JP2014214995A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner capable of effectively using supercooling circuit not only during a cooling operation but also during a heating operation.SOLUTION: An air conditioner comprises: a heat source machine; and a use-side unit connected to the heat source machine via a gas pipe and a fluid pipe. The heat source machine includes: a compressor; a heat source-side heat exchanger; a first pipe that enables liquid refrigerant to flow between the heat source-side heat exchanger and the liquid pipe; and a supercooling circuit provided in the first pipe. The supercooling circuit includes: a supercooling heat exchanger for turning the liquid refrigerant flowing in the first pipe into a supercooled state; a second pipe that connects the first pipe to the supercooling heat exchanger and in which a part of the liquid refrigerant flowing in the first pipe flows; a third pipe connecting the second pipe to the compressor and feeding the liquid refrigerant flowing in the second pipe to the compressor; and switching means switching a flow direction of the liquid refrigerant flowing in the second pipe from the first pipe over between a flow to the supercooling heat exchanger and a flow to the compressor via the third pipe.

Description

  The present invention relates to an air conditioner having a supercooling circuit.

  2. Description of the Related Art Conventionally, an air conditioner that includes a heat source device having a supercooling circuit and a use side unit, and in which the heat source device and the use side unit are connected by a refrigerant connection pipe is known (for example, see Patent Document 1). . The supercooling circuit includes a flow rate adjustment valve and a supercooling heat exchanger, and is used to improve cooling performance during cooling operation.

  And in the case of an air conditioner that has many use-side units connected and has long gas refrigerant connection pipes that are significantly affected by pressure loss, such as a building multi-air conditioner, it is possible to overcool by adjusting the flow rate adjustment valve. Cooling performance is improved by bypassing a part of the refrigerant flowing to the use side unit in the heat exchanger, increasing the degree of supercooling, and reducing the pressure loss.

JP 2003-269808 A

  However, in the above-described air conditioner, the supercooling circuit is utilized during the cooling operation, but during the heating operation, the role of reducing the pressure loss is not necessary and cannot be effectively utilized.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an air conditioner that can effectively utilize a supercooling circuit not only during cooling operation but also during heating operation.

  In order to solve the above-described problems, an air conditioner according to one aspect of the present invention includes a heat source device, air connected to the heat source device via a gas pipe and a liquid pipe, and air and a refrigerant supplied from the heat source device. A heat-source side heat for exchanging heat between the compressor that discharges the refrigerant and the refrigerant and outside air. An exchanger, a first pipe that enables a liquid refrigerant to flow between the heat source side heat exchanger and the liquid pipe, and the liquid refrigerant that flows from the heat source side heat exchanger to the first pipe. And a supercooling circuit provided in the first pipe, wherein the supercooling circuit is in a supercooled state of the liquid refrigerant flowing through the first pipe. A supercooling heat exchanger for connecting the first pipe and the supercooling heat exchanger. And connecting the second pipe into which a part of the liquid refrigerant flowing through the first pipe flows, the second pipe and the compressor, and compressing the liquid refrigerant flowing through the second pipe. A third pipe for flowing into the machine, and the third pipe in the second pipe is provided on the upstream side of the flow of the liquid refrigerant with respect to the connection portion connected to the second pipe, A subcooling flow rate adjustment valve capable of adjusting a flow rate of the liquid refrigerant flowing from the second pipe to the supercooling heat exchanger or a flow rate of the liquid refrigerant flowing from the second pipe to the third pipe; The liquid refrigerant flowing into the second pipe from the first pipe can be switched to the supercooling heat exchanger or to the compressor via the third pipe. Switching means.

  ADVANTAGE OF THE INVENTION According to this invention, the air conditioning apparatus which can utilize a subcooling circuit effectively not only at the time of air_conditionaing | cooling operation but at the time of heating operation can be provided.

