JP2014190642A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner capable of ensuring small internal heat loss in a channel switching mechanism.SOLUTION: An air conditioner comprises a refrigerant circuit in which a compressor, a channel switching mechanism, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected by a high-pressure-side connection pipe and a low-pressure-side connection pipe. The channel switching mechanism includes: a first channel switching mechanism that connects the compressor to the indoor heat exchanger during a heating operation; and a second channel switching mechanism that connects the outdoor heat exchanger to the compressor during the heating operation. The first channel switching mechanism and the second channel switching mechanism each include a valve body switching a channel of the refrigerant circuit, and the high-pressure-side connection pipe is connected to the second channel switching mechanism above the valve body of the second channel switching mechanism.

Description

  The present invention relates to an air conditioner including a flow path switching mechanism.

  Patent Document 1 describes a four-way valve that includes a high-pressure three-way valve and a low-pressure three-way valve, flows high-temperature refrigerant discharged from a compressor through the high-pressure three-way valve, and flows low-temperature refrigerant that has passed through an expansion valve through the low-pressure three-way valve. . According to the four-way valve described in Patent Document 1, heat exchange between the high-temperature refrigerant and the low-temperature refrigerant in the four-way valve can be suppressed.

JP 2012-211688 A

  However, in the four-way valve described in Patent Document 1, high-temperature refrigerant discharged from the compressor flows not only in the high-pressure three-way valve but also in the slide valve outer space of the low-pressure three-way valve. Since the low-temperature refrigerant flows in the space inside the slide valve of the low-pressure three-way valve, the high-temperature refrigerant flowing through the low-pressure three-way valve comes into contact with the low-temperature refrigerant through the slide valve. Then, the high-temperature refrigerant that has flowed to the low-pressure three-way valve is condensed by the low-temperature refrigerant at the low-pressure three-way valve and becomes a liquid state.

  Since the density of the high-temperature refrigerant in the liquid state is higher than that of the high-temperature refrigerant in the gas state, the high-temperature refrigerant in the liquid state flows out from the low-pressure three-way valve, and instead, the high-temperature refrigerant in the gas state flows into the low-pressure three-way valve. .

  That is, in the four-way valve described in Patent Document 1, condensation of the high-temperature refrigerant is continuously generated in the space outside the slide valve of the low-pressure three-way valve, and heat exchange between the high-temperature refrigerant and the low-temperature refrigerant cannot be suppressed. Internal heat loss cannot be reduced.

  Then, an object of this invention is to provide the air conditioner with a small heat loss in a flow-path switching mechanism.

  In order to solve the above problems, an air conditioner according to the present invention includes a compressor, a flow path switching mechanism, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger, which are connected to a high-pressure side connection pipe and a low-pressure pipe. A refrigerant circuit connected by the side connection pipe, and the flow path switching mechanism includes a first flow path switching mechanism that connects the compressor and the indoor heat exchanger during the heating operation, and an outdoor heat exchanger and the compression during the heating operation. And a second flow path switching mechanism for connecting the machine, the first flow path switching mechanism and the second flow path switching mechanism have a valve body for switching the flow path of the refrigerant circuit, The pipe is connected to the second flow path switching mechanism above the valve body of the second flow path switching mechanism.

  ADVANTAGE OF THE INVENTION According to this invention, the air conditioner with a small heat loss in a flow-path switching mechanism can be provided.

It is a distribution diagram at the time of heating operation of the air harmony machine concerning a 1st embodiment. It is a figure which shows the experimental result of the heat exchange amount at the time of heating operation of a flow-path switching mechanism. It is a figure explaining the internal state of the 2nd flow-path switching mechanism in the case where it arrange | positions so that 2nd discharge side connection piping may be connected to a 2nd flow-path switching mechanism above a valve body. It is a figure explaining the internal state of the 2nd flow-path switching mechanism at the time of the heating operation which concerns on 1st Embodiment. It is a systematic diagram at the time of switching from the heating operation of the air conditioner which concerns on 1st Embodiment to the cooling operation. It is a systematic diagram when the positions of the valve bodies of the first flow path switching mechanism and the second flow path switching mechanism of the air conditioner according to the first embodiment are reversed. It is a systematic diagram at the time of air_conditionaing | cooling operation of the air conditioner which concerns on 1st Embodiment. It is a systematic diagram at the time of the switching from the cooling operation of the air conditioner which concerns on 1st Embodiment to a heating operation. It is a distribution diagram at the time of heating operation of the air harmony machine concerning a 2nd embodiment. It is a figure explaining the internal state of the 2nd flow-path switching mechanism at the time of the heating operation which concerns on 2nd Embodiment.

  Embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a system diagram showing a refrigerant circuit during heating operation of the air conditioner according to the first embodiment. In FIG. 1, the flow path switching mechanism 20 is shown enlarged as a cross-sectional view. The air conditioner S1 includes an outdoor unit Uo that is installed on the heat source side and outdoors (non-air-conditioned space), and an indoor unit Ui that is installed on the usage side and indoors (air-conditioned space).

