Battery cover plate explosion-proof valve area calculation method and device and electronic equipment

Abstract

The application discloses a battery cover plate explosion-proof valve area calculation method and device and electronic equipment. The method comprises the following steps: obtaining test data of a battery to be measured under thermal runaway test conditions; determining a first theoretical model among an explosion-proof valve area, an explosion-proof valve inner side trigger temperature and a theoretical maximum volume flow of the explosion-proof valve according to the choked flow theory; then, calculating a target gas production rate peak value in a thermal runaway state; and finally, calculating the theoretical safety area of the explosion-proof valve of the battery to be measured according to the first theoretical model and the target gas production rate peak value. The scientific calculation of the explosion-proof valve area is realized, the subjectivity of traditional experience design is got rid of, the accuracy of the calculation result is greatly improved, the safety, cost and structural strength are taken into account, the problems of design deficiency or overdesign are effectively avoided, reliable theoretical support is provided for the safety design of the power battery, the risk of battery explosion and fire in the thermal runaway process is significantly reduced, and the overall safety performance of the battery is improved.

Description

Technical Field

[0001] This specification relates to one or more embodiments in the field of battery safety technology, and in particular to a method for calculating the area of ​​an explosion-proof valve on a battery cover. Background Technology

[0002] In recent years, with the rapid development of new energy vehicles, the safety of power batteries has received increasing attention. Especially in the event of thermal runaway, a large amount of heat and gas is generated inside the battery. If the pressure cannot be released in time, it could potentially trigger serious catastrophic accidents such as explosions and fires. To address this issue, current single-cell batteries typically have explosion-proof valves installed on their covers. When a thermal runaway event occurs, as the internal pressure of the battery accumulates, once a pre-set opening pressure threshold is reached, the explosion-proof valve automatically opens to release pressure, effectively preventing the internal pressure of the battery from exceeding the limit. However, the area of ​​the explosion-proof valve directly affects its safety protection effect. If the area is too small, insufficient pressure release may lead to an explosion; if the area is too large, it reduces structural strength and increases costs. Currently, the design of existing explosion-proof valve areas is mainly based on competitive product analysis and engineers' experience, lacking theoretical basis and failing to form a theoretical system with practical guiding significance. This results in design subjectivity and reduces user satisfaction. Summary of the Invention

[0003] This application provides a method, apparatus, and electronic device for calculating the explosion-proof valve area of ​​a battery cover, the technical solution of which is as follows:

[0004] In a first aspect, embodiments of this application provide a method for calculating the area of ​​the explosion-proof valve on a battery cover, the method comprising:

[0005] Acquire test data of the battery model under thermal runaway test conditions, including the trigger temperature inside the explosion-proof valve and the peak gas generation rate inside the cavity;

[0006] A first theoretical model is used to determine the relationship between the explosion-proof valve area, the inner trigger temperature of the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve based on the congestion flow theory.

[0007] The target peak gas production rate under thermal runaway state is calculated based on the inner trigger temperature of the explosion-proof valve, the peak gas production rate in the cavity, and the standard thermal runaway test parameters. The standard thermal runaway test parameters include the thermal runaway test environment pressure, the thermal runaway test environment temperature, and the downstream outlet pressure of the explosion-proof valve.

[0008] Under the thermal runaway state, the theoretical safe area of ​​the explosion-proof valve of the battery under test is calculated based on the first theoretical model and the target peak gas production rate.

[0009] Secondly, a device for calculating the area of ​​an explosion-proof valve on a battery cover is provided, the device comprising:

[0010] The acquisition module is used to acquire test data of the battery under test model under thermal runaway test conditions. The test data includes the trigger temperature inside the explosion-proof valve and the peak gas generation rate inside the cavity.

[0011] The determination module is used to determine a first theoretical model between the explosion-proof valve area, the inner trigger temperature of the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve based on the congestion flow theory;

[0012] The testing module is used to calculate the target peak gas production rate under thermal runaway state based on the trigger temperature inside the explosion-proof valve, the peak gas production rate in the cavity, and standard thermal runaway test parameters. The standard thermal runaway test parameters include thermal runaway test environment pressure, thermal runaway test environment temperature, and downstream outlet pressure of the explosion-proof valve.

[0013] The calculation module is used to calculate the theoretical safe area of ​​the explosion-proof valve of the battery under test model based on the first theoretical model and the target peak gas production rate under the thermal runaway state.

[0014] Thirdly, an electronic device is provided, including a device processor and a memory;

[0015] The device processor is connected to the memory;

[0016] The memory is used to store executable program code;

[0017] The device processor runs a program corresponding to the executable program code stored in the memory to perform the steps of the method provided as in the first aspect or any possible implementation thereof.

[0018] Fourthly, a computer-readable storage medium is provided having a computer program stored thereon, the computer-readable storage medium storing instructions that, when executed on a computer or device processor, cause the computer or device processor to perform the method provided as in the first aspect or any possible implementation thereof.

