CN114927740B - A fuel cell stack and its compression assembly method - Google Patents

Abstract

The invention discloses a fuel cell stack and a compression assembly method thereof, which includes a tensioning component, a fuel cell repeating unit and two main end plates. The tensioning component includes two auxiliary end plates and is arranged on the two auxiliary end plates. The elastic component between them; the number of fuel cell repeating units is several, and the fuel cell repeating unit includes multiple pole pieces, and the tensioning member is sandwiched between two adjacent fuel cell repeating units; two The main end plates are respectively arranged on both ends of several fuel cell repeating units; straps are bundled and wrapped around several fuel cell repeating units, and the two main end plates and tensioning members are stacked to form the outer periphery of the entire battery stack. While not affecting the external power output of the stack, the thickness of a single stack is reduced and the accuracy of stack stacking is improved. The elastic force of the elastic component on the two auxiliary end plates allows the two auxiliary end plates to stay away from each other. trend, compressing several fuel cell repeating units into the straps.

Description

A fuel cell stack and its compression assembly method

Technical field

The invention relates to the technical field of fuel cells, and in particular to a fuel cell stack and a compression assembly method thereof.

Background technique

As an efficient device for utilizing hydrogen energy, fuel cells have become an important direction of research. The voltage generated by a single fuel cell is about 0.7V, which is often not enough to meet the needs of use. Therefore, multiple fuel cells are usually stacked into a stack. A stack usually contains hundreds of fuel cells. When the number of fuel cells stacked in a stack is high, the following problems often occur: (1) In order to ensure the gas flow required for the reaction, the more stacked fuel cells there are, the more gas the stack will produce. The cooling medium inlet and outlet need to be made larger, resulting in an increase in the volume and weight of the fuel cell; (2) The difficulty of stacking fuel cell units flat and neatly will increase as the number of stacked cells increases, which can easily affect the performance and performance of the fuel cell. life.

When the fuel cells are stacked, there is also the issue of compressing the stacks. There are usually two ways to tighten the stack, one is the screw type and the other is the strap type. Stacks that use screw compression need to reserve space for screw installation, so the end plate area is often larger, which increases the volume and weight of the stack. The strap-type stack often causes uneven distribution of the pressing force on the stack. The fuel cell is prone to displacement during assembly, causing the fuel cell stack to be uneven and uneven, which affects the performance of the stack.

Contents of the invention

The purpose of the present invention is to provide a fuel cell stack and a compression assembly method thereof, so as to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or creation condition.

Technical solutions adopted to solve the above technical problems:

First, the present invention provides a fuel cell stack, which includes: a tensioning member, a fuel cell repeating unit and two main end plates. The tensioning member includes two auxiliary end plates, and an elastic member disposed between the two auxiliary end plates. Assembly; the number of fuel cell repeating units is several, and the fuel cell repeating unit includes a plurality of pole pieces stacked in sequence, and several fuel cell repeating units are arranged side by side in sequence, sandwiched between two adjacent fuel cell repeating units. The tensioning component; the two main end plates are respectively arranged on both ends of several fuel cell repeating units; straps are tied around several fuel cell repeating units, and the two main end plates and the tensioning components are stacked to form The overall periphery of the battery stack.

The beneficial effect of the fuel cell stack provided by the invention is that the pole pieces in the fuel cell stack are divided into several fuel cell repeating units, and the multiple pole pieces of each fuel cell repeating unit are stacked together in sequence without affecting the stack. While outputting external power, the thickness of a single stack is reduced and the accuracy of the stack is improved. In this way, the gas and cooling medium inlets and outlets of the fuel cell can be set slightly smaller, reducing the overall volume of the fuel cell, and Under the binding and fixation of the straps, the tensioning component provided between two adjacent fuel cell repeating units further fixes the stack, and the elastic force of the elastic component on the two auxiliary end plates makes the two auxiliary end plates move away from each other. The trend is to compress several fuel cell repeating units into the straps.

