A battery pack and cooling control method

Abstract

The present application discloses a battery pack and a cooling control method, wherein the battery pack includes a box, a heat sink, a battery module and a first detection member, wherein a phase change material is arranged inside the box, the heat sink is fitted with the box, the battery module is arranged on the bottom wall of the box and immersed in the phase change material, and the first detection member is electrically connected to the battery module and extends into the phase change material relative to the battery module to detect the temperature of the phase change material. The heat sink, the battery module and the first detection member are all used to be electrically connected to the control system, and when the temperature of the phase change material meets the first preset condition, the heat sink is turned on to improve the heat dissipation efficiency of the box, and when the temperature of the phase change material meets the second preset condition, the heat sink is turned off to reduce energy consumption, and by immersing the first detection member in the phase change material, the error range of the detection result is reduced, and the accuracy of the detection result is improved, so that the control system can control the timing of turning on or off the heat sink more accurately.

Description

Technical Field

[0001] The present application relates to the technical field of battery thermal management, and in particular to a battery pack and a cooling control method. Background Art

[0002] The current battery thermal management system mainly cools the battery pack through air cooling, liquid cooling and phase change materials to ensure that the battery modules inside the battery pack can be within the appropriate operating temperature range and improve the safety of the battery modules.

[0003] In the prior art, the battery pack box is filled with phase change material, the phase change material immerses the battery module, and the inner wall of the box is provided with a temperature sensor. When the temperature sensor detects the temperature of the phase change material, the detection result is the temperature of the phase change material near the box. There is a temperature difference between the detection result and the actual temperature of the phase change material, which makes the accuracy of the detection result low.

[0004] During the operation of the battery pack, when the actual temperature of the phase change material is higher than the safe temperature of the battery module, the control system cannot control the start-up of the heat dissipation device according to the detection results of the temperature sensor, and thus cannot cool down the battery pack in time, which in turn causes a major safety hazard to the battery module during operation. Summary of the invention

[0005] In view of this, the present application provides a battery pack and a cooling control method to solve the technical problem in the prior art that the temperature sensor has low accuracy in detecting the temperature of the phase change material.

[0006] The present application provides a battery pack, which includes: a case, a heat dissipation device, a battery module and a first detection member, wherein a phase change material is arranged inside the case, the heat dissipation device is fitted with the case, the battery module is arranged on the bottom wall of the case and immersed in the phase change material, the first detection member is electrically connected to the battery module and extends into the phase change material relative to the battery module for detecting the temperature of the phase change material; wherein the heat dissipation device, the battery module and the first detection member are all used to be electrically connected to a control system; when the temperature of the phase change material meets a first preset condition, the heat dissipation device is in an open state, and when the temperature of the phase change material meets a second preset condition, the heat dissipation device is in a closed state.

[0007] In the embodiment of the present application, by immersing the battery module in the phase change material, heat can be directly transferred between the two, so that the heat generated by the battery module can be transferred to the box through the phase change material, and then the heat of the battery pack can be discharged through the heat dissipation device attached to the box, which is beneficial to improving the overall heat dissipation efficiency of the battery pack to ensure the stability and reliability of the battery pack during operation.

[0008] Among them, the first detection component extends toward the interior of the phase change material relative to the battery module, and is used to detect the temperature of the phase change material in real time, and transmit the detection result to the control system in real time, so that the control system can judge whether the temperature of the phase change material meets the preset conditions according to the detection result of the first detection component, thereby controlling the heat dissipation device to be turned on or off.

[0009] When the temperature of the phase change material meets the first preset condition, the control system can timely control the heat dissipation device to open, so as to improve the heat dissipation efficiency of the box, thereby accelerating the heat transfer efficiency between the phase change material and the box, so that the phase change material can absorb more heat released by the battery module, and then the overall operating temperature of the battery pack can be maintained within a suitable temperature range to avoid the risk of thermal runaway of the battery module due to further increase in temperature, which is beneficial to improving the stability and reliability of the battery pack during operation and extending the service life of the battery pack. At the same time, when the temperature of the phase change material meets the second preset condition, the control system can timely control the heat dissipation device to close, so that the box dissipates heat through natural heat dissipation, which is beneficial to saving energy.

[0010] In addition, during the operation of the battery pack, since the temperature of the phase change material near the battery module is higher and the temperature near the box is lower, there is a large error in the detection result of the first detection component. In this embodiment, by immersing the first detection component in the phase change material, it is beneficial to narrow the error range of the detection result and improve the accuracy of the detection result, so that the control system can more accurately control the timing of opening or closing the heat dissipation device.

[0011] In a possible embodiment, the heat dissipation device includes a liquid cooling plate, which is connected to the outer wall of the box body. The outer wall of the box body is provided with a groove. The liquid cooling plate is located in the groove and abuts against the bottom wall and side walls of the groove.

[0012] In a possible embodiment, the heat dissipation device includes a plurality of liquid cooling tubes, all of which are connected to the inner wall of the box body, and are distributed at intervals along the circumference of the battery module, and there is a gap between each of the liquid cooling tubes and the battery module along the length and width directions of the battery pack.

