Integrated packaged fuel cell stack, its stacking method, and its application in fuel cells

Abstract

The integrated encapsulated fuel cell stack, its stacking method, and its application in fuel cells belong to the field of fuel cell stacks. To solve the problem of exceeding the electrical limit of the encapsulation shell during the stacking process, the key technical points include an encapsulation shell, stack plates, and membrane electrode assembly (MEA). The stack plates and MEA are stacked in the encapsulation shell, which also includes an encapsulation cover plate. The encapsulation cover plate is provided with a set screw, which is located on the plate surface of the encapsulation cover plate of the encapsulation shell. The set screw presses against the fuel cell stack inside the encapsulation shell.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell stacks, and relates to an integrated packaged fuel cell stack, its stacking method, and its application in fuel cells. Background Technology

[0002] Fuel cell stacking is the core process of sequentially stacking fuel cell cells (bipolar plates, membrane electrode assemblies, seals, etc.) and applying pressure to form a complete fuel cell stack. The main process is as follows: The encapsulation shell is installed on the stacking platform, ensuring horizontal alignment. Limiting blocks are fixed to the inner wall of the shell, and stacking limiting blocks are installed using limiting pins to form a guiding reference. Bipolar plates, membrane electrode assemblies, and other components are placed sequentially, using the semi-cylindrical structure on the limiting blocks to guide precise alignment between layers and avoid lateral displacement. The elastic design of the stacking limiting blocks absorbs assembly tolerances, ensuring a tight fit between layers. Vertical pressure is applied to the top of the stack using a hydraulic press, compressing it in stages to the target thickness to prevent sudden material cracking. Before encapsulation, set screws are used to apply localized pressure to the top electrode to compensate for material compression deformation and ensure uniform pressure distribution. The stacking limiting blocks are removed to release external constraints. The cover plate is installed and bolts are tightened to complete the hermetic sealing, leaving a thermal expansion gap.

[0003] However, fuel cell stacking involves laying the electrodes layer by layer into the package and then pressing them together using a stack press. In order for the stack to meet the required height after being pressed, the electrode laying height often exceeds the height of the package, which causes the excess electrodes to lose the limiting effect of the limiting pads. Summary of the Invention

[0004] To address the issue of exceeding the electrical limit of the encapsulation shell during fuel cell stacking, an integrated encapsulation fuel cell stack according to some embodiments of this application includes an encapsulation shell, stack plates, and membrane electrode assemblies (MEAs). The stack plates and MEAs are stacked within the encapsulation shell. The stack also includes an encapsulation cover plate with set screws disposed on the surface of the cover plate, pressing the fuel cell stack within the encapsulation shell. Furthermore, the integrated encapsulation fuel cell stack includes a limiting pad and a stacking limiting block. The limiting pad is fixed to the inner wall of the encapsulation shell and is lower than the upper edge of the encapsulation shell in the height direction. The stacking limiting block is detachably disposed at the end of the limiting pad facing the upper part of the encapsulation shell and is detachably connected to the encapsulation shell.

[0005] According to some embodiments of this application, an integrated packaged fuel cell stack has an opening in the middle of the package cover plate of the package housing through which the press head of the stacker can pass.

[0006] According to some embodiments of this application, an integrated packaged fuel cell stack has a third through hole on the edge of the package cover plate of the package housing. The third through hole corresponds to a third bolt hole of the package housing. The third bolt hole is opened on the upper edge wall of the package housing, and the third bolt is fixed to the upper edge wall of the package housing by a third bolt through the third through hole.

[0007] According to some embodiments of this application, an integrated packaged fuel cell stack includes a limiting pad comprising a first column, the first column comprising an inner shell mounting surface and a first limiting surface disposed opposite to each other, the inner shell mounting surface being fixed to the inner shell of the packaged shell, a semi-cylinder being disposed on the first limiting surface along the axial direction of the first column, the semi-cylinder surface of the semi-cylinder being disposed facing the interior of the packaged shell, and a limiting pin hole being disposed on the bottom surface of the first column facing the upper part of the packaged shell.

[0008] The stacking limiting block includes a second column, which includes a second limiting surface. An extension plate with the limiting surface and an outer shell mounting plate are disposed opposite to the bottom surface of the second column facing the lower part of the encapsulation housing. The limiting pin is disposed on the bottom surface of the extension plate facing the lower part of the encapsulation housing. A semi-cylinder is disposed along the axis of the second column on the second limiting surface and the extension plate, with the semi-cylindrical surface of the semi-cylinder facing inwards towards the encapsulation housing. A certain separation space exists between the extension plate and the outer shell mounting plate. Along the axial direction of the second column, the extension plate is shorter than the outer shell mounting plate. The thickness of the extension plate is less than the thickness of the first column, and the thickness of the first column is less than the distance between the second limiting surface and the inner surface of the outer shell mounting plate. The mounting plate is installed on the outer shell of the encapsulation housing, limiting the encapsulation housing between the mounting plate and the inner shell mounting surface of the first column. The limiting pin of the stacking limiting block is inserted into the limiting pin hole of the limiting pad to allow the stacking limiting block to be detachably disposed on the upper end of the limiting pad facing the encapsulation housing.

