中文摘要：

光煤互补发电系统是一种将聚光太阳能与化石燃料化学能相结合的互补发电系统.已有光煤互补发电系统研究多为针对具体互补形式或具体光煤互补电站的案例研究,目前尚缺乏统一性的理论.本研究摆脱具体互补形式的限制,基于品位耦合思想,对光煤互补发电系统整体建模并进行统一性理论分析,提出了更为合理的光煤互补发电系统统一评价标准——节煤系数,并获得了适用于各类互补形式的统一理论表达式.该表达式指出了不同光煤互补发电系统间的联系与区别,揭示了节煤系数的＂叠加效应＂.通过对表达式的详尽分析,明确了太阳能投入份额和太阳能集热品位同工质品位的匹配程度为节煤系数的主要影响因素.研究结果对于光煤互补电站设计以及各类燃煤电站的光煤互补改造均具有重要的理论指导意义.

英文摘要：

As a clean, free and non-depleting energy source, solar energy is attracting more and more attention. Owing to the defects such as low intensity and periodicity, the levelized cost of electricity （LCOE） of current solar-only power plant keeps high and the annual efficiency keeps low. Solar-coal hybrid power generation system is the power generation system which integrates the solar energy into the conventional coal-fired power cycle. This hybrid system is thought to be an efficient, economic and low risk approach for promising solar thermal energy utilizing as it possesses the advantages such as higher thermodynamic efficiency and lower LOCE. However, existing studies are mostly case studies, which merely focus on specific types of hybrid power generation systems. Unified theory has not yet been proposed. Based on the existing classification, the solar-coal hybrid power generation is normally classified into power-boosting and coal-saving types. The boosted power output and the saved coal amount are used for evaluating the performance of power-boosting and coal-saving hybrid power generation systems, respectively. It is found that the coal-saving hybrid power generation system is more suitable for practical occasions due to the dispatch of the national grid and the boosted power output could be equivalently transformed into the saved coal amount. Therefore, the coal-saving coefficient, indicating the relative saved coal amount, is chosen as the unified criterion for the performance evaluation of solar-coal hybrid power generation systems. Expressions for the coal-saving coefficient of various types of hybrid power generation systems are primarily conducted based on reasonable hypotheses. Then, the unified theoretical expression for the coal-saving coefficient is derived out. The physical meaning of each item in the unified expression is revealed in details. The relationship and differences between various types of hybrid power generation systems are also expounded based on the unified theoretical expressio