准东煤掺烧NH4H2PO4对灰分变化和灰熔融特性的影响  

Influence of NH4H2PO4 on Ash Composition and Ash-forming Characteristics During Combustion of Zhundong Coal

作　　者：高满达 孙保民[1] 苏逸峰 GAO Mada;SUN Baomin;SU Yifeng(Key Laboratory of Condition Monitoring and Control for Power Plant Equipment Ministry of Education（North China Electric Power University）,Changping District,Beijing 102206,China)

机构地区：[1]电站设备状态监测与控制教育部重点实验室(华北电力大学)

出　　处：《中国电机工程学报》2018年第20期6012-6020,共9页Proceedings of the CSEE

基　　金：国家科技支撑计划项目(2015BAA04B02);中央高校基本科研业务费专项资金资助项目(JB2016119)~~

摘　　要：通过X射线衍射图谱分析结合灰熔融性测定,研究了准东煤燃烧过程中的矿物质赋存形态变化及添加NH4H2PO4对准东煤灰分特征和灰熔融特性的影响。试验结果表明,空气气氛下,随着准东煤燃烧温度从800℃升高至1100℃,灰中钠长石、钙铁辉石和蓝方石等熔点较低且熔融性较强矿物质含量升高,灰中主要矿物质皆为助熔性矿物质。煤中添加比例PO4^（3-）/Na≥0.5、温度800℃以上,混煤灰中生成新的Ca（2.71）Mg（0.29）（PO4）2、 Al PO4、 Ca3（PO4）2、Ca9Fe（PO4）7、Ca9Al（PO4）7、Ca2P2O7和Mg2P2O7等高熔点物质。当PO4^（3-）/Na〉 1时,混煤灰熔融性温度明显升高,软化温度由1144℃增加至1418℃（PO4^（3-）/Na=4）,煤改善为中等结渣倾向。可见添加NH4H2PO4能够有效抑制低熔点、助熔性含钠矿物生成,促进高熔点物质形成,提高灰熔融特性温度。The X-ray diffraction （XRD） analysis combined with ash melting temperature tests were used to study the morphological changes of minerals in the combustion process of Zhundong coal and the effects of NH4H2PO4 on the formation characteristics of ash and the characteristics of ash fusion. The results show that, with the increasing combustion temperature from 800℃ to 1100℃, albite, hedenbergite, hauyne and other low melting temperature and high meltability minerals were on the rise, the main minerals in the ash were all fused minerals under air atmosphere. The new minerals with high melting temperature such as Ca2.71Mg0.29（PO4）2, AlPO4, Ca3（PO4）2, Ca9（Fe,Al）（PO4）7, Ca2P2O7 and Mg2P2O7 were formed in the mixed ash when temperature was higher than 800℃ and the ratio of pO34-/Na was greater than or equal to 0.5. When the ratio of pO3-/Na was more than 1, the melting point of coal ash was obviously higher, and the softening temperature （tsv） increased from 1144 ℃ to 1418 ℃（PO3-/Na = 4）. Coal slagging tends to moderate. It can be seen that the addition of NH4H2PO4 can effectively inhibit the formation of low melting temperature and fluxing sodium minerals, promote the formation of high melting temperature materials and improve the ash melting characteristic temperature

关 键 词：准东煤 NH4H2PO4 成灰特性 矿物质演变 富磷添加剂 灰熔融性温度 

分 类 号：TM611[电气工程—电力系统及自动化]