Outdoor unit and air conditioner

Abstract

To provide an outdoor unit capable of suppressing generation of dew condensation in a power module while cooling the power module with a refrigerant, and an air conditioner comprising the outdoor unit.SOLUTION: An outdoor unit 1000 comprises a compressor 1, an outdoor heat exchanger 3, an expansion valve 4, a refrigerant pipe P, a power module, and a cooling plate 9. The refrigerant pipe P includes a first pipe P1 that branches off after the expansion valve 4, and a second pipe P2 that branches off before the expansion valve 4. The cooling plate 9 is connected to the first pipe P1 and the second pipe P2. The refrigerant pipe P is configured so that the refrigerant flows through the first pipe P1 and accumulates in the second pipe P2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an outdoor unit and an air conditioner. [Background technology]

[0002] Conventionally, there have been air conditioners that have the function of cooling heat-generating components of a power conversion device housed in a controller using a refrigerant flowing through a refrigerant circuit. Japanese Patent Application Laid-Open Publication No. 2009-281602 (Patent Document 1) describes an air conditioner provided with two refrigerant flow paths for cooling power semiconductor elements that control components in the refrigerant circuit. The two refrigerant flow paths are provided between an expansion mechanism and a heat source-side heat exchanger. The two refrigerant flow paths are formed so that the thermal resistance between one flow path and the power semiconductor elements is greater than the thermal resistance between the other flow path and the power semiconductor elements. By switching between the two refrigerant flow paths depending on the operating state, it is possible to adjust the temperature of the power semiconductor elements. This makes it possible to efficiently cool the power semiconductor elements using the refrigerant while preventing condensation from forming on the power semiconductor elements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-281602 Summary of the Invention [Problem to be solved by the invention]

[0004] The cooling structure described in the publication switches the refrigerant flow path depending on the operating state. However, because the temperature of the refrigerant flowing through the two refrigerant flow paths remains the same, if the refrigerant temperature is too low or the refrigerant flow rate is too high, sufficient thermal resistance cannot be ensured between the refrigerant flow path and the power semiconductor elements, which can lead to condensation. If condensation occurs, there is a risk of the power semiconductor elements shorting out, which reduces reliability.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide an outdoor unit that can cool a power module with a refrigerant while suppressing the occurrence of condensation in the power module, and an air conditioning apparatus equipped with the same. [Means for solving the problem]

[0006] The outdoor unit of the present disclosure includes a compressor that compresses a refrigerant, an outdoor heat exchanger that condenses the refrigerant compressed by the compressor, an expansion valve that decompresses the refrigerant condensed by the outdoor heat exchanger, refrigerant piping through which the refrigerant flows, a power module that controls the compressor, and a cooling plate that cools the power module. The refrigerant piping includes a first piping that branches off after the expansion valve and a second piping that branches off before the expansion valve. The cooling plate is connected to the first piping and the second piping. The refrigerant piping is configured so that the refrigerant flows in the first piping and accumulates in the second piping. [Effects of the Invention]

[0007] According to the outdoor unit of the present disclosure, it is possible to suppress the occurrence of condensation in the power module while cooling the power module with a refrigerant. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a refrigerant circuit diagram of an air conditioner according to Embodiment 1. FIG. [Figure 2] 1 is a refrigerant circuit diagram showing the flow of refrigerant during refrigerant operation of the air conditioner according to Embodiment 1. FIG. [Figure 3] 1 is a refrigerant circuit diagram showing the flow of refrigerant during heating operation of the air conditioner according to Embodiment 1. FIG. [Figure 4] 1 is a perspective view schematically showing the configuration of a cooling plate according to a first embodiment. [Figure 5] 3 is a cross-sectional view showing a schematic configuration in which a cooling plate and a controller module according to the first embodiment are attached. FIG. [Figure 6] 4 is a refrigerant circuit of an air conditioner according to a second embodiment. [Figure 7] FIG. 11 is a cross-sectional view schematically showing a configuration in which a cooling plate and a controller module according to a third embodiment are attached. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and description thereof will not be repeated.

[0010] Embodiment 1 First, with reference to FIG. 1, the configuration of an air conditioning apparatus 1000 according to the first embodiment will be described.

