Condensation prevention and control method, device and system of battery pack and storage medium

Abstract

The invention provides a condensation prevention and control method, device and system for a battery pack and a storage medium, and the method comprises the steps: constructing a multi-physical field coupling model of the battery pack based on temperature field related parameters and humidity field related parameters of the battery pack; inputting the initial working condition data of the battery pack into the multi-physical field coupling model to obtain the initial temperature of the material surface corresponding to the target area of the battery pack; and based on the dew point temperature of the target area and the initial temperature, determining a risk level of condensation formed on the material surface corresponding to the target area, and performing condensation prevention and control on the target area according to the risk level. Through implementation of the scheme of the invention, the possibility of condensation in each region in the battery pack is accurately evaluated and quantified, so that condensation prevention and control measures can be actively taken before condensation is formed, and potential safety hazards brought to the battery pack due to condensation formed in a dead angle region which cannot be visually observed can be avoided as far as possible.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a condensation prevention and control method, device and system for a battery pack and a storage medium. BACKGROUND

[0002] With the rapid development of new energy technology, the reliability of a battery pack is widely concerned. The condensation phenomenon may be caused by the influence of temperature and humidity changes and other factors in the battery pack, which may increase the liquid water in the battery pack, and even cause short circuit, corrosion and performance degradation of the battery. There are many quality problems caused by condensation in the market. The related technology usually adopts a passive protection method to prevent and control condensation, that is, after the external environment changes and the battery pack charging and discharging test is completed, it is determined whether condensation occurs in the battery pack by function checking and opening the cover for visual inspection. The condensation can be found and relevant measures can be taken only after the condensation has occurred. However, the structure of the battery pack is relatively complex, and the function checking and opening the cover for visual inspection may not be able to timely find the condensation in the internal structure of the battery pack, so that the condensation failure problem is difficult to be solved in time. SUMMARY

[0003] The present application provides a condensation prevention and control method, device and system for a battery pack and a storage medium, aiming to solve the problem of untimely condensation prevention and control of the battery pack in the related technology.

[0004] To achieve the above-mentioned purpose, the first aspect of the present application provides a condensation prevention and control method for a battery pack, which comprises: constructing a multi-physical field coupling model of the battery pack based on temperature field related parameters and humidity field related parameters of the battery pack; inputting initial working condition data of the battery pack into the multi-physical field coupling model to obtain an initial temperature of a material surface corresponding to a target region of the battery pack; determining a risk level of the material surface corresponding to the target region forming condensation based on a dew point temperature of the target region and the initial temperature, and performing condensation prevention and control on the target region according to the risk level.

[0005] In the scheme provided by the present application, the multi-physical field coupling model is constructed based on the temperature field related parameters and the humidity field related parameters, so that the occurrence probability of condensation in the target region of the battery pack can be quantitatively evaluated, that is, the risk level of the material surface corresponding to the target region forming condensation is determined, and then the condensation prevention and control measures can be actively taken before the condensation is formed, so as to avoid the condensation failure of the battery pack as much as possible. Furthermore, by implementing the scheme of the present application, the possibility of condensation in each region of the battery pack can be accurately evaluated and quantified based on the working condition data of the battery pack by using the multi-physical field coupling model, so as to avoid the safety hazards caused by the condensation in the blind area which cannot be visually observed.

[0006] In some optional embodiments, the constructing the multi-physical field coupling model of the battery pack based on the temperature field related parameter and the humidity field related parameter comprises: determining a temperature field model based on the temperature field related parameter; determining a humidity field model based on the humidity field related parameter; and coupling the temperature field model and the humidity field model to determine the multi-physical field coupling model of the battery pack.

[0007] In the scheme provided in the present application, the linkage relationship among temperature, humidity and dew point can be established through the coupling between the temperature field model and the humidity field model, and then the temperature of the surface of each region inside the battery pack can be accurately calculated.

[0008] In some optional embodiments, the temperature field related parameter at least comprises theoretical working condition data of the battery pack, a fluid velocity field, and thermal physical parameters of materials corresponding to each region in the battery pack, and the thermal physical parameters at least comprise a thermal conductivity coefficient, a density and a specific heat capacity of the material; the determining the temperature field model based on the temperature field related parameter comprises: determining a total heat source term of a first control equation according to the theoretical working condition data, wherein the theoretical working condition data comprises a first theoretical heat corresponding to self-generated heat of the battery pack and a second theoretical heat corresponding to an external heat source, and the total heat source term is a sum of the first theoretical heat and the second theoretical heat; determining a heat conduction term of the first control equation according to the thermal conductivity coefficient; determining a heat convection term of the first control equation based on the fluid velocity field, the density and the specific heat capacity; and determining the temperature field model based on the total heat source term, the heat conduction term and the heat convection term.

[0009] In the scheme provided in the present application, the working condition data, the fluid velocity field, the thermal physical parameters of the material and other influencing factors are introduced in the construction process of the temperature field model, so as to more accurately quantify the influence of heat source change, heat conduction, heat convection and other processes on the temperature field change, and then the temperature distribution and change rule of the battery pack temperature field can be more accurately predicted.

[0010] In some optional embodiments, the method further comprises: obtaining theoretical working condition current and theoretical cell resistance of the battery pack; and determining the first theoretical heat based on the theoretical working condition current and the theoretical cell resistance of the battery pack.

[0011] In the scheme provided in the present application, the self-generated heat of the battery pack under the theoretical working condition can be determined based on the theoretical working condition current and the cell resistance, and applied in the construction process of the temperature field model, so as to better realize the condensation prevention and control and thermal management of the battery pack.

[0012] In some optional embodiments, the temperature field related parameter further comprises a first convection heat transfer coefficient. The method further includes determining a first boundary condition of the temperature field model based on the thermophysical parameter and the first convective heat exchange coefficient; and determining a first target output result of the first control equation based on the first boundary condition.

[0013] In the scheme provided in the application, the heat exchange mode of the temperature field model and the external environment is defined through the setting of the boundary condition, and the physical constraints in the actual working condition are fully considered, so that the temperature field model can accurately reflect the actual physical process, thereby improving the calculation efficiency and stability of the temperature field model.

[0014] In some optional embodiments, the humidity field related parameters include a humidity diffusion coefficient of the battery pack, a fluid velocity field accumulation item, and a humidity source item, the accumulation item is used to indicate a humidity change rate over time, and the humidity source item is used to indicate a humidity generation rate or a humidity consumption rate of the battery pack per unit volume per unit time; and the determining of the humidity field model according to the humidity field related parameters includes: determining a diffusion item of a second control equation based on the humidity diffusion coefficient; determining a convective transport item of the second control equation based on the fluid velocity field; and determining the humidity field model based on the diffusion item, the convective transport item, the accumulation item, and the humidity source item.

[0015] In the scheme provided in the application, the temperature field model of the battery pack is determined based on the diffusion item, the convective transport item, the accumulation item, and the humidity source item, so that the moisture distribution and transmission in the internal or surrounding environment of the battery pack can be better simulated, and the condensation prediction can be more accurate.

[0016] In some optional embodiments, the humidity field related parameters further include a second convective heat exchange coefficient, and the method further includes: determining a second boundary condition of the humidity field model based on the second convective heat exchange coefficient; and determining a second target output result of the second control equation based on the second boundary condition.

[0017] In the scheme provided in the application, the second boundary condition of the humidity field model is determined based on the second convective heat exchange coefficient, so that the change rule of the humidity field on the model boundary is defined, the humidity field model can accurately reflect the actual physical process of the humidity field, and the complexity of calculation is reduced.

[0018] In some optional embodiments, the model coupling of the temperature field model and the humidity field model to determine the multi-physical field coupling model of the battery pack comprises: identifying a correlation factor between the temperature field model and the humidity field model; embedding a quantitative relationship of the correlation factor into the temperature field model and the humidity field model respectively to determine a bidirectional data interaction logic between the temperature field model and the humidity field model; and based on the bidirectional data interaction logic, bidirectionally correcting parameters of the temperature field model and the humidity field model to obtain a converged multi-physical field coupling model of the battery pack.

