Liquid cooling and fire prevention system for electrochemical energy storage devices
By introducing liquid cooling modules and fireproof modules into electrochemical energy storage devices, effective heat dissipation and fire control are achieved, solving the problems of heat accumulation and fire risk in energy storage systems and ensuring the safe and stable operation of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO ANTON ELECTRICAL TECH CO
- Filing Date
- 2025-05-23
- Publication Date
- 2026-06-09
AI Technical Summary
Electrochemical energy storage systems cannot effectively dissipate the heat generated during operation, leading to heat accumulation that affects the normal operation of the system and may even cause a fire. Furthermore, the coolant in existing liquid cooling systems may exacerbate the fire and endanger electrical safety during a fire.
The heat dissipation is achieved through liquid cooling modules and return modules of the thermal management subsystem. In the event of fire risk or fire, the fireproof module uses liquid carbon dioxide to extinguish fires and dissipate heat in the coolant pipeline, ensuring that the energy exchanger operates in a low-temperature environment.
It effectively dissipates heat from energy storage devices, prevents fire spread, ensures electrical safety, reduces equipment damage and the probability of accident reignition, and improves system reliability.
Smart Images
Figure CN224342339U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage systems, and in particular to a liquid cooling and fire protection system for an electrochemical energy storage device. Background Technology
[0002] Energy storage technologies include mechanical energy storage, electrical energy storage, electrochemical energy storage, thermal energy storage, and chemical energy storage.
[0003] Electrochemical energy storage is suitable for large-scale, high-capacity applications such as system peak shaving, large-scale emergency power supply, and renewable energy integration. Electrochemical energy storage systems are providing increasingly comprehensive power storage solutions for industrial and commercial users in various regions.
[0004] Lithium-ion battery solutions in electrochemical energy storage systems require integrated installation during construction. However, these systems inevitably generate heat during operation. If this heat is not dissipated in time, it can affect the normal operation of the system and even the safety of the batteries, such as causing battery explosions. Due to the integrated installation, airflow cooling is generally insufficient or cannot ensure that all parts of the energy storage system meet the heat dissipation requirements. Therefore, liquid cooling is a better approach.
[0005] Since liquid cooling requires the use of coolant, if the characteristics of the coolant do not meet the performance requirements such as electrical insulation and fire extinguishing, when a certain part of the energy storage system overheats and causes a fire risk or a fire has already occurred, the coolant delivery pipe may burst due to overheating, which will aggravate the fire and endanger the electrical safety characteristics, especially when the battery itself explodes. Utility Model Content
[0006] In order to better dissipate heat from the chemical energy storage system without affecting fire relief, this application provides a liquid cooling and fire protection system for electrochemical energy storage equipment.
[0007] The liquid cooling and fire protection system for an electrochemical energy storage device provided in this application adopts the following technical solution:
[0008] A liquid cooling and fire protection system for an electrochemical energy storage device includes a thermal management subsystem and an emergency subsystem. The thermal management subsystem includes a liquid cooling module and a return module. The liquid cooling module includes a liquid cooling tank, a delivery pump, a shut-off solenoid valve, a coolant pipe, and an energy exchanger. The return module includes a liquid cooling tank, a return solenoid valve, and a return pipe. The delivery pump inputs coolant from the liquid cooling tank into the coolant pipe. The shut-off solenoid valve is installed on the coolant pipe, and the return solenoid valve is installed on the return pipe. The shut-off solenoid valve and the return solenoid valve open and close synchronously with the delivery pump. The coolant pipe connects the liquid cooling tank, the delivery pump, the shut-off solenoid valve, and the energy exchanger. The return pipe connects the liquid cooling tank, the return solenoid valve, and the energy exchanger. The coolant pipe is provided with a distribution section for distributing coolant to the energy exchanger, and the return pipe is provided with a return section for the coolant in the energy exchanger to flow back into the liquid cooling tank. The emergency subsystem includes... The fireproof module includes a liquid carbon dioxide tank, an inlet pipe, a pressure reducing valve, an on / off solenoid valve, a spray solenoid valve, and a spray nozzle. The on / off solenoid valve and the spray solenoid valve open and close synchronously. When the spray solenoid valve opens, the closing switch solenoid valve and the return solenoid valve close simultaneously. When the spray solenoid valve closes, the closing switch solenoid valve and the return solenoid valve open simultaneously. Liquid carbon dioxide passes through the liquid carbon dioxide tank, the pressure reducing valve, and the on / off solenoid valve, and exits through the inlet pipe, the coolant pipe, the spray solenoid valve, and the spray nozzle. The spray solenoid valve and the spray nozzle are arranged parallel to the end of the coolant pipe at each energy exchanger, and the nozzle of the spray nozzle faces the heat source at the energy exchanger. The liquid carbon dioxide in the liquid carbon dioxide tank is forced into the inlet pipe through the pressure reducing valve and enters the coolant pipe, and is sprayed out from the nozzle of the spray nozzle.
