【摘要】 为深入研究高岭土对减缓新疆准东高碱煤沾污结渣特性的影响规律与作用机制,利用3 MW_th多功能煤燃烧中试平台模拟实际电站锅炉四角切圆燃烧环境下研究高岭土对新疆准东高碱煤燃烧过程中灰的生成及沾污结渣特性的影响。试验结果表明:高岭土成分以SiO₂为主,虽然SiO₂单质熔点高达到1 730℃,但煤灰中SiO₂主要以非晶体状态存在,有时可提高熔融温度,有时则起到助熔作用;添加10%高岭土后,其炉膛结焦比纯烧准东高碱煤要好一些,虽然仍有流渣,但其渣的致密程度要比纯烧准东高碱煤要低;在炉膛燃烧区域准东高碱煤的碱酸比（B/A值）高于添加高岭土对应灰样的碱酸比值,而在高温对流受热面烟温区域（末级过热器、末级再热器区域）,添加高岭土后其灰样的碱酸比值比燃准东高碱煤工况下灰样的碱酸比要低,添加高岭土后,与纯烧准东高碱煤相比,高碱酸比分布温度区间沿烟气流向方向向后推移,即易发生严重沾污的烟温区间向低温区域偏移。因此,相同条件下其在对流受热面上的沾污烧结程度要低,添加高岭土对降低锅炉对流受热面发生大面积沾污具有一定的效果。更多还原

【Abstract】 In order to study the mechanism effect of clay on ash fusion characteristics of Zhundong high alkali coal,3 MW pilot-scale facility tests were used to simulate coal tangential firing process in boiler and to study the ash deposition/slagging behavior in it.The experimental results show that the effect of quartz（SiO₂） can not only increase the ash fusion temperature but also decrease the ash fusion temperature,which depend on the chemical/mineral composition of coal ash,even quartz has high melting point,1 730 ℃.As compared with combusting with Xingjiang High alkali coal,the slagging tendency of coal ash in furnace was alleviated in the case of adding 10 wt%clay.Although there still was slagging in the furnace wall,the slag looks looser.The basic to acidic ratio（B/A） of high alkali coal ash deposits in the furnace and high temperature convective section is higher than that of adding clay.The distribution of high B/A high alkali coal value is moved from high temperature area to relative low temperature area.That is main reason for relieving ash fouling degree by adding clay.更多还原