Enhancement performance of a diaphragm compressor in hydrogen refueling stations by managing hydraulic oil temperature

The objective of this study is to address the issue of high gas temperature for diaphragm compressors in hydrogen refueling stations, which leads to a high failure rate and low volumetric efficiency. The heat transfer between the gas and oil through the diaphragm is a significant heat dissipation path of the diaphragm compressor. This paper studies the performance of a 90 MPa diaphragm compressor used in hydrogen refueling stations by managing hydraulic oil temperature. Experimental results indicate that lowering the oil temperature can significantly improve the compressor volumetric efficiency and reduce the discharge temperature. For the test case, as the oil temperature decreases from 95 °C to 35 °C, the volumetric efficiency increases from 36.2 % to 43.5 %, and the measured discharge temperature decreases by 49 °C. This study proposes a thermodynamic simulation model for diaphragm compressors, and the simulation results agree with the experimental results. This model can be used to calculate the thermodynamic characteristics of diaphragm compressors and provide guidance to designers.