JP2014088997A - Cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device capable of efficiently cooling a heating source with low power.SOLUTION: A cooling device 1 cools a heating source using a refrigerant and includes: a heat exchanger 14 which conducts heat exchange between the refrigerant and outer air; a cooling part 30 which cools the heating source using the refrigerant; refrigerant passages 22, 33 to 36 for circulating the refrigerant between the heat exchanger 14 and the cooling part 30; a first check valve 62 and a second check valve 64 which are provided in the refrigerant passage leading from the heat exchanger 14 to the cooling part 30 and are connected in series; and a heating part 80 which applies heat to the refrigerant in the refrigerant passage 34 between the first check valve 62 and the second check valve 64.

Description

  The present invention relates to a cooling device, and more particularly to a cooling device that cools a heat generation source using a refrigerant.

  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, Japanese Patent Application Laid-Open No. 2007-69733 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2005-2005). -90862 (patent document 2)).

  On the other hand, various technologies related to a cooler for cooling a heating element have been proposed (for example, Japanese Patent Laid-Open No. 9-23081 (Patent Document 3), Japanese Patent Laid-Open No. 2001-168256 (Patent Document 4), and Japanese Patent Laid-Open No. 2008-253057. No. (Patent Document 5)).

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

  In the cooling systems disclosed in Patent Documents 1 and 2, it is necessary to operate the compressor in order to circulate the refrigerant in the vapor compression refrigeration cycle. In addition, the refrigerant is supplied to the heating element to cool the heating element. Therefore, it is necessary to drive the pump at all times. Since external power is required for the circulation of the refrigerant, there is a problem that the power cost increases.

  The present invention has been made in view of the above problems, and a main object thereof is to provide a cooling device that can cool a heat source efficiently with low power.

  A cooling device according to the present invention is a cooling device that cools a heat generation source using a refrigerant, a heat exchanger that exchanges heat between the refrigerant and outside air, and a cooling unit that cools the heat generation source using the refrigerant, A refrigerant passage that circulates the refrigerant between the heat exchanger and the cooling section, and a first check valve and a second check valve that are provided in a refrigerant passage from the heat exchanger to the cooling section and connected in series. And a heating unit for applying heat to the refrigerant in the refrigerant passage between the first check valve and the second check valve.

  In the cooling device, the heating unit itself may generate heat. Or the said cooling device may be provided with the gaseous-phase refrigerant | coolant supply path for supplying a refrigerant | coolant to the heating part from the exit side of a cooling part, and the on-off valve which opens and closes a gaseous-phase refrigerant | coolant supply path.

Preferably, in the cooling device, the cooling unit is disposed above the heat exchanger.
Preferably, the cooling device further includes a liquid accumulator that stores liquid refrigerant condensed by the heat exchanger, and the liquid refrigerant flows from the accumulator through the first check valve.

  Preferably, in the cooling device, the heat exchanger is a heat exchanger included in the vapor compression refrigeration cycle, and the vapor compression refrigeration cycle includes a compressor, and the heat exchanger and the cooling unit are stopped while the compressor is stopped. Circulate the refrigerant between the two.

  According to the cooling device of the present invention, the heat source can be efficiently cooled with low power.

It is the schematic which shows the structure of the vehicle to which a cooling device is applied. 2 is a schematic diagram illustrating a configuration of a cooling device according to Embodiment 1. FIG. It is a schematic diagram which shows the structure of a cooler. 3 is a flowchart illustrating an operation of circulating a refrigerant in the cooling device according to the first embodiment. 6 is a schematic diagram illustrating a configuration of a cooling device according to Embodiment 2. FIG. 6 is a flowchart illustrating an operation of circulating a refrigerant in the cooling device according to the second embodiment. 6 is a schematic diagram illustrating a configuration of a cooling device according to Embodiment 3. FIG. 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.

  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.

(Embodiment 1)
[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 illustrating a configuration of the cooling device 1 according to the first embodiment. The cooling device 1 is mounted on the vehicle 1000 and used to cool equipment mounted on the vehicle 1000 such as the drive unit 200. As shown in FIG. 2, the cooling device 1 includes a heat exchanger 14 and a cooling unit 30, and circulates the refrigerant between the heat exchanger 14 and the cooling unit 30, thereby heat from the heat source to the refrigerant. To cool the heat source.

  The cooling unit 30 includes an electric vehicle (EV) device that is an electric device mounted on the electric vehicle, and a cooler 32 (described later) through which the refrigerant flows. The EV device is an example of a heat source that is cooled by the cooling device 1 using a refrigerant. The EV device 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.

  The heat exchanger 14 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 14. The heat exchanger 14 performs heat exchange between the refrigerant and the outside air, and heats the refrigerant gas evaporated by receiving heat transfer from the heat generation source in the cooling unit 30 to the external medium in an isobaric manner, and the refrigerant liquid and To do. The vapor-phase refrigerant evaporated in the cooling unit 30 is radiated to the surroundings and cooled by heat exchange between the cooling air and the refrigerant in the heat exchanger 14.

  The cooling air may be supplied to the heat exchanger 14 by natural ventilation generated by traveling of the vehicle 1000. Alternatively, the cooling air may be supplied to the heat exchanger 14 by forced ventilation from an outside 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, rotates to generate an air flow, and supplies cooling air to the heat exchanger.

  The cooling device 1 also includes a gas-liquid separator 40, a first check valve 62, and a second check valve 64. The gas-liquid separator 40, the first check valve 62, and the second check valve 64 are disposed on the refrigerant path from the heat exchanger 14 toward the cooling unit 30, and are connected in series. The cooling device 1 includes a refrigerant passage 22 that communicates the heat exchanger 14 and the gas-liquid separator 40, a refrigerant passage 33 that communicates the gas-liquid separator 40 and the first check valve 62, and a first check valve. 62, a refrigerant passage 34 that communicates with the second check valve 64, a refrigerant passage 35 that communicates between the second check valve 64 and the cooling unit 30, and a refrigerant passage that communicates between the cooling unit 30 and the heat exchanger 14. 36.

  The refrigerant passages 22 and 33 to 35 are refrigerant passages from the heat exchanger 14 toward the cooling unit 30. The refrigerant passes from the refrigerant passages 22, 33 to 35, the gas-liquid separator 40, the first check valve 62 and the second check valve 64 toward the inlet of the cooling unit 30 from the outlet of the heat exchanger 14. Flowing. The refrigerant passage 36 is a refrigerant passage from the cooling unit 30 toward the heat exchanger 14. The refrigerant flows from the outlet of the cooling unit 30 toward the inlet of the heat exchanger 14 via the refrigerant passage 36.

