A temperature difference test method, system and device for a liquid cooling system of a power battery

Abstract

The present application discloses a temperature difference test method, system and device for a liquid cooling system of a power battery. The method is based on a temperature difference test system which is sequentially provided with a liquid cooling system, a heating film, a test module and a temperature sensor from bottom to top. During the temperature difference test, the liquid cooling system is operated according to a first operating parameter to adjust the temperature of the heating film, and the heating film is operated according to a second operating parameter to adjust the temperature of the upper surface of the test module. The temperature sensor is further used to collect the temperature of multiple temperature collection points arranged on the upper surface of the test module to determine the test temperature difference. Since the operating parameters of the heating film are determined according to the power of the power battery under the target test conditions, and the test module is pre-constructed according to the design parameters of the power battery, the test module and the heating film can be used to jointly simulate various performance parameters of the actual battery module, thereby enabling the temperature difference test of the liquid cooling system to be realized in the early stage of project development before the actual battery module of the power battery is obtained.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a temperature difference testing method, system and device for a liquid cooling system of a power battery. Background Art

[0002] Power batteries are storage batteries that provide power for electric vehicles, electric trains and other tools. They are usually composed of battery cells, battery management systems, liquid cooling systems, and related components such as shells. Among them, battery cells, as the smallest energy storage unit in power batteries, generally exist in the form of battery modules in power batteries. Specifically, multiple battery cells are packaged into a battery module. Finally, multiple battery modules and related components such as battery management systems and liquid cooling systems are managed together to form a unified whole, which is the power battery.

[0003] The electrochemical reaction rate constant of the power battery is exponentially related to the temperature, and the electrochemical characteristics are different at different temperatures. In order to ensure that the temperature of the power battery meets the performance requirements of the power battery, a liquid cooling system is usually used to dissipate heat or heat the power battery. If the system temperature difference of the liquid cooling system is large, the temperature environment of each battery cell of the power battery will be inconsistent, thereby affecting the performance and service life of the power battery. In the related technology, the temperature difference of the liquid cooling system is calibrated using the actual battery module in order to adjust and optimize the design of the liquid cooling system.

[0004] However, this method requires waiting for the physical production of the battery module to be completed before the temperature difference of the liquid cooling system can be calibrated, thereby extending the project development cycle. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a temperature difference testing method, system and device for a liquid cooling system of a power battery, which realizes the testing of the temperature difference of the liquid cooling system of the power battery during the project development cycle.

[0006] The embodiments of the present application disclose the following technical solutions:

[0007] On the one hand, an embodiment of the present application provides a temperature difference test method for a liquid cooling system of a power battery, the method being applied to a temperature difference test system, the temperature difference test system being provided with a liquid cooling system, a heating film, a test module and a temperature sensor in sequence from bottom to top, the method comprising:

[0008] The liquid cooling system is operated according to a first operating parameter to adjust the temperature of the heating film, and the heating film is operated according to a second operating parameter to adjust the temperature of the upper surface of the test module; the first operating parameter is determined according to a target test condition of the power battery, and the second operating parameter is determined according to a target power of the power battery under the target test condition;

[0009] The temperature sensor collects the temperatures of a plurality of temperature collection points disposed on the upper surface of the test module; the test module is pre-constructed according to the design parameters of the power battery;

[0010] The test temperature difference of the liquid cooling system under the target test condition is determined according to the temperatures of the multiple temperature collection points.

[0011] On the other hand, an embodiment of the present application provides a temperature difference test system for a liquid cooling system of a power battery, wherein the temperature difference test system comprises a liquid cooling system, a heating film, a test module and a temperature sensor arranged in sequence from bottom to top. During the temperature difference test of the liquid cooling system:

[0012] The liquid cooling system is used to operate according to a first operating parameter to adjust the temperature of the heating film; the first operating parameter is determined according to a target test condition of the power battery;

[0013] The heating film is used to operate according to a second operating parameter to adjust the temperature of the upper surface of the test module; the second operating parameter is determined according to the target power of the power battery under the target test condition;

[0014] The test module is pre-built according to the design parameters of the power battery;

[0015] The temperature sensor is used to collect temperatures at multiple temperature collection points set on the upper surface of the test module, so as to determine the test temperature difference of the liquid cooling system under the target test conditions based on the temperatures of the multiple temperature collection points.

