CN108346814B - Fastening device for fuel cell stack - Google Patents

Abstract

The invention provides a fastening device of a fuel cell stack, which comprises a front tail plate, a back tail plate, a first anti-arc part, a first positive arc part, a second anti-arc part, a second positive arc part, a first binding belt, a second binding belt and a third binding belt which are arranged at two ends of the stacking direction of the fuel cell stack, wherein the arc surface of the first anti-arc part is arranged on the side surface of the front tail plate back to the front tail plate, the arc surface of the first positive arc part is arranged on the side surface of the front tail plate back to the front tail plate, the second anti-arc part is arranged on the side surface of the back tail plate, the second positive arc part is arranged on the side surface of the back tail plate, the first binding belt is sleeved on two ends of the first anti-arc part and two ends of the second anti-arc part, the second binding belt is sleeved on the arc surface of the first positive arc part and the arc surface of the second positive arc part, the third binding belt is sleeved on the side surface of the first binding belt, the second binding belt and the side surface of the fuel cell stack, and the first anti-arc part, the second anti-arc part and the second positive arc part are respectively made of elastic materials. The fastening device has a simple and compact structure and ensures that the stress of the fuel cell stack is uniform.

Description

Fuel cell stack fastening device

Technical field

The present invention relates to the technical field of fuel cells, and in particular, to a simple fastening device for a fuel cell stack.

Background technique

A fuel cell is a device that directly converts chemical energy into electrical energy. Due to its high efficiency, zero emissions, and low starting temperature, it is very suitable for transportation, stationary power generation, and portable fields. In recent years, countries around the world have been actively studying the application of fuel cells as power sources in the automotive field. Since the voltage of a single battery is small and cannot meet the needs of automobile power, several single batteries need to be assembled in series to form a stack and fastened through mechanical pressure. If the fastening pressure is too large, stress concentration may easily occur and cause a film. The rupture or deformation of key components such as electrodes or plates, or even punctures and tears, will also reduce the porosity of the gas diffusion layer, causing gas leakage, performance degradation, lifespan reduction and a series of other problems. If the tightening pressure is too small, , it is easy to increase the contact resistance, causing the performance of the stack to decline. Therefore, appropriate tightening pressure is crucial to the performance, safety and durability of the stack. Usually, complex fastening methods tend to cause more stress concentration problems and cumbersome assembly procedures, with low reliability and low efficiency. Therefore, it is of great significance to find a simple, compact, and lightweight fastening method.

Currently, most stacks are fastened using screws. Among them, the screw fastening method has many inherent disadvantages. First, the cross-sectional area of the stack is increased, thereby increasing the volume of the stack, which is not conducive to improving the volumetric power density of the stack. Secondly, the stress at the position where the screw and nut are fastened is high, and the tail plate is usually required to have a certain thickness to conduct the pressure evenly. To this end, the thickness of the tail plate must be increased, which will increase the volume and weight, which is important for improving the power of the stack. Density is detrimental. Finally, since multiple sets of screws need to be tightened, the assembly and disassembly process is cumbersome and inefficient, and it is difficult to ensure the consistency of the force between each set of screws, resulting in uneven stress on the stack.

The invention patent application with application number 201710138182.2 discloses a fastening structure, which sequentially includes a gas port end plate, a gas port end collector plate, a flow field plate and a membrane electrode group, a blind end collector plate and a stack elastic compensation structure. The above structures are sequentially fastened with multiple sets of drawstring structures. The drawstring structure includes a U-shaped metal drawstring. The end of the metal drawstring is bent into a ring that matches the round rod of the T-bolt and is then welded to the metal drawstring. At the end overlap, the T-bolts on the metal strap pass through the fixing holes on the air port end plate, and are connected and tightened with the air port end plate through nuts. The limitations of this fastening structure are: 1. Using springs and pressure plates to realize the elastic compensation structure of the stack, which increases the volume and weight of the fuel cell; 2. Using a drawstring structure for fastening. During assembly, the metal drawstrings and The matching of T-bolts and the connection and fastening of the air port end plate with nuts are complex in actual operation, and have very high requirements on the consistency of the fastening force and the stacking process.

Contents of the invention

The main purpose of the present invention is to provide a fastening device for a fuel cell stack that is easy to operate, has a simple and compact structure, is evenly stressed, is convenient for maintenance and disassembly, and is cost-effective.

