Experimental study on the performance of single-screw expander with different inlet vapor dryness

• A single-screw expander was developed.
• An ORC system prototype with single-screw expander was integrated.
• The performance of the expander with different vapor dryness was obtained.

A single-screw expander with 155 mm diameter screw has been developed. In order to investigate the performance of this prototype with different inlet vapor dryness, an organic Rankine cycle experimental system was built, and experiments were conducted at different inlet vapor dryness by adjusting the mass flow rate of working fluid into evaporator. The results indicated that with the increase of inlet vapor dryness, the power output and expansion ratio were increased，however， the volume efficiency and overall efficiency were decreased. The maximums of power output, expansion ratio, volumetric efficiency and total efficiency of single-screw expander were 5.12 kW, 4.55, 80.5% and 49.5%, respectively.