[0016] On the other hand, an embodiment of the present application provides a temperature difference test device for a liquid cooling system of a power battery, wherein the device is deployed in a temperature difference test system, wherein the temperature difference test system includes a liquid cooling system, a heating film, a test module, and a temperature sensor arranged in sequence from bottom to top, and the device includes an operation unit, a collection unit, and a determination unit:

[0017] The operating unit is used to operate the liquid cooling system according to a first operating parameter to adjust the temperature of the heating film, and to operate the heating film according to a second operating parameter to adjust the temperature of the upper surface of the test module; the first operating parameter is determined according to a target test condition of the power battery, and the second operating parameter is determined according to a target power of the power battery under the target test condition;

[0018] The acquisition unit is used to acquire the temperatures of a plurality of temperature acquisition points arranged on the upper surface of the test module through the temperature sensor; the test module is pre-constructed according to the design parameters of the power battery;

[0019] The determination unit is used to determine the test temperature difference of the liquid cooling system under the target test condition according to the temperatures of the multiple temperature collection points.

[0020] It can be seen from the above technical scheme that based on the temperature difference test system which is sequentially provided with a liquid cooling system, a heating film, a test module and a temperature sensor from bottom to top, the temperature difference test of the liquid cooling system of the power battery is realized; wherein, the operating parameters of the heating film are determined according to the power of the power battery under the target test conditions, and the test module is pre-constructed according to the design parameters of the power battery, so that the heating performance parameters of the actual battery module of the power battery can be simulated by the heating film, and other performance parameters of the actual battery module can be simulated by the test module. Based on this, in the temperature difference test process of the liquid cooling system of the power battery, the liquid cooling system is operated according to the first operating parameter determined based on the target test condition, the temperature of the heating film is adjusted, the heating film is operated according to the second operating parameter, the temperature of the upper surface of the test module is adjusted, and the temperature of the multiple temperature collection points arranged on the upper surface of the test module are further collected by the temperature sensor to determine the test temperature difference of the liquid cooling system under the target test condition. It can be seen that by using the test module and the heating film to jointly simulate the various performance parameters of the actual battery module, the temperature difference of the liquid cooling system can be tested in the early stage of project development before the actual battery module of the power battery is obtained. In other words, in the early stage of project development, there is no need to wait for the actual battery module of the power battery to be produced and offline to test the temperature difference of the liquid cooling system, and then adjust and optimize the design parameters of the liquid cooling system based on the temperature difference obtained from the test, thereby shortening the project development cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A method flow chart of a temperature difference test method for a liquid cooling system of a power battery provided in an embodiment of the present application;

[0023] Figure 2 A schematic diagram of the structure of a temperature difference test system for a liquid cooling system of a power battery provided in an embodiment of the present application;

[0024] Figure 3 A structural diagram of a temperature difference testing device for a liquid cooling system of a power battery provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] Power batteries, also known as battery packs, are used to power electric vehicles, electric trains and other tools. They are composed of battery cells, battery management systems, liquid cooling systems, and related components such as shells. Usually, a power battery contains multiple battery cells, and battery cells, as the smallest energy storage unit, generally exist in the form of battery modules. Specifically, multiple battery cells are packaged in the same shell according to design specifications and design requirements to form a battery module. Finally, multiple battery modules and related components such as battery management systems and liquid cooling systems are managed together to form a unified whole, which is the power battery.

[0027] It can be seen from the Arrhenius equation that the electrochemical reaction rate constant is exponentially related to temperature, and the electrochemical characteristics are different at different temperatures. Specifically, temperature will affect the operation of the electrochemical system of the power battery, coulomb efficiency, charge and discharge capacity, output power, capacity, reliability and cycle life. For example, relevant experiments have shown that the charge and discharge power of a certain type of power battery will drop significantly in a high temperature environment of 50°C, the chemical reaction rate of its internal active substances will accelerate, and the risk of explosion and fire will increase.

[0028] In order to keep the temperature within the ideal temperature range of the power battery as much as possible, a liquid cooling system is installed in the power battery to dissipate heat or heat the power battery to ensure that the temperature of the power battery meets the performance requirements of the power battery. That is, the liquid cooling system is used to adjust the temperature of the power battery, specifically the temperature of the battery module in the power battery. If the system temperature difference of the liquid cooling system is large, the temperature environment of each cell of the power battery will be inconsistent, which cannot effectively adjust the temperature of the power battery. Therefore, during the project development process, the temperature difference of the liquid cooling system needs to be verified.

