Thermodynamic modeling and comprehensive off-design performance analysis of a real integrated solar combined cycle power plant

In this paper thermodynamic modeling and comprehensive performance analysis of a real integrated solar combined cycle (ISCC) power plant are performed. Performance of the plant cycle is assessed in off-design condition and in two operation modes of power-boosting and fuel-saving. Such an approach has not been considered for an ISCC plant in the previous studies. Under studied ISCC which is located in Yazd city, consists of parabolic collectors which are connected to a combined cycle section. The simulation results are presented at different times of design day and twelve months of the year. According to these results, in the power-boosting mode steam production of fossil section is reduced by 12 kg/s from 6:00 AM to 3:00 PM on design day while solar steam is increased by 36 kg/s. By stabilizing the oil temperature on 392°C, the control philosophy of starting steam production in the solar field is also discussed. In the fuel-saving mode, if the solar field is in service, fuel consumption of the auxiliary burners is reduced by 28,000 kg on design day. The results of this paper indicate that the power output of ISCCs is more stable than conventional combined cycles on hot days of the year.