Circulation device for two-phase cooling system, and two-phase cooling system

Abstract

A circulation device (100) for a two-phase cooling system comprises: a liquid feed pump (10); an inlet-side connection part (15) that is in thermal contact with a battery (81) of a moving body (80) and can be attached to and detached from a refrigerant inlet of an evaporator (60) into which flows a liquid-phase refrigerant having a boiling point lower than the usage temperature of the battery (81); an outlet-side connection part (16) that can be attached to and detached from a refrigerant outlet of the evaporator (60); and a phase conversion unit (11) that converts a gas-phase refrigerant flowing out of the evaporator (60) into a liquid phase.

Description

Circulation device for two-phase cooling system and two-phase cooling system

[0001] The present invention relates to a circulation device for a two-phase cooling system and to a two-phase cooling system.

[0002] Conventionally, cooling systems are known, such as that disclosed in U.S. Patent Application Publication No. 2022 / 0396165.

[0003] U.S. Patent Application Publication No. 2022 / 0396165 discloses a charging station for charging the battery of an electric vehicle. The charging station includes a charging unit, a refrigerant connector, and a cooling unit. The refrigerant connector connects the cooling unit to a heat exchanger of the battery of the electric vehicle. The cooling unit includes a cold storage tank, a hot storage tank, and a heat pump. The cold storage tank and the hot storage tank are connected to the heat exchanger of the electric vehicle via the refrigerant connector. The refrigerant is cooled by heat exchange between a gas / liquid medium in the heat pump and the refrigerant in the cold storage tank. When charging the battery of the electric vehicle at the charging station, the refrigerant connector is connected to the connector of the heat exchanger of the electric vehicle. As a result, the liquid phase refrigerant from the cooling unit circulates through the heat exchanger of the battery of the electric vehicle, thereby cooling the battery of the electric vehicle.

[0004] US Patent Application Publication No. 2022 / 0396165

[0005] In recent years, there has been a demand for rapid charging of batteries in electric vehicles. However, rapid charging of batteries also increases the rate at which the battery temperature rises. Therefore, there is a demand for improving the cooling performance of batteries in electric vehicles (mobile objects).

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a circulation device for a two-phase cooling system and a two-phase cooling system that can improve the cooling performance of a battery in a mobile body.

[0007] A circulation device for a two-phase cooling system in a first aspect of the present invention comprises a liquid feed pump that feeds a refrigerant, an inlet side connector that is detachably attached to a refrigerant inlet of an evaporator that is arranged inside a mobile body and is in thermal contact with a battery of the mobile body and into which a liquid phase refrigerant having a boiling point lower than the operating temperature of the battery flows, and that is provided downstream of the liquid feed pump, an outlet side connector that is detachably attached to a refrigerant outlet of the evaporator and that is provided downstream of the liquid feed pump, and a phase change unit that is provided downstream of the outlet side connector and that converts the gas phase refrigerant flowing out of the evaporator into a liquid phase.

[0008] In a second aspect of the present invention, a two-phase cooling system includes a liquid feed pump that feeds a refrigerant, an evaporator that is provided downstream of the liquid feed pump and is arranged inside a mobile body, and is in thermal contact with a battery of the mobile body, and into which a liquid-phase refrigerant having a boiling point lower than the operating temperature of the battery flows, an inlet-side connector that is provided downstream of the liquid feed pump and is attachable and detachable to a refrigerant inlet of the evaporator, and an outlet-side connector that is attachable and detachable to a refrigerant outlet of the evaporator, and a phase change unit that is provided downstream of the outlet-side connector and converts the gas-phase refrigerant flowing out of the evaporator into a liquid phase.

[0009] According to a first aspect of the present invention, a circulation device for a two-phase cooling system and a two-phase cooling system for a second aspect of the present invention each include a liquid pump, an evaporator disposed inside a vehicle and in thermal contact with the vehicle's battery, a refrigerant inlet connector detachably attached to a refrigerant inlet of the evaporator, the refrigerant having a boiling point lower than the operating temperature of the battery, an outlet connector detachably attached to a refrigerant outlet of the evaporator, and a phase converter that converts the gaseous refrigerant flowing out of the evaporator to a liquid phase. This allows efficient cooling of the vehicle's battery through two-phase cooling utilizing the heat of vaporization (latent heat of evaporation) generated when the refrigerant changes from liquid to gas, thereby improving the cooling performance of the vehicle's battery.

[0010] FIG. 1 is a schematic diagram showing the configuration of a circulator for a two-phase cooling system according to the first embodiment, with an evaporator connected and a battery being charged; FIG. 2 is a block diagram showing the configuration of a circulator for a two-phase cooling system according to the first embodiment; FIG. 3 is a schematic diagram showing the configuration of a circulator for a two-phase cooling system according to the first embodiment, with an evaporator not connected; FIG. 4 is a schematic diagram showing the configuration of a circulator for a two-phase cooling system according to the first embodiment, with an evaporator connected, before charging begins, and in a vacuum state; FIG. 5 is a schematic diagram showing the configuration of a circulator for a two-phase cooling system according to the first embodiment, with an evaporator connected, after charging has ended, and in a state in which refrigerant is being recovered; FIG. 6 is a schematic diagram showing the configuration of a circulator for a two-phase cooling system according to the first embodiment, with an evaporator connected, after refrigerant recovery has ended, and in which refrigerant from the evaporator is being discharged to the outside; FIG. 7 is a graph for explaining a set liquid level; and FIG. 8 is a flowchart for explaining a refrigerant recovery process and a replenishment refrigerant supply process by a control unit according to the first embodiment. FIG. 9 is a schematic diagram showing the configuration of a circulator for a two-phase cooling system according to the first embodiment, with an evaporator connected and a battery being charged. FIG. 5 is a schematic diagram of an inlet and outlet connection according to a second embodiment.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0012] First Embodiment (Overall Configuration of a Two-Phase Cooling System Including a Circulation Device for a Two-Phase Cooling System) The overall configuration of a two-phase cooling system 200 including a circulation device 100 for a two-phase cooling system according to a first embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 illustrates the two-phase cooling system 200 including the circulation device 100 for a two-phase cooling system, to which a removable evaporator 60 is connected, and in which a battery 81 of a vehicle 80 is being charged by a charging device 90. The circulation device 100 for a two-phase cooling system constitutes the two-phase cooling system 200 that circulates a refrigerant by connecting the removable evaporator 60. That is, the two-phase cooling system 200 includes the circulation device 100 for a two-phase cooling system and the evaporator 60 that is detachable from the circulation device 100 for a two-phase cooling system. Here, two-phase cooling refers to cooling using a gas-liquid mixture fluid that utilizes the heat of vaporization (latent heat of vaporization) generated when a refrigerant changes from a liquid phase to a gas phase. Also in the drawings, refrigerant moves in the illustrated two-phase refrigeration system circulation device 100 in the direction indicated by the arrows.

[0013] The evaporator 60 is provided in the vehicle 80 to cool the battery 81 of the vehicle 80. The evaporator 60 is configured to cool the battery 81 of the vehicle 80 when the battery 81 of the vehicle 80 is being charged. The evaporator 60 is disposed inside the vehicle 80 and configured to be in thermal contact with the battery 81 of the vehicle 80. The state in which the evaporator 60 is connected refers to, for example, a state in which the evaporator 60 is attached to the circulation device 100 for a two-phase cooling system when the battery 81 of the vehicle 80 is being charged by the charging device 90. The vehicle 80 is, for example, an electric vehicle. The vehicle 80 may be, for example, a plug-in hybrid vehicle, as long as it is configured to be externally charged. The vehicle 80 is an example of a "mobile body" in the claims.

[0014] The battery 81 of the vehicle 80 is a secondary battery that uses an electrolyte. The battery 81 is, for example, a lithium-ion battery that uses a non-aqueous electrolyte. The battery 81 is not limited to a lithium-ion battery, and may be, for example, a nickel-metal hydride battery, a nickel-cadmium battery, or a lead-acid battery. The battery 81 may also be an all-solid-state battery that does not use an electrolyte.

[0015] The circulation device 100 for a two-phase cooling system is installed next to a charging device 90 that charges a battery 81 of a vehicle 80. FIG. 1 shows a state in which the vehicle 80 and the charging device 90 are electrically connected by a charging cable 70. The charging device 90 is installed at a charging station or the like. The charging device 90 is a DC (Direct Current) charger that supports rapid charging. One end of the charging cable 70 is connected to the charging device 90, and a plug 71 at the other end is connected to a receptacle 82 of the vehicle 80. When the battery 81 of the vehicle 80 is charged by the charging device 90, the circulation device 100 for a two-phase cooling system circulates refrigerant through the evaporator 60 with the evaporator 60 connected to the inlet-side connector 15 and the outlet-side connector 16.

[0016] As shown in FIG. 1 , a circulation device 100 for a two-phase cooling system includes a circulation device main body 1, a refrigerant replenishment storage unit 2, a vacuum pump 3, a control unit 4, and an alarm unit 6. The circulation device main body 1 includes a liquid feed pump 10, a condenser 11, a vacuum pump-side opening / closing valve 12, a storage unit 13, a detection unit 14, an inlet-side connection unit 15, an outlet-side connection unit 16, an inlet-side opening / closing valve 17, an outlet-side opening / closing valve 18, an inlet-side opening / closing valve opening / closing mechanism 19, an outlet-side opening / closing valve opening / closing mechanism 20, a flow rate adjustment unit 21, and a refrigerant flow path 30. The circulation device main body 1 is provided adjacent to a charging device 90. A two-phase cooling system 200 also includes the circulation device 100 for a two-phase cooling system and an evaporator 60 provided downstream of the liquid feed pump 10 and installed in a vehicle 80 to cool a battery 81 of the vehicle 80. The "inlet side" refers to the inlet side of the evaporator 60, and the "outlet side" refers to the outlet side of the evaporator 60. The condenser 11 is an example of a "phase conversion unit" in the claims.

[0017] The refrigerant flow path 30 includes a first refrigerant flow path 31, a second refrigerant flow path 32, a third refrigerant flow path 33, a fourth refrigerant flow path 34, a fifth refrigerant flow path 35, a sixth refrigerant flow path 36, and a bypass flow path 37.

[0018] One end of the first refrigerant flow path 31 is connected to the outlet of the liquid feed pump 10, and the other end is connected to the inlet-side connector 15. A first branch section 40 is formed between one end and the other end of the first refrigerant flow path 31. One end of the second refrigerant flow path 32 is connected to the outlet-side connector 16, and the other end is connected to the inlet of the condenser 11. A second branch section 42 and a junction section 41 are formed between one end and the other end of the second refrigerant flow path 32. The second branch section 42 is formed downstream of the outlet-side connector 16 and upstream of the junction section 41 in the second refrigerant flow path 32. The junction section 41 is formed downstream of the second branch section 42 and upstream of the condenser 11 in the second refrigerant flow path 32.

