Analysis of valve-retainer orientation influence on a reciprocating compressor for natural gas vehicle refueling stations

The present analysis was carried out by taking advantage of a hybrid time-frequency domain numerical model, able to provide a significant increase of the accuracy level and reduced computational costs. The model was also integrated with FEM acoustic and CFD steady-state simulations to characterize the acoustic response of the plenum and the pressure losses, respectively. As a case study, a double acting compressor with two different orientations of the valve-retainer was analyzed by simulating the interaction between the compressor and its plenums. The compressor performance was evaluated in terms of indicated power, specific power, suction and discharge mass flow profiles and pressure oscillations inside the compressor plenums. The robustness and accuracy of the approach allowed one to assess that the influence of the valve-retainer orientation on the compressor performance is indeed negligible. It was observed that a 6% variation of the pressure loss across the plenum between the two configurations led to an absorbed power variation lower than 0.2% and a variation of compressed gas mass lower than 1%.