[0011] 1, the air conditioner 1000 includes an outdoor unit 100 and an indoor unit 101. The outdoor unit 100 includes a compressor 1, a four-way switching valve 2, an outdoor heat exchanger 3, an expansion valve 4, a cooling inlet check valve 5, a heating outlet check valve 6, a heating inlet check valve 7, a cooling outlet check valve 8, a cooling plate 9, a controller module 10, an indoor heat exchanger 11, an outdoor blower 12, an indoor blower 13, and refrigerant piping P. The indoor unit 101 includes the indoor heat exchanger 11 and the indoor blower 13.

[0012] The components of the outdoor unit 100 and the indoor unit 101 are sequentially connected by refrigerant piping P to form a single refrigerant circuit 200 through which refrigerant circulates. The refrigerant piping P is connected to a compressor 1, an outdoor heat exchanger 3, and an expansion valve 4. The refrigerant piping P is also connected to a four-way switching valve 2 and the like. The refrigerant piping P is configured to allow refrigerant to flow.

[0013] The refrigerant piping P includes a first piping P1 that branches off after the expansion valve 4 and a second piping P2 that branches off before the expansion valve 4. The cooling plate 9 is connected to the first piping P1 and the second piping P2. The refrigerant piping P is configured so that the refrigerant flows through the first piping P1 and accumulates in the second piping P2.

[0014] An outdoor fan 12 is disposed near the outdoor heat exchanger 3. The outdoor fan 12 is configured to blow outdoor air to the outdoor heat exchanger 3. An indoor fan 13 is disposed near the indoor heat exchanger 11. The indoor fan 13 is configured to blow indoor air to the indoor heat exchanger 11.

[0015] The cooling inlet check valve 5 and the heating outlet check valve 6 are installed in parallel in the refrigerant circuit 200. The heating inlet check valve 7 and the cooling outlet check valve 8 are installed in parallel in the refrigerant circuit 200.

[0016] During cooling operation, the first pipe P1 is a cooling refrigerant pipe 14, and the second pipe P2 is a heating refrigerant pipe 15. During heating operation, the first pipe P1 is a heating refrigerant pipe 15, and the second pipe P2 is a cooling refrigerant pipe 14. The cooling refrigerant pipe 14 is connected in the refrigerant circuit 200 between the expansion valve 4 and the heating inlet check valve 7. The cooling refrigerant pipe 14 is connected in the refrigerant circuit 200 between the heating inlet check valve 7 and the indoor heat exchanger 11. The heating refrigerant pipe 15 is connected in the refrigerant circuit 200 between the expansion valve 4 and the cooling inlet check valve 5. The heating refrigerant pipe 15 is connected in the refrigerant circuit 200 between the cooling inlet check valve 5 and the outdoor heat exchanger 3. A cooling plate 9 is connected to the cooling refrigerant pipe 14 and the heating refrigerant pipe 15. The cooling plate 9 is connected so as to be thermally coupled to the cooling refrigerant pipe 14 and the heating refrigerant pipe 15. A controller module 10 is connected to the cooling plate 9. The controller module 10 is connected in thermal communication with the cooling plate 9 .

[0017] The compressor 1 is configured to compress a refrigerant. The compressor 1 is configured to draw in a low-temperature, low-pressure refrigerant, compress the drawn in refrigerant, and discharge the refrigerant as a high-temperature, high-pressure gas refrigerant. The compressor 1 is, for example, a scroll compressor.

[0018] The four-way switching valve 2 is a device that switches the direction in which the refrigerant flows in the refrigerant circuit 200. The four-way switching valve 2 is configured to switch between cooling operation and heating operation by switching whether the refrigerant discharged from the compressor 1 flows to the outdoor heat exchanger 3 or the indoor heat exchanger 11.

[0019] The refrigerant flowing through the refrigerant circuit 200 may be R410A or R407, or may be a mildly flammable refrigerant such as R1234yf, R1234ze, R32 or R290, or may be a natural refrigerant such as CO2.

