【摘要】 对某2500 t/d双喷腾型分解炉,按1∶1比例建立物理模型,采用数值模拟方法,研究空气分级改造条件下分风比和三次风温对炉内无烟煤燃烧、生料分解以及NO减排的影响,并通过实验验证了数值模拟的可靠性。研究结果表明:随着分风比增长,煤粉燃尽率以及生料分解率逐渐降低,脱硝效率逐渐增大;随着三次风温提高,煤粉燃尽率和生料分解率逐渐增加,脱硝率呈先增后减变化。综合考虑炉内燃烧、生料分解以及脱硝情况,分风比取15%、三次风温取1370 K为最佳值,在此最佳分风比和三次风温下,炉内流场合理,高温区范围大,炉内温度值能满足生料分解要求,此时煤粉燃尽率、生料分解率、分解炉出口脱硝率分别为:94. 40%、94. 79%、33. 98%,较未分风改造前分别提高:1. 13%、-0. 32%、33. 98%。更多还原

【Abstract】 The physical model was established according to the 1 ∶ 1 ratio,on the basis of a 2500 t/d Dual-sprayed Precalciner. The air staging reforming was conducted on this basic model,and the method of numerical simulation was used to investigate the effects of anthracitic combustion,raw material decomposition and NO emission reduction under different air staging ratios and temperature of tertiary air,and the reliability of the numerical simulation was certificated with experiments. The results of the study show that with the increase of the proportion of the air staging,the burnout rate of coal and the decomposition rate of raw material decrease gradually,and the denitration efficiency increase gradually.Besides,with the increase of the temperature of tertiary air, the burning rate of coal and the decomposition rate of raw material increase gradually,but the denitration efficiency increase firstly and then decrease. Taking the precalciner ’s coal combustion,raw material decomposition and denitration efficiency into comprehensive consideration,it is the best working condition when the values of air staging ratio and temperature of tertiary air are 15% and 1370 K respectively. In the best working condition,the flow field in the precalciner is reasonable,the range of high temperature area is large, and the temperature value can meet the requirement of raw material decomposition,the burnout rate of coal,decomposition rate of raw material and the rate of exportation denitration are 94. 40%,94. 79% and 33.98% respectively,which increase by 1. 13%,-0. 32%,33. 98% compared with the situation of no air staging reforming.更多还原