Dynamic modeling of a liquid piston compressor system including conjugate heat transfer

Abstract

Efficient and cost-effective hydrogen storage necessitatesquick compression across significant pressure ranges(usually up to 700 bar), while keeping heat generation to aminimum during the process. This can be achieved byimproved understanding of gas-to-wall heat transferenhancement in hydrogen compression systems, careful designand operational optimisation. In this context, the presentpaper introduces a 0D/1D lumped numerical model of a liquidpiston compressor for hydrogen applications. Heat transferis considered as (i) convective at the liquid-gasinterface, (ii) conductive within the gas volume based on a1D approach accounting for thermal stratification, and(iii) as conjugate at the gas-to-wall interface. To achievea pressure ratio of 30 (from 15 to 450) bar, at a powerdensity of approximately 65kW /m3 , the compression energycost reaches 1.85kW h/kg. Further, various standardpressure vessels materials with different thermal andmechanical properties are considered, highlighting thepotential compromise between lightweight and thermalefficiency.