标题：Study on integrated solar combined cycle system with a new operation strategy of changeable integration mode under different Direct Normal Irradiance (DNI) conditions
摘要：Integrated solar combined cycle (ISCC) system, which integrates solar thermal energy into traditional gas turbine combined cycle (GTCC) system, has become an efficient way to reduce the levelized cost of electricity (LCOE) and improve the thermal efficiency of the GTCC system. However, the volatility of solar energy usually results in low ISCC system thermal efficiency when no or low direct normal irradiance (DNI) is available because the ISCC system is usually not equipped with thermal energy storage system. In this paper, the ISCC system with a new operation strategy of changeable integration mode under different DNI conditions is proposed. The ISCC system model is constructed using the EBSILON software. Performance of ISCC system using the new operation strategy is investigated deeply. The results show that the ISCC system using the new operation strategy has higher annual solar to electricity efficiency (19.08%), 1.1% higher than that of the traditional ISCC system. Due to different DNI distributions in a whole year, the larger the distribution proportion of the low‐value DNI is, the greater the thermodynamic performance advantage of ISCC system with the optimization strategy is. Through the economic performance analysis, the LCOE of the ISCC system with the new optimization strategy is 0.223 $/kW·h, 0.01 $/kW·h lower than that of the traditional ISCC system. The LCOE decreases at first and then increases with the increase of the number of the parabolic trough collector. The optimal number of the parabolic trough collector corresponding to the new optimization strategy is 500. So this new operation strategy provides a new way for adequately utilizing the solar energy in ISCC system.
关键词：economic performance;heat transfer fluid;ISCC;solar energy;thermodynamic performance
