Abstract:At present, the thermodynamic researches on organic Rankine cycle (ORC) systems mainly focus on the optimization of circulating working fluid and optimization and parameter simulation of the circulatory system under the fixed conditions both at home and abroad. The projects concerning variable operation and safe operation are rarely mentioned. Flow software Aspen Plus is used to simulate the ORC system under variable working conditions and analyze the simulation results. Thus, our research may provide some reference value for engineering applications which use ORC system especially turbines as a power plant.