刘上光

摘要：以某化工废气焚烧厂两台SCR 脱硝系统为研究对象，分别研究了导流板、混合器、整流器等装置对SCR脱硝系统中温度场、氨浓度场、速度场的影响，经过分析比较两种负荷运行条件下的各个要求指标，可以看出PROJIECT1方案中，采用一二三级静态混合器、弯管导流板、扩口导流板结合整流器的方案最优，额定工况下速度偏差降低至2.01%，氨浓度偏差降低至2.33%，温度偏差为±3K，整个烟道阻力为1393K，整个优化设计均远优于技术指标要求;而PROJIECT2方案中，采用相同的方案，额定工况下能够使得速度偏差降低至1.76%，氨浓度偏差降低至4.31%，温度偏差为±2K，整个烟道阻力为1183K，整个优化设计均远优于技术指标要求。

关键词：废气焚烧;SCR;烟道设计;仿真优化

Abstract  Two SCR denitrification systems of a waste gas incineration plant are analyzed by CFD，and the effects of the devices such as deflectors，mixers and rectifiers on the temperature field，ammonia concentration field and speed field in SCR denitrification system were studied respectively. The requirements indicators under the two load operating conditions are analyzed，and the results show that it can be seen that the scheme of using one-two-three static mixers，elbow guide plates，expanded vent guide plates combined with rectifiers is optimal in the PROJIECT1 scheme. Under rated operating conditions in the PROJIECT1，the speed deviation can be reduce to 2.01%，and ammonia concentration deviation can be reduced to 2.33%. The temperature deviation is only ±3K，and the entire flue resistance is 1393K.The entire optimization design is far better than the technical specifications. Under rated operating conditions in the PROJIECT2，the speed deviation can be reduce to 1.76%，and ammonia concentration deviation can be reduced to4.31%. The temperature deviation is only ±2K，and the entire flue resistance is 1183K.The entire optimization design is far better than the technical specifications.

Keywords   Waste gas incineration，SCR，flue design，simulation optimization.

前言

隨着 “碳达峰”“碳中和”发展路线的提出，对环境要求也越来越提高。其中垃圾分类也在上海等地区实施，为废气焚烧厂提供了更加优秀的焚烧垃圾，同时各界对废气焚烧厂的要求也越来越严。目前，废气焚烧处理具有技术可靠、容量大、对垃圾适应性强、运行维护方便等优点，具有较高的推广价值[1]。但是，其会排放大量的污染烟气，如NOx、Sox以及二恶英等。因此，需采用过不同治理方法对其污染烟气进行处理，其中选择性催化还原法（SCR）脱硝工艺是目前我国使用较为广泛的脱硝技术，该技术具有脱硝效率高、控制方便、运行可靠等特点[2，3]。

Liu 等[4]针对低挥发分燃煤锅炉系统中 SCR系统烟道和导流板布置进行了优化设计仿真，有效降低了 NOx 排放，并减少了氨耗量。……