  In the refrigerant circuit of the air conditioner S1, the compressor 10, the flow path switching mechanism 20, the outdoor heat exchanger 60, the expansion valve 70, and the indoor heat exchanger 80 are annularly connected by a pipe a. . The compressor 10, the flow path switching mechanism 20, the outdoor heat exchanger 60, and the expansion valve 70 are installed in the outdoor unit Uo, and the indoor heat exchanger 80 is installed in the indoor unit Ui.

  The outdoor heat exchanger 60 performs heat exchange between the air (outdoor air) sent from the outdoor fan 60f and the refrigerant. The expansion valve 70 functions as a decompression device that decompresses the refrigerant. The indoor heat exchanger 80 performs heat exchange between the air (room air) sent from the indoor fan 80f and the refrigerant.

  In addition, each operation | movement of the compressor 10, the flow-path switching mechanism 20, the outdoor fan 60f, the indoor fan 80f, and the expansion valve 70 is based on the signal input from sensors (not shown) and a remote control (not shown). Controlled by a control device (not shown).

  The flow path switching mechanism 20 includes a first flow path switching mechanism 21a, a second flow path switching mechanism 21b, an electromagnetic flow path switching valve 40, and an electromagnetic three-way valve 50. The flow path switching mechanism 20 allows the high-temperature refrigerant in a gas state discharged from the compressor 10 during the heating operation to flow into the indoor heat exchanger 80, and the low-temperature refrigerant flowing out of the expansion valve 70 during the cooling operation causes the indoor heat exchanger to Switch to 80.

  The first flow path switching mechanism 21 a has a first discharge side connection pipe 23 a that communicates with the high pressure side connection pipe 12 of the compressor 10 on one side surface of the valve body 22 a that is sealed at both ends of the cylindrical shape. The first flow path switching mechanism 21a includes a first suction side connection pipe 24a communicating with the low pressure side connection pipe 11 of the compressor 10 on the opposite side of the first discharge side connection pipe 23a, and a first suction side. Adjacent to one side of the connection pipe 24a, adjacent to the indoor heat exchanger side connection pipe 25a communicating with the indoor heat exchanger 80, and the other side of the first suction side connection pipe 24a, and connected to the electromagnetic three-way valve 50 And a first opening / closing mechanism connection pipe 26a communicating with each other.

  The valve seat 27a has a flat valve seat surface 28a. The valve seat surface 28a has openings connected to the indoor heat exchanger side connection pipe 25a, the first suction side connection pipe 24a, and the first opening / closing mechanism connection pipe 26a on the inner side of the valve body 22a. Have.

  The valve body 29a slides on the valve seat surface 28a to switch the flow path of the refrigerant circuit. One of the indoor heat exchanger side connection pipe 25a and the first opening / closing mechanism connection pipe 26a is in communication with the first suction side connection pipe 24a, and the other is in communication with the first discharge side connection pipe 23a.

  The piston 30a and the piston 31a form a sealed space V1a and a sealed space V2a at both ends of the valve body 22a, respectively, and are connected by a connecting plate 32a. The valve body 29a is fixed to a hole (not shown) provided in the connecting plate 32a, and moves in the cylindrical axis direction together with the connecting plate 32a, the piston 30a, and the piston 31a.

  The second flow path switching mechanism 21b communicates with the high pressure side connection pipe 12 of the compressor 10 on one side surface of the valve main body 22b having both cylindrical ends sealed in the same manner as the first flow path switching mechanism 21a. The second discharge side connection pipe 23b is provided. The second flow path switching mechanism 21b includes a second suction side connection pipe 24b communicating with the low pressure side connection pipe 11 of the compressor 10 on the opposite side of the second discharge side connection pipe 23b, and a second suction side connection. Adjacent to one side of the pipe 24b and adjacent to the other side of the second opening / closing mechanism connecting pipe 26b communicating with the electromagnetic three-way valve 50 and the second suction side connecting pipe 24b and communicating with the outdoor heat exchanger 60 And an outdoor heat exchanger side connection pipe 25b.

  The valve seat 27b has a flat valve seat surface 28b. The valve seat surface 28b has openings connected to the second opening / closing mechanism connection pipe 26b, the second suction side connection pipe 24b, and the outdoor heat exchanger side connection pipe 25b on the inner side of the valve body 22b. Have.

  The valve body 29b slides on the valve seat surface 28b to bring one of the second opening / closing mechanism connection pipe 26b and the outdoor heat exchanger side connection pipe 25b into communication with the second suction side connection pipe 24b, The other is in communication with the second discharge side connection pipe 23b.

