Air tightness detection method, device, equipment, storage medium and program product

Abstract

The application relates to an air tightness detection method, device, equipment, storage medium and program product. The method comprises the following steps: obtaining actual concentration curves of each detection position on a battery pack in the process of charging the battery pack with tracer gas; the actual concentration curve comprises data of concentration change of the tracer gas with time in the gas replacement process; determining air tightness detection results of each detection position according to reference concentration curves of each detection position and the actual concentration curves; the reference concentration curve comprises data of concentration change of the tracer gas with time calculated by a flow field model in advance, and the air tightness detection result is used for characterizing whether the tracer gas leaks at the detection position. The air tightness detection efficiency can be improved by adopting the application.

Description

Technical Field

[0001] This application relates to the field of airtightness testing technology, specifically to an airtightness testing method, apparatus, equipment, storage medium, and program product. Background Technology

[0002] With the development of new energy technologies, battery packs have been applied in various fields. To improve the safety performance of battery packs, various tests are required, among which airtightness testing is a particularly important one.

[0003] Currently, airtightness testing typically involves filling the battery pack with tracer gas to replace the air inside, and then checking for leaks at multiple locations on the battery pack casing. Because replacing the air with tracer gas takes a considerable amount of time, airtightness testing is inefficient. Summary of the Invention

[0004] To address the aforementioned issues, this application provides an airtightness testing method, apparatus, equipment, storage medium, and program product, which can improve the efficiency of airtightness testing.

[0005] In a first aspect, this application provides an airtightness detection method, which includes: acquiring actual concentration curves at each detection location on the battery pack during the process of charging a tracer gas into the battery pack; the actual concentration curves include data on the change of tracer gas concentration over time during the gas replacement process; determining the airtightness detection result at each detection location based on the reference concentration curve and the actual concentration curve at each detection location; the reference concentration curves include data on the change of tracer gas concentration over time calculated in advance using a flow field model, and the airtightness detection results are used to characterize whether there is a tracer gas leak at the detection location.

[0006] In the technical solution of this application embodiment, a reference concentration curve is obtained by pre-simulation. Since both the actual concentration curve and the reference concentration curve are data on the change of tracer gas concentration over time, reflecting the change of gas concentration at the detection location during the entire gas replacement process, it is not necessary to wait for the tracer gas to completely replace the air in the battery pack and reach an equilibrium state before judging whether there is a tracer gas leak. Therefore, the air tightness detection time can be shortened, thereby improving the air tightness detection efficiency.

[0007] In some embodiments, the airtightness detection result for each detection location is determined based on the reference concentration curve and the actual concentration curve for each detection location. This includes: for each detection location, determining the first gas concentration corresponding to a preset detection time in the actual concentration curve and the second gas concentration corresponding to a preset detection time in the reference concentration curve; if the first gas concentration is greater than the second gas concentration, determining that the airtightness detection result indicates the presence of tracer gas leakage at the detection location. In the technical solution of this application embodiment, by utilizing the reference concentration curve, airtightness detection can be performed in the non-equilibrium state of the gas replacement process, which can shorten the detection time and improve detection efficiency.

[0008] In some embodiments, the method further includes: acquiring the structural model and simulation conditions of the battery pack respectively; simulating the gas flow state using the structural model, simulation conditions, and flow field model to obtain reference concentration curves for each detection location. In the technical solution of this application embodiment, the reference concentration curves allow for airtightness detection even in the non-equilibrium state of the gas replacement process, thereby shortening the detection time and improving detection efficiency.

[0009] In some embodiments, the simulation conditions include multiple replacement methods, each including information on the gas inlet and outlet. The simulation utilizes a structural model, simulation conditions, and a flow field model to simulate the gas flow state and obtain reference concentration curves for each detection location. This includes: under different replacement methods, using a flow field model to simulate the gas flow state at preset locations on the structural model, obtaining reference concentration curves for each detection location under each replacement method; wherein the preset locations correspond one-to-one with the detection locations. In the technical solution of this application embodiment, reference concentration curves can be simulated for battery packs with different structures and different replacement methods, so that in actual detection, a suitable reference concentration curve can be selected according to the actual situation to determine whether tracer gas leakage exists.

[0010] In some embodiments, the method further includes: simulating the flow state of gas within a structural model using a flow field model under different replacement methods, obtaining a first concentration uniformity of the tracer gas in the battery pack and a first replacement time required for gas replacement to reach equilibrium; determining the optimal replacement method from multiple replacement methods based on the first concentration uniformity and the first replacement time; and using the optimal replacement method to optimize the detection structure. In the technical solution of this application embodiment, the use of a flow field model for simulation can identify a superior replacement method, thereby effectively improving the gas replacement effect and increasing the accuracy of airtightness detection; and effectively improving the gas replacement efficiency and increasing the efficiency of airtightness detection.

[0011] In some embodiments, the simulation conditions include multiple tracheal lengths; the gas flow state is simulated using a structural model, simulation conditions, and a flow field model to obtain reference concentration curves for each detection location, including: under different tracheal lengths for the target replacement method, the flow field model is used to simulate the gas flow state at each preset position on the structural model to obtain reference concentration curves for each detection location under each tracheal length; wherein, the preset positions correspond one-to-one with the detection locations. In the technical solution of this application embodiment, reference concentration curves can be simulated for various tracheal lengths, so that in actual detection, a suitable reference concentration curve can be selected according to the actual situation to determine whether there is a tracer gas leak.

