再燃、喷钙对燃烧神华煤炉内沾污结渣特性的影响

Effect of coal reburning and injected calcium on fouling and slagging characteristics in Shenhua coal combustion

为了研究再燃、喷钙时炉内沾污结渣特性,采用低熔点神华煤在2.11 MW四角试验炉中分别进行无再燃工况、有再燃工况和喷钙再燃工况试验.通过宏观现象描述、微观扫描电镜(SEM)分析、电子探针和x射线衍射仪(XRD)物相分析,对炉内主燃区、再燃区和燃尽区沾污结渣状况进行研究,重点分析再燃区的沾污结渣差异及原因.结果表明,从炉内沾污结渣总体而言,喷钙再燃工况明显恶化,而有再燃和无再燃工况变化并不明显.神华煤中铁、硅在沾污结渣过程中作用很突出,而喷钙再燃工况时钙、硅、铁对沾污结渣的贡献最显著.

Shenhua coal was burned in the conditions of no reburning, reburning and reburning with injected calcium in 2.11 MW boiler with four-cornered combustor to study the fouling and slagging characteristics with coal reburning and injected calcium. Macroscopical phenomenon description, scanning electron microscope （SEM） analysis, electronic probe and X-ray diffraction （XRD） analysis were used to analyze the phenomena of fouling and slagging in the main combustion zone, reburning zone and burned zone, with emphasis on the difference and its reason in reburning zone. The results showed that the characteristics of fouling and slagging under condition of reburning did not remarkably change compared to no reburning, however, the reburning with injected calcium was distinctly deteriorated. Fe and Si were important factors for the fouling and slagging of Shenhua coal, and Ca, Si and Fe were prominent factors in the reburning with injected calcium.