[0019] The beneficial effects of the technical solutions provided in some embodiments of this application include at least the following:

[0020] In one or more embodiments of this application, test data of the battery under test model is obtained under thermal runaway test conditions. Then, a first theoretical model is determined based on the congestion flow theory to establish the relationship between the explosion-proof valve area, the explosion-proof valve inner trigger temperature, and the theoretical maximum volumetric flow rate of the explosion-proof valve. Next, the target gas generation rate peak under thermal runaway state is calculated based on the explosion-proof valve inner trigger temperature, the peak gas generation rate in the cavity, and standard thermal runaway test parameters. Finally, the theoretical safe area of ​​the explosion-proof valve of the battery under test model is calculated based on the first theoretical model and the target gas generation rate peak. This achieves scientific calculation of the explosion-proof valve area, eliminates the subjectivity of traditional empirical design, significantly improves the accuracy of the calculation results, and balances safety, cost, and structural strength. It effectively avoids the problems of under-design or over-design, providing reliable theoretical support for the safe design of power batteries. It can significantly reduce the risk of battery explosion and fire during thermal runaway and improve the overall safety performance of the battery. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A flowchart illustrating a method for calculating the area of ​​an explosion-proof valve on a battery cover, provided in this application embodiment;

[0023] Figure 2 A schematic diagram of the structure of an explosion-proof valve area calculation device for a battery cover provided in an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0025] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0026] The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0027] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made to the function and arrangement of the described elements without departing from the scope of this application. Various processes or components may be appropriately omitted, substituted, or added to the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

[0028] Please see Figure 1 , Figure 1 The diagram shows an overall flowchart of a method for calculating the area of ​​an explosion-proof valve on a battery cover according to an embodiment of this application.

[0029] like Figure 1 As shown, the method for calculating the explosion-proof valve area of ​​the battery cover may include at least the following steps:

[0030] Step 101: Obtain test data of the battery model under thermal runaway test conditions.

[0031] The above includes the inner trigger temperature of the explosion-proof valve and the peak value of the gas generation rate inside the cavity.

[0032] In this embodiment, to calculate the safe area of ​​the explosion-proof valve based on the gas generation under thermal runaway conditions, it is first necessary to obtain the basic test data collected during the standard thermal runaway test of the battery model under test. This data serves as the input basis for all subsequent theoretical calculations. In practical applications, thermal runaway testing can be different types of trigger tests, such as nail penetration testing, heating testing, and overcharge testing, as long as the battery thermal runaway process can be simulated and the corresponding gas generation and temperature data can be collected. Among them, the trigger temperature inside the explosion-proof valve in the test data refers to the temperature value of the battery's interior near the inside of the explosion-proof valve at the moment the explosion-proof valve opens during the thermal runaway process. This temperature directly affects the maximum gas flow rate under the subsequent choke flow state. The peak gas generation rate inside the cavity in the test data is the maximum value of the gas generation rate inside the battery during the thermal runaway process. This value determines the maximum gas flow rate that needs to be discharged during the depressurization process and is the core indicator for evaluating the depressurization capability of the explosion-proof valve.

[0033] When obtaining the trigger temperature inside the explosion-proof valve, a temperature sensor can be placed upstream of the explosion-proof valve and in the gas phase region inside the battery cell to obtain the temperature change curve over time, and the temperature value corresponding to the peak gas production rate is taken. When a large-diameter explosion-proof valve is used for unlimited flow and pressure-free thermal runaway testing, the exhaust is unobstructed during the test, and there is no pressure accumulation or adiabatic compression effect inside the battery cell. The measured trigger temperature inside the explosion-proof valve is the intrinsic temperature of the battery cell, which is determined only by the battery cell material system and the degree of thermal runaway response, and is independent of the explosion-proof valve area. It has universality and can be used as a unified parameter for theoretical calculations of different explosion-proof valve areas.

[0034] When obtaining the peak gas generation rate in the cavity, the constant volume sealed tank method is used for testing. During the test, a large-size explosion-proof valve with a flow capacity significantly greater than the maximum gas generation rate of the cell is used (which can be determined by fluid simulation method) to ensure that the valve port is not restricted and the cell is not pressurized. At this time, the gas generation rate measured is determined only by the thermal runaway reaction of the cell itself and is independent of the area of ​​the explosion-proof valve, which is the intrinsic gas generation rate of the cell.

[0035] Step 103: Determine the first theoretical model between the explosion-proof valve area, the inner trigger temperature of the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve based on the congestion flow theory.