In order to achieve the main purpose of the present invention, the present invention provides a fuel cell stack fastening device, which includes a front tail plate and a rear tail plate located at both ends of the fuel cell stack in the stacking direction. The fuel cell stack fastening device also includes a first The arcuate part, the first arcuate part, the second arcuate part, the second arcuate part, the first strap, the second strap and the third strap, the arc surface of the first antiarc part faces away from the front and tail. The base is arranged on the side of the front and rear panels, the arc surface of the first positive arc portion is arranged on the side of the front and rear panels so that it faces the front and rear panels, and the arc surface of the second reverse arc portion is arranged on the rear panel and faces away from the rear and rear panels. On the side of the tailboard, the arc surface of the second positive arc portion is arranged on the side of the rear tailboard with the arc surface facing the rear tailboard, and the first strap is placed on both ends of the first reverse arc portion and both ends of the second reverse arc portion. On the top, the second strap is put on the arc surface of the first positive arc part and the arc surface of the second positive arc part, and the third strap is put on the first strap, the second strap and the side of the fuel cell stack. The first reverse arc part, the first forward arc part, the second reverse arc part and the second forward arc part are respectively made of elastic material.

A further solution is to provide a first current collecting plate and a first insulating plate between the front and rear plates and the fuel cell stack. The first insulating plate is located between the front and rear plates and the first current collecting plate. The first current collecting plate Connected to one end of the fuel cell stack, a second current collecting plate and a second insulating plate are provided between the rear tail plate and the fuel cell stack. The second insulating plate is located between the rear tail plate and the second current collecting plate. The flow plate is connected to the other end of the fuel cell stack.

A further solution is that the central angles of the first reverse arc part, the first positive arc part, the second reverse arc part and the second positive arc part are all less than 90 degrees.

A further solution is that the number of the first positive arc portion and the second positive arc portion is both two, the number of the second straps is also two, and the first reverse arc portion is located between the two first positive arc portions. The second reverse arc portion is located between the two second forward arc portions.

A further solution is that the number of the first anti-arc parts and the second anti-arc parts is three, and the number of the first straps is also three.

A further solution is that the distance between two adjacent first arcuate parts is equal, and the distance between two adjacent second arcuate parts is also equal.

A further solution is that the first reverse arc part and the second reverse arc part are located on the same plane, and the first positive arc part and the second positive arc part are also located on the same plane.

A further solution is that the third strap is placed in the middle of the first strap, the second strap and the fuel cell stack.

A further solution is that the front tail panel is provided with five first positioning grooves, and the rear tail panel is provided with five second positioning grooves. The first reverse arc part and the first positive arc part are respectively located in the first positioning grooves. The second reverse arc part and the second positive arc part are respectively located in the second positioning groove.

A further solution is that the distance between two adjacent first positioning grooves is equal, and the distance between two adjacent second positioning grooves is also equal.

It can be seen from the above solution that the first strap, the second strap and the third strap are stretchable, the length is easy to adjust, and they are very tight after being bonded using a welding device, which improves the vibration and impact resistance of the fuel cell stack. The first reverse arc part, the first forward arc part, the second reverse arc part and the second forward arc part are respectively made of elastic materials. The front and back arc surface compensation structures can compensate for the thermal expansion and cooling of the stack due to internal temperature changes. The change in assembly force caused by shrinkage makes the force on the fuel cell stack uniform. Moreover, the fastening device of the fuel cell stack is easy to operate, has a simple and compact structure, is convenient for maintenance and disassembly, and has low production cost.

Description of drawings

Figure 1 is a first perspective structural view of an embodiment of a fastening device for a fuel cell stack according to the present invention.

Figure 2 is a second perspective structural view of an embodiment of a fastening device for a fuel cell stack according to the present invention.

Figure 3 is an exploded structural view of an embodiment of a fastening device for a fuel cell stack according to the present invention.

Figure 4 is a first partial structural view of an embodiment of a fastening device for a fuel cell stack according to the present invention.

Figure 5 is a second partial structural view of an embodiment of a fastening device for a fuel cell stack according to the present invention.

Figure 6 is a third partial structural view of the fastening device embodiment of the fuel cell stack of the present invention.

Detailed ways

Referring to Figures 1 to 6, the fastening device of the fuel cell stack includes a front tail plate 2, a rear tail plate 3, a first reverse arc portion 8, a first positive arc portion 7, a second reverse arc portion 10, a second positive arc portion Part 9, first strap 5, second strap 4, third strap 6, first current collecting plate 12, first insulating plate 11, second current collecting plate 14 and second insulating plate 13, front and rear panels 2 and rear tail plate 3 are respectively provided at both ends of the fuel cell stack 1 in the stacking direction. The first insulating plate 11 is located between the front and rear panels 2 and the first current collecting plate 12 , and the first current collecting plate 12 is connected to one end of the fuel cell stack 1 . The second insulating plate 13 is located between the rear tail panel 3 and the second current collecting plate 14 , and the second current collecting plate 14 is connected to the other end of the fuel cell stack 1 .

