Design and experimental study of a small-sized organic Rankine cycle system under various cooling conditions

This paper experimentally studies the performance and feature of a kW-scale organic Rankine cycle system which was operated under various cooling conditions using R123 as working fluid. A self-designed radial inflow turbine was applied to this system in order to testing its performance. A test of the power generation system under various cooling conditions was conducted. The system performance and turbine operational state are distinctly influenced by the cooling water mass flow rate. The experiment results show the turbine performances for various rotational speeds, isentropic efficiencies, and thermal efficiencies. The maximum thermal efficiency 5.30% and a turbine isentropic efficiency 75.2% can be obtained with a water flow rate of 0.591 kg/s. The system net power increased from 889.47 W to 1242.67, with the flow rate of water increasing. With the increase of water flow rate, the exergy loss of evaporator increased, and those of condenser and turbine decreased.