摘要
以某台350t/d垃圾焚烧炉为研究对象,利用CFD数值模拟方法,研究掺混不同比例半干化污泥(含水率60%)下的燃烧特性以及污染物排放特性,并对选择性非催化还原(selective non catalytic reduction,SNCR)脱硝喷枪位置进行了优化研究。结果表明:一烟道烟气温度与污泥掺混量成反比,氧含量与污泥掺混量成正相关,在3%~13%的污泥掺混量中,7%是比较合适的污泥掺混量,污泥掺混量低于10%时,第一烟道高温区的燃烧状态能达到二恶英控制的燃烧要求。NO_x生成量与污泥掺混量成正相关,在10%掺混量时仅采用SNCR方法焚烧炉出口烟气NO_x含量高达278.63mg/m^3,未能达到排放标准。但通过对SNCR喷枪位置进行调整,可利用烟气涡旋回流提高脱硝效率,相同氨氮比下出口烟气NO_x含量降低到245.25mg/m^3。模拟计算得出不同污泥掺混量时的温度和NO_x的变化趋势,提出适宜的污泥掺混量及SNCR喷枪布置优化方案,可为垃圾焚烧炉污泥掺混焚烧及SNCR脱硝提供参考。
In the present work, computational fluid dynamics(CFD) numerical simulation method was used to study the combustion characteristics and pollutant emission characteristics of a 350 t/d municipal solid wastes(MSW) incinerator, with different blending proportions of semi-dried sludge(60% moisture content). The selective non catalytic reduction(SNCR) denitration simulation was carried out and the position of spray gun was optimized. Results show that the gas temperature of the first flue gas channel is inversely proportional to the sludge blending amount, and the oxygen content is positively correlated. In 3% to 13% of the blending proportions, 7% is the appropriate sludge blending proportion and the combustion state in high temperature area of the first flue gas channel can satisfy the combustion requirements of dioxin control when the sludge blending amount is less than 10%. NOx production is positively correlated with the proportion of sludge blending. In the case of 10% blending proportion, the NOx content at the outlet of the incinerator is as high as 278.63 mg/m3 when using the SNCR method alone, which fails to meet the emission standards. Focus on the vortex flow of flue gas, by adjusting the SNCR spray gun position of 10% blending condition, the denitration efficiency is improved and the NOx content of the flue gas at the outlet under the same normalized stoichiometric ratio(2nurea/nNO) is reduced to 245.25 mg/m3. The variation trend of temperature and NOx under different sludge mixing amount is obtained by simulation calculation, the appropriate sludge blending proportion and SNCR spray gun layout optimization are put forward, which can provide reference for sludge blending incineration and SNCR denitration.
作者
杨栩聪
廖艳芬
林涛
马晓茜
YANG Xucong;LIAO Yanfen;LIN Tao;MA Xiaoqian(Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization(South China University of Technology),Guangzhou 510640,Guangdong Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2020年第21期6964-6972,共9页
Proceedings of the CSEE
基金
广州市科学研究计划(201804020082)
国家质量监督检验检疫总局科技项目(2017QK152)。
关键词
垃圾焚烧
污泥掺烧
选择性非催化还原
数值模拟
municipal solid wastes(MSW)incineration
sludge blending combustion
selective non catalytic reduction(SNCR)
numerical simulation
