JP2009264688A - Air conditioner for railway vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner for a railway vehicle capable of preventing the occurrence of abnormal high pressure in a refrigerant circuit and increasing an air conditioning range even in a simple refrigerating cycle having a simple expansion machine. <P>SOLUTION: This air conditioner includes a first bypass circuit 5 connecting a discharge side of a compressor 1 to a refrigerant outlet of an outdoor heat exchanger 2, a third capillary tube 10 provided at a middle part of a pipe connecting the refrigerant outlet of the outdoor heat exchanger 2 to a refrigerant outlet of the first bypass circuit 5, a second bypass circuit 6 bypassing the third capillary tube 10, and a first capillary tube 3 having the same number of capillary tubes as the number of paths of an indoor heat exchanger 4 provided at a middle part of a pipe connecting the refrigerant outlet of the first bypass circuit 5 to the indoor heat exchanger 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for preventing an abnormal high pressure from being generated in a refrigerant circuit and expanding an operating range of the air conditioner by providing a bypass circuit in the refrigeration cycle of the railway vehicle air conditioner.

  As a technique for providing a bypass circuit in the refrigeration cycle, there is a technique as disclosed in Japanese Patent Laid-Open No. 2006-170529 (Patent Document 1). In the technique described in Patent Document 1, when the condensation temperature detected by the condensation temperature detecting means is detected at a predetermined temperature or higher, a bypass valve opens between the discharge side and the suction side of the compressor, and the refrigerant on the compressor discharge side is opened. This is a technique for reducing the discharge pressure of the compressor in the refrigerant circuit by returning the pressure to the suction side and preventing the occurrence of abnormal high pressure.

JP 2006-170529 A

  The railway vehicle air conditioner has a high thermal load due to the heat generated by the human body because a large number of passengers get inside the air-conditioned space, and the door is opened and closed every time the vehicle starts and stops, so the thermal load due to the ventilation load is also high. For this reason, the railway vehicle air conditioner has a higher frequency of overload operation than a general air conditioner such as a room air conditioner.

  On the other hand, the equipment constituting the refrigeration cycle of railway vehicle air conditioners uses a constant-speed compressor for the compressor and a capillary tube made of a long thin tube for the decompressor to ensure reliability. There are many things to do. The pressure reducing action of the capillary tube is caused by friction generated between the refrigerant and the tube wall by causing the refrigerant to circulate in the elongated inner diameter pipe to increase the flow rate of the refrigerant. For this reason, since an opening cannot be changed like an expansion valve, a flow control width is not large.

  When the air conditioning load is overloaded, in the case of a refrigeration cycle consisting of a constant speed compressor, the circulation rate increases as the evaporation temperature rises, and the amount of heat released from the condenser becomes insufficient. In some cases, the discharge temperature rises and exceeds the operating range of the air conditioner. The technique disclosed in Patent Document 1 is applied to a refrigeration cycle using such a constant speed compressor. When the condensation temperature detected by the condensation temperature detecting means detects a temperature above a predetermined level, compression is performed. This is a technique for reducing the compressor discharge pressure by opening the bypass valve between the discharge side and the suction side of the compressor and returning the refrigerant on the compressor and the discharge side to the suction side.

  On the other hand, when the technique described in Patent Document 1 is applied to a refrigeration cycle using a capillary tube as a decompression device, the flow rate flowing into the capillary tube is reduced, so that the amount of decompression generated in the capillary tube is reduced and the evaporation pressure is reduced. To rise. For this reason, it has the subject that the effect by a bypass circuit cannot be exhibited effectively.

  In order to solve the above-described problems, the air conditioner for a railway vehicle according to the present invention includes a compressor, an outdoor heat exchanger, a first capillary tube acting as a pressure reducing device, and an indoor heat exchanger connected by piping. The compressor and the refrigerant outlet of the indoor heat exchanger are connected by piping, and the first capillary tube has the same number of capillary tubes as the number of passes of the indoor heat exchanger, and the path of the indoor heat exchanger A rail vehicle air conditioner having a refrigeration cycle connected in series to a first bypass circuit that connects a discharge side of the compressor and a refrigerant outlet of the outdoor heat exchanger, and the outdoor heat exchanger A second bypass circuit at an intermediate portion of a pipe connecting the refrigerant outlet and the first bypass circuit refrigerant outlet, a detecting means for detecting a discharge pressure of the compressor, the first bypass circuit, and a second bypass And control means for controlling the road, and has a.