  The cooling device 1 is configured by connecting a heat exchanger 14, a gas-liquid separator 40, a first check valve 62, a second check valve 64, and a cooling unit 30 through refrigerant passages 22, 33 to 36. The refrigerant passages 22, 33 to 36 are passages for circulating the refrigerant between the heat exchanger 14 and the cooling unit 30. In addition, as a refrigerant | coolant which circulates through the cooling device 1, hydrocarbons, such as a carbon dioxide, a propane, and isobutane, ammonia, CFCs, or water can be used, for example.

  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. A refrigerant passage 22 and a refrigerant passage 33 are connected to the gas-liquid separator 40.

  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 equipment can be stabilized.

  The refrigerant liquid condensed in the heat exchanger 14 is supplied to the gas-liquid separator 40 through the refrigerant passage 22. The 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 been subjected to gas-liquid separation flows out of the gas-liquid separator 40 via the refrigerant passage 33. The end of the refrigerant passage 33 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.

  Inside the gas-liquid separator 40, the refrigerant liquid accumulates on the lower side and the refrigerant vapor accumulates on the upper side. An end portion of the refrigerant passage 33 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 liquid is sent out of the gas-liquid separator 40 from the bottom side of the gas-liquid separator 40 via the refrigerant passage 33. As a result, the gas-liquid separator 40 can reliably separate the gas-phase refrigerant and the liquid-phase refrigerant.

  A refrigerant passage 33 and a refrigerant passage 34 are connected to the first check valve 62. The first check valve 62 allows the flow of the refrigerant from the refrigerant passage 33 toward the refrigerant passage 34 and prohibits the reverse flow of the refrigerant. The refrigerant passage 34 and the refrigerant passage 35 are connected to the second check valve 64. The second check valve 64 allows the flow of the refrigerant from the refrigerant passage 34 toward the refrigerant passage 35 and prohibits the reverse flow. By providing the first check valve 62 and the second check valve 64, the flow of the refrigerant liquid from the gas-liquid separator 40 toward the cooling unit 30 is allowed, and the gas-liquid separator 40 side from the cooling unit 30 side is allowed. Back flow of refrigerant into the is prohibited.

  A heating unit 80 is disposed adjacent to the refrigerant passage 34 between the first check valve 62 and the second check valve 64. The heating unit 80 is a device that generates heat, such as an electric heater or an induction heating device. The heating unit 80 applies heat to the refrigerant in the refrigerant passage 34 to evaporate the refrigerant liquid in the refrigerant passage 34.

  FIG. 3 is a schematic diagram showing the configuration of the cooler 32. The cooling unit 30 includes a cooler 32 that performs heat exchange between the heat generation source and the refrigerant when the refrigerant flows therein. As shown in FIG. 3, the cooler 32 has a housing 70.

  The casing 70 is formed in a hollow shape and defines an internal space therein. The casing 70 of the cooler 32 has a rectangular plate shape. The cooler 32 also has a refrigerant inlet 71 and a refrigerant outlet 72. The refrigerant inlet 71 and the refrigerant outlet 72 are arranged on a rectangular diagonal formed by the housing 70. That is, the refrigerant inlet 71 is provided at the position of one vertex of the rectangle, and the refrigerant outlet 72 is provided at the position of the other vertex that is not adjacent to the one vertex.

  The refrigerant inlet 71 and the refrigerant outlet 72 communicate the inside and the outside of the housing 70. The refrigerant passage 35 is connected to the refrigerant inlet 71, and the refrigerant passage 36 is connected to the refrigerant outlet 72. Thereby, the refrigerant inlet 71 has a function as an inlet through which the refrigerant flows into the internal space of the housing 70, and the refrigerant outlet 72 has a function as an outlet through which the refrigerant flows out of the housing 70. The refrigerant supplied to the cooling unit 30 flows from the refrigerant passage 35 through the refrigerant inlet 71 into the internal space inside the housing 70 of the cooler 32. The refrigerant exchanges heat with the EV device while flowing in the housing 70 toward the refrigerant outlet 72. The refrigerant further flows out of the housing 70 via the refrigerant outlet 72 and flows into the refrigerant passage 36.

  A plurality of protrusions 75 are formed on the outer surface of the housing 70. The protrusion 75 is a pedestal for fixing the heat generating chip, and is provided for the purpose of insulating the heat generating chip and relaxing thermal expansion.

  The refrigerant inlet 71 is disposed relatively downward with respect to the casing 70, and the refrigerant outlet 72 is disposed relatively upward. The refrigerant inlet 71 and the refrigerant outlet 72 have a height difference, and the refrigerant inlet 71 that functions as an inflow port is disposed lower than the refrigerant outlet 72 that functions as an outflow port. The rectangular plate-shaped casing 70 extends in a direction inclined with respect to the horizontal plane, and the refrigerant inlet 71 and the refrigerant outlet 72 also extend along a direction inclined with respect to the horizontal plane.

  With this configuration, the flow of the refrigerant flowing through the cooling unit 30 is defined. That is, the vapor phase refrigerant that is vaporized by receiving heat from the EV device inside the casing 70 has a lower specific gravity than the liquid phase refrigerant, and therefore flows upward with respect to the horizontal plane and rises in the internal space of the casing 70. To do. If the inflow port is disposed at a relatively low position with respect to the housing 70 and the outflow port is disposed at a relatively high position with respect to the housing 70, it is newly supplied from the inflow port to the inside of the housing 70. The refrigerant does not hinder the upward flow of the gas-phase refrigerant vaporized inside the housing 70. Therefore, the refrigerant flowing inside the housing 70 can flow upward smoothly with respect to the horizontal plane.

  By providing an inflow port so that the refrigerant flows in from below the housing 70 and an outflow port so that the refrigerant flows out from above the housing 70, the refrigerant can flow smoothly inside the housing 70. it can. Thereby, it is possible to avoid the occurrence of dryout in which the gas-phase refrigerant locally accumulates in the internal space of the housing 70 and insufficient cooling capacity, and to efficiently transfer heat from the heat generation source to the refrigerant. it can. Since a new refrigerant can be continuously supplied to the housing 70 via the inflow port, a decrease in the cooling performance of the heat source can be suppressed, and the cooling capacity of the heat source by the cooler 32 can be improved.

