Effect of Porosity and Thermal Conductivity of a Porous Transport Layer on Saturation and Thermal Transport in a Low-Temperature Fuel Cell

Abstract

Water transport in the Porous Transport Layer (PTL) plays an important role in the efficient operation of polymer electrolyte membrane fuel cells (PEMFC). Excessive water content as well as dry operating conditions are unfavorable for efficient and reliable operation of the fuel cell. The effect of thermal conductivity and porosity on water management are investigated by simulating two-phase flow in the PTL of the fuel cell using a network model. In the model, the PTL consists of a pore-phase and a solid-phase. Different models of the PTLs are generated using independent Weibull distributions for the pore-phase and the solid-phase. The specific arrangement of the pores and solid elements is varied to obtain different PTL realizations for the same Weibull parameters. The properties of PTL are varied by changing the porosity and thermal conductivity. The parameters affecting operating conditions include the temperature, relative humidity in the flow channel and voltage and current density. A parametric study of different solid-phase distributions of the PTL and its effect on thermal, vapor and liquid transport in the PTL under different operating conditions are discussed.

Key findings

• ▸Excessive water content and dry operating conditions are unfavorable for efficient and reliable fuel cell operation.
• ▸Porosity and thermal conductivity of the porous transport layer significantly affect water management and thermal transport.
• ▸Different solid-phase distributions of the PTL have varying effects on thermal, vapor, and liquid transport under different operating conditions.

Keywords

Identifiers

DOI

10.1115/fuelcell2013-18160

Journal

ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology

Year

2013