[0009] According to some embodiments of this application, an integrated packaged fuel cell stack has a first mounting plate extending away from the bottom surface of the first column on the side near the inner shell mounting surface. One side of the first mounting plate, which is disposed on the first column in the direction of the upper part of the packaged shell, abuts against the side of the extended plate relative to the outer shell mounting plate.

[0010] According to some embodiments of this application, an integrated packaged fuel cell stack includes two or more semi-cylinders arranged at intervals and in parallel, with a certain gap between adjacent semi-cylinders.

[0011] According to some embodiments of this application, in an integrated packaged fuel cell stack, the semi-cylinders provided on the second limiting surface and the extension plate correspond to the semi-cylinders provided on the first limiting surface.

[0012] According to some embodiments of this application, an integrated packaged fuel cell stack is provided with a first through hole, which corresponds to a first bolt hole of the packaged housing. The first bolt is fixed to the inner housing of the packaged housing by the first bolt through the first through hole.

[0013] The outer casing mounting plate is provided with a second through hole, which corresponds to the second bolt hole of the encapsulation housing. The second bolt is fixed to the outer casing of the encapsulation housing by the second bolt through the second through hole.

[0014] A method for pressing an integrated packaged fuel cell stack according to some embodiments of this application, used for constant pressure stacking, includes the following steps:

[0015] The stacking limiting block is installed on the end of the limiting pad that faces the upper part of the packaging shell;

[0016] The bipolar plates and membrane electrodes of the fuel cell stack are stacked alternately, wherein the bulk height of the fuel cell stack is higher than the height of the package housing, and the fuel cell stack exceeding the height is limited by the limiting pads;

[0017] The stacker head is pressed down in sections to the preset stacking force, and the stacker head is kept stationary. At this point, the height of the fuel cell stack core is lower than the height of the encapsulation shell.

[0018] Remove the stacking limiting block from the limiting pad, drop the encapsulation cover from the stacking machine head, and fasten the encapsulation cover to the encapsulation housing with bolts. At this time, the stacking machine head remains pressed and stationary.

[0019] Limit the pressure by gradually tightening the set screws on the encapsulation cover plate in a crisscross pattern until the pressure displayed on the stack pressor drops to 0 kN. The set screws then apply and maintain the pressure of the encapsulation cover plate on the stack, and the stack pressor head is raised to complete the stacking process.

[0020] A method for stacking an integrated packaged fuel cell stack according to some embodiments of this application, used for stacking at a constant core height, includes the following steps:

[0021] Calculate the core height after the fuel cell stack core is compressed, and calculate the length of the set screw that should extend into the encapsulation shell based on the core height;

[0022] The stacking limiting block is installed on the end of the limiting pad that faces the upper part of the packaging shell;

[0023] The bipolar plates and membrane electrodes of the fuel cell stack are stacked alternately, wherein the bulk height of the fuel cell stack is higher than the height of the package housing, and the fuel cell stack exceeding the height is limited by the limiting pads;

[0024] The stacker head is pressed down in sections to the preset stacking force, and the stacker head is kept stationary. At this point, the height of the fuel cell stack core is lower than the height of the encapsulation shell.

[0025] Remove the stacking limiting block from the limiting pad, drop the encapsulation cover from the stacking machine head, and fasten the encapsulation cover to the encapsulation housing with bolts. At this time, the stacking machine head remains pressed and stationary.

[0026] Adjust the set screw on the encapsulation cover to extend to the length of the encapsulation housing to reach the calculated length, and fix the set screw at this length. The set screw maintains this length and keeps the encapsulation cover pressed against the fuel cell stack. Raise the stacker head to complete the stacking.

[0027] Beneficial effects:

[0028] In the first aspect, the stacking limiting block of the present invention is a detachable connection, meaning it can be installed and removed. This allows the stacking limiting block to be installed on the upper part of the limiting pad before stacking, limiting electrodes that exceed the height of the encapsulation shell before and during stacking. When the pressing head presses the electrode into the encapsulation shell to a certain height, the stacking limiting block can be removed because the pressing head applies pressure to the electrode plate at this time. The pressing head can then continue to press down to reach the final pressing depth. Finally, the encapsulation cover plate is fastened to the top surface of the encapsulation shell to complete the stacking. This achieves the ability to limit electrodes that exceed the height of the encapsulation shell before and during stacking without affecting the pressing action of the pressing head.

