基于小波神经网络的油气水三相流相含率的软测量方法

利用高速摄影仪对垂直上升管中油气水三相流的流动进行了动态图像的拍摄,提取每一帧图像的灰度均值组成灰度时间序列,并从时间序列中提取了能反映油气水三相流流动特性的统计和分形特征量,将这些特征量作为人工神经网络的输入量。在水的体积流量为1.32~12.15 m3/h,油的体积流量为0.01~0.43 m3/h,空气的体积流量为0.75~2.5 m3/h条件下,采用小波神经网络作为相含率预测模型,结果表明,小波神经网络的预测值与测试值非常吻合,含气率预测最大误差为3.57%,含水率最大误差为3.3%,较好地实现了油气水三相流相含率的预测,为油气水三相流相含率测量提供了一种有效的软测量方法。     

倾斜下降管内油气水三相流流型转变的实验研究

对倾斜下降管倾角变化对油气水三相流流型转变的影响进行了研究 ,通过大量实验得到流型图 ,发现倾角对流型转变有重大影响 :倾角增大到 3 0°时 ,增大气流量 ,泡状流已不再转变为间歇流 ,而是分层流 ;倾角变化对环状流和间歇流之间的转变影响显著。得到的界限方程规律与实验现象及流型图符合良好     

水平射孔井段油气水三相变质量流动分散流压降模型

通过对微元井段压降的分析,考虑了壁面入流的影响,那么根据质量守恒,动量守恒定理可以推导变质量流动模型。由于油气水三相变质量流动分散流的混合程度均匀,因此在研究的时候将分散流看成了一种黏度比较复杂的均质液体。考虑到存在壁面入流对射孔井段分散流压降的影响,得到水平射孔井段油气水三相变质量流动分散流的压降计算方法。     

水平管中油气水三相流动研究进展

对国内外油气水三相管流中的关键问题,如流型划分、油水反相以及水力计算(包括持液率和压降)等的研究成果进行综合评述,同时指出了研究中的问题所在和今后的研究方向。     

水平管内油气水三相流动摩擦阻力压降特性研究

对水平管内油气水三相流动的摩擦压降特性进行系统的理论和实验研究 ,建立了泡状流和环状流摩擦压力降的理论模型 ,揭示了摩擦压力降随折算气速、折算液速、油水混合物含水率及管径的变化规律。实验结果与理论计算结果相吻合。     

油气水三相流管道流动规律研究进展

随着管道混输技术越来越受到重视,多相流动的研究已经成为国内外研究的热点。本文就国内混输管道流动规律研究的现状和研究进展进行了综述。指出只有在对多相流动的流型和压降规律有足够认识的基础上,才能提出准确、合理的流型判别方法和压降模型,才能使油气水多相管流的研究工作取得突破性的进展,为实现油气水多相输送提出理论支持。     

改进的小波消噪阈值方法在油气水三相流图像信号中的应用

应用高速摄像机拍摄了油气水三相流典型流型的图像视频,提取其灰度均值构成时间序列,为了更好地研究其流动机理。需将时间序列进行消噪。在研究传统的平稳小波理论和分析传统阅值函数存在问题的基础上,提出了一种新的小波消噪阚值方法。在MATLAB实验平台上证明了这种新的阈值方法能有效弥补传统软、硬阈值的不足,并具有很好的数学性质。将基于平稳小波变换的新闻值方法应用到灰度时间序列的消噪中,实验结果表明,该方法能很好地保留油气水三相流图像信号的特征并能有效地消除噪声,有利于对油气水三相流流动特性的理解。     

油气多相流流动特性分析

油气混输作为管道输送中一种常见形式,它在管道中的流动比较复杂,不同的参数会发生变化,特性也会发生相应的变化,所以本文主要分析了多相流流型的分类和流动特性,还对多相流的几种经典模型进行了分析。通过对多相流模型进行分析及探究,选取了其中两种模型进行了压降计算。根据多相流的特点以及其主要模型的对比,笔者认为:当管道内混合物容量减少,气体容量不变的情况下与气体容量增加,混合物容量不变的情况下多相流流型的变化与理论分析结果基本一致。     

油气水三相流流型的灰度波动时间序列分析

三相流流型极大地影响三相流的流动和传热特性,准确表征流型对相关设备的设计和运行具有重要意义。在水体积流量为1.32—12.15 m3/h,油体积流量为0.01—0.43 m3/h,空气体积流量为0.75—2.5 m3/h时,对垂直上升管中油气水三相流的6种典型流型进行了动态图像的拍摄,提取每一帧图像的灰度均值组成灰度波动信号,进行了分形及混沌时间序列分析。分析结果为:当空气流量在0.75—2.5 m3/h之间变化时,所提取的分形维数及吸引子关联维数分别在0.924 7—1.223 4及1.493 7—5.498 2之间,且分形维数及混沌吸引子关联维数随气相流量呈不规则突变,并与流型的Wigner-Ville分布(WVD)特征相对应,表明了分形维数及混沌吸引子关联维数对油气水三相流流型变化具有敏感的指示器特性,可以较好地表征油气水三相流流型变化。     

