螺旋片导流式分离器压力简化计算

应用计算流体力学CFD(ComputationalFluidDynamics)方法,对湍流状态下不同结构参数的螺旋片导流式气液分离器螺旋结构中的流体流动场进行了数值模拟。通过分析比较螺旋个数和螺距分别对压力降的影响,从而修正达西公式,拟合出螺旋结构压力降的简化计算公式,并通过了试验验证。结果表明,用此简化计算公式计算的结果与试验数据基本一致,可以用于螺旋片导流式气液分离器螺旋结构设计计算。     

螺旋拧装式导流叶片对超音速分离器旋流管速度场的影响

超音速气液分离技术是天然气脱水工业的一大突破,分离翼是超音速气液分离管的核心部件,是形成高速旋流高效分离的主体。在传统三角分离翼存在诸多不足的基础上提出表面光滑的螺旋拧装式导流叶片的设计,建立旋流管三维物理模型。运用Fluent14.5对气流绕导流叶片的旋流速度场进行了数值模拟,结果显示,在导流叶片尾端气流平均切向速度达到最大值163.28 m/s,气流在导流叶片后可形成较为稳定的强旋流场,x=0.30 m处特征截面的平均切线速度达131.50 m/s,可实现较理想的气液旋流分离。     

以设计为中心的虚拟制造技术及在化工过程装备中的应用

简述了虚拟制造技术的内涵、关键技术及应用现状。在分析化工过程装备特点基础上 ,对过程装备虚拟制造技术平台的体系结构进行了探讨 ,以典型过程装备螺旋片导流式气液分离器为例 ,对其数字化建模方法、数值仿真技术、虚拟设计和制造环境进行了研究。初步结果表明 :以设计为中心的虚拟制造技术的应用 ,可以有效地减少产品开发的时间和成本 ,提高产品质量     

离心式气液分离器分离性能的数值模拟

离心式气液分离器具有结构紧凑、体积小、高效等优点,被广泛的应用于石油、化工、等行业。文章基于CFD方法,使用Fluent软件对某种离心式气液分离器进行全三维数值模拟,采用正交试验设计方法安排模拟步骤,研究得到流量、气泡直径、含气量三因素对气液分离效率的影响规律,为离心式气液分离器的结构优化和高效性提供参考。     

基于油滴粒度测量的螺旋分离器CFD模拟与验证

针对一种叶片导流式螺旋分离器结构特点,设计一种模拟螺旋分离器螺旋流场中流体转速对油滴粒度分布影响的测量实验,并通过马尔文激光粒度仪实验仪器对油水混合液中的分散相粒度及其分布进行测量。研究获得油相体积分数2%情况下,各转速状态下油滴粒径典型频率分布规律,揭示了平均粒径与流体转速近似成幂指数关系。通过基于测量粒度分布开展的CFD数值模拟与实验测得的分离效率数据对比,二者基本一致,表明了该方法在特定转速下的粒度分布可有效用于开展CFD数值模拟计算。研究对于进一步开展螺旋分离器结构、操作等参数优化及油水两相流场分析等数值模拟及分析提供参考。     

导流板对旋风分离器内气固两相分离性能的影响

通过数值模拟对环形空间设有导流板的旋风分离器进行了研究. 与常规单入口旋风分离器相比,设置导流板显著改善了旋风分离器内的非轴对称流动,使流场的旋转中心与分离器的几何中心重合,从而抑制了旋风分离器内的涡核摆动现象. 气固两相模拟结果表明,加入导流板可明显提高旋风分离器的分离效率,尤其是对于粒径为5 mm的小颗粒,分离效率从53.4%提高到94.6%,捕集效率显著提高.     

井下微型气液旋流分离器优化设计与性能分析

针对采油井筒内产出液含气对油田同井注采开发模式的不利影响,基于旋流分离原理提出一种井下微型气液旋流分离器结构。借助Plackett-Burman设计、最陡爬坡设计与响应曲面设计结合计算流体动力学方法,对井下微型气液旋流分离器结构参数进行显著分析及优化设计,构建了显著性结构参数与分离效率间的二次多项式数学关系。系统分析了入口进液量、分流比及气相体积分数对气液分离性能的影响规律。构建室内微型气液旋流分离性能测试系统,对数值模拟结果的准确性及优化结果的高效性进行了验证性试验。试验结果表明优化后的微型气液旋流分离器结构可使液相效率由优化前的84.10%提高到87.22%。获得了微型气液旋流分离器最佳溢流分流比为6%,最佳入口流量为13.77 L/h,最适用的气相体积分数为5.5%,最佳工况下气液平均分离效率为99.66%。为了指导分离器在不同含气量条件下的最佳运行参数调控,构建了气相体积分数及溢流分流比与分离效率间的数学关系模型,获得了不同气相体积分数条件下的最佳分流比。     

