Air-cooled battery pack, design method and equipment thereof, storage medium and product

Abstract

The invention discloses an air-cooled battery pack and a design method, equipment, a storage medium and a product thereof, the air-cooled battery pack comprises a box body and a plurality of battery cell groups arranged in the box body, and a plurality of first air inlets are formed in the top surface of the box body corresponding to the interval between two adjacent battery cell groups; a plurality of second air inlets are formed in two side surfaces of the box body, a plurality of third air inlets are formed in the tail surface of the box body, and an air outlet is formed in the head surface of the box body corresponding to an interval between two adjacent battery cell groups; the multiple first air inlets and the multiple second air inlets are arranged at unequal intervals, the distance between the first air inlets or the second air inlets which are farther away from the air outlet is smaller, and the distance between the first air inlets or the second air inlets which are closer away from the air outlet is larger. And a cooling fan is arranged at the air outlet. The surface temperature uniformity of the battery cell group is remarkably improved, and the heat dissipation effect of the battery pack is optimized.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat dissipation of energy storage batteries, and in particular relates to an air-cooled battery pack and a design method, equipment, storage medium and product thereof. Background Art

[0002] Lithium batteries are a commonly used type of battery in the field of energy storage systems. They have characteristics such as high energy density, long charge and discharge cycle life, and low risk of thermal runaway. However, under the combined influence of factors such as ohmic heat, polarization heat, and chemical reaction heat, as well as the inevitable high current density at the tabs and busbars, lithium battery packs have a large amount of heat generated by the cell group and a more obvious non-uniformity. High temperature and high temperature non-uniformity will affect the battery's charge and discharge performance and battery life, and even greatly increase the risk of thermal runaway, posing hidden dangers to the entire energy storage system. Therefore, the safety of the energy storage system is greatly affected by the heat dissipation performance of the battery pack.

[0003] At present, the mainstream technical routes for heat dissipation design of lithium battery packs for energy storage include air cooling, liquid (water) cooling and air cooling using phase change materials. Among them, the use of phase change materials is still mainly in the laboratory stage, and the stability of phase change materials and the complexity of heat dissipation design are relatively high; although the technical route of liquid (water) cooling is relatively mature, it has advantages such as good cooling efficiency and heat dissipation uniformity, high space utilization, and low noise. It has many applications in the field of lithium battery heat dissipation. However, its high manufacturing cost and subsequent maintenance cost make it not advantageous in the field of energy storage. Compared with the field of power batteries, lithium battery packs in the field of energy storage systems have lower requirements for space and noise control, and higher requirements for cost control. Therefore, air cooling is still the mainstream technical route in this field. The design of traditional air-cooled battery packs is relatively simple, with low heat dissipation efficiency and poor heat dissipation uniformity, which seriously affects the battery charging and discharging performance and battery life, and seriously restricts the development of energy storage systems towards high-rate charging and discharging. Summary of the invention

[0004] The purpose of the present invention is to provide an air-cooled battery pack and its design method, equipment, storage medium and product to solve the problems of low heat dissipation efficiency and poor heat dissipation uniformity of traditional air-cooling heat dissipation technology.

[0005] The present invention solves the above technical problems through the following technical solutions: an air-cooled battery pack, comprising a box body and a plurality of battery cell groups arranged in the box body, the plurality of battery cell groups are arranged at intervals along a first direction, each of the battery cell groups is formed by stacking a plurality of battery cell monomers along a second direction, and the second direction is perpendicular to the first direction; the wall surface parallel to the first direction and the second direction and close to the pole ear of the battery cell group is the top surface of the box body, the wall surface perpendicular to the first direction and parallel to the second direction is the side surface of the box body, and the wall surface parallel to the first direction and perpendicular to the second direction is the head surface or tail surface of the box body;

[0006] A plurality of first air inlets are provided on the top surface of the box body corresponding to the interval between two adjacent battery cell groups, a plurality of second air inlets are provided on the two side surfaces of the box body, a plurality of third air inlets are provided on the rear surface of the box body, and an air outlet is provided on the head surface of the box body corresponding to the interval between two adjacent battery cell groups; the plurality of first air inlets are arranged at unequal intervals, and the intervals between the first air inlets farther away from the air outlet are smaller, while the intervals between the first air inlets closer to the air outlet are larger; the plurality of second air inlets are arranged at unequal intervals, and the intervals between the second air inlets farther away from the air outlet are smaller, while the intervals between the second air inlets closer to the air outlet are larger; the plurality of third air inlets are arranged at equal intervals; and a cooling fan is provided at the air outlet.

