基于ICA和ES-SVM的油气两相流空隙率测量

基于12电极电容层析成像系统(ECT),提出了一种油气两相流空隙率测量的新方法.实际测量时,以ECT电容传感器获得的66个电容测量值作为输入,利用空隙率测量模型计算空隙率.建模过程中,首先采用独立分量分析(ICA),对66个电容测量值进行特征提取.然后以特征参数作为输入,空隙率作为输出,用最小二乘支持向量机(LS-SVM)建立回归函数,并运用进化策略(ES)寻找最优LS-SVM参数.实验结果验证了本文方法的有效性,测量精度和实时性满足工业应用的要求.     

基于ECT和蚂蚁算法的油气两相流空隙率在线测量

基于电容层析成像系统（ECT）和蚂蚁算法，提出了一种油气两相流空隙率在线测量的新方法。该方法利用电容层析成像系统12电极电容传感器所获取的66个测量电容信息，首先根据电容层析成像系统所获取的流型辨识结果确定对应流型下的实际空隙率测量模型参数f和b，然后利用蚂蚁算法的信息素信息，找到当前测量状态下对空隙率起主要作用的组合电容集合和相应的权重系数，从而实现空隙率测量。与流型相对应的空隙率测量线性模型参数f和b基于先验数据通过最小二乘方法确定。油气两相流的实验结果表明，该方法对空隙率的在线测量是有效的，避免了复杂的图像重建计算，实时性能佳，测量时间小于0.08 s。在几种典型流型下，提出的空隙率测量方法与常用的快关阀方法相比最大测量偏差小于5.5%。     

利用电容层析成像技术快速测量油气两相流空隙率的研究

基于12电极阵列式电容传感器电容测量信息,提出了一种油气两相流空隙率测量的新方法.该方法在实际测量过程中,首先对当前流型进行辨识,然后应用相应的空隙率测量模型计算空隙率.空隙率测量模型本质上是不同流型下对空隙率测量敏感的多个测量电容的最佳组合,该组合采用改进的遗传算法并辅以偏最小二乘获得,而流型辨识的结果则是采用电容层析成像技术结合模糊模式识别技术获得.实验结果表明,提出的空隙率测量新方法是有效的,测量精度满足工业应用的要求.     

基于改进de Leeuw关系式的两相流质量流量测量

基于电容层析成像技术和文丘里管流量计,提出改进的de Leeuw关系式来实现油气两相流质量流量测量.实际测量中应用电容层析成像技术获取两相流空隙率和流型信息,由获取的空隙率通过关联Lockhart-Martinelli参数得到质量流量含气率.该改进关系式根据不同的流型信息选择经验参数 (该参数与气相弗劳德准数有关),结合质量流量含气率及文丘里管流量计获取的差压信息实现两相流质量流量测量.油气两相流的实验结果表明所提出的改进de Leeuw关系式是有效的.     

人造板胶粘剂现场固化监测系统

介绍了人造板胶粘剂现场固化监测的系统组成,尤其对同面叉指电极电容传感器涉及的边缘电场、电极电容形态参数的计算方法以及测量终端连线方法等进行了分析.利用该介电测量方法可以准确了解人造板胶粘剂在实际热压时的固化开始温度和时间,对改进现有胶粘剂配方、优化热压工艺曲线具有明确的指导作用.     

基于最小二乘支持向量机的复合肥装置养分含量的软测量建模

针对复合肥装置养分含量无法用常规的传感器在线测量的问题,提出了基于最小二乘支持向量机(LS-SVM)的软测量方法来在线估计养分含量.LS-SVM用等式约束代替传统的标准支持向量机中的不等式约束,求解过程从解二次规划问题变成解线性方程组,求解速度相对加快.工业实例表明LS-SVM所建模型的预测精度较高,能满足实际工业应用的需求.     