[0036] In this embodiment, after obtaining the basic test data, to establish a quantitative relationship between the explosion-proof valve area and gas flow rate and temperature, a corresponding theoretical model can be constructed based on the choke flow theory to describe the physical laws of gas flow during thermal runaway pressure relief, providing theoretical support for subsequent area calculation. During thermal runaway pressure relief, when the ratio of the internal pressure to the external pressure of the battery exceeds the critical pressure ratio, the gas flow at the explosion-proof valve will enter a choke flow state. At this time, the gas velocity will reach the speed of sound and will no longer increase with the increase of the internal and external pressure difference. This is the limiting state of gas flow during pressure relief. The model established based on this can ensure that the calculated explosion-proof valve area can cover the most stringent pressure relief requirements. Through this first theoretical model, a quantitative relationship between the explosion-proof valve area, trigger temperature, and maximum pressure relief flow rate can be directly established, providing a core theoretical basis for subsequent area calculation.

[0037] In one possible implementation, the first theoretical model for determining the relationship between the explosion-proof valve area, the explosion-proof valve inner trigger temperature, and the explosion-proof valve's theoretical maximum volumetric flow rate based on congestion flow theory includes:

[0038] A second theoretical model is determined based on the choke flow theory to establish the relationship between the inner trigger temperature of the explosion-proof valve and the maximum flow velocity at the choke critical point.

[0039] A third theoretical model is established to determine the relationship between the maximum flow velocity at the choking critical point, the area of ​​the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0040] By integrating the second theoretical model and the third theoretical model, a first theoretical model is obtained relating the explosion-proof valve area, the explosion-proof valve inner trigger temperature, and the explosion-proof valve's theoretical maximum volumetric flow rate.

[0041] In this embodiment, firstly, since the gas velocity reaches the speed of sound at the choking critical point, and the speed of sound is directly related to the gas temperature, a second theoretical model can be determined based on choking flow theory regarding the relationship between the inner trigger temperature of the explosion-proof valve and the maximum flow velocity at the choking critical point. This model describes the influence of gas temperature on its maximum flow velocity under choking flow conditions. Specifically, the formula for this second theoretical model can be expressed as:

[0042]

[0043] Among them, among them, The maximum flow velocity at the critical point of congestion. The trigger temperature inside the explosion-proof valve. The specific heat ratio of the gas mixture. The gas constant is used as the specific gas velocity. Using the second theoretical model, the maximum gas velocity under choked flow conditions can be directly calculated from the temperature parameters.

[0044] Next, a third theoretical model is established to describe the maximum pressure relief flow rate that different explosion-proof valve areas can provide at the maximum flow rate, i.e., the maximum gas volume that can be discharged per unit time. Finally, by integrating these two sub-models, and replacing the maximum flow rate at the choking critical point with an equivalent intermediate quantity, a first theoretical model is obtained to determine the relationship between the explosion-proof valve area, the explosion-proof valve inner trigger temperature, and the explosion-proof valve's theoretical maximum volumetric flow rate. This model directly establishes the quantitative relationship between the core parameters.

[0045] In one possible implementation, the third theoretical model for determining the relationship between the maximum flow velocity at the choking critical point, the explosion-proof valve area, and the theoretical maximum volumetric flow rate of the explosion-proof valve includes:

[0046] Determine the flow loss coefficient and melt blockage loss coefficient corresponding to the battery model under test;

[0047] Calculate the product data between the maximum flow velocity at the choking critical point, the explosion-proof valve area, the flow loss coefficient, and the melt blockage loss coefficient;

[0048] The third theoretical model is determined based on the product data and the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0049] In this embodiment, when constructing the third theoretical model, various loss factors exist in the actual pressure relief process. Therefore, it is necessary to introduce corresponding loss coefficients to correct the theoretical calculation results under ideal conditions, making the model more consistent with the actual pressure relief scenario and avoiding deviations between the ideal model and the actual situation. Specifically, the flow loss coefficient corresponding to the battery model under test can be determined first. and melt blockage loss coefficient In this case, because the actual gas stream will contract due to inertia when passing through the explosion-proof valve opening, and friction on the channel wall will also lose some flow energy, resulting in stream loss, a coefficient is set. The melt blockage loss coefficient is used to account for flow losses caused by flow stream contraction and channel friction during actual flow processes. This is used to account for flow losses caused by the melting of the lower plastic inside the battery and the blockage of the pressure relief channels by the electrode contents during thermal runaway. These are unique loss factors in thermal runaway scenarios. Next, the product of the maximum flow velocity at the choking critical point, the explosion-proof valve area, the flow loss coefficient, and the molten material blockage loss coefficient is calculated. Since this product corresponds to the maximum volumetric flow rate achievable by the explosion-proof valve area under actual conditions, the third theoretical model can be determined based on this product and the theoretical maximum volumetric flow rate of the explosion-proof valve. The specific model formula can be expressed as:

[0050]

[0051] in, S represents the theoretical maximum volumetric flow rate of the explosion-proof valve, and S represents the area of ​​the explosion-proof valve. The maximum flow velocity at the critical point of congestion. The stream loss coefficient is... This is the melt blockage loss coefficient. As an example, 0.5 is acceptable. 0.6 is acceptable.