[0007] Furthermore, the spacing between the first air inlets and the spacing between the second air inlets are both arranged in a manner of the Fibonacci sequence.

[0008] Further, when each battery cell group includes 8 battery cell units, the number of the first air inlets is 6, and the distances between the 6 first air inlets and the air outlet are, from far to near, 21mm, 33mm, 54mm, 87mm, and 141mm respectively; the number of the second air inlets is 6, and the distances between the 6 second air inlets and the air outlet are, from far to near, 21mm, 33mm, 54mm, 87mm, and 141mm respectively.

[0009] Furthermore, the first air inlet, the second air inlet and the third air inlet are all long round-headed holes, the long side of the first air inlet is parallel to the first direction and perpendicular to the second direction, the long side of the second air inlet is perpendicular to the first direction and the second direction, and the long side of the third air inlet is perpendicular to the first direction and the second direction.

[0010] Furthermore, an air guide plate is provided at a long side of the third air inlet opposite to the interval between two adjacent battery cell groups.

[0011] Furthermore, the third air inlet opposite to the interval between two adjacent battery cell groups and the air guide plate at its long side are shaped like a trumpet, and the width of the trumpet mouth is consistent with the width of the interval cross section between two adjacent battery cell groups.

[0012] Based on the same concept, the present invention also provides a design method for an air-cooled battery pack, comprising:

[0013] Step S1: constructing a simplified model of the air-cooled battery pack as described above;

[0014] Step S2: meshing the simplified model of the air-cooled battery pack;

[0015] Step S3: Based on the meshed model, a finite element calculation model of a thermal-fluid-solid coupled air-cooled battery pack is constructed;

[0016] Step S4: Based on the finite element calculation model of the thermal-fluid-solid coupled air-cooled battery pack, simulation calculation is performed to obtain the surface temperature field distribution of the battery cell and the flow field distribution in the air domain;

[0017] Step S5: judging whether the maximum temperature, average temperature and maximum temperature difference meet the thermal management design requirements according to the surface temperature field distribution of the battery cell and the air flow field distribution; if so, obtaining the positions and sizes of the first air inlet, the second air inlet, the third air inlet and the air outlet;

[0018] If not, adjust the positions and sizes of the first air inlet, the second air inlet, the third air inlet and the air outlet, and proceed to step S2.

[0019] Based on the same concept, the present invention also provides an electronic device, including a memory, a processor, and a computer program / instructions stored in the memory, wherein the processor executes the computer program / instructions to implement the design method of the air-cooled battery pack as described above.

[0020] Based on the same concept, the present invention also provides a computer-readable storage medium on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the design method of the air-cooled battery pack as described above is implemented.

[0021] Based on the same concept, the present invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the design method of the air-cooled battery pack as described above.

[0022] Beneficial Effects

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] The present invention provides an air-cooled battery pack, which has multiple air inlets on the top and rear surfaces of the box body. When the cooling fan at the front and rear air outlets draws air outward, negative pressure is generated in the box body, and external cold air enters from the air inlet on the top surface of the box body (i.e., the first air inlet), flows to the front and rear air outlet through the gap between the top surface of the box body and the battery cell group, forming a Z-shaped air duct; external cold air enters from the air inlet on the side of the box body (i.e., the second air inlet), flows to the front and rear air outlet through the gap between the side of the box body and the battery cell group, forming a U-shaped air duct; external cold air enters from the air inlet on the rear surface of the box body (i.e., the third air inlet), flows to the front and rear air outlet through the gap between two adjacent battery cell groups, forming an I-shaped air duct; external cold air is sucked in through air inlets at different positions, passes through three air ducts and takes away the heat from the surface of the battery cell monomers through forced convection heat exchange, significantly improves the surface temperature uniformity of the battery cell group, and optimizes the heat dissipation effect of the battery pack.

