共查询到18条相似文献,搜索用时 187 毫秒
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传统电脱水器采用裸电极,乳化液含水率较高时高强电场作用下容易发生击穿现象,设计了包覆绝缘层的高压电极并加工了新型静电聚结器,采用水/原油乳状液为实验介质,并利用显微高速摄像系统结合图像处理技术,考察了电场强度,乳化液流量、含水率对液滴滴粒径分布特性的影响。结果表明,现场与室内实验的液滴粒径分布与Rosin-Rammler分布均吻合较好;包覆绝缘层的高压电极可有效防止电击穿现象的发生;增加电场强度有助于油、水分离,但高于临界电场强度后,容易导致液滴破碎,并且含水率越高,最优电场强度越低;随着乳化液流量的增加,电场作用降低,但高强电场在高流量下依然使液滴粒径明显增大。 相似文献
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采用两种不同结构的聚结构件进行室内实验,通过变化构件尺寸考察电场强度、电场作用时间对脱水效果的影响。电场中液滴的变形率与电场强度、表面张力、液滴尺寸以及连续相的介电常数有关。增大电场强度可显著提高静电聚结器的聚结效果,但由于电分散现象会对聚结产生一定的限制作用,因此,静电聚结器存在一个最优电场强度范围,超过此范围聚结效果下降。在一定范围内,延长电场作用时间可提高聚结器的聚结效果,但是达到一定限度后,电场作用时间的变化对聚结效果影响不大。电场强度对聚结效果的影响高于电场作用时间。静电聚结器的聚结构件结构影响乳状液的流场分布,这对聚结效果有显著影响。 相似文献
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鉴于电破乳法在油田生产中广阔的应用前景,为完善电破乳微观液滴聚结机理,从分散相液滴变形、靠近、破裂与聚结等动力学过程着手,系统梳理了国内外有关聚结机理的研究进展。从乳状液含水率、黏度、导电性、液滴表面张力四个方面详细叙述了物理因素对液滴聚结的影响,针对电场参数对聚结速度的影响,着重综述了电场形式、电场强度、频率等对液滴聚结速度的影响。 相似文献
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采用显微实验方法,全面考察高频高压脉冲电场下W/O乳状液中水滴的聚并行为。结果表明,实验范围内,随着脉冲电场强度、占空比和频率的增加,W/O乳状液中的水滴相互靠近的速率相应增大;当聚并时刻比超过0.8,水滴的靠近速率迅速增加。在脉冲电场中,W/O乳状液中的水滴融合时间与电场参数间并无直接关系,而与油-水界面张力紧密相关;油-水界面张力越大,水滴融合速率越快。静电脱水过程中,施加于W/O乳状液的电场强度应小于过度极化临界电场强度,否则将显著降低乳状液破乳脱水效果。上述研究成果为高压高频脉冲静电破乳机理的深入探讨奠定了基础。 相似文献
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为揭示聚合物经地层剪切后对油田产出液的影响,通过室内静电聚结快速评价系统研究了破乳剂YFPC-792和降解非离子型聚丙烯酰胺(NPAM)对巴西Peregrino油田W/O型乳状液静电分离效果的影响。结果表明,YFPC-792可提高W/O型乳状液的静电脱水效果,在150 Hz、294.44 k V/m的电场作用下,乳状液最佳电场停留时间为100 min;随NPAM浓度增加,乳状液分离效率和液滴平均粒径降低,NPAM溶液黏度增加;由于NPAM分子间的"架桥絮凝"效应,未降解的NPAM加量为200 mg/L时乳状液的静电聚结效果最好,电分离效率达81%;含降解NPAM的乳状液电分离效率随聚合物浓度增加而减小;含水率20%乳状液静电分离效率为49%,聚结效果最差,而含水率30%乳状液静电分离效率为81%,聚结效果最好。含YFPC-792和降解NPAM的乳状液脱水开始后的5数15 min,重力沉降的分离效果优于电脱水效果,而后电脱水效果优于重力沉降。 相似文献
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针对目前高含水原油采出液采用传统三相分离与热化学分离和电脱水方法存在分离级数和设备多、油水分离效率低、电脱水运行不稳定等问题,在静电预聚结研究基础上,采用自制绝缘电极和乳化液,开展静电聚结脱水研究,使水滴预聚结和沉降分离同时进行。通过静态聚结脱水试验考察了乳化液水含量、电压、温度和沉降时间等因素对静电聚结脱水效果的影响,结果表明乳化液脱水率随温度升高、电压增大和沉降时间延长而提高。其中温度影响最大,电压和沉降时间影响较小。在动态静电聚结原油脱水试验装置上进行验证,同时对不同分离器结构和不同电极结构及进料方式进行了对比,对试验条件进行了优化。动态试验结果表明,在电压2 kV,温度65~70℃,停留时间不大于10 min的条件下,高含水乳化液的脱水率均可达95%以上。 相似文献
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随着原油重质化、劣质化,原油脱水变得更加困难,造成常规电脱水器的极板之间会产生电弧及短路、电脱水电流大,甚至造成变压器跳闸、烧毁现象发生.尝试采用氟塑料设计制造平板绝缘电极静电聚结器,并进行室内实验.通过分析实验结果,总结绝缘材料、电极结构和电场作用时间等因素对聚结效果的影响规律,评价该结构的静电聚结器及制作工艺的优缺点.实验结果表明,对含水特高的原油乳化液,该静电聚结器的脱水效果非常理想.对含水率为70%和80%的原油乳化液,脱水效率可达95%以上. 相似文献
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Electric coalescence in alternating current (AC) electric field is one of the important electrical dehydrate technologies. In this study, the coalescence behavior of two water drops in an AC electric field was studied experimentally using a high-speed camera. There is a critical electric field strength above which the two drops would not coalescence. Such coalescence behavior was supposed to be depended on the electric field strength and the frequency. Lower electric field strength, lower frequency and smaller size would facilitate the coalescence of drops. The understanding of the electric coalescence could be helpful to advance the design of the electrocoalescencers. 相似文献
