啤酒糟流化床气化中颗粒粒径对气固流动和产气影响的CPFD模拟  

Effects of particle sizes on gas-solid flow and gas production in fluidized-bed gasification of brewer’s spent grains based on CPFD simulations

作　　者：国洪帅 姜华伟 杨海瑞[2] 王翠苹 李延辉[1] GUO Hongshuai;JIANG Huawei;YANG Hairui;WANG Cuiping;LI Yanhui(College of Mechanical and Electrical Engineering,Qingdao University,Qingdao 266071,China;Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;College of Energy Storage Technology,Shandong University of Science and Technology,Qingdao266590,China)

机构地区：[1]青岛大学机电工程学院,山东青岛266071 [2]清华大学能源与动力工程系,北京海淀100084 [3]山东科技大学储能技术学院,山东青岛266590

出　　处：《煤炭学报》2024年第10期4177-4187,共11页Journal of China Coal Society

基　　金：国家重点研发计划资助项目(2023YFB4104301-3);青岛市创新生态营造专项国际科技合作计划资助项目(24-1-6-ghgg-9-hz)。

摘　　要：我国酿酒工业每年产生大量废弃啤酒糟,其具有挥发分含量高、硫含量低的特点,特别适合作为气化原料,而流化床气化炉以优异的气固混合和温度均匀性而著称,通过流化床气化实现啤酒糟的资源化和能源化利用具有重要意义。为探究啤酒糟流化床气化过程中颗粒粒径对气固流动行为和产气的影响,基于计算颗粒流体动力学(CPFD)方法,对以空气和水蒸气为气化剂的啤酒糟鼓泡流化床气化过程进行了数值模拟,研究了床料粒径和啤酒糟粒径的影响。通过CPFD数值模拟,获得了鼓泡流化床气化炉内颗粒体积分数分布、酒糟和床料的颗粒分布等流动特征,以及产气中主要气体组分的摩尔分数。借助鼓泡流化床气化实验装置,研究了床料粒径和啤酒糟粒径对产气中各气体组分体积分数的影响规律,并对数值模拟结果进行了验证。结果表明,床料粒径的增加不利于气化炉内的充分流态化和颗粒混合,使气化炉内温度沿高度的分布不均匀,并且不利于碳颗粒和水蒸气的充分混合以及气固反应和气相反应的均匀吸放热,造成H_(2)摩尔分数显著降低;啤酒糟粒径的适当增大有助于延长其在气化炉内的停留时间,从而提高固态碳与水蒸气、二氧化碳之间的反应转化率,生成更多的H_(2)和CO,但过大的啤酒糟粒径会造成啤酒糟和床料的混合较差,使啤酒糟比表面积减小,不利于热解和气化反应,导致H_(2)、CO、CH_(4)和NH_(3)等可燃组分的摩尔分数均降低。A large number of waste brewer’s spent grains(BSGs)have been produced every year in brewing industry of China,which have the advantages of high volatile matter content and low sulfur content,especially suitable for being utilized as gasification raw materials.Fluidized-bed gasifiers are famous for their excellent gas-solid mixing and temperature uniformity.Therefore,it is of great significance to realize the resource use and energy utilization of BSGs by fluidized-bed gasification.In order to investigate the effects of particle sizes on gas-solid flow behavior and gas production in the fluidized-bed gasification of BSGs,the numerical simulations of the gasification of BSGs in a bubbling fluidized-bed gasifier with air and water vapor as gasification agents were performed,based on computational particle fluid dynamics(CPFD)method.The effects of bed-materials particle sizes and BSGs particle sizes were both studied.The distribution of particle volume fraction,the particle distributions of BSGs and bed materials,and the mole fractions of main gas components were obtained by the CPFD numerical simulation.An experimental apparatus for bubbling fluidized-bed gasification was used to study the effects of bed-materials particle sizes and BSGs particle sizes on the volume fractions of main gas components in the product gas,which validated the numerical simulation results.The results showed that the increases of bed-materials particle sizes were not conductive to adequate fluidization and particle mixing,which made the temperature distribution uneven along the height.The increases of bed-materials particle sizes were also not conductive to the intensive mixing of carbon particles and water vapor,and the uniform heat absorption or heat release of gas-solid reaction and gas-phase reaction,resulting in a significant reduction of H_(2)mole fraction.The appropriate increases of BSGs particle sizes helped to prolong their residence time in the gasifier,thus improving the reaction conversion rate between solid carbon and water

关 键 词：流化床气化 啤酒糟 床料 计算颗粒流体动力学 颗粒粒径 

分 类 号：TK16[动力工程及工程热物理—热能工程]