Coupling cooling battery thermal management system

Abstract

The invention discloses a coupling cooling battery thermal management system, which comprises a battery module, heat dissipation modules and mixed fins, the battery module comprises a plurality of battery monomers arranged side by side, the battery monomers are provided with electrodes, the left and right sides of each battery monomer are symmetrically provided with the heat dissipation modules, and the mixed fins are arranged on the heat dissipation modules. The heat dissipation module comprises a heat conduction gasket, a flat plate heat pipe and a cold plate which are arranged far away from the battery monomers, the heat conduction gasket, the flat plate heat pipe and the cold plate are sequentially and closely arranged, and the cold plate is internally provided with a bionic flow channel through which a cooling liquid passes; the mixed fins comprise fin substrates and a plurality of fins arranged on the fin substrates, and condensation sections at the bottoms of the flat heat pipes are connected with the corresponding fins. According to the invention, a plurality of cooling technologies are cooperated to achieve the effects of efficient heat dissipation and temperature equalization, so that the heat dissipation capability of the battery in high-power charging and discharging and severe environments is obviously improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal management systems, and in particular to a coupled cooling battery thermal management system suitable for efficient heat dissipation. The system improves the heat dissipation efficiency of the battery system by combining a hybrid fin and a high thermal conductivity heat pipe, and is suitable for thermal management of lithium-ion batteries, fuel cells and other types of batteries. Background Art

[0002] Lithium-ion batteries generate a lot of heat during the charging and discharging process. If the heat is not dissipated in time, the internal temperature of the battery will rise, affecting the battery performance and safety. There are various existing thermal management methods for new energy vehicle batteries, including air cooling, liquid cooling, direct cooling, and phase change material cooling. However, each method has its limitations. The air cooling method has low heat dissipation efficiency and is difficult to meet the heat dissipation requirements of high-power battery packs; although the liquid cooling method has high heat dissipation efficiency, it has a complex structure and high cost; the direct cooling method directly cools the battery through a refrigerant, but may cause uneven temperature distribution inside the battery; the phase change material cooling method absorbs heat during the phase change process, but the thermal conductivity is low and the phase change material is prone to leakage when it melts. For high discharge rates and high temperature conditions, it is particularly important to prevent thermal runaway of the battery and maintain battery temperature uniformity.

[0003] Therefore, the present invention aims to provide a coupled cooling battery thermal management system, which achieves efficient, uniform and reliable battery thermal management by combining the advantages of multiple cooling methods. Summary of the invention The purpose of the present invention is to provide a battery thermal management system with coupled cooling. The present invention synergizes multiple cooling technologies to achieve the effects of efficient heat dissipation and temperature balance, significantly improving the heat dissipation capacity of the battery under high-power charging and discharging and harsh environments, and extending the service life of the battery.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a coupled cooling battery thermal management system, comprising a battery module, a heat dissipation module and a hybrid fin, the battery module comprising a plurality of battery cells arranged side by side, the battery cells being provided with electrodes, the heat dissipation modules being symmetrically arranged on the left and right sides of each battery cell, the heat dissipation module comprising a thermally conductive gasket, a flat heat pipe and a cold plate arranged away from the battery cells, and the thermally conductive gasket, the flat heat pipe and the cold plate are arranged closely in sequence, a bionic flow channel for passing a coolant is provided in the cold plate, the hybrid fin comprises a fin substrate and a plurality of fins arranged on the fin substrate, and the condensation section at the bottom of the flat heat pipe is connected to the corresponding fin.

[0005] The present invention is further configured such that two groups of heat dissipation modules between two adjacent battery cells share a cold plate.

[0006] The present invention is further configured such that two fins form a group and a plug-in gap is formed between the two fins in the same group, and the condensing section at the bottom of the flat heat pipe is inserted in the corresponding plug-in gap.

[0007] The present invention is further configured such that the bionic flow channel includes an inlet main channel, a branch flow channel and an outlet main channel, the inlet main channel extends to the upper end of the cold plate to form a coolant inlet, the outlet main channel extends to the lower end of the cold plate to form a coolant outlet, the branch flow channels are the largest in number in the middle, and the number gradually decreases towards the upper and lower ends.

[0008] The present invention is further configured as follows: the outer shell of the battery cell is made of aluminum-plastic film material, the internal material of the battery cell is a composite material containing lithium iron phosphate components, the thermal conductive gasket is made of silicone material, the cold plate is made of aluminum alloy material, the coolant fluid introduced into the bionic flow channel is 50% water-ethylene glycol solvent, the outer shell and hybrid fin material of the flat heat pipe are both made of aluminum alloy, and the internal working fluid of the flat heat pipe is acetone.