  The piston 30b and the piston 31b form sealed spaces V1b and V2b at both ends of the valve body 22b, respectively, and are connected by a connecting plate 32b. The valve body 29b is fixed to a hole (not shown) provided in the connection plate 32b, and moves in the cylindrical axis direction together with the connection plate 32b, the piston 30b, and the piston 31b.

  The electromagnetic flow path switching valve (pilot valve) 40 includes a pressure of the second discharge side connection pipe 23b (discharge pressure of the compressor 10) and a pressure of the second suction side connection pipe 24b of the second flow path switching mechanism 21b. The piston 30a and the piston 31a of the first flow path switching mechanism 21a and the piston 30b and the piston 31b of the second flow path switching mechanism 21b are operated by a differential pressure with respect to (the suction pressure of the compressor 10).

  The electromagnetic flow path switching valve (pilot valve) 40 includes a flow path switching section 41 and an electromagnetic coil 42. The flow path switching section 41 includes a first piston side communication port 43c and a second piston side communication port 43d. The flow path is switched so that one of them is in communication with the suction side communication port 43b and the other is in communication with the discharge side communication port 43a.

  The discharge side communication port 43 a is connected to the second discharge side connection pipe 23 b of the second flow path switching mechanism 21 b via a capillary (narrow tube) 44. The suction side communication port 43b is connected to the second suction side connection pipe 24b of the second flow path switching mechanism 21b via the capillary 45. The first piston side communication port 43c is connected to the sealed space V1a of the first flow path switching mechanism 21a and the sealed space V2a of the second flow path switching mechanism 21b via the capillary 46 and the capillary 47. The second piston side communication port 43d is connected to the sealed space V2a of the first channel switching mechanism 21a and the sealed space V2b of the second channel switching mechanism 21b via capillaries 48 and 49.

  During the heating operation, in the flow path switching unit 41, the first piston side communication port 43c is in communication with the discharge side communication port 43a, and the second piston side communication port 43d is in communication with the suction side communication port 43b.

  During the cooling operation, in the flow path switching unit 41, the first piston side communication port 43c is in communication with the suction side communication port 43b, and the second piston side communication port 43d is in communication with the discharge side communication port 43a.

  As described above, according to the present embodiment, the electromagnetic flow path switching valve 40 is operated by operating both the first flow path switching mechanism 21a and the second flow path switching mechanism 21b. While reducing the number of switching valves and reducing the cost, the size can be reduced by reducing the occupied volume.

  The electromagnetic three-way valve 50 includes a flow path switching unit 51 and an electromagnetic coil 52, and the flow path switching unit 51 includes a first flow path switching mechanism side communication port 53c and a second flow path switching mechanism side communication port 53d. The flow path is switched so that one of them communicates with the suction side communication port 53b.

  The first opening / closing mechanism connecting pipe 26a of the first flow path switching mechanism 21a or the second opening / closing mechanism connecting pipe 26b of the second flow path switching mechanism 21b is communicated with the low pressure side connecting pipe 11 of the compressor 10. The low pressure side connection pipe 11 of the compressor 10 is connected to the suction side communication port 53 b via a capillary (narrow tube) 54. The first flow path switching mechanism side communication port 53 c is connected to the first opening / closing mechanism connection pipe 26 a of the first flow path switching mechanism 21 a via the capillary 55. The second channel switching mechanism side communication port 53d is connected to the second opening / closing mechanism connection pipe 26b of the second channel switching mechanism 21b via the capillary 56.

  During the heating operation, the electromagnetic three-way valve 50 causes the first flow path switching mechanism side communication port 53c to communicate with the suction side communication port 53b, and the second flow path switching mechanism side communication port 53d to communicate with the electromagnetic three-way valve 50. It is sealed by the first opening / closing mechanism. On the other hand, during the cooling operation, the electromagnetic three-way valve 50 causes the second flow path switching mechanism side communication port 53d to communicate with the suction side communication port 53b, and the second flow path switching mechanism side communication port 53d to communicate with the electromagnetic three-way valve. The valve 50 is sealed by the second opening / closing mechanism.

  In the present embodiment, since one electromagnetic three-way valve 50 is responsible for the first opening / closing mechanism and the second opening / closing mechanism, the number of the opening / closing valves can be reduced and the cost can be reduced rather than the number of the opening / closing valves being two. Compactness can be achieved by reducing the volume. The first opening / closing mechanism and the second opening / closing mechanism may be configured by separate opening / closing valves.

  Next, the operation | movement at the time of the heating operation of air conditioner S1 is demonstrated. The arrow shown in FIG. 1 has shown the flow of the refrigerant | coolant at the time of heating operation.

  During the heating operation, in the electromagnetic flow path switching valve 40, the first piston-side communication port 43c is in communication with the discharge-side communication port 43a, and the second piston-side communication port 43d is in communication with the suction-side communication port 43b. .

