Numerical study of vapor behavior in high temperature PEM fuel cell under key material and operating parameters

Abstract

The water issue of high temperature proton exchange membrane fuel cell (HT-PEMFC) is rarely studied in the previous work. However, the different water vapor behaviors might greatly influence both cell performance and stability. In order to gain a fundamental understanding of the vapor behaviors in HT-PEMFC, a 3D computational fluid dynamics model and a 2D transient model were developed to investigate the effects of materials properties and operating parameters on the vapor behavior. Temperature, membrane materials and phosphoric acid doping degrees are examined. The results shows that higher temperature and phosphoric acid doping degrees with PBI membrane would lead to a significant increase of water vapor generation at cathode. For the transient model, the dynamics of vapor accumulation were observed with the dead-end anode. It is revealed that vapor transport and distribution get adapted to a dynamic equilibrium after 18 s. According to these results, a periodic purging at anode with optimized purging time is still needed to remove the accumulated water vapor. The findings of this paper can be further applied in the design of fuel cell controller.

Modeling and analysis of water vapor dynamics in high-temperature proton exchange membrane fuel cell coupling gas-crossover phenomena

“…As can be seen from is in dynamic equilibrium. Moreover, the maximum time step of the solution process is set to 0.02s [19]. To reduce the requirements for computing resources and shorten the computing time, this simulation is carried out under a larger current.…”

Effect of Flow Field Structure and Operating Condition on the Distributions of Water and Phosphoric Acid in High Temperature Proton Exchange Membrane Fuel Cell (HT-PEMFC)

“…27,28 Bezmalinovic et al 21 built a two-dimensional steady-state isothermal HT-PEMFC model to predict the distribution of water vapor. Xia et al 29 developed a three-dimensional steady-state model to explore the distribution of water vapor in the HT-PEMFC for different temperatures and a two-dimensional transient model to predict the changes of anode water vapor concentration with time under anode dead-end mode. Recently, Zhang et al 30 established a three-dimensional nonisothermal model coupled with a gas-crossover submodel to explore the transport behavior of water vapor.…”

“…However, there are still many key factors that have not been investigated and the mechanism is still unclear. − Since the transport and reaction in fuel cell involves multiphase and multiregion of porous media, it is difficult to carry out in situ characterization of water and PA experimentally. − Building a reasonable model is an effective means to deal with this problem. , Bezmalinovic et al built a two-dimensional steady-state isothermal HT-PEMFC model to predict the distribution of water vapor. Xia et al developed a three-dimensional steady-state model to explore the distribution of water vapor in the HT-PEMFC for different temperatures and a two-dimensional transient model to predict the changes of anode water vapor concentration with time under anode dead-end mode. Recently, Zhang et al established a three-dimensional nonisothermal model coupled with a gas-crossover submodel to explore the transport behavior of water vapor.…”