A kind of air-cooled battery system and thermal management method thereof

Abstract

The present invention discloses an air-cooled battery system and a thermal management method thereof. Battery cells at multiple air-cooled electric box levels are stacked and arranged to form a battery cluster which is enclosed in a battery compartment to improve energy density and IP protection level. An air-conditioning outlet and an air-conditioning return outlet are arranged on the battery compartment and connected to an air conditioner. The air-conditioning outlet is guided to a cooling fin cold plate below the air-cooled electric box through an air guide cover to dissipate heat from the air-cooled electric box, thereby forming an air-cooling loop to ensure heat dissipation of the system. At the same time, considering that the density and heat capacity of air are relatively low, compared with the inlet and outlet water temperatures of a water-cooled unit, under the same heat exchange capacity, the temperature difference between the inlet and outlet air of the air conditioner is greater, so the temperature difference of the battery cells at the electric box level is greater, resulting in a larger temperature difference of the battery cells at the battery cluster level. A corresponding thermal management strategy is matched to control the temperature of the battery cells to solve the problem of the temperature difference of the battery cells.

Description

Technical Field

[0001] The present invention relates to the technical field of battery temperature control, and in particular to an air-cooled battery system and a thermal management method thereof. Background Art

[0002] In the field of energy storage, lithium batteries are often grouped with an electric box as the basic unit, and multiple electric boxes are stacked to form a battery cluster. A single battery cluster is mostly used for industrial and commercial energy storage, and multiple battery clusters can match power demand and thus be used for grid-side energy storage. At the same time, as the requirements for high-capacity and high-rate charging and discharging of systems become increasingly popular, the heat generated by battery charging and discharging increases, and water cooling gradually replaces air cooling as the trend in thermal management system selection. A single battery cluster uses a water cooling system, while multiple battery clusters use a shared water cooling system. In addition to the electric box cold plate, the water-cooled thermal management system also includes a water cooling unit and liquid cooling pipelines.

[0003] Disadvantages of traditional air cooling systems in the energy storage field: 1. Low energy density, which does not match the current market demand for high capacity and high energy density; 2. Low IP protection level, moisture and dust can easily enter the battery system and other electrical systems, which has an adverse effect on reliability and even safety performance; 3. In addition to air conditioning, most traditional air cooling systems use additional fans to increase the convective heat exchange air volume, resulting in frequent failures and high after-sales maintenance costs.

[0004] The shortcomings of existing liquid cooling systems in the energy storage field are: 1. The entire energy storage system is highly dependent on the water-cooled unit. When the water-cooled unit fails and stops operating, the battery system's charging and discharging is restricted and has a greater impact; 2. When a leak occurs in the water circulation of the thermal management system, the severity is high, and the reliability maintenance cost of the water system over the entire life cycle is high; 3. When the coolant temperature is low, condensation water is prone to occur in the electrical box and pipelines, affecting the insulation and withstand voltage of the system. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an air-cooled battery system and a thermal management method thereof, which are more reliable than the existing refrigeration system.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] An air-cooled battery system includes a controller, an air conditioner, a battery compartment, and a battery cluster arranged in the battery compartment and formed by stacking and arranging air-cooled electric boxes;

[0008] The battery compartment encloses and wraps the air-cooled electric box, and is provided with an air guide cover and an air-conditioning outlet and an air-conditioning return outlet connected to the air-conditioning;

[0009] The air-conditioning outlet is evenly distributed to the heat dissipation fin cold plate below the air-cooled electric box through the air-conditioning outlet and the air guide cover;

[0010] The battery compartment forms an air cooling circuit through the air outlet of the air conditioner, the air return outlet of the air conditioner and the air guide cover;

[0011] The controller is connected to the air conditioning control and detects the temperature of the battery cells at each level of the electric box in real time to perform thermal management.

[0012] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0013] A thermal management method for an air-cooled battery system, applicable to the thermal management of the air-cooled battery system described above, comprises the following steps:

[0014] S1, controlling the air conditioner to enter a cooling or heating operation mode according to a maximum battery core temperature, a minimum battery core temperature, a preset cooling start threshold, and a heating start threshold;

[0015] S2. Calculate the maximum temperature difference of the battery cells in real time, and adjust the cooling stop threshold and the heating stop threshold according to the current operation strategy of the air conditioner, the minimum battery cell temperature and the maximum battery cell temperature, so that the air conditioning system stops cooling and heating when the maximum temperature difference of the battery cells exceeds the preset temperature difference threshold.

