Energy Conversion and Management, Vol.196, 1433-1444, 2019
Experimental and theoretical study on improving the operating characteristics of an open-cathode PEMFC stack by generating periodic disturbances at anode
Water management is the key to achieving higher performance and better stability of fuel cells with dead-ended anodes. A fuel supply mode called two-way hydrogen supply mode is applied to a 10-cell open-cathode proton exchange membrane fuel cell stack in this study to improve the water management of the stack. In the new mode, hydrogen can be intermittently supplied from the anode outlet to the stack under the mutual cooperation of two solenoid valves, in addition to the conventional anode inlet. A series of experiments are performed and the relevant parameters such as temperature, voltage and pressure are analyzed to investigate the effects of the applied mode on the operating characteristics of the stack. The results show that the new mode can generate periodic disturbances in the anode compartment, which is beneficial to the uniform distribution of species and the mass transfer enhancement of hydrogen. As a result, the voltage decay is significantly decelerated and the output performance is more stable. Meanwhile, it turns out that this mode is preferable for applications at high currents. Finally, an improvement is made to address the problems of the mode. The results show that the improved mode can further reduce the voltage decay rate and increase net power by 3%.
Keywords:Open-cathode;Proton exchange membrane fuel cell;Dead-ended anode;Water management;Mass transfer enhancement