Mechanism and method for fuel cell double stack assembly

Abstract

The present application relates to the field of fuel cell, in particular to a mechanism and method for fuel cell double stack assembly, comprising a support frame, a sliding rail fixed on the surface of the support frame, a pushing assembly fixed on the support frame and located at the beginning of the sliding rail, a second stack fixed on the beginning of the sliding rail through a sliding guide block and a first stack fixed on the end of the sliding rail through a fixed guide block; the pushing assembly comprises a bracket and a cylinder fixed on the bracket; the first stack is fixed on the fixed guide block for fixed positioning; the second stack is fixed on the sliding guide block for fixed positioning; the second stack is pushed by the cylinder to slide along the sliding rail to approach and compress the first stack; the first stack and the second stack are locked by bolts to complete the double stack assembly. Compared with the prior art, the present application ensures the flatness of the two stacks on the manifold mounting surface, reduces the height difference after the integrated manifold is mounted, and reduces the risk of gas and liquid leakage in each cavity.

Description

Technical Field

[0001] This invention relates to the field of fuel cells, and more specifically to a mechanism and method for assembling dual stacks of fuel cells. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) is a power generation device that directly converts the chemical energy present in fuel and oxidant into electrical energy. In a typical PEMFC, the membrane electrode assembly (MEA) is generally placed between two conductive plates, each with a flow channel. The flow channels are formed on the surfaces in contact with the MEA through die casting, stamping, or mechanical milling, and there are usually more than one such channel. The single plates can be made of metallic or graphite materials.

[0003] In a single-cell configuration of a proton exchange membrane fuel cell, there is only one membrane electrode assembly (MEA) and two monopolar plates. The two monopolar plates are located on opposite sides of the MEA: one is the anode monopolar plate for fuel, and the other is the cathode monopolar plate for oxidant. The antifreeze flow surfaces of the two plates are bonded together to form a complete bipolar plate. This bipolar plate serves both as a current collector and as a mechanical support for the MEA.

[0004] A typical fuel cell stack consists of end plates, insulating plates, current collectors, and multiple individual cells. Multiple bipolar plates and membrane electrode assemblies are encapsulated together to form the fuel cell stack core. The core is encased internally by external supporting end plates, and the electrical energy generated by the chemical reaction is extracted through current collectors at both ends of the inner core. The hydrogen cavity, water cavity, and air cavity of the core are isolated externally by manifolds.

[0005] To achieve greater fuel cell power, with the membrane electrode reaction area remaining unchanged, one of the more direct methods, besides increasing the number of bipolar plates on a single stack, is to use a dual-stack parallel configuration to increase fuel cell power.

[0006] The patent application CN202111604583.5, entitled "A Parallel Connection Device for Dual Stacks of Fuel Cells," primarily discloses a method for splicing dual stack manifolds, designing an integrated manifold that merges the water, hydrogen, and air cavities of the two stacks. The patent application CN202110999813.6, entitled "A Dual Stack Packaging Structure for Fuel Cells in Electric Forklifts," primarily discloses a structure for fixing fuel cells and lithium batteries to improve space utilization. However, the devices and structures provided in these two prior art applications cannot solve the problem of maintaining a high degree of flatness consistency between the two stacks on the manifold mounting surface. After installation and fixing, height differences will occur, leading to the risk of gas and liquid leakage. Summary of the Invention

[0007] The purpose of this invention is to provide a mechanism and method for assembling dual stacks of fuel cells in order to solve at least one of the above problems, ensure the flatness of the two stacks on the manifold mounting surface, reduce the height difference after the integrated manifold is installed, and reduce the risk of gas and liquid leakage in each cavity.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] The first aspect of the present invention discloses a mechanism for assembling dual stacks of fuel cells, including a support frame, a slide rail fixed to the surface of the support frame, a pushing component fixed to the support frame and located at the beginning of the slide rail, a second stack slidably fixed to the beginning of the slide rail by a sliding guide block, and a first stack fixed to the end of the slide rail by a fixed guide block.

[0010] The pushing assembly includes a bracket and a cylinder fixed on the bracket; the cylinder pushes the second fuel cell stack to slide along the slide rail, so that the second fuel cell stack presses against the first fuel cell stack.

[0011] Preferably, the pushing assembly further includes a translational push plate, which is slidably fixed on the bracket and located in front of the cylinder output end. The cylinder pushes the translational push plate, causing it to abut against and push the second fuel cell stack to slide along the slide rail. The contact area between the translational push plate and the second fuel cell stack is much larger than that of the cylinder output end, thus protecting the structure of the second fuel cell stack by dispersing the pressure (thrust) of the cylinder.

