Sequentially coupled lumped-parameter modelling of a double-stage metal hydride hydrogen compressor

This study reports a sequentially coupled lumped parameter modelling framework for double-stage metal hydride hydrogen compressor (DSMHHC) in which three independently validated sub-models are logically coupled through evolving pressure, temperature and hydrogen concentration. This framework serves as a fast and computationally efficient tool for DSMHHC system design, which can be used to predict system level performance by incorporating alloy-specific equilibrium, kinetic, and thermophysical properties. Employing this framework, a DSMHHC is designed and its performance over multiple cycle is predicted. A technical guideline is also proposed to find the optimum discharge pressure for receiver tank filling. It takes approximately 10 h and nine cycles to fill up a 0.05 m 3 receiver tank from 1 bar to 300 bar. Hydrogen throughput ranging from 1.15 to 2.28 Nm 3 h −1 was projected for discharge pressures between 100 and 305 bar, with an estimated specific thermal energy consumption of 79-192 MJ kgH 2 −1 and an isentropic efficiency of 2-3%.