[0012] In some embodiments, the method further includes: simulating the gas flow state within a structural model using a flow field model under different tracheal lengths for the target replacement method, obtaining a second concentration uniformity of the tracer gas in the battery pack and a second replacement time required for gas replacement to reach equilibrium; determining an optimal tracheal length from multiple tracheal lengths based on the second concentration uniformity and the second replacement time; and using the optimal tracheal length to optimize the detection structure. In the technical solution of this application embodiment, the use of a flow field model for simulation can identify a better tracheal length, thereby effectively improving gas replacement efficiency and increasing the efficiency of airtightness detection.

[0013] Secondly, this application also provides an airtightness testing device, which includes:

[0014] The actual concentration acquisition module is used to acquire the actual concentration curves at each detection location on the battery pack during the process of charging the tracer gas into the battery pack; the actual concentration curves include data on the change of tracer gas concentration over time during the gas replacement process;

[0015] The airtightness detection module is used to determine the airtightness detection results of each detection location based on the reference concentration curve and the actual concentration curve of each detection location. The reference concentration curve includes data on the concentration change of tracer gas over time, which is obtained by pre-simulating the flow field model. The airtightness detection results are used to characterize whether there is a tracer gas leak at the detection location.

[0016] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method as described in the first aspect.

[0017] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in the first aspect.

[0018] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the method as described in the first aspect. Attached Figure Description

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the alternative embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0020] Figure 1 This is a schematic diagram illustrating the application environment of an airtightness testing method according to an embodiment of this application;

[0021] Figure 2 This is a schematic flowchart of an airtightness testing method according to an embodiment of this application;

[0022] Figure 3 This is a concentration curve diagram of an embodiment of this application;

[0023] Figure 4 This is a flowchart illustrating the airtightness testing steps according to an embodiment of this application;

[0024] Figure 5 This is a schematic flowchart illustrating the simulation steps using a flow field model according to an embodiment of this application.

[0025] Figure 6a This is a schematic diagram of a structural model according to an embodiment of this application;

[0026] Figure 6b This is a partial enlarged view of an embodiment of this application;

[0027] Figure 6c This is a schematic diagram of a replacement method according to an embodiment of this application;

[0028] Figure 7 This is a schematic flowchart illustrating the simulation steps using a flow field model according to an embodiment of this application.

[0029] Figure 8 This is a schematic flowchart illustrating the simulation steps using a flow field model according to an embodiment of this application.

[0030] Figure 9 This is a structural block diagram of an airtightness testing device according to an embodiment of this application;

[0031] Figure 10 This is a structural block diagram of an airtightness testing device according to an embodiment of this application;

[0032] Figure 11 This is an internal structural diagram of a computer device according to an embodiment of this application. Detailed Implementation

[0033] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0035] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0036] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0038] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0039] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0040] With the development of new energy technologies, battery packs have been applied in various fields. To improve the safety performance of battery packs, various tests are required, among which airtightness testing is particularly important. Currently, airtightness testing typically involves filling the battery pack with tracer gas to replace the air inside, and then checking for tracer gas leaks at multiple locations on the battery pack casing. Usually, airtightness testing is performed only after the tracer gas has completely replaced the air inside the battery pack and reached an equilibrium state. However, because the tracer gas replacement of the air takes a considerable amount of time, airtightness testing efficiency is relatively low.

[0041] This application provides an airtightness detection method. A reference concentration curve is pre-simulated using a flow field model. Then, during the process of filling the battery pack with tracer gas, the actual concentration curves at each detection location on the battery pack are acquired. Based on the reference and actual concentration curves at each detection location, the airtightness detection result at each location is determined. Since both the actual and reference concentration curves represent the change in tracer gas concentration over time, reflecting the gas concentration change at the detection location during the entire gas replacement process, it is unnecessary to wait for the tracer gas to completely replace the air in the battery pack and reach equilibrium before determining whether a tracer gas leak exists. Therefore, the airtightness detection time can be shortened, thereby improving the efficiency of airtightness detection.

[0042] The airtightness testing method provided in this application embodiment can be applied to, for example... Figure 1The application environment shown may include a battery pack 101, a battery pack detection system 102, and a computer device 103. The battery pack detection system 102 can communicate with the computer device 103 via a network. The battery pack can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. The battery pack detection system 102 may include, but is not limited to, a gas transmission structure and a gas sensor. The gas transmission structure can be fixedly connected to the battery pack 101 to fill the battery pack with tracer gas and to transmit the gas at the detection location of the battery pack to the gas sensor. For example, the gas transmission structure includes an inflation pipe for filling the battery pack, a cover covering the detection location, and an exhaust pipe disposed on the cover. It should be noted that the gas transmission structure is not limited to the above description and can be configured according to actual conditions. The gas sensor can transmit the collected data to the computer device 103 via a network. The computer device may be, but is not limited to, various personal computers, laptops, smartphones, and tablets.