  As described above, according to the present invention, the flow of the refrigerant discharged from the compressor can be separated into two flows that flow into the outdoor heat exchanger and the bypass circuit, and flow into the outdoor heat exchanger. The amount of refrigerant to be reduced can be reduced. As a result, since the heat radiation amount per unit mass of the refrigerant flowing into the outdoor heat exchanger increases, the discharge pressure of the compressor can be reduced.

  FIG. 1 shows an embodiment of the present invention, FIG. 2 shows an enthalpy-pressure diagram showing the operation of FIG. 1, the broken line shows normal cooling operation, and the solid line shows operation of the embodiment of the present invention. Yes. FIG. 3 shows a flowchart of the present invention. Embodiments of the present invention will be described below with reference to FIGS. In addition, this invention is not limited by this Example.

  The railway vehicle air conditioner in one embodiment of the present invention includes a compressor 1, an outdoor heat exchanger 2, a first capillary tube 3, an indoor heat exchanger 4, a first bypass circuit 5, and a second bypass circuit 6. , A detector 11 for detecting the condensation temperature, a detector 12 for detecting the evaporation temperature, a detector 13a for detecting the compressor suction temperature, a detection value collecting device 14 for collecting all detection values, and a predetermined value for the detection values. It is comprised from the arithmetic unit 15 which calculates and transmits a control signal to a controller.

  The compressor 1, the outdoor heat exchanger 2, the first capillary tube 3, and the indoor heat exchanger 4 are connected to a pipe so that the refrigerant can circulate to constitute a refrigeration cycle. The first capillary tubes 3 are configured in the same number as the paths of the indoor heat exchanger 4, and each is connected in series with each path of the indoor heat exchanger. The first bypass circuit 5 is a bypass circuit that bypasses the piping of the discharge part of the compressor 1 and the discharge part of the outdoor heat exchanger 2, and is constructed by connecting the control valve 7 and the second capillary tube 8 in series. Has been. The second bypass circuit 6 is provided in the middle of a connection pipe connecting the refrigerant outlet of the outdoor heat exchanger 2 and the refrigerant outlet of the first bypass circuit 5, and includes a control valve 9 and a third capillary tube 10. Is built from. The control valve 9 and the third capillary tube 10 are constructed by being connected in parallel to the connection pipe.

  In a normal cooling operation in the refrigeration cycle constructed in this way, the refrigerant sucked into the compressor 1 (point b) is compressed and overheated by the compressor 1 and discharged (point b), and the outdoor heat exchanger. 2 is cooled by exchanging heat with outdoor air (point c). At this time, the control valve 7 of the first bypass circuit 5 is closed, and the control valve 9 of the second bypass circuit 6 is opened. Therefore, the refrigerant is depressurized by passing through the first capillary tube 3 (point d), heated by exchanging heat with the room air in the indoor heat exchanger 4, and supplied to the suction port (point a) of the compressor 1. Build a refrigeration cycle back. Therefore, the refrigeration cycle is constructed as a cycle of point a → b → point c → point d → point a as shown by the broken line in FIG. 2, and the flow rate of the refrigerant passing through each heat exchanger is discharged from the compressor. Total refrigerant flow rate (Gt).

  On the other hand, in the case of an overload operation where the outdoor temperature is relatively high and the cooling load is high, the refrigerant circuit is controlled based on the control flow shown in FIG. In the case of overload operation, the discharge temperature and discharge pressure of the compressor 1 increase, and the condensation temperature (Tcd) increases. The condensation temperature (Tcd) is detected by the detector 11 that detects the condensation temperature, and is taken into the arithmetic device 15 through the detection value collecting device 14.

  The arithmetic unit 15 calculates the saturated steam pressure from the condensation temperature (Tcd) and calculates the compressor discharge pressure (Pd). When the calculated discharge pressure (Pd) is higher than the upper limit value (Pdmax) of the discharge pressure, the control valve 7 of the first bypass circuit 5 is opened and the control valve 9 of the second bypass circuit 6 is closed. The detection value collecting device 14 also collects the evaporation temperature (Te) and the compressor suction temperature (Tcp) from the evaporation temperature detector 12 and the compressor suction temperature detector 13a, and opens the control valve 7 and the control valve 9. After the closing of the compressor, the compressor intake superheat degree (SH) is calculated by the arithmetic unit 15 from the evaporation temperature (Te) and the compressor intake temperature (Tcp).