[0019] In the scheme provided in the present application, two independent single-field models (i.e., the temperature field model and the humidity field model) are connected into an overall coupled model capable of mutual information transmission based on the correlation factor effect, so that the solid surface temperature and the risk level evaluation result closer to the actual situation can be obtained.

[0020] In some optional embodiments, the method further comprises: based on the multi-physical field coupling model, performing finite element mesh division on a three-dimensional geometric model of the battery pack to obtain a finite element mesh model, wherein the finite element mesh model comprises mesh elements corresponding to respective regions of the battery pack; loading the multi-physical field coupling model to the finite element mesh model for simulation processing to obtain a simulation result, and based on the simulation result, determining a solving coupled model corresponding to each mesh element of the three-dimensional geometric model, wherein each solving coupled model is used to determine the material surface temperature of the corresponding mesh element under different working conditions.

[0021] In the scheme provided in the present application, the multi-physical field coupling model is optimized by means of mesh cutting and simulation processing, which can effectively reduce the calculation amount of the model and improve the calculation accuracy.

[0022] In some optional embodiments, the method further comprises: comparing the simulation result of the multi-physical field coupling model with an actual measurement result of the battery pack to obtain an error comparison result, wherein the simulation result comprises a simulation temperature of a material surface of each mesh element under all working conditions, and the actual measurement result comprises a measurement temperature of a material surface of a region corresponding to each mesh element in the battery pack under all working conditions; and based on the error comparison result, correcting a related solving coupled model to obtain a corrected target solving coupled model, wherein the related solving coupled model comprises all the solving coupled models that cause the error.

[0023] In the scheme provided in the application, after the construction of the multi-physical field coupling model is completed, the model parameters can be corrected based on the simulation results and actual measurement results, the determined influence factors (including the above-mentioned temperature field related parameters and humidity field related parameters) can be corrected based on the error comparison results, and when a new influence factor is found, it can be introduced into the multi-physical field coupling model, so as to continuously improve the calculation accuracy of the coupling model.

[0024] In some optional embodiments, the risk level of the target region corresponding to the material surface forming condensation is determined based on the dew point temperature of the target region and the initial temperature, comprising: inputting the dew point temperature of the target region and the initial temperature into a preset condensation probability evaluation model to determine the condensation occurrence probability of the target region; and determining the risk level of the target region corresponding to the material surface forming condensation according to the condensation occurrence probability.

[0025] In the scheme provided in the application, the mapping standard of the condensation probability corresponding to the failure rate is determined through the condensation probability evaluation model, so that the condensation probability evaluation model can quantitatively evaluate whether the battery pack as a whole and the local position will occur condensation failure based on the calculation results of the multi-physical field coupling model and the related dew point temperature, that is, determine the risk level of the target region corresponding to the material surface forming condensation of the battery pack, so as to take preventive measures in time when condensation may occur.

[0026] In some optional embodiments, the method further comprises: obtaining the water vapor temperature and humidity ratio and the environment temperature in the environment where the target region is located; and determining the dew point temperature of the target region based on the water vapor temperature and humidity ratio and the environment temperature.

[0027] In the scheme provided in the application, the dew point temperature of the target region is determined in combination with the water vapor temperature and humidity ratio and the environment temperature in the environment where the target region is located, without using expensive special dew point measuring equipment, which is conducive to reducing the production cost and maintenance cost of the battery pack.

[0028] In some optional embodiments, the battery pack is connected with a gas adjusting device; and the condensation prevention and control on the target region according to the risk level comprises: controlling the gas adjusting device to replace nitrogen with the battery pack to adjust the humidity field of the battery pack; obtaining a real-time humidity value of the battery pack and determining the real-time humidity value as real-time working condition data of the battery pack; inputting the real-time working condition data into the multi-physical field coupling model to output a real-time temperature of the material surface of the target region; re-determining the risk level of the target region occurring condensation based on the dew point temperature of the target region and the real-time temperature; and if the re-determined risk level does not satisfy a preset condensation prevention and control condition of the battery pack, controlling the gas adjusting device to stop the nitrogen replacement operation.

[0029] In the scheme provided in the present application, when the risk level of condensation of the battery pack is high, the humidity field of the battery pack can be adjusted by the gas adjusting device until the humidity value in the battery pack is controlled within a reasonable range. Through the cooperation between the multi-physical field coupling model and the gas adjusting device, the condensation problem of the battery pack can be improved from the source, and the reliability of the battery pack can be improved.

[0030] The second aspect of the present application provides a condensation prevention and control device for a battery pack, comprising: a construction module configured to construct a multi-physical field coupling model of the battery pack based on temperature field related parameters and humidity field related parameters of the battery pack; a determination module configured to input initial operating condition data of the battery pack into the multi-physical field coupling model to obtain an initial temperature of a material surface corresponding to a target region of the battery pack; and a prevention and control module configured to determine a risk level of condensation formation on the material surface corresponding to the target region based on a dew point temperature of the target region and the initial temperature, and to perform condensation prevention and control on the target region according to the risk level.

[0031] The third aspect of the present application provides a condensation prevention and control system for a battery pack, comprising: a processor and a memory, wherein the processor is configured to execute a determination program stored in the memory; and the processor, when executing the determination program, implements the condensation prevention and control method for the battery pack provided in the first aspect of the present application.

[0032] In some optional embodiments, the condensation prevention and control system for the battery pack further comprises a gas adjusting device in communication connection with the processor, and the gas adjusting device is further connected with the battery pack for nitrogen replacement with the battery pack.

[0033] The fourth aspect of the present application provides a computer readable storage medium having a computer program stored thereon, and the computer program, when executed by a processor, implements the condensation prevention and control method for the battery pack provided in the first aspect of the present application.

[0034] It can be understood that the beneficial effects of the second aspect to the fourth aspect can be referred to the related description in the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0036] Figure 1A scene schematic diagram of a condensation prevention and control method of a battery pack provided for some embodiments of the present application; Figure 2 A flow schematic diagram of a condensation prevention and control method of a battery pack provided for some embodiments of the present application; Figure 3 A detailed flow schematic diagram of a condensation prevention and control method of a battery pack provided for some embodiments of the present application; Figure 4 A module schematic diagram of a condensation prevention and control device provided for some embodiments of the present application; Figure 5 A structure schematic diagram of a condensation prevention and control system of a battery pack provided for some embodiments of the present application; Figure 6 A structure schematic diagram of a gas adjusting device and a battery pack provided for some embodiments of the present application; Figure 7 A structure schematic diagram of a computer readable storage medium for storing or carrying program codes for implementing a condensation prevention and control method of a battery pack provided for some embodiments of the present application. DETAILED DESCRIPTION

[0037] In order to make the objectives, characteristics and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0038] The following description refers to the accompanying drawings. Unless otherwise indicated, same numbers in different drawings indicate same or similar elements. The following description of the example embodiments is not representative of all embodiments consistent with the present application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the present application as detailed in the appended claims.

[0039] It should be understood that when used in the specification and appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0040] It should also be understood that the terms used in the present application specification are only for the purpose of describing particular embodiments and are not intended to limit the present application. As used in the present application specification and the appended claims, "a", "an", and "the" are intended to include both singular and plural forms, unless the context clearly indicates otherwise.

[0041] It should be further understood that the term "and / or" used in the present application specification and the appended claims means one or more of the associated listed items as well as all possible combinations of the items, and includes the combinations.

[0042] In addition, in the description of the present application, the terms "first", "second" are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0043] In the related art, the condensation prevention method of the battery pack is usually passive prevention. In view of the safety problems caused by possible condensation, the measures taken are usually passive bearing rather than active solution. In addition, the structure design of the battery pack is relatively complex. Condensation may occur in a position that cannot be directly observed by the human eye. Condensation cannot be found in time through visual inspection. For a battery pack with a multi-layer structure, the condensed water may flow along the structure interface to the bottom layer position, causing the risk range of the battery pack to expand. Therefore, how to quantitatively characterize the condensation occurrence probability of the battery pack and take active prevention measures to prevent condensation has become a big problem for designers.

