Study On Consistency And Dynamic Parameters Of Proton Exchange Membrane Fuel Cell

Up to now,the clean energy is imminent in the pursuit of healthy earth.In which,a proton exchange membrane fuel cell(PEMFC),as a novel clean energy source,breaks through the restriction of the Carnot cycle,can directly convert the chemical energy into electric energy,has the advantages of low working temperature,high power density and quick start,and is of great concern to the world.The object to be used as the power source must be in accord with the conditions of dynamic multi-working and the consistency,so the research of this aspect is very necessary.The aim of this paper is to study the consistency and parameters of PEMFC under multi-working conditions.Aiming at the various parameter changes in fuel cell,a dynamic parameter model(DP Model)based on the dynamic variation of parameters is put forward in this paper.DP model takes into account the changes of water content,temperature and relative humidity during fuel cell operation.The parameters are formulated by self-defined function and used for fuel cell simulation calculation.Based on equivalent circuit,the equivalent modeling of fuel cell system is carried out.Considering the influence of fuel cell parameters,the PEMFC three-dimensional two-phase flow model was established by using Fluent and Gambit.The irregular grid was divided,the material was set up and the simulation calculation was carried out.The convergence conditions were set up to obtain the PEMFC visualization contours,including:water content in the membrane,distribution of gas concentration and relative humidity in the channel and so on.The fuel cell test platform is set up,and the existing stack with the effective area of275cm~2 PEMFC single cell and 10 single cells are tested by Volt-ampere cycle method and Taguchi cross-test method.The test system adopts the PC terminal to set up the parameters and carry on the backward feedback regulation.The experimental conditions were as follows:different inlet temperature(43?,50?,55?),different working temperature(60?,65?,70?),symmetrical and asymmetric humidification(0~100%RH).The whole and single cell PEMFC performances of the stack were recorded during the test,after that,the test data were collected and the corresponding simulation results were compared and analyzed.The results are as follows:1)The consistency of the reactor is shown as follows:starting from the gas inlet of the reactor,the voltage of the single cell gradually decreases,the voltage of the single cell FC10decreases the fastest,and its performance is the worst under the same test conditions.The temperature and relative humidity have great influence on the whole reactor,and the voltage drop decreases when the humidity increases.The voltage drop increases as the temperature increases,but the single cell consistency improves.2)With the increase of inlet temperature and relative humidity,the dynamic range and stable time of temperature gradually decrease.When the inlet relative humidity is higher,the initial reaction temperature is lower.In the overall changing trend,when the inlet temperature is lower than the working temperature,the fuel cell performance increases with the inlet temperature,but the tendency of flooding is germinated due to the high relative humidity.3)The influence of cathode relative humidity and anode relative humidity on the performance of fuel cell is different.The influence of cathode relative humidity on fuel cell performance is more obvious than that of anode relative humidity on fuel cell performance.