[0013] In a possible embodiment, the heat dissipation device includes a plurality of fins, the plurality of fins are connected to the outer side wall of the box body, the plurality of fins are spaced apart along the height direction of the battery pack, and the cross-sectional shape of the fins is a U-shaped structure or a V-shaped structure.

[0014] In a possible implementation, the heat dissipation device and the housing are an integrally formed structure.

[0015] In a possible implementation, the battery pack further includes a nickel sheet, one end of the nickel sheet is connected to the first detection element, and the other end of the nickel sheet is connected to the battery module.

[0016] The present application also provides a cooling control method for a battery pack, which is used to cool the battery pack described above, and the cooling control method includes: detecting the temperature of the phase change material; when the temperature of the phase change material meets the first preset condition, controlling the heat dissipation device to turn on so that the heat dissipation device cools down the phase change material; when the temperature of the phase change material meets the second preset condition, controlling the heat dissipation device to turn off so that the box body dissipates heat and cools down the phase change material.

[0017] In an embodiment of the present application, the first detection member extends toward the interior of the phase change material relative to the battery module, and is used to detect the temperature of the phase change material in real time, and transmit the detection result to the control system in real time, so that the control system can determine whether the temperature of the phase change material meets the preset conditions based on the detection result of the first detection member, thereby controlling the heat dissipation device to be turned on or off.

[0018] Specifically, when the control system determines that the temperature of the phase change material meets the first preset condition, the temperature of the phase change material is within the range of the phase change temperature, and the control system controls the heat dissipation device to open, so as to cool the box through the heat dissipation device, improve the heat dissipation effect of the box, thereby accelerating the efficiency of the phase change material to transfer heat to the box, and then improve the overall heat dissipation efficiency of the battery pack to ensure the stability and reliability of the battery pack during operation. When the control system determines that the temperature of the phase change material meets the second preset condition, the temperature of the phase change material is lower than the range of the phase change temperature, and the control system controls the heat dissipation device to close, so that the box dissipates heat naturally and reduces energy consumption.

[0019] In a possible implementation, when the temperature of the phase change material meets the first preset condition, the heat dissipation device is controlled to turn on so that the heat dissipation device cools the phase change material, and the cooling control method further includes: controlling the battery module to stop charging or discharging.

[0020] In a possible embodiment, the heat dissipation device also includes an electronic water pump, and the control system also has a third preset condition. When the temperature of the phase change material meets the first preset condition, the heat dissipation device is controlled to be turned on so that the heat dissipation device cools the phase change material. The cooling control method also includes: when the temperature of the phase change material meets the first preset condition, the electronic water pump is controlled to be turned on, and the electronic water pump is controlled to be at a first speed; when the temperature of the phase change material meets the third preset condition, the electronic water pump is controlled to be turned on, and the electronic water pump is controlled to be at a second speed; wherein the second speed is greater than the first speed.

[0021] In a possible implementation, the first preset condition is: the temperature of the phase change material is t1, and t1 satisfies 55°C≤t1≤65°C; the second preset condition is: the temperature of the phase change material is t2, and t2 satisfies t2<55°C; the third preset condition is: the temperature of the phase change material is t3, and t3 satisfies t3>65°C.

[0022] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 A top view of the interior of the battery pack provided in this application;

[0025] Figure 2 A side view of the interior of the battery pack provided in this application.

[0026] Description of reference numerals:

[0027] 1-Box;

[0028] 11- Phase change material;

[0029] 12-groove;

[0030] 2- heat dissipation device;

[0031] 21- fin;

[0032] 22-Liquid cooling plate;

[0033] 23-liquid cooling pipe;

[0034] 24-liquid inlet;

[0035] 25-liquid outlet;

[0036] 3-Battery module;

[0037] 4- first test piece;

[0038] 5-Nickel sheet. DETAILED DESCRIPTION

[0039] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0040] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0041] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0042] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0043] The embodiment of the present application provides a battery pack, such as Figure 1 and Figure 2 As shown, the battery pack includes a box body 1, a heat dissipation device 2, a battery module 3 and a first detection member 4. A phase change material 11 is arranged inside the box body 1, the heat dissipation device 2 is attached to the box body 1, the battery module 3 is arranged on the bottom wall of the box body 1 and immersed in the phase change material 11, and the first detection member 4 is electrically connected to the battery module 3 and extends into the phase change material 11 relative to the battery module 3, and is used to detect the temperature of the phase change material 11.

[0044] Among them, the heat dissipation device 2, the battery module 3 and the first detection component 4 are all used to be electrically connected to the control system, and when the temperature of the phase change material 11 meets the first preset condition, the heat dissipation device 2 is in the open state, and when the temperature of the phase change material 11 meets the second preset condition, the heat dissipation device 2 is in the closed state.

[0045] In the embodiment of the present application, by immersing the battery module 3 in the phase change material 11, heat can be directly transferred between the two, so that the heat generated by the battery module 3 can be transferred to the case 1 through the phase change material 11, and then the heat of the battery pack can be discharged through the heat dissipation device 2 attached to the case 1, which is beneficial to improve the overall heat dissipation efficiency of the battery pack to ensure the stability and reliability of the battery pack during operation.

