CN2763995Y - Front/rear end board for fuel cell stack - Google Patents

Abstract

The utility model provides a front/rear end plate of a fuel cell stack. The front/rear end plate is composed of a rectangular flat plate and reinforcing ribs arranged on one side of the rectangular flat plate. There are two rows of mounting holes, and the reinforcing rib is arranged between the two rows of mounting holes. The front/rear end plate of the fuel cell stack of the utility model is used for assembling the fuel cell stack. While ensuring its tensile strength, it also has the advantages of being beautiful, reducing the volume and weight of the fuel cell stack, and increasing the power density of the fuel cell stack. advantage.

Description

A front/rear end plate of a fuel cell stack

technical field

The utility model relates to a fuel cell, in particular to a front/rear end plate of a fuel cell stack.

Background technique

A fuel cell is a device that converts the chemical energy generated during the electrochemical reaction of fuel and oxidant into electrical energy. The core component of the device is the membrane electrode (Membrane Electrode Assembly, referred to as MEA). The membrane electrode is composed of a proton exchange membrane and two conductive porous diffusion materials (such as carbon paper) sandwiched on both sides of the membrane. A finely dispersed catalyst (such as metal platinum) that can initiate an electrochemical reaction is evenly distributed on the two interface surfaces where the conductive material contacts. On both sides of the membrane electrode, the electrons generated during the electrochemical reaction are drawn out through the external circuit with conductive objects, forming a current loop.

At the anode end of the membrane electrode, the fuel can permeate through the porous diffusion material (such as carbon paper), and an electrochemical reaction occurs on the surface of the catalyst, losing electrons to form positive ions, which can migrate through the proton exchange membrane to reach The other end of the membrane electrode - the cathode end. At the cathode end of the membrane electrode, a gas (such as air) containing an oxidant (such as oxygen) penetrates through a porous diffusion material (such as carbon paper) and undergoes an electrochemical reaction on the surface of the catalyst to obtain electrons to form negative ions. It further combines with positive ions migrated from the anode end to form a reaction product.

In a proton exchange membrane fuel cell using hydrogen as fuel and oxygen-containing air as oxidant (or pure oxygen as oxidant), fuel hydrogen undergoes a catalytic electrochemical reaction in which electrons are lost in the anode region to form hydride ions (protons), Its electrochemical reaction equation is:

Oxygen undergoes a catalytic electrochemical reaction in the cathode region to obtain electrons to form negative ions, which are further combined with hydrogen positive ions migrated from the anode terminal to form the reaction product water. Its electrochemical reaction equation is:

The proton exchange membrane in the fuel cell is not only used for the electrochemical reaction and the protons generated in the transfer exchange reaction, but also to separate the gas flow containing fuel hydrogen from the gas flow containing oxidant (oxygen) so that they do not Will mix with each other to produce an explosive reaction.

In a typical proton exchange membrane fuel cell, the membrane electrode is generally placed between two conductive plates, and diversion grooves are opened on both plates, so it is also called a diversion plate. The diversion groove is opened on the surface in contact with the membrane electrode, formed by die-casting, stamping or mechanical milling, and its number is more than one. The guide plate can be made of metal material or graphite material. The function of the diversion groove on the diversion plate is to introduce fuel or oxidant into the anode area or cathode area on both sides of the membrane electrode respectively. In the structure of a single proton exchange membrane fuel cell, there is only one membrane electrode and two guide plates, and the two guide plates are arranged on both sides of the membrane electrode, one is used as the guide plate for the anode fuel, and the other As a guide plate for cathode oxidant. These two guide plates are not only used as current collector plates, but also as mechanical support on both sides of the membrane electrode. The diversion groove on the diversion plate is not only a channel for fuel or oxidant to enter the surface of the anode or cathode, but also a water outlet channel to take away the water generated during the operation of the battery.

