Experimental investigation of the two-phase flow distribution and pressure drop characteristic within the cathode bending type channel of fuel cell

Abstract

The accurate prediction of the two-phase flow distribution within the channel is of great significance for enhancing fuel cell water management and improving output efficiency. The current study constructs a novel transparent fuel cell visualization test system and experimentally investigates the characteristics of two-phase flow pattern distribution, pressure drop, and output voltage within the bending type channel. Furthermore, a focused analysis of slug flow which may induce fuel cell flooding is conducted. The results show that the two-phase flow pattern maps of both the bent and straight channels are highly consistent. The force balance analysis is performed to explain the internal mechanism that the bending structure has less influence on the two-phase flow pattern. Additionally, the bending structure has a significant impact on the channel pressure drop magnitude and time-domain characteristics. The two-phase pressure drop can be used as an empirical tool to judge the flow pattern and occurrence position. The fuel cell output voltage jump phenomenon occurs under slug flow pattern, and there is a strong positive correlation between the voltage jump amplitude and current density, with a Pearson correlation coefficient of 0.924. The research results provide theoretical guidance for two-phase flow prediction within the channel and flood prevention of the fuel cell.