300MW CFB锅炉大气污染物超低排放改造技术研究

Technical route of air pollutants ultra low emission modification for 300 MW CFB boilers

为了指导CFB电厂选择科学、合理的大气污染物超低排放改造技术路线,选取某厂2台300MW CFB锅炉为研究对象,从技术指标、系统投资、运行维护等方面,比较了不同脱硫、脱硝、除尘工艺对工程的影响。结果表明,最优技术路线为:加装炉外半干法脱硫工艺,炉内与炉外脱硫效率分别按70%与96.59%分配;加装SNCR脱硝工艺,按入口NOx浓度200 mg/m3设计,要求效率大于75%;拆除现有电袋复合除尘器袋区,仅保留电除尘器作为脱硫塔前置除尘器,脱硫塔后加装高效布袋除尘器,要求总体除尘效率大于99.971%。

In order to choose a scientific technology to realize air pollution ultra low emission during CFB power plant transformation, two 300 MW CFB boilers were chosen as the research object. The influence of different desulfurization,denitration and dust removal processes on the project was compared according to the technical indicators, system investment, operation and maintenance, etc. The results showed that the optimal technical route was applying semi-dry flue gas desulfurization and SNCR technology, dismantling the bag area of the existing electric-bag filter, and increasing high efficiency bag filter ＂after semi-dry flue gas desulfurization tower. Moreover,desulfurization effi- ciencies inside and outside the furnace were 70% and 96.59% respectively. Concentration of nitrogen oxide at the entrance to SNCR device was designed as 200 mg/m3 ,while the denitration and dust collection efficiencies were over 75% and 99. 971% respectively.