[0025] Since the negative pressure at the air inlet close to the cooling fan is larger (i.e., the cold air flow rate is large), and the negative pressure at the air inlet far from the cooling fan is smaller (i.e., the cold air flow rate is small), in order to achieve more uniform heat dissipation, the distances between the air inlets on the top and sides of the box body are not equal. The farther the distance from the air outlet, the smaller the distance between the air inlets, and the closer the distance to the air outlet, the larger the distance between the air inlets, so that the cold air flow at different positions on the top and side is uniform, thereby improving the uniformity of heat dissipation.

[0026] The present invention does not require major changes to the battery pack, has low process costs, controls the battery pack temperature more reasonably and effectively, and has higher temperature field uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 is a schematic diagram of the structure of an air-cooled battery pack in an embodiment of the present invention;

[0029] Figure 2 : is a simulation result diagram of an air-cooled battery pack in an embodiment of the present invention; wherein the numbers in the color code represent the temperature;

[0030] Figure 3 is a schematic diagram of a Z-shaped air duct in a simulation result of an air-cooled battery pack in an embodiment of the present invention;

[0031] Figure 4 It is a schematic diagram of a U-shaped air duct and an I-shaped air duct in the simulation result of an air-cooled battery pack in an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of the spacing between the first air inlets on the top surface in the simulation results of the air-cooled battery pack in an embodiment of the present invention;

[0033] Figure 6 is a schematic diagram of the spacing between the second air inlets on the side in the simulation results of the air-cooled battery pack in an embodiment of the present invention;

[0034] Figure 7 is a schematic diagram of a conventional battery pack structure in an embodiment of the present invention;

[0035] Figure 8 1 is a diagram of simulation results of a conventional battery pack in an embodiment of the present invention; wherein the numbers in the color code represent the temperature.

[0036] Explanation of the reference numerals: 1-box body, 11-first air inlet, 12-second air inlet, 13-third air inlet, 14-air outlet, 2-battery cell, 21-ear, 22-busbar. DETAILED DESCRIPTION

[0037] The following is a clear and complete description of the technical solutions in the present invention in conjunction with the drawings 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.

[0038] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0039] like Figure 1As shown, an air-cooled battery pack provided by an embodiment of the present invention comprises a box body and a plurality of battery cell groups arranged in the box body, wherein the plurality of battery cell groups are arranged at intervals along a first direction, and each battery cell group is formed by stacking a plurality of battery cell monomers 2 along a second direction, and the second direction is perpendicular to the first direction; the wall surface parallel to the first direction and the second direction and close to the pole ear 21 of the battery cell group is the top surface of the box body, the wall surface perpendicular to the first direction and parallel to the second direction is the side surface of the box body, and the wall surface parallel to the first direction and perpendicular to the second direction is the head surface or tail surface of the box body; a plurality of first air inlets 11 are provided on the top surface of the box body corresponding to the interval between two adjacent battery cell groups, and a plurality of second air inlets 12 are provided on the two side surfaces of the box body. , a plurality of third air inlets 13 are arranged on the rear surface of the box body, an air outlet 14 is arranged on the head surface of the box body corresponding to the interval between two adjacent battery cell groups, and the air outlet 14 is directly opposite to the interval between two adjacent battery cell groups; a plurality of first air inlets 11 are arranged at unequal intervals, and the interval between the first air inlets 11 farther away from the air outlet 14 is smaller, and the interval between the first air inlets 11 closer to the air outlet 14 is larger; a plurality of second air inlets 12 are arranged at unequal intervals, and the interval between the second air inlets 12 farther away from the air outlet 14 is smaller, and the interval between the second air inlets 12 closer to the air outlet 14 is larger; a plurality of third air inlets 13 are arranged at equal intervals; a cooling fan is provided at the air outlet 14. In this embodiment, the cooling fan is an axial flow fan.