It is a refrigerating cycle system diagram of the air harmony device by a 1st embodiment of the present invention. It is a refrigerating cycle system diagram at the time of air_conditionaing | cooling operation of the air conditioning apparatus of FIG. It is a refrigerating cycle system diagram at the time of heating operation of the air conditioning apparatus of FIG. It is a refrigerating-cycle system diagram at the time of the heating operation of the air conditioning apparatus by the 2nd Embodiment of this invention. It is the refrigeration cycle system diagram at the time of the heating operation of the air conditioning apparatus which changed a part of structure of the air conditioning apparatus by 2nd Embodiment shown in FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 is a refrigeration cycle system diagram of an air-conditioning apparatus 100 according to the first embodiment. The refrigerant used in the air-conditioning apparatus 100 of the present embodiment is a refrigerant composed only of R32 or a refrigerant containing 50% by weight or more of R32, and more preferably a refrigerant containing 70% by weight or more of R32.

  As shown in FIG. 1, the air conditioning system (air conditioning apparatus) 100 includes a heat source unit 12 and a plurality of usage side units 16a, 16b, and 16c. In FIG. 1, three usage-side units are installed, but more usage-side units can be connected depending on the capacity of the heat source unit. In addition, the alphabetic subscripts are basically used in the sense that they are individual parts of each usage-side unit, but may be omitted when each part is representatively handled.

  The heat source unit 12 mainly includes a compressor 1, an oil separator 2, a capillary 3, a check valve 4, a four-way valve 5, a heat source side heat exchanger 6, a blower 7, and a flow rate adjustment valve 8. The subcooling circuit 9, the accumulator 11, the gas blocking valve 19, the liquid blocking valve 20, and the pipes 30 to 34 are provided. The pipe 32 corresponds to a first pipe, the pipe 33 corresponds to a fourth pipe, and the flow rate adjustment valve 8 corresponds to a heat source flow rate adjustment valve.

  The compressor 1 and the oil separator 2 are connected by a pipe 30, the four-way valve 5 and the heat source side heat exchanger 6 are connected by a pipe 31, and the flow rate adjusting valve 8 and the liquid blocking valve 9 are connected by a pipe 32, The four-way valve 5 and the accumulator 11 are connected by a pipe 33. The compressor 1 is configured to be capable of being injected into the compression process. By switching the four-way valve 8, the flow of the refrigerant changes, and the cooling operation and the heating operation are switched.

  The supercooling circuit 9 includes a supercooling heat exchanger 9A, a flow rate adjustment valve 10, a first electromagnetic valve 21a, a second electromagnetic valve 21b, and pipes 35 to 39. The pipe 35 connects the pipe 32 and the flow rate adjustment valve 10, the pipe 36 connects the flow rate adjustment valve 10, the first electromagnetic valve 21a, and the second electromagnetic valve 21b, and the pipe 37 sets the first electromagnetic valve 21a. And the supercooling heat exchanger 9A are connected, the pipe 38 connects the supercooling heat exchanger 9A and the pipe 33, and the pipe 39 connects the second electromagnetic valve 21b and the compressor 1. The flow rate adjusting valve 10 corresponds to a subcooling flow rate adjusting valve, and the first electromagnetic valve 21a and the second electromagnetic valve 21b correspond to switching means.

  The pipe 36 includes a main flow portion 36A that connects the flow rate adjusting valve 10 and the first electromagnetic valve 21a, and a branch portion 36B that branches from the main flow portion 36A and connects to the second electromagnetic valve 21b. And the branch portion 36B are connected at a connection portion 36C. In addition, the main flow part 36A and the pipe 37 of the pipe 35 and the pipe 36 are the second pipe, the pipe 33 is the fourth pipe, the pipe 38 is the fifth pipe, the branch part 36B and the pipe 39 of the pipe 36 are This corresponds to the third pipe. The first electromagnetic valve 21a opens and closes the flow path of the first pipe, and the second electromagnetic valve 21b opens and closes the flow path of the third pipe.

  The heat source device 12 further includes an outside air thermistor 22, a heat exchanger outlet thermistor 23, a discharge temperature thermistor 24, a bypass thermistor 25, a low pressure sensor 26, and a high pressure sensor 27. The refrigerant temperature detected by the outside air thermistor 22, the heat exchanger outlet thermistor 23, the discharge temperature thermistor 24, and the bypass thermistor 25, and the refrigerant pressure detected by the low pressure sensor 26 and the high pressure sensor 27 are not shown. The control unit (not shown) controls the opening degree of the flow rate adjusting valves 8, 10, 15 and the opening / closing of the first electromagnetic valve 21a and the second electromagnetic valve 21b.

