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
The aim of this study was to assess the performance of the combustion process during medical waste incineration by studying physical properties of the ashes produced. Combustion characteristics data including maximum ...The aim of this study was to assess the performance of the combustion process during medical waste incineration by studying physical properties of the ashes produced. Combustion characteristics data including maximum temperatures, total weight of waste loaded, weight of ashes, weight reduction, sieve analysis and particle size distribution were determined experimentally. The test runs were conducted in a newly installed incinerator at Temeke district hospital. The average maximum temperatures achieved in the primary chamber was 397.8℃and 839℃ for secondary chamber with average incineration cycle time of 99 minutes. These temperatures were lower compared to the design temperatures of 650℃ and 950℃ as a result of loading wet waste. The ash samples were collected under the incinerator grate by randomly sampling the ashes for each run after weighing the total ash. The particle size distribution of ashes observed was not uniform due to presence of non-combustible materials in the sharps waste. However, the fineness modulus ranged between 2.0 and 4.0, which is in the acceptable range. From the above results it was concluded that, the incinerator performance was high in terms of the parameters assessed. To improve the incinerator performance further, it was recommended that the medical waste should be stored in a dry place away from rain.展开更多
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。
文摘The aim of this study was to assess the performance of the combustion process during medical waste incineration by studying physical properties of the ashes produced. Combustion characteristics data including maximum temperatures, total weight of waste loaded, weight of ashes, weight reduction, sieve analysis and particle size distribution were determined experimentally. The test runs were conducted in a newly installed incinerator at Temeke district hospital. The average maximum temperatures achieved in the primary chamber was 397.8℃and 839℃ for secondary chamber with average incineration cycle time of 99 minutes. These temperatures were lower compared to the design temperatures of 650℃ and 950℃ as a result of loading wet waste. The ash samples were collected under the incinerator grate by randomly sampling the ashes for each run after weighing the total ash. The particle size distribution of ashes observed was not uniform due to presence of non-combustible materials in the sharps waste. However, the fineness modulus ranged between 2.0 and 4.0, which is in the acceptable range. From the above results it was concluded that, the incinerator performance was high in terms of the parameters assessed. To improve the incinerator performance further, it was recommended that the medical waste should be stored in a dry place away from rain.
