高频/高压静电聚结破乳评价方法及电场频率选择研究

为满足当前所处理原油劣质化的新挑战,实现设备紧凑高效、运行节能降耗等发展目标,采用高频/高压电场进行W/O型乳化液静电聚结破乳脱水已经成为国内外的研究热点。采用自主研制开发的全数字控制高频/高压脉冲方波交流电源,基于矩形流道连续流动实验装置,采用Turbiscan Lab分散稳定性分析仪评估静电聚结破乳特性,并系统研究了电场频率和乳化液含水率对分散相水液滴聚结长大的影响。研究结果表明,W/O型模拟乳化液含水率5%时,施加电压为5.4 kV、频率为1.1 kHz的电场,分散相水液滴的平均体积粒径增大39.75倍,稳定动力学参数增加3.12倍,破乳效果非常明显;W/O型模拟乳化液的含水率不同,分散相水液滴取得最佳聚结效果所对应的电场频率也不同,工程应用中应该根据不同油田原油乳化液的实际情况进行具体评估。     

非均匀高频电场下W/O型乳化液动态破乳聚结特性的实验研究

采用自主设计搭建的非均匀电场动态破乳聚结特性实验装置,首次在国内配套使用高频/高压脉冲交流电源和FBRM G600型聚焦光束反射仪,建立了W/O型乳化液中分散相水颗粒粒径分布的在线测试评价方法,进而系统研究了电场参数和流动参数对W/O型乳化液在非均匀电场作用下动态破乳聚结特性的影响规律。实验结果表明,对于所配制含水率为20%的W/O型乳化液,在电场强度为2.87 kV×cm~(-1)、电场频率为2 kHz、占空比为50%时,分散相水颗粒体积平均粒径(VMD)值较初始稳定状态的增长倍数达到最大值,为3.81倍;小粒径水颗粒(粒径小于10μm)数目较初始稳定状态减小至最小值,减少了62%;充分证明在非均匀电场下,合理电场参数的筛选对于乳化液破乳聚结具有重要意义。在实验流速范围内,VMD值增大倍数随着流速的增加先增大后减小,表明在确保足够停留时间的前提下,适度增加乳化液流速方能显著提升破乳聚结效率,因此合理流速的确定应当优先满足乳化液在电场中最短停留时间的要求。     

低压脉冲电场对高浓度O/W型乳化液破乳特性的影响

为实现高含油浓度O/W型乳化液的电场破乳预分水,借鉴电絮凝技术的工作原理自行设计了静态序批式电场破乳预分水实验装置。在对乳化液理化特性进行量化表征以确保其稳定性的基础上,以预分水率为主要评价指标,系统实验研究了电场形式、峰值电压、脉冲频率、占空比及含水率对O/W型乳化液静态破乳预分水特性的影响。结果发现,脉冲直流方波电场下乳化液的破乳效果比直流电场较好;含水率降低使乳化液的破乳程度减弱;峰值电压、脉冲频率和占空比都存在一个最优值。当施加脉冲直流方波电场、电压幅值为40V、脉冲频率为2kHz、占空比为0.5、加电时间为30min时,含水率90%乳化液的预分水率达87.18%。基于实验过程中的现象推测,高含油浓度O/W乳化液的破乳预分水机理包括双电子层作用和类似电絮凝作用。     

电场-旋流场耦合强化乳化液脱水技术研究进展

以油包水乳化液为对象，阐述了电场-旋流场耦合作用下液滴聚结和强化分离机理，介绍了现阶段耦合装置结构的发展，分析了速度、电压幅值、频率及乳化液特性等操作参数对液滴聚结、破碎及油水两相分离性能的影响。同时指出了现阶段研究的局限，探讨了今后的研究方向，为耦合场下液滴聚结特性和操作参数的研究提供借鉴。     