[0029] Secondly, this invention reduces the contact area through multi-point line contact. The invention uses a semi-cylindrical line to contact the electrode, significantly reducing the contact area compared to a flat surface. However, compared to features like triangular protrusions, it greatly reduces sharpness, preventing damage to the membrane electrode caused by sharpness. Furthermore, the semi-cylindrical spacing design distributes contact pressure across multiple points, reducing localized stress concentration and preventing deformation or damage to the electrode material due to excessive pressure.

[0030] On a third-party level, this invention, through the separation space between the molded extension plate and the outer casing mounting plate, and by designing the thickness relationship between the extension plate, the first column, and the second column, creates a space for accommodating the encapsulation shell. This design reliably limits the encapsulation shell between the mounting plate and the inner casing mounting surface of the first column. This method allows for a longer distance within a compact space, ensuring the stability of the stacking limiting block mounted on the shell. Furthermore, the side of the first mounting plate facing upwards towards the encapsulation shell abuts against the side of the extension plate opposite the outer casing mounting plate, further increasing the contact area between the inner casing mounting surface of the first column and the inner casing, thus improving installation stability.

[0031] Fourthly, both constant pressure stacking and constant stack height stacking have their own application scenarios and advantages. Often, different stacking methods need to be used in different scenarios, and current technology lacks a better way to achieve these objectives using a single device. In particular, constant stack height stacking often requires the use of precision sensors, which increases cost and operational difficulty. The solution of this invention, through the adjustment of the set screw during the stacking process, can achieve both stacking methods separately, and more importantly, can switch between them. Attached Figure Description

[0032] Figure 1 This is a diagram of the stacking process.

[0033] Figure 2 This is a schematic diagram of the first type of limiting pad and stacking limiting block.

[0034] Figure 3 This is a schematic diagram of the second type of limiting pad and stacking limiting block working together.

[0035] Figure label:

[0036] 100. Limiting pad, 110. First column, 111. Inner shell mounting surface, 112. First limiting surface, 113. Semi-cylinder, 114. Limiting pin hole, 115. First mounting plate

[0037] 200. Stacking limit block; 210. Second column; 211. Limiting pin; 212. Second limiting surface; 213. Extension plate; 214. Outer shell mounting plate; 2141. Second through hole; 215. Dividing space;

[0038] 300. Encapsulation housing; 310. Set screw; 320. Upper edge wall of the encapsulation housing;

[0039] 400. Encapsulation cover plate;

[0040] 500. Compactor head. Detailed Implementation

[0041] The embodiments of this application are described in detail below with reference to the accompanying drawings, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0042] The fuel cell stack assembly device of the present invention can serve as a carrier for the fuel cell stack and also as a stacking tool for the fuel cell stack, used for limiting the stack plates and membrane electrode assembly during the stacking process. The encapsulation shell 300 can be integrally cast or machined. The encapsulation cover plate 400 and the encapsulation shell 300 are designed separately to facilitate the stacking of the stack plates and membrane electrode assembly through the opening of the encapsulation shell 300.

[0043] like Figure 1-3 As shown, the fuel cell stack assembly includes a limiting pad 100 and a stacking limiting block 200. The limiting pad 100 is fixed to the inner shell wall of the fuel cell stack's encapsulation housing 300 and is lower than the upper edge wall 320 of the encapsulation housing in the height direction. The stacking limiting block 200 is detachably disposed at the end of the limiting pad 100 facing the upper part of the encapsulation housing 300, and the stacking limiting block 200 is detachably connected to the encapsulation housing 300. It can be understood that the limiting pad 100 of the present invention is lower than the upper edge wall 320 of the encapsulation housing to avoid its length affecting the pressure head's downward pressing height.

[0044] Electron stacking involves laying electrodes layer by layer into the encapsulation housing 300 and then pressing them using a stacking press. To ensure the stack reaches the required height after pressing, the electrode layering height often exceeds the height of the encapsulation housing 300. This causes the excess electrodes to lose the limiting function of the limiting pad 100. To provide limiting for electrodes exceeding the encapsulation housing 300 during stacking without hindering the pressing head's downward pressure, the stacking limiting block 200 of this invention is detachably connected, allowing for both installation and removal. This allows the stacking limiting block 200 to be installed on top of the limiting pad 100 before stacking, thus limiting the electrodes exceeding the encapsulation housing height. The electrodes with a height of 300 are limited before and during the pressing process. When the pressing head presses the electrodes into the encapsulation housing 300 to a certain height, the pressing head applies pressure to the electrode plate at this time, so the stacking limiting block 200 can be removed, and the pressing head can continue to press down to reach the final pressing depth. Then the encapsulation cover plate 400 is fastened to the top surface of the encapsulation housing 300 to complete the pressing process. This achieves the limitation of electrodes exceeding the height of the encapsulation housing 300 before and during the pressing process without affecting the pressing head's downward pressing function.