[0016] The beneficial effects of the present invention are as follows: an air-cooled battery system and a thermal management method thereof of the present invention, stacking and arranging battery cells at multiple air-cooled electric box levels to form a battery cluster enclosed in a battery compartment to improve energy density and IP protection level, and providing an air-conditioning outlet and an air-conditioning return air outlet on the battery compartment, which are connected to the air conditioner, and the air-conditioning outlet is guided to the heat dissipation fin cold plate below the air-cooled electric box through an air guide cover to dissipate heat from the air-cooled electric box, thereby forming an air-cooling circuit to ensure heat dissipation of the system; at the same time, considering that the density and heat capacity of air are relatively low, compared with the inlet and outlet water temperatures of a water-cooled unit, under the same heat exchange capacity, the temperature difference between the inlet and outlet air of the air conditioner is greater, so the temperature difference of the battery cells at the electric box level is greater, resulting in a larger temperature difference of the battery cells at the battery cluster level, and a corresponding thermal management strategy is matched to control the temperature of the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural diagram of an air-cooled battery system according to an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of air conditioning outlet and return air of an air-cooled battery system according to an embodiment of the present invention;

[0019] Figure 3 A schematic diagram of an air-conditioning air duct and an electric box of an air-cooled battery system according to an embodiment of the present invention;

[0020] Figure 4 A flow chart of a thermal management method for an air-cooled battery system according to an embodiment of the present invention;

[0021] Figure 5 This is a specific flow chart of a thermal management method for an air-cooled battery system according to an embodiment of the present invention;

[0022] Description of labels:

[0023] 1. Air-cooled electric box; 2. Battery compartment; 3. Air-conditioning outlet; 4. Air-conditioning return air outlet; 5. Air guide hood. DETAILED DESCRIPTION

[0024] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0025] Please refer to Figures 1 to 3 , an air-cooled battery system, comprising a controller, an air conditioner, a battery compartment, and a battery cluster arranged in the battery compartment and formed by stacking air-cooled electric boxes;

[0026] The battery compartment encloses and wraps the air-cooled electric box, and is provided with an air guide cover and an air-conditioning outlet and an air-conditioning return outlet connected to the air-conditioning;

[0027] The air-conditioning outlet is evenly distributed to the heat dissipation fin cold plate below the air-cooled electric box through the air-conditioning outlet and the air guide cover;

[0028] The battery compartment forms an air cooling circuit through the air outlet of the air conditioner, the air return outlet of the air conditioner and the air guide cover;

[0029] The controller is connected to the air conditioning control and detects the temperature of the battery cells at each level of the electric box in real time to perform thermal management.

[0030] From the above description, it can be seen that the beneficial effects of the present invention are: an air-cooled battery system of the present invention stacks and arranges battery cells of multiple air-cooled electric box levels to form a battery cluster enclosed in a battery compartment to improve energy density and IP protection level, and an air-conditioning outlet and an air-conditioning return air outlet are set on the battery compartment, which are connected to the air conditioner, and the air-conditioning outlet is guided to the heat dissipation fin cold plate under the air-cooled electric box through an air guide cover to dissipate the air of the air-cooled electric box, thereby forming an air-cooling circuit to ensure system heat dissipation.

[0031] Please refer to Figure 4 and Figure 5 , a thermal management method for an air-cooled battery system, applicable to the thermal management of an air-cooled battery system described above, comprising the steps of:

[0032] S1, controlling the air conditioner to enter a cooling or heating operation mode according to a maximum battery core temperature, a minimum battery core temperature, a preset cooling start threshold, and a heating start threshold;

[0033] S2. Calculate the maximum temperature difference of the battery cells in real time, and adjust the cooling stop threshold and the heating stop threshold according to the current operation strategy of the air conditioner, the minimum battery cell temperature and the maximum battery cell temperature, so that the air conditioning system stops cooling and heating when the maximum temperature difference of the battery cells exceeds the preset temperature difference threshold.

