Experimental study on a two-stage rolling piston CO 2 compressor based on p–V indicator diagrams

In this article, a new two-stage rolling piston CO 2 compressor was developed. A test rig was designed to measure the performance of this compressor. Based on the measured p–V indicator diagram, the distributions of indicated power and compressor performance under various operating conditions have been analysed in detail. It is shown that the discharge passage loss of the first stage and the suction passage loss of the second stage are much higher than other losses for the tested compressor. The overall efficiency of the tested compressor decreases by 1.2 per cent with the decrease of the discharge pressure at the same suction conditions. It is also found that the superheating at the compressor inlet has very small (0.3 per cent) effect on the compressor performance.