[0052] Step 105: Calculate the target gas production rate peak under thermal runaway state based on the inner trigger temperature of the explosion-proof valve, the peak gas production rate in the cavity, and the standard thermal runaway test parameters.

[0053] The standard thermal runaway test parameters include thermal runaway test environment pressure, thermal runaway test environment temperature, and downstream outlet pressure of the explosion-proof valve.

[0054] In this embodiment, after constructing the theoretical model, the gas production rate obtained from the thermal runaway test can be converted into the target peak gas production rate under actual thermal runaway depressurization conditions. Since the gas production rate obtained from the test is a value under test environmental conditions, and the temperature and pressure conditions during the actual depressurization process differ from the test environment, a state conversion is required to obtain the true gas production rate under the actual depressurization scenario, which serves as the basis for evaluating the depressurization flow rate. Specifically, this conversion process can be performed based on the ideal gas law, because the gas during thermal runaway can be approximated as an ideal gas, and its pressure, volume, and temperature satisfy the ideal gas state change law. This law allows the gas production rate under test conditions to be converted into a value under actual depressurization conditions, ensuring the accuracy of subsequent calculations.

[0055] In one possible implementation, calculating the target gas production rate peak under thermal runaway conditions based on the inner trigger temperature of the explosion-proof valve, the peak gas production rate within the cavity, and standard thermal runaway test parameters includes:

[0056] The trigger temperature on the outside of the explosion-proof valve corresponding to the trigger temperature on the inside of the explosion-proof valve is determined based on the temperature conversion between the inside and outside of the explosion-proof valve.

[0057] The target peak gas production rate under thermal runaway conditions is calculated based on the trigger temperature outside the explosion-proof valve, the peak gas production rate inside the cavity, and the standard thermal runaway test parameters.

[0058] In this embodiment, considering the differences in temperature acquisition locations during testing, the temperature parameters need to be converted first, followed by a state conversion of the gas production rate, to adapt to different temperature acquisition scenarios. Specifically, the trigger temperature of the explosion-proof valve corresponding to the trigger temperature of the inner side of the explosion-proof valve can be determined based on the temperature conversion between the inner and outer sides of the explosion-proof valve. Since in some test scenarios, the temperature of the inner side of the explosion-proof valve is acquired, while the subsequent gas production rate conversion requires the use of the outer temperature parameters, a corresponding conversion is necessary. According to a large amount of test data statistics, this conversion coefficient is approximately 0.833, i.e.:

[0059]

[0060] in, The trigger temperature is the temperature outside the explosion-proof valve. This is the trigger temperature inside the explosion-proof valve.

[0061] Next, the target peak gas production rate under thermal runaway state is calculated based on the trigger temperature outside the explosion-proof valve, the peak gas production rate inside the cavity, and the standard thermal runaway test parameters. This completes the conversion of test data to actual state data, ensuring that the parameters input into the model are consistent with the actual pressure relief scenario.

[0062] In one possible implementation, calculating the target gas production rate peak under thermal runaway conditions based on the trigger temperature outside the explosion-proof valve, the peak gas production rate inside the cavity, and standard thermal runaway test parameters includes:

[0063] The first product result is obtained by multiplying the trigger temperature outside the explosion-proof valve, the peak gas generation rate inside the cavity, and the pressure of the thermal runaway test environment.

[0064] The second product result is obtained by multiplying the thermal runaway test environment temperature and the downstream outlet pressure of the explosion-proof valve.

[0065] The target gas production rate peak under thermal runaway state is obtained by calculating the ratio of the first product result and the second product result.

[0066] In this embodiment, after obtaining the trigger temperature outside the explosion-proof valve, the converted target gas production rate peak value can be calculated based on the ideal gas law by multiplying and rationing the parameters. Specifically, the trigger temperature T outside the explosion-proof valve and the peak gas production rate inside the cavity can be calculated first. Thermal runaway test environment pressure The product calculation yields the first product result, which corresponds to the product of the gas state parameters under the test conditions. Next, the thermal runaway test environment temperature is... and the downstream outlet pressure of the explosion-proof valve A product calculation is performed to obtain the second product result, which corresponds to the product of state parameters under actual depressurization conditions. Finally, the ratio of the first and second product results is calculated, and combined with the temperature conversion coefficient, to obtain the target peak gas production rate under thermal runaway conditions. The specific formula can be expressed as:

[0067]

[0068] in, For thermal runaway test environment pressure, The ambient temperature for thermal runaway testing. For the downstream outlet pressure of the explosion-proof valve, The peak gas production rate inside the cavity was obtained during the test.

[0069] Step 107: Under the thermal runaway state, calculate the theoretical safe area of ​​the explosion-proof valve of the battery under test based on the first theoretical model and the target gas production rate peak value.