[0046] Among them, the phase change material 11 can be paraffin, so that the phase change material 11 has good thermal conductivity, and can be changed from solid to liquid at the melting point temperature, so that the phase change material 11 has fluidity, which is convenient for reducing the thermal resistance between the box 1 and the battery module 3 and improving the heat transfer efficiency. At the same time, the melting latent heat of the phase change material 11 is relatively high, so that it can store or release more heat during the phase change process, so as to provide a suitable ambient temperature for the battery module 3 in a low temperature environment, thereby ensuring the stability and reliability of the battery module 3 working in a low temperature environment. In addition, the phase change material 11 is also non-toxic, non-corrosive, recyclable and easy to manufacture, which is conducive to controlling the production cost of the battery pack while improving the heat dissipation efficiency of the battery pack, and is more in line with actual production needs.

[0047] The battery pack further includes a first detection component 4 connected to the battery module 3, and the heat dissipation device 2, the battery module 3 and the first detection component 4 are all electrically connected to the control system.

[0048] Specifically, the first detection member 4 extends toward the interior of the phase change material 11 relative to the battery module 3, and is used to detect the temperature of the phase change material 11 in real time, and transmit the detection result to the control system in real time, so that the control system can judge whether the temperature of the phase change material 11 meets the preset conditions according to the detection result of the first detection member 4, thereby controlling the heat dissipation device 2 to be turned on or off.

[0049] When the control system determines that the temperature of the phase change material 11 meets the first preset condition, the temperature of the phase change material 11 is within the phase change temperature range, and the control system controls the heat dissipation device 2 to be in an on state, so as to cool the box body 1 through the heat dissipation device 2, thereby improving the heat dissipation effect of the box body 1, thereby accelerating the efficiency of heat transfer from the phase change material 11 to the box body 1, and then improving the overall heat dissipation efficiency of the battery pack, so as to ensure the stability and reliability of the battery pack during operation.

[0050] When the control system determines that the temperature of the phase change material 11 meets the second preset condition, the temperature of the phase change material 11 is lower than the phase change temperature range, and the control system controls the heat dissipation device 2 to be in a closed state to allow the box 1 to dissipate heat naturally and reduce energy consumption.

[0051] Therefore, in this embodiment, the control system can timely control the heat dissipation device 2 to open when the temperature of the phase change material 11 meets the first preset condition, so as to improve the heat dissipation efficiency of the box 1, thereby accelerating the heat transfer efficiency between the phase change material 11 and the box 1, so that the phase change material 11 can absorb more heat released by the battery module 3, and thus the overall operating temperature of the battery pack can be maintained within a suitable temperature range to avoid the risk of thermal runaway of the battery module 3 due to further increase in temperature, which is beneficial to improving the stability and reliability of the battery pack during operation and extending the service life of the battery pack. At the same time, the control system can timely control the heat dissipation device 2 to close when the temperature of the phase change material 11 meets the second preset condition, so that the box 1 dissipates heat through natural heat dissipation, which is beneficial to saving energy. In addition, during the operation of the battery pack, since the temperature of the phase change material 11 near the battery module 3 is higher and the temperature near the box 1 is lower, there is a large error in the detection result of the first detection component 4. In this embodiment, by immersing the first detection component 4 in the phase change material 11, it is helpful to narrow the error range of the detection result and improve the accuracy of the detection result, so that the control system can more accurately control the timing of opening or closing the heat dissipation device 2.

[0052] In a specific embodiment, Figure 1 and Figure 2 As shown, the heat dissipation device 2 includes a liquid cooling plate 22 , which is connected to the outer wall of the box body 1 . The outer wall of the box body 1 is provided with a groove 12 . The liquid cooling plate 22 is located in the groove 12 and abuts against the bottom wall and side walls of the groove 12 .

[0053] In the embodiment of the present application, a coolant flows in the liquid cooling plate 22 so as to cool down the box body 1 by means of liquid cooling. Specifically, when the liquid cooling plate 22 is connected to the outer wall of the box body 1, the liquid cooling plate 22 fits the box body 1 so that there is a large contact area between the two, thereby facilitating direct heat exchange between the liquid cooling plate 22 and the box body 1, so as to improve the heat dissipation efficiency of the box body 1, avoid the risk of excessively high internal temperature of the box body 1 due to low heat dissipation efficiency, thereby reducing the possibility of thermal runaway of the battery module 3, and further improving the stability and reliability of the battery pack during operation.

[0054] The outer wall of the box body 1 is provided with a groove 12 for accommodating the liquid cooling plate 22. When the liquid cooling plate 22 is located in the groove 12, the liquid cooling plate 22 can abut against the bottom wall and the side wall of the groove 12 to further expand the contact area between the liquid cooling plate 22 and the box body 1, thereby facilitating the improvement of the heat dissipation effect of the heat dissipation device 2 on the box body 1. At the same time, by providing the groove 12, the overall size of the battery pack can be reduced to avoid the possibility of inconvenience in installation or interference with other components due to the excessive volume of the battery pack, thereby facilitating the improvement of the space utilization rate of the space accommodating the battery pack.

