CN100536217C - Integral type fuel battery stack tandem method - Google Patents

Abstract

The invention relates to a method for connecting an integrated fuel cell stack in series. The method includes a central collector plate, a rear end plate, four or more fuel cell stacks, and a conductor. The four or more fuel cells The processing of each guide plate in the stack is exactly the same. The two electric stacks on both sides of the central current collecting plate form a group. The positive and negative electrodes of each single cell in this group are in the same orientation. The conductors of the central collector plate are connected in series, while the positive and negative poles of the single cells in the two stacks of the adjacent group are in the same orientation, but opposite to the positive and negative poles of the single cells in the adjacent group. The electric stack realizes the positive and negative poles are connected in series through the conductors between the respective current collector motherboards, so that the positive and negative lead wires are on the same side of the entire electric stack; compared with the prior art, the present invention has the advantages of material saving, space saving, safety Reliable and other advantages.

Description

A series method of integrated fuel cell stack

technical field

The invention relates to a fuel cell, in particular to a series connection method of an integrated fuel cell stack with a compact structure and easy installation.

Background technique

An electrochemical fuel cell is a device that converts hydrogen fuel and oxidant into electrical energy and reaction products. The internal core component of the device is the membrane electrode (Membrane Electrode Assembly, referred to as MEA). The membrane electrode (MEA) is composed of a proton exchange membrane and two porous conductive materials, such as carbon paper, sandwiched between the two sides of the membrane. On the two boundary surfaces of the membrane and the carbon paper, there are even and finely dispersed catalysts for initiating electrochemical reactions, such as metal platinum catalysts. Conductive objects can be used on both sides of the membrane electrode to draw the electrons generated during the electrochemical reaction through an external circuit to form a current loop.

At the anode end of the membrane electrode, the fuel can permeate through the porous diffusion material (carbon paper), and an electrochemical reaction occurs on the surface of the catalyst, losing electrons and forming positive ions, which can migrate through the proton exchange membrane, Reach the cathode end of the other end of the membrane electrode. At the cathode end of the membrane electrode, a gas containing an oxidant (such as oxygen), such as air, penetrates through the porous diffusion material (carbon paper), and electrochemically reacts on the surface of the catalyst to obtain electrons to form negative ions. Anions formed at the cathode end react with positive ions migrating from the anode end to form reaction products.

In a proton exchange membrane fuel cell that uses hydrogen as fuel and air containing oxygen as the oxidant (or pure oxygen as the oxidant), the catalytic electrochemical reaction of fuel hydrogen in the anode region produces positive hydride ions (or protons). The proton exchange membrane facilitates the migration of positive hydride ions from the anode region to the cathode region. In addition, the proton exchange membrane separates the hydrogen-containing fuel gas stream from the oxygen-containing gas stream so that they do not mix with each other and cause an explosive reaction.

In the cathode area, oxygen gets electrons on the surface of the catalyst to form negative ions, and reacts with positive hydrogen ions migrated from the anode area to generate water as a reaction product. In a proton exchange membrane fuel cell using hydrogen and air (oxygen), the anode reaction and cathode reaction can be expressed by the following equation:

Anode reaction: H ₂ → 2H ⁺ +2e

Cathode reaction: 1/2O ₂ +2H ⁺ +2e→H ₂ O

In a typical proton exchange membrane fuel cell, the membrane electrode (MEA) is generally placed between two conductive plates, and the surface of each guide electrode plate in contact with the membrane electrode is formed by die casting, stamping or mechanical milling to form More than one diversion groove. These current-guiding electrode plates can be pole plates of metal material or graphite material. The diversion channels and diversion grooves on these diversion electrode plates guide the fuel and oxidant into the anode region and the cathode region 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 the two sides of the membrane electrode are respectively the guide plate of the anode fuel and the guide plate of the cathode oxidant. These guide plates not only serve as the current collector mother plate, but also serve as the mechanical support on both sides of the membrane electrode. The guide grooves on the guide plate serve as channels for fuel and oxidant to enter the surface of the anode and cathode, and serve as a way to take away the fuel cell. Channels for water generated during operation.

In order to increase the total power of the entire proton exchange membrane fuel cell, two or more single cells can usually be stacked in series to form a battery pack or connected in a tiled manner to form a battery pack. In direct-stacked and series-connected battery packs, there can be diversion grooves on both sides of a pole plate, one of which can be used as the anode diversion surface of one membrane electrode, and the other side can be used as the cathode of another adjacent membrane electrode. The diversion surface, this kind of plate is called a bipolar plate. A series of cells are connected together in a certain way to form a battery pack. The battery pack is usually fastened together by the front end plate, the rear end plate and the tie rods to form a whole.