[0009] Compared with the prior art, the present invention has the following beneficial effects: the coupled cooling battery thermal management system of the present invention overcomes the limitations of the traditional single cooling method through an innovative combination of multiple cooling technologies, greatly improves the heat dissipation performance and temperature balance of the system, and can be widely used in electric vehicles, power storage systems and other fields, helping to promote the development and application of lithium-ion battery technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a three-dimensional exploded schematic diagram of a thermal flow simulation model of a battery thermal management system with coupled cooling according to the present invention; Figure 2 It is a three-dimensional combined schematic diagram of a thermal flow simulation model of a battery thermal management system with coupled cooling according to the present invention; Figure 3 A schematic diagram of a hybrid fin structure of a thermal flow simulation model of a battery thermal management system with coupled cooling according to the present invention; Figure 4 This is a schematic diagram of the cold plate cross-sectional structure of the heat flow simulation model of the battery thermal management system with coupled cooling of the present invention.

[0011] In the figure: 1. Battery module; 2. Heat dissipation module; 3. Hybrid fin; 4. Battery cell; 5. Electrode; 6. Thermal pad; 7. Flat heat pipe; 8. Cold plate; 9. Bionic flow channel; 10. Fin substrate; 11. Fin; 12. Insertion gap; 13. Inlet main channel; 14. Branch flow channel; 15. Outlet main channel; 16. Coolant inlet; 17. Coolant outlet. DETAILED DESCRIPTION

[0012] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0013] Example: As shown in the attached Figures 1 to 4 A coupled cooling battery thermal management system is shown, comprising a battery module 1, a heat dissipation module 2 and a hybrid fin 3, wherein the battery module 1 comprises a plurality of battery cells 4 arranged side by side, wherein the battery cells 4 are provided with electrodes 5 (positive and negative electrodes 5), and the heat dissipation modules 2 are symmetrically arranged on the left and right sides of each battery cell 4, wherein the heat dissipation module 2 comprises a thermally conductive gasket 6, a flat heat pipe 7 and a cold plate 8 arranged away from the battery cells 4, wherein two groups of heat dissipation modules 2 between two adjacent battery cells 4 share a cold plate 8, and the thermally conductive gasket 6, the flat heat pipe 7 and the cold plate 8 are arranged closely in sequence, wherein a bionic flow channel 9 for passing a coolant is arranged in the cold plate 8, wherein the bionic flow channel 9 comprises an inlet main channel 13, a branch flow channel 14 and an outlet main channel 15, wherein the inlet main channel 13 extends to the upper end of the cold plate 8 to form a coolant inlet 16, and the outlet main channel 15 extends to the lower end of the cold plate 8 to form a coolant outlet 17, wherein the number of the branch flow channels 14 is the largest in the middle part and gradually decreases towards the upper and lower ends. The hybrid fin 3 includes a fin substrate 10 and a plurality of fins 11 disposed on the fin substrate 10. The condensing section at the bottom of the flat heat pipe 7 is connected to the corresponding fin 11. The fins 11 are grouped in two and a plug-in gap 12 is formed between the two fins 11 in the same group. The condensing section at the bottom of the flat heat pipe 7 is plugged into the corresponding plug-in gap 12.