[0012] Preferably, the pushing assembly further includes a manual control valve, which is fixed to the side of the bracket and connected to the cylinder drive. The manual control valve controls the cylinder output to push the translation push plate, causing the translation push plate to abut against and push the second fuel cell stack to slide along the slide rail. The translation push plate can be adjusted manually, facilitating adjustment and maintenance.

[0013] Preferably, the translational push plates are provided in pairs, and the two translational push plates are fixed together by a crossbar, with the cylinder output end aligned with the crossbar. The two translational push plates can apply force evenly during clamping, ensuring a clamping and sealing effect.

[0014] Preferably, the cylinders are provided in pairs, with the output ends of the two cylinders respectively aligned with the crossbar. The two cylinders can provide sufficient thrust, and together with the two translational push plates, they can provide uniform pressure.

[0015] Preferably, the actuation component further includes a flow valve, which is fixed on the bracket and connected to the cylinder. The flow valve controls the flow rate of compressed air entering the cylinder, so that the cylinder operates at a speed of 0.2-0.8 m / min.

[0016] Preferably, after the second fuel cell stack presses against the first fuel cell stack, the compression ratio of the seal between the first and second fuel cell stacks is 15-25%.

[0017] Preferably, the actuating assembly further includes a pressure reducing valve, which is fixed on the bracket and connected to the cylinder, and the pressure reducing valve controls the pressure of the compressed air entering the cylinder to be 0.5-0.65 MPa.

[0018] Controlling the compression ratio of the seal between the two fuel cells effectively ensures the sealing performance of the dual fuel cells after clamping and locking. By controlling the compressed air flow rate to adjust the cylinder operating speed, the consistency of pressure on the pressure-bearing surface of the second fuel cell can be controlled; by controlling the compressed air pressure, the compression ratio can be kept between 15-25%.

[0019] Preferably, the support frame further includes a support backing fixed to the end of the slide rail, and after the first fuel cell stack is fixed by a fixed guide block, its back is pressed against the support backing. The support backing prevents the first fuel cell stack from tilting when it is compressed.

[0020] Preferably, the support frame is equipped with casters at the bottom. The casters facilitate transportation.

[0021] Preferably, the casters are movable casters with brakes. This allows for easy locking when relocation is not required.

[0022] A second aspect of the present invention discloses a method for assembling a dual stack of fuel cells, using any of the mechanisms described above, comprising the following steps:

[0023] The first fuel cell stack is placed against the support and fixed to the fixed guide block for positioning; the second fuel cell stack is fixed to the sliding guide block for positioning; the second fuel cell stack is pushed along the slide rail by the cylinder to approach and press against the first fuel cell stack; the first and second fuel cell stacks are locked with bolts to complete the assembly of the dual fuel cell stacks.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. After the first and second fuel cell stacks are fixedly positioned on the guide block, the manifold mounting ends of the two stacks fall on the slide rail. Due to gravity, they can maintain relative stability. After being pressed, fixed and locked, the flatness of the bottom manifold mounting surfaces of the two stacks can be ensured to be consistent, reducing the height difference between the bottom mounting surfaces of the two stacks and ensuring the sealing of the manifold mounting surfaces, effectively reducing the possibility of gas or liquid leakage inside the fuel cell.

[0026] 2. By controlling the pressure and flow rate of the compressed gas entering the cylinder, the compression ratio of the seal between the two fuel cells after locking is precisely controlled to 15-25%, ensuring the sealing performance and installation reliability of the two fuel cells. Furthermore, a manual control valve is provided, allowing manual control of the cylinder's operation and adjustment of the translational push plate's movement, facilitating adjustments and control during maintenance and testing.

[0027] 3. Fix the first fuel cell stack firmly against the support to ensure that it will not tilt during compression, thereby improving the consistency of the compression effect and ensuring the sealing of the dual fuel cell stacks. Attached Figure Description

[0028] Figure 1 This is a front view schematic diagram of the mechanism of the present invention;

[0029] Figure 2 This is a rear view structural diagram of the mechanism of the present invention;

[0030] Figure 3 This is a schematic diagram of the working process of the mechanism of the present invention;

[0031] In the diagram: 1-First fuel cell stack; 2-Second fuel cell stack; 3-Cylinder; 4-Pressure reducing valve; 5-Transfer push plate; 6-Manual control valve; 7-Slide rail; 8-Support frame; 9-Support backrest. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] A mechanism for assembling dual stacks of fuel cells, such as Figure 1 and Figure 2 As shown, it includes a support frame 8, a slide rail 7 fixed to the surface of the support frame 8, a push assembly fixed to the support frame 8 and located at the beginning of the slide rail 7, a second battery stack 2 slidably fixed to the beginning of the slide rail 7 by a sliding guide block, and a first battery stack 1 fixed to the end of the slide rail 7 by a fixed guide block.

