【作者】 秦岭；

【导师】 谢峻林；

【作者基本信息】 武汉理工大学 ， 材料学， 2011， 硕士

【摘要】 随着水泥工业NOx排放标准的逐步提高,减少氮氧化物的排放是未来很长一段时间内水泥工作者关注的重点。而分解炉是实施干法水泥窑低NOx煅烧技术的关键设备之一。本论文对水泥分解炉内选择性非催化还原法(SNCR)脱除氮氧化物的过程展开理论研究,旨在为我国水泥工业NOx的减排提供理论参考依据,具有重要的现实意义。本论文采用CFD技术,结合定性与定量分析的研究手段,对一实际尺寸的TDF型分解炉建立模型,首先进行了煤粉燃烧与碳酸钙分解耦合作用的数值模拟,并对NOx的生成与分布情况进行了分析,在此基础上,开展了SNCR法脱除NOx的过程的数值模拟,并通过研究喷氨高度、喷氨速度、喷氨高角度、氨氮摩尔比等展开了进一步的优化设计。主要结论如下：(1)针对TDF型6000t/d的分解炉建立的模型模拟结果较为合理,与实际工况相一致；(2)对NO浓度场分布情况的研究结果表明：NO高浓度区域集中在在Z=8m处,此处位于柱体上部区域,NO的生成集中高温区域所在的煤粉富集区,而在此区域生成的NO随着气流的上的升最终聚集在上部柱体壁边,初步考虑在Z=8m高度上对其进行喷氨；(3)还原剂的不同喷射高度对脱硝效果的影响规律为：当喷射还原剂喷射高度为8m时,还原剂与烟气的混合较为充分,有利于NO的脱除；(4)还原剂的不同氨氮摩尔比对脱硝的影响规律为：当随着比例(NSR)的增加,出口处的NO平均浓度逐渐减小,且变化有减缓的趋势,出口处的NH3平均浓度逐渐增大,但脱硝率逐渐上升且上升有明显减缓的趋势。当喷射还原剂喷射高度为8m处,以NSR=1.4为最佳；(5)还原剂的不同喷射速率对脱硝的影响规律为：在喷射高度8m处,氨氮摩尔比(NSR)为1.4时,当喷射速率为40m/s时,还原剂与烟气的混合较为充分,有利于NO的脱除；(6)还原剂的不同喷射角度对脱硝的影响规律为：随着还原剂喷射角度的增加,脱硝率呈先上升后下降的趋势。在喷射高度8m处,氨氮摩尔比(NSR)为1.4时,当喷射速率为40m/s时,且当喷射角度为60°时,脱硝率最佳。更多还原

【Abstract】 Now, along with strict NOx emission standards, reducing the gradual improvement of the emissions of nitrogen oxides is the focus of the researchers in the future for a long period of time. Precalciner is a key equipment to implement the low NOx technology. This paper makes theoretic researches on the process of SNCR in precalciner, aimed at offering theoretic references on the NOx emission reduction of the cement industry in our country, which shows a realistic significance.This paper built a numerical model of actual size precalciner by using CFD technology, combining qualitative and quantitative analysis, and then simulated coal combustion and calcium carbonate decomposition. On the basis of NOx formation and distribution analysis, this paper carried out the removing NOx numerical simulation by SNCR ways, and proceeded further optimization design by research of ammonia height, spray ammonia speed, spray ammonia Angle, ammonia nitrogen mole ratio,etc.The main conclusions are as follows:(1) For TDF-based 6000t/d of decomposition of the model furnace is more accurate and more reasonable distribution of income flow. Temperature, the decomposition rate of the system concide with the actual production needs;(2) Nitric oxide (NO) high concentrations focus on upper mantle in upper area area, the distribution of NO presented among low and high distribution characteristics of both sides. The generation of NO concentrated in the Z=8m high-temperature region where the coal-rich region. The NO generated in this region increases as the air eventually gathered in the upper edge of cylinder wall.and In the Z =8m spray them on a high ammonia can inhibit the formation of NO;(3) The different installation height of Reductant affects performance of denitration. It shows:When the jet spray height of 8m reducing agent, the reducing agent mixed with the flue gas is more fully conducive to the removal of NO;(4) The different ammonia molar ratio of Reductant affects performance of denitration. It shows:As with the ratio (NSR) increases, the average concentration of NO at the outlet decreases, and the change has slowed the trend, the average concentration of NH3 at the exit increases. When the jet spray height of 8m, To NSR =1.4 is suitable;(5) The different injection rate of reductant affects performance of denitra-tion.It shows:Height of 8m at the spray, when the NSR of 1.4 and the injection rate of 40m/s, the reducing agent mixed with the flue gas is more fully conducive to the removal of NO;(6) The different injection rate of Reductant affects performance of denitration. It shows:with the increase of reductant injection Angle, denitration rate are the first decline after rising trend. The optimal denitration rate can only be obtained with the optimized parameters as follows:the spray height of 8m, the NSR of 1.4, the spray rate of 40 m/s and at the jet angle of 60°.更多还原