辽河油田高凝油三元驱采出液高频脉冲电脱水实验研究

辽河油田高凝油三元驱采出液成分复杂,常温下为固态,因性质恶劣导致水滴聚并困难。采用高压高频脉冲电脱水技术对该采出液进行脱水处理,研究了不同药剂组合下,电场参数、操作温度、电脱时间对采出液电脱后油中含水率和切水含油浓度的影响。结果显示:高压高频脉冲电场存在最优的电压幅值、频率和脉宽比,使采出液电脱后油中含水率和切水含油浓度降至最低;随操作温度的升高,油水乳状液热稳定性降低,电脱后油中含水率和切水含油浓度减小;增大电脱时间可提高电脱水效果,但持续增加电脱时间不会提升脱水效果,选择适中的脱水时间最为经济。     

流花油田老化油高频/高压脉冲交流电场破乳脱水研究

在测定老化油乳化液粘度-温度曲线、含水率反相点曲线的基础上,采用静态静电聚结破乳实验装置研究了油水反相特性对电场破乳脱水效果的影响,使用自主搭建的动态破乳脱水特性快速评价装置研究了高频/高压脉冲交流电场下电场强度和频率对老化油乳化液破乳脱水效果的影响. 结果表明,流花油田老化油反相点含水率约为40%,油水反相过程中乳化液粘度增加,电场破乳脱水难度增大;老化油乳化液含水率为30%时,最优电场强度1.25 kV/cm、电场频率2.5 kHz下破乳后的离心脱水率为97.8%,远高于工频电场下的离心脱水率(4.2%),高频/高压电场破乳比工频/高压电场破乳优势明显.     

不同含水率下电场参数对动态脉冲电脱水的影响

为全面考察不同含水率下各电场参数对动态脉冲电脱水性能的影响规律,进行了动态高压高频脉冲电脱水室内实验研究。结果表明:乳状液含水率较高时,分散相水滴粒径较大、间距较低,所需静电极化作用力大大降低,低电压下也能保证较高的水处理效率。电场频率为4 kHz时,动态电脱水器的性能较优,动态电脱水过程中的剪切弥散效应,增加了水滴间的碰撞聚结,高频条件下高含水率的乳状液破乳所需电场能减小,脱水功率降低。脉宽比为0.5时,动态电脱水器的脱水性能最优,而当含水率较高、脉宽比较大时,脱水电流过大导致垮电场,严重影响脱水器的安全稳定运行。上述成果为高效紧凑静电脱水设备的研究开发奠定了实验基础。     

高压高频脉冲电脱水机理探析

对电场作用下W/O乳化液中分散相水滴进行了受力分析,并探讨了高压高频脉冲电脱水机理。分析表明,水滴相互靠近、即将聚并时,阻力显著增加,阻力大小与水滴粒径、间距、连续相粘度以及排液系数等有关;电场强度介于临界破乳场强和临界乳化场强时,水滴发生聚并且不发生电分散;水滴在脉冲电场下的受迫振动频率与其固有频率相接近时,共振效应最为明显;脉宽比适中时,静电极化效应明显,可避免电场能泄漏、垮电场等事故的发生。     

四氢呋喃和一氟二氯乙烷水合物颗粒聚结特性

实验研究了四氢呋喃（THF）水合物和一氟二氯乙烷（HCFC-141b）水合物颗粒聚结特性,将实验得到的水合物颗粒聚结粒度分布（PSD）与正态分布、对数正态分布、伽马分布、威布尔分布拟合曲线对比,探讨了初始四氢呋喃溶液和一氟二氯乙烷溶液浓度以及搅拌速度对水合物颗粒聚结的影响,并对四氢呋喃水合物和一氟二氯乙烷水合物颗粒特性进行了对比。结果表明,四氢呋喃水合物和一氟二氯乙烷水合物颗粒聚结粒径符合对数正态分布;初始溶液浓度越低、搅拌速度越大,水合物颗粒聚结粒径越小,可以起到防治水合物颗粒聚结的作用;四氢呋喃水合物颗粒粒径是一氟二氯乙烷水合物颗粒粒径的1.3倍左右,从成浆输送的角度来说,一氟二氯乙烷水合物颗粒更易于在管道中输送。     