[0040] When the cooling fan of the air outlet 14 draws air outward, negative pressure is generated in the box body, and external cold air enters from the multiple first air inlets 11, flows to the air outlet 14 through the gap between the top surface of the box body and the battery cell group, and flows out from the air outlet 14, forming a Z-shaped air duct. Figure 3 As shown, the Z-shaped air duct can effectively take away the heat of the temperature-concentrating components such as the tabs 21 and the busbars 22, effectively reducing the upper temperature limit of the highest temperature area of ​​the battery pack during the charging and discharging process, and improving the overall temperature uniformity of the battery pack; the external cold air enters from the multiple second air inlets 12, flows to the air outlet 14 through the gap between the side of the box body and the battery pack, and flows out from the air outlet 14, forming a U-shaped air duct, as shown in FIG. Figure 4 As shown, the U-shaped air duct can effectively take away the heat from the side wall of the battery cell, eliminate the heat concentration in the high temperature area on the outer wall of the battery cell group, and improve the temperature uniformity of the battery cell group; the external cold air enters from the multiple third air inlets 13, flows to the air outlet 14 through the gap between two adjacent battery cell groups, and flows out from the air outlet 14, forming an I-shaped air duct, as shown in FIG. Figure 4 As shown, the I-shaped air duct effectively alleviates the heat concentration in the middle area of ​​two adjacent battery cell groups, further improving the overall temperature uniformity of the battery pack.

[0041] In view of the high heat transfer coefficient of the square battery pack in the height and width directions, and the concentrated ohmic heat due to the higher current density at the tabs 21 and the busbar 22, the present invention designs a three-duct cooling structure, in which external cold air is sucked into the box body through air inlets at different positions, and the heat on the surface of the battery cell 2 is taken away by forced convection heat exchange, which can effectively reduce the surface temperature of the battery cell and improve the heat dissipation effect and uniformity.

[0042] The closer to the cooling fan, the higher the negative pressure in the box body, and the greater the cold air flow rate sucked in by the first air inlet 11 and the second air inlet 12; conversely, the farther away from the cooling fan, the lower the negative pressure in the box body, and the smaller the cold air flow rate sucked in by the first air inlet 11 and the second air inlet 12. In order to ensure the uniformity of the cold air flow rate at each location of the U-shaped air duct and the Z-shaped air duct, and thus ensure the uniformity of the heat dissipation effect at each location, multiple first air inlets 11 are arranged at unequal intervals, and the farther the distance from the air outlet 14, the smaller the distance between the first air inlets 11, and the closer the distance to the air outlet 14, the larger the distance between the first air inlets 11; multiple second air inlets 12 are arranged at unequal intervals, and the farther the distance from the air outlet 14, the smaller the distance between the second air inlets 12, and the closer the distance to the air outlet 14, the larger the distance between the second air inlets 12; multiple third air inlets 13 are arranged at equal intervals.

[0043] In a specific embodiment of the present invention, the spacing between the first air inlets 11 and the spacing between the second air inlets 12 are arranged in the Fibonacci sequence. For example, when each battery cell group includes 8 battery cells 2, the number of the first air inlets 11 is 6, and the distances between the first air inlets 11 and the air outlet 14 are from far to near, and the spacings between the 6 first air inlets 11 are 21mm, 33mm, 54mm, 87mm, and 141mm, respectively. Figure 5 As shown; the number of the second air inlet 12 is 6, and the distance between the air outlet 14 is from far to near, and the spacing between the 6 second air inlets 12 is 21mm, 33mm, 54mm, 87mm, and 141mm, respectively, as Figure 6 shown.

[0044] In a specific embodiment of the present invention, the first air inlet 11, the second air inlet 12 and the third air inlet 13 are all long round holes. The directions of the first air inlet 11, the second air inlet 12 and the third air inlet 13 are designed according to the heating characteristics and geometric characteristics of the heat dissipation area targeted by each air duct to improve the heat dissipation effect and temperature uniformity. The long side of the first air inlet 11 is parallel to the first direction and perpendicular to the second direction, the long side of the second air inlet 12 is perpendicular to the first direction and the second direction, and the long side of the third air inlet 13 is perpendicular to the first direction and the second direction.