  The outside air thermistor 22 is disposed at the suction port of the blower 7, the heat exchanger outlet thermistor 23 is disposed at the outlet of the heat source side heat exchanger 6, and the discharge temperature thermistor 24 is disposed near the outlet of the compressor 1 in the pipe 30. The bypass thermistor 25 is disposed in the pipe 38. The low pressure sensor 26 is disposed on the inflow side of the accumulator 11 in the pipe 33, and the high pressure sensor 27 is disposed in the vicinity of the outlet of the compressor 1 in the pipe 30.

  The heat source device 12 and the use side unit 16 are connected by a connection pipe including a gas connection pipe 17 and a liquid connection pipe 18. The gas connection pipe 17 is connected to the gas blocking valve 19 of the heat source apparatus 12, and the liquid connection pipe 18 is connected to the liquid blocking valve 20 of the heat source apparatus 12. The gas blocking valve 19 opens and closes the flow path between the heat source unit 1 and the gas connection pipe 17, and the liquid blocking valve 20 opens and closes the flow path between the heat source unit 1 and the liquid connection pipe 18.

  The use side unit 16 includes an indoor heat exchanger 13, a blower 14, and a flow rate adjustment valve 15. Each use side unit 16 controls the indoor temperature of each room individually by controlling the opening degree of the flow rate adjusting valve 15.

  Moreover, as the air conditioning system 100 of this embodiment, the opening degree of the flow control valve 15 of the use side unit 16 or the compressor based on the difference between the suction temperature or refrigerant temperature of each use side unit 16 and the set temperature of each room. The temperature is controlled by controlling the frequency of 1 and circulating an arbitrary amount of refrigerant from the heat source unit 12 to each use side unit 16.

  Next, the cooling operation in the air conditioning system 100 will be described. FIG. 2 shows the flow of the refrigerant in the cooling operation of the air conditioning system 100. Further, during the cooling operation, the first electromagnetic valve 21a is opened and the second electromagnetic valve 21b is closed.

  During the cooling operation, the refrigerant flows in the direction of the arrow shown in FIG. At this time, in the four-way valve 5, the discharge side (high pressure side) of the compressor 1 is connected to the gas side of the outdoor heat exchanger 6, and the gas connection pipe 17 is connected to the suction side (low pressure side) of the compressor 1. .

  The gas refrigerant compressed by the compressor 1 and discharged to the pipe 30 flows into the oil separator 2, and the oil in the gas refrigerant is separated by the oil separator 2. The separated oil is sent to the suction side of the compressor 1 through the capillary 3. On the other hand, the gas refrigerant that has passed through the oil separator 2 passes through the check valve 4, passes through the four-way valve 5, and flows into the heat source side heat exchanger 6 including a plurality of refrigerant passages via the piping 31. The gas refrigerant entering the heat source side heat exchanger 6 is liquefied by releasing condensation latent heat by the blower 7, and the condensed liquid refrigerant is decompressed by the flow rate adjusting valve 8 and flows through the pipe 32.

  And the liquid refrigerant which flows through the piping 32 branches upstream of 9 A of supercooling heat exchangers. One of the branched liquid refrigerants flows to the liquid blocking valve 20, and the other liquid refrigerant flows to the flow rate adjusting valve 10 via the pipe 35.

  The liquid refrigerant headed to the liquid blocking valve 20 passes through the supercooling heat exchanger 9A and enters a supercooled state, and then is connected to the respective use side units 16a, 16b, 16c from the liquid connection pipe 18 via the liquid blocking valve 20. Sent to. In the usage-side unit 16, the liquid refrigerant evaporates in the usage-side heat exchanger 13 configured from a plurality of refrigerant passages. At this time, the throttle amount of the flow rate adjustment valve 15 is adjusted so that the degree of superheat of the refrigerant at the outlet of the use side heat exchanger 13 becomes a predetermined degree of superheat. The use side heat exchanger 13 absorbs heat from the atmospheric air sent to each use side unit 16 by the blower 14 by the amount of latent heat of evaporation of the liquid refrigerant, whereby cool air is sent to each room to perform the cooling operation.