[0020] The outdoor heat exchanger 3 is connected in the refrigerant circuit 200 between the four-way switching valve 2 and the cooling inlet check valve 5. The outdoor heat exchanger 3 is also connected in the refrigerant circuit 200 between the four-way switching valve 2 and the heating outlet check valve 6. The outdoor heat exchanger 3 is configured to allow a refrigerant to flow through it. The outdoor heat exchanger 3 is, for example, a device that exchanges heat between outdoor air and the refrigerant. The outdoor heat exchanger 3 acts as a condenser during cooling operation and as an evaporator during heating operation. Note that, although the case where the heat medium that exchanges heat with the refrigerant is outdoor air is exemplified, the heat medium is not limited to outdoor air and may be a liquid such as water.

[0021] The outdoor fan 12 is provided near the outdoor heat exchanger 3 and is a device that sends outdoor air to the outdoor heat exchanger 3.

[0022] The cooling inlet check valve 5 and the cooling outlet check valve 8 are configured to allow refrigerant flowing from the outdoor heat exchanger 3 to the indoor heat exchanger 11 to flow into the cooling refrigerant piping 14 during cooling operation. The cooling inlet check valve 5 is configured to allow refrigerant to flow from the outdoor heat exchanger 3 to the expansion valve 4 during cooling operation, but not allow refrigerant to flow in the opposite direction. The cooling outlet check valve 8 is configured to allow refrigerant that has passed through the cooling inlet check valve 5 to flow, but not allow refrigerant to flow in the opposite direction during cooling operation. The heating inlet check valve 7 and the heating outlet check valve 6 are configured to allow refrigerant flowing from the indoor heat exchanger 11 to the outdoor heat exchanger 3 to flow into the heating refrigerant piping 15 during heating operation. The heating inlet check valve 7 is configured to allow refrigerant to flow from the indoor heat exchanger 11 to the expansion valve side during heating operation, but not allow refrigerant to flow in the opposite direction. The heating outlet check valve 6 is configured to allow the refrigerant that has passed through the heating inlet check valve 7 to flow during heating operation, but not to allow the refrigerant to flow in the opposite direction.

[0023] The expansion valve 4 is provided in the refrigerant circuit 200 between the cooling inlet check valve 5 and the cooling outlet check valve 8. In addition, the expansion valve 4 is provided in the refrigerant circuit 200 between the heating inlet check valve 7 and the heating outlet check valve 6. The expansion valve 4 is configured to reduce the pressure of the refrigerant to expand it. The expansion valve 4 is, for example, an electronic expansion valve whose valve opening is adjustable.

[0024] The indoor heat exchanger 11 is connected in the refrigerant circuit 200 between the heating inlet check valve 7 and the four-way switching valve 2. The indoor heat exchanger 11 is also connected in the refrigerant circuit 200 between the cooling outlet check valve 8 and the four-way switching valve 2. The indoor heat exchanger 11 is, for example, a device that exchanges heat between indoor air and a refrigerant. The indoor heat exchanger 11 acts as an evaporator during cooling operation and as a condenser during heating operation. Note that, although the case where the heat medium that exchanges heat with the refrigerant is indoor air is exemplified, the heat medium is not limited to indoor air and may be a liquid such as water.

[0025] The indoor fan 13 is a device that is provided near the indoor heat exchanger 11 and sends indoor air to the indoor heat exchanger 11.

[0026] Referring to FIG. 2, a refrigerant flow 20 during cooling operation of the air conditioner 1000 according to the first embodiment will be described. The refrigerant flowing through the cooling plate 9 during cooling operation will be described together with the refrigerant flow 20 during cooling operation. During cooling operation, high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way switching valve 2 and enters the outdoor heat exchanger 3. There, the high-temperature, high-pressure gas refrigerant is condensed by heat exchange with outdoor air sent by the outdoor blower 12, becoming a high-temperature, high-pressure liquid refrigerant (e.g., 30°C). The refrigerant condensed in the outdoor heat exchanger 3 then passes through the cooling inlet check valve 5 and enters the expansion valve 4, where it is decompressed to become a low-temperature, low-pressure, gas-liquid two-phase refrigerant (e.g., 0°C). The low-temperature, low-pressure refrigerant decompressed by the expansion valve 4 passes through the cooling refrigerant pipe 14 to which the cooling outlet check valve 8 is connected. As a result, the cooling plate 9 connected to the cooling refrigerant pipe 14 is cooled by the low-temperature, low-pressure refrigerant. At this time, since the heating outlet check valve 6 is connected to the heating refrigerant pipe 15, the refrigerant does not pass through the heating refrigerant pipe 15, and the high-temperature, high-pressure liquid refrigerant before passing through the expansion valve 4 remains in the heating refrigerant pipe 15.

