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%。     

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LS-SVM测量油气两相流空隙率

利用ECT电容传感器提供的电容测量值,基于改进的最小二乘支持向量机(LS-SVM),提出了一种油气两相流空隙率测量的新方法.运用该方法测量空隙率时,以ECT电容传感器获取的66个独立电容值作为空隙率模型的输入,计算即可得空隙率.建模阶段,针对LS-SVM使用中存在的问题,首先运用训练数据筛选技巧,对LS-SVM进行稀疏化改进,接着引入实数编码的遗传算法(RC-GA)优化LS-SVM参数,然后运用改进后的LS-SVM和基于RC-GA的参数选取方法建立空隙率测量模型.所提出的空隙率测量方法省去了常用ECT方法测量空隙率时的复杂耗时的图像重建过程,提高了空隙率测量的实时性.实验结果表明,提出的LS-SVM改进和参数优化方法是有效的,提出的空隙率测量方法具有实时性佳的优点,测量精度满足实际应用要求.     

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.     

基于空隙率的油气两相流流量测量的研究

利用文丘里管进行油气两相流流量测量的研究,在考虑了气液滑移比对流量测量的影响,对均相流流量测量模型进行了修正,得到了空隙率和文丘里管两端差压与两相流总质量流量及液相质量流量的关系式。实验结果表明利用这两个关系式,在干度小于2％,空隙率在15%～83％范围内,总质量流量测量和液相质量流量测量的均方根误差均小于5％。针对不同的流型,对关系式中的系数作了修正计算,进一步降低了测量误差。     

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…     

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.     

水平管内油气两相弹状流的产生

<正>近几十年来,水平管内气水两相弹状流发生的研究已引起各研究者的注意.Koldyhan＆a[什1970年）首先采用了古典的线性稳定分析方法研究了弹状流发生的初始条件,并得到了其发生     

水平油气两相流中液滴分布的衰减系数

引　言在石油、天然气的开发过程中 ,在通常的操作条件下 ,水平管线中的两相分离流 (指分层流和环状流 )是常见的流动结构 在较高的气相流速时 ,液滴可从液膜表面上被撕破而进入到中心气核中去 .液滴和其携带流体间的相互作用和相间滑移的存在强烈地影响着流动时的压降特性 ,而液滴浓度在管截面上的不均匀分布 ,也影响气相速度的分布以及对相份额的准确计算和测量 .众所周知 ,管路的压降和相份额数据是两相或多相流输送管线和管路终端处理设备的设计及安全、经济运行的最重要依据 .由此可见 ,在两相输送过程中对液滴传输特性研究的重要性 .…     

Void Fraction Measurement for Two‐Phase Flow Using Electrical Resistance Tomography

Measurement of void fraction of two‐phase flows remains a challenging area. In this paper the application of an electrical resistance tomography (ERT) system for this purpose has been studied. A new approach through the direct use of the voltage data measured by the ERT system is presented. The measured voltage data are first compressed through a feature extraction, and a polynomial regression procedure is followed to obtain the relationship between the void fraction and the feature extracted. Both simulation and experiment are carried out to verify the approach. The methodology of the new approach, simulation and experimental results are presented in the paper.     

电阻层析成像技术测量两相流气相流量

提出利用双截面电阻层析成像(ERT)系统,并采用相关方法进行两相流气相流量的测量。介绍像素相关与基于边界电压特征值相关两种相关方法,并进行单气泡模拟实验。实验结果表明用这两种相关方法进行两相流的气相流量测量是可行的。     

