Wind and fog combined battery thermal management system

Abstract

The invention relates to the technical field of battery pack cooling, and discloses a wind-fog combined battery thermal management system, which comprises a battery pack provided with a temperature measuring device; the first pipeline is communicated with the battery pack, and is also communicated with an air cooling device and a fog cooling device; in the first working state, the battery pack is cooled by the gas; in the second working state, the battery pack is cooled by the first mixed cooling medium; and in the third working state, the battery pack is cooled by the second mixed cooling medium, and the concentration of the atomized body in the second mixed cooling medium is greater than that of the atomized body in the first mixed cooling medium. The safety performance of the battery pack working in a high-temperature environment can be effectively improved, further occurrence of thermal runaway is stopped in time, and the service life of the battery pack is prolonged. And the thermal runaway controllability of the battery pack is improved on the whole, and the runaway risk and the fire loss are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pack cooling, and in particular to a wind-mist combined battery thermal management system. Background Art

[0002] The performance of lithium-ion batteries is closely related to temperature changes, and the standard operating temperature is usually no more than 60°C. When the temperature is too high, side reactions may occur, causing irreversible damage to lithium-ion batteries. Therefore, while lithium-ion batteries are widely used, a series of fire safety issues have also arisen.

[0003] At present, some application scenarios of lithium-ion batteries do not have an effective thermal runaway suppression system. After the lithium battery thermal runaway, the battery temperature will rise rapidly and cause a fire. The existing fire protection system is difficult to suppress the development of thermal runaway hazards before the fire occurs. When lithium batteries are densely arranged, thermal runaway will spread to the entire battery pack, causing serious fire losses.

[0004] When considering thermal management measures during the operation of lithium batteries, we must also consider how to suppress the spread of thermal runaway. Most existing thermal management systems use traditional air cooling or mist cooling systems, which are not only difficult to effectively suppress the spread of thermal runaway in a timely manner, but also have a very complicated layout inside the battery pack. Summary of the invention

[0005] The object of the present invention is to provide a wind-and-fog combined battery thermal management system, aiming to solve or improve at least one of the above-mentioned technical problems.

[0006] To achieve the above object, the present invention provides the following solution: The present invention provides a battery thermal management system combined with wind and fog, comprising:

[0007] The battery pack is provided with a temperature measuring device;

[0008] A first pipeline is connected to the battery pack, and the first pipeline is also connected to an air cooling device and a mist cooling device;

[0009] In a first working state, when the temperature measuring device obtains that the battery pack is at a first preset temperature, the air cooling device delivers gas toward the first pipeline to cool the battery pack by the gas;

[0010] In the second working state, when the temperature measuring device obtains that the battery pack is at a second preset temperature, the air cooling device flows gas toward the first pipeline, and at the same time, the mist cooling device conveys atomized body toward the first pipeline, and the gas and the atomized body are combined to form a first mixed cooling medium, and the battery pack is cooled by the first mixed cooling medium;

[0011] In the third working state, when the temperature measuring device obtains that the battery pack is at a third preset temperature, the air cooling device conveys gas toward the first pipeline, and at the same time, the mist cooling device conveys atomized body toward the first pipeline, and the gas and the atomized body combine to form a second mixed cooling medium, and the battery pack is cooled by the second mixed cooling medium, and the concentration of the atomized body in the second mixed cooling medium is greater than the concentration of the atomized body in the first mixed cooling medium.

[0012] Optionally, the temperature measuring device includes a plurality of thermocouples distributed inside the battery pack.

[0013] Optionally, the air cooling device is a fan.

[0014] Optionally, the mist cooling device comprises:

[0015] A liquid storage tank, used for storing cooling liquid for forming an atomized body;

[0016] a second pipeline, connected to the liquid storage tank and the first pipeline;

[0017] The atomizing nozzle is arranged between the second pipeline and the first pipeline.

[0018] Optionally, a metering pump and a solenoid valve are provided on the second pipeline.

[0019] Optionally, the cooling liquid is pure water or deionized water.

[0020] Optionally, a wind speed sensor and a wind temperature sensor are provided on the first pipeline.

[0021] Optionally, the first preset temperature is less than 60°C.

[0022] Optionally, the second preset temperature is 60°C-100°C.

[0023] Optionally, the third preset temperature is greater than 100°C.

[0024] The present invention discloses the following technical effects: by setting the first working state, the second working state and the third working state, timely collecting the temperature changes of the battery pack, adjusting the temperature control mode in real time according to the temperature changes of the battery pack, realizing hierarchical disposal to achieve cooling, control, and suppression of all-round disaster prevention and control, which can effectively improve the safety performance of the battery pack when working in a high temperature environment, timely stop the further occurrence of thermal runaway, and reduce the economic losses or personal injuries caused by thermal runaway. It not only achieves the purpose of economy, but also can efficiently cool and extinguish the battery pack in stages. After the battery thermal runaway, the sprayed first mixed cooling medium will cover the battery surface. Overall, the controllability of the thermal runaway of the battery pack is improved, and the risk of runaway and fire losses are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 It is a structural schematic diagram of the present invention;

[0027] Figure 2 It is a flow chart of the present invention.