[0070] In this embodiment, after obtaining the target peak gas production rate, the theoretical safe area of ​​the explosion-proof valve that meets the pressure relief requirements can be calculated using the previously constructed first theoretical model. This area is the minimum area that ensures timely gas discharge during thermal runaway, thus avoiding insufficient pressure relief due to an excessively small area and theoretically ensuring the safety of the battery during thermal runaway. Specifically, the target peak gas production rate can be used as the maximum volumetric flow rate that the explosion-proof valve needs to achieve. This can be substituted into the first theoretical model, and the corresponding explosion-proof valve area can be obtained by reverse calculation. This area is the theoretically minimum safe area that can meet the pressure relief requirements, ensuring that the maximum gas production rate of the battery does not exceed the maximum pressure relief capacity of the explosion-proof valve and preventing the continuous accumulation of internal pressure.

[0071] In one possible implementation, the step of calculating the theoretical safe area of ​​the explosion-proof valve of the battery under test based on the first theoretical model and the target peak gas production rate under the thermal runaway state includes:

[0072] Under the thermal runaway state, the theoretical maximum volumetric flow rate of the explosion-proof valve is determined based on the target peak gas production rate.

[0073] Based on the first theoretical model, determine the theoretical safe area of ​​the explosion-proof valve corresponding to the battery model under test at the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0074] In this embodiment of the application, under thermal runaway conditions, in order to ensure that the pressure inside the battery does not continue to accumulate, the maximum pressure relief flow rate of the explosion-proof valve must be at least equal to the maximum gas production rate of the battery. The theoretical maximum volumetric flow rate of the explosion-proof valve can be determined based on the peak value of the target gas production rate. Therefore, the peak value of the target gas production rate can be used as the theoretical maximum volumetric flow rate that the explosion-proof valve needs to achieve, that is, let This ensures that the pressure relief capacity matches the gas production demand. Next, the theoretical safe area of ​​the explosion-proof valve corresponding to the theoretical maximum volumetric flow rate of the battery model under test can be determined based on the first theoretical model. Specifically, the above relationship can be substituted into the first theoretical model and solved in reverse to obtain:

[0075]

[0076] in, The theoretical safe area of ​​the explosion-proof valve is the minimum safe pressure relief area. As long as the area of ​​the explosion-proof valve is not less than this value, it can ensure that the gas can be discharged in time during thermal runaway and avoid excessive internal pressure.

[0077] In one possible implementation, the method further includes:

[0078] Receive security level instructions and determine the security redundancy coefficient corresponding to the security level instructions based on the security redundancy database;

[0079] The design area of ​​the explosion-proof valve is determined based on the safety redundancy coefficient and the theoretical safe area of ​​the explosion-proof valve.

[0080] In this embodiment, to meet the safety requirements of different scenarios, a safety redundancy coefficient can be introduced to correct the theoretical safety area, resulting in the final explosion-proof valve design area. This adapts to different application scenarios, balancing safety and cost. Specifically, a user-inputted safety level command can be received first. This command indicates the required safety level for the current battery, such as different safety levels like automotive power level or energy storage level, as different application scenarios have different safety requirements. Then, based on the safety redundancy database, the safety redundancy coefficient corresponding to the safety level command is determined. This database stores redundancy coefficients corresponding to different safety levels, derived from extensive test data and industry standard statistics. For example, the redundancy coefficient for high-safety-level automotive power batteries can be set to 1.25, while for energy storage batteries, it can be set to 1.1, and so on. Furthermore, the final explosion-proof valve design area is determined based on the safety redundancy coefficient and the theoretical safe area of ​​the explosion-proof valve. The specific formula is as follows:

[0081]

[0082] By following the above steps, the design area of ​​the explosion-proof valve can be flexibly adjusted according to different safety requirements, which not only ensures safety but also avoids cost and structural strength problems caused by over-design, thus improving the versatility and flexibility of the method.

[0083] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0084] Please refer to the following. Figure 2 , Figure 2 A schematic diagram of the structure of a battery cover explosion-proof valve area calculation device provided in an embodiment of this application is shown. It should be noted that... Figure 2 The explosion-proof valve area calculation device shown for the battery cover is used to perform the functions described in this application. Figure 1 The methods shown in the embodiments are for illustrative purposes only, illustrating the parts relevant to the embodiments of this application. For specific technical details not disclosed, please refer to this application. Figure 1 The example shown.

[0085] like Figure 2 As shown, the explosion-proof valve area calculation device for the battery cover may include at least:

[0086] The acquisition module 201 is used to acquire test data of the battery under test model under thermal runaway test conditions. The test data includes the trigger temperature inside the explosion-proof valve and the peak gas generation rate inside the cavity.

[0087] The determination module 202 is used to determine a first theoretical model between the explosion-proof valve area, the inner trigger temperature of the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve based on the congestion flow theory.

[0088] Test module 203 is used to calculate the target gas production rate peak under thermal runaway state based on the inner trigger temperature of the explosion-proof valve, the peak gas production rate in the cavity, and standard thermal runaway test parameters. The standard thermal runaway test parameters include thermal runaway test environment pressure, thermal runaway test environment temperature, and downstream outlet pressure of the explosion-proof valve.

