Experimental investigation on the hydraulic-driven piston compressor for hydrogen under varied operating conditions

The hydraulic-driven piston compressor is promising in the application of pressurising hydrogen gas. The reliability of the compressor directly affects the performance and safety of an overall hydrogen station. In this study, the p-V curve of the two-stage hydraulic-driven piston compressor is experimentally obtained by a non-destructive monitoring method proposed under different operating pressures. The performance of the compressor under different working pressures is calculated and analysed. Results indicate that the discharge loss is higher than the suction loss. The discharge losses are found around 14.6% and 16.3% in Stages 1 and 2, respectively. The volumetric efficiency is found around 90%, which is slightly affected by the change in the operating condition. The overall efficiency of the hydraulic-driven piston compressor decreases from 59.27% to 50.40% when the operating pressure declines. The findings can contribute to the improvement in the performance and reliability of the hydraulic-driven piston compressor for hydrogen storage.