两相流管线振动分析

对于两相流引起的管线振动,首先必须对管线内流体进行分析。该文给出了流体振动频率的计算方法。即:先用流型图判断流体流型,然后分析各流型中最易引起管线振动的段塞流。若为段塞流,应再进一步分析并计算段塞流的频率。     

固液两相流诱发变径及T型管道振动实验研究及数值模拟

管道结构中存在变径或开孔,输送介质不可避免会引起管道振动。为准确模拟固液两相流在变径及T型管道内流动所诱发的振动情况,搭建了实验装置,设计了实验流程和实验工况。针对管道的变径和开孔特点,将管道简化成缩径管及T型管进行有限元数值模拟分析,对缩径管及T型管的实验测试数据和数值模拟结果进行拟合处理,得到了固体颗粒比例、出口流量对变径及T型管道振动的影响规律。可为固液两相流在变径及T型管道内诱发的振动分析提供技术支持。     

两相流化工流程泵的设计特点

简要介绍了两相流泵的设计假设、方程组、结构特点和使用实例。     

气液两相流确定性混沌分析

采用确定性混沌理论研究了空气 水两相流压力和压差信号的重构相空间、吸引子不变量的规律。结果表明 ,气液两相流是 1个低维混沌动力学系统 ,各流型间的非线性动力学特性不同。气液两相流的吸引子不变量 ,如Hurst指数、关联维数和Kolmogorov熵等都与流型关系密切。在多数流型内参数波动具有持久性特征 ,首次发现了高气速环状流区的反持久特征。     

流体力学因素对液固两相流冲刷腐蚀的影响

分析了流体力学因素对冲刷腐蚀的影响机制,并应用计算流体动力学(CFD)软件对流速、流动切应力以及近壁处的湍流强度等流体力学参数在冲蚀过程中的实际情况进行了数值模拟。     

气液两相流管道振动测试分析

对大型多相流实验管道进行了振动测试和分析,用双通道数据采集器对单相气和两相流进行了频谱测试。通过频谱分析,分析了管内为单相气和气液两相流时振动频谱信号的异同,发现在单相气中加入液相后,振动频谱频带范围明显变宽,振动能量值变大。     

煤层气两相流阶段的热流固耦合渗流数学模型

我国煤层气资源相当丰富，如何有效地开发是当今面临的一个难题。由于煤岩的特殊性，煤层气在煤层中赋存的状态和流动机理与常规砂岩储层中不同，其开采过程是一个流体渗流、多孔介质弹塑性变形与温度场耦合作用极强的过程。考虑煤层气渗流场、温度场、变形场耦合关系，根据多相流体达西渗流定律、质量守恒定律、多孔介质弹塑性理论、有效应力原理、传热学理论建立了煤层气的气、水两相流阶段渗流方程、变形方程及温度场方程，给出了数值求解渗流方程的定解条件，从而得到煤层气在气、水两相流阶段热流固渗流数学模型，为改进和完善煤层气开采方法、技术提供了理论依据。     

气水两相流滑动比的实验研究

通过气水两相流在垂直管中的流动实验，分别用滑动比模型法和密度差模型求取气水滑动比。在剔了段塞滑比数据后，给出了气水两相泡状流情况下的滑动比实验关系式，为油气中两相流的检测处理提供了一种新的处理方法。     

Modelling of Two-Phase Flow Through Concentric Annuli

A mathematical model is introduced in order to predict the flow characteristics of multiphase flow through an annulus. Flow patterns and frictional pressure losses estimated using the proposed model are compared with the experimental data of a wide range of liquid and gas flow rates recorded at a flow loop consisting of numerous circular pipes and annulus. The results showed that the model predictions for flow patterns and frictional pressure losses are reasonably accurate. Moreover, it is observed that geometry and liquid phase viscosity have a significant influence on flow pattern transitions and frictional pressure losses.     

Modelling of Two-Phase Flow Through Concentric Annuli

Abstract

A mathematical model is introduced in order to predict the flow characteristics of multiphase flow through an annulus. Flow patterns and frictional pressure losses estimated using the proposed model are compared with the experimental data of a wide range of liquid and gas flow rates recorded at a flow loop consisting of numerous circular pipes and annulus. The results showed that the model predictions for flow patterns and frictional pressure losses are reasonably accurate. Moreover, it is observed that geometry and liquid phase viscosity have a significant influence on flow pattern transitions and frictional pressure losses.     

Experimental Research on Gas-Liquid Two-Phase Spiral Flow in Horizontal Pipe

In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different parameters investigated by means of observation and a high-speed camera.Since the appearance of spiral flow makes the distribution of twophase flow more complicated,the flow patterns appearing in the experiments were divided into the Spiral Wavy Stratified Flow(SWS),the Spiral Bubble Flow(SB),the Spiral Slug Flow(SS),the Spiral Linear Flow(SL),the Spiral Axial Flow(SA),and the Spiral Dispersed Flow(SD) by the observations and with reference to the predecessors’ research achievements.A flow pattern map has been drawn up.The influence of velocity,vane angle and vane area on flow pattern conversion boundary and pressure drop has been studied,with a solid foundation laid for the future research work.     

