烟气回收水水质水量特点及回收水利用途径分析

Characteristics of water quality and quantity of flue gas recovery water from coal-fired power plants and analysis of utilization methods of recycled water

研究分析了燃煤电厂湿烟气水分来源,以及经湿法脱硫后的饱和水蒸气对环境的影响。归纳分析不同烟气水回收工艺的烟气回收水水质特点。以某电厂(330 MW机组)运行数据为例,计算了其湿法脱硫系统(WFGD)的出口烟气中含水量,若按烟气水回收率60%回收利用,可实现该电厂脱硫系统零水耗。根据火力发电厂用水系统的水质要求,简要给出烟气回收水用于烟气脱硫补水、循环冷却水、锅炉补给水等用水单元的途径。最后将烟气水回收工艺进行技术经济对比分析,电厂在选择合适工艺时,应结合电厂自身特点综合考虑。从冷凝法烟气回收水水质中含有盐分和微细颗粒物,可见冷凝法烟气水回收工艺对烟气中污染物有一定的深度脱除作用。深入认识水蒸气对环境的影响,是打好蓝天保卫战的关键之一。

The source of moisture in wet flue gas discharged by coal-fired power plants was studied,and the impact of saturated water vapor after wet desulfurization on environment were explored.The water quality characteristics of the recovery water from different flue gas water recovery processes were inductively analyzed.Taking the operation data of a 330 MW unit as an example,the moisture content in the flue gas at the outlet of its wet desulfurization system(WFGD)is calculated.If 60%moisture in the flue gas can be recycled,the power plant will realize zero consumption of desulfurization water.Following the requirements on the water quality of thermal power plant water systems,the routes of the flue gas recovery water recycled as flue gas desulfurization makeup water,circulating cooling water,boiler makeup water and other unit water are briefly described.Finally,the techno-economic comparison of the flue gas water recovery processes is carried out.Comprehensive consideration should be made on a power plant characteristics while selecting a suitable process for it.Since condensed flue gas recovery water contains minerals and fine particles,condensed flue gas recovery process is considered to have certain removal effect on pollutants in the flue gas.A deepen understanding of water vapor impacts on environment is one of the keys to the Battle for Blue Sky.