[0045] like Figure 2-3As shown, in one embodiment, the limiting pad 100 includes a first column 110, which includes an inner shell mounting surface 111 and a first limiting surface 112 disposed opposite to each other. The inner shell mounting surface 111 is fixed to the inner shell of the encapsulation shell 300. A semi-cylinder 113 is disposed on the first limiting surface 112 along the axial direction of the first column 110, with the semi-cylinder surface of the semi-cylinder 113 facing inward toward the encapsulation shell 300. Preferably, there are two or more semi-cylinders 113, which are spaced apart and arranged in parallel, with a certain gap between adjacent semi-cylinders 113. In a preferred embodiment, the limiting pad 100 serves as the main limiting device during the stacking process of the bipolar plates and membrane electrodes. Five limiting pads 100 can be installed on the entire encapsulation shell 300, and each limiting pad 100 is limited by the semi-cylinder 113 to limit the bipolar plates and membrane electrodes. The five limiting blocks adopt the same limiting surface shape, and the semi-circular positioning surface helps with accurate positioning.

[0046] The limiting pad 100 serves to limit the electrodes inside the encapsulation housing 300. Ideally, this limiting should involve contact without compression. Therefore, the pressure exerted by the limiting pad 100 on the electrodes should be minimized, especially since the membrane electrode is made of soft plastic. The inventors discovered that when the limiting pad 100 contacts the membrane electrode with a flat surface as its limiting point, the large contact area increases the likelihood of compression on the soft plastic material over a larger area, leading to electrode deformation or even damage. Therefore, this invention aims to reduce the contact area through multi-point line contact. The above-described solution uses the cylindrical line of the semi-cylinder 113 to contact the electrode, significantly reducing the contact area relative to the flat surface. However, compared to features like triangular protrusions, it greatly reduces sharpness, avoiding damage to the membrane electrode caused by sharpness. Furthermore, the spaced design of the semi-cylinder 113 disperses the contact pressure to multiple points, reducing local stress concentration and preventing deformation or damage to the electrode material due to excessive pressure.

[0047] Figure 2 The schematic stacking limit block 200 has an inner shell mounting surface 111 in Figure 2 The groove in the design is an avoidance slot designed to avoid mounting parts in the inner housing of the encapsulation housing 300.

[0048] like Figure 2-3As shown, in one embodiment, a first mounting plate 115 extending away from the bottom surface of the first column 110 is provided on the side of the bottom surface of the first column 110 near the inner housing mounting surface 111. Preferably, the first mounting plate 115 is provided with a first through hole, which corresponds to the first bolt hole of the encapsulation housing 300. The first bolt is fixed to the inner housing of the encapsulation housing 300 by the first bolt through the first through hole. The present invention achieves a detachable connection through bolt connection, and by using the first mounting plate 115 extending on the first column 110 for opening, it can avoid opening directly on a thick column, ensuring the stability of the connection while reducing the difficulty and cost of opening.

[0049] like Figure 2-3 As shown, in one embodiment, the first column 110 has a limiting pin hole 114 on its bottom surface facing the upper part of the packaging housing 300, and the stacking limiting block 200 includes a second column 210, with a limiting pin 211 on its bottom surface facing the lower part of the packaging housing 300; wherein, the limiting pin 211 of the stacking limiting block 200 is inserted into the limiting pin hole 114 of the limiting pad 100 so that the stacking limiting block 200 is detachably disposed at the end of the limiting pad 100 facing the upper part of the packaging housing 300. As described above, the present invention achieves a detachable connection between the limiting pad 100 and the stacking limiting block 200 through the cooperation of the limiting pin hole 114 and the limiting pin 211. Preferably, the same number of stacking limiting blocks 200 as the limiting pad 100 are fixed on the packaging housing 300, and each stacking limiting block 200 is an extension of the limiting pad 100.