[0044] In view of the above problems, considering that the formation of condensation depends on two key factors of temperature and humidity, and the temperature field and the humidity field also interact with each other, the condensation prevention method, device, system and storage medium of the battery pack provided by the embodiments of the present application construct a multi-physical field coupling model based on the temperature field related parameters and the humidity field related parameters of the battery pack. The dynamic correlation between the temperature field and the humidity field is located through the multi-physical field coupling model, so as to accurately evaluate the risk level of condensation occurrence. Then, active prevention measures can be taken before condensation occurs, which greatly improves the reliability of the battery pack.

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. It should be noted that the description order of the following embodiments is not limited as the preferred order of the embodiments.

[0046] Please refer to Figure 1 , Figure 1is a scene schematic diagram of a condensation prevention and control method of a battery pack 101 provided by some embodiments of the present application. The application scenario of the condensation prevention and control method can be a condensation prevention and control system 100 of the battery pack 101, which can be integrated into a battery management system (BMS) or be a system independent of the battery management system, which is not limited here.

[0047] The condensation prevention and control system 100 can include an acquisition module 1001, a decision module 1002, and an execution module 1003, which can be connected with the battery pack 101 respectively; wherein the acquisition module 1001 can be used to obtain the working condition data of the battery pack 101, which can include the working condition current of the battery pack 101, the cell resistance, the temperature value inside the battery pack 101, the temperature value outside the battery pack 101, the humidity value inside the battery pack 101, the humidity value outside the battery pack 101, etc. Correspondingly, the acquisition module 1001 can include a temperature sensor, a humidity sensor, and an acquisition sub-module for obtaining battery state parameters, etc. The acquisition sub-module can be a sensor or a specific sampling circuit, etc., which is used to directly or indirectly obtain the working condition current, the cell resistance, and other battery state parameters of the battery pack 101. The temperature sensor can be provided in multiple, and the multiple temperature sensors can be respectively arranged inside and outside the battery pack 101 to obtain the temperature values inside and outside the battery pack 101. The humidity sensor can also be provided in multiple, and the multiple humidity sensors can also be arranged inside and outside the battery pack 101 to obtain the humidity values inside and outside the battery pack 101, which is not limited here. The decision module 1002 can evaluate the risk level of the condensation of the battery pack 101 based on the working condition data obtained by the acquisition module 1001 of the battery pack 101. The execution module 1003 can actively prevent and control the condensation of the battery pack 101 based on the risk level determined by the decision module 1002.

[0048] Please refer to Figure 2 , Figure 2 is a flow schematic diagram of a condensation prevention and control method of a battery pack provided by some embodiments of the present application. In specific embodiments, the condensation prevention and control method of the battery pack can be applied to a condensation prevention and control system as shown in Figure 1 The specific flow of the condensation prevention and control method of the battery pack is as follows: S201, based on the temperature field related parameters and the humidity field related parameters of the battery pack, a multi-physical field coupling model of the battery pack is constructed.

[0049] In the embodiment of the present application, the temperature field related parameter can refer to a heat source related parameter that can affect the change of the temperature field, and the humidity field related parameter can refer to various moisture source related parameters that can cause the change of the humidity field of the battery pack. In the condensation prevention and control method of the embodiment, the influence of temperature and humidity on the condensation generation probability is fully considered, and the multi-physical field coupling model is constructed based on the temperature field related parameter and the humidity field related parameter, which is beneficial to improving the accuracy of the material surface temperature calculation and the accuracy of the risk level prediction.

[0050] In some optional embodiments, based on the temperature field related parameter and the humidity field related parameter of the battery pack, the multi-physical field coupling model of the battery pack is constructed, including: determining a temperature field model based on the temperature field related parameter; determining a humidity field model based on the humidity field related parameter; and coupling the temperature field model and the humidity field model to determine the multi-physical field coupling model of the battery pack.

[0051] In the scheme provided in the present application, the temperature field model can refer to a temperature field mathematical model of the temperature change of each spatial position in the battery pack over time, and the humidity field model can refer to a humidity field mathematical model of the relative humidity or absolute humidity change of each spatial position in the battery pack over time. In the embodiment, the linkage relationship among temperature, humidity and dew point can be established through the coupling between the temperature field model and the humidity field model, and then the temperature of the surface of each region in the battery pack can be accurately calculated.

[0052] In some optional embodiments, the temperature field related parameter at least includes theoretical working condition data of the battery pack, a fluid velocity field, and thermal physical parameters of materials corresponding to each region in the battery pack, and the thermal physical parameters at least include a thermal conductivity, a density and a specific heat capacity of the material; based on the temperature field related parameter, the temperature field model is determined, including: determining a total heat source term of a first control equation according to the theoretical working condition data, wherein the theoretical working condition data includes a first theoretical heat corresponding to the self-heat generation of the battery pack and a second theoretical heat corresponding to an external heat source, and the total heat source term is the sum of the first theoretical heat and the second theoretical heat; determining a heat conduction term of the first control equation according to the thermal conductivity; determining a heat convection term of the first control equation based on the fluid velocity field, the density and the specific heat capacity; and determining the temperature field model based on the total heat source term, the heat conduction term and the heat convection term.

[0053] In the scheme provided in the present application, each temperature field related parameter can be obtained by theoretical calculation, database lookup or empirical test, etc., which is not limited herein. The theoretical working condition data can be working condition data determined in the battery pack design or test stage. By introducing the theoretical working condition data when constructing the temperature field model, the model can better simulate the temperature change of the battery pack under transient and alternating loads. The fluid velocity field describes the flow of fluid medium (such as air, cooling liquid in the liquid cooling plate, etc.) inside the battery pack, including flow rate, flow direction and distribution. In the product development process, the fluid velocity field can be determined by fluid dynamics software and stored in the database. When the temperature field model needs to be constructed, it can be directly obtained from the database. The thermal physical parameters can be used to characterize the thermal physical properties of various materials (such as cells, busbars, cooling plates, thermal insulation cotton, thermal conductive glue, shells, etc.) constituting the battery pack. By applying the thermal physical parameters of the materials of different components in the model, the change of the temperature field under different working conditions can be better simulated. Based on the embodiments of the present application, the working condition data, fluid velocity field, thermal physical parameters of materials, etc. are introduced in the construction process of the temperature field model, so as to more accurately quantify the influence of heat source change, heat conduction, heat convection, etc. on the change of the temperature field, and then the temperature distribution and change rule of the battery pack temperature field can be more accurately predicted. In the present embodiment, the process of determining the temperature field model mainly includes: determining the first control equation of the temperature field model.

[0054] In some embodiments, the first control equation can be expressed as:

[0055] wherein, represents a heat conduction term, represents a heat convection term, represents a total heat source term, represents a thermal conductivity, represents a density, represents a specific heat capacity, represents a gradient operator, represents a temperature variable, represents a change rate and a change direction in the temperature field, represents a fluid velocity field.

[0056] In some optional embodiments, the condensation prevention and control method further includes: obtaining a theoretical working condition current and a theoretical cell resistance of the battery pack; and determining a first theoretical heat based on the theoretical working condition current and the theoretical cell resistance of the battery pack.

[0057] In the scheme provided in the application, the self-heat generation of the battery pack under the theoretical working condition can be determined based on the theoretical working current and the cell resistance, and applied in the construction process of the temperature field model, so as to better realize the condensation prevention and control and thermal management of the battery pack.

[0058] In some embodiments, the first theoretical heat can be calculated by the following formula:

[0059] wherein, the first theoretical heat is represented by Q, the theoretical working current is represented by I, the theoretical cell resistance is represented by R, the heat of other heat sources in the self-heat source of the battery pack except for the Joule heat is represented by Q other, and the other heat sources can be one or more of the reaction heat, the side reaction heat, and the polarization heat of the battery pack.

[0060] In some optional embodiments, the temperature field related parameters further include a first convective heat transfer coefficient; and the condensation prevention and control method further includes: determining a first boundary condition of the temperature field model based on the thermal physical parameters and the first convective heat transfer coefficient; and determining a first target output result of the first control equation based on the first boundary condition.

