A method and system for assembling hydrogen fuel cell stacks based on edge geometric feature accuracy constraints

Abstract

This invention relates to a method and system for assembling a hydrogen fuel cell stack based on edge geometric feature precision constraints. The method includes acquiring component information of the fuel cell stack; controlling a pressurizing device based on the component information; and stacking the components of the fuel cell stack layer by layer. During the layer-by-layer stacking process, in response to the completion of bipolar plate stacking and pressurization, the edge dimension deviation of the stacked stack is calculated by scanning the edge dimension deviation of the stacked stack. Based on the edge dimension deviation of the stacked stack, a stack component deviation transmission model is constructed to predict the deviation distribution range of subsequent stacking. Based on the predicted deviation distribution range of subsequent stacking, it is determined whether it is within the stack deviation limit containment range. If so, stacking continues; otherwise, stacking stops, and the parameters of the stacked fuel cell stack are stored. Compared with the prior art, this invention has advantages such as high flexibility in the stack assembly process and adaptability to the needs of mass production and high-quality production of fuel cell stacks.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell stack assembly technology, and in particular to a hydrogen fuel cell stack assembly method and system based on edge geometric feature precision constraints. Background Technology

[0002] Hydrogen energy is abundant, green, and low-carbon, making it a crucial vehicle for global energy transition. Hydrogen fuel cells directly convert the chemical energy of hydrogen and oxygen into electrical energy, breaking through the efficiency limits of internal combustion engines and becoming a clean and efficient way to utilize hydrogen energy. A single hydrogen fuel cell consists of metal bipolar plates, sealing rubber, and membrane electrode assemblies. Typically, a single hydrogen fuel cell has a low output voltage; to improve its power generation capacity, a large number of individual cells need to be stacked and connected in series to form a high-power stack.

[0003] The assembly process of a hydrogen fuel cell stack includes material handling, stacking, and pressing. At specific workstations, bipolar plates, sealing rubber, membrane electrode assemblies, and other stack components are stacked sequentially using manual or mechanical equipment. Hundreds of individual cells are assembled in series to form a large stack. Then, a press is used to control the assembly pressure or displacement for pressing. Finally, fastening bolts are installed around the end plates, and other components are added to complete the final assembly of the stack. During the assembly process, deviations in all directions of the stack accumulate. These deviations originate from several sources. One source is manufacturing errors in the individual stack components, such as bipolar plates and sealing rubber. Another source is positioning errors and errors caused by slippage of components under compressive loads.

[0004] Achieving precise stacking of components in a hydrogen fuel cell stack cannot rely solely on improving component machining accuracy; it also depends to a certain extent on assembly process technology. Chinese patent application publication number CN117039089A discloses a stack assembly fixture and method to address the overpressure problem in the center of the stack core caused by uneven endplate thickness. Chinese patent application publication number CN117317332A provides a fuel cell stack assembly method and apparatus. This stack assembly method uses image recognition technology to detect the stacking process of individual cells, achieving automated operation of fuel cell stack assembly. However, single-station stacking does not consider the impact of component machining quality and stacking order on assembly quality, easily leading to poor stack consistency.

[0005] Chinese patent application publication number CN112836391A proposes a model-driven fuel cell stack assembly method. This method collects stack component parameters, evaluates and hierarchically stores the processing quality of stack components, plans the assembly sequence of stack components, performs modular assembly of stack components, collects stack module parameters, evaluates and hierarchically stores the assembly quality of stack modules, plans the assembly sequence of stack modules, and assembles the overall stack. Group assembly considers the processing errors and stacking order of the electrode plates, meeting high-quality assembly requirements. However, the group assembly method requires processes such as measurement, hierarchical classification, storage, and transportation, complicating the assembly process and affecting assembly efficiency.

[0006] Therefore, for hydrogen fuel cell assembly, how to establish a more refined stacking pattern to meet the high-quality and high-efficiency assembly requirements of fuel cell stacks is an urgent problem to be solved. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art by providing a hydrogen fuel cell stack assembly method and system based on edge geometric feature precision constraints, so as to solve or partially solve the problems of difficulty in controlling stacking precision during the component stacking process of hydrogen fuel cell assembly, which affects assembly efficiency and product quality.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] One aspect of the present invention provides a method for assembling a hydrogen fuel cell stack based on edge geometric feature accuracy constraints, comprising the following steps:

[0010] Step S1: Obtain component information of the fuel cell stack, control the pressurization device according to the component information, and stack the components of the fuel cell stack layer by layer.