[0045] In order to provide sufficient cold air flow and velocity for the I-shaped air duct, an air guide plate is added at the long side of the third air inlet 13 opposite to the gap between two adjacent battery cell groups, so that the cold air flowing in from the third air inlet 13 flows directly to the gap between two adjacent battery cell groups. In a specific embodiment of the present invention, the third air inlet 13 opposite to the gap between two adjacent battery cell groups and the air guide plate at the long side are formed in a trumpet shape, and the width of the trumpet mouth is consistent with the width of the cross section of the gap between two adjacent battery cell groups.

[0046] In order to verify the heat dissipation effect and temperature uniformity of the air-cooled battery pack of the present invention, a 1P16S battery pack with two rows of cells (i.e., including two cell groups, each cell group including 8 cell monomers, and 16 cell monomers connected in series through a busbar) is taken as an example to compare the simulation results of the traditional battery pack and the air-cooled battery pack of the present invention. The traditional battery pack only has air inlets designed on the two sides of the box body, and the air inlets are arranged at equal intervals, such as Figure 7 The number of the first air inlet and the second air inlet of the air-cooled battery pack of the present invention are both 6, and the spacing between the 6 first air inlets or the 6 second air inlets is 21mm, 33mm, 54mm, 87mm, and 141mm respectively. Figure 5 and Figure 6 The specific simulation process includes:

[0047] Step S1: construct an air-cooled battery pack model, extract the air domain in the box body, and couple the fluid-solid interface;

[0048] Step S2: The air inlet, air outlet and positive and negative electrode surfaces are named separately to prepare for the boundary condition setting of the simulation process; the air-cooled battery pack model is meshed separately, and the meshes of the air inlet, air outlet, pole ear and busbar are encrypted to obtain the mesh file of the air-cooled battery pack model; the embodiment of the present invention preferably adopts the hexahedral meshing method for meshing;

[0049] Step S3: importing the mesh file of the air-cooled battery pack model into the finite element analysis software Fluent to establish a finite element model of the air-cooled battery pack;

[0050] Step S4: Introduce CFD software, set the air outlet as Exhaust fan outlet, and the air inlet as Pressure inlet. After global initialization, use the steady-state solver and turbulence model to calculate the air flow field of each air duct of the air-cooled battery pack model, obtain the air flow velocity and distribution of each air duct, and obtain the air flow trajectory (such as Figure 2 to Figure 6 The curve in

[0051] Step S5: Based on the calculation result of step S4, switch to the transient solver, and based on the MSMD battery model built into Fluent (the MSMD battery model is set according to the battery charging and discharging characteristics, etc.), calculate the heating characteristics of the finite element model of the air-cooled battery pack under normal charge and discharge rate conditions through the transient solver;

[0052] Step S6: setting the material properties of the finite element model of the air-cooled battery pack based on the thermal physical property parameters of the battery cell, and setting the solution domain and boundary conditions according to the actual working conditions;

[0053] Step S7: closing the flow equation, turbulence equation and residual monitoring, and setting the key physical parameters of the key positions to be monitored; wherein closing the flow equation, turbulence equation and residual monitoring are built-in solution equations and monitoring functions used in the calculation process of the steady-state solver and the turbulence model;

[0054] Step S8: Initialize the MSMD (Multi-Scale Multi-Dimension) battery model separately, set the time step and number of steps according to the charge and discharge time, and then perform CFD simulation calculation of the air-cooled battery pack finite element model.

[0055] The simulation results of the finite element model of the air-cooled battery pack of the present invention are as follows: Figure 2 to Figure 6 Similarly, the CFD simulation calculation of the traditional battery pack finite element model is performed, and the simulation results are shown as follows Figure 8 shown.

[0056] like Figure 2 to Figure 6 , Figure 8 As shown in the figure, when in the charge and discharge working state, the battery cell generates reaction heat under electrochemical action, as well as polarization heat and ohmic heat generated by electron movement. Due to the anisotropic thermal conductivity of the battery cell, this heat is largely gathered in the width direction and top direction of the battery cell; due to the smaller conductor cross-section and increased current density at the tabs and busbars, a large amount of ohmic heat is generated, and due to the small geometric size, high-temperature areas with concentrated heat appear at the corners. In addition, since the battery cell group is a double-row arrangement structure, the high-temperature area appears more concentratedly on the inner wall of the battery cell group between the two battery cell groups and the top tabs, busbars and other components.

