玉米秆在流化床中燃烧特性的初步研究  

STUDY ON COMBUSTION IN A FLUIDIZED BED

作　　者：孙志翱[1] 金保升[1] 章名耀[1] 刘仁平[1] 张华钢[1] 

机构地区：[1]东南大学洁净煤发电及燃烧技术教育部重点实验室,南京210096

出　　处：《太阳能学报》2008年第12期1563-1568,共6页Acta Energiae Solaris Sinica

基　　金：国家重点基础研究发展(973)计划项目(2007CB210208)

摘　　要：对玉米秆与弱酸性床料的混合流化特性进行了研究,结果表明,长度为20～50mm 玉米秆与一定粒径分布的床料,当质量配比为1%,流化数 N=3～6时,能较均匀地混合流化,但 N>6后,混合的均匀度有所下降。根据热重试验结果可以看出玉米秆着火温度低,挥发份析出速度快,并容易燃尽。在0.2MW_(th)流化床试验台上研究发现,当 N>6时,玉米秆和床料分层严重,密相区温度在820℃以下,当 N=3～6时,密相区温度能达到设计要求,说明冷态试验结果能够指导热态运行,玉米秆流化床燃烧时流化风速不能太大。经过24h 热态试验后,床料没有出现烧结现象,利用 XRF 技术分析发现玉米秆灰中碱金属含量较高,高温对流受热面的沾灰可能性较大。The mixing and fluidizing characteristics of cornstalk and weak acidic bed material were studied. Experiments show that cornstalk with 20 - 50mm in length can mix well with bed material of certain particle-size distribution when mass ratio is 1 ： 1 and fluidization number N = 3 - 6. However, when N is more than 6, the mixing bed will have a little segregation. The thermo gravimetrie experiment result of cornstalk show that cornstalk can be ignited easily at the lower temperature and its devolatilization is prompt. The fluidized bed combustion of cornstalk was investigated in a 0.2MWth, test apparatus. According to the temperature distribution along the bed height, cornstalk can be burned stably in the dense bed at N = 3 - 6. However, cornstalk cannot be burned stably in the dense bed when N is more than 6 and the bed temperature is below 820℃. Weak acidic bed material didn＇t react with alkali metals from cornstalk ash after 24h combustion. The XRF analyses of component show that high alkali metals in cornstalk ash are potentially harmful to heated bed.

关 键 词：玉米秆 流化床燃烧 热重分析 燃烧特性 弱酸性床料 

分 类 号：TK6[动力工程及工程热物理—生物能]