四氢呋喃和一氟二氯乙烷水合物颗粒聚结特性

实验研究了四氢呋喃(THF)水合物和一氟二氯乙烷(HCFC-141b)水合物颗粒聚结特性,将实验得到的水合物颗粒聚结粒度分布(PSD)与正态分布、对数正态分布、伽马分布、威布尔分布拟合曲线对比,探讨了初始四氢呋喃溶液和一氟二氯乙烷溶液浓度以及搅拌速度对水合物颗粒聚结的影响,并对四氢呋喃水合物和一氟二氯乙烷水合物颗粒特性进行了对比。结果表明,四氢呋喃水合物和一氟二氯乙烷水合物颗粒聚结粒径符合对数正态分布;初始溶液浓度越低、搅拌速度越大,水合物颗粒聚结粒径越小,可以起到防治水合物颗粒聚结的作用;四氢呋喃水合物颗粒粒径是一氟二氯乙烷水合物颗粒粒径的1.3倍左右,从成浆输送的角度来说,一氟二氯乙烷水合物颗粒更易于在管道中输送。     

重力分离器聚结构件数值模拟及优化研究

使用Fluent数值模拟软件,采用标准k-ε湍流模型和多项混合算法对不同入口分散相粒径和不同构造聚结板的分离器内部流场进行了三维数值模拟,对比通过聚结板前后油水浓度分布以确定分离器有效处理分散相颗粒的粒径范围;同时在尺寸为384mm×20mm×1800mm的分离器上更换4种不同材料与流道形状的聚结板进行了分离特性研究,得出了影响聚结板分离特性的因素和处理分散相粒径的范围,选出适于本分离器的聚结板;通过对比实验数据评价不同聚结板下分离器的聚结分离效率,提出了不同工况下选取聚结构件的依据。     

Synthesis of novel reactive coalescing agents and their application in a latex coating

The syntheses and the performance of five glycidyl compounds as novel reactive coalescing agents are presented. The reactive coalescing agents were synthesized with moderate yields, structures were verified using spectroscopic methods, and the properties of glycidyl compounds such as boiling points and evaporation rates were measured. The applicability of five glycidyl compounds as reactive coalescing agents was tested in characterized carboxyl functional latex. Properties like pendulum hardness, gloss, and efficiency of the glycidyl compound to reduce the minimum film‐formation temperature (MFFT) of the latex were measured from the cured latex films. The application test results were compared to the commercial nonreactive coalescing agent, Nexcoat? 795. The films with synthesized reactive coalescing agents with carboxyl functional latex were found to have good pendulum hardness and excellent gloss. Also, the efficiency of three glycidyl compounds in lowering the MFFT of the latex was competitive with the commercial coalescing agent. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 610–615, 2003     

疏油改性对玻纤聚结元件气液过滤性能的影响

气液聚结元件在压缩气体净化等工业领域应用广泛,目前聚结元件的性能难以满足行业不断增长的需求,但是提高聚结元件过滤效率的同时,阻力也会随之升高,不利于其综合性能的优化。为研制低阻高效的聚结元件,利用不同浓度氟硅氧烷丙烯酸酯溶液对聚结滤材进行疏油改性,分析了表面能不同的滤材在气液过滤过程中压降、过滤效率以及二次夹带现象的变化,并对改性在聚结滤芯上的应用效果进行研究。结果表明,改性滤材在过滤效率提高10%的同时,稳态压降可降低约30%。滤材表面性质变化导致的跳跃压降减小是稳态压降降低的主要原因;滤材内液体分布对扩散、惯性分离作用的增强以及二次夹带的减少是效率提高的主要原因。对于表面能不同的疏油滤材,稳态压降和效率均随表面能的减小而升高。聚结滤芯经过改性后品质因子最大可提高92%。     

Influence of oleophobic modification on gas-liquid filtration performance of glass fiber coalescing elements