[0027] The refrigerant that has passed through the cooling refrigerant pipe 14 passes through the cooling outlet check valve 8 and enters the indoor heat exchanger 11, where it evaporates by exchanging heat with indoor air sent by the indoor blower 13, then passes through the four-way switching valve 2 and is compressed by the compressor 1. In this way, during cooling operation, the refrigerant circulates through the refrigerant circuit 200, repeating the refrigeration cycle.

[0028] Referring to FIG. 3, a refrigerant flow 21 during heating operation of the air conditioner 1000 according to the first embodiment will be described. During heating operation, high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way selector valve 2 and enters the indoor heat exchanger 11. There, the refrigerant is condensed by heat exchange with indoor air sent by the indoor blower 13. The refrigerant condensed in the indoor heat exchanger 11 then passes through the heating inlet check valve 7 and enters the expansion valve 4, where it is decompressed into a low-temperature, low-pressure, gas-liquid two-phase refrigerant. The low-temperature, low-pressure refrigerant passes through the heating outlet check valve 6 connected to the heating refrigerant pipe 15. As a result, the cooling plate 9 connected to the heating refrigerant pipe 15 is cooled by the low-temperature, low-pressure refrigerant. At this time, because the cooling outlet check valve 8 is connected to the cooling refrigerant pipe 14, the refrigerant does not pass through the cooling refrigerant pipe 14, and the high-temperature, high-pressure liquid refrigerant before passing through the expansion valve 4 remains in the cooling refrigerant pipe 14.

[0029] The refrigerant that has passed through the heating refrigerant pipe 15 passes through the heating outlet check valve 6 and enters the outdoor heat exchanger 3, where it is evaporated by exchanging heat with outdoor air sent by the outdoor blower 12, and then passes through the four-way switching valve 2 and is compressed by the compressor 1. In this way, during heating operation, the refrigerant circulates through the refrigerant circuit 200, repeating the refrigeration cycle.

[0030] The cooling plate 9 will be described in more detail with reference to FIG. 4. The cooling plate 9 is made of a material with high thermal conductivity, such as aluminum or copper. The cooling plate 9 is configured as a thick plate. The cooling plate 9 is provided with a groove G for bringing the cooling refrigerant pipe 14 and the heating refrigerant pipe 15 into contact with each other. The cooling refrigerant pipe 14 and the heating refrigerant pipe 15 are connected to the groove G by, for example, brazing, and are thermally coupled to the cooling plate 9. The cooling refrigerant pipe 14 is disposed below the heating refrigerant pipe 15. The cooling plate 9 has a screw hole 30 on the surface opposite the groove G for mounting the controller module 10.

[0031] During cooling operation, low-temperature, low-pressure refrigerant passes through the cooling refrigerant pipe 14, and the controller module 10 is cooled by the low-temperature, low-pressure refrigerant flowing through the cooling refrigerant pipe 14. During heating operation, low-temperature, low-pressure refrigerant passes through the heating refrigerant pipe 15, and the controller module 10 is cooled by the low-temperature, low-pressure refrigerant flowing through the heating refrigerant pipe 15.

[0032] In the above, an example is shown in which the cooling refrigerant pipes 14 and the heating refrigerant pipes 15 are connected to the cooling plate 9 by brazing, but the cooling refrigerant pipes 14 and the heating refrigerant pipes 15 may also be crimped into the groove G of the cooling plate 9.

[0033] With reference to Fig. 5, a configuration in which a cooling plate 9 and a controller module 10 are attached will be described. The controller module 10 is equipped with an inverter for driving the compressor 1. The controller module 10 is configured by mounting electronic components such as a power module 40, a coil 41, and an electrolytic capacitor 42 that constitute the inverter on a printed wiring board 43 by soldering. The power module 40 is configured to control the compressor 1. The cooling plate 9 is configured to cool the power module 40.

