垃圾衍生燃料在水泥窑分解炉内的减氮效应

Nitrogen reduction effect of refuse derived fuel in cement kiln calciner

将垃圾衍生燃料(RDF)作为替代燃料投加到水泥窑炉内进行高温焚烧,是水泥工业降低熟料生产过程中化石燃料消耗的主要技术手段之一。本文在管式炉中研究了粒径和助燃空气温度这两个因素对RDF热解燃烧气体组分的影响,并利用CFD软件模拟了RDF在分解炉内的减氮效应。研究结果表明:对不同粒径的RDF颗粒,总体上呈现出热解燃烧气体中CO、CmHn和H2还原性小分子气体浓度随着助燃空气温度的升高而增加。基于华新某工厂的运行工况进行了CFD模拟计算,当RDF的粒径分布取<50 mm(占80%),三次风温度为900℃时,过剩空气系数取1.2,燃烧室出口NOx浓度小于280 ppm,减氮效果明显,与实际情况一致。

RDF as an alternative fuel is added to cement kiln for high-temperature incineration,which is one of the main technical means for cement industry to reduce the consumption of fossil fuels in clinker production.In this paper,the effects of particle size and the temperature of combustion gas on the gas composition of RDF combustion pyrolysis were studied in a tubular furnace,and the nitrogen reduction effect of RDF in calciner was simulated by CFD software.The results showed that for RDF particles with different particle sizes,the concentration of CO,CmHn and H2 in pyrolysis combustion gas increases with the increase of the temperature of combustion air.CFD simulation calculation is carried out based on the operating conditions of Huaxin plant.When the particle size distribution of RDF is 80%(less than 50 mm),tertiary air temperature is 900℃,excess air coefficient is 1.2 and NOx concentration at the outlet of combustion chamber is less than 280 ppm,the nitrogen reduction effect is obvious,which is consistent with actual situation.