[0034] From the above description, it can be seen that the beneficial effects of the present invention are: providing a thermal management method for an air-cooled battery system, which is applied to an air-cooled battery system of the present invention. Considering that the air density and heat capacity are relatively low, compared with the inlet and outlet water temperatures of the water-cooling unit, under the same heat exchange capacity, the temperature difference between the inlet and outlet air of the air conditioner is larger, so the temperature difference of the battery cells at the electric box level is larger, resulting in a larger temperature difference of the battery cells at the battery cluster level. A thermal management method for an air-cooled battery system of the present invention adjusts the operation strategy according to the battery cell temperature, and adjusts the refrigeration stop threshold based on the battery cell temperature difference, so that the air conditioner stops refrigeration when the battery cell temperature difference is large, raising the air conditioner outlet temperature, thereby delaying the trend of amplification of the battery cell temperature difference or even reducing the battery cell temperature difference. That is, because the refrigeration stop point is set relatively high, it is not easy to trigger refrigeration, and the internal fan stop point is set relatively low, so the internal fan circulation mode will be triggered. In this mode, the air conditioner neither cools nor heats, and the air in the battery compartment is driven by the air conditioner internal fan to self-circulate, thereby reducing the battery temperature difference.

[0035] Further, step S1 comprises the steps of:

[0036] S11, determining whether the maximum battery cell temperature is greater than a preset cooling start threshold, and if so, entering a cooling strategy;

[0037] S12: Determine whether the lowest battery cell temperature is less than a preset heating start threshold, and if so, enter a heating strategy.

[0038] From the above description, it can be seen that the cooling or heating strategy is selected according to the highest and lowest battery cell temperatures.

[0039] Further, step S2 comprises the steps of:

[0040] Control the air conditioner to power on;

[0041] Obtain the first cooling stop threshold, cooling hysteresis, heating stop threshold, heating hysteresis and indoor fan stop threshold preset under the cooling strategy to control the air conditioner;

[0042] Calculating the maximum temperature difference of the battery cell in real time for judgment, if the maximum temperature difference of the battery cell is greater than a preset temperature difference threshold, increasing the first cooling stop threshold to a preset second cooling stop threshold, and controlling the air conditioner according to the second cooling stop threshold;

[0043] When the highest battery core temperature is lower than a preset cooling power-off temperature, the air conditioner is controlled to power off.

[0044] From the above description, it can be seen that in cooling mode, the preset corresponding air-conditioning control parameters are obtained to control the air-conditioning, and it is judged in real time whether the maximum temperature difference of the battery cell exceeds the preset threshold. If so, it is considered that the temperature difference of the battery cell is too large, and the cooling stop threshold is adjusted, thereby raising the air outlet temperature of the air conditioner in disguise, delaying the change trend of high-temperature battery cells and low-temperature battery cells, thereby delaying the trend of amplification of the battery cell temperature difference or even reducing the battery cell temperature difference.

[0045] Further, when the heating strategy is executed, step S2 includes the steps of:

[0046] Control the air conditioner to power on;

[0047] Obtain the preset heating stop threshold, heating hysteresis, indoor fan stop threshold, cooling stop threshold and cooling hysteresis under the heating strategy to control the air conditioner;

[0048] When the lowest battery core temperature is greater than a preset heating power-off temperature, the air conditioner is controlled to power off.

[0049] It can be seen from the above description that the air conditioning control of the heating strategy is performed through the above steps.

[0050] Furthermore, step S1 further includes the steps of:

[0051] If the maximum battery cell temperature is lower than the cooling start threshold and the minimum battery cell temperature is higher than the heating start threshold, the maximum battery cell temperature difference is calculated in real time. When the maximum battery cell temperature difference is higher than the preset temperature difference threshold, the temperature difference reduction strategy is implemented.

[0052] From the above description, it can be seen that when the cooling or heating strategy is not entered and the battery cell temperature difference is high, the temperature difference reduction strategy is executed to control the air conditioner.

[0053] Further, when the temperature difference reduction strategy is executed, step S2 includes the steps of:

[0054] Control the air conditioner to power on;

[0055] Obtaining the preset cooling stop threshold, cooling hysteresis, heating stop threshold, heating hysteresis and indoor fan stop threshold under the temperature drop strategy to control the air conditioner;

[0056] The maximum temperature difference of the battery cell is calculated in real time, and when the maximum temperature difference of the battery cell is less than a preset power-off temperature difference threshold, the air conditioner is controlled to power off.

