Effects of operating parameters on the performance of an embedded two-piston compressor system for green hydrogen.

The hydrogen compressor is a key component in the refuelling station. As one type of hydrogen compressor, the ionic compressor applied in the refuelling station is essentially a liquid piston compressor. The structure and operating condition would significantly influence the system efficiency of the liquid piston compressor. This paper investigated the impact of three key operating factors on the compressor performance of a novel embedded two-piston compressor, based on which the optimal operating values were identified by the Taguchi method when the hydrogen was compressed from 12 to 45 MPa. It was revealed that the movement time ratio of Piston A was the dominating factor for the power consumption and specific consumption while the upward time ratio of Piston B was the most influential parameter for the mass delivered. The optimal combination was 0.4 for the movement time ratio of Piston A, 0.45 for the upward time ratio of Piston A and 0.5 for the upward time ratio of Piston B. Under the predicted optimal operating conditions, the lowest specific energy consumption was obtained as 2733.75 kJ/kg. [ABSTRACT FROM AUTHOR]