[0009] By adopting the above technical solution, the liquid cooling module and return module of the thermal management subsystem dissipate heat from the energy exchanger. When the energy storage device enters the normal operation program, the operation programs of the liquid cooling module and return module are started simultaneously, so that the coolant always circulates between the liquid cooling tank, coolant pipe, energy exchanger, return pipe, and liquid cooling tank, ensuring that the energy exchanger always operates in a normal low-temperature environment. The fire prevention module is set up so that when the energy exchanger or other parts are at risk of fire due to overheating or a fire has already occurred, the injection solenoid valve and start solenoid valve at the accident site are opened, and the infusion pump, the closing switch solenoid valve, and the return solenoid valve are closed simultaneously. Liquid carbon dioxide is then injected into the coolant pipe. Initially, the liquid carbon dioxide is injected into the coolant pipe and, together with the coolant in the pipe, is forced out of the energy exchanger or other parts at the accident site, accelerating the heat dissipation at the accident site.
[0010] Optionally, the coolant pipe includes an input end, a distribution section, and a cooling section; the solenoid valve for sealing is installed after the input end, and the infusion pump is installed before the input end.
[0011] Optionally, the return module further includes a return pipe, which includes the return section and a confluence section, and the return solenoid valve is installed in front of the return section.
[0012] Optionally, the fireproof module further includes an accelerated cooling pipe, which includes the inlet pipe, a liquid distribution section, and a cooling section. The pressure reducing valve is installed before the solenoid valve, and the injection solenoid valve is installed after the cooling section.
[0013] Optionally, when the infusion pump starts, the shut-off solenoid valve and the return solenoid valve are opened simultaneously, allowing the coolant in the liquid cooling tank to flow into the coolant pipe. When the infusion pump stops, the shut-off solenoid valve and the return solenoid valve are closed simultaneously, blocking the flow of coolant between the liquid cooling tank and the coolant in the coolant pipe.
[0014] By adopting the above technical solution, when the injection solenoid valve at the accident site is opened, the infusion pump, return solenoid valve, and shut-off solenoid valve are simultaneously shut down, and the opening and closing solenoid valves are simultaneously opened, ensuring the effectiveness of the fire protection module function of the emergency subsystem.
[0015] Optionally, when the injection solenoid valve is activated, the opening and closing solenoid valve is opened simultaneously, and the infusion pump, the shut-off solenoid valve, and the return solenoid valve are closed simultaneously, so that the liquid carbon dioxide in the carbon dioxide tank can be forced into the coolant pipe and sprayed out from the spray nozzle. When the injection solenoid valve is closed, the opening and closing solenoid valve is closed simultaneously to block the spraying of liquid carbon dioxide in the carbon dioxide tank, and the infusion pump, the shut-off solenoid valve, and the return solenoid valve are opened simultaneously to activate the liquid cooling function.
[0016] In summary, the liquid cooling module and return module of the thermal management subsystem dissipate heat from the energy exchanger. When the energy storage device enters its normal operating procedure, the operation procedures of the liquid cooling module and return module are simultaneously activated, ensuring that the coolant continuously circulates between the liquid cooling tank, coolant pipes, energy exchanger, return pipes, and liquid cooling tank, thus ensuring that the energy exchanger always operates in a normal low-temperature environment. The fire prevention module, when the energy exchanger or other components overheat and pose a fire risk, or when a fire has already occurred, opens the injection solenoid valve and start solenoid valve at the location of the incident, simultaneously closing the infusion pump, shutting off the switch solenoid valve, and the return solenoid valve. Liquid carbon dioxide is then pressurized into the coolant pipes. Initially, the liquid carbon dioxide is forced into the coolant pipes and, together with the coolant in the pipes, is forced out of the energy exchanger or other components at the location of the incident, accelerating heat dissipation at the incident site. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the basic scheme of the fire protection system in the embodiments of this application;
[0018] Figure 2 This is a side view of the fire protection system in the embodiments of this application;
[0019] Figure 3 This is a schematic diagram of an optimized fire protection system according to an embodiment of this application.
