Integrally-packaged fuel cell stack, stacking method thereof and application of fuel cell stack in fuel cell

Abstract

The invention relates to an integrally packaged fuel cell stack, a stack pressing method thereof and an application of the fuel cell stack in a fuel cell, belongs to the field of fuel cell stacks, and aims to solve the problem of electrode limit exceeding a packaging shell in a cell stack process. The electric pile polar plate and the membrane electrode are stacked in the packaging shell, the packaging cover plate is provided with a jackscrew, the jackscrew is arranged on the plate surface part of the packaging cover plate of the packaging shell, and an electric pile in the packaging shell is jacked and pressed through the jackscrew.

Description

Technical Field

[0001] The present invention belongs to the field of fuel cell stacks, and relates to an integrally packaged fuel cell stack, a method for pressing the stack, and an application in a fuel cell. Background Art

[0002] Stack pressing is the core process of stacking fuel cell single cells (bipolar plates, membrane electrodes, seals, etc.) in sequence and applying pressure to form a complete stack. The main process is as follows: Install the packaging shell on the stacking platform to ensure horizontal alignment. Fix the limiting pads on the inner wall of the shell, and install the stacking limiting block through the positioning pins to form a guiding reference. Sequentially place components such as bipolar plates and membrane electrodes, and use the semi-cylindrical structure on the limiting block to guide precise alignment between layers to avoid lateral offset. The elastic design of the stacking limiting block absorbs assembly tolerances to ensure tight fit between layers. Apply vertical pressure to the top of the stack through a hydraulic press and compress it in stages to the target thickness to avoid cracking of the material due to sudden stress. Apply local pressure to the uppermost electrode with a setscrew before packaging to compensate for the compression deformation of the material and ensure uniform pressure distribution. Remove the stacking limiting block to release the external constraint. Install the cover plate and tighten the bolts to complete the airtight packaging, leaving a thermal expansion gap.

[0003] However, in stack assembly, the electrodes are laid layer by layer into the packaging shell and then pressed by a stack press. In order to meet the height requirement of the stack after being pressed, the laying height of the electrodes often exceeds the height of the packaging shell, which causes the excess electrodes to lose the limiting effect of the limiting pads. Summary of the Invention

[0004] To solve the problem of limiting the electrodes exceeding the packaging shell during the process of the fuel cell stack, an integrally packaged fuel cell stack according to some embodiments of the present application includes a packaging shell, a stack electrode plate, and a membrane electrode. The stack electrode plate and the membrane electrode are stacked in the packaging shell, and further includes a packaging cover plate. The packaging cover plate is provided with a setscrew, and the setscrew is arranged on the plate surface of the packaging cover plate of the packaging shell, and the stack in the packaging shell is pressed by the setscrew; wherein, the integrally packaged fuel cell stack further includes a limiting pad and a stacking limiting block. The limiting pad is fixed on the inner wall of the packaging shell of the integrally packaged fuel cell stack and is lower than the upper edge wall of the packaging shell in the height direction; the stacking limiting block is detachably arranged at the end of the limiting pad facing the upper part of the packaging shell, and the stacking limiting block is detachably connected to the packaging shell.

[0005] According to some embodiments of the present application, an integrally packaged fuel cell stack, an opening through which the press head of the stack press can pass is provided in the middle of the packaging cover plate of the packaging shell.

[0006] An integrated packaged fuel cell stack according to some embodiments of the present application. A third through hole is provided at the edge of the packaging cover plate of the packaging housing. The third through hole corresponds to a third bolt hole of the packaging housing. The third bolt hole is opened on the upper edge wall of the packaging housing. A third bolt is fixed in the third bolt hole through the third through hole to fix the packaging cover plate on the upper edge wall of the packaging housing.

[0007] An integrated packaged fuel cell stack according to some embodiments of the present application. The limit cushion block includes a first column body. The first column body includes an inner housing mounting surface and a first limit surface which are oppositely arranged. The inner housing mounting surface is fixed to the inner housing of the packaging housing. A semi-cylinder is arranged on the first limit surface along the axis direction of the first column body. The semi-cylindrical surface of the semi-cylinder faces the inside direction of the packaging housing. A limit pin hole is provided on the bottom surface of the first column body facing the upper part of the packaging housing.