[0050] As described above, before stacking, the stacking limiting block 200 of this invention is fixed to the outer shell of the encapsulation housing 300 by bolts. To ensure consistency in the transition between the stacking limiting block 200 and the limiting pad 100, and to prevent jamming at the joint between the two limiting blocks during the stacking of the bipolar plates and membrane electrodes, this invention provides a limiting pin hole 114 at the top of the limiting pad 100 and a limiting pin 211 at the bottom of the stacking limiting block 200. Before stacking, the stacking limiting block 200 is installed on the limiting pad 100, and the limiting pin and the limiting pin hole cooperate to provide horizontal limiting.

[0051] like Figure 2-3As shown, in one embodiment, the second column 210 includes a second limiting surface 212. An extension plate 213 with the limiting surface and a housing mounting plate 214 are disposed opposite to the bottom surface of the second column 210 facing the lower part of the encapsulation housing 300. Preferably, the housing mounting plate 214 is provided with a second through hole 2141, which corresponds to a second bolt hole in the encapsulation housing 300. A second bolt is used to fix the housing mounting plate 214 to the outer housing of the encapsulation housing 300 through the second through hole 2141. The above solution also achieves stable fixing and detachability between the stacking limiting block 200 and the encapsulation housing 300. Furthermore, the present invention achieves detachable connection through bolt connection, and by opening the outer housing mounting plate 214, it avoids directly opening into a thicker column, ensuring connection stability while reducing the difficulty and cost of opening the hole.

[0052] like Figure 2-3 As shown, in one embodiment, a limiting pin 211 is provided on the bottom surface of the extension plate 213 facing the lower part of the encapsulation housing 300; a certain separation space 215 exists between the extension plate 213 and the outer shell mounting plate 214; along the axial direction of the second column 210, the extension plate 213 is shorter than the outer shell mounting plate 214; the thickness of the extension plate 213 is less than the thickness of the first column 110, and the thickness of the first column 110 is less than the distance between the second limiting surface 212 and the inner plate surface of the outer shell mounting plate 214; the mounting plate is installed on the outer shell of the encapsulation housing 300, so that the encapsulation housing 300 is limited between the mounting plate and the inner shell mounting surface 111 of the first column 110. Preferably, one side of the first mounting plate 115 of the first column 110 facing the upper part of the encapsulation housing 300 abuts against the side of the extension plate 213 opposite to the outer shell mounting plate 214. The present invention, through the forming of the partition space 215 between the extension plate 213 and the outer casing mounting plate 214, and by designing the thickness relationship of the extension plate 213, the first column 110, and the second column 210, forms a space for accommodating the encapsulation housing 300. This design reliably limits the encapsulation housing 300 between the mounting plate and the inner casing mounting surface 111 of the first column 110. This method, by making the accommodating space between the mounting plate and the inner casing mounting surface 111 of the first column 110, allows for a longer distance in a compact space, ensuring the stability of the stacking limiting block 200 mounted on the housing. Furthermore, in a preferred embodiment, one side of the first mounting plate 115, which is positioned towards the upper part of the encapsulation housing 300, abuts against the side of the extension plate 213 opposite to the outer casing mounting plate 214, further increasing the contact area between the inner casing mounting surface 111 of the first column 110 and the inner casing, thereby improving installation stability.

[0053] like Figure 2-3As shown, in one embodiment, a semi-cylinder 113 is provided on the second limiting surface 212 and the extension plate 213 along the axial direction of the second column 210, with the semi-cylindrical surface of the semi-cylindrical column 113 facing inward toward the encapsulation housing 300. Preferably, there are two or more semi-cylinders 113, spaced apart and arranged in parallel, with a certain gap between adjacent semi-cylinders 113. More preferably, the semi-cylinders 113 provided on the second limiting surface 212 and the extension plate 213 correspond to the semi-cylinders 113 provided on the first limiting surface 112, and this correspondence results in the semi-cylinders 113 forming continuous guide limiting.

[0054] like Figure 1 As shown, in one embodiment, the edge of the encapsulation cover plate 400 of the encapsulation housing 300 is provided with a third through hole, which corresponds to a third bolt hole in the encapsulation housing 300. The third bolt hole is opened on the upper edge wall 320 of the encapsulation housing. The fuel cell stack assembly device also includes a third bolt and a set screw 310. The third bolt is fixed to the third bolt hole through the third through hole to fix the encapsulation cover plate 400 on the upper edge wall 320 of the encapsulation housing. The set screw 310 is provided on the plate surface of the encapsulation cover plate 400 of the encapsulation housing 300, and the set screw 310 presses against the uppermost electrode inside the encapsulation housing 300.

[0055] Preferably, the set screws 310 on the encapsulation cover plate 400 can be designed as eight, spaced apart and evenly distributed on the plate portion of the encapsulation cover plate 400, for limiting the stack after press-fitting. The stack can be assembled by a fixed force or by a fixed distance through the set screws 310.

