Numerical study of a liquid-piston compressor system for hydrogen applications

The use of a liquid-piston system for hydrogen compression is investigated in this paper by means computational fluid dynamics (CFD) analysis. In the specific context hydrogen-driven vehicles, high-pressure storage tanks are key to provide substantial range. present study focuses on intermediary stage compression-storage-dispensing (CSD) station, bringing gas from 15 bar 450 bar, i.e., pressure ratio 30. Until now technology has not been at very high pressure, which purpose study. Simulations compressible two-phase flow problem performed with volume-of-fluid (VOF) framework using real model gaseous phase account compressibility effects large ratios. A particular attention paid numerical formulation and treatment thermal boundary conditions. Results reported both time-resolved instantaneous bulk thermodynamic variables global integrated quantities. Different scenarios investigated, highlights compromise between efficiency power density. To achieve targeted density approximately 540 kW/m3, energy cost reaches 1.67 kWh/kg. Finally proposes an innovative solution minimise quasi-isothermal compression, based internal forced convection. For similar density, high-speed fan top part chamber (modelled as volumetric momentum source 2500 N/m3) increases heat transfer leads 25-% reduction consumption.