A Study of Cycle Analysis and Turbine Design for Obtaining Small-Scaled Power from the Organic Rankine Cycle Using R245fa

Abstract

The organic Rankine cycle (ORC) has been widely applied to convert the renewable energy to the electric power. Some previous studies focused to find what kind of refrigerant would be a best working fluid for the ORC. In this study, R245fa was chosen as the working fluid, and the cycle analysis was conducted when the small scaled output power less than 30kW was required. In addition, properties of the working fluid on the cycle were predicted when the turbine output power was controlled by the mass flowrate. The configuration of the turbine was the radial-type turbine and the supersonic nozzles were applied as stator. So, the turbine was operated in partial admission. The turbine efficiency as well as the optimum velocity ratio was considered in the cycle analysis with the low partial admission rate. The computed results show that the partial admission rate was more important factor on the system efficiency than the temperature at the evaporator.