[0011] Step S2: During the layer-by-layer stacking process, in response to the completion of bipolar plate stacking and pressure application, the edge size deviation of the stacked battery pack is calculated by scanning the edge of the stacked battery pack.

[0012] Step S3: Based on the edge size deviation of the already stacked fuel cell stacks, predict the deviation distribution range of the fuel cell stack components to be stacked by constructing a fuel cell stack component deviation propagation model;

[0013] Step S4: Based on the predicted deviation distribution range of subsequent stacking, determine whether the deviation distribution range of the stacked battery pack components to be stacked is within the preset stack deviation limit range. If yes, continue stacking and execute step S2; if no, stop stacking and execute step S5.

[0014] Step S5: End the current fuel cell stack stacking and store the parameters of the stacked fuel cell stack.

[0015] As a preferred technical solution, the following are also included:

[0016] Step S6: Repeat steps S1-S5 to obtain multiple fuel cell stack modules that meet the assembly accuracy requirements.

[0017] As a preferred technical solution, in step S1, in response to the completion of one or more battery stacks, the pressurizing device is controlled to apply pressure to the fuel cell stack.

[0018] As a preferred technical solution, step S2, the process of calculating the edge size deviation of the stacked fuel cell stack, includes the following steps:

[0019] Step S201: Obtain the position data of each layer of the fuel cell stack components along a direction parallel to the stacking direction of the fuel cell stack;

[0020] Step S202: Based on the position data of each layer of fuel cell stack components, calculate the deviation of each measurement point relative to the reference position to obtain the fuel cell stack edge size deviation.

[0021] As a preferred technical solution, step S3, which involves constructing a stack component deviation transmission model to predict the deviation distribution range of subsequent stacking, includes the following steps:

[0022] Step S301: Based on the dimensional error and assembly error of the fuel cell stack unit, establish a deviation transmission model for the fuel cell stack unit to obtain the error distribution of the fuel cell stack unit.

[0023] Step S302: Based on the edge size deviation of the already stacked battery pack, predict the size deviation of the next layer of stacking through regression analysis;

[0024] Step S303: Based on the error distribution and the size deviation, predict the deviation distribution range of the subsequent components to be stacked.

[0025] As a preferred technical solution, the deviation distribution range of the subsequent components to be stacked is calculated based on the following formula:

[0026]

[0027] in, For the subsequent i Layer component size deviation distribution For the dimensional deviation of stacked components, For the subsequent i Dimensional tolerances of layer components For the subsequent i Assembly errors of layer components, For error terms, α , β , γis the regression coefficient.

[0028] Another aspect of the present invention provides a hydrogen fuel cell stack assembly system based on edge geometric feature precision constraints, for implementing the aforementioned hydrogen fuel cell stack assembly method based on edge geometric feature precision constraints, the system comprising:

[0029] fuel cell stack assembly platform;

[0030] A press, in conjunction with the fuel cell stack assembly platform, pressurizes the hydrogen fuel cell stack.

[0031] An optical inspection device is installed on at least one side of the hydrogen fuel cell stack to collect information on the dimensional deviation of the stacked stack edges.

[0032] As a preferred technical solution, the hydrogen fuel cell stack includes:

[0033] A positioning worktable is connected to the press. The positioning worktable is provided with a bipolar plate, sealing rubber and membrane electrode assembly, wherein the sealing rubber is connected to the bipolar plate and the membrane electrode assembly respectively.

[0034] A positioning rod passes through the press.

[0035] As a preferred technical solution, the press includes:

[0036] Pressure plate;

[0037] The screw, and the pressure plate are connected to the fuel cell stack assembly platform via the screw;

[0038] The guide rod is arranged along the pressure application direction of the press.

[0039] As a preferred technical solution, the following are also included:

[0040] A computer is connected to the optical detection equipment.

[0041] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0042] (1) Ensure the assembly accuracy of hydrogen fuel cells: This invention detects the deviation of stacked bipolar plates during the assembly process, comprehensively considers the size error of single components, assembly error and the size deviation of the stacked stack edge, predicts the error distribution of the components to be stacked, guides the continued stacking or planting stacking, ensures that the assembly deviation of the stack module is within the assembly accuracy requirement range, and ensures that the quality of the stack module meets the requirements.

[0043] (2) High assembly flexibility: This invention determines whether the stack meets the preset assembly accuracy requirements by considering whether the predicted value of the stack deviation distribution exceeds the assembly accuracy requirements. It dynamically determines the number of stack layers based on the size characteristics of its bipolar plates, thereby improving the flexibility of the stack assembly process.

