Investigation And Application Of In Situ Water Distribution Detection Technology In Proton Exchange Membrane Fuel Cells(PEMFC)

With the energy crisis and environmental pollution issues becoming increasingly serious,the new clean energy such as fuel cell has been rapidly developed.Among all of them,Proton Exchange Membrane fuel cells(PEMFC)have many advantages: low temperature operatio,fast start-up,high power density,and outstanding dynamic response.Therefore,PEMFC has been recognized as a ideal power source for stationary applications,portable and mobile.The polymer electrolyte must be hydrated enough to effectively facilitate the proton transfer process inside.And in the meanwhile the only product of the electrochemical reaction of PEMFC is water.Current research shows that the water content distribution in the different components of PEMFC during operation has a major influence in the cell and stack performance as well as its stability and lifetime.Water emerges in channels of PEMFC forming different two-phase flow patterns.In addition,water is distributed in a gradient inside the stack,which causes great difficulties for the in-situ detection and water management.Therefore,it is of great practical significance to study an effective PEMFC in-situ water distribution detection technology as well as to propose a reasonable water management strategy.The contents of this paper are as follows:1.The segmented fuel cell(SFC)hardware system was designed and improved.This SFC system includes SFC stack as well as SFC detection system,which consists of hydrogen supply module,air supply module,nitrogen purge module,reaction gas humidification module,cooling water circulation module,electronic load,data acquisition module and system controller.According to the functional requirements of SFC,the software system was determined which includes protection function module,shut-down module,gas supply module,temperature control module,and data acquisition module.2.A visualization fuel cell in-situ detection system was designed for characterization of liquid water in the cell,which includes visualization fuel cell stack as well as visualization fuel cell system.According to the functional requirements of this visualization fuel cell,the hardware and software structures aiming at acquiring and controlling electrical signal were designed.Furthermore,according to the contour characteristics of liquid water in the flow channel,a liquid water measurement algorithm which based on image acquisition and processing technology was proposed.3.After the analysis of the way opration parameters affecting the performance of PEMFC,a series of experimental schemes were designed.The results reinforced the importance of these parameters for the water distribution and the performance of PEMFC.Based on the above experimental results and analysis,a series of optimized management strategies were formulated.After testing this fuel cell under these strategies and comparing its performance with the former,these strategies had been proven to be effective.