基于烟气余热回收某600MW机组FGD水平衡问题分析

文章对火电厂石灰石-石膏湿法烟气脱硫装置(FGD)的水系统进行分析,找出了FGD系统主要水耗因素-塔内蒸发。针对国内某电厂600MW机组,提出了几种通过烟气余热回收方式降低其FGD系统入口烟气温度的方案,分析对比了不同烟气余热回收方案下FGD水平衡情况。数据表明,通过烟气余热回收降低脱硫系统吸收塔入口烟气温度可以显著降低FGD装置的总耗水量,但同时带来FGD系统水量不平衡的问题。针对FGD水平衡的优化措施进一步被提出。

This paper analyzes the water system of limestone-gypsum wet flue gas desulfurization(FGD) unit in thermal power plant, and finds out the main water consumption factor of FGD system-evaporation in the tower. Aiming at the 600 MW unit of a power plant in China, several schemes to reduce the inlet flue gas temperature of its FGD system by flue gas waste heat recovery are proposed, and the FGD water balance under different flue gas waste heat recovery schemes is analyzed and compared. The data show that reducing the flue gas temperature at the inlet of the absorption tower of the desulfurization system by flue gas waste heat recovery can significantly reduce the total water consumption of the FGD unit, but it also brings the problem of water imbalance in the FGD system. The optimization measures for FGD water balance are further proposed.