[0029] In the related art, the temperature difference of the liquid cooling system is verified by using the actual battery module in order to adjust and optimize the design of the liquid cooling system. However, this method requires waiting for the actual production of the battery module to be completed before the temperature difference of the liquid cooling system can be verified, thereby prolonging the project development cycle.

[0030] To this end, the present application provides a temperature difference testing method, system and device for a liquid cooling system of a power battery, which realizes the testing of the temperature difference of the liquid cooling system of the power battery during the project development cycle.

[0031] It should be noted that the temperature difference testing method of the liquid cooling system of a power battery provided in an embodiment of the present application can be applied to a temperature difference testing system, which is provided with a liquid cooling system, a heating film, a test module and a temperature sensor in sequence from bottom to top.

[0032] Since the battery module of the power battery is encapsulated with battery cells, its production design requirements are relatively high. In order to achieve a rapid test of the temperature difference of the liquid cooling system, the embodiment of the present application jointly simulates the battery module by designing a test module and a heating film. Specifically, the heating performance parameters of the battery module during charging and discharging are simulated by using the heating condition of the heating film during operation, and the test module is used to simulate other performance parameters of the battery module, such as: specific heat capacity parameters, design parameters of temperature collection points, etc.

[0033] During the temperature difference test of the liquid cooling system of the power battery, for a certain test condition, for example: the target test condition, a coolant of a certain temperature is introduced into the liquid cooling system to start operation, the temperature of the heating film arranged above the liquid cooling system is adjusted, and the heating film is operated based on the current target test condition to simulate the heating condition of the actual battery module under the target test condition; finally, the temperature of the upper surface of the test module is adjusted based on heat conduction. Therefore, after the temperature difference test system runs stably, the temperatures of multiple temperature collection points arranged on the upper surface of the test module can be collected by temperature sensors to determine the test temperature difference of the liquid cooling system under the current target test condition.

[0034] Since the temperature difference test process is based on the principle of heat conduction, in order to avoid uneven temperature conduction between the liquid cooling system and the heating film due to different design materials of the liquid cooling system and the heating film, a thermal pad can be arranged between the liquid cooling system and the heating film. That is, the above-mentioned temperature difference test system also includes a thermal pad, so that the heat conduction between the liquid cooling system and the heating film is more uniform.

[0035] Figure 1 A method flow chart of a temperature difference test method of a liquid cooling system of a power battery provided in an embodiment of the present application, the method comprising S101-S103:

[0036] S101: operating the liquid cooling system according to the first operating parameter to adjust the temperature of the heating film, and operating the heating film according to the second operating parameter to adjust the temperature of the upper surface of the test module.

[0037] During the temperature difference test of the liquid cooling system of the power battery, for the target test conditions, the liquid cooling system is operated according to the first operating parameter, and the heating film is operated according to the second operating parameter. Based on the specific settings of the liquid cooling system, the heating film and the test module and the principle of heat conduction, the temperature of the heating film will be adjusted after the liquid cooling system is operated. After the heating film is operated, the temperature of the upper surface of the test module will be adjusted by simulating the heat generation of the battery cells in the actual battery module of the power battery during the charge and discharge process under the target test conditions.

[0038] The first operating parameter may be determined according to the target test condition of the power battery, and specifically, the initial temperature, flow rate, and system pressure of the coolant entering the liquid cooling system may be determined according to the target test condition. The second operating parameter may be determined according to the target power of the power battery under the target test condition.

[0039] For power batteries, although there are various working conditions, they can basically be divided into the following two categories: high temperature heat dissipation working conditions and low temperature heating working conditions. Therefore, the embodiment of the present application provides temperature difference tests for these two typical working conditions: high temperature heat dissipation working conditions and low temperature heating working conditions. Specifically:

[0040] In a possible implementation, if the target test condition is a high-temperature heat dissipation condition, the target power of the power battery under the high-temperature heat dissipation condition can be determined according to the cell internal resistance parameter, cell capacity parameter and cell series-parallel relationship of the power battery, and then the target power is set as the second operating parameter, and the heating pad is operated to simulate the heating of the battery module of the power battery under the high-temperature heat dissipation condition. For example: for a 51AH cell, under the 1C charging condition, the cell internal resistance parameter is 0.002Ω, and the cell series-parallel relationship is 3P96S, then the target power under this condition is 512×0.002×3×96=1.5kW, so the operating power of the heating film is 1.5kW.