  The discharge pressure (high pressure) of the compressor 10 is changed from the discharge side communication port 43a through the first piston side communication port 43c to one sealed space V1a of the first flow path switching mechanism 21a and the second flow. It is guided to one sealed space V1b of the path switching mechanism 21b. On the other hand, the suction pressure (low pressure) of the compressor 10 is changed from the suction side communication port 43b through the second piston side communication port 43d to the other sealed space V2a of the first flow path switching mechanism 21a and the second To the other sealed space V2b of the flow path switching mechanism 21b.

  Due to the differential pressure acting on the piston 30a and the piston 31a of the first flow path switching mechanism 21a and the piston 30b and the piston 31b of the second flow path switching mechanism 21b, the piston 30a and the piston 31a, the piston 30b and the piston 31b moves in the right direction, and the valve bodies 29a and 29b move in the right direction in conjunction with the movement.

  When the valve bodies 29a and 29b move to the right, the first flow path switching mechanism 21a is in communication between the first discharge side connection pipe 23a and the indoor heat exchanger side connection pipe 25a. The suction side connection pipe 24a and the first opening / closing mechanism connection pipe 26a are in communication with each other. In the second flow path switching mechanism 21b, the second discharge side connection pipe 23b and the second opening / closing mechanism connection pipe 26b are in communication with each other, and the second suction side connection pipe 24b and the outdoor heat exchanger side connection are connected. The pipe 25b is in a communication state.

  In the electromagnetic three-way valve 50, the first flow path switching mechanism side communication port 53c is in communication with the suction side communication port 53b. Therefore, the first opening / closing mechanism connection pipe 26 a of the first flow path switching mechanism 21 a communicates with the low-pressure side connection pipe 11. On the other hand, the second opening / closing mechanism connecting pipe 26b of the second flow path switching mechanism 21b is sealed by the electromagnetic three-way valve 50.

  The gas refrigerant compressed to high temperature and high pressure by the compressor 10 sequentially passes through the first discharge-side connection pipe 23a, the discharge-side internal space V0a, and the indoor heat exchanger-side connection pipe 25a of the first flow path switching mechanism 21a. It flows into the indoor heat exchanger 80 that functions as a condenser. The high-temperature and high-pressure gas refrigerant flowing through the indoor heat exchanger 80 exchanges heat with the indoor air sent by the indoor fan 80f and condenses.

  The condensed refrigerant is decompressed by the expansion valve 70 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant and flows to the outdoor heat exchanger 60 that functions as an evaporator. The gas-liquid two-phase refrigerant flowing in the outdoor heat exchanger 60 evaporates by exchanging heat with the outdoor air sent by the outdoor fan 60f, and becomes a low-temperature and low-pressure gas refrigerant.

  The low-temperature and low-pressure gas refrigerant flowing out of the outdoor heat exchanger 60 flows in the order of the outdoor heat exchanger side connection pipe 25b, the suction side internal space V4b, and the second suction side connection pipe 24b of the second flow path switching mechanism 21b. Return to the compressor 20.

  Next, the experimental result regarding the internal heat loss of the flow path switching mechanism of the present invention is shown. FIG. 2 is a diagram illustrating an experimental result of the heat exchange amount during the heating operation of the flow path switching mechanism. FIG. 3 shows a second flow path switching mechanism 21b according to the experimental result B. FIG. 4 shows the second flow path switching mechanism 21b related to the experimental result C.

  The experimental result A is an experimental result of the conventional flow path switching mechanism 20 and is an experimental result when the flow path switching mechanism 20 is configured by one four-way valve.

  The experimental result B is an experimental result of the flow path switching mechanism 20 according to Patent Document 1, and the flow path switching mechanism 20 includes two parts, a first flow path switching mechanism 21a and a second flow path switching mechanism 21b. And it is an experimental result at the time of comprising the 2nd flow-path switching mechanism 21b so that it may become above the 2nd discharge side connection piping 23b. As shown in FIG. 3, the 2nd discharge side connection piping 23b here is located in the lower part.

  The experimental result C is an experimental result of the flow path switching mechanism 20 according to the present embodiment, and the flow path switching mechanism 20 includes two parts, a first flow path switching mechanism 21a and a second flow path switching mechanism 21b. The first flow path switching mechanism 21a is configured to be lower than the first discharge side connection pipe 23a, and the second flow path switching mechanism 21b is configured to be lower than the second discharge side connection pipe 23b. It is an experimental result at the time of comprising so that it may become downward.

  As shown in the experimental result B, even if the flow path switching mechanism 20 is composed of the first flow path switching mechanism 21a and the second flow path switching mechanism 21b, the flow path switching mechanism 20 is composed of one four-way valve. Compared with the configured experiment result A, the heat loss inside the flow path switching mechanism 20 was not reduced.

