Numerical Simulation of a Two-Stage Centrifugal Air Compressor Cooling Structure for Hydrogen Fuel Cells

A two-stage centrifugal Air compressor cooling system for a hydrogen fuel cell with a rated power of 17.5 kw and a rotating speed of 95,000 rpm was numerically simulated. Firstly, the accuracy of CFD method to calculate air friction loss is verified by empirical formula, and then the advantages and disadvantages of three different cooling cases are analyzed. The results show that the rotor air friction loss increases with the increase of axial cooling air flow, rotating speed and Surface roughness. The air friction loss is negligible when the rotating speed is below 35000r/min. The average temperature of the stator coil is reduced by 20.9% compared with that of the fully enclosed motor due to internal air cooling. In addition, because of the high temperature distribution of the thrust disc, it is necessary to increase the cooling of the thrust disc if the design conditions permit.