  The cooling unit 30 is provided in the cooler 32 so as to have a structure capable of exchanging heat between the EV device 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 housing 70 is in direct contact with the housing of the EV device. The cooler 32 has a portion adjacent to the housing of the EV device. In this portion, heat exchange is possible between the refrigerant flowing through the cooler 32 and the EV device. Since the EV device is disposed outside the cooler 32, the EV device does not interfere with the flow of the refrigerant flowing through the cooler 32. Therefore, an increase in pressure loss of the refrigerant circulating in the cooling device 1 can be suppressed.

  FIG. 2 illustrates the ground G. In the vertical direction perpendicular to the ground G, the cooling unit 30 is disposed above 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 on the upper side and the heat exchanger 14 is disposed on the lower side. The heat exchanger 14 and the gas-liquid separator 40 are disposed at a position lower than the cooling unit 30.

  In order to circulate the refrigerant through a loop heat pipe having the heat exchanger 14 as a condenser and the cooling unit 30 as an evaporator, the vapor-phase refrigerant evaporated in the cooling unit 30 is moved to the heat exchanger 14 for heat exchange. It is necessary to form a cycle in which the liquid-phase refrigerant condensed in the vessel 14 is returned to the cooling unit 30 to perform steady heat transfer. In the configuration shown in FIG. 2 in which the cooling unit 30 is disposed at a position higher than the heat exchanger 14, liquid reflux from the heat exchanger 14 to the cooling unit 30 due to the action of gravity cannot be performed. However, in the cooling device 1 of the present embodiment, the first check valve is provided in the refrigerant passage 34 through which the liquid refrigerant flows from the gas-liquid separator 40 that stores the refrigerant liquid condensed in the heat exchanger 14 to the cooling unit 30. 62, the second check valve 64, and the heating unit 80 are provided so that the refrigerant liquid can be recirculated from the heat exchanger 14 to the cooling unit 30.

[Operation of cooling device 1]
FIG. 4 is a flowchart showing an operation of circulating the refrigerant in the cooling device 1 according to the first embodiment. With reference to FIG. 2 and FIG. 4, the operation of the cooling device 1 of the first embodiment will be described. A two-dot chain line shown in FIG. 2 indicates a full water line WL. The refrigerant circulating through the cooling device 1 is in a liquid phase state on the ground G side with respect to the full water line WL. The refrigerant from the heat exchanger 14 toward the cooling unit 30 is in a liquid phase, and the refrigerant passages 33, 34, and 35 are filled with the refrigerant liquid in a steady state. The refrigerant evaporates by being heated by the cooling unit 30, and the refrigerant enters a gas phase state at the outlet of the cooling unit 30, that is, the refrigerant outlet 72 shown in FIG.

  In a state where the refrigerant liquid is filled in the refrigerant passage 34, the heating unit 80 is started in step (S10), and the heating unit 80 starts to generate heat. Subsequently, in step (S20), the refrigerant liquid in the refrigerant passage 34 between the first check valve 62 and the second check valve 64 is partially vaporized by receiving heat from the heating unit 80, and volume expands. . At this time, since the refrigerant cannot flow back to the refrigerant passage 33 side via the first check valve 62, a driving force for pushing up the refrigerant liquid in the refrigerant passage 34 is generated by the vaporized refrigerant. Accordingly, a refrigerant flow that passes through the second check valve 64 toward the refrigerant passage 35 from the refrigerant passage 34 is generated.

  The refrigerant passage 34 has a first reverse passage so that the flow of the vaporized refrigerant vapor going up in the refrigerant passage 34 can be used for the flow from the refrigerant passage 34 to the refrigerant passage 35 through the second check valve 64. It is desirable that the position is gradually increased from the stop valve 62 toward the second check valve 64. Typically, as shown in FIG. 2, the refrigerant passage 34 extends vertically, the first check valve 62 is on the lower side, and the second check valve 64 is on the upper side. It is desirable to arrange.

  Further, it is desirable that the heating unit 80 is disposed so as to heat a position closer to the first check valve 62 of the refrigerant passage 34. By disposing the heating unit 80 closer to the first check valve 62, a larger amount of the refrigerant liquid can be transferred from the refrigerant passage 34 to the refrigerant passage 35 by the vaporized refrigerant. In order to make it easy to fill the refrigerant passage 34 with the liquid refrigerant, it is desirable to bring the first check valve 62 closer to the gas-liquid separator 40. That is, the length of the refrigerant passage 33 is preferably as small as possible. For example, the refrigerant passage 33 may be shorter than the refrigerant passage 35, the refrigerant passage 33 may be shorter than the refrigerant passage 34, or the refrigerant passage 22. Alternatively, the refrigerant passage 33 may be formed shorter.

  Next, in step (S30), it is determined whether or not the gaseous refrigerant has passed through the second check valve 64. If it is determined as NO in step (S30) and it is determined that the gas-phase refrigerant has not yet passed through the second check valve 64, the heating and vaporization of the refrigerant in the refrigerant passage 34 is continued. If it is determined as YES in step (S30) and it is determined that the gas-phase refrigerant has passed through the second check valve 64, it is determined that almost no liquid refrigerant is present in the refrigerant passage 34, and the process proceeds to step (S40). The heating unit 80 is stopped and the heat generation of the heating unit 80 is stopped. At this time, when the dryness is equal to or higher than a predetermined value, the liquid amount is equal to or lower than the predetermined value, or the amount of heat supplied to the heating unit 80 is equal to or higher than the predetermined value, the liquid refrigerant in the refrigerant passage 34 is obtained. It may be determined that is almost gone.

  By stopping the heat generation of the heating unit 80, the refrigerant in the refrigerant passage 34 does not receive heat from the heating unit 80. Therefore, the vaporized refrigerant is cooled by the surrounding liquid, condensed again, and returns to the liquid state. When the vaporized and expanded refrigerant is cooled, the volume of the refrigerant contracts and the pressure in the refrigerant passage 34 decreases. Therefore, the liquid refrigerant flows from the refrigerant passage 33 into the refrigerant passage 34 via the first check valve 62, and the amount of the refrigerant liquid in the refrigerant passage 34 increases. Subsequently, in step (S60), it is determined whether or not the refrigerant passage 34 between the first check valve 62 and the second check valve 64 is filled with the refrigerant liquid.