[0020] Explanation of reference numerals in the attached diagram: 1. Energy exchanger; 2. Liquid cooling tank; 3. Infusion pump; 4. Coolant pipe; 41. Input end; 42. Return section; 43. Distributor section; 44. Cooling section; 45. Merging section; 5. Return pipe; 6. Injection solenoid valve; 7. Accelerated cooling pipe; 71. Liquid carbon dioxide tank; 73. Inlet pipe; 74. On / off solenoid valve; 8. Spray nozzle; 9. Closing switch solenoid valve; 10. Pressure reducing valve; 11. Return solenoid valve. Detailed Implementation
[0021] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.
[0022] This application discloses a liquid cooling and fire protection system for an electrochemical energy storage device.
[0023] A liquid cooling and fire protection system for an electrochemical energy storage device includes a thermal management subsystem and an emergency subsystem. The thermal management subsystem monitors the temperature of the energy exchanger 1 in the energy storage system and dissipates heat from the energy exchanger 1. The emergency subsystem is used for emergency handling when the temperature of the energy exchanger 1 becomes too high and out of control. The energy exchanger 1 is integrated, with multiple sets of energy exchangers 1 interconnected and arranged independently. The thermal management subsystem also independently controls each set of energy exchangers 1, and can independently control each set of energy exchangers 1 according to its status.
[0024] Specifically, the thermal management subsystem includes a liquid cooling module and a detection module. The liquid cooling module dissipates heat from the energy exchanger 1, and the detection module monitors the temperature of the energy exchanger 1 in real time. Based on the temperature of the energy exchanger 1 detected by the detection module, the operation of the liquid cooling module and the activation of the emergency subsystem are controlled. The various probes (temperature sensors) of the detection module are distributed in parallel at the maximum temperature rise points of each energy exchanger 1, such as the battery connection terminals and electrical switch contacts, to monitor the temperature status at each location and thereby control the opening and closing of the solenoid valves and the start and stop of the infusion pump 3 in the thermal management subsystem and the emergency management subsystem. The liquid cooling module includes a liquid cooling tank 2, an infusion pump 3, and a coolant pipe 4. The liquid cooling tank 2 is used to store coolant. In this embodiment, the liquid cooling tank 2 contains coolant suitable for electrochemical energy storage equipment, specifically Anmei data center cooling medium YT198. Heat dissipation devices can be arranged around the liquid cooling tank 2 for heat dissipation and exchange of the coolant. The capacity of the liquid cooling tank 2 can be configured according to the capacity of the electrochemical energy storage equipment.
[0025] The infusion pump 3 inputs the coolant from the liquid cooling tank 2 into the coolant pipe 4. The infusion pump 3 is installed and fixed on the liquid cooling tank 2 and draws coolant from the bottom of the liquid cooling tank 2. Specifically, the infusion pump 3 is installed on the top of the liquid cooling tank 2, and part of the infusion pump 3 extends into the interior of the liquid cooling tank 2 to draw coolant from the bottom of the liquid cooling tank 2, which makes the sealing requirements between the infusion pump 3 and the liquid cooling tank 2 lower, and the vertically extended part of the output end of the infusion pump 3 can be shorter.