  The evaporated gas refrigerant passes through the gas connection pipe 17 and flows into the heat source unit 12 through the gas blocking valve 19. The gas refrigerant that has returned to the heat source machine 12 passes through the four-way valve 5 and flows into the accumulator 11 through the pipe 33, is adjusted to an appropriate suction degree, and passes through the pipe 34 to the suction side of the compressor 1. Return. Usually, in the air conditioning system 100 of this embodiment, the opening degree of the flow control valve 15 of the use side unit 16 or the compressor is determined based on the difference between the suction temperature or refrigerant temperature of each use side unit 16 and the set temperature of each room. The temperature is controlled by controlling the frequency of 1 and circulating an arbitrary amount of refrigerant from the heat source unit 12 to each use side unit 16.

  Moreover, in the air conditioning system 100 in which a large number of use-side units 16 are connected and the connection piping connecting the heat source unit 12 and the use-side unit 16 is extremely long as in the present embodiment, gas connection during cooling operation is performed. Due to the pressure loss that occurs when passing through the pipe 17, the suction superheat degree of the gas refrigerant flowing into the compressor 1 increases, and the cooling performance significantly decreases. In such a state, the pressure loss can be reduced by using the supercooling heat exchanger 9A.

  On the other hand, the other branched liquid refrigerant is depressurized by the flow rate adjusting valve 10 and the second electromagnetic valve 21b is closed, so that it is supercooled via the pipe 36, the first electromagnetic valve 21a, and the pipe 37. It flows into the heat exchanger 9A. In the supercooling heat exchanger 9A, the liquid refrigerant exchanges heat with the liquid refrigerant from the flow rate adjusting valve 8 toward the liquid blocking valve 20, and becomes overheated, and is bypassed to the accumulator 11 of the low-pressure side pipe via the pipe 38. The At this time, the flow rate adjustment valve 10 adjusts the flow rate of the refrigerant to be bypassed to the suction side of the compressor 1 via the supercooling heat exchanger 9A. In this way, the flow rate adjustment valve 10 of the regenerative circuit 9 functions as a subcooling flow rate adjustment valve during the cooling operation.

  A control unit (not shown) detects the degree of superheat based on the temperature of the gas refrigerant detected by the bypass thermistor 25 and the pressure of the low-pressure sensor 26 so as to keep the degree of superheat at a predetermined value. Thereby, it can control to exhibit the performance of 9 A of supercooling heat exchangers to the maximum. With the above control, the flow rate of the refrigerant flowing from the heat source device 12 to the use side unit 16 is reduced, so that the pressure loss in the gas connection pipe 17 connected to the use side unit 16 can be reduced.

  Next, the heating operation in the air conditioning system 100 will be described. FIG. 3 shows the flow of the refrigerant in the heating operation of the air conditioning system 100. During the heating operation, the first electromagnetic valve 21a is closed and the second electromagnetic valve 21b is opened.

  During the heating operation, the refrigerant flows in the direction of the arrow shown in FIG. At this time, in the four-way valve 5, the discharge side (high pressure side) of the compressor 1 is connected to the gas side of the outdoor heat exchanger 6, and the gas connection pipe 17 is connected to the suction side (low pressure side) of the compressor 1. .

  The gas refrigerant compressed by the compressor 1 and discharged to the pipe 30 flows into the oil separator 2, and the oil in the gas refrigerant is separated by the oil separator 2. The separated oil is sent to the suction side of the compressor 1 through the capillary 3. On the other hand, the gas refrigerant that has passed through the oil separator 2 passes through the check valve 4, passes through the four-way valve 5, and is sent from the gas connection pipe 17 to the use side units 16 a, 16 b, 16 c through the gas blocking valve 19. It is done.

