阀门开度对油水环状流的影响研究

发布时间：2018-02-03 12:29

本文关键词： 阀门开度数值模拟油水环状流　出处：《广州大学》2016年硕士论文　论文类型：学位论文

【摘要】：油水环状流主要应用于稠油的长距离管道输送方面,可以很好的解决稠油因为粘度过大而产生的流动性差、输送过程中压降过大的问题,且投入小、效果明显,但稳定性较差,在管道输送过程中通过阀门后易产生漩涡、射流等现象,使流型遭到破坏,严重影响输送效率。因此,本论文对油水环状流通过不同的阀门开度后的流动规律展开研究,为稠油的稳定输送的参数选择提供依据。本文主要研究对象是油水环状流,通过数值模拟和实验研究相结合的方法探究其通过不同开度的阀门时所受到的扰动,对模拟结果进行分析,总结了油水环状流通过不同开度的阀门后管道内部流动参数的变化规律。具体内容如下:(1)利用流体仿真软件Fluent基于VOF多相流模型耦合Level Set算法和标准k-?湍流模型,针对阀门开度对油水环状流的影响进行了瞬态和动态数值模拟,得到不同开度下的流动变化情况;(2)针对模拟的工况进行了实验研究,利用高速摄像机拍摄流型,同时获得了不同开度下阀门前后的压力差和流量变化数据,与模拟结果进行比较,发现误差在允许范围内,验证了数值模拟的准确性;(3)分别分析了不同阀门开度和不同流速对油水环状流的流动结构产生的影响,发现阀门开度30%时对管道冲蚀最严重,漩涡最强烈;总结了油水环状流通过阀门时的流动演化规律,发现阀门开度达到40%以前,随着开度增加漩涡逐渐靠近阀芯,而在40%以后,漩涡则开始远离阀芯;(4)对不同开度下截面上油相体积分数的变化规律进行分析,发现在阀门开度30%时油相体积分数达到最大;对不同流速下的分析发现当油相流速达到2.06m/s时,其体积分数达到最大;(5)对管道壁面的粘附距离分析发现油相流速在1.2m/s时最容易粘附,且粘度越大越容易粘附在壁面上,而增大流速会降低粘度对粘附距离的影响;(6)对油水环状流的动态模拟发现,增大阀门开启速度,有利于改善阀后流场,但同时也会增大开启阻力。
[Abstract]:The oil-water annular flow is mainly used in the long distance pipeline transportation of heavy oil, which can solve the problem of poor fluidity of heavy oil due to excessive viscosity, too large pressure drop in the transportation process, and small investment, the effect is obvious. But the stability is poor, after passing through the valve in the pipeline easy to produce swirl, jet and other phenomena, so that the flow pattern is destroyed, seriously affect the transport efficiency. In this paper, the flow law of oil-water annular flow through different valve opening degree is studied to provide the basis for the parameter selection of heavy oil stable transportation. The main research object of this paper is oil-water annular flow. Through the combination of numerical simulation and experimental research, the disturbance of the valve with different opening was investigated, and the simulation results were analyzed. The variation of internal flow parameters of oil-water annular flow through the valve with different opening is summarized. The specific contents are as follows: 1). Using fluid simulation software Fluent to couple Level Set algorithm and standard k-model based on VOF multiphase flow model. The transient and dynamic numerical simulation of the effect of valve opening on the oil-water annular flow is carried out to obtain the flow change under different opening. The flow pattern was captured by high speed camera, and the pressure difference and flow rate data before and after the valve were obtained at the same time, and the results were compared with the simulation results. The detection error is within the allowable range, which verifies the accuracy of the numerical simulation. The influence of different valve opening and different flow velocity on the flow structure of oil-water annular flow is analyzed respectively. It is found that the valve opening 30 is the most serious erosion and the strongest swirl. The evolution law of the oil-water annular flow through the valve is summarized. It is found that before the valve opening reaches 40%, the swirl gradually approaches the valve core with the increase of opening, and after 40%, the swirl begins to be far away from the valve core. (4) the variation law of the oil phase volume fraction on the cross section under different opening degree is analyzed. It is found that the oil phase volume fraction reaches the maximum when the valve opening is 30; It is found that when the flow rate of oil phase reaches 2.06 m / s, the volume fraction of the oil phase reaches the maximum. 5) the analysis of the adhesion distance on the pipe wall shows that the oil phase flow rate is 1.2 m / s, and the higher the viscosity is, the easier it is to adhere to the wall surface, and the higher the flow rate is, the lower the effect of viscosity on the adhesion distance is. 6) dynamic simulation of oil-water annular flow shows that increasing the valve opening speed is beneficial to improve the flow field behind the valve, but it also increases the opening resistance.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE832

【参考文献】