  When the calculated compressor suction heating degree SH is higher than the upper limit value (SHmax) of the heating degree, the operation of the compressor is stopped as an abnormal operation because the load exceeds the operation limit value. When the heating degree is lower than the upper limit value (SHmax), the condensation temperature (Tcd) is detected again, the discharge pressure (Pd) is calculated, and compared with the upper limit value (Pdmax) of the discharge pressure. When the discharge pressure (Pd) is lower than the upper limit (Pdmax) of the discharge pressure, the control valve 7 is closed and the control valve 9 is opened to form a cycle as a normal refrigeration cycle.

  By the control operation as described above, the refrigerant discharged from the compressor 1 can be separated into the refrigerant flowing into the outdoor heat exchanger 2 and the refrigerant flowing into the bypass circuit 5, and the refrigerant passing through the outdoor heat exchanger Can be reduced from Gt → Gcd (Gcd = Gt−Cb).

  Further, since the second capillary tube 8 is provided in the first bypass circuit 5, a bypass flow rate (Gb) corresponding to the resistance value of the second capillary tube 8 can be obtained.

  Further, the second bypass circuit 6 is provided with a third capillary tube 10.

  Therefore, the length of the third capillary tube 10 can be adjusted to the pressure of the refrigerant passing through the second bypass circuit 6. As a result, the pressure passing through the first bypass circuit 5 and the second bypass circuit 6 can be maintained at an appropriate value, and problems such as backflow occur when the refrigerant that has passed through the bypass circuits 5 and 6 is merged. Does not occur. On the other hand, since the refrigerant that has passed through the first and second bypass circuits 5 and 6 merges upstream of the first capillary tube 3, the flow rate of the refrigerant flowing into the first capillary tube 3 becomes Gt.

  Therefore, the circulation amount of the refrigerant passing through the first capillary tube 3 is not reduced by the bypass. As a result, the first capillary tube 3 does not have a shortage of pressure reduction due to a decrease in the circulation rate, and a predetermined pressure reduction amount can be obtained with the first capillary tube 3.

  Since the refrigeration cycle (point a → point b → point c → point f → point d → point a, point a → point b → point e → point f → point d → point a) can be constructed as described above. The flow rate of the refrigerant flowing into the outdoor heat exchanger 2 can be changed from Gt to Gcd, and the amount of heat released per unit mass of the refrigerant flowing into the outdoor heat exchanger can be improved. As a result, the compressor discharge pressure (Pd) can be reduced, and the high pressure in the overload operation can be reduced.

  4 and 5 show the second embodiment and its control flow. In this second embodiment, in the case of an overload operation, the condensation temperature (Tcd) is detected by the detector 11 that detects the condensation temperature, and is taken into the arithmetic device 15 through the detection value collecting device 14.

  The arithmetic unit 15 calculates the saturated steam pressure from the condensation temperature (Tcd) and calculates the compressor discharge pressure (Pd). When the calculated discharge pressure (Pd) is higher than the upper limit value (Pdmax) of the discharge pressure, the control valve 7 of the first bypass circuit 5 is opened and the control valve 9 of the second bypass circuit 6 is closed. The detection value collecting device 14 also collects the compressor discharge temperature (Td) from the compressor discharge temperature detector 13b, and after the control valve 7 is opened and the control valve 9 is closed, the compressor discharge temperature (Td) is discharged. When the temperature is higher than the upper limit value (Tdmax), the compressor operation is stopped as an abnormal operation because the load exceeds the operation limit value. When it is lower than the upper limit value (Tdmax) of the discharge temperature, the condensation temperature (Tcd) is detected again, the discharge pressure (Pd) is calculated, and compared with the upper limit value (Pdmax) of the discharge pressure. When the discharge pressure (Pd) is lower than the upper limit (Pdmax) of the discharge pressure, the control valve 7 is closed and the control valve 10 is opened to form a cycle as a normal refrigeration cycle.