[0055] In a specific embodiment, Figure 1 and Figure 2 As shown, the heat dissipation device 2 includes a plurality of liquid cooling tubes 23, and the plurality of liquid cooling tubes 23 are all connected to the inner wall of the box body 1. The plurality of liquid cooling tubes 23 are distributed at intervals along the circumference of the battery module 3, and there is a gap between each liquid cooling tube 23 and the battery module 3 along the length and width directions of the battery pack.

[0056] In the embodiment of the present application, a coolant flows in the liquid cooling tube 23 so as to cool down the phase change material 11 by liquid cooling. Specifically, when the liquid cooling tube 23 is connected to the inner wall of the box body 1, the liquid cooling tube 23 can be immersed in the phase change material 11 so that there is a large contact area between the two, thereby facilitating direct heat exchange between the liquid cooling tube 23 and the phase change material 11, so as to improve the heat dissipation efficiency of the phase change material 11, avoid the risk of thermal runaway of the battery module 3 due to the excessive temperature of the phase change material 11, thereby further reducing the possibility of damage to the battery module 3, which is conducive to extending the service life of the battery module 3, and further improving the stability and reliability of the battery pack during operation.

[0057] Among them, due to the small volume of the liquid cooling tube 23, the inner wall of the box body 1 can be connected with multiple liquid cooling tubes 23, and the multiple liquid cooling tubes 23 can be distributed along the circumferential intervals of the battery module 3, so that in the process of heat exchange between the liquid cooling tube 23 and the phase change material 11, the cooling effect on the phase change material 11 is more uniform, thereby avoiding the risk of low temperature in one area of ​​the battery pack and high temperature in another area, which is conducive to improving the thermal uniformity of the battery pack. At the same time, along the length and width directions of the battery pack, there are intervals between each cooling tube 23 and the battery module 3, so as to avoid interference with the cooling tube 23 during the installation or removal of the battery module 3, which is conducive to improving the assembly efficiency of the battery module 3.

[0058] In a possible embodiment, the heat dissipation device 2 includes a liquid cooling plate 22 and / or a liquid cooling tube 23, and the liquid cooling plate 22 and / or the liquid cooling tube 23 are provided with a liquid inlet 24 and a liquid outlet 25. The heat dissipation device 2 also includes a compressor (not shown in the figure), one end of the compressor is connected to the liquid inlet 24, and the other end of the compressor is connected to the liquid outlet 25.

[0059] In the embodiment of the present application, a refrigerant flows through the liquid cooling plate 22 and / or the cooling tube 23 so as to cool the battery pack by liquid cooling.

[0060] Specifically, one end of the compressor is communicated with the liquid inlet 24 of the liquid cooling plate 22 and / or the liquid cooling pipe 23 , and the other end of the compressor is communicated with the liquid outlet 25 of the liquid cooling plate 22 and / or the liquid cooling pipe 23 .

[0061] When the heat dissipation device 2 includes a liquid cooling plate 22 and / or a liquid cooling tube 23, during the process of the heat dissipation device 2 cooling down the battery pack, the liquid cooling plate 22 is connected to the outer wall of the box body 1, and the liquid cooling tube 23 is connected to the inner wall of the box body 1, so that the heat dissipation device 2 can cool down the inside and outside of the battery pack at the same time, which is beneficial to improving the heat dissipation efficiency of the battery pack and improving the heat dissipation effect of the heat dissipation device 2 on the battery pack.

[0062] Among them, the liquid refrigerant is converted into a gaseous refrigerant after being processed by the compressor. The gaseous refrigerant can flow into the liquid cooling plate 22 and the liquid cooling tube 23 through the liquid inlet 24 respectively, and after absorbing the heat on the wall of the liquid cooling plate 22 and the liquid cooling tube 23, it is converted into a gas-liquid two-phase mixed refrigerant or completely converted into a liquid refrigerant, and then flows out of the liquid cooling plate 22 and the liquid cooling tube 23 respectively through the liquid outlet 25, and finally flows back to the compressor for a new round of processing. Thus, the heat of the box 1 and the phase change material 11 is taken out of the battery pack through the gaseous refrigerant and circulated, which is beneficial to further improve the heat dissipation efficiency of the battery pack and improve the heat dissipation effect of the heat dissipation device 2 on the battery pack.

[0063] In a possible embodiment, the heat dissipation device 2 also includes an electronic water pump (not shown in the figure), which is connected in series in the pipeline of the liquid cooling plate 22 and / or the liquid cooling tube 23 to drive the flow of the coolant or refrigerant to ensure the stability and reliability of the cooling operation of the heat dissipation device 2.

[0064] Among them, the control system also has a third preset condition. When the temperature of the phase change material 11 meets the first preset condition, the electronic water pump is controlled to turn on and the electronic water pump is controlled to be at a first speed. When the temperature of the phase change material 11 meets the third preset condition, the electronic water pump is controlled to turn on and the electronic water pump is controlled to be at a second speed, wherein the second speed is greater than the first speed.

