Study on the integration characteristics of a novel integrated solar combined cycle system

This paper proposes a novel integration system of integrated solar energy combined cycle (ISCC), which uses the compressed air from the gas turbine compressor to heat the water from heat recovery steam generator (HRSG) with three pressure levels and to be the Heat Transfer Fluid (HTF) of solar collectors. For each high pressure integration and intermediate pressure integration, the solar energy is used to heat the water from the high pressure feedwater pump and the intermediate pressure feedwater pump, respectively. Then the water is preheated, evaporated, even superheated. Different ISCC configurations with 30 MW design capacity of solar power are compared, including a solar field based on parabolic trough collectors working with the HTF and the compressed air. The results show that the maximum annual solar power efficiency of the novel system is 13.6%, 1.3% higher than that with the HTF, and the minimum electricity cost is 0.266€/kWh, 0.094€/kWh lower than that with the HTF. Meanwhile, considering the efficiency reductions at the pump and turbine working on the off-design condition, the optimal HTF temperature is obtained for each pressure integration with different design capacities of solar power. This novel ISCC system offers a new utilization way for the parabolic trough collector technology.