冷热电联产(combined cooling,heat and power,CCHP)系统的效率评价指标对其优化设计、经济运行等至关重要。基于小功率燃气轮机为核心的CCHP系统基本元件的变工况典型解析特性,对比分析了CCHP系统当量烟撤率、经济火用效率、总能利用率、节能系数等“效率”形式及其影响因素。采用不同的效率指标评价以小功率燃气轮机为原动力的2类CCHP系统的全工况性能,以说明不同效率指标的差异。分析表明,前述效率形式都不能给出完全合理的评价结果。但相对而言,节能系数能比较合理评价文中所述两种CCHP系统的优劣,但部分评价结论仍存商榷之处;CCFIP系统的部件匹配及经济运行,可综合按全工况节能系数及经济[火用]率来评价。
Indicators for evaluating the efficiency of combined cooling, heat and power (CCHP) systems are vital for optimal design and economic operation. Based on the typical analytical performances of gasturbine-based CCHP components, some intrinsic parameters related to the efficiencies with different definitions (i.e., total energy utilization efficiency, equivalent exergy efficiency, economic exergy efficiency and energy saving indicator) were thoroughly discussed. To compare the different efficiencies or indicators, overall off-design characteristics of two types of gasturbine-based CCHP systems were evaluated with the efficiencies. The results show that, none of the above efficiencies evaluate CCHP completely. However, energy saving indicator comparatively distinguishes the two systems studied, except for some incomplete evaluation conclusions. It is proposed that the optimal configuration and economic operation can be evaluated by integrating energy saving indicator with economic exergy efficiency at off-design conditions.