阳极燃料流速对SOFC性能影响的研究

Effect of fuel flow rate on performance of solid oxide fuel cells

燃料在SOFC作还原气体反应时,面临部分反应尾气不能被充分利用而导致其经济性较低的问题,而燃料进气流速与其有着直接的关联。通过建立电-化-热多物理场耦合的SOFC三维模型,研究了阳极燃料流速对SOFC输出性能、组分传递、温度分布的影响规律。结果显示,在给定流速范围内,随燃料流速的增大,电池的功率密度呈上升趋势;沿电池长度方向,阳极电极层的H_(2)浓度梯度随流速增加而减小,由此阳极-电解质界面的电流密度愈加均匀;电池X-Y截面的温度梯度随流速增加而升高,在进气顺流时,较低流速下(v=0.8 m/s)沿电池长度方向的最高温度出现在电池中部位置,其它流速下出现在出气口附近,而进气逆流时最高温度均在电池中部位置,且随流速的增加,最高温度处距离出气口越近。

When the fuel reacts with reducing gas in solid oxide fuel cells,it faces the current situation that the reaction tail gas can not be fully utilized,resulting in its low economy.The main influencing factors of this phenomenon are directly related to the fuel inlet flow rate.Based on this,a three-dimensional simulation model of solid oxide fuel cell coupled with electro chemical thermal multi physical fields was established,and the effects of anode fuel flow rates on the output performance,component transfer and heat distribution of solid oxide fuel cell were studied.The results show that in the given flow rate range,the power density of the battery shows an upward trend,Along the length of the cell,the H_(2)concentration gradient of the anode electrode layer decreases with the increase of the flow rate,thus the current density of the anode electrolyte interface becomes more uniform.The temperature gradient of the X-Y direction section of the battery increases with the increase of the flow rate.When the inlet air flows forward,the highest temperature along the battery length at a lower flow rate(v=0.8 m/s)appears in the middle of the battery,and at other flow rates,it appears near the air outlet.When the inlet air flows backward,the highest temperature is in the middle of the battery,and with the increase of the flow rate,the highest temperature is closer to the air outlet.