The arc surface of the first reverse arc portion 8 is arranged on the side of the front tail panel 2 away from the front tail panel 2 , and the arc surface of the first forward arc portion 7 is arranged on the side of the front tail panel 2 facing the front tail panel 2 . . The arc surface of the second reverse arc portion 10 is arranged on the side surface of the rear tail panel 3 and faces away from the rear tail panel 3 . The arc surface of the second forward arc portion 9 is arranged on the side surface of the rear tail panel 3 and faces the rear tail panel 3 . . The first strap 5 is put on both ends of the first inverted arc part 8 and the two ends of the second inverted arc part 10, and the second strap 4 is put on the arc surface of the first positive arc part 7 and the second positive arc part. On the arc surface of the part 9, the third strap 6 is put on the first strap 5, the second strap 4 and the side of the fuel cell stack 1. In this embodiment, the third strap 6 is put on the first strap 5 , the second strap 4 and the middle part of the fuel cell stack 1 .

The central angles of the first reverse arc portion 8, the first positive arc portion 7, the second reverse arc portion 10 and the second positive arc portion 9 are all less than 90 degrees. The two anti-arc parts 10 and the second positive arc part 9 are respectively made of elastic materials, and the first anti-arc part 8 and the second anti-arc part 10 are located on the same plane. The first positive arc part 7 and the second positive arc part 9 is also on the same plane. In this embodiment, the number of the first positive arc portions 7 and the second positive arc portions 9 is two, the number of the second straps 4 is also two, and the first reverse arc portion 8 is located between the two first positive arc portions 7 , the second reverse arc portion 10 is located between the two second forward arc portions 9 . In this embodiment, the number of the first anti-arc parts 8 and the second anti-arc parts 10 is both three, the number of the first straps 5 is also three, and the distance between two adjacent first anti-arc parts 8 is equal. The distance between two adjacent second arc portions 10 is also equal. The front tail panel 2 is provided with five first positioning grooves 21, and the rear tail panel 3 is provided with five second positioning grooves (not labeled). The first reverse arc portion 8 and the first forward arc portion 7 are respectively located in the first positioning grooves. 21, the second reverse arc portion 10 and the second positive arc portion 9 are respectively located in the second positioning grooves, and the distance between two adjacent first positioning grooves 21 is equal, and the distance between two adjacent second positioning grooves is also equal. .

During the assembly process of the fuel cell stack fastening device, a layer of pressure paper is inserted between each component to measure the pressure distribution. Both the front tail panel 2 and the rear tail panel 3 have arc surfaces that are very consistent with the strap structure. The straps pass through the first reverse arc portion 8 and the first positive arc portion 7 on the front tail panel 2 and the rear tail panel 3. , the second reverse arc part 10 and the second positive arc part 9, compress the fuel cell stack 1 under the action of the assembly pressure of 50KN, and after reaching the preset compression ratio, use a welding device to bond the first strap 5 and the second strap respectively. The strap 4 and the third strap 6 complete the packaging of the entire fuel cell stack 1. The first strap 5, the second strap 4 and the third strap 6 are high-strength straps that are stretchable and easily adjustable in length. Their materials include but are not limited to polymer materials, fiber-based composite materials, laminate materials, Carbon fiber, natural fiber, stainless steel, other metal materials including surface treatment, etc. The number of the first strap 5, the second strap 4 and the third strap 6 is at least one but not more than twenty, and the number of the first strap 5, the second strap 4 and the third strap 6 is The arrangement includes but is not limited to criss-cross arrangement or parallel arrangement. The intersection of the first strap 5, the second strap 4 and the third strap 6 may be fixed by welding or not. Welding strap methods include but are not limited to resistance welding, arc welding, ultrasonic welding, laser welding, and capacitor spot welding. The material used for welding can be the same as the strap material, or it can be different.