基于PTV法对油气水三相流流场的测定

以35^#润滑油、空气和自来水为实验介质,对垂直上升管内的油气水三相流的流场与流速进行了实验研究。在水流量为3.18 m ³·h ^-1、空气流量为0.25 m³·h ^-1、油流量为0.4 m³·h ^-1的工况下应用高速摄像机对水包油流型进行了拍摄,并跟踪气泡及油滴,对流速与流场进行了测定,同时与DPIV中的互相关法求出的流速进行了对比,实验结果表明,应用跟踪气泡及油滴的方法同DPIV的互相关法求出的流速与流场存在较小的误差,可以应用于油气水三相流中的流速与流场的测定。     

油水两相流相含率的软测量方法

对垂直上升管中油水两相流流动测得的电导波动信号,从时频域内提取了11个反映油水两相流流动特性的特征量.频域内特征量提取采用了语音信号处理中的线性预测方法,时域内特征量提取采用了时间序列统计分析方法.将这些特征量作为人工神经网络的输入量,在总流量10～60 m³•d^-1及含水率51%～91%范围内,采用基于Levenbery-Marquardt算法的BP人工神经网络作为相含率预估模型,较好地实现了油水两相流含水率预测,为两相流相含率测量提供了一种新的软测量途径.     

油气水三相段塞流与滚动波流型的转变

Compared with gas-liquid two-phase flow,oil-gas-water three-phase flow is much more complex. There is immiscible oil-water,whose interaction and dispersion greatly affects the flow characteristics. The slug flow pattern of oil-gas-water three-phase and its flow pattern transition were studied in a 95 m long,51 mm i. d. horizontal pipe. The oil-gas-water three-phase slug flow pattern could be classified into five sub-flow patterns. The slug flow was W/O or O/W one during its transition to roll wave,which was three-layer flow pattern without mixed-phase on the interface. An even larger superficial gas velocity was needed for the transition boundary of slug flow and roll wave flow when the superficial liquid velocity is large. Besides,the region of roll wave flow pattern became smaller. The above-mentioned transition only happened when the water cut of liquid was between 30% and 70%. At the same superficial liquid velocity,there appeared a minimum superficial gas velocity corresponding to the transition of flow pattern when the water cut of liquid was between 40% and 50%.     

Soft measurement of pulp suspension flow velocity based on wavelet transform

A soft measurement technique is presented, which the pulp suspension flow velocity (PSFV) can be obtained by analysis of pulp fibre consistency signal without using the flow sensor or flow meter. Doppler Effect in pulp fibre consistency signal, which is caused by the relative motion between pulp suspension flowing in pulp pipe and consistency sensor fixed in the pipe, is discovered on the basis of studying the structure of pulp suspension and the properties of pulp fibre consistency signal, and it is proved by wavelet transform (WT) in this paper. WT are used to analyse pulp fibre consistency signal based on Doppler Effect. PSFV can be determined by the average period of WT which is used to analyse pulp fibre consistency signal based on Doppler Effect. The corresponding tests indicate that the measurement technique is feasible with high precision and better dynamic characteristics.     

基于经验模式分解三相流型信号去噪方法研究

经验模式分解(EMD)作为一种信号处理技术,它是基于数据本身的,且能在空间域中将信号进行分解,从而可以区分噪声和有用信号。应用经验模式分解(EMD)对模拟信号及实测油气水三相流压差波动信号进行滤波去噪处理,分别与db8小波及Haar小波的滤波去噪效果进行定量比较。结果表明:EMD方法与小波方法一样能有效地处理短时瞬态及含宽带噪声的信号,但EMD方法更直接,更方便,且不受小波基函数选择的影响,因此EMD方法更具有通用性和稳定性,从而为三相流流型信号的预处理提供了又一种有效的方法。     

Electrochemical measurement of flow parameters in dilute solution

A new theoretical method is proposed in the electrochemical measurement to obtain therelationship between flow parameter and the electrode current under the existence of ion migration ef-fect.In this way the measurement of local mass transfer coefficient,wall shear stress and liquid veloc-ity are presented and the experiment results are also described.     

Liquid holdup measurement with double helix capacitance sensor in horizontal oil-water two-phase flow pipes

This paper presents the characteristics of a double helix capacitance sensor for measurement of the liquid holdup in horizontal oil–water two-phase flow. The finite element method is used to calculate ...     

双螺旋电容传感器水平油水两相流液相持率测量特性(英文)

This paper presents the characteristics of a double helix capacitance sensor for measurement of the liquid holdup in horizontal oil–water two-phase flow. The finite element method is used to calculate the sensitivity field of the sensor in a pipe with 20 mm inner diameter and the effect of sensor geometry on the distribution of sensitivity field is presented. Then, a horizontal oil–water two-phase flow experiment is carried out to measure the response of the double helix capacitance sensor, in which a novel method is proposed to calibrate the liquid holdup based on three pairs of paral el-wire capacitance probes. The performance of the sensor is analyzed in terms of the flow structures detected by mini-conductance array probes.