[0043] According to some embodiments of this application, refer to Figure 2 This paper provides a method for airtightness testing, which can be applied to... Figure 1 Taking a computer device as an example, the process can include the following steps:

[0044] Step 201: During the process of filling the battery pack with tracer gas, obtain the actual concentration curves at each detection location on the battery pack.

[0045] The tracer gas may include hydrogen or a mixture of hydrogen and nitrogen. The actual concentration curve includes data on the change in the concentration of the tracer gas over time during the gas displacement process.

[0046] During the process of charging the battery pack with tracer gas, multiple gas sensors in the battery pack detection system collect data on the gas concentration at various detection locations on the battery pack and transmit the collected concentration data to a computer in real time. The computer receives the concentration data transmitted in real time from the multiple gas sensors and plots the concentration data collected by each gas sensor into curves in chronological order to obtain the actual concentration curves at each detection location on the battery pack.

[0047] Step 202: Determine the airtightness test results for each detection location based on the reference concentration curve and the actual concentration curve for each detection location.

[0048] The reference concentration curve includes data on the concentration of the tracer gas over time, simulated beforehand using a flow field model. The flow field model is based on fluid mechanics and is used to simulate gas flow conditions; it can include turbulence models, eddy current models, etc. The airtightness test results are used to characterize whether a tracer gas leak exists at the detection location.

[0049] Computer equipment can simulate the flow state of the tracer gas in advance using a flow field model. For example, the flow field model can simulate the tracer gas entering the battery pack through the filling port, flowing inside the battery pack, and finally exiting through the exhaust port. Understandably, during the replacement process, the concentration of the tracer gas at each detection location on the battery pack will change over time. Furthermore, since the gas concentration is higher at the filling port and lower at the exhaust port in the initial stage of gas replacement, the gas concentration at different detection locations will differ at the same detection moment. As time progresses, the tracer gas gradually replaces the air inside the battery pack. After the gas replacement reaches equilibrium, the gas concentration at the filling port and the gas concentration at the exhaust port become close, therefore, the gas concentration at different detection locations will also be relatively similar.

[0050] After simulation using a flow field model, the concentration data of tracer gas at multiple detection times at each detection location can be obtained. By plotting the concentration data in chronological order, a reference concentration curve for each detection location can be obtained.

[0051] In the actual testing process, for each detection location, the actual concentration curve at that location is first obtained. Then, this actual concentration curve is compared with a pre-simulated reference concentration curve to obtain the airtightness test result indicating whether there is a tracer gas leak at the detection location. (Reference) Figure 3 The horizontal axis represents time, and the vertical axis represents the concentration of the tracer gas. The solid line is the reference concentration curve, and the dashed line is the actual concentration curve. In the graph, if the actual concentration curve is higher than the reference concentration curve, the airtightness test result indicates that there is a tracer gas leak at the detection location; if the actual concentration curve is lower than the reference concentration curve, the airtightness test result indicates that there is no tracer gas leak at the detection location.

[0052] In the above embodiments, during the process of charging the battery pack with tracer gas, the actual concentration curves at each detection location on the battery pack are obtained; based on the reference concentration curves and actual concentration curves at each detection location, the airtightness test results at each detection location are determined. In the technical solution of this application embodiment, the reference concentration curve is obtained in advance through simulation. Since both the actual concentration curve and the reference concentration curve are data on the concentration change of the tracer gas over time, reflecting the gas concentration change at the detection location during the entire gas replacement process, it is not necessary to wait for the tracer gas to completely replace the air in the battery pack and reach an equilibrium state before determining whether there is a tracer gas leak. Therefore, the airtightness test time can be shortened, thereby improving the airtightness test efficiency.

[0053] According to some embodiments of this application, refer to Figure 4 After obtaining the actual concentration curve, the process of determining the airtightness test results for each detection location based on the reference concentration curve and the actual concentration curve at each detection location can include the following steps:

[0054] Step 301: For each detection location, determine the first gas concentration corresponding to the preset detection time in the actual concentration curve and the second gas concentration corresponding to the preset detection time in the reference concentration curve.

[0055] For each detection location, the gas concentration corresponding to the same preset detection time is determined in both the actual concentration curve and the reference concentration curve, thus obtaining the first gas concentration in the actual concentration curve and the second gas concentration in the reference concentration curve.

[0056] by Figure 3 For example, in actual concentration curve 1, the first gas concentration corresponding to the preset detection time of 30s is 0.0006, in actual concentration curve 2, the first gas concentration corresponding to the preset detection time of 30s is 0.0004, and in reference concentration curve, the second gas concentration corresponding to the preset detection time of 30s is 0.0005.

[0057] Step 302: If the first gas concentration is greater than the second gas concentration, determine that the airtightness test result indicates that there is a tracer gas leak at the detection location.

[0058] If the first gas concentration curve is greater than the second gas concentration curve, it indicates that there is a large amount of tracer gas at the detection location, thus confirming that there is a tracer gas leak at the detection location.

