Battery immersion thermal management safety device

Abstract

The application discloses a battery immersion type heat management safety device, wherein the upper portion of a compressor assembly is connected with the first connecting port of a four-way reversing valve, the third connecting port of the four-way reversing valve is connected with one end of a gas-liquid separator, the other end of the gas-liquid separator is connected with the compressor assembly to form a loop, one end of a condenser is connected with the second connecting port of the four-way reversing valve, the other end of the condenser is connected with a parallel circuit, the parallel circuit comprises two branches, and a heating electronic expansion valve and a refrigerating electronic expansion valve are arranged on one of the two branches. The four-way reversing valve is arranged to switch the refrigerant flow direction, the traditional secondary water cooling heat exchange loop is omitted, the refrigerating or heating capacity of the compressor assembly is directly utilized to directly cool or heat the battery pack, the indirect energy loss is reduced, and the system components are simplified. The automatic liquid supplementing system formed by cooperating with a liquid supplementing tank, a battery pack liquid level switch and an electronic oil pump ensures that the battery pack is always kept with sufficient immersion liquid, and provides liquid level safety guarantee for completely immersed battery cells.

Description

Technical Field

[0001] This invention relates to battery safety technology, and more particularly to a battery immersion thermal management safety device. Background Technology

[0002] Currently, power batteries, as the power source for everyday tools such as electric vehicles, are a key component in improving overall vehicle performance and reducing costs. Their temperature characteristics directly affect the performance, lifespan, and durability of a vehicle. Lithium-ion batteries are currently the preferred power batteries due to their advantages such as high energy density, long cycle life, low self-discharge rate, wide allowable operating temperature range, and good low-temperature effect. Therefore, while ensuring that each individual cell in the battery operates within a reasonable temperature range, it is also necessary to maintain the temperature uniformity between the individual cells.

[0003] Patent application CN202010326615.9 discloses a system and method for managing thermal energy in a vehicle with a battery and an electric propulsion system. The system monitors the current battery temperature, calculates the actual average battery temperature, and compares the calculated actual average battery temperature with a target lifespan battery temperature. If the actual average battery temperature is higher than the target lifespan battery temperature, and the current battery temperature is also higher than the target lifespan battery temperature, the system cools the battery to a temperature below the current battery temperature. However, if the actual average battery temperature is lower than the target lifespan battery temperature, and the current battery temperature is higher than the target lifespan battery temperature, the system delays cooling the battery. Therefore, in some cases, the system can avoid consuming energy to cool the battery.

[0004] Patent document with application number CN202380015705.8 discloses a heat exchanger for a battery. The battery includes one or both of a first stack and a second stack of battery cells. The heat exchanger includes heat exchanger legs and heat exchanger feet. The heat exchanger legs are positioned to be thermally coupled to one or both of the first stack and the second stack of battery cells. Furthermore, the heat exchanger legs are arranged to transfer heat energy from one or both of the first stack and the second stack to the heat exchanger feet.

[0005] The aforementioned patent documents, in conjunction with existing technology, reveal the following deficiencies in current battery immersion thermal management safety devices: As energy storage applications become more widespread, thermal management and safety of batteries are becoming increasingly important. Currently, there are almost no compatible solutions for thermal management and safety. Water-based coolants are currently used, which have poor insulation properties and can cause safety issues and easily lead to fires when leaks occur.

[0006] Specifically, the existing technology involves bottom cooling and placing an aerosol fire extinguishing device inside the battery pack; however, this solution can only delay the ignition of the fire for a period of time and cannot completely extinguish the fire source, thus failing to solve the problem of cell fires.

[0007] The existing solution involves a multi-level fire suppression system connected to an external water-based fire suppression system, which is activated directly upon ignition for a creeping fire suppression approach. Therefore, this existing technology has the following drawbacks: It is impossible to directly extinguish the fire at the point of ignition when it first starts; at the same time, coolant leakage into the battery pack can easily cause insulation problems in the entire system, which can then lead to a fire. Summary of the Invention

[0008] To overcome the shortcomings of the prior art, the present invention provides a battery immersion thermal management safety device, which solves the related problems of battery immersion thermal management safety devices.