[0008] The stack loading limit block includes a second column body. The second column body includes a second limit surface. On the bottom surface of the second column body facing the lower part of the packaging housing, an extension plate with a limit surface and a housing mounting plate are oppositely arranged. The limit pin is provided on the extension plate facing the bottom surface of the lower part of the packaging housing. A semi-cylinder is arranged on the second limit surface and the extension plate along the axis direction of the second column body. The semi-cylindrical surface of the semi-cylinder faces the inside direction of the packaging housing. There is a certain separation space between the extension plate and the housing mounting plate. Along the axial direction of the second column body, the extension plate is shorter than the housing mounting plate. The thickness of the extension plate is less than the thickness of the first column body. The thickness of the first column body is less than the distance between the second limit surface and the inner plate surface of the housing mounting plate. The mounting plate is mounted on the outer housing of the packaging housing, so that the packaging housing is limited between the mounting plate and the inner housing mounting surface of the first column body. The limit pin of the stack loading limit block is inserted and matched with the limit pin hole of the limit cushion block, so that the stack loading limit block is detachably arranged at the end of the limit cushion block facing the upper part of the packaging housing.

[0009] An integrated packaged fuel cell stack according to some embodiments of the present application. On the bottom surface of the first column body, on one side close to the inner housing mounting surface, a first mounting plate extending in the direction away from the bottom surface of the first column body is provided. One side surface of the first mounting plate of the first column body facing the upper part of the packaging housing abuts against the side surface of the extension plate opposite to the housing mounting plate.

[0010] An integrated packaged fuel cell stack according to some embodiments of the present application. The semi-cylinders include two or more, which are arranged at intervals and in parallel. There is a certain gap between two adjacent semi-cylinders.

[0011] An integrated - packaged fuel - cell stack according to some embodiments of the present application, 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] An integrated - packaged fuel - cell stack according to some embodiments of the present application, the first mounting plate is provided with a first through - hole, the first through - hole corresponds to the first bolt - hole of the packaging shell, and the first bolt passes through the first through - hole and is fixed in the first bolt - hole to fix the first mounting plate on the inner shell of the packaging shell;

[0013] The outer - shell mounting plate is provided with a second through - hole, the second through - hole corresponds to the second bolt - hole of the packaging shell, and the second bolt passes through the second through - hole and is fixed in the second bolt - hole to fix the outer - shell mounting plate on the outer shell of the packaging shell.

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

[0015] Install the stacking limiting block at the end of the limiting cushion block facing the upper part of the packaging shell;

[0016] Stack the fuel - cell bipolar plates and membrane - electrode alternately, wherein the un - packaged height of the fuel - cell stack is higher than the height of the packaging shell, and the part of the fuel - cell stack exceeding the height is limited by the limiting cushion block;

[0017] Lower the stacking machine press head in sections to a preset stacking force, and keep the stacking machine press head stationary. At this time, the height of the fuel - cell stack core is lower than the height of the packaging shell;

[0018] Remove the stacking limiting block from the limiting cushion block, let the packaging cover fall from the stacking machine press head, and fasten the packaging cover on the packaging shell with bolts. At this time, the stacking machine press head remains in the pressed state and does not move;

[0019] Carry out limiting by gradually and cross - locking the set screws on the packaging cover until the stacking force displayed on the fuel - cell stacker drops to 0 KN. The set screws implement and maintain the pressing state of the packaging cover on the fuel - cell stack, and raise the stacking machine press head to complete the stacking.

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

[0021] Calculate the core height of the fuel - cell stack after being pressed tightly, and calculate the length of the set screw that should penetrate into the packaging shell according to the core height;

[0022] Install the stacking limiting block at the end of the limiting cushion block facing the upper part of the packaging shell;

[0023] The bipolar plates and membrane electrode assemblies of the stack are stacked alternately. Among them, the bulk height of the stack is higher than the height of the encapsulation housing, and the part of the stack exceeding the height is limited by the limiting pads.

[0024] Lower the press head of the stacking machine in segments to a preset stacking force and keep the press head of the stacking machine stationary. At this time, the height of the stack core is lower than the height of the encapsulation housing.

[0025] Remove the stacking limiting block from the limiting pad, let the encapsulation cover plate drop from the press head of the stacking machine, and fasten the encapsulation cover plate to the encapsulation housing with bolts. At this time, the press head of the stacking machine remains in the pressed state and does not move.

[0026] Adjust the length of the setscrew on the encapsulation cover plate inserted into the encapsulation housing to reach the calculated length and fix the setscrew at this length. Maintain the pressing state of the encapsulation cover plate against the stack by the setscrew, and raise the press head of the stacking machine to complete the stacking.

[0027] Beneficial effects:

[0028] In the first aspect, the stacking limiting block of the present invention is detachably connected, that is, a connection method that can be installed and removed. It is allowed to install the stacking limiting block on the upper part of the limiting pad before stacking to limit the electrodes exceeding the height of the encapsulation housing before and during the stacking process. When the press head presses the electrodes into the encapsulation housing to a certain height, since the press head applies pressure to the electrode plates at this time, the stacking limiting block can be removed, and the press head can continue to be lowered to reach the final pressing depth. Then, fasten the encapsulation cover plate to the top surface of the encapsulation housing to complete the stacking, so as to realize that the electrodes exceeding the height of the encapsulation housing can be limited before and during the stacking process, and it does not affect the function of the press head to press down.