[0065] When the control system determines that the temperature of the phase change material 11 meets the first preset condition, the temperature of the phase change material 11 is within the range of the phase change temperature, and the control system controls the electronic water pump to be in an on state, and controls the speed of the electronic water pump to be at a first speed, so as to cool the box body 1 through the liquid cooling plate 22 and / or the liquid cooling tube 23, thereby improving the heat dissipation effect of the box body 1, thereby accelerating the efficiency of heat transfer from the phase change material 11 to the box body 1, and then improving the overall heat dissipation efficiency of the battery pack, so as to ensure the stability and reliability of the battery pack during operation.

[0066] When the control system determines that the temperature of the phase change material 11 satisfies the third preset condition, the temperature of the phase change material 11 is higher than the phase change temperature range, and the control system controls the electronic water pump to be in an on state, and controls the speed of the electronic water pump to be at a second speed, so as to accelerate the flow speed of the coolant or refrigerant in the liquid cooling plate 22 and / or the liquid cooling tube 23, thereby increasing the cooling power of the heat dissipation device 2 to meet the cooling requirements of the battery pack and ensure the stability and reliability of the battery pack during operation.

[0067] Therefore, by connecting an electronic water pump in series in the pipeline of the liquid cooling plate 22 and / or the liquid cooling tube 23, the flow rate of the coolant or refrigerant can be controlled, so that when the temperature of the phase change material 11 meets the first preset condition, the electronic water pump can be controlled to turn on and operate at a first speed to meet the cooling requirements of the battery pack and improve the stability and reliability of the battery pack during operation. When the temperature of the phase change material 11 meets the third preset condition, the electronic water pump can be controlled to turn on and operate at a second speed to improve the working efficiency of the electronic water pump, thereby further enhancing the heat dissipation effect on the battery pack.

[0068] In a specific embodiment, Figure 1 and Figure 2 As shown, the heat dissipation device 2 includes a plurality of fins 21, and the plurality of fins 21 are all connected to the outer wall of the box body 1, and the plurality of fins 21 are distributed at intervals along the height direction of the battery pack, and the cross-sectional shape of the fins 21 is a U-shaped structure or a V-shaped structure.

[0069] In the embodiment of the present application, the cross-sectional shape of the fin 21 is a U-shaped structure or a V-shaped structure, so that there is a larger contact area between the fin 21 and the external environment. When the fin 21 is connected to the outer wall of the box body 1, the fin 21 fits with the box body 1 so that there is a larger contact area between the two, so that the box body 1 can transfer heat directly to the fin 21, and improve the heat dissipation efficiency of the box body 1 by increasing the heat dissipation area, avoiding the risk of excessive internal temperature of the box body 1 due to too low heat dissipation efficiency, thereby reducing the possibility of thermal runaway of the battery module 3, and then improving the stability and reliability of the battery pack during operation.

[0070] The outer wall of the box body 1 may also be provided with a groove for accommodating the fin 21. When the fin 21 is located in the groove, the fin 21 can abut against the bottom wall and the side wall of the groove to further expand the contact area between the fin 21 and the box body 1, thereby facilitating the heat dissipation effect of the heat dissipation device 2 on the box body 1. At the same time, by providing the groove, the overall size of the battery pack can be reduced to avoid the possibility of inconvenience in installation or interference with other components due to the excessive volume of the battery pack, thereby facilitating the space utilization rate of the battery pack accommodation space. In addition, the fin 21 has the characteristics of simple structure and easy processing, which is conducive to reducing the production cost of the heat dissipation device 2.

[0071] In other embodiments, the heat sink 2 may include fins 21, liquid cooling plates 22, and liquid cooling tubes 23. When the temperature of the phase change material 11 meets the second preset condition, the control system controls the heat sink 2 to be in a closed state, at which time the battery pack can dissipate heat through the fins 21; when the temperature of the phase change material 11 meets the first preset condition, the control system controls the heat sink 2 to be in an open state, at which time the battery pack can dissipate heat through the fins 21, liquid cooling plates 22, and liquid cooling tubes 23 at the same time, so as to further improve the heat dissipation effect of the heat sink 2 on the battery pack and ensure the stability and reliability of the battery pack during operation.

[0072] In a possible embodiment, the heat dissipation device 2 also includes a baffle (not shown in the figure), which is connected to both ends of the fin 21 along a direction perpendicular to the extension of the fin 21 to avoid the possibility that the edges of the fin 21 may damage other components around the battery pack. At the same time, it can also avoid the possibility that impurities may adhere to the fin 21, thereby reducing its heat dissipation effect.

[0073] In a specific embodiment, the heat dissipation device 2 and the housing 1 are an integrally formed structure.

[0074] In the embodiment of the present application, when the fins 21 and the housing 1 are an integrally formed structure, the fins 21 can all serve as the side walls of the housing 1, so as to simultaneously expand the contact area between the phase change material 11 and the housing 1, and between the external environment and the housing 1, which is beneficial to improving the heat dissipation efficiency of the housing 1; when the liquid cooling plate 22 and the housing 1 are an integrally formed structure, the liquid cooling plate 22 can all serve as the side walls of the housing 1, so that the liquid cooling plate 22 and the liquid cooling tube 23 can all be in direct contact with the phase change material 11, shortening the heat transfer path, which is beneficial to improving the heat dissipation phase rate of the phase change material 11. At the same time, this design method can improve the overall structural strength, stability and durability of the battery pack, and can also reduce the assembly time of the heat dissipation device 2 and the housing 1, thereby reducing the production cost of the battery pack.

