Experimental study of clamping effects on the performances of a single proton exchange membrane fuel cell and a 10-cell stack

Chih-yung Wen, Yu Sheng Lin, Chien Heng Lu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

82 Citations (Scopus)

Abstract

The contact pressure distribution is known to have significant influences on the contact ohmic resistance, porosity of gas diffusion layers (GDLs) and performance of the proton exchange membrane fuel cell (PEMFC) consequently. This work experimentally investigated the effects of various combinations of bolt configuration and clamping torque on the corresponding contact pressure distributions and performances of a single PEMFC and a 10-cell stack. The pressure-sensitive films (FUJI-FILM I&I) were used to visualize the contact pressure distributions under three different clamping torques and three different bolt configurations in the experiments. The importance of the proper stacking design was clearly demonstrated by these contact pressure images. The mean value and the fluctuation intensity of the contact pressure were extracted statistically from the data of pressure-sensitive films. A non-dimensional pressure fluctuation intensity, which indicates the relative dispersion to its mean value, was proposed to gauge the uniformity of the contact pressure distribution, similar to the definition of the turbulence intensity in fluid mechanics. The experimental results showed that, for the single cell under the current experiment conditions, the larger mean contact pressure tends to yield the higher maximum power, regardless of the bolt configuration and the applied torque. The uniformity of the contact pressure distribution, the ohmic resistance and the mass transport limit current had highly linear correlations with the mean contact pressure. In the case of the 10-cell stack, the effects of various combinations of bolt configuration and clamping torque on its performance and the mass transport limit current could not be reflected by the stack mean contact pressure only. Increasing the mean contact pressure improved the uniformity of the contact pressure distribution and reduced the contact ohmic resistance, in general. However, the maximum power did not increase monotonically with the mean contact pressure and no linear correlation was found. The detailed contact pressure distribution may have important influences on the local electrochemical reactions and heat and mass transfer processes involved in the stack.
Original languageEnglish
Pages (from-to)475-485
Number of pages11
JournalJournal of Power Sources
Volume192
Issue number2
DOIs
Publication statusPublished - 15 Jul 2009
Externally publishedYes

Keywords

  • Mean contact pressure
  • Non-dimensional pressure fluctuation intensity
  • Proton exchange membrane fuel cell

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Energy Engineering and Power Technology
  • Renewable Energy, Sustainability and the Environment
  • Physical and Theoretical Chemistry

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