[0019] The third refrigerant flow path 33 has one end connected to the outlet of the condenser 11 and the other end connected to the inlet of the storage portion 13. The fourth refrigerant flow path 34 has one end connected to the outlet of the storage portion 13 and the other end connected to the inlet of the liquid feed pump 10. The fifth refrigerant flow path 35 has one end connected to a second branch portion 42 formed in the second refrigerant flow path 32 and the other end connected to the outside. The sixth refrigerant flow path 36 has one end connected to the outlet of the replenishment refrigerant storage portion 2 and the other end connected to the replenishment refrigerant supply port of the storage portion 13.

[0020] The bypass flow path 37 branches from the first refrigerant flow path 31 to the second refrigerant flow path 32 downstream of the liquid feed pump 10 and upstream of the inlet connector 15 in the first refrigerant flow path 31, and is configured to circulate the refrigerant to the condenser 11 without passing through the inlet connector 15 and the outlet connector 16. The bypass flow path 37 branched from the first refrigerant flow path 31 is connected to the second refrigerant flow path 32 downstream of the outlet connector 16 and upstream of the condenser 11. One end of the bypass flow path 37 is connected to a first branch portion 40 formed in the first refrigerant flow path 31, and the other end is connected to a junction portion 41 formed in the second refrigerant flow path 32.

[0021] A portion of the other end of the first refrigerant flow path 31 connected to the inlet connector 15 and a portion of one end of the second refrigerant flow path 32 connected to the outlet connector 16 are made of a resin material. The refrigerant flow path 30 other than the portion of the other end of the first refrigerant flow path 31 and the portion of one end of the second refrigerant flow path 32 are made of a metal material.

[0022] The liquid feed pump 10 is configured to feed a liquid-phase refrigerant. The liquid feed pump 10 is operated at a predetermined output. The liquid feed pump 10 is configured to feed the refrigerant to the evaporator 60 via the first refrigerant flow path 31. The liquid feed pump 10 is configured to feed the refrigerant to the condenser 11 via the first refrigerant flow path 31, the bypass flow path 37, and the second refrigerant flow path 32. The refrigerant flows into the liquid feed pump 10 from the reservoir 13 via the fourth refrigerant flow path 34. The liquid feed pump 10 is provided downstream of the reservoir 13 in the fourth refrigerant flow path 34 and upstream of the evaporator 60 in the first refrigerant flow path 31. Here, "upstream of the liquid feed pump 10" refers to a portion upstream of the liquid feed pump 10 and does not include the liquid feed pump 10. Furthermore, "downstream of the liquid feed pump 10" refers to a portion downstream of the liquid feed pump 10 and does not include the liquid feed pump 10. The same applies to the upstream and downstream sides of the condenser 11, the upstream and downstream sides of the storage section 13, and the upstream and downstream sides of the evaporator 60.

[0023] The liquid feed pump 10 takes in a liquid-phase refrigerant from an inlet of the liquid feed pump 10 and discharges the liquid-phase refrigerant from an outlet of the liquid feed pump 10. The liquid feed pump 10 is a centrifugal pump. However, the liquid feed pump 10 is not limited to a centrifugal pump. The liquid feed pump 10 may be a mixed-flow pump, an axial-flow pump, or another known pump. The liquid feed pump 10 may also be a positive displacement pump. Note that the liquid feed pump 10 is not a compressor for compressing the refrigerant.

[0024] When the evaporator 60 is connected, the condenser 11 is configured to condense the gas phase refrigerant in the gas-liquid mixed refrigerant flowing out from the evaporator 60 to generate liquid phase refrigerant. The condenser 11 is configured to cool and condense the refrigerant by exchanging heat with a cooling liquid flowing in from the chiller 22 provided outside. The condenser 11 condenses the refrigerant by causing the cooling liquid flowing from the chiller 22 to absorb heat of the refrigerant. In other words, the condenser 11 functions as a phase change unit that changes the phase of the gas phase refrigerant flowing out from the evaporator 60 to a liquid phase. The condenser 11 includes a flow path through which the refrigerant flows and a cooling liquid flow path through which the cooling liquid flows.

[0025] The refrigerant used has a boiling point lower than the operating temperature of the battery 81. It is desirable that the refrigerant is neither toxic nor flammable. As an example, carbon dioxide, which is an inexpensive natural refrigerant, is used. The refrigerant is not limited to carbon dioxide, and may be, for example, a fluorocarbon-based refrigerant such as HCFO-1224yd. The higher the insulating properties of the refrigerant, the more desirable it is.

[0026] The cooling liquid used is a cooling liquid that is lower in temperature than the liquid-phase refrigerant. For example, a liquid containing hydrofluoroether as a main component is used. The cooling liquid is not particularly limited as long as it is a known cooling liquid.

[0027] The condenser 11 receives a gas-liquid mixed refrigerant from an inlet of the condenser 11 and discharges a liquid phase refrigerant from an outlet of the condenser 11. The condenser 11 is provided downstream of the outlet-side connecting portion 16 in the second refrigerant flow path 32. The refrigerant flows into the condenser 11 via the second refrigerant flow path 32. The refrigerant condensed by the condenser 11 flows into the storage portion 13 via a third refrigerant flow path 33.

[0028] The storage unit 13 is configured to store liquid-phase refrigerant. Furthermore, when there is a gas-liquid mixture of refrigerant that was not completely condensed in the condenser 11, the storage unit 13 is configured to separate and store gas bubbles (gas-phase refrigerant) contained in the gas-liquid mixture at an upper portion. The storage unit 13 is provided downstream of the condenser 11 in the third refrigerant flow path 33. The storage unit 13 allows the liquid-phase refrigerant to flow in from an inlet of the storage unit 13 and allows the liquid-phase refrigerant to flow out from an outlet of the storage unit 13. The storage unit 13 is configured to send the liquid-phase refrigerant to the liquid feed pump 10 via the fourth refrigerant flow path 34. Furthermore, replenishment refrigerant supplied from the replenishment refrigerant storage unit 2 flows into the storage unit 13 from a replenishment refrigerant supply port via the sixth refrigerant flow path 36.

[0029] The replenishment refrigerant storage unit 2 is configured to store replenishment refrigerant to be supplied to the storage unit 13. The replenishment refrigerant storage unit 2 supplies the replenishment refrigerant stored in the replenishment refrigerant storage unit 2 to the storage unit 13 under the control of the control unit 4. The replenishment refrigerant storage unit 2 is provided downstream of the storage unit 13 in the sixth refrigerant flow path 36. The replenishment refrigerant storage unit 2 causes the refrigerant to flow out from an outlet of the replenishment refrigerant storage unit 2.

[0030] The vacuum pump 3 is configured to evacuate the refrigerant flow path 64 of the evaporator 60. The vacuum pump 3 is provided in the fifth refrigerant flow path 35 downstream of the second branch portion 42.

[0031] When charging the battery 81 of the vehicle 80, with the evaporator 60 connected to the inlet-side connector 15 and the outlet-side connector 16, the vacuum pump 3 is configured to evacuate the refrigerant flow path 64 of the evaporator 60 before circulating the refrigerant through the evaporator 60. Specifically, the vacuum pump 3 is configured to evacuate the refrigerant flow path from the inlet-side opening / closing valve 17 through the evaporator 60 to the outlet-side opening / closing valve 18.

[0032] Furthermore, with the evaporator 60 connected to the inlet-side connector 15 and the outlet-side connector 16, the vacuum pump 3 is configured to suck the refrigerant from the evaporator 60 and discharge the sucked refrigerant to the outside after charging of the battery 81 of the vehicle 80 is completed. Specifically, the vacuum pump 3 is configured to suck the refrigerant remaining in the refrigerant flow path from the inlet-side opening / closing valve 17 through the evaporator 60 to the outlet-side opening / closing valve 18 after charging of the battery 81 of the vehicle 80 is completed, and discharge the sucked refrigerant to the outside of the circulation cycle system via the fifth refrigerant flow path 35.

[0033] The vacuum pump side on-off valve 12 is provided downstream of the second branch 42 in the fifth refrigerant flow path 35 and upstream of the vacuum pump 3. The vacuum pump side on-off valve 12 is configured to be able to open and close the flow path. The vacuum pump side on-off valve 12 is, for example, an on-off valve that can switch the flow path between a fully open state and a fully closed state. The vacuum pump side on-off valve 12 may be opened and closed manually, or may be opened and closed under the control of the control unit 4 via a vacuum pump side on-off valve opening and closing mechanism (not shown).

[0034] The detection unit 14 is configured to detect the amount of recovered refrigerant. Specifically, the detection unit 14 is configured to detect the amount of refrigerant stored in the storage unit 13 as the amount of recovered refrigerant. The detection unit 14 is, for example, a liquid level sensor, and measures the liquid level of the liquid-phase refrigerant stored in the storage unit 13. The recovered refrigerant is the refrigerant that remains in the refrigerant flow path 64 of the evaporator 60 after charging of the battery 81 of the vehicle 80 is completed. The recovery of the refrigerant that remains in the refrigerant flow path 64 of the evaporator 60 will be described later.

[0035] The inlet-side connector 15 is configured to connect the first refrigerant flow path 31 to the refrigerant inlet of the evaporator 60. The inlet-side connector 15 connects the other end of the first refrigerant flow path 31 to the refrigerant inlet provided in the evaporator 60. The inlet-side connector 15 is, for example, a one-touch type pipe joint that can be attached and detached to an inlet-side joint member 61 formed at the refrigerant inlet of the evaporator 60. However, the connection between the inlet-side connector 15 and the refrigerant inlet provided in the evaporator 60 is not limited to a one-touch type joint. The inlet-side connector 15 is not particularly limited as long as it is easily attached and detached to the refrigerant inlet of the evaporator 60 and is difficult to detach during refrigerant flow. The inlet-side connector 15 is located downstream of the liquid feed pump 10. The location of the refrigerant inlet of the evaporator 60 in the vehicle 80 is not particularly limited. The refrigerant inlet of the evaporator 60 may be provided so as to be exposed on the outer surface of the vehicle 80 by removing a cover or the like, or may be provided inside the passenger compartment or in the engine compartment. Also, a connecting member may be provided to connect the main body of the evaporator 60 and the refrigerant inlet of the evaporator 60.

