油水旋流分离器研究方法分析

从流动机理模型理论和计算流体动力学(CFD)模拟等方面综述了油水旋流分离器的研究进展状况.应用计算流体力学软FLUENT得到模拟结论,建立模型时运用RSM湍流模型和基于欧拉法的MIXTUER两相流模型.数值模拟得到的结论对油水旋流分离器的设计具有指导意义,为进一步研究油水旋流分离性能提供了参考依据,并且通过对用于油水旋...     

脱气除油旋流系统流场分布及分离特性

目前我国大部分油田已进入高含水阶段，且采出液中常带有大量伴生气，采用旋流分离法实现采出液高效分离对于简化陆上油田地面处理工艺及提升海上平台经济环保的采出液处理技术具有重要意义。脱气除油旋流系统由GLCC型气液分离器和油滴重构旋流器串联组成，设计的目的是在保证高效脱气的同时进一步改善对小油滴的去除效果，实现油气水三相高效分离。本文基于计算流体动力学（computational fluid dynamics，CFD）方法，利用种群平衡模型（population balance model，PBM）模拟油滴破碎与聚结，对脱气除油旋流系统内部流场特性及粒度分布进行模拟分析，并采用数值模拟与试验相结合的研究方法，对比分析不同含气体积分数和气相出口分流比对脱气除油旋流系统分离性能的影响规律。结果表明：含气体积分数与气相出口分流比对脱气除油旋流系统分离效率的交互作用较显著，在研究范围内综合脱气效率和除油效率可以得到，含气10%、20%、30%的最佳分流比分别为25%、30%、35%，数值模拟结果与试验结果吻合良好，验证了数值模拟方法的可靠性。另外，含气体积分数越大，油滴重构旋流器的油滴分层重构现象越明显，油滴重构旋流器可以在一定程度上改善含气情况下油水分离效果差的现象，脱气除油旋流系统对油气水三相分离的适用性较好。     

纯化天然气水合物螺旋分离器流场与性能分析

基于海洋天然气水合物固态流化开采方法的井下原位除砂提纯回填工艺,本文结合试采所得水合物浆体特征,设计用于解决设备磨损、储层坍塌等问题的井下除砂螺旋分离器,利用CFD数值模拟方法研究了入口速度和水合物体饱和度对井下除砂螺旋分离器流场和性能的影响,得到了随着入口速度增加,流场中流体的速度急剧增大,特别是切向速度、分离效率增加。当分离效率为70%以上,分离器内压降急剧增大,表明分离器内部的能量损耗不断增加;随着入口水合物体积分数的增加,螺旋分离器内流场变化微小,水合物分离效率降低,砂分离效率增加;分离效率为80%以上,压降逐渐降低。说明该分离器的最佳操作区为入口速度范围为3～5m/s,水合物入口体积分数15%以下。研究结果表明：本螺旋分离器具有极佳的除砂效果;切向速度是决定分离器分离性能的关键速度,处理量的增大有利于水合物的提纯;海底水合物储层中水合物饱和度变化对螺旋分离器分离效率具有一定的影响,但螺旋分离器对其具有一定的适应能力;揭示了水合物井下螺旋分离器除砂的分离机理,为其设计提供了一定的依据,为海洋水合物储层开采防砂提了一种新的技术及装备。     

CFD simulation of chemical reaction between sulfur dioxide and water in a venturi scrubber

ABSTRACT

The use of fossil fuel, i.e., coal, was first initiated in 1880s for electricity generation. It was used extensively worldwide due to its cheap rate. Consequently, there is an adverse effect on the environment that results in a climate change. Many industries were working on cleaning flue gases emitted from coal power plants according to Environmental Protection Agency (EPA) standards by using different scrubbing technologies and venturi scrubber is one of them having ability to remove particulates and toxic gases simultaneously. Industries were using computational fluid dynamics (CFD) techniques to fully understand the gases behavior inside scrubbing technologies prior employed in the project. This research represents CFD simulation to study abatement process of sulfur dioxide through chemical reaction with water in a venturi scrubber. Parameters such as mass concentration of sulfurous acid formation, sulfur dioxide and water mass content distribution inside venturi scrubber were analyzed. The sulfur dioxide removal efficiency was also investigated. The results show that water mass content distribution was greatly influenced by sulfur dioxide mass flow rates. Desulfurization efficiency depreciates with an increase in sulfur dioxide mass flow rate, whereas efficiency increases with accession in liquid to gas ratio. Maximum sulfur dioxide removal was observed at lower sulfur dioxide concentration comparatively to higher concentration of sulfur dioxide.     