[0035] The pushing component includes a bracket and a cylinder 3 fixed on the bracket; the cylinder 3 pushes the second electric stack 2 to slide along the slide rail 7, so that the second electric stack 2 presses against the first electric stack 1.

[0036] More specifically, in this embodiment:

[0037] like Figure 1As shown, this mechanism can be divided into a bottom support section and an upper working section. The bottom support section includes a support frame 8 and casters fixed to the bottom of the support feet of the support frame 8 for easy transport. The upper working section includes a pushing component, a first fuel cell stack 1, a second fuel cell stack 2, a slide rail 7, and a support backrest 9. The slide rail 7 extends from one end of the support frame 8 (as the end of the slide rail 7) to about 2 / 3 of the position of the support frame 8 (as the beginning of the slide rail 7), and the remaining 1 / 3 of the position of the support frame 8 is used to fix the pushing component. A sliding guide block that can slide along the slide rail 7 and a fixed guide block fixed to the slide rail 7 are slidably arranged at the beginning and end of the slide rail 7, respectively. The first fuel cell stack 1 is fixed to the fixed guide block, while the second fuel cell stack 2 is fixed to the sliding guide block. To improve the smoothness of sliding and the fixing performance of the first fuel cell stack 1 and the second fuel cell stack 2, as follows... Figure 1 As shown, a slide rail 7 is fixedly installed on the left and right sides of the support frame 8, so that the guide blocks (including sliding guide blocks and fixed guide blocks) can be fixed from both sides of the fuel cell stack, improving the stability of fixing and sliding. A support backing 9 is also fixedly installed on the support frame 8 at the end of the slide rail 7, such as... Figure 2 As shown, after the first fuel cell stack 1 is fixed to the slide rail 7 by the fixed guide block, the back of the first fuel cell stack 1 is pressed against the support backing 9. Therefore, during the pressing process of the two fuel cell stacks, the first fuel cell stack 1 will not tilt due to pressure, ensuring the airtightness of the double fuel cell stacks after locking. The pushing assembly includes a bracket fixedly connected to the support frame 8. A pair of cylinders 3 and a pair of translation push plates 5 are fixed at the upper front end of the bracket. The two translation push plates 5 are fixedly connected by a crossbar, and the crossbar is set on the line connecting the output ends of the two cylinders 3. When the cylinder 3 is activated, it will push the crossbar to move, thereby driving the translation push plates 5 to move back and forth. The translation push plates 5 are located at both ends of the bracket, close to the side of the second fuel cell stack 2. When the cylinder 3 is activated, the translation push plates 5 on both sides and the crossbar in the middle will abut against the back of the second fuel cell stack 2 to increase the contact area, and under the action of the cylinder 3, push it along the slide rail 7 towards the first fuel cell stack 1. A pressure reducing valve 4 and a flow valve are also fixedly installed on the bracket. Both valves are used to control the compressed air entering the cylinder 3. The pressure reducing valve 4 adjusts the compressed air pressure to 0.5-0.65 MPa, while the flow valve controls the compressed air flow rate to keep the operating speed of the cylinder 3 between 0.2-0.8 m / min. This ensures that the compression ratio of the seal between the two fuel cell stacks can be maintained between 15-25%, providing sealing and installation reliability for the dual fuel cell stacks. In addition, a manual control valve 6 is fixed to the side of the bracket. This manual control valve 6 is connected to the cylinder 3, allowing the operation of the cylinder 3 to be controlled manually.

[0038] A flowchart illustrating the organization's workflow can be found here. Figure 3 :

[0039] First, place the first fuel cell stack 1 on the side of the mechanism close to the support 9, and position and fix it according to the fixed guide block and the support 9. Then place the second fuel cell stack 2 on the side of the mechanism close to the bracket, and position it according to the sliding guide rail. At this point, the manifold mounting faces of both fuel cell stacks fall onto the slide rail 7. Under the action of gravity, they can maintain relative stability and consistency, thus ensuring the consistency of the flatness of the bottom manifold mounting surfaces of the two fuel cell stacks after locking.

[0040] Adjust the opening of the pressure reducing valve 4 to maintain the compressed air pressure between 0.5-0.65 MPa, thus controlling the compression ratio of the seals between the two fuel cells after clamping to be between 15-25%. Then, adjust the opening of the flow valve to control the compressed air flow rate, thereby controlling the operating speed of cylinder 3 within the range of 0.2-0.8 m / min, to ensure consistent pressure on the pressure-bearing surface of the second fuel cell stack 2. By separately controlling the compressed air pressure and flow rate, the sealing performance of the dual fuel cell stacks and the reliability of the installation are ensured. The specific compressed air pressure and cylinder 3 operating speed should be determined based on the specifications of the selected seals and the required compression ratio.