  5 and 6 show a third embodiment and its control flow. In the case of overload operation in the third embodiment, the evaporation temperature (Te) is detected by the detector 12 that detects the evaporation temperature, and the compressor suction temperature (Tcp) is detected by the detector 13a that detects the compressor suction temperature. The compressor discharge temperature (Td) is detected by a detector 13b that detects the compressor discharge temperature. The detection values detected by the detectors 12, 13 a, and 13 b are taken into the arithmetic device 15 through the detection value collection device 14. The arithmetic unit 15 calculates the saturated vapor pressure from the evaporation temperature (Te) and calculates the compressor suction pressure (Ps). The compressor discharge pressure (Pd) is calculated from the calculated compressor suction pressure (Ps), the detected and collected compressor suction temperature (Ts), and the compressor discharge temperature (Td). When the calculated discharge pressure (Pd) is higher than the upper limit value (Pdmax) of the discharge pressure, the control valve 7 of the first bypass circuit 5 is opened and the control valve 9 of the second bypass circuit 6 is closed.

  After the control valve 7 is opened and the control valve 9 is closed, when the compressor discharge temperature (Td) is higher than the upper limit value (Tdmax) of the discharge temperature, it is compressed as an abnormal operation because the load is higher than the operation limit value. Stop the machine. If the discharge temperature is lower than the upper limit (Tdmax), the evaporation temperature (Te), the compressor suction temperature (Tcp), and the compressor discharge temperature (Td) are detected again, and the discharge pressure (Pd) is calculated. Compare with the upper limit (Pdmax). When the discharge pressure (Pd) is lower than the upper limit (Pdmax) of the discharge pressure, the control valve 7 is closed and the control valve 9 is opened to form a cycle as a normal refrigeration cycle.

  8 and 9 show a control flow according to the fourth embodiment of the present invention. In the fourth embodiment of the present invention, in the case of an overload operation, the condensation temperature (Tcd) is detected by the detector 11 that detects the condensation temperature, and is taken into the arithmetic device 15 through the detection value collecting device 14. The arithmetic unit 15 calculates the saturated steam pressure from the condensation temperature (Tcd) and calculates the compressor discharge pressure (Pd). When the calculated discharge pressure (Pd) is higher than the first upper limit value (Pdmax1) of the discharge pressure, the control valve 7 of the first bypass circuit 5 is opened and the control valve 9 of the second bypass circuit 6 is opened. The control valve 17a is closed, the control valve 17b is closed.

  After controlling the control valves 7, 9, 17 a, 17 b, the condensation temperature (Tcd) is detected again, and the compressor pressure (Pd) is calculated by the arithmetic unit 15. When the compressor discharge pressure (Pd) calculated by the arithmetic unit 15 is higher than the second discharge pressure (Pdmax2), the control valve 17a is closed and 17b is opened. As in the second embodiment, the detection value collecting device 14 also collects the compressor discharge temperature (Td) from the compressor discharge temperature detector 13b. After the control valve 7 is opened and the control valve 9 is closed, When the compressor discharge temperature (Td) is higher than the upper limit value (Tdmax) of the discharge temperature, the operation of the compressor is stopped as an abnormal operation because the load exceeds the operation limit value. When it is lower than the upper limit value (Tdmax) of the discharge temperature, the condensation temperature (Tcd) is detected again, the discharge pressure (Pd) is calculated, and compared with the second upper limit value (Pdmax2) of the discharge pressure. When the discharge pressure (Pd) is lower than the second upper limit value (Pdmax2) of the discharge pressure, the control valve 17a is opened and the control valve 17b is closed. After the control of the control valves 17a and 17b, the condensation temperature (Td) is detected again, the discharge pressure (Pd) is calculated, and compared with the first upper limit value (Pdmax1) of the discharge pressure, the discharge pressure (Pd) is the discharge pressure. Is lower than the first upper limit value (Pdmax1), the control valve 7 is closed, the control valve 9 is opened, and the control valves 17a and 17b are closed to form a normal refrigeration cycle.

