Liquid cooling heat management system and control method thereof

Abstract

The invention discloses a liquid cooling heat management system and a control method thereof, which overcome the problems of poor heat dissipation capability and uneven heat dissipation of an automobile battery pack heat dissipation device in the prior art, the liquid cooling heat management system comprises a cooling box and a battery pack, the cooling box comprises a liquid cavity filled with liquid and an air cavity positioned above the liquid cavity, the whole battery pack is immersed in the liquid, and the air cavity is communicated with the liquid cavity. The liquid cavity is connected with a compressor integral liquid cooling system through a flow management unit to form a first circulation loop, the air cavity is connected with the compressor integral liquid cooling system to form a second circulation loop, and the flow management unit is connected with a control panel. The whole battery pack is immersed in the heat-conducting and non-conducting liquid, so that the battery can be cooled more efficiently or heated at low temperature, the heat dissipation effect is good, heat dissipation is more uniform, meanwhile, if the battery pack has the phenomena of sparking and the like, the battery pack can be extinguished in time, further expansion of accidents is avoided, and the safety of the battery pack is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile thermal management, and in particular to a liquid cooling thermal management system and a control method thereof. Background Art

[0002] The battery pack is one of the core components of pure electric vehicles and hybrid electric vehicles. Its performance directly affects the performance of the vehicle, and the performance and life of the battery are closely related to its operating temperature. The battery pack generates heat during the charging and discharging process, which increases the overall temperature of the battery pack. Excessive temperature will seriously affect the performance and life of the battery pack. When the ambient temperature is very low, the battery needs to be heated to improve its charging and discharging efficiency. Therefore, effective thermal management of the battery pack to maintain its operating temperature within an optimal temperature range plays a decisive role in improving the performance of the battery and extending the battery life.

[0003] However, traditional air-cooled radiators for battery packs have defects. Traditional air-cooling methods achieve heat exchange through thermal convection with the battery surface, with a small heat exchange coefficient and are limited by the heat exchange area of ​​the battery pack, resulting in low cooling efficiency. In addition, structurally, the battery pack surface in the central area of ​​the battery pack of traditional air-cooled radiators cannot be fully exposed to the air, causing the temperature of the local battery cells in the battery pack to be too high, which will ultimately reduce the efficiency and reliability of the battery pack. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems of poor heat dissipation capacity and uneven heat dissipation of automobile battery pack heat dissipation devices in the prior art, and provide a liquid-cooled thermal management system and a control method thereof, in which the battery pack is immersed in liquid as a whole, so that the battery can be more efficiently dissipated or heated at low temperatures, with good heat dissipation effect and more uniform heat dissipation. At the same time, if the battery pack has ignition or the like, it can be extinguished in time to avoid further expansion of the accident, thereby improving the safety of the battery pack; at the same time, an air cavity is provided to collect evaporated liquid, thereby improving heat dissipation efficiency and improving resource utilization.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A liquid-cooled thermal management system comprises: a cooling box and a battery pack, wherein the cooling box comprises a liquid cavity provided with liquid and an air cavity located above the liquid cavity, wherein the battery pack is entirely immersed in the liquid, wherein the liquid cavity is connected to an overall liquid cooling system of a compressor via a flow management unit to form a first circulation loop, wherein the air cavity is connected to the overall liquid cooling system of the compressor to form a second circulation loop, and wherein the flow management unit is connected to a control board.

[0006] When the battery pack is working, the heat generated by the battery pack during charging and discharging can be efficiently removed by cooling the liquid. When the battery pack needs to be heated, the liquid can be heated to heat the battery, so that the vehicle battery pack can be maintained at a suitable operating temperature for a long time and work reliably. It can keep the vehicle battery pack within the appropriate temperature range, improve the charging efficiency of the battery pack, and improve the safety performance and service life of the battery pack.

[0007] Preferably, the air cavity is connected to a first condenser via an exhaust pipe, and the first condenser is connected to an overall liquid cooling system of the compressor.

[0008] Preferably, the control board controls the operating status of the overall liquid cooling system of the compressor and the flow management unit through the temperature of the battery pack and the temperature of the liquid.