[0059] Still with Figure 3 For example, in actual concentration curve 1, the concentration of the first gas corresponding to a preset detection time of 30 seconds is greater than the concentration of the second gas corresponding to a preset detection time of 30 seconds in the reference concentration curve. This indicates that there is a tracer gas leak at the detection location corresponding to actual concentration curve 1. Conversely, in actual concentration curve 2, the concentration of the first gas corresponding to a preset detection time of 30 seconds is less than the concentration of the second gas corresponding to a preset detection time of 30 seconds in the reference concentration curve. This indicates that there is no tracer gas leak at the detection location corresponding to actual concentration curve 2.

[0060] In the above embodiments, for each detection location, the first gas concentration corresponding to a preset detection time in the actual concentration curve and the second gas concentration corresponding to a preset detection time in the reference concentration curve are determined respectively; when the first gas concentration is greater than the second gas concentration, the airtightness detection result indicates that there is a tracer gas leak at the detection location. In the technical solution of this application embodiment, by using the reference concentration curve, airtightness detection can be performed in the non-equilibrium state of the gas replacement process, which can shorten the detection time and improve the detection efficiency.

[0061] Before conducting airtightness testing, a flow field model is used to simulate and determine the reference concentration curves for each testing location. Figure 5 The simulation process in this application embodiment may include the following steps:

[0062] Step 401: Obtain the structural model and simulation conditions of the battery pack.

[0063] The structural model can include structural information about the battery pack, such as its length, width, height, and other dimensions, as well as internal spatial division information. The structural model can also include, for example, information about the battery pack's internal dimensions. Figure 6a In the model diagram shown, 11 is the inflation pipe and 12 is the exhaust pipe; Figure 6b for Figure 6a The enlarged view within the dashed circle shows the intake pipe (13) and a leak on the battery pack surface (14). Simulation conditions can include the type of tracer gas and its charging / discharging method. For example, simulation conditions could include a mixture of 5% hydrogen and 95% nitrogen by volume. It should be noted that simulation conditions include, but are not limited to, the above descriptions and can be set according to actual conditions.

[0064] In one implementation, the tester first uses structural drawing software to create a structural model of the battery pack and adds corresponding annotations to the model. Then, the drawn structural model is imported into the computer device to be used for simulation, allowing the computer device to obtain the structural model of the battery pack. In another implementation, the tester inputs the structural information of the battery pack into the computer device, which then determines the structural model of the battery pack based on this information.

[0065] Similarly, testers can input simulation conditions such as gas composition into a computer device, which will then obtain the simulation conditions.

[0066] Step 402: Simulate the gas flow state using the structural model, simulation conditions, and flow field model to obtain the reference concentration curves for each detection location.

[0067] After obtaining the structural model and simulation conditions, the space for gas flow and potential gas leak detection locations can be determined based on the structural model. Then, a flow field model is used to simulate the gas flow state within this space, as well as the gas leakage state from the detection locations. During the simulation, the previously obtained simulation conditions are used as boundary conditions.

[0068] For example, based on the structural model, the length, width, and height of the gas flow space are first determined, along with the locations of partitions within this space and potential gas leak locations. Then, a simulation is performed to fill the battery pack with a mixture of 5% hydrogen and 95% nitrogen by volume. The flow field model calculates the flow state of this mixture within the aforementioned space and the concentration of the mixture at the detection locations. Finally, a reference concentration curve is plotted for the concentrations at each detection location in chronological order.

[0069] In the above embodiments, the structural model and simulation conditions of the battery pack are obtained respectively; the gas flow state is simulated using the structural model, simulation conditions, and flow field model to obtain reference concentration curves at each detection location. In the technical solution of this application embodiment, the structural model and simulation conditions are used as boundary conditions for flow field simulation, which can make the simulation closer to the actual situation, thereby making the reference concentration curves more reliable.

[0070] According to some embodiments of this application, the simulation conditions described above include multiple replacement methods, each including information on the gas inlet and outlet. The gas inlet information may include the layout of the gas inlets, such as the number and location of the gas inlets, and may also include the pressure of the gas inlets. The outlet information may include the layout of the outlets, such as the number and location of the outlets, and may also include the pressure of the outlets. It is understood that different layouts of the gas inlets and outlets, as well as different pressures, can constitute different replacement methods. The process described above, which uses a structural model, simulation conditions, and a flow field model to simulate the gas flow state and obtain reference concentration curves for each detection location, may include: under different replacement methods, using a flow field model to simulate the gas flow state at each preset location on the structural model, and obtaining reference concentration curves for each detection location under each replacement method.

[0071] The aforementioned preset locations are areas where tracer gas leaks are likely to occur in the battery pack, such as the mounting bolts and the connections between the battery pack's outer casing. Because these locations are prone to tracer gas leaks, the preset locations correspond one-to-one with the actual testing locations.

[0072] Under each replacement method, a flow field model is used to simulate the flow state of the gas and obtain the concentration data of the tracer gas at each preset location. Then, the concentration data of each preset location are plotted into a curve in chronological order to obtain the reference concentration curve of each detection location.