[0075] In a specific embodiment, Figure 1 and Figure 2 As shown, the battery pack further includes a nickel sheet 5 , one end of the nickel sheet 5 is connected to the first detection component 4 , and the other end of the nickel sheet 5 is connected to the battery module 3 .

[0076] In the embodiment of the present application, during the operation of the battery pack, when the phase change material 11 absorbs the heat released by the battery module 3 and reaches the phase change temperature, it can change from solid to liquid, and the liquid phase change material 11 has fluidity in the box body 1. The nickel sheet 5 can improve the stability and reliability of the connection between the first detection component 4 and the battery module 3, thereby reducing the possibility of the first detection component 4 falling off from the battery module 3 under the impact of the liquid phase change material 11, so as to further ensure the accuracy of the detection result.

[0077] In a possible implementation manner, the volume of the phase change material 11 is V1, the volume of the housing 1 is V2, and V1 and V2 satisfy 0.98≤V1 / V2≤1.

[0078] In the embodiment of the present application, when the ratio of the volume of the phase change material 11 to the volume of the housing 1 satisfies 0.98≤V1 / V2≤1, the phase change material 11 can completely immerse the heat dissipation device 2 and the battery module 3 located in the housing 1, and fill the remaining space in the housing 1. At the same time, it can also avoid the possibility of excessive filling of the phase change material 11, which increases the internal pressure of the housing 1 and causes the melting point of the phase change material 11 to change, thereby ensuring the stability and reliability of the battery module 3 during operation.

[0079] In a possible implementation manner, the volume V1 of the phase change material 11 satisfies the following relationship:

[0080] V1=(K×Q) / ((t2-t1)×c×ρ)×100%;

[0081] Among them, K is the charge and discharge efficiency of the battery module 3, Q is the heat generated by the battery module 3 during the charge and discharge process, t1 is the initial temperature of the phase change material 11, t2 is the temperature of the phase change material 11 during the phase change, c is the specific heat capacity of the phase change material 11, and ρ is the density of the phase change material 11.

[0082] In the embodiment of the present application, when the volume V1 of the phase change material 11 satisfies the above relationship, the filling amount of the phase change material 11 can be accurately calculated through the above relationship to further avoid the possibility of a change in the melting point of the phase change material 11 due to excessive filling of the phase change material 11, so as to ensure the working performance of the battery pack. At the same time, quantitative filling can be performed when filling the phase change material 11 to avoid the possibility of overflow of the phase change material 11 during the filling process, thereby reducing the proportion of waste of the phase change material 11 and reducing the production cost of the battery pack.

[0083] An embodiment of the present application also provides a cooling control method for a battery pack, which is used to cool the battery pack described in any of the above items, and the cooling control method includes: detecting the temperature of the phase change material 11; when the temperature of the phase change material 11 meets a first preset condition, controlling the heat dissipation device 2 to turn on, so that the heat dissipation device 2 cools down the phase change material 11; when the temperature of the phase change material 11 meets a second preset condition, controlling the heat dissipation device 2 to turn off, so that the box 1 dissipates heat and cools down the phase change material 11.

[0084] In the embodiment of the present application, the first detection element 4 is used to detect the temperature of the phase change material 11 and transmit the detection result to the control system in real time. The control system determines whether the temperature of the phase change material 11 meets the preset conditions according to the detection result of the first detection element 4.

[0085] When the control system determines that the temperature of the phase change material 11 meets the first preset condition, the temperature of the phase change material 11 is within the phase change temperature range, and the control system controls the heat dissipation device 2 to turn on, so as to cool the box body 1 through the heat dissipation device 2, thereby improving the heat dissipation effect of the box body 1, thereby accelerating the efficiency of heat transfer from the phase change material 11 to the box body 1, and then improving the overall heat dissipation efficiency of the battery pack, so as to ensure the stability and reliability of the battery pack during operation.

[0086] When the control system determines that the temperature of the phase change material 11 meets the second preset condition, the temperature of the phase change material 11 is lower than the phase change temperature range, and the control system controls the heat dissipation device 2 to be closed to allow the box 1 to dissipate heat naturally and reduce energy consumption.

[0087] Therefore, in this embodiment, the control system can timely control the heat dissipation device 2 to open when the temperature of the phase change material 11 meets the first preset condition, so as to improve the heat dissipation efficiency of the box 1, thereby accelerating the heat transfer efficiency between the phase change material 11 and the box 1, so that the phase change material 11 can absorb more heat released by the battery module 3, and then the overall operating temperature of the battery pack can be maintained within a suitable temperature range to avoid the risk of thermal runaway of the battery module 3 due to further temperature increase, which is conducive to improving the stability and reliability of the battery pack during operation and extending the service life of the battery pack. At the same time, the control system can timely control the heat dissipation device 2 to close when the temperature of the phase change material 11 meets the second preset condition, so that the box 1 dissipates heat through natural heat dissipation, which is conducive to energy saving.

