Micro-channel flat tube battery thermal management system and preparation method thereof

Abstract

The invention provides a micro-channel flat tube battery thermal management system and a preparation method thereof, and belongs to the technical field of liquid-cooled battery thermal management systems. According to the invention, silica gel in the loading mold is mixed with silicon carbide to enhance heat conduction, the silicon carbide serving as a heat-conducting medium is added to ensure the heat conductivity coefficient of the silica gel and reduce the viscosity and potting difficulty of the silica gel at the same time, the loading mold is filled between the battery and the micro-channel flat tube to reduce heat transfer resistance, and a cooling medium is driven by a water pump. After the flow is adjusted by the flow control valve, the flow flows into the micro-channel flat pipes, and the micro-channel flat pipes penetrate through gaps among batteries in the battery module, so that the heat exchange efficiency is high, heat generated by the batteries is quickly absorbed, and the temperature consistency of the battery module is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid-cooled battery thermal management systems, and in particular to a microchannel flat tube battery thermal management system and a preparation method and application thereof. Background Art

[0002] As a key component and power source for electric vehicles, the operational safety and performance of power batteries are directly related to the overall operating status and safety assurance of electric vehicles. During the actual driving process of electric vehicles, the power battery system often needs to operate under various operating conditions, such as high temperature environments, high-rate discharge and other extreme conditions. These operating conditions can easily cause a large amount of heat accumulation in the battery system. If the heat generated during battery operation cannot be dissipated in time, the excessively high temperature will cause the battery performance to deteriorate, shorten its service life, and may even cause thermal runaway of the battery. Therefore, the power battery system needs to be equipped with an efficient thermal management system that not only ensures the operational safety of the battery module, but also improves the overall operating efficiency of the battery.

[0003] Currently, mainstream battery thermal management technologies include air cooling, liquid cooling, and phase change material cooling, but these technologies generally have problems of high operating temperature and uneven temperature distribution. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a microchannel flat tube battery thermal management system and a preparation method thereof. The microchannel flat tube battery thermal management system of the present invention has a low operating temperature and uniform temperature distribution.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a microchannel flat tube battery thermal management system, comprising:

[0007] A battery module 4 includes a battery 1, a loading mold 2, and a microchannel flat tube 3. The loading mold 2 is provided with a loading hole for the battery 1 and a through hole for loading the microchannel flat tube 3. The through holes are arranged parallel to the cross section of the loading mold 2, and the openings of the through holes are located on the side of the loading mold 2. The raw materials for preparing the loading mold 2 include silicon carbide and silicone. The through holes are composed of a plurality of through holes.

[0008] A flow control valve 9, through which the microchannel flat tube 3 is connected to the water pump 8;

[0009] a temperature acquisition system 6 connected to the loading mold 2 via a thermocouple 5;

[0010] A controller 7 connected to the temperature acquisition system 6 .

[0011] Preferably, the spacing between the loading holes is 4 to 6 mm, and the loading holes are arranged in an array, with 4 to 6 holes in each row of the array.

[0012] Preferably, the microchannel flat tubes are arranged parallel to each other.

[0013] Preferably, the thickness of the microchannel flat tube 3 is independently 2 to 3 mm, and the height is independently 20 to 25 mm.

[0014] Preferably, the number of the microchannel flat tubes 3 is 4 to 6.

[0015] Preferably, the battery 1 and the loading mold 2 have the same height.

[0016] Preferably, the battery 1 is cylindrical in shape.

[0017] Preferably, the mass ratio of the silica gel to silicon carbide is (90-70):(10-30).

[0018] The present invention also provides a method for preparing the microchannel flat tube battery thermal management system described in the above technical solution, comprising the following steps:

[0019] The silicon carbide and silicone are mixed and then molded to obtain a pre-loaded mold;

[0020] Punching holes on the surface of the pre-loading mold to form a battery loading hole and a through hole to form a loading mold 2, loading the battery 1 in the battery loading hole and loading the microchannel flat tube 3 in the through hole to obtain a battery module 4;

[0021] The battery module 4, thermocouple 5, temperature acquisition system 6, water pump 8 and flow control valve 9 are connected to obtain the microchannel flat tube battery thermal management system.