[0029] In the second aspect, the present invention reduces the contact area by means of multi-point line contact. The present invention uses a semi-cylindrical cylindrical line to contact the electrode, which greatly reduces the contact area compared with a plane. However, compared with, for example, triangular protrusions, it can greatly reduce the sharpness and avoid the damage of the membrane electrode caused by sharpness. In addition, the semi-cylindrical interval design disperses the contact pressure to multiple points, reduces local stress concentration, and can also avoid the deformation or damage of the electrode material due to excessive pressure.

[0030] In a third aspect, the present invention forms a separation space between the formed extension plate and the housing mounting plate, and designs the thickness relationship of the extension plate, the first cylinder, and the second cylinder, so that the separation space forms a space for accommodating the encapsulation housing, and this design reliably limits the encapsulation housing between the mounting plate and the inner housing mounting surface of the first cylinder. This method enables the accommodation space to be between the mounting plate and the inner housing mounting surface of the first cylinder, and a longer distance can be achieved in a compact space, ensuring the stability of the stacking limit block mounted on the housing. Moreover, one side of the first mounting plate of the first cylinder facing the upper part of the encapsulation housing abuts against the side surface of the extension plate relative to the housing mounting plate, which can further increase the contact area between the inner housing mounting surface of the first cylinder and the inner housing, improving the mounting stability.

[0031] In a fourth aspect, each of the two stacking methods of constant-pressure stacking and constant-height stacking of the battery stack has its application scenarios and advantages. Often, the stacking method needs to be changed in different scenarios. However, there is still no better method in the prior art to achieve the above purpose with one device. In particular, the constant-height stacking of the battery stack often requires cooperation with precise sensors, etc., resulting in high costs and operational difficulties. Through the adjustment of the setscrew during the stacking process, the above-mentioned two stacking methods can be respectively achieved, especially the switching between the two can be realized by the above solution of the present invention. Description of the Drawings

[0032] Figure 1 is a stacking schematic diagram.

[0033] Figure 2 is a schematic diagram of the cooperation between the first limit pad and the stacking limit block.

[0034] Figure 3 is a schematic diagram of the cooperation between the second limit pad and the stacking limit block.

[0035] Reference Numerals:

[0036] 100. Limit Pad, 110. First Cylinder, 111. Inner Housing Mounting Surface, 112. First Limit Surface, 113. Semi-Cylinder, 114. Limit Pin Hole, 115. First Mounting Plate

[0037] 200. Stacking Limit Block, 210. Second Cylinder, 211. Limit Pin, 212. Second Limit Surface, 213. Extension Plate, 214. Housing Mounting Plate, 2141. Second Through-Hole, 215. Separation Space;

[0038] 300. Encapsulation Housing, 310. Setscrew, 320. Upper Edge Wall of the Encapsulation Housing;

[0039] 400. Encapsulation Cover;

[0040] 500. Stacking Machine Ram. Detailed implementation mode

[0041] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. The examples of the embodiments are shown in the drawings, where 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 be used as a carrier of the fuel cell stack and also as a stack assembly tool for the fuel cell stack, and is used for limiting the position during the stacking process of the stack plates and the membrane electrode assembly. The encapsulation housing 300 can be integrally cast and processed or machined into shape. The encapsulation cover plate 400 is separately designed from the encapsulation housing 300, which is convenient for the stack plates and the membrane electrode assembly to be stacked through the opening of the encapsulation housing 300.

[0043] As Figures 1-3 shown, the fuel cell stack assembly device includes a limiting spacer 100 and a stacking limiting block 200. The limiting spacer 100 is fixed on the inner wall of the encapsulation housing 300 of the fuel cell stack and is lower than the upper edge wall 320 of the encapsulation housing in the height direction; the stacking limiting block 200 is detachably arranged at the end of the limiting spacer 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 spacer 100 of the present invention is lower than the upper edge wall 320 of the encapsulation housing to avoid affecting the pressing height of the pressing head due to its length.

