神华煤粒径在分级燃烧中对NOx排放的影响

在多路进风一维炉上,研究不同粒径的神华煤在分级燃烧中氮氧化物的排放规律.结果表明:不分级燃烧时中等粒径煤粉氮氧化物的排放较高;分级燃烧时,分级的程度越大,氮氧化物排放越低;普通分级燃烧时粒径的影响很明显,但仍是中等粒径的氮氧化物的排放明显较高;深度分级燃烧时粒径的影响被削弱;在主燃烧区固定风量时,燃尽风的增加会导致氮氧化物的排放略微升高;并且分级燃烧会减少神华煤的飞灰含碳量.

Size Effect of Pulverized Shenhua Coal Particles on NOx Emission in Combustion with Air Staging

NO_x emission properties during combustion with air staging of differently sized Shenhua coal particles were investigated in an one-dimensional furnace with multipath air inlet.Results indicate that,with non-staged combustion,relatively more NO_x is emitted by medium sized coal particles,while in case of combustion with air staging,the higher the staging rate the less NO_x emission;in case of conventional air staging,though the effect of particle size is remarkable,particles of medium size still emit noticeably more NO_x.The size effect reduces with rising degree of staging.In case the stoichiometry amount of air in the main combustion zone is kept constant,an increase in over fire air tends to increase NO_x emission somewhat.Moreover,combustion with staging causes the carbon content in Shenhua coal's fly ash to get less.