[0073] For example, under replacement mode 1, a flow field model is used to simulate the flow state of the tracer gas as it enters the battery pack from the filling port, flows inside the battery pack, and finally flows out from the exhaust port, including its flow direction and velocity. Based on the simulation, reference concentration curves for each detection location under replacement mode 1 are obtained. Similarly, under other replacement modes, the flow field model is used to simulate the process, obtaining reference concentration curves for each replacement mode.

[0074] Understandably, reference concentration curves can be simulated for battery packs with different structures and different replacement methods, so that in actual testing, an appropriate reference concentration curve can be selected to determine whether there is a tracer gas leak.

[0075] Based on the above embodiments, referring to Figure 7 The embodiments of this application may further include:

[0076] Step 501: Under different replacement methods, the flow field model is used to simulate the flow state of the gas in the structural model to obtain the first concentration uniformity of the tracer gas in the battery pack and the first replacement time required for the gas replacement to reach the equilibrium state.

[0077] Concentration uniformity characterizes the average gas concentration within the battery pack. After gas replacement reaches equilibrium, the change in gas concentration inside the battery pack is within a relatively small range. However, in the non-equilibrium state before reaching equilibrium, the gas concentration inside the battery pack gradually increases.

[0078] During the simulation, a biasing experiment can be conducted to test the displacement methods. That is, under each displacement method, a flow field model is used to simulate the flow state of the tracer gas within the structural model, thus obtaining the flow state of the tracer gas inside the battery pack. Based on the flow state, the average and / or minimum gas concentration of the tracer gas in the battery pack can be determined, and the first concentration uniformity can be determined based on the average and / or minimum gas concentration. Based on the flow state, the first displacement time from the start of gas filling to the point where gas displacement reaches equilibrium can also be determined.

[0079] In one alternative approach, multiple concentration ranges can be set. After determining the average gas concentration of the tracer gas in the battery pack, the concentration range in which the average gas concentration is located is determined to obtain the first concentration uniformity.

[0080] The data obtained by simulation using the flow field model are shown in Table 1. Unless otherwise specified in the table, the pressure at the inflation port is 3.5 kPa and the pressure at the exhaust port is standard atmospheric pressure.

[0081]

[0082]

[0083] Table 1 details the specific gas replacement methods within the battery pack as follows: Method 1 includes one inflation port and one deflation port, both positioned along the length (vertical axis) of the battery pack, with both pressures at standard atmospheric pressure; Method 2 includes one inflation port and one deflation port, both positioned along the width (horizontal axis) of the battery pack, with both pressures at standard atmospheric pressure; Method 3 includes one inflation port and one deflation port, both positioned along the diagonal of the battery pack, with both pressures at standard atmospheric pressure. All pressures are at standard atmospheric pressure; Replacement method 4 has 1 inflation port and 2 deflation ports, symmetrically distributed, and all pressures are at standard atmospheric pressure; Replacement method 5 has 1 inflation port and 4 deflation ports, symmetrically distributed, and all pressures are at standard atmospheric pressure; Replacement method 6 has 2 inflation ports and 4 deflation ports, symmetrically distributed, and all pressures are at standard atmospheric pressure; Replacement method 7 has 2 inflation ports and 4 deflation ports, symmetrically distributed, and refers to... Figure 6c The pressure at the inflation port is higher than the standard atmospheric pressure, and the pressure at the exhaust port is lower than the standard atmospheric pressure. Replacement method 8 has 4 inflation ports and 2 exhaust ports, with the inflation ports and exhaust ports symmetrically distributed and the pressure at both ports being the standard atmospheric pressure. Replacement method 9 has 4 inflation ports and 2 exhaust ports, with the inflation ports and exhaust ports symmetrically distributed and the pressure at the inflation ports being higher than the standard atmospheric pressure, and the pressure at the exhaust ports being lower than the standard atmospheric pressure.

[0084] It should be noted that the information on the inflation port, the exhaust port, and the replacement method includes, but is not limited to, the above descriptions and can be set according to the actual situation.

[0085] Step 502: Based on the first concentration uniformity and the first replacement time, determine the optimal replacement method from multiple replacement methods; wherein, the optimal replacement method is used to optimize the detection structure.

[0086] The simulated first concentration uniformity and first replacement time differ under different replacement methods. By comparing the first concentration uniformity and first replacement time of multiple replacement methods, the replacement method with good concentration uniformity and short replacement time can be selected and determined as the optimal replacement method.

[0087] Referring to Table 1, displacement method 9 exhibits excellent concentration uniformity and the shortest displacement time, indicating that displacement method 9 provides a good gas displacement effect and high displacement efficiency. Therefore, displacement method 9 can be identified as the optimal displacement method in Table 1.

[0088] After determining the optimal replacement method, the detection structure can be optimized using replacement method 9 during the actual testing process. This means the detection structure adopts a 4-inlet, 2-outlet configuration. Simultaneously, to improve the air replacement speed of the battery pack, positive pressure is used at the filling port to accelerate filling, and negative pressure is used at the exhaust port to accelerate exhaust. Understandably, better gas replacement results in higher accuracy for airtightness testing; higher gas replacement efficiency improves the efficiency of airtightness testing.

