双级料腿循环流化床流动特性及HCl脱除机理的研究
文献类型：学位论文
| 作者 | 曲丰作 |
| 学位类别 | 硕士 |
| 答辩日期 | 2003 |
| 授予单位 | 中国科学院过程工程研究所 |
| 授予地点 | 中国科学院过程工程研究所 |
| 导师 | 林伟刚 |
| 关键词 | 垃圾焚烧 干式净化 气-固反应 动力学模型 流化床 |
| 其他题名 | Investigation on Flow Pattern of Double-dipleg CFB and De-chlorine Mechanisms |
| 学位专业 | 化学工艺 |
| 中文摘要 | 该文重点对双级料腿循环流化床的流动特性和就地脱氯的机理进行了研究.在冷态实验装置上对燃烧室流化风速、第一、二级循环料腿流化风速、脱氯床层高度变化对双级料腿循环流化床垃圾焚烧炉颗粒循环流率以及系统压力平衡的影响进行了研究.实验结果表明,新型双级料腿循环流化床的压力平衡分布主要依靠第二级循环料腿中物料的停留量来维持;循环流率随着燃烧室流化风速的升高而增加;回料腿流化风速的增加,在一定范围内可以增大循环流率;双级料腿循环流化床内存在两路的压力平衡分布:一路为系统整体压力平衡,另一路为系统局部气相的压力平衡,主要为二级回料腿内的压力平衡.根据压力平衡分布,得到了最大脱氯床阻力的计算公式,从而为双级料腿循环流化床垃圾焚烧炉提供了重要的设计参数. |
| 英文摘要 | A new concept of double-dipleg circulating fluidized bed incinerator has been proposed by the Institute of Process Engineering, Chinese Academy of Sciences in order to solve some major problems during combustion of municipal solid wastes (MSWs). Based on stage conversion, capture of chlorine in situs can be realized, which may solve the coupling of HCl-induced corrosion and emission of dioxins. This work is focused on the flow pattern of the new type of CFB and the de-chlorine mechanisms for better understanding of the double-dipleg CFB (DDCFB). In order to obtain the knowledge of the fluid dynamics of DDCFB, experiments were carried out in a lab-scale multi-dipleg circulating fluidized bed. The experimental results indicated that the pressure distribution in the DDCFB is dependent on the solid inventory in the secondary dipleg; The recirculating rate of solids increases with the increasing of gas velocity in the combustor; The pressure drop over the bed for HCI removal affects the pressure distribution, but does not influence the recirculating rate of solids. Based on the pressure distribution, the maximum allowable pressure over the de-HCl bed is derived, which is one of the important parameters for design of the DDCFB. The kinetics of the capture of HCI by CaO was studied in a fixed-bed reactor. The effect of temperature, HCI inlet concentration , particle size of CaO powders, water vapour concentration, CO2 concentration and SO2 concentration on conversion of CaO to CaCb were examined experimentally. The results showed that the controlling mechanisms of HCI capture by CaO changed with the reaction proceeded. It was found that the reaction was controlled by chemical reaction at the initial stage. After that, the reaction was controlled by both of the chemical reaction and the product layer diffusion. The controlling mechanism shifted to the product layer diffusion with the CaO conversion increased. The optimized temperature was found to be around 873K. The higher the inlet concentration was, the higher the CaO conversion reached. The conversion of CaO decreased with the increasing of particle size. A high concentration of water vapour resulted in a high conversion of CaO. The conversion of CaO decreased with the increase of CO2 concentration. The conversion of CaO to CaCb increased slightly with the presence of SO2, and the total conversion of CaO increased significantly. A kinetic model for the capture of HCl by CaO was proposed by use of the unreacted shrinking core model. Based on the model and experimental results, the activation energy of reaction between CaO and HCl was determined to be 14.02KJ/mol; and the activation energy of product layer diffusion was 27.32KJ/mol. |
| 语种 | 中文 |
| 公开日期 | 2013-09-16 |
| 页码 | 73 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1367]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 曲丰作. 双级料腿循环流化床流动特性及HCl脱除机理的研究[D]. 中国科学院过程工程研究所. 中国科学院过程工程研究所. 2003. |
入库方式： OAI收割
来源：过程工程研究所
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