[0057] From the above description, it can be seen that when the cooling or heating strategy is not entered and the battery cell temperature difference is high, the temperature difference reduction strategy powers on the air conditioner and drives the air to circulate through the internal fan circulation mode, thereby reducing the battery temperature difference.

[0058] Furthermore, if the maximum battery cell temperature is lower than the cooling start threshold, the minimum battery cell temperature is higher than the heating start threshold, and the maximum battery cell temperature difference is lower than the preset temperature difference threshold, the return air temperature of the air-conditioning return air outlet is obtained in real time, and when the return air temperature is higher than the preset return air temperature threshold, the anti-sun exposure strategy is entered.

[0059] From the above description, it can be seen that if the battery cell temperature reaches the cooling condition, but the return air temperature in the battery compartment exceeds 45°C, it is considered that there is sun exposure, and the anti-exposure control strategy is triggered.

[0060] Further, the air conditioner is controlled to power on and perform cooling;

[0061] Obtain the preset cooling stop threshold, cooling hysteresis, heating stop threshold, heating hysteresis and indoor fan stop threshold under the anti-exposure strategy to control the air conditioner;

[0062] The return air temperature is monitored in real time, and when the return air temperature is lower than a preset return air shutdown temperature threshold, the air conditioner is controlled to power off.

[0063] It can be seen from the above description that under the anti-exposure strategy, the corresponding control parameters are obtained and the air conditioning cooling is controlled to adjust the temperature in the battery compartment.

[0064] An air-cooled battery system and a thermal management method thereof of the present invention are suitable for scenarios where an air-cooled battery system is required.

[0065] Please refer to Figures 1 to 3 , Embodiment 1 of the present invention is:

[0066] An air-cooled battery system comprises a controller, an air conditioner, an air-cooled electric box 1 and a battery compartment 2;

[0067] The battery cluster obtained by stacking and arranging the air-cooled electric boxes 1 is arranged in the battery compartment 2;

[0068] The battery compartment 2 encloses and wraps the air-cooled electric box 1, and is provided with an air guide cover 5 and an air-conditioning outlet 3 and an air-conditioning return air outlet 4 connected to the air conditioner;

[0069] The air-conditioning outlet air is evenly distributed to the heat dissipation fin cold plate below the air-cooled electric box 1 through the air-conditioning outlet 3 and the air guide cover 5;

[0070] The battery compartment 2 forms an air cooling circuit through the air conditioning outlet 3 , the air conditioning return air outlet 4 and the air guide cover 5 .

[0071] like Figure 2As shown in the schematic diagram of air conditioning outlet and return air, the air conditioning outlet air first enters the battery compartment 2 from the air conditioning outlet 3, and then passes through the air guide cover 5 and is distributed to the bottom of each electric box. After the air conditioning outlet air fully exchanges heat with the cooling fin cold plate of the air-cooled electric box 1, the return air returns to the air conditioning return outlet 4 from the upper and lower spaces of the battery compartment 2.

[0072] The air cooling circuit formed above generates heat from the battery and is cooled by the air conditioner. The cooling medium is the circulating air in the battery compartment 2, and the circulating air is driven by the fan in the air conditioner. Figure 3 The air conditioning hood shown in the figure indicates that the air conditioning air is blown into the air conditioning hood 5 through the air conditioning outlet 3. The outlet of the air conditioning hood 5 is provided with air outlets of different areas. Each air outlet faces the heat dissipation fin cold plate of an electric box. The air outlets are provided with different areas to affect the wind resistance. In this way, the air volume of each air outlet is designed to be consistent, thereby ensuring that the air conditioning air volume allocated to each air-cooled electric box 1 in the battery cluster is consistent.

[0073] The controller is connected to the air conditioning control and detects the temperature of the battery cells at each level of the electric box in real time to perform thermal management.

[0074] Please refer to Figure 4 and Figure 5 , Embodiment 2 of the present invention is:

[0075] A thermal management method for an air-cooled battery system, applicable to the thermal management of the air-cooled battery system described above, comprises the following steps:

[0076] S1, controlling the air conditioner to enter a cooling or heating operation mode according to a maximum battery core temperature, a minimum battery core temperature, a preset cooling start threshold, and a heating start threshold;

[0077] Step S1 includes the steps of:

[0078] S11, determining whether the maximum battery cell temperature is greater than a preset cooling start threshold, and if so, entering a cooling strategy;

[0079] S12: Determine whether the lowest battery cell temperature is less than a preset heating start threshold, and if so, enter a heating strategy.

