CN108550875B

CN108550875B - Proton exchange membrane fuel cell flow channel

Info

Publication number: CN108550875B
Application number: CN201810378148.7A
Authority: CN
Inventors: 蔡永华; 方舟; 陈明韬; 朱宇烽; 王力; 徐乐; 严先亮; 王朋; 高斯诚
Original assignee: Wuhan University of Technology WUT
Current assignee: Wuhan University of Technology WUT
Priority date: 2018-04-25
Filing date: 2018-04-25
Publication date: 2021-11-16
Anticipated expiration: 2038-04-25
Also published as: CN108550875A

Abstract

The invention provides a proton exchange membrane fuel cell flow passage, which comprises a cathode flow passage arranged on a bipolar plate, wherein the cathode flow passage comprises an inlet flow passage with an inlet, an outlet flow passage with an outlet and at least one branch flow passage, the inlet of the branch flow passage is communicated with the inlet flow passage, the outlet of the branch flow passage is communicated with the outlet flow passage, and a blocking block is arranged in the at least one branch flow passage at intervals, so that the sectional area of the branch flow passage at the blocking block is reduced. According to the invention, the blocking blocks are arranged in the gas flowing direction, so that the flow velocity of gas is increased in the process of passing through the flow channel, the gas is easier to transfer to the diffusion layer, the gas utilization rate is greatly improved, and the overall level of the battery is improved.

Description

Proton exchange membrane fuel cell flow channel

Technical Field

The invention belongs to the field of fuel cells, and particularly relates to a proton exchange membrane fuel cell flow channel.

Background

Proton Exchange Membrane Fuel Cells (PEMFCs) have become a hotspot in the research of the energy field as a novel energy processing mode due to the advantages of low working temperature, no pollution, no corrosion, large specific power, rapid start and the like, and the research investment on the technology is increased in recent years both at home and abroad, and some key progresses are made. The design and fabrication of bipolar plate flow channels has a large impact on PEMFC performance, efficiency, and cost. The proper flow channel design can improve the performance of the fuel cell by about 50 percent, thereby ensuring that the fuel cell has better performance and stability.

The typical direct flow channel of the pem fuel cell is shown in fig. 1, and most of the reaction gas in the direct flow channel enters the electrode through diffusion phenomenon, which causes severe shortage of oxygen at the cathode outlet of the fuel cell, thereby reducing the performance and life of the fuel cell. Therefore, through carrying out the structural optimization design to fuel cell's negative pole runner, can promote the transmission of oxygen, make fuel cell have better mass transfer nature, be the important means that promotes battery performance and life-span.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: provides a proton exchange membrane fuel cell flow passage, which improves the utilization rate of gas in the flow passage.

The technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides a proton exchange membrane fuel cell runner, is including setting up the cathode flow channel on bipolar plate, and the cathode flow channel is including the entry runner that has the entry, the exit runner that has the export and at least one branch runner, and the entry runner intercommunication of branch runner, the export and the exit runner intercommunication of branch runner, its characterized in that: the blocking blocks are arranged in at least one branch flow passage at intervals, so that the sectional area of the branch flow passage at the blocking blocks is reduced.

According to the scheme, the blocking block covers 60% -80% of the cross section area of the branch flow passage.

According to the scheme, the structure between the branch flow channels is a bank, the top of the block is level with the top of the bank, a space for air to pass through is arranged between the bottom of the block and the bottom of the branch flow channel, and the block is fixedly connected with the bank.

According to the scheme, the blocking blocks are arranged at equal intervals along the branch flow channels.

According to the scheme, the width of the branch flow channel is 1mm, and the height of the branch flow channel is 0.85 mm; the structure between the branch runners is a bank, and the width of the bank is 0.5 mm; the width of the plugging block is 1mm, the height of the plugging block is 0.595mm, and the length of the plugging block is 1 mm.

According to the scheme, the distance between the adjacent blocks is 2.5 mm; the distance between the block closest to the inlet channel and the inlet was 2 mm.

According to the scheme, the overall layout of the cathode flow channel is a rectangle of 20mm x 21 mm.

The invention has the beneficial effects that: through set up the sprue on the gas flow direction for gas is increasing at the in-process velocity of flow through the runner, changes and transmits to the diffusion layer in, very big promotion gas utilization ratio, make the whole level of battery obtain improving.

Drawings

Fig. 1 is a schematic view of a typical conventional pem fuel cell flow channel.

Fig. 2 is a schematic structural diagram according to an embodiment of the present invention.

Fig. 3 is a cross-sectional view AA of fig. 2.

FIG. 4 is a graph comparing the molar concentration of oxygen in the present invention and a typical prior art flow channel.

FIG. 5 is a graph comparing the mass transfer effect of the present invention with that of a typical prior art flow channel.

In the figure: 1-inlet flow channel, 2-outlet flow channel, 3-branch flow channel, 4-block and 5-bank.

Detailed Description

The invention is further illustrated by the following specific examples and figures.