[0034] The printed wiring board 43 is fixed to the cooling plate 9 by screwing screws 44 into screw holes 30 provided in the cooling plate 9. The power module 40 is placed between the cooling plate 9 and the printed wiring board 43 to be cooled by contact with the cooling plate 9. The coil 41 and the electrolytic capacitor 42 are placed on the side of the printed wiring board 43 opposite the cooling plate 9. The power module 40 is placed away from the cooling refrigerant pipes 14 and near the heating refrigerant pipes 15.

[0035] The heating refrigerant pipe 15 (second pipe P2) is disposed above the cooling refrigerant pipe 14 (first pipe P1). During cooling operation, the refrigerant flows through the cooling refrigerant pipe 14 (first pipe P1) and accumulates in the heating refrigerant pipe 15 (second pipe P2). During heating operation, the refrigerant flows through the heating refrigerant pipe 15 (second pipe P2) and accumulates in the cooling refrigerant pipe 14 (first pipe P1).

[0036] The power module 40 is disposed above the cooling refrigerant pipe 14 (first pipe P1). The power module 40 is also disposed above the heating refrigerant pipe 15 (second pipe P2).

[0037] During cooling operation, low-temperature, low-pressure refrigerant flows through the cooling refrigerant pipe 14, cooling the lower part of the cooling plate 9. At this time, high-temperature, high-pressure liquid refrigerant before passing through the expansion valve 4 accumulates in the heating refrigerant pipe 15. When the power module 40 generates heat, the upper part of the cooling plate 9, which is distant from the cooling refrigerant pipe 14, is warmed by the power module 40, causing the temperature of the upper part of the cooling plate 9 to rise. If the outdoor air temperature of the outdoor unit 100 is, for example, 30°C during cooling operation, the temperature difference between the outdoor air temperature and the low-temperature, low-pressure refrigerant is large, causing condensation to form on the lower part of the cooling plate 9, which comes into contact with the cooling refrigerant pipe 14 through which the low-temperature, low-pressure refrigerant flows. Because the power module 40 is separated from the cooling refrigerant pipe 14, the heat generated by the power module 40 increases the temperature of the cooling plate 9 around the power module 40. Furthermore, because the power module 40 is disposed above the heating refrigerant pipe 15, where high-temperature, high-pressure liquid refrigerant accumulates, the temperature of the cooling plate 9 also increases. Therefore, condensation does not occur on the power module 40 and the cooling plate 9 around the power module 40. Furthermore, condensation that occurs on the lower part of the cooling plate 9 due to cooling by the refrigerant flowing through the air-conditioning refrigerant pipes 14 drips downward, so by arranging the power module 40 above the air-conditioning refrigerant pipes 14, it is possible to prevent condensation water from getting on the power module 40.

[0038] During heating operation, a low-temperature, low-pressure refrigerant flows through the heating refrigerant pipe 15, so the distance between the power module 40 and the heating refrigerant pipe 15 through which the refrigerant flows is closer than the distance between the power module 40 and the cooling refrigerant pipe 14 through which the refrigerant flows during cooling operation. Therefore, the temperature of the power module 40 and the cooling plate 9 around it is lower than during cooling operation. However, because the outside air temperature during heating operation is lower than during cooling operation, for example, 5°C, the temperature difference between the outside air temperature and the temperature of the low-temperature, low-pressure refrigerant is smaller than during cooling operation. Therefore, even if the distance between the power module 40 and the heating refrigerant pipe 15 is shorter than the distance between the power module 40 and the cooling refrigerant pipe 14, the temperature of the cooling plate around the power module 40 can be raised above the outside air temperature. Therefore, condensation does not occur on the power module 40 and the cooling plate 9 around the power module 40.

[0039] Next, the effects of the first embodiment will be described.

