摘要
在提升管直径为100mm、高为6000mm,立管直径为44mm、高为3000mm,热解室的截面积为200mm×200mm、高770mm的循环流化床煤燃烧/热解双反应器冷态实验装置上,考察了提升管中的表观气速、系统循环量以及加到热解室里的松动气量等因素对立管中的压力梯度、气固相对流动速度等的影响.在实验范围内,立管内的流动形式主要为气固并流下行移动床流动.随着表观气速的增加,立管中负压差梯度逐渐减小,最终基本保持不变;随着循环量的增大,立管内的负压差梯度及气固相对速度也随之增大;加到热解室内的松动气对立管内气固流动状态影响比较复杂,在提升管内表观气速及立管底部阀门开度一定的情况下,随着松动气量的增加,立管内会出现从负压差流动到正压差流动的转变.而在松动气量保持一定时,随着提升管内表观气速的增大,同样的情况也会出现.
The effects of superficial gas velocity in the riser, circulating rate, and aeration added to the pyrolysis chamber on the pressure gradient and slip velocity etc in standpipe are studied in the cold model of circulating fluidized bed combined with a pyrolysis reactor. The riser column is 100 mm in diameter, 6 000 mm in height. And the standpipe is 44 mm in diameter, 3 000 mm in height. The rectangular pyrolysis chamber with cone-shaped distributing plates lies between the cyclone dipleg and the standpipe, with a cross section of 200 mm × 200 mm and height of 770 mm. The flow pattern in the standpipe is moving bed flow in experiment. With the increase of superficial gas velocity in the riser, the negative pressure gradient in standpipe decreases gradually and keeps steady finally. The negative pressure gradient and slip velocity in standpipe increase with the increase of circulating rate. Effects of aeration added to pyrolysis chamber on the gas/solid flow state are complicated. With superficial gas velocity in the riser and valve orifice at the bottom of the standpipe kept invariable, the flow pattern in the standpipe changes from negative pressure difference to positive pressure difference as the aeration increases. The same phenomenon will appear when the aeration is kept at 5 m^3/h and superficial gas velocity increases.
出处
《燃烧科学与技术》
EI
CAS
CSCD
北大核心
2005年第5期443-447,共5页
Journal of Combustion Science and Technology
基金
广东坪石电厂有限公司资助项目
淮南市科技计划资助项目.
关键词
循环流化床
热解
立管
压力梯度
相对速度
circulating fluidized bed
pyrolysis
standpipe
pressure gradient
slip velocity