[0089] In the above embodiments, under different replacement methods, a flow field model is used to simulate the flow state of gas within the structural model, obtaining the first concentration uniformity of the tracer gas in the battery pack and the first replacement time required for the gas replacement to reach an equilibrium state. Based on the first concentration uniformity and the first replacement time, the optimal replacement method is determined from multiple replacement methods. In the technical solution of this application embodiment, the use of a flow field model for simulation can find a better replacement method, thereby effectively improving the gas replacement effect and increasing the accuracy of airtightness detection; and effectively improving the gas replacement efficiency and increasing the efficiency of airtightness detection.

[0090] According to some embodiments of this application, the simulation conditions include multiple tracheal tube lengths. The length of the inflation tube and the exhaust tube affect the gas flow state; therefore, different tracheal tube lengths result in different gas replacement effects and efficiencies. During the simulation, various tracheal tube lengths such as 1m, 100mm, and 6mm can be selected.

[0091] The process described above, which uses structural models, simulation conditions, and flow field models to simulate the gas flow state and obtain reference concentration curves for each detection location, may include: using a flow field model to simulate the gas flow state at each preset location on the structural model under different duct lengths for the target replacement method, and obtaining reference concentration curves for each detection location under each duct length; wherein, the preset location corresponds one-to-one with the detection location.

[0092] During the simulation, tracheal length stretching experiments can be performed for each replacement method, or only for the target replacement method. Understandably, stretching the tracheal length only for the target replacement method can improve simulation efficiency.

[0093] In one optional implementation, the tracheal length is first fixed, and simulations are performed under each replacement method to obtain the simulation results corresponding to each replacement method. Then, the target replacement method is determined based on the simulation results, and simulations are performed under the target replacement method using different tracheal lengths to obtain the reference concentration curves for each detection location under each tracheal length.

[0094] For example, first, the tracheal length is fixed at 6 mm, and then simulations are performed sequentially under replacement methods 1-9 to obtain the first concentration uniformity and first replacement time corresponding to each replacement method. Based on the first concentration uniformity and first replacement time, replacement method 8 is determined as the target replacement method. Then, under replacement method 8, the tracheal length is set to 6 mm, and a flow field model is used to simulate the flow state of gas at each preset position on the structural model, obtaining the reference concentration curves at each detection position when the tracheal length is 6 mm. Subsequently, under replacement method 8, simulations can be performed with the tracheal length set to 100 mm and 1 m.

[0095] Understandably, reference concentration curves can be simulated for various tracheal lengths, so that in actual testing, an appropriate reference concentration curve can be selected to determine whether there is a tracer gas leak.

[0096] Based on the above embodiments, referring to Figure 8 The embodiments of this application may further include:

[0097] Step 601: Under different duct lengths for the target replacement method, the flow field model is used to simulate the flow state of the gas in the structural model, and the second concentration uniformity of the tracer gas in the battery pack and the second replacement time required for the gas replacement to reach equilibrium are obtained.

[0098] Referring to the simulation method described above, the length of the gas tube is adjusted under the target replacement method. Specifically, a flow field model is used to simulate the flow of tracer gas entering from the inflation port, flowing within the battery pack, and exiting from the exhaust port at various gas tube lengths, including the flow direction and velocity. Based on the flow state, the average gas concentration of the tracer gas in the battery pack can be determined, and the second concentration uniformity can be determined based on the average gas concentration. Furthermore, based on the flow state, the second replacement time from the start of inflation to the gas replacement reaching equilibrium can also be determined.

[0099] The data obtained by simulation using the flow field model are shown in Table 2. Unless otherwise specified in the table, the pressure at the inflation port is 3.5 kPa and the pressure at the exhaust port is standard atmospheric pressure.

[0100] Table 2

[0101]

[0102]

[0103] Step 602: Determine the optimal tracheal length from multiple tracheal lengths based on the second concentration uniformity and the second replacement time; the optimal tracheal length is used to optimize the detection structure.

[0104] The simulated second concentration uniformity and second replacement time differ for different tracheal lengths. By comparing the second concentration uniformity and second replacement time for multiple tracheal lengths, the tracheal length with the best concentration uniformity and the shortest replacement time can be selected and determined as the optimal tracheal length.

[0105] Referring to Table 2, a tracheal length of 6 mm corresponds to excellent concentration uniformity and the shortest replacement time, indicating that a tracheal length of 6 mm provides good gas replacement effect and high replacement efficiency. Therefore, a tracheal length of 6 mm can be determined as the optimal tracheal length in Table 2.

[0106] After determining the optimal replacement method, in the actual testing process, replacement method 8 and tracheal length 6 can be used to optimize the testing structure. That is, the testing structure adopts a 4-inlet, 2-outlet structure, and the tracheal lengths of both the inflation and exhaust pipes are 6mm. Understandably, a better gas replacement effect can improve the accuracy of airtightness testing; a higher gas replacement efficiency can improve the efficiency of airtightness testing.

[0107] In the above embodiments, under different tracheal lengths for the target replacement method, a flow field model is used to simulate the gas flow state within the structural model, obtaining the second concentration uniformity of the tracer gas in the battery pack and the second replacement time required for gas replacement to reach equilibrium. Based on the second concentration uniformity and the second replacement time, the optimal tracheal length is determined from multiple tracheal lengths. In the technical solution of this application embodiment, the use of a flow field model for simulation can find a better tracheal length, thereby effectively improving the gas replacement efficiency and increasing the efficiency of airtightness detection.

