JP2014029232A - Cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device capable of suppressing variation of cooling efficiency when it cools a heating source.SOLUTION: A cooler 32 has: a housing 70 defining an internal space 74; a flow inlet 71 from which a refrigerant flows in the internal space 74; a flow outlet 72 through which the refrigerant flows out of the internal space 74; and plural fins 73 provided in the internal space 74. The fins 73 block the internal space 74 into plural parallel flow passages 80, and the refrigerant flows in the internal space 74 from the flow inlet 71 toward the flow outlet 72 via any of the plural parallel flow passages 80. The plural parallel flow passages 80 include a nearest flow passage 84 in which an inlet 81 of the parallel flow passage 80 is nearest the flow inlet 71, and a farthest flow passage 88 in which the inlet 81 of the parallel flow passage 80 is farthest from the flow inlet 71. Pressure loss of a path 76 from the flow inlet 71 to the inlet 81 of the farthest flow passage 88 is smaller than pressure loss of the nearest flow passage 84.

Description

  The present invention relates to a cooling device, and more particularly to a cooling device that cools a heat generation source using a vapor compression refrigeration cycle.

  In recent years, attention has been focused on hybrid vehicles, fuel cell vehicles, electric vehicles, and the like that travel with the driving force of a motor as one of the environmental countermeasures. In such a vehicle, electric devices such as a motor, a generator, an inverter, a converter, and a battery generate heat when power is transferred. Therefore, it is necessary to cool these electric devices. In view of this, a technique for cooling a heating element using a vapor compression refrigeration cycle used as a vehicle air conditioner has been proposed.

  For example, JP 2007-69733 A (Patent Document 1) discloses a heat exchanger that exchanges heat with air for air conditioning, a heat exchanger that exchanges heat with a heating element, in a refrigerant passage from an expansion valve to a compressor. , Are arranged in parallel, and a system for cooling a heating element using a refrigerant for an air conditioner is disclosed. Japanese Patent Laid-Open No. 2005-90862 (Patent Document 2) is provided with a heating element cooling means for cooling the heating element in a bypass passage that bypasses the decompressor, evaporator and compressor of the refrigeration cycle for air conditioning. A cooling system is disclosed.

  On the other hand, various technologies related to a cooler for cooling a heating element have been proposed. For example, in Japanese Patent Application Laid-Open No. 9-23081 (Patent Document 3), in a boiling cooling device, a partition that divides a refrigerant tank into three refrigerant chambers, and a plurality of refrigerants that divide the boiling region of each refrigerant chamber in the vertical direction. There is disclosed a configuration in which a flow control plate is provided and the refrigerant flow control plate is provided in an inclined state at equal intervals in the vertical direction. Japanese Patent Laying-Open No. 2001-168256 (Patent Document 4) discloses a structure in which a power module is incorporated in a boiling radiator in a structure for cooling a semiconductor power module.

  JP-A-8-258548 (Patent Document 5) discloses a configuration in which an refrigerant flows in from the lower side of the heat exchanger and discharges the refrigerant from the upper side in the outdoor heat exchanger. Japanese Patent Laying-Open No. 2008-253057 (Patent Document 6) discloses a configuration in which a refrigerant is introduced from the lower side of the cooler and discharged from the upper side in a water-cooled element cooling structure.

JP 2007-69733 A JP-A-2005-90862 JP-A-9-23081 JP 2001-168256 A JP-A-8-258548 JP 2008-253057 A

  In a cooling device using a vapor compression refrigeration cycle, a refrigerant with a change in state between the gas phase and the liquid phase is used, so the refrigerant is easy to gasify, and the specific gravity difference between the gas phase and the liquid phase of the refrigerant is large. There is a characteristic that the responsiveness of the refrigerant cycle is slow. Due to these characteristics, when heat generation conditions such as heat spots or sudden fluctuations in heat load occur in electrical equipment, the refrigerant can be bubbled and the bubbles can interfere with each other or cause local dryout. There is sex. As a result, there is a concern that the cooling efficiency of the electrical equipment varies.

  The present invention has been made in view of the above problems, and a main object thereof is to provide a cooling device capable of suppressing variation in cooling efficiency of a heat source.

  A cooling device according to the present invention is a cooling device that cools a heat generation source, and includes a compressor that compresses a refrigerant, a heat exchanger that exchanges heat between the refrigerant and outside air, and cools the heat generation source using the refrigerant. Cooler, a first passage through which the refrigerant discharged from the compressor flows to the cooler through the heat exchanger, and between the heat exchanger and the cooler without applying power when the compressor stops And a switching valve that switches between communication of the first passage and communication of the second passage. The cooler includes a housing that defines the internal space, an inflow port through which the refrigerant flows into the internal space, an outflow port through which the refrigerant flows out from the internal space, and a plurality of fins provided in the internal space. The fin divides the internal space into a plurality of parallel flow paths, and the refrigerant flows in the internal space from one of the plurality of parallel flow paths toward the outlet. The plurality of parallel flow paths include a nearest flow path where the inlet of the parallel flow path is closest to the inflow opening and a farthest flow path where the inlet of the parallel flow path is farthest from the inflow opening. The pressure loss of the path from the inlet to the inlet of the farthest channel is smaller than the pressure loss of the latest channel.

  In the cooling device, preferably, the inlet of the parallel flow path is disposed below the outlet of the parallel flow path.

  Preferably, in the above cooling device, the height difference between the inlet and outlet of the parallel flow path is such that the product of the refrigerant density, the gravitational acceleration and the height difference is less than the pressure loss of the path from the inlet to the inlet of the farthest flow path. It is defined to be larger.

  In the cooling device, the inlet and the outlet may be arranged on a diagonal line of the casing, may be arranged on the same side of the casing, and the center of the refrigerant flowing through the inlet and the outlet It may be arranged so that the center of the flow of the refrigerant flowing through is on the same line.

  Preferably, the cooling device includes a liquid accumulator that stores liquid refrigerant condensed in the heat exchanger, and a pump that transfers the refrigerant from the liquid accumulator to the cooler.

  According to the cooling device of the present invention, variation in the cooling efficiency of the heat source can be suppressed, and the cooling performance can be improved.

It is the schematic which shows the structure of the vehicle to which a cooling device is applied. It is a schematic diagram which shows the structure of the cooling device of this Embodiment. It is a Mollier diagram which shows the state of the refrigerant | coolant of a vapor compression refrigeration cycle. It is a schematic diagram which shows the flow of the refrigerant | coolant which cools EV apparatus during the driving | operation of a vapor compression refrigeration cycle. It is a schematic diagram which shows the flow of the refrigerant | coolant which cools EV apparatus during the stop of a vapor compression refrigeration cycle. It is a figure which shows the setting of the compressor for every operation mode of a cooling device, a flow regulating valve, and an on-off valve. It is a Mollier diagram which shows the state of the refrigerant | coolant in heat pipe operation mode. It is a schematic diagram which shows the structure of the cooling device of a modification. It is a schematic diagram which shows the structure of the cooler of a 1st example. It is a cross-sectional schematic diagram of the cooler along the XX line shown in FIG. It is a graph which shows the pressure loss of the path | route of the refrigerant | coolant which passes along a flow path recently. It is a graph which shows the pressure loss of the path | route of the refrigerant | coolant which passes along the farthest flow path. It is a schematic diagram which shows the structure of the cooler of a 2nd example. It is a schematic diagram which shows the structure of the cooler of a 3rd example. It is a schematic diagram which shows the structure of the cooler of a 4th example. It is a schematic diagram which shows the structure of the cooler of a 5th example. It is a cross-sectional schematic diagram of the cooler along the XVII-XVII line shown in FIG. It is a schematic diagram which shows the structure of the cooler of a 6th example.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

[Configuration of vehicle 1000]
FIG. 1 is a schematic diagram illustrating a configuration of a vehicle 1000 to which the cooling device 1 is applied. A vehicle 1000 according to the present embodiment includes an engine 100 that is an internal combustion engine, a drive unit 200 that is an electric motor, a PCU (Power Control Unit) 700, and a traveling battery 400. This is a hybrid vehicle using the drive unit 200 as a power source. Note that the cooling device 1 of the present invention is not limited to a hybrid vehicle that uses an engine and an electric motor as power sources, but also to a vehicle that uses only an electric motor as a power source (in this specification, both are referred to as an electric vehicle). Applicable.

  Engine 100 may be a gasoline engine or a diesel engine. Drive unit 200 generates a driving force for driving vehicle 1000 together with engine 100. Engine 100 and drive unit 200 are both provided in the engine room of vehicle 1000. Drive unit 200 is electrically connected to PCU 700 via cable 500. PCU 700 is electrically connected to traveling battery 400 via cable 600.

[Configuration of Cooling Device 1]
FIG. 2 is a schematic diagram showing the configuration of the cooling device 1 of the present embodiment. As shown in FIG. 2, the cooling device 1 includes a vapor compression refrigeration cycle 10. The vapor compression refrigeration cycle 10 is mounted on the vehicle 1000 in order to cool the inside of the vehicle, for example. The cooling using the vapor compression refrigeration cycle 10 is selected, for example, when the switch for performing the cooling is turned on or the automatic control mode for automatically adjusting the temperature of the vehicle interior to the set temperature is selected. This is performed when the temperature in the passenger compartment is higher than the set temperature.

  The vapor compression refrigeration cycle 10 includes a compressor 12, a heat exchanger 14 as a first heat exchanger, a heat exchanger 15 as a second heat exchanger, an expansion valve 16 as an example of a decompressor, And a heat exchanger 18 as a third heat exchanger. The vapor compression refrigeration cycle 10 also includes a gas-liquid separator 40 disposed on the refrigerant path between the heat exchanger 14 and the heat exchanger 15.

  The compressor 12 operates using a motor or engine mounted on the vehicle as a power source, and compresses the refrigerant gas in an adiabatic manner to form an overheated refrigerant gas. The compressor 12 sucks and compresses the refrigerant flowing from the heat exchanger 18 when the vapor compression refrigeration cycle 10 is operated, and discharges a high-temperature and high-pressure gas-phase refrigerant into the refrigerant passage 21. The compressor 12 circulates the refrigerant in the vapor compression refrigeration cycle 10 by discharging the refrigerant into the refrigerant passage 21.