[0036] The outlet-side connector 16 is configured to connect the refrigerant outlet of the evaporator 60 to the second refrigerant flow path 32. The outlet-side connector 16 connects the refrigerant outlet of the evaporator 60 to one end of the second refrigerant flow path 32. The outlet-side connector 16 is, for example, a one-touch pipe joint that can be attached to and detached from an outlet-side joint member 62 formed at the refrigerant outlet of the evaporator 60. However, the connection between the outlet-side connector 16 and the refrigerant outlet of the evaporator 60 is not limited to a one-touch joint. The outlet-side connector 16 is not particularly limited as long as it is easily attached to and detached from the refrigerant outlet of the evaporator 60 and is difficult to detach during refrigerant flow. The outlet-side connector 16 is located downstream of the liquid feed pump 10 and the evaporator 60 and upstream of the condenser 11. The location of the refrigerant outlet of the evaporator 60 in the vehicle 80 is not particularly limited. The refrigerant outlet of the evaporator 60 may be provided so as to be exposed on the exterior surface of the vehicle 80 by removing a cover or the like, or may be provided inside the vehicle interior or in the engine compartment. A connecting member may be provided to connect the main body of the evaporator 60 to the refrigerant outlet of the evaporator 60. The inlet-side connector 15 and the outlet-side connector 16 may be configured as separate bodies, or may be configured as a single component that includes both the inlet-side connector 15 and the outlet-side connector 16. A portion of the first refrigerant flow path 31, a portion of the second refrigerant flow path 32, and a portion of the charging cable 70 may be integrally configured, thereby configuring the inlet-side connector 15, the outlet-side connector 16, and the plug 71 of the charging cable 70 as a single component.

[0037] The inlet-side on-off valve 17 is provided between the first branch portion 40 provided in the first refrigerant flow path 31 and the inlet-side connecting portion 15. That is, the inlet-side on-off valve 17 is provided between the branch portion where the bypass flow path 37 branches off from the first refrigerant flow path 31 and the inlet-side connecting portion 15. The inlet-side on-off valve 17 is configured to be able to open and close the flow path. The inlet-side on-off valve 17 is, for example, an on-off valve that can switch the flow path between a fully open state and a fully closed state. The inlet-side on-off valve 17 is not an expansion valve for decompressing the refrigerant. The inlet-side on-off valve 17 may also be provided in the first branch portion 40.

[0038] The outlet-side on-off valve 18 is provided between the second branch portion 42 provided in the second refrigerant flow path 32 and the confluence portion 41 provided in the second refrigerant flow path 32. That is, the outlet-side on-off valve 18 is provided between the branch portion where the fifth refrigerant flow path 35 branches from the second refrigerant flow path 32 and the connection portion of the second refrigerant flow path 32 where the bypass flow path 37 is connected. The outlet-side on-off valve 18 is configured to be able to open and close the flow path. The outlet-side on-off valve 18 is, for example, an on-off valve that can switch the flow path between a fully open state and a fully closed state. The outlet-side on-off valve 18 is not an expansion valve for decompressing the refrigerant. The outlet-side on-off valve 18 may also be provided at the confluence portion 41.

[0039] The inlet-side on-off valve opening / closing mechanism 19 is configured to be able to switch the inlet-side on-off valve 17 between an open state and a closed state. The inlet-side on-off valve opening / closing mechanism 19 includes, for example, a motor and an actuator. The inlet-side on-off valve opening / closing mechanism 19 is connected to the control unit 4. The inlet-side on-off valve 17 is opened and closed by the inlet-side on-off valve opening / closing mechanism 19 under the control of the control unit 4.

[0040] The outlet side on-off valve opening / closing mechanism 20 is configured to be able to switch the outlet side on-off valve 18 between an open state and a closed state. The outlet side on-off valve opening / closing mechanism 20 includes, for example, a motor, an actuator, etc. The outlet side on-off valve opening / closing mechanism 20 is connected to the control unit 4. The outlet side on-off valve 18 is opened and closed by the outlet side on-off valve opening / closing mechanism 20 under the control of the control unit 4. Note that the configurations of the inlet side on-off valve opening / closing mechanism 19 and the outlet side on-off valve opening / closing mechanism 20 are not particularly limited as long as they are known valve opening / closing mechanisms.

[0041] The flow rate adjustment unit 21 is provided in the bypass flow path 37. The flow rate adjustment unit 21 is, for example, a flow rate adjustment valve. The flow rate adjustment valve is not particularly limited as long as it is a known valve, such as a needle valve, that can be shut off and adjust the flow rate. The opening degree of the flow rate adjustment valve is adjusted, for example, based on the flow rate of refrigerant flowing into the evaporator 60 and the minimum flow rate of the liquid feed pump 10 when the evaporator 60 is connected.

[0042] By adjusting the flow rate using the flow rate adjustment unit 21 based on the refrigerant flow rate flowing into the evaporator 60 and the minimum flow rate of the liquid feed pump 10, it is possible to appropriately distribute the refrigerant flow rate flowing into the evaporator 60 and the refrigerant flow rate flowing into the bypass flow path 37 at the first branch section 40 while maintaining a refrigerant flow rate equal to or greater than the minimum flow rate of the liquid feed pump 10. Therefore, by adjusting the flow rate using the flow rate adjustment unit 21, the same circulation device 100 for a two-phase cooling system can be applied to evaporators 60 of different sizes.

[0043] The notification unit 6 is configured to notify that the refrigerant recovery process, which will be described later, has been completed. The notification unit 6 includes, for example, a display unit. Under the control of the control unit 4, the notification unit 6 displays a notification that "the refrigerant recovery process has been completed" on the display unit. Alternatively, the notification unit 6 may include an audio output unit instead of or in addition to the display unit, and under the control of the control unit 4, the notification unit 6 may announce that "the refrigerant recovery process has been completed" on the audio output unit.

[0044] 2 , the control unit 4 includes a processor such as a CPU (Central Processing Unit) and a storage unit 5. The control unit 4 is configured to be able to communicate with a control device 91 that controls the charging device 90. Specifically, the control unit 4 is configured to be able to acquire information about the completion of charging of the battery 81 by the charging device 90 through communication with the control device 91 of the charging device 90.

[0045] Furthermore, the control unit 4 is configured to perform control to close the inlet side opening / closing valve 17 via the inlet side opening / closing valve opening / closing mechanism 19 after charging of the battery 81 of the vehicle 80 is completed. By closing the inlet side opening / closing valve 17 via the inlet side opening / closing valve opening / closing mechanism 19, the control unit 4 circulates the refrigerant via the bypass flow path 37 without passing through the evaporator 60, and guides the refrigerant in the evaporator 60 to the condenser 11.

[0046] Furthermore, the control unit 4 is configured to control the outlet side opening / closing valve 18 using the outlet side opening / closing valve opening / closing mechanism 20 based on the detection result by the detection unit 14, thereby preventing the refrigerant from flowing out from the outlet side opening / closing valve 18 to the outlet side connection unit 16. Furthermore, the control unit 4 is configured to control the notification unit 6 to notify that the refrigerant recovery process has been completed, based on the control that closes the outlet side opening / closing valve 18 and ends the refrigerant recovery process.

[0047] In addition, when the refrigerant is circulating through the bypass flow path 37 without passing through the evaporator 60, the control unit 4 is configured to control the supply of replenishment refrigerant stored in the replenishment refrigerant storage unit 2 to the storage unit 13 based on the detection result of the amount of refrigerant stored in the storage unit 13 by the detection unit 14.

[0048] As shown in FIG. 1 , an evaporator 60 is provided in a vehicle 80 to cool a battery 81 of the vehicle 80. The refrigerant inlet of the evaporator 60 is configured to be detachable from an inlet-side connector 15, and the refrigerant outlet of the evaporator 60 is configured to be detachable from an outlet-side connector 16. The evaporator 60 cools the battery 81 by utilizing the heat of vaporization (latent heat of vaporization) generated when a portion of the liquid-phase refrigerant delivered through the inlet-side connector 15 evaporates and changes into a gas-liquid mixture of refrigerant. The evaporator 60 includes a cold plate 63 and a refrigerant flow path 64 provided in the cold plate 63. The cold plate 63 is formed of a metal with high thermal conductivity, such as aluminum or copper. The evaporator 60 may further include a connecting member connecting the refrigerant inlet of the evaporator 60 to the inlet-side connector 15 and a connecting member connecting the refrigerant outlet of the evaporator 60 to the outlet-side connector 16.

[0049] A battery 81 is installed on one surface of the cold plate 63. The refrigerant flow path 64 has a structure that bends multiple times inside the evaporator 60 to perform efficient heat exchange. The refrigerant flow path 64 may be formed so that it splits into multiple paths at the inlet, passes through the inside of the evaporator 60, and merges into one path at the outlet. The structure of the evaporator 60 is not particularly limited.

[0050] 3 shows the circulation device 100 for a two-phase cooling system in a state where the evaporator 60 provided in the vehicle 80 is not connected. In the circulation device 100 for a two-phase cooling system in a state where the evaporator 60 is not connected, the inlet side opening / closing valve 17, the outlet side opening / closing valve 18, and the vacuum pump side opening / closing valve 12 are in a closed state.

[0051] The condenser 11 is configured to cool the liquid-phase refrigerant sent from the liquid feed pump 10 via the bypass flow path 37 when the evaporator 60 is not connected. When the evaporator 60 is not connected, the condenser 11 allows the liquid-phase refrigerant to flow in from the inlet of the condenser 11 and allows the cooled liquid-phase refrigerant to flow out from the outlet of the condenser 11. Note that other configurations of the circulation device 100 for a two-phase refrigeration system when the evaporator 60 is not connected are the same as the configuration of the circulation device 100 for a two-phase refrigeration system when the evaporator 60 is connected, as described with reference to FIG. 1, and therefore description thereof will be omitted.

[0052] (Refrigerant circulation and valve opening / closing states) With reference to Figures 1 and 3 to 6, the circulation of the refrigerant in the circulation device 100 for a two-phase cooling system and the opening / closing states of the inlet side opening / closing valve 17, the outlet side opening / closing valve 18, and the vacuum pump side opening / closing valve 12 will be described.

[0053] 3 shows the circulation device 100 for a two-phase cooling system in a state where the evaporator 60 provided in the vehicle 80 is not connected. The inlet side opening / closing valve 17, the outlet side opening / closing valve 18, and the vacuum pump side opening / closing valve 12 are all fully closed.

[0054] Liquid-phase refrigerant is sent from the liquid feed pump 10. The liquid-phase refrigerant flows through the first refrigerant flow path 31. At the first branching portion 40 of the first refrigerant flow path 31, the liquid-phase refrigerant flows into the bypass flow path 37. The liquid-phase refrigerant that has flowed into the bypass flow path 37 flows through the flow rate adjusting portion 21 provided in the bypass flow path 37 and flows into the junction portion 41 of the second refrigerant flow path 32. The liquid-phase refrigerant that has flowed into the junction portion 41 flows through the second refrigerant flow path 32 and into the condenser 11. The liquid-phase refrigerant that has flowed into the condenser 11 is cooled or maintained in a cooled state. The liquid-phase refrigerant flows from the condenser 11 through the third refrigerant flow path 33 and flows into the storage portion 13. The refrigerant that has flowed into the storage portion 13 flows through the fourth refrigerant flow path 34 and flows into the liquid feed pump 10.