可用于MVR蒸发系统的气液分离器改进结构分析

针对常规气液分离器对微小液滴分离效率低的不足,提出一种可用于MVR蒸发系统的气液分离器结构,并采用数值模拟结合实验验证的方法对其分离特性进行研究。首先,利用数值模拟的方法分析了气液分离器内部流场和压力场,确定了影响分离效果最明显的位置,然后提出了在该位置加装不同数量3/4圆环形挡板的分离器结构。其次,模拟研究了此种新结构的分离效率和压降等分离特性以及挡板数量变化的影响规律。最后,通过实验验证的方法分析了数值模拟结果的可靠性和新结构的分离效果。研究结果表明：圆柱型筒体是影响分离器分离特性的关键部位,在气液分离器圆柱形筒体内部增加3/4环形挡板,能够增加物料切向运动的有效长度,降低物料的径向速度,从而显著提高微小液滴的分离效率,气液分离器整体压降却增加不多;而且随着环形挡板数量的增加,该结构气液分离器的分离效率和压降均明显提高。在本文计算条件下,加装3/4圆环形挡板的气液分离器结构,可以将直径在3 μm以下的液滴分离效率提高15%,而压降仅增加了200Pa。综合气液分离器效率和压降影响,加装两个3/4圆环形挡板的气液分离器性能最佳。     

钻井液气液旋流分离器内部流场的CFD模拟

采用计算流体力学数值模拟方法研究了钻井液气液旋流分离器的内部流场,模拟出了分离器内部的压力分布、轴向速度和切向速度的变化规律,得到了钻井液气液旋流器内部流场的特征,为钻井液气液旋流器分离器的工艺设计提供了参考依据。     

三相旋流分离器气液固耦合数值模拟研究

针对工程实际三相旋流分离器结构优化设计和特性难于把握问题,基于计算流动动力学CFD理论,建立了三相旋流分离器气液固耦合数值分析模型,采用Mixture多相流模型对旋流分离器进行气液固三相数值模拟,研究了不同进口流量工况下旋流分离器的分离效率与压力损失,确定了结构优化后旋流分离器的最优进口流量区间。     

螺旋片导流式气液分离器的数值模拟与试验研究

The gas/liquid spiral separator, a key component in the compressed air system, was used to remove liquid and oil from gas stream by centrifugal and gravitational forces. To optimize the design of the separator, the relationship between the performance and structural parameters of separators is studied. Computational fluid dynamics （CFD） method is employed to simulate the flow fields and calculate the pressure drop and separation efficiency of air-liquid spiral separators with different structural parameters. The RSM （Reynolds stress model） turbulence model is used to analyze the highly swirling flow fields while the stochastic trajectory model is used to simulate the traces of liquid droplets in the flow field. A simplified calculation formula of pressure drop in spiral structures is obtained by modifying Darcy＇s equation and verified by experiment.     

Numerical Simulation of the Separating Performance of Hydrocyclones

The flow behavior in hydrocyclones is quite complex. The Computational Fluid Dynamics (CFD) method was used to simulate the flow fields inside a hydrocyclone in order to improve its separation efficiency. The RSM turbulent model (Reynolds Stress Model), which abandons the isotropic eddy‐viscosity hypothesis, was used to analyze the highly swirling flow fields in hydrocyclones. The ASM Model (Algebraic Slip Mixture Model) was used to simulate the separation performance. The volume fraction distribution and grade efficiency curve are given. The separating efficiency for 60 μm water particles is more than 90 %. The majority of 60 μm water particles are carried to the underflow. An increase in particle size will improve the efficiency by increasing the centrifugal force on the particles. Based on the simulation, the effects of the overflow tube dimensions on the separation performance were studied. The overflow tube dimensions of the hydrocyclone were modified, and the results showed that the Reynolds Stress Model successfully predicted the characteristics of the flow, and the simulated performances were in good agreement with those obtained by tests.     

升气管插入深度对旋风分离器内部流场影响的数值模拟

针对旋风分离器内部复杂的三维强湍流,在仿真过程中,采用雷诺应力模型(RSM),利用贴体网格技术,模拟得到不同升气管插入深度时的旋风分离器内的切向速度分布、轴向速度分布和进出口压降。结果表明,当升气管插入深度减小时,会使总压力损失有所降低,但有一部分气流将从入口直接进入升气管形成短路,使旋风分离器的分离性能下降;对于特定的旋风分离器,升气管插入深度存在最优值,可保证较高的分离效率和较低的压降。     

Numerical simulation of effect of inlet configuration on square cyclone separator performance