[0041] In a possible implementation, if the target test condition is a low-temperature heating condition, considering the design logic that the power battery is not allowed to start under low-temperature conditions, the target power of the power battery under low-temperature heating conditions can be set to zero, and then the second operating parameter can be set to zero, that is, under low-temperature heating conditions, the heating film is not operated. It should be noted that when the temperature reaches the allowable starting temperature of the power battery, the heating film can be operated, and its operating parameter can be the power of the power battery when it is stably running after starting under the current low-temperature heating condition.

[0042] It should be noted that tests can also be performed on other working conditions based on actual conditions. Specifically, the operating parameters of the heating film are adjusted according to the working conditions to be tested, and the temperature difference of the liquid cooling system under the tested working conditions is determined by the temperature difference testing method provided in the embodiment of the present application.

[0043] S102: collecting temperatures at a plurality of temperature collection points disposed on the upper surface of the test module through a temperature sensor.

[0044] The test module is pre-built according to the design parameters of the power battery and is used to simulate other performance parameters of the battery module of the power battery. There are many ways to build the test module. The following methods are provided as examples in the embodiments of the present application. It should be noted that the present application does not make any limitation on this.

[0045] In a possible implementation, the test module can be constructed according to the mass parameters and specific heat parameters of the battery module of the power battery, that is, the aforementioned design parameters include the mass parameters and specific heat parameters of the battery module of the power battery. 1 *c 1 =m 2 *c 2 Construct a test module, where m 1 and c 1 are the mass parameter and specific heat parameter of the battery module, m 2 and c 2 They are the mass parameters and specific heat parameters of the test module respectively.

[0046] Considering that different design materials have different specific heat and exhibit different thermal conductivity capabilities, in one possible implementation, aluminum can be used as a material for constructing a test module to make it closer to the thermal conductivity performance of a battery module.

[0047] In addition, a plurality of temperature collection points are arranged on the upper surface of the test module. In order to enable the test module to better simulate the battery module, in a possible implementation, the following is further included:

[0048] The temperature collection point design parameters of the battery module of the power battery are obtained, and a plurality of temperature collection points on the upper surface of the test module are set according to the temperature collection point design parameters.

[0049] When setting multiple temperature collection points on the upper surface of the test module, an appropriate setting method can be selected according to the actual situation, and this application does not make any limitation on this. Specifically, the embodiment of this application provides the following method as an example:

[0050] In a possible implementation, the obtained temperature collection point design parameters of the battery module can be directly used as setting parameters for setting the temperature collection points on the upper surface of the test module, which may include the same number of temperature collection points, the same temperature collection point distribution spacing, distribution shape, etc. For example: the obtained temperature collection point design parameters of the battery module indicate that 9 temperature collection points are set in a grid-like manner, and then the same 9 temperature collection points are set on the upper surface of the test module according to the design parameters.

[0051] In a possible implementation, the obtained temperature collection point design parameters of the battery module can be adjusted according to the obtained temperature collection point design parameters of the battery module, combined with the actual size of the test module and the requirements of temperature test accuracy, to determine the setting parameters of the temperature collection points on the upper surface of the test module. For example: the obtained temperature collection point design parameters of the battery module indicate that 9 temperature collection points are set in a grid-like manner, and the final setting parameters of the temperature collection points on the upper surface of the test module can be to set only 5 temperature collection points at the vertex position and the center position in a grid-like manner.

[0052] During the temperature difference test of the liquid cooling system of the power battery, after running the liquid cooling system and the heating film for the target test conditions, a temperature sensor is used to collect the temperatures of multiple temperature collection points set on the upper surface of the test module in order to determine the test temperature difference of the liquid cooling system under the current target test conditions.

[0053] The setting method of the temperature sensor can be selected according to the actual testing requirements, for example: the upper surface of the test module is divided into multiple test areas, and a temperature sensor is set in each test area to collect the temperature of the temperature collection point in the test area. This application does not impose any restrictions on this.

[0054] Specifically, taking the aforementioned setting of 5 temperature collection points on the upper surface of the test module as an example, the embodiment of the present application provides the following method as an example:

[0055] In a possible implementation, a temperature sensor may be provided at each temperature collection point, that is, there is a one-to-one correspondence between the temperature collection points and the temperature sensors.

[0056] In a possible implementation, only one temperature sensor may be provided at the temperature collection point at the central position, which is responsible for collecting the temperatures of the five temperature collection points at the same time.

[0057] S103: Determine a test temperature difference of the liquid cooling system under a target test condition according to the temperatures of the multiple temperature collection points.