[0022] The present invention provides a microchannel flat tube battery thermal management system, comprising: a battery module 4, wherein the battery module 4 includes a battery 1, a loading mold 2 and a microchannel flat tube 3, the loading mold 2 is provided with a loading hole for the battery 1 and a through hole for loading the microchannel flat tube 3, the through holes are parallel to the cross section of the loading mold 2, and the openings of the through holes are located on the side of the loading mold 2; the raw materials for preparing the loading mold 2 include silicon carbide and silica gel; the through holes are composed of a plurality of through holes; a flow control valve 9, the microchannel flat tube 3 is connected to a water pump 8 through the flow control valve 9; a temperature acquisition system 6 connected to the loading mold 2 via a thermocouple 5; and a controller 7 connected to the temperature acquisition system 6.

[0023] In the present invention, the silicone in the loading mold 2 is mixed with silicon carbide to enhance thermal conductivity. By adding the heat-conducting medium silicon carbide, the viscosity of the silicone can be reduced while ensuring the thermal conductivity of the silicone, thereby reducing the difficulty of later molding and potting. The loading mold 2 is filled between the battery 1 and the microchannel flat tube 3 to reduce the heat transfer resistance. The cooling medium is driven by a water pump 8 and flows into the microchannel flat tube 3 after the flow is adjusted by a flow control valve 9. The microchannel flat tube 3 passes through the gaps between the batteries 1 in the battery module 4, has high heat exchange efficiency, quickly absorbs the heat generated by the battery, and improves the temperature consistency of the battery module 4.

[0024] At the same time, the loading mold 2 can improve the impact resistance of the battery module 4.

[0025] The present invention also provides a method for preparing the microchannel flat tube battery thermal management system described in the above technical solution. The preparation method of the present invention is simple to operate, low in cost, simple and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The thermal conductivity results of the loaded molds obtained in Example 1 of the present invention and Comparative Examples 1 to 4 are shown;

[0027] Figure 2 Schematic diagrams of the preparation of raw materials for loading molds at different silicon carbide addition ratios of the present invention, wherein (a) to (f) are actual images of pure silica gel without any additives and silicon carbide addition mass fractions of 10, 15, 20, 25, and 30 wt% before solidification, respectively;

[0028] Figure 3 Schematic diagram of the structure of the microchannel flat tube battery thermal management system of the present invention, wherein 1 is a cylindrical battery, 2 is a loading mold, 3 is a microchannel flat tube, 4 is a battery module, 5 is a thermocouple, 6 is a temperature acquisition system, 7 is a controller, 8 is a water pump, and 9 is a flow control valve;

[0029] Figure 4 Schematic diagram of the structure of the battery module of the present invention;

[0030] Figure 5 This is the refrigeration control logic diagram of the present invention.

[0031] Figure 6 This is a diagram of heat generation during the battery module cycle of the present invention. DETAILED DESCRIPTION

[0032] The present invention provides a microchannel flat tube battery thermal management system, comprising:

[0033] A battery module 4 includes a battery 1, a loading mold 2, and a microchannel flat tube 3. The loading mold 2 is provided with a loading hole for the battery 1 and a through hole for loading the microchannel flat tube 3. The through holes are arranged parallel to the cross section of the loading mold 2, and the openings of the through holes are located on the side of the loading mold 2. The raw materials for preparing the loading mold 2 include silicon carbide and silicone. The through holes are composed of a plurality of through holes.

[0034] A flow control valve 9, through which the microchannel flat tube 3 is connected to the water pump 8;

[0035] a temperature acquisition system 6 connected to the loading mold 2 via a thermocouple 5;

[0036] A controller 7 connected to the temperature acquisition system 6 .

[0037] Figure 4 is a schematic structural diagram of the battery module of the present invention, Figure 3 The schematic diagram of the thermal management system of the microchannel flat tube battery of the present invention is shown in FIG1 , wherein 1 is a cylindrical battery, 2 is a loading mold, 3 is a microchannel flat tube, 4 is a battery module, 5 is a thermocouple, 6 is a temperature acquisition system, 7 is a controller, 8 is a water pump, 9 is a flow control valve, and the like are combined. Figures 3-4 The microchannel flat tube battery thermal management system of the present invention is described.

[0038] In the present invention, the spacing between the loading holes is preferably 4 to 6 mm, and the loading holes are preferably arranged in an array, with the number of holes in each row of the array being preferably 4 to 6.

[0039] In the present invention, the shape of the battery 1 is preferably cylindrical. The present invention has no particular limitation on the specific size of the cylindrical shape, and cylindrical batteries well known to those skilled in the art can be used.

[0040] In the present invention, the microchannel flat tubes are arranged parallel to each other, that is, the microchannel flat tubes 3 in the through holes are parallel to each other. In the present invention, the heights of the through holes in the vertical direction are consistent.

