基于电化学阻抗法的油液在线监测传感器应用特性研究

大型机械装备润滑系统油况的在线监测是润滑故障诊断的关键技术之一，难点在于准确监测水分异常和润滑油老化失效临界点。根据油液老化过程缓慢且复杂、各种因素导致润滑油阻抗值变化的特性，研究基于电化学阻抗谱技术的油况传感器；通过连续在线监测不同润滑油状态下传感器的体相阻抗、界面阻抗和高频阻抗的变化趋势，发现体相阻抗、界面阻抗和高频阻抗的数据趋势可以用来判断油的状况，具体表现为润滑油状态影响传感器体相阻抗数值和界面阻抗数值，添加剂状态影响界面阻抗数值；油液使用时间越长，老化程度越高，体相阻抗值越高；污染物和分解产物影响高频阻抗数值。介绍油液状态传感器的实现原理，通过实验和工程论证油液状态传感器监测水分和润滑油老化失效临界点的可行性。结果表明，在特定应用场景下，电化学阻抗谱油液传感器能区分不同油液状态，能准确监测润滑系统水分异常和老化失效临界点，为设备润滑安全运维策略提供依据。

Research on the Application Characteristics of Electrochemical Impedance Spectroscopy Oil Condition Sensor

On-line monitoring of oil conditions in the lubrication system of large machinery and equipment is one of the key technologies for lubrication fault diagnosis,and the difficulty lies in accurately monitoring the critical points of abnormal moisture and lubricating oil aging failure.According to the characteristics of slow and complex oil aging process and the change of lubricating oil impedance value caused by various factors,an oil condition sensor based on electrochemical impedance spectroscopy technology was studied.By continuously on-line monitoring the changes in bulk impedance,interface impedance,and high-frequency impedance of sensors under different lubricating oil states,it is found that the data trend of bulk impedance,interface impedance and high-frequency impedance can be used to judge the oil conditions.It is manifested that the lubricating oil state affects the bulk impedance and interface impedance values of the sensor,while the additive state affects the interface impedance values.The longer the oil is used,the higher the degree of aging and the higher the bulk impedance value.Pollutants and decomposition products affect high-frequency impedance values.The realization principle of the oil condition sensor was introduced,and the feasibility of the oil condition sensor to monitor the critical point of moisture and lubricating oil aging failure was demonstrated through experiments and engineering.The results show that,in a specific application scenario,the electrochemical impedance spectroscopy oil condition sensor can distinguish different oil conditions,and can accurately monitor the abnormal moisture and the critical point of aging failure in the lubrication system,which provides a basis for the safe operation and maintenance strategy of equipment lubrication.