Experimental study on Organic Rankine cycle for low grade thermal energy recovery

• A small scale ORC experiment system for waste heat recovery was built and tested.
• A turbine expander without oil lubricant was coupled with a synchronous generator.
• R245fa and the environmentally friendly HFE7100 were selected as the working fluids.
• The influences of the operation parameters on overall system performance were discussed.

A small scale Organic Rankine cycle experiment system capable of generating electric power using a low temperature heat source was built and experimental study was conducted. A single stage axial turbine expander coupled with a permanent magnet synchronous generator was used, where no lubricant oil was used. R245fa and the new environmentally friendly HFE7100 were selected as the working fluids in the experimental system. The influences of the evaporating pressure, pressure drop and mass flow rate on overall system performance were discussed. The maximum electric output generated by the turbine expander was 1979 W for R245fa, while the maximum electric power output was 1027 W for HFE7100.