[0040] According to the outdoor unit 100 of the first embodiment, the refrigerant pipe P includes a cooling refrigerant pipe 14 (first pipe P1) that branches after the expansion valve 4 and a heating refrigerant pipe 15 (second pipe P2) that branches before the expansion valve 4 in the refrigerant flow. The cooling plate 9 is connected to the cooling refrigerant pipe 14 (first pipe P1) and the heating refrigerant pipe 15 (second pipe P2). The refrigerant pipe P is configured so that the refrigerant flows through the cooling refrigerant pipe 14 (first pipe P1) and accumulates in the heating refrigerant pipe 15 (second pipe P2). Therefore, the low-temperature refrigerant that has passed through the expansion valve 4 flows into the cooling refrigerant pipe 14 (first pipe P1), thereby cooling the cooling plate 9 that cools the power module 40. Therefore, the power module 40 can be cooled by the refrigerant. Furthermore, the high-temperature refrigerant that has not passed through the expansion valve 4 accumulates in the heating refrigerant pipe 15 (second pipe P2), thereby increasing the temperature of the cooling plate 9, thereby suppressing condensation in the power module 40. Therefore, it is possible to prevent the power module 40 from shorting out due to condensation, thereby improving reliability.

[0041] According to the outdoor unit 100 according to the first embodiment, the heating refrigerant pipe 15 (second pipe P2) is disposed above the cooling refrigerant pipe 14 (first pipe P1). During cooling operation, the refrigerant flows through the cooling refrigerant pipe 14 (first pipe P1) and accumulates in the heating refrigerant pipe 15 (second pipe P2). During heating operation, the refrigerant flows through the heating refrigerant pipe 15 (second pipe P2) and accumulates in the cooling refrigerant pipe 14 (first pipe P1). Therefore, during cooling operation and heating operation, the power module 40 can be cooled by the refrigerant, while preventing condensation from forming on the power module 40.

[0042] According to the outdoor unit 100 of the first embodiment, the power module 40 is disposed above the cooling refrigerant pipes 14 (first pipes P1). Therefore, when condensation occurs on the lower part of the cooling plate 9 due to cooling by the refrigerant flowing through the cooling refrigerant pipes 14, the condensation drips downward, so that the condensed water can be prevented from getting on the power module 40.

[0043] The air conditioning apparatus 1000 according to the first embodiment includes the above-described outdoor unit 100. Therefore, it is possible to provide an air conditioning apparatus 1000 including an outdoor unit 100 that can suppress the occurrence of condensation in the power module 40 while cooling the power module 40 with a refrigerant.

[0044] Embodiment 2 Unless otherwise specified, the outdoor unit 100 and the air conditioner 1000 according to the second embodiment have the same configuration and effects as the outdoor unit 100 and the air conditioner 1000 according to the first embodiment.

[0045] An air conditioning apparatus 1000 according to the second embodiment will be described with reference to FIG.

[0046] As shown in Fig. 6, the outdoor unit 100 includes a compressor 1, a four-way switching valve 2, an outdoor heat exchanger 3, an expansion valve 4, a cooling plate 9, a controller module 10, a cooling bypass valve 50, and a heating bypass valve 51. The cooling bypass valve 50 is arranged in parallel to the refrigerant piping P inside the outdoor unit 100 between the expansion valve 4 of the outdoor unit 100 and the indoor heat exchanger 11 of the indoor unit 101. The cooling bypass valve 50 is connected to the cooling refrigerant piping 14 (first piping P1). The heating bypass valve 51 is arranged in parallel to the refrigerant piping inside the outdoor unit 100 between the outdoor heat exchanger 3 and the expansion valve 4 of the outdoor unit 100. The heating bypass valve 51 is connected to the heating refrigerant piping 15 (second piping P2).

[0047] The cooling refrigerant pipe 14 is arranged in the refrigerant circuit 200 between the cooling bypass valve 50 and the expansion valve 4. The heating refrigerant pipe 15 is arranged in the refrigerant circuit 200 between the heating bypass valve 51 and the expansion valve 4. The cooling bypass valve 50 is configured to allow refrigerant to flow only during cooling operation. The heating bypass valve 51 is configured to allow refrigerant to flow only during heating operation. The cooling bypass valve 50 and the heating bypass valve 51 are preferably valves whose opening can be adjusted to adjust the refrigerant flow rate, and are preferably solenoid valves, for example.