[0108] According to some embodiments of this application, an airtightness testing method is provided, which is applied to... Figure 1 Taking a computer device as an example, the process can include the following steps:

[0109] Step 1: Obtain the structural model and simulation conditions of the battery pack;

[0110] Step 2: Under different replacement methods, the flow field model is used to simulate the flow state of gas at each preset position in the structural model, and the reference concentration curves of each detection position under each replacement method are obtained.

[0111] In the above simulation process, the first concentration uniformity of the tracer gas in the battery pack and the first replacement time required for the gas replacement to reach equilibrium can also be obtained; based on the first concentration uniformity and the first replacement time, the optimal replacement method is determined from multiple replacement methods.

[0112] Step 3: Under different tracheal lengths for the target replacement method, a flow field model is used to simulate the flow state of gas at each preset position in the structural model, and the reference concentration curves at each detection position under each tracheal length are obtained.

[0113] In the above simulation process, the second concentration uniformity of the tracer gas in the battery pack and the second replacement time required for the gas replacement to reach equilibrium can also be obtained; based on the second concentration uniformity and the second replacement time, the optimal tracheal length can be determined from multiple tracheal lengths.

[0114] Step 4: During the process of filling the battery pack with tracer gas, obtain the actual concentration curves at each detection location on the battery pack.

[0115] Step 5: For each detection location, determine the first gas concentration corresponding to the preset detection time in the actual concentration curve and the second gas concentration corresponding to the preset detection time in the reference concentration curve.

[0116] Step 6: If the concentration of the first gas is greater than the concentration of the second gas, determine that the airtightness test result indicates that there is a tracer gas leak at the detection location.

[0117] In the above embodiments, a reference concentration curve is obtained through pre-simulation. Since both the actual concentration curve and the reference concentration curve are data on the change of tracer gas concentration over time, reflecting the change of gas concentration at the detection location during the entire gas replacement process, it is not necessary to wait for the tracer gas to completely replace the air in the battery pack and reach an equilibrium state before determining whether there is a tracer gas leak. Therefore, the airtightness detection time can be shortened, thereby improving the airtightness detection efficiency.

[0118] It should be understood that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.

[0119] Based on the same inventive concept, this application also provides an air tightness detection device for implementing the aforementioned air tightness detection method. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more air tightness detection device embodiments provided below can be found in the limitations of the air tightness detection method described above, and will not be repeated here.

[0120] According to some embodiments of this application, refer to Figure 9 An airtightness testing device is provided, the device comprising:

[0121] The actual concentration acquisition module 701 is used to acquire the actual concentration curves at each detection location on the battery pack during the process of charging the tracer gas into the battery pack; the actual concentration curves include data on the change of the concentration of the tracer gas over time during the gas replacement process.

[0122] The airtightness detection module 702 is used to determine the airtightness detection results of each detection location based on the reference concentration curve and the actual concentration curve of each detection location. The reference concentration curve includes data on the concentration change of tracer gas over time, which is calculated in advance using a flow field model. The airtightness detection results are used to characterize whether there is a tracer gas leak at the detection location.

[0123] In some embodiments, the airtightness detection module 702 is specifically used to determine, for each detection location, a first gas concentration corresponding to a preset detection time in the actual concentration curve and a second gas concentration corresponding to a preset detection time in the reference concentration curve; if the first gas concentration is greater than the second gas concentration, it is determined that the airtightness detection result indicates that there is a tracer gas leak at the detection location.

[0124] In some embodiments, refer to Figure 10 The device also includes:

[0125] The condition acquisition module 703 is used to acquire the structural model and simulation conditions of the battery pack, respectively.

[0126] The simulation module 704 is used to simulate the gas flow state using a structural model, simulation conditions, and a flow field model to obtain reference concentration curves at each detection location.

[0127] In some embodiments, the simulation conditions include multiple replacement methods, and the replacement methods include inlet information and outlet information; the simulation module 704 is specifically used to simulate the flow state of gas at each preset position on the structural model under different replacement methods using a flow field model, and obtain the reference concentration curve of each detection position under each replacement method; wherein, the preset position corresponds one-to-one with the detection position.

[0128] In some embodiments, the simulation module 704 is further configured to simulate the flow state of gas in the structural model using a flow field model under different replacement methods, to obtain the first concentration uniformity of the tracer gas in the battery pack and the first replacement time required for the gas replacement to reach an equilibrium state; and to determine the optimal replacement method from multiple replacement methods based on the first concentration uniformity and the first replacement time; the optimal replacement method is used to optimize the detection structure.

[0129] In some embodiments, the simulation conditions include multiple tracheal lengths; the simulation module 704 is specifically used to simulate the flow state of gas at each preset position on the structural model under different tracheal lengths of the target replacement method using a flow field model, and obtain reference concentration curves for each detection position under each tracheal length; wherein, the preset position corresponds one-to-one with the detection position.