  The heat exchangers 14 and 15 include tubes through which the refrigerant flows, and fins for exchanging heat between the refrigerant flowing through the tubes and the air around the heat exchangers 14 and 15. The heat exchangers 14 and 15 exchange heat between the refrigerant and the outside air, and heat the overheated refrigerant gas compressed in the compressor 12 to the external medium in an isobaric manner to obtain a refrigerant liquid. The high-pressure gas-phase refrigerant discharged from the compressor 12 dissipates heat to the surroundings and is cooled by heat exchange between the cooling air and the refrigerant in the heat exchangers 14 and 15.

  The cooling air may be supplied to the heat exchangers 14 and 15 by natural ventilation generated by traveling of the vehicle. Alternatively, the cooling air may be supplied to the heat exchangers 14 and 15 by forced ventilation from an external air supply fan such as the condenser fan 42 or a radiator fan for cooling the engine. The condenser fan 42 receives the driving force from the motor 44, rotates to generate an air flow, and supplies cooling air to the heat exchanger. By the heat exchange in the heat exchangers 14 and 15, the temperature of the refrigerant is lowered and the refrigerant is condensed (liquefied).

  The expansion valve 16 expands by injecting a high-pressure liquid-phase refrigerant flowing through the refrigerant passage 25 from a small hole, and changes it into a low-temperature / low-pressure mist refrigerant. The expansion valve 16 depressurizes the refrigerant liquid condensed by the heat exchangers 14 and 15 to obtain wet steam in a gas-liquid mixed state. Note that the decompressor for decompressing the refrigerant liquid is not limited to the expansion valve 16 that is squeezed and expanded, and may be a capillary tube. The expansion valve 16 may be a temperature type expansion valve or an electric type expansion valve.

  The heat exchanger 18 includes a tube through which the refrigerant flows, and fins for exchanging heat between the refrigerant flowing through the tube and the air around the heat exchanger 18. A wet steam refrigerant circulates in the tube. The heat exchanger 18 absorbs heat of ambient air introduced so as to come into contact with the heat exchanger 18 by vaporizing the mist refrigerant flowing through the heat exchanger 18. The heat exchanger 18 is disposed in the duct 90 and exchanges heat between the air-conditioning air flowing in the duct 90 and the refrigerant. The temperature of the air conditioning air is adjusted by heat exchange between the refrigerant circulating in the vapor compression refrigeration cycle 10 via the heat exchanger 18 and the air conditioning air.

  The heat exchanger 18 uses the refrigerant depressurized by the expansion valve 16 to absorb the heat of vaporization when the refrigerant's wet vapor evaporates into the refrigerant gas from the air conditioning air flowing into the vehicle interior, Cool the interior of the vehicle. In the heat exchanger 18, air-conditioning air that has been absorbed by the refrigerant and reduced in temperature is supplied to the interior of the vehicle, thereby cooling the interior of the vehicle. When the refrigerant circulates in the tube, the refrigerant evaporates by absorbing the heat of the air-conditioning air as latent heat of evaporation via the fins, and becomes low-pressure high-temperature gas, and further becomes superheated steam by sensible heat. The vaporized refrigerant returns to the compressor 12 via the refrigerant passage 27. The compressor 12 compresses the refrigerant flowing from the heat exchanger 18.

  The vapor compression refrigeration cycle 10 also includes a refrigerant passage 21 that communicates the compressor 12 and the heat exchanger 14, a refrigerant passage 22, 23, and 24 that communicates the heat exchanger 14 and the heat exchanger 15, and heat exchange. A refrigerant passage 25 communicating with the heat exchanger 15 and the expansion valve 16, a refrigerant passage 26 communicating with the expansion valve 16 and the heat exchanger 18, and a refrigerant passage 27 communicating with the heat exchanger 18 and the compressor 12. Including.

  The refrigerant passage 21 is a passage for circulating the refrigerant from the compressor 12 to the heat exchanger 14. The refrigerant flows between the compressor 12 and the heat exchanger 14 from the outlet of the compressor 12 toward the inlet of the heat exchanger 14 via the refrigerant passage 21. The refrigerant passages 22 to 25 are passages for circulating the refrigerant from the heat exchanger 14 to the expansion valve 16. The refrigerant flows between the heat exchanger 14 and the expansion valve 16 from the outlet of the heat exchanger 14 toward the inlet of the expansion valve 16 via the refrigerant passages 22 to 25.

  The refrigerant passage 26 is a passage for circulating the refrigerant from the expansion valve 16 to the heat exchanger 18. The refrigerant flows between the expansion valve 16 and the heat exchanger 18 from the outlet of the expansion valve 16 toward the inlet of the heat exchanger 18 via the refrigerant passage 26. The refrigerant passage 27 is a passage for circulating the refrigerant from the heat exchanger 18 to the compressor 12. The refrigerant flows between the heat exchanger 18 and the compressor 12 from the outlet of the heat exchanger 18 toward the inlet of the compressor 12 via the refrigerant passage 27.

  The vapor compression refrigeration cycle 10 is configured by connecting a compressor 12, heat exchangers 14 and 15, an expansion valve 16, and a heat exchanger 18 through refrigerant passages 21 to 27. As the refrigerant of the vapor compression refrigeration cycle 10, for example, carbon dioxide, hydrocarbons such as propane and isobutane, ammonia, chlorofluorocarbons or water can be used.

  The gas-liquid separator 40 separates the refrigerant that flows out of the heat exchanger 14 and flows into the gas-liquid separator 40 into a gas-phase refrigerant and a liquid-phase refrigerant. Inside the gas-liquid separator 40, a refrigerant liquid that is a liquid phase refrigerant and a refrigerant vapor that is a gas phase refrigerant are stored. The gas-liquid separator 40 is connected to refrigerant passages 22 and 23 and a refrigerant passage 34 described later.

  The refrigerant condensed in the heat exchanger 14 is in the state of wet steam in a gas-liquid two-phase state in which saturated liquid and saturated steam are mixed on the outlet side of the heat exchanger 14. The high-pressure refrigerant liquid flowing out from the heat exchanger 14 is supplied to the gas-liquid separator 40 through the refrigerant passage 22. The gas-liquid two-phase refrigerant flowing into the gas-liquid separator 40 from the refrigerant passage 22 is separated into a gas phase and a liquid phase inside the gas-liquid separator 40. The gas-liquid separator 40 separates the refrigerant condensed by the heat exchanger 14 into a liquid refrigerant liquid and a gaseous refrigerant vapor and temporarily stores them.

  The refrigerant liquid that has undergone gas-liquid separation flows out of the gas-liquid separator 40 via the refrigerant passage 34. The end of the refrigerant passage 34 is connected to a refrigerant liquid storage part in which a liquid-phase refrigerant is stored in the gas-liquid separator 40, and forms an outlet for the liquid-phase refrigerant from the gas-liquid separator 40. The gas-liquid separated refrigerant vapor flows out of the gas-liquid separator 40 via the refrigerant passage 23. The end of the refrigerant passage 23 is connected to a refrigerant vapor storage part in which a gas-phase refrigerant is stored in the gas-liquid separator 40, and forms an outlet from the gas-liquid separator 40 for the gas-phase refrigerant. The refrigerant passage 23 forms part of a path through which the refrigerant from the gas-liquid separator 40 toward the expansion valve 16 flows, and the gas-phase refrigerant separated by the gas-liquid separator 40 flows out from the gas-liquid separator 40. Form a passage.

  Inside the gas-liquid separator 40, the refrigerant liquid accumulates on the lower side and the refrigerant vapor accumulates on the upper side. The end portion of the refrigerant passage 23 for leading the refrigerant vapor from the gas-liquid separator 40 is connected to the ceiling portion of the gas-liquid separator 40. The end portion of the refrigerant passage 34 for leading the refrigerant liquid from the gas-liquid separator 40 is connected to the bottom of the gas-liquid separator 40. Only the refrigerant vapor is sent out of the gas-liquid separator 40 from the ceiling side of the gas-liquid separator 40 via the refrigerant passage 23, and only the refrigerant liquid is sent from the bottom side of the gas-liquid separator 40 via the refrigerant passage 34. Is sent out of the gas-liquid separator 40. As a result, the gas-liquid separator 40 can reliably separate the gas-phase refrigerant and the liquid-phase refrigerant.

  The path through which the refrigerant flowing from the outlet of the heat exchanger 14 toward the inlet of the expansion valve 16 flows is the refrigerant passage 22 extending from the outlet side of the heat exchanger 14 to the gas-liquid separator 40 and from the gas-liquid separator 40 to the refrigerant. The refrigerant flows through the expansion valve 16 from the refrigerant passage 23 through which the steam flows out and passes through a flow rate adjusting valve 28 described later, the refrigerant passage 24 connected to the inlet side of the heat exchanger 15, and the outlet side of the heat exchanger 15. Refrigerant passage 25. The refrigerant passage 23 is a passage through which the gas-phase refrigerant separated by the gas-liquid separator 40 flows. The vapor-phase refrigerant vapor derived from the gas-liquid separator 40 is condensed by releasing heat to the surroundings and cooling in the heat exchanger 15 provided between the heat exchanger 14 and the expansion valve 16.

  The cooling device 1 includes two refrigerant paths connected in parallel between the heat exchangers 14 and 15. The refrigerant path flowing between the heat exchanger 14 and the heat exchanger 15 includes refrigerant paths 22 to 24. The refrigerant path that circulates between the heat exchanger 14 and the heat exchanger 15 also includes a refrigerant passage 34 that communicates the gas-liquid separator 40 and the cooling unit 30, a cooling unit 30, and the cooling unit 30 and the refrigerant passage. 24, and a refrigerant passage 36 communicating with 24. The refrigerant liquid flows from the gas-liquid separator 40 to the cooling unit 30 via the refrigerant passage 34. The refrigerant that has passed through the cooling unit 30 returns to the refrigerant passage 24 via the refrigerant passage 36. The cooling unit 30 is provided on a refrigerant path that flows from the heat exchanger 14 toward the heat exchanger 15.

