单喷嘴混流压力式喷雾干燥三维数值模拟

以两相流及传热传质理论为基础，采用FLUENT软件对PD100型单喷嘴混流压力式喷雾干燥器进行了三维数值模拟，从而实现了对塔内雾化液滴粒径及粒径分布、塔内温度场、速度场的仿真，为单喷嘴混流压力式喷雾干燥塔的优化设计提供理论依据。     

一种用于气液间传质的新型轴流式叶轮

一种用于气液间传质的新型轴流式叶轮黄庆民林齐浩李启恩（华南理工大学化学工程研究所，广州５１０６４１）关键词气液传质轴流式叶轮１前言在液体搅拌器中，轴流式叶轮由于功耗较小且泵吸量较大而被广泛采用。在气液两相搅拌器中，由于轴流式叶轮有气泛问题，一般均采...     

旋流锥尾管底磨蚀机理分析

油气混输泵管道多次出现破漏,造成较大的经济损失与环境污染。割开检查发现底部有一道深深的沟槽,沟槽较窄,棱角分明。研究认为,这种沟槽的形成不是化学腐蚀,也不是材质缺陷,与层流、紊流无关,而是油气混输泵运行产生的一种固有的旋流造成的。由于油井出砂,砂子通过油气混输泵后获得新的能量,在管线内作旋转运动,其运行轨迹先是柱状,后逐渐转变为斜锥状,最后旋流锥尾与管底接触,对管底进行径向切削,从而形成沟槽,这种沟槽长度有限,位置相对固定。除砂或采用局部外加厚管道是解决该问题的主要措施。     

油气混输泵的研究与发展

多相混输泵是多相混输技术的核心,国外各公司、科研机构都投入大量的人力财力进行研究。分析了气液两相流动的主要计算模型,简要综述国内外混输泵的发展情况以及各种油气混输泵的结构和工作原理。与传统泵相比,油气混输泵具有十分广阔的前景。     

具有长短叶片离心泵的全三维湍流数值模拟

使用FLUENT软件模拟计算具有长短叶片叶轮的离心泵的全三维流场。选用多重参考坐标系及标准k-ε湍流模型,计算对包括导入管、叶轮、泵壳及出水管在内的整个离心泵系统。计算结果表明,在大部分长短叶片的通道内,射流区偏向于叶片背面,尾迹区则位于叶片工作面出口附近。泵叶轮各通道的流量、流速及压力等流动参数的分布表现出明显的非对称性,流动参数的大小与叶轮、泵壳的相对位置密切相关。将泵性能的预测值与实测值作了对比,以验证计算结果的准确性。     

同步回转油气混输装置在油田的试验及推广

本文介绍了油田混输原油和伴生气的新型设备即同步回转油气混输装置的结构特点及原理,阐述了同步回转油气混输泵在现场实验及推广中的情况,分析了其应用效果,同时提出了在油气混输中推广应用的建议。     

我国油气混输技术研究现状及发展建议

我国油气混输技术研究目前主要集中在油气混输泵研究,油气混输管路流动规律研究和油气混输附加设备研究三方面。油气混输泵内部特性指标方面研究少且停留于模拟研究状态,外部宏观特性指标停留于单因素定性分析状态,难以为油气混输泵的发展提供足够的理论基础。油气混输管路流动规律研究还没有经实践检验的精度较高的计算公式和统一公认的模型。附加设备的投入使油气混输系统相对复杂,投资加大。为促进油气混输技术发展,建议加大各方面研究力度。     

某沙漠油田未稳定凝析油长距离输送投产异常原因分析及对策

某沙漠油田中心分输站主要设备为一级两相分离器、二级油气分离器、压缩机和外输泵。前期油气混输，随着油气快速增长，混输改为油气分输，油气经一级两相分离器分离后分别管输至联合站处理。混输改分输时，从节能角度出发，考虑只投用一级分离器，不投用二级分离器、压缩机和泵，试投产证明天然气管线运行正常，凝析油输量达不到设计值。经分析，是未稳定凝析油在输送过程中随着压力降低，凝析油中溶解气析出，在大型沙丘地段出现气阻现象，造成管线输送能力大幅下降。为此，及时投用二级闪蒸分离流程，一级分离器出口未稳定凝析油经二级闪蒸分离器再次分离，闪蒸气经压缩机增压后汇入一级分离器气相出口，闪蒸后凝析油经外输泵增压外输，此后凝析油管线平稳运行。     