[0044] (3) High production efficiency: This invention reduces the need for rework or readjustment due to non-conforming stacking in single-station stacking by using modular stacking of fuel cell stacks. The stacked modules are easy to stack, transport and fix, which can effectively save storage space. Setting up multiple stacking stations on the production line can achieve continuous production with high production cycle and can well adapt to the mass production and high-quality production requirements of fuel cell stacks. Attached Figure Description

[0045] Figure 1 This is a flowchart of the hydrogen fuel cell stack assembly method based on edge geometric feature accuracy constraints in the embodiment.

[0046] Figure 2 This is a structural diagram of the hydrogen fuel cell stack assembly system based on edge geometric feature precision constraints in the embodiment;

[0047] Figure 3 This is a schematic diagram of the three-dimensional structure of the fuel cell stack in the embodiment;

[0048] Figure 4 This is a schematic diagram of the measurement plane projection for the assembly accuracy requirements in the embodiment;

[0049] Figure 5 This is a schematic diagram of the measurement plane projection of the stack deviation distribution in the embodiment;

[0050] Figure 6 This is a schematic diagram of the measurement plane projection of the modular stacking of the fuel cell stack in the embodiment.

[0051] The components include: 1. Fuel cell stack assembly platform; 2. Hydrogen fuel cell stack; 201. Positioning workbench; 202. Positioning rod; 203. Sealing rubber; 204. Membrane electrode assembly; 205. Stacked bipolar plates; 206. Bipolar plates to be stacked; 3. Optical inspection equipment; 4. Computer; 5. Press; 501. Pressure plate; 502. Screw; 503. Guide rod. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0053] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0054] Example 1

[0055] To address the aforementioned problems in the existing technology and to establish a more refined stacking pattern that meets the high-quality and high-efficiency assembly requirements of fuel cell stacks, this embodiment provides a hydrogen fuel cell stack assembly method based on edge geometric feature precision constraints. (See [link to relevant documentation]). Figure 1 ,include:

[0056] Step S1, assembling hydrogen fuel cell components: Obtain the part numbers, geometric dimensions, and process parameters of the fuel cell stack components such as bipolar plates, sealing rubber 203, membrane electrode assembly 204, and end plates. Stack the bipolar plates, sealing rubber 203, and membrane electrode assembly 204 layer by layer. Apply appropriate pressure using a press 5 to ensure that each part is fully compressed while avoiding damage due to overload.

[0057] Step S2: Collect stack edge size deviation parameters: After each layer of bipolar plates is stacked and pressure is applied, scan the edge of the stacked hydrogen fuel cell stack 2 and calculate the edge size deviation of the stacked hydrogen fuel cell stack 2.

[0058] Preferably, the process of collecting fuel cell stack size deviation parameters mainly includes steps S201-S202:

[0059] Step S201, Edge Scanning of Stacked Electron Stacks: Calibrate Optical Inspection Device 3. The optical inspection device 3 performs real-time scanning along the edge of the stacked electron stack 2 to acquire position data of the electron stack components. The edge of the electron stack refers to the edge of the electron stack parallel to the stacking direction.

[0060] Step S202, Calculation of edge deviation of stacked battery pack: Based on the measured position data of each layer of battery pack components, calculate the deviation of each measurement point relative to the reference position to obtain the edge size deviation of the stacked battery pack.

[0061] Step S3, predict the stack deviation distribution: establish a stack component deviation propagation model. After stacking the second layer of bipolar plates, analyze the edge size deviation data of the already stacked stacks, and predict the deviation distribution range ε ​​of subsequent stacks based on the already stacked data.

[0062] Preferably, during the assembly of hydrogen fuel cell components, depending on the assembly conditions, the press can apply pressure after each layer of single cells is stacked, or after multiple layers of single cells are stacked.

[0063] Preferred, see Figure 4 Predicting the distribution of fuel cell stack deviation mainly includes the following steps:

[0064] Step S301: Establish a single-component deviation model for the fuel cell stack: Considering the dimensional and assembly errors of the single-component fuel cell stack, establish a deviation transmission model for the single-component fuel cell stack and establish the deviation distribution of the single-component fuel cell stack.

[0065] Step S302: Analyze the edge dimension deviation data of the stacked battery packs: After stacking the second layer of bipolar plates, based on the edge dimension deviation data collected in S2, analyze the edge straightness and dimension deviation direction of the stacked battery packs. Through regression analysis, establish a dimension deviation model for the subsequent h-layer component stacking to predict the dimension deviation of the subsequent h-layer component stacking.