[0055] <State in which the evaporator is connected, charging has not yet begun, and vacuuming has been performed> Figure 4 shows the circulation device 100 for a two-phase cooling system in a state in which the evaporator 60 provided in the vehicle 80 is connected, charging of the battery 81 has not yet begun using the charging device 90, and vacuuming has been performed using the vacuum pump 3. The inlet side opening / closing valve 17 and the outlet side opening / closing valve 18 are fully closed. The vacuum pump side opening / closing valve 12 is fully open. Note that the refrigerant circulation in the state in which the evaporator 60 is connected, charging has not yet begun, and vacuuming has been performed is the same as the refrigerant circulation in the state in which the evaporator 60 provided in the vehicle 80 is not connected in Figure 3, and therefore will not be described again.

[0056] 1 shows the circulation device 100 for a two-phase cooling system in a state where the evaporator 60 provided in the vehicle 80 is connected and the battery 81 is being charged by the charging device 90. The inlet side opening / closing valve 17 and the outlet side opening / closing valve 18 are fully open. The vacuum pump side opening / closing valve 12 is fully closed.

[0057] Liquid-phase refrigerant is sent from the liquid feed pump 10. The refrigerant flows through the first refrigerant flow path 31. In the first branch 40 of the first refrigerant flow path 31, a portion of the refrigerant flows through the fully open inlet-side on-off valve 17 and the inlet-side connector 15 and enters the evaporator 60, which has been evacuated. The remainder of the refrigerant flows into the bypass flow path 37. The liquid-phase refrigerant that flows into the evaporator 60 partially evaporates and changes into a gas-liquid mixed refrigerant. The gas-liquid mixed refrigerant flows from the evaporator 60 through the outlet-side connector 16 into the second refrigerant flow path 32. The gas-liquid mixed refrigerant that flows into the second refrigerant flow path 32 flows through the second branch 42, the fully open outlet-side on-off valve 18, and the junction 41. In the junction 41, the gas-liquid mixed refrigerant merges with the liquid-phase refrigerant that flows from the bypass flow path 37. The merged gas-liquid mixed refrigerant and the liquid-phase refrigerant that has flowed in from the bypass flow path 37 flow into the condenser 11 in a gas-liquid mixed state. The gas-phase refrigerant of the gas-liquid mixed refrigerant that has flowed into the condenser 11 is condensed and changes to liquid-phase refrigerant. The condensed liquid-phase refrigerant flows from the condenser 11 through the third refrigerant flow path 33 and into the storage unit 13. The refrigerant that has flowed into the storage unit 13 flows through the fourth refrigerant flow path 34 and into the liquid feed pump 10.

[0058] <State in which the evaporator is connected, charging has been completed, and refrigerant is being recovered> Figure 5 shows the circulation device 100 for a two-phase cooling system in a state in which the evaporator 60 provided in the vehicle 80 is connected, and after charging of the battery 81 by the charging device 90 has been completed, the refrigerant from the evaporator 60 is being recovered by guiding it to the condenser 11.

[0059] The evaporator 60 attached to the circulation device 100 for a two-phase cooling system is removed from the circulation device 100 for a two-phase cooling system after charging of the battery 81 by the charging device 90 is completed. When the evaporator 60 is removed from the circulation device 100 for a two-phase cooling system, if liquid-phase refrigerant remains in the refrigerant flow path 64 inside the evaporator 60, the remaining liquid-phase refrigerant may vaporize and flow out, causing freezing. Therefore, in order to prevent the liquid-phase refrigerant remaining in the refrigerant flow path 64 inside the evaporator 60 from vaporizing when the evaporator 60 is removed from the circulation device 100 for a two-phase cooling system, it is necessary to recover the refrigerant remaining in the refrigerant flow path 64 inside the evaporator 60 into the reservoir 13 before removing the evaporator 60 from the circulation device 100 for a two-phase cooling system.

[0060] When the refrigerant in the evaporator 60 is being collected by guiding it to the condenser 11, the inlet-side opening / closing valve 17 and the vacuum pump-side opening / closing valve 12 are fully closed, and the outlet-side opening / closing valve 18 is fully open.

[0061] Liquid-phase refrigerant is sent from the liquid feed pump 10. The liquid-phase refrigerant flows through the first refrigerant flow path 31. At the first branching portion 40 of the first refrigerant flow path 31, the liquid-phase refrigerant flows into the bypass flow path 37. The liquid-phase refrigerant that has flowed into the bypass flow path 37 flows into the junction portion 41 of the second refrigerant flow path 32. The liquid-phase refrigerant that has flowed into the junction portion 41 flows through the second refrigerant flow path 32 and into the condenser 11. The refrigerant that has flowed into the condenser 11 flows through the third refrigerant flow path 33 and into the storage portion 13. The refrigerant that has flowed into the storage portion 13 flows through the fourth refrigerant flow path 34 and into the liquid feed pump 10.

[0062] Liquid-phase refrigerant is not sent from the liquid feed pump 10 to the evaporator 60. Therefore, in the refrigerant recovery state, the liquid-phase refrigerant circulating through the two-phase cooling system circulation device 100 does not flow into the evaporator 60. Then, immediately after the inlet opening / closing valve 17 is fully closed, a gas-liquid mixture of refrigerant remains in the refrigerant flow path 64 inside the evaporator 60.

[0063] Here, the liquid-phase refrigerant sent from the liquid feed pump 10 flows from the bypass flow path 37 into the confluence 41 of the second refrigerant flow path 32 and circulates through the second refrigerant flow path 32, the condenser 11, the third refrigerant flow path 33, the reservoir 13, and the fourth refrigerant flow path 34. This circulating liquid-phase refrigerant is cooled or maintained in a cooled state by the condenser 11. Therefore, the pressure of the gas-phase refrigerant in the gas-liquid mixed refrigerant stored in the evaporator 60 is higher than the pressure of the liquid-phase refrigerant circulating through the circulation device 100 for a two-phase cooling system. In other words, the pressure difference between the pressure of the gas-phase refrigerant contained in the gas-liquid mixed refrigerant in the evaporator 60 and the pressure of the liquid-phase refrigerant circulating in the path from the confluence 41 of the second refrigerant flow path 32 through the condenser 11, the reservoir 13, the liquid feed pump 10, and the bypass flow path 37 becomes large. This pressure difference causes the gas-liquid refrigerant mixture in the evaporator 60 to flow out from the evaporator 60 toward the confluence 41 of the second refrigerant flow path 32. Specifically, the gas phase refrigerant of the gas-liquid refrigerant mixture in the evaporator 60 flows out from the evaporator 60 toward the confluence 41 of the second refrigerant flow path 32, and also flows out so as to push out the liquid phase refrigerant of the gas-liquid refrigerant of the gas-liquid refrigerant mixture in the evaporator 60. Then, at the confluence 41, the gas-liquid refrigerant mixture flowing out from the evaporator 60 merges with the liquid phase refrigerant flowing in from the bypass flow path 37, and the gas phase refrigerant contained in the merged gas-liquid refrigerant mixture is condensed. The liquid phase refrigerant after the merger flows through the second refrigerant flow path 32 and flows into the condenser 11. That is, the gas-liquid refrigerant mixture in the evaporator 60 flows through the second refrigerant flow path 32 and is guided to the condenser 11. As a result, the refrigerant remaining in the refrigerant flow path 64 inside the evaporator 60 is collected into the reservoir 13 .

[0064] 6 shows the two-phase cooling system circulation device 100 in a state where the evaporator 60 is connected, charging of the battery 81 by the charging device 90 is completed, refrigerant recovery from the evaporator 60 is completed, and the vacuum pump 3 is sucking the refrigerant remaining in the evaporator 60 and discharging the sucked refrigerant to the outside. In this state, the inlet-side opening / closing valve 17 and the outlet-side opening / closing valve 18 are fully closed. Furthermore, the vacuum pump-side opening / closing valve 12 is fully opened by a user operating the valve 17 in response to a notification from the notification unit 6. Therefore, the refrigerant delivered from the liquid delivery pump 10 circulates through the bypass flow path 37 without passing through the evaporator 60, without flowing out from the outlet-side opening / closing valve 18 to the outlet-side connection portion 16.

[0065] In the refrigerant recovery process, the refrigerant in the evaporator 60 is recovered by guiding it to the condenser 11, but because it is not possible to create a vacuum in the flow path 64 inside the evaporator 60, it is not possible to recover all of the refrigerant in the evaporator 60. Therefore, based on the user's operation, the vacuum pump 3 sucks out the refrigerant remaining in the evaporator 60, thereby removing the refrigerant remaining in the evaporator 60 and discharging the sucked refrigerant outside the circulation cycle system.

[0066] Because the vacuum pump side on-off valve 12 is fully open and the inlet side on-off valve 17 and the outlet side on-off valve 18 are fully closed, the inside of the refrigerant flow path from the inlet side on-off valve 17 to the outlet side on-off valve 18 via the evaporator 60 is evacuated by suction by the vacuum pump 3. Therefore, the refrigerant remaining in the refrigerant flow path from the inlet side on-off valve 17 to the outlet side on-off valve 18 via the evaporator 60 flows through the fifth refrigerant flow path 35, the vacuum pump side on-off valve 12, and the vacuum pump 3, and is discharged to the outside of the circulation cycle system.

[0067] In addition, the circulation of refrigerant within the circulation device 100 for a two-phase cooling system when the evaporator 60 is connected, refrigerant recovery is completed, and the refrigerant from the evaporator 60 is being discharged outside the circulation cycle system is the same as the circulation of refrigerant when the evaporator 60 installed in the vehicle 80 is not connected in Figure 3, so a description thereof will be omitted.

[0068] Furthermore, in a state where the evaporator 60 provided in the vehicle 80 is connected, charging of the battery 81 by the charging device 90 is completed, and recovery of the refrigerant in the evaporator 60 is completed, and the refrigerant is circulating through the bypass flow path 37 without passing through the evaporator 60, replenishment refrigerant to be stored in the replenishment refrigerant storage unit 2 is supplied to the storage unit 13 based on the detection result of the amount of refrigerant stored in the storage unit 13 by the detection unit 14. When the replenishment refrigerant stored in the replenishment refrigerant storage unit 2 is supplied to the storage unit 13, the electromagnetic valve 23 provided in the sixth refrigerant flow path 36 is opened.

[0069] The replenishment refrigerant stored in the replenishment refrigerant storage unit 2 flows into the sixth refrigerant flow path 36 from the outlet of the replenishment refrigerant storage unit 2. The replenishment refrigerant flows through the sixth refrigerant flow path 36 and flows into the storage unit 13 from the replenishment refrigerant supply port of the storage unit 13.

[0070] (Control of Start and End of Refrigerant Recovery Process by Control Unit) With reference to FIGS. 5 and 7, the control of start and end of the refrigerant recovery process by the control unit 4 will be described.

