Study of an Integrated Tower Solar Energy Combined Cycle System with the Simultaneous Integration Solar Energy with Top and Bottom Cycle

In this paper, based on a conventional integrated solar combined cycle system (ISCC), a novel integrated tower solar energy combined cycle system (ITSCC) with the simultaneous integration the solar energy with top and bottom cycle of combined cycle system is proposed. The system models are developed and different system performance evaluation indices are proposed. Then in the condition of the same solar radiation the thermal performance of new system is analyzed and compared with the reference ISCC system and gas-steam combined cycle (GTCC) system. Furthermore, the operating characteristics of the new system in the summer solstice are deeply investigated in consideration of the heat variation from direct solar radiation and the effect of the ambient temperature change on the solar collector system. The efficiency of solar energy utilization and the thermodynamic properties of different systems are analyzed. The result shows that, in the summer solstice the natural gas input of new system is less 3.28% than that of GTCC system and the net output power is increased by 1.5%, the solar-to-electric efficiency and the exergy efficiency can achieve 27.3% and 28.4%, respectively. In addition, the annual performance of new system is also better than that of the reference system.