Gas-liquid coalescing elements are widely used in industrial fields such as compressed gas purification. Currently, the performance of coalescing elements is difficult to meet the growing needs of the industry. However, while increasing the filtration efficiency of the coalescing element, the resistance will increase simultaneously, which is not conducive to the optimization of the comprehensive performance. To develop low-resistance high-efficiency coalescing elements, the coalescing filter materials are modified by different concentrations of fluorosilicone acrylate solution. The evolution of pressure drop, filtration efficiency and secondary entrainment of the filter materials with different surface energy during the gas-liquid filtration process were analyzed, the modified filter materials were fabricated into coalescing filters for verification. The results showed that, the filtration efficiency of the modified filter materials was increased by approximately 10%, and the steady-state pressure drop was reduced by approximately 30%. The decrease in jump pressure drop caused by changes in the surface properties of the filter materials is the main cause of the decrease in steady-state pressure drop. The increase in filtration efficiency is caused by the enhancement of diffusion and inertial separation, and the reduction of secondary entrainment. For oleophobic filter materials with different surface energy, the pressure drop and filtration efficiency increase with the decrease of surface energy. The quality factor of the coalescing filter element can be increased by up to 92% after modification.     

流化床电化学反应器研究——(Ⅱ)导电机理及电位波动特性的实验研究

以电沉积金属银为实验体系,对流化床电化学反应器的电位波动特性进行了实验研究,考察了床层膨胀率、外加电压、流化状态等因素对电位波动的影响,并验证了本文(I)所提出的导电机理.     

聚结构件结构对重力分离器油水分离性能的影响

为考察聚结构件结构对油水重力分离器分离性能的影响,在理论分析的基础上,采用错搭波纹板、开孔波纹板以及网状波纹板进行了室内实验研究,并从停留时间、油相浓度分布、分离效率、聚结结构前后油相浓度及中位粒径差等方面进行了全面对比。结果表明,网状波纹板结构对小液滴具有较好的聚并作用,能显著提高油水分离效果,缩短停留时间;开孔波纹板次之,而错搭波纹板效果最差。实验发现,良好的亲油疏水性、具有足够的油滴上浮通道以及与混合相具有较大的接触面积,是性能优良的聚结结构所应具备的三个条件。上述工作为进一步开发高效紧凑的油水重力分离设备提供了依据。     

Low VOC self-crosslinking waterborne acrylic coatings incorporating fatty acid derivatives

Acrylic waterborne coatings free of volatile coalescing agents were produced and characterized. The film-formers used in the coatings were resins incorporating an allylic fatty acid derivative (AFAD) and an acrylic fatty acid derivative (AcFAD), either as reactive (non-volatile) coalescing agents or as co-monomers. The minimum film-forming temperatures of the new coatings were lower than the reference, confirming that AFAD and AcFAD act as coalescing agents. On the other hand, the observed reductions in through drying-time and increase in scrub resistance, more evident for AcFAD, indicating that reaction between the conjugated double bonds in the fatty acid derivatives and atmospheric oxygen–oxidative cure–took place and provided an effective self-crosslinking drying mechanism.     

Gas Flow Behavior in a Two‐Phase Reactor Stirred with Triple Turbines

Gas behavior was studied in a gas‐liquid reactor stirred with multiple turbines. Triple PBTs pumping either down or up and BT‐6's were used. The behavior of coalescing (water) and non‐coalescing (sodium sulfate solution) systems was investigated. The gas phase behavior was characterized by means of the RTD and modeled with the axial dispersion model. This model was confirmed to interpret the experimental data well for water and satisfactorily for the coalescence‐inhibiting solutions. The influence of the operating conditions, turbine type and system coalescing behavior on the model parameters is discussed. Comparison is also made with similar data regarding Rushton turbines and high‐solidity ratio hydrofoils, as well as gas holdup.     

聚结元件性质对水-柴油混合液聚结分离效果的影响

研究了聚结元件空隙率、润湿性、长度以及乳化态液滴的停留时间对水-柴油混合液聚结分离效果的影响,其中通过轴向压缩获得了不同的空隙率,而通过改变流速获得不同的停留时间。结果表明,亲水性、空隙率较低的聚结元件具有更好的分离效果;聚结元件的长度存在着1个最小值L_min,只有实际聚结元件长度大于该值时才会有较好的分离效果,但此时继续增长聚结元件并不会明显提升分离效果。