Three‐dimensional Modeling of Gas Purge in a Polymer Electrolyte Membrane Fuel Cell with Co‐flow and Counter‐flow Pattern

Abstract

Gas purge is commonly utilized to minimize residual water after shutdown of proton exchange membrane fuel cell (PEMFC) in cold weather, aiming to reduce damage of ice formation on cell performance and durability. In this paper, a three‐dimensional multiphase gas purge model of proton exchange membrane fuel cell with co‐flow and counter‐flow pattern is established to investigate water removal characteristics using two‐fluid model. The present model mainly includes water transport in membrane, mass transfer between dissolved water and water vapor in catalyst layer (CL), phase change between liquid water and water vapor in porous media. Several cases with co‐flow and counter‐flow pattern have been investigated numerically. In the last, gas purge time comparison between a fresh cell and degraded cell is conducted. The numerical results show that counter‐flow pattern is better in keeping even water content distribution and avoiding over‐drying of membrane. Time constant for gas purge is different in terms of different final target value: water vapor, liquid water saturation, membrane water content. Degraded cells have 2 more seconds than fresh cells when cell temperature is 80 °C and velocity of purge gas 1m s−1.

Analyze the effects of flow mode and humidity on PEMFC performance by equivalent membrane conductivity

“…Basic assumptions are made to simplify the model and reduce calculation consumption: The surfaces of PEMFC and the gas inlet temperature are constantly at 80°C. The PEMFC is under steady state. The porosity and conductivity in porous zone (CLs and GDLs) are uniform and isotropic. The reactant gases are incompressible ideal gases. The laminar flow is supposed in the flow channel. …”

“…Computational fluid dynamics (CFD) simulation can provide detailed information of PEMFC that cannot be tested directly in the experiments, eg, distributions of the local current flux, gases concentration, temperature, and membrane conductivity. Consequently, many researchers have made great efforts to exploit CFD modeling of PEMFCs from one‐dimensional (1D), two‐dimensional (2D) to three‐dimensional (3D) . Nowadays, 3D numerical models are the mainstream to study the electrochemical and multiphysics processes of PEMFC.…”

“…Yin et al employed a 3D CFD model to study the effects of patent sulfonated polybenzimidazole membranes and baffle plates on the high‐temperature PEMFC. Xu and Xu developed a 3D multiphase CFD model to study the water behaviors during the gas cleaning process. Zhang and Jiao reviewed the recent development of multiphase PEMFC models and suggested adding the agglomerate models of CLs in the 3D CFD PEMFC models.…”

“…Consequently, many researchers have made great efforts to exploit CFD modeling of PEMFCs from one-dimensional (1D), [4][5][6][7] two-dimensional (2D) 8,9 to three-dimensional (3D). [10][11][12][13][14][15][16][17] Nowadays, 3D numerical models are the mainstream to study the electrochemical and multiphysics processes of PEMFC. For example, Cao et al 10 investigated the coupled water and heat management by a 3D, two-phase, and nonthermal model.…”

Comparative Analysis of Two Online Identification Algorithms in a Fuel Cell System

“…Such performance drifts have made the design of a complete PEMFC model immensely complicated. There exists various PEMFC models capable of dealing with the variations of the operating conditions . These models are by some means convincing, though not perfect, with regard to coping with the operating conditions variations.…”