垂直气固并流上行/下行系统完全发展段的混沌研究  

CHAOTIC CHARACTERISTICS OF COCURRENT UPFLOW AND DOWNFLOW GAS／SOLIDS SYSTEMS IN DEVELOPED REGIME OF VERTICAL PIPES

作　　者：程易[1] 魏飞[1] 林仟 金涌[1] 俞芷青[1] 

机构地区：[1]清华大学化工系,北京100084

出　　处：《化工学报》1998年第2期185-185,共1页CIESC Journal

基　　金：国家自然科学基金!No.29290500;石化总公司基础研究基金

摘　　要：针对垂直气固并流上行（提升管）／下行系统（下行床）的完全发展段，使用光纤密度探头测得反映系统局部密度涨落信息的时间序列，利用确定性混沌理论进行分析，获得表征系统自由度的关联维数（D_（ml））和反映系统信息丢失速率的Kolmogorov熵（K_（ml）），并对上行和下行系统做比较研究．研究发现反映局部瞬态行为特征的D_（ml）和K_ml在上行和下行系统中一定的操作条件下具有大致相同的数值，且混沌参数与局部固含率表现出对应关系．同时局部混饨参数的径向分布对应于上行和下行系统存在的典型的径向流动结构．This paper aimed to study the developed cocurrent upflow and downflow gas／solids systems in vertical pipes using deterministic chaos theory.Fluctuation signals which reflect the density pulsation in systems were obtained by an optical fiber density probe.The effects of gas velocity and solids flux were investigated and the differences of local chaos characteristics between upflow and downflow systems were compared.The result shows that chaos parameters can be used to describe the radial structure of gas／solids wto phase flow in the fully developed regime of vertical pipes.The local D_(ml) and K_(ml) are in the same range of magnitude in both riser and downer and are strongly correlated with the local solids fraction,which implies that the solids fraction is a key factor of influencing the turbulent structure in twophase flow systems and must be considered carefully in modeling the riser and downer.

关 键 词：提升管 下行床 发展段 混沌分析 气固流动 

分 类 号：TQ022.4[化学工程]