锅炉结渣初始沉积层微观沉积机理研究  

Micromechanism of deposition for initial layer sediments of boiler

作　　者：李明强 杜梅芳 乌晓江[2] 周磊 张忠孝[3] 

机构地区：[1]海理工大学理学院,上海200093 [2]上海锅炉厂有限公司,上海200245 [3]上海交通大学机械与动力工程学院,上海200240

出　　处：《燃料化学学报》2013年第2期157-162,共6页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(51276212);上海市青年科技启明星计划(11QB1402100)

摘　　要：选取矾土Al2O3和赤铁矿Fe2O3,对这两种矿物做弹性常数的微观分析、对比,X射线衍射分析表明,煤灰与初始沉积层中的矿物种类相同,但两者中矾土Al2O3和赤铁矿Fe2O3的含量相差很大。采用第一性原理(first-principles)的超软赝势平面波方法,对Al2O3和Fe2O3的电子结构、弹性常数进行了计算。结果表明,从两种物质的结构角度分析,Al2O3晶体中Al3+、O2-的堆积排列相对于Fe2O3中Fe3+、O2-要稀疏,这是它们性质不同的结构原因;对于两晶体在<100>方向和切向上的化学键,Fe-O键比Al-O键更容易变形或者断裂,从而导致Fe2O3极易沉积在清洁水冷壁上;对Fe2O3,切向面对其沉积起了关键性的作用。The analysis of XRD indicates that slag is similar with minerals in the initial sediments. However, the proportion of bauxite Al2O3, hematite Fe2O3 has a big difference. The electric structure, elastic constants of Al2O3 and Fe2O3 were calculated using the ultra soft pseudo-potential plane-wave method based on the first- principles. The results show that from the structure of material, the accumulation mode of Al3＋ and 02. in Al2O3 crystal is sparser than that of Fe3＋ and O2- in Fe2O3, which is the reason for their different properties. For their chemical bonds in the direction of 〈 100 〉 and in tangential, Fe-O is more easy to deformate and fracture than Al-O, leading to Fe2O3 deposition in the clean water wall. For Fe2O3 , tangential surface plays a key role for its deposit.

关 键 词：弹性性质 电子结构 煤灰 第一性原理 

分 类 号：O641[理学—物理化学]