[0009] Preferably, the compressor overall liquid cooling system comprises an evaporator tube, the outlet of the evaporator tube is connected to a compressor, the compressor is connected to a condenser, and the condenser is connected to an inlet of the evaporator tube via a capillary tube.

[0010] Preferably, the compressor overall liquid cooling system comprises a water tank, the evaporating tube is installed in the water tank, the water tank inlet is connected to the heat exchange mechanism, and the water tank outlet is connected to the heat exchange mechanism via a water pump.

[0011] Preferably, the liquid chamber is connected to a liquid inlet pipe and a liquid outlet pipe, the flow management unit is installed on the liquid inlet pipe, the liquid inlet pipe is connected to the outlet of the compressor's overall liquid cooling system, and the liquid outlet pipe is connected to the inlet of the compressor's overall liquid cooling system to form a circulation pipeline.

[0012] Preferably, the liquid is a heat-conducting but non-conductive liquid.

[0013] A liquid cooling thermal management system control method comprises the following steps: S1: Collect battery pack temperature data and battery working status; S2: If the battery pack is in an abnormal working state, increase the liquid flow rate; S3: If the battery pack is in normal working condition, adjust the liquid flow rate and the compressor power according to the battery pack temperature data and the battery pack charge state; S4: If the battery pack is in a static state, the liquid flow rate and the compressor power are adjusted according to the battery pack temperature data and the temperature relationship of the water outlet of the compressor overall liquid cooling system.

[0014] During operation, the liquid temperature is less than a first threshold value and the liquid temperature is greater than a second threshold value. The first threshold value is the maximum temperature at which the battery can work normally, and the second threshold value is the minimum temperature at which the battery can work normally. This prevents the normal operation of the battery from being affected by the excessively high or low temperature of the liquid itself when the liquid is used to cool or heat the battery.

[0015] Preferably, step S3 includes: if the battery pack is in a normal working state and the battery pack temperature is in a set working range, obtaining the battery pack charge state; if the battery pack charge state is greater than a threshold, obtaining the water inlet temperature of the compressor overall liquid cooling system; and adjusting the compressor power and liquid flow rate according to the relationship between the water outlet temperature of the compressor overall liquid cooling system and the battery pack temperature; if the battery pack temperature is lower than the set working range, closing the flow management unit.

[0016] Preferably, step S4 includes: if the battery pack temperature is in the set working range, the flow management unit is turned off; if the battery pack temperature is lower than the set working range, and the water outlet temperature of the compressor overall liquid cooling system is between the battery pack temperature and the set working range, the liquid flow rate is increased; if the water outlet temperature of the compressor overall liquid cooling system is lower than the battery pack temperature, the compressor overall liquid cooling system is in heating mode; if the battery pack temperature is higher than the set working range, and the water outlet temperature of the compressor overall liquid cooling system is lower than the set working range, the original working state of the thermal management system is maintained; if the water outlet temperature of the compressor overall liquid cooling system is in the set working range, the liquid flow rate is increased; if the water outlet temperature of the compressor overall liquid cooling system is higher than the set working range, the refrigeration power of the compressor overall liquid cooling system is increased.

[0017] Therefore, the present invention has the following beneficial effects: 1. By immersing the battery pack in liquid and connecting the liquid to the compressor as a whole liquid cooling system, when the battery pack is working, the liquid can be cooled by the compressor as a whole liquid cooling system, thereby efficiently taking away the heat generated by the battery pack during charging and discharging. When the battery pack needs to be heated, the liquid can be heated by the compressor as a whole liquid cooling system to heat the battery, thereby maintaining the on-board battery pack at a suitable operating temperature for a long time and working reliably.

[0018] 2. Immerse the entire battery pack in a heat-conductive non-conductive liquid. This will allow the battery to dissipate heat more efficiently or heat it at low temperatures. At the same time, if the battery pack ignites, it can be extinguished in time to prevent the accident from further expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall architecture of the vehicle-mounted liquid cooling thermal management system in the present invention.

[0020] Figure 2 It is a schematic diagram of the immersion heat exchange of the battery pack in the present invention.

