Liquid flooded compression and expansion in scroll machines – Part II: Experimental testing and model validation

Abstract

The use of liquid-flooding in the compression and expansion of non-condensable gas in scroll compressors and expanders enables the possibility of quasi-isothermal working processes. Liquid-flooded scroll machines were installed in a fully-instrumented Liquid-Flooded Ericsson Cycle test rig to conduct entire cycle performance tests. In addition, detailed compressor and expander performance data was obtained. Oil mass fractions of up to 92% and 76% were added to the gas entering the scroll compressor and expander respectively. The overall isentropic efficiency of the scroll compressor based on the shaft power with flooding was up to 73% and the volumetric efficiency was above 92%. For the expander, the best overall isentropic and volumetric efficiencies achieved were 66% and 105% respectively. The mechanistic model presented in the companion paper was validated against the experimental data for both the compressor and the scroll expander with good agreement, though the agreement is better for the scroll compressor.