A typical battery pack usually includes: (1) diversion inlet and diversion channel of fuel and oxidant gas, fuel (such as hydrogen, methanol or hydrogen-rich gas obtained by reforming methanol, natural gas, gasoline) and oxidant ( (mainly oxygen or air) is evenly distributed into the diversion grooves of each anode and cathode surface; (2) the inlet and outlet and diversion channels of the cooling fluid (such as water), and the cooling fluid is evenly distributed into the cooling channels in each battery pack , absorb the heat generated by the electrochemical exothermic reaction of hydrogen and oxygen in the fuel cell and take it out of the battery pack to dissipate heat; (3) The outlet of the fuel and oxidant gas and the corresponding guide channel, when the fuel gas and oxidant gas are discharged , can carry out the liquid and vapor state water generated in the fuel cell. Usually, the inlets and outlets of all fuels, oxidants, and cooling fluids are opened on one or both end plates of the fuel cell stack.

Proton exchange membrane fuel cells can be used not only as power systems for vehicles, ships, etc., but also as mobile or stationary power stations.

The fuel cell power generation system is mainly composed of a fuel cell stack and a battery stack support operation system. As a vehicle, ship power or high-power fuel cell power generation system application in a power station, it is required to output tens of kilowatts, or even hundreds of kilowatts of power. For such a high-power output requirement, there must be a corresponding high-power output fuel cell stack and supporting operating system.

The engineering design and manufacture of fuel cell stacks with high power output, in terms of technology and manufacturing costs, generally cannot adopt a giant high-power single-stack method composed of many large active surface positive plates, but use multiple small and medium power stacks. A method for integrating fuel cell stack modules together to meet high power output requirements.

Existing large-scale, high-power fuel cells are shown in Figure 1, where 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16 are The current collecting motherboard on each battery stack module is used as positive and negative poles. 17 is the central total current collecting and deflecting panel. A is the first pair of corresponding second battery stack modules, B is the second pair of corresponding second battery stack modules, C and D are the third and fourth corresponding second battery stack modules. The existing positive and negative connections between the stacks are 3 in series with 2, 1 in series with 8, 7 in series with 6, 5 in series with 12, 11 in series with 10, 9 in series with 16, 15 in series with 14, and finally 13 in series with 4 The current collector motherboard serves as the output terminal of the positive and negative poles of the entire integrated fuel cell. It can be seen that several positive and negative electrode series leads of this integrated fuel cell are on both sides of the entire integrated stack, and there are a large number of independent stack modules, and the space layout of the leads is very long and unreasonable.

Shanghai Shenli Technology Co., Ltd. invented a method to make the positive and negative lead wires of the integrated fuel cell rationally arranged (invention patent application number: 200510026002.9, utility model patent application number: 200520041695.4). As shown in Figure 2, the labels 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 represent the current collectors on each battery stack module plate, as the positive and negative poles. 17 is the central total collector motherboard. A is the first pair of corresponding second battery stack modules, B is the second pair of corresponding second battery stack modules, C and D are the third and fourth corresponding second battery stack modules. In the present invention, the positive and negative poles between stacks are connected in series with 3 and 2, 1 and 5 in series, 6 and 7 in series, 8 and 12 in series, 11 and 10 in series, 9 and 13 in series, 14 and 15 in series, and finally 16 and 4 The current collecting motherboard serves as the output terminal of the positive and negative poles of the whole integrated fuel cell. It can be seen that the positive and negative leads of this integrated fuel cell are on the same side of the entire stack, and the space span is more reasonable than the original lead arrangement.

However, this design needs to process all the guide plates in the same group of two stack modules on the left and right sides of the fuel cell exactly the same, and make the orientation of the positive and negative electrodes of each single cell exactly the same, so that the two modules can pass through directly. The respective current collecting motherboards are connected in series; while the processing of each current guide plate of the fuel cell in the two adjacent stack modules is exactly the same, but it is the same as that of the fuel cell current guide plates in the adjacent group. Mirror image processing, so that although the orientation and arrangement of the positive and negative electrodes of each single cell in this group are exactly the same, they are exactly opposite to the orientation of the positive and negative electrodes of the adjacent group, so that the adjacent two groups of electric stack modules can pass through their respective current collectors. The motherboard is easy to connect the positive and negative poles in series, so that the positive and negative poles are on the same side of the entire stack, and the space connection distance is minimized.