[0021] Figure 3 It is a flow chart of the steps of the vehicle-mounted liquid cooling thermal management system control method of the present invention.

[0022] In the figure: 1. cooling box; 2. liquid chamber; 3. air chamber; 4. battery pack; 5. first condenser; 6. second condenser; 7. flow meter; 8. water tank; 9. evaporation tube; 10. compressor; 11. second drying filter; 12. fan; 13. second drying filter; 14. capillary tube; 15. fan; 16. water pump; 17. temperature sensor; 18. flow control valve. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments: Embodiment 1: like Figure 1 In the illustrated embodiment, a liquid-cooled thermal management system can be seen, comprising: a cooling box 1, a battery pack 4 and an overall liquid cooling system for a compressor, wherein a liquid is provided in the cooling box, the battery pack is entirely immersed in the liquid, the cooling box is connected to the overall liquid cooling system for the compressor, and the liquid exchanges heat with the overall liquid cooling system for the compressor.

[0024] The liquid-cooled thermal management system provided in this embodiment adopts a liquid immersion cooling method for the battery pack. The liquid (insulating coolant) is in direct contact with the surface of the battery pack, which can improve the heat exchange efficiency and uniformity, so that the battery pack is always in a safe temperature environment, and will not cause corrosion, short circuit and other phenomena of the battery pack.

[0025] The technical scheme and technical effects of the present invention will be further described below through specific examples. The following examples are explanations of the present invention and the present invention is not limited to the following examples.

[0026] The cooling box includes a liquid cavity 2 and an air cavity 3, a first condenser 5, an exhaust pipe, a liquid inlet pipe, and a liquid outlet pipe. The air cavity is located above the liquid cavity, the liquid cavity is filled with liquid, the battery pack is immersed in the liquid in the liquid cavity, the liquid cavity is connected to the liquid inlet pipe and the liquid outlet pipe, the air cavity is connected to the exhaust pipe, the exhaust pipe is connected to the first condenser, and the first condenser is connected to the overall liquid cooling system of the compressor.

[0027] The liquid is an insulating coolant that is heat-conductive but not electrically conductive, such as a fluorinated liquid. A groove is provided at the connection between the air cavity and the liquid cavity to receive the liquid attached to the inner wall of the air cavity.

[0028] During operation, when the low-temperature liquid in the liquid cavity cools the battery with a higher temperature, the liquid can evaporate faster after heating up, and the heat in the liquid cavity is taken away to the gas cavity by the principle of evaporation and heat absorption, further promoting the reduction of the overall temperature in the cooling box. The evaporated liquid enters the first condenser through the exhaust pipe, condenses into liquid in the first condenser, and enters the compressor overall liquid cooling system. After being uniformly cooled by the compressor overall liquid cooling system, it enters the cooling box again to cool the battery pack and realize resource recycling.

[0029] The overall liquid cooling system of the compressor includes a water inlet pipe, a water outlet pipe, a water tank 8, an evaporating tube 9, a capillary tube 14, a first drying filter 13, a second drying filter 11, a fan 12, a second condenser 6 and a compressor 10, a flow meter 7, a water pump 16, and a temperature sensor 17, wherein the water inlet pipe is connected to the liquid cavity outlet pipe, and the water inlet pipe is connected to the water inlet of the water tank; the water outlet pipe is connected to the liquid cavity inlet pipe, and the water outlet pipe is connected to the water outlet of the water tank; the evaporating tube is installed in the water tank, the evaporating tube outlet is connected to the compressor, the compressor is connected to the second condenser, the fan is installed next to the second condenser, the second condenser is connected to the second drying filter, the second drying filter is connected to the first drying filter, the first drying filter is connected to the capillary tube, the capillary tube is connected to the evaporating tube inlet, and the temperature sensor is installed on the water outlet pipe; the flow meter is installed on the water inlet pipe.

