Research On Fault Diagnosis Of Air Tightness Of Control Valve Based On HHT

In the production process of the process industry,due to the high temperature,high pressure,low temperature,toxic,crystal or strong corrosive medium environment and frequent adjustment action,the control valve is prone to various faults.In the process of controlling the flow of the fluid,the sensitivity of the valve is directly related to the quality of the whole control system.Once the control valve fails,it may bring huge economic losses to industrial production,and even cause casualties.Therefore,it is the basis of ensuring the safe,reliable and stable operation of the automatic control system in the industrial process to find out the various faults in the operation of the control valve and take corresponding measures.At present,the fault diagnosis method of adjusting valve most commonly used are:1)when the passive diagnosis failure after valve repair or replacement;2)combined with the equipment overhaul,the expected diagnosis arrange all control valves for maintenance and overhaul;however,these two methods will not only cause the interruption of industrial production the process and control valve can be normally used for unified disassembly and inspection,not only a waste of time and resources,and delay in industrial production,the two kinds of maintenance methods have drawbacks.This paper mainly from the control valve on the line that the valve in accordance with the original operation of the normal operation of the angle,according to the valve operating signal parameters of the valve on line detection and diagnosis research.From the viewpoint of fault detection using multi-scale wavelet transform,linear fitting,the control valve action signal analysis,gives a new idea of online fault detection,combined with the experimental model and real valve simulation verify the effectiveness of the two methods.In order to control the valve chamber air tightness fault case study of Hilbert Huang transform to analyze the action of the valve position signal based on each modal and energy ratio characteristics,get online diagnosis of control valve chamber air tightness fault categories,fault strength,through simulation experiments verify the effectiveness of the valve and the real diagnosis method in this paper the.This study will be the first HHT fault diagnosis based on signal analysis method is introduced into the control valve to complete the implementation of fault detection,fault diagnosis and intensity,the important meaning is that past studies of these methods have mostly been used in fault diagnosis of rotating machinery,such as a motor,a transmission shaft,which is characterized by periodic signal with the control valve,this paper carries on the analysis to the valve position signal,in the actual condition of the signal is non-stationary signal cycle process,and this kind of non periodic non literature research rare fault diagnosis signal analysis.