油气两相流试验数据微机采集系统

新型的油气两相流试验数据计算机采集系统，可以采集16个通道的油气两相流压力、持液率、流量等传感器送出的电信号。该系统充分发挥了目前试验室用微机的潜力，特别适合于较长时间的瞬态测量，不需要特殊的附加设备，对微机的内存要求也不高。使用C语言编写的微机程序即可实现自动采集、分析、处理、存储数据。     

油水两相流动生产测井解释中关键参数的确定

基于模拟井中油水两相流实验,本文提出了油水两相流动中关键参数——相分布系数与状态分布指数的确定方法,并用该模型求得的油表观速度与大庆油田、阿特拉斯、哈里伯顿测井服务公司模拟井中的实验结果进行了对比,取得了较好的效果。本文提出的确定油水两相流动生产测井解释关键参数的新方法为更好地把漂移模型用于生产测井解释奠定了基础。     

Experimental Investigation and Numerical Simulation of Two-Phase Flow in a Large-Diameter Horizontal Flow Line Vertical Riser

Abstract

As oil and gas field development moves further into deep seas, maximizing hydrocarbon extraction at an acceptable cost is one of the greatest challenges facing the industry today. In this regard, considerable attention has been given to understanding the flow behavior in long and deep flow line risers of different topologies through transient multiphase simulation. However, the application of the large diameter to the above scenario is still an unresolved issue creating a great deal of uncertainty. This is mainly due to the limitation of the available experimental and field data being confined to much smaller diameters.

In view of the aforementioned, an experimental campaign to investigate the flow behavior in a 254-mm nominal-diameter horizontal flow line vertical riser has been performed. A numerical model to study the dynamic behavior of the large-diameter horizontal flow line vertical riser system is also developed using OLGA software with the intention of identifying the capability of this software. This article presents the comparison of the simulation and experimental data in terms of near riser base and flow line pressure variations along with flow regime predictions. The existence of the multiple roots in the OLGA code is also reported for the first time. Additionally, a review on the state-of-the-art application of the code and analysis of the numerical experiment performance of the code are included.     

水平管内气液两相流中气泡滑移速度的数值模拟

基于多相流Euler模型,采用Fluent软件对水平管道内的气液两相流进行数值模拟,在水和气体初始速度相同的情况下,考察气泡直径、气泡体积分数和流体流速对气泡滑移速度的影响。模拟结果表明,气泡直径、气泡体积分数和流体流速对气泡滑移速度都有影响,其中流体流速的影响较大;在气泡直径小于等于0.10 mm,或气泡体积分数大于等于10%,或流体流速大于等于0.10 m/s时,对气泡滑移速度的影响可忽略;与水和气泡的速度相比,气泡滑移速度很小,可忽略不计。     

鼓泡塔与气流内循环式反应器内两相流模拟

利用计算流体力学软件FLUENT6.2对低气速下的鼓泡塔和气流内循环式反应器内的湍流两相流动进行了二维非定常模拟,两相流模型为欧拉模型(双流体模型),湍流模型为标准k-ε模型。将两种反应器的模拟结果进行了比较,结果显示,由于气升式反应器内存在导流筒,使得两种反应器内的两相流动特性有较大的不同。对此进行了定量的研究,并与相关文献的研究结论进行了对比分析。     

基于气固两相流的割缝筛管冲蚀模拟研究

目前对气井中防砂筛管的冲蚀研究较少,在设计过程中主要采用经验法来选择筛管精度及气井的生产参数。采用计算流体力学(CFD)方法对气井中割缝筛管的单缝的内部流动规律进行分析,并引入 Tulsa大学冲蚀与腐蚀联合研究中心(E/CRC)提出的冲蚀模型,分析不同生产压差下割缝筛管缝隙的冲蚀特征及最大冲蚀量。结果表明:①筛管梯形缝口窄边处的流速最大,且冲蚀速率最大。随着生产压差增大,穿过筛管缝隙进入筛管内环空的粒子数增多。在流速激增的作用下,增大了粒子对筛管缝隙的冲蚀破坏程度; ②割缝筛管的冲蚀量随着生产压差增大而增加,两者呈指数关系; ③筛管的冲蚀区域主要集中于割缝的两端处,随着生产压差的增加,上端的冲蚀剧烈区域逐渐增大,但下端冲蚀的剧烈区域逐渐缩小。在气井的生产过程中合理设定生产压差,对于长效防砂及提高筛管的使用寿命至关重要。