title   
  

Design of anode flow channels and headers for a large PEMFC operating at ultra-low stoichiometric flow conditions at the anode exit

Babaie Rizvandi, Omid and Yeşilyurt, Serhat (2016) Design of anode flow channels and headers for a large PEMFC operating at ultra-low stoichiometric flow conditions at the anode exit. In: ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels (ICNMM2016), Washington, DC, USA (Accepted/In Press)

WarningThere is a more recent version of this item available.

[img]PDF - Repository staff only - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
965Kb

Abstract

High utilization of hydrogen is desired in operation of PEM fuel cells. Typically, additional devices for hydrogen recovery at the anode exit are necessary. Alternatively, dead-ended anode (DEA) operation may be considered, however this mode causes severe voltage transients and loss of catalyst support in hydrogen-depleted regions of the active area. Here. ultra-low stoichiometric (ULS) flow conditions that deliver very high hydrogen utilization is considered, however uniform flow distribution is necessary in this case. In order to obtain the flow distribution in the channels and in the inlet and exhaust headers in the anode, a three-dimensional CFD model is developed based on the finite-element method to solve Stokes equations subject to no-slip boundary conditions on the walls, specified pressure at the inlet and specified flow rate at the exit, which is set to a very low value comparable to the typical rate of nitrogen accumulation in the anode side in order to simulate the ULS flow. Uniformity of the flow distribution between the channels is quantified by means of two performance metrics: (i) the root-mean-square (rms) of the channel average velocities; (ii) the ratio of maximum and minimum values of the channel averages. Effects of geometric parameters, such as the widths of the channels and ribs and the position and lengths of the baffles in the inlet and exhaust headers are studied. The final design has less than 5% rms, and less than 1.2 for maximum to minimum average channel velocity ratio.

Item Type:Papers in Conference Proceedings
Subjects:UNSPECIFIED
ID Code:29425
Deposited By:Serhat Yeşilyurt
Deposited On:13 Jul 2016 15:12
Last Modified:13 Nov 2016 13:06

Available Versions of this Item

Repository Staff Only: item control page