利用网络窄缝通道模拟实验研究DMFC多孔扩散层气液两相逆流传输特性,结果表明,网络结构喉道内水侵渗机制呈"活塞状",孔内侵渗机制包含三种:"弯月形"、"球冠形"和几何截面突变处"夹断"气柱方式;网络结构内空气驱替水的机制包含两种:喉道内呈"活塞状"驱替,孔内呈"球冠形"驱替;气体流量小,气驱液在网络结构内呈现稳定驱替现象,随着气体流量的增加,逐渐向"树冠形"分布转变;网络结构内气相驱动压力随气相流量和水流量的增加而增加;气相饱和度略有减小。
Visual experiments were conducted for current flow in a reticulate structure with uniform studying the characteristics of gas/liquid counter- small channels. The results show that the process of water invasion is piston-like in throats, but in the pores, three types of invasion can be observed under different gas/liquid phase distribution: meniscus-like invasion; spherical-crown-like invasion and snap-off invasion. The process of gas replacement includes two patterns: piston-like in throats and spherical-crown-like in pores. The stable displacement occurs at a smaller gas flow rate. With the increasing of gas flow rate, gas distribution in the reticulate structure can be transformed to dendrite. The gas actuating pressure increases and gas saturation slightly reduces with increasing the gas and liquid flow rate in the reticulate structure.