烧结工序余热发电回收方案的热力学分析

Thermodynamic Analysis of Calcination Waste Heat Recovery Schemes

根据热力分析方法和二个企业烧结系统运行情况,分别计算A厂、B厂烧结工序及其余热回收系统流分布,从而对两厂各子系统的普通效率、目的效率、损系数进行比较,得出了由于回收方案的不同,A厂烧结机目的效率比B厂高8%,B厂余热锅炉目的效率比A厂高30%,烧结余热回收系统目的效率B厂比A厂高2.42%。表明:对于采用烟气全循环的余热回收系统,发电回收优于纯热回收方案。

By using the thermal exergy analytic methods and data obtained from two calcination enterprises,the authors have calculated respectively the calcination processes of Plant A and B and the exergy flow distribution of their waste heat recovery systems.On this basis,the common exergy efficiency,target exergy efficiency and exergy loss coefficients of various subsystems of the two plants were compared.The authors have concluded that because of the recovery schemes being different,the target exergy efficiency of the calcinator of Plant A is 8% higher than that of Plant B,the target exergy efficiency of the heat recovery steam generator of Plant B is 30% higher than that of Plant A and the target exergy efficiency of the calcination waste heat recovery system of Plant B is 2.42% higher than that of Plant A.This indicates that for waste heat recovery systems with flue gases being fully circulated,the power generation-purposed waste heat recovery scheme is superior to the heat-supply-purposed waste heat recovery one.