  If it is determined NO in step (S60) and it is determined that the refrigerant passage 34 is not yet full, the suction of the refrigerant liquid from the refrigerant passage 33 to the refrigerant passage 34 is continued. If YES is determined in step (S60) and it is determined that the refrigerant passage 34 is full, the control flow is returned, and the process returns to step (S10) again, and the heating of the heating unit 80 is resumed. By repeating this cycle, a refrigerant flow is formed which flows from the refrigerant passage 33 to the refrigerant passage 34 via the first check valve 62 and further to the refrigerant passage 35 via the second check valve 64. The

  The refrigerant flows from the refrigerant passage 35 to the cooler 32 of the cooling unit 30, and cools the EV device by absorbing heat from the EV device in the cooling unit 30. The heat exchange with the EV equipment heats the refrigerant and gradually evaporates while maintaining the constant pressure, thereby increasing the dryness of the refrigerant. In the cooling unit 30, the refrigerant is vaporized by the heat generated by the EV device and expands. Typically, in the cooling unit 30, the refrigerant is heated until all the refrigerant becomes dry saturated vapor and further becomes superheated vapor. Since the vaporized and volume-expanded refrigerant cannot return to the second check valve 64 side, it flows out from the cooling unit 30 to the refrigerant passage 36 and pushes out the liquid and gaseous refrigerant to the heat exchanger 14 side. As the refrigerant evaporates in the cooling unit 30, a refrigerant flow from the cooling unit 30 toward the heat exchanger 14 through the refrigerant passage 36 is formed.

  The refrigerant that has flowed into the heat exchanger 14 is condensed (liquefied) by being radiated and cooled to the surroundings when being circulated through the tube of the heat exchanger 14 due to vehicle running wind or ventilation from the fan. 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 liquid-phase refrigerant condensed in the heat exchanger 14 flows to the gas-liquid separator 40 via the refrigerant passage 22, and the liquid-phase refrigerant is stored in the gas-liquid separator 40. The refrigerant liquid is supplied from the gas-liquid separator 40 to the refrigerant passage 33, and further passes through the first check valve 62 and flows into the refrigerant passage 34 according to the cycle shown in FIG.

  In addition, the heat source cooled in the cooling unit 30 may be a device that is continuously operated, or may be a device that is operated intermittently by repeatedly starting and stopping. When the heat source is operated intermittently, the refrigerant liquid amount in the cooler 32, the surface temperature of the cooler 32, the pressure in the cooler 32, or the like is monitored, and any value is used as a parameter. The on / off of the heat source may be appropriately controlled. A sight glass that can monitor the state of the refrigerant in the cooler 32 from the outside may be installed, and the sight glass preferably extends along the direction in which the cooler 32 extends. A part of the refrigerant passage 35 may constitute the sight glass.

  The cooling device 1 according to Embodiment 1 described above is arranged in series on an annular path for circulating the refrigerant between the heat exchanger 14 and the cooling unit 30 and a path from the heat exchanger 14 toward the cooling unit 30. The first check valve 62 and the second check valve 64, and the heating unit 80 for heating the refrigerant in the refrigerant passage 34 between the first check valve 62 and the second check valve 64 are provided. In the cooling device 1 configured as described above, the heating unit 80 is controlled according to the cycle shown in FIG. 4 and the heating unit 80 is repeatedly turned on and off, whereby the volume expansion and contraction of the refrigerant are repeated. Accordingly, the transfer of the refrigerant from the refrigerant passage 34 to the refrigerant passage 35 and the transfer of the refrigerant from the refrigerant passage 33 to the refrigerant passage 34 are repeated, and as a result, the liquid refrigerant is transferred from the heat exchanger 14 to the cooling unit 30. It is transferred continuously.

  Therefore, even if the top heat type configuration in which the cooling unit 30 for heating the refrigerant is arranged above the heat exchanger 14, the refrigerant circulation flow is not required for the circulation of the refrigerant without requiring a compressor or a liquid pump. Can be formed. Since a new refrigerant can be continuously supplied to the cooling unit 30 with low power, the cooling capacity of the heat source in the cooling unit 30 can be made permanent. Therefore, it can be avoided that the refrigerant in the cooling unit 30 is deficient and the cooling capacity is insufficient, and the heat generation source can be efficiently cooled. By enabling the cooling of the heat source with low power, when the cooling device 1 is mounted on a vehicle, the fuel consumption of the vehicle 1000 can be improved and the driving conditions of the vehicle 1000 can be further improved.

  Since the circulation of the refrigerant can be caused by the pump action using the heat source between the first check valve 62 and the second check valve 64, it is not necessary to install a compressor or a pump, and the cooling device 1 The device cost can be reduced and the size can be reduced. In addition, since quality defects due to malfunctions of devices such as compressors and pumps can be avoided, the reliability of the cooling device 1 can be improved, and the costs associated with countermeasures for quality defects can be reduced.

(Embodiment 2)
[Configuration of Cooling Device 1]
FIG. 5 is a schematic diagram illustrating a configuration of the cooling device 1 according to the second embodiment. The cooling device 1 of the second embodiment shown in FIG. 5 has the same configuration as that of the first embodiment shown in FIG. However, the cooling device 1 of the second embodiment is different from the cooling device 1 of the first embodiment in the configuration of the heating unit 80.

  Specifically, the cooling device 1 of the second embodiment includes a gas-phase refrigerant supply path 82 for supplying a refrigerant from the outlet side of the cooling unit 30 to the heating unit 80. The gas-phase refrigerant supply path 82 communicates the refrigerant path 36 on the outlet side of the cooling unit 30 and the refrigerant path 34 between the first check valve 62 and the second check valve 64. The gas-phase refrigerant supply path 82 is a path through which the refrigerant heated and vaporized in the cooling unit 30 flows.

  As shown in FIG. 5, the heating unit 80 of the second embodiment shows a part of the piping system where the gas-phase refrigerant supply path 82 is connected to the refrigerant path 34. That is, unlike the first embodiment, the heating unit 80 of the second embodiment is not a device that generates heat, but has a configuration capable of supplying a high-temperature refrigerant to the refrigerant passage 34 from the outside. As the refrigerant receives heat from the heat generation source in the cooling unit 30, the refrigerant is entirely vaporized at the outlet of the cooling unit 30, and is typically in a state of high-temperature and high-pressure superheated steam. The superheated high-temperature gas-phase refrigerant is supplied to the refrigerant passage 34 via the gas-phase refrigerant supply path 82. As a result, the refrigerant vapor flows into the refrigerant passage 34, the refrigerant liquid in the refrigerant passage 34 is heated, and the refrigerant liquid in the refrigerant passage 34 is transferred to the refrigerant passage 35 via the second check valve 64. Force is generated.