[0009] The first aspect of this invention is to provide a battery immersion thermal management safety device, comprising a compressor assembly, a four-way reversing valve, a gas-liquid separator, a parallel circuit, a first one-way valve, a liquid receiver, a dryer filter, a heating electronic expansion valve, a second one-way valve, a cooling electronic expansion valve, a condenser, and an AC EC fan. The upper part of the compressor assembly is connected to the first connection port of the four-way reversing valve, the third connection port of the four-way reversing valve is connected to one end of the gas-liquid separator, and the other end of the gas-liquid separator is connected to the compressor assembly to form a circuit. One end of the condenser is connected to the second connection port of the four-way reversing valve, and the other end is connected to the... The system is connected in parallel, with two branches. One branch is equipped with a heating electronic expansion valve and a cooling electronic expansion valve, while the other branch is equipped with a second check valve and a first check valve. The two branches are connected at the middle, and a liquid storage tank and a drying filter are installed on the connecting line. Multiple parallel branch lines are provided between the fourth connection port of the four-way reversing valve and the parallel line. Each branch line is equipped with a manual shut-off ball valve, a battery pack level switch, a battery pack, and a manual shut-off valve. One branch line is connected in parallel to a liquid replenishment line at both ends, and the liquid replenishment line is equipped with a liquid replenishment tank, a liquid replenishment tank level switch, and an electronic oil pump.

[0010] In a first aspect of the present invention, as a preferred embodiment, a high-pressure sensor and a compressor exhaust temperature sensor are provided between the compressor assembly and the first connection port of the four-way reversing valve.

[0011] In a first aspect of the present invention, as a preferred embodiment, the battery pack is provided with an evaporator, a plurality of battery modules arranged in parallel, and an immersion liquid is also provided in the battery pack.

[0012] In a first aspect of the present invention, as a preferred embodiment, the battery pack is provided with a high-voltage connector and a low-voltage connector on its side.

[0013] In a first aspect of the invention, as a preferred embodiment, the battery immersion thermal management safety device further includes a heat pump system controller for connection to a control valve and a sensor.

[0014] In a first aspect of the invention, as a preferred embodiment, the battery immersion thermal management safety device further includes an ambient temperature sensor connected to the heat pump system controller.

[0015] In a first aspect of the present invention, as a preferred embodiment, a refrigeration expansion valve outlet temperature sensor is provided at the end of the parallel circuit, and the refrigeration expansion valve outlet temperature sensor is connected to the heat pump system controller.

[0016] In a first aspect of the present invention, as a preferred embodiment, a compressor suction temperature sensor and a low-pressure sensor are provided on the connection line between the third connection port of the four-way reversing valve and the gas-liquid separator, and the compressor suction temperature sensor and the low-pressure sensor are connected to the heat pump system controller.

[0017] In a first aspect of the invention, as a preferred embodiment, an AC EC fan is provided on the side of the condenser.

[0018] In a first aspect of the present invention, as a preferred embodiment, a heating expansion valve outlet temperature sensor is provided between the condenser and the parallel circuit.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: The upper part of the compressor assembly is connected to the first connection port of the four-way reversing valve, the third connection port of the four-way reversing valve is connected to one end of the gas-liquid separator, and the other end of the gas-liquid separator is connected to the compressor assembly to form a circuit; one end of the condenser is connected to the second connection port of the four-way reversing valve, and the other end is connected to the parallel circuit. The parallel circuit includes two branches, one of which is equipped with a heating electronic expansion valve and a cooling electronic expansion valve, and the other branch is equipped with a second check valve and a first check valve. The two branches are connected in the middle and a liquid storage tank and a drying filter are installed on the connecting line; multiple parallel branch lines are provided between the fourth connection port of the four-way reversing valve and the parallel circuit. Each branch line is equipped with a manual shut-off ball valve, a battery pack level switch, a battery pack, and a manual shut-off valve. One branch line is connected in parallel to a liquid replenishment line at both ends, and the liquid replenishment line is equipped with a liquid replenishment tank, a liquid replenishment tank level switch, and an electronic oil pump. By setting the four-way reversing valve to switch the refrigerant flow direction, the traditional secondary water-cooled heat exchange circuit is eliminated. The cooling or heating capacity of the compressor assembly is directly used to directly cool / heat the battery pack, reducing indirect energy loss and simplifying system components. At the same time, the automatic liquid replenishment system, consisting of the liquid replenishment tank, the battery pack level switch, and the electronic oil pump, ensures that the battery pack always has sufficient immersion liquid, providing a liquid level safety guarantee for the complete immersion of the battery cells. Attached Figure Description

[0020] Figure 1 This is a structural block diagram of the present invention; Figure 2 This is a diagram of the internal structure of the battery pack; Figure 3 This is a side view of the battery pack; Figure 4 This is a connection diagram of the heat pump system controller.