[0041] In the present invention, the thickness of the microchannel flat tube 3 is preferably independently 2-3 mm, the height is preferably independently 20-25 mm, and the interval between two adjacent through holes is preferably independently 22-24 mm.

[0042] In the present invention, the number of the microchannel flat tubes 3 is preferably 4 to 6.

[0043] In the present invention, the material of the microchannel flat tube 3 is preferably aluminum.

[0044] In the present invention, the microchannel flat tubes 3 are preferably connected to the flow control valve 9 , and the cooling medium passes through the water pump, flows through the flow control valve 9 to adjust the flow rate, and then flows into the microchannel flat tubes 3 .

[0045] The present invention has no particular limitation on the type of the cooling medium, and any type known to those skilled in the art may be used. In a specific embodiment of the present invention, the cooling medium is preferably water, which is located in a water tank, which is preferably connected to the water pump 8.

[0046] In the present invention, the lift of the water pump 8 is preferably 8 to 10 m.

[0047] In the present invention, the water outlet of the water tank is preferably provided with a mesh filter element. The present invention has no special limitation on the pore size and material of the mesh filter element.

[0048] In the present invention, the mass ratio of the silica gel to silicon carbide is preferably (90-70):(10-30).

[0049] In the present invention, the particle size of the silicon carbide is preferably 1 to 5 μm.

[0050] In the present invention, the silica gel preferably includes glue A and curing agent glue B. The present invention has no special limitation on the amount of glue A and curing agent glue B, and sources well known to those skilled in the art can be used.

[0051] In the present invention, the raw materials for preparing the loading mold 2 preferably also include a thermal conductive additive, and the thermal conductive additive preferably includes silicon carbide and / or aluminum nitride. When the thermal conductive additive is preferably a mixture of silicon carbide and / or aluminum nitride, the mass ratio of silicon carbide and / or aluminum nitride in the mixture is preferably (1.5~2.5): (1~2.5).

[0052] In the present invention, the mass ratio of the silica gel to the thermal conductive additive is preferably (90-70): (10-30).

[0053] The present invention also provides a method for preparing the microchannel flat tube battery thermal management system described in the above technical solution, comprising the following steps:

[0054] The silicon carbide and silicone are mixed and then molded to obtain a pre-loaded mold;

[0055] Punching holes on the surface of the pre-loading mold to form a battery loading hole and a through hole to form a loading mold 2, loading the battery 1 in the battery loading hole and loading the microchannel flat tube 3 in the through hole to obtain a battery module 4;

[0056] The battery module 4, thermocouple 5, temperature acquisition system 6, water pump 8 and flow control valve 9 are connected to obtain the microchannel flat tube battery thermal management system.

[0057] The present invention mixes silicon carbide and silica gel and then forms the mixture to obtain a pre-loaded mold.

[0058] In a specific embodiment of the present invention, the mass of the silicon carbide is preferably divided into two parts, one part is mixed with the A glue in the silicone to obtain a first mixture, and the other part is mixed with the curing agent B glue in the silicone to obtain a second mixture, and then the first mixture and the second mixture are mixed for a third time to obtain the material to be formed.

[0059] In the present invention, the first mixing, the second mixing and the third mixing are preferably performed under stirring conditions, and the stirring speed is independently preferably 300 to 500 rad / min.

[0060] In the present invention, the molding is preferably performed in a mold. The present invention has no special limitation on the material of the mold, and any material well known to those skilled in the art can be used.

[0061] In the present invention, the molding temperature is preferably 20-40° C., and the molding time is preferably 16 hours.

[0062] After the molding, the present invention performs demoulding to obtain the pre-loaded mold.

[0063] After obtaining the pre-loading mold, the present invention punches holes on the surface of the pre-loading mold to form battery loading holes and microchannel flat tube through-holes to form a loading mold 2, loads a battery 1 in the battery loading hole, and loads a microchannel flat tube 3 in the through-hole to form a battery module 4.

[0064] The present invention has no special limitation on the specific methods of punching and loading, and methods well known to those skilled in the art may be used.

[0065] After obtaining the battery module 4, the present invention connects the battery module 4, the thermocouple 5, the temperature acquisition system 6, the water pump 8 and the flow control valve 9 to obtain the microchannel flat tube battery thermal management system.

[0066] The present invention has no particular limitation on the specific manner of connection, and any manner well known to those skilled in the art may be used.