[0089] The calculation module 204 is used to calculate the theoretical safe area of ​​the explosion-proof valve of the battery under test based on the first theoretical model and the target peak gas production rate under the thermal runaway state.

[0090] In one possible implementation, the determining module 202 is specifically used for:

[0091] A second theoretical model is determined based on the choke flow theory to establish the relationship between the inner trigger temperature of the explosion-proof valve and the maximum flow velocity at the choke critical point.

[0092] A third theoretical model is established to determine the relationship between the maximum flow velocity at the choking critical point, the area of ​​the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0093] By integrating the second theoretical model and the third theoretical model, a first theoretical model is obtained relating the explosion-proof valve area, the explosion-proof valve inner trigger temperature, and the explosion-proof valve's theoretical maximum volumetric flow rate.

[0094] In one possible implementation, the determining module 202 is further configured to:

[0095] Determine the flow loss coefficient and melt blockage loss coefficient corresponding to the battery model under test;

[0096] Calculate the product data between the maximum flow velocity at the choking critical point, the explosion-proof valve area, the flow loss coefficient, and the melt blockage loss coefficient;

[0097] The third theoretical model is determined based on the product data and the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0098] In one possible implementation, the test module 203 is specifically used for:

[0099] The trigger temperature on the outside of the explosion-proof valve corresponding to the trigger temperature on the inside of the explosion-proof valve is determined based on the temperature conversion between the inside and outside of the explosion-proof valve.

[0100] The target peak gas production rate under thermal runaway conditions is calculated based on the trigger temperature outside the explosion-proof valve, the peak gas production rate inside the cavity, and the standard thermal runaway test parameters.

[0101] In one possible implementation, the test module 203 is further configured to:

[0102] The first product result is obtained by multiplying the trigger temperature outside the explosion-proof valve, the peak gas generation rate inside the cavity, and the pressure of the thermal runaway test environment.

[0103] The second product result is obtained by multiplying the thermal runaway test environment temperature and the downstream outlet pressure of the explosion-proof valve.

[0104] The target gas production rate peak under thermal runaway state is obtained by calculating the ratio of the first product result and the second product result.

[0105] In one possible implementation, the computing module 204 is specifically used for:

[0106] Under the thermal runaway state, the theoretical maximum volumetric flow rate of the explosion-proof valve is determined based on the target peak gas production rate.

[0107] Based on the first theoretical model, determine the theoretical safe area of ​​the explosion-proof valve corresponding to the battery model under test at the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0108] In one possible implementation, the computing module 204 is further configured to:

[0109] Receive security level instructions and determine the security redundancy coefficient corresponding to the security level instructions based on the security redundancy database;

[0110] The design area of ​​the explosion-proof valve is determined based on the safety redundancy coefficient and the theoretical safe area of ​​the explosion-proof valve.

[0111] Those skilled in the art will clearly understand that the technical solutions of the embodiments of this application can be implemented by means of software and / or hardware. In this application, "unit" and "module" refer to software and / or hardware that can independently complete or cooperate with other components to complete a specific function, wherein the hardware may be, for example, a field-programmable gate array (FPGA), an integrated circuit (IC), etc.

[0112] Each processing unit and / or module in the embodiments of this application can be implemented by an analog circuit that implements the functions described in the embodiments of this application, or by software that executes the functions described in the embodiments of this application.

[0113] Please refer to the following. Figure 3 , Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown.

[0114] like Figure 3As shown, the electronic device 300 may include at least one device processor 301, at least one network interface 304, a user interface 303, a memory 305, and at least one communication bus 302.

[0115] The communication bus 302 can be used to realize the connection and communication of the above components.

[0116] The user interface 303 may include buttons, and the optional user interface may also include a standard wired interface or a wireless interface.

[0117] The network interface 304 may include, but is not limited to, Bluetooth modules, NFC modules, Wi-Fi modules, etc.

[0118] The device processor 301 may include one or more processing cores. The device processor 301 connects to various parts within the electronic device 300 using various interfaces and lines. It executes various functions and processes data of the electronic device 300 by running or executing instructions, programs, code sets, or instruction sets stored in the memory 305, and by calling data stored in the memory 305. Optionally, the device processor 301 may be implemented using at least one hardware form of DSP, FPGA, or PLA. The device processor 301 may integrate one or more of the following: CPU, GPU, and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for display; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the device processor 301 and may be implemented as a separate chip.

[0119] The memory 305 may include RAM or ROM. Optionally, the memory 305 may include a non-transitory computer-readable medium. The memory 305 may be used to store instructions, programs, code, code sets, or instruction sets. The memory 305 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-described method embodiments, etc.; the data storage area may store data involved in the above-described method embodiments, etc. Optionally, the memory 305 may also be at least one storage device located remotely from the aforementioned device processor 301. Figure 3 As shown, the memory 305, which serves as a computer storage medium, may include an operating system, a network communication module, a user interface module, and program instructions.