丙烯腈装置气液分离器的出口结构

气液分离器是丙烯腈生产装置的关键设备之一,用于除去气体产品中的酸雾. 分离器的出口结构是影响分离效率的关键因素之一. 本研究借助通用流体分析软件PHOENICS对气液分离器内流场进行了分析,结果发现,增大液滴向器壁运动机会和减弱二次夹带效应均有利于提高分离效率. 基于此原则,对气体出口结构进行了优化实验,并提出了最佳的分离器双层套筒出口结构. 这种结构与其他几种结构相比除雾效果更佳,不管在低空速还是高空速下都能保持较高的除雾效率,操作弹性较好. 工业应用也表明,采用双层套筒出口结构的气液分离器具有较高的除酸雾效果,优于原分离器.     

Design Criteria for Oilfield Separators Improved by Computational Fluid Dynamics

Oilfield separator data ranging from light‐oil conditions to heavy‐oil conditions were incorporated into suitable two‐phase and three‐phase computational fluid dynamics (CFD) models to provide improved design criteria for separator design methods. The CFD simulation results revealed that the most important affecting parameters are vapor density and oil viscosity. In contrast with the classic design methods, noticeable residence times were required for liquid droplets to penetrate through the fluid interfaces. Moreover, it was indicated that the Abraham equation should be used instead of the Stokes' law in the liquid‐liquid separation calculations. The velocity constraints caused by re‐entrainment in horizontal separators were also studied and led to novel correlations.     

Performance evaluation of a bubble generator and a bubble separator designed for the gas removal system of a small thorium molten salt reactor

In the present study, a bubble generator and a bubble separator were designed and evaluated for an independent off-gas removal system of a small thorium molten salt reactor(TMSR) with reference to the design of the Oak Ridge National Laboratory(ONRL). The bubble generator employed a Venturi tube as its main body owing to its simplicity and highly reliable structure. A centrifugal separator was used as the bubble separator, taking advantage of the kinetic energy of fluid to create a centrifugal force to separate gas bubbles from the mixture flow. Both the bubble generator and the separator were demonstrated to have good potential to meet the performance requirements of an off-gas removal system for a small TMSR. With water and air as the working fluids, for the final designs of the two key pieces of equipment, a liquid flow rate exceeding 15 m~3·h~(-1) can essentially make their performance meet the requirements of the off-gas removal system in terms of the average size of the generated bubbles and gas separation efficiency.     

Investigations on various characteristics of novel cyclone separator with helical square fins

ABSTRACT

Cyclone separators are very energy intensive devices primarily used in power and process industries to separate the particles from hot gases. Hence in the present study, the barrel wall of the cyclone separator was modified by fixing the helical square fins of sizes 5, 7.5, and 10 mm, with 30 and 50 mm pitch variations to improve its separation efficiency. Hence in the present study, various fluid dynamic characteristics which affect the separation efficiency such as axial and tangential velocities, axial pressure drops were investigated. Computational results were validated using the published experimental data for the non-finned cyclone separator and further CFD simulations were performed for novel finned cyclone separators. It was observed that for the particles’ sizes below 3 µm, finned cyclone separator with fin size 10 mm and pitch 50 mm was giving separation efficiency more than other 5 finned cyclone separators. Also 5 to 10% improvement in the separation efficiency was observed over the separation efficiency of the non-finned cyclone separator. Since main function of separating the particles from gas was unaffected rather it was improved using finned cyclone separator(s) which is important in a view of reducing serious fine particulate matter (PM2.5) emissions causing serious health issues.     

