High-performance coupling thermal management system for thermal runaway suppression of power and energy storage battery

Abstract

The invention discloses a high-performance coupling thermal management system for power and energy storage battery thermal runaway suppression, which comprises batteries, a box body and a bottom plate, the batteries are placed in the box body, the top end of the box body is covered with a vapor chamber, the vapor chamber is tightly attached to the positive and negative electrodes of the batteries, and a heat pipe is arranged between the left and right adjacent batteries. One ends of the heat pipes are arranged on the periphery of the battery at equal intervals, the space among the ends, the battery and the box body is filled with phase-change insulating flame-retardant gel, the other ends of the heat pipes extend into the bottom plate from round holes reserved in the top end of the bottom plate, the intersection positions of the heat pipes and the bottom plate are welded, cooling liquid is contained in the bottom plate, and the bottom plate is provided with a liquid inlet channel and a liquid outlet channel; according to the invention, heat pipe cooling, phase change material cooling and liquid cooling are combined, so that a battery thermal management function under a normal working condition of the battery can be realized, and when thermal runaway occurs due to abnormal heat production of the battery, the system has the effects of inhibiting thermal runaway and preventing thermal runaway propagation, and the system is suitable for the field of power and energy storage batteries.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal management, and in particular to a high-performance coupled thermal management system for suppressing thermal runaway of power and energy storage batteries. Background Art

[0002] The thermal safety of electric vehicles has become a bottleneck problem restricting the development of the entire industry, which will directly affect the vehicle's driving range, operating safety, etc. Temperature is a key technical indicator that directly affects the thermal safety of power batteries. Too high or too low temperature will cause a certain degree of decline and decay in battery performance. It is crucial to control the battery within a reasonable operating temperature range and maintain good temperature consistency throughout the life cycle.

[0003] Battery thermal management is to solve the problem of thermal dissipation or thermal runaway caused by excessively high or low temperature of the battery. It is used to reduce the maximum temperature of the battery module to avoid thermal runaway, play a role in thermal runaway protection, and reduce the maximum temperature difference to extend battery life. Power and energy storage battery thermal management technology is mainly divided into air cooling technology, liquid cooling technology, heat pipe cooling technology and PCM cooling technology according to the different heat transfer media. Air cooling is widely used due to its advantages such as simple system, easy repair and maintenance, and low cost, but the low cooling efficiency cannot match the growing large-scale power battery system, and the temperature consistency is poor. Phase change material cooling can achieve the advantages of battery temperature equalization and temperature control, and has high heat dissipation efficiency. However, key technical indicators such as low mechanical strength and low thermal conductivity during use have largely limited its industrial application in the field of electric vehicles and energy storage. At the same time, technical problems such as thermal conductivity, mechanical strength, chemical stability, flame retardancy and electrical insulation performance still need to be solved. The liquid cooling system uses flowing working fluid as the heat dissipation medium to cool the battery, and has high heat dissipation efficiency. However, the liquid cooling system bears all the heat dissipation functions, resulting in high power consumption, and a large number of metal accessories and their rigid connection structures increase the weight, complexity and cost of the entire system.

[0004] However, with the continuous evolution of the energy density of power batteries, the heat generated by batteries at high charge and discharge rates has increased dramatically. It is often difficult for a single thermal management method to meet the needs of high-rate discharge, high ambient temperature or ultra-low temperature environments. Therefore, this application proposes a high-performance coupled thermal management system for thermal runaway suppression of power and energy storage batteries. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a high-performance coupled thermal management system for suppressing thermal runaway of power and energy storage batteries, which combines heat pipe cooling, phase change material cooling and liquid cooling to solve the problems raised in the above-mentioned background technology.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A high-performance coupled thermal management system for suppressing thermal runaway of power and energy storage batteries comprises a battery, a box and a bottom plate, wherein the battery is placed in the box, the top of the box is sealed with a temperature averaging plate, the temperature averaging plate is tightly fitted with the positive and negative electrodes of the battery, a heat pipe is arranged between the left and right adjacent batteries, one end of the heat pipe is arranged at equal intervals around the battery, the space between the end and the battery and the box is filled with phase-change insulating flame-retardant gel, the other end of the heat pipe extends from a circular hole reserved at the top of the bottom plate into the interior of the bottom plate, the heat pipe is welded at the intersection with the bottom plate, the bottom plate contains coolant, and is provided with a liquid inlet channel and a liquid outlet channel.

