Effects of operating parameters and fluids on the performance of a hydrogen regenerative flow compressor in a proton exchange membrane fuel cell system

Abstract

Regenerative flow compressors (RFCs) have garnered significant attention for hydrogen recirculation in proton exchange membrane fuel cell systems due to their simple structure and oil-free operation. The compression performance of RFCs is intimately linked to the operating pressure, temperature, and gas composition. This study delves into the specific effects of these three parameters on the pressurization and power consumption characteristics of hydrogen RFCs. Results indicate that the hydrogen mass flow rate is 1.69 g s⁻¹, the parasitic power is 599 W, the adiabatic efficiency is 37.2 %, and the specific work is 23.6 J kg⁻¹ Pa⁻¹ under 70 kW operating condition. An augmentation in the inlet pressure by 10 kPa engenders an escalation in the hydrogen mass flow rate by 0.24 g s⁻¹ and a reduction of specific work by 2.6 J kg⁻¹ Pa⁻¹. A diminution in inlet temperature of 10°C leads to an increase of 0.15 g s⁻¹ in hydrogen mass flow rate and a decrease of 1.7 J kg⁻¹ Pa⁻¹ in specific work. An increase in the proportion of nitrogen and water vapor results in an increase in hydrogen mass flow rate and an improvement in adiabatic efficiency, but with a consequential higher specific work. Additionally, this study demonstrates that RFCs are characterized by a constant dimensionless performance curve, which is independent of environmental parameters. Consequently, predicting the operation of RFC under various operating conditions becomes feasible.