  In the usage side unit 16, the gas refrigerant is condensed in the usage side heat exchanger 13 composed of a plurality of refrigerant passages, and then the throttle amount is arbitrarily controlled by the flow rate control valve 15 in order to ensure a predetermined degree of supercooling. adjust. At this time, the latent heat of condensation of the refrigerant is released by the heat exchanger 13 in the use side unit, so that warm air is sent to each room to perform the heating operation. The condensed liquid refrigerant passes through the liquid connection pipe 18 that connects the heat source unit 12 and the use side unit 16 and flows into the heat source unit 12 through the liquid blocking valve 20.

  The liquid refrigerant returned to the heat source unit 12 flows through the pipe 32, passes through the supercooling heat exchanger 9A, and branches downstream of the supercooling heat exchanger 9A. One of the branched liquid refrigerants flows to the heat source side heat exchanger 6, and the other liquid refrigerant flows to the flow rate adjustment valve 10 via the pipe 35.

  The liquid refrigerant headed to the heat source side heat exchanger 6 is depressurized in accordance with an arbitrary throttle amount of the flow rate adjusting valve 8, and the depressurized liquid refrigerant is in the heat source side heat exchanger 6 constituted by a large number of refrigerant passages. Evaporate. The evaporated gas refrigerant is adjusted to an appropriate suction degree by the accumulator 11 through the pipe 31, the four-way valve 5, and the pipe 33, and returns to the suction side of the compressor 1 through the pipe 34.

  On the other hand, the other branched liquid refrigerant is decompressed to a gas-liquid two-layer state by the flow rate adjusting valve 10 and the first electromagnetic valve 21a is closed, so the pipe 36, the second electromagnetic valve 21b, and the pipe The liquid is injected into the compressor 1 through 39. During the heating operation, particularly when the outside air is at a low temperature, the discharge temperature of the compressor 1 rapidly increases. Therefore, by performing liquid injection at that time, the discharge temperature of the compressor 1 can be lowered.

  Control of the amount of refrigerant to be injected into the compressor 1 detects the degree of superheat determined from the temperature (discharge temperature) of the discharge temperature thermistor 24 installed at the outlet of the compressor 1 or the pressure and discharge temperature of the high pressure sensor 27. When each value exceeds a predetermined value, the throttle amount of the flow rate adjusting valve 10 is adjusted to control the discharge temperature to be equal to or lower than the predetermined temperature. In this way, the flow rate adjustment valve 10 of the regenerative circuit 9 functions as a liquid injection flow rate adjustment valve during heating operation. Further, the degree of superheat of the gas refrigerant at the outlet of the use side heat exchanger 13 (calculated from the pressure of the low pressure sensor 26 and the temperature of the heat exchanger outlet thermistor 23) is controlled to a predetermined value when the outside air is at a low temperature. In this case, since the discharge temperature of the compressor 1 is likely to increase, this control is effective.

  In addition, the subcooling circuit 9 is not often used because it is not affected by pressure loss during heating operation. Further, if the supercooling circuit 9 is used during heating operation, the flow rate flowing to the heat source side heat exchanger 6 is reduced, the heating performance is lowered due to the reduction of the heat transfer coefficient, and the refrigerant when flowing into the use side heat exchanger 13. However, there are disadvantages such as an increase in the amount of refrigerant in the entire system due to an increase in the amount of refrigerant held in the evaporator due to a decrease in the degree of air quality. However, in the above-described embodiment, the supercooling circuit 9 has a circuit configuration that allows the compressor 1 to perform liquid injection during the heating operation. Therefore, the supercooling circuit 9 can be effectively used.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 shows a refrigeration cycle diagram at the time of heating operation of the air-conditioning apparatus 200 according to the second embodiment. The arrows shown in FIG. 4 indicate the flow direction during heating operation. In addition, the same number is attached | subjected about the member same as the air conditioning apparatus 100 by 1st Embodiment, description is abbreviate | omitted, and only a different part is demonstrated.