黄磷脱砷装置中分相器的CFD数值模拟研究

介绍了黄磷脱砷工艺及该工艺中黄磷-双氧水分相器的基本结构、工作原理、优点和应用,着重研究了分相器旋流腔内流场特性。由于通过实验的方法无法全面地揭示其流场性质,采用计算流体力学的方法,用Gambit对该分相器进行几何建模、网格划分和边界条件的定义,应用Fluent软件,选用雷诺应力模型(RSM模型)作为湍流模型对黄磷-双氧水分相器进行了数值模拟计算,得到分相器内部流场、速度场和压力场的信息,还有黄磷体积分数等物理量的变化规律,并将数值模拟分离效率与实验结果进行了比较,分析了分相器内部流场的分布规律和两相流的分离特性,为黄磷-双氧水分相器的工业化放大设计提供参考依据。     

计算流体动力学(CFD)在化工领域的应用

计算流体动力学(CFD)是一种以流体为研究对象的数值模拟技术。相对于实验流体动力学而言,它具有资金投入少、计算速度快、信息完备且不受模型尺寸限制等优点。因此是研究流体动力学有力的工具。本文主要综述了CFD技术在化工领域内的填料塔、旋流分离器、生化反应器、干燥器、流化床、换热器方面的应用。     

离心式气液分离器内流场的数值模拟与结构优化

基于计算流体动力学(CFD)方法,采用Gambit建模,利用Fluent软件,对常规立罐式离心气液分离器进行了模拟仿真。通过流场分析可以看出,流场对称性很差,底流出口附近气体含量较多,说明气液分离效果不好。通过结构优化,包括将底流出口改为正下方排液,单入口改为双入口结构,减小罐体直径,溢流管伸入分离器内部入口管之下,以及将分离器下端改为锥形结构等,改善分离器内部流场的轴对称性及气相体积分数分布情况,并提高分离器的净化程度。     

仰角式游离水脱除器的应力分析及其应用程序

仰角式游离水脱除器作为一种新型高效的油水分离器,是针对高含水采出液而提出的.本研究采用有限元软件ANSYS对仰角式游离水脱除器进行了数值模拟研究.通过改变游离水脱除器的结构参数对游离水脱除器的应力分布及位移变化进行了有限元分析,全面搭配试验及回归分析,确定了挠度、支座反力、当量应力、等效应力和最大轴向拉应力与仰角角度、...     

Energie- und Ressourceneinsparung durch Innovative und CFD-basierte Auslegung von Flüssig/Flüssig-Schwerkraftabscheidern

Computational fluid dynamics (CFD) simulations in combination with droplet population balances lead to a practical standard for calculating the flow pattern – and thus the residence time distribution – in horizontal separators of any size based on available process data. The implementation of the droplet behavior also enables the calculation of a droplet-specific separator efficiency. The method development was carried out at identical plants at three different locations. The CFD simulations were successfully validated with experimental data from the participating industrial partners.     

The downhole hydrocyclone separator for purifying natural gas hydrate:structure design,optimization, and performance

ABSTRACT

The exploitation efficiency of natural gas hydrate is highly affected by sand production. In this paper, hydrocyclone purification separator was designed. A combination of single factor with computational fluid dynamics (CFD) was used to optimize the structure parameters. The performance of optimized hydrocyclone was also investigated. It shows that the sand separation efficiency increases from 90.4% to 98.7%, and the natural gas hydrate separation efficiency increases from 89.5% to 97.8%. Furthermore, the cut size of sand and natural gas hydrate are as low as 3 and 2 µm, respectively, and separation efficiency remains above 80% under inlet parameters. It can provide some reference for the design and manufacture of the in situ purification separator for gas hydrate mixture slurry.     

旋风分离器分离性能的数值模拟与分析

以XLPB-5.0和XCX-5.0两种旋风分离器为原型,采用CFD软件对这两种旋风分离器进行了流场与分离效率的数值模拟,初步探讨了入口蜗壳形式与芯管结构对分离效率的影响。模拟结果显示:旋风分离器内流场呈各向异性分布特点,切向速度是影响分离效率的首要因素,径向速度的存在会造成"流场短路"现象,使轴向速度呈不对称分布,导致分离效率的降低。轴向速度与径向速度的共同作用促使颗粒在旋风分离器内做螺旋运动;XLPB-5.0和XCX-5.0的分离效率分别为92.55%和94.96%,与实验结果基本吻合,且不同芯管参数下XCX型的分离效率比XLPB型高;螺旋式入口蜗壳(XCX-5.0型)对旋风分离器上部流场的影响相比直流式入口蜗壳(XLPB-5.0型)复杂;对于两种旋风分离器,随着芯管直径的增大,分离效率逐渐变小;随着芯管深度的增大,分离效率先增大后减小。     

