Study On Hydrothermal Distribution Characteristics Of Dead-ended Proton Exchange Membrane Fuel Cells

In recent years,due to the increasing environmental awareness and consensus on the limitations of fossil fuels,more and more countries around the world have participated in the research of Proton Exchange Membrane Fuel Cell(PEMFC).PEMFC is a power generation device that can directly convert the chemical energy of gas fuels into electrical energy under the action of a catalyst.It has the advantages of high efficiency,low pollution,low noise,long lifespan,fuel diversity,low working temperature,short start-up time,and high specific power and energy.It can be used as a power source for the new generation of electric vehicles,a portable small power source,a household cogeneration system,and other purposes,thus receiving widespread attention from governments in various fields such as energy,automobiles,and home appliances.The hydrothermal distribution of a closed hydrogen oxygen proton exchange membrane fuel cell has a significant impact on its performance,durability,and safety.This article studies the formation and location distribution of water in the cell through visualization,allowing for a visual view of the location,growth,and movement of liquid water in the flow channel.Real time monitoring of cell temperature can be achieved by collecting data from T-type thermocouples.These are beneficial for understanding its hydrothermal distribution characteristics,optimizing the internal hydrothermal management of the cell,and thereby improving the performance,durability,and safety of the cell.This article designs a transparent visualization window and real-time temperature monitoring proton exchange membrane fuel cell,and studies the water heat distribution characteristics in the cathode channel of the fuel cell under different operating conditions and the impact of different operating conditions on the performance of the fuel cell.The specific conclusions are as follows:(1)With the operation of the cell,when the cell is flooded,the hot spot of the cell remains in the inlet section.When the cell temperature is high,the hot spots of the cell are all in the inlet section,and the temperature decreases sequentially along the flow channel,with the lowest temperature appearing in the outlet section.When the temperature is low,the higher the liquid water content in the flow channel at the same time,and it accumulates in the outlet section of the cell.As the cell temperature increases,the liquid water content decreases,and the liquid water tends to aggregate in the inlet section.(2)There is a one-to-one correspondence between downtime,current density,and water ratio,current density.The lower the current density,the longer the shutdown time,and the higher the proportion of liquid water.When operating stably at low current density,i.e.without water flooding,the hot spots of temperature are concentrated in the middle of the cell.When water flooding occurs,the temperature hotspot shifts from the middle of the cell to the inlet section of the cell.At high current density,the hot spot of cell temperature is always in the inlet section of the cell.(3)The smaller the pressure difference(cathode pressure anode pressure),the smaller the impact on operating time compared to output performance.When the pressure difference is small,temperature hotspots are distributed in the inlet section of the cell;When the pressure difference is large,the temperature hotspots are distributed in the inlet section and the middle of the cell.(4)When the positive and negative poles are the same,the voltage performance is the best,and the voltage values are consistent.During stable operation,the temperature hotspots with strong negative and positive electrode pressures are located in the inlet section,while the ones with low pressure are located in the middle of the inlet section and cell.