[0008] Furthermore, the heat pipe is an L-shaped heat pipe, in which a section arranged around the battery, i.e., the longer section, is the evaporation end, and a section extending into the interior of the base plate, i.e., the shorter section, is the condensation end. The evaporation end and the condensation end are connected through a turning section of the heat pipe, and the turning section of the L-shaped heat pipe is also arranged inside the base plate to ensure the connection strength.

[0009] Furthermore, the evaporation end tube is filled with porous foam metal, and the outer wall is wrapped by the phase change insulation flame retardant gel.

[0010] Furthermore, the condensation end is immersed in the cooling liquid of the bottom plate, and a plurality of heat dissipation vertical pipes extend from the outer wall of the condensation end.

[0011] Furthermore, the porous foam metal filled in the evaporation end tube is foam copper, foam nickel or foam aluminum.

[0012] As a preferred solution, the temperature averaging plate is a 2 mm flat rectangular aluminum temperature averaging plate.

[0013] As a preferred solution, the material of the base plate is aluminum.

[0014] As a preferred solution, the coolant is a mixed nanofluid of aluminum nitride-aluminum oxide-water.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The present invention provides a heat pipe between adjacent batteries on the left and right, one end of the heat pipe is arranged at equal intervals around the battery, the space between the end and the battery and the box is filled with phase-change insulating flame-retardant gel, the other end of the heat pipe extends from the circular hole reserved at the top of the bottom plate into the bottom plate, and the bottom plate contains coolant; heat pipe cooling, phase change material cooling and liquid cooling are combined, and the latent heat in the phase change process of the phase change material is used to absorb the heat generated by the battery pack; the evaporation end of the L-shaped heat pipe in the phase change material can also absorb a certain amount of heat from the battery, and the phase change material cooperates with the heat pipe to transfer the heat generated by the battery to the coolant on the bottom plate through the heat pipe; thereby improving the heat dissipation effect of the battery and achieving consistency of battery temperature, and then through the active cooling liquid cooling technology, the heat generated by the high-power battery pack under high-rate discharge and high ambient temperature conditions is taken away in time, the heat transfer rate of the battery is improved, and the battery pack is guaranteed to be within a suitable temperature operating range.

[0017] 2. The present invention provides a temperature averaging plate on the top cover of the box body, and the temperature averaging plate is tightly fitted with the positive and negative electrodes of the battery to solve the problem that the battery is cooled and dissipated quickly by phase change materials and heat pipes around it, but the surface temperature of the positive and negative electrodes of the battery is still relatively high. Therefore, the temperature averaging plate is provided to ensure that the heat generated at the positive and negative electrodes of the battery can be evaporated into steam and absorb heat through the liquid working medium on the heating surface of the temperature averaging plate, and the steam is cooled and condensed into liquid on the other side to take away the heat; the temperature averaging plate can transfer the heat of the concentrated heat source to a larger area. Applying the temperature averaging plate to battery thermal management helps to achieve uniform surface temperature of the power battery.

[0018] 3. The phase change material used in the present invention is a phase change insulating flame retardant gel, which is different from the most commonly used paraffin-based phase change material currently. It has good thermal conductivity, latent heat performance, insulation, and good thermal insulation and flame retardant properties. When a single or several batteries experience thermal runaway, its flame retardant additive can quickly take effect to suppress fire and prevent further more severe thermal runaway. Its gel state acts as a barrier to prevent the spread of thermal runaway, and can quickly absorb the large amount of heat generated instantly and transfer the heat to the outside to prevent the surrounding batteries from experiencing thermal runaway.

