掺烧污泥煤粉锅炉燃烧特性的数值模拟

摘要

采用单、双混合分数／PDF 模型，对某台420 t／h 四角切圆燃烧锅炉燃烧单煤和掺烧生活污泥进行了数值模拟，研究了炉内流动、燃烧和污染物排放特性。结果表明，在相同条件下燃烧单煤，锅炉70％负荷和100％负荷工况下的模拟数据与现场试验数据相符合；锅炉100％负荷下煤泥混烧时的 NOx 排放浓度低于燃烧单煤工况，随着污泥掺混比的增加煤粉燃尽率稍有下降，炉膛整体温度分布和烟气组分分布大致相同，对炉内流动、燃烧和污染物排放特性不会产生明显影响。%Numerical simulation using single-and double-mixture-fraction /PDF (Probability Density Function) transport model was carried out to evaluate the characteristics of coal burning alone and with domestic sludge on a 420 t/h tangentially coal-fired boiler.The flow,combustion and NOx emission properties were investigated.The sim-ulation results were consistent with the field test under the same working condition,when the coal was burned alone and the load is 70% and 1 00%.Under 1 00% load condition,the NOx emission reduced after co-combustion.With the increasing mass ratio of sludge,the burn out rate of coal decreased slightly.Temperature distribution and flue gas composition distribution in the furnace were roughly the same.All these above indicated that the co-combustion had little influence on characteristics of flow,combustion and NOx emission of this boiler.