Modeling And Optimization Of Heat Transfer In Proton Exchange Membrane Fuel Cell Stack

Proton exchange membrane fuel cell (PEMFC) is a new energy disposal mode, it has a lot of virtues, such as high power density, high efficiency, low-temperature operation, fast start-up and zero-emission. But the actual fuel cell is in the research stage, and some of the critical questions aren't dissolved. The cooling of the PEMFC stack is one of them, but the heat of the PEMFC is non-reversible and nearly 50% of the energy dissipation is heat energy, and the temperature of the stack will ascend endlessly, then the membrane will dehydrate and shrink, and the performance of the stack will decrease, even not work. So the cooling of the PEMFC stack is important to maintain electricity chemistry reaction on the rails.This paper is aim at the cooling of the PEMFC stack by use of the commercial computational fluid dynamics (CFD) software Fluent.The structural and working principle are introduced, and the physical and mathematic model of the module of the Fluent package are illuminated particularly. The parallel efficiency and accelerate ratio of the PEMFC model of the Fluent software and the high performance computer cluster (HPCC) is tested and analyzed, and, and the results show that the parallel efficiency and accelerate ratio of the PEMFC model of the Fluent software are lower than that of HPCC. The reason is that communication quantity between the nodes is too much, and the current Ethernet kilo mega exchanger can not meet the requirement.The influence of the positions of the cooling flow field on temperature distribution in membrane is discussed, and the results show that the cooling effect is well when the cooling grooves lying below the gas flow field. But the differences are not very big. When the cooling water is in downstream, the temperature differences are less than that is in upstream.The influence of cooling effects of 300mm single fuel cell is simulated and calculated which has different cooling channel shape, distribution and the cooling water speed. From the result we can see the cooling effects increases with the speed of cooling water, the quantity of decalescence of cooling decreases with the speed of cooling water; difference in temperature of cooling water between inlet and outlet decreases with temperature and increases with the contact area between cooling water and channel wall; The effect of membrane temperature due to the speed of cooling water is very small when its speed is range of 0.25～6m/s; This channel field design of single cell has a small difference in temperature of membrane,only about 4K.Calculating the heat balance of a 60kW stack, and validating the calculating...