Turbo-expander is one of the critical components in the ORCsystem, such that its performances are the key factors affecting theperformance of system. A large number of studies have beenconcentrated in this field, primarily including: scroll expander ,screw expander and the radial inflow turbine . Thesestudies suggest that scroll expander and screw expander are mainlysuitable for the small-scale power applications.