碳氢燃料热解气再燃还原NO的化学动力学研究

Chemical Kinetics Numerical Investigation of NO Reduction by Hydrocarbon Fuel Pyrolysis Gas Reburning Technology

为探究碳氢类燃料热解产生的还原性气体在氮氧化物减排中的应用,采用化学动力学软件CHEMKIN-PRO和Shrestha综合机理,模拟研究了反应温度、还原气体体积分数、过量空气系数和停留时间对还原性气体H_(2)、CO、CH_(4)和NH_(3)还原NO的影响规律。结果表明:随着反应温度、还原性气体体积分数和停留时间的增加,H_(2)、CO、CH_(4)和NH_(3)对NO的还原率升高。在模拟工况中,较高温度下,相同体积分数的H_(2)对NO的还原率要高于CO、低于CH_(4)和NH_(3);在模拟工况中脱硝效率越高的气体,其受到体积分数增加所提升的对NO还原率也越高;存在最佳当量比使H_(2)和CH_(4)对NO的还原率达到最高;温度越高时反应完全发生所需的停留时间越短。该结论能够为碳氢燃料再燃脱硝的工业应用提供一定参考。

To explore the application of reducing gases from pyrolysis of hydrocarbon fuels to nitrogen oxide emission reduction,using CHEMKIN-PRO software and Shrestha comprehensive mechanism,the effects of reaction temperature,reduction gas volume fraction,excess air coefficient and residence time on reduction NO of reductive gases H_(2),CO,CH_(4)and NH_(3)were simulated.The results showed that the reduction rate of H_(2),CO,CH_(4)and NH_(3)increased with the increase of reaction temperature,reduction gas volume fraction and residence time.At higher temperature,the reduction rate of H_(2)to NO was higher than that of CO and lower than that of CH_(4)and NH_(3).The higher the denitrification efficiency of gases in simulated working conditions,the higher the NO reduction rate increased by increasing volume fraction.The existence of an optimal equivalent ratio resulted in the highest reduction rate of H_(2)and CH_(4)to NO;The higher the temperature,the shorter the residence time required for the reaction to fully occur.This conclusion can provide some reference for the industrial application of reignition and denitrification of hydrocarbon fuel.