电容层析成像技术在线测量气固流化床空隙率的研究

基于电容层析成像技术，提出了一种在线测量气固流化床空隙率的新方法。建立了相应的12电极电容层析成像气固流化床空隙率测量系统，可同时实现气固 流化床空隙率分布的在线显示和整体空隙率测量。选择加权反投影算法进行图像重建以保证空隙率分布显示的实时性和有效性。采用Tikhonov正则化原理和ART算法相结合的组合型新图像重建算法来实现整体空隙率的测量。Tikhonov正则化原理用于克服图像重建过程中的不适定问题，ART算法用于提高最终重建图像的质量。研究表明以上提出的空隙率测量新方法是有效的。空隙率分布在线测量的速度可达25幅／秒以上，整体空隙率测量的最大误差可小于5％。     

碳纤维增强塑料的纤维取向介电测量方法

针对碳纤维增强塑料的纤维取向测量中制样复杂、基体和纤维对比度不高的现状,提出了基于叉指电容的纤维取向介电测量方法。本文建立了各向异性材料的介电-取向理论模型,完成了叉指电容(IDC)传感器的结构设计与优化,最后通过单向碳纤维增强聚醚醚酮(CFR/PEEK)板材的电容测量实验和超景深显微观测结果,验证了该方法的可行性。     

灰色关联分析法对润滑油微量水分测量的改进

针对润滑油中微量水分测量中存在的问题,提出了一种新型变介电常数电容传感器.根据差分的思想改进了润滑油微量水分测量的方法,并用灰色系统理论对实验数据进行了多因素灰色关联度分析.实验结果表明：采用改进的传感器和测量方法能提高传感器对含水率的关联度,显著降低温度和磨粒的交叉灵敏度,能够更准确地反映真实水分含量.     

相位法含水率测量传感器的模型研究

相位法原油含水率测量方法是基于同轴线传感器的一种测量方法,同轴线传感器的结构与参数对测量准确性有着重要影响。利用ANSYS HFSS电磁仿真软件研究同轴线传感器的设计优化方法,分析同轴线内导体的长度对传感器性能的影响,依据仿真结果,确定传感器的优化参数。仿真结果证明了相位法原油含水率测量的有效性和可行性。     

基于ERT传感器和数据挖掘技术的空气水两相流空隙率测量(英文)

Based on an electrical resistance tomography(ERT) sensor and the data mining technology,a new voidage measurement method is proposed for air-water two-phase flow.The data mining technology used in this work is a least squares support vector machine(LS-SVM) algorithm together with the feature extraction method,and three feature extraction methods are tested:principal component analysis(PCA),partial least squares(PLS) and independent component analysis(ICA).In the practical voidage measurement process,the flow pattern is firstly identified directly from the conductance values obtained by the ERT sensor.Then,the appropriate voidage measurement model is selected according to the flow pattern identification result.Finally,the voidage is calculated.Experimental results show that the proposed method can measure the voidage effectively,and the measurement accuracy and speed are satisfactory.Compared with the conventional voidage measurement methods based on ERT,the proposed method doesn’t need any image reconstruction process,so it has the advantage of good real-time performance.Due to the introduction of flow pattern identification,the influence of flow pattern on the voidage measurement is overcome.Besides,it is demonstrated that the LS-SVM method with PLS feature extraction presents the best measurement performance among the tested methods.     

Reconstruction of electrical capacitance tomography images based on fast linearized alternating direction method of multipliers for two-phase flow system

Electrical capacitance tomography (ECT) has been applied to two-phase flow measurement in recent years. Image reconstruction algorithms play an important role in the successful applications of ECT. To solve the il-posed and nonlinear inverse problem of ECT image reconstruction, a new ECT image reconstruction method based on fast lin-earized alternating direction method of multipliers (FLADMM) is proposed in this paper. On the basis of theoretical analysis of compressed sensing (CS), the data acquisition of ECT is regarded as a linear measurement process of permittivity distribution signal of pipe section. A new measurement matrix is designed and L1 regularization method is used to convert ECT inverse problem to a convex relaxation problem which contains prior knowledge. A new fast alternating direction method of multipliers which contained linearized idea is employed to minimize the objective function. Simulation data and experimental results indicate that compared with other methods, the quality and speed of reconstructed images are markedly improved. Also, the dynamic experimental results in-dicate that the proposed algorithm can fulfil the real-time requirement of ECT systems in the application.     