  The cooling device 1 according to the second embodiment further includes an on-off valve 84. The on-off valve 84 is a valve that is provided in the gas-phase refrigerant supply path 82 and can be opened and closed. The on-off valve 84 opens and closes the gas-phase refrigerant supply path 82 by switching the opening and closing thereof. The on-off valve 84 may be a valve with a specification that can be switched between fully open and fully closed, and may be, for example, an electromagnetic valve. By opening the on-off valve 84, the outlet of the cooling unit 30 and the refrigerant passage 34 communicate with each other, and the high-temperature gas-phase refrigerant at the outlet of the cooling unit 30 flows to the refrigerant passage 34 through the gas-phase refrigerant supply passage 82. When the on-off valve 84 is closed, the gas-phase refrigerant supply path 82 is closed, and the outlet of the cooling unit 30 and the refrigerant passage 34 are disconnected.

[Operation of cooling device 1]
FIG. 6 is a flowchart showing an operation of circulating the refrigerant in the cooling device 1 according to the second embodiment. With reference to FIG. 5 and FIG. 6, the operation of the cooling device 1 of the second embodiment will be described.

  In a state where the refrigerant passage 34 is filled with the refrigerant liquid, in step (S110), the on-off valve 84 is opened, and the refrigerant passage 36 and the refrigerant passage 34 at the outlet of the cooling unit 30 via the gas-phase refrigerant supply passage 82 are connected. A communication path is formed. Subsequently, in step (S120), the refrigerant vapor evaporated by the cooling unit 30 in the refrigerant passage 34 between the first check valve 62 and the second check valve 64 via the gas-phase refrigerant supply path 82. Supply.

  The refrigerant vapor supplied to the refrigerant passage 34 has a higher pressure than the refrigerant liquid filling the refrigerant passage 34. Therefore, the refrigerant vapor is sent from the gas-phase refrigerant supply path 82 to the refrigerant passage 34 and pushes the refrigerant liquid filled in the refrigerant passage 34 toward the second check valve 64 side. At this time, the liquid is transferred without transferring the vapor. Since the refrigerant cannot flow back to the refrigerant passage 33 via the first check valve 62, the refrigerant liquid in the refrigerant passage 34 is pushed up by the refrigerant supplied from the gas-phase refrigerant supply passage 82 to the refrigerant passage 34. Driving force is generated. In this way, the refrigerant flows from the refrigerant passage 34 through the second check valve 64 toward the refrigerant passage 35.

  The gas-phase refrigerant supply path 82 is preferably connected to a position closer to the first check valve 62 of the refrigerant path 34. By connecting the gas-phase refrigerant supply path 82 to the first check valve 62 side, the heating unit 80 is disposed closer to the first check valve 62, so that the refrigerant vapor supplied to the refrigerant passage 34 increases more. This amount of the refrigerant liquid can be transferred from the refrigerant passage 34 to the refrigerant passage 35.

  Next, in step (S130), it is determined whether the refrigerant liquid is flowing through the second check valve 64 or not. While the pressure of the refrigerant on the outlet side of the cooling unit 30 is higher than the pressure of the refrigerant liquid in the refrigerant passage 34, the refrigerant is transferred from the gas-phase refrigerant supply passage 82 to the refrigerant passage 34 by the refrigerant pressure difference, and the second reverse A driving force of the refrigerant flowing through the stop valve 64 is generated. When it is determined YES in step (S130) and it is determined that the refrigerant liquid is flowing through the second check valve 64, there is a pressure difference of the refrigerant, which drives the refrigerant in the refrigerant passage 34. Power is given. Therefore, the on-off valve 84 remains open, and the supply of refrigerant from the gas-phase refrigerant supply path 82 to the refrigerant path 34 is continued. When the temperature and pressure exceed the reference values, the on-off valve 84 may be closed.

  When it is determined NO in step (S130) and it is determined that the refrigerant liquid has stopped flowing through the second check valve 64, the pressure of the refrigerant in the gas-phase refrigerant supply path 82 and the refrigerant in the refrigerant path 34 are Since the pressure is equalized and the refrigerant cannot be pushed into the refrigerant passage 34, it is determined that the driving force is no longer applied to the refrigerant in the refrigerant passage 34. When the refrigerant in the gas-phase refrigerant supply path 82 and the refrigerant in the refrigerant path 34 are in an equilibrium state, the process proceeds to step (S140), the open / close valve 84 is closed, and the gas-phase refrigerant supply path 82 is closed. As a result, the gas-phase refrigerant supply path 82 does not communicate the refrigerant passage 36 at the outlet of the cooling unit 30 and the refrigerant passage 34.

  By switching the gas-phase refrigerant supply path 82 to the non-communication state, the flow of the refrigerant from the gas-phase refrigerant supply path 82 to the refrigerant passage 34 is stopped. Therefore, the refrigerant vapor transferred into the refrigerant passage 34 is cooled by the surrounding liquid, condensed, and returned to the liquid state. As a result, the volume of the refrigerant contracts and the pressure in the refrigerant passage 34 decreases. Therefore, the liquid refrigerant flows from the refrigerant passage 33 into the refrigerant passage 34 via the first check valve 62, and the amount of the refrigerant liquid in the refrigerant passage 34 increases. Subsequently, in step (S160), it is determined whether the refrigerant liquid is flowing through the first check valve 62 or not.