[0056] In one embodiment, the encapsulation cover plate 400 has an opening at its center, the shape of which is the same as the shape of the pressure head of the stacking machine. Before stacking the fuel cell stack, the encapsulation cover plate 400 is pre-installed on the pressure head of the stacking machine through its central opening. After the fuel cell stack is pressed, the stacking limit block 200 is removed, and the encapsulation cover plate 400 is lowered to the upper part of the encapsulation housing 300. The edges of the encapsulation cover plate 400 and the upper edge of the encapsulation housing 300 are bolted together. The fuel cell stack is fastened by the set screw 310 on the encapsulation cover plate 400 with a fixed force or a fixed distance.

[0057] In another embodiment, the present invention proposes a fuel cell stack assembly method, implemented using the assembly apparatus described in the above embodiments, to achieve constant pressure assembly, comprising the following steps:

[0058] The stacking limit block 200 is installed on the end of the limit pad block 100 facing the upper part of the encapsulation housing 300.

[0059] The battery stack is assembled by alternately stacking bipolar plates and membrane electrodes. The bulk height of the battery stack is higher than the height of the packaging shell by 300. The battery stack exceeding the height is limited by the limiting pad 100. The bulk height of the battery stack refers to the height of the battery stack core when hundreds of bipolar plates and membrane electrodes are stacked without pre-compression.

[0060] First, press down the stacker head in sections to the preset stacking force, and keep the stacker head stationary. At this time, the height of the fuel cell stack core is already lower than the height of the encapsulation shell by 300.

[0061] At this point, the stacking limit block 200 used to limit the bipolar plate and membrane electrode that are higher than the packaging housing 300 is removed, the packaging cover plate 400 is dropped from the stacker head, and the packaging cover plate 400 is fastened to the packaging housing 300 with bolts. At this time, the stacker head remains in a pressed state and does not move.

[0062] At this point, the capping screws 310 on the encapsulation cover plate 400 are gradually tightened in a crisscross pattern to limit the position until the stacking force displayed on the stack pressor drops to 0 kN, thus completing the stack assembly. The capping screws 310 are used to implement and maintain the pressing state of the encapsulation cover plate 400 on the stack. At this point, the stack pressor head can be raised to complete the integrated encapsulation and stacking process.

[0063] During the stacking process, pressure is adjusted in real time to ensure that each layer of the fuel cell stack is always subjected to a constant pressure value. For components with different compression moduli, constant pressure can ensure uniform compression of each layer and avoid local overpressure or underpressure caused by differences in material properties. It is suitable for fuel cell stacks with large batch fluctuations in materials or a high proportion of flexible components.

[0064] Applicable scenarios: fuel cell stacks with large batch fluctuations in materials (e.g., graphite bipolar plate porosity deviation ±10%) or a high proportion of flexible components (e.g., silicone sealing rings).

[0065] In another embodiment, the present invention proposes a fuel cell stack assembly method, implemented using the assembly apparatus described in the above embodiments, to achieve constant core height during assembly, comprising the following steps:

[0066] Calculate the core height after the fuel cell stack core is compressed, and calculate the length of the set screw 310 extending into the encapsulation housing 300 based on the core height;

[0067] The stack bipolar plates and membrane electrodes are stacked alternately to complete the stacking. First, the stacker head is pressed down in sections to the preset stacking force. The stacker head is kept still. The height of the stack core is already lower than the height of the packaging shell by 300.

[0068] At this point, the stacking limit block 200 used to limit the bipolar plate and membrane electrode that are higher than the packaging housing 300 is removed, the packaging cover plate 400 is dropped from the stacker head, and the packaging cover plate 400 is fastened to the packaging housing 300 with bolts. At this time, the stacker head remains in a pressed state and does not move.

[0069] At this point, adjust the length of the set screw 310 on the encapsulation cover plate 400 into the encapsulation housing 300 to reach the calculated length and fix the set screw 310 at this length. Then, the stacker head can be raised to complete the integrated encapsulation and stacking process.

[0070] During the stacking process, the final physical height of the fuel cell stack is strictly fixed at a constant stack height. This method ensures the consistency of the stack's external dimensions and reduces the cost of subsequent adjustments.

[0071] The two aforementioned reactor compression methods each have their own application scenarios and advantages. Therefore, it is often necessary to change the reactor compression method in different scenarios. However, current technology does not offer a better way to achieve the above objectives using a single device. In particular, constant reactor height compression often requires the use of precision sensors, which increases cost and operational difficulty. The solution of this invention, through the adjustment of the top screw 310 during the reactor compression process, can achieve both reactor compression methods separately, and in particular, can switch between the two.

