交流和直流电场作用下的乳化液电脱水特性  

Characteristics of Emulsion Electric Dehydration Under AC and DC Electric Field

作　　者：陈庆国[1] 梁雯[1] 宋春辉[1] 刘增[2] 赵忠山[2] 魏新劳[1] 

机构地区：[1]哈尔滨理工大学工程电介质及其应用教育部重点实验室,哈尔滨150080 [2]大庆油田设计院,大庆163712

出　　处：《高电压技术》2014年第7期2162-2172,共11页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2012CB723308);黑龙江省杰出青年基金(201009);黑龙江省科技攻关项目(GZ11A210)~~

摘　　要：电场类型及电场强度对原油电脱水效率及脱水电场的稳定性有显著影响。为研究不同初始含水率原油乳化液在电脱水时宜采用的脱水电场类型及电场强度,在实验室试验研究了原油乳化液在交流电场和直流电场作用下的电脱水效果;并从理论上分析了交流电场和直流电场作用下的原油乳化液电脱水机理,建立了交流电场和直流电场作用下的水滴运动模型,得到了水滴电分散电场强度和水滴电泳速度的表达式。结果表明:乳化液电脱水存在最佳临界电场强度,当电场强度超过临界电场强度时将引起水滴电分散,导致脱水率下降;交流电场对高含水率乳化液的脱水速度高于直流电场下的脱水速度,且脱水电场稳定;直流电场对低含水率乳化液有深度净化作用,可提高乳化液的脱水率;所建立的电脱水理论模型较好地解释了不同电压下的电脱水试验现象,并为确定最佳脱水电场强度和选择不同含水率乳化液的脱水电场类型提供了理论依据。In electric dehydration of crude oil, the type and intensity of the applied electric field determine the efficiency and the electric field stability. To obtain an appropriate type and intensity of dehydration electric field for crude oil emulsions with various initial moisture contents, we tested the dehydration effectiveness of crude oil emulsion in laboratory experiments under AC and DC electric field, respectively. We also theoretically analyzed the dehydration mechanism, consequently established a water droplet motion model in electric field, and obtained the expressions of the electrodispersion field intensity and the electrophoretic velocity of water droplets. The results show that there exists optimal critical electric field strength： once the electric field exceeds this critical value, electrodispersion occurs and it lowers the electric dehydration efficiency. Compared with that under DC electric field, the dehydration of emulsion with high moisture con- tent under AC electric field is faster and the dehydration electric field is more stable. However, the DC electric field can enhance the dehydration effectiveness for emulsions with low moisture content, which can be used for deep purification. The proposed theoretical model can well explain the dehydration phenomenon under different voltages, and it provides a theoretical foundation for determining the optimal intensity and type of dehydration electric field for oil emulsion with different moisture contents.

关 键 词：乳化液 电泳 聚结 界面张力 电脱水 电分散 

分 类 号：TE624.1[石油与天然气工程—油气加工工程]