[0057] The heat dissipation process of the air duct of the traditional battery pack finite element model is as follows: cold air flows from the air inlet on the side of the box body, flows through the outer wall of the battery cell group (i.e., the wall close to the side of the box body), flows through the top of the battery cell group and the gap between the two battery cell groups, and the hot air is extracted by the axial flow fan, such as Figure 8The duct heat dissipation process of the air-cooled battery pack finite element model includes the U-shaped duct heat dissipation process (i.e., side heat dissipation), the Z-shaped duct heat dissipation process (i.e., top surface heat dissipation), and the I-shaped duct heat dissipation process (i.e., heat dissipation between battery packs). The U-shaped duct heat dissipation process is as follows: cold air flows from the second air inlet through the outer wall of the battery pack, takes away the heat of the outer wall of the battery pack in the form of forced convection heat exchange, and then the high-temperature air is extracted by the axial fan. The heat dissipation duct path presents a U-shape, as shown in FIG. Figure 4 As shown; the Z-shaped air duct heat dissipation process is: cold air flows from the first air inlet, through the top wall of the battery cell group (i.e., the wall close to the top of the box body), the tabs and the busbars, and takes away the surface heat in the form of forced convection heat exchange, and then the high-temperature air is drawn out by the axial fan. The heat dissipation air duct path presents a Z shape, as shown Figure 3 As shown; the I-shaped air duct heat dissipation process is: cold air flows from the third air inlet through the gap between the two battery cell groups (i.e., the inner wall of the battery cell group), removes the surface heat in the form of forced convection heat exchange, and then the high-temperature air is extracted by the axial flow fan. The heat dissipation air duct path presents an I-shape, as shown Figure 4 shown.

[0058] According to the simulation results Figure 2 and Figure 8 It can be seen that: based on the unified cell group surface temperature threshold (based on the temperature distribution threshold of 300.6~306.4K of the present invention), the surface temperature distribution of the cell group of the present invention and the traditional air-cooled battery pack is compared. It can be clearly seen that there is no obvious high temperature accumulation on the surface temperature of the cell of the air-cooled battery pack of the present invention, and the temperature uniformity is better. Compared with the cell surface temperature field of the same rate charge and discharge condition under natural convection heat exchange conditions, the maximum surface temperature and temperature distribution threshold of the cell group are reduced by 15.5% and 60%, respectively, verifying the effectiveness of air cooling and heat dissipation. However, due to the small amount of air at the top and middle of the traditional battery pack, local high temperature occurs, while the high temperature area of ​​the air-cooled battery pack of the present invention only exists at the bottom of the cell group. In actual situations, since the bottom is contact heat transfer, heat accumulation is not easy to occur, and if the top and inner wall of the cell group are not dissipated in time, local high temperature is very likely to occur. At the same time, the characteristics of the temperature field distribution are characterized by Figure 2 It can be seen that the three air ducts of the air-cooled battery pack of the present invention can achieve good control of the uniformity of the surface temperature of the battery cell group. Therefore, the simulation calculation results show that the present invention can effectively control the maximum temperature value and distribution threshold value of the battery cell group under the charging and discharging conditions.

[0059] Example 2

[0060] A design method for an air-cooled battery pack provided by an embodiment of the present invention comprises the following steps:

[0061] Step S1: construct a simplified model of the air-cooled battery pack as described in Example 1.

[0062] A simplified model of the air-cooled battery pack is constructed according to its three-dimensional structure. The simplified model includes a box body, a cell group in the box body, a tab, a busbar, and a first air inlet, a second air inlet, a third air inlet and an air outlet on the box body.

[0063] Step S2: Meshing the simplified model of the air-cooled battery pack.

[0064] This embodiment uses hexahedral meshes + polyhedral meshes to mesh the simplified model of the air-cooled battery pack; sets the local minimum mesh size according to the local heat transfer calculation accuracy requirements and geometric characteristics, and performs adaptive mesh encryption; and divides different numbers of meshes by setting different mesh sizes to facilitate subsequent mesh independence testing.

[0065] Step S3: Based on the meshed model, a finite element calculation model of a thermal-fluid-solid coupled air-cooled battery pack is constructed.