[0028] In the figure: 1. Fan; 2. Atomizing nozzle; 3. First pipeline; 4. Wind speed sensor; 5. Wind temperature sensor; 6. Battery pack; 7. Solenoid valve; 8. Metering pump; 9. Liquid storage tank. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Reference Figure 1-Figure 2 The present invention provides a battery thermal management system combining wind and fog, comprising:

[0032] The battery pack 6 is provided with a temperature measuring device;

[0033] The first pipeline 3 is connected to the battery pack 6, and the first pipeline 3 is also connected to the air cooling device and the mist cooling device;

[0034] In the first working state, when the temperature measuring device obtains that the battery pack 6 is at a first preset temperature, the air cooling device delivers gas toward the first pipeline 3, and the gas cools the battery pack 6;

[0035] In the second working state, when the temperature measuring device obtains that the battery pack 6 is at the second preset temperature, the air cooling device sends gas toward the first pipeline 3, and at the same time, the mist cooling device sends atomized body toward the first pipeline 3, and the gas and the atomized body are combined to form a first mixed cooling medium, and the battery pack 6 is cooled by the first mixed cooling medium;

[0036] In the third working state, when the temperature measuring device obtains that the battery pack 6 is at a third preset temperature, the air cooling device conveys gas toward the first pipeline 3, and at the same time, the mist cooling device conveys atomized body toward the first pipeline 3, and the gas and the atomized body combine to form a second mixed cooling medium, and the battery pack 6 is cooled by the second mixed cooling medium, and the concentration of the atomized body in the second mixed cooling medium is greater than the concentration of the atomized body in the first mixed cooling medium.

[0037] By setting the first working state, the second working state and the third working state, the temperature change of the battery pack 6 is collected in time, and the temperature control mode is adjusted in real time according to the temperature change of the battery pack 6, so as to achieve hierarchical treatment to achieve cooling, control, and suppression of all-round disaster prevention and control, which can effectively improve the safety performance of the battery pack 6 when working in a high temperature environment, and timely stop the further occurrence of thermal runaway, and reduce the economic losses or personal injuries caused by thermal runaway. It not only achieves the purpose of economy, but also can efficiently cool and extinguish the fire of the battery pack 6 in stages. After the battery thermal runaway, the sprayed first mixed cooling medium will cover the battery surface. Overall, the controllability of the thermal runaway of the battery pack 6 is improved, and the risk of runaway and fire losses are reduced.

[0038] In one embodiment of the present invention, the temperature measuring device includes a plurality of thermocouples distributed inside the battery pack 6 .

[0039] Multiple thermocouples are evenly arranged at different positions on the battery surface, which is conducive to detecting the temperature at different positions on the battery surface.

[0040] In one embodiment of the present invention, the air cooling device is a fan 1 .

[0041] Fan 1 can be selected from centrifugal fans, axial flow fans, etc.

[0042] In one embodiment of the present invention, the mist cooling device comprises:

[0043] A liquid storage tank 9, used for storing cooling liquid for forming an atomized body;

[0044] a second pipeline, connected to the liquid storage tank and the first pipeline;

[0045] The atomizing nozzle 2 is arranged between the second pipeline and the first pipeline 3 .

[0046] The second pipeline is provided with a metering pump 8 and a solenoid valve 7 .

[0047] The cooling liquid in the liquid storage tank 9 is pumped into the first pipeline 3 through the second pipeline by the metering pump 8 . The cooling liquid is atomized to form an atomized body when passing through the atomizing nozzle 2 , and then mixed with the gas generated by the fan 1 .

[0048] In one embodiment of the present invention, the cooling liquid is pure water or deionized water, which has good heat absorption performance and does not affect the normal operation of the battery pack 6.

[0049] In one embodiment of the present invention, a wind speed sensor 4 and a wind temperature sensor 5 are provided on the first pipeline 3 .

[0050] In one embodiment of the present invention, the first preset temperature is less than 60°C.

[0051] In one embodiment of the present invention, the second preset temperature is 60°C-100°C.

[0052] In one embodiment of the present invention, the third preset temperature is greater than 100°C.

[0053] Furthermore, it also includes a controller and a data acquisition instrument. The data acquisition instrument records the temperature collected by the thermocouple and feeds it back to the controller together with the amount of droplets introduced by the metering pump 8. The controller then adjusts the working status of the fan 1 and the atomizing nozzle 2.