In order to increase the power of a proton exchange membrane fuel cell, two or more single cells are usually connected together in a straight stacked or tiled manner to form a cell group, or called a cell stack. Such a battery pack is usually fastened together by a front end plate, a rear end plate and a pull rod to form a whole. In the battery pack, the two sides of the pole plate between the two proton exchange membranes are provided with diversion grooves, which are called bipolar plates. One side of the bipolar plate is used as the anode flow guide surface of one membrane electrode, and the other side is used as the cathode flow guide surface of another adjacent membrane electrode. A typical battery pack usually also includes: 1) Inlets and diversion channels for fuel and oxidant gases. Its function is to evenly distribute fuel (such as hydrogen, methanol, or hydrogen-rich gas obtained by reforming methanol, natural gas, and gasoline) and oxidant (mainly oxygen or air) into the diversion grooves on each anode and cathode surface ; 2) The inlet, outlet and diversion channel of the cooling fluid (such as water). Its function is to evenly distribute the cooling fluid to the cooling channels in each battery pack, absorb the reaction heat generated in the fuel cell and take it out of the battery pack for heat dissipation; 3) the outlet and guide channel of fuel and oxidant gas. Its function is to discharge the excess fuel gas and oxidant that did not participate in the reaction, and at the same time take out the liquid or gaseous water generated by the reaction. The above-mentioned fuel inlet and outlet, oxidant inlet and outlet and cooling fluid inlet and outlet are usually set on one end plate of the fuel cell stack or respectively set on two end plates.

Proton exchange membrane fuel cells can be used as power systems for vehicles, ships and other vehicles, and can also be made into mobile or fixed power generation systems.

The composition of the fuel cell stack is shown in Figure 1. A plurality of single cells are connected together by direct stacking or flat laying to form a fuel cell stack body 11. The fuel cell stack bodies 11 are fastened together. On the one hand, this connection method can make the electrodes in the fuel cell stack body 11 fully contact with the bipolar plate, uniformly bear force, reduce the internal resistance of the entire fuel cell stack, and on the other hand, improve the anti-vibration performance of the fuel cell stack. Therefore, it is required that the front end plate and the rear end plate must have sufficient strength to ensure that they are not deformed under the firm tension of the tie rod. However, if the front end plate and the rear end plate are made too thick in order to improve the strength of the fuel cell stack, the weight of the entire fuel cell stack will be increased, and its power density will be reduced. It is necessary to design a fuel cell stack front/rear end plate that is as light as possible while maintaining strength.

Utility model content

The purpose of this utility model is to provide a front/rear end plate of a fuel cell stack, which can reduce the weight and increase the power density of the fuel cell stack while ensuring the strength.

The purpose of this utility model is achieved in this way: a front/rear end plate of a fuel cell stack is composed of a rectangular flat plate and a reinforcing rib arranged on one side of the rectangular flat plate, and a row of mounting holes, and the reinforcing rib is arranged between two rows of mounting holes.

The reinforcing rib is left by milling some areas of a relatively thick metal plate or a composite reinforced material plate through mechanical processing, or directly adopts mold metal die-casting or injection molding.

The reinforcing ribs include a rectangular frame composed of four long ribs and a plurality of short ribs connected in the rectangular frame, the size of the rectangular frame can at least cover the end surface of the fuel cell stack body.

The plurality of short ribs connected in the rectangular frame perpendicularly intersect with each other, and a plurality of rectangles are formed between each short rib and between each short rib and each long rib of the rectangular frame.

The plurality of short ribs connected in the rectangular frame obliquely intersect with each other, and a plurality of triangles are formed between each short rib and between each short rib and each long rib of the rectangular frame.

The distances between the four long ribs of the rectangular frame and the four sides of the front/rear end plate are equal.

The distances between the four long ribs of the rectangular frame and the four sides of the front/rear end plate are not equal, and the left and right long ribs are flush with the left and right sides of the front/rear end plate.