This integrated fuel cell stack needs to process two different deflectors, the process is complicated, the installation is inconvenient, and the cost is high, which causes great trouble for mass production. Therefore, the integrated fuel cell deflectors commonly used at present are the same, and the positive and negative lead wires are connected as shown in Figure 3. The conductive rods 20 pierced through the central collector plate are connected in series, the positive and negative orientations of the single cells of the battery stacks C and D are the same as those of A and B, and the battery stacks B and C are diagonally connected in series through wires 19, so that the entire integrated battery Heap concatenation. However, this connection method takes up space and wastes materials due to the need for a long wire on the outside. Once the outer insulating layer of the wire is worn out, it is very unsafe.

Contents of the invention

The object of the present invention is to provide a material-saving, space-saving, safe and reliable method for connecting integrated fuel cell stacks in series in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions: a series connection method of an integrated fuel cell stack, which is characterized in that the method includes a central collector plate, a rear end plate, four or more fuel cell stacks, a conductive body, the processing of each guide plate in the four or more fuel cell stacks is exactly the same, and through the setting of each guide channel and guide hole in the central collector plate, the two sides of the central collector plate The two electric stacks are a group, and the positive and negative poles of each single cell in this group are in the same orientation. The orientation of the positive and negative poles of each single cell in the two stacks is the same, but the orientation of the positive and negative poles of each single cell in the adjacent group is opposite. connected in series, so that the positive and negative lead wires are on the same side of the entire integrated stack; the central collector plate is provided with passages for hydrogen, air, and cooling fluid to enter and exit, and each fluid flows from both ends or the middle of the central collector plate or from the The collector plate in front of the rear end plate of each electric stack enters and leaves the electric stack, and each fluid inlet and outlet channel is connected with the corresponding fluid inlet and outlet of each electric stack.

A gap perpendicular to the central collector plate is formed between the adjacent two groups of electric stacks of the fuel cell stack, and the air, hydrogen, and cooling fluid in the central collector plate corresponding to the adjacent two groups of electric stacks enter and exit the fluid holes and the gap The spacing is the same, and the guide holes corresponding to the same fluid are arranged symmetrically.

Two groups of electric stacks adjacent to the same side on the central collector plate, wherein the diversion field on the guide plate close to the first block and opposite to the central collector plate in one group is the guide air flow field, The diversion field on the diversion plate close to the first block and facing the central collector plate in the other group is the hydrogen diversion field.

The shape of the conductor includes a cylinder, a cuboid, a cube, and a hoof.

There are 2 to 20 conductors pierced through the central current collecting plate.

The positive and negative poles of the stacks arranged on both sides of the central collector plate have the same orientation, and the positive and negative poles of the stacks adjacent to each other have opposite orientations.

Compared with the prior art, there is a central collector plate in the middle of the fuel cell stack of the present invention, and a rear collector plate is provided in front of the rear end plate for integrated packaging. Hydrogen, air and cooling fluid can flow from different directions of the fuel cell stack as required. The utility model has a compact structure and is easy to install, and can be designed in conjunction with a fuel cell guide plate with an aspect ratio greater than 1:1.

Description of drawings

Figure 1 is a schematic diagram of the layout of the positive and negative lead wires of the existing integrated fuel cell stack;

Fig. 2 is a schematic diagram of another existing integrated fuel cell stack positive and negative leads layout;

Fig. 3 is a schematic diagram of the positive and negative connections of the existing integrated fuel cell stack;

Fig. 4 is a schematic diagram of the positive and negative connections of the integrated fuel cell stack in the embodiment of the present invention;

Fig. 5 is the sectional view of Fig. 4;

Fig. 6 is a flow deflector in front of the current collector on the central current collector of the battery stack in Fig. 4 .