  The cooling device 1 includes a refrigerant path arranged in parallel with the refrigerant passage 23, and the cooling unit 30 is provided on the refrigerant path. The cooling unit 30 is provided in one of a plurality of passages connected in parallel in the path of the refrigerant flowing between the heat exchanger 14 and the expansion valve 16 from the gas-liquid separator 40 toward the heat exchanger 15. It has been. The cooling unit 30 includes an EV (Electric Vehicle) device 31 that is an electric device mounted on the electric vehicle, and a cooler 32 through which the refrigerant flows. The EV device 31 is an example of a heat source. The inlet side of the cooler 32 is connected to the refrigerant passage 34, and the outlet side of the cooler 32 is connected to the refrigerant passage 36.

  The refrigerant passage 23 constitutes one of the refrigerant paths connected in parallel between the gas-liquid separator 40 and the heat exchanger 15. The refrigerant passage 34 that communicates the gas-liquid separator 40 and the cooling unit 30, the cooler 32 included in the cooling unit 30, and the refrigerant passage 34 that communicates the outlet side of the cooling unit 30 and the refrigerant passage 24 include a gas passage. The other of the refrigerant paths connected in parallel between the liquid separator 40 and the heat exchanger 15 is configured. The refrigerant path connected in parallel to the refrigerant passage 23 includes a refrigerant passage 34 upstream of the cooling unit 30 (a side closer to the gas-liquid separator 40), a cooler 32 included in the cooling unit 30, and cooling. And a refrigerant passage 36 on the downstream side of the portion 30 (side closer to the heat exchanger 15).

  The refrigerant passage 34 is a refrigerant path upstream of the cooling unit 30, and the refrigerant flows into the cooling unit 30 via the refrigerant passage 34. The refrigerant passage 34 is a passage through which liquid-phase refrigerant flows from the gas-liquid separator 40 to the cooling unit 30. The refrigerant passage 36 is a refrigerant path downstream of the cooling unit 30, and the refrigerant flows out of the cooling unit 30 and flows into the refrigerant passage 36. The refrigerant passage 36 is a passage for returning the refrigerant from the cooling unit 30 to the refrigerant passage 24.

  The refrigerant liquid that has flowed out of the gas-liquid separator 40 flows through the refrigerant passage 34 toward the cooling unit 30. The refrigerant flowing through the cooling unit 30 and flowing through the cooler 32 takes heat from the EV device 31 and cools the EV device 31 according to the temperature difference between the EV device 31 serving as a heat source and the refrigerant. . The cooling unit 30 cools the EV device 31 using the saturated liquid refrigerant separated in the gas-liquid separator 40 and flowing to the cooler 32 via the refrigerant passage 34. In the cooling unit 30, the refrigerant circulating in the cooler 32 and the EV device 31 exchange heat, whereby the EV device 31 is cooled and the refrigerant is heated. The refrigerant further flows from the cooling unit 30 via the refrigerant passage 36 and reaches the heat exchanger 15 via the refrigerant passage 24.

  A refrigerant liquid in a saturated liquid state is stored inside the gas-liquid separator 40. The gas-liquid separator 40 functions as a liquid accumulator that temporarily stores a liquid refrigerant that is a liquid refrigerant. By storing a predetermined amount of the refrigerant liquid in the gas-liquid separator 40, the flow rate of the refrigerant flowing from the gas-liquid separator 40 to the cooling unit 30 can be maintained even when the load changes. Since the gas-liquid separator 40 has a liquid reservoir function and becomes a buffer against load fluctuations and can absorb the load fluctuations, the cooling performance of the EV device 31 can be stabilized.

  The cooling unit 30 is provided in the cooler 32 so as to have a structure capable of exchanging heat between the EV device 31 and the refrigerant. In the present embodiment, the cooling unit 30 includes, for example, a cooler 32 formed so that the outer peripheral surface of the cooler 32 is in direct contact with the housing of the EV device 31. The cooler 32 has a portion adjacent to the housing of the EV device 31. In this part, heat exchange can be performed between the refrigerant flowing through the cooler 32 and the EV device 31.

  The EV device 31 is directly connected to the outer peripheral surface of the cooler 32 that forms part of the refrigerant path from the heat exchanger 14 to the heat exchanger 15 of the vapor compression refrigeration cycle 10 to be cooled. The refrigerant and the EV device 31 may exchange heat directly, or the refrigerant and a secondary medium such as water or oil flowing through the EV device 31 may exchange heat. Since the EV device 31 is disposed outside the cooler 32, the EV device 31 does not interfere with the flow of the refrigerant flowing through the cooler 32. Therefore, since the pressure loss of the vapor compression refrigeration cycle 10 does not increase, the EV device 31 can be cooled without increasing the power of the compressor 12.

  Alternatively, the cooling unit 30 may include any known heat transfer device disposed between the EV device 31 and the cooler 32. In this case, the EV device 31 is connected to the outer peripheral surface of the cooler 32 via a heat transfer device, and is cooled by transferring heat from the EV device 31 to the cooler 32 via the heat transfer device. As the heat transfer device, for example, a wick-type heat pipe can be used. Since the EV device 31 is a heating part of the heat pipe and the cooler 32 is a cooling part of the heat pipe, the heat transfer efficiency between the cooler 32 and the EV device 31 can be increased. It can be improved.

  Since heat can be reliably transferred from the EV device 31 to the cooler 32 by the heat transfer device, there may be a distance between the EV device 31 and the cooler 32, and the cooler 32 is brought into contact with the EV device 31. Therefore, there is no need to arrange a complicated route for the purpose. As a result, the arrangement of the EV device 31 is not limited, and the degree of freedom of the arrangement of the EV device 31 can be improved.

  The EV device 31 includes an electric device that generates heat when power is transferred. The electrical equipment includes, for example, an inverter for converting DC power to AC power, a motor generator that is a rotating electrical machine, a battery that is a power storage device, a boost converter that boosts the voltage of the battery, and a voltage that lowers the voltage of the battery. It includes at least one of a DC / DC converter and the like. The battery is a secondary battery such as a lithium ion battery or a nickel metal hydride battery. A capacitor may be used instead of the battery.

  Of the refrigerant paths connected in parallel between the gas-liquid separator 40 and the heat exchanger 15, a flow rate adjusting valve 28 is provided in the refrigerant path 23 that forms one path that does not pass through the cooling unit 30. Is provided. The flow rate adjustment valve 28 fluctuates the valve opening, and increases or decreases the pressure loss of the refrigerant flowing through the refrigerant passage 23. As a result, the flow rate adjustment valve 28 includes the refrigerant flow rate that flows directly between the gas-liquid separator 40 and the heat exchanger 15 via the refrigerant passage 23 without going through the cooling unit 30, and the EV including the cooler 32. The flow rate of the refrigerant flowing through the cooling system of the device 31 is arbitrarily adjusted.

  If the valve opening degree of the flow rate adjustment valve 28 is increased, the flow rate of the refrigerant flowing from the heat exchanger 14 to the refrigerant passage 22 directly flowing to the heat exchanger 15 via the refrigerant passage 23 increases, and the refrigerant passage 34 is The flow rate of the refrigerant that flows to the cooling unit 30 via the route and cools the EV device 31 decreases. If the valve opening degree of the flow rate adjusting valve 28 is reduced, the flow rate of the refrigerant flowing from the heat exchanger 14 to the refrigerant passage 22 directly flowing to the heat exchanger 15 via the refrigerant passage 23 is reduced, and the cooling portion 30 is supplied. The flow rate of the refrigerant that cools the flow EV device 31 increases.

  When the valve opening degree of the flow rate adjusting valve 28 is increased, the flow rate of the refrigerant that cools the EV device 31 is decreased, and the cooling capacity of the EV device 31 is decreased. When the valve opening degree of the flow rate adjusting valve 28 is reduced, the flow rate of the refrigerant that cools the EV device 31 is increased, and the cooling capacity of the EV device 31 is improved. Since the amount of the refrigerant flowing through the EV device 31 can be optimally adjusted using the flow rate adjusting valve 28, overheating and overcooling of the EV device 31 can be reliably prevented. In addition, it is possible to reliably reduce the pressure loss associated with the refrigerant flow in the cooling system of the EV device 31 and the power consumption of the compressor 12 for circulating the refrigerant.

  The heat exchanger 18 is disposed inside a duct 90 through which air-conditioning air flows. The duct 90 has a duct inlet 91 that is an inlet through which air-conditioning air flows into the duct 90, and a duct outlet 92 that is an outlet through which air-conditioning air flows out from the duct 90. An air conditioning fan 93 is arranged in the vicinity of the duct inlet 91 inside the duct 90. The air conditioning fan 93 is connected to a motor 94 that rotationally drives the air conditioning fan 93.

  When the air conditioning fan 93 is driven, an air flow is generated in the duct 90 and air is supplied to the heat exchanger 18. When the air conditioning fan 93 is in operation, the air conditioning air flows into the duct 90 via the duct inlet 91. The air flowing into the duct 90 may be outside air or air in the vehicle interior. An arrow 95 in FIG. 2 indicates the flow of air-conditioning air that circulates through the heat exchanger 18 and exchanges heat with the refrigerant of the vapor compression refrigeration cycle 10. During the cooling operation, the air-conditioning air is cooled in the heat exchanger 18, and the refrigerant is heated by receiving heat transfer from the air-conditioning air. An arrow 96 indicates the flow of air-conditioning air that is temperature-adjusted by the heat exchanger 18 and flows out of the duct 90 via the duct outlet 92.

[Operation of cooling device 1]
The refrigerant passes through the refrigerant circulation passage in which the compressor 12, the heat exchangers 14 and 15, the expansion valve 16, and the heat exchanger 18 are sequentially connected by the refrigerant passages 21 to 27, and passes through the vapor compression refrigeration cycle 10. Circulate. FIG. 3 is a Mollier diagram showing the state of the refrigerant in the vapor compression refrigeration cycle 10. The horizontal axis in FIG. 3 indicates the specific enthalpy of the refrigerant, and the vertical axis indicates the absolute pressure of the refrigerant. The unit of specific enthalpy is kJ / kg, and the unit of absolute pressure is MPa. The curves in the figure are the saturated vapor line and saturated liquid line of the refrigerant.