[0058] By collecting the temperatures of multiple temperature collection points, a series of temperatures are obtained, and then the test temperature difference of the liquid cooling system under the current target test conditions is determined based on the obtained series of temperatures.

[0059] In a possible implementation, the maximum temperature difference in a series of temperature test data obtained can be used as the test temperature difference. Specifically, the temperature range of multiple temperature collection points can be calculated and the range can be used as the test temperature difference of the liquid cooling system under the target test conditions. It should be noted that the range is used to represent the difference between the maximum and minimum values ​​in a set of data.

[0060] It should be noted that other calculation methods can be selected for determining the test temperature difference, and this application does not impose any restrictions on this. For example: considering that the closer the position is to the edge of the upper surface of the test module, the better its own heat dissipation performance is, therefore, according to the distribution position of the temperature collection point on the upper surface of the test module, a weight can be determined for the temperature value collected at each temperature collection point, and then the test temperature difference can be determined according to the collected temperatures at each location and their corresponding weights.

[0061] The purpose of testing the temperature difference of the liquid cooling system is to verify whether the current design parameters of the liquid cooling system can meet the performance requirements of the power battery. Based on this, it is determined whether the design parameters of the liquid cooling system need to be adjusted and optimized, so as to obtain a liquid cooling system whose temperature difference design meets the performance requirements of the power battery through the test results and the adjustment and optimization process. Therefore, in a possible implementation, after determining the test temperature difference, the following steps are also included:

[0062] S11: Obtaining a temperature difference threshold of the liquid cooling system under a target test condition;

[0063] S12: If the test temperature difference is greater than the temperature difference threshold, adjust the design parameters of the liquid cooling system according to the test temperature difference.

[0064] Among them, the temperature difference threshold represents the upper limit of the design requirements, specifically, the design upper limit of the temperature difference of the liquid cooling system that can make the temperature of the power battery within the ideal temperature range. Therefore, when the determined test temperature difference is greater than the temperature difference threshold, it is necessary to adjust the design parameters of the liquid cooling system and retest and verify the adjusted design parameters. Generally, the design parameters of the liquid cooling system may include the initial temperature, flow rate, flow velocity of the coolant, and the pipeline parameters of the liquid cooling system.

[0065] It should be noted that if the determined test temperature difference is greater than or equal to the temperature difference threshold, subsequent production can be carried out to verify other performance parameters, such as the sealing performance of the liquid cooling system.

[0066] It can be seen that based on the temperature difference test system which is sequentially provided with a liquid cooling system, a heating film, a test module and a temperature sensor from bottom to top, the temperature difference test of the liquid cooling system of the power battery is realized; wherein, the operating parameters of the heating film are determined according to the power of the power battery under the target test conditions, and the test module is pre-constructed according to the design parameters of the power battery, so that the heating film can be used to simulate the heating performance parameters of the battery module of the power battery, and the test module can be used to simulate other performance parameters of the battery module. Based on this, in the temperature difference test process of the liquid cooling system of the power battery, the liquid cooling system is operated according to the first operating parameter determined based on the target test conditions, the temperature of the heating film is adjusted, the heating film is operated according to the second operating parameter, the temperature of the upper surface of the test module is adjusted, and the temperature of the multiple temperature collection points set on the upper surface of the test module is further collected by the temperature sensor to determine the temperature difference of the liquid cooling system under the target test conditions. It can be seen that the various performance parameters of the battery module are simulated by the test module and the heating film, so that the temperature difference of the liquid cooling system can be tested in the early stage of project development before the battery module of the power battery is obtained. That is to say, in the early stage of project development, there is no need to wait for the physical production of the battery module of the power battery to roll off the production line in order to test the temperature difference of the liquid cooling system, and then adjust and optimize the design parameters of the liquid cooling system based on the temperature difference obtained from the test, thereby shortening the project development cycle.

[0067] A temperature difference test method for a liquid cooling system of a power battery provided in an embodiment of the present application can be applied to a temperature difference test system which is provided with a liquid cooling system, a heating film, a test module and a temperature sensor in sequence from bottom to top. During the temperature difference test process of the liquid cooling system:

[0068] The liquid cooling system is used to operate according to a first operating parameter to adjust the temperature of the heating film; the first operating parameter is determined according to a target test condition of the power battery;

[0069] The heating film is used to operate according to a second operating parameter to adjust the temperature of the upper surface of the test module; the second operating parameter is determined according to the target power of the power battery under the target test condition;

[0070] The test module is pre-built according to the design parameters of the power battery;

[0071] The temperature sensor is used to collect temperatures at multiple temperature collection points set on the upper surface of the test module, so as to determine the test temperature difference of the liquid cooling system under the target test conditions based on the temperatures of the multiple temperature collection points.