[0044] Stacking the fuel cell stack is to lay the electrodes layer by layer into the encapsulation housing 300 and then perform stack pressing through a stack press. In order to make the stacked fuel cell stack meet the height requirements after being pressed, the laying height of the electrodes often exceeds the height of the encapsulation housing 300, which causes the electrodes exceeding the height to lose the limiting function of the limiting spacer 100. In order to provide the electrodes exceeding the height of the encapsulation housing 300 with position limitation during the stack pressing process and not hinder the pressing height of the pressing head, the stacking limiting block 200 of the present invention is detachably connected, that is, a detachable connection method that can be installed and removed. It is allowed to install the stacking limiting block 200 on the upper part of the limiting spacer 100 before stacking to limit the electrodes exceeding the height of the encapsulation housing 300 before and during the stack pressing process. When the pressing head presses the electrodes into the encapsulation housing 300 to a certain height, since the pressing head applies pressure to the stack plates at this time, the stacking limiting block 200 can be removed, and the pressing head can continue to press down to reach the final pressing depth, and then the encapsulation cover plate 400 is fastened on the top surface of the encapsulation housing 300 to complete the stack pressing, so as to realize the position limitation of the electrodes exceeding the height of the encapsulation housing 300 before and during the stack pressing process without affecting the pressing of the pressing head.

[0045] As Figures 2-3As shown, in one embodiment, the limit pad 100 includes a first cylinder 110. The first cylinder 110 includes an inner housing mounting surface 111 and a first limit surface 112 which are oppositely arranged. The inner housing mounting surface 111 is fixed to the inner housing of the encapsulation housing 300. Along the axial direction of the first cylinder 110, a semi-cylinder 113 is arranged on the first limit surface 112, and the semi-cylindrical surface of the semi-cylinder 113 faces the inside of the encapsulation housing 300. Preferably, there are two or more semi-cylinders 113, which are arranged at intervals and in parallel, and there is a certain gap between two adjacent semi-cylinders 113. In a preferred solution, the limit pad 100 serves as the main limiting device during the stacking process of the fuel cell bipolar plates and membrane electrode assemblies. A total of five limit pads 100 can be installed on the entire encapsulation housing 300, and each limit pad 100 uses the semi-cylinder 113 to limit the bipolar plates and membrane electrode assemblies. The five limit pads adopt the same limit surface shape, and the semi-circular positioning surface helps for accurate positioning.

[0046] The limit pad 100 limits the electrodes inside the encapsulation housing 300. Ideally, this limit should be contact only without extrusion. For this reason, the pressure of the limit pad 100 on the electrodes should be minimized. Especially for the membrane electrode assembly which is made of soft plastic material, the inventor found that when the limit pad 100 limits and contacts the membrane electrode assembly with a plane, the contact area is large, and there is a greater chance of extruding the soft plastic material over a larger area, resulting in electrode deformation or even damage. For this reason, the present invention hopes to reduce the contact area by means of multi-point line contact. In the above solution of the present invention, the cylindrical line of the semi-cylinder 113 is used to contact the electrode, which greatly reduces the contact area compared with a plane. However, compared with, for example, triangular protrusions, it can greatly reduce the sharpness and avoid the damage of the membrane electrode assembly caused by sharpness. In addition, the spaced design of the semi-cylinders 113 disperses the contact pressure to multiple points, reducing local stress concentration, and can also avoid the deformation or damage of the electrode material due to excessive pressure.

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

[0048] Such as Figures 2-3As shown, in one embodiment, on the bottom surface of the first cylinder 110, on the side close to the inner housing mounting surface 111, a first mounting plate 115 extending in the direction away from the bottom surface of the first cylinder 110 is provided. Preferably, the first mounting plate 115 is provided with a first through hole, and the first through hole corresponds to the first bolt hole of the encapsulation housing 300. The first bolt passes through the first through hole and is fixed in the first bolt hole to fix the first mounting plate 115 on the inner housing of the encapsulation housing 300. The present invention realizes detachable connection through a bolt connection method, and opens holes on the extended first mounting plate 115 on the first cylinder 110, which can avoid directly opening holes on the relatively thick cylinder, ensuring the connection stability and reducing the hole-opening difficulty and cost.

[0049] As Figures 2-3 shown, in one embodiment, a limit pin hole 114 is provided on the bottom surface of the first cylinder 110 facing the upper part of the encapsulation housing 300. The stacking limit block 200 includes a second cylinder 210, and a limit pin 211 is provided on the bottom surface of the second cylinder 210 facing the lower part of the encapsulation housing 300. Among them, the limit pin 211 of the stacking limit block 200 is inserted and matched with the limit pin hole 114 of the limit pad 100 so that the stacking limit block 200 is detachably arranged at the end of the limit pad 100 facing the upper part of the encapsulation housing 300. As described above, the present invention realizes the detachable connection between the limit pad 100 and the stacking limit block 200 through the cooperation of the limit pin hole 114 and the limit pin 211. Preferably, the same number of stacking limit blocks 200 as the limit pads 100 are fixed on the encapsulation housing 300, and each stacking limit block 200 belongs to the extension of the limit pad 100.