[0019] 4. The high-performance coupled thermal management system of the present invention can not only realize the battery thermal management function under normal working conditions, but also has the function of suppressing thermal runaway and preventing the spread of thermal runaway when the battery generates heat abnormally and thermal runaway occurs. The system is suitable for power and energy storage battery areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an exploded view of the overall structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 3It is a three-dimensional schematic diagram of the partial assembly of the temperature averaging plate and the battery of the present invention;

[0023] Figure 4 It is a schematic diagram of the structure of the L-shaped heat pipe of the present invention;

[0024] Figure 5 It is a structural schematic diagram of the bottom plate of the present invention;

[0025] Figure 6 It is a three-dimensional schematic diagram of the partial assembly of the L-shaped heat pipe and the bottom plate of the present invention;

[0026] Figure 7 It is a schematic front view of the partial assembly of the L-shaped heat pipe and the bottom plate of the present invention;

[0027] Figure 8 It is a three-dimensional schematic diagram of the partial assembly of the phase-change insulating flame-retardant gel and the heat pipe of the present invention;

[0028] In the figure: 1. Temperature equalizing plate; 2. Box; 3. Battery; 4. Phase change insulating flame retardant gel; 5. Heat pipe; 5-1. Evaporation end; 5-2. Condensation end; 5-3. Turning section; 6. Bottom plate; 7. Liquid inlet channel; 8. Liquid outlet channel. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0030] A high-performance coupled thermal management system for suppressing thermal runaway of power and energy storage batteries comprises a battery 3, a box body 2 and a bottom plate 6, wherein the battery 3 is placed in the box body 2, and the top of the box body 2 is sealed with a temperature averaging plate 1, which is tightly fitted with the positive and negative electrodes of the battery 3, and a heat pipe 5 is arranged between the left and right adjacent batteries 3, and one end of the heat pipe 5 is arranged at equal intervals around the battery 3, and the space between the end and the battery 3 and the box body 2 is filled with a phase-change insulating flame-retardant gel 4, and the other end of the heat pipe 5 extends from a circular hole reserved at the top of the bottom plate 6 into the inside of the bottom plate 6, and the intersection of the heat pipe 5 and the bottom plate 6 is welded, and the bottom plate 6 contains coolant and is provided with a liquid inlet channel 7 and a liquid outlet channel 8.

[0031] In this embodiment, heat pipes 5 are arranged between adjacent batteries 3 on the left and right. One end of the heat pipe 5 is arranged around the battery 3 at equal intervals. The space between the end and the battery 3 and the box 2 is filled with phase-change insulating flame-retardant gel 4. The other end of the heat pipe 5 extends from the circular hole reserved at the top of the bottom plate 6 into the bottom plate 6, and the bottom plate 6 contains coolant. Heat pipe cooling, phase change material cooling and liquid cooling are combined, and the latent heat in the phase change process of the phase change material is used to absorb the heat generated by the battery pack. The evaporation end 5-1 of the L-shaped heat pipe 5 in the phase change material can also absorb a certain amount of heat from the battery 3. The phase change material cooperates with the heat pipe 5 to transfer the heat generated by the battery 3 to the coolant on the bottom plate 6 through the heat pipe 5. In this way, the heat dissipation effect of the battery 3 is improved, and the temperature consistency of the battery 3 is achieved. Then, through the active cooling liquid cooling technology, the heat generated by the high-power battery pack under high-rate discharge and high ambient temperature conditions is taken away in time, the heat transfer rate of the battery 3 is improved, and the battery pack is ensured to be within a suitable temperature working range. Secondly, in this embodiment, a temperature averaging plate 1 is provided at the top of the box body 2, and the temperature averaging plate 1 is tightly fitted with the positive and negative electrodes of the battery 3 to solve the problem that the battery 3 is cooled and dissipated quickly by the phase change material and the heat pipe 5 around it, but the surface temperature of the positive and negative electrodes of the battery 3 is still relatively high. Therefore, the temperature averaging plate 1 is provided to ensure that the heat generated at the positive and negative electrodes of the battery 3 can be evaporated into steam and absorb heat through the liquid working medium on the heating surface of the temperature averaging plate 1, and the steam is cooled and condensed into liquid on the other side to take away the heat; the temperature averaging plate 1 can transfer the heat of the concentrated heat source to a larger area, and applying the temperature averaging plate 1 to the thermal management of the battery 3 helps to achieve uniformity of the surface temperature of the power battery 3.