  If YES is determined in step (S160) and it is determined that the refrigerant liquid is flowing through the first check valve 62, the suction of the refrigerant liquid from the refrigerant passage 33 to the refrigerant passage 34 is continued as it is. If NO is determined in step (S160), and it is determined that the refrigerant liquid has stopped flowing through the first check valve 62, the refrigerant in the refrigerant passage 33 and the refrigerant in the refrigerant passage 34 are in an equilibrium state. Typically, it is determined that the refrigerant passage 34 has become full. It may be determined that the equilibrium state is reached based on temperature and pressure. In this case, the control flow is returned, and the process returns to step (S110) again, the on-off valve 84 is opened, and the supply of the high-temperature refrigerant to the refrigerant passage 34 is resumed. By repeating this cycle, a refrigerant flow is formed which flows from the refrigerant passage 33 to the refrigerant passage 34 via the first check valve 62 and further to the refrigerant passage 35 via the second check valve 64. The

  In the cooling device 1 of the second embodiment described above, it is possible to continuously transfer the liquid refrigerant from the heat exchanger 14 to the cooling unit 30 by repeatedly opening and closing the on-off valve 84 according to the cycle shown in FIG. become. Therefore, similarly to the first embodiment, even if the top heat type configuration in which the cooling unit 30 to which the refrigerant is heated is arranged above the heat exchanger 14, a liquid pump or the like is not required for circulation of the refrigerant. A circulating flow of refrigerant can be formed. Since a new refrigerant can be continuously supplied to the cooling unit 30 with low power, the cooling capacity of the heat source in the cooling unit 30 can be made permanent. Therefore, it can be avoided that the refrigerant in the cooling unit 30 is deficient and the cooling capacity is insufficient, and the heat generation source can be efficiently cooled.

  The refrigerant heated by the cooling unit 30 is supplied to the refrigerant passage 34, and a driving force for transferring the refrigerant is generated by the pressure of the supplied refrigerant. Using the energy of the refrigerant itself, the refrigerant liquid can be transferred from the refrigerant passage 34 to the refrigerant passage 35 through the second check valve 64. The heating unit 80 itself does not generate heat, and power for operating the heating unit 80 is only power for switching the opening / closing of the on-off valve 84. Since energy consumption in the heating unit 80 can be suppressed, the refrigerant can be transferred from the refrigerant passage 34 to the refrigerant passage 35 with lower power. Therefore, it is possible to provide the cooling device 1 with further power saving.

(Embodiment 3)
[Apparatus Configuration of Embodiment 3]
FIG. 7 is a schematic diagram illustrating a configuration of the cooling device 1 according to the third embodiment. In the third embodiment, the cooling device 1 having the configuration described in the first embodiment is incorporated in a vapor compression refrigeration cycle 10 for an air conditioner for performing a cooling operation, and the heat exchanger 14 shown in FIG. The heat exchanger included in the vapor compression refrigeration cycle 10 is used as one of the heat exchangers. In the example shown in FIG. 7, the heat exchanger 14 functions as a condenser of the vapor compression refrigeration cycle 10.

  As shown in FIG. 7, the vapor compression refrigeration cycle 10 is mounted on a 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 gas-liquid separator 40 is 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 during the operation of the vapor compression refrigeration cycle 10, discharges high-temperature and high-pressure gas-phase refrigerant into the refrigerant passage 21, and supplies the refrigerant to the vapor compression refrigeration cycle 10. Circulate.

  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 dissipate the superheated refrigerant gas compressed in the compressor 12 isothermally to an external medium to obtain a refrigerant liquid. The refrigerant is cooled by heat exchange with the cooling air in the heat exchangers 14 and 15, the temperature of the refrigerant decreases, and the refrigerant condenses (liquefies). The condenser fan 42 receives the driving force from the motor 44 and rotates to supply cooling air to the heat exchanger.

  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. The expansion valve 16 may be a temperature type expansion valve or an electric type expansion valve. 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 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. In the tube, the wet vapor refrigerant decompressed by the expansion valve 16 flows. The heat exchanger 18 absorbs the heat of vaporization when the mist refrigerant flowing in the tube evaporates (vaporizes) into a refrigerant gas from the surrounding air conditioning air introduced so as to come into contact with the heat exchanger 18. To do. The refrigerant evaporates by absorbing the heat of the air-conditioning air as latent heat of evaporation via the fins, becomes low-pressure high-temperature gas, and further absorbs sensible heat to become superheated steam. 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.

  In the heat exchanger 18, air-conditioning air that has been absorbed by the refrigerant and reduced in temperature is supplied to the vehicle interior, thereby cooling the vehicle interior. 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 vapor compression refrigeration cycle 10 also includes refrigerant passages 21 to 27. The refrigerant passage 21 is a passage through which the compressor 12 and the heat exchanger 14 are communicated and the refrigerant is circulated from the outlet of the compressor 12 to the inlet of the heat exchanger 14. The refrigerant passages 22 to 25 are passages for allowing the heat exchanger 14 and the expansion valve 16 to communicate with each other and allowing the refrigerant to flow from the outlet of the heat exchanger 14 to the inlet of the expansion valve 16. The refrigerant passage 26 is a passage through which the expansion valve 16 and the heat exchanger 18 are communicated, and the refrigerant flows from the outlet of the expansion valve 16 to the inlet of the heat exchanger 18. The refrigerant passage 27 is a passage through which the heat exchanger 18 and the compressor 12 are communicated and the refrigerant is circulated from the outlet of the heat exchanger 18 to the inlet of the compressor 12.

  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.

  Refrigerant passages 22 and 23 and a refrigerant passage 33 are connected to the gas-liquid separator 40. 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 refrigerant that has flowed out of the heat exchanger 14 is supplied to the gas-liquid separator 40 through the refrigerant passage 22. The refrigerant liquid that has been subjected to gas-liquid separation flows out of the gas-liquid separator 40 via the refrigerant passage 33. 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 gas-phase refrigerant flows out of the gas-liquid separator 40 and travels toward the heat exchanger 15.

  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. An end portion of the refrigerant passage 33 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 to the outside 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 33. 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 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 a refrigerant passage 22 extending from the outlet side of the heat exchanger 14 to the gas-liquid separator 40, and refrigerant vapor flows out of the gas-liquid separator 40. And a refrigerant passage 23 that passes through a flow rate adjusting valve 28 that will be described later, and a refrigerant passage 24 that is connected to the inlet side of the heat exchanger 15. The gas-phase refrigerant derived from the gas-liquid separator 40 is condensed by releasing heat to the surroundings in the heat exchanger 15 and being cooled.