[0041] The manual control valve 6 is operated to activate cylinder 3. The output end of cylinder 3 pushes the second fuel cell stack 2 along slide rail 7 towards the first fuel cell stack 1, causing the two fuel cell stacks to approach each other laterally and gradually close together. Subsequently, cylinder 3 continuously applies pressure, causing the seal between the two fuel cell stacks to be compressed under pressure. The compression ratio of the seal is determined based on the pressure displayed on the pressure gauge connected to cylinder 3, thereby ensuring the sealing performance of the dual fuel cell stack structure.

[0042] After compaction, the positioning holes on the fuel cell stack are used to determine whether the dual fuel cell stack assembly position is qualified. Once it is confirmed to be qualified, a torque wrench is used to install and tighten the bolts between the two fuel cell stacks to complete the assembly of the dual fuel cell stacks.

[0043] After the dual fuel cell stack is assembled, install the airtight manifold and check whether the sealing is qualified. If it is qualified, the subsequent assembly verification and performance test can be carried out. If the sealing is not qualified, check whether the above-mentioned set parameters meet the requirements, or whether the components of the dual fuel cell stack and the purchased parts are well sealed, and repeat the above steps.

[0044] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A mechanism for fuel cell double stack assembly, characterized by, It includes a support frame (8), a slide rail (7) fixed to the surface of the support frame (8), a push assembly fixed to the support frame (8) and located at the beginning of the slide rail (7), a second stack (2) slidably fixed to the beginning of the slide rail (7) by a sliding guide block, and a first stack (1) fixed to the end of the slide rail (7) by a fixed guide block. The pushing assembly includes a bracket and a cylinder (3) fixed on the bracket; the cylinder (3) pushes the second fuel cell stack (2) to slide along the slide rail (7), so that the second fuel cell stack (2) presses against the first fuel cell stack (1). The propulsion assembly also includes a flow valve, which is fixed on the bracket and connected to the cylinder (3). The flow valve controls the flow rate of compressed air entering the cylinder (3) so that the operating speed of the cylinder (3) is 0.2-0.8 m / min. The actuation assembly also includes a pressure reducing valve (4), which is fixed on the bracket and connected to the cylinder (3). The pressure reducing valve (4) controls the pressure of the compressed air entering the cylinder (3) to be 0.5-0.65 MPa. By controlling the pressure and flow rate of the compressed gas entering the cylinder (3), the compression ratio of the seal between the two electric stacks after locking and fixing can be precisely controlled. The support frame (8) also includes a support backing (9) fixed to the end of the slide rail (7). After the first fuel cell stack (1) is fixed by the fixed guide block, its back is pressed against the support backing (9).

2. A mechanism for fuel cell double stack assembly according to claim 1, wherein The pushing assembly also includes a translation push plate (5), which is slidably fixed on the bracket and located in front of the output end of the cylinder (3); the cylinder (3) pushes the translation push plate (5) so that the translation push plate (5) abuts against and pushes the second electric stack (2) to slide along the slide rail (7).

3. A mechanism for fuel cell double stack assembly according to claim 2, wherein The pushing assembly also includes a manual control valve (6), which is fixed to the side of the bracket and connected to the cylinder (3) in a transmission manner. The manual control valve (6) controls the output end of the cylinder (3) to push the translation push plate (5), so that the translation push plate (5) abuts against and pushes the second electric stack (2) to slide along the slide rail (7).

4. The mechanism for fuel cell double stack assembly according to claim 2, wherein The translation push plate (5) is provided in pairs, and the two translation push plates (5) are fixed together by a crossbar. The output end of the cylinder (3) is aligned with the crossbar.

5. A mechanism for fuel cell double stack assembly according to claim 4, wherein The cylinder (3) is provided in pairs, and the output ends of the two cylinders (3) are respectively aligned with the crossbar.

6. The mechanism for fuel cell double stack assembly according to claim 1, wherein After the second stack (2) presses against the first stack (1), the compression ratio of the seal between the first stack (1) and the second stack (2) is 15-25%.

7. A method for fuel cell double stack assembly, characterized by, Using the mechanism as described in any one of claims 1-6 includes the following steps: The first fuel cell stack (1) is fixed on the fixed guide block for fixed positioning; the second fuel cell stack (2) is fixed on the sliding guide block for fixed positioning; the second fuel cell stack (2) is pushed along the slide rail (7) by the cylinder (3) to slide close to and press the first fuel cell stack (1); the first fuel cell stack (1) and the second fuel cell stack (2) are locked by bolts to complete the assembly of the two fuel cell stacks.

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