The long ribs on the left and right sides of the rectangular frame are also connected with two short ribs, the two short ribs are respectively perpendicular to the long ribs on the left and right sides and are arranged in the middle of the front/rear end plates and extend respectively to the left and right edges of the front/rear end panels.

The reinforcing ribs are formed by opening several round holes in a rectangular plate, and the reinforcing ribs have a size that can at least cover the end surface of the fuel cell stack body.

The circular holes provided in the rectangular plate include four large circular holes provided in the four corners of the rectangular plate and a small circular hole provided in the middle of the rectangular plate.

The front/rear end plate of the fuel cell stack of the utility model is used for assembling the fuel cell stack. While ensuring its tensile strength, it also has the advantages of being beautiful, reducing the volume and weight of the fuel cell stack, and increasing the power density of the fuel cell stack. advantage.

Description of drawings

FIG. 1 is a schematic structural view of a fuel cell stack in the prior art;

Fig. 2 is a structural schematic diagram of an embodiment of the front/rear end plate of the fuel cell stack of the present invention;

Fig. 3 is a structural schematic diagram of a fuel cell stack composed of front/rear end plates of the fuel cell stack shown in Fig. 2;

Fig. 4 is a structural schematic diagram of another embodiment of the front/rear end plate of the fuel cell stack of the present invention;

Fig. 5 is a structural schematic diagram of a fuel cell stack composed of front/rear end plate connections of the fuel cell stack shown in Fig. 4;

Fig. 6 is a structural schematic diagram of another embodiment of the front/rear end plate of the fuel cell stack of the present invention;

FIG. 7 is a schematic structural view of a fuel cell stack composed of the connection of the front/rear end plates of the fuel cell stack shown in FIG. 6 .

Detailed ways

Please refer to Fig. 2, and refer to Fig. 4 and Fig. 6 for cooperation. The front/rear end plate of the 10KW fuel cell stack of the present utility model is made up of a rectangular flat plate 2 and a reinforcing rib 3 arranged on one side of the rectangular flat plate 2, and the reinforcing rib is made of a thicker metal plate or composite reinforcing material plate ( The size of the plate is: length x height x thickness = 210 x 250 x 30mm) left by milling some areas by machining methods. A row of installation holes 4 are respectively provided at the upper and lower ends of the rectangular flat plate 2, and the reinforcing rib 3 is arranged between the two rows of installation holes. The fuel cell stack formed by connecting the front/rear end plates of the fuel cell stack of the utility model is shown in Fig. 3 , Fig. 5 and Fig. 7 .

The front/rear end plate of the fuel cell stack of the present utility model, the size of the front/rear end plate is length × height × thickness = 210 × 250 × 30mm, can be designed into the structural form shown in Figure 2 and Figure 4, in a rectangular A rectangular frame composed of four long ribs 31 and a plurality of short ribs 32, 33 connected in the rectangular frame are arranged on the flat plate 2, and the plurality of short ribs can be mutually perpendicular intersecting short ribs as shown in FIG. 2 The strips 32 form a plurality of rectangles enclosed between the short ribs 32 and between the short ribs and the long ribs 31 of the rectangular frame. A plurality of short ribs also can be as shown in Figure 4 the short ribs 33 that intersect obliquely with each other, between each short rib 33 and between each short rib and each long rib 31 of the rectangular frame, a plurality of ribs are formed. triangle. The size of the rectangular frame can at least cover the end face of the fuel cell stack body, and the distances between its four long ribs 31 and the four sides of the front/rear end plate can be equal, as shown in Figure 2; or they can be unequal, as shown in Figure 4 When not equal, it is still necessary to ensure that the size of the rectangular frame can cover the end face of the fuel cell stack body, and the long ribs on the left and right sides can be widened to be flush with the left and right sides of the front/rear end plate. Under the situation that the distances between the four long ribs and the four sides of the front/rear end plate as shown in Figure 2 are equal, two short ribs 34 can be connected outside the long ribs on the left and right sides, and the two short ribs 34 are arranged perpendicular to the left and right sides of the long ribs 31 in the middle of the front/rear end plate and extend to the edges of the left and right sides of the front/rear end plate respectively. This further increases the tensile strength of the front/rear end panels.

