화학공학소재연구정보센터
Journal of Power Sources, Vol.280, 612-620, 2015
Pressure distribution method for ex-situ evaluation of flow distribution in polymer electrolyte membrane fuel cells
Fuel cells for automotive applications consist of cells with large active areas. The active area is generally between 150 cm(2) and 400 cm(2). The reaction gases and the cooling media are distributed via bipolar plates to the reaction zones. Understanding local and cell wide gas distribution within the flow field at high current densities greater than 2.0 A/cm(2) is a key factor regarding efficiency at low stoichiometry, lambda less than 2. In this paper a new method is introduced, which can be used as ex-situ evaluation of flow distribution. The gas pressure distribution is mapped with an array of 5 x 12 membrane differential pressure sensors by measuring the static pressure locally against the outlet pressure. Below a differential pressure of 100 mbar the signal measurement accuracy is +/- 2.5 mbar. This is demonstrated in a flow field with an active area of 250 cm(2). The sensors are located next to the micro porous layer of the gas diffusion layer to avoid any impact of dynamic pressure. The effect of the intrusion of gas diffusion layer material into the flow channels on the fluid distribution is evaluated at clamping pressures between 0.6 MPa and 4.2 MPa. (C) 2015 Elsevier B.V. All rights reserved.