[0120] Specifically, the device processor 301 can be used to call the explosion-proof valve area calculation application for the battery cover stored in the memory 305, and specifically perform the following operations:

[0121] Acquire test data of the battery model under thermal runaway test conditions, including the trigger temperature inside the explosion-proof valve and the peak gas generation rate inside the cavity;

[0122] A first theoretical model is used to determine the relationship between the explosion-proof valve area, the inner trigger temperature of the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve based on the congestion flow theory.

[0123] The target peak gas production rate under thermal runaway state is calculated based on the inner trigger temperature of the explosion-proof valve, the peak gas production rate in the cavity, and the standard thermal runaway test parameters. The standard thermal runaway test parameters include the thermal runaway test environment pressure, the thermal runaway test environment temperature, and the downstream outlet pressure of the explosion-proof valve.

[0124] Under the thermal runaway state, the theoretical safe area of ​​the explosion-proof valve of the battery under test is calculated based on the first theoretical model and the target peak gas production rate.

[0125] As an optional embodiment of this application, the first theoretical model for determining the relationship between the explosion-proof valve area, the inner trigger temperature of the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve based on the congestion flow theory includes:

[0126] A second theoretical model is determined based on the choke flow theory to establish the relationship between the inner trigger temperature of the explosion-proof valve and the maximum flow velocity at the choke critical point.

[0127] A third theoretical model is established to determine the relationship between the maximum flow velocity at the choking critical point, the area of ​​the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0128] By integrating the second theoretical model and the third theoretical model, a first theoretical model is obtained relating the explosion-proof valve area, the explosion-proof valve inner trigger temperature, and the explosion-proof valve's theoretical maximum volumetric flow rate.

[0129] As an optional embodiment of this application, the third theoretical model for determining the relationship between the maximum flow velocity at the choking critical point, the explosion-proof valve area, and the theoretical maximum volumetric flow rate of the explosion-proof valve includes:

[0130] Determine the flow loss coefficient and melt blockage loss coefficient corresponding to the battery model under test;

[0131] Calculate the product data between the maximum flow velocity at the choking critical point, the explosion-proof valve area, the flow loss coefficient, and the melt blockage loss coefficient;

[0132] The third theoretical model is determined based on the product data and the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0133] As an optional embodiment of this application, the step of calculating the target gas production rate peak under thermal runaway state based on the inner trigger temperature of the explosion-proof valve, the peak gas production rate in the cavity, and standard thermal runaway test parameters includes:

[0134] The trigger temperature on the outside of the explosion-proof valve corresponding to the trigger temperature on the inside of the explosion-proof valve is determined based on the temperature conversion between the inside and outside of the explosion-proof valve.

[0135] The target peak gas production rate under thermal runaway conditions is calculated based on the trigger temperature outside the explosion-proof valve, the peak gas production rate inside the cavity, and the standard thermal runaway test parameters.

[0136] As an optional embodiment of this application, the step of calculating the target gas production rate peak under thermal runaway state based on the trigger temperature outside the explosion-proof valve, the peak gas production rate in the cavity, and standard thermal runaway test parameters includes:

[0137] The first product result is obtained by multiplying the trigger temperature outside the explosion-proof valve, the peak gas generation rate inside the cavity, and the pressure of the thermal runaway test environment.

[0138] The second product result is obtained by multiplying the thermal runaway test environment temperature and the downstream outlet pressure of the explosion-proof valve.

[0139] The target gas production rate peak under thermal runaway state is obtained by calculating the ratio of the first product result and the second product result.

[0140] As an optional embodiment of this application, the step of calculating the theoretical safe area of ​​the explosion-proof valve of the battery under test based on the first theoretical model and the target peak gas production rate under the thermal runaway state includes:

[0141] Under the thermal runaway state, the theoretical maximum volumetric flow rate of the explosion-proof valve is determined based on the target peak gas production rate.

[0142] Based on the first theoretical model, determine the theoretical safe area of ​​the explosion-proof valve corresponding to the battery model under test at the theoretical maximum volumetric flow rate of the explosion-proof valve.

[0143] As an optional embodiment of this application, the method further includes:

[0144] Receive security level instructions and determine the security redundancy coefficient corresponding to the security level instructions based on the security redundancy database;

[0145] The design area of ​​the explosion-proof valve is determined based on the safety redundancy coefficient and the theoretical safe area of ​​the explosion-proof valve.

[0146] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the above-described method. The computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives, as well as magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0147] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0148] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0149] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0150] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0151] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0152] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0153] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0154] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for calculating the explosion-proof valve area of ​​a battery cover, characterized in that, The method includes: Acquire test data of the battery model under thermal runaway test conditions, including the trigger temperature inside the explosion-proof valve and the peak gas generation rate inside the cavity; A first theoretical model is used to determine the relationship between the explosion-proof valve area, the inner trigger temperature of the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve based on the congestion flow theory. The target peak gas production rate under thermal runaway state is calculated based on the inner trigger temperature of the explosion-proof valve, the peak gas production rate in the cavity, and the standard thermal runaway test parameters. The standard thermal runaway test parameters include the thermal runaway test environment pressure, the thermal runaway test environment temperature, and the downstream outlet pressure of the explosion-proof valve. Under the thermal runaway state, the theoretical safe area of ​​the explosion-proof valve of the battery under test is calculated based on the first theoretical model and the target peak gas production rate.