[0026] Coolant pipe 4 is arranged in contact with energy exchanger 1. The flow of coolant within coolant pipe 4 removes heat from energy exchanger 1, thus completing heat dissipation. Coolant pipe 4 is equipped with an inlet 41, a return section 42, a distribution section 43, a cooling section 44, and a confluence section 45. Multiple cooling sections 44 correspond one-to-one with multiple sets of energy exchangers 1. The distribution section 43 is horizontally arranged and connects to each cooling section 44. The end of each cooling section 44 furthest from the distribution section 43 connects to the confluence section 45. The confluence section 45 is also horizontally arranged, with its height lower than that of the distribution section 43. The cooling sections 44 surround energy exchanger 1 and are installed in contact with its outer surface for heat dissipation. The position of the distribution section 43 includes... In the primary circuit of the electrochemical energy storage device, where the heat generation is high, such as at the contact points of various control and protection switches and the connection points of wiring terminals, and at the terminal position of the liquid distribution section 43, a jet solenoid valve 6 is required. The outlet of the jet solenoid valve 6 is equipped with a spray nozzle 8, which is directed towards the heat-generating parts, such as the connection terminals of various energy exchangers 1 and the contacts of electrical switches. The cooling section 44 gradually decreases in height from the end connected to the liquid distribution section 43 to the end connected to the confluence section 45. At the same time, the input end 41 is vertically set to raise the height of the coolant input and connect to the liquid distribution section 43. The return section 42 connects the confluence section 45 and the liquid cooling tank 2 for the coolant to return to the liquid cooling tank 2. Ultimately, when there is no further power, the coolant can also flow back into the liquid cooling tank 2 under the action of gravity.
[0027] The aforementioned return section 42 is connected to the upper part of the liquid cooling tank 2 and is higher than the height of the coolant inside the liquid cooling tank 2.
[0028] When the infusion pump 3 is installed on the top of the liquid cooling tank 2, the height of the input end 41 does not need to be raised too much. It is only necessary that there is sufficient distance between the height of the coolant in the liquid cooling tank 2 and the top wall of the liquid cooling tank 2.
[0029] The emergency subsystem includes a fire protection module, which includes a liquid carbon dioxide tank 71, an accelerated cooling pipe 7, an on / off solenoid valve 74, and the aforementioned injection solenoid valve 6. A shut-off solenoid valve 9 is installed between the accelerated cooling pipe 7 and the infusion pump 3 on the coolant pipe 4.
[0030] The accelerated cooling pipe 7 includes an inlet pipe 73, the aforementioned liquid distribution section 43, and a cooling section 44.
[0031] Liquid carbon dioxide in liquid carbon dioxide tank 71 enters coolant pipe 4 through inlet pipe 73. Solenoid valve 74 is installed on inlet pipe 73, and inlet pipe 73 is connected to input end 41 of coolant pipe 4. A pressure reducing valve 10 is provided between solenoid valve 74 and coolant pipe 4. The pressure reducing valve 10 is the same as the pressure reducing valve 10 used on gas cylinders in households.
[0032] The pressure reducing valve 10 is installed before the opening and closing solenoid valve 74, and the injection solenoid valve 6 is installed after the cooling section 44. When the injection solenoid valve 6 is activated, the opening and closing solenoid valve 74 is opened simultaneously, and the infusion pump 3, the shut-off solenoid valve 9, and the return solenoid valve 11 are closed simultaneously. This allows the liquid carbon dioxide in the carbon dioxide tank 71 to be forced into the coolant pipe 4 and sprayed out from the spray nozzle 8. When the injection solenoid valve 6 is closed, the opening and closing solenoid valve 74 is closed simultaneously, blocking the spraying out of the liquid carbon dioxide in the carbon dioxide tank 71. At the same time, the infusion pump 3, the shut-off solenoid valve 9, and the return solenoid valve 11 are opened, thus activating the liquid cooling function.
[0033] In the above implementation scheme, coolant recovery and liquid carbon dioxide injection are performed synchronously by all energy exchangers 1. In order to allow each energy exchanger 1 to handle emergency situations independently, the optimized scheme is as follows: there are multiple coolant pipes 4, and the coolant pipes 4 do not have a confluence section 45 and a distribution section 43. There are multiple infusion pumps 3 and multiple coolant pipes 4. The infusion pumps 3, coolant pipes 4 and energy exchangers 1 are all in one-to-one correspondence. Each coolant pipe 4 includes only one cooling section 44 and is installed at the corresponding energy exchanger 1. The infusion pump 3 is still installed at the input end 41 of the coolant pipe 4. Multiple accelerated cooling pipes 7 are also provided. Multiple accelerated cooling pipes 7 are connected to the input end 41 of each coolant pipe 4 in one-to-one correspondence. Each accelerated cooling pipe 7 is equipped with an on / off solenoid valve 74.