[0014] In the above scheme, the cold plate 8 is the core heat dissipation component of the system, and a carefully designed bionic flow channel 9 is arranged inside. The inspiration of the bionic flow channel 9 comes from the human vascular network. The human vascular network is an efficient fluid transport system that transports blood to all parts of the body through arteries, veins and capillaries to regulate body temperature and supply oxygen. The bionic flow channel 9 draws on the design concept of the branch network in the vascular system. On the basis of the main channel, a multi-level branch flow channel 14 is designed so that the coolant can achieve rapid flow and heat exchange in different areas, just like blood flows in the body, effectively regulating the temperature of the battery pack. It is used to guide the flow of the coolant. The design of the bionic flow channel 9 takes into account the principles of fluid mechanics and heat exchange efficiency, optimizes the shape and path of the flow channel, and enables the coolant to take away the heat of the battery in the shortest time. The coolant flows through the inside of the cold plate 8, and absorbs the heat generated by the battery during operation in the process of flowing under the battery module 1, thereby reducing the overall temperature of the battery. The design of the bionic flow channel 9 can be adjusted according to the heat distribution of the battery module 1 to ensure uniform cooling. The flat heat pipe 7 is an efficient heat-conducting component based on the principle of phase change heat transfer. It is a mature component and is easily available on the market. Through the internal liquid evaporation and condensation cycle, it quickly transfers the heat generated by the battery to the cold plate 8 area under the influence of gravity, thereby realizing rapid diffusion and transfer of heat. The design of the flat heat pipe 7 takes into account its thickness and the selection of heat-conducting medium to ensure the best heat conduction effect under limited volume. One end of the flat heat pipe 7 is in direct contact with the battery cell 4, and the other end is tightly combined with the cold plate 8 through the thermal pad 6, forming an efficient channel for heat transfer. The hybrid fin 3 includes an aluminum heat sink (fin 11) mounted on the fin substrate 10. The fin 11 promotes the heat release of the cooling system by increasing the surface area in contact with the air. The hybrid fin 3 is combined with the flat heat pipe 7 and the cold plate 8 to further improve the overall heat dissipation performance, so that the system can still maintain good heat dissipation effect in a high temperature environment. The thermal pad 6 is used to fill the gap between the battery and the cold plate 8 and provide a good heat conduction path. Its high thermal conductivity and softness can ensure a close fit between the battery and the cooling system, thereby improving the overall heat transfer efficiency. While ensuring thermal conductivity, the thermally conductive gasket 6 also has a certain flexibility, which can buffer the thermal expansion and contraction of the battery pack. During the operation of the battery, the charging and discharging of the lithium-ion battery will generate a large amount of heat, which will be transferred to the flat heat pipe 7 along the thermally conductive gasket 6. The flat heat pipe 7 uses the phase change medium inside it to transfer heat directly from the battery to the cold plate 8 and the hybrid fin 3 area. When the coolant inside the cold plate 8 flows in the flow channel, it absorbs heat and leaves the system with heat, thereby reducing the temperature of the battery. At the same time, the combination of the cold plate 8 and the hybrid fin 3 further enhances the heat exchange between the coolant and the ambient air, and releases heat to the surrounding environment through natural convection and radiation heat dissipation.In this way, an effective heat transfer path is formed between the cold plate 8, the flat heat pipe 7, and the hybrid fin 3, which can quickly and efficiently reduce the battery temperature and ensure the temperature stability of the battery during high-power discharge or charging. The present invention forms a multi-level heat dissipation channel through the organic combination of the cold plate 8, the flat heat pipe 7 and the hybrid fin 3, so that heat can be quickly transferred from the battery pack to various parts of the cooling system. Compared with a single cooling method, the multiple heat dissipation pathways significantly improve the heat dissipation efficiency of the system. The thermal pad 6 ensures that the heat in various parts of the battery pack is evenly conducted, reducing the temperature difference inside the battery. The use of the flat heat pipe 7 allows heat to be quickly transferred from the high-temperature area to the low-temperature area, effectively achieving balanced temperature control. The design structure of the system is compact and can adapt to battery packs of different specifications. The design of the bionic flow channel 9 of the cold plate 8, the size and shape of the flat heat pipe 7, and the specifications of the hybrid fin 3 can be adjusted according to actual needs, suitable for various lithium-ion power battery application scenarios. By effectively controlling the temperature of the battery pack, thermal runaway caused by excessive battery temperature is prevented, thereby improving the safety of the battery. At the same time, the modular design of the cooling system enables it to be quickly repaired or replaced in the event of a failure, improving the reliability of the overall system.

[0015] The following is a thermal simulation of the coupled battery thermal management cooling structure and a description of the relevant component materials: The battery module 1 includes an electrode 5 and a battery cell 4. The outer shell of the battery cell 4 is made of aluminum-plastic film. The internal material of the battery cell 4 is a composite material containing lithium iron phosphate components. The thermal conductive gasket 6 is made of silicone. The cold plate 8 is made of aluminum alloy. The coolant working fluid is a 50% water-ethylene glycol solvent. The outer shell and the mixed fin 3 of the flat heat pipe 7 are made of aluminum alloy. The internal working fluid of the flat heat pipe 7 is acetone. According to the parameters of the battery pack discharge test, the ambient temperature is 40°C, the battery discharge rate is 3C, the coolant inlet 16 temperature is 40°C, and the coolant inlet 16 mass flow rate is 9L / min. Combined with the thermal simulation software, first, the solver type is set to the implicit unsteady solver, and the Realizable k-ε turbulence model is selected. The internal working fluid of the flat heat pipe 7 adopts the VOF multiphase flow solver. The pressure-velocity coupling scheme is set to coupled, the gradient discretization format selects the least squares method based on the unit cell, the pressure term discretization format selects the standard format, and the momentum equation, turbulent kinetic energy, turbulent dissipation rate and energy terms all select the first-order upwind format.

