摘要
对4种典型贫煤与无烟煤分别进行了不同混煤方式下的可磨性、粒径分布变化规律实验室试验研究,试验结果表明,混煤的可磨性趋向于难磨煤种、成粉样品中粗颗粒难磨煤多、细颗粒易磨煤种多。从可磨性标准测试角度对试验结果进行了物理解释,提出混煤的可磨性必须由实验确定、"炉前掺混"时混煤的煤粉细度必须由挥发份较低的煤种决定、"分磨制粉"时各组份煤选取各自合理细度的结论。针对几种可磨性差异较大煤种的掺烧,根据制粉系统、燃烧系统的特点,进行了3种不同方式的"分磨制粉"掺烧方式优化试验,通过较好地控制难磨、难燃尽煤种的煤粉细度,锅炉效率较传统的"炉前掺混"方式均提高1.5%以上。
Experimentally studied were the grindability and the variation law of the particle diameter distribution of four kinds of typical lean coal and anthracite respectively in different coal mixing modes in a laboratory.The test results show that the grindability of the blended coal tends to be such,as assumed by coal ranks diffifult to grind,i.e.in the pulverized coal samples,the coarse particles pertain to more-difficult-to-grind coals while the fine particles involve more easily grindable coal ranks.The test results were explained physically from the angle of the standard testing of grindability.It has been concluded that the grindability of a blended coal must be determined through tests.The pulverized coal fineness of a blended coal must be decided by a coal rank with a relatively low volatile content when it is 'mixed and diluted in front of the furnace' and a rational fineness for each coal component must be chosen when separate milling is adopted.For the mixed/diluted combustion of coal ranks with a relatively big difference in grindability,an optimization test was performed of three 'separate milling' mixed/diluted combustion modes in the light of specific features of the milling and combustion system.By controlling relatively well the pulverized coal finenesses of difficult-to-grind and difficult-to-burn-out coal ranks,the boiler efficiencies were invariably enhanced by more than 1.5% when compared with that in the traditional 'mixing/dilution in front of the furnace' combustion mode.
出处
《热能动力工程》
CAS
CSCD
北大核心
2010年第4期410-413,共4页
Journal of Engineering for Thermal Energy and Power
关键词
混煤
可磨性
粒径分布
燃尽特性
分磨制粉
blended coal,grandability,particle diameter distribution,burn-out characteristics,separate milling