[0021] In the diagram: 1. Compressor assembly; 2. High-pressure sensor; 3. Compressor discharge temperature sensor; 4. Four-way reversing valve; 5. Compressor suction temperature sensor; 6. Low-pressure sensor; 7. Gas-liquid separator; 8. Manual shut-off ball valve; 9. Battery pack level switch; 10. Battery pack; 101. Evaporator; 102. Battery module; 103. High-pressure connector; 104. Low-pressure connector; 105. Immersion liquid; 11. Replenishment tank; 12. Replenishment tank level switch; 13. Electronic oil pump; 14. Manual shut-off valve; 15. Refrigeration expansion valve outlet temperature sensor; 16. First check valve; 17. Liquid receiver; 18. Dryer filter; 19. Heating electronic expansion valve; 20. Second check valve; 21. Refrigeration electronic expansion valve; 22. Heating expansion valve outlet temperature sensor; 23. Condenser; 24. AC EC fan; 25. Ambient temperature sensor. Detailed Implementation

[0022] The invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise specified, the materials and equipment used in this embodiment are commercially available. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0023] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In the description of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a connection through an intermediary, or a connection within two elements or an interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0026] like Figure 1-4As shown, a battery immersion thermal management safety device includes a compressor assembly 1, a four-way reversing valve 4, a gas-liquid separator 7, a parallel circuit, a first one-way valve 16, a liquid storage tank 17, a dryer filter 18, a heating electronic expansion valve 19, a second one-way valve 20, a cooling electronic expansion valve 21, a condenser 23, and an AC EC fan 24. The upper part of the compressor assembly 1 is connected to the first connection port of the four-way reversing valve 4, the third connection port of the four-way reversing valve 4 is connected to one end of the gas-liquid separator 7, and the other end of the gas-liquid separator 7 is connected to the compressor assembly 1 to form a circuit. One end of the condenser 23 is connected to the second connection port of the four-way reversing valve 4, and the other end is connected to the parallel circuit. The parallel circuit includes two branches. One branch is equipped with a heating electronic expansion valve 19 and a cooling electronic expansion valve 21, while the other branch is equipped with a second one-way valve 20 and a first one-way valve 16. The two branches are connected at the middle, and a liquid storage tank 17 and a dryer filter 18 are installed on the connecting line. Multiple parallel branch lines are provided between the fourth connection port of the four-way reversing valve 4 and the parallel circuit. Each branch line is equipped with a manual shut-off ball valve 8, a battery pack level switch 9, a battery pack 10, and a manual shut-off valve 14. A liquid replenishment line is connected in parallel to both ends of one branch line, and this line is equipped with a liquid replenishment tank 11, a liquid replenishment tank level switch 12, and an electronic oil pump 13. By using the four-way reversing valve 4 to switch the refrigerant flow, the traditional secondary water-cooled heat exchange circuit is eliminated. The cooling or heating capacity of the compressor assembly 1 is directly used to directly cool / heat the battery pack 10, reducing indirect energy loss and simplifying system components. Meanwhile, the automatic replenishment system consisting of the replenishment tank 11, the battery pack level switch 9, and the electronic oil pump 13 ensures that the battery pack 10 always has sufficient immersion liquid 105, providing a liquid level safety guarantee for the complete immersion of the battery cells.

[0027] In a preferred embodiment of the first aspect of the present invention, a high-pressure sensor 2 and a compressor discharge temperature sensor 3 are provided between the compressor assembly 1 and the first connection port of the four-way reversing valve 4. The high-pressure sensor 2 and the compressor discharge temperature sensor 3 are used to monitor the refrigerant status at the discharge end in real time, providing direct feedback parameters for adjusting the operating frequency of the compressor assembly 1, and ensuring the reliable operation of the compressor under different ambient temperatures and heat loads.

[0028] In a preferred embodiment of the first aspect of the present invention, the battery pack 10 includes an evaporator 101 and multiple battery modules 102 arranged in parallel. The battery pack 10 also contains an immersion liquid 105. This ensures that the battery modules 102 are completely submerged in the immersion liquid 105, allowing for comprehensive heat exchange and eliminating excessive temperature differences between the top and bottom of the battery cells. Furthermore, in the initial stage of thermal runaway and fire in the battery cells, the immersion liquid 105 can directly target the ignition point for physical cooling and oxygen-blocking fire extinguishing, fundamentally solving the problem of the spread of battery thermal runaway.

[0029] In a preferred embodiment of the first aspect of the present invention, a high-voltage connector 103 and a low-voltage connector 104 are provided on the side of the battery pack 10. This achieves high and low voltage electrical isolation between the inside and outside of the battery module 102, and, in conjunction with the non-conductive immersion liquid 105, prevents safety accidents caused by insulation failure.