[0030] When the compressor overall liquid cooling system is working, the compressor starts, compresses the refrigerant into high-temperature and high-pressure gas and transmits it to the second condenser. The fan dissipates heat from the second condenser. The refrigerant gas exchanges heat with the cooling water in the second condenser and condenses into liquid. The refrigerant liquid is dried and filtered by the dry filter, and then flows into the evaporator tube after throttling and reducing the pressure through the capillary tube, absorbing the heat of the heated cooling water in the water tank (i.e. the liquid that immerses the battery pack). After that, the refrigerant is compressed by the compressor again, thus forming a cycle. The cooled cooling water in the water tank flows into the liquid cavity of the cooling box through the outlet pipe to cool the battery pack in the liquid cavity.

[0031] If the compressor's overall liquid cooling system needs to heat the liquid, a pipe can be connected between the compressor and the evaporator tube. The high-temperature gas compressed by the compressor directly enters the evaporator tube through the pipe to heat the liquid in the water tank. The heated liquid passes through the water pump through the water outlet pipe-liquid inlet pipe, and finally flows into the liquid cavity of the cooling box to heat the battery pack in the liquid cavity.

[0032] The control board includes a first temperature sensor disposed on the battery pack, a second temperature sensor disposed in the liquid cavity, and a flow management unit disposed on the liquid inlet pipe of the liquid cavity. In this embodiment, the flow management unit is a flow regulating valve 18 .

[0033] When the control board is working, the compressor power and the opening of the flow regulating valve are adjusted according to the battery pack temperature data detected by the first temperature sensor and the liquid temperature data detected by the second temperature sensor, so as to control the liquid temperature and the battery pack temperature.

[0034] In other embodiments, a radiator may be installed on the outer wall of the liquid cavity to dissipate heat and improve the heat dissipation efficiency. Alternatively, a fan 15 may be installed in the liquid cavity, the fan being installed at the bottom of the battery pack and blowing in the direction of the fan toward the battery gap of the battery pack.

[0035] When the liquid-cooling thermal management system provided in this embodiment is working, first, the liquid inlet pipe, the compressor overall liquid cooling system, the liquid outlet pipe and the cooling box form a circulation loop, the battery pack is installed in the liquid cavity of the cooling box, and the insulating coolant generated by the compressor overall liquid cooling system is injected into the liquid cavity through the liquid inlet pipe until the liquid cavity is filled and the battery pack is completely immersed for contact heat exchange. The temperature of the insulating coolant rises and is discharged from the liquid outlet pipe to the compressor overall liquid cooling system. The compressor overall liquid cooling system cools the heated insulating coolant and then enters the liquid cavity through the liquid inlet pipe to realize circulation.

[0036] At the same time, during the heat exchange process between the insulating coolant and the battery pack, due to the increase in the temperature of the insulating coolant, part of the insulating coolant evaporates and turns into gas and enters the gas cavity, taking away part of the heat and improving the cooling effect of the battery pack. The gaseous insulating coolant enters the first condenser through the exhaust pipe, condenses into liquid in the first condenser, and then flows into the compressor overall liquid cooling system, where it merges with the insulating coolant flowing out of the liquid cavity, and then flows into the liquid cavity through the liquid inlet pipe, forming another cycle.

[0037] During this process, the control panel can adjust the cooling capacity of the compressor's overall liquid cooling system and the valve opening of the flow control valve according to the temperature of the battery pack and the temperature of the insulating coolant in the liquid cavity, thereby controlling the heat exchange rate and achieving energy saving.

[0038] The vehicle-mounted liquid cooling thermal management system with battery temperature control provided in this embodiment has the following beneficial effects: 1. Use the direct immersion method of the battery pack, immersing the entire battery pack in a heat-conductive, non-conductive insulating cooling liquid. This can dissipate heat more efficiently or heat the battery at low temperatures. At the same time, if the battery pack ignites, it can be extinguished in time to prevent the accident from further expansion.

[0039] 2. During the immersion contact heat exchange, the liquid can accelerate evaporation after heating up, and the principle of evaporation heat absorption can be used to further promote the reduction of the overall temperature in the cooling box, thereby greatly improving the cooling effect. The evaporated gas can enter the air cavity and be recycled by condensation and then put into the cooling circulation system again, effectively saving resources and improving resource utilization.