[0048] During cooling operation, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way switching valve 2 and enters the outdoor heat exchanger 3, where it is condensed by exchanging heat with outdoor air sent by the outdoor blower 12. The refrigerant condensed in the outdoor heat exchanger 3 then passes through the expansion valve 4 to become low-temperature, low-pressure refrigerant. The low-temperature, low-pressure refrigerant that has passed through the expansion valve 4 branches into refrigerant that flows to the indoor heat exchanger 11 and refrigerant that flows to the cooling refrigerant pipe 14. The refrigerant flowing through the cooling refrigerant pipe 14 cools the cooling plate 9 that is thermally coupled to the cooling refrigerant pipe 14.

[0049] During heating operation, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way selector valve 2 and enters the indoor heat exchanger 11, where it is condensed by exchanging heat with the indoor air sent by the indoor blower 13. The refrigerant condensed in the indoor heat exchanger 11 then passes through the expansion valve 4 to become low-temperature and low-pressure refrigerant. The low-temperature, low-pressure refrigerant that has passed through the expansion valve 4 branches into refrigerant that flows to the outdoor heat exchanger 3 and refrigerant that flows to the heating refrigerant pipe 15. The refrigerant flowing through the heating refrigerant pipe 15 cools the cooling plate 9 that is thermally coupled to the heating refrigerant pipe 15.

[0050] Next, the effects of the second embodiment will be described.

[0051] According to the outdoor unit 100 according to the second embodiment, the cooling bypass valve 50 is configured to allow the refrigerant to flow only during cooling operation. The heating bypass valve 51 is configured to allow the refrigerant to flow only during heating operation. Therefore, during cooling operation and heating operation, the cooling bypass valve 50 and the heating bypass valve 51 can cool the power module 40 with the refrigerant while suppressing the occurrence of condensation in the power module 40.

[0052] Embodiment 3 Unless otherwise specified, the outdoor unit 100 and the air conditioner 1000 according to the third embodiment have the same configuration and effects as the outdoor unit 100 and the air conditioner 1000 according to the first and second embodiments.

[0053] Referring to FIG. 7, a configuration in which the cooling plate 9 and the controller module 10 are attached in the outdoor unit 100 of the air conditioner 1000 according to the third embodiment will be described.

[0054] As shown in FIG. 7 , the cooling plate 9 is provided with a groove G for contacting the cooling refrigerant pipe 14. The cooling plate 9 is also provided with a through hole H. It is desirable to provide the through hole H on the side surface of the cooling plate 9. The cooling refrigerant pipe 14 is connected to the groove G by, for example, brazing. The heating refrigerant pipe 15 (second pipe P2) is inserted through the through hole H. This thermally couples the cooling refrigerant pipe 14 and the heating refrigerant pipe 15 to the cooling plate 9. A temperature thermistor 16 is attached to the cooling plate 9 below the power module 40. The temperature thermistor 16 is connected to the printed wiring board 43.

[0055] Heating refrigerant pipes 15, in which high-temperature, high-pressure liquid refrigerant accumulates, are inserted into through-holes H on the side of the cooling plate 9. Therefore, the refrigerant flowing through the heating refrigerant pipes 15 increases the temperature of the cooling plate 9 around the power modules 40, while increasing the thermal resistance from the power modules 40 to the cooling refrigerant pipes 14. Therefore, by suppressing the cooling capacity of the cooling refrigerant pipes 14, it is possible to suppress the occurrence of condensation.

[0056] Furthermore, by adjusting the opening of the cooling bypass valve 50 and the heating bypass valve 51, it is possible to adjust the amount of refrigerant flowing through the cooling refrigerant pipe 14 and the heating refrigerant pipe 15. Therefore, by adjusting the amount of refrigerant flowing through the cooling refrigerant pipe 14 and the heating refrigerant pipe 15 so that the temperature thermistor 16 is equal to or higher than the outside air temperature, it is possible to suppress the occurrence of condensation on the power module 40 and the cooling plate 9 around the power module 40.

[0057] Next, the effects of the third embodiment will be described.

[0058] According to the outdoor unit 100 according to the third embodiment, the heating refrigerant pipes 15 (second pipes P2) are inserted through the through-holes H. Therefore, the refrigerant flowing through the heating refrigerant pipes 15 can increase the temperature of the cooling plate 9 around the power module 40, while increasing the thermal resistance from the power module 40 to the cooling refrigerant pipes 14. Therefore, by suppressing the cooling capacity of the cooling refrigerant pipes 14, it is possible to suppress the occurrence of condensation on the power module 40.