As a further improvement of the above technical solution, the number of the straps is multiple, and the plurality of straps are arranged at intervals around the outer periphery of the entire battery stack.

Determine the number of straps according to the size of the fuel cell stack. If the fuel cell stack is larger, select more straps for fixation.

As a further improvement of the above technical solution, the elastic component includes a plurality of elastic members, and the plurality of elastic members are evenly distributed between the two auxiliary end plates.

This solution uses multiple elastic members to exert an outward expansion elastic force on the two auxiliary end plates. This can make the force exerted on the fuel cell repeating unit more uniformly by all parts of the auxiliary end plates, and avoid damage to the pole pieces caused by excessive local stress, and causing tilt.

As a further improvement of the above technical solution, the elastic member is a spring, and the two ends of the spring are respectively in contact with the two auxiliary end plates.

This solution uses springs to exert elastic force, and the number and size of the springs are determined according to the size of the stack.

As a further improvement of the above technical solution, a plurality of grooves are provided on the end surface of one of the auxiliary end plates, and one end of the spring is sleeved in the groove.

This solution provides grooves to position and install the spring, which can avoid tilt and displacement of the spring, further improve the stability between the two auxiliary end plates, and keep the two auxiliary end plates in a parallel state.

As a further improvement of the above technical solution, the end surface of the other auxiliary end plate is a flat surface, and the other end of the spring conflicts with the flat surface. Planar structures are more evenly stressed.

In addition, the present invention also provides a compression assembly method of the fuel cell stack. The specific steps are as follows:

Step 1: Arrange the elastic component between the two auxiliary end plates, use fasteners to clamp and fix the two auxiliary end plates together to form a tensioning component, and prefabricate a plurality of the tensioning components;

Step 2: Stack multiple pole pieces together to form a fuel cell repeating unit, and prefabricate multiple fuel cell repeating units;

Step 3: Stack the two main end plates, several fuel cell repeating units, and several tensioning parts to form the battery stack as a whole. There is a tensioning part sandwiched between two adjacent fuel cell repeating units. Main end plates are respectively arranged on both ends of several fuel cell repeating units;

Step 4: Use straps to secure the stacked battery stack as a whole;

Step 5: Remove the fasteners.

As a further improvement of the above technical solution, in the step, each tightening component is clamped around the periphery between the two auxiliary end plates using a plurality of fasteners. Multiple fasteners improve the stability of the clamping between the two auxiliary end plates and prevent the two auxiliary end plates from tilting.

As a further improvement of the above technical solution, in the step, the number of pole pieces of each fuel cell repeating unit is equal. This allows for high installation accuracy of the compactly assembled stack, uniform stress inside the fuel cell, and long operating life of the stack.

The beneficial effects of the compression assembly method provided by the present invention are: due to the sequential installation of elastic components, the compression force to the stack will often be unevenly distributed, which may cause the fuel cell to be displaced. This technology can tighten the tension in advance. Fix the components, use fasteners to compress the elastic components and fix the two auxiliary end plates. After completing the fixation of the straps, remove the fasteners to release the elastic force of the elastic components, effectively solving the problems caused by installing elastic components. The problem of uneven pressure distribution.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and examples;

Figure 1 is a schematic structural diagram of an embodiment of the fuel cell stack provided by the present invention, in which the two arrows indicate left and right directions respectively;

Figure 2 is an exploded view of an embodiment of the fuel cell stack provided by the present invention;

Figure 3 is a cross-sectional view of an embodiment of the fuel cell stack provided by the present invention;

FIG. 4 is a partial enlarged view A of FIG. 3 .

Detailed ways

This section will describe the specific embodiments of the present invention in detail. The preferred embodiments of the present invention are shown in the accompanying drawings. The function of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand the present invention. Each technical feature and overall technical solution of the invention shall not be construed as limiting the scope of protection of the invention.

In the description of the present invention, it should be understood that orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or position relationships shown in the drawings and are only In order to facilitate the description of the present invention and simplify the description, it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In the description of the present invention, if there are words such as "several", the meaning is one or more, the meaning of plural is two or more, greater than, less than, more than, etc. are understood to not include the number, above, below , within, etc. shall be understood as including the original number.

