脉冲电场强度及频率对乳化液脱水的影响

摘要

In order to improve the efficiency of oil dehydration and maintain the stability of dehydration electric field to satisfy the technical requirements of compactness and efficiency on onshore and offshore oil processing platform, effects of pulsed electric field strength and frequency on the emulsion dehydration are studied. The relationship between water droplet deformation and electric field strength is derived based on the telescopic model and force balance of water droplet. The expression of applied electric field frequency is obtained based on the vibration kinetic model and force balance with water droplet vibration, so that the optimal dehydration electric field frequency can be determined theoretically. The results show that there exist optimal dehydration electric field strength and frequency during electric dehydration of emulsion. The dehydration rate first increases with the external electric field, and then declines when the external electric field exceeds the critical breakdown strength, with the dehydration electric unstable. When the external electric field frequency reaches the resonance frequency of water droplet, the amplitude of water droplet is the maximum and the dehydration effect is the best.%为提高油田原油脱水处理效率，保证脱水电场的稳定性，满足陆上及海上石油处理设备紧凑、高效的技术要求，开展了脉冲电场下电场强度和频率对乳化液脱水效果影响的研究；通过水滴伸缩模型的建立，分析了水滴在电场作用下的受力情况，推导得出水滴形变量与电场强度的关系式；建立水滴振动动力学模型，分析水滴振动时的受力情况，得出水滴共振时外施电场频率的表达式，从理论上给出了最佳脱水频率的选择方法。研究结果表明，乳化液脱水过程中存在最佳脱水电场强度和最佳脱水频率。随着外施电场强度增加，脱水率逐渐升高，当外施电场强度超过水滴临界破裂电场强度时，脱水率有所下降，且脱水电场不稳定；当外施电场频率使水滴达到共振时，水滴振幅最大、脱水效果最好。