[0050] From the above, before stacking, the stacking limit block 200 of the present invention is fixed on the outer housing of the encapsulation housing 300 by bolts. Since it is necessary to ensure the consistency of the transition between the stacking limit block 200 and the limit pad 100 to prevent jamming at the joint of the two limit blocks during the stacking process of the fuel cell bipolar plates and membrane electrodes. The present invention provides a limit pin hole 114 at the top of the limit pad 100 and a limit pin 211 at the bottom of the stacking limit block 200. Before stacking, the stacking limit block 200 is installed on the limit pad 100, and horizontal direction limitation is performed through the cooperation of the limit pin and the limit pin hole.

[0051] As Figures 2-3As shown, in one embodiment, the second cylinder 210 includes a second limiting surface 212. The second cylinder 210 is provided with an extension plate 213 and a housing mounting plate 214 with limiting surfaces opposite to the bottom surface of the lower part of the encapsulation housing 300. Preferably, the housing mounting plate 214 is provided with a second through hole 2141, and the second through hole 2141 corresponds to the second bolt hole of the encapsulation housing 300. The second bolt passes through the second through hole 2141 and is fixed in the second bolt hole to fix the housing mounting plate 214 on the housing of the encapsulation housing 300. The above solution also realizes the stable fixation and detachable function of the stacking limiting block 200 and the encapsulation housing 300. In addition, the present invention realizes detachable connection through a bolt connection method, and opens holes in the housing mounting plate 214, which can avoid directly opening holes in a relatively thick cylinder, ensuring the stability of the connection while reducing the difficulty and cost of opening holes.

[0052] As Figures 2-3 shown, in one embodiment, the extension plate 213 is provided with a limiting pin 211 on the bottom surface facing the lower part of the encapsulation housing 300; there is a certain separation space 215 between the extension plate 213 and the housing mounting plate 214. Along the axial direction of the second cylinder 210, the extension plate 213 is shorter than the housing mounting plate 214; the thickness of the extension plate 213 is less than the thickness of the first cylinder 110, and the thickness of the first cylinder 110 is less than the distance between the second limiting surface 212 and the inner plate surface of the housing mounting plate 214; the mounting plate is mounted on the housing of the encapsulation housing 300, so that the encapsulation housing 300 is limited between the mounting plate and the inner housing mounting surface 111 of the first cylinder 110. Preferably, one side surface of the first mounting plate 115 provided on the first cylinder 110 facing the upper part of the encapsulation housing 300 abuts against the side surface of the extension plate 213 relative to the housing mounting plate 214. By forming the separation space 215 between the extension plate 213 and the housing mounting plate 214, and designing the thickness relationship among the extension plate 213, the first cylinder 110 and the second cylinder 210, the present invention makes the separation space 215 form a space for accommodating the encapsulation housing 300, and this design makes the encapsulation housing 300 be reliably limited between the mounting plate and the inner housing mounting surface 111 of the first cylinder 110. This way makes this accommodation space be between the mounting plate and the inner housing mounting surface 111 of the first cylinder 110, and a longer distance can be achieved in a compact space, ensuring the stability of the stacking limiting block 200 mounted on the housing. And in the preferred solution, one side surface of the first mounting plate 115 provided on the first cylinder 110 facing the upper part of the encapsulation housing 300 abuts against the side surface of the extension plate 213 relative to the housing mounting plate 214, which can further increase the contact area between the inner housing mounting surface 111 of the first cylinder 110 and the inner housing, improving the mounting stability.

[0053] As Figures 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 axis direction of the second cylinder 210, and the semi-cylindrical surface of the semi-cylinder 113 faces the inside of the encapsulation housing 300. Preferably, there are two or more semi-cylinders 113, which are arranged at intervals and in parallel, and there is a certain gap between two 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 guiding and limiting.

[0054] As Figure 1 As shown, in one embodiment, a third through hole is provided at the edge of the encapsulation cover plate 400 of the encapsulation housing 300, and the third through hole corresponds to the third bolt hole of the encapsulation housing 300, and the third bolt hole is opened on the upper edge wall 320 of the encapsulation housing; the fuel cell stack assembly device further includes a third bolt and a setscrew 310, and the third bolt is fixed in 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 setscrew 310 is arranged on the plate surface of the encapsulation cover plate 400 of the encapsulation housing 300, and the uppermost electrode in the encapsulation housing 300 is pressed by the setscrew 310.

[0055] Preferably, eight setscrews 310 on the encapsulation cover plate 400 can be designed, which are spaced and evenly distributed on the plate part of the encapsulation cover plate 400, and are used for limiting the pressed stack. The stack can be assembled according to a fixed force or a fixed distance through the setscrews 310.

