An Experimental Investigation of Air-Water Flow Through the Serpentine Flow Field of a Bipolar Plate in Presence of Powdered Wax

Abstract

Water management in Proton Exchange Membrane Fuel Cell (PEMFC) is an important issue that needs to be addressed appropriately at all loads. Water is formed as a product of reaction, which is removed by airflow at the cathode. However, at part load operations, when the required airflow is less, water can build up inside the cell resulting in reduction of fuel cell output. A bio-mimetic solution to this problem is proposed where a minute amount of powdered wax is introduced along with the incoming air into the gas distribution channel of a bipolar plate. The bi-polar plate is covered with a transparent plexi-glass and water is introduced using a syringe pump through a minute hole on the cover at a location downstream of the air inlet. The air and water flow rates are varied simulating the different load conditions observed in a typical PEMFC. The movement of water inside the serpentine channel is recorded using a high-speed camera. Presence of micronized wax resulted in significant increase in water movement inside the channels.