[0066] Step S303: Predict the deviation distribution of subsequent stacks based on the already stacked data: The deviation of each layer is the result of the component deviation of the previous layer plus the current component size error and assembly error. Considering the size deviation, component size error, and component assembly error of the already stacked components in S301 and S302, establish a size deviation distribution model for the subsequent h layers of components, and predict the deviation distribution interval ε of the subsequent h layers of components.

[0067] The next-level component size deviation distribution model can be established according to the following formula:

[0068]

[0069] In the formula: For the subsequent i Layer component size deviation distribution For the dimensional deviation of stacked components, For the subsequent i Dimensional tolerances of layer components For the subsequent i Assembly errors of layer components, For error terms, α , β , γ is the regression coefficient.

[0070] Step S4, modular stacking of fuel cell stacks: Determine whether the deviation distribution range ε ​​of the fuel cell stack components exceeds the limit tolerance range δ of the fuel cell stack deviation, which is the fuel cell stack assembly accuracy requirement. If the deviation distribution range ε ​​of the fuel cell stack components does not exceed the limit tolerance range δ, stacking continues; if the deviation distribution range ε ​​of the fuel cell stack components exceeds the limit tolerance range δ, stacking stops, and the stacked components form an independent fuel cell stack module.

[0071] Preferred, see Figure 5 and Figure 6 Modular stacking of fuel cell stacks mainly includes the following steps:

[0072] Step S401: Determine whether the deviation distribution range ε ​​of the fuel cell assembly exceeds the limit tolerance range δ of the fuel cell deviation, which is the fuel cell assembly accuracy requirement. If the deviation distribution range ε ​​of the fuel cell assembly does not exceed the limit tolerance range δ of the fuel cell deviation, continue stacking the next layer of components.

[0073] Step S402: If the stack component deviation distribution range ε ​​reaches or exceeds the stack deviation limit containment range δ, then the stacking operation is stopped.

[0074] Step S403: If step S402 is executed, the current stacked portion is separated to form an independent fuel cell stack module. The number of layers in each independent fuel cell stack module is dynamically determined by the fuel cell stack deviation to ensure that each independent fuel cell stack module meets the assembly accuracy requirements.

[0075] Step S5, store single stack module and its parameters: store the physical stack module in the storage location, and store the corresponding stack module related parameters, such as the number of single cells and the stack edge size deviation, in the database of computer 4.

[0076] Step S6, stacking multiple battery stack modules: After physically storing the battery stack modules in the storage location, continue stacking from new components, repeating the detection and stacking process until multiple battery stack modules that meet the assembly accuracy requirements are formed.

[0077] Preferably, the stacking of multiple fuel cell stack modules in step S6 can be completed at a single workstation or at multiple workstations simultaneously.

[0078] Example 2

[0079] Based on Example 1, this example provides a hydrogen fuel cell stack assembly system based on edge geometric feature precision constraints. Its characteristic is that it implements the aforementioned hydrogen fuel cell stack assembly method based on edge geometric feature precision constraints. (See also...) Figure 2 and Figure 3 The system includes:

[0080] (1) Stack assembly platform 1.

[0081] (2) Press 5, in conjunction with the stack assembly platform, to pressurize the hydrogen fuel cell stack;

[0082] Preferably, the hydrogen fuel cell stack includes a positioning worktable connected to a press, a positioning rod penetrating the press, a membrane electrode assembly located on the positioning worktable, and a sealing rubber connected to the membrane electrode assembly.

[0083] Preferably, the press includes a pressure plate and a guide rod arranged along the pressure application direction of the press, the pressure plate being connected to the fuel cell stack assembly platform via a screw.

[0084] (3) An optical inspection device is installed on at least one side of the hydrogen fuel cell stack to collect information on the edge size deviation of the stacked stack.

[0085] (4) Computer, connected to optical inspection equipment.

[0086] In summary, the hydrogen fuel cell stack assembly method based on edge geometric feature precision constraints provided by this invention has at least the following advantages compared to the prior art:

[0087] (1) By assembling fuel cell components, collecting stack size deviation parameters, predicting stack deviation distribution, and modularizing the stack, the assembly deviation of the stack modules is ensured to be within the assembly accuracy requirements, thus ensuring that the quality of the stack modules meets the requirements.

[0088] (2) By considering whether the predicted value of the stack deviation distribution exceeds the assembly accuracy requirement range, it is determined whether the stack meets the preset assembly accuracy requirements. The number of stack layers is dynamically determined based on the size characteristics of its bipolar plates, thereby improving the flexibility of the stack assembly process.