[0034] The implementation principle of the liquid cooling and fire prevention system for an electrochemical energy storage device according to an embodiment of this application is as follows: When the system enters the working state and the liquid cooling function of the thermal management subsystem is activated, the inlet pump 3 is started, and the closing switch solenoid valve 9 and the return solenoid valve 11 are opened simultaneously. The coolant in the liquid cooling tank 2 flows through the inlet pump 3, the input end 41, the closing switch solenoid valve 9, the liquid distribution part 43, and the coolant flow into the energy exchanger 1 to cool it. Then, the coolant is collected at the confluence part 45, the return part 42, and the return solenoid valve 11, and flows back into the liquid cooling tank 2. In this way, the liquid cooling technology is used to circulate the heat-generating parts of the energy storage device, effectively and reliably preventing the energy exchanger 1 and other parts of the energy storage device from overheating, and maximizing the working efficiency of the energy storage device. The detection module is always in an automatic monitoring program. When one or more parts of the energy exchanger 1 overheat and pose a fire risk, or when a fire has already occurred at the energy exchanger 1, the detection module automatically detects the accident. The control system, according to the control program requirements, when it confirms the need to execute a certain protection function, sends an abnormal working status information to the administrator via local and remote alarm transmission or real-time video to notify them to immediately initiate maintenance and repair procedures (this is the alarm information condition during the alarm phase). When in automatic protection mode, the control system simultaneously sends an abnormal working status information to the administrator via local and remote alarm transmission or real-time video to notify them to immediately initiate maintenance and repair procedures, and issues a command to switch the equipment's power supply to mains power (in the same state, it also activates the corresponding ventilation louvers and exhaust system of the energy storage equipment). Simultaneously, it activates the accelerated cooling function of the emergency subsystem, first opening the injection solenoid valve 6 to directly spray coolant onto the accident site for cooling, and immediately opening and closing the valve. Solenoid valve 74 pressurizes the liquid carbon dioxide in liquid carbon dioxide tank 71 into return liquid section 42, shuts off infusion pump 3, closes switch solenoid valve 9, and closes return liquid solenoid valve 11. The liquid carbon dioxide, along with the coolant stored in return liquid section 42 and distribution section 43, is then expelled from the spray nozzle 8 at the accident site. Due to the large amount of heat absorbed during the vaporization of coolant and liquid carbon dioxide (and because coolant and carbon dioxide have excellent electrical insulation properties, electrical breakdown between the positive and negative electrodes of the battery pack will not occur, nor will the electrical insulation performance be reduced). The system implements rapid cooling and / or fire extinguishing operations at the accident site. The duration is controlled according to the accident condition. After the coolant in the liquid distribution section 43 is exhausted, the system will be cooled and / or extinguished entirely by liquid carbon dioxide or its vaporized form. This ensures that the risk of fire due to overheating or the extinguishing of a fire accident is minimized in its early stages. The system can also quickly cool down the accident site to ensure that no open flames are generated (even if there are open flames, the fire extinguishing function of carbon dioxide can quickly extinguish them).This system not only saves on material losses (such as coolant) but also enhances arc-extinguishing capabilities (using carbon dioxide cooling fire extinguishing technology). Once the temperature at the accident site drops below a low temperature and the monitoring module detects that the energy storage device is in a safe state, the control system stops the accelerated cooling function of the emergency subsystem and restores the liquid cooling function of the thermal management subsystem. It issues a shutdown / opening solenoid valve 74, closes the injection solenoid valve 6 at the accident site, then starts the infusion pump 3, and simultaneously opens the closing switch solenoid valve 9 and the return solenoid valve 11, thus restarting the liquid cooling process normally. During this patented function, because the accelerated cooling function is accompanied by cooling and / or fire extinguishing at the accident site, it greatly facilitates the administrator's subsequent investigation and handling of the accident site, and significantly reduces the probability of reignition at the accident site.