[0056] In one embodiment, an opening is designed at the center position of the encapsulation cover plate 400, and the shape of the opening is the same as the shape of the pressing head of the used stacker. Before the stack assembly of the fuel cell stack, the encapsulation cover plate 400 is pre-installed on the pressing head of the stacker through the opening at its center. After the stack is pressed, the stack limiting block 200 is removed, and the encapsulation cover plate 400 is dropped to the upper part of the encapsulation housing 300, and the edge of the encapsulation cover plate 400 and the upper edge of the encapsulation housing 300 are bolted and tightened. The fuel cell stack is tightened according to a fixed force or a fixed distance through the setscrews 310 on the encapsulation cover plate 400.

[0057] In another embodiment, the present invention proposes a fuel cell stack assembly method, which is implemented using the stack assembly device in the above embodiments to achieve constant pressure stack assembly, and includes the following steps:

[0058] Install the stack limiting block 200 at the end of the limiting cushion block 100 facing the upper part of the encapsulation housing 300.

[0059] The bipolar plates and membrane electrode assemblies of the stack are alternately stacked to complete the stack loading. The uncompressed height of the stack is higher than the height of the encapsulation housing 300, and the stack exceeding the height is limited by the limiting spacer block 100. Herein, the uncompressed height of the stack refers to the height of the stack core of the stack after hundreds of bipolar plates and membrane electrode assemblies are stacked without preloading.

[0060] First, the pressing head of the stack loading machine is pressed down in sections to the preset stack loading force, and the pressing head of the stack loading machine is kept stationary. At this time, the height of the stack core is already lower than the height of the encapsulation housing 300.

[0061] At this time, the stack loading limiting block 200 used to limit the bipolar plates and membrane electrode assemblies higher than the encapsulation housing 300 is removed, the encapsulation cover plate 400 is dropped from the pressing head of the stack loading machine, and the encapsulation cover plate 400 is fastened to the encapsulation housing 300 with bolts. At this time, the pressing head of the stack loading machine still remains in the pressed state and does not move.

[0062] At this time, the set screws 310 on the encapsulation cover plate 400 are gradually tightened crosswise for limiting until the pressing force displayed on the stack pressing machine drops to 0 KN, that is, the stack assembly is completed. The set screws 310 implement and maintain the pressing state of the encapsulation cover plate 400 on the stack. At this time, the pressing head of the stack loading machine can be raised to complete the integrated encapsulation and stack loading process.

[0063] During the stack loading process, by adjusting the pressure in real time, each layer of components of the stack always bears a constant pressure value. For components with different compression moduli, the constant pressure can ensure uniform compression of each layer and avoid local overpressure or underpressure caused by material property differences. It is applicable to stacks with large fluctuations in material batches or a high proportion of flexible components.

[0064] Applicable scenarios: Stacks with large fluctuations in material batches (such as a ±10% deviation in the porosity of graphite bipolar plates) or a high proportion of flexible components (such as silicone rubber seals).

[0065] In another embodiment, the present invention proposes a stack loading method for a fuel cell stack, which is implemented using the stack loading device in the above embodiments to achieve stack loading with a constant stack core height, including the following steps:

[0066] Calculate the stack core height in the state after the stack core is pressed, and calculate the length of the set screws 310 extending into the encapsulation housing 300 according to the stack core height;

[0067] The bipolar plates and membrane electrode assemblies of the stack are alternately stacked to complete the stack loading. First, the pressing head of the stack loading machine is pressed down in sections to the preset stack loading force, and the pressing head of the stack loading machine is kept stationary. The height of the stack core is already lower than the height of the encapsulation housing 300;

[0068] At this time, the stacking limiting block 200 for limiting the bipolar plate and the membrane electrode that are higher than the encapsulation housing 300 is removed, the encapsulation cover plate 400 is dropped from the stacking machine press head, and the encapsulation cover plate 400 is fastened to the encapsulation housing 300 with bolts. At this time, the stacking machine press head still remains in the pressed state without moving.

[0069] At this time, adjust the length of the setscrew 310 on the encapsulation cover plate 400 that penetrates into the encapsulation housing 300 to reach the calculated length and fix the setscrew 310 at this length. At this time, the stacking machine press head can be raised to complete the integrated encapsulation and stacking process.

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

[0071] Each of the above two stacking methods has its application scenarios and advantages. Therefore, it is often necessary to change the stacking method in different scenarios. However, there is still no better method in the existing technology to achieve the above purpose with one device. In particular, the constant stack height stacking often requires cooperation with precise sensors, etc., with high costs and operational difficulties. In the above solution of the present invention, through the adjustment of the setscrew 310 during the stacking process, the two stacking methods can be respectively achieved, especially the switching between the two can be realized.

