Experimental study of single screw expander with different oil-gas separators in compressed air powered system

The compressed air-powered system is widely studied as a promising, environment-friendly, and high-efficiency technology. The influences of centrifugal and filter oil-gas separator on the performance of single screw expanders for compressed air-powered systems are experimentally investigated. Results show that the intake volume flow rate using the centrifugal oil-gas separator is lower than that of the filter oil-gas separator. Meanwhile, the temperature difference between the inlet and outlet of a single screw expander, the average output power, and the average shaft efficiency by using the centrifugal oil-gas separator is 1.88, 1.67, and 1.42 times higher than that of the filter oil-gas separator under the same working condition in this study. The maximum expansion ratio in this work is 8.5 by using the centrifugal oil-gas separator. The actual total output power, effective working time, and exergy efficiency by using the centrifugal oil-gas separator are respectively 56.67%, 4.51%, and 92.52% substantially higher than that of the filter oil-gas separator. The performance of single screw expanders in compressed air-powered systems can be improved by using the centrifugal oil-gas separator. •Single screw expander is employed as an engine in air compressed powered system.•The maximum expansion ratio is 8.5 by using the centrifugal oil-gas separator.•Actual total output power, effective working time and exergy efficiency are studied.•Single screw expander with centrifugal oil-gas separator has better performance.