  In FIG. 3, during the heating operation, the high-temperature refrigerant in the gas state discharged from the compressor 10 flows into the outer space V0b of the valve body 29b of the second flow path switching mechanism 21b via the second discharge side connection pipe 23b. . In the second flow path switching mechanism 21b, the low-temperature refrigerant flows into the inner space V4b of the valve body 29b. Contact. Then, the high-temperature refrigerant in the gas state is condensed by the low-temperature refrigerant in the second flow path switching mechanism 21b and becomes a liquid state.

  The density of the high-temperature refrigerant in the liquid state is higher than that of the high-temperature refrigerant in the gas state. Therefore, the high-temperature refrigerant in the liquid state flows out from the outer space V0b of the second flow path switching mechanism 21b to the second discharge-side connection pipe 23b, and the high-temperature refrigerant in the gas state is replaced by the second flow path switching mechanism. It flows into 21b. Then, the high-temperature refrigerant in the gas state continuously flows into the second flow path switching mechanism 21b, and the high-temperature refrigerant is continuously condensed. Therefore, compared with the experimental result A, the experimental result B cannot suppress the heat exchange between the high-temperature refrigerant and the low-temperature refrigerant, and does not reduce the heat loss in the second flow path switching mechanism 21b.

  On the other hand, in the experimental result C, the heat exchange amount was suppressed to half compared to the experimental result A. Since the second flow path switching mechanism 21b related to the experimental result C is located below the second discharge-side connection pipe 23b, the refrigerant that is in a liquid state having a higher density than the gas state is the second flow path. It does not flow out from the switching mechanism 21b to the second discharge side connection pipe 23b. For a predetermined time from the start of operation, condensation of the high-temperature refrigerant in the gas state occurs in the second flow path switching mechanism 21b. However, after a predetermined time has elapsed from the start of the operation, as shown in FIG. The refrigerant accumulates in the outer space V0b of the second flow path switching mechanism 21b. Then, the high temperature refrigerant in the gas state does not flow into the second flow path switching mechanism 21b, and the condensation of the high temperature refrigerant in the gas state stops.

  Therefore, since the condensation of the high-temperature refrigerant can be prevented from occurring continuously, the experiment result C is a result that the heat exchange amount is suppressed to half compared with the experiment result A.

  Next, the operation | movement at the time of switching from heating operation of the air conditioner S1 to cooling operation is demonstrated using FIG.5 and FIG.7. FIG. 5 is a system diagram at the time of switching from the heating operation to the cooling operation of the air conditioner according to the first embodiment. FIG. 7 is a system diagram at the time of cooling operation of the air conditioner according to the first embodiment.

  When switching from the heating operation to the cooling operation, first, the electromagnetic three-way valve 50 starts from the state where the first flow path switching mechanism side communication port 53c shown in FIG. 1 is connected to the suction side communication port 53b, as shown in FIG. The second flow path switching mechanism side communication port 53d is switched to a state of being connected to the suction side communication port 53b. Then, the outer space V0b (high pressure) of the valve body 29b of the second flow path switching mechanism 21b communicates with the low pressure side connection pipe 11 (low pressure), and the condensate Lb retained in the outer space V0b is on the low pressure side connection pipe 11 side. To be discharged. In this state, the high pressure outer space V0b (high pressure) and the low pressure low pressure side connection pipe 11 (low pressure) are connected via the capillary 54 and the capillary 56, so the pressure difference is maintained.

  Next, after a predetermined time when the condensate in the outer space V0b (high pressure) is discharged to the low pressure side connection pipe 11 (low pressure), the electromagnetic flow path switching valve 40 has the first piston side communication port 43c shown in FIG. The state connected to the discharge side communication port 43a is switched to the state where the first piston side communication port 43c shown in FIG. 7 is connected to the suction side communication port 43b. Further, the electromagnetic flow path switching valve 40 has the second piston side communication port 43d shown in FIG. 7 connected to the discharge side communication from the state where the second piston side communication port 43d shown in FIG. 5 is connected to the suction side communication port 43b. The state is switched to the state connected to the mouth 43a.

  Then, the suction pressure (low pressure) of the compressor 10 is guided to one sealed space V1a of the first channel switching mechanism 21a and one sealed space V1b of the second channel switching mechanism 21b. Further, the discharge pressure (high pressure) of the compressor 10 is guided to the other sealed space V2a of the first channel switching mechanism 21a and the other sealed space V2b of the second channel switching mechanism 21b. As a result, the pressure difference acting on the piston 30a and the piston 31a of the first flow path switching mechanism 21a and the piston 30b and the piston 31b of the second flow path switching mechanism 21b is reversed, and the piston 30a and the piston 31a, The piston 30b and the piston 31b move to the left, and the valve body 29a and the valve body 29b also move to the left in conjunction. The air conditioner S1 is switched from the heating operation to the cooling operation by the movement of the valve body 29a and the valve body 29b.

