Thermodynamic investigation of solar energy-based triple combined power cycle

The present work deals with the thermodynamic analysis of a solar-powered triple combined power cycle to generate emission-free power. The triple combined cycle comprises one topping cycle as Brayton cycle and two bottoming cycles, namely, steam Rankine cycle (SRC) and organic Rankine cycle (ORC). The Brayton cycle employs double-stage compression with intercooling. During intercooling, heat energy rejected by the compressed air was further utilized in the ORC. The energy carried away after the turbine exit was used in the SRC. The proposed cycle performance is investigated for three working fluids to use with the bottoming ORC. Results showed that the maximum overall thermal efficiency and work output of solar energy-based triple combined cycle are found 21.89% and 218.98 kJ/kg air, respectively, for organic fluid R245fa at the topping cycle pressure ratio of 31.