FCVs, Scroll Compressor, Transient Model, Hydrogen Recycle, Volumetric Effeciency
Fuel cell vehicles (FCVs) have become a research hotspot because of the continuous increase in transportation needs, energy needs, and environmental issues. However, several challenges must be overcome to be competitive with conventional vehicles. The performance of air and hydrogen cycles depends on compressors. It is a key issue to guarantee the efficiency and reliability of FCVs. In this paper, the working conditions of hydrogen and air scroll compressors in FCVs were described in details. 3D transient CFD numerical simulations with dynamic meshing of the air scroll compressor and the hydrogen compressor/pimp were presented. The performance of scroll compressors in various working conditions was studied including different fluid, rotating speed, pressure ratio and axial clearances. The simulated results were validated experimentally. The results show that the large air demand is a challenge for the scroll-type air compressor to apply in FCVs. The scroll compressor is a good way to recycle the unreacted hydrogen in FCVs. However, method should be taken to solve the leakage issue through the axial clearance and radial clearance. The axial clearance has a significant influence on the hydrogen compressor, which dropped from 95.12% without axial clearance to 70.00% with 0.04 mm axial clearance.