[0061] In the scheme provided in the application, the boundary condition of the temperature field model is determined based on the thermal physical parameters and the first convective heat transfer coefficient, the heat exchange mode (convection, heat transfer) between the temperature field model and the external environment is defined through the setting of the boundary condition, and the physical constraints in the actual working condition are fully considered, so that the temperature field model can accurately reflect the actual physical process, thereby improving the calculation efficiency and stability of the temperature field model.

[0062] In some embodiments, the expression of the first boundary condition can be:

[0063] wherein, the thermal conductivity is represented by k, the temperature is represented by T, the solid surface normal is represented by n, the gradient of the temperature along the solid surface normal direction is represented by ∇T·n, the first convective heat transfer coefficient is represented by h, the solid surface temperature output by the temperature field model is represented by T s, the fluid temperature output by the temperature field model is represented by T f.

[0064] In some optional embodiments, the humidity field related parameters comprise a humidity diffusion coefficient of the battery pack, a fluid velocity field accumulation term, and a humidity source term, the accumulation term being used to indicate a change rate of humidity over time, and the humidity source term being used to indicate a humidity generation rate or a humidity consumption rate of the battery pack per unit volume per unit time; and the humidity field model is determined according to the humidity field related parameters, comprising: determining a diffusion term of the second control equation based on the humidity diffusion coefficient; determining a convection transport term of the second control equation based on the fluid velocity field; and determining the humidity field model based on the diffusion term, the convection transport term, the accumulation term, and the humidity source term.

[0065] In the scheme provided in the present application, the humidity field model related parameters can be obtained by theoretical calculation, database lookup or empirical test, etc., which is not limited herein. The humidity diffusion coefficient can be used to indicate the ease or difficulty of moisture diffusion in materials or air. The diffusion term indicates the humidity diffusion caused by the concentration gradient. The convection transport term indicates the humidity transport caused by fluid flow (such as cooling air). The temperature field model of the battery pack is determined based on the diffusion term, the convection transport term, the accumulation term, and the humidity source term, which can better simulate the moisture distribution and transport in the internal or surrounding environment of the battery pack, so that the condensation prediction can be more accurate. In the present embodiment, the process of determining the humidity field model mainly comprises determining a second control equation of the humidity field model.

[0066] In some embodiments, the second control equation can be expressed as:

[0067] wherein, represents a humidity variable, represents time, represents a fluid velocity field, represents a gradient operator, represents a change rate and a change direction in the humidity field, represents a humidity diffusion coefficient, represents an accumulation term, represents a convection transport term, represents a diffusion term, represents a humidity source term.

[0068] In some optional embodiments, the humidity field related parameters further comprise a second convection heat transfer coefficient, and the condensation prevention and control method further comprises: determining a second boundary condition of the humidity field model based on the second convection heat transfer coefficient; and determining a second target output result of the second control equation based on the second boundary condition.

[0069] In the scheme provided in the application, the second boundary condition of the humidity field model is determined based on the second convective heat exchange coefficient, and by defining the change rule of the humidity field on the model boundary, the humidity field model can accurately reflect the actual physical process of the humidity field, while reducing the complexity of the calculation. It can be understood that the setting of the second boundary condition not only meets the completeness of the mathematical solution of the second control equation, but also realizes the reasonable physical constraint and efficiency optimization of the humidity field, lays a calculation foundation for subsequent multi-field coupling and risk level assessment processes, and also enables the humidity field model to truly and efficiently guide the design and optimization of the battery pack.

[0070] In some embodiments, the expression of the second boundary condition can be:

[0071] wherein, represents the normal of the solid surface, represents the gradient of the humidity in the normal direction of the solid surface, represents the second convective heat exchange coefficient, represents the solid surface humidity output by the humidity field model, represents the fluid humidity output by the humidity field model.

[0072] In some optional embodiments, the temperature field model and the humidity field model are coupled to determine a multi-physical field coupling model of the battery pack, including: identifying an associated factor between the temperature field model and the humidity field model; embedding the quantitative relationship of the associated factor into the temperature field model and the humidity field model respectively to determine a bidirectional data interaction logic between the temperature field model and the humidity field model; based on the bidirectional data interaction logic, bidirectionally correcting the parameters of the temperature field model and the humidity field model to obtain a converged multi-physical field coupling model of the battery pack.

[0073] In the scheme provided in the application, the associated factor can refer to specific factors that affect each other between the temperature field and the humidity field. For example, the associated factor can be relative humidity, moisture diffusion coefficient, etc. In the condensation prevention and control method of the embodiments of the application, the associated factor between the temperature field model and the humidity field model is identified, and then the associated factor can be quantified and embedded into the model in the form of an expression, so that the temperature field model and the humidity field model can be bidirectionally corrected based on the calculation results of each other. Thus, based on the effect of the associated factor, two independent single-field models (i.e., the temperature field model and the humidity field model) are connected into an overall coupled model that can transmit information to each other, and a solid surface temperature and a risk level assessment result that are closer to the actual situation can be obtained.

[0074] In some optional embodiments, the condensation prevention and control method further comprises: performing finite element meshing on the three-dimensional geometric model of the battery pack based on the multi-physics field coupling model to obtain a finite element mesh model, wherein the finite element mesh model comprises mesh elements corresponding to respective regions of the battery pack; loading the multi-physics field coupling model to the finite element mesh model for simulation processing to obtain simulation results, and determining a solving coupling model corresponding to each mesh element of the three-dimensional geometric model based on the simulation results, wherein each solving coupling model is used to determine the material surface temperature of the corresponding mesh element under different working conditions.

[0075] In the scheme provided in the present application, the finite element method is used to perform meshing on the three-dimensional geometric model of the battery pack, the multi-physics field coupling model is decomposed to each mesh element, and a calculation framework is built for simulation processing, so that the simulation software can be used to perform simulation calculation based on the calculation framework to obtain simulation results and determine the corresponding solving coupling model. The present embodiment optimizes the multi-physics field coupling model by means of mesh cutting and simulation processing, which can effectively reduce the calculation amount of the model and improve the calculation accuracy.

[0076] It can be understood that, in some specific embodiments, when the three-dimensional geometric model of the battery pack is meshed, the high-risk areas of condensation can be meshed densely, the high-risk areas can refer to the gaps between the battery cells, the contact between the shell and the battery cells, the vicinity of the heat dissipation components, the poorly sealed seams, etc., so that the temperature and humidity calculation accuracy of these areas is high enough; for large-area shells, open areas and other parts with lower risk, the mesh can be appropriately simplified to balance the calculation efficiency.

[0077] In some optional embodiments, the condensation prevention and control method further comprises: comparing the simulation results of the multi-physics field coupling model with the actual measurement results of the battery pack to obtain an error comparison result, wherein the simulation results comprise the simulation temperatures of the material surfaces of each mesh element under all working conditions, and the actual measurement results comprise the measured temperatures of the material surfaces of the regions corresponding to each mesh element in the battery pack under all working conditions; and modifying the relevant solving coupling models according to the error comparison result to obtain a modified target solving coupling model, wherein the relevant solving coupling models comprise all solving coupling models that cause errors.

[0078] In the scheme provided in the present application, after the construction of the multi-physics field coupling model is completed, the model parameters can be modified based on the simulation results and the actual measurement results, that is, the already determined influence factors (including the temperature field related parameters and the humidity field related parameters) are modified, and the database table storing the influence factors can be updated based on the re-determined influence factors, and new influence factors can be introduced into the multi-physics field coupling model when they are found, so as to continuously improve the calculation accuracy of the solving coupling model.

[0079] It can be understood that in some specific embodiments, the actual measurement result described above can be an actual measurement result at a market end or an actual measurement result at a test end, and error analysis is performed based on error comparison results between the actual measurement result and the simulation result to find a source of an influence factor affecting the simulation result; and then the model parameters can be gradually corrected according to the source of the influence factor, that is, iterative verification is performed based on the simulation result and the actual measurement result until the error comparison result between the simulation result and the actual measurement result is less than a preset threshold, and finally a target solving coupled model meeting a calculation accuracy requirement is obtained. The battery pack in this embodiment can refer to a battery pack installed in an electric vehicle. When the model is corrected by using the measurement result at the market end, the environmental temperature inside and outside the battery pack, the environmental humidity inside and outside the battery pack, the running working condition data of the vehicle where the battery pack is located, the insulation state of the battery pack, and the like can be taken as the main concerned source of the influence factor. When the model is corrected by using the measurement result at the test end, the environmental temperature inside and outside the battery pack, the environmental humidity inside and outside the battery pack, the running working condition data of the vehicle where the battery pack is located, the insulation state of the battery pack, the temperature of other heat sources of the battery pack, and the fluid speed, and the like can be taken as the main concerned source of the influence factor. This is not limited herein.