[0072] In the specific temperature difference test process, in order to avoid uneven temperature conduction between the liquid cooling system and the heating film due to different design materials of the liquid cooling system and the heating film, a thermal pad can be set between the liquid cooling system and the heating film to obtain the following Figure 2 A temperature difference test system of a liquid cooling system of a power battery is shown. Specifically, the temperature difference test system includes a liquid cooling system 201, a thermal pad 202, a heating film 203 and a test module 204 which are arranged in sequence from bottom to top.

[0073] It should be noted that a temperature sensor is also disposed on the upper surface of the test module 204. Since the temperature sensor can be disposed in a variety of ways, Figure 2 The temperature sensor is not shown. For example, only one temperature sensor is provided on the upper surface of the test module to collect the temperatures of multiple temperature collection points on the upper surface of the test module, or a temperature sensor is provided at each temperature collection point on the upper surface of the test module, and each temperature sensor is only responsible for collecting the temperature at the temperature collection point where it is located.

[0074] The liquid cooling system 201 is used to operate according to a first operating parameter to adjust the temperature of the heating film; wherein the first operating parameter is determined according to a target test condition of the power battery;

[0075] The thermal pad 202 is used for uniform heat conduction;

[0076] The heating film 203 is used to operate according to a second operating parameter to adjust the temperature of the upper surface of the test module; wherein the second operating parameter is determined according to the target power of the power battery under the target test condition;

[0077] The test module 204 is pre-built according to the design parameters of the power battery;

[0078] The temperature sensor is used to collect temperatures at multiple temperature collection points set on the upper surface of the test module, so as to determine the test temperature difference of the liquid cooling system under the target test conditions based on the temperatures of the multiple temperature collection points.

[0079] Specifically, during the temperature difference test of the liquid cooling system of the power battery, the liquid cooling system is operated according to a first operating parameter determined based on the target test condition of the power battery, the temperature of the heating film is adjusted by the thermal pad, and the heating film is operated according to a second operating parameter determined based on the target power of the power battery under the target test condition to adjust the temperature of the upper surface of the test module; further, the temperatures of multiple temperature collection points set on the upper surface of the test module are collected by temperature sensors to obtain a series of temperature test values; finally, the test temperature difference of the liquid cooling system under the target test condition is determined based on the obtained series of temperature test values.

[0080] It can be understood that it basically corresponds to the method embodiment, so the relevant parts can be referred to the partial description of the method embodiment.

[0081] Figure 3 The device structure diagram of a temperature difference test device for a liquid cooling system of a power battery provided in an embodiment of the present application, wherein the device is deployed in a temperature difference test system, wherein the temperature difference test system includes a liquid cooling system, a heating film, a test module and a temperature sensor arranged in sequence from bottom to top, and the device includes an operation unit 301, a collection unit 302 and a determination unit 303:

[0082] The operating unit 301 is used to operate the liquid cooling system according to a first operating parameter to adjust the temperature of the heating film, and to operate the heating film according to a second operating parameter to adjust the temperature of the upper surface of the test module; the first operating parameter is determined according to a target test condition of the power battery, and the second operating parameter is determined according to a target power of the power battery under the target test condition;

[0083] The acquisition unit 302 is used to acquire the temperature of multiple temperature acquisition points arranged on the upper surface of the test module through the temperature sensor; the test module is pre-built according to the design parameters of the power battery;

[0084] The determining unit 303 is used to determine the test temperature difference of the liquid cooling system under the target test condition according to the temperatures of the multiple temperature collection points.

[0085] In a possible implementation, the design parameters include mass parameters and specific heat parameters of a battery module of the power battery.

[0086] In a possible implementation, if the target test condition is a high-temperature heat dissipation condition, the determination unit is further configured to:

[0087] The target power of the power battery under the high-temperature heat dissipation condition is determined according to the cell internal resistance parameters, cell capacity parameters and the series-parallel relationship of the cells of the power battery.

[0088] In a possible implementation, if the target test condition is a low-temperature heating condition, the determination unit is further configured to:

[0089] The target power of the power battery under the low-temperature heating condition is set to zero.

[0090] In a possible implementation manner, the determining unit is further configured to:

[0091] Calculating the temperature range of the multiple temperature collection points;

[0092] The range difference is used as the test temperature difference of the liquid cooling system under the target test condition.