[0032] In this embodiment, Figure 4 , Figure 6 and Figure 8 As shown, the heat pipe 5 is an L-shaped heat pipe, wherein a section arranged around the battery 3, i.e., the longer section is the evaporation end 5-1, and a section extending into the interior of the bottom plate 6, i.e., the shorter section is the condensation end 5-2. The evaporation end 5-1 and the condensation end 5-2 are connected through a turning section 5-3 of the heat pipe 5, and the turning section 5-3 of the L-shaped heat pipe 5 is also arranged inside the bottom plate 6 to ensure the connection strength; this embodiment utilizes the high thermal conductivity and excellent temperature uniformity characteristics of the heat pipe 5 and improves its structure, with the purpose of allowing the evaporation end 5-1 to absorb more heat generated by the battery 3 and quickly transfer it to the condensation end 5-2; the condensation end 5-2 is placed in the coolant of the bottom plate 6 to adapt to the change in heat transfer by enhancing its heat dissipation area, so as to achieve the purpose of keeping the temperature of the heat source of the evaporation section constant at a certain specific temperature.

[0033] In this embodiment, the evaporation end 5-1 is filled with porous foam metal, and the outer wall is wrapped by the phase change insulating flame retardant gel 4; this embodiment utilizes the advantages of porous foam metal such as high thermal conductivity, large specific surface area, and good permeability, so that the evaporation end 5-1 of the heat pipe 5 can absorb more heat under the same volume, and enhance the heat transfer of the heat pipe 5. In addition, the phase change insulating flame retardant gel 4 is a combination of phase change material and aerogel. By adding high thermal conductivity materials such as expanded graphite, foamed copper or foamed nickel to improve its thermal conductivity, it plays an efficient thermal management function under normal operating conditions; the addition of flame retardant components and the flame retardant aerogel itself have a synergistic effect, which has an inhibitory effect when the battery 3 abnormally experiences thermal runaway, thereby preventing the spread of thermal runaway.

[0034] In this embodiment, Figure 4 As shown, the condensation end 5-2 is immersed in the coolant of the base plate 6, and a plurality of heat dissipation vertical tubes extend from the outer wall of the condensation end 5-2; wherein the heat dissipation vertical tubes spread out in all directions, and the heat dissipation vertical tubes in the same row are parallel to each other. The heat dissipation vertical tubes spread out in all directions can increase the heat dissipation area of ​​the condensation end 5-2, and also increase the contact area with the coolant.

[0035] The porous foam metal filled in the tube of the evaporation end 5 - 1 in this embodiment is foam copper, foam nickel, or foam aluminum.

[0036] To further enhance the rapid heat conduction and heat diffusion functions of this embodiment, as Figure 3 As shown, the temperature equalizing plate 1 adopts a 2mm flat rectangular aluminum temperature equalizing plate 1; the temperature equalizing plate 1 of this embodiment fits tightly with the positive and negative electrodes of the battery 3, and can quickly convert the points with high heat flux into the surfaces with low heat flux, so that it can be quickly evenly heated, thereby realizing the functions of rapid heat conduction and heat diffusion.

[0037] In the present embodiment, the material of the bottom plate 6 is aluminum; the bottom plate 6 of the present embodiment adopts a square cavity structure, and its exterior can be connected to a liquid cooling system with high heat dissipation power, so as to timely conduct away the excess heat generated during the operation of the battery 3 and avoid the occurrence of excessive temperature rise. At the same time, it has high reliability and can adapt to high and low temperature alternating environments.

[0038] In order to further improve the heat transfer efficiency of this embodiment, the coolant is an aluminum nitride-aluminum oxide-water mixed nanofluid; the aluminum nitride-aluminum oxide-water mixed nanofluid used in this embodiment has high thermal conductivity to enhance heat transfer efficiency, can maintain stable performance in a wide temperature range, and is suitable for fields with high requirements for thermal management.

[0039] It should be noted that the high-performance coupled thermal management system of this embodiment can not only realize the thermal management function of battery 3 under normal working conditions, but also has the function of suppressing thermal runaway and preventing the propagation of thermal runaway when battery 3 generates heat abnormally and thermal runaway occurs. The system is suitable for power and energy storage battery areas.