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example

As shown in Figures 4, 5, and 6, a 50KW-100KW integrated fuel cell stack series method includes four sets of fuel cell stacks A, B, C, D and a central collector plate. These four sets of fuel cell stacks The processing of each guide plate in the battery stack is exactly the same. A and B are arranged on both sides of the central collector plate. The conductors 20 passing through the central collector plate are connected in series, and the diversion field on the guide plate that is close to and opposite to the central collector plate is the guide air flow field, which is the positive pole; The flow guide plates of the fuel cells in the two stack modules C and D are arranged with the flow guide plates of the fuel cells in the adjacent group and the positive and negative electrodes of each single cell are in opposite orientations, and the ones close to the central collector plate are the hydrogen conduction gas electrodes The plate is the negative pole, and the adjacent two groups of electric stack modules B and D are connected in series through the conductors 19 between the respective current collector motherboards, so that the positive lead 21 and the negative lead 22 are on the same side of the entire electric stack; Air enters the air channel from one end of the central collector plate, enters the stack from the air inlet 23, exits the stack from the air outlet 26, and flows out from the other end of the central collector plate; hydrogen enters from one end of the central collector plate and passes through the hydrogen inlet 24 Flow into the electric stack, and flow out of the electric stack from the collector plate in front of the rear end plate along 28, the cooling fluid enters the electric stack from one end of the central collector plate through the cooling fluid inlet 25, flows out from the cooling fluid outlet 27, and flows from the other end of the central collector plate Outflow from one end. As shown in Figure 6, the integrated fuel cell stacks B and D are closest to the flow deflectors in front of the current collecting motherboard of the central collecting plate 18: the air guiding flow channel plate 29, the hydrogen guiding air flow channel plate 30, the described A gap perpendicular to the central collector plate 18 is formed between the adjacent two stacks B and D of the fuel cell stack, and the air inlet 23 and the hydrogen inlet port 23 in the central collector plate corresponding to the two adjacent stacks B and D are Air port 24, cooling fluid inlet fluid hole 25, air outlet 26, hydrogen gas outlet 28, cooling fluid outlet fluid hole 27 are identical with this slit spacing respectively, promptly two air inlets 23 are identical to the spacing of this slit, two air The distance from the air outlet hole 26 to the gap is the same, the corresponding hydrogen gas and cooling fluid inlet and outlet are also at the same distance from the gap, and the corresponding guide holes are arranged opposite to each other, and are located at the nearest or the farthest position. One of the flow deflectors in front of the current collector motherboards of the adjacent electric stacks on the same side of the central current collector is an air guide flow channel plate 29 , and the other is a hydrogen guide air flow channel plate 30 .

The inlet and outlet passages for hydrogen, air, and cooling fluid can be arranged in the central collector plate or in the collector plate in front of the rear end plate, and each fluid flows from both ends of the central collector plate or from the collector plate in front of the rear end plate of each stack. In and out of the stack, and each fluid inlet and outlet channel is connected with the corresponding fluid inlet and outlet of each stack.

Hydrogen, air, and cooling fluid can also enter the central collector plate from one or both ends of the gap perpendicular to the central collector plate in the middle of the stack (the middle of the stack B, D or the middle of A, C), and pass the same distance from both sides respectively. Enter the electric stack, and flow out from the central collector plate or the collector plate in front of the rear end plate.

Claims (6)

1. the series connection method of an integrated fuel cell pile, it is characterized in that, this method comprises central collector plate, end plate, four fuel cell packs, the design of electric conductor, each guide plate processing is just the same in described four fuel cell packs, by to each fluid access way in the central collector plate and the setting of pod apertures, making two piles of central collector plate both sides is one group, each monocell both positive and negative polarity orientation of this group is consistent, be connected in series by the electric conductor that vertically is arranged in central collector plate between these two piles, and each monocell both positive and negative polarity orientation is consistent in two piles of another adjacent group, but with each monocell both positive and negative polarity opposite orientation of adjacent set, the two adjacent groups pile realizes that by the electric conductor between flow-collection mother-board separately both positive and negative polarity is connected in series, and makes positive and negative lead wires be in the homonymy of whole integrated form pile; Be provided with hydrogen, air, cooling fluid access way in the described central collector plate, each fluid is from central collector plate two ends or collector plate turnover pile middle or before each pile end plate, and each fluid access way is imported and exported with each pile corresponding fluids and linked to each other.

2. the series connection method of a kind of integrated fuel cell pile according to claim 1, it is characterized in that, form the slit vertical between the two adjacent groups pile of described fuel cell pack with central collector plate, air in the two adjacent groups pile corresponding central collector plate, hydrogen, cooling fluid turnover pod apertures are identical with this slit spacing, and each corresponding same fluid passes in and out pod apertures and is and is symmetrical arranged.

3. the series connection method of a kind of integrated fuel cell pile according to claim 1 is characterized in that, one of baffler on the described central collector plate before the flow-collection mother-board of adjacent two piles of homonymy is an airflow guiding slot plate, and another piece is a hydrogen flow guiding slot plate.

4. the series connection method of a kind of integrated fuel cell pile according to claim 1 is characterized in that, described electric conductor shape comprises cylinder, cuboid, cube, ungulate body.

5. the series connection method of a kind of integrated fuel cell pile according to claim 1 is characterized in that, the described electric conductor that is arranged in central collector plate has 2～20.

6. the series connection method of a kind of integrated fuel cell pile according to claim 1 is characterized in that, the both positive and negative polarity orientation of the pile that described central collector plate both sides are provided with is identical, the pile both positive and negative polarity opposite orientation of the adjacent setting in front and back.

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