摘要
变压器油受潮及劣化分解等状况会析出气体乃至形成悬浮气泡,受电磁、热、流等多物理场耦合作用,气泡将呈现出极其复杂的电流体动力学行为,从而显著影响变压器油的绝缘性能,因此研究变压器油中气泡的形态演变和运动规律具有重要意义。为此,采用湍流模型模拟变压器油流状态,构建了多场耦合作用下悬浮气泡的动力学分析模型,研究了极间电压、油流速度、气泡尺寸及气泡数目等因素对悬浮气泡聚并行为的影响,并分析了气泡形态演变过程中其内部电场的分布特征。研究结果表明:极间电压的升高、气泡尺寸的增大均会延迟气泡聚并行为的发生,气泡一旦开始聚并形成连接体,其内部场强将呈现极大值,且该极大值与极间电压、气泡尺寸呈正相关关系;油流速度和气泡数目的增加将促使气泡聚并行为提前发生;油流速度越大,气泡受到的压力梯度和形变越大,而气泡连接体内部场强将越小,而气泡数量的增加将导致气泡连接体内部场强随之增大。
The transformer oil will release gas and even form suspended bubbles under the conditions of moisture,dete-rioration and decomposition.Under the coupling action of electromagnetic,thermal,flowing and other physical fields,the bubbles will show extremely complex electric fluid dynamics behavior,which will significantly affect the insulation per-formance of transformer oil.Therefore,it is of great significance to study the morphological evolution and motion law of bubbles in transformer oil.In this paper,a turbulent model is used to simulate the state of transformer oil flow,and a dy-namic analysis model of suspended bubbles under multi-field coupling is constructed.The effects of interelectrode voltage,oil flow velocity,bubble size and bubble number on the coalescence behavior of suspended bubbles are studied,and the distribution characteristics of internal electric field during the evolution of bubble morphology are analyzed.The results show that the increase of interelectrode voltage and bubble size will delay the occurrence of bubble coalescence behavior.Once bubbles begin to coalesce and form a connector,the internal field strength will show a maximum value,which is positively correlated with interelectrode voltage and bubble size.The increase of oil flow velocity and bubble number will promote bubble coalescence in advance.The greater the oil flow velocity is,the greater the pressure gradient and deformation of the bubble will be,and the smaller the field strength inside the bubble connector will be,meanwhile,the increase of the number of bubbles will lead to the increase of the field strength inside the bubble connector.
作者
刘士利
韩继涛
张宁
张飞
LIU Shili;HAN Jitao;ZHANG Ning;ZHANG Fei(Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology Ministry of Education,Northeast Electric Power University,Jilin 132012,China;State Grid Xinjiang Electric Power Research Institute,Urumqi 830013,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2023年第8期3534-3543,共10页
High Voltage Engineering
关键词
变压器油
气泡
电场强度
聚并
湍流
形变
transformer oil
bubble
electric field intensity
coalescence
turbulence
deformation
