循环流化床生物质气化炉内计算流体动力学模拟——鼓泡流化床内改进的颗粒床模型(英文)  

CFD simulation in a circulating fluidized-bed biomass gasifier ——A modified particle bed model in bubbling fluidized beds

作　　者：张锴[1,2] BRANDANI Stefano 

机构地区：[1]伦敦大学学院(UCL)化工系CO_2技术中心 [2]石油大学(北京)化工学院重质油国家重点实验室,北京昌平102249

出　　处：《燃料化学学报》2005年第1期1-5,共5页Journal of Fuel Chemistry and Technology

基　　金：欧盟第五框架协议 (ENK5-CT2000-00314);国家自然科学基金 (20476057)。~~

摘　　要：采用改进颗粒床模型的CFD方法模拟了实验室规模冷模装置内鼓泡床的流体流动时空特性。模拟结果表明表观气速是影响气固动态特征和压力波动的主要因素之一:随表观气速的增大,气泡数目增加,气泡体积增大,压力波动增强;气速越高时均压降越大;在内循环鼓泡流化床内固体颗粒呈“单室”流型。上述与实验观察相吻合的模拟结果将有助于放大和设计商业化的内循环流化床生物质气化炉。The circulating fluidized-bed gasification is a potential industrial technology for high efficient utilization of biomass in middle- and large-scaled power stations. A fast internally circulating fluidized-bed steam gasification technology has developed to obtain a high-grade synthesis gas without using pure O_2. Some demonstration and/or commercial plants supported by European Union and its members are in underway. Computational fluid dynamics (CFD), an alternative method to the step-by-step experimental scale-up, is employed to simulate a laboratory-sized cold set-up in this paper. A modified particle-bed model has been attempted to investigate the fluid dynamic stability of gas-solid system in the bubbling fluidized bed. Superficial gas velocity is one of vital factors to influence the dynamic flow behaviour and pressure fluctuation. The bubble number and the size of the bubble increase with an increase of superficial gas velocity. Pressure fluctuation becomes higher with increasing inlet gas velocity. The higher gas velocity is and the greater time-averaged pressure drop is. Solid circulation is a single-cell pattern in the fast internally circulating fluidized bed. These results appear in good agreement with the experiments, which will be helpful for scaling up and designing the fast internally circulating fluidized-bed biomass gasifier.

关 键 词：循环流化床生物质气化炉 鼓泡床 计算流体动力学(CFD)模拟 改进的颗粒床模型 

分 类 号：TQ052.71[化学工程]