Effects of Impeller Blade Shape on the Hydrogen Recirculation Blower of a Fuel Cell System

The hydrogen recirculation blower recirculates the remaining hydrogen that has not been electrolyzed in the stack of the fuel cell system.Hydrogen is mixed through the hydrogen recirculation blower with hydrogen supplied from the tank.Then, it flows back into the stack of the fuel cell system to produce electricity with a chemical reaction.In this study, the simulation was conducted to analyze the performance characteristics of a recirculation blower with the variation of the number and shape of blades.Flow analysis was performed while changing the number of impeller blades to 24, 30, 36, 42, and 48, respectively.In addition, the impeller shape was analyzed based on the blade inclination of 0, and the blade inclination was changed by 10 and 20 in the forward and backward directions.As a result of the simulation, when the number of impeller blades was increased by six from 24 to 48, the highest differential pressure was 6,255 pa with the blade number of 30, and the blower efficiency was also highest at 16.8%.The blower efficiency with the variation of blade inclination represented the highest efficiency of 17.2% at the blade inclination of 10 in impeller's rotation direction.