  The operation of the refrigeration cycle by the control as described above is as follows. The refrigeration cycle when the control valve 7 is opened, the control valve 9 is closed, the control valve 17a is opened, and the control valve 17b is closed is the same as that of the second embodiment of the present invention. Omitted. When the control valve 7 is opened, the control valve 9 is closed, the control valve 17 a is closed, and the control valve 17 b is opened, the refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2 and the bypass circuit 5. Separated into refrigerant. Similar to the first embodiment, a bypass flow rate (Gb) corresponding to the resistance value of the second capillary tube 8 flows into the first bypass circuit 5. As a result, the circulation amount of the refrigerant passing through the outdoor heat exchanger can be reduced from Gt → Gcd (Gcd = Gt−Cb). The second bypass circuit 6 is provided with a second outdoor heat exchanger 16, and a fourth control valve 17b and a fourth capillary tube 10b are connected to the second outdoor heat exchanger. Yes. The refrigerant discharged from the outdoor heat exchanger 2 flows into the fourth capillary tube 10b because the control valve 9 is closed, the control valve 17a is closed, and the control valve 17b is opened. As a result, the refrigerant pressure and temperature are reduced. The refrigerant discharged from the fourth capillary tube 10 b flows into the second outdoor heat exchanger 16 and exchanges heat with the refrigerant discharged from the outdoor heat exchanger 2. As a result, the apparent heat radiation amount of the outdoor heat exchanger can be improved and the compressor discharge pressure (Pd) can be further reduced. As a result, the compressor discharge pressure (Pd) can be reduced, and the high pressure in the overload operation can be reduced.

  As described above, the operation of the compressor discharge pressure detection means and the bypass circuit has been described as an embodiment of the present invention. However, the compressor discharge pressure detection means is not limited to the embodiment of the present invention. You may implement | achieve by various systems, such as what uses the compressor discharge pressure detection means detected from temperature and outdoor air temperature, and a pressure switch.

  According to the above configuration, by constructing the refrigeration cycle, the refrigerant passing through the first bypass circuit and the refrigerant passing through the outdoor heat exchanger can be merged upstream of the first capillary tube. As a result, the amount of refrigerant flowing into the first capillary tube does not change excessively. Therefore, a predetermined amount of reduced pressure can be obtained with the first capillary tube. In addition, since the second capillary tube is provided in the first bypass circuit, when the first bypass circuit is opened during overload operation, the flow rate of the refrigerant flowing into the first bypass circuit is set to an appropriate amount of refrigerant. Can be controlled. In addition, since the second bypass circuit is provided in the intermediate portion of the connecting pipe connecting the outdoor heat exchanger refrigerant outlet and the first bypass circuit refrigerant outlet, and the third capillary tube is provided in the second bypass circuit, It becomes possible to adjust the pressure of the refrigerant that has passed through the second bypass circuit to an appropriate pressure. As a result, the pressure of the refrigerant that has passed through the first bypass circuit and the refrigerant that has passed through the second bypass circuit can be controlled to an appropriate value, and problems such as backflow can occur even when the refrigerant merges. There is no.

  Moreover, the detection means for detecting the compressor discharge pressure for opening and closing the bypass circuit is constructed by the detection means for detecting the condensation temperature and the detection means for detecting the compressor discharge temperature. Therefore, the saturated steam pressure is calculated from the detected condensation temperature, and the compressor discharge pressure can be obtained. As a result, when the detected compressor discharge pressure exceeds a predetermined pressure, the first bypass circuit can be opened and the second bypass circuit can be closed. Thereby, the refrigerant | coolant which flows in into an outdoor heat exchanger can be decreased, and discharge pressure can be reduced. When the detected compressor discharge temperature exceeds a predetermined value, the refrigeration cycle can be stopped as an abnormal operation.

  Further, the second means for detecting the compressor discharge pressure is constructed by means for detecting the evaporation temperature, detection means for detecting the compressor suction temperature, and detection means for detecting the compressor discharge temperature. Therefore, the saturated vapor pressure is calculated from the detected evaporation temperature, and the compressor suction pressure can be obtained. Further, the compressor discharge pressure can be obtained from the obtained compressor suction pressure, compressor suction temperature, and compressor discharge temperature. As a result, when the detected compressor discharge pressure exceeds a predetermined pressure, the first bypass circuit can be opened and the second bypass circuit can be closed. Thereby, the refrigerant | coolant which flows in into an outdoor heat exchanger can be decreased, and discharge pressure can be reduced. When the detected compressor discharge temperature exceeds a predetermined value, the refrigeration cycle can be stopped as an abnormal operation.

