SCR反应器入口参数与反应温度对脱硝性能的交互作用

Interaction effect of inlet parameters and reaction temperature on denitration performance of SCR reactor

为系统研究选择性催化还原(SCR)反应器入口参数与反应温度对脱硝性能的交互作用,基于E-R机理,通过建立SCR脱硝反应一维模型,结合燃煤电厂调峰实际运行数据设定入口参数界限,利用MATLAB数值仿真,分别对反应温度同氨氮摩尔比(NSR)、入口NO质量浓度和入口速度对脱硝效率及氨逃逸率的耦合效应进行了重点分析。结果表明:入口参数对最佳反应温度影响较大;偏离最佳反应温度越多,NSR对氨逃逸率影响程度越低,NSR>1时,脱硝性能对NSR敏感性降低;增大入口NO质量浓度可改善整体脱硝性能,当入口质量NO浓度为1 050 mg·Nm-3时,脱硝效率可达82.42%,氨逃逸率低至0.33%;入口速度与反应温度的交互作用最大,降低入口速度可拓宽催化剂高活性温度窗口,显著提升脱硝性能,将入口速度由7 m·s-1降至1 m·s-1,最佳脱硝效率由69.32%升至89.17%,最低氨逃逸率由8.11%趋近于0;燃煤电厂调峰运行负荷上升会导致脱硝效率下降和氨逃逸加剧。该研究结果可为燃煤电厂SCR脱硝性能的整体优化提供参考。

In order to systematically study the interaction effects between inlet parameters and reaction temperature of selective catalytic reduction(SCR) reactor on denitration performance,a one-dimensional model of SCR denitration reaction was established based on the E-R mechanism,the inlet parameter boundaries were set by combining actual coal-fired power plant operation data of different loads in peak shaving.The coupling effects of reaction temperature with molar ratio of NH_(3) to NOx(NSR),inlet NO concentration,inlet velocity on denitration efficiency and ammonia escape rate were examined separately by numerical simulation in MATLAB.The results showed that all the inlet parameters had great influence on the optimum reaction temperature,and the impact of NSR on ammonia escape rate dampened with the increase of deviation from the ideal reaction temperature.When NSR>1,the denitration performance was less sensitive to NSR.By raising the inlet NO concentration,denitration performance could be made better generally.When the concentration of NO was1 050 mg·Nm^(-3),the denitration efficiency reached 82.42% and the ammonia escape rate was as low as 0.33%.The interaction between the inlet velocity and reaction temperature was the largest,reducing the inlet velocity could broaden the high activity temperature window of the catalyst and significantly improve the denitration performance.When the inlet velocity was reduced from 7 m·s^(-1) to 1 m·s^(-1),the optimal denitration efficiency increased from 69.32% to 89.17%,and the lowest ammonia escape rate approached to 0 from 8.11%.The increase of peak load in coal-fired power plants would lead to the decrease of denitration efficiency and the intensification of ammonia escape.The results of this study can provide a reference for the overall optimization of SCR denitration performance in coal-fired power plants.