[0040] Embodiment 2: This embodiment provides a liquid cooling thermal management system and brings it into a specific scenario for application. In the vehicle-mounted heat exchange system, the current vehicle-mounted systems that directly experience heat exchange with the occupants include the in-vehicle air-conditioning system, the car seat ventilation system, the in-vehicle refrigerator, the battery pack temperature control, etc. The in-vehicle air-conditioning system is often implemented by a compressor temperature control system, and the seat ventilation is often driven by a fan. The in-vehicle refrigerator has TEC-type temperature control or compressor-type temperature control. The several major systems are relatively independent, which to a certain extent causes low energy efficiency. At the same time, battery pack temperature control has always been a very critical link in new energy vehicles. Efficient and safe use of batteries is a major difficulty. Therefore, this embodiment provides an integrated temperature control solution.

[0041] A vehicle-mounted liquid cooling thermal management system with battery control includes a vehicle-mounted air-conditioning system, a seat ventilation system, a vehicle-mounted refrigerator system and a battery pack temperature control system, wherein one end of the vehicle-mounted air-conditioning system, the seat ventilation system, the vehicle-mounted refrigerator system and the battery pack temperature control system are all connected to the water inlet of the compressor overall liquid cooling system, and the other ends of the vehicle-mounted air-conditioning system, the seat ventilation system, the vehicle-mounted refrigerator system and the battery pack temperature control system are all connected to the water inlet of the compressor overall liquid cooling system, a first flow valve is provided between the vehicle-mounted air-conditioning system and the water inlet of the compressor overall liquid cooling system, a second flow valve is provided between the seat ventilation system and the water inlet of the compressor overall liquid cooling system, a third flow valve is provided between the vehicle-mounted refrigerator system and the water inlet of the compressor overall liquid cooling system, a fourth flow valve is provided between the battery pack temperature control system and the water inlet of the compressor overall liquid cooling system, and the first flow valve, the second flow valve, the third flow valve and the fourth flow valve are all connected to a control panel. The vehicle air conditioning system is provided with a first temperature sensor, the seat ventilation system is provided with a second temperature sensor, the vehicle refrigerator system is provided with a third temperature sensor, and the battery pack temperature control system is provided with a fourth temperature sensor, and the first temperature sensor, the second temperature sensor, the third temperature sensor, and the fourth temperature sensor are all connected to the control board. The control board adjusts the opening of the first flow valve, the second flow valve, the third flow valve, and the fourth flow valve according to the temperature data of the corresponding system collected by the first temperature sensor, the second temperature sensor, the third temperature sensor, and the fourth temperature sensor, so as to control the temperature of the vehicle air conditioning system, the seat ventilation system, the vehicle refrigerator system, and the battery pack temperature control system respectively.

[0042] Specific: The overall liquid cooling system of the compressor includes a water inlet pipe, a water outlet pipe, a water tank, an evaporating tube, a capillary tube, a first drying filter, a second drying filter, a fan, a second condenser, a compressor, and a water pump, wherein the water inlet pipe is connected to one end of the vehicle air-conditioning system, the seat ventilation system, the vehicle refrigerator system, and the battery pack temperature control system, and the water inlet pipe is connected to the water inlet of the water tank; the water outlet pipe is connected to the other end of the vehicle air-conditioning system, the seat ventilation system, the vehicle refrigerator system, and the battery pack temperature control system, and the water outlet pipe is connected to the water outlet of the water tank; the evaporating tube is installed in the water tank, the evaporating tube outlet is connected to the compressor, the compressor is connected to the second condenser, the fan is installed next to the second condenser, the second condenser is connected to the second drying filter, the second drying filter is connected to the first drying filter, the first drying filter is connected to the capillary tube, and the capillary tube is connected to the evaporating tube inlet.

