding indoor cooling is performed.

 The refrigerant that has flowed out of each indoor unit (40A, 40B) flows through the low-pressure gas pipe (12) of each BS unit (30A, 30B) and is divided into each outdoor unit (20A, 20B). ) And is compressed again.

<Simultaneous heating / cooling operation>
In the heating / cooling simultaneous operation, indoor heating is performed in some indoor units, while indoor cooling is performed in other indoor units. In the heating / cooling simultaneous operation, the outdoor heat exchanger (22) serves as an evaporator or a condenser according to the operation conditions. Moreover, in each indoor unit (40A, 40B), the indoor heat exchanger in the room where there is a heating request is a condenser, while the indoor heat exchanger in the room where there is a cooling request is an evaporator.

(First coexistence operation)
In the first coexistence operation, the indoor unit (40A) heats the room while the indoor unit (40B) cools the room. As shown in FIG. 8, in this operation, the first and second four-way selector valves (26, 27) of the outdoor unit (20A) are connected to the first port, the fourth port, the second port, and the third port, respectively. It is set to the state which makes it communicate. In the BS unit (30A), the high-pressure side control valve (31) is opened and the low-pressure side control valve (32) is closed. In the BS unit (30B), the high pressure side control valve (31) is closed and the low pressure side control valve (32) is opened.

  In this operation, while using the indoor heat exchanger (41) of the indoor unit (40A) as a condenser, the outdoor heat exchangers (22, 22) and the indoor heat exchanger (41) of the indoor unit (40B) A refrigeration cycle is performed as an evaporator. Specifically, the refrigerant discharged from the compressor (21) passes through the second four-way switching valve (27) and flows into the BS unit (30A) side. The refrigerant that has flowed out of the BS unit (30A) flows through the indoor heat exchanger (41) of the indoor unit (40A). In the indoor heat exchanger (41), the refrigerant dissipates heat to the indoor air and condenses. As a result, room heating corresponding to the indoor unit (40A) is performed. The refrigerant used for indoor heating in the indoor unit (40A) flows out to the liquid pipe (15).

  The refrigerant flowing through the liquid pipe (15) is divided into the outdoor unit (20A, 20B) and the indoor unit (40B). This refrigerant is decompressed to a low pressure when passing through the indoor expansion valve (42), and then flows through the indoor heat exchanger (41). In the indoor heat exchanger (41), the refrigerant absorbs heat from the indoor air and evaporates. As a result, indoor cooling corresponding to the indoor unit (40B) is performed. The refrigerant used for indoor cooling in the indoor unit (40B) passes through the BS unit (30B), and is then sucked into the compressor (21) and compressed again.

  On the other hand, the refrigerant flowing into the outdoor units (20A, 20B) is reduced to a low pressure when passing through the outdoor expansion valve (24), and flows through the outdoor heat exchanger (22). In the outdoor heat exchanger (22), the refrigerant absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (22) passes through the first four-way switching valve (26), and then is sucked into the compressor (21) and compressed again.

(Second coexistence operation)
In the second coexistence operation, the indoor unit (40A) cools the room while the indoor unit (40B) heats the room. As shown in FIG. 9, in this operation, the first and second four-way selector valves (26, 27) are set to communicate with the first port and the fourth port, and the second port and the third port, respectively. The In the BS unit (30A), the high pressure side control valve (31) is closed and the low pressure side control valve (32) is opened. In the BS unit (30B), the high pressure side control valve (31) is opened, and the low pressure side control valve (32) is closed.

  In this operation, while using the indoor heat exchanger (41) of the indoor unit (40B) as a condenser, the outdoor heat exchangers (22, 22) and the indoor heat exchanger (41) of the indoor unit (40A) A refrigeration cycle is performed as an evaporator. Specifically, the refrigerant discharged from the compressor (21) passes through the second four-way switching valve (27) and flows into the BS unit (30B) side. The refrigerant that has flowed out of the BS unit (30B) flows through the indoor heat exchanger (41) of the indoor unit (40B). In the indoor heat exchanger (41), the refrigerant dissipates heat to the indoor air and condenses. As a result, room heating corresponding to the indoor unit (40B) is performed. The refrigerant used for indoor heating in the indoor unit (40B) flows out into the liquid pipe (15).