  In FIG. 3, the refrigerant flows from the refrigerant passage 22 at the outlet of the heat exchanger 14 to the refrigerant passage 34 via the gas-liquid separator 40 and flows into the cooling unit 30 to cool the EV device 31. The thermodynamic state of the refrigerant at each point in the vapor compression refrigeration cycle 10 returning to the refrigerant passage 24 on the inlet side of the heat exchanger 15 via the refrigerant passage 36 is shown. A path through which the refrigerant flows, that is, the refrigerant path 21, the refrigerant path 22, the refrigerant path 34, the refrigerant path 36, and the refrigerant paths 24 to 27 form a first path.

  As shown in FIG. 3, the refrigerant sucked into the compressor 12 is adiabatically compressed along the isentropic line in the compressor 12. As the compressor is compressed, the pressure and temperature of the refrigerant rise, and the refrigerant becomes superheated steam at a high temperature and high pressure superheat degree at the outlet of the compressor 12.

  The high-temperature and high-pressure superheated steam refrigerant adiabatically compressed in the compressor 12 flows to the heat exchanger 14 and is cooled in the heat exchanger 14. The high-pressure gas-phase refrigerant discharged from the compressor 12 is condensed (liquefied) by releasing heat to the surroundings and cooling in the heat exchanger 14. By the heat exchange with the outside air in the heat exchanger 14, the temperature of the refrigerant is lowered and the refrigerant is liquefied. The high-pressure refrigerant vapor that has entered the heat exchanger 14 changes from superheated steam to dry saturated vapor while maintaining the same pressure in the heat exchanger 14, releases latent heat of condensation, gradually liquefies, and becomes wet vapor in a gas-liquid mixed state. .

  The gas-liquid two-phase refrigerant cooled to such an extent that it is not completely liquefied by the heat exchanger 14 is gas-liquid separated in the gas-liquid separator 40 into a saturated vapor state refrigerant vapor and a saturated liquid state refrigerant liquid. . Among the gas-liquid separated refrigerant, the liquid-phase refrigerant liquid flows out of the gas-liquid separator 40, flows to the cooler 32 of the cooling unit 30 via the refrigerant passage 34, and cools the EV device 31. In the cooling unit 30, the EV device 31 is cooled by releasing heat to the liquid refrigerant in a saturated liquid state condensed by the heat exchanger 14 and separated by the gas-liquid separator 40. By the heat exchange with the EV device 31, the refrigerant is heated and the dryness of the refrigerant increases. The refrigerant receives the latent heat from the EV device 31 and partially vaporizes, so that the refrigerant becomes wet vapor in a gas-liquid two-phase state in which saturated liquid and saturated vapor are mixed at the outlet of the cooling unit 30.

  The refrigerant that has flowed out of the cooling unit 30 flows into the heat exchanger 15 via the refrigerant passages 36 and 24. The wet steam of the refrigerant dissipates heat to the surroundings in the heat exchanger 15 and is cooled again by exchanging heat with the outside air to be condensed again. When all of the refrigerant condenses, it becomes a saturated liquid, and further releases sensible heat to supercool. It becomes a supercooled liquid. The refrigerant is cooled to the saturation temperature or lower in the heat exchanger 15. The reason why the heat exchanger 15 turns the refrigerant into a supercooled liquid is to facilitate control of the subsequent decompression amount, refrigerant flow rate, and cooling capacity in the expansion valve 16.

  The refrigerant cooled to the supercooled liquid in the heat exchanger 15 flows into the expansion valve 16 via the refrigerant passage 25. In the expansion valve 16, the refrigerant in the supercooled liquid state is expanded and expanded, the specific enthalpy does not change, the temperature and pressure decrease, and the mixture becomes wet steam in a low-temperature and low-pressure gas-liquid mixed state.

  The wet steam refrigerant that has flowed out of the expansion valve 16 flows into the heat exchanger 18 via the refrigerant passage 26. A wet steam refrigerant flows into the tube of the heat exchanger 18. The heat exchanger 18 absorbs the heat of the air-conditioning air introduced so as to come into contact with the heat exchanger 18 by vaporizing the mist refrigerant flowing through the heat exchanger 18. The heat exchanger 18 uses the refrigerant depressurized by the expansion valve 16 to absorb the heat of vaporization when the refrigerant's wet vapor evaporates into the refrigerant gas from the air conditioning air flowing into the vehicle interior, Cool the interior of the vehicle. The air-conditioning air whose temperature has been reduced by the heat being absorbed by the heat exchanger 18 is returned again to the vehicle interior, thereby cooling the vehicle interior.

  When the refrigerant circulates in the tube of the heat exchanger 18, it absorbs the heat of the air in the vehicle interior via the fins as latent heat of vaporization, and evaporates at a constant pressure. When all the refrigerant is dry and becomes saturated vapor, the refrigerant vapor further rises in temperature by sensible heat and becomes superheated vapor. During the cooling operation, heat exchange between the high-temperature air-conditioning air and the refrigerant in the heat exchanger 18 cools the air-conditioning air, lowers the temperature of the air-conditioning air, and the refrigerant receives heat transfer from the air-conditioning air. Heated. Thereafter, the refrigerant is sucked into the compressor 12 via the refrigerant passage 27. The compressor 12 compresses the refrigerant flowing from the heat exchanger 18.

  In accordance with such a cycle, the refrigerant continuously repeats the compression, condensation, throttle expansion, and evaporation state changes. In the above description of the vapor compression refrigeration cycle, the theoretical refrigeration cycle is described. However, in the actual vapor compression refrigeration cycle 10, it is necessary to consider the loss in the compressor 12, the pressure loss of the refrigerant, and the heat loss. Of course there is.

  During the operation of the vapor compression refrigeration cycle 10, the refrigerant absorbs heat of vaporization from the air in the vehicle interior when evaporating in the heat exchanger 18 acting as an evaporator, thereby cooling the vehicle interior. In addition, the high-pressure liquid refrigerant that has flowed out of the heat exchanger 14 and separated into gas and liquid by the gas-liquid separator 40 flows to the cooling unit 30, and heat-exchanges with the EV device 31 to cool the EV device 31. The cooling device 1 cools an EV device 31 that is a heat source mounted on a vehicle by using a vapor compression refrigeration cycle 10 for air conditioning in a vehicle interior. The temperature required for cooling the EV device 31 is desirably a temperature lower than the upper limit value of the target temperature range as the temperature range of the EV device 31.

  Since the EV equipment 31 is cooled using the vapor compression refrigeration cycle 10 provided to cool the part to be cooled in the heat exchanger 18, a dedicated water circulation pump is used to cool the EV equipment 31. Or it is not necessary to provide equipment, such as a cooling fan. Therefore, the configuration necessary for the cooling device 1 of the EV device 31 can be reduced and the device configuration can be simplified, so that the manufacturing cost of the cooling device 1 can be reduced. In addition, it is not necessary to operate a power source such as a pump or a cooling fan for cooling the EV device 31, and power consumption for operating the power source is not required. Therefore, power consumption for cooling the EV device 31 can be reduced, and the EV device 31 can be cooled with low power.

  In the heat exchanger 14, it is only necessary to cool the refrigerant to a wet steam state, the refrigerant in the gas-liquid mixed state is separated by the gas-liquid separator 40, and only the refrigerant liquid in the saturated liquid state is supplied to the cooling unit 30. . The refrigerant in the state of wet steam that has received the latent heat of vaporization from the EV device 31 and is partially vaporized is cooled again by the heat exchanger 15. The refrigerant changes its state at a constant temperature until the wet vapor state refrigerant is condensed and completely saturated. The heat exchanger 15 further subcools the liquid refrigerant to a degree of supercooling necessary for cooling the vehicle interior. Since it is not necessary to excessively increase the degree of supercooling of the refrigerant, the capacity of the heat exchangers 14 and 15 can be reduced. Therefore, the cooling capacity for the passenger compartment can be ensured, and the size of the heat exchangers 14 and 15 can be reduced, so that the cooling device 1 that is downsized and advantageous for in-vehicle use can be obtained.

  When the specifications of the heat exchangers 14 and 15 are determined at the design stage of the cooling device 1, the maximum heat generation amount of the EV device 31 is used as a design value. At the time of normal heat generation in which the EV device 31 generates heat less than the maximum heat generation amount, the capacity of the heat exchangers 14 and 15 can be afforded. Therefore, when the EV device 31 having the maximum heat generation amount is not cooled, the refrigerant can exchange heat with more air in the heat exchangers 14 and 15. This can be considered that the heat exchangers 14 and 15 are apparently larger, and the temperature efficiency φc of the heat exchangers 14 and 15 is increased.

  The air side heat dissipation capability Qca in the heat exchangers 14 and 15 is the difference (Ter−Tea) obtained by subtracting the intake air temperature Tea from the temperature efficiency φc of the heat exchanger, the air specific heat Ca, the air heavy air volume Gea, and the refrigerant temperature Ter. ). The required heat radiation capacity Qca does not change, and the air specific heat Ca, the air weight air volume Gea, and the intake air temperature Tea are determined according to the outside air temperature and the vehicle speed, so that the refrigerant temperature Ter decreases as the temperature efficiency φc increases. . Referring to the Mollier diagram, when the refrigerant is in a gas-liquid two-phase state, the refrigerant temperature and pressure have a linear relationship, and the refrigerant temperature changes according to the refrigerant pressure change. That is, that the refrigerant temperature Ter in the heat exchangers 14 and 15 is low means that the pressure of the refrigerant flowing through the heat exchangers 14 and 15 is low.

  As a result of the refrigerant pressure at the heat exchangers 14 and 15 decreasing and the high pressure of the vapor compression refrigeration cycle 10 decreasing, the refrigerant pressure at the outlet of the compressor 12 may be relatively low. Therefore, the power for adiabatically compressing the refrigerant by the compressor 12 can be reduced, and further power saving can be achieved. Therefore, the fuel consumption of the vehicle can be improved. Particularly in an electric vehicle, power consumption can be directly improved by power saving.