[0067] The present invention also provides a specific application of the microchannel flat tube battery thermal management system described in the above technical solution.

[0068] In the present invention, the temperature acquisition system 6 receives the temperature of the battery module 4, determines the battery cooling demand, controls the operation of the water pump 8 and the flow control valve 9, and controls the battery temperature at 20-50°C. Preferably, by controlling the opening of the flow control valve 9, the coolant flow of different battery cooling branches is adjusted to control the battery temperature difference within 5°C, thereby ensuring the temperature consistency of the battery module 4.

[0069] Figure 5 The cooling control logic diagram of the microchannel flat tube battery thermal management system of the present invention includes the following steps:

[0070] The temperature acquisition system 6 receives the temperature information of the battery 1 in the battery module 4 in real time, and the maximum temperature is T max When Tmax≥30℃, the microchannel flat tube battery thermal management system starts to operate, and the flow control valve 9 is controlled by the controller 7 to be fully opened, and the opening of the flow control valve 9 is preferably set to 60%. When Tmax<30℃, the microchannel flat tube battery thermal management system is turned off and the water pump 8 is turned off.

[0071] In the present invention, if Tmax≥40°C, the controller 7 adjusts the opening of the flow control valve 9 to preferably 100%, so as to control the maximum temperature of the battery 1 within 50°C.

[0072] To further illustrate the present invention, the microchannel flat tube battery thermal management system, its preparation method and application provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of protection of the present invention.

[0073] Example 1

[0074] The structural diagram of the microchannel flat tube battery thermal management system is as follows Figure 3 As shown, the schematic diagram of the battery module is as follows Figure 4 .

[0075] (1) Divide the mass of silicon carbide (particle size 1-5 μm) into two parts, add silicone glue A and curing agent B respectively, and the amount of silicon carbide added is 25% of the total mass of silicone glue A and curing agent B;

[0076] (2) Stir the two mixtures at a speed of 300 rad / min respectively;

[0077] (3) The two mixtures were mixed and stirred at a speed of 500 rad / min;

[0078] (4) The resulting mixture was placed in air at 20°C for 16 hours to solidify and form a pre-loaded mold.

[0079] After obtaining the pre-loading mold, holes are punched on the surface of the pre-loading mold 2 to form battery loading holes and through holes. Cylindrical batteries 1 are loaded in the battery loading holes, and microchannel flat tubes are loaded in the through holes to form a battery module 4. There is a microchannel flat tube between every two rows of batteries. The spacing between the batteries is 4 mm, and the number of batteries in series is 4. The microchannel flat tubes 3 in the microchannel flat tube through holes are parallel to each other. The thickness of the microchannel flat tubes 3 is 2 mm, the height is 20 mm, the interval between every two microchannel flat tubes 3 is 22 mm, the number of microchannel flat tubes 3 is 5, and the material of the microchannel flat tubes 3 is aluminum. The microchannel flat tubes 3 are all connected to the flow control valve 9. The cooling medium passes through the water pump 8, flows through the flow control valve 9 to adjust the flow, and then flows into the microchannel flat tube 3. The water tank is connected to the water pump 8. The lift of the water pump 8 is 8 m. The water outlet of the water tank has a mesh filter element. The battery module 4, the thermocouple 5, the temperature acquisition system 6, the water pump 8 and the flow control valve 9 are connected to obtain a microchannel flat tube battery thermal management system.

[0080] The obtained microchannel flat tube battery thermal management system is used for cooling control, and the logic diagram is as follows Figure 5 , including the following steps:

[0081] The temperature acquisition system 6 receives the temperature information of the battery 1 in the battery module 4 in real time, and the highest temperature is T max When Tmax≥30℃, the microchannel flat tube battery thermal management system starts to operate, and the controller 7 controls the flow control valve 9 to be fully opened, and the opening of the flow control valve 9 is set to 60%. When Tmax<30℃, the microchannel flat tube battery thermal management system is shut down and the water pump is turned off;

[0082] When the temperature Tmax of the battery module 4 is ≥ 40°C, the controller 7 adjusts the opening of the flow control valve 9 to 100%, so as to control the maximum temperature of the battery 1 within 50°C.

[0083] Figure 6 A graph showing the maximum temperature, minimum temperature, and maximum temperature difference over time for the battery module of Example 1 during six 3C discharge cycles is shown. The graph shows that after six 3C discharge cycles, the maximum temperature of the battery module is below 47°C, and the maximum temperature difference is below 6.0°C. This demonstrates that the battery module of Example 1 not only operates within a safe operating temperature range, but also achieves temperature uniformity within the battery module, ensuring high-performance operation of the battery module.

