SNCR脱硝特性的模拟及优化

摘要/Abstract

摘要： 本文对某台使用尿素为还原剂的100 t·h-1循环流化床锅炉的SNCR性能进行了CFD数值模拟，分析了温度、氨氮摩尔比等影响因素对SNCR脱硝效率、氨泄漏以及N2O浓度的影响规律。结果表明，SNCR最佳温度窗口的范围为850-1050 ℃，且随着氨氮比的增大，温度窗口范围变宽；随着温度的升高，氨逃逸量明显下降，当温度超过940 ℃后，氨逃逸量基本可以忽略不计，而N2O的生成量则呈现出先增大后减少的趋势。随着氨氮摩尔比的增加，脱硝效率逐渐增大，980 ℃左右达到峰值；氨泄漏随氨氮摩尔比的增加而增大；N2O浓度与脱硝效率呈正比关系，最大生成量约为30 ppm。

关键词: 选择性非催化还原, 温度窗口, 氨氮比, 氨逃逸, CFD, SNCR, Temperature window, NSR, NH3 slip, CFD

Abstract: Numerical simulations for urea-based Selective Non-Catalytic Reduction (SNCR) process of a 100 t·h-1 Circulating Fluidized Bed (CFB) boiler was investigated by Computational Fluid Dynamics (CFD) method to study the effect of temperature and Normalized Stoichiometric Ratio (NSR) on NOx conversion efficiency, NH3 slip and N2O formation. It is observed that the temperature window of SNCR process is 850~1050 ℃ and the ‘temperature window’ becomes wider with the increase of NSR; when temperature rises, NH3 slip decreases obviously and can be ignored when temperature is higher than 940 ℃. With the rising of temperature, the amount of N2O formation increases first and then decreases. NOx removal efficiency and NH3 slip increase at higher NSR; the formation of N2O is in proportion to NOx removal efficiency and the maximum amount is about 30 ppm.

中图分类号:

李穹吴玉新杨海瑞吕俊复. SNCR脱硝特性的模拟及优化[J]. CIESC Journal, 2013, 64(5): 0-0.

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