[0059] The above embodiments can be combined as appropriate.

[0060] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0061] Various aspects of the present disclosure will be summarized below as appendices.

[0062] (Appendix 1) a compressor that compresses a refrigerant; an outdoor heat exchanger through which the refrigerant flows; an expansion valve that reduces the pressure of the refrigerant; a refrigerant pipe connected to the compressor, the outdoor heat exchanger, and the expansion valve, through which the refrigerant flows; a power module for controlling the compressor; a cooling plate that cools the power module, the refrigerant piping includes a first piping branching after the expansion valve and a second piping branching before the expansion valve in the flow of the refrigerant, the cooling plate is connected to the first pipe and the second pipe; The refrigerant piping is configured so that the refrigerant flows in the first piping and accumulates in the second piping.

[0063] (Appendix 2) The second pipe is disposed above the first pipe, The refrigerant piping is During cooling operation, the refrigerant flows through the first pipe and accumulates in the second pipe, The outdoor unit according to claim 1, wherein the outdoor unit is configured such that the refrigerant flows through the second pipe during heating operation and the refrigerant accumulates in the first pipe.

[0064] (Appendix 3) The outdoor unit according to Supplementary Note 2, wherein the power module is disposed above the second pipe.

[0065] (Appendix 4) a first bypass valve connected to the first pipe; a second bypass valve connected to the second pipe, the first bypass valve is configured to allow the refrigerant to flow only during cooling operation, The outdoor unit according to any one of appendixes 1 to 3, wherein the second bypass valve is configured to allow the refrigerant to flow only during heating operation.

[0066] (Appendix 5) The cooling plate is provided with a through hole, 5. The outdoor unit according to any one of claims 1 to 4, wherein the second pipe is inserted into the through-hole of the cooling plate.

[0067] (Appendix 6) The outdoor unit according to any one of Supplementary Notes 1 to 5; and an indoor unit including an indoor heat exchanger. [Explanation of symbols]

[0068] 1 compressor, 2 four-way switching valve, 3 outdoor heat exchanger, 4 expansion valve, 5 cooling inlet check valve, 6 heating outlet check valve, 7 heating inlet check valve, 8 cooling outlet check valve, 9 cooling plate, 10 controller module, 11 indoor heat exchanger, 12 outdoor blower, 13 indoor blower, 14 cooling refrigerant piping, 15 heating refrigerant piping, 16 temperature thermistor, 40 power module, 50 cooling bypass valve, 51 heating bypass valve, 100 outdoor unit, 101 indoor unit, 200 refrigerant circuit, 1000 air conditioning unit, G groove, H through hole, P refrigerant piping, P1 first piping, P2 second piping.

Claims

1. a compressor that compresses a refrigerant; an outdoor heat exchanger through which the refrigerant flows; an expansion valve that reduces the pressure of the refrigerant to expand it; a refrigerant pipe connected to the compressor, the outdoor heat exchanger, and the expansion valve, through which the refrigerant flows; a power module for controlling the compressor; a cooling plate that cools the power module, the refrigerant piping includes a first piping branching after the expansion valve and a second piping branching before the expansion valve in the flow of the refrigerant, the cooling plate is connected to the first pipe and the second pipe, The refrigerant piping is configured so that the refrigerant flows through the first piping and accumulates in the second piping.

2. The second pipe is disposed above the first pipe, During cooling operation, the refrigerant flows through the first pipe and accumulates in the second pipe, The outdoor unit according to claim 1 , wherein the refrigerant flows through the second pipe during heating operation, and the refrigerant remains in the first pipe.

3. The outdoor unit according to claim 2 , wherein the power module is disposed above the first pipe.

4. a cooling bypass valve connected to the first pipe; a heating bypass valve connected to the second pipe, The cooling bypass valve is configured to allow the refrigerant to flow only during cooling operation, The outdoor unit according to claim 1 , wherein the heating bypass valve is configured to allow the refrigerant to flow only during heating operation.

5. The cooling plate is provided with a through hole, The outdoor unit according to claim 1 , wherein the second pipe is inserted through the through hole.

6. The outdoor unit according to any one of claims 1 to 5; and an indoor unit including an indoor heat exchanger.

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