石灰立窑代焦型煤燃烧特性的实验研究  

Experimental Study of the Combustion Characteristics of Briquette as a Substitute for Coke in a Vertical Lime Kiln

作　　者：彭好义[1] 刘艳军[1] 周孑民[1] 

机构地区：[1]中南大学能源科学与工程学院,湖南长沙410083

出　　处：《热能动力工程》2010年第1期82-86,共5页Journal of Engineering for Thermal Energy and Power

基　　金：湖南省科技厅科技创新环境建设重大基金资助项目(2007CK3070)

摘　　要：在SDTQ600差热-热重联用仪上对石灰立窑代焦型煤试样进行了热重分析,研究了不同升温速率对其燃烧特性的影响,并以5℃/min的升温速率将型煤、焦炭和无烟煤块煤试样进行对比。利用马弗炉研究了单颗粒代焦型煤的燃烧速率。结果表明,代焦型煤的燃烧过程经历了干燥预热、挥发份析出、碳粒燃烧和残碳燃尽4个阶段;随着升温速率的增加,代焦型煤燃烧各阶段的反应时间缩短,反应速率加快;当升温速率由5℃/min提高至10和15℃/min时,代焦型煤的着火时间由28.12min下降至14.01和10.13min,其燃尽时间也由36.82min下降至27.59和22.47min。通过对比,型煤在着火、稳燃性能及综合燃烧特性方面最好,而燃尽性能居中;代焦型煤、焦炭与无烟煤块煤3种试样的综合燃烧指数分别为53.25×10-9、30.14×10-9和11.53×10-9。燃烧温度对型煤燃烧速率影响较小,而型煤尺寸对后期燃烧速率影响较明显,减小型煤尺寸可增大燃烧速率;相同条件下,代焦型煤的燃烧速率低于焦炭而高于无烟煤块煤。实验结果可为石灰立窑型煤代焦提供指导。On a SDTQ600 type temperature-difference-thermogravimetric combined analyzer,a thermogravimetric analysis was performed of the briquette sample,which substituted the coke in a vertical lime kiln,and the influence of the different temperature rising speeds on its combustion characteristics was studied. In the meantime,the briquette,coke and anthracite block coal sample were compared with each other at a temperature rising speed of 5 ℃/min. The combustion rate of a single particle of the briquette was investigated by employing a muffle furnace. It has been found that the briquette coal combustion process experiences four stages,i.e. drying and preheating,volatile element precipitation,carbon particle combustion and carbon residue burn-out. With an increase of the temperature rising speed,the reaction time required by various combustion stages of the briquette was shortened and the reaction rate was speeded up. When the temperature rising speed increases from 5 ℃/min to 10 ℃/min and 15 ℃/min,the briquette ignition time will be shortened from 28.12 min to 14.01 min and 10.13 min while the burn-out time will also be reduced from 36.82 min to 27.59 min and 22.47 min. Through a contrast,the briquette is the best in terms of the ignition,stable combustion performance and comprehensive combustion characteristics while the burn-out performance ranks at the middle place. The comprehensive combustion indexes of briquette,coke and anthracite block coal representing three kinds of sample are 53.25×10-9,30.14×10-9 and 11.53×10-9 respectively. The combustion temperature exercises a relatively small influence on the combustion speed of the briquette while the briquette size has a relatively conspicuous impact on the combustion speed at the later stage. To reduce the size of the briquette can increase its combustion speed. Under the same conditions,the combustion speed of the briquette is lower than that of coke but higher than that of anthracite block coal. The test results can offer guidance for the briquette as a sub

关 键 词：代焦型煤 燃烧特性 热重分析 燃烧速率 石灰立窑 

分 类 号：TQ054[化学工程] TQ534