基于Winpak的模块化催化规整填料

发布时间：2018-02-23 02:51

本文关键词： 催化精馏计算流体力学模块化催化规整填料平均停留时间分布　出处：《天津大学》2015年博士论文　论文类型：学位论文

【摘要】：本文开发了一种基于Winpak#174;的新型模块化催化规整填料Winpak-C,并采用理论模拟与实验验证相结合的方法对其进行了系统地研究,包括基础数据的测定、填料结构的优化、流动与传质机理的探究等。最终利用研究成果指导工业生产,成功实现了Winpak-C在多个工业生产过程中的应用,显著提高了催化精馏塔的效率。本文第二部分先对Winpak-C-500X-2-2、Winpak-C-250X-3-2和催化剂捆包这三种填料进行对比,测试了其直径、盘高、比表面积、空隙率、装填系数、干塔压降、湿塔压降、静持液量、动持液量、载点气速等参数。通过这些参数,提出了基于填料物理性质的湿塔压降修正模型,与实验结果相比符合程度较好。此外,还使用了文献中的模型对持液量进行拟合,与经验公式拟合值相比,模型的普适性更高,而经验公式的精度更高。本文第三部分对Winpak-C的干塔压降进行优化,借助Solidworks、Gambit、Fluent、Tecplot 360等一系列前中后处理软件,将Winpak-C的压降分为六种贡献机理。通过分析相邻填料盘之间的气速和气体流形,将下层填料盘的反应元件高度降低,为气体提供过渡区域,使气体流线变得比较平缓。将所提出的压降贡献模型以及优化方案进行实验验证,符合程度较好。在进行湿塔压降实验和其他物系模拟时,也得到比较理想的结果。此外,对优化前后的阻力损失系数与反应元件降低高度进行拟合,得到了总阻力损失系数与雷诺数、填料盘高、反应元件降低高度的关联式。也讨论了实际工程应用时,降低高度、压降减少与固定投资、操作费用的选择问题。本文第四部分是关于第二部分中三种填料的平均停留时间分布实验,通过脉冲法示踪、电导仪记录的方法,对三种填料的RTD进行研究。从平均停留时间、无因次方差、偏度等方面评价三者,并比较了重力排水法和RTD计算法两种方法所得的持液量。根据RTD曲线以及轴向扩散模型,计算出三种填料的Peclet数与轴向扩散系数。本文第五部分比较了六种反应元件的轴向扩散与径向扩散能力,通过设计一套实验装置,借助电导仪对示踪剂进行记录,得到了一系列RTD曲线。从这些曲线中计算出这六种反应元件的平均停留时间、无因次方差、偏度、轴向扩散系数与径向扩散系数,同时对它们进行评价。
[Abstract]:In this paper, a novel modular catalytic regularization filler Winpak-C- based on Winpak #174; is developed, and the method of theoretical simulation and experimental verification is used to study it systematically, including the determination of basic data, the optimization of packing structure. Research on the mechanism of flow and mass transfer, etc. Finally, the application of Winpak-C in many industrial processes has been successfully realized by using the research results to guide industrial production. In the second part of this paper, we compare Winpak-C-500X-2-2n Winpak-C-250X-3-2 with catalyst bundles, and measure its diameter, plate height, specific surface area, porosity, filling coefficient, dry column pressure drop and wet column pressure drop. The parameters of static liquid holdup, moving liquid holdup and gas velocity of carrier point are discussed. Based on these parameters, a modified model of wet tower pressure drop based on the physical properties of packing is proposed, which is in good agreement with the experimental results. The model in literature is also used to fit the liquid holdup. Compared with the fitting value of empirical formula, the model has higher universality and higher precision. The third part of this paper optimizes the pressure drop of dry tower of Winpak-C. The pressure drop of Winpak-C is divided into six contributing mechanisms by means of a series of pre-and post-processing software such as SolidworksGambitt Fluent.Through analyzing the gas velocity and gas manifold between adjacent packing plates, the reaction element height of the lower packing plate is reduced to provide a transition region for the gas. The proposed contribution model of pressure drop and the optimized scheme are verified by experiments, which are in good agreement with each other. The results are also satisfactory when the wet column pressure drop experiment is carried out and other material systems are simulated. By fitting the coefficient of resistance loss before and after optimization with the height of reaction element, the correlation between the coefficient of total resistance loss and Reynolds number, the height of packing plate and the height of reaction element is obtained. Reduction of pressure drop, fixed investment and selection of operating expenses. Part 4th is about the experiment of average residence time distribution of three kinds of fillers in the second part, which is recorded by pulse tracer and conductance meter. The RTD of three fillers was studied. The average residence time, dimensionless variance and deviation were evaluated. The liquid holdup obtained by gravity drainage method and RTD calculation method was compared. According to the RTD curve and the axial diffusion model, The Peclet number and axial diffusion coefficient of three kinds of fillers are calculated. The axial and radial diffusivity of six kinds of reaction elements are compared in the 5th part of this paper. By designing a set of experimental device, the tracer can be recorded by means of conductance meter. A series of RTD curves are obtained from which the mean residence time dimensionless variance deviation axial diffusion coefficient and radial diffusion coefficient of the six kinds of reaction elements are calculated and evaluated.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ050.45

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