Cooling Flow Field Design And Thermal Simulation Of Proton Exchange Membrane Fuel Cell

Proton exchange membrane fuel cell(PEMFC)has become one of the hots pots in the research of new energy sources because of its high power density and fast start-up.The fuel cell will produce a lot of heat due to the electrochemical reaction and the loss of electric energy.About 40%～60%of the energy will be dissipated into heat energy.Effective cooling measures should be taken to maintain the stability of the temperature in the stack,so as to ensure the long-term stable operation of the stack.Otherwise,the temperature of the stack will continue to rise,which may cause a series of problems such as dehydration,contraction and even rupture of the proton exchange membrane.In this paper,numerical simulation is used to study the influence of cooling channel on the temperature distribution of battery.Firstly,the significance and requirements of the thermal management of PEMFC are introduced,the sources and emission ways of the heat in PEMFC are analyzed,the mathematical model of the working process of PEMFC is described,and the thermal simulation analysis of the cooling plate and the single cell is carried out by using the fluid dynamics software Fluent.The high power fuel cell is usually cooled by liquid.In this paper,two kinds of cooling channels are designed and compared with the traditional serpentine channel.The cooling performance of three kinds of cooling plates under different cooling water flow rate is simulated and analyzed.The results show that the larger the flow rate is,the more uniform the temperature distribution on the surface of the cooling plate will be,but at the same time,the cooling water pressure loss will be increased,and more pump power is needed to deliver cooling water.At the same cooling water flow rate,the serpentine channel has the best cooling performance,but the pressure drop is also the largest.The cooling performance of the B-type channel is better,and the pressure drop is relatively small.The cooling performance of the A-type channel is the worst,and the pressure drop is the smallest.The results show that the temperature on the membrane increases with the increase of current density and the temperature uniformity is poor.Then,based on the above model,a single cell model including B-type cooling channel is established,and the influence of cooling water on the temperature distribution of the cell under different working conditions is discussed.The results show that the cooling water has a good downstream effect at 60~°C,the standard deviation of temperature on the membrane first decreases and then increases with the increase of flow velocity;the counterflow effect is good at 80~°C,and the temperature on the membrane first decreases and then increases with the increase of flow velocity The better the uniformity is,the better the effect is when the cooling water is close to the working temperature of the battery.