In the description of the present invention, unless otherwise explicitly limited, words such as setting, installation, and connection should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meaning of the above words in the present invention in combination with the specific content of the technical solution.

Referring to Figures 1 to 4, the following embodiments of the fuel cell stack of the present invention are made:

As shown in FIGS. 1 to 4 , the fuel cell stack of this embodiment includes a tensioning member, a fuel cell repeating unit 200 and a main end plate 300 .

The fuel cell repeating unit 200 is formed by stacking multiple pole pieces 210 in sequence. The multiple pole pieces 210 in this embodiment are stacked together in the left and right directions. This embodiment is provided with two of the above fuel cell repeating units 200 , two fuel cell repeating units 200 are arranged at intervals left and right. In other embodiments, several fuel cell repeating units 200 may be provided according to the size of the fuel cell, and several fuel cell repeating units 200 are arranged side by side in sequence.

The tightening parts are disposed between two fuel cell repeating units 200. In other and some embodiments, the number of tightening parts is set according to the number of fuel cell repeating units 200. If there are three fuel cell repeating units 200, then There are two tightening parts. That is to say, if the number of fuel cell repeating units 200 is N, the number of tightening parts is N-1. The tightening parts mainly include two auxiliary ends arranged in parallel on the left and right. The plate 100 is an elastic component installed between the two auxiliary end plates 100. The elastic component is used to provide the two auxiliary end plates 100 with elastic force to move away from each other. That is to say, the elastic component causes the two auxiliary end plates 100 to expand left and right. , the two auxiliary end plates 100 respectively conflict with the ends of two adjacent fuel cell repeating units 200 that are close to each other, the left end surface of the left auxiliary end plate 100 conflicts with the right end of the left fuel cell repeating unit 200, and the right end The right end surface of the auxiliary end plate 100 conflicts with the left end of the fuel cell repeating unit 200 on the right side.

Main end plates 300 are provided at both left and right ends of the battery stack formed by stacking two fuel cell repeating units 200 and tension members. The main end plates 300 are closely attached to the outer ends of the fuel cell repeating units 200. Two The main end plate 300 mainly plays the role of receiving the force.

The strap 400 is bundled and wound around the outer periphery of the entire battery stack. The strap 400 exerts a force on the two fuel cell repeating units 200 and the tensioning member to approach each other through the two main end plates 300, and the elastic component exerts a force on the two fuel cell repeating units 200 and the tensioning member. The auxiliary end plates 100 exert an elastic force away from each other, thereby pressing the fuel cell repeating unit 200 between the auxiliary end plates 100 and the main end plate 300 .

Another effect of the auxiliary end plate 100 is that the fuel cell can be divided into two parts by using the two auxiliary end plates 100. The auxiliary end plate 100 completely isolates the two parts of the fuel cell repeating unit 200, that is, water and gas will not pass through the auxiliary end plate 100. The end plate 100 and the number of pole pieces 210 of each part of the fuel cell repeating unit 200 are reduced, thereby improving the accuracy of the entire fuel cell stack. At this time, only the fuel cell repeating units 200 need to be accurately stacked, unlike the traditional , the stacking operation of the entire fuel cell stack together greatly reduces the stacking difficulty.

The number of straps 400 is determined according to the size of the fuel cell stack. In this embodiment, two straps 400 are provided, and the two straps 400 are arranged at intervals up and down.

In some other embodiments, if the fuel cell stack is larger, more straps 400 may be selected for fixation, and three or more straps 400 may be selected.

Furthermore, in order to improve the stability and parallelism between the two auxiliary end plates 100, the elastic component of this embodiment is provided with multiple elastic members, and the multiple elastic members are evenly arranged between the two auxiliary end plates 100. This embodiment The embodiment uses multiple elastic members to exert an outward expansion elastic force on the two auxiliary end plates 100. This can make the force exerted on the fuel cell repeating unit 200 by the auxiliary end plates 100 more uniform, and avoid damage to the electrodes caused by excessive local stress. piece 210, and causes tilt.