[0043] When the compressor integral liquid cooling system is working, the compressor starts, compresses the refrigerant into high-temperature and high-pressure gas and transmits it to the second condenser. The fan dissipates heat from the second condenser. The refrigerant gas exchanges heat with the cooling water in the second condenser and condenses into liquid. The refrigerant liquid is dried and filtered by the dry filter, and then flows into the evaporator after throttling and reducing the pressure by the capillary tube, absorbing the heat of the heated cooling water in the water tank (i.e. the liquid immersing the battery pack). After that, the refrigerant is compressed by the compressor again, thus forming a cycle. The cooled cooling water in the water tank flows into the vehicle air conditioning system, seat ventilation system, vehicle refrigerator system and battery pack temperature control system through the outlet pipe, cooling the vehicle air conditioning system, seat ventilation system, vehicle refrigerator system and battery pack temperature control system.

[0044] When the control panel is working, the first-level adjustment is: collecting the temperatures of the vehicle air-conditioning system, seat ventilation system, vehicle refrigerator system and battery pack temperature control system, comparing the temperature of each system with the set target temperature, and increasing the flow control valve opening if the temperature is greater than the target temperature; when the temperature is less than the target temperature, if the difference between the temperature and the target temperature is greater than the first temperature threshold, reducing the flow control valve opening; if the difference between the temperature and the target temperature is less than the first temperature threshold, if the water outlet temperature of the compressor overall liquid cooling system is less than the second temperature threshold, reducing the flow control valve opening; if the water outlet temperature of the compressor overall liquid cooling system is greater than the second temperature threshold and less than the third temperature threshold, maintaining the flow control valve opening unchanged; if the water outlet temperature of the compressor overall liquid cooling system is greater than the third temperature threshold, increasing the flow control valve opening.

[0045] Specific: If it is detected that the temperature of a certain system is greater than the set target temperature, and the water outlet temperature of the compressor's overall liquid cooling system is greater than the fourth temperature threshold, then simply adding a flow regulating valve can no longer meet the cooling demand of the system, and the compressor power needs to be adjusted to increase the cooling capacity.

[0046] During adjustment, adjust the compressor power according to the relationship between the temperature of the remaining systems and the set target. After adjusting the compressor power cooling capacity, the water outlet temperature of the compressor overall liquid cooling system cannot be lower than the minimum operating temperature of the battery pack temperature control system.

[0047] The battery pack temperature control system uses a direct immersion method to immerse the battery pack in a heat-conducting, non-conductive liquid. This allows the battery to dissipate heat more efficiently or heat it at low temperatures. At the same time, if there is a fire in the battery pack, it can be extinguished in time to prevent the accident from further expansion. Figure 2 As shown, the heat-conductive non-conductive liquid exchanges heat with the overall liquid cooling system of the compressor through the heat exchange mechanism to achieve a heat dissipation effect.

[0048] The traditional compressor air conditioning system is a fan that blows air through the evaporator tube of the air conditioning system for direct cooling. The present embodiment is provided with liquid cooling. The evaporator tube first cools the liquid, and then the fan drives the air to cool it through the liquid heat exchanger. The compressor system liquid cooling solution of the present embodiment is easier to implement modularly than the compressor direct cooling system, and the performance matching is more independent. The external load has less impact on the refrigeration system, and it is easy to maintain.

[0049] In addition to the compressor overall liquid cooling system, the seat ventilation system adds a heating device to simultaneously realize the cold air and hot air system. At the same time, the liquid flows through the car seat back for cooling or heating. It can flow only to the backrest or through the seat cushion. Different flow densities can also be arranged according to different needs.

[0050] The liquid cooling thermal management system provided in this embodiment implements the integrated temperature control of the automobile air-conditioning system + vehicle refrigerator + seat ventilation system + battery pack through a set of compressor refrigeration liquid cooling system; a set of compressor liquid cooling system outputs liquid of suitable temperature and delivers it to the air-conditioning system, vehicle refrigerator system, seat ventilation and heating system, and battery pack temperature control system, and a liquid flow distribution device is used to realize relatively independent temperature control of the air-conditioning system, vehicle refrigerator, and seat ventilation system.