[0030] In a first aspect of the invention, as a preferred embodiment, the battery immersion thermal management safety device further includes a heat pump system controller, which is used to connect to control valves and sensors. As the "brain" of the system, it centrally processes data fed back from various sensors and uniformly issues control commands to achieve intelligent and automated operation of the cooling cycle, heating cycle, and automatic liquid replenishment system.

[0031] In a first aspect of the invention, as a preferred embodiment, the battery immersion thermal management safety device further includes an ambient temperature sensor 25, which is connected to the heat pump system controller. Real-time acquisition of the external ambient temperature allows the heat pump system controller to dynamically adjust the speed of the AC EC fan 24 based on the ambient temperature, thereby improving condensation or evaporation efficiency.

[0032] In a first aspect of the invention, as a preferred embodiment, a refrigerant expansion valve outlet temperature sensor 15 is provided at the end of the parallel circuit, and the refrigerant expansion valve outlet temperature sensor 15 is connected to the heat pump system controller. This accurately obtains the refrigerant temperature before it flows into the battery pack 10, providing data support for adjusting the opening of the refrigerant electronic expansion valve 21 and preventing overcooling or incomplete evaporation.

[0033] In a preferred embodiment of the first aspect of the invention, a compressor suction temperature sensor 5 and a low-pressure sensor 6 are provided on the connection line between the third connection port of the four-way reversing valve 4 and the gas-liquid separator 7. The compressor suction temperature sensor 5 and the low-pressure sensor 6 are connected to the heat pump system controller. By accurately calculating the return gas superheat using the compressor suction temperature sensor 5 and the low-pressure sensor 6, the refrigerant entering the compressor assembly 1 is ensured to be in a gaseous state, preventing liquid slugging from damaging the compressor.

[0034] In a first aspect of the invention, as a preferred embodiment, an AC EC fan 24 is provided on the side of the condenser 23. The AC EC fan 24 forces air convection, accelerating heat exchange between the condenser 23 and the external environment, and supports stepless speed regulation, reducing energy consumption and noise.

[0035] In a first aspect of the invention, as a preferred embodiment, a heating expansion valve outlet temperature sensor 22 is provided between the condenser 23 and the parallel circuit. During the heating cycle, the state of the refrigerant flowing out of the condenser 23 is monitored, providing a control basis for the precise throttling and pressure reduction of the heating electronic expansion valve 19.

[0036] It should be specifically noted that the immersion fluid 105 is an insulating coolant such as electronic fluorinated liquid or insulating silicone oil, which has high insulation strength and excellent specific heat capacity. This solves the short circuit and fire hazards caused by leakage in traditional water cooling systems, and even if leakage occurs inside the battery pack 10, it will not damage the electrical insulation performance of the system.

[0037] It should be specifically explained that the refrigeration cycle operation of this device is as follows: when the cell temperature is higher than the target temperature value, a command is issued to start the refrigeration cycle. After being compressed by the compressor assembly 1, the refrigerant becomes a high-temperature and high-pressure gas, which passes through the high-pressure sensor 2 and the compressor exhaust temperature sensor 3 in sequence and enters the four-way reversing valve 4, flowing to the condenser 23 for heat dissipation and condensation. The condensed liquid refrigerant is throttled and depressurized by the refrigeration electronic expansion valve 21, and enters the evaporator 101 inside each battery pack 10 through the manual shut-off valve 14 to absorb the heat of the immersion liquid 105. The evaporated gaseous refrigerant passes through the battery pack liquid level switch 9 and the manual shut-off ball valve 8, passes through the four-way reversing valve 4 again, and returns to the compressor assembly 1 through the gas-liquid separator 7.

[0038] It should be specifically explained that the heating cycle operation of this device is as follows: when the cell temperature is lower than the target temperature, a command is issued to start the heating cycle. After the refrigerant is compressed by the compressor assembly 1, it flows directly to the branch pipeline through the four-way reversing valve 4 and enters the evaporator 101 inside the battery pack 10 for condensation and heat release, heating the submerged liquid 105; after releasing heat, the refrigerant is throttled and depressurized by the heating electronic expansion valve 19 and enters the external condenser 23 to absorb ambient heat, and finally returns to the compressor assembly 1 through the four-way reversing valve 4 and the gas-liquid separator 7.