  The air conditioning apparatus 200 according to the present embodiment further includes a branch portion 38A of the pipe 38, a branch portion 39A of the pipe 39, and a third part with respect to the supercooling circuit 9 of the air conditioning system 100 of the first embodiment. It is the structure which added the solenoid valve 21c and the 4th solenoid valve 21d. The third solenoid valve 21c is provided so as to connect the branch portion 38A of the pipe 38 and the branch portion 39A of the pipe 39, and the fourth solenoid valve 21d is connected to the pipe 33 and the pipe on the downstream side of the branch portion 38A. 38 is connected. The branch part 38A of the pipe 38 and the branch part 39A of the pipe 39 correspond to a sixth pipe. Therefore, the third electromagnetic valve 21c opens and closes the flow path of the sixth pipe, and the fourth electromagnetic valve opens and closes the flow path of the fifth pipe. The first to fourth solenoid valves 21a to 21d correspond to switching means.

  According to the subcooling circuit 9 of the present embodiment, the flow rate adjusting valve can be caused to function in three patterns by controlling the opening and closing of the first to fourth electromagnetic valves 21a to 21d. In other words, the supercooling circuit 9 can function in three patterns.

  The first is mainly effective during cooling operation, and the flow rate adjusting valve 10 is in a state where the first and fourth electromagnetic valves 21a and 21d are opened and the second and third electromagnetic valves 21b and 21c are closed. It is a pattern which adjusts the refrigerant | coolant amount which flows into the supercooling heat exchanger 9. The second is mainly effective at the time of heating operation. In the state where the first, third, and fourth electromagnetic valves 21a, 21c, and 21d are closed and the third electromagnetic valve 21b is opened, the flow rate adjustment valve 10 is turned on. This is a pattern for adjusting the amount of refrigerant injected into the compressor 1. Since the first and second patterns are the same as the control described in the first embodiment, detailed description thereof is omitted.

  The third is mainly effective during the cooling operation. In the state where the first and third electromagnetic valves 21a and 21c are opened and the second and fourth electromagnetic valves 21b and 21d are closed, the flow rate adjusting valve 10 This is a pattern for adjusting the amount of refrigerant gas injected into the compressor 1.

  Specifically, the liquid refrigerant is decompressed by the flow rate adjusting valve 10 and flows into the supercooling heat exchanger 9A through the pipe 36, the first electromagnetic valve 21a, and the pipe 37. In the subcooling heat exchanger 9A, the liquid refrigerant is heat-exchanged with the liquid refrigerant from the flow rate adjustment valve 8 to the liquid blocking valve 20, and is vaporized to become a gas refrigerant. The pipe 38, the third electromagnetic valve 21c, and Gas is injected into the compressor 1 through the pipe 39. In this manner, the refrigerant is ensured to have a predetermined degree of superheat before and after the supercooling heat exchanger 9 and is injected into the compressor 1 in a gas state.

  Gas injection may be performed in any of the cooling operation and the heating operation. Gas injection has a smaller effect of suppressing the discharge temperature of the compressor than liquid injection. Therefore, it is effective mainly in a state in which the outside air temperature is relatively high during heating operation, and is not effective in an environment where the discharge temperature of the compressor 1 is likely to increase, such as when the outside air is extremely low temperature. Further, at the time of cooling operation, the discharge enthalpy of the compressor 1 is increased and the degree of cleaning of the evaporator inlet is reduced, so that an effect of increasing the cooling capacity can be expected. As described above, in the circuit of the air conditioning system 200, the flow rate adjusting valve 10 (supercooling circuit 9) can be provided with three patterns of functions by switching the electromagnetic valves 21a to 21d, which is relatively simple. A highly versatile system can be constructed with a circuit configuration.

  In addition, this invention is not limited to the Example mentioned above. A person skilled in the art can make various additions and changes within the scope of the present invention.

  For example, instead of the first and second electromagnetic valves 21a, 21b, pipes 36, 37, 39 are connected by a three-way valve to control the flow of refrigerant from the pipe 36 to the pipe 37 or the pipe 39. Also good.