混流泵启动过程中的水动力瞬态特性研究

为研究混流泵启动过程中的水动力瞬态特性,通过建立混流泵三维模型进行了数值模拟,分析了在启动过程中混流泵内的压力场变化规律,采用频谱法研究了泵运行过程叶轮流道与导叶流道内流体的压力脉动变化规律。分析表明：在启动过程中,泵内的压力逐渐增加,压力最高处集中在叶轮与导叶交界处;在达到额定转速以后,泵内流体压力脉动呈周期性变化;叶轮流道压力脉动与叶轮转频、导叶叶片数有关;导叶流道压力脉动与叶轮转频、叶轮叶片数有关。     

试论油田多相混输泵的应用

油田开发过程中,需要对从油井直接采出的含有油、气、水及各种杂质的多相混合物进行集输,运用多相混输泵可以解决这种已超过普通的泵和压缩机的工作范围的复杂多相混输条件。结合多相混输技术,列举了主要的油田运用混输泵,阐述了各类型混输泵的技术特点,对现在油田多相混输泵的应用情况进行分析,对多相混输泵的优势和应用前景提出了意见和建议。     

叶片圆盘泵叶轮无叶区内部流场数值模拟

为研究叶片圆盘泵叶轮无叶区内的流动特征,采用RNGk-ε湍流模型与SIMPLEC算法,对叶片圆盘泵内三维不可压湍流场进行数值模拟,得到速度等值线图和压力等值线图,并对模拟结果进行分析。发现周向流动是叶片圆盘泵叶轮无叶区内的主要流动方式,无叶区内较大部分是低压区,无叶区内除存在轴向流动外还存在径向回流。     

混流式风机内部流体力学行为研究

基于k-ε湍流模型和三维时均N-S方程,进行了混流式风机的全流道三维定常湍流计算,得到了风机内部压力分布和速度分布等许多重要的流动现象。结果表明,风机的全通道CFD分析能够较为准确地预测出风机内部流场结构。     

Axial thrust of axial flow impellers

This paper presents an analysis of the axial thrust of axial flow high-speed impellers under a turbulent regime of flow of an agitated liquid. The axial thrust is calculated from the measured total axial force affecting the cylindrical fully baffled mixing vessel and from the radial profile of the axial component of the ensemble-averaged mean velocity in the impeller discharge stream. The results of experimentally determined values of the dimensionless criteria (thrust number and momentum number) are successfully compared with the axial thrust of the pitched blade impellers calculated from the theoretically predicted simplified radial profiles of the axial component of the mean velocity in the impeller discharge stream.     

轴流式翼型-透平组合桨在搅拌釜内的流动

<正>搅拌反应器是化工、医药、食品工业中广泛应用的基础设备之一,当搅拌釜内液深与搅拌釜直径相比较大时(通常比值大于1),往往采用双层或多层桨,以保证顶部到底部的循环流动。 透平桨产生的是径向流,形成以桨叶为中心线的上、下2个循环区,桨叶附近剪切速率高,气体分散能力强。翼型桨产生的流型是轴向流,形成全釜循环,混合均匀,剪切温和。为充分利用两者优势,加强全釜混合,剪切适度,特别是在粘稠物系中,可采用组合桨。目前尚未看到对翼型-透平组合桨流动状况的研究,而对于非牛顿流体中的组合桨流动状况则了解     

On the hydrodynamics characterization of the straight Maxblend impeller with Newtonian fluids

The hydrodynamics generated by the straight version of the Maxblend^® impeller with Newtonian fluids in a baffled stirred vessel under the transitional and turbulent regime has been experimentally characterized by means of the particle image velocimetry technique. The flow fields obtained with the Maxblend were compared with those obtained with a double stage classical pitched blade turbine (PBT) and a double Ekato Intermig^® impellers under the same specific power draw. It is shown that these open impellers induce complex local flows in the radial and axial direction, with an intensity decreasing away from the blades. By contrast, the Maxblend impeller generates a more regular circulation pattern, with efficient top-to-bottom pumping.     