  As described above, after the liquid refrigerant staying inside the second flow path switching mechanism 21b is discharged, the second flow path switching mechanism 21b is switched, so that the liquid in the second flow path switching mechanism 21b. Switching failure due to refrigerant stagnation can be prevented.

  Next, in FIG. 6, the piston 30a and the piston 31a of the first flow path switching mechanism 21a and the piston 30b and the piston 31b of the second flow path switching mechanism 21b of the air conditioner S1 of FIG. The system diagram when the positions of the valve body 29a of the first flow path switching mechanism 21a and the valve body 29b of the second flow path switching mechanism 21b are not moved at the same time due to the difference or the like is shown.

  In the air conditioner according to the second embodiment to be described later, the piston 30a and the piston 31a of the first flow path switching mechanism 21a and the piston 30b and the piston 31b of the second flow path switching mechanism 21b move simultaneously. Otherwise, the high-pressure side connecting pipe 12 and the low-pressure side connecting pipe 11 are in communication, and the pressure difference between the high-pressure side and the low-pressure side cannot be maintained. Therefore, the piston that cannot move first cannot move.

  On the other hand, in the air conditioner according to the present embodiment, the low pressure side connection pipe 11 and the high pressure side connection pipe 12 do not communicate with each other even when the pistons do not move simultaneously. Specifically, the high pressure side connection pipe 12 of the compressor 10 includes a high pressure side connection pipe 14, a first discharge side connection pipe 23a of the first flow path switching mechanism 21a, an indoor heat exchanger side connection pipe 25a, an indoor The heat exchanger 80, the expansion valve 70, the outdoor heat exchanger 60, the outdoor heat exchanger side connection pipe 25b of the second flow path switching mechanism 21b, the second discharge side connection pipe 23b, and the discharge high pressure side connection pipe 13 communicate with each other. To do. On the other hand, the low-pressure side connection pipe 11 of the compressor 10 includes a first suction side connection pipe 24a, a first opening / closing mechanism connection pipe 26a, and a second flow path switching mechanism 21b of the first flow path switching mechanism 21a. 2 suction side connection piping 24b and the second opening / closing mechanism connection piping 26b.

  That is, even if the positions of the valve body 29a of the first flow path switching mechanism 21a and the valve body 29b of the second flow path switching mechanism 21b are reversed, according to the air conditioner of the present embodiment. The pressure difference between the high pressure side and the low pressure side is maintained. Therefore, even if movement of either the piston 30a and the piston 31a of the first flow path switching mechanism 21a or the piston 30b and the piston 31b of the second flow path switching mechanism 21b is delayed, the electromagnetic flow A differential pressure works through the path switching valve 40, and finally both pistons move.

  Next, the operation | movement at the time of air_conditionaing | cooling operation is demonstrated using FIG. FIG. 7 is a system diagram at the time of cooling operation of the air conditioner according to the first embodiment. The arrows shown in FIG. 7 indicate the direction in which the refrigerant flows during the cooling operation.

  The flow paths of the electromagnetic flow path switching valve 40 and the electromagnetic three-way valve 50 are the same as the flow paths after switching from the heating operation to the cooling operation described above. Accordingly, in the first flow path switching mechanism 21a, the first discharge side connection pipe 23a and the first opening / closing mechanism connection pipe 26a are in communication with each other, and the first suction side connection pipe 24a and the indoor heat exchanger side connection are connected. The pipe 25a is in communication. In the second flow path switching mechanism 21b, the second discharge side connection pipe 23b and the outdoor heat exchanger side connection pipe 25b are in communication with each other, and the second suction side connection pipe 24b and the second opening / closing mechanism are connected. The pipe 26b is in communication.

  The second opening / closing mechanism connection pipe 26b of the second flow path switching mechanism 21b communicates with the low-pressure side connection pipe 11. On the other hand, the second opening / closing mechanism connecting pipe 26b of the first flow path switching mechanism 21a is sealed by the electromagnetic three-way valve 50.

  The gas refrigerant compressed into the high temperature and high pressure by the compressor 10 is in the order of the second discharge side connection pipe 23b, the discharge side internal space V0b, and the outdoor heat exchanger side connection pipe 25b of the second flow path switching mechanism 21b. It flows into the outdoor heat exchanger 60 that functions as a condenser. The high-temperature and high-pressure gas refrigerant flowing through the outdoor heat exchanger 60 exchanges heat with the outdoor air sent by the outdoor fan 60f and condenses.

  The condensed high-temperature refrigerant becomes a low-temperature low-pressure gas-liquid two-phase refrigerant decompressed by the expansion valve 70 and flows to the indoor heat exchanger 80 that functions as an evaporator. The gas-liquid two-phase refrigerant flowing through the indoor heat exchanger 80 evaporates by exchanging heat with the indoor air sent by the indoor fan 80f, and becomes a low-temperature and low-pressure gas refrigerant.