  Here, FIG. 5 shows a refrigeration cycle system diagram during the heating operation of the air conditioner 300 in which a part of the configuration of the air conditioner 200 according to the second embodiment shown in FIG. 4 is changed. The air conditioner 300 has a circuit configuration in which the first electromagnetic valve 21a of the air conditioner 200 is omitted. And if it is a circuit structure shown in the air conditioning apparatus 300, compared with the air conditioning apparatus 200, one electromagnetic valve can be reduced and it can have the same function as the air conditioning apparatus 200. First, it is effective mainly during the cooling operation, and the fourth solenoid valve 21d is opened and the second and third solenoid valves 21b and 21c are closed, and the supercooling heat exchange is performed by the flow rate adjustment valve 10. This is a pattern for adjusting the amount of refrigerant flowing in the vessel 9. The second is mainly effective during the heating operation, and the second electromagnetic valve 21b is opened and the third and fourth electromagnetic valves 21c and 21d are closed. It is a pattern which adjusts the refrigerant | coolant amount which carries out liquid injection. The third is mainly effective during cooling operation, and the third electromagnetic valve 21c is opened and the second and fourth electromagnetic valves 21b and 21d are closed. It is a pattern which adjusts the refrigerant | coolant amount which carries out gas injection.

1: compressor, 30-39: piping, 9: supercooling circuit, 9A: supercooling heat exchanger, 10: flow control valve, 12: heat source machine, 16a, 16b, 16c: use side unit, 21a: first 21B: second solenoid valve, 36A: main flow portion, 36B: branching portion, 36C: connection portion, 6: heat source side heat exchanger, 8: flow rate adjustment valve, 21c: third solenoid valve, 21d : 4th solenoid valve, 100, 200, 300: Air conditioning system

Claims (6)