  A refrigerant passage 23 that forms a part of the refrigerant path from the outlet of the heat exchanger 14 to the inlet of the expansion valve 16 is provided between the heat exchanger 14 and the heat exchanger 15. The refrigerant flow from the gas-liquid separator 40 to the expansion valve 16 is a refrigerant path 23 that is a path that does not pass through the cooling unit 30 and a refrigerant path that cools the EV device 31 via the cooling unit 30. The refrigerant passages 34 and 36 and the cooler 32 are provided in parallel. The cooling system of the EV device 31 including the refrigerant passages 34 and 36 is connected in parallel to the refrigerant passage 23. Therefore, only a part of the refrigerant that has flowed out of the heat exchanger 14 flows to the cooling unit 30. By adjusting the opening degree of the flow rate adjusting valve 28 provided in the refrigerant passage 23, the flow rates of the refrigerant flowing from the gas-liquid separator 40 to the refrigerant passage 23 and the refrigerant flowing through the cooling unit 30 are appropriately adjusted. By this flow rate adjustment, an amount of refrigerant necessary for cooling the EV device 31 flows to the cooling unit 30, and the EV device 31 is appropriately cooled.

  A refrigerant path flowing directly from the heat exchanger 14 to the heat exchanger 15 without passing through the cooling unit 30 and a refrigerant path flowing from the heat exchanger 14 through the cooling unit 30 to the heat exchanger 15 are arranged in parallel. The pressure loss when the refrigerant flows through the cooling system of the EV device 31 can be reduced by providing only a part of the refrigerant to the refrigerant passages 34 and 36. Since all the refrigerant does not flow to the cooling unit 30, it is possible to reduce pressure loss related to the circulation of the refrigerant passing through the cooling unit 30, and accordingly, consumption necessary for the operation of the compressor 12 for circulating the refrigerant. Electric power can be reduced.

  When the low-temperature and low-pressure refrigerant that has passed through the expansion valve 16 is used for cooling the EV device 31, the cooling capacity of the air in the passenger compartment in the heat exchanger 18 decreases, and the cooling capacity for the passenger compartment decreases. On the other hand, in the cooling device 1 of the present embodiment, the high-pressure refrigerant discharged from the compressor 12 in the vapor compression refrigeration cycle 10 is converted into the heat exchanger 14 as the first condenser, and the second It is condensed by both the heat exchanger 15 as a condenser. The two-stage heat exchangers 14 and 15 are disposed between the compressor 12 and the expansion valve 16, and the cooling unit 30 that cools the EV device 31 is provided between the heat exchanger 14 and the heat exchanger 15. ing. The heat exchanger 15 is provided on the path of the refrigerant that flows from the cooling unit 30 toward the expansion valve 16.

  The refrigerant heated by receiving the latent heat of vaporization from the EV device 31 is sufficiently cooled in the heat exchanger 15, so that the refrigerant at the outlet of the expansion valve 16 has a temperature originally required for cooling the vehicle interior. And having pressure. Therefore, since the amount of heat received from the outside when the refrigerant evaporates in the heat exchanger 18 can be sufficiently increased, the air-conditioning air passing through the heat exchanger 18 can be sufficiently cooled. Thus, by defining the heat dissipation capability of the heat exchanger 15 that can sufficiently cool the refrigerant, the EV device 31 can be cooled without affecting the cooling capability of cooling the air in the passenger compartment. Therefore, both the cooling capacity of the EV device 31 and the cooling capacity for the passenger compartment can be reliably ensured.

  The refrigerant flowing from the heat exchanger 14 to the cooling unit 30 receives heat from the EV device 31 and is heated when the EV device 31 is cooled. When the refrigerant is heated to the saturated vapor temperature or higher in the cooling unit 30 and the entire amount of the refrigerant is vaporized, the amount of heat exchange between the refrigerant and the EV device 31 is reduced, and the EV device 31 cannot be efficiently cooled. Pressure loss during flow increases. Therefore, it is desirable to cool the refrigerant sufficiently in the heat exchanger 14 so that the entire amount of the refrigerant does not vaporize after the EV device 31 is cooled.

  Specifically, the state of the refrigerant at the outlet of the heat exchanger 14 is brought close to the saturated liquid, and typically, the refrigerant is on the saturated liquid line at the outlet of the heat exchanger 14. As a result of the heat exchanger 14 having the ability to sufficiently cool the refrigerant in this way, the heat dissipating ability for releasing heat from the refrigerant of the heat exchanger 14 is higher than the heat dissipating ability of the heat exchanger 15. By sufficiently cooling the refrigerant in the heat exchanger 14 having a relatively large heat dissipation capability, the refrigerant that has received heat from the EV device 31 can be kept in a wet steam state, and heat exchange between the refrigerant and the EV device 31 can be achieved. Since the decrease in the amount can be avoided, the EV device 31 can be cooled sufficiently efficiently. The refrigerant in the state of wet steam after cooling the EV device 31 is efficiently cooled again in the heat exchanger 15 and cooled to the state of the supercooled liquid below the saturation temperature. Therefore, it is possible to provide the cooling device 1 that secures both the cooling capacity for the passenger compartment and the cooling capacity of the EV device 31.

  The refrigerant in a gas-liquid two-phase state at the outlet of the heat exchanger 14 is separated into a gas phase and a liquid phase in the gas-liquid separator 40. The gas-phase refrigerant separated by the gas-liquid separator 40 flows through the refrigerant passages 23 and 24 and is directly supplied to the heat exchanger 15. The liquid phase refrigerant separated by the gas-liquid separator 40 flows through the refrigerant passage 34 and is supplied to the cooling unit 30 to cool the EV device 31. This liquid-phase refrigerant is a truly saturated liquid refrigerant with no excess or deficiency. By extracting only the liquid-phase refrigerant from the gas-liquid separator 40 and flowing it to the cooling unit 30, the EV device 31 can be cooled by utilizing the capacity of the heat exchanger 14 to the maximum, so that the EV device 31 is cooled. The cooling device 1 with improved performance can be provided.

  By introducing the refrigerant in a saturated liquid state at the outlet of the gas-liquid separator 40 into the cooler 32 that cools the EV device 31, the refrigerant flows through the cooling system of the EV device 31 including the refrigerant passages 34 and 36 and the cooler 32. Among the refrigerants, the gas-phase refrigerant can be minimized. Therefore, the flow velocity of the refrigerant vapor flowing through the cooling system of the EV device 31 can be prevented from increasing and the pressure loss can be suppressed, and the power consumption of the compressor 12 for circulating the refrigerant can be reduced. Therefore, the vapor compression refrigeration cycle 10 The deterioration of the performance can be avoided.

[Heat pipe operation mode]
Returning to FIG. 2, the cooling device 1 further includes a communication path 51. The communication passage 51 is a refrigerant downstream of the cooling unit 30 among the refrigerant passage 21 through which the refrigerant flows between the compressor 12 and the heat exchanger 14 and the refrigerant passages 34, 36 through which the refrigerant flows through the cooling unit 30. The passage 36 communicates with the passage 36. The refrigerant passage 36 is divided into a refrigerant passage 36 a upstream from the branch with the communication passage 51 and a refrigerant passage 36 b downstream from the branch with the communication passage 51.

  The refrigerant passage 36 is provided with a switching valve 52 that switches a communication state between the communication passage 51 and the refrigerant passages 21 and 36. The switching valve 52 enables or disables the circulation of the refrigerant via the communication path 51 by switching its opening and closing. By switching the path of the refrigerant flowing out of the cooling unit 30 using the switching valve 52, the refrigerant after cooling the EV device 31 is transferred to the heat exchanger 15 via the refrigerant passages 36b and 24, or connected to the heat exchanger 15. Any of the paths to the heat exchanger 14 via the passage 51 and the refrigerant passage 21 can be arbitrarily selected and distributed.

  More specifically, as the switching valve 52, an opening / closing valve that switches between communication and blocking of the refrigerant passage 36b is provided in the refrigerant passage 36b. By switching the opening and closing of the switching valve 52, the communication state of the first passage including the refrigerant passage 36b is switched.

  During the cooling operation of the vapor compression refrigeration cycle 10, the switching valve 52 is fully opened (valve opening degree 100%), and the cooling capacity required by the cooling unit 30 is obtained by adjusting the valve opening degree of the flow regulating valve 28. Adjust the refrigerant flow rate to Thereby, the refrigerant | coolant which distribute | circulates the refrigerant path 36a after cooling the EV apparatus 31 can be reliably distribute | circulated to the heat exchanger 15 via the refrigerant path 36b.

  On the other hand, while the vapor compression refrigeration cycle 10 is stopped, the switching valve 52 is fully closed and the flow rate adjustment valve 28 is fully closed. Accordingly, the refrigerant flowing through the refrigerant passage 36a after cooling the EV device 31 is circulated to the heat exchanger 14 via the communication passage 51, and the cooling unit 30 and the heat exchanger are not passed through the compressor 12. 14 can form an annular path for circulating the refrigerant.

  The flow rate adjusting valve 28 is a valve having a specification that allows the opening degree to be adjusted, and may be an electric valve, for example. The switching valve 52 may be a valve having a specification that can be switched between full open and fully closed, and may be, for example, an electromagnetic valve.

  A check valve 58 is provided in the communication path 51. The check valve 58 allows the refrigerant flow from the refrigerant passage 36 to the refrigerant passage 21 via the communication passage 51 and prohibits the reverse refrigerant flow. By providing the check valve 58, the flow of the refrigerant flowing from the refrigerant passage 21 to the refrigerant passage 36 via the communication passage 51 during the operation of the compressor 12 is prohibited. In addition, during operation of the compressor 12, the refrigerant flowing through the refrigerant passage 21 has a higher pressure than the refrigerant flowing through the refrigerant passage 36, and thus the refrigerant flows from the refrigerant passage 36 toward the refrigerant passage 21 via the communication passage 51. Does not occur.

  Therefore, during the operation of the vapor compression refrigeration cycle 10, all of the refrigerant adiabatically compressed by the compressor 12 can flow to the heat exchanger 14, and the refrigerant after cooling the EV device 31 can be reliably The heat exchanger 15 can be circulated. In addition, if the switching valve 52 is switched between open and closed when the compressor 12 is stopped and the switching valve 52 is fully closed, a path that leads from the outlet of the cooling unit 30 to the refrigerant passage 21 through the check valve 58 is formed. A refrigerant path for circulating the refrigerant can be formed between the cooling unit 30 and the heat exchanger 14 via the communication path 51.

  The cooling device 1 further includes a check valve 54. The check valve 54 is disposed on the refrigerant passage 21 between the compressor 12 and the heat exchanger 14 on the side closer to the compressor 12 than the connection point between the refrigerant passage 21 and the communication passage 51. The check valve 54 allows the refrigerant flow from the compressor 12 to the heat exchanger 14 and prohibits the reverse refrigerant flow. In this way, in the heat pipe operation mode shown in FIG. 5, which will be described in detail later, a closed loop refrigerant path for circulating the refrigerant between the heat exchanger 14 and the cooling unit 30 is surely formed. Can do.

