摘要
煤灰的烧结和熔融是电站锅炉灰沉积的重要过程，熔体的结构特性是沉积物生长和强度形成的决定性因素。本文给出了煤灰熔体的聚合作用及其结构模型。依据结构模型，研究了７１种煤灰（包括我国２６种烟煤、２２种褐煤、５种神府东胜煤、１８种美国西部煤）的ＮＢＯ／Ｔ（即每个四面体中的非桥氧数，评价铝硅酸盐聚合程度的指标）特性。由于成煤的无机地球化学条件相似，我国的一些褐煤和神府东胜煤田的煤与美国西部煤具有相似的ＮＢＯ／Ｔ特性。但是对于我国的烟煤，由于缺少碱性金属及碱土金属，ＮＢＯ／Ｔ＝０，因此它不能用来详细区分煤灰熔体的结构特性。为克服这个缺陷，本文提出了Ｐ／Ｍ比的新指标（其中Ｐ＝∑ｍｏｌｐｏｌｙｍｅｒ（ｉ）×Ｌ（ｉ），Ｍ＝∑ｍｏｌｍｏｄｉｆｉｅｒ（ｉ）÷Ｌ（ｉ）Ｌ（Ｉ）是离子ｉ的电离势）。Ｐ／Ｍ考虑了不同离子在熔体结构中的分布及其作用大小，其物理意义为熔体结构的库仑缔合力。本文依据煤灰熔体结构模型，讨论了结渣特性常用指标酸碱比Ｂ／Ａ的不合理性，以及熔体物理化学特性与熔体结构特性的关系等。
Sintering and melting of coal ash is a key process of ash deposition in furnace of utility boilers. Melt structure characteristics is a determining factor in deposit growth and strength development.This paper introduces the polymerization and stucture model of coal ash melts.Based on the structure model,the structure property index NBO/ T(non bridging oxygen pertetrahedrally coordinated cation) ,which is used for accessing the polymerization of aluminum silicate,is studied from 71 coals (including 26 bituminous,22 lignites,9 Shenfu-Dongsheng coals in China and 18 coals in west America) .Some lignites and the coals from Shenfu-Dongsheng coal field have the similar NBO/T characteristics compared with coals in west America because of the similar inorganic geochemical conditions NBO/T is not suitable for differentiating the difference between some Chinese bituminous,which are lack of alkali and alkaline earth elements,and so NBO/T=0.For overcoming this defect, P/M(P=∑molpolymer(i)×L(i),M=∑molmodifier(i)÷L(i), L(i) is the ionization potential) is put forward.P/M takes account into the roles and the contributions of each element in structure,it stands for the Kulun strength of ash melt structure,Unreasonableness of B/A,which is widely used for predicting slagging propensity,and the relations between physical-chemical properties and structure characteristics are discussed in this paper.
出处
《煤炭转化》
CAS
CSCD
北大核心
1996年第4期85-91,共7页
Coal Conversion
关键词
结构
煤灰
熔体结构
计算
structure,polymer,modifier,B/A,NBO/T,P/M