An air conditioner comprising: a heat source unit; and a utilization side unit that is connected to the heat source unit via a gas pipe and a liquid pipe and performs heat exchange between air and a refrigerant supplied from the heat source unit. ,
The heat source machine is
A compressor that discharges the refrigerant;
A heat source side heat exchanger for exchanging heat between the refrigerant and outside air;
A first pipe that enables liquid refrigerant to flow between the heat source side heat exchanger and the liquid pipe;
A heat source flow rate adjustment valve capable of adjusting the flow rate of the liquid refrigerant flowing from the heat source side heat exchanger to the first pipe;
A subcooling circuit provided in the first pipe;
With
The supercooling circuit is
A supercooling heat exchanger for bringing the liquid refrigerant flowing through the first pipe into a supercooled state;
A second pipe that connects the first pipe and the supercooling heat exchanger and into which a part of the liquid refrigerant flowing through the first pipe flows;
A third pipe for connecting the second pipe and the compressor and flowing the liquid refrigerant flowing through the second pipe to the compressor;
In the second pipe, the third pipe is provided on the upstream side of the flow of the liquid refrigerant with respect to the connection portion connected to the second pipe, and the supercooling heat exchanger is provided from the second pipe. A subcooling flow rate adjustment valve capable of adjusting the flow rate of the liquid refrigerant flowing to the flow rate or the flow rate of the liquid refrigerant flowing from the second pipe to the third pipe;
Switching capable of switching whether the liquid refrigerant flowing from the first pipe to the second pipe flows to the supercooling heat exchanger or to the compressor via the third pipe Means,
An air conditioner comprising: The switching means includes a first solenoid valve that is provided between the connection portion of the second pipe and the supercooling heat exchanger and opens and closes a flow path of the second pipe; and the third pipe And a second solenoid valve that opens and closes the flow path of the third pipe,
During the cooling operation, the first solenoid valve is opened and the second solenoid valve is closed, so that the subcooling flow rate adjustment valve flows into the second pipe from the first pipe. Flowing the liquid refrigerant to the supercooling heat exchanger, and making the liquid refrigerant flowing through the first pipe by the supercooling heat exchanger into a supercooled state,
During the heating operation, the first solenoid valve is closed and the second solenoid valve is opened, so that the subcooling flow control valve flows into the second pipe from the first pipe. The air conditioning apparatus according to claim 1, wherein the liquid refrigerant to be injected is injected into the compressor through the third pipe. The heat source machine further includes a fourth pipe for flowing the gas refrigerant from the gas pipe or the heat source side heat exchanger to the compressor,
The supercooling circuit is
The supercooling heat exchanger and the fourth pipe are connected, and the gas refrigerant vaporized by heat exchange with the liquid refrigerant flowing through the first pipe in the supercooling heat exchanger is the fourth refrigerant. A fifth pipe for flowing to the pipe;
A sixth pipe that connects a portion of the third pipe downstream of the second solenoid valve and the fifth pipe;
Further comprising
The switching means is
A third solenoid valve provided in the sixth pipe and opening and closing a flow path of the sixth pipe;
A fourth solenoid valve provided on the downstream side of the connecting portion connecting the fifth pipe to the fifth pipe in the fifth pipe, and opening and closing the flow path of the fifth pipe;
Further comprising
By switching the opening and closing of the first to fourth solenoid valves, the supercooling circuit is supercooled by the supercooling heat exchanger and the liquid refrigerant flowing through the first pipe is liquidated to the compressor. The air conditioning apparatus according to claim 2, wherein the air conditioner functions as either a circuit that performs injection or a circuit that performs gas injection to the compressor. During the cooling operation, the first and fourth solenoid valves are opened, and the second and third solenoid valves are closed. The liquid refrigerant flowing into the second pipe is caused to flow to the supercooling heat exchanger, the liquid refrigerant flowing through the first pipe is brought into a supercooled state by the supercooling heat exchanger, and the supercooling heat exchange is performed. A gas refrigerant vaporized by heat exchange with the liquid refrigerant flowing through the first pipe in the vessel is caused to flow to the fourth pipe via the fifth pipe, and the supercooling circuit is connected to the supercooling circuit. Function as a circuit for supercooling the liquid refrigerant flowing through the first pipe by a heat exchanger;
During the heating operation, the first solenoid valve is opened, and the first, third, and fourth solenoid valves are closed, so that the first piping is controlled by the supercooling flow rate adjustment valve. The liquid refrigerant flowing from the second pipe into the second pipe is liquid-injected into the compressor via the third pipe, and the supercooling circuit functions as a circuit for liquid injection into the compressor.
The air conditioning apparatus according to claim 3. During the cooling operation, the first and third solenoid valves are opened, and the second and fourth solenoid valves are closed. The liquid refrigerant flowing into the second pipe is caused to flow to the supercooling heat exchanger, and the gas refrigerant vaporized by heat exchange with the liquid refrigerant flowing through the first pipe in the supercooling heat exchanger. Flowing to the third pipe through the fifth and sixth pipes, causing the compressor to perform gas injection, and causing the supercooling circuit to function as a circuit for performing gas injection to the compressor;
During the heating operation, the second solenoid valve is opened and the first, second, and fourth solenoid valves are closed, so that the supercooling flow rate adjustment valve allows the first piping to be removed from the first pipe. Causing the liquid refrigerant flowing into the second pipe to be liquid-injected into the compressor via the third pipe, and causing the supercooling circuit to function as a circuit for performing liquid injection into the compressor;
The air conditioning apparatus according to claim 3. During the cooling operation, the first and fourth solenoid valves are opened, and the second and third solenoid valves are closed. The liquid refrigerant flowing into the second pipe is caused to flow to the supercooling heat exchanger, the liquid refrigerant flowing through the first pipe is brought into a supercooled state by the supercooling heat exchanger, and the supercooling heat exchange is performed. A gas refrigerant vaporized by heat exchange with the liquid refrigerant flowing through the first pipe in the vessel is caused to flow to the fourth pipe via the fifth pipe, and the supercooling circuit is connected to the supercooling circuit. Function as a circuit for supercooling the liquid refrigerant flowing through the first pipe by a heat exchanger;
During the heating operation, the first and third solenoid valves are opened, and the second and fourth solenoid valves are closed. The liquid refrigerant flowing into the second pipe flows to the supercooling heat exchanger, and gas refrigerant is vaporized by heat exchange with the liquid refrigerant flowing through the first pipe in the supercooling heat exchanger. 4 is caused to flow to the third pipe through the fifth and sixth pipes, and gas is injected into the compressor so that the supercooling circuit functions as a circuit for performing gas injection into the compressor. The air conditioning apparatus described in 1.

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