[0080] S202, input initial working condition data of the battery pack to the multi-physical field coupled model to obtain an initial temperature of a material surface corresponding to a target region of the battery pack.

[0081] In this embodiment, the working condition data can include external environmental parameters of the battery pack and material related parameters in the battery pack, and the like, wherein the external environmental parameters can include an external environmental temperature of the battery pack, an external environmental humidity, and a vehicle current working condition, and the like, and the material related parameters in the battery pack can include material models of materials in different regions of the battery pack and battery pack numerical models, and the like. The battery pack numerical model can include a working current of the battery pack, a cell resistance, heat values of various heat sources inside and outside the battery pack, and a heat value of total heat sources of the battery pack, and the like, which are not limited herein. The initial working condition data of the battery pack is input to the multi-physical field coupled model, and then the initial temperature of the material surface corresponding to the target region of the battery pack under the current working condition can be calculated by a solving coupled model of the multi-physical field coupled model. It can be understood that the target region can refer to a high-risk region in the battery pack where condensation is prone to be generated, or can refer to all regions in the battery pack, which are not limited herein.

[0082] S203, determine a risk level of the material surface corresponding to the target region forming condensation based on a dew point temperature and the initial temperature of the target region, and prevent and control condensation of the target region according to the risk level.

[0083] In this embodiment, the condensation prevention and control measures include, but are not limited to, real-time state monitoring, sending an alarm signal, temperature adjustment of the battery pack, humidity adjustment of the battery pack, etc., which are not limited herein. In this embodiment, the risk level of the condensation formation on the surface of the material of the battery pack can be predicted based on the calculation result of the multi-physical field coupling model, and then the condensation prevention and control measures can be actively taken before the condensation formation, so as to avoid the condensation failure of the battery pack as much as possible.

[0084] In some optional embodiments, based on the dew point temperature and the initial temperature of the target region, the risk level of the condensation formation on the surface of the material corresponding to the target region is determined, including: inputting the dew point temperature and the initial temperature of the target region into a preset condensation probability evaluation model to determine the condensation occurrence probability of the target region; and determining the risk level of the condensation formation on the surface of the material corresponding to the target region according to the condensation occurrence probability.

[0085] In the scheme provided in this application, the mapping standard of the condensation probability to the failure rate is determined through the condensation probability evaluation model, so that the condensation probability evaluation model can quantitatively evaluate whether the condensation failure is likely to occur in the whole battery pack and the local position based on the calculation result of the multi-physical field coupling model and the related dew point temperature, that is, determine the risk level of the condensation formation on the surface of the material corresponding to the target region of the battery pack, so as to take prevention and control measures in time when the condensation is likely to occur.

[0086] It should be noted that the traditional condensation prevention and control method is usually passive protection after the condensation risk is found in the product test or use process. However, the multi-physical field coupling model and the condensation probability evaluation model of the embodiments of the present application can be applied to various stages of product development; for example, in the early stage of product development, the multi-physical field coupling model and the condensation probability evaluation model can be used to predict the risk level of the condensation formation in the battery pack, and the high-risk areas can be designed to avoid in advance; in the middle stage of product development, the multi-physical field coupling model and the condensation probability evaluation model can be used to guide the risk judgment of the market end product; after the model is optimized, the product does not need to be actually tested, and the risk of the product in the actual market can be evaluated in advance through modeling.

[0087] In some embodiments, the expression of the condensation probability evaluation model can be:

[0088] wherein, represents the condensation occurrence probability, represents the initial temperature, represents the dew point temperature, represents a preset temperature difference interval; when , ; when , the temperature difference is linearly decreased.

[0089] Exemplarily, in some embodiments, the risk level can be divided into low risk, medium risk and high risk. If the result output by the condensation probability evaluation model is: it can be determined that the probability of condensation occurring on the material surface corresponding to the target region is low, which can be recorded as low risk, and the corresponding prevention and control measures can be: maintaining moderate attention and not performing special treatment. If the result output by the condensation probability evaluation model is: it can be determined that the probability of condensation occurring on the material surface corresponding to the target region is general, which can be recorded as medium risk, and the corresponding prevention and control measures can be: not performing treatment temporarily, issuing an alarm signal and maintaining attention. If the result output by the condensation probability evaluation model is: it can be determined that the probability of condensation occurring on the material surface corresponding to the target region is high, which can be recorded as high risk, and the corresponding prevention and control measures can be: issuing an alarm signal and adjusting the temperature and / or humidity of the battery pack.

[0090] In some optional embodiments, the condensation prevention and control method further includes: acquiring a water vapor temperature and humidity ratio and an environment temperature in an environment in which the target region is located; and determining a dew point temperature of the target region based on the water vapor temperature and humidity ratio and the environment temperature.

[0091] In the scheme provided in the present application, the dew point temperature of the target region is determined in combination with the water vapor temperature and humidity ratio and the environment temperature in the environment in which the target region is located, without the need to use expensive special dew point measurement equipment, which is beneficial to reduce the production cost and maintenance cost of the battery pack.

[0092] In some embodiments, the dew point temperature calculation formula of the target region can be:

[0093] wherein, represents the dew point temperature, represents the environment temperature, represents the water vapor temperature and humidity ratio. The dew point temperature is calculated by using the above dew point calculation formula, the calculation formula is simple, the calculation delay is extremely low, the change of the environment in the battery pack can be quickly responded, the condensation prevention and control measures can be triggered in time, and the occurrence of situations such as short circuit, corrosion or performance decline caused by condensed water can be avoided as much as possible.

[0094] In some optional embodiments, the battery pack is connected with the gas adjusting device; and condensation prevention and control is performed on the target area according to the risk level, including: controlling the gas adjusting device to perform nitrogen replacement with the battery pack to adjust the humidity field of the battery pack; obtaining a real-time humidity value of the battery pack, and determining the real-time humidity value as real-time working condition data of the battery pack; inputting the real-time working condition data into the multi-physical field coupling model to output a real-time temperature of a material surface of the target area; re-determining a risk level of the target area from condensation based on a dew point temperature and the real-time temperature of the target area; and if the re-determined risk level does not satisfy a preset condensation prevention and control condition of the battery pack, controlling the gas adjusting device to stop the nitrogen replacement operation.

[0095] In the scheme provided in the present application, when the risk level of the target area of the battery pack corresponding to the material surface from forming condensation is high risk, the gas adjusting device can be controlled to perform nitrogen replacement with the battery pack, and at the same time, the real-time humidity value of the battery pack can be collected through the humidity sensor to re-determine the risk level of the target area from condensation based on the collected real-time humidity value, and when the re-determined risk level becomes medium risk or low risk, the gas adjusting device is controlled to stop the nitrogen replacement operation. In the embodiments of the present application, when the risk level of the battery pack from condensation is high, the humidity field of the battery pack can be adjusted through the gas adjusting device until the humidity value in the battery pack is controlled within a reasonable range. Through the cooperation between the multi-physical field coupling model and the gas adjusting device, the condensation problem of the battery pack can be improved from the source, and the reliability of the battery pack can be greatly improved.

[0096] In some embodiments, the gas adjusting device can be connected with the battery management system of the battery pack, and the gas adjusting device can not only be used for condensation prevention and control of the battery pack, but also can block the fire through nitrogen replacement when the battery cell is in thermal runaway. It can be understood that in other embodiments, when condensation prevention and control is performed, other dry gases can also be filled into the battery pack through the gas adjusting device to replace the humid gas in the battery pack, which can also achieve the effect of reducing the humidity of the battery pack.