[0080] In this embodiment, Figure 4 As shown, at the maximum cell temperature T max When the temperature is greater than 30℃, the cooling strategy is activated. min When the temperature is less than 5℃, it enters heating mode.

[0081] S2. Calculate the maximum temperature difference of the battery cells in real time, and adjust the cooling stop threshold and the heating stop threshold according to the current operation strategy of the air conditioner, the minimum battery cell temperature and the maximum battery cell temperature, so that the air conditioning system stops cooling and heating when the maximum temperature difference of the battery cells exceeds the preset temperature difference threshold.

[0082] When executing the cooling strategy, step S2 includes the steps of:

[0083] S211, control the air conditioner to power on;

[0084] S212, obtaining a first cooling stop threshold, cooling hysteresis, heating stop threshold, heating hysteresis, and indoor fan stop threshold preset under the cooling strategy, and controlling the air conditioner;

[0085] In this embodiment, in the cooling mode, the cooling stop point (i.e., the cooling stop threshold) is 20°C, the cooling hysteresis is 5°C, the heating stop point (i.e., the heating stop threshold) is 10°C, the heating hysteresis is 5°C, and the indoor fan stop point (i.e., the indoor fan stop threshold) is 30°C.

[0086] S213, calculating the maximum temperature difference of the battery cell in real time for judgment, if the maximum temperature difference of the battery cell is greater than a preset temperature difference threshold, increasing the first cooling stop threshold to a preset second cooling stop threshold, and controlling the air conditioner according to the second cooling stop threshold.

[0087] In this embodiment, if the maximum temperature difference of the battery cell is greater than a preset temperature difference threshold (7° C. in this embodiment), the refrigeration stop point is increased to 25° C.

[0088] S214: When the highest battery core temperature is lower than a preset cooling power-off temperature, control the air conditioner to power off.

[0089] In this embodiment, when the maximum temperature of the battery cell is less than or equal to 25° C., the air conditioner is controlled to power off.

[0090] When executing the heating strategy, step S2 includes the following steps:

[0091] S221, control the air conditioner to power on;

[0092] S222: Obtain the preset heating stop threshold, heating hysteresis, indoor fan stop threshold, cooling stop threshold and cooling hysteresis under the heating strategy to control the air conditioner.

[0093] In this embodiment, under the heating strategy, the cooling stop point is 30°C, the cooling hysteresis is 5°C, the heating stop point is 20°C, the heating hysteresis is 5°C, and the indoor fan stop point is 0°C.

[0094] S223: When the lowest battery core temperature is greater than a preset heating power-off temperature, control the air conditioner to power off.

[0095] In this embodiment, when the lowest battery cell temperature is greater than 10° C., the air conditioner is controlled to power off.

[0096] Please refer to Figure 4 , Embodiment 3 of the present invention is:

[0097] A thermal management method for an air-cooled battery system is different from the first embodiment in that step S1 further includes the following steps:

[0098] If the maximum battery cell temperature is lower than the cooling start threshold and the minimum battery cell temperature is higher than the heating start threshold, the maximum battery cell temperature difference is calculated in real time. When the maximum battery cell temperature difference is higher than the preset temperature difference threshold, the temperature difference reduction strategy is implemented.

[0099] In this embodiment, when the maximum temperature difference of the battery cell is greater than 7° C., a temperature difference reduction strategy (or temperature difference reduction mode) is entered.

[0100] When the temperature difference reduction strategy is executed, step S2 includes the steps of:

[0101] Control the air conditioner to power on;

[0102] The preset cooling stop threshold, cooling hysteresis, heating stop threshold, heating hysteresis and indoor fan stop threshold under the temperature reduction difference strategy are obtained to control the air conditioner.

[0103] In this embodiment, under the temperature difference reduction strategy, the cooling stop point is 45°C, the cooling hysteresis is 5°C, the heating stop point is 20°C, the heating hysteresis is 5°C, and the indoor fan stop point is 0°C.