The fastening device of the fuel cell stack can be used to assemble at least two groups of fuel cell units. The integrated rear tail plate 3 design reduces the use of other components, reduces the cost, and is conducive to increasing the power density of the fuel cell stack 1. The materials of the fastening device include but are not limited to aluminum alloy, copper alloy, stainless steel, high molecular polymer, laminated materials, etc., and can be machined, cast, molded, injection molded, and laminated in one go, and the processing techniques are diverse. The strap structure can be stretched freely and the length is easily adjusted. It is very tight after being bonded using a welding device, which improves the vibration and impact resistance of the fuel cell stack 1. The positive and negative arc surface compensation structure of elastic material can compensate for the change in assembly force caused by the thermal expansion and contraction of the stack caused by internal temperature changes. The first insulating plate 11 and the second insulating plate 13 are used for insulation and stress dispersion. The materials of the first insulating plate 11 and the second insulating plate 13 include but are not limited to Teflon, polyformaldehyde, ABS engineering plastic, etc. Therefore, the fastening device of the fuel cell stack of this embodiment is easy to operate, has a simple and compact structure, is convenient for maintenance and disassembly, and saves costs, and the fuel cell stack 1 is evenly stressed.

The above embodiments are only preferred examples of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made based on the structures, features and principles described in the patent scope of the present invention shall be included in the present invention. Within the scope of invention patent application.

Claims (10)

1. The fastening device of the fuel cell stack comprises a front tail plate and a rear tail plate which are arranged at two ends of the stacking direction of the fuel cell stack, and is characterized in that:

the fastening device of the fuel cell stack further comprises a first reverse arc part, a first positive arc part, a second reverse arc part, a second positive arc part, a first strap, a second strap and a third strap;

the arc surface of the first arc-resisting part is arranged on the side surface of the front tail plate back to the front tail plate, and the arc surface of the first arc-resisting part is arranged on the side surface of the front tail plate towards the front tail plate;

the arc surface of the second anti-arc part is arranged on the side surface of the back plate back to the back plate, and the arc surface of the second positive arc part is arranged on the side surface of the back plate towards the back plate;

the first binding band is sleeved on two ends of the first anti-arc part and two ends of the second anti-arc part, the second binding band is sleeved on the arc surface of the first positive arc part and the arc surface of the second positive arc part, and the third binding band is sleeved on the first binding band, the second binding band and the side surface of the fuel cell stack;

the first anti-arc part is positioned between the two first positive arc parts, and the second anti-arc part is positioned between the two second positive arc parts

The first reverse arc portion, the first positive arc portion, the second reverse arc portion, and the second positive arc portion are respectively made of an elastic material.

2. The fastening device of a fuel cell stack according to claim 1, wherein:

a first current collecting plate and a first insulating plate are arranged between the front tail plate and the fuel cell stack, the first insulating plate is positioned between the front tail plate and the first current collecting plate, and the first current collecting plate is connected with one end of the fuel cell stack;

a second current collecting plate and a second insulating plate are arranged between the back tail plate and the fuel cell stack, the second insulating plate is positioned between the back tail plate and the second current collecting plate, and the second current collecting plate is connected with the other end of the fuel cell stack.

3. The fastening device of a fuel cell stack according to claim 1, wherein:

the central angles of the first reverse arc part, the first positive arc part, the second reverse arc part and the second positive arc part are all smaller than 90 degrees.

4. A fastening device for a fuel cell stack according to any one of claims 1 to 3, characterized in that:

the number of the first positive arc parts and the number of the second positive arc parts are two, and the number of the second binding bands is also two.

5. The fastening device of a fuel cell stack according to claim 4, wherein:

the number of the first anti-arc parts and the second anti-arc parts is three, and the number of the first binding bands is also three.

6. The fastening device of a fuel cell stack according to claim 5, wherein:

the distances between the adjacent two first anti-arc parts are equal, and the distances between the adjacent two second anti-arc parts are also equal.

7. The fastening device of a fuel cell stack according to claim 6, wherein:

the first anti-arc part and the second anti-arc part are positioned on the same plane, and the first positive arc part and the second positive arc part are also positioned on the same plane.

8. The fastening device of a fuel cell stack according to claim 7, wherein:

the third strap is sleeved on the first strap, the second strap and the middle of the fuel cell stack.

9. The fastening device of a fuel cell stack according to claim 8, wherein:

five first positioning grooves are formed in the front tail plate, five second positioning grooves are formed in the rear tail plate, the first anti-arc portion and the first positive arc portion are respectively located in the first positioning grooves, and the second anti-arc portion and the second positive arc portion are respectively located in the second positioning grooves.

10. The fastening device of a fuel cell stack according to claim 9, wherein:

the distances between two adjacent first positioning grooves are equal, and the distances between two adjacent second positioning grooves are also equal.