  The refrigerant path flowing between the heat exchanger 14 and the heat exchanger 15 also includes refrigerant passages 33 to 35 communicating with the gas-liquid separator 40 and the cooling unit 30, the cooling unit 30, and the cooling unit 30. And a refrigerant passage 36 communicating with the refrigerant passage 24. The refrigerant liquid flows from the gas-liquid separator 40 to the cooling unit 30 via the refrigerant passages 33 to 35. 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 unit 30 includes an EV device 31 and a cooler 32. The inlet side of the cooler 32 is connected to the refrigerant passage 35, 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 that does not pass through the cooling unit 30. The refrigerant passages 33 to 35 that communicate the gas-liquid separator 40 and the cooling unit 30, the cooler 32 included in the cooling unit 30, and the refrigerant passage 36 that communicates the outlet side of the cooling unit 30 and the refrigerant passage 24. The other of the refrigerant paths connected in parallel between the gas-liquid separator 40 and the heat exchanger 15 is configured.

  The refrigerant passages 33 to 35 are refrigerant paths upstream of the cooling unit 30 (on the side close to the gas-liquid separator 40), and the liquid-phase refrigerant flows from the gas-liquid separator 40 to the cooling unit 30. It is a passage. The refrigerant passage 36 is a refrigerant path downstream from the cooling unit 30 (on the side close to the heat exchanger 15), and is a passage for returning the refrigerant from the cooling unit 30 to the refrigerant passage 24.

  The refrigerant liquid flowing out from the gas-liquid separator 40 flows toward the cooling unit 30 through the refrigerant passage 33, the first check valve 62, the refrigerant passage 34, the second check valve 64, and the refrigerant passage 35 in order. To do. The refrigerant flowing to the cooling unit 30 and flowing via 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 and the refrigerant. 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.

  A heating unit 80 is disposed adjacent to the refrigerant passage 34. The heating unit 80 is a device that generates heat, such as an electric heater or an induction heating device. The heating unit 80 applies heat to the refrigerant in the refrigerant passage 34 to evaporate the refrigerant liquid in the refrigerant passage 34. During the operation of the compressor 12, the heating unit 80 stops its operation, and heat transfer from the heating unit 80 to the refrigerant in the refrigerant passage 34 does not occur.

  A flow rate adjustment valve 28 is provided in the refrigerant passage 23. 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 adjusting valve 28 allows the flow rate of the refrigerant flowing directly from the gas-liquid separator 40 to the heat exchanger 15 via the refrigerant passage 23 without passing through the cooling unit 30, and the EV device 31 including the cooler 32. The flow rate of the refrigerant flowing through the cooling system is arbitrarily adjusted. 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.

  If the valve opening degree of the flow rate adjusting valve 28 is increased, among the refrigerant flowing out from the gas-liquid separator 40, the flow rate directly flowing to the heat exchanger 15 via the refrigerant passage 23 increases and passes through the refrigerant passage 34. Thus, the flow rate of the refrigerant that flows to the cooling unit 30 and cools the EV device 31 decreases. Therefore, the cooling capacity of the EV device 31 is reduced. If the valve opening degree of the flow rate adjusting valve 28 is reduced, the flow rate of the refrigerant flowing out from the gas-liquid separator 40 directly flows to the heat exchanger 15 via the refrigerant passage 23 is reduced, and the refrigerant passage 34 passes through the refrigerant passage 34. Thus, the flow rate of the refrigerant that flows to the cooling unit 30 and cools the EV device 31 increases. Therefore, the cooling capacity of the EV device 31 is improved.

  Since the flow rate adjusting valve 28 is used to increase / decrease the amount of refrigerant flowing to the EV device 31 and the cooling capacity of the EV device 31 can be optimally adjusted, 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.

[Operation of Vapor Compression Refrigeration Cycle 10]
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. The refrigerant also flows from the refrigerant passage 22 at the outlet of the heat exchanger 14 to the refrigerant passages 33 to 35 via the gas-liquid separator 40 and flows into the cooling unit 30 to cool the EV device 31. The refrigerant returns to the refrigerant passage 24 on the inlet side of the heat exchanger 15 via the refrigerant passage 36. The path when the refrigerant discharged from the compressor 12 flows to the cooling unit 30 via the heat exchanger 14 during the startup of the compressor 12, that is, the refrigerant paths 21, 22, the refrigerant paths 33 to 36, and the refrigerant paths 24 to 27 forms a first passage.

  The state of the refrigerant when the refrigerant flows through the first passage and cools the heat generation source will be described. The refrigerant sucked into the compressor 12 is adiabatically compressed in the compressor 12 along the isentropic line. 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 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 dissipates heat to the surroundings and is cooled by heat exchange with the outside air in the heat exchanger 14. The high-pressure refrigerant vapor that has entered the heat exchanger 14 is dried from the superheated steam to the saturated vapor while maintaining the constant pressure in the heat exchanger 14, releases latent heat of condensation, and gradually liquefies, so that the saturated liquid and the saturated vapor are mixed. It becomes the wet steam of the mixed gas-liquid 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 from the gas-liquid separator 40, flows to the cooler 32 of the cooling unit 30 via the refrigerant passages 33 to 35, 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. 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. 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 refrigerants are dry and become saturated steam, the sensible heat is further absorbed and the temperature of the refrigerant vapor rises to become superheated steam.

  The heat exchanger 18 absorbs the heat of vaporization when the wet vapor of the refrigerant decompressed by the expansion valve 16 evaporates into the refrigerant gas from the air-conditioning air flowing into the vehicle interior, and cools the interior of the vehicle interior. To do. The air-conditioning air that has been cooled by the absorption of heat into the heat exchanger 18 and whose temperature has decreased is returned to the vehicle interior, thereby cooling the vehicle interior. 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 cools the air-conditioning air to cool the interior of the vehicle interior, and cools the EV equipment 31 by flowing to the cooling unit 30 and exchanging heat with the EV equipment 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.

  It is not necessary to provide a dedicated water circulation pump or a cooling fan for cooling the EV device 31. 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 can be reduced. Therefore, the EV device 31 can be cooled with low power.

  In the vapor compression refrigeration cycle 10, the high-pressure refrigerant discharged from the compressor 12 is condensed by both the heat exchanger 14 as the first condenser and the heat exchanger 15 as the second condenser. Is done. The cooling unit 30 that cools the EV device 31 is provided between the heat exchanger 14 and the heat exchanger 15.

  In the heat exchanger 14, the refrigerant is cooled to the 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 heat exchanger 15 further subcools the liquid refrigerant to a degree of supercooling necessary for cooling the vehicle interior. 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. And since it is not necessary to enlarge the supercooling degree of a refrigerant | coolant too much, the capacity | capacitance and size of the heat exchangers 14 and 15 can be reduced.