The front/rear end plate of the fuel cell stack of the present utility model, the size of the front/rear end plate is length × height × thickness = 210 × 250 × 30mm, can also be designed as the structural form shown in Figure 6, in the rectangular plate 2 A reinforcing rib 35 formed by opening several circular holes in a rectangular plate is arranged on the top, and the size of the reinforcing rib 35 can at least cover the end surface of the fuel cell stack body. The circular holes that are offered in the rectangular plate should be determined according to the size and shape of the rectangular frame. When the rectangular frame is a square as shown in Figure 6, four large circular holes 351 can be opened at the four corners of the rectangular plate, and four large circular holes 351 can be opened at the four corners of the rectangular plate. Open a small circular hole 352 again between. To further reduce the weight of the front/rear end panels. The structure of the fuel cell stack formed by connecting the front/rear end plates of the fuel cell stack shown in FIG. 6 is shown in FIG. 7 .

Claims (10)

1. A front/rear end plate of a fuel cell stack, characterized in that: the front/rear end plate is composed of a rectangular flat plate and reinforcing ribs arranged on one side surface of the rectangular flat plate, the upper end and the lower end of the rectangular flat plate are respectively provided with a row of mounting holes, and the reinforcing ribs are arranged between the two rows of mounting holes.

2. The front/rear end plate of a fuel cell stack according to claim 1, wherein: the reinforcing rib is formed by milling certain areas of a thicker metal plate or a composite reinforcing material plate through a mechanical processing method or directly adopting die metal die casting or injection molding.

3. The front/rear end plate of a fuel cell stack according to claim 1, wherein: the reinforcing ribs comprise a rectangular frame consisting of four long ribs and a plurality of short ribs connected in the rectangular frame, and the size of the rectangular frame can at least cover the end face of the fuel cell stack body.

4. The front/rear end plate of a fuel cell stack according to claim 3, wherein: the short ribs connected in the rectangular frame are mutually vertical and intersected, and a plurality of rectangles are formed by enclosing among the short ribs and between the short ribs and the long ribs of the rectangular frame.

5. The front/rear end plate of a fuel cell stack according to claim 3, wherein: the short ribs connected in the rectangular frame are crossed in an inclined mode, and a plurality of triangles are formed by enclosing among the short ribs and between the short ribs and the long ribs of the rectangular frame.

6. The front/rear end plate of a fuel cell stack according to claim 3, 4 or 5, wherein: the distances between the four long ribs of the rectangular frame and the four sides of the front/rear end plate are equal.

7. The front/rear end plate of a fuel cell stack according to claim 3, 4 or 5, wherein: the distances between the four long ribs of the rectangular frame and the four sides of the front/rear end plate are unequal, and the long ribs on the left and right sides of the rectangular frame are flush with the left and right sides of the front/rear end plate.

8. The front/rear end plate of a fuel cell stack according to claim 4, wherein: the rectangular frame is characterized in that two short ribs are connected outside the long ribs on the left side and the right side of the rectangular frame, are respectively perpendicular to the long ribs on the left side and the right side, are arranged in the middle of the front/rear end plate and respectively extend to the edges of the left side and the right side of the front/rear end plate.

9. The front/rear end plate of a fuel cell stack according to claim 1, wherein: the reinforcing ribs are formed by forming a plurality of round holes in a rectangular plate, and the size of the reinforcing ribs can at least cover the end face of the fuel cell stack body.

10. The front/rear end plate of afuel cell stack according to claim 9, wherein: the round holes arranged in the rectangular plate comprise four large round holes arranged at four corners of the rectangular plate and a small round hole arranged in the middle of the rectangular plate.

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