EXPERIMENTAL APPROACHES FOR WATER DISCHARGE CHARACTERISTICS IN PEMFC USING NEUTRON IMAGING TECHNIQUE AT CONRAD, HMI

Abstract

In this investigation, we prepared a 1 and 3-parallel serpentine single PEMFC, which has an active area of 100 cm(2) and a flow channel cross section of 1 x 1 mm. Distribution and transport of water in a non-operating PEMFC were observed by varying flow types and the flow rates (250, 400, and 850 cc/min). This investigation was performed at the neutron imaging facility at the COld Neutron RAdiography facility (CONRAD), HMI, Germany of which the collimation ratio and neutron fluence rate are 250, 1 x 10(6) n/s/cm(2), respectively. The neutron image was continuously recorded by a scintillator and lens-CCD coupled detector system every 10 seconds. It has been observed that although the distilled water was supplied into the cathode channel only, the neutron image showed a water movement from the cathode to the anode channel. The water at the cathode channel was completely discharged as soon as the pressurized air was supplied. But the water at the anode channel was not easily removed by the pressurized air except for the 3-parallel serpentine type with 850 cc/min of air flow rate. Moreover, the water at the MEA wasn't removed for any of the cases.