[0051] Embodiment three: like Figure 3 In the illustrated embodiment, a liquid cooling thermal management system control method can be seen, and its operation process is as follows: step one, collecting battery pack temperature data and battery operating status, and collecting the temperature of the liquid immersed in the battery pack; step two, if the battery pack is in an abnormal operating state, increasing the compressor power and increasing the liquid flow rate; step three, if the battery pack is in a normal working state, adjusting the liquid flow rate and the compressor power according to the relationship between the battery pack temperature data and the temperature of the liquid immersed in the battery pack; step four, if the battery pack is in a resting state, adjusting the liquid flow rate according to the relationship between the battery pack temperature data and the temperature of the liquid immersed in the battery pack.

[0052] The cooling capacity is precisely controlled through the battery pack temperature, liquid temperature and battery operating status, reducing energy consumption while ensuring the normal operation of the battery pack.

[0053] The technical scheme and technical effects of the present invention will be further described below through specific examples. The following examples are explanations of the present invention and the present invention is not limited to the following examples.

[0054] Step 1: Collect battery pack temperature data and battery working status.

[0055] The working status of the battery pack includes abnormal working status, normal working status and resting status. The abnormal working status includes battery fire, battery temperature reaching a critical value, etc.

[0056] Step 2: If the battery pack is in abnormal working condition, increase the compressor power and increase the liquid flow rate.

[0057] If the battery pack is in an abnormal working state, the battery needs to be completely immersed in liquid at all times and the battery needs to be cooled down as quickly as possible.

[0058] Step 3: If the battery pack is in normal working condition, adjust the liquid flow rate and the compressor power according to the temperature relationship between the battery pack temperature data and the liquid immersing the battery pack.

[0059] If the battery pack is in normal working condition: If the battery pack temperature is in the set working range, obtain the battery pack charge state. If the battery pack charge state is greater than the threshold, obtain the water inlet temperature of the compressor overall liquid cooling system. According to the relationship between the water outlet temperature of the compressor overall liquid cooling system and the battery pack temperature, adjust the compressor power and liquid flow.

[0060] If the water outlet temperature of the compressor's overall liquid cooling system is lower than the battery pack temperature, and the difference between the two is greater than the first threshold, the thermal management system maintains its original working state; if the difference between the two is lower than the first threshold and higher than the second threshold, the liquid flow rate is increased; if the difference between the two is lower than the second threshold, the compressor power is increased.

[0061] If the battery pack temperature is lower than the set operating range, the flow management unit is turned off.

[0062] If the battery pack temperature is greater than the set working range, increase the compressor power and liquid flow rate to reduce the battery pack temperature as quickly as possible.

[0063] Step 4: If the battery pack is in a resting state, adjust the liquid flow rate according to the temperature data of the battery pack and the temperature relationship of the liquid immersing the battery pack.

[0064] If the battery pack temperature is within the set operating range, the flow management unit and the compressor overall refrigeration system are turned off.

[0065] If the battery pack temperature is lower than the set working range: The water outlet temperature of the compressor overall liquid cooling system is within the range of the battery pack temperature and the set working range. If the difference between the battery pack temperature and the set working range is less than the threshold, the original working state of the thermal management system is maintained; if the difference between the battery pack temperature and the set working range is greater than the threshold, the compressor overall liquid cooling system is in heating mode.

[0066] If the water outlet temperature of the compressor's overall liquid cooling system is greater than the set working range, the liquid flow rate is increased.

[0067] If the water outlet temperature of the compressor overall liquid cooling system is lower than the battery pack temperature, the compressor overall liquid cooling system is in heating mode.

[0068] If the battery pack temperature is greater than the set working range: If the water outlet temperature of the compressor's overall liquid cooling system is lower than the set working range, the thermal management system will maintain its original working state.

[0069] If the water outlet temperature of the compressor's overall liquid cooling system is within the set working range, increase the liquid flow rate.

[0070] If the water outlet temperature of the compressor overall liquid cooling system is greater than the set working range, the refrigeration power of the compressor overall liquid cooling system is increased.

[0071] After determining the battery pack temperature, the water outlet temperature of the compressor overall liquid cooling system is used as a criterion for switching the compressor overall liquid cooling system mode and the liquid flow rate of the flow management unit to conduct thermal management tests, which improves the rationality and convenience of the thermal management test of the compressor overall liquid cooling system and reduces the energy consumption of the thermal management system.