This paper presents a numerical study of the gas-solid flow in square cyclone separators with three types of inlet configuration. Three-dimensional Reynolds Stress Model (RSM) was used to simulate the turbulent flow of gas phase and a Lagrangian equation was used to simulate the particle motion. The resulting velocity, separation efficiency and pressure drops were verified by comparison with measured data. The effect of inlet configurations on the turbulent dynamics in the cyclone and the separation efficiency and pressure drop was analyzed. Results showed that inlet configurations influenced the turbulent dynamics in the cyclone and led to different pressure drop and separation efficiency. The separator with double declining inlets (DDI) had the minimum pressure drop and similar efficiency to the separator with double normal inlets (DNI). The separator with single normal inlet (SNI) had the best separation efficiency and the maximum pressure drop. When a baffle was installed in the inlet of separator SNI, the pressure drop increased by about 191% and 34% for the separator with a straight (SNI-1) and curved (SNI-2) baffle respectively on the basis of the pressure drop of separator SNI. The cut and critical diameter of particles were 2 μm and 14 μm for separator SNI-1 and 4 μm and 14 μm for separator SNI-2, while they were 8 μm and 30 μm for separator SNI at the same inlet conditions.     

喷灌用水力旋流器的设计与数值模拟

针对新疆井灌区地下水的实际情况,介绍了喷灌用水力旋流器的设计方法,并运用流体模拟软件Fluent6．3,基于雷诺应力（RSM）模型结合分散相模型（DPM）,采用SIMPLEC对速度一压力耦合,选取差分格式为QUICK格式,压力差补格式为PRESTO格式进行了数值模拟,验证了设计的正确性,对水力旋流器的设计有一定的参考价值。     

Numerical simulations of airflow and droplet transport in a wave-plate mist eliminator

In this paper, the droplet transport and deposition in the turbulent airflow inside a wave-plate mist eliminator was studied using an Eulerian–Lagrangian computational method. The Reynolds Stress Transport Model (RSTM) with standard wall functions and with enhanced wall treatment was used for simulating the airflow field. A computer code for solving the Reynolds-averaged Navier–Stokes (RANS) equations in conjunction with the RSTM on two-dimensional collocated unstructured meshes was developed. For droplet trajectory analysis, another computer code was developed that accounts for the drag and lift forces action on the droplets. The Eddy Interaction Model (EIM) was used to model the droplet dispersion in turbulent airflow. The gas flow code was validated by comparing the computational model results for a fully developed asymmetric channel turbulent flow with the experimental data. Then the airflow and droplet trajectory analysis were performed for a mist eliminator with smooth walls and the resultant removal efficiency curves were evaluated and compared with the available experimental data. The results showed that the enhanced wall treatment improved the predictions of the droplet removal efficiency especially for small droplets in which the removal efficiency was lower than 50%. On the other hand, the Reynolds Stress Transport Model (RSTM) with standard wall functions cannot predict the removal efficiency correctly, especially for low gas velocities.     

螺旋折流板换热器数值模拟及入口结构改进研究

利用FLUENT软件,采用雷诺应力湍流模型模拟了不同流量下常规螺旋折流板换热器壳程的流动与传热性能,并用实验验证了模拟的可靠性。为了减少换热器壳侧入口处压降,对螺旋折流板换热器壳侧入口结构进行改进,将流体垂直流入壳体改为入口与壳体形成一定角度。对结构改进后的螺旋折流板换热器进行的数值模拟表明,采用倾斜入口结构时进口处压力降比采用垂直入口结构时低52%以上,且流量越大,这种降低幅度越明显。     

Prediction of strongly swirling flow within an axial hydrocyclone using two commercial CFD codes

Two commercial CFD codes were used to simulate the strongly swirling single-phase flow with core recirculation within an axial hydrocyclone. Both packages used a Differential Reynolds Stress Model with default constants for the turbulence closure. The effect of omitting wall reflection terms was also investigated and it was generally found that this lead to better agreement with experiment. Interestingly, the predicted velocity profiles from the two CFD codes did not agree with each other. Possible reasons for this are different turbulence modelling approaches with different terms for the turbulent diffusion and rapid pressure-strain terms.     

文丘里分离罐气相流场特性及分离效率研究

采用雷诺应力湍流模型和离散颗粒模型对2种不同结构文丘里分离罐内气相和颗粒相进行了数值模拟,对比了其气相流场特性和分离效率。结果表明,侧出口分离罐A内的切向速度分布对称性较差,外旋流区较小,对分离不利;上出口分离罐B内的切向速度分布呈兰金涡分布,对称性良好,外旋流区较大,适合分离。2分离罐对粒径小于5μm颗粒的分离效率比较接近;粒径5μm~45μm的颗粒,B罐的分离效率明显高于A罐;粒径大于45μm的颗粒,A罐的分离效率略高于B罐。