[0071] The control unit 4 starts the refrigerant recovery process based on information indicating the completion of charging of the battery 81 by the charging device 90, obtained through communication with the control device 91 of the charging device 90. Specifically, the control unit 4 closes the inlet-side opening / closing valve 17 via the inlet-side opening / closing valve opening / closing mechanism 19 based on the information indicating the completion of charging of the battery 81 by the charging device 90, obtained from the battery 81 of the vehicle 80. The outlet-side opening / closing valve 18 remains open. By closing the inlet-side opening / closing valve 17 via the inlet-side opening / closing valve opening / closing mechanism 19, the control unit 4 circulates the refrigerant via the bypass flow path 37 without passing through the evaporator 60, and guides the refrigerant in the evaporator 60 to the condenser 11 and causes it to flow into the storage unit 13.

[0072] 7 , in the refrigerant recovery state, when the amount of stored refrigerant detected by the detector 14 while circulating the refrigerant through the bypass flow path 37 without passing through the evaporator 60 becomes equal to or exceeds a preset amount, the controller 4 controls the outlet valve opening / closing mechanism 20 to close the outlet valve 18 to prevent refrigerant from flowing out of the outlet valve 18 toward the outlet connector 16, thereby terminating the refrigerant recovery process. The preset amount includes the preset liquid level 50. The stored refrigerant amount also includes the refrigerant liquid level.

[0073] When the evaporator 60 is not connected to the two-phase cooling system circulation device 100 (see FIG. 3 ), the detection unit 14 measures the liquid level of the liquid-phase refrigerant stored in the storage unit 13 in advance. The liquid level of the liquid-phase refrigerant stored in the storage unit 13 when the evaporator 60 is not connected, detected by the detection unit 14, is stored in the memory unit 5 as a reference liquid level 51. When the liquid level 52 of the liquid-phase refrigerant stored in the storage unit 13 in the refrigerant recovery state becomes equal to the reference liquid level 51, it can be said that the refrigerant remaining in the evaporator 60 has been recovered to the storage unit 13. However, as described above, it is not possible to recover all of the refrigerant in the evaporator 60, so the set liquid level 50 is set based on the reference liquid level 51. The set liquid level 50 is the liquid level of the liquid-phase refrigerant stored in the storage unit 13 in the refrigerant recovery state, set by subtracting a margin from the reference liquid level 51, such as the amount of refrigerant that cannot be recovered in the evaporator 60. Then, when the liquid level 52 of the liquid phase refrigerant stored in the storage section 13 during refrigerant recovery reaches or exceeds the set liquid level 50, the outlet side opening / closing valve 18 is closed via the outlet side opening / closing valve opening / closing mechanism 20 to terminate the refrigerant recovery process.

[0074] The control unit 4 acquires the reference liquid level 51 stored in the memory unit 5, and sets the set liquid level 50 by executing a program for setting the set liquid level 50 stored in the memory unit 5. The set set liquid level 50 is stored in the memory unit 5.

[0075] When the evaporator 60 is removed from the two-phase cooling system circulation device 100 after charging of the battery 81 by the charging device 90 is completed, the refrigerant is recovered from the evaporator 60 before the evaporator 60 is removed. That is, as shown in FIG. 5 , in a refrigerant recovery state in which the inlet-side opening / closing valve 17 and the vacuum pump-side opening / closing valve 12 are closed and the outlet-side opening / closing valve 18 is open, the refrigerant is circulated through the bypass flow path 37 without passing through the evaporator 60. At this time, the detection unit 14 measures the liquid level 52 of the liquid-phase refrigerant stored in the storage unit 13 in the refrigerant recovery state. When the liquid level 52 of the liquid-phase refrigerant detected by the detection unit 14 reaches or exceeds a predetermined liquid level 50 (at time t1), the control unit 4 controls the outlet-side opening / closing valve 18 via the outlet-side opening / closing valve opening / closing mechanism 20 to prevent refrigerant from flowing out of the outlet-side opening / closing valve 18 toward the outlet-side connection unit 16, thereby ending the refrigerant recovery process. Since the liquid transfer pump 10 continues to operate, the refrigerant does not flow out from the outlet side opening / closing valve 18 to the outlet side connecting portion 16 side, but circulates through the bypass flow path 37 without passing through the evaporator 60.

[0076] Furthermore, the control unit 4 closes the outlet-side opening / closing valve 18 to terminate the refrigerant recovery process, and then causes the notification unit 6 to notify the user that the refrigerant recovery process has ended. This allows the user to recognize that the refrigerant recovery process has ended, and the user can quickly open the vacuum pump-side opening / closing valve 12 and use the vacuum pump 3 to suction the refrigerant remaining in the evaporator 60. After the user uses the vacuum pump 3 to suction the refrigerant remaining in the evaporator 60 and discharge the suctioned refrigerant to the outside of the circulation cycle, the user removes the evaporator 60 installed in the vehicle 80 from the inlet-side connecting portion 15 and the outlet-side connecting portion 16. In other words, the evaporator 60 is disconnected from the circulation device 100 for a two-phase cooling system.

[0077] (Control of Replenishing Refrigerant Supply Process by Control Unit) With reference to FIG. 6, the control of replenishing refrigerant supply process by the control unit 4 will be described.

[0078] The control unit 4 is configured to supply the replenishment refrigerant stored in the replenishment refrigerant storage unit 2 to the storage unit 13 based on the detection result of the amount of refrigerant stored in the storage unit 13 by the detection unit 14 when the refrigerant is circulating through the bypass flow path 37 without passing through the evaporator 60.

[0079] Because the refrigerant recovery process cannot recover all of the refrigerant in the evaporator 60, the control unit 4 closes the outlet-side opening / closing valve 18 and terminates the refrigerant recovery process when the liquid level 52 of the liquid phase refrigerant detected by the detection unit 14 reaches or exceeds the set liquid level 50. Therefore, the total amount of refrigerant circulating through the bypass flow path 37 without passing through the evaporator 60 after the charging of the battery 81 by the charging device 90 and the refrigerant recovery process are completed is less than the total amount of refrigerant circulating through the bypass flow path 37 without passing through the evaporator 60 before the charging of the battery 81 by the charging device 90 begins and in a state where the evaporator 60 is not connected to the two-phase cooling system circulation device 100.

[0080] Therefore, after performing control to close outlet-side opening / closing valve 18 and terminate the refrigerant recovery process, control unit 4 supplies replenishment refrigerant to be stored in replenishment refrigerant storage unit 2 to storage unit 13 based on the liquid level of the liquid phase refrigerant stored in storage unit 13 detected by detection unit 14 in a state in which the refrigerant is circulating via bypass flow path 37 without passing through evaporator 60 and the reference liquid level 51 stored in memory unit 5. Specifically, when the liquid level of the liquid phase refrigerant stored in storage unit 13 detected by detection unit 14 is lower than reference liquid level 51, control unit 4 opens electromagnetic valve 23 provided in sixth refrigerant flow path 36 to supply replenishment refrigerant to be stored in replenishment refrigerant storage unit 2 to storage unit 13 so that the liquid level of the liquid phase refrigerant stored in storage unit 13 detected by detection unit 14 becomes equal to reference liquid level 51. In other words, the replenishment refrigerant stored in the replenishment refrigerant storage section 2 is supplied to the reservoir 13 so that the total amount of circulating refrigerant that has decreased after the charging of the battery 81 by the charging device 90 and the refrigerant recovery process are completed is equal to the total amount of refrigerant that circulates through the bypass flow path 37 without passing through the evaporator 60 before the charging of the battery 81 by the charging device 90 begins and when the evaporator 60 is not connected to the circulation device 100 for a two-phase cooling system.

[0081] Then, when the liquid level of the liquid phase refrigerant stored in the storage section 13 detected by the detection section 14 becomes equal to or higher than the reference liquid level 51, the control section 4 closes the electromagnetic valve 23 provided in the sixth refrigerant flow path 36 and stops the supply of replenishment refrigerant stored in the replenishment refrigerant storage section 2 to the storage section 13.

[0082] (Refrigerant Recovery Process and Refill Refrigerant Supply Process by Control Unit) The refrigerant recovery process and replenishment refrigerant supply process by the control unit 4 will be described with reference to Fig. 8. Note that the order of the processing steps can be reversed or can be executed simultaneously as long as there is no mutual contradiction.

[0083] In step S1, if the control unit 4 acquires information that charging of the battery 81 by the charging device 90 has been completed through communication with the control device 91 of the charging device 90 (Yes in step S1), the processing proceeds to step S2, and if the control unit 4 has not acquired information that charging of the battery 81 has been completed (No in step S1), the processing proceeds to step S1.

[0084] In step S2, the control unit 4 closes the inlet-side on-off valve 17 via the inlet-side on-off valve on-off mechanism 19. As a result, the refrigerant circulates through the bypass flow path 37 without passing through the evaporator 60, and the refrigerant in the evaporator 60 is led to the condenser 11 and flows into the storage unit 13. Then, the process proceeds to step S3.

[0085] In step S3, the control unit 4 acquires the liquid level 52 of the liquid-phase refrigerant stored in the storage unit 13, which is detected by the detection unit 14. Thereafter, the process proceeds to step S4.

[0086] In step S4, if the liquid level 52 of the liquid phase refrigerant acquired by the control unit 4 is equal to or greater than the set liquid level 50 (Yes in step S4), the processing proceeds to step S5, and if it is less than the set liquid level 50 (No in step S4), the processing proceeds to step S3.

[0087] In step S5, the control unit 4 closes the outlet-side opening / closing valve 18 using the outlet-side opening / closing valve opening / closing mechanism 20. After that, the process proceeds to step S6.

[0088] In step S6, the control unit 4 notifies the user that the refrigerant recovery process has been completed by the notification unit 6. After that, the process proceeds to step S7.

[0089] In step S7, if the liquid level of the liquid phase refrigerant acquired by the control unit 4 is less than the reference liquid level 51 (Yes in step S7), the processing proceeds to step S8, and if it is not less than the reference liquid level 51 (No in step S7), the processing ends.

[0090] In step S8, the control unit 4 opens the electromagnetic valve 23 to supply the refrigerant for replenishment stored in the refrigerant for replenishment storage unit 2 to the reservoir 13. Thereafter, the process proceeds to step S9.

[0091] In step S9, if the liquid level of the liquid phase refrigerant acquired by the control unit 4 is equal to or higher than the reference liquid level 51 (Yes in step S8), the processing proceeds to step S10, and if it is lower than the reference liquid level 51 (No in step S8), the processing proceeds to step S9.

[0092] In step S10, the control unit 4 closes the electromagnetic valve 23 to stop the supply of the refrigerant for replenishment stored in the refrigerant for replenishment storage unit 2 to the reservoir 13. Then, the process ends.

[0093] (Effects of First Embodiment) In the first embodiment, the following effects can be obtained.