  The low-temperature and low-pressure gas refrigerant flowing out from the indoor heat exchanger 80 flows in the order of the indoor heat exchanger-side connection pipe 25a, the suction-side internal space V4a, and the first suction-side connection pipe 24a of the first flow path switching mechanism 21a. Return to the compressor 20 through the low-pressure side connection pipe 11.

  At this time, the condensate stays in the outer space V0a of the valve body 29a of the first flow path switching mechanism 21a in the same manner as in the heating operation. When the outside of the valve body 29a is covered with the condensate, the high-temperature refrigerant in the gas state does not flow to the first flow path switching mechanism 21a, and the continuous high-temperature refrigerant in the gas state is stopped by the first flow path switching mechanism 21a. Condensation is prevented.

  Next, the operation at the time of switching from the cooling operation to the heating operation of the air conditioner S1 will be described with reference to FIG. FIG. 8 is a system diagram at the time of switching from the cooling operation to the heating operation of the air conditioner according to the first embodiment.

  When switching from the cooling operation to the heating operation, first, the electromagnetic three-way valve 50 starts the suction shown in FIG. 8 from the state where the suction side communication port 53b shown in FIG. 7 communicates with the second flow path switching mechanism side communication port 53d. The side communication port 53b is switched to a state of communicating with the first flow path switching mechanism side communication port 53c.

  Then, the outer space V0a (high pressure) of the valve body 29a of the first flow path switching mechanism 21a communicates with the low pressure side connection pipe 11 (low pressure), and the condensate accumulated in the outer space V0a is discharged to the low pressure side connection pipe 11. Is done. At this time, since the high pressure outer space V0a and the low pressure low-pressure side connection pipe 11 communicate with each other via the capillary 54 and the capillary 55, the pressure difference is maintained.

  Next, after a predetermined time when the condensate is discharged, the electromagnetic flow path switching valve 40 starts from the state where the first piston side communication port 43c shown in FIG. 8 communicates with the suction side communication port 43b, as shown in FIG. The first piston-side communication port 43c is switched to a state in which it is in communication with the discharge-side communication port 43a. On the other hand, the state is switched from the state where the second piston side communication port 43d shown in FIG. 8 communicates with the discharge side communication port 43a to the state where the second piston side communication port 43d shown in FIG. 1 communicates with the suction side communication port 43b. .

  Then, the discharge pressure (high pressure) of the compressor 10 is guided to one sealed space V1a of the first channel switching mechanism 21a and one sealed space V1b of the second channel switching mechanism 21b. The suction pressure (low pressure) of the compressor 10 is guided to the other sealed space V2a of the one channel switching mechanism 21a and the other sealed space V2b of the second channel switching mechanism 21b. Then, the piston 30a and the piston 31a of the first flow path switching mechanism 21a, and the differential pressure acting on the piston 30b and the piston 31b of the second flow path switching mechanism 21b, the piston 30a and the piston 31a, and the piston 30b and the piston 31b. Moves to the right, and the valve bodies 29a and 29b also move to the right, and the air conditioner S1 is switched from the cooling operation to the heating operation.

  As described above, since the first flow path switching mechanism 21a is switched after the liquid refrigerant staying inside the first flow path switching mechanism 21a is discharged, the liquid in the first flow path switching mechanism 21a. Switching failure due to refrigerant stagnation can be prevented.

  FIG. 9 is a system diagram at the time of heating operation of the air conditioner according to the second embodiment. In the third flow path switching mechanism 21c, the third discharge side connection pipe 23c is connected to the high pressure side connection pipe 12 of the compressor 10, and the indoor heat exchanger side connection pipe 25c is connected to the indoor heat exchanger 80. Yes. The fourth suction side connection pipe 24 d is connected to the low pressure side connection pipe 11 of the compressor 10, and the outdoor heat exchanger side connection pipe 26 d is connected to the outdoor heat exchanger 60.

  The indoor heat exchanger side connection pipe 25 c is connected to the indoor heat exchanger 80 and is connected to the indoor heat exchanger side connection pipe 25 d via the high pressure side connection pipe 15.

  The outdoor heat exchanger side connection pipe 26c is connected to the third suction side connection pipe 24c via the discharge side flow path switching valve 21c, and the indoor heat exchanger side connection pipe 25d is the fourth suction side flow path switching. It is connected to the fourth discharge side connection pipe 23d through the mechanism 21d. As shown in FIG. 9, the fourth discharge side connection pipe 23d and the third suction side connection pipe 24c are sealed.

  During the heating operation, the high-temperature and high-pressure gas refrigerant flows in the order of the discharge side pipe 23c of the discharge side flow path switching valve 21c, the discharge side internal space V0c, and the indoor heat exchanger side connection pipe 25c. On the other hand, the low-temperature and low-pressure liquid refrigerant flows in the order of the outdoor heat exchanger-side connection pipe 26d, the suction-side internal space V4d, and the fourth suction-side connection pipe 24d of the fourth suction-side flow path switching mechanism 21d.