用于两相流流型显示和空隙率测量的电容层析成像技术

引　言两相流流型的实时显示和空隙率的在线测量对两相流系统的控制、运行乃至机理研究等均具有重要意义 ,一直是两相流领域中重要的研究方向 .现已提出多种实现流型显示和空隙率测量的方法 ,例如用于流型显示的核辐射线法和光学法 ,用于空隙率 (或浓度 )测量的机理估算法、核辐射线法、电学法、光学法、微波法、热学法和核磁共振法等 ,但是总的来讲还未能满足应用要求 ,实际应用的例子也较少[1] .电容层析成像 (ｅｌｅｃｔｒｉｃａｌｃａｐａｃｉｔａｎｃｅｔｏｍｏｇｒａｐｈｙ ,简记ＥＣＴ)技术由于可在不干扰流场的情况下获取反映两相流…     

用改进ECT技术测定油气两相流中空泡分数的测量研究

To measure the void fraction online in oil-gas pipeline, an improved electrical capacitance tomography (ECT) system has been designed. The capacitance sensor with new structure has twelve internal electrodes and overcomes the influence of the pipe wall. The data collection system is improved by using high performance IC (integrated circuit). Static tests of bubble flow, stratified flow and annular flow regime are carried out. Measurements are taken on bubble flow, stratified flow and slug flow. Results show that the new ECT system performs well on void fraction measurement of bubble flow and stratified flow, but the error of measurement for slug flow is more than 10%.     

油气两相流空隙率测量

A new method for the voidage measurement of gas-oil two-phase flow was proposed.The voidage measurement was implemented by the identification of flow pattern and a flow pattern specific voidage measurement model.The flow pattern identification was achieved by combining the fuzzy pattern recognition technique and the crude cross-sectional image reconstructed by the simple back projection algorithm.The genetic algorithm and the partial least square method were applied to develop the voidage measurement models.Experimental results show that the proposed method is effective.It can overcome the influence of flow pattern on the voidage measurement,and also has the advantages of simplicity and speediness.     

基于改进的RBF网络和自适应小波图像增强的ECT两相流测量系统(英文)

Electrical capacitance tomography(ECT) is a non-invasive imaging technique that aims at visualizing the cross-sectional permittivity distribution and phase distribution of solid/gas two-phase flow based on the measured capacitance.To solve the nonlinear and ill-posed inverse problem:image reconstruction of ECT system,this paper proposed a new image reconstruction method based on improved radial basis function(RBF) neural network combined with adaptive wavelet image enhancement.Firstly,an improved RBF network was applied to establish the mapping model between the reconstruction image pixels and the capacitance values measured.Then,for better image quality,adaptive wavelet image enhancement technique was emphatically analyzed and studied,which belongs to a space-frequency analysis method and is suitable for image feature-enhanced.Through multi-level wavelet decomposition,edge points of the image produced from RBF network can be determined based on the neighborhood property of each sub-band;noise distribution in the space-frequency domain can be estimated based on statistical characteristics;after that a self-adaptive edge enhancement gain can be constructed.Finally,the image is reconstructed with adjusting wavelet coefficients.In this paper,a 12-electrode ECT system and a pneumatic conveying platform were built up to verify this image reconstruction algorithm.Experimental results demonstrated that adaptive wavelet image enhancement technique effectively implemented edge detection and image enhancement,and the improved RBF network and adaptive wavelet image enhancement hybrid algorithm greatly improved the quality of reconstructed image of solid/gas two-phase flow [pulverized coal(PC)/air].