  If the check valve 54 is not provided, the refrigerant may flow from the communication passage 51 to the refrigerant passage 21 on the compressor 12 side. By providing the check valve 54, the flow of the refrigerant from the communication path 51 toward the compressor 12 can be surely prohibited. Therefore, the stop of the vapor compression refrigeration cycle 10 using the heat pipe formed by the annular refrigerant path is used. It is possible to prevent a decrease in the cooling capacity of the EV device 31 at the time. Therefore, the EV device 31 can be efficiently cooled even when the cooling for the passenger compartment of the vehicle is stopped.

  In addition, when the amount of refrigerant in the closed loop refrigerant path is insufficient while the vapor compression refrigeration cycle 10 is stopped, the compressor 12 is operated only for a short time, thereby passing through the check valve 54. Thus, the refrigerant can be supplied to the closed loop path. Thereby, the refrigerant | coolant amount in a closed loop can be increased and the heat exchange processing amount of a heat pipe can be increased. Therefore, since the amount of refrigerant in the heat pipe can be secured, it is possible to avoid insufficient cooling of the EV device 31 due to an insufficient amount of refrigerant.

  FIG. 4 is a schematic diagram showing a refrigerant flow for cooling the EV device 31 during operation of the vapor compression refrigeration cycle 10. FIG. 5 is a schematic diagram showing the flow of the refrigerant that cools the EV device 31 while the vapor compression refrigeration cycle 10 is stopped. FIG. 6 is a diagram illustrating settings of the compressor 12, the flow rate adjustment valve 28, and the switching valve 52 for each operation mode of the cooling device 1. Among the operation modes shown in FIG. 6, the “air conditioner operation mode” refers to a case where the vapor compression refrigeration cycle 10 shown in FIG. 4 is operated, that is, the compressor 12 is operated and Is shown. On the other hand, the “heat pipe operation mode” refers to a case where the vapor compression refrigeration cycle 10 shown in FIG. 5 is stopped, that is, the compressor 12 is stopped and an annular path connecting the cooling unit 30 and the heat exchanger 14 is passed. In this case, the refrigerant is circulated.

  As shown in FIGS. 4 and 6, when in the “air conditioner operation mode” in which the compressor 12 is driven and the vapor compression refrigeration cycle 10 is operating, the flow rate adjustment valve 28 allows sufficient refrigerant to flow through the cooling unit 30. Thus, the valve opening is adjusted. The switching valve 52 is operated so that the refrigerant flows from the cooling unit 30 to the expansion valve 16 via the heat exchanger 15. That is, the refrigerant path is selected so that the refrigerant flows through the entire cooling device 1 by fully opening the switching valve 52. Therefore, the cooling capacity of the vapor compression refrigeration cycle 10 can be ensured and the EV device 31 can be efficiently cooled.

  As shown in FIGS. 5 and 6, in the “heat pipe operation mode” in which the compressor 12 is stopped and the vapor compression refrigeration cycle 10 is stopped, the refrigerant is circulated from the cooling unit 30 to the heat exchanger 14. The switching valve 52 is operated. That is, the switching valve 52 is fully closed. Further, by fully closing the flow rate adjusting valve 28, the refrigerant flows through the communication passage 51 without flowing from the refrigerant passage 36a to the refrigerant passage 36b. As a result, the heat exchanger 14 reaches the cooling unit 30 through the refrigerant passage 22, the gas-liquid separator 40, and the refrigerant passage 34 in this order, and further passes through the refrigerant passage 36a, the communication passage 51, and the refrigerant passage 21 in order. Thus, a closed annular path is formed back to the heat exchanger 14. A path through which the refrigerant flows, that is, the refrigerant path 21, the refrigerant path 22, the refrigerant path 34, the refrigerant path 36a, and the communication path 51 form a second path.

  Via this annular path, the refrigerant can be circulated between the heat exchanger 14 and the cooling unit 30 without operating the compressor 12. When the EV device 31 is cooled, the refrigerant receives evaporation latent heat from the EV device 31 and evaporates. The refrigerant vapor evaporated by heat exchange with the EV device 31 flows to the heat exchanger 14 through the refrigerant passage 36a, the communication passage 51, and the refrigerant passage 21 in order. In the heat exchanger 14, the refrigerant vapor is cooled and condensed by the running air of the vehicle or the ventilation from the condenser fan 42 or the radiator fan for cooling the engine. The refrigerant liquid liquefied by the heat exchanger 14 returns to the cooling unit 30 via the refrigerant passages 22 and 34.

  In this way, a heat pipe is formed by the annular path passing through the cooling unit 30 and the heat exchanger 14, with the EV device 31 as a heating unit and the heat exchanger 14 as a cooling unit. Therefore, even when the vapor compression refrigeration cycle 10 is stopped, that is, when cooling for the vehicle is stopped, the EV device 31 can be reliably cooled without having to start the compressor 12. Since it is not necessary to always operate the compressor 12 for cooling the EV equipment 31, the power consumption of the compressor 12 can be reduced and the fuel consumption of the vehicle can be improved. In addition, the compressor 12 has a long service life. Therefore, the reliability of the compressor 12 can be improved.

  An occupant of an electric vehicle switches the cooling of the passenger compartment from ON to OFF by operating an air conditioning control panel provided on an instrument panel in front of the vehicle. With this operation, the operation mode of the cooling device 1 for cooling the EV device 31 is switched from the air conditioner operation mode to the heat pipe operation mode. That is, the compressor 12 is stopped, the switching valve 52 is fully closed, and the flow rate adjustment valve 28 is fully closed. Thus, the first passage for cooling the EV device 31 by flowing the refrigerant discharged from the compressor 12 to the cooling unit 30 is blocked, and natural circulation between the heat exchanger 14 and the cooling unit 30 is performed. A second passage for circulating the refrigerant is communicated. In this way, the refrigerant can be supplied to the cooling unit 30 without going through the compressor 12.

  By switching the opening / closing of the switching valve 52, the communication of the first passage and the communication of the second passage are switched. Thereby, the EV device 31 is cooled from the air conditioner operation mode in which the first passage is communicated and the second passage is blocked to the heat pipe operation mode in which the first passage is blocked and the second passage is communicated. Therefore, the operation mode of the cooling device 1 is switched. In this way, even when the compressor 12 is stopped, the refrigerant naturally circulates and cools the EV device 31 in the cooling unit 30, whereby the cooling capacity of the EV device 31 by the cooling device 1 is maintained.

  4 and 5 show the ground surface 60. In the vertical direction perpendicular to the ground 60, the cooling unit 30 is disposed below the heat exchanger 14 and the gas-liquid separator 40. In an annular path for circulating the refrigerant between the heat exchanger 14 and the cooling unit 30, the cooling unit 30 is disposed below and the heat exchanger 14 is disposed above. The heat exchanger 14 and the gas-liquid separator 40 are disposed at a position higher than the cooling unit 30.

  In this case, the refrigerant vapor heated and vaporized in the cooling unit 30 rises in the annular path and reaches the heat exchanger 14, and the liquid refrigerant cooled and condensed in the heat exchanger 14 is in the gas-liquid separator 40. Can be stored. Further, the liquid refrigerant descends in the annular path from the gas-liquid separator 40 by the action of gravity, using the position head of the liquid refrigerant from the gas-liquid separator 40 to the cooling unit 30 as a driving force, and returns to the cooling unit 30. That is, a thermosiphon heat pipe is formed by the cooling unit 30, the gas-liquid separator 40, the heat exchanger 14, and the refrigerant path (that is, the second passage) connecting them. Since the heat transfer efficiency from the EV device 31 to the heat exchanger 14 can be improved by forming the heat pipe, the EV can be applied without applying power even when the vapor compression refrigeration cycle 10 is stopped. The device 31 can be cooled more efficiently.

  FIG. 7 is a Mollier diagram showing the state of the refrigerant in the heat pipe operation mode. The horizontal axis in FIG. 7 indicates the specific enthalpy of the refrigerant, and the vertical axis indicates the absolute pressure of the refrigerant. The unit of specific enthalpy is kJ / kg, and the unit of absolute pressure is MPa. The curves in the figure are the saturated vapor line and saturated liquid line of the refrigerant. FIG. 7 shows the thermodynamic state of the refrigerant circulating in the closed loop formed by the refrigerant path connecting the heat exchanger 14, the gas-liquid separator 40, and the cooling unit 30.

  In the case of the heat pipe operation mode, the refrigerant flowing into the heat exchanger 14 is radiated and cooled to the surroundings when flowing through the tube of the heat exchanger 14 due to the running air of the vehicle or the ventilation from the cooling fan. Condensed (liquefied). By the heat exchange with the outside air in the heat exchanger 14, the temperature of the refrigerant is lowered and the refrigerant is liquefied. The refrigerant releases the latent heat of condensation in the heat exchanger 14 and gradually liquefies while maintaining a constant pressure to become wet vapor in a gas-liquid mixed state. The refrigerant in the gas-liquid two-phase state flows to the gas-liquid separator 40 via the refrigerant passage 22 and is gas-liquid separated into the refrigerant vapor in the saturated vapor state and the refrigerant liquid in the saturated liquid state in the gas-liquid separator 40. The

  The saturated liquid refrigerant flows out from the gas-liquid separator 40, flows through the refrigerant passage 34 to the cooler 32 of the cooling unit 30, and cools the EV device 31. In the cooling unit 30, the EV device 31 is cooled by releasing heat to the liquid refrigerant in the saturated liquid state condensed by the heat exchanger 14 and separated by the gas-liquid separator 40. Through heat exchange with the EV device 31, the refrigerant is heated and gradually evaporates while maintaining a constant pressure, thereby increasing the dryness of the refrigerant. Typically, in the cooling unit 30, heat exchange between the refrigerant and the EV device 31 is performed until all the refrigerant is dry and becomes saturated vapor. The refrigerant partially or wholly vaporized by heat exchange with the EV device 31 flows out of the cooling unit 30 and returns to the heat exchanger 14 through the communication path 51 and the refrigerant path 21 in order.