[0097] Based on the technical scheme of the above embodiments of the present application, the multi-physical field coupling model is constructed based on the temperature field related parameters and the humidity field related parameters, so that the condensation occurrence probability of the target area in the battery pack can be quantitatively evaluated, that is, the risk level of the material surface corresponding to the target area from forming condensation is determined, and then condensation prevention and control measures can be actively taken before condensation is formed to avoid the condensation failure of the battery pack as much as possible. Furthermore, through the implementation of the scheme of the present application, the multi-physical field coupling model can be used to accurately evaluate and quantify the possibility of condensation occurrence of each area in the battery pack based on the working condition data of the battery pack, so as to avoid the safety hazards of the battery pack caused by the condensation in the dead angle area which cannot be visually observed.

[0098] To better illustrate the condensation prevention and control of the battery pack in the foregoing embodiments, the embodiments of the present application further provide a refined condensation prevention and control method of the battery pack, please refer to Figure 3 , Figure 3 is a refined flowchart of the condensation prevention and control method of the battery pack provided by some embodiments of the present application, which includes the following steps: S301, determining a temperature field model based on temperature field related parameters; S302, determining a humidity field model based on humidity field related parameters; S303, identifying an association factor between the temperature field model and the humidity field model; S304, embedding the quantitative relationship of the association factor into the temperature field model and the humidity field model respectively, and determining a bidirectional data interaction logic between the temperature field model and the humidity field model; S305, based on the bidirectional data interaction logic, bidirectionally correcting the parameters of the temperature field model and the humidity field model to obtain a converged multi-physical field coupling model of the battery pack; S306, based on the multi-physical field coupling model, performing finite element mesh division on a three-dimensional geometric model of the battery pack to obtain a finite element mesh model; In the embodiments of the present application, the finite element mesh model includes mesh elements corresponding to each region of the battery pack respectively; S307, loading the multi-physical field coupling model to the finite element mesh model for simulation processing to obtain a simulation result, and determining a solving coupling model corresponding to each mesh element of the three-dimensional geometric model based on the simulation result; In the embodiments of the present application, each solving coupling model is used to determine the material surface temperature of the corresponding mesh element under different working conditions; S308, inputting initial working condition data of the battery pack to the solving coupling model corresponding to the target region of the battery pack to obtain an initial temperature of the material surface corresponding to the target region; S309, based on the dew point temperature and the initial temperature of the target region, determining the risk level of the formation of condensation on the material surface corresponding to the target region, and performing condensation prevention and control on the target region according to the risk level.

[0099] Based on the technical solutions of the embodiments of the present application, the temperature field model and the humidity field model are first constructed respectively, the multi-physical field coupling model of the temperature field model and the humidity field model is constructed based on the correlation factor effect, and the multi-physical field coupling model is optimized by means of grid division and numerical simulation, so as to determine the required coupling model for solving; while ensuring the accuracy of the model calculation, the calculation complexity of the model is reduced as much as possible. The calculation results of the model are used to evaluate the risk level of the material surface in the battery pack to form condensation, and then condensation prevention and control measures can be actively taken before the condensation is formed, so as to avoid the condensation failure of the battery pack as much as possible, and the dead angle area that cannot be visually observed can be avoided to form condensation and bring safety hazards to the battery pack.

[0100] It should be understood that the size of the serial number of each step in the embodiments does not mean the sequence of the execution of the steps, and the execution sequence of each step should be determined according to its function and inherent logic, and should not constitute the only limitation on the implementation process of the embodiments of the present application.

[0101] Based on the same inventive concept, the embodiments of the present application also provide related products for implementing the above-mentioned method. It should be understood that the implementation scheme of the related products for solving the problem is similar to the above-mentioned method.

[0102] The embodiments of the present application also provide a condensation prevention and control device for a battery pack. Please refer to Figure 4 , Figure 4 A structural schematic diagram of a condensation prevention and control device provided for some embodiments of the present application, which can include a construction module 401, a determination module 402 and a prevention and control module 403, as follows: The construction module 401 is configured to construct a multi-physical field coupling model of the battery pack based on temperature field related parameters and humidity field related parameters of the battery pack. The determination module 402 is configured to input initial working condition data of the battery pack into the multi-physical field coupling model to obtain an initial temperature of a material surface corresponding to a target region of the battery pack. The prevention and control module 403 is configured to determine a risk level of the material surface corresponding to the target region to form condensation based on a dew point temperature and the initial temperature of the target region, and to prevent and control condensation of the target region according to the risk level.

[0103] In some embodiments, the construction module 401 can be configured to determine a temperature field model based on the temperature field related parameters, determine a humidity field model based on the humidity field related parameters, and perform model coupling on the temperature field model and the humidity field model to determine the multi-physical field coupling model of the battery pack.

[0104] In some embodiments, the temperature field related parameters at least include theoretical working condition data of the battery pack, a fluid velocity field, and thermal physical property parameters of materials corresponding to respective regions in the battery pack, the thermal physical property parameters at least including a thermal conductivity coefficient, a density, and a specific heat capacity of the materials; the construction module 401 can be further configured to: determine a total heat source term of the first control equation according to the theoretical working condition data, wherein the theoretical working condition data includes a first theoretical heat corresponding to self-heat generation of the battery pack and a second theoretical heat corresponding to an external heat source, and the total heat source term is a sum of the first theoretical heat and the second theoretical heat; determine a heat conduction term of the first control equation according to the thermal conductivity coefficient; determine a heat convection term of the first control equation based on the fluid velocity field, the density, and the specific heat capacity; and determine the temperature field model based on the total heat source term, the heat conduction term, and the heat convection term.

[0105] In some embodiments, the construction module 401 can be further configured to: obtain a theoretical working condition current and a theoretical cell resistance of the battery pack; and determine the first theoretical heat based on the theoretical working condition current and the theoretical cell resistance of the battery pack.

[0106] In some embodiments, the temperature field related parameters further include a first convective heat transfer coefficient; the construction module 401 can be further configured to: determine a first boundary condition of the temperature field model based on the thermal physical property parameters and the first convective heat transfer coefficient; and determine a first target output result of the first control equation based on the first boundary condition.

[0107] In some embodiments, the humidity field related parameters include a humidity diffusion coefficient of the battery pack, a fluid velocity field accumulation term, and a humidity source term, the accumulation term being used to indicate a rate of change of humidity over time, and the humidity source term being used to indicate a humidity generation rate or a humidity consumption rate per unit volume per unit time of the battery pack; the construction module 401 can be further configured to: determine a diffusion term of the second control equation based on the humidity diffusion coefficient; determine a convective transport term of the second control equation based on the fluid velocity field; and determine the humidity field model based on the diffusion term, the convective transport term, the accumulation term, and the humidity source term.

[0108] In some embodiments, the humidity field related parameters further include a second convective heat transfer coefficient; the construction module 401 can be further configured to: determine a second boundary condition of the humidity field model based on the second convective heat transfer coefficient; and determine a second target output result of the second control equation based on the second boundary condition.

[0109] In some embodiments, the construction module 401 can be further configured to: identify a correlation factor between the temperature field model and the humidity field model; embed a quantitative relationship of the correlation factor into the temperature field model and the humidity field model respectively to determine a bidirectional data interaction logic between the temperature field model and the humidity field model; and perform bidirectional correction on parameters of the temperature field model and the humidity field model based on the bidirectional data interaction logic to obtain a converged multi-physical field coupling model of the battery pack.

[0110] In some embodiments, the construction module 401 can be further configured to perform finite element meshing on the three-dimensional geometric model of the battery pack based on the multi-physics coupling model to obtain a finite element mesh model, wherein the finite element mesh model comprises mesh cells corresponding to respective regions of the battery pack; load the multi-physics coupling model to the finite element mesh model for simulation processing to obtain simulation results, and determine a solving coupling model corresponding to each mesh cell of the three-dimensional geometric model based on the simulation results, wherein each solving coupling model is used to determine the material surface temperature of the corresponding mesh cell under different working conditions.