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He Li-min Yang Dong-hai Gong Rong-n Ye Tuan-jie Lü Yu-ling Luo Xiao-ming 《石油科学(英文版)》2013,10(4):548-561
Drop-drop coalescence is important in electric dehydrators used for oil-water separation in the oil industry.The deformation degree,angle between the electric field and the center line of two drops,effects of intensities and frequencies of the electric field have been studied by analyzing droplet images.However,seldom have people investigated the movement and the relative velocity in the process of dropdrop coalescence.In this paper forces acting on a single droplet and horizontal water droplets in an AC electric field were analyzed,and experiments were carried out to investigate the deformation,movement and coalescence characteristics of droplets with white oil and water.With a micro high-speed camera system and image processing technology,the droplet images were collected and analyzed.The results indicate that the deformation is mainly affected by the electric field intensity,frequency,droplet diameter and the oil viscosity.High field strength and large diameter facilitate deformation of drops in the electric field.The effect of frequency and oil viscosity is not obvious.Higher frequency and higher oil viscosity will lead to smaller oscillation amplitude.The effect of electric field intensity and droplet diameter on oscillation amplitude is not obvious.When the center-to-center distance between droplets is large,the forces acting on droplets in the horizontal direction are mainly dipole-dipole attraction and drag forces.There is also the film-thinning force when droplets get closer.The forces are simplified and derived.Based on force analysis and Newton’s second law,the relative movement is analyzed in different parts,and the relationship of center-to-center distance and time is in accordance with an explinear function at different stages.According to experimental data,the movement of 145 μm double droplets before coalescence can be fitted well with an explinear function at two stages.In addition,the whole movement process is investigated and can be estimated with a fourth order polynomial curve,from which the relative velocity of droplet movement can also be obtained.With an increases in electric field intensity and droplet diameter and a decrease in oil viscosity,the relative velocity increases.Only when the oil-water interfacial tension is obviously high,can it influence the relative movement significantly.The coalescence is mainly dipole coalescence and chain coalescence under influence of the AC electric field. 相似文献
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高含水乳状液静电聚结脱水研究 总被引:1,自引:0,他引:1
随着原油重质化、劣质化、高含水时期的到来,原油静电聚结脱水出现了电弧及短路现象,造成静电聚结脱水电流增大,甚至造成变压器跳闸、烧损,致使常规电脱水器的稳定运行出现问题。为了解决这些问题,采用改性Teflon绝缘材料,通过热缩工艺制备复合电极。使用制备的复合电极进行了高含水乳状液静电聚结脱水研究,首先制备不同乳化状态乳状液并考察其脱水效果,然后采用不同含水量乳状液考察了静电聚结温度、停留时间、电压等因素对脱水效果的影响。结果表明,该复合电极对高含水乳状液静电聚结脱水不会产生电弧、短路等问题,并且有很好的脱水效果.对于40%含水量乳状液,当电压为1800 V,温度为80℃,停留时间10 min时,脱水效率可达85.8%。 相似文献
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三相分离器外加电流阴极保护技术是对分离器筒体施加阴极电流,使其电极电位从平衡电位向负移动至免腐蚀区,强行抑制阴极表面的腐蚀化学反应。结合濮城油田含油污水矿化度高、pH 值低的腐蚀特点,经过大量的现场试验,实施了对三相分离器的外加电流阴极保护,并在应用中取得了良好的效果。 相似文献