[0089] (3) By modularizing the fuel cell stacks, the need for rework or readjustment due to non-compliance in single-station stacking is reduced. The modularized fuel cell stacks are easy to stack, transport and fix, which can effectively save storage space. Setting up multiple stacking stations on the production line can achieve continuous production and can well adapt to the needs of mass production and high-quality production of fuel cell stacks.

[0090] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for assembling a hydrogen fuel cell stack based on edge geometric feature precision constraints, characterized in that, Includes the following steps: Step S1: Obtain component information of the fuel cell stack, control the pressurization device according to the component information, and stack the components of the fuel cell stack layer by layer. Step S2: During the layer-by-layer stacking process, in response to the completion of bipolar plate stacking and pressure application, the edge size deviation of the stacked battery pack is calculated by scanning the edge of the stacked battery pack. Step S3: Based on the edge size deviation of the already stacked fuel cell stacks, predict the deviation distribution range of subsequent fuel cell stack components by constructing a fuel cell stack component deviation propagation model; Step S4: Based on the predicted deviation distribution range of subsequent stacking, determine whether the deviation distribution range of the stacked battery pack components to be stacked is within the preset stack deviation limit range. If yes, continue stacking and execute step S2; if no, stop stacking and execute step S5. Step S5: End the current fuel cell stack stacking process and store the parameters of the completed fuel cell stack. In step S3, the process of predicting the deviation distribution range of subsequent stacking by constructing a stack component deviation propagation model includes the following steps: Step S301: Based on the dimensional error and assembly error of the fuel cell stack unit, establish a deviation transmission model for the fuel cell stack unit to obtain the error distribution of the fuel cell stack unit. Step S302: Based on the edge size deviation of the already stacked battery pack, predict the size deviation of the next layer of stacking through regression analysis; Step S303: Based on the error distribution and the size deviation, predict the deviation distribution range of the subsequent components to be stacked. The deviation distribution range of the subsequent components to be stacked is calculated based on the following formula: in, For the subsequent i Layer component size deviation distribution For the dimensional deviation of stacked components, For the subsequent i Dimensional tolerances of layer components For the subsequent i Assembly errors of layer components, For error terms, α , β , γ is the regression coefficient.

2. The hydrogen fuel cell stack assembly method based on edge geometric feature precision constraints according to claim 1, characterized in that, Also includes: Step S6: Repeat steps S1-S5 to obtain multiple fuel cell stack modules that meet the assembly accuracy requirements.

3. The hydrogen fuel cell stack assembly method based on edge geometric feature precision constraints according to claim 1, characterized in that, In step S1, in response to the completion of one or more battery stacks, the pressurization device is controlled to apply pressure to the fuel cell stack.

4. The hydrogen fuel cell stack assembly method based on edge geometric feature precision constraints according to claim 1, characterized in that, In step S2, the process of calculating the edge dimension deviation of the stacked fuel cell stack includes the following steps: Step S201: Obtain the position data of each layer of the fuel cell stack components along a direction parallel to the stacking direction of the fuel cell stack; Step S202: Based on the position data of each layer of fuel cell stack components, calculate the deviation of each measurement point relative to the reference position to obtain the fuel cell stack edge size deviation.

5. A hydrogen fuel cell stack assembly system based on edge geometric feature precision constraints, characterized in that, The system for implementing the hydrogen fuel cell stack assembly method based on edge geometric feature accuracy constraints as described in any one of claims 1-4 includes: Fuel cell stack assembly platform (1); The press (5) works in conjunction with the stack assembly platform (1) to pressurize the hydrogen fuel cell stack (2); An optical inspection device (3) is disposed on at least one side of the hydrogen fuel cell stack (2) for collecting edge size deviation information of the stacked stack.

6. The hydrogen fuel cell stack assembly system based on edge geometric feature precision constraints according to claim 5, characterized in that, The hydrogen fuel cell stack (2) includes: A positioning worktable (201) is connected to the press (5). The positioning worktable (201) is provided with a bipolar plate (206), a sealing rubber (203) and a membrane electrode assembly (204). The sealing rubber (203) is connected to the bipolar plate (206) and the membrane electrode assembly (204) respectively. The positioning rod (202) passes through the press (5).

7. A hydrogen fuel cell stack assembly system based on edge geometric feature precision constraints according to claim 5, characterized in that, The press (5) includes: Pressure plate (501); The screw (502) and the pressure plate (501) are connected to the fuel cell assembly platform (1) through the screw (502); Guide rod (503) is set along the pressure direction of the press (5).

8. A hydrogen fuel cell stack assembly system based on edge geometric feature precision constraints according to claim 5, characterized in that, Also includes: The computer (4) is connected to the optical detection device (3).

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