As shown in Figures 3 and 4, the elastic member of this embodiment uses a spring 500. The spring 500 extends left and right. Both ends of the spring 500 are respectively in contact with the end surfaces of the two auxiliary end plates 100. This embodiment uses a spring 500. To apply elastic force, the number and size of the springs 500 can be determined according to the size of the electric stack.

Furthermore, a plurality of grooves 110 are provided on the right end surface of the left auxiliary end plate 100. The plurality of grooves 110 correspond to the plurality of springs 500. The left ends of the springs 500 are sleeved in the grooves 110. The springs 500 The left end of the spring 500 is in contact with the bottom of the groove 110, and the right end of the spring 500 is in contact with the left end surface of the auxiliary end plate 100 on the right side. In this embodiment, the groove 110 is provided to position and install the spring 500, so that the spring 500 can be prevented from being 500 produces inclination and displacement, further improving the stability between the two auxiliary end plates 100 and keeping the two auxiliary end plates 100 in a parallel state.

Among them, the left end surface of the auxiliary end plate 100 on the right side of this embodiment has a planar structure, and the force of the planar structure is more uniform.

In addition, this embodiment also provides a compression assembly method suitable for the above-mentioned fuel cell stack. The specific operation steps are as follows:

Step 1: Install multiple springs 500 between two auxiliary end plates 100, clamp and fix the two auxiliary end plates 100 together through fasteners to form a tensioning component, one of the auxiliary end plates 100 is provided with a groove 110. When the two auxiliary end plates 100 are clamped together, the spring 500 can be completely pressed into the groove 110, and the two auxiliary end plates 100 fit together, thus ensuring that the two auxiliary end plates 100 remain In a mutually parallel state, the pressure generated by each spring 500 between the two auxiliary end plates 100 after compression is the same, and a plurality of the above-mentioned tightening parts are prefabricated;

Step 2: Stack a set number of pole pieces 210 together according to the size of the stack to form a fuel cell repeating unit 200, and prefabricate a plurality of the above fuel cell repeating units 200;

Step 3: Stack the main end plate 300, the fuel cell repeating unit 200, the tensioning member, the fuel cell repeating unit 200 and the main end plate 300 in sequence to form the battery stack as a whole. The two main end plates 300 are respectively arranged with The ends of the two fuel cell repeating units 200 collide;

Step 4: Use two straps 400 to bundle and fix the stacked battery stack as a whole;

Step 5: Loosen and remove the fasteners, that is, loosen the two auxiliary end plates 100 fixed together, release the spring 500, and use the elastic force of the spring 500 to compress the stack.

Furthermore, this embodiment is provided with a plurality of fasteners. The plurality of fasteners are arranged around the periphery between the two auxiliary end plates 100. The plurality of fasteners improve the clamping force between the two auxiliary end plates 100. To ensure stability and prevent the two auxiliary end plates 100 from tilting, the fasteners adopt conventional C-type clamps with bolts.

The installation accuracy of the press-fitted stack is high, the internal force of the fuel cell is uniform, and the stack has a long operating life. The number of pole pieces 210 in each fuel cell repeating unit 200 is the same, which enables the press-fit stack to be installed with high accuracy. The internal force of the fuel cell is uniform and the stack has a long operating life.

For example, for a fuel cell stack with 300 pole pieces 210 stacked, the 300 pole pieces 210 are divided into two parts, each part has 150 pieces, and are stacked respectively. For a fuel cell stack with 260 pole pieces 210 stacked The fuel cell stack divides the 260 pole pieces 210 into two parts, each part has 130 pole pieces, which are stacked respectively.

While not affecting the external power output of the stack, the thickness of a single stack is reduced and the accuracy of stack stacking is improved. In this way, the gas and cooling medium inlets and outlets of the fuel cell can be set slightly smaller, reducing the overall size of the fuel cell. volume.

In some embodiments, spring 500 may be elastically flat.