  As a path for the refrigerant flowing from the gas-liquid separator 40 to the heat exchanger 15, 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. Certain refrigerant passages 33 to 36 and the cooler 32 are provided in parallel. 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.

  Since only a part of the refrigerant flows through the cooling system of the EV device 31 including the refrigerant passages 33 to 36 so that all the refrigerant does not flow to the cooling unit 30, the pressure when the refrigerant flows to the cooling system of the EV device 31. Loss can be reduced. Accordingly, it is possible to reduce the power consumption necessary for the operation of the compressor 12 for circulating the refrigerant.

[Heat pipe operation mode]
The cooling device 1 further includes a communication path 51. The communication passage 51 communicates the refrigerant passage 21 and the refrigerant passage 36 on the downstream side with respect to the cooling portion 30 among the refrigerant passages 33 to 36 that allow the refrigerant to flow through the cooling portion 30. 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. 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.

  During the cooling operation, the switching valve 52 is fully opened (valve opening degree 100%), and the refrigerant flow rate is adjusted so that the cooling unit 30 can obtain the required cooling capacity by adjusting the valve opening degree of the flow rate adjusting valve 28. To do. 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.

  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. 9, 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. 8 is a schematic diagram illustrating the flow of the refrigerant that cools the EV device 31 during operation of the vapor compression refrigeration cycle 10. FIG. 9 is a schematic diagram illustrating the flow of the refrigerant that cools the EV device 31 while the vapor compression refrigeration cycle 10 is stopped. When the vapor compression refrigeration cycle 10 shown in FIG. 8 is operated, that is, the operation mode in which the compressor 12 is operated and the refrigerant is circulated through the vapor compression refrigeration cycle 10 is referred to as “air conditioner operation mode”. On the other hand, when the vapor compression refrigeration cycle 10 shown in FIG. 9 is stopped, that is, the operation mode in which the compressor 12 is stopped and the refrigerant is circulated through an annular path connecting the cooling unit 30 and the heat exchanger 14. Is referred to as a “heat pipe operation mode”.

  As shown in FIG. 8, 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 is configured so that sufficient refrigerant flows through the cooling unit 30. 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 FIG. 9, in the “heat pipe operation mode” in which the compressor 12 is stopped and the vapor compression refrigeration cycle 10 is stopped, the switching valve is configured to circulate the refrigerant from the cooling unit 30 to the heat exchanger 14. 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 paths 33 to 35, 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 traveling wind of the vehicle or the ventilation from a cooling fan such as the condenser fan 42. The refrigerant liquid liquefied by the heat exchanger 14 returns to the cooling unit 30 via the refrigerant passages 22 and 33 to 35.

  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. In accordance with this operation, the operation mode of the cooling device 1 for cooling the EV device 31 is changed from the air conditioner operation mode in which the first passage is communicated and the second passage is shut off, and the first passage is cut off and the second passage is turned on. Is switched 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. Thereby, 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 the refrigerant is circulated between the heat exchanger 14 and the cooling unit 30. The second passage for communicating is communicated, and the communication of the first passage and the communication of the second passage are switched. In this way, even when the compressor 12 is stopped, the refrigerant circulates through the second passage and cools the EV device 31 in the cooling unit 30, thereby maintaining the cooling capacity of the EV device 31 by the cooling device 1. The

  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. Therefore, the cooling device 1 that can appropriately cool the EV device 31 both during operation and when the vapor compression refrigeration cycle 10 is operated can be realized with a simple configuration. The power of the compressor 12 is not always required for cooling the EV device 31, and the power consumption of the compressor 12 can be reduced. Therefore, since the EV device 31 can be cooled with low power, further power saving and improvement in comfort can be achieved.

  In the cooling device 1 according to the third embodiment, in the annular refrigerant path shown in FIG. 9, the refrigerant path from the gas-liquid separator 40 that stores the refrigerant liquid condensed in the heat exchanger 14 to the cooling unit 30 is provided in the embodiment. The first check valve 62, the second check valve 64, and the heating unit 80 described in 1 are provided. When the compressor 12 is stopped, the heating unit 80 is repeatedly turned on and off according to the cycle shown in FIG. This makes it possible to transfer the liquid refrigerant from the heat exchanger 14 to the cooling unit 30 even when the cooling unit 30 in which the refrigerant is heated is disposed above the heat exchanger 14. . Since a liquid pump or the like is not required for the circulation of the refrigerant, the refrigerant can be circulated with power saving. Therefore, the fuel consumption of the vehicle 1000 equipped with the cooling device 1 can be improved.

  In the third embodiment, the example in which the cooling device 1 according to the first embodiment is arranged in the vapor compression refrigeration cycle 10 has been described. However, the cooling device 1 according to the second embodiment is arranged in the vapor compression refrigeration cycle 10. Of course, it may be.

  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 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.

  The heat 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 Heat exchanger, 22, 33-36 Refrigerant passage, 30 Cooling part, 40 Gas-liquid separator, 62 1st check valve, 64 2nd check Valve, 80 heating section, 82 gas-phase refrigerant supply path, 84 on-off valve.

Claims (6)

A cooling device that cools a heat source using a refrigerant,
A heat exchanger for exchanging heat between the refrigerant and outside air;
A cooling unit that cools the heat source using the refrigerant;
A refrigerant passage for circulating the refrigerant between the heat exchanger and the cooling unit;
A first check valve and a second check valve which are provided in the refrigerant passage from the heat exchanger toward the cooling unit and connected in series;
And a heating unit that applies heat to the refrigerant in the refrigerant passage between the first check valve and the second check valve.   The cooling device according to claim 1, wherein the heating unit itself generates heat. A gas-phase refrigerant supply path for supplying the refrigerant from the outlet side of the cooling unit to the heating unit;
The cooling device according to claim 1, further comprising: an on-off valve that opens and closes the gas-phase refrigerant supply path.   The cooling device according to any one of claims 1 to 3, wherein the cooling unit is disposed above the heat exchanger. Further comprising a reservoir for storing the liquid refrigerant condensed by the heat exchanger;
The cooling device according to any one of claims 1 to 4, wherein the liquid refrigerant flows from the liquid reservoir through the first check valve. The heat exchanger is a heat exchanger included in a vapor compression refrigeration cycle,
The vapor compression refrigeration cycle includes a compressor,
The cooling device according to any one of claims 1 to 5, wherein the refrigerant is circulated between the heat exchanger and the cooling unit while the compressor is stopped.

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