Study On The Influencing Factors Of Performance Of PEMFC With Dead-Ended Anode Mode

Nowadays,the core issues of sustainable development are to improve the utilization rate of fuel and seek for clean energy.Proton exchange membrane fuel cell(PEMFC)with dead-ended anode mode has the advantages of complete reaction of hydrogen,simplifying the system greatly,and having a more compact structure by improving the structure of fuel cell.Periodic purge is the common method to solve the problem that liquid water,nitrogen and other impurities accumulated in the channel.However,the efficiency of this working mode was affected by the channel structure and operating parameters.In this paper,the combination of computational fluid dynamics(CFD)numerical simulation and experimental research were used to study the effects of channel structure and operating parameters on the performance and purge cycle of the PEMFC with dead-ended anode mode.The main contents were as follows:Firstly of all,the development history and classification of fuel cell were introduced,the structure and working principle of PEMFC were described briefly,and the research status of PEMFC with open anode mode and PEMFC with dead-ended anode mode were summarized,the basic control equation and water transport model of PEMFC were analyzed in this paper.Taking the single channel PEMFC with deadended anode mode as the research object,the model assumptions and boundary conditions were set up,and the numerical simulation method of PEMFC with deadended anode mode was expounded.Secondly,the discrete model of anode channel was established to predict the distribution of each component and the voltage of fuel cell in the PEMFC with deadended anode mode.Based on the FLUENT software,the effect of channel structure such as cross-section shape and channel depth on the performance and component distribution of the PEMFC with dead-ended anode mode were studied by numerical simulation,and the optimum channel structure of the PEMFC with dead-ended anode mode was determined to be rectangular shape with the depth of 0.6 mm.Thirdly,according to the optimal channel structure,the CFD model of PEMFC was established,and the effects of the main operating parameters(temperature,inlet pressure,relative humidity of reaction gas,and stoichiometric ratio)of the fuel cell on the performance of the PEMFC with dead-ended anode mode are studied through numerical simulation.The influence of each parameter on the performance of the PEMFC with dead-ended anode mode were analyzed and obtained.Compared with the PEMFC with open anode mode,the results showed that the dead-ended anode mode working method can improve the performance of PEMFC and hydrogen utilization effectively.Finally,the effect of operating parameters on the purge cycle of the PEMFC with dead-ended anode mode was experimentally studied through a fuel cell test bench.Experiments were conducted on the effects of different operating loads(low,medium,and high)and operating parameters(stoichiometric ratio,relative humidity of the reaction gas,temperature,and inlet pressure)on the fuel cell purge cycle to obtain the influence of fuel cell loads and operating parameters on the purge cycle.Through comprehensive consideration of equipment cost,performance and purge cycle,it was determined that the most suitable combination of operating parameters for the PEMFC with dead-ended anode mode is: fuel cell temperature is 338 K,inlet pressure is 50 kPa,anode and anode gas relative humidity are 50% and 100%,cathode stoichiometry is 2.