  Further, as a third means for detecting the compressor discharge pressure, a means for detecting the evaporation temperature, a detection means for detecting the compressor suction temperature, and a detection means for detecting the condensation temperature are constructed. Therefore, the saturated steam pressure is calculated from the detected condensation temperature, and the compressor discharge pressure can be obtained. Furthermore, the compressor suction heating degree can be obtained from the detected evaporation temperature and compressor suction temperature. As a result, when the detected compressor discharge pressure exceeds a predetermined pressure, the first bypass circuit can be opened and the second bypass circuit can be closed. Thereby, the refrigerant | coolant which flows in into an outdoor heat exchanger can be decreased, and discharge pressure can be reduced. When the detected compressor superheat degree exceeds a predetermined value, the refrigeration cycle can be stopped as an abnormal operation.

The figure explaining the 1st Example of this invention. Enthalpy-pressure diagram. The control flow figure of a 1st Example. The figure explaining the 2nd Example of this invention. The control flowchart of a 2nd Example. The figure explaining the 3rd Example of this invention. The control flow figure of a 3rd Example. The figure explaining the 4th Example of this invention. The control flow figure of a 4th example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Outdoor heat exchanger 3 1st capillary tube 4 Indoor heat exchanger 5 1st bypass circuit 6 2nd bypass circuit 7 1st control valve 8 2nd capillary tube 9 2nd control valve 10 , 10a Third capillary tube 10b Fourth capillary tube 11 Condensation temperature detector 12 Evaporation temperature detector 13a Compressor suction temperature detector 13b Compressor discharge temperature detector 14 Detected value collection device 15 Arithmetic device 16 Second outdoor Heat exchanger 17a Third control valve 17b Fourth control valve

Claims (6)

  A compressor, an outdoor heat exchanger, a first capillary tube acting as a pressure reducing device, an indoor heat exchanger are connected by piping, and the compressor and a refrigerant outlet of the indoor heat exchanger are connected by piping; In the air conditioner for a railway vehicle, the first capillary tube has the same number of capillary tubes as the number of passes of the indoor heat exchanger, and has a refrigeration cycle connected in series to the path of the indoor heat exchanger. A first bypass circuit connecting between the discharge side of the machine and the refrigerant outlet of the outdoor heat exchanger, and an intermediate portion of a pipe connecting the refrigerant outlet of the outdoor heat exchanger and the first bypass circuit refrigerant outlet And a control means for controlling the first bypass circuit and the second bypass circuit, and a second bypass circuit, a detection means for detecting the discharge pressure of the compressor.   2. The rail vehicle air conditioner according to claim 1, wherein the first bypass circuit includes a first control valve that opens and closes the first bypass circuit, and a second capillary tube that functions as a pressure reducing device. A railway vehicle air conditioner in which the first control valve and the second capillary tube are connected in series.   3. The railway vehicle air conditioner according to claim 2, wherein the second bypass circuit includes a second control valve that opens and closes the second bypass circuit, and a third capillary tube that functions as a pressure reducing device. A railway vehicle air conditioner in which the second control valve and the third capillary tube are connected in parallel.   The air conditioner for a railway vehicle according to claim 3, wherein the compressor discharge pressure detecting means includes a detecting means for detecting a condensation temperature and a detecting means for detecting the compressor discharge temperature, and is obtained from the detected condensation temperature. An air conditioner for a railway vehicle that controls the first control valve and the second control valve based on a compressor discharge pressure and the compressor discharge temperature.   4. The railway vehicle air conditioner according to claim 3, wherein the compressor discharge pressure detecting means includes a detecting means for detecting an evaporation temperature, a detecting means for detecting a compressor suction temperature, and a detecting means for detecting a compressor discharge temperature. A railway vehicle air conditioner that controls the first control valve and the second control valve based on a compressor discharge pressure obtained from the detected evaporation temperature, compressor suction temperature, and discharge temperature.   4. The railway vehicle air conditioner according to claim 3, wherein the compressor discharge pressure detection means includes detection means for detecting an evaporation temperature, detection means for detecting a compressor suction temperature, and detection means for detecting a condensation temperature. A railway vehicle air conditioner that controls the first control valve and the second control valve based on a compressor discharge pressure, an evaporation temperature, and a compressor suction temperature obtained from the detected condensation temperature.

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