[0130] In some embodiments, the simulation module 704 is further configured to simulate the flow state of gas in the structural model using a flow field model under different tracheal lengths of the target replacement method, to obtain the second concentration uniformity of the tracer gas in the battery pack and the second replacement time required for the gas replacement to reach an equilibrium state; and to determine the optimal tracheal length from multiple tracheal lengths based on the second concentration uniformity and the second replacement time; the optimal tracheal length is used to optimize the detection structure.

[0131] Each module in the aforementioned airtightness testing device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the electronic device in hardware form or independent of it, or stored in the memory of the electronic device in software form, so that the processor can call and execute the corresponding operations of each module.

[0132] According to some embodiments of this application, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 11As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements an airtightness detection method. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0133] Those skilled in the art will understand that Figure 11 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0134] According to some embodiments of this application, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory including instructions that can be executed by a processor of an electronic device to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0135] According to some embodiments of this application, a computer program product is also provided, which, when executed by a processor, can implement the above-described methods. The computer program product includes one or more computer instructions. When these computer instructions are loaded and executed on a computer, some or all of the above-described methods can be implemented, wholly or partially, according to the processes or functions described in the embodiments of this application.

[0136] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0137] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0138] The embodiments described above merely illustrate several implementation methods of this application to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A method for detecting airtightness, characterized in that, The method includes: The structural model and simulation conditions of the battery pack are obtained separately; the simulation conditions include multiple replacement methods and multiple air tube lengths, and the replacement methods include air inlet information and air outlet information. The gas flow state is simulated using the structural model, the simulation conditions, and the flow field model to obtain reference concentration curves at each detection location; During the process of charging the battery pack with tracer gas, the actual concentration curves at each detection location on the battery pack are obtained; the actual concentration curves include data on the change of the concentration of the tracer gas over time during the gas replacement process; Based on the reference concentration curves and the actual concentration curves at each detection location, the airtightness detection results at each detection location are determined; the reference concentration curves include data on the concentration of tracer gas over time, calculated in advance using a flow field model, and the airtightness detection results are used to characterize whether there is a tracer gas leak at the detection location.

2. The method according to claim 1, characterized in that, The step of determining the airtightness test result for each detection location based on the reference concentration curve and the actual concentration curve at each detection location includes: For each of the aforementioned detection locations, the first gas concentration corresponding to the preset detection time in the actual concentration curve and the second gas concentration corresponding to the preset detection time in the reference concentration curve are determined respectively. If the concentration of the first gas is greater than the concentration of the second gas, the airtightness test result indicates that there is a tracer gas leak at the detection location.

3. The method according to claim 1, characterized in that, The process of simulating gas flow using the structural model, the simulation conditions, and the flow field model to obtain reference concentration curves for each detection location includes: Under different replacement methods, the flow field model is used to simulate the flow state of gas at each preset position on the structural model, and reference concentration curves at each detection position under each replacement method are obtained; wherein, the preset position corresponds one-to-one with the detection position.

4. The method according to claim 3, characterized in that, The method further includes: Under different replacement methods, the flow field model is used to simulate the flow state of the gas in the structural model to obtain the first concentration uniformity of the tracer gas in the battery pack and the first replacement time required for the gas replacement to reach an equilibrium state. Based on the first concentration uniformity and the first replacement time, the optimal replacement method is determined from multiple replacement methods; the optimal replacement method is used to optimize the detection structure.

5. The method according to claim 3, characterized in that, The process of simulating gas flow using the structural model, the simulation conditions, and the flow field model to obtain reference concentration curves for each detection location includes: Under different tracheal lengths for the target replacement method, the flow field model is used to simulate the flow state of gas at each preset position on the structural model, and a reference concentration curve for each detection position under each tracheal length is obtained; wherein, the preset position corresponds one-to-one with the detection position.

6. The method according to claim 5, characterized in that, The method further includes: Under different duct lengths of the target replacement method, the flow field model is used to simulate the flow state of the gas in the structural model to obtain the second concentration uniformity of the tracer gas in the battery pack and the second replacement time required for the gas replacement to reach an equilibrium state. Based on the second concentration uniformity and the second replacement time, an optimal tracheal length is determined from a plurality of tracheal lengths; the optimal tracheal length is used to optimize the detection structure.

7. An airtightness testing device, characterized in that, The device includes: The condition acquisition module is used to acquire the structural model and simulation conditions of the battery pack respectively; the simulation conditions include multiple replacement methods and multiple air tube lengths, and the replacement methods include air inlet information and air outlet information. The simulation module is used to simulate the gas flow state using the structural model, the simulation conditions, and the flow field model to obtain reference concentration curves at each detection location; The actual concentration acquisition module is used to acquire the actual concentration curves at each detection location on the battery pack during the process of charging the tracer gas into the battery pack; the actual concentration curves include data on the change of the concentration of the tracer gas over time during the gas replacement process; An airtightness detection module is used to determine the airtightness detection result of each detection location based on the reference concentration curve and the actual concentration curve of each detection location; the reference concentration curve includes data on the concentration change of tracer gas over time obtained by pre-simulating the flow field model; and the airtightness detection result is used to characterize whether there is a tracer gas leak at the detection location.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

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