[0111] In some embodiments, the construction module 401 can be further configured to perform error comparison between the simulation results of the multi-physics coupling model and the actual measurement results of the battery pack to obtain an error comparison result, wherein the simulation results comprise simulation temperatures of the material surface of each mesh cell under all working conditions, and the actual measurement results comprise measured temperatures of the material surface of the regions corresponding to each mesh cell in the battery pack under all working conditions; modify the relevant solving coupling models according to the error comparison result to obtain a modified target solving coupling model, wherein the relevant solving coupling models comprise all solving coupling models that cause errors.

[0112] In some embodiments, the prevention and control module 403 can be configured to input the dew point temperature and the initial temperature of the target region into a preset condensation probability evaluation model to determine a condensation occurrence probability of the target region; and determine a risk level of the target region in forming condensation on the material surface according to the condensation occurrence probability.

[0113] In some embodiments, the prevention and control module 403 can be further configured to obtain a water vapor temperature and humidity ratio and an environment temperature in an environment where the target region is located; and determine the dew point temperature of the target region based on the water vapor temperature and humidity ratio and the environment temperature.

[0114] In some embodiments, the battery pack is connected with a gas adjusting device; and the prevention and control module 403 can be further configured to control the gas adjusting device to perform nitrogen replacement with the battery pack to adjust the humidity field of the battery pack; obtain a real-time humidity value of the battery pack and determine the real-time humidity value as real-time working condition data of the battery pack; input the real-time working condition data into the multi-physics coupling model to output a real-time temperature of the material surface of the target region; re-determine a risk level of the target region in forming condensation based on the dew point temperature and the real-time temperature of the target region; and if the re-determined risk level does not satisfy a preset condensation prevention and control condition of the battery pack, control the gas adjusting device to stop the nitrogen replacement operation.

[0115] It should be noted that the condensation prevention and control method of the battery pack in the foregoing embodiments can be implemented based on the condensation prevention and control device provided in the embodiment. It can be clearly understood by those skilled in the art that, for the convenience and brevity of description, the specific working process of the condensation prevention and control device described in the embodiment can refer to the corresponding process in the foregoing method embodiments, which will not be described herein.

[0116] Based on the technical solutions of the foregoing embodiments of the present application, the multi-physical field coupling model is constructed in combination with the temperature field related parameters and the humidity field related parameters, so that the condensation occurrence probability of the target region in the battery pack can be quantitatively evaluated, that is, the risk level of the target region for forming condensation on the surface of the material is determined, and then the condensation prevention and control measures can be actively taken before the condensation is formed, so as to avoid the condensation failure of the battery pack as much as possible. Moreover, through the implementation of the solutions of the present application, the possibility of condensation of each region in the battery pack can be accurately evaluated and quantified based on the working condition data of the battery pack by using the multi-physical field coupling model, so as to avoid the safety hazards of the battery pack caused by the condensation in the dead angle region which cannot be visually observed.

[0117] In addition, the present application also provides a condensation prevention and control system of a battery pack, please refer to Figure 5 , Figure 5 The structure schematic diagram of the condensation prevention and control system of the battery pack provided for some embodiments of the present application, the condensation prevention and control system 500 of the battery pack can be used to implement the condensation prevention and control method of the battery pack in the foregoing embodiments, mainly including a processor 501 and a memory 502. Wherein, the processor 501 is electrically connected with the memory 502.

[0118] The processor 501 is the control center of the condensation prevention and control system 500 of the battery pack, which connects each part of the condensation prevention and control system of the battery pack by using various interfaces and lines, executes various functions of the condensation prevention and control system of the battery pack and processes data by running or calling the computer programs stored in the memory 502 and calling the data stored in the memory 502, so as to perform overall monitoring on the condensation prevention and control system of the battery pack.

[0119] The memory 502 can be used to store software programs and modules, and the processor 501 executes various function applications and data processing by running the computer programs and modules stored in the memory 502. The memory 502 can mainly include a storage program area and a storage data area, wherein the storage program area can store an operating system, at least one computer program required by a function, etc.; the storage data area can store data created according to the use of the condensation prevention and control system of the battery pack, etc.

[0120] In addition, the memory 502 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state memory device. Accordingly, the memory 502 can also include a memory controller to provide the processor 501 with access to the memory 502.

[0121] In the present embodiment, the processor 501 in the condensation prevention and control system 500 of the battery pack will load the instructions corresponding to the processes of one or more computer programs into the memory 502 according to the following steps, and run the computer programs stored in the memory 502 by the processor 501, so as to realize various functions.

[0122] In some embodiments, the condensation prevention and control system of the battery pack further comprises a gas adjusting device in communication with the processor, and the gas adjusting device is also connected with the battery pack for nitrogen replacement with the battery pack. In the present embodiment, when the risk level of condensation of the battery pack is high, the humidity field of the battery pack can be adjusted by the gas adjusting device until the humidity value in the battery pack is controlled within a reasonable range. Through the cooperation between the multi-physical field coupling model and the gas adjusting device, the condensation problem of the battery pack can be improved from the source, and the reliability of the battery pack can be greatly improved.

[0123] Further, in some embodiments, as Figure 6As shown, the gas adjusting device includes an air compressor 601 and a nitrogen replacement host 602. The input pipeline of the nitrogen replacement host 602 is connected with the air compressor 601. The output pipeline of the nitrogen replacement host 602 is connected with the nitrogen filling port 6034 of the battery pack 603. The input pipeline can be provided with a disconnecting ball valve 604. The output pipeline can be provided with a balance valve 605 and a flow meter 606. The nitrogen replacement host 602 is provided with a nitrogen stick 6021, a nitrogen dryer 6022, an air filter 6023 and the like. The battery pack 603 can be provided with a temperature sensor 6031, an oxygen sensor 6032, a pressure sensor 6033 and the like. After the disconnecting ball valve 604 is opened, the air compressor 601 can input nitrogen to the nitrogen replacement host 602 (for example, the air compressor 601 can be controlled to stably output nitrogen with a pressure of 7 Bar to the nitrogen replacement host 602). In the nitrogen replacement host 602, the air source impurities can be filtered through the air filter 6023. The nitrogen can be separated from the air source through the nitrogen stick 6021. The nitrogen can be dried through the nitrogen dryer 6022. Finally, the dry nitrogen is output. After the dry nitrogen is adjusted in pressure through the balance valve 605, the dry nitrogen enters the battery pack 603 from the nitrogen filling port 6034 of the battery pack 603 under the control of the flow meter 606 (for example, the flow is controlled to be 2 L / min). After the nitrogen enters the battery pack 603, the replaced air is discharged through the pressure relief port 6035 of the battery pack 603. The internal air is gradually replaced, so that the humidity in the battery pack 603 is reduced. At the same time, the temperature sensor 6031, the oxygen sensor 6032 and the pressure sensor 6033 can be used for real-time monitoring of the internal environment.

[0124] Please refer to Figure 7 which shows a structure diagram of a computer readable storage medium provided by an embodiment of the present application. The computer readable storage medium 700 stores program code 701. The program code 701 can be called and executed by a processor to perform the method described in the above method embodiments.

[0125] The computer readable storage medium 700 can be an electronic storage such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. Alternatively, the computer readable storage medium 700 includes a non-volatile computer readable medium. The computer readable storage medium 700 has a storage space for program code 701 for performing any of the above methods. These program codes can be read from or written into one or more computer program products. The program code 701 can be compressed in an appropriate form, for example.

[0126] Due to the instructions stored in the storage medium, the steps in any of the battery pack condensation prevention and control methods provided in the embodiments of the present application can be performed, thus the beneficial effects of any of the battery pack condensation prevention and control methods provided in the embodiments of the present application can be achieved, which are described in detail in the foregoing embodiments and will not be repeated here.

[0127] In several embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented by other manners. For example, the apparatus embodiments described above are only schematic, for example, the division of the modules is only a logical function division, and actual implementation can have another division manner, for example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed modules can be indirect coupling or communication connection through some interfaces, apparatuses or modules, and can be electrical, mechanical or other forms.

[0128] The modules described as separate components can or can not be physically separated, and the components displayed as modules can or can not be physical modules, that is, can be located in one place, or can be distributed to a plurality of network modules. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0129] In addition, the functional modules in each embodiment of the present application can be integrated in one processing module, or each module can exist physically, or two or more modules can be integrated in one module. The integrated module can be realized in the form of hardware or in the form of a software functional module.