油-水旋流分离器计算流体力学模拟效果分析

油-水旋流分离器是一种新型的水力旋流设备之一。在石化等行业中显示出越来越广泛的应用前景。掌握旋流分离器内液体的流动特性对旋流分离器的应用是非常重要的。利用计算流体力学（CFD）软件对其流体的分析是分析方法之一。通过CFD对油-水旋流分离器内流态的三维数值模拟,发现这种研究方法存在一定的局限性和不完全性,如所采用的迭代次数就对液分离器的模拟效果有著明显的影响。     

Experimental and CFD analysis of photocatalytic gas phase vinyl chloride (VC) oxidation

Photocatalytic destruction of gas phase vinyl chloride (VC) was examined using experimental and computational fluid dynamics (CFD) approaches. Experimental work involved using a differential photoreactor for determining kinetics of oxidation and an annular flow photoreactor for overall removal investigations as well as comparison with CFD models. The kinetic data obtained from differential photoreactor were used to model and predict the performance of the annular photoreactor using CFD. The photocatalytic oxidation of VC followed first order kinetics for inlet concentrations up to about and CFD was able to predict the removal of VC in the system. Both experimental and CFD modeling showed the removal of VC in the system increased with increasing the VC loading rate. CFD analysis of the photoreactor also provided insight into the detailed concentration gradient of VC within the reactor. The modeling results indicated significant radial VC concentration gradient and non-uniform flow distributions in the annular photoreactor. This non-uniform flow distribution, in turn, resulted in short circuiting of the VC contaminated gas and may have resulted in less than optimum removal efficiency for VC in the annular reactor over the entire range of inlet VC concentrations. Overall, the information provided by CFD modeling and simulation showed to be valuable for reactor design modification and for improving the reactor performance.     

碟式分离机向心泵流体仿真分析

针对碟式分离机向心泵进行流体动力学分析研究。通过建立碟式分离机向心泵有限元模型,利用数值计算流体动力学软件(CFX)模拟研究了向心泵结构对碟式分离机性能的影响。通过样机实验验证,表明利用数值计算流体动力学(CFD)可以有效指导向心泵的结构设计。     

Computational Fluid Dynamics Simulation of Pilot‐Plant‐Scale Two‐Phase Separators

Two computational fluid dynamics (CFD) modeling approaches, the discrete phase model (DPM) and the combination of volume of fluid (VOF) and DPM, are developed to simulate the phase separation phenomenon in four pilot‐plant‐scale separators. The incipient vapor phase velocity, at which liquid droplet carryover occurs, and separation efficiency plots are used as criteria for evaluating the developed CFD models. The simulation results indicate that the VOF‐DPM approach is a substantial modification to the DPM approach in terms of the predicted separation efficiency data and diagrams. CFD simulation profiles demonstrate that all the separators are essentially operating at a constant pressure. The CFD results also show that mist eliminators may operate more efficiently in horizontal separators than in vertical separators.     

天然气脱蜡旋风分离器分离效率的模拟

旋风分离器分离效率高,不易堵塞,用于天然气脱蜡效果显著。通过CFD软件Fluent模拟CYG-S型天然气脱蜡旋风分离器的两相流场,得到了旋风分离器内的压力、切向速度、轴向速度分布。对比了不同入口速度下的模拟与理论计算的分割粒径x50,发现具有很好的吻合度,两相模拟有一定的可靠性。结果表明：在旋风分离器锥段底部靠近壁面处的石蜡液滴质量浓度较高;随着进口流量的增加,旋风分离器分离效率提高,当进口流量为1000 m3/h时,x50可以达到5.3 μm;大粒径液滴的分离效果明显,但在所研究的进口流量范围内,进口流量的变化不能明显地影响粒径小于5 μm液滴的分离效率;柱段和锥段长度的增加使得旋风分离器的整体长度增加,延长了液滴在旋风分离器内的停留时间,提高了旋风分离器的分离效率。