[0072] In another embodiment, the present invention proposes a fuel cell stack including the aforementioned stacking device. Specifically, it includes a casing 300, stack plates, and membrane electrode assemblies (MEAs), which are stacked within the casing 300. The invention is characterized by further including a casing cover 400, which is provided with a set screw 310 on its surface. The set screw 310 presses against the fuel cell stack within the casing 300. The integrated fuel cell stack also includes a limiting pad 100 and a stacking limiting block 200. The limiting pad 100 is fixed to the inner wall of the casing 300 and is lower than the upper edge wall 320 of the casing in the height direction. The stacking limiting block 200 is detachably disposed at the end of the limiting pad 100 facing the upper part of the casing 300, and is detachably connected to the casing 300. The encapsulation cover plate 400 of the encapsulation housing 300 has an opening in the middle through which the press head 500 of the press can pass. The encapsulation cover plate 400 of the encapsulation housing 300 has a third through hole along its edge, corresponding to a third bolt hole in the encapsulation housing 300. The third bolt hole is located on the upper edge wall 320 of the encapsulation housing, and a third bolt is used to fix the encapsulation cover plate 400 to the upper edge wall 320 of the encapsulation housing through the third through hole. The limiting pad 100 and the stacking limiting block 200 are any one of those in the above embodiments.

[0073] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to 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.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0075] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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, an electrical connection, or a connection that allows communication between them; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0077] In this invention, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following associated objects are in an "or" relationship. "At least one" refers to one or more; "at least one of A and B," similar to "A and / or B," describes the relationship between associated objects, indicating that three relationships can exist. For example, at least one of A and B can represent: A alone, A and B simultaneously, or B alone.

[0078] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0079] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An integrated encapsulated fuel cell stack, comprising an encapsulation housing (300), stack plates, and membrane electrode assemblies (MEAs), wherein the stack plates and MEAs are stacked within the encapsulation housing (300), characterized in that, It also includes a package cover plate (400), the package cover plate (400) is provided with a set screw (310), the set screw (310) is provided on the plate surface of the package cover plate (400) of the package housing (300), and the set screw (310) presses against the internal fuel cell stack of the package housing (300); The integrated packaged fuel cell stack also includes a limiting pad (100) and a stacking limiting block (200). The limiting pad (100) is fixed on the inner shell wall of the packaged housing (300) of the integrated packaged fuel cell stack and is lower than the upper edge wall (320) of the packaged housing in the height direction. The stacking limiting block (200) is detachably disposed at the end of the limiting pad (100) facing the upper part of the packaging shell (300), and the stacking limiting block (200) is detachably connected to the packaging shell (300); The limiting pad (100) includes a first column (110), the first column (110) includes an inner shell mounting surface (111) and a first limiting surface (112) disposed opposite to each other, the inner shell mounting surface (111) is fixed to the inner shell of the encapsulation shell (300), a semi-cylinder (113) is provided on the first limiting surface (112) along the axial direction of the first column (110), the semi-cylinder surface of the semi-cylinder (113) is disposed facing the inside of the encapsulation shell (300), and a limiting pin hole (114) is provided on the bottom surface of the first column (110) facing the upper part of the encapsulation shell (300); The stacking limiting block (200) includes a second column (210), the second column (210) includes a second limiting surface (212), the second column (210) is provided with an extension plate (213) with the limiting surface and an outer shell mounting plate (214) opposite to the bottom surface of the second column (210) facing the lower part of the encapsulation shell (300), and the limiting pin (211) is provided on the bottom surface of the extension plate (213) facing the lower part of the encapsulation shell (300); A semi-cylinder (113) is provided on the second limiting surface (212) and the extension plate (213) along the axial direction of the second column (210), and the semi-cylinder surface of the semi-cylinder (113) is arranged facing the inside of the encapsulation shell (300); There is a certain separation space (215) between the extension plate (213) and the outer shell mounting plate (214). Along the axial direction of the second column (210), the extension plate (213) is shorter than the outer shell mounting plate (214). The thickness of the extension plate (213) is less than the thickness of the first column (110), and the thickness of the first column (110) is less than the distance between the second limiting surface (212) and the inner surface of the outer shell mounting plate (214). The mounting plate is installed on the outer shell of the encapsulation housing (300), so that the encapsulation housing (300) is limited between the mounting plate and the inner shell mounting surface (111) of the first column (110). The limiting pin (211) of the stacking limiting block (200) is inserted into the limiting pin hole (114) of the limiting pad (100) so that the stacking limiting block (200) is detachably disposed at the end of the limiting pad (100) facing the upper part of the encapsulation housing (300).

