SNCR（selective non-catalytic reduction） using urea solution was used in a HG-410/9.8-YW15 boiler,whose combustion system included a pulverized-coal reburning system to control NOx production.Tests were carried out a...SNCR（selective non-catalytic reduction） using urea solution was used in a HG-410/9.8-YW15 boiler,whose combustion system included a pulverized-coal reburning system to control NOx production.Tests were carried out at the load of 280 t·h-1,345 t·h-1 and 410 t·h-1.The experimental results showed that NOx emission could be reduced under 200 mg·m-3（standard condition,6%O2,dry gas） with the SNCR system running.The increment of NSR（normalized stoichiometric ratio） resulted in an improvement of NOx reduction efficiency,but the improvement was weak when NSR was greater than 2.5.A greater NSR also resulted in more ammonia slip,especially when NSR was greater than 1.25.N2O emission reached the maximum as NSR was about 2.0.Ammonia slip increased and the existence time of the urea solution droplets decreased with increasing atomization steam pressure and the track distance of the droplets reached the maximum at an intermediate pressure.There was an optimal atomization steam pressure,which would result in the highest NOx reduction efficiency of SNCR.And there was another optimal pressure of atomization steam,about 0.3 MPa,which would result in the least N2O emission.展开更多
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...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。展开更多
文摘SNCR（selective non-catalytic reduction） using urea solution was used in a HG-410/9.8-YW15 boiler,whose combustion system included a pulverized-coal reburning system to control NOx production.Tests were carried out at the load of 280 t·h-1,345 t·h-1 and 410 t·h-1.The experimental results showed that NOx emission could be reduced under 200 mg·m-3（standard condition,6%O2,dry gas） with the SNCR system running.The increment of NSR（normalized stoichiometric ratio） resulted in an improvement of NOx reduction efficiency,but the improvement was weak when NSR was greater than 2.5.A greater NSR also resulted in more ammonia slip,especially when NSR was greater than 1.25.N2O emission reached the maximum as NSR was about 2.0.Ammonia slip increased and the existence time of the urea solution droplets decreased with increasing atomization steam pressure and the track distance of the droplets reached the maximum at an intermediate pressure.There was an optimal atomization steam pressure,which would result in the highest NOx reduction efficiency of SNCR.And there was another optimal pressure of atomization steam,about 0.3 MPa,which would result in the least N2O emission.
文摘以某台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。
