In this study, both the dynamic characteristics and the hydrogen throttling and heat release behaviours of a two-stage hydraulic-driven hydrogen compressor in a 120 MPa ultrahigh-pressure scenario were comprehensively investigated. First, an innovative coupled numerical model that integrates a hydraulic drive system with multistage booster cylinders was systematically established, thereby effectively addressing a notable gap in system-level simulation analysis within this research domain. On the basis of this model and in combination with experimental validation, the dynamic characteristics—specifically, the displacement and velocity profiles of the hydraulically driven piston—were rigorously examined. Concurrently, the transient variations in pressure and temperature within each stage of the compression cylinders were analytically studied. The numerically predicted results are verified experimentally, and the discrepancies between the test and numerical values were within 5%. Moreover, the characteristics of hydrogen throttling and heat release during the incomplete closure of the suction and discharge valves were analysed in detail. • A coupled numerical model integrating hydraulic and booster systems was established. • Thermodynamic and dynamic behaviour of a hydraulic-driven compressor were exhibited. • Hydrogen throttling exothermic and temperature stratification pattern were analysed. • Deviation between predicted interstage pressure and measured ones is less than 5%.
Wang et al. (Mon,) studied this question.