The invention provides a proton exchange membrane fuel cell flow passage, as shown in fig. 2 and fig. 3, the proton exchange membrane fuel cell flow passage comprises a cathode flow passage arranged on a bipolar plate, the cathode flow passage comprises an inlet flow passage 1 with an inlet, an outlet flow passage 2 with an outlet and at least one branch flow passage 3, the inlet of the branch flow passage 3 is communicated with the inlet flow passage 1, the outlet of the branch flow passage 3 is communicated with the outlet flow passage 2, and a blocking block 4 is arranged in the at least one branch flow passage 3 at intervals, so that the sectional area of the branch flow passage 3 at the blocking block 4 is reduced. The structure between the branched runners 3 is a land 5. The top of the plugging block 4 is level with the top of the bank 5, a space for gas to pass through is arranged between the bottom of the plugging block 4 and the bottom of the branch flow channel 3, and the plugging block 4 is fixedly connected with the bank 5. The blocking block 4 covers 60-80% of the sectional area of the branch flow passage 3. The blocks 4 are arranged at equal intervals along the branch flow path 3.

In this embodiment, on a flow field plate of a proton exchange membrane fuel cell, the overall layout of a cathode flow channel is a rectangle with 20mm × 21mm, the width of the branch flow channel 3 is 1mm, and the height of the branch flow channel 3 is 0.85 mm; the width of the bank 5 is 0.5 mm; the width of the block 4 is 1mm, the height of the block 4 is 0.595mm (namely accounting for 70% of the height of the branch flow passage 3), and the length of the block 4 is 1 mm. The distance between the adjacent blocks 4 is 2.5 mm; each branch flow passage 3 is provided with 5 blocks 4, and the distance between the block 4 closest to the inlet flow passage and the inlet is 2 mm. The transmission characteristics of the reaction gas are optimized by the concentration gradient and the pressure gradient of the reaction gas in each flow channel, the utilization efficiency of the reaction gas is improved, the mass transfer resistance is reduced, and the mass transfer efficiency is improved.

Comparative example of the invention: the comparative example adopts the traditional straight flow channel design, the parameters are the same as those of the flow channel in the embodiment, the length of the branch flow channel is 20mm, the width of the branch flow channel is 1mm, the height of the branch flow channel is 0.85mm, and the width of the bank of the branch flow channel is 0.5 mm.

The performance of this example was compared with the conventional straight flow channel of the comparative example under the same operating conditions, and the test conditions were as follows: air humidity 10%, operation pressure 1ATM, operation temperature 363K, H₂O and O₂The mass fractions of the components are 0.018 and 0.229 respectively. The results of the performance comparison are shown in fig. 4 and 5.

Figure 4 shows a comparison of the molar concentration of oxygen in two flow channels. The oxygen molar concentration of the comparative example in the flow channel direction is always smaller than that of the inventive example, so that the gas pressure drop in the flow channel is larger, the gas flow speed is higher and the mass transfer effect is more obvious than that of the comparative example due to the existence of the blocking block.

Figure 5 shows a comparison of the effective mass transfer coefficients in two flow channels. In the embodiment of the invention, the effective mass transfer coefficient is improved by adding the blocking block, so that the utilization rate of gas in the electrode flow channel is greatly improved.

The improvement of the traditional proton exchange membrane parallel flow passage structure of the invention improves the transmission utilization rate of reaction gas, improves the performance of the battery and prolongs the service life of the battery according to the characteristics that the overall layout shape of the flow passage, the geometric shape and the size of the blocking blocks in the single flow passage, and the spacing and the arrangement can be regulated and controlled.

The above embodiments are only used for illustrating the design idea and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the content of the present invention and implement the present invention accordingly, and the protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes and modifications made in accordance with the principles and concepts disclosed herein are intended to be included within the scope of the present invention.

Claims

1. The utility model provides a proton exchange membrane fuel cell runner, is including setting up the cathode flow channel on bipolar plate, and the cathode flow channel is including the entry runner that has the entry, the exit runner that has the export and at least one branch runner, and the entry runner intercommunication of branch runner, the export and the exit runner intercommunication of branch runner, its characterized in that: the blocking blocks are arranged in at least one branch flow passage at intervals, so that the sectional area of the branch flow passage at the blocking blocks is reduced; the structure and the connection mode of each block are the same;

the blocking block covers 60% -80% of the cross section area of the branch flow passage;

the structure between the branch flow channels is a bank, the top of the block is level with the top of the bank, a space for gas to pass through is arranged between the bottom of the block and the bottom of the branch flow channel, and the block is fixedly connected with the bank;

the blocking blocks are arranged at equal intervals along the branch flow channel;

the width of the branch flow channel is 1mm, and the height of the branch flow channel is 0.85 mm; the structure between the branch runners is a bank, and the width of the bank is 0.5 mm; the width of the blocking block is 1mm, the height of the blocking block is 0.595mm, and the length of the blocking block is 1 mm;

the distance between the adjacent blocks is 2.5 mm; the distance between the block closest to the inlet channel and the inlet was 2 mm.

2. The pem fuel cell flow-channel of claim 1 wherein: the overall layout of the cathode flow channels is a rectangle with 20mm x 21 mm.