For a fuel cell stack composed of 300 pole pieces 210, since there are many pole pieces 210, in order to improve the assembly accuracy and reduce the volume of a single stack, the fuel cell stack structure of the present invention is used for compression packaging. , the pressing and assembly steps are as follows:

Step 1: Clamp and fix the two auxiliary end plates 100 together with fasteners to form a tensioning component, and prefabricate multiple above-mentioned tensioning components;

Step 2: Divide the 300 pole pieces 210 into two parts, with 150 pieces in each part, and stack them up to form two fuel cell repeating units 200;

Step 3: Stack the main end plate 300, 150 pieces of fuel cell repeating units 200, the tensioning member, 150 pieces of fuel cell repeating units 200 and the main end plate 300 in sequence to form the entire battery stack;

Step 4: Use three straps 400 to bundle and fix the stacked battery stack as a whole;

Step 5: Loosen and remove the fasteners, that is, loosen the two auxiliary end plates 100 fixed together, release the spring 500, and use the elastic force of the spring 500 to compress the stack.

Under the binding and fixation of the straps 400, the tensioning member provided between two adjacent fuel cell repeating units 200 further compresses and fixes the stack, and the elastic force of the spring 500 on the two auxiliary end plates 100 makes the two auxiliary end plates 100 The end plates 100 tend to move away from each other, compressing the two fuel cell repeating units 200 between the two main end plates 300 .

The above completes the pressing and fixing of the entire stack, which effectively solves the problem of uneven elastic force of the spring 500 during the pressing process of the stack.

The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the embodiments. Those skilled in the art can also make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims (6)

1. A fuel cell stack, characterized in that: it includes: A tightening component, which includes two auxiliary end plates (100) and an elastic component disposed between the two auxiliary end plates (100); Several fuel cell repeating units (200). The fuel cell repeating unit (200) includes multiple pole pieces (210) stacked in sequence. The several fuel cell repeating units (200) are arranged side by side in sequence. Between two adjacent fuel cells, The tensioning parts are sandwiched between battery repeating units (200); Two main end plates (300), the two main end plates (300) are respectively arranged on both ends of several fuel cell repeating units (200); A strap (400), which is bundled and wound around the outer periphery of the entire battery stack formed by stacking several fuel cell repeating units (200), two main end plates (300) and tensioning components; The elastic component includes a plurality of elastic pieces; The elastic member is a spring (500), and the two ends of the spring (500) are respectively in contact with the two auxiliary end plates (100); A plurality of grooves (110) are provided on the end surface of one of the auxiliary end plates (100), and one end of the spring (500) is sleeved in the grooves (110). 2. A fuel cell stack according to claim 1, characterized in that: The number of the straps (400) is multiple, and the plurality of straps (400) are arranged at intervals around the outer periphery of the entire battery stack. 3. A fuel cell stack according to claim 1, characterized in that: The end surface of the other auxiliary end plate (100) is a flat surface, and the other end of the spring (500) conflicts with the flat surface. 4. A compression assembly method of the fuel cell stack according to claim 1, characterized in that: the specific steps are as follows: Step 1: Use fasteners to clamp and fix the two auxiliary end plates (100) together to form a tensioning component; Step 2: Stack multiple pole pieces (210) together to form a fuel cell repeating unit (200); Step 3: Stack the two main end plates (300), several fuel cell repeating units (200), and several tensioning parts to form a battery stack as a whole, between two adjacent fuel cell repeating units (200) A tensioning component is clamped, and two main end plates (300) are respectively arranged on both ends of several fuel cell repeating units (200); Step 4: Use straps (400) to fix the stacked battery stack as a whole; Step 5: Remove the fasteners. 5. The compression assembly method of the fuel cell stack according to claim 4, characterized in that: Use multiple fasteners to clamp around the perimeter between the two auxiliary end plates (100). 6. The compression assembly method of the fuel cell stack according to claim 4, characterized in that: Each fuel cell repeating unit (200) has an equal number of pole pieces (210).