[0088] In a specific embodiment, when the temperature of the phase change material 11 meets the first preset condition, the control system controls the heat dissipation device 2 to turn on so that the heat dissipation device 2 cools the phase change material 11, and the cooling control method also includes: controlling the battery module 3 to stop charging or discharging.

[0089] In the embodiment of the present application, since the battery module 3 is electrically connected to the control system, the control system can control the battery module 3 to stop charging or discharging when the temperature of the phase change material 11 reaches the phase change temperature, and wait for the temperature of the phase change material 11 to drop below the phase change temperature, and then control the battery module 3 to start charging or discharging, thereby avoiding the risk of thermal runaway caused by the battery module 3 continuing to work in a high temperature environment, which is beneficial to improving the safety of the battery module 3 during operation.

[0090] Among them, when the temperature of the phase change material 11 meets the first preset condition, the control system can control the battery module 3 to stop charging or discharging while controlling the heat dissipation device 2 to turn on, so as to shut down the heat source during the process of the heat dissipation device 2 cooling the battery pack, thereby further improving the heat dissipation efficiency of the battery pack.

[0091] In a specific embodiment, when the temperature of the phase change material 11 meets the first preset condition, the heat sink 2 is controlled to start so that the heat sink 2 cools the phase change material 11, and the cooling control method also includes: when the temperature of the phase change material 11 meets the first preset condition, the electronic water pump is controlled to start, and the electronic water pump is controlled to be at a first speed; when the temperature of the phase change material 11 meets the third preset condition, the electronic water pump is controlled to start, and the electronic water pump is controlled to be at a second speed; wherein the second speed is greater than the first speed.

[0092] In the embodiment of the present application, the control system can control the flow rate of the coolant or refrigerant through an electronic water pump, so as to improve the cooling effect of the battery pack by increasing the output power of the heat dissipation device 2, thereby improving the heat dissipation efficiency of the battery pack.

[0093] When the control system determines that the temperature of the phase change material 11 meets the first preset condition, the temperature of the phase change material 11 is within the range of the phase change temperature, and the control system controls the electronic water pump to be in an on state, and controls the speed of the electronic water pump to be at a first speed, so as to cool the box body 1 through the liquid cooling plate 22 and / or the liquid cooling tube 23, thereby improving the heat dissipation effect of the box body 1, thereby accelerating the efficiency of heat transfer from the phase change material 11 to the box body 1, and then improving the overall heat dissipation efficiency of the battery pack, so as to ensure the stability and reliability of the battery pack during operation.

[0094] When the control system determines that the temperature of the phase change material 11 satisfies the third preset condition, the temperature of the phase change material 11 is higher than the phase change temperature range, and the control system controls the electronic water pump to be in an on state, and controls the speed of the electronic water pump to be at a second speed, so as to accelerate the flow speed of the coolant or refrigerant in the liquid cooling plate 22 and / or the liquid cooling tube 23, thereby increasing the cooling power of the heat dissipation device 2 to meet the cooling requirements of the battery pack and ensure the stability and reliability of the battery pack during operation.

[0095] In one possible implementation, when the temperature of the phase change material 11 meets the third preset condition, the control system can control the battery module 3 to stop charging or discharging while controlling the electronic water pump to operate at the second speed, so as to shut down the heat source while the heat dissipation device 2 cools the battery pack, thereby further improving the heat dissipation efficiency of the battery pack.

[0096] In a specific embodiment, the first preset condition is: the temperature of the phase change material 11 is t1, and t1 satisfies 55°C≤t1≤65°C; the second preset condition is: the temperature of the phase change material 11 is t2, and t2 satisfies t2<55°C; the third preset condition is: the temperature of the phase change material 11 is t3, and t3 satisfies t3>65°C.

[0097] In the embodiment of the present application, the control system can determine whether the temperature of the phase change material 11 meets the preset conditions based on the detection results of the first detection component 4, thereby controlling the opening or closing of the heat dissipation device 2 and the battery module 3, as well as the speed of the electronic water pump, which is beneficial to improving the safety of the battery pack during operation and better meeting actual usage requirements.

[0098] Specifically, during the process of the battery pack, the heat generated by the battery module 3 gradually increases, and the phase change material 11 continuously absorbs the heat generated by the battery module 3 until the temperature of the phase change material 11 reaches the phase change temperature (that is, the temperature of the phase change material 11 is t1, and t1 satisfies 55°C≤t1≤65°C). At this time, the phase change material 11 changes from a solid state at room temperature to a liquid state, so that the heat is transferred to the box 1 through the fluidity of the liquid phase change material 11, and the heat is dissipated through the box 1. At the same time, since the heat dissipation efficiency of the box 1 is low, the control system can control the heat dissipation device 2 to turn on, and control the electronic water pump to work at the first speed, so as to cool the box 1 and / or the phase change material 11 through the heat dissipation device 2, thereby improving the heat dissipation efficiency of the battery pack, so as to ensure the stability and reliability of the battery pack during operation. Among them, the control system can control the battery pack to stop working, and can also control the battery pack to continue working.