以葡辛胺为拆分剂拆分酮基布洛芬

The process of resolution of racemic ketoprofen using n-octyl-d-glucamine as an optical resolution agent was investigated. The process consists of preparation of the diastereomer salt of ketoprofen with n-octyl-d-glucamine, liberation of S-（＋）-ketoprofen from its diastereomer salt and recovery of the remaining ketoprofen and n-octyl-d- glucamine. The suitable conditions for preparation of the diastereomer salt were methanol and ethyl acetate （1：1 by volume） as the solvent, the ratio of solvent volume to ketoprofen mass at 8 ml：1 g, and the molar ratio of ketoprofen to n-octyl-d-glucamine at 1：1. The preferred approach to liberate S-（＋）-ketoprofen from its diastereomer salt was alkali dissolution, acid adjustment and ethyl acetate extraction. Racemization of the recovered ketoprofen could be achieved by reacting the recovered ketoprofen with 10% NaOH at 507kPa for 6h. The recovered n-octyl-d- glucamine could be refined by acid dissolution and alkali adjustment. S-（＋）-ketoprofen can be obtained with high optical purity and yield, showing that the present process is a practical and efficient one which can be used in industrial scale for preparation of S-（＋）-ketoprofen.     

基于前项补偿的12电极的ECT数据采集系统的设计

以12电极油水两相流电容层析成像系统为研究对象,在分析电容层析成像系统的测量原理的基础上,设计了电容层析成像数据采集系统,系统采用前项补偿方法完成了微小电容的测量,并根据实际测量过程所涉及的关键性问题进行了分析和讨论,通过实验验证了此方法是实用可行的,较好地解决了微小电容精确测量问题.     

气升式环流反应器内传质行为的分析与测量

1 INTRODUCTION Airlift loop reactors have emerged as one of the most promising devices in chemical, biochemical and environmental engineering operations. Its main ad-vantages over conventional reactors include excellent contact among different phases, ease of removal or replenishment of particles, and high heat and mass transfer rates[1]. High gas-liquid contacting area and favorable flow pattern are the attractive features of this type of three-phase contactors. Typical processes that ca…     

Dynamics of segregation and fluidization of binary mixtures in a cylindrical fluidized bed

Dynamics of segregation and fluidization of unary particles and binary mixtures in a cylindrical fluidized bed is investigated using temporally– and spatially–resolved measurements of solids volume fraction (α_s) performed using Electrical Capacitance Tomography (ECT). Through the comparison with high-speed imaging, we have shown that ECT can be used to measure the segregation behavior in cylindrical fluidized beds quantitatively. ECT measurements have been used further to quantify the effects of mixture composition, particle–diameter ratio, and superficial gas velocity on the bed segregation behavior. Dynamics of fluidization behavior is characterized using the time–evolution of local α_s fluctuations, corresponding frequency distribution, and bubble size distribution. Further, a relation between the measured variance of α_s fluctuations at different radial locations and corresponding flow structures under different fluidization conditions is established. The present work helps to understand dynamics of segregation and fluidization of binary mixtures and to provide a database for validation of Eulerian multifluid CFD models.     

ECT系统微弱电容检测

针对电容层析成像系统电容检测信号微弱的特点,使用交流法电容测量电路,依据直接数字合成技术原理,以AD9953为核心,设计双路正弦信号发生器电路。根据相敏解调原理,通过四象限模拟乘法器AD734和滤波电路,对信号进行解调,获得直流信号。为了简化数据采集系统,使用多通道切换开关电路,实现了单通道电容检测。最后应用该系统测量管道空管和满管的电容值,较好地解决了电容层析成像系统微弱电容检测问题。     

2，6-萘二甲酸二甲酯在有机溶剂中溶解度的测定与关联

Solubility of dimethyl-2,6-naphthalene dicarboxylate in acetic acid, N,N-dimethylfonnamide, N,N-dimethyl acetamide, dimethyl sulphoxide, and N-methyl-2-ketopyrrolidine were determined using a dynamic method. The measured systems were correlated by UNIFAC group contribution method. A new main group （aromatic ester, ACCOO） was defined to express the activity coefficients of the aromatic ester. New interaction parameters of the ACCOO group were expressed as the first-order function of temperature and were determined from the experimental data. The calculated results for the new interaction parameters were satisfactory. The measured systems were also correlated with the Wilson and 2-h models, and the results were compared with those of the UNIFAC model.