FUEL CELL SYSTEMS WITH EVAPORATIVE COOLING AND METHODS FOR HUMIDIFYING AND ADJUSTING THE TEMPERATURE OF THE REACTANT STREAMS

摘要

A fuel cell (1) using fuel (11) and oxidant (9) resulting in the production of water (12) and heat in addition to electrical power. The fuel cell (1) employs an evaporative cooler (5) and has methods to adjust the moisture and temperature for the fuel (11) and oxidant (9) flows to improve the fuel cell efficiency. The water (12) produced by the fuel cell (1) is used to provide the water for the wet channels (8) of the evaporative cooler (5). The evaporative cooler (5) has separate product channels (6) and dry working channels (7) that are cooled by heat transfer across a heat exchanger plate (39). The heat exchanger plate (39) forms a part of each wet working channel (8) on the wet side (43) of the heat exchanger plate (39) and part of the product channel (6) and the dry working channel (7) on the dry side (44). The fuel (11) passes first through the dry working channel (7) then the wet working channel (8) becoming humidified by the evaporation therein and cooling the heat exchanger plate (39) before going to the anode (3) of the fuel cell (1). The oxidant (9) is cooled by passing through the product channel (6) before being directed to the cathode (4). In another embodiment, the evaporative cooler is incorporated with the fuel cell.