[0099] When the control system controls the battery pack to stop working, the battery module 3 no longer generates heat, and the battery pack dissipates heat under the action of the box 1 and the heat dissipation device 2, so that the temperature of the phase change material 11 is reduced to below the phase change temperature (that is, the temperature of the phase change material 11 is t2, and t2 satisfies t2<55℃). At this time, the control system can control the heat dissipation device 2 to close to reduce energy loss, and control the battery module 3 to open so that the battery pack continues to work.

[0100] When the control system controls the battery pack to continue working, the heat generated by the battery module 3 continues to gradually increase, and the phase change material 11 continuously absorbs the heat generated by the battery module 3 until the temperature of the phase change material 11 rises above the phase change temperature (i.e., the temperature of the phase change material 11 is t3, and t3 satisfies t3>65°C). At this time, the control system can control the electronic water pump to work at the second speed, so as to increase the output power of the heat sink 2, thereby improving the cooling effect of the heat sink 2 on the box 1 and / or the phase change material 11, thereby further improving the heat dissipation efficiency of the battery pack, so as to ensure the stability and reliability of the battery pack during operation. At the same time, the control system controls the battery pack to stop working, so as to turn off the heat source and reduce the possibility of further temperature increase.

[0101] In a possible implementation, the battery pack further includes a second detection member (not shown in the figure), which is installed on the battery module 3 and electrically connected to the control system, and is used to detect the temperature of the battery module 3 in real time, and transmit the detection result to the control system in real time, so that the control system can judge whether the temperature of the battery module 3 meets the fourth preset condition according to the detection result of the second detection member, thereby controlling the battery module 3 to be turned on or off. The fourth preset condition is: the temperature of the battery module 3 is t4, and t4 satisfies 60℃≤t4≤70℃.

[0102] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery pack, characterized in that: The battery pack comprises: A box body, wherein a phase change material is arranged inside the box body; A heat dissipation device, wherein the heat dissipation device is attached to the box body; A battery module, the battery module is arranged on the bottom wall of the box and immersed in the phase change material; a first detection member, the first detection member being electrically connected to the battery module and extending into the phase change material relative to the battery module, and being used to detect a temperature of the phase change material; Wherein, the heat dissipation device, the battery module and the first detection component are all used to be electrically connected to a control system; When the temperature of the phase change material meets a first preset condition, the heat dissipation device is in an on state, and when the temperature of the phase change material meets a second preset condition, the heat dissipation device is in a off state; The battery pack further includes a nickel sheet, one end of which is connected to the first detection element, and the other end of which is connected to the battery module.

2. The battery pack according to claim 1, characterized in that: The heat dissipation device comprises a liquid cooling plate, which is connected to the outer side wall of the box body. The outer side wall of the box body is provided with a groove. The liquid cooling plate is located in the groove and abuts against the bottom wall and side wall of the groove.

3. The battery pack according to claim 1, characterized in that: The heat dissipation device includes a plurality of liquid cooling tubes, all of which are connected to the inner wall of the box body, and are distributed at intervals along the circumference of the battery module. There is a gap between each of the liquid cooling tubes and the battery module along the length and width directions of the battery pack.

4. The battery pack according to claim 1, characterized in that: The heat dissipation device includes a plurality of fins, each of which is connected to the outer side wall of the box body, and each of which is spaced apart along the height direction of the battery pack, and the cross-sectional shape of the fin is a U-shaped structure or a V-shaped structure.

5. The battery pack according to any one of claims 1 to 4, characterized in that: The heat dissipation device and the box body are an integrally formed structure.

6. A battery pack cooling control method, used to cool the battery pack according to any one of claims 1 to 5, characterized in that: The cooling control method comprises: detecting a temperature of the phase change material; When the temperature of the phase change material meets the first preset condition, controlling the heat dissipation device to turn on, so that the heat dissipation device cools down the phase change material; When the temperature of the phase change material meets the second preset condition, the heat dissipation device is controlled to be closed, so that the box body dissipates heat and cools down the phase change material.

7. The cooling control method according to claim 6, characterized in that: When the temperature of the phase change material meets the first preset condition, the heat sink is controlled to be turned on so that the heat sink cools the phase change material, the cooling control method further includes: Control the battery module to stop charging or discharging.

8. The cooling control method according to claim 6, characterized in that: The heat dissipation device further includes an electronic water pump, and the control system further has a third preset condition. When the temperature of the phase change material meets the first preset condition, the heat dissipation device is controlled to be turned on so that the heat dissipation device cools the phase change material. The cooling control method further includes: When the temperature of the phase change material meets the first preset condition, controlling the electronic water pump to start, and controlling the electronic water pump to be at a first speed; When the temperature of the phase change material meets the third preset condition, controlling the electronic water pump to start, and controlling the electronic water pump to be at a second speed; Wherein, the second rotation speed is greater than the first rotation speed.

9. The cooling control method according to claim 8, characterized in that: The first preset condition is: the temperature of the phase change material is t1, and t1 satisfies 55°C≤t1≤65°C; the second preset condition is: the temperature of the phase change material is t2, and t2 satisfies t2<55°C; the third preset condition is: the temperature of the phase change material is t3, and t3 satisfies t3>65°C.

Images