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题名	气固流态化非均匀结构的动态行为
作者	崔和平
学位类别	博士
答辩日期	1998-12-02
授予单位	中国科学院研究生院
导师	李静海
关键词	流态化 非均匀结构 动态行为 动态模拟
其他题名	Dynamic Behaviors of Heterogeneous Flow Structure in Gas-Solid Fluidization
学位专业	流态化
中文摘要	采用多元分解和时间序列重构的方法，分析了气固流态化非均匀结构的动态行为。首先在循环流化床（FCC/air）上进行了系列实验，采用光纤探头测量了局部颗粒浓度，提出一种确定最佳采样频率的方法。然后根据动态行为多元分解思想，发展了动态信号多元分解方法，将复杂的动态行为分解成一个周期的规则成分和三类非规则波动（微尺度波动、幅度非规则波动和时间非规则波动）成分；分析表明：三类非规则波动成分呈随机性，随操作条件变化，其概率分布均复杂演变；采用 Weibull分布描述了微尺度和幅度非规则波动，与应用数学所合作发展了 7参数复合Weibull分布函数，用它描述了时间非规则波动。最后，建立了非线性动态模型，实现了对非均匀结构动态行为的定量描述和模拟；并将以上方法总结为一个用户友好软件包。
英文摘要	This paper is devoted to establishing a method to quantitatively describe nonlinear dynamic behavior of heterogeneous flow structure in gas-solid fluidization by carrying out multiple resolution and time series reconstruction. Qualitative analysis indicated that dynamic behaviors are dominated not only by deterministic mechanism but also by random mechanism, which play different roles on different scales and under different operating conditions. Experiments were carried out in a Circulating Fluidized Beds of 90 mm in diameter and 10 m in height. Local instantaneous particle volume concentration was measured with an optic fiber probe placed successively at different radial positions of the bottom dense section. Operating conditions cover the whole regime spectrum of fluidization from bubbling to dilute transport regime. Optimum sampling frequency was specified by analyzing the dependence of Kolmogorov entropy of time series on sampling frequencies. Multiple resolution of dynamic behaviors of heterogeneous structure (Li et al., 1998) was performed, including scale resolution of flow structure into three scales of components, amplitude resolution of meso-scale dominant component into extremum behavior with irregular occurrence time and irregular changes of amplitude of the dilute phase and the dense phase, and time resolution of the extremum meso-signals into periodic structure and irregular change of its phase alteration. Dynamic behaviors were therefore resolved into a periodic regular component and three irregular components. Statistic analysis indicated that three kinds of irregular components show complicated random characteristics, and their probability density distributions change with increasing gas velocity, that is, irregular occurrence time fluctuations of all three kinds of elements of heterogeneous structure (the dilute phase, the dense phase and the dilute/dense cycle elements) evolve similarly from symmetric distribution similar to Gauss distribution at low gas velocities to double-peak distribution at medium gas velocities, and become dissymmetric single-peak distribution at high gas velocities. The irregular fluctuations of heterogeneous structure with the single-peak distribution can be described by the Weibull distribution. For reasonable description of the double-peak distribution, a new distribution function called Compound Weibull distribution with 7 parameters was developed in cooperation with Institute of Applied Mathematics, which was used to describe irregular fluctuations of phase alternation. Finally, a nonlinear dynamic model was developed to simulate dynamic behaviors of heterogeneous structure in gas-solid fluidization, which could be formulated by integrating the regular component and all three kinds of the irregular components. Such a model was then programmed into a software packet with a user-friendly interface.
语种	中文
公开日期	2013-09-27
页码	144
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/2021]
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	崔和平. 气固流态化非均匀结构的动态行为[D]. 中国科学院研究生院. 1998.

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