[0016] Set the parameters of each component of the battery pack. The length, width and height of the experimental battery cell 4 are 140 mm × 25 mm × 65 mm, respectively. The shell thickness of the battery cell 4 is 1 mm, and the shell material is aluminum plastic film. The density of the battery cell 4 is 2140 kg / m³, the specific heat capacity is 1633 J / (kg·K), the thermal conductivity in the length and width directions is 29 W / (m·K), and the thermal conductivity in the height direction is 1 W / (m·K). The thickness of the flat heat pipe 7 is 2 mm, the material is aluminum alloy, the internal working fluid is acetone, the density is 784 kg / m³, the specific heat capacity is 2180 J / (kg·K), and the thermal conductivity of acetone is 0.16 W / (m·K). The thickness of the thermal pad 6 is 1 mm, the density is 2684 kg / m³, the specific heat capacity is 2255.85 J / (kg·K), and the thermal conductivity is 1.4 W / (m·K). The material of the cold plate 8 is aluminum alloy, and the coolant is a 50% by mass ethylene glycol-water solution, with a density of 1069 kg / m³, a specific heat capacity of 3319 J / (kg·K), a thermal conductivity of 0.387 W / (m·K), and a dynamic viscosity of 0.00294 kg / (m·s).

[0017] The heat exchange parameters between the battery pack and the external environment are set, the convection heat transfer coefficient of the outer surface of each component is set to 5 W / (m²·K), and the ambient temperature is set to 40°C. Three temperature measurement points are set on the top, middle and bottom of the battery pack to monitor the temperature change trend of the battery. At the same time, two measurement points are set in the bionic flow channel 9 from the coolant inlet 16 to the outlet to monitor the temperature change of the coolant.

[0018] According to the duration of the battery discharge test, the time step is set to 1 s, the total number of time steps is 1200, and the solution calculation is started. After the solution is completed, the temperature rise curve of the battery pack is drawn according to the output data file, and the overall and local temperature cloud maps of the battery pack are generated to visualize the simulation results.

Claims

1. A battery thermal management system with coupled cooling, characterized in that: The invention comprises a battery module (1), a heat dissipation module (2) and a hybrid fin (3), wherein the battery module (1) comprises a plurality of battery cells (4) arranged side by side, wherein the battery cells (4) are provided with electrodes (5), and the heat dissipation module (2) is symmetrically arranged on the left and right sides of each battery cell (4), wherein the heat dissipation module (2) comprises a heat conductive pad (6), a flat plate heat pipe (7) and a cold plate (8) arranged away from the battery cells (4), and the heat conductive pad (6), the flat plate heat pipe (7) and the cold plate (8) are arranged in sequence and closely, and a bionic flow channel (9) for passing a coolant is arranged in the cold plate (8), and the hybrid fin (3) comprises a fin substrate (10) and a plurality of fins (11) arranged on the fin substrate (10), and the condensation section at the bottom of the flat plate heat pipe (7) is connected to the corresponding fin (11).

2. A battery thermal management system with coupled cooling according to claim 1, characterized in that: Two groups of heat dissipation modules (2) between two adjacent battery cells (4) share a cold plate (8).

3. A battery thermal management system with coupled cooling according to claim 1, characterized in that: The fins (11) are grouped in two and a plug-in gap (12) is formed between the two fins (11) in the same group, and the condensing section at the bottom of the flat heat pipe (7) is inserted into the corresponding plug-in gap (12).

4. The battery thermal management system with coupled cooling according to claim 1, characterized in that: The bionic flow channel (9) comprises an inlet main channel (13), a branch flow channel (14) and an outlet main channel (15); the inlet main channel (13) extends to the upper end of the cold plate (8) to form a coolant inlet (16); the outlet main channel (15) extends to the lower end of the cold plate (8) to form a coolant outlet (17); the branch flow channels (14) are the most numerous in the middle and gradually decrease in number towards the upper and lower ends.

5. The battery thermal management system with coupled cooling according to claim 1, characterized in that: The outer shell of the battery cell (4) is made of an aluminum-plastic film, the internal material of the battery cell (4) is a composite material containing a lithium iron phosphate component, the thermally conductive gasket (6) is made of a silicone material, the cold plate (8) is made of an aluminum alloy, the coolant fluid introduced into the bionic flow channel (9) is a 50% water-ethylene glycol solvent, the outer shell of the flat heat pipe (7) and the hybrid fin (3) are both made of an aluminum alloy, and the internal fluid of the flat heat pipe (7) is acetone.

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