  By operating a loop heat pipe having the heat exchanger 14 as a condenser and the cooling unit 30 as an evaporator, the EV device 31 is reliably cooled. The power of the compressor 12 is not necessary for cooling the EV device 31, and the EV device 31 can be cooled without power. Therefore, the cooling device 1 that can appropriately cool the EV equipment 31 both during operation and when the vapor compression refrigeration cycle 10 is operated can be realized with a simple configuration. Since the EV device 31 can be cooled without power, the power consumption of the compressor 12 can be reduced, and further power saving and improved comfort can be achieved.

[Modification of Cooling Device 1]
FIG. 8 is a schematic diagram illustrating a configuration of a cooling device 1 according to a modification. As described above, in the heat pipe operation mode, the refrigerant is circulated in the closed loop path using the position head of the liquid refrigerant from the gas-liquid separator 40 to the cooling unit 30 as a driving force. When the difference in height between the cooling unit 30 and the gas-liquid separator 40 cannot be sufficiently secured due to the arrangement of the devices in the vehicle, and as a result, the driving force of the refrigerant in the heat pipe operation mode becomes insufficient, FIG. As shown in FIG. 4, a pump 41 that transfers the refrigerant from the gas-liquid separator 40 to the cooling unit 30 may be provided, and the driving force may be assisted by the pump 41.

  Providing the pump 41 makes it possible to continuously supply the refrigerant to the cooling unit 30 reliably in the heat pipe operation mode, so that the cooling capacity of the EV device 31 by the cooler 32 can be ensured. The pump 41 may be disposed in the gas-liquid separator 40 as shown in FIG. 8 or may be disposed in the refrigerant passage 34 that connects the gas-liquid separator 40 and the cooling unit 30.

[Detailed structure of cooler 32]
Hereinafter, the structure of the cooler 32 included in the cooling unit 30 in the present embodiment will be described in detail. FIG. 9 is a schematic diagram showing the configuration of the cooler 32 of the first example in the cooling device 1 according to the embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of the cooler 32 taken along line XX in FIG.

  As shown in FIGS. 9 and 10, the cooler 32 includes a housing 70, an inflow port 71, and an outflow port 72. The housing 70 is formed in a hollow shape and defines an internal space 74 therein. The inflow port 71 is an inlet through which the refrigerant flows into the internal space 74, and the outflow port 72 is an outlet through which the refrigerant flows out of the internal space 74. The refrigerant passage 34 is connected to the inlet 71, and the refrigerant passage 36 is connected to the outlet 72. The casing 70 of the cooler 32 has a rectangular plate shape. The inflow port 71 and the outflow port 72 are arranged on a rectangular diagonal line formed by the housing 70. That is, the inflow port 71 is provided at the position of one vertex of the rectangle, and the outflow port 72 is provided at the position of the other vertex that is not adjacent to the one vertex.

  With this configuration, the flow of the refrigerant flowing through the cooling unit 30 is defined. That is, the refrigerant supplied to the cooling unit 30 flows from the refrigerant passage 34 through the inlet 71 into the internal space 74 inside the housing 70 of the cooler 32. The refrigerant exchanges heat with the EV device 31 while flowing in the internal space 74 toward the outlet 72. The refrigerant further flows out from the internal space 74 via the outlet 72 and flows to the refrigerant passage 36.

  A plurality of fins 73 are provided in the internal space 74. The fins 73 increase the contact area between the refrigerant flowing in the internal space 74 and the cooler 32, and facilitate heat exchange between the EV device 31 and the refrigerant via the cooler 32. That is, since the heat transmitted from the EV device 31 to the cooler 32 is easily transmitted to the refrigerant through the fins 73, the heat transfer efficiency is further improved.

  The fin 73 also has a function of rectifying the refrigerant flowing from the inlet 71 to the outlet 72 in the internal space 74. Referring to FIGS. 9 and 10, the plurality of fins 73 are arranged in parallel with each other along the short side direction of a rectangle formed by the outer shape of the housing 70. Thereby, the fin 73 partitions the internal space 74 into a plurality of parallel flow paths 80. Each parallel flow path 80 is formed between adjacent fins 73. The refrigerant flows in the internal space 74 from the inlet 71 toward the outlet 72 via any one of the plurality of parallel flow paths 80.

  Each parallel flow path 80 has an inlet 81 through which the refrigerant flows into the parallel flow path 80 and an outlet 82 through which the refrigerant flows out of the parallel flow path 80. The intervals between the fins 73 are set to be equal to each other, and each parallel flow path 80 has the same cross-sectional area perpendicular to the flow direction of the refrigerant flowing in the parallel flow path 80. Thereby, the dispersion | variation in the pressure loss of each parallel flow path 80 is reduced.

  The refrigerant flowing into the internal space 74 from the inlet 71 reaches the inlet 81 of each parallel flow path 80 via the path 76 where the fins 73 are not formed. The inlet 81 of the parallel flow path 80 is open to the path 76, and the refrigerant flows into each parallel flow path 80 from the path 76. The path 76 is formed so that the cross-sectional area perpendicular to the flow direction of the refrigerant flowing in the path 76 is larger than the cross-sectional area of the parallel flow path 80 described above.

  The refrigerant flowing out from the outlet 82 of each parallel flow path 80 reaches the outlet 72 via a path 78 where the fins 73 are not formed. The outlet 82 of the parallel flow path 80 is open to the path 78, and the refrigerant flows into the path 78 from each parallel flow path 80. The path 78 is formed so that the cross-sectional area perpendicular to the flow direction of the refrigerant flowing in the path 78 is larger than the cross-sectional area of the parallel flow path 80 described above.

  Among the plurality of parallel flow paths 80, the parallel flow path 80 in which the inlet 81 of the parallel flow path 80 is closest to the inflow port 71 is particularly referred to as a recent flow path 84. Among the plurality of parallel flow paths 80, the parallel flow path 80 in which the inlet 81 of the parallel flow path 80 is farthest from the inflow port 71 is particularly referred to as a farthest flow path 88. The plurality of parallel channels 80 includes a nearest channel 84 and a farthest channel 88. The fins 73 are arranged in the internal space 74 so that the pressure loss from the inlet 71 to the inlet 81 of the farthest flow path 88 is smaller than the pressure loss of the latest flow path 84. That is, the pressure difference between the refrigerant pressure at the inlet 71 and the refrigerant pressure at the inlet 81 of the farthest flow path 88 is smaller than the refrigerant pressure difference at the inlet 81 and outlet 82 of the latest flow path 84. It has become.

  FIG. 11 is a graph showing the pressure loss of the refrigerant path from the inlet 71 to the outlet 72 via the closest flow path 84. FIG. 12 is a graph showing the pressure loss in the refrigerant path from the inlet 71 to the outlet 72 via the farthest flow path 88. 11 and 12 indicate the positions of the inlet 71, the inlet 81 of the parallel channel 80, the outlet 82 of the parallel channel 80, and the outlet 72, respectively. The vertical axis indicates the path pressure loss ΔP with the inlet 71 as a reference.

  As described above, the path 76 communicating with the inlet 81 of the parallel flow path 80 and the path 78 communicating with the outlet 82 of the parallel flow path 80 have a cross-sectional area larger than the cross-sectional area of the parallel flow path 80. Therefore, as shown in FIGS. 11 and 12, the degree of increase in pressure loss from the inlet 71 to the inlet 81 is relatively small, and the degree of increase in pressure loss from the inlet 81 to the outlet 82 is large. The degree of increase in pressure loss up to the outlet 72 is small.

  A pressure loss ΔP1 shown in FIG. 11 indicates a pressure difference between the inlet 81 and the outlet 82 of the nearest flow path 84. That is, the pressure loss ΔP1 indicates the pressure loss of the latest flow path 84. The pressure loss ΔP1 indicates the total value of the pressure loss due to the sudden reduction at the inlet 81 of the channel 84, the pressure loss in the path from the inlet 81 to the outlet 82, and the pressure loss due to the sudden expansion at the outlet 82. A pressure loss ΔP <b> 2 illustrated in FIG. 12 indicates a pressure loss in a path from the inlet 71 to the inlet 81 of the farthest flow path 88. As shown in FIGS. 11 and 12, the pressure loss ΔP <b> 2 from the inlet 71 to the inlet 81 of the farthest flow path 88 is smaller than the pressure loss ΔP <b> 1 of the nearest flow path 84.

  By defining the pressure loss of the refrigerant path in the cooler 32 in this manner, the refrigerant flowing into the path 76 from the inlet 71 is positioned in the innermost portion of the path 76 without passing through the parallel flow path 80. Can reach the inlet 81 of the farthest flow path 88. Among the plurality of parallel flow paths 80, the pressure loss from the inlet 71 to the inlet 81 is the smallest in the latest flow path 84, and the pressure loss from the inlet 71 to the inlet 81 is the farthest. This is a flow path 88. Other refrigerant reaches the inlet 81 of the farthest flow path 88 before a part of the refrigerant that has flowed into the internal space 74 from the inflow port 71 reaches the outlet 82 of the latest flow path 84.

  The path 76 has a header function for each parallel flow path 80. Each parallel flow path 80 including the latest flow path 84 and the farthest flow path 88 functions as a branch pipe branched from the path 76. Therefore, the refrigerant that has flowed into the path 76 from the inlet 71 reaches the innermost part of the path 76, can improve the uniformity of the refrigerant flow rate through each parallel flow path 80, and the refrigerant flowing into each parallel flow path 80. The flow can be made uniform easily.

  By supplying a new refrigerant over the entire cooler 32, the heat source can be uniformly cooled in the entire cooler 32. It can be avoided that a local refrigerant flow shortage occurs in a part of the cooler 32 and the cooling capacity becomes insufficient, and variation in the cooling efficiency of the heat source can be suppressed. Therefore, heat transfer from the heat generation source to the refrigerant can be performed efficiently, so that the cooling capacity of the heat generation source by the cooler 32 can be improved.