[0066] Step S4: Based on the finite element calculation model of the thermal-fluid-solid coupled air-cooled battery pack, simulation calculation is performed to obtain the surface temperature field distribution of the battery cell and the flow field distribution in the air domain.

[0067] Before calculating the flow field in the air domain of the box body, the solver uses the pressure-based steady-state solver, and the viscosity model uses the k-Omega SST turbulence model. According to the type of cooling fan and the external environment, the inlet and outlet boundary condition types, momentum and temperature are set, and then the calculation is submitted. In this embodiment, the boundary condition type uses pressure inlet and mass flow outlet.

[0068] Before calculating the surface temperature field of the battery cell, the solver is switched to a transient solver, the energy equation is turned on, and the parameters and properties of the model are set according to the parameters and properties of the air-cooled battery pack. For example, the battery cell parameters of the model are set according to the actual parameters of the battery cell (such as density, equivalent specific heat capacity, anisotropic equivalent thermal conductivity and electrical conductivity, etc.). If the tabs and busbars are made of copper or aluminum, then the tabs and busbars of the model are set to copper or aluminum. When solving, close the flow equation, turbulence equation, residual monitor, initialize the model separately, and initialize the temperature variable locally to the corresponding area. After completing the settings, fully charge and fully discharge at a charge and discharge rate of 0.5C for a total of 7200s, submit the transient calculation, and obtain the surface temperature field distribution of the battery cell.

[0069] Step S5: Determine whether the maximum temperature, average temperature and maximum temperature difference meet the thermal management design requirements based on the surface temperature field distribution of the battery cell and the flow field distribution in the air domain. If so, obtain the positions and sizes of the first air inlet, the second air inlet, the third air inlet and the air outlet; if not, based on the theoretical basis of air cooling and heat dissipation and design experience, take strengthening the air flow in the high-temperature gathering area as the optimization design direction, adjust the positions and sizes of the first air inlet, the second air inlet, the third air inlet and the air outlet, and proceed to step S2.

[0070] Exemplarily, the thermal management design requires that the maximum temperature is not higher than 40°C, the average temperature is not higher than 35°C, and the difference between the maximum temperature and the minimum temperature (i.e., the maximum temperature difference) is not more than 10°C. When the thermal management design requirements are not met, the positions and / or sizes of the first air inlet, the second air inlet, the third air inlet, and the air outlet are adjusted to improve the air domain flow field characteristics and optimize the surface temperature distribution characteristics of the battery cell until the thermal management design requirements are met and the heat dissipation performance is better than that of the traditional design.

[0071] Example 3

[0072] An embodiment of the present invention also provides an electronic device, which includes: a memory, a processor, and a computer program / instructions stored in the memory, and the processor executes the computer program / instructions to implement the design method of the air-cooled battery pack in the embodiment of the present application.

[0073] Although not shown, the electronic device includes a processor, which can perform various appropriate operations and processes according to the program and / or data stored in the read-only memory (ROM) or the program and / or data loaded from the storage portion into the random access memory (RAM). The processor can be a multi-core processor, or it can include multiple processors. In some embodiments, the processor can include a general main processor and one or more special coprocessors, such as a central processing unit, a graphics processing unit (GPU), a neural network processor (NPU), a digital signal processor (DSP), etc. In RAM, various programs and data required for device operation are also stored. The processor, ROM and RAM are connected to each other via a bus. The input / output (I / O) interface is also connected to the bus.

[0074] The processor and memory are used together to execute the program / instructions stored in the memory. When the program / instructions are executed by the computer, the methods, steps or functions described in the above embodiments can be implemented.

[0075] Although not shown, an embodiment of the present invention further provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the design method of the air-cooled battery pack in the embodiment of the present application.

[0076] Storage media in embodiments of the present invention include permanent and non-permanent, removable and non-removable items that can be implemented by any method or technology to store information. Examples of storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

[0077] Readable storage media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0078] Although not shown, an embodiment of the present invention further provides a computer program product, including: a computer program / instructions, which, when executed by a processor, implements the design method of the air-cooled battery pack in the embodiment of the present application.

[0079] What is disclosed above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, which should be covered within the protection scope of the present invention.