[0104] The maximum temperature difference of the battery cell is calculated in real time, and when the maximum temperature difference of the battery cell is less than a preset power-off temperature difference threshold, the air conditioner is controlled to power off.

[0105] In this embodiment, the maximum temperature difference of the battery cell is calculated in real time, and when the maximum temperature difference of the battery cell is less than the power-off temperature difference threshold (4° C. in this embodiment), the air conditioner is controlled to power off.

[0106] Please refer to Figure 4 , Embodiment 4 of the present invention is:

[0107] A thermal management method for an air-cooled battery system is different from the first embodiment in that step S1 further includes the following steps:

[0108] If the maximum battery cell temperature is lower than the cooling start threshold, the minimum battery cell temperature is higher than the heating start threshold, and the maximum battery cell temperature difference is lower than the preset temperature difference threshold, the return air temperature of the air-conditioning return air outlet is obtained in real time. When the return air temperature is higher than the preset return air temperature threshold, the anti-sun exposure strategy is implemented.

[0109] In this embodiment, when the return air temperature is greater than 45° C., the anti-exposure mode is entered.

[0110] When executing the sun protection strategy, step S2 includes the following steps:

[0111] Control the air conditioner to power on;

[0112] The preset cooling stop threshold, cooling hysteresis, heating stop threshold, heating hysteresis and indoor fan stop threshold under the anti-exposure strategy are obtained to control the air conditioner.

[0113] In this embodiment, in the anti-exposure mode, the cooling stop point is 25°C, the cooling hysteresis is 5°C, the heating stop point is 0°C, the heating hysteresis is 5°C, and the internal fan stop point is 30°C.

[0114] The return air temperature is monitored in real time, and when the return air temperature is lower than a preset return air shutdown temperature threshold, the air conditioner is controlled to power off.

[0115] In this embodiment, the return air temperature is monitored in real time, and when the return air temperature is less than or equal to 35° C., the air conditioner is controlled to be powered off.

[0116] The temperature values ​​involved in the thermal management strategy introduced in this patent include but are not limited to the specific values ​​introduced above. The battery cell-related setting temperature can be within the range of ±10°C, and the air conditioning-related setting temperature can be within the range of ±20°C.

[0117] In summary, the present invention provides an air-cooled battery system and a thermal management method thereof, in which battery cells at multiple air-cooled electric box levels are stacked and arranged to form a battery cluster which is enclosed in a battery compartment to improve energy density and IP protection level; an air-conditioning outlet and an air-conditioning return air outlet are arranged on the battery compartment and connected to the air conditioner; the air-conditioning outlet is guided to the heat dissipation fin cold plate below the air-cooled electric box through an air guide cover to dissipate heat from the air-cooled electric box, thereby forming an air-cooling circuit to ensure heat dissipation of the system; at the same time, considering that the density and heat capacity of air are relatively low, the temperature difference between the inlet and outlet air of the air conditioner is greater than that of the inlet and outlet water of the water-cooled unit under the same heat exchange capacity, so that the temperature difference of the battery cells at the electric box level is greater, resulting in a greater temperature difference of the battery cells at the battery cluster level; a thermal management method for an air-cooled battery system of the present invention adjusts the operation strategy according to the battery cell temperature, and adjusts the refrigeration stop threshold based on the battery cell temperature difference, so that the air conditioner stops refrigeration when the battery cell temperature difference is large, thereby raising the air conditioner outlet temperature, thereby delaying the trend of amplification of the battery cell temperature difference or even reducing the battery cell temperature difference. That is, since the refrigeration stop point is set relatively high, it is not easy to trigger refrigeration, and the internal fan stop point is set relatively low, so the internal fan circulation mode will be triggered. In this mode, the air conditioner neither cools nor heats, and the air in the battery compartment is self-circulated under the drive of the air conditioner internal fan, thereby reducing the battery temperature difference.