[0072] In another embodiment, the present invention proposes a fuel cell stack, including the above-mentioned stacking device. Specifically, it includes an encapsulation housing 300, a stack electrode plate and a membrane electrode. The stack electrode plate and the membrane electrode are stacked in the encapsulation housing 300. It is characterized in that it further includes an encapsulation cover plate 400. The encapsulation cover plate 400 is provided with a setscrew 310. The setscrew 310 is arranged on the plate surface of the encapsulation cover plate 400 of the encapsulation housing 300, and the stack in the encapsulation housing 300 is pressed by the setscrew 310. Among them, the integrated encapsulation fuel cell stack further includes a limiting cushion block 100 and a stacking limiting block 200. The limiting cushion block 100 is fixed on the inner wall of the encapsulation housing 300 of the integrated encapsulation fuel cell stack and is lower than the upper edge wall 320 of the encapsulation housing in the height direction. The stacking limiting block 200 is detachably arranged at the end of the limiting cushion block 100 facing the upper part of the encapsulation housing 300, and the stacking limiting block 200 is detachably connected to the encapsulation housing 300. Among them, an opening through which the press head 500 of the stacking machine can pass is provided in the middle of the encapsulation cover plate 400 of the encapsulation housing 300. Among them, a third through hole is provided at the edge of the encapsulation cover plate 400 of the encapsulation housing 300. The third through hole corresponds to the third bolt hole of the encapsulation housing 300. The third bolt hole is opened on the upper edge wall 320 of the encapsulation housing, and the encapsulation cover plate 400 is fixed on the upper edge wall 320 of the encapsulation housing by the third bolt passing through the third through hole and being fixed in the third bolt hole. Among them, the limiting cushion block 100 and the stacking limiting block 200 are any one of the above embodiments.

[0073] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0074] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0075] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0077] In the present invention, the term "and / or" describes the associated relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one" means one or more; "at least one of A and B" is similar to "A and / or B", describing the associated relationship of associated objects, indicating that three relationships may exist. For example, at least one of A and B may represent: A exists alone, A and B exist simultaneously, and B exists alone.

[0078] In the present invention, terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0079] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An integrated packaged fuel cell stack, comprising a packaging shell (300), a stack plate and a membrane electrode, wherein the stack plate and the membrane electrode are stacked in the packaging shell (300), characterized in that: It also includes a packaging cover plate (400), the packaging cover plate (400) is provided with a top screw (310), the top screw (310) is arranged on the plate surface of the packaging cover plate (400) of the packaging shell (300), and the stack in the packaging shell (300) is pressed by the top screw (310); wherein the integrated packaged fuel cell stack also includes a limit pad (100) and a stacking limit block (200), the limit pad (100) is fixed on the inner shell wall of the packaging shell (300) of the integrated packaged fuel cell stack, and is lower than the upper edge wall (320) of the packaging shell in the height direction; the stacking limit block (200) is detachably arranged on the end of the limit pad (100) facing the upper part of the packaging shell (300), and the stacking limit block (200) is detachably connected to the packaging shell (300).

2. The integrated packaged fuel cell stack according to claim 1, characterized in that: An opening through which the pressing head (500) of the stacking machine can pass is provided in the middle of the packaging cover plate (400) of the packaging shell (300).

3. The integrated packaged fuel cell stack according to claim 1, characterized in that: A third through hole is provided at the edge of the packaging cover plate (400) of the packaging shell (300), the third through hole corresponding to the third bolt hole of the packaging shell (300), the third bolt hole is opened on the upper edge wall (320) of the packaging shell, and a third bolt is fixed to the third bolt hole through the third through hole to fix the packaging cover plate (400) on the upper edge wall (320) of the packaging shell.

4. The integrated packaged fuel cell stack according to claim 1, characterized in that: The limiting pad (100) comprises a first column (110), the first column (110) comprising an inner shell mounting surface (111) and a first limiting surface (112) which are arranged opposite to each other, the inner shell mounting surface (111) being fixed to the inner shell of the encapsulating shell (300), a semi-cylinder (113) being arranged on the first limiting surface (112) along the axial direction of the first column (110), the semi-cylindrical surface of the semi-cylinder (113) being arranged toward the interior of the encapsulating shell (300), and a limiting pin hole (114) being arranged on the bottom surface of the first column (110) facing the upper part of the encapsulating shell (300); The stacking limit block (200) comprises a second column (210), the second column (210) comprises a second limit surface (212), an extension plate (213) of the limit surface and an outer shell mounting plate (214) are arranged on the bottom surface of the second column (210) facing the lower part of the packaging shell (300), and the limit pin (211) is arranged on the bottom surface of the extension plate (213) facing the lower part of the packaging shell (300); a semi-cylinder (113) is arranged on the second limit surface (212) and the extension plate (213) along the axial direction of the second column (210), and the semi-cylindrical surface of the semi-cylinder (113) is arranged towards the inside of the packaging shell (300); a certain separation space (215) is provided between the extension plate (213) and the outer shell mounting plate (214), and a space (215) is provided along the second column (210) ) in the axial direction, 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 packaging shell (300) so that the packaging shell (300) is limited between the mounting plate and the inner shell mounting surface (111) of the first column (110), and the limiting pin (211) of the stacking limiting block (200) is inserted and matched with the limiting pin hole (114) of the limiting pad block (100) so that the stacking limiting block (200) can be detachably arranged at the end of the limiting pad block (100) facing the upper part of the packaging shell (300).