[0035] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A liquid cooling and fire protection system for an electrochemical energy storage device, characterized in that: The system includes a thermal management subsystem and an emergency subsystem. The thermal management subsystem includes a liquid cooling module and a return module. The liquid cooling module includes a liquid cooling tank (2), a delivery pump (3), a shut-off solenoid valve (9), a coolant pipe (4), and an energy exchanger (1). The return module includes a liquid cooling tank (2), a return solenoid valve (11), a return pipe (5), and an energy exchanger (1). The delivery pump (3) inputs the coolant from the liquid cooling tank (2) into the coolant pipe (4). The shut-off solenoid valve (9) is installed on the coolant pipe (4), and the return solenoid valve (11) is installed on the return pipe (5). The solenoid valve (9), the return solenoid valve (11), and the infusion pump (3) are switched synchronously. The coolant pipe (4) is connected to the liquid cooling tank (2), the infusion pump (3), the shut-off solenoid valve (9), and the energy exchanger (1). The return pipe (5) is connected to the liquid cooling tank (2), the return solenoid valve (11), and the energy exchanger (1). The coolant pipe (4) is provided with a distribution section (43) for distributing coolant to the energy exchanger (1). The return pipe (5) is provided with a return section (42) for the coolant in the energy exchanger (1) to flow back to the liquid cooling tank (2). The emergency subsystem includes a fire prevention module. The fire module includes a liquid carbon dioxide tank (71), an inlet pipe (73), a pressure reducing valve (10), an on / off solenoid valve (74), an injection solenoid valve (6), and a spray nozzle (8). The on / off solenoid valve (74) opens and closes synchronously with the injection solenoid valve (6). Simultaneously, when the injection solenoid valve (6) is open, the closing switch solenoid valve (9) and the return solenoid valve (11) are closed synchronously. When the injection solenoid valve (6) is closed, the closing switch solenoid valve (9) and the return solenoid valve (11) are opened synchronously. Liquid carbon dioxide passes through the liquid carbon dioxide tank (71), the pressure reducing valve (10), the on / off solenoid valve (74), and the inlet pipe (73). The inlet pipe (73), the coolant pipe (4), the injection solenoid valve (6), and the spray nozzle (8) are arranged at the end of the coolant pipe (4) at each energy exchanger (1) and are parallel to the energy exchanger (1). The nozzle of the spray nozzle (8) faces the heat point at the energy exchanger (1). The liquid carbon dioxide tank (71) is pressurized into the inlet pipe (73) through the pressure reducing valve (10) and enters the coolant pipe (4), and is sprayed out from the nozzle of the spray nozzle (8).
2. The liquid cooling and fire prevention system for an electrochemical energy storage device according to claim 1, characterized in that: The liquid cooling module also includes a coolant pipe (4), which includes an input end (41), a liquid distribution section (43), and a cooling section (44). The solenoid valve (9) is installed after the input end (41), and the liquid pump (3) is installed before the input end (41).
3. The liquid cooling and fire prevention system for an electrochemical energy storage device according to claim 1, characterized in that: The liquid return module also includes a liquid return pipe (5), which includes the liquid return section (42) and a confluence section (45). The liquid return solenoid valve (11) is installed in front of the liquid return section (42).
4. The liquid cooling and fire protection system for an electrochemical energy storage device according to claim 2, characterized in that: The fireproof module also includes an accelerated cooling pipe (7), which includes the inlet pipe (73), the liquid distribution section (43) and the cooling section (44). The pressure reducing valve (10) is installed before the solenoid valve (74), and the injection solenoid valve (6) is installed after the cooling section (44).
5. The liquid cooling and fire prevention system for an electrochemical energy storage device according to claim 3, characterized in that: When the infusion pump (3) starts, the solenoid valve (9) and the return solenoid valve (11) are opened simultaneously, so that the coolant in the liquid cooling tank (2) can be pumped into the coolant pipe (4). When the infusion pump (3) is shut down, the solenoid valve (9) and the return solenoid valve (11) are closed simultaneously, so that the flow of coolant in the liquid cooling tank (2) and coolant in the coolant pipe (4) is blocked.
6. The liquid cooling and fire protection system for an electrochemical energy storage device according to claim 1, characterized in that: When the injection solenoid valve (6) is activated, the opening and closing solenoid valve (74) is opened simultaneously, and the infusion pump (3), the shut-off solenoid valve (9), and the return solenoid valve (11) are closed simultaneously. This allows the liquid carbon dioxide in the carbon dioxide tank (71) to be forced into the coolant pipe (4) and sprayed out from the spray nozzle (8). When the injection solenoid valve (6) is closed, the opening and closing solenoid valve (74) is closed simultaneously, blocking the spraying out of the liquid carbon dioxide in the carbon dioxide tank (71). At the same time, the infusion pump (3), the shut-off solenoid valve (9), and the return solenoid valve (11) are opened, activating the liquid cooling function.