[0094] As described above, the first embodiment includes the liquid feed pump 10, the inlet connector 15 that is detachably attached to a refrigerant inlet of the evaporator 60 that is disposed inside the vehicle 80 and in thermal contact with the battery 81 of the vehicle 80 and into which a liquid-phase refrigerant having a boiling point lower than the operating temperature of the battery 81 flows, and that is provided downstream of the liquid feed pump 10, the outlet connector 16 that is detachably attached to a refrigerant outlet of the evaporator 60 and that is provided downstream of the liquid feed pump 10, and the condenser 11 that converts the gas-phase refrigerant flowing out of the evaporator 60 to a liquid phase. This allows the battery 81 of the vehicle 80 to be efficiently cooled by two-phase cooling that utilizes the heat of vaporization (latent heat of evaporation) generated when the refrigerant changes from a liquid phase to a gas phase. This improves the cooling performance of the battery 81 of the vehicle 80.

[0095] Furthermore, in the first embodiment, the following additional effects can be obtained by configuring as follows.

[0096] That is, in the first embodiment, the bypass flow path 37 is provided, which branches downstream of the liquid feed pump 10 and upstream of the inlet-side connector 15, and causes the refrigerant to flow to the condenser 11 without passing through the inlet-side connector 15 and the outlet-side connector 16. The inlet-side connector 15 and the outlet-side connector 16 are detachable from the evaporator 60 provided in the vehicle 80. Therefore, by circulating the refrigerant through the bypass flow path 37 without passing through the inlet-side connector 15 and the outlet-side connector 16, the evaporator 60 provided in the vehicle 80 can be removed from the inlet-side connector 15 and the outlet-side connector 16, and the evaporator 60 provided in the vehicle 80 can be connected to the inlet-side connector 15 and the outlet-side connector 16 to cause the refrigerant to flow through the evaporator 60 when cooling the battery 81 of the vehicle 80. Therefore, even immediately after the evaporator 60 is connected to the inlet side connection portion 15 and the outlet side connection portion 16, cooled refrigerant at a low temperature can be flowed into the evaporator 60, so that the evaporator 60 can immediately cool the battery 81 of the vehicle 80.

[0097] Furthermore, in the first embodiment, as described above, the circulation device main body 1 includes at least the liquid feed pump 10, the condenser 11, and the bypass flow path 37. The circulation device main body 1 is provided adjacent to a charging device 90 that charges the battery 81 of the vehicle 80. When the charging device 90 is charging the battery 81 of the vehicle 80, the evaporator 60 is connected to the inlet-side connector 15 and the outlet-side connector 16, and the refrigerant is circulated through the evaporator 60. As a result, since the circulation device main body 1 including at least the liquid feed pump 10, the condenser 11, and the bypass flow path 37 is provided adjacent to the charging device 90 that charges the battery 81 of the vehicle 80, an increase in the weight of the vehicle 80 can be easily suppressed. Furthermore, when the charging device 90 is charging the battery 81 of the vehicle 80, the evaporator 60 can be easily connected to the inlet-side connector 15 and the outlet-side connector 16, and the battery 81 of the vehicle 80 can be easily and efficiently cooled.

[0098] Furthermore, in the first embodiment, as described above, the vacuum pump 3 is provided to evacuate the refrigerant flow path 64 of the evaporator 60. This makes it possible to remove impurities such as air from the refrigerant flow path 64 of the evaporator 60. Therefore, the evaporator 60 can cool the battery 81 more efficiently.

[0099] Furthermore, in the first embodiment, as described above, when the evaporator 60 is connected to the inlet-side connector 15 and the outlet-side connector 16 during charging of the battery 81 of the vehicle 80, the vacuum pump 3 draws a vacuum from the refrigerant flow path 64 of the evaporator 60 before circulating the refrigerant through the evaporator 60. This allows impurities such as air to be removed from the refrigerant flow path 64 of the evaporator 60 by drawing a vacuum before circulating the refrigerant through the evaporator 60 during charging of the battery 81 of the vehicle 80. Therefore, after circulating the refrigerant through the evaporator 60, the battery 81 can be cooled by the evaporator 60 more efficiently.

[0100] Furthermore, in the first embodiment, as described above, when the evaporator 60 is connected to the inlet-side connection 15 and the outlet-side connection 16, the vacuum pump 3 sucks the refrigerant from the evaporator 60 and discharges the sucked refrigerant to the outside after charging of the battery 81 of the vehicle 80 is completed. As a result, even if it is not possible to recover all of the refrigerant in the evaporator 60 during the refrigerant recovery process, the vacuum pump 3 can suck the refrigerant remaining in the evaporator 60, thereby removing the refrigerant remaining in the evaporator 60 and discharging the sucked refrigerant to the outside. Therefore, when the evaporator 60 is removed from the circulation device 100 for a two-phase cooling system, it is possible to prevent the liquid-phase refrigerant remaining in the evaporator 60 from vaporizing and flowing out and freezing.

[0101] Furthermore, as described above, the first embodiment includes the reservoir 13 provided downstream of the condenser 11 and upstream of the liquid feed pump 10, and the replenishment refrigerant reservoir 2 that stores replenishment refrigerant to be supplied to the reservoir 13. As a result, even if it is not possible to recover all of the refrigerant in the evaporator 60 during the refrigerant recovery process, the replenishment refrigerant stored in the replenishment refrigerant reservoir 2 can be supplied to the reservoir 13. This makes it possible to prevent the circulation device 100 for a two-phase cooling system from operating with a small total amount of circulating refrigerant.

[0102] Furthermore, as described above, the first embodiment includes the detection unit 14 that detects the amount of refrigerant stored in the storage unit 13, and the control unit 4 that controls the supply of replenishment refrigerant to be stored in the replenishment refrigerant storage unit 2 to the storage unit 13 based on the detection result of the detection unit 14 of the amount of refrigerant stored in the storage unit 13. As a result, the control unit 4 can supply the replenishment refrigerant to be stored in the replenishment refrigerant storage unit 2 to the storage unit 13 based on the detection result of the detection unit 14, so that the circulation device 100 for a two-phase cooling system can easily be prevented from operating in a state where the total amount of refrigerant circulating is small.

[0103] Furthermore, in the first embodiment, as described above, the control unit 4 is configured to supply replenishment refrigerant to be stored in the replenishment refrigerant storage unit 2 to the storage unit 13 based on the detection result of the amount of refrigerant stored in the storage unit 13 by the detection unit 14 when the refrigerant is circulating through the bypass flow path 37 without passing through the evaporator 60. This allows the control unit 4 to supply replenishment refrigerant to be stored in the replenishment refrigerant storage unit 2 to the storage unit 13 based on the amount of refrigerant stored in the storage unit 13 when the refrigerant is circulating through the bypass flow path 37 without passing through the evaporator 60, making it easier to prevent the two-phase cooling system circulation device 100 from operating in a state where the total amount of refrigerant circulating is small.

[0104] As described above, the first embodiment includes the inlet-side opening / closing valve 17, which is provided downstream of the liquid feed pump 10 between the branching portion of the bypass flow path 37 and the inlet-side connecting portion 15 and can open and close the refrigerant flow path, and the control unit 4 that controls the opening and closing of the inlet-side opening / closing valve 17. After charging of the battery 81 of the vehicle 80 is completed, the control unit 4 controls to close the inlet-side opening / closing valve 17, thereby circulating the refrigerant through the bypass flow path 37 without passing through the evaporator 60 and directing the refrigerant from the evaporator 60 to the condenser 11. Because the inlet-side opening / closing valve 17 is closed, the circulating liquid-phase refrigerant does not flow into the evaporator 60, and the evaporator 60 receives heat from the outside air, so that the temperature inside the evaporator 60 rises. Therefore, the temperature and pressure of the liquid-phase refrigerant remaining in the evaporator 60 rise, and a portion of the liquid-phase refrigerant in the evaporator 60 evaporates and changes into a gas-liquid mixture refrigerant. This creates a pressure difference between the pressure of the gas-phase refrigerant contained in the gas-liquid mixture in the evaporator 60 and the pressure of the liquid-phase refrigerant circulating in the path from the confluence 41 of the second refrigerant flow path 32 through the condenser 11, the storage 13, the liquid feed pump 10, and the bypass flow path 37, allowing the gas-liquid mixture refrigerant in the evaporator 60 to flow out from the evaporator 60 toward the confluence 41 of the second refrigerant flow path 32. Furthermore, because the liquid-phase refrigerant in the evaporator 60 can be converted into a gas-liquid mixture refrigerant by the increase in the temperature inside the evaporator 60, there is no need to provide additional equipment such as a heater for converting the refrigerant into a gas-liquid mixture. For these reasons, the refrigerant remaining in the refrigerant flow path 64 inside the evaporator 60 can be easily recovered while suppressing an increase in the number of parts and a complex structure.

[0105] Second Embodiment Next, a circulation device 110 for a two-phase cooling system and a two-phase cooling system 210 according to a second embodiment of the present invention will be described with reference to Figures 9 and 10. Unlike the first embodiment, the second embodiment describes an example in which the circulation device 110 for a two-phase cooling system includes a circulating portion 74 for circulating a refrigerant arranged therein, an inflow connection portion 75 through which the refrigerant delivered from the liquid delivery pump 10 flows into the circulating portion 74, and an outflow connection portion 76 through which the refrigerant that has flowed into the circulating portion 74 flows out. Note that the same components as those in the first embodiment are designated by the same reference numerals, and descriptions thereof will be omitted.

[0106] In the second embodiment, the circulation device 110 for a two-phase cooling system includes a charging cable 170. The charging cable 170 includes a conductor 72 disposed therein, a flow-through portion 74 through which the refrigerant disposed therein flows, an inflow connection portion 75 through which the refrigerant delivered from the liquid delivery pump 10 flows into the flow-through portion 74, and an outflow connection portion 76 through which the refrigerant that has flowed into the flow-through portion 74 flows out. When the evaporator 60 is connected to the inlet-side connection portion 15 and the outlet-side connection portion 16 during charging of the battery 81 of the vehicle 80 by the charging device 90, the circulation device 110 for a two-phase cooling system circulates the refrigerant through the flow-through portion 74 of the charging cable 170 and the evaporator 60.

[0107] The overall configuration of a circulation device 110 for a two-phase cooling system according to a second embodiment will be described with reference to Figures 9 and 10. Figures 9 and 10 show a two-phase cooling system 210 including the circulation device 110 for a two-phase cooling system in a state where an evaporator 60 is connected and a battery 81 of a vehicle 80 is being charged by a charging device 90.

[0108] 10 , the circulation device 110 for a two-phase cooling system includes a charging cable 170 configured to be able to connect the charging device 90 and the battery 81 of the vehicle 80. The charging cable 170 includes a conductor 72, a conductor accommodating portion 73, a flow-through portion 74, an inflow connection portion 75, and an outflow connection portion 76.

[0109] The conductor 72 is made of a superconducting wire. The conductor 72 is covered with an insulating sheet. The conductor 72 is disposed inside the conductor accommodating portion 73. The conductor accommodating portion 73 is made of an insulating resin material. A space is formed between the inner peripheral surface of the charging cable 170 and the outer peripheral surface of the conductor 72 covered with the insulating sheet. The conductor accommodating portion 73 may have a single-tube structure made of a resin material, or may have a double-tube structure made of a heat-insulating material.

