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以某600 MW燃煤机组为例,基于热力学第二定律的(火用)分析方法,建立太阳能、地热能辅助燃煤机组热力系统的(火用)平衡矩阵模型,分析主要设备的(火用)损失及(火用)损率.对该耦合系统中CO2、SO2、Nox、Hg、As、Se、Pb等污染物排放潜力进行研究.结果表明:可再生能源系统辅助燃煤机组中,各级加热器的(火用)损系数随着排挤抽汽比例的增加而成阶梯状递减;辅助系统取代不同的加热器时,污染物减排量随着排挤抽汽比例的变化而变化;在相同排挤抽汽比例情况下,取代2号高压加热器时,耦合系统的热经济性最好,污染物减排量最大,排挤抽汽比为80％时,CO2、SO2、Nox、Hg、As、Se、Pb的减排量为:149.09、4.55、2.24万t/a,9.48、240.0、272.72 kg/a,l157.55g/a.“,”This paper took a 600 MW unit for instance and established general matrix model based on exergy analysis when renewable energy auxiliary system preheats feed water.Exergy analysis of the coupling system was conducted by this new model.CO2,SO2,NOx,Hg,As,Se and Pb emission reductions of the coupling system were investigated.Analysis indicated that the exergy loss ratio of each heater has a descending trend with the increase of exclude extraction.The emission reductions vary with the exclude extraction ratio when coupling system replaces different heaters.If the exclude extraction ratio is same,the coupling system has the potential of a higher thermo-economy.Therefore the fuel saving rate was improved when No.2 heater was replaced.When the exclude extraction ratio reaches the value of 80％,emission reductions of CO2,SO2,NOx,Hg,As,Se and Pb reach 1490900 t/a,45500 t/a,22400 t/a,9.48 kg/a,240.0 kg/a,272.72 kg/a and 1157.55 g/a,respectively.