在沉降炉上对无烟煤、贫煤、烟煤、褐煤以及不同配比(25%、50%、75%)混煤开展了过量空气系数对混煤燃尽特性影响的实验研究.结果表明,混煤燃烧中挥发分高的煤对挥发分低的煤存在促进和抑制2种交互作用.“炉外”掺烧方式下,低挥发分煤与高挥发分煤掺混时,抢风抑制作用表现明显;尤其是掺烧75%高挥发分煤时,抢风抑制作用最为显著;提高过量空气系数可以改善贫氧气氛,减弱混煤燃烧中的抢风抑制作用,提高混煤燃尽率.“炉内”掺烧方式下,过量空气系数的增加,交互作用减弱,各单煤的燃烧独立性增强,混煤燃尽率逐渐接近计算线性燃尽率.%The experiment of the influence of excess air coefficient on the burnout characteristics are performed under four coals and their blended coals (0% 、25% 、50% 、75% 、100%) The resuhs show that the combustion of blended coal is impacted by two opposite effects:the promote function and the restrain function.Under the out-furnace coal blending method,the interaction of blended coal is obvious when low-volatile coal is blended with high-volatile coals (especially,under the blending ratio of 75%).Enhancing the excess air coefficient can weaken the restrain function.Under the in-furnace coal blending method,when low-volatile coal is blended with high-volatile coals,as increasing the excess air coefficient,the restrain function is also lower,and the combustion independence of individual coals gradually increases,and the burnout of blended coal approaches the linear value.
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