  The refrigerant flowing through the liquid pipe (15) is divided into the outdoor unit (20A, 20B) and the indoor unit (40A). The refrigerant is reduced to a low pressure when passing through the indoor expansion valve (42), and then flows through the indoor heat exchanger (41). In the indoor heat exchanger (41), the refrigerant absorbs heat from the indoor air and evaporates. As a result, room cooling corresponding to the indoor unit (40A) is performed. The refrigerant used for indoor cooling in the indoor unit (40A) passes through the BS unit (30A), and is then sucked into the compressor (21) and compressed again.

  On the other hand, the refrigerant flowing into the outdoor units (20A, 20B) is reduced to a low pressure when passing through the outdoor expansion valve (24), and flows through the outdoor heat exchanger (22). In the outdoor heat exchanger (22), the refrigerant absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (22) passes through the first four-way switching valve (26), and then is sucked into the compressor (21) and compressed again.

<Defrost operation>
Next, when frost is generated in the outdoor heat exchanger (22) of the outdoor unit (20A) during all heating operation or simultaneous heating / cooling operation, defrost operation for defrosting while continuing the heating cycle This will be described with reference to FIG.

  As shown in FIG. 10, when there is a defrost request to the outdoor heat exchanger (22) of any of the plurality of outdoor units (20A, 20B) during the heating operation, the controller (50) Without switching the entire conditioner (100) from the heating operation to the cooling operation, the first four-way switching valve (26) of only the outdoor unit (20A) for which the defrost is requested is switched, and the outdoor unit for which the defrost is requested. The outdoor heat exchanger (22A) of (20A) is communicated with the discharge side of the compressor (21). Thereby, the high temperature refrigerant | coolant discharged from the compressor (21) can be directly introduce | transduced into the outdoor heat exchanger (22) with which the defrost request | requirement was carried out, and a defrost operation | movement can be performed.

  That is, the air conditioner (100) as a whole can be appropriately defrosted with respect to the outdoor heat exchanger (22) that requires defrosting while performing the heating operation, and after the defrosting, the outdoor unit (20A) The air conditioning load at the time of returning to the heating cycle can be reduced, the rise of the heating operation is quick, and it is advantageous in suppressing the heating capacity of the air conditioning apparatus as a whole.

  Further, in this air conditioner, the controller (50) adjusts the opening degree of the indoor expansion valve (42) of the indoor unit (40A, 40B) during the defrost operation so that the pressure of the high-pressure refrigerant or the equivalent saturation temperature is predetermined. You may make it control to a value.

  In this way, when there is a defrost request for any of the outdoor heat exchangers (22) of the plurality of outdoor units (20A, 20B) during the heating operation, the indoor unit (40A, 40B) The amount of refrigerant flowing to the indoor unit (40A, 40B) side can be adjusted by adjusting the opening of the expansion valve (42). In other words, when it is necessary to rapidly defrost, the opening of the indoor expansion valve (42) of the indoor unit (40A, 40B) is slightly opened to the outdoor heat exchanger (22) side where the defrost is requested. If you do not want to distribute more of the high-temperature refrigerant discharged from the compressor (21) or reduce the air conditioning capacity of the air conditioner (100) as a whole, use the indoor unit (40A, 40B). The opening of the indoor expansion valve (42) may be fully opened to reduce the amount of refrigerant flowing to the outdoor heat exchanger (22) that has requested defrost.

<Other embodiments>
About each embodiment mentioned above, it is good also as the following structures. The number of indoor units and outdoor units described in the above embodiments is merely an example. That is, the air conditioner may be configured by further increasing the number of indoor units and outdoor units.

  As described above, the present invention is extremely useful because it provides a highly practical effect that the defrost operation can be performed on the outdoor heat exchanger that has requested defrost even during the heating operation. Industrial applicability is high.