[0039] It should be noted that during system operation, the heat pump system controller employs multiple control algorithms to achieve precise thermal management: 1. The cooling electronic expansion valve 21 and the heating electronic expansion valve 19 use the TD algorithm or a similar predictive control algorithm to adjust the opening of the expansion valve, so as to quickly respond to changes in cell temperature and reduce temperature fluctuations; 2. The compressor assembly 1 uses a PID algorithm for speed regulation, and avoids sudden increases in energy consumption and equipment impact through smooth frequency conversion; 3. The AC EC fan 24 adopts a proportional adjustment method, and adjusts the fan speed in real time according to the temperature data collected by the ambient temperature sensor 25.

[0040] Regarding the automatic fluid replenishment logic, it should be noted that: when any of the battery pack level switches 9 detects a level alarm, the heat pump system controller starts the electronic oil pump 13 to pump the immersion fluid 105 in the replenishment tank 11 into the corresponding battery pack 10; excess immersion fluid 105 can flow back to the replenishment tank 11 through the drain pipe. If the replenishment tank level switch 12 triggers an alarm, it prompts manual replenishment.

[0041] Regarding the safety extinguishing mechanism, it should be noted that when a battery cell experiences a short circuit or thermal runaway, because the battery cell is completely submerged in the insulating impregnation liquid 105, the ignition point is directly surrounded by the insulating liquid. The system utilizes the sensible heat absorption and latent heat of vaporization of the impregnation liquid 105 to rapidly remove a large amount of heat and physically isolates oxygen, thereby extinguishing the fire source instantly in its early stages. This completely solves the industry problem that traditional aerosol fire extinguishing devices can only delay ignition but cannot completely eliminate the fire source.

[0042] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A battery immersion thermal management safety device, characterized in that, The system includes a compressor assembly, a four-way reversing valve, a gas-liquid separator, a parallel circuit, a first check valve, a liquid receiver, a dryer filter, a heating electronic expansion valve, a second check valve, a cooling electronic expansion valve, a condenser, and an AC EC fan. The upper part of the compressor assembly is connected to the first connection port of the four-way reversing valve, the third connection port of the four-way reversing valve is connected to one end of the gas-liquid separator, and the other end of the gas-liquid separator is connected to the compressor assembly to form a circuit. One end of the condenser is connected to the second connection port of the four-way reversing valve, and the other end is connected to the parallel line. The parallel line includes two branches, one of which is equipped with a heating electronic expansion valve and a cooling electronic expansion valve, and the other branch is equipped with a second check valve and a first check valve. The two branches are connected in the middle and a liquid storage tank and a drying filter are installed on the connecting line. The fourth connection port of the four-way reversing valve is provided with multiple parallel branch lines between it and the parallel line. Each branch line is equipped with a manual shut-off ball valve, a battery pack level switch, a battery pack, and a manual shut-off valve. One branch line is connected to a replenishment line in parallel at both ends. The replenishment line is equipped with a replenishment tank, a replenishment tank level switch, and an electronic oil pump.

2. The battery immersion thermal management safety device as described in claim 1, characterized in that: A high-pressure sensor and a compressor exhaust temperature sensor are installed between the compressor assembly and the first connection port of the four-way reversing valve.

3. The battery immersion thermal management safety device as described in claim 1, characterized in that: The battery pack contains an evaporator, multiple battery modules arranged in parallel, and an immersion liquid.

4. The battery immersion thermal management safety device as described in claim 3, characterized in that: The battery pack is provided with a high-voltage connector and a low-voltage connector on its side.

5. The battery immersion thermal management safety device as described in claim 1, characterized in that: The battery immersion thermal management safety device also includes a heat pump system controller, which is used to connect to control valves and sensors.

6. The battery immersion thermal management safety device as described in claim 5, characterized in that: The battery immersion thermal management safety device also includes an ambient temperature sensor, which is connected to the heat pump system controller.

7. The battery immersion thermal management safety device as described in claim 5, characterized in that: A refrigeration expansion valve outlet temperature sensor is installed at the end of the parallel circuit, and the refrigeration expansion valve outlet temperature sensor is connected to the heat pump system controller.

8. The battery immersion thermal management safety device as described in claim 5, characterized in that: A compressor suction temperature sensor and a low-pressure sensor are installed on the connection line between the third connection port of the four-way reversing valve and the gas-liquid separator. The compressor suction temperature sensor and the low-pressure sensor are connected to the heat pump system controller.

9. The battery immersion thermal management safety device as described in claim 1, characterized in that: An AC EC fan is installed on the side of the condenser.

10. The battery immersion thermal management safety device as described in claim 1, characterized in that: A heating expansion valve outlet temperature sensor is installed between the condenser and the parallel circuit.

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