[0110] The flow section 74 is formed in the space between the inner circumferential surface of the charging cable 170 and the outer circumferential surface of the conductor 72, and is configured to allow the refrigerant to flow through the flow section 74. The flow section 74 constitutes a part of the first refrigerant flow path 31.

[0111] The inflow connection part 75 is configured to allow the refrigerant sent from the liquid feed pump 10 to flow into the circulating part 74. The inflow connection part 75 is provided at the end of the charging cable 170 on the charging device 90 side. The inflow connection part 75 includes an inflow port 75a through which the refrigerant flows and through which the inflowing refrigerant flows into the circulating part 74. The inflow port 75a is connected to the first refrigerant flow path 31 to which the liquid feed pump 10 is connected. When the evaporator 60 is connected, the refrigerant sent from the liquid feed pump 10 flows from the first refrigerant flow path 31 through the inflow connection part 75 into the circulating part 74. The inflow connection part 75 is made of a metal material.

[0112] The outflow connection portion 76 is configured to allow the refrigerant that has flowed into the flow portion 74 to flow out. The outflow connection portion 76 is provided at the end of the charging cable 170 on the vehicle 80 side. The outflow connection portion 76 includes an outlet 76a through which the refrigerant flowing through the flow portion 74 flows out. The outlet 76a is connected to the first refrigerant flow path 31 that includes the inlet-side connection portion 15. When the evaporator 60 is connected, the refrigerant that has flowed into the flow portion 74 via the inflow connection portion 75 flows out via the outflow connection portion 76 and also flows into the evaporator 60 via the first refrigerant flow path 31 and the inlet-side connection portion 15. The outflow connection portion 76 is made of a metal material.

[0113] 9, the circulation of refrigerant in the two-phase cooling system circulation device 110 when the evaporator 60 provided in the vehicle 80 is connected and the battery 81 is being charged by the charging device 90 will be described. The inlet side opening / closing valve 17 and the outlet side opening / closing valve 18 are fully open. The vacuum pump side opening / closing valve 12 is fully closed.

[0114] Liquid-phase refrigerant is sent from the liquid feed pump 10. The refrigerant flows through the first refrigerant flow path 31. At the first branch portion 40 of the first refrigerant flow path 31, a portion of the refrigerant flows through the inlet-side opening / closing valve 17, which is fully open, and flows into the flow path 74 via the inlet connection portion 75 of the charging cable 170. The remainder of the refrigerant flows into the bypass flow path 37. The liquid-phase refrigerant that flows into the flow path 74 partially evaporates and changes into a gas-liquid mixed refrigerant. The gas-liquid mixed refrigerant flows out from the outlet connection portion 76 and flows into the first refrigerant flow path 31. The gas-liquid mixed refrigerant that flows into the first refrigerant flow path 31 flows into the evaporator 60 via the inlet connection portion 15. The liquid-phase refrigerant of the gas-liquid mixed refrigerant flowing through the refrigerant flow path 64 of the evaporator 60 partially evaporates. The gas-liquid mixed refrigerant flows out through the outlet connection portion 16 and flows into the second refrigerant flow path 32. The gas-liquid mixed refrigerant that flows into the second refrigerant flow path 32 flows through the second branch 42, the outlet-side opening / closing valve 18 that is fully open, and the junction 41. At the junction 41, the gas-liquid mixed refrigerant merges with the liquid-phase refrigerant that flows in from the bypass flow path 37. The merged gas-liquid mixed refrigerant and the liquid-phase refrigerant that flows in from the bypass flow path 37 flow into the condenser 11 in a gas-liquid mixed state. The gas-phase refrigerant of the gas-liquid mixed refrigerant that flows into the condenser 11 is condensed and changes to liquid-phase refrigerant. The condensed liquid-phase refrigerant flows from the condenser 11 through the third refrigerant flow path 33 and into the storage portion 13. The refrigerant that flows into the storage portion 13 flows through the fourth refrigerant flow path 34 and into the liquid feed pump 10.

[0115] The other configurations of the second embodiment are similar to those of the first embodiment.

[0116] (Effects of Second Embodiment) In the second embodiment, the following effects can be obtained.

[0117] As described above, the second embodiment includes a charging cable 170 configured to be connectable between the charging device 90 and the battery 81 of the vehicle 80, the charging cable 170 including an internally disposed conductor 72, a flow-through portion 74 through which a refrigerant flows, an inlet connection portion 75 through which the refrigerant delivered from the liquid delivery pump 10 flows into the flow-through portion 74, and an outlet connection portion 76 through which the refrigerant that has flowed into the flow-through portion 74 flows out. When the battery 81 of the vehicle 80 is charged by the charging device 90, with the evaporator 60 connected to the inlet-side connection portion 15 and the outlet-side connection portion 16, the refrigerant is circulated through the flow-through portion 74 and the evaporator 60 of the charging cable 170. As a result, the refrigerant cooled by the condenser 11 circulates through the flow-through portion 74 and the evaporator 60 of the charging cable 170, and therefore both the charging cable 170 and the battery 81 can be cooled when the battery 81 of the vehicle 80 is charged by the charging device 90.

[0118] The other effects of the second embodiment are the same as those of the first embodiment.

[0119] [Modifications] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above-mentioned embodiments, and further includes all modifications (modifications) within the meaning and scope of the claims.

[0120] For example, in the first and second embodiments, the circulation device for a two-phase cooling system and the two-phase cooling system are shown to have a bypass flow path that allows the refrigerant to flow to the condenser without passing through the inlet-side connector and the outlet-side connector, but the present invention is not limited to this. For example, the circulation device for a two-phase cooling system and the two-phase cooling system do not need to have a bypass flow path that allows the refrigerant to flow to the condenser without passing through the inlet-side connector and the outlet-side connector.

[0121] In the first and second embodiments, the control unit closes the inlet valve after charging of the vehicle battery is completed, thereby circulating the refrigerant through the bypass flow path without passing through the evaporator and directing the refrigerant from the evaporator to the condenser. However, the present invention is not limited to this. For example, the control unit may close the inlet valve before charging of the vehicle battery is completed, thereby circulating the refrigerant through the bypass flow path without passing through the evaporator and directing the refrigerant from the evaporator to the condenser. In this case, the control unit is configured to acquire information about the charging rate of the battery by the charging device through communication with the control device of the charging device, and to control the inlet valve to close via the inlet valve mechanism when the acquired charging rate of the battery exceeds a predetermined value. That is, in the present invention, the control unit may acquire information about charging of the battery by the charging device through communication with the control device of the charging device, and to control the inlet valve to close via the inlet valve mechanism before charging of the vehicle battery is completed based on the acquired information about charging of the battery.

[0122] In the first and second embodiments, the vacuum pump is configured to suck refrigerant from the evaporator and discharge the sucked refrigerant to the outside after charging of the vehicle battery is completed. However, the present invention is not limited to this. For example, as in the above-described modified example, the refrigerant recovery process may be started by the control unit closing the inlet valve before charging of the vehicle battery is completed, and if the refrigerant recovery process ends before charging of the vehicle battery is completed, the user may operate the vacuum pump to suck refrigerant from the evaporator and discharge the sucked refrigerant to the outside before charging of the vehicle battery is completed based on a notification from the notification unit. That is, in the present invention, the vacuum pump may be configured to suck refrigerant from the evaporator and discharge the sucked refrigerant to the outside before charging of the vehicle battery is completed.

[0123] In the first and second embodiments, the control unit controls the inlet valve to close using the inlet valve mechanism and controls the outlet valve to close using the outlet valve switch based on the detection result of the detection unit, but the present invention is not limited to this. For example, the user may perform either or both of the operations to close the inlet valve and the outlet valve.

[0124] In the second embodiment, the circulating portion of the charging cable constitutes a part of the first refrigerant flow path, and the refrigerant flows from the first refrigerant flow path into the circulating portion through an inlet connector provided at the end of the charging cable on the charging device side, flows out through an outlet connector provided at the end of the charging cable on the vehicle side, and flows into the evaporator through the first refrigerant flow path and the inlet connector. However, the present invention is not limited to this. For example, the inlet connector may be provided at the end of the charging cable on the vehicle side, the outlet connector may be provided at the end of the charging cable on the charging device side, the circulating portion of the charging cable constitutes a part of the second refrigerant flow path, and when an evaporator provided in the vehicle is connected and the battery is being charged by the charging device, refrigerant delivered from the delivery pump flows into the circulating portion through the evaporator, the outlet connector, and the inlet connector of the charging cable, flows out through the outlet connector into the second refrigerant flow path, and then flows into the condenser.

[0125] In the first and second embodiments, the evaporator is provided in a vehicle to cool the battery of the vehicle, but the present invention is not limited to this. For example, the evaporator may be provided in a mobile body to cool the battery of a mobile body including an aircraft such as a drone, a motorcycle, a ship, and a railroad car.

[0126] In addition, although the first and second embodiments have been described as including an inlet-side opening / closing valve and an outlet-side opening / closing valve, the present invention is not limited to this. For example, both the inlet-side opening / closing valve and the outlet-side opening / closing valve may not be provided, or either the inlet-side opening / closing valve or the outlet-side opening / closing valve may not be provided.

[0127] In the first and second embodiments, the bypass flow path is connected downstream of the outlet connector and upstream of the condenser, but the present invention is not limited to this. For example, the bypass flow path may be directly connected to the condenser, and may not be connected to the flow path between the outlet connector and the condenser.

[0128] In the first and second embodiments, the vacuum pump, the reservoir, and the replenishment refrigerant storage unit are provided, but the present invention is not limited to this. For example, the vacuum pump, the reservoir, and the replenishment refrigerant storage unit may not be provided.

[0129] In the first and second embodiments, the refrigerant flows from the evaporator into the condenser in a gas-liquid mixed state, but the present invention is not limited to this. For example, the refrigerant may be in a single-phase gas state when it flows from the evaporator.

[0130] In the first and second embodiments, the detection unit is a liquid level sensor, and the amount of refrigerant stored in the storage unit (the amount of recovered refrigerant) is detected by measuring the liquid level of the liquid refrigerant stored in the storage unit. However, the present invention is not limited to this. For example, the detection unit may be a differential pressure level sensor, and the amount of refrigerant stored in the storage unit (the amount of recovered refrigerant) may be detected by measuring the height of the liquid surface based on the pressure applied to the bottom surface of the storage unit. The detection unit may also be another known sensor.

[0131] In the first and second embodiments, the control unit controls the refrigerant recovery process to end when the amount of stored refrigerant detected by the detection unit becomes equal to or greater than a preset amount, but the present invention is not limited to this. For example, the control unit may control the refrigerant recovery process to end when the amount of change in the amount of stored refrigerant detected by the detection unit becomes equal to or less than a preset amount of change.

[0132] In the first and second embodiments, the condenser cools and condenses the refrigerant by heat exchange with the cooling liquid flowing in from the external chiller, but the present invention is not limited to this. For example, the refrigerant in the refrigeration cycle of the chiller may be directly flowed into the condenser of the two-phase cooling system, so that the condenser of the two-phase cooling system dissipates heat from the refrigerant in the two-phase cooling system.