2. The method according to claim 1, characterized in that, The first theoretical model, which determines the relationship between the explosion-proof valve area, the explosion-proof valve inner trigger temperature, and the explosion-proof valve's theoretical maximum volumetric flow rate based on congestion flow theory, includes: A second theoretical model is determined based on the choke flow theory to establish the relationship between the inner trigger temperature of the explosion-proof valve and the maximum flow velocity at the choke critical point. A third theoretical model is established to determine the relationship between the maximum flow velocity at the choking critical point, the area of ​​the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve. By integrating the second theoretical model and the third theoretical model, a first theoretical model is obtained relating the explosion-proof valve area, the explosion-proof valve inner trigger temperature, and the explosion-proof valve's theoretical maximum volumetric flow rate.

3. The method according to claim 2, characterized in that, The third theoretical model for determining the relationship between the maximum flow velocity at the choking critical point, the area of ​​the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve includes: Determine the flow loss coefficient and melt blockage loss coefficient corresponding to the battery model under test; Calculate the product data between the maximum flow velocity at the choking critical point, the explosion-proof valve area, the flow loss coefficient, and the melt blockage loss coefficient; The third theoretical model is determined based on the product data and the theoretical maximum volumetric flow rate of the explosion-proof valve.

4. The method according to claim 1, characterized in that, The calculation of the target gas production rate peak under thermal runaway state based on the inner trigger temperature of the explosion-proof valve, the peak gas production rate in the cavity, and standard thermal runaway test parameters includes: The trigger temperature on the outside of the explosion-proof valve corresponding to the trigger temperature on the inside of the explosion-proof valve is determined based on the temperature conversion between the inside and outside of the explosion-proof valve. The target peak gas production rate under thermal runaway conditions is calculated based on the trigger temperature outside the explosion-proof valve, the peak gas production rate inside the cavity, and the standard thermal runaway test parameters.

5. The method according to claim 4, characterized in that, The calculation of the target gas production rate peak under thermal runaway state based on the trigger temperature outside the explosion-proof valve, the peak gas production rate in the cavity, and standard thermal runaway test parameters includes: The first product result is obtained by multiplying the trigger temperature outside the explosion-proof valve, the peak gas generation rate inside the cavity, and the pressure of the thermal runaway test environment. The second product result is obtained by multiplying the thermal runaway test environment temperature and the downstream outlet pressure of the explosion-proof valve. The target gas production rate peak under thermal runaway state is obtained by calculating the ratio of the first product result and the second product result.

6. The method according to claim 1, characterized in that, The calculation of the theoretical safe area of ​​the explosion-proof valve for the battery under test, based on the first theoretical model and the target peak gas production rate under the thermal runaway state, includes: Under the thermal runaway state, the theoretical maximum volumetric flow rate of the explosion-proof valve is determined based on the target peak gas production rate. Based on the first theoretical model, determine the theoretical safe area of ​​the explosion-proof valve corresponding to the battery model under test at the theoretical maximum volumetric flow rate of the explosion-proof valve.

7. The method according to claim 1, characterized in that, The method further includes: Receive security level instructions and determine the security redundancy coefficient corresponding to the security level instructions based on the security redundancy database; The design area of ​​the explosion-proof valve is determined based on the safety redundancy coefficient and the theoretical safe area of ​​the explosion-proof valve.

8. A device for calculating the area of ​​an explosion-proof valve on a battery cover, characterized in that, The device includes: The acquisition module is used to acquire test data of the battery under test model under thermal runaway test conditions. The test data includes the trigger temperature inside the explosion-proof valve and the peak gas generation rate inside the cavity. The determination module is used to determine a first theoretical model between the explosion-proof valve area, the inner trigger temperature of the explosion-proof valve, and the theoretical maximum volumetric flow rate of the explosion-proof valve based on the congestion flow theory; The testing module is used to calculate the target peak gas production rate under thermal runaway state based on the trigger temperature inside the explosion-proof valve, the peak gas production rate in the cavity, and standard thermal runaway test parameters. The standard thermal runaway test parameters include thermal runaway test environment pressure, thermal runaway test environment temperature, and downstream outlet pressure of the explosion-proof valve. The calculation module is used to calculate the theoretical safe area of ​​the explosion-proof valve of the battery under test model based on the first theoretical model and the target peak gas production rate under the thermal runaway state.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer or processor, cause the computer or processor to perform the steps of the method as described in any one of claims 1-7.

Images