[0118] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A thermal management method for an air-cooled battery system, characterized in that: Applicable to thermal management of an air-cooled battery system, including a controller, an air conditioner, a battery compartment, and a battery cluster arranged in the battery compartment and formed by stacking air-cooled electric boxes; The battery compartment encloses and wraps the air-cooled electric box, and is provided with an air guide cover and an air-conditioning outlet and an air-conditioning return outlet connected to the air-conditioning; The air-conditioning outlet is evenly distributed to the heat dissipation fin cold plate below the air-cooled electric box through the air-conditioning outlet and the air guide cover; The battery compartment forms an air cooling circuit through the air outlet of the air conditioner, the air return outlet of the air conditioner and the air guide cover; The controller is connected to the air conditioner control and detects the temperature of the battery cells at each level of the electric box in real time, and the implementation includes the steps of: S1, controlling the air conditioner to enter a cooling or heating operation strategy according to a maximum battery core temperature, a minimum battery core temperature, a preset cooling start threshold, and a heating start threshold; S2. Calculate the maximum temperature difference of the battery cells in real time, and adjust the cooling stop threshold and the heating stop threshold according to the current operation strategy of the air conditioner, the minimum battery cell temperature and the maximum battery cell temperature, so that the air conditioning system stops cooling and heating when the maximum temperature difference of the battery cells exceeds the preset temperature difference threshold.

2. The thermal management method of an air-cooled battery system according to claim 1, characterized in that: Step S1 includes the steps of: S11, determining whether the maximum battery cell temperature is greater than a preset cooling start threshold, and if so, entering a cooling strategy; S12: Determine whether the lowest battery cell temperature is less than a preset heating start threshold, and if so, enter a heating strategy.

3. The thermal management method of an air-cooled battery system according to claim 2, characterized in that: When executing the cooling strategy, step S2 includes the steps of: Control the air conditioner to power on; Obtain the first cooling stop threshold, cooling hysteresis and indoor fan stop threshold preset under the cooling strategy to control the air conditioner; Calculating the maximum temperature difference of the battery cell in real time for judgment, if the maximum temperature difference of the battery cell is greater than a preset temperature difference threshold, increasing the first cooling stop threshold to a preset second cooling stop threshold, and controlling the air conditioner according to the second cooling stop threshold; When the highest battery core temperature is lower than a preset cooling power-off temperature, the air conditioner is controlled to power off.

4. The thermal management method of an air-cooled battery system according to claim 2, characterized in that: When executing the heating strategy, step S2 includes the following steps: Control the air conditioner to power on; Obtain the preset heating stop threshold, heating hysteresis and internal fan stop threshold under the heating strategy to control the air conditioner; When the lowest battery core temperature is greater than a preset heating power-off temperature, the air conditioner is controlled to power off.

5. The thermal management method of an air-cooled battery system according to claim 2, characterized in that: Step S1 also includes the steps of: If the maximum battery cell temperature is lower than the cooling start threshold and the minimum battery cell temperature is higher than the heating start threshold, the maximum battery cell temperature difference is calculated in real time. When the maximum battery cell temperature difference is higher than the preset temperature difference threshold, the temperature difference reduction strategy is implemented.

6. A thermal management method for an air-cooled battery system according to claim 5, characterized in that: When the temperature difference reduction strategy is executed, step S2 includes the steps of: Control the air conditioner to power on; Obtain the preset cooling stop threshold, cooling hysteresis, heating stop threshold, heating hysteresis and indoor fan stop threshold under the temperature drop strategy to control the air conditioner; The maximum temperature difference of the battery cell is calculated in real time, and when the maximum temperature difference of the battery cell is less than a preset power-off temperature difference threshold, the air conditioner is controlled to power off.

7. The thermal management method of an air-cooled battery system according to claim 2, characterized in that: Step S1 also includes the steps of: If the maximum battery cell temperature is lower than the cooling start threshold, the minimum battery cell temperature is higher than the heating start threshold, and the maximum battery cell temperature difference is lower than the preset temperature difference threshold, the return air temperature of the air-conditioning return air outlet is obtained in real time. When the return air temperature is higher than the preset return air temperature threshold, the anti-sun exposure strategy is implemented.

8. The thermal management method of an air-cooled battery system according to claim 7, characterized in that: When executing the sun protection strategy, step S2 includes the following steps: Control the air conditioner to power on; Obtain the preset cooling stop threshold, cooling hysteresis, heating stop threshold, heating hysteresis and indoor fan stop threshold under the anti-exposure strategy to control the air conditioner; The return air temperature is monitored in real time, and when the return air temperature is lower than a preset return air shutdown temperature threshold, the air conditioner is controlled to power off.

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