[0133] Aspects It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0134] (Item 1) A circulation device for a two-phase cooling system, comprising: a liquid feed pump that feeds a refrigerant; an inlet side connector that is detachably attached to an inlet of an evaporator that is disposed inside a mobile body and is in thermal contact with a battery of the mobile body and into which the refrigerant in liquid phase flows, the inlet side connector being provided downstream of the liquid feed pump; an outlet side connector that is detachably attached to an outlet of the evaporator and being provided downstream of the liquid feed pump; and a phase change unit that is provided downstream of the outlet side connector and that converts the refrigerant in gas phase flowing out of the evaporator into liquid phase.

[0135] (Item 2) The circulation device for a two-phase cooling system according to Item 1, further comprising: a bypass flow path that branches off downstream of the liquid feed pump and upstream of the inlet connection portion, and that allows the refrigerant to flow to the phase change portion without passing through the inlet connection portion and the outlet connection portion.

[0136] (Item 3) The circulation device for a two-phase cooling system according to Item 2, further comprising a circulation device main body including at least the liquid feed pump, the condenser, and the bypass flow path, wherein the circulation device main body is attached to a charging device that charges the battery of the mobile body, and when the battery of the mobile body is being charged by the charging device, the evaporator is connected to the inlet side connection portion and the outlet side connection portion, and the refrigerant is circulated through the evaporator.

[0137] (Item 4) The circulation device for a two-phase cooling system according to any one of Items 1 to 3, further comprising a vacuum pump that draws a vacuum through the refrigerant flow path of the evaporator.

[0138] (Item 5) The circulation device for a two-phase cooling system according to Item 4, wherein the vacuum pump evacuates the refrigerant flow path of the evaporator before circulating the refrigerant through the evaporator in a state where the evaporator is connected to the inlet side connection portion and the outlet side connection portion during charging of the battery of the mobile body.

[0139] (Item 6) The circulation device for a two-phase cooling system according to Item 4 or 5, wherein the vacuum pump sucks the refrigerant from the evaporator and discharges the sucked refrigerant to the outside when charging of the battery of the mobile body is completed in a state where the evaporator is connected to the inlet side connection portion and the outlet side connection portion.

[0140] (Item 7) The circulation device for a two-phase cooling system according to any one of Items 1 to 6, further comprising: a reservoir provided downstream of the condenser and upstream of the liquid feed pump; and a refrigerant replenishment reservoir configured to store refrigerant for replenishment to be supplied to the reservoir.

[0141] (Item 8) The circulation device for a two-phase cooling system according to Item 7, further comprising: a detection unit that detects the amount of refrigerant stored in the storage unit; and a control unit that controls the supply of replenishment refrigerant to be stored in the replenishment refrigerant storage unit to the storage unit based on the detection result of the amount of refrigerant stored in the storage unit by the detection unit.

[0142] (Item 9) The circulation device for a two-phase cooling system according to item 8, further comprising: a bypass flow path that branches downstream of the liquid feed pump and upstream of the inlet connection portion, and that circulates the refrigerant to the condenser without passing through the inlet connection portion and the outlet connection portion; and the control unit is configured to supply the refrigerant for replenishment to be stored in the replenishment refrigerant storage portion to the storage portion based on a detection result of the amount of the refrigerant stored in the storage portion by the detection unit when the refrigerant is circulating through the bypass flow path without passing through the evaporator.

[0143] (Item 10) The circulation device for a two-phase cooling system according to any one of items 2 to 8, further comprising: an inlet-side opening / closing valve that is provided downstream of the liquid feed pump between the inlet-side connecting portion and a branching portion where the bypass flow path branches, and that is capable of opening and closing the flow path of the refrigerant; and a control unit that controls the opening and closing of the inlet-side opening / closing valve, wherein the control unit controls the inlet-side opening / closing valve to close when charging of the battery of the mobile body is completed, thereby circulating the refrigerant through the bypass flow path without passing through the evaporator, and directing the refrigerant in the evaporator to the condenser.

[0144] (Item 11) The circulation device for a two-phase cooling system according to item 3, further comprising: a charging cable configured to be connectable between the charging device and the battery of the mobile body, the charging cable including a conductor arranged therein, a circulation portion arranged therein through which the refrigerant circulates, an inflow connection portion through which the refrigerant delivered from the liquid delivery pump flows into the circulation portion, and an outflow connection portion through which the refrigerant that has flowed into the circulation portion flows out; and when the battery of the mobile body is charged by the charging device, the refrigerant circulates through the circulation portion of the charging cable and the evaporator when the evaporator is connected to the inlet side connection portion and the outlet side connection portion.

[0145] (Item 12) A two-phase cooling system comprising: a liquid feed pump that feeds a refrigerant; an evaporator that is provided downstream of the liquid feed pump, is disposed inside a mobile body, and is in thermal contact with a battery of the mobile body, into which the refrigerant in a liquid phase having a boiling point lower than the operating temperature of the battery flows; an inlet side connector that is provided downstream of the liquid feed pump and is attachable / detachable to an inlet of the evaporator for the refrigerant, and an outlet side connector that is attachable / detachable to an outlet of the evaporator for the refrigerant; and a phase change unit that is provided downstream of the outlet side connector and converts the gas phase refrigerant flowing out of the evaporator into a liquid phase.

[0146] REFERENCE SIGNS LIST 1 Circulation device main body 2 Replenishing refrigerant storage section 3 Vacuum pump 4 Control section 10 Liquid transfer pump 11 Condenser (phase conversion section) 13 Storage section 14 Detection section 15 Inlet side connection section 16 Outlet side connection section 17 Inlet side opening / closing valve 37 Bypass flow path 60 Evaporator 70, 170 Charging cable 72 Conductor 74 Flow section 75 Inflow connection section 76 Outflow connection section 80 Vehicle (mobile body) 81 Battery 90 Charging device 100, 110 Circulation device for two-phase cooling system 200, 210 Two-phase cooling system

Claims

1. A circulation device for a two-phase cooling system comprising: a liquid feed pump that feeds a refrigerant; an inlet side connector that is detachably attached to an inlet of an evaporator that is arranged inside a mobile body and is in thermal contact with a battery of the mobile body and into which the refrigerant in liquid phase flows, the inlet side connector being located downstream of the liquid feed pump; an outlet side connector that is detachably attached to an outlet of the evaporator and is located downstream of the liquid feed pump; and a phase change section that is located downstream of the outlet side connector and that changes the phase of the refrigerant in gas phase flowing out of the evaporator to liquid phase.

2. The circulation device for a two-phase cooling system described in claim 1, further comprising a bypass flow path that branches downstream of the liquid feed pump and upstream of the inlet side connection portion, and that circulates the refrigerant to the phase change portion without passing through the inlet side connection portion and the outlet side connection portion.

3. A circulation device for a two-phase cooling system as described in claim 2, further comprising a circulation device main body including at least the liquid feed pump, the phase change unit, and the bypass flow path, wherein the circulation device main body is attached to a charging device that charges the battery of the mobile body, and when the battery of the mobile body is being charged by the charging device, the refrigerant is circulated through the evaporator in a state where the evaporator is connected to the inlet side connection unit and the outlet side connection unit.

4. The circulation device for a two-phase refrigeration system according to claim 1, further comprising a vacuum pump for drawing a vacuum through the refrigerant flow path of the evaporator.

5. The circulation device for a two-phase cooling system described in claim 4, wherein the vacuum pump draws a vacuum from the refrigerant flow path of the evaporator before circulating the refrigerant through the evaporator when the evaporator is connected to the inlet side connection portion and the outlet side connection portion during charging of the battery of the mobile body.

6. A circulation device for a two-phase cooling system as described in claim 4, wherein the vacuum pump sucks the refrigerant from the evaporator and discharges the sucked refrigerant to the outside when charging of the battery of the mobile body is completed while the evaporator is connected to the inlet side connection portion and the outlet side connection portion.

7. The circulation device for a two-phase cooling system according to claim 1, further comprising: a reservoir section provided downstream of the phase change section and upstream of the liquid feed pump; and a refrigerant replenishment storage section for storing refrigerant to be supplied to the reservoir section.

8. The circulation device for a two-phase cooling system described in claim 7, further comprising: a detection unit that detects the amount of refrigerant stored in the storage unit; and a control unit that controls the supply of replenishment refrigerant stored in the replenishment refrigerant storage unit to the storage unit based on the detection result of the amount of refrigerant stored in the storage unit by the detection unit.

9. The circulation device for a two-phase cooling system described in claim 8, further comprising a bypass flow path that branches downstream of the liquid feed pump and upstream of the inlet side connection part, and circulates the refrigerant to the phase change part without passing through the inlet side connection part and the outlet side connection part, wherein the control part is configured to supply the refrigerant for replenishment to be stored in the replenishment refrigerant storage part to the storage part based on the detection result of the detection part of the amount of the refrigerant stored in the storage part when the refrigerant is circulating through the bypass flow path without passing through the evaporator.

10. A circulation device for a two-phase cooling system as described in claim 2, further comprising: an inlet-side opening / closing valve that is provided downstream of the liquid feed pump between the branching point where the bypass flow path branches and the inlet-side connecting part and is capable of opening and closing the flow path of the refrigerant; and a control part that controls the opening and closing of the inlet-side opening / closing valve, wherein the control part controls the inlet-side opening / closing valve to close when charging of the battery of the mobile body is completed, thereby circulating the refrigerant through the bypass flow path without passing through the evaporator and directing the refrigerant from the evaporator to the phase conversion part.

11. A circulation device for a two-phase cooling system as described in claim 3, further comprising a charging cable configured to be able to connect the charging device and the battery of the mobile body, the charging cable including a conductor arranged inside, a circulation section arranged inside and through which the refrigerant circulates, an inlet connection section through which the refrigerant delivered from the liquid delivery pump flows into the circulation section, and an outlet connection section through which the refrigerant that has flowed into the circulation section flows out, wherein when the battery of the mobile body is being charged by the charging device, the refrigerant is circulated through the circulation section of the charging cable and the evaporator when the evaporator is connected to the inlet side connection section and the outlet side connection section.

12. A two-phase cooling system comprising: a liquid feed pump that feeds a refrigerant; an evaporator that is provided downstream of the liquid feed pump and is disposed inside a mobile body, that is in thermal contact with a battery of the mobile body, and into which the refrigerant in liquid phase having a boiling point lower than the operating temperature of the battery flows; an inlet side connector that is provided downstream of the liquid feed pump and is attachable / detachable to an inlet of the evaporator for the refrigerant, and an outlet side connector that is attachable / detachable to an outlet of the evaporator for the refrigerant; and a phase conversion unit that is provided downstream of the outlet side connector and converts the refrigerant in gas phase flowing out of the evaporator into liquid phase.

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