[0093] In a possible implementation manner, the determining unit is further configured to:

[0094] Obtaining temperature collection point design parameters of the battery module of the power battery;

[0095] A plurality of temperature collection points are set on the upper surface of the test module according to the temperature collection point design parameters.

[0096] In a possible implementation, the temperature difference testing system further includes a thermally conductive pad, and the thermally conductive pad is disposed between the liquid cooling system and the heating film.

[0097] In a possible implementation manner, the device further includes an adjustment unit, and the adjustment unit is configured to:

[0098] Obtaining a temperature difference threshold value of the liquid cooling system under the target test condition;

[0099] If the test temperature difference is greater than the temperature difference threshold, the design parameters of the liquid cooling system are adjusted according to the test temperature difference.

[0100] It can be seen that based on the temperature difference test system which is sequentially provided with a liquid cooling system, a heating film, a test module and a temperature sensor from bottom to top, the temperature difference test of the liquid cooling system of the power battery is realized; wherein, the operating parameters of the heating film are determined according to the power of the power battery under the target test conditions, and the test module is pre-constructed according to the design parameters of the power battery, so that the heating performance parameters of the battery module of the power battery can be simulated by the heating film, and the other performance parameters of the battery module can be simulated by the test module. Based on this, in the temperature difference test process of the liquid cooling system of the power battery, the liquid cooling system is operated according to the first operating parameter determined based on the target test conditions, the temperature of the heating film is adjusted, the heating film is operated according to the second operating parameter, the temperature of the upper surface of the test module is adjusted, and the temperature of the multiple temperature collection points set on the upper surface of the test module are further collected by the temperature sensor to determine the temperature difference of the liquid cooling system under the target test conditions. It can be seen that the various performance parameters of the battery module are simulated by the test module and the heating film, so that the temperature difference of the liquid cooling system can be tested in the early stage of project development before the battery module of the power battery is obtained. That is to say, in the early stage of project development, there is no need to wait for the physical production of the battery module of the power battery to roll off the production line in order to test the temperature difference of the liquid cooling system, and then adjust and optimize the design parameters of the liquid cooling system based on the temperature difference obtained from the test, thereby shortening the project development cycle.

[0101] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0102] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0103] The above is a detailed introduction to the temperature difference test method, system and device of the liquid cooling system of a power battery provided by the embodiment of the present application. The principle and implementation method of the present application are described in detail using specific examples herein. The description of the above embodiments is only used to help understand the method of the present application. At the same time, for those skilled in the art, according to the method of the present application, there will be changes in the specific implementation method and application scope.

[0104] In summary, the content of this specification should not be understood as limiting the present application, and any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in this application should be included in the protection scope of this application. Moreover, based on the implementations provided in the above aspects, this application can also be further combined to provide more implementations.

Claims

1. A temperature difference test method for a liquid cooling system of a power battery, It is characterized in that The method is applied to a temperature difference test system, wherein the temperature difference test system is provided with a liquid cooling system, a heat conductive film, a heating film, a test module and a temperature sensor in sequence from bottom to top, and the method comprises: The liquid cooling system is operated according to a first operating parameter to adjust the temperature of the heating film, and the heating film is operated according to a second operating parameter to adjust the temperature of the upper surface of the test module; the first operating parameter is determined according to a target test condition of the power battery, wherein the process of determining the first operating parameter includes: determining an initial temperature, flow rate, and system pressure parameter of the coolant introduced into the liquid cooling system according to the target test condition, and the second operating parameter is determined according to a target power of the power battery under the target test condition; The temperature sensor collects the temperatures of a plurality of temperature collection points disposed on the upper surface of the test module; the test module is pre-constructed according to the design parameters of the power battery; Determining a test temperature difference of the liquid cooling system under the target test condition according to the temperatures of the multiple temperature collection points; Wherein, determining the test temperature difference of the liquid cooling system under the target test condition according to the temperatures of the multiple temperature collection points includes: determining a weight for the temperature value collected at each temperature collection point according to the distribution positions of the multiple temperature collection points on the upper surface of the test module, and determining the test temperature difference according to the collected temperatures at each location and their corresponding weights; Obtaining a temperature difference threshold value of the liquid cooling system under the target test condition; If the test temperature difference is greater than the temperature difference threshold, adjusting the design parameters of the liquid cooling system according to the test temperature difference, the design parameters of the liquid cooling system including: initial temperature, flow rate, flow velocity of the coolant and pipeline parameters of the liquid cooling system; The heat conductive film makes the heat conduction between the liquid cooling system and the heating film more uniform.