[0084] Comparative Example 1

[0085] (1) Divide the mass of silicon carbide (particle size 1-5 μm) into two parts, add glue A and curing agent B respectively, and the amount of silicon carbide added is 10% of the total mass of glue A and curing agent B;

[0086] (2) Stir the two mixtures at a speed of 300 rad / min respectively;

[0087] (3) The two mixtures were mixed and stirred at a speed of 500 rad / min;

[0088] (4) The resulting mixture was placed in air at 20°C for 16 hours to solidify.

[0089] Comparative Example 2

[0090] The same as Comparative Example 1, the only difference is that the amount of expanded graphite added is 15% of the total mass of glue A and curing agent glue B.

[0091] Comparative Example 3

[0092] The same as Comparative Example 1, the only difference is that the amount of expanded graphite added is 20% of the total mass of glue A and curing agent glue B.

[0093] Comparative Example 4

[0094] The same as Comparative Example 1, the only difference is that the amount of expanded graphite added is 30% of the total mass of glue A and curing agent glue B.

[0095] Figure 1 The thermal conductivity results of the molds prepared in Example 1 and Comparative Examples 1 to 4 of the present invention are shown in FIG. Figure 1 It can be seen that the thermal conductivity of thermally conductive enhanced silica gel is positively correlated with the mass percentage of added expanded graphite;

[0096] Figure 2 Schematic diagram of the preparation of the raw materials for loading the mold under different expansion graphite addition ratios of the present invention, wherein (a) to (f) are respectively the physical diagrams of pure silica gel without any addition and silicon carbide with a mass fraction of 10, 15, 20, 25 and 30wt% before solidification. Figure 2 It can be seen that the viscosity of the thermally conductive enhanced silicone increases with the increase in the mass percentage of added silicon carbide.

[0097] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation thereto. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications shall also be considered within the scope of protection of the present invention.

Claims

1. A microchannel flat tube battery thermal management system, characterized in that: include: A battery module (4), the battery module (4) comprising a battery (1), a loading mold (2) and a microchannel flat tube (3), the loading mold (2) being provided with a loading hole for the battery (1) and a through hole for loading the microchannel flat tube (3), the through hole being on a cross section of the loading mold (2), and the opening of the through hole being located on a side surface of the loading mold (2); the raw materials for preparing the loading mold (2) comprising silicon carbide and silica gel; the through hole being composed of a plurality of through holes; a flow control valve (9), wherein the microchannel flat tube (3) is connected to the water pump (8) via the flow control valve (9); a temperature acquisition system (6) connected to the loading mold (2) via a thermocouple (5); A controller (7) connected to the temperature acquisition system (6).

2. The microchannel flat tube battery thermal management system according to claim 1, characterized in that: The spacing between the loading holes is 4 to 6 mm, and the loading holes are arranged in an array, with 4 to 6 holes in each row of the array.

3. The microchannel flat tube battery thermal management system according to claim 1, characterized in that: The microchannel flat tubes are arranged parallel to each other.

4. The microchannel flat tube battery thermal management system according to claim 1, characterized in that: The thickness of the microchannel flat tube (3) is independently 2 to 3 mm, and the height is independently 20 to 25 mm.

5. The microchannel flat tube battery thermal management system according to claim 1 or 5, characterized in that: The number of the microchannel flat tubes (3) is 4 to 6.

6. The microchannel flat tube battery thermal management system according to claim 1, characterized in that: The battery (1) is at the same height as the loading mold (2).

7. The microchannel flat tube battery thermal management system according to claim 1, characterized in that: The battery (1) is cylindrical in shape.

8. The microchannel flat tube battery thermal management system according to claim 1, characterized in that: The mass ratio of the silica gel to silicon carbide is (90-70):(10-30).

9. The method for preparing a microchannel flat tube battery thermal management system according to any one of claims 1 to 8, characterized in that: The following steps are involved: The silicon carbide and silicone are mixed and then molded to obtain a pre-loaded mold; Punching holes on the surface of the pre-loading mold to form a battery loading hole and a through hole to form a loading mold (2), loading a battery (1) in the battery loading hole, and loading a microchannel flat tube (3) in the through hole to obtain a battery module (4); The battery module (4), thermocouple (5), temperature acquisition system (6), water pump (8) and flow control valve (9) are connected to obtain the microchannel flat tube battery thermal management system.

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