[0054] Furthermore, the method for calculating the amount of atomized body introduced into the mist cooling device is:

[0055] c b m b (T-T0) = h f / a A(T-T0)

[0056] where h fa It represents the heat transfer coefficient, A is the cooling area, T0 represents the ambient temperature, c b is the specific heat capacity of the battery, m b is the battery mass, c cu and m cu are the specific heat capacity and mass of the wind tube respectively. To obtain h F / a Assuming that the surface temperature distribution of the wind tube is uniform, an air cooling experiment was carried out using the wind tube, and h was determined using the following formula fa Values:

[0057]

[0058] h measured under specific conditions F / a The value is approximately maintained at 83.9~95.1Wm -2 K -1 The fluctuation of the air supply of the fan used in the experiment is a systematic error, which will also affect the value of the experimental parameters. The final average value is 90.9Wm -2 K -1 It is used to calculate the values ​​of relevant parameters in the water mist cooling process, and finally the consumption of droplets can be calculated.

[0059] Working principle:

[0060] First, when the temperature measuring device detects that the battery temperature is normal, it will transmit a first-level signal to the controller, and then the controller will send a signal to adjust the working state to level one (first working state). At this time, only fan 1 is enabled to cool the battery. When the temperature measuring device detects that the battery temperature exceeds the normal operating temperature of the power battery of 60°C, it will transmit a second-level signal to the controller, and then the controller will send a signal to adjust the working state to level two (second working state). At this time, the controller controls the mist cooling device to start and increase the humidity of the cooling gas by spraying an appropriate amount of cooling liquid into the gas to enhance the cooling effect, and ensure that there are no droplets remaining on the battery surface. When the temperature measuring device detects that the battery temperature exceeds 100°C, it will transmit a third-level signal to the controller, and then the controller will send a signal to adjust the working state to level three (third working state). At this time, the controller opens the solenoid valve 7 and the metering pump 8 and controls the mist cooling device to pass an excessive amount of coolant. At this time, the interior of the battery pack 6 is completely soaked in coolant, which can minimize the thermal hazards caused by thermal runaway.

[0061] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A battery thermal management system combining wind and fog, characterized in that: include: The battery pack (6) is provided with a temperature measuring device; A first pipeline (3) is connected to the battery pack (6), and the first pipeline (3) is also connected to an air cooling device and a mist cooling device; In a first working state, when the temperature measuring device obtains that the battery pack (6) is at a first preset temperature, the air cooling device delivers gas toward the first pipeline (3), and the gas cools the battery pack (6); In a second working state, when the temperature measuring device obtains that the battery pack (6) is at a second preset temperature, the air cooling device passes gas toward the first pipeline (3), and at the same time, the mist cooling device conveys atomized body toward the first pipeline (3), the gas and the atomized body are combined to form a first mixed cooling medium, and the battery pack (6) is cooled by the first mixed cooling medium; In a third working state, when the temperature measuring device obtains that the battery pack (6) is at a third preset temperature, the air cooling device conveys gas toward the first pipeline (3), and at the same time, the mist cooling device conveys atomized body toward the first pipeline (3), and the gas and the atomized body combine to form a second mixed cooling medium, and the battery pack (6) is cooled by the second mixed cooling medium, and the concentration of the atomized body in the second mixed cooling medium is greater than the concentration of the atomized body in the first mixed cooling medium.

2. The wind-mist combined battery thermal management system according to claim 1, characterized in that: The temperature measuring device comprises a plurality of thermocouples distributed inside the battery pack (6).

3. The wind-mist combined battery thermal management system according to claim 1, characterized in that: The air cooling device is a fan (1).

4. The wind-mist combined battery thermal management system according to claim 1, characterized in that: The mist cooling device comprises: A liquid storage tank (9), used for storing cooling liquid for forming an atomized body; a second pipeline, connected to the liquid storage tank and the first pipeline; An atomizing nozzle (2) is arranged between the second pipeline and the first pipeline (3).

5. The wind-mist combined battery thermal management system according to claim 4, characterized in that: The second pipeline is provided with a metering pump (8) and a solenoid valve (7).

6. The wind-mist combined battery thermal management system according to claim 4, characterized in that: The cooling liquid is pure water or deionized water.

7. The wind-mist combined battery thermal management system according to claim 1, characterized in that: The first pipeline (3) is provided with a wind speed sensor (4) and a wind temperature sensor (5).

8. The wind-mist combined battery thermal management system according to claim 1, characterized in that: The first preset temperature is less than 60°C.

9. The wind-mist combined battery thermal management system according to claim 1, characterized in that: The second preset temperature is 60°C-100°C.

10. The wind-mist combined battery thermal management system according to claim 1, characterized in that: The third preset temperature is greater than 100°C.

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