[0130] If the integrated module is realized in the form of a software functional module and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the whole or part of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the embodiments of the present application.

[0131] It should be noted that, for the foregoing method embodiments, for the convenience of description, they are all described as a combination of a series of actions, but those skilled in the art should know that the present application is not limited to the order of the actions described, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0132] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0133] The above is the description of the condensation prevention and control method, device, system and storage medium of the battery pack provided by the present application. For those skilled in the art, according to the idea of the embodiments of the present application, there will be changes in specific implementation and application range. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method for preventing condensation of a battery pack, characterized by, The method comprises: constructing a multi-physical field coupling model of the battery pack based on temperature field related parameters and humidity field related parameters of the battery pack, wherein the temperature field related parameters at least include theoretical working condition data of the battery pack; inputting initial working condition data of the battery pack into the multi-physical field coupling model to obtain an initial temperature of a material surface corresponding to a target region of the battery pack; based on a dew point temperature of the target region and the initial temperature, determining a risk level of the material surface corresponding to the target region forming condensation, and performing condensation prevention and control on the target region according to the risk level.

2. The condensation preventing method according to claim 1, wherein The method of constructing a multi-physical field coupling model of the battery pack based on temperature field related parameters and humidity field related parameters of the battery pack comprises: determining a temperature field model based on the temperature field related parameters; determining a humidity field model based on the humidity field related parameters; model coupling the temperature field model and the humidity field model to determine the multi-physical field coupling model of the battery pack.

3. The condensation control method according to claim 2, characterized by, The temperature field related parameters further include a fluid velocity field of the battery pack and thermal physical property parameters of materials corresponding to each region in the battery pack, and the thermal physical property parameters at least include a thermal conductivity, a density and a specific heat capacity of the material; The method of determining a temperature field model based on the temperature field related parameters comprises: determining a total heat source term of a first control equation according to the theoretical working condition data, wherein the theoretical working condition data includes a first theoretical heat corresponding to self-heat generation of the battery pack and a second theoretical heat corresponding to an external heat source, and the total heat source term is a sum of the first theoretical heat and the second theoretical heat; determining a heat conduction term of the first control equation according to the thermal conductivity; determining a heat convection term of the first control equation based on the fluid velocity field, the density and the specific heat capacity; determining the temperature field model based on the total heat source term, the heat conduction term and the heat convection term.

4. The condensation preventing method according to claim 3, wherein The method further comprises: obtaining a theoretical working condition current and a theoretical cell resistance of the battery pack; determining the first theoretical heat based on the theoretical working condition current and the theoretical cell resistance of the battery pack.

5. The condensation preventing method according to claim 3, wherein The temperature field related parameters further include a first convective heat transfer coefficient; The method further comprises: determining a first boundary condition of the temperature field model based on the thermal physical property parameters and the first convective heat transfer coefficient; determining a first target output result of the first control equation based on the first boundary condition.

6. The condensation preventing method according to claim 2, wherein The humidity field related parameters include a humidity diffusion coefficient, a fluid velocity field cumulative term and a humidity source term of the battery pack, the cumulative term is used to indicate a humidity change rate over time, and the humidity source term is used to indicate a humidity generation rate or a humidity consumption rate per unit volume per unit time of the battery pack; The method of determining a humidity field model based on the humidity field related parameters comprises: determining a diffusion term of a second control equation based on the humidity diffusion coefficient; determining a convective transport term of the second control equation based on the fluid velocity field; determining the humidity field model based on the diffusion term, the convective transport term, the cumulative term and the humidity source term.

7. The condensation control method according to claim 6, wherein The humidity field related parameter further includes a second convective heat transfer coefficient; the method further includes: determining a second boundary condition of the humidity field model based on the second convective heat transfer coefficient; determining a second target output result of the second control equation based on the second boundary condition.

8. The condensation control method according to claim 2, wherein The model coupling of the temperature field model and the humidity field model to determine the multi-physical field coupling model of the battery pack includes: identifying a correlation factor between the temperature field model and the humidity field model; embedding a quantitative relationship of the correlation factor into the temperature field model and the humidity field model respectively to determine a bidirectional data interaction logic between the temperature field model and the humidity field model; based on the bidirectional data interaction logic, bidirectionally correcting parameters of the temperature field model and the humidity field model to obtain a converged multi-physical field coupling model of the battery pack.

9. The condensation control method according to claim 8, characterized in that, The method further includes: based on the multi-physical field coupling model, performing finite element mesh division on the three-dimensional geometric model of the battery pack to obtain a finite element mesh model, wherein the finite element mesh model includes grid cells corresponding to each region of the battery pack respectively; loading the multi-physical field coupling model to the finite element mesh model for simulation processing to obtain a simulation result, and determining a solution coupling model corresponding to each grid cell of the three-dimensional geometric model based on the simulation result, wherein each solution coupling model is used to determine the material surface temperature of the corresponding grid cell under different working conditions.

10. The condensation control method according to claim 9, characterized in that, The method further includes: comparing the simulation result of the multi-physical field coupling model with the actual measurement result of the battery pack to obtain an error comparison result, wherein the simulation result includes the simulation temperature of the material surface of each grid cell under all working conditions, and the actual measurement result includes the measured temperature of the material surface of the region corresponding to each grid cell in the battery pack under all working conditions; correcting the relevant solution coupling model according to the error comparison result to obtain a corrected target solution coupling model, wherein the relevant solution coupling model includes all the solution coupling models that cause the error.

11. The condensation control method according to claim 1, characterized in that, The method further includes: inputting the dew point temperature of the target region and the initial temperature into a preset condensation probability evaluation model to determine the condensation occurrence probability of the target region; determining the risk level of the target region corresponding to the material surface forming condensation according to the condensation occurrence probability.

12. The condensation control method according to claim 1, characterized in that, The method further includes: obtaining the water vapor temperature and humidity ratio and the environment temperature in the environment where the target region is located; determining the dew point temperature of the target region based on the water vapor temperature and humidity ratio and the environment temperature.

13. The condensation control method according to claim 1, characterized in that, The battery pack is connected with a gas adjusting device; The condensation prevention and control of the target region according to the risk level includes: controlling the gas adjusting device and the battery pack to replace nitrogen to adjust the humidity field of the battery pack; acquire a real-time humidity value of the battery pack, and determine the real-time humidity value as real-time working condition data of the battery pack; input the real-time working condition data into the multi-physical field coupling model to output a real-time temperature of a material surface of the target region; redetermine a risk level of the target region from condensation based on a dew point temperature of the target region and the real-time temperature; if the redetermined risk level does not satisfy a preset condensation prevention and control condition of the battery pack, control the gas adjusting device to stop nitrogen replacement operation.

14. A condensation prevention and control device for a battery pack, comprising: comprise: a construction module configured to construct a multi-physical field coupling model of the battery pack based on temperature field related parameters and humidity field related parameters of the battery pack, wherein the temperature field related parameters at least include theoretical working condition data of the battery pack; a determination module configured to input initial working condition data of the battery pack into the multi-physical field coupling model to obtain an initial temperature of a material surface corresponding to a target region of the battery pack; a prevention and control module configured to determine a risk level of the material surface corresponding to the target region from condensation based on a dew point temperature of the target region and the initial temperature, and perform condensation prevention and control on the target region according to the risk level.

15. A condensation control system for a battery pack, characterized in that, comprise a memory and a processor, wherein the processor is configured to execute a determination program stored in the memory; when the processor executes the determination program, the steps in the condensation prevention and control method according to any one of claims 1 to 13 are implemented.

16. The condensation control system of claim 15, wherein further comprise a gas adjusting device in communication connection with the processor, and the gas adjusting device is further connected with the battery pack for nitrogen replacement with the battery pack.

17. A deterministic machine-readable storage medium having a deterministic machine program stored thereon, characterized in that, when the determination program is executed by the processor, the steps in the condensation prevention and control method according to any one of claims 1 to 13 are implemented.

Images