计算流体国学在精馏塔板上的应用

本文对计算机流体力学（CFD）在精馏塔板上的应用进综述。介绍了计算流体力学对塔板流场的模拟,数值解法,实验研究及对塔板传质过程的理论研究。同时给出了典型数学模型的主要计算结果,并对以后的研究工作给出了建议。     

用MicrosoftExcel计算精馏塔理论塔板数

用Ｍｉｃｒｏｓｏｆｔ Ｅｘｃｅｌ（微软电子表格）的函数和图表功能,通过实例介绍了精馏塔理论塔板数的２种计算方法,较手工计算法快捷、方便、准确,便于应用。     

精馏塔塔板数计算一例

在仲丁胺常压催化生产过程小试的基础上作了中试规模的设计,鉴于数据的不全,笔者作了简捷处理,投运后证明是可行的。文章对氨以及2—丁醇对精馏的影响;塔的计算等问题予以了论述。     

基于Excel的精馏塔理论塔板数的图解法

本文介绍了用Excel图解法求精馏塔理论板数的方法,采用Excel电子表格作为输入输出界面,用VBA程序进行理论塔板数的计算,计算结果以表格和图形的方式表示。该方法可以快速计算出理论塔板数、加料板位置及每一块理论塔板上的气液组成。通过实例证明该方法较为准确并且简单实用。     

气液隔离相变全效塔板与小板距精馏塔

介绍了一项关于精馏塔板的最新发明专利。该发明抛开目前的气液两相在直接接触的传热中进行的实际上无法达到平衡的传质方式,使气液两相的传热过程在彼此隔离的情况下进行。每层塔板由两块无板孔的薄板组成,凭借间接传热在一层塔板上完成一次平衡蒸馏和一次平衡分凝:蒸馏残液流到下一层塔板,蒸馏产生的蒸气被分凝,凝液留在本层板继续蒸馏,分凝剩余则蒸气上升。汽、液的运动靠塔内3种不同的通道实现,该发明具有如下创新点:具有板效率高、板间距小、没有雾沫夹带。全效塔板的优势在于热力学上是在平衡状态下进行精馏;不足之处就在于动力学方面传热速率慢,弥补的方法是延长传热时间:现有塔板气相垂直穿过液相显然很快,新塔板气液两相水平逆向流动接触时间由塔径决定,大为延长。     

利用计算流体力学方法研究精馏塔板上的液相流动

A computational fluid-dynamics model is presented for predicting the two-phase two-dimensional liquid phase flow on a distillation column tray based on the modification of Navier-Stokes Equation by considering both the resistance and the enhanced turbulence created by the uprising vapor. Experimental measurement of the local liquid phase velocity on an air-water simulator of 1.2 m in divaneter by using the hot film anemometer is briefly described. Two of the conventional fluid-dynamic constants are readjusted for the case of liquid flow on a tray byfitting the experimental data. The predicted local liquid phase velocity and direction of flow by the present model are confirmed satisfactorily by the authors‘ experimental measurements and by the data from literature. By the aid of the present model, the concentration field on the tray can be computed for the evaluation of the enhancement of liquid phase concentration across a tray. The advantages of applying computational fluid-dynamics to tray column design are discussed.     

丁二烯萃了精馏塔的流体力学计算

本文考虑了二烯萃取塔真实汽，液相负荷分布和塔板结构，完成了流体力学核算，对实际操作具有一定的指导意义。     

计算流体力学在精馏塔板上的应用

本文对计算流体力学 (CFD)在精馏塔板上的应用进行了综述。介绍了计算流体力学对塔板流场的模拟 ,数值解法、实验研究及对塔板传质过程的理论研究。同时给出了典型数学模型的主要计算结果 ,并对以后的研究工作给出了建议     

二元系精馏塔理论塔板数的逐板计算与简捷计算新方法

本文对二元系精馏塔理论塔板数提出了新的逐板计算与简捷计算新方法。修正了M_0—T_0经典的精馏理论中的错误。     

精馏塔加料位置的实验研究

论述了操作型精镏镏塔加料板位置与产品浓度（Ｘｄ）之间的联系。不能用下降进料口位置的方法去提高产品浓度Ｘｄ。     

精馏塔板液相流场三维模拟

The liquid flow on a single-pass sieve distillation tray is simulated with a three-dimensionM computational fluid dynamics (CFD) program with the K-e turbulence model. In the model, a source term SMi is formulated in the Navier-Stokes equations to represent the interfacial momentum transfer and another term Sc is added to the mass transfer equation as the source of interfacial mass transfer. The simulation provides the detailed information of the three-dimensionM distribution of liquid velocity on the tray, the circulation area and the concentration profile along the height of liquid layer.     

Three Dimensional Simulation of Liquid Flow on Distillation Tray

The liquid flow on a single-pass sieve distillation tray is simulated with a three-dimensional computational fluid dynamics (CFD) program with the K-ε turbulence model. In the model, a source term SMi is formulated in the Navier-Stokes equations to represent the interfacial momentum transfer and another term SC is added to the mass transfer equation as the source of interfacial mass transfer. The simulation provides the detailed information of the three-dimensional distribution of liquid velocity on the tray, the circulation area and the concentration profile along the height of liquid layer.     