It is a refrigerant circuit diagram which shows the structure of the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is a refrigerant circuit figure for demonstrating the flow of the refrigerant | coolant in heating operation. It is a refrigerant circuit diagram for demonstrating the flow of the refrigerant | coolant in a cooling operation. It is a refrigerant circuit diagram for demonstrating the flow of the refrigerant | coolant in a defrost driving | operation. It is a refrigerant circuit diagram which shows the structure of the air conditioning apparatus which concerns on this Embodiment 2. It is a refrigerant circuit diagram for demonstrating the flow of the refrigerant | coolant in all heating operation. It is a refrigerant circuit diagram for demonstrating the flow of the refrigerant | coolant in all the cooling operation. It is a refrigerant circuit diagram for demonstrating the flow of the refrigerant | coolant of the 1st coexistence driving | operation in heating / cooling operation time. It is a refrigerant circuit diagram for demonstrating the flow of the refrigerant | coolant of the 2nd coexistence driving | operation at the time of heating / cooling operation. It is a refrigerant circuit diagram for demonstrating the flow of the refrigerant | coolant in a defrost driving | operation.

Explanation of symbols

10 Air conditioner
11 High-pressure gas piping
12 Low pressure gas piping
20A, 20B outdoor unit (heat source side unit)
21 Compressor
22 Outdoor heat exchanger (heat source side heat exchanger)
24 Outdoor expansion valve (heat source side expansion valve)
26 First four-way selector valve (first selector valve)
27 Second four-way selector valve (second selector valve)
30A, 30B BS unit (switching mechanism)
31 High-pressure side control valve
32 Low pressure side control valve
40 Indoor unit (use side unit)
41 Indoor heat exchanger (use side heat exchanger)
42 Indoor expansion valve (use side expansion valve)
43 Indoor fans (user fans)
50 Controller (defrost means)

Claims (5)

The compressor (21), the heat source side heat exchanger (22), and one end side of the heat source side heat exchanger (22) communicate with either the suction side or the discharge side of the compressor (21). A plurality of heat source side units (20A, 20B) having a first switching valve (26) and a second switching valve (27) for switching the refrigerant flow path and connected in parallel to each other;
One end is connected to the other end side of the heat source side heat exchanger (22) of each heat source side unit (20A, 20B), and the other end is connected to the compressor (21) via the second switching valve (27). An air conditioner comprising: a use side unit (40) having a use side heat exchanger (41) connected to one of a suction side and a discharge side in a switchable manner;
The first switching valve (26) of only the heat source side unit (20A) requested to defrost is switched to compress the heat source side heat exchanger (22) of the heat source side unit (20A) requested to defrost. An air conditioner comprising defrost means (50) for performing defrost operation by communicating with the discharge side of the machine (21). In claim 1,
The utilization side unit (40) includes a utilization side fan (43) disposed in the vicinity of the utilization side heat exchanger (41),
The defrost means (50) reduces the air volume of the use side fan (43) or stops air blowing when the pressure of the high-pressure refrigerant or the equivalent saturation temperature becomes a predetermined value or less during the defrost operation. An air conditioner characterized by being configured. In claim 1 or 2,
A heat source side expansion valve (24) which is provided on the other end side of the heat source side heat exchanger (22) of each of the heat source side units (20A, 20B) and adjusts the flow rate of the refrigerant flowing through the heat source side heat exchanger (22). )
The defrosting means (50) adjusts the opening degree of the heat source side expansion valve (24) of the heat source side unit (20A), which requested the defrost during the defrost operation, to adjust the pressure of the high pressure refrigerant or the equivalent saturation temperature. An air conditioner configured to control the air pressure to a predetermined value. In any one of Claims 1 thru | or 3,
The defrost means (50) controls the capacity of the compressor (21) of the heat source side unit (20A) that has requested the defrost during the defrost operation, and sets the pressure of the high pressure refrigerant or the equivalent saturation temperature to a predetermined value. It is comprised so that it may control to the air conditioning apparatus characterized by the above-mentioned. In any one of Claims 1 thru | or 4,
The usage side unit (40) includes a usage side expansion valve (42) connected to a liquid side end of the usage side heat exchanger (41),
The defrost means (50) is configured to control the pressure of the high-pressure refrigerant or the equivalent saturation temperature to a predetermined value by adjusting the opening of the use side expansion valve (42) during the defrost operation. An air conditioner characterized by.

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