A fuel cell channel with variable cross-section

Abstract

The invention relates to a variable cross-section fuel cell runner. The variable cross-section fuel cell runner comprises a cell runner arranged on a flow field plate, the cell runner comprises a runner inlet, a runner outlet, and stop blocks in the runner, and the structure of the cell runner is arranged in a way that different amount of differently distributed stop blocks with different cross sections at different heights and widths are arranged in the parallel direct runners in the direction of the cell runner. The structure of the cell runner is simple, the cell runner is easy to process,and the cost is relatively low. The local airflow velocity of the runner is strengthened under the condition that the pressure difference of the runner inlet and the runner outlet is not greatly increased, the pressure difference between the adjacent runners is established, the water removal capability of the parallel direct runner is reinforced, the transmission of a reaction gas to an electrodeis promoted, so that the transmission efficiency and the distribution uniformity of the reaction gas are improved, and the working performance of a fuel cell is improved. Compared with the traditionalparallel runner, the increase of the pressure drop of the runner provided with the stop block is not large, and the increase of pumping loss is not high, and is far less than the pumping loss of a snakelike runner. The advantages of the variable cross-section fuel cell runner are particularly remarkable on the electrode with a larger area at the higher working current density.

Description

technical field [0001] The invention relates to a variable-section fuel cell flow channel, in particular to a flow channel used for water removal and reaction gas transmission of the porous electrode of the fuel cell. Background technique [0002] The liquid water produced by the reaction in the porous electrode of the fuel cell needs to be removed in time to realize the effective transmission of the reactant gas and the efficient operation of the fuel cell. The flow channel of the fuel cell is an important transmission channel for reactant gases and reaction products, which directly affects the mass transfer efficiency of the entire fuel cell and the performance of the cell. [0003] Traditional fuel cell flow channels are all of equal cross-section, and the common forms are parallel straight channels (such as figure 1 shown) and serpentine runners (such as figure 2 shown). The parallel straight channels are short, the air velocity is low, and there is no pressure diffe...

AI Technical Summary

Problems solved by technology

The parallel straight channels are short, the air velocity is low, and there is no pressure difference between adjacent channels, which is not conducive to the removal of liquid water and the transmission of reaction gas in the porous electrode. The advantage is that the pressure difference between the inlet and outlet of the channel is small, and the pump gas The loss is small; the serpentine flow channel is longer and the air velocity is high, which is beneficial to the removal of liquid water in the porous electrode under the flow channel. At the same time, there is a pressure difference between adjacent flow channels, which can also eliminate the liquid water in the electrode below the bank of the flow field plate. , these characteristics are conducive to the transmission of the reaction gas in the electrode, but the disadvantage is that the pressure difference between the inlet and the outlet of the flow channel is large, the pumping loss is large, and the long flow channel will also make the distribution of the reaction gas along the length of the flow channel uneven.

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