垃圾焚烧电厂焚烧炉-余热锅炉性能及NOx排放

Performance of incinerator-waste heat boiler and NOx emissions in solid waste incineration power plants

为了掌握新建机组运行状况,探索烟气再循环对垃圾焚烧电厂污染物排放的影响,针对某垃圾处理量为500 t/d的垃圾焚烧电厂,现场测试省煤器出口烟气成分及炉内烟气温度,试验研究焚烧炉-余热锅炉性能,定量计算焚烧炉-余热锅炉效率及各项热损失,并根据试验测试结果,分析炉内NOx生成的影响因素.结果表明:在不同负荷下,机组总热损失中排烟热损失所占比例最大,其次为炉渣热损失,在试验范围内,烟气再循环量对焚烧炉-余热锅炉效率影响较小;烟气中氧气的体积分数及烟气再循环对NOx排放影响显著,省煤器出口氧气的体积分数由4.52%增加到8.00%,NOx质量浓度由209.54 mg/m^3升高到307.30 mg/m^3,增加46.65%;与烟气再循环系统停运相比,当烟气再循环阀门全开时,省煤器出口NOx质量浓度由209.54 mg/m^3降为126.15 mg/m^3.

The flue gas composition on the outlet of economizer and the flue gas temperature in the furnace were tested in a waste incineration power plant with a waste disposal capacity of 500 t/d,in order to master the operation status of a newly built units and explore the influence of flue gas recirculation on the pollutant emission of a waste incineration power plant.The performance of the incinerator-waste heat boiler was experimentally studied,and the efficiency of the incinerator-waste heat boiler and the heat losses were quantitatively calculated.The influencing factors of NOx emissions were analyzed based on the test results.Results indicate that the largest proportion of the total heat loss is the exhaust heat loss under different loads,and the next is the heat loss of slag.The influence of flue gas recirculation on the efficiency of incinerator-waste heat boiler is small within the test range.The oxygen volume fraction in the flue gas and the flue gas recirculation have significant influence on NOx emissions.The NOx mass concentration on the outlet of the economizer increased from 209.54 mg/m^3 to 307.30 mg/m^3,that is an increase of 46.65%,when the oxygen volume fraction on the outlet of the economizer increased from 4.52%to 8.00%.The NOx mass concentration on the outlet of the economizer decreased from 209.54 mg/m^3 to 126.15 mg/m^3 when the flue gas recirculation valve was fully opened,compared with the shutdown of flue gas recirculation system.