组合导向浮阀塔板多相流的数值模拟

为了深入了解组合导向浮阀塔板的流体力学性能,在阀片全开状态下,利用计算流体力学(CFD)方法对700 mm中试规模的组合导向浮阀塔塔板上的气液两相三维流场进行模拟研究,采用欧拉-欧拉非稳态模型(Eulerian),考虑气液两相间的动量传递现象,将清液层高度作为衡量非稳态流场收敛的判别标准。通过关联实验数据,得出适合组合导向浮阀塔板的清液层高度关系式,并与模拟结果进行对比。模拟结果表明,组合导向浮阀塔板的液面梯度和弓形区域回流面积小,具有良好的流体力学性能。     

Computational Fluid-dynamics of Liquid Phase Flow on Distillation Column Trays

A computational fluid-dynamics model is presented for predicting the two-phase two-dimensional liquid phase flow on a distillation column tray based on the modification of Navier-Stokes Equation by considering both the resistance and the enhanced turbulence created by the uprising vapor. Experimental measurement of the local liquid phase velocity on an air-water simulator of 1.2m in diameter by using the hot film anemometer is briefly described. Two of the conventional fluid-dynamic constants are readjusted for the case of liquid flow on a tray by fitting the experimental data. The predicted local liquid phase velocity and direction of flow by the present model are confirmed satisfactorily by the authors' experimental measurements and by the data from literature. By the aid of the present model, the concentration field on the tray can be computed for the evaluation of the enhancement of liquid phase concentration across a tray. The advantages of applying computational fluid-dynamics to tray column design     

The Mai-distribution of Weeping from a Distillation Tray and Its Effect on Tray Efficiency

Experiments demonstrated that the weeping is mal-distributed and occurs mainly in a region of tray deck next to the inlet weir. The amount of weeping in this region depends on the weeping rate. On this basis, three types of weeping distribution are proposed. The effect of mal-distributed weeping on the Murphree tray efficiency is evaluated by using the three-dimensional non-equilibrium mixing pool model, where the influences of the flow pattern and the variation of Murphree point efficiency on a tray are taken into account. The calculated results reveal that the extent of Murphree tray efficiency drop depends chiefly on the degree of mal-distribution and the percentage of weeping. It is also demonstrated that in the determination of the lowest operating limit of vapor velocity, the unfavorable effect of mal-distributed weeping should be considered as an important factor and cannot be ignored.     

塔板不均匀漏液的规律及对板效率的影响

Experiments demonstrated that the weeping is mal-distributed and occurs mainly in a region of tray deck next to the inlet weir. The amount of weeping in this region depends on the weeping rate. On this basis, three types of weeping distribution are proposed. The effect of real-distributed weeping on the Murphree tray efficiency is evaluated by using the three-dimensional non-equilibrium mixing pool model, where the influences of the flow pattern and the variation of Murphree point efficiency on a tray are taken into account. The calculated results reveal that the extent of Murphree tray efficiency drop depends chiefly on the degree of mal-distribution and the percentage of weeping. It is also demonstrated that in the determination of the lowest operating limit of vapor velocity, the unfavorable effect of real-distributed weeping should be considered as an important factor and cannot be ignored.     

利用计算流体力学及计算传质的方法研究精馏塔传质效率

It has long been found that the flow pattern of the liquid phase on distillation tray is of great importance on distillation process performance. But until now, there was very few published work on quantitative investigation of this subject. By combining the computational fluid dynamics (CFD) with the mass transfer equation, a theoretical model is proposed for predicting the details of velocity and concentration distributions as well as the tray efficiency of distillation tray column. Using the proposed model, four different cases corresponding to different assumptions of liquid and vapor flowing condition for a distillation tray column were investigated. In Case I, the distributions of velocity and concentration of the incoming liquid from the downcomer and the uprising vapor from the underneath tray spacing are uniform. In Case Ⅱ, the distribution of the incoming liquid is non-uniform but the uprising vapor is uniform. In Case Ⅲ, the distribution of the incoming liquid is uniform but the uprising vapor is non-uniform.In Case IV, the distributions of both the incoming liquid and the uprising vapor are non-uniform. The details of velocity and concentration distributions on a multiple sieve tray distillation column in four different cases were simulated using the proposed model. It is found that the shape of the simulated concentration profiles of vapor and the liquid is quite different from case to case. The computed results also show that the tray efficiency is highly reduced by the maldistribution of velocity and concentration of the incoming liquid and uprising vapor. The tray efficiency for Case Ⅰ is higher than Case Ⅱ or Case Ⅲ, and that for Case Ⅳis the lowest. It also reveals that the accumulated effect of maldistribution becomes more pronounced when the number of column trays increased. The present study demonstrates that the use of computational method to predict the mass transfer efficiency for the tray column, especially for the large one, is feasible.     

多种塔板组合的板式塔改造技术

介绍综合板式塔技术在重油加氢ＳＳＯＴ装置分馏塔技术改造中的应用,特别是其中采用作者开发的导向梯形浮阀塔板是首次应用于工业装置中,取得了成功。生产实践表明,导向梯形浮阀塔板具有优良的性能,同时应用多种塔板组合的综合板式塔技术,可适应于各种不同的操作工况,值得在板式塔设计和技术改造中推广应用