5. The integrated packaged fuel cell stack according to claim 4, characterized in that: A first mounting plate (115) extending in a direction away from the bottom surface of the first column (110) is provided on one side of the bottom surface of the first column (110) close to the inner shell mounting surface (111), and a side surface of the first mounting plate (115) of the first column (110) disposed toward the upper part of the packaging shell (300) is pressed against a side surface of the extension plate (213) relative to the outer shell mounting plate (214).

6. The integrated packaged fuel cell stack according to claim 4, characterized in that: The semi-circular cylinders (113) include two or more, which are arranged in parallel and at intervals, and there is a certain gap between two adjacent semi-circular cylinders (113).

7. The integrated packaged fuel cell stack according to claim 4, characterized in that: The semi-cylinder (113) arranged on the second limiting surface (212) and the extension plate (213) corresponds to the semi-cylinder (113) arranged on the first limiting surface (112).

8. 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, the first through hole corresponding to the first bolt hole of the packaging shell (300), and the first bolt is fixed to the first bolt hole through the first through hole to fix the first mounting plate (115) to the inner shell of the packaging shell (300); The outer shell mounting plate (214) is provided with a second through hole (2141), and the second through hole (2141) corresponds to the second bolt hole of the packaging shell (300), and the second bolt is fixed to the second bolt hole through the second through hole (2141) to fix the outer shell mounting plate (214) to the outer shell of the packaging shell (300).

9. The method for pressing a fuel cell stack according to any one of claims 1 to 8, characterized in that: For constant pressure stacking, including the following steps: The stacking limit block (200) is installed on the end of the limit cushion block (100) facing the upper part of the packaging shell (300); The bipolar plates and membrane electrodes of the battery stack are stacked alternately, wherein the bulk height of the battery stack is higher than the height of the packaging shell (300), and the battery stack exceeding the height is limited by the limiting pad (100); Pressing the stacking machine pressure head downward in sections to a preset stacking force, keeping the stacking machine pressure head stationary, at which point the height of the stack core is lower than the height of the packaging shell (300); The stacking limit block (200) is removed from the limit pad (100), the packaging cover plate (400) is dropped from the stacking machine pressure head, and the packaging cover plate (400) is fastened to the packaging shell (300) using bolts, and the stacking machine pressure head remains in a tight state and does not move; The top screws (310) on the packaging cover plate (400) are gradually locked and limited by crossing until the pressing force displayed on the stack pressing machine drops to 0 KN, the top screws (310) implement and maintain the pressing state of the packaging cover plate (400) on the stack, and the stacking machine pressure head is raised to complete the stacking.

10. The method for pressing a fuel cell stack according to any one of claims 1 to 8, characterized in that: It is used for loading the core at a constant height, and includes the following steps: Calculating the core height of the fuel cell stack after the core is compressed, and calculating the length of the top screw (310) that should penetrate into the packaging shell (300) according to the core height; The stacking limit block (200) is installed on the end of the limit cushion block (100) facing the upper part of the packaging shell (300); The bipolar plates and membrane electrodes of the battery stack are stacked alternately, wherein the bulk height of the battery stack is higher than the height of the packaging shell (300), and the battery stack exceeding the height is limited by the limiting pad (100); Pressing the stacking machine pressure head downward in sections to a preset stacking force, keeping the stacking machine pressure head stationary, at which point the height of the stack core is lower than the height of the packaging shell (300); The stacking limit block (200) is removed from the limit pad (100), the packaging cover plate (400) is dropped from the stacking machine pressure head, and the packaging cover plate (400) is fastened to the packaging shell (300) using bolts, and the stacking machine pressure head remains in a tight state and does not move; The length of the top screw (310) on the packaging cover plate (400) penetrating into the packaging shell (300) is adjusted to reach the calculated length and the top screw (310) is fixed at the length. The top screw (310) maintains the length to implement and maintain the packaging cover plate (400) in a tight state against the battery stack, and the stacking machine pressure head is raised to complete the stacking.

Images