针对锅炉燃用新疆准东高钠煤存在严重的结渣问题,本文通过一维火焰炉模拟实际燃烧环境,试验研究了多种添加剂的防结渣效果,并对其防结渣机理进行了分析.试验结果表明:试验所用的高岭土、黏土类矿物对缓解结渣有较好的效果,试验样品中添加剂添加比例达到3%以上时防结渣效果更明显;添加剂起作用的前提是将煤灰中钠、钙、铁等元素质量分数降低到合理水平,尤其是将煤灰中Na2O质量分数降低到3%以下,且钙、铁元素质量分数不大幅增加;添加剂加入后煤灰中的硅铝比对防结渣也起重要作用,合理的硅铝比有利于使低熔点的钠、钾、钙等碱/碱土金属化合物形成熔点相对较高的硅铝酸盐,单纯提高煤灰中Al2O3质量分数防结渣效果不明显.%To solve the serious coking and contamination problems occurred on heating surface of utility boilers firing Xinjiang Zhundong coal, a one-dimensional furnace was used to simulate the actual combustion environment and the anti-slagging effects of several additives were experimentally investigated. Moreover, the mechanism against slagging was also analyzed. The results show that, the kaolin and clay have better anti-slagging effect. There are two additives having great effect in against slagging and the proportion of practical application in utility boilers shall not be less than 3%. By appearance comparison and phase analysis of slag, it is found that the additives act when the content of Na, Ca and Fe is controlled in a reasonable level, especially the content of Na2O is declined below 3% and there is no obvious increase in that of Ca and Fe. In addition, the SiO2/Al2O3 ratio in coal ash with additives plays an important role in against slagging. A rational SiO2/Al2O3 ratio helps alkali/alkaline metal compounds with low melting point to form high-melting-point aluminosilicate. Only increasing mass fraction of Al2O3 has no obvious effect on anti-slagging.
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