Fuel battery bipolar plate cooling flow field structure

Abstract

The invention relates to a fuel battery bipolar plate cooling flow field structure. The fuel battery bipolar plate cooling flow field structure is arranged on a bipolar plate body (1) and composed ofa cooling liquid inlet (2), a cooling liquid outlet (4), and a flow passage connecting the cooling liquid inlet (2) and the cooling liquid outlet (4), wherein the flow passage is composed of an inlettransitional cooling flow passage (5), a cooling liquid main flow passage (3) and an outlet transitional cooling flow passage (6) which are sequentially connected; the inlet transitional cooling flowpassage (5) and the outlet transitional cooling flow passage (6) are in an arc structure with the middle higher than the outside. Compared with the prior art, the fuel battery bipolar plate cooling flow field structure ensures uniform distribution of cooling liquid, reduces pressure drop at the cooling liquid inlet and outlet and stabilizes the output performance of batteries.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a fuel cell bipolar plate cooling flow field structure. Background technique [0002] In order to ensure the performance and life of the proton exchange membrane fuel cell, it is necessary to keep the performance of each point of the membrane electrode consistent, so it is necessary to maintain uniform gas distribution and temperature distribution at each point of the membrane electrode. If the gas distribution is inconsistent and the heat dissipation conditions of each point of the membrane electrode are inconsistent, the actual performance of each point of the membrane electrode will be quite different, and in severe cases, it will cause local overheating in the membrane electrode, or even burn through the proton exchange membrane. In addition, if the excess water generated during the operation of the fuel cell cannot be removed in time, it will block the flow channel and ca...

AI Technical Summary

Problems solved by technology

If the gas distribution is inconsistent and the heat dissipation conditions of each point of the membrane electrode are inconsistent, the actual performance of each point of the membrane electrode will be quite different, and in severe cases, it will cause local overheating in the membrane electrode, or even burn through the proton exchange membrane

In addition, if the excess water generated during the operation of the fuel cell cannot be removed in time, it will block the flow channel and cause gas flow to be blocked

[0003] At present, the types of plate flow field mainly include serpentine flow field, interdigitated flow field and parallel flow field. The serpentine flow field is a kind of flow channel form proposed earlier. Water, but its disadvantages are also obvious. For a flow field with a relatively large area, because of its long flow channel length and many bends, the pressure drop is large, the gas concentration distribution is large, and water is easy to accumulate at the bends, resulting in system low efficiency

The interdigitated flow field directs all the gas passing through the flow field to the gas diffusion layer of the membrane electrode, increases the contact between the gas and the catalyst, and effectively avoids the accumulation of liquid water in the gas diffusion layer, but the pressure drop is too large, which makes it difficult to select parts And the disadvantage of high energy consumption

Aiming at these problems of the serpentine flow field, there are many improved patents, such as patent number CN03806839, which divides the flow field into main and auxiliary flow fields. Although the problem of gas concentration difference is solved, the pressure drop is still large

[0004] The parallel flow field has the characteristics of pressure drop, but the slight difference in the flow and reaction of the gas in the flow channel will disturb the overall performance of the battery, and it is prone to unstable performance

In addition, in the current prior art, the bipolar plate cooling channel is narrow, the pressure drop at the inlet and outlet is large, and the distribution of each cooling channel is not uniform, and the bipolar plate needs to provide sufficient thickness to meet the cooling liquid circulation. In this way, the overall length and weight of the overall bipolar plate assembled into a stack cannot be reduced

When the battery output is working, the cooling liquid passes through the cooling flow channel. Due to the distance between each cooling flow channel and the inlet, the distribution of the cooling liquid will be uneven, which will cause the heat generated by the reaction to be unable to exchange heat with the cooling liquid evenly. The generated water condenses and accumulates to block some of the flow channels, resulting in battery failure

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