气液两相对机械密封润滑膜超声检测精度的影响

机械密封动环和静环之间形成的润滑膜厚度是其稳定运行的一个重要评价指标,为实现润滑膜厚度的非接触检测,根据机械密封润滑膜的特点,构建了接触式机械密封润滑膜的超声检测模型,并推导了润滑膜厚度的计算公式.指出机械密封在运行过程中会产生两相流,准确测量机械密封润滑膜的厚度,必须考虑密封介质的两相问题.引入中间变量混合因子,通过...

Influence of Gas Liquid Two Phase on Ultrasonic Testing Accuracy of Mechanical Seal Lubrication Film

The thickness of the lubricating film formed between the moving ring and the static ring of the mechanical seal is an important evaluation index for its stable operation.In order to realize the non-contact detection of the lubricating film thickness,according to the characteristics of the mechanical seal lubricating film,an ultrasonic testing model of the contact mechanical seal lubricating film was constructed,and the calculation formula of the lubricating film thickness was deduced.It is pointed out that the mechanical seal of the turbo pump will produce two-phase flow during the operation,and the two-phase problem of the sealing medium must be considered in order to accurately measure the thickness of the lubricating film.A mixed factor of intermediate variables was introduced,and the relationship between mixed factor and the density of the sealing lubrication medium was obtained through experiments,and the mechanical seal lubrication medium density under gas-liquid two-phase lubrication was characterized.The thickness of lubrication film of mechanical seal under two-phase lubrication was measured by ultrasonic method,the calculated values of lubricant film thickness with and without two phases were compared and analyzed.The results show that when the degree of gasification is not high,the calculated value of lubricant film thickness with two phases is closer to the real value,and with the increase of the degree of gasification,the accuracy of ultrasonic detection is reduced.It is necessary to consider comprehensively the change of the parameters such as the acceleration and the acoustic impedance.