[0040] On the basis of the above technical solution, this embodiment also provides a method for implementing a high-performance coupled thermal management system for suppressing thermal runaway of power and energy storage batteries, including:

[0041] When the battery 3 is in a high temperature condition and the heat generated by the battery 3 rises within the normal thermal management temperature range, the heat is directly transferred to the phase change insulating flame retardant gel 4 in contact with the battery 3, and the evaporation end 5-1 of the heat pipe 5 arranged around the battery 3 is heated so that the internal working fluid evaporates and absorbs heat and brings it to the condensation end 5-2. The condensation end 5-2 of the heat pipe 5 is cooled and transfers the heat to the cooling water of the bottom plate 6.

[0042] When the temperature of the battery 3 continues to rise and reaches the threshold of the thermal management temperature control strategy, on the one hand, the phase-change flame-retardant insulating gel reaches the phase-change temperature and melts, which can absorb a large amount of latent heat of phase change; on the other hand, the outside of the base plate 6 can be connected to the liquid cooling system. At this time, the flow pump of the liquid cooling system starts to start, and low-temperature coolant is injected to carry away the coolant with a higher temperature inside the base plate 6, thereby achieving rapid cooling of the battery 3.

[0043] When the battery 3 is in a low temperature condition, it is necessary to turn on the flow pump of the liquid cooling system, so that the high-temperature coolant flows into the bottom plate 6 in the reverse direction to transfer the heat to the phase-change insulating flame-retardant gel 4 and the heat pipe 5, thereby heating the battery 3 so that its temperature rises to the normal working range.

[0044] When a battery 3 generates abnormal heat and the heat accumulates, triggering thermal runaway, the adjacent heat pipe 5 quickly transfers the heat to the outside of the base plate 6. The phase change insulating flame retardant gel 4 filled around the battery 3 also absorbs a large amount of heat from the battery 3 and transfers it to the base plate 6. When thermal runaway and fire occur, the flame retardant effect will be fully exerted to suppress the further spread of thermal runaway.

[0045] The above is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A high-performance coupled thermal management system for thermal runaway suppression of power and energy storage batteries, comprising a battery, characterized in that: It also includes a box body and a bottom plate, the battery is placed in the box body, the top of the box body is covered with a temperature averaging plate, the temperature averaging plate is tightly fitted with the positive and negative electrodes of the battery, a heat pipe is arranged between the left and right adjacent batteries, one end of the heat pipe is arranged at equal intervals around the battery, the space between this end and the battery and the box body is filled with phase change insulating flame retardant gel, the other end of the heat pipe extends from the circular hole reserved at the top of the bottom plate into the inside of the bottom plate, the heat pipe and the bottom plate are welded at the intersection, the bottom plate contains coolant, and is provided with a liquid inlet channel and a liquid outlet channel.

2. The high performance coupled thermal management system according to claim 1, characterized in that: The heat pipe is an L-shaped heat pipe, in which a section arranged around the battery, i.e., the longer section, is the evaporation end, and a section extending into the interior of the bottom plate, i.e., the shorter section, is the condensation end. The evaporation end and the condensation end are connected through the turning section of the heat pipe, and the turning section of the L-shaped heat pipe is also arranged inside the bottom plate to ensure the connection strength.

3. The high performance coupled thermal management system according to claim 2, characterized in that: The evaporation end tube is filled with porous foam metal, and the outer wall is wrapped by the phase-change insulation flame-retardant gel.

4. The high performance coupled thermal management system according to claim 2, characterized in that: The condensation end is immersed in the cooling liquid of the bottom plate, and a plurality of heat dissipation vertical pipes extend from the outer wall of the condensation end.

5. The high performance coupled thermal management system according to claim 3, characterized in that: The porous foam metal filled in the evaporation end tube is foam copper, foam nickel or foam aluminum.

6. The high performance coupled thermal management system according to claim 1, characterized in that: The temperature averaging plate is a 2 mm flat rectangular aluminum temperature averaging plate.

7. The high performance coupled thermal management system according to claim 1, characterized in that: The material of the bottom plate is aluminum.

8. The high performance coupled thermal management system according to claim 1, characterized in that: The cooling liquid is a mixed nanofluid of aluminum nitride, aluminum oxide and water.

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