Research On The Effects Of Anode Water Content On Performance Of Vehicle Fuel Cell

Proton exchange membrane(PEMFC)is a new type of energy conversion device based on hydrogen.Because of its zero emission of pollutants,very high energy conversion efficiency and fast start-up speed at low temperature,more and more scholars and enterprises have attracted more and more attention In order to study the effect of relative humidity on fuel cell water management,a fuel cell water management(WM,Water Management)model was proposed.The working temperature of the fuel cell at 60 ? was deduced according to the condensation phenomenon of water vapor in the humidified gas in the fuel cell channel and the influence of the inlet pressure on the water activity in the fuel cell.The effect of relative humidity of 25% to 100% anode intake on water management.This article is divided into the following three parts:The first part describes the basic theory of PEMFC and the control equation of PEMFC water management(WM)model.The computational model and grid of fuel cell were established,and the WM model and hydrodynamic software Fluent were used to simulate the water distribution process of PEMFC under different working conditions,and the hydrogen gas was obtained.The distribution of oxygen and water mole fraction and the polarization curve of simulation performance.In the second part,a test system with DC channel PEMFC as the test object is designed and built.At the fuel cell working temperature of 60?,the inlet pressure is fixed at 0.1 MPa,the relative humidity of the cathode inlet is 100%.The PEMFC performance test was carried out under the working conditions of 25% and 100% relative humidity of the anode inlet,respectively,and the polarization curves of the performance test were obtained.In the third part,the distribution of reactants and the mass distribution of reactants in the battery are simulated by the model to study the transport law of water and reactant in the battery.By comparing the simulation results in the WM model with the experimental data in the performance test under different operating conditions,it is verified that the WM type can accurately predict the influence of the relative humidity of the anode inlet on the performance of PEMFC.The results show that when the working temperature of fuel cell is 60 ? and the relative humidity of cathode intake is 100%,the hydration of proton exchange membrane is more adequate with the increase of gaseous water in anode channel,and the proton conductivity of proton exchange membrane increases.The performance of fuel cell is enhanced.When the working temperature of fuel cell is 60 ?,the inlet pressure of cathode and anode is 100 KPa,and the saturation and humidification of cathode and anode will accumulate the liquid water content in the flow channel,and the probability of flooding at high current density will increase.Thus,the capillary of PEMFC gas diffusion layer is blocked,the concentration polarization of PEMFC is intensified and the performance of the battery is attenuated.