不同煤种燃烧过程中NO_x形成规律的数值模拟与分析

Simulation and analysis on formation regularity of NOx duringdifferent coal combustion process

燃煤过程对大气造成的污染正日益引起人们的关注,控制NOx的排放是煤燃烧利用研究中亟需解决的课题。采用数值模拟方法,研究不同煤种在不同燃烧温度下NOx的生成规律,并对燃烧过程中的NOx生成的影响因素及抑制方法进行分析和归纳。结果表明:中挥发分煤(mv)燃烧生成的NOx最多,低挥发分煤(lv)燃烧生成的NOx最少;热力型NOx的生成与温度有直接的关系。因此,缩短燃烧产物在高温区的滞留时间有助于减少NOx的生成,减少反应中氧气的质量浓度能够抑制NOx的生成,其计算结果可为今后的工业性实验提供理论依据。

The atmospheric pollution caused by coal combustion is increasingly concerned,the controlling of NOx is becoming a very important issue to resolve during the research of coal combustion and coal utility.In this paper,numerical simulation is performed to investigate the information mechanism of NOx of different coal under different combustion temperature,and to analyze and summarize the influencing factors and control measure during the combustion of NOx.The result shows that：the combustion of middling-volatile coal（mv）generates the most NOx,the low-volatile coal（lv）combustion generates the least NOx;the thermal NOx generation has a direct relationship with the temperature.Therefore,shortening the stranded time of combustion product at high temperature region can effectively reduce the formation of NOx;reducing the concentration of oxygen in reaction region can control the formation of NOx.The result provides a theoretical basis for future industrial experiment.