[0072] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A liquid cooling thermal management system, characterized in that: include: A cooling box and a battery pack, wherein the cooling box includes a liquid cavity provided with liquid and an air cavity located above the liquid cavity, the battery pack is entirely immersed in the liquid, the liquid cavity is connected to the overall liquid cooling system of the compressor through a flow management unit to form a first circulation loop, the air cavity is connected to the overall liquid cooling system of the compressor to form a second circulation loop, and the flow management unit is connected to a control board.

2. A liquid cooling thermal management system according to claim 1, characterized in that: The air cavity is connected to a first condenser through an exhaust pipe, and the first condenser is connected to an overall liquid cooling system of the compressor.

3. A liquid cooling thermal management system according to claim 1, characterized in that: The control board controls the operating status of the compressor overall liquid cooling system and the flow management unit through the battery pack temperature and the temperature of the liquid.

4. A liquid cooling thermal management system according to claim 1, 2 or 3, characterized in that: The compressor overall liquid cooling system comprises an evaporator tube, the outlet of the evaporator tube is connected to a compressor, the compressor is connected to a condenser, and the condenser is connected to an inlet of the evaporator tube via a capillary tube.

5. A liquid cooling thermal management system according to claim 4, characterized in that: The compressor overall liquid cooling system comprises a water tank, the evaporating pipe is installed in the water tank, the water tank inlet is connected to the heat exchange mechanism, and the water tank outlet is connected to the heat exchange mechanism through a water pump.

6. A liquid cooling thermal management system according to claim 1 or 2, characterized in that: The liquid cavity is connected to a liquid inlet pipe and a liquid outlet pipe, the flow management unit is installed on the liquid inlet pipe, the liquid inlet pipe is connected to the outlet of the compressor overall liquid cooling system, and the liquid outlet pipe is connected to the inlet of the compressor overall liquid cooling system to form a circulation pipeline.

7. A liquid cooling thermal management system according to claim 1, 2 or 3, characterized in that: The liquid is a heat-conducting but non-conductive liquid.

8. A liquid cooling thermal management system control method, applied to the liquid cooling thermal management system according to any one of claims 1 to 7, characterized in that: Includes steps: S1: Collect battery pack temperature data and battery working status; S2: If the battery pack is in an abnormal working state, increase the liquid flow rate; S3: If the battery pack is in normal working condition, adjust the liquid flow rate and the compressor power according to the battery pack temperature data and the battery pack charge state; S4: If the battery pack is in a static state, the liquid flow rate and the compressor power are adjusted according to the battery pack temperature data and the temperature relationship of the water outlet of the compressor overall liquid cooling system.

9. The liquid cooling thermal management system control method according to claim 8, characterized in that: The step S3 includes: if the battery pack is in a normal working state and the battery pack temperature is in a set working range, obtaining the battery pack charge state; if the battery pack charge state is greater than a threshold, obtaining the water inlet temperature of the compressor overall liquid cooling system; and adjusting the compressor power and liquid flow rate according to the relationship between the water outlet temperature of the compressor overall liquid cooling system and the battery pack temperature; if the battery pack temperature is lower than the set working range, closing the flow management unit.

10. A liquid cooling thermal management system control method according to claim 8 or 9, characterized in that: The step S4 includes: if the battery pack temperature is in the set working range, the flow management unit is turned off; if the battery pack temperature is lower than the set working range, and the water outlet temperature of the compressor overall liquid cooling system is higher than the set working range, the liquid flow is increased; if the water outlet temperature of the compressor overall liquid cooling system is lower than the battery pack temperature, the compressor overall liquid cooling system is in heating mode; if the battery pack temperature is higher than the set working range, and the water outlet temperature of the compressor overall liquid cooling system is lower than the set working range, the original working state of the thermal management system is maintained; if the water outlet temperature of the compressor overall liquid cooling system is in the set working range, the liquid flow is increased; if the water outlet temperature of the compressor overall liquid cooling system is higher than the set working range, the refrigeration power of the compressor overall liquid cooling system is increased.

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