  FIG. 10 is a diagram illustrating an internal state of the fourth flow path switching mechanism during the heating operation according to the second embodiment. FIG. 10 shows an internal state of the fourth flow path switching mechanism 21d in FIG. 9 and a state in which the indoor heat exchanger side connection pipe 25d is located above the fourth flow path switching mechanism 21d.

  The low temperature refrigerant flows into the inner space V4d of the valve body 29d, and the high temperature refrigerant in the gas state flows from the indoor heat exchanger side connection pipe 25d into the outer space V0d of the valve body 29d. The high-temperature refrigerant in the gas state that flows into the outer space V0d exchanges heat with the low-temperature refrigerant in the inner space V4d through the valve body 29d and condenses. Here, since the fourth discharge side connection pipe 23d is sealed, the high-temperature refrigerant condensed in the outer space V0d of the valve body 29d stays in the outer space V0d.

  When the outer space V0b of the valve body 29b is covered with the condensate, the high-temperature refrigerant in the gas state is not in direct contact with the valve body 29b, so heat exchange due to condensation is prevented, and the discharge side flow switching valve 21b Heat exchange between the high-temperature refrigerant and the low-temperature refrigerant is suppressed.

  Thus, in order to retain the condensate and suppress the internal heat exchange of the discharge side flow path switching valve 21b, the outer space V4b of the valve body 29b needs to be covered with the condensate. For this purpose, the indoor heat exchanger side connection pipe 25d needs to be positioned above the fourth flow path switching mechanism 21d.

S1, S2 Air conditioner 10 Compressor 12, 13, 14, 15 High pressure side connection pipe 11 Low pressure side connection pipe 20 Flow path switching mechanism 21a First flow path switching mechanism 21b Second flow path switching mechanism 23a First Discharge side connection pipe 23b Second discharge side connection pipe 25a Indoor heat exchanger side connection pipe 25b Outdoor heat exchanger side connection pipe 26a First opening / closing mechanism connection pipe 26b Second opening / closing mechanism connection pipe 40 Electromagnetic flow path switching valve 50 Electromagnetic three-way valve 60 Outdoor heat exchanger 70 Expansion valve 80 Indoor heat exchanger

Claims (6)

A compressor, a flow path switching mechanism, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are provided with a refrigerant circuit connected by a high-pressure side connection pipe and a low-pressure side connection pipe,
The flow path switching mechanism includes a first flow path switching mechanism that connects the compressor and the indoor heat exchanger during heating operation, and a second flow path that connects the outdoor heat exchanger and the compressor during heating operation. A flow path switching mechanism,
The first flow path switching mechanism and the second flow path switching mechanism have a valve body that switches the flow path of the refrigerant circuit,
The high-pressure side connection pipe is an air conditioner connected to the second flow path switching mechanism above the valve body of the second flow path switching mechanism.   The high-pressure side connection pipe is an air conditioner connected to the first flow path switching mechanism above the valve body of the first flow path switching mechanism. The flow path switching mechanism includes a first opening / closing mechanism and a second opening / closing mechanism,
During heating operation, the compressor is connected to the indoor heat exchanger via the first flow path switching mechanism, and the compressor is connected to the second opening / closing mechanism via the second flow path switching mechanism. And the second opening / closing mechanism is in a closed state,
During the cooling operation, the compressor is connected to the first opening / closing mechanism via the first flow path switching mechanism, and the compressor is connected to the outdoor heat exchanger via the second flow path switching mechanism. The air conditioner according to claim 1 or 2, wherein the air conditioner is connected and the first opening / closing mechanism is in a closed state. A state where the compressor is connected to the outdoor heat exchanger via the second flow path switching mechanism from a state where the compressor is connected to the second opening / closing mechanism via the second flow path switching mechanism. Before switching to the second open / close mechanism from the closed state to the open state,
A state where the compressor is connected to the indoor heat exchanger via the first flow path switching mechanism from a state where the compressor is connected to the first opening / closing mechanism via the first flow path switching mechanism. 4. The air conditioner according to claim 3, wherein the first opening / closing mechanism is switched from a closed state to an open state before switching to.   The air conditioner according to claim 4, further comprising a three-way valve having the first opening / closing mechanism and the second opening / closing mechanism. The refrigerant circuit is
A first opening / closing mechanism connection pipe connecting the first flow path switching mechanism and the first opening / closing mechanism;
A second opening / closing mechanism connecting pipe for connecting the second flow path switching mechanism and the second opening / closing mechanism;
The air conditioner according to claim 3, wherein the diameters of the first opening / closing mechanism connection pipe and the second opening / closing mechanism connection pipe are smaller than the diameters of the high pressure side connection pipe and the low pressure side connection pipe. .