  When the EV device 31 is cooled in the above-described air conditioner operation mode, the cooling is performed effectively using forced convection heat transfer. On the other hand, when the EV device 31 is cooled in the heat pipe operation mode, the latent heat is effectively used, that is, cooling using boiling heat transfer is performed. Therefore, in the heat pipe operation mode, the flow rate of the refrigerant passing through the cooler 32 is reduced to less than half compared to the air conditioner operation mode. Even when the flow rate of the refrigerant greatly increases / decreases in this way, by adopting the configuration of the cooler 32 of the present embodiment, the refrigerant is spread from the inlet side to the far side of the path 76, and the refrigerant is supplied to the entire cooler 32. Since it can supply, a refrigerant | coolant can be uniformly flowed through each parallel flow path 80. FIG. Since the EV device 31 can be reliably cooled with a small amount of refrigerant, the cooler 32 can be reduced in size.

FIG. 9 shows the ground 60. In the vertical direction perpendicular to the ground 60, the inflow port 71 is disposed relatively downward, and the outflow port 72 is disposed relatively upward. The paths 76 and 78 extend along the horizontal direction. The inlet 81 of the parallel flow path 80 is disposed below the outlet 82 of the parallel flow path 80. Therefore, the refrigerant flowing in the parallel flow path 80 flows upward with respect to the ground 60. Assuming that the altitude difference between the inlet 81 and the outlet 82 of the parallel flow path 80 is H (unit: m), the pressure of the refrigerant to rise in the parallel flow path 80 from the inlet 81 to the outlet 82 is ρgH (unit: Pa). ). Here, ρ is the density of the refrigerant (unit: kg / m ³ ), and g is the acceleration of gravity (unit: m / s ² ).

  By defining the arrangement of the inlet 81 and outlet 82 of the parallel flow path 80 in the height direction as described above, the refrigerant flowing into the parallel flow path 80 from the inlet 81 reaches the outlet 82 as described above. In addition to the pressure loss ΔP2, the pressure of ρgH is required. That is, when ΔP2 is compared with the sum of ΔP1 and ρgH, if ΔP2 is smaller, the refrigerant flows evenly from the path 76 to all the parallel flow paths 80. Since the difference between (ΔP1 + ρgH) and ΔP2 can be further increased by adding ρgH, the refrigerant flow to each parallel flow path 80 can be made more uniform, and the cooling capacity of the cooler 32 can be further improved. Can do. For example, the height difference H between the inlet 81 and the outlet 82 and the interval between the adjacent fins 73 may be set so that the pressure loss of the parallel flow path 80 becomes smaller than ρgH.

  More desirably, the pressure loss from the inlet 71 to the inlet 81 of the farthest flow path 88 (the pressure loss ΔP2 described above) is smaller than the refrigerant pressure for flowing from the inlet 81 to the outlet 82 of the parallel flow path 80. Thus, the altitude difference H is set. That is, the cooler 32 is arranged so that the height difference H satisfying ρgH> ΔP2 can be defined. In this way, no matter how the cross-sectional area of each parallel flow path 80 is defined by the arrangement of the fins 73, the sum of ΔP1 and ρgH is always larger than ΔP2. Therefore, since the refrigerant can be surely spread to the innermost part of the path 76 and the flow of the refrigerant to each parallel flow path 80 can be made uniform, the cooling capacity of the cooler 32 can be further improved.

[Modification of Cooler 32]
In the cooler 32 illustrated in FIG. 9, the inflow port 71 and the outflow port 72 are disposed on the diagonal line of the rectangular casing 70, but the configuration is not limited thereto. FIG. 13 is a schematic diagram illustrating the configuration of the cooler 32 of the second example. For example, as illustrated in FIG. 13, the inflow port 71 and the outflow port 72 may be disposed on the same side of the housing 70. For example, the inflow port 71 and the outflow port 72 may be arranged at the apex adjacent to each other on the short side of the rectangular casing 70 so that the inflow port 71 is located below the outflow port 72.

  The flow direction of the refrigerant at the inflow port 71 and the outflow port 72 is not limited to the horizontal direction parallel to the ground surface 60. FIG. 14 is a schematic diagram showing the configuration of the cooler 32 of the third example. For example, as shown in FIG. 14, the flow direction of the refrigerant at the inflow port 71 and the outflow port 72 may be an upward direction. The inflow port 71 and the outflow port 72 may be arranged so that the center of the refrigerant flow flowing through the inflow port 71 and the center of the refrigerant flow flowing through the outflow port 72 are on the same line.

  If the above-described magnitude relationship between the pressure loss ΔP1 and the pressure loss ΔP2 can be reliably defined, the arrangement of the inlet 71 and the outlet 72 with respect to the housing 70 and the inlet 71 and the outlet 72 are routed. The flow direction of the refrigerant may be arbitrarily determined. However, when the inflow port 71 is provided on the upper side with respect to the outflow port 72, a part of the refrigerant flowing into the internal space 74 from the inflow port 71 flows through the latest flow path 84 by the action of gravity, and as a result. Then, the refrigerant flowing through each parallel flow path 80 becomes non-uniform, and dryout occurs locally in the internal space 74, resulting in a decrease in cooling capacity. Therefore, it is desirable that the inflow port 71 is arranged at the same height or lower than the outflow port 72. When the cooling device 1 is mounted on the vehicle 1000, the cooler 32 is provided so that the positional relationship in the height direction between the inflow port 71 and the outflow port 72 can always be maintained even when the vehicle 1000 is traveling regardless of the road surface gradient. It is desirable to design.

  The housing 70 is not limited to the configuration extending in the vertical direction perpendicular to the ground 60. FIG. 15 is a schematic diagram illustrating the configuration of the cooler 32 of the fourth example. For example, as shown in FIG. 15, the housing 70 may be arranged so as to extend along a direction that forms an acute angle θ with respect to the horizontal direction.

  FIG. 16 is a schematic diagram showing the configuration of the cooler 32 of the fifth example. FIG. 17 is a schematic cross-sectional view of the cooler 32 along the line XVII-XVII shown in FIG. As shown in FIGS. 16 and 17, the housing 70 may be disposed so as to extend along a horizontal direction parallel to the ground 60. In this case, as clearly shown in FIG. 16, an inflow port 71 is provided so that the refrigerant rises from below the casing 70 and flows into the internal space 74, and the refrigerant further rises from above the casing 70. An outlet 72 may be provided so as to flow out from the internal space 74.

  The outer shape of the housing 70 is not limited to the rectangular plate shape. FIG. 18 is a schematic diagram illustrating the configuration of the cooler 32 of the sixth example. For example, the housing 70 may have a trapezoidal outer shape shown in FIG. 18 or may have any other shape.

  In the embodiments described so far, the cooling device 1 that cools the electric device mounted on the vehicle has been described using the EV device 31 as an example. The electric device is not limited to the exemplified electric device such as an inverter and a motor generator as long as it is an electric device that generates heat at least by operation, and may be any electric device. When there are a plurality of electrical devices to be cooled, it is desirable that the plurality of electrical devices have a common temperature range to be cooled. The target temperature range for cooling is a temperature range suitable as a temperature environment for operating the electrical equipment.

  Furthermore, the heat generation source cooled by the cooling device 1 of the present invention is not limited to an electric device mounted on a vehicle, and may be an arbitrary device that generates heat, or a part that generates heat from an arbitrary device.

  Although the embodiment of the present invention has been described as above, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The cooling device of the present invention is an electrical device using a vapor compression refrigeration cycle for cooling the interior of a vehicle such as a hybrid vehicle, a fuel cell vehicle, and an electric vehicle equipped with electrical devices such as a motor generator and an inverter. It can be applied particularly advantageously to cooling.

  DESCRIPTION OF SYMBOLS 1 Cooling device, 10 Vapor compression refrigeration cycle, 12 Compressor, 14, 15, 18 Heat exchanger, 16 Expansion valve, 21-27, 34, 36, 36a, 36b Refrigerant passage, 28 Flow control valve, 30 Cooling part , 31 EV equipment, 32 cooler, 40 gas-liquid separator, 41 pump, 51 communication path, 52 switching valve, 54, 58 check valve, 60 ground, 70 housing, 71 inlet, 72 outlet, 73 fin 74 internal space, 76, 78 path, 80 parallel flow path, 81 inlet, 82 outlet, 84 nearest flow path, 88 farthest flow path, 1000 vehicles.

Claims (7)

A cooling device for cooling a heat source,
A compressor for compressing the refrigerant;
A heat exchanger for exchanging heat between the refrigerant and outside air;
A cooler that cools the heat source using the refrigerant;
A first passage for flowing the refrigerant discharged from the compressor to the cooler via the heat exchanger;
A second passage for circulating the refrigerant between the heat exchanger and the cooler without applying power when the compressor is stopped;
A switching valve for switching between the communication of the first passage and the communication of the second passage,
The cooler includes a housing that defines an internal space, an inflow port through which the refrigerant flows into the internal space, an outflow port through which the refrigerant flows out from the internal space, and a plurality of fins provided in the internal space. Have
The fin divides the internal space into a plurality of parallel flow paths, and the refrigerant flows in the internal space from the inlet to the outlet through any of the plurality of parallel flow paths,
The plurality of parallel flow paths includes a nearest flow path where an inlet of the parallel flow path is closest to the inlet, and a farthest flow path where the inlet of the parallel flow path is farthest from the inlet,
The cooling device in which the pressure loss of the path from the inlet to the inlet of the farthest flow path is smaller than the pressure loss of the nearest flow path.   The cooling device according to claim 1, wherein an inlet of the parallel flow path is disposed below an outlet of the parallel flow path.   The height difference between the inlet and outlet of the parallel flow path is such that the product of the refrigerant density, gravitational acceleration and the height difference is larger than the pressure loss of the path from the inlet to the inlet of the farthest flow path. The cooling device according to claim 2, which is defined as follows.   The cooling device according to claim 1, wherein the inflow port and the outflow port are disposed on a diagonal line of the housing.   The cooling device according to claim 1, wherein the inflow port and the outflow port are disposed on the same side of the housing.   The said inflow port and the said outflow port are arrange | positioned so that the center of the flow of the refrigerant | coolant which flows through the said inflow port and the center of the flow of the said refrigerant | coolant which flows through the said outflow port may be on the same line. Item 4. The cooling device according to Item 3. A reservoir for storing the liquid refrigerant condensed in the heat exchanger;
The cooling apparatus in any one of Claims 1-6 provided with the pump which transfers the said refrigerant | coolant to the said cooler from the said liquid storage device.

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