Claims

1. An air-cooled battery pack, comprising a box body and a plurality of battery cell groups arranged in the box body, wherein the plurality of battery cell groups are arranged at intervals along a first direction, each of the battery cell groups is formed by stacking a plurality of battery cell monomers along a second direction, and the second direction is perpendicular to the first direction; the wall surface parallel to the first direction and the second direction and close to the pole ear of the battery cell group is the top surface of the box body, the wall surface perpendicular to the first direction and parallel to the second direction is the side surface of the box body, and the wall surface parallel to the first direction and perpendicular to the second direction is the head surface or tail surface of the box body; characterized in that: A plurality of first air inlets are provided on the top surface of the box body corresponding to the interval between two adjacent battery cell groups, a plurality of second air inlets are provided on the two side surfaces of the box body, a plurality of third air inlets are provided on the rear surface of the box body, and an air outlet is provided on the head surface of the box body corresponding to the interval between two adjacent battery cell groups; the plurality of first air inlets are arranged at unequal intervals, and the intervals between the first air inlets farther away from the air outlet are smaller, while the intervals between the first air inlets closer to the air outlet are larger; the plurality of second air inlets are arranged at unequal intervals, and the intervals between the second air inlets farther away from the air outlet are smaller, while the intervals between the second air inlets closer to the air outlet are larger; the plurality of third air inlets are arranged at equal intervals; and a cooling fan is provided at the air outlet.

2. The air-cooled battery pack according to claim 1, characterized in that: The spacing between the first air inlets and the spacing between the second air inlets are both arranged in a Fibonacci sequence.

3. The air-cooled battery pack according to claim 2, characterized in that: When each battery cell group includes 8 battery cells, the number of the first air inlets is 6, and the distances between the 6 first air inlets and the air outlet are 21mm, 33mm, 54mm, 87mm, and 141mm respectively from far to near; the number of the second air inlets is 6, and the distances between the 6 second air inlets and the air outlet are 21mm, 33mm, 54mm, 87mm, and 141mm respectively from far to near.

4. The air-cooled battery pack according to claim 1, characterized in that: The first air inlet, the second air inlet and the third air inlet are all long round-headed holes, the long side of the first air inlet is parallel to the first direction and perpendicular to the second direction, the long side of the second air inlet is perpendicular to the first direction and the second direction, and the long side of the third air inlet is perpendicular to the first direction and the second direction.

5. The air-cooled battery pack according to any one of claims 1 to 4, characterized in that: An air guide plate is additionally provided at the long side of the third air inlet opposite to the interval between two adjacent battery cell groups.

6. The air-cooled battery pack according to claim 5, characterized in that: The third air inlet opposite to the interval between two adjacent battery cell groups and the air guide plate at its long side are shaped like a trumpet, and the width of the trumpet mouth is consistent with the width of the interval cross section between two adjacent battery cell groups.

7. A method for designing an air-cooled battery pack, characterized in that: include: Step S1: constructing a simplified model of the air-cooled battery pack according to any one of claims 1 to 6; Step S2: meshing the simplified model of the air-cooled battery pack; Step S3: Based on the meshed model, a finite element calculation model of a thermal-fluid-solid coupled air-cooled battery pack is constructed; Step S4: Based on the finite element calculation model of the thermal-fluid-solid coupled air-cooled battery pack, simulation calculation is performed to obtain the surface temperature field distribution of the battery cell and the flow field distribution in the air domain; Step S5: judging whether the maximum temperature, average temperature and maximum temperature difference meet the thermal management design requirements according to the surface temperature field distribution of the battery cell and the air flow field distribution; if so, obtaining the positions and sizes of the first air inlet, the second air inlet, the third air inlet and the air outlet; If not, adjust the positions and sizes of the first air inlet, the second air inlet, the third air inlet and the air outlet, and proceed to step S2.

8. An electronic device comprising a memory, a processor, and a computer program / instruction stored in the memory, characterized in that: The processor executes the computer program / instructions to implement the design method of the air-cooled battery pack as claimed in claim 7.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instructions are executed by the processor, the design method of the air-cooled battery pack as described in claim 7 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by the processor, the design method of the air-cooled battery pack as described in claim 7 is implemented.

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