Design and Evaluation of an Evaporator for a 1 kW Organic Rankine Cycle System

A 1 kW organic Rankine cycle (ORC) was designed, produced and evaluated. The system used an organic working fluid to generate power from a low temperature heat source. Considering both safety and performance, R-245fa was selected as the optimum organic fluid for the application. The necessary evaporator coil sizing was calculated and a standard air handler burner was modified to provide a heat source. An exhaust gas dilution system was developed to reduce the evaporator heat transfer temperature and protect the working fluid from thermal decomposition. A kinematically rigid scroll expander produced 334 W of electrical power, while the ORC system achieved a cycle efficiency of 1.9%. It is hypothesized that the reduced power output was due mainly to pump delivery issues leading to an instable refrigerant mass flow rate. Moreover, the pump did not provide the desired amount of pressure head, resulting in off-design operating conditions throughout the cycle.M.A.S.2019-11-16 00:00:0