Thermo-economic assessment and multi-objective optimization of organic Rankine cycle driven by solar energy and waste heat

An organic Rankine cycle (ORC) power generation system driven by integrated solar energy and waste heat is proposed based on the concept of multi-energy complementarity. Three types of solar collectors, two different heat source integration schemes and nine different candidate organic fluids are studied and compared. The effects of main operating parameters on thermo-economic performance are analyzed. A multi-objective optimization framework with a competitive mechanism based multi-objective particle swarm optimizer (CMOPSO) as the core is constructed and the system is optimized. The results of the multi-objective optimization guide the design of the multi-heat source ORC and the selection of the working fluid. When the temperature difference between two heat sources is greater than 50 °C, the heat exchangers are recommended to be connected in series for better overall performance. Besides, the series scheme favors the working fluid with a higher critical temperature, whereas the working fluid with a lower critical temperature is appropriate for the parallel scheme.