2. The integrated packaged fuel cell stack according to claim 1, characterized in that, The encapsulation cover plate (400) of the encapsulation housing (300) is provided with an opening in the middle through which the press head (500) of the press can pass.

3. The integrated packaged fuel cell stack according to claim 1, characterized in that, The packaging cover plate (400) of the packaging housing (300) has a third through hole on its edge. The third through hole corresponds to the third bolt hole of the packaging housing (300). The third bolt hole is opened on the upper edge wall (320) of the packaging housing. The third bolt is fixed to the upper edge wall (320) of the packaging housing by the third bolt through the third through hole.

4. The integrated packaged fuel cell stack according to claim 1, characterized in that, A first mounting plate (115) extending away from the bottom surface of the first column (110) is provided on the side of the bottom surface of the first column (110) near the inner housing mounting surface (111). One side of the first mounting plate (115) of the first column (110) facing the upper part of the encapsulation housing (300) abuts against the side of the extension plate (213) relative to the outer housing mounting plate (214).

5. The integrated packaged fuel cell stack according to claim 1, characterized in that, The semi-cylinders (113) include two or more, which are spaced apart and arranged in parallel, and there is a certain gap between two adjacent semi-cylinders (113).

6. The integrated packaged fuel cell stack according to claim 1, characterized in that, The semi-cylinder (113) provided on the second limiting surface (212) and the extension plate (213) corresponds to the semi-cylinder (113) provided on the first limiting surface (112).

7. The integrated packaged fuel cell stack according to claim 4, characterized in that, The first mounting plate (115) is provided with a first through hole, which corresponds to the first bolt hole of the encapsulation housing (300). The first bolt is fixed to the first bolt hole through the first through hole to fix the first mounting plate (115) on the inner shell of the encapsulation housing (300). The outer casing mounting plate (214) is provided with a second through hole (2141), which corresponds to the second bolt hole of the encapsulation housing (300). The second bolt is fixed to the second bolt hole through the second through hole (2141) to fix the outer casing mounting plate (214) to the outer casing of the encapsulation housing (300).

8. The method for pressurizing the fuel cell stack according to any one of claims 1-7, characterized in that, For constant pressure stacking, the following steps are included: The stacking limiting block (200) is installed at the end of the limiting pad (100) facing the upper part of the encapsulation housing (300); The bipolar plates and membrane electrodes of the fuel cell stack are stacked alternately, wherein the bulk height of the fuel cell stack is higher than the height of the packaging shell (300), and the fuel cell stack exceeding the height is limited by the limiting pad (100); The stacker head is pressed down in sections to the preset stacking force, and the stacker head is kept stationary. At this time, the height of the fuel cell stack core is lower than the height of the encapsulation shell (300). Remove the stacking limiting block (200) from the limiting pad (100), drop the encapsulation cover plate (400) from the stacker head, and fasten the encapsulation cover plate (400) to the encapsulation housing (300) with bolts. At this time, the stacker head remains pressed and does not move. Limiting is achieved by gradually tightening the set screws (310) on the encapsulation cover (400) in a crisscross pattern until the stacking force displayed on the stack pressor drops to 0 kN. The set screws (310) then apply and maintain the encapsulation cover (400) pressing against the stack, and the stack pressor head is raised to complete the stacking process.

9. The method for pressurizing the fuel cell stack according to any one of claims 1-7, characterized in that, For constant core height stacking, the following steps are included: Calculate the core height after the fuel cell stack core is compressed, and calculate the length of the set screw (310) that should extend into the encapsulation shell (300) based on the core height; The stacking limiting block (200) is installed at the end of the limiting pad (100) facing the upper part of the encapsulation housing (300); The bipolar plates and membrane electrodes of the fuel cell stack are stacked alternately, wherein the bulk height of the fuel cell stack is higher than the height of the packaging shell (300), and the fuel cell stack exceeding the height is limited by the limiting pad (100); The stacker head is pressed down in sections to the preset stacking force, and the stacker head is kept stationary. At this time, the height of the fuel cell stack core is lower than the height of the encapsulation shell (300). Remove the stacking limiting block (200) from the limiting pad (100), drop the encapsulation cover plate (400) from the stacker head, and fasten the encapsulation cover plate (400) to the encapsulation housing (300) with bolts. At this time, the stacker head remains pressed and does not move. Adjust the length of the set screw (310) on the encapsulation cover (400) into the encapsulation housing (300) to reach the calculated length and fix the set screw (310) at this length. The set screw (310) maintains this length and keeps the encapsulation cover (400) pressed against the stack. The stacker head is then raised to complete the stacking.

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