2. The method according to claim 1, It is characterized in that The design parameters include mass parameters and specific heat parameters of the battery module of the power battery.

3. The method according to claim 1, It is characterized in that If the target test condition is a high temperature heat dissipation condition, it also includes: The target power of the power battery under the high-temperature heat dissipation condition is determined according to the cell internal resistance parameters, cell capacity parameters and the series-parallel relationship of the cells of the power battery.

4. The method according to claim 1, It is characterized in that If the target test condition is a low temperature heating condition, it also includes: The target power of the power battery under the low-temperature heating condition is set to zero.

5. The method according to any one of claims 1 to 4, It is characterized in that The step of determining the test temperature difference of the liquid cooling system under the target test condition according to the temperatures of the multiple temperature collection points also includes: Calculating the temperature range of the multiple temperature collection points; The range difference is used as the test temperature difference of the liquid cooling system under the target test condition.

6. The method according to any one of claims 1 to 4, It is characterized in that Also includes: Obtaining temperature collection point design parameters of the battery module of the power battery; A plurality of temperature collection points are set on the upper surface of the test module according to the temperature collection point design parameters.

7. A temperature difference test system for a liquid cooling system of a power battery, It is characterized in that The temperature difference test system includes a liquid cooling system, a thermal conductive film, a heating film, a test module and a temperature sensor which are arranged in sequence from bottom to top. During the temperature difference test of the liquid cooling system: The liquid cooling system is used to operate according to the first operating parameter to adjust the temperature of the heating film; The first operating parameter is determined according to a target test condition of the power battery, wherein the process of determining the first operating parameter includes: determining an initial temperature, flow rate, and system pressure parameter of the coolant introduced into the liquid cooling system according to the target test condition; The heating film is used to operate according to a second operating parameter to adjust the temperature of the upper surface of the test module; the second operating parameter is determined according to the target power of the power battery under the target test condition; The test module is pre-built according to the design parameters of the power battery; The temperature sensor is used to collect temperatures at multiple temperature collection points arranged on the upper surface of the test module, so as to determine the test temperature difference of the liquid cooling system under the target test condition according to the temperatures of the multiple temperature collection points; Wherein, determining the test temperature difference of the liquid cooling system under the target test condition according to the temperatures of the multiple temperature collection points comprises: determining a weight for the temperature value collected at each temperature collection point according to the distribution positions of the multiple temperature collection points on the upper surface of the test module, and determining the test temperature difference according to the collected temperatures at each location and their corresponding weights; The heat conductive film makes the heat conduction between the liquid cooling system and the heating film more uniform.

8. A temperature difference test device for a liquid cooling system of a power battery, It is characterized in that The device is deployed in a temperature difference test system, which includes a liquid cooling system, a heating film, a test module and a temperature sensor arranged in sequence from bottom to top. The device includes an operation unit, a collection unit, a determination unit and an adjustment unit: The operating unit is used to operate the liquid cooling system according to the first operating parameter to adjust the temperature of the heating film, and operate the heating film according to the second operating parameter to adjust the temperature of the upper surface of the test module; The first operating parameter is determined according to a target test condition of the power battery, and the second operating parameter is determined according to a target power of the power battery under the target test condition, wherein the process of determining the first operating parameter includes: determining an initial temperature, flow rate, and system pressure parameter of the coolant introduced into the liquid cooling system according to the target test condition; The acquisition unit is used to acquire the temperatures of a plurality of temperature acquisition points arranged on the upper surface of the test module through the temperature sensor; the test module is pre-constructed according to the design parameters of the power battery; The determining unit is used to determine the test temperature difference of the liquid cooling system under the target test condition according to the temperatures of the multiple temperature collection points; The determination unit is specifically used to: determine a weight for the temperature value collected at each temperature collection point according to the distribution positions of the multiple temperature collection points on the upper surface of the test module, and determine the test temperature difference according to the collected temperatures at each location and their corresponding weights; The adjustment unit is used to obtain the temperature difference threshold of the liquid cooling system under the target test conditions; if the test temperature difference is greater than the temperature difference threshold, the design parameters of the liquid cooling system are adjusted according to the test temperature difference, and the design parameters of the liquid cooling system include: the initial temperature, flow rate, flow velocity of the coolant and the pipeline parameters of the liquid cooling system.

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