SOLIDS DISTRIBUTION IN STIRRED SLURRY REACTORS: INFLUENCE OF SOME MIXER CONFIGURATIONS AND LIMITS TO THE APPLICABILITY OF A SIMPLE MODEL FOR PREDICTIONS

The features of solids concentration distribution were investigated in baffled and unbaffled tanks of high aspect ratio, stirred with multiple radial, mixed-flow or axial impellers. In the baffled tanks the average profiles can be predicted with the sedimentation-dispersion model regardless of impeller type - in spite of slight systematic departures from the average trend at the impeller plane and/or midway between the impellers. This is hardly possible for the unbaffled tanks due to lack of physical foundation of this simple model. When the unbaffled tank is stirred with hydrofoil impellers, an inverted profile is even obtained. The mentioned departures and this last anomalous behaviour are qualitatively discussed with reference to particle-turbulence interaction.     

SOLIDS DISTRIBUTION IN STIRRED SLURRY REACTORS: INFLUENCE OF SOME MIXER CONFIGURATIONS AND LIMITS TO THE APPLICABILITY OF A SIMPLE MODEL FOR PREDICTIONS

The features of solids concentration distribution were investigated in baffled and unbaffled tanks of high aspect ratio, stirred with multiple radial, mixed-flow or axial impellers. In the baffled tanks the average profiles can be predicted with the sedimentation-dispersion model regardless of impeller type - in spite of slight systematic departures from the average trend at the impeller plane and/or midway between the impellers. This is hardly possible for the unbaffled tanks due to lack of physical foundation of this simple model. When the unbaffled tank is stirred with hydrofoil impellers, an inverted profile is even obtained. The mentioned departures and this last anomalous behaviour are qualitatively discussed with reference to particle-turbulence interaction.     

Turbulent flow field in a stirred vessel agitated by an Impeller with flexible blades

In order to reveal the effect of the blades normal vibration on flow turbulence in the stirred vessel, we designed three kinds of blades: the flexible, flat‐rigid and curved‐rigid blades. The flow fields produced by the impellers with these three kinds of blades were measured by two‐dimensional particle image velocimetry. The results showed that the calculated turbulent kinetic energy (TKE) based on the pseudo‐isotropic assumption is slightly higher than that by the three fluctuating velocities for the flexible and curved‐rigid impellers, and the difference between above two calculations is smaller for the former impeller. For the flexible blades, the trailing vortices slightly move outwards in radial direction than those for the curved‐rigid blades, enhancing TKE transport from the blade to the bulk region of the vessel. For the flexible impeller, the phase‐averaged TKE differs slightly from that for the flat‐rigid impeller, but is higher than that for the curved‐rigid impeller. © 2018 American Institute of Chemical Engineers AIChE J, 64: 4148–4161, 2018     

旋喷泵的效率及集流管水力设计方法探讨

通过分析得出,旋喷泵在小流量、高扬程工况下运行时的效率高于多级泵和高速泵。在研究旋喷泵集流管与叶轮匹配及集流管扩散损失的基础上,给出了设计扩散管水力参数的公式。     

基于ANSYS的离心泵叶轮优化设计

在对原设计泵试验性能曲线分析的基础上,建立了以减小圆盘摩擦损失、提高离心泵效率为目标的叶轮优化设计数学模型,利用有限元分析软件ANSYS对离心泵的叶轮直径和出口几何参数进行优化设计。结果表明,优化后叶轮的圆盘摩擦损失有较为显著的下降,泵的效率有所提高。