Vibration generator fault diagnosis
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Abstract: This article describes the use of ENTEK vibration monitoring system, the turbo-generator power plant for regular monitoring, and fault diagnosis technology for generating friction movement of the fault exists to make an accurate diagnosis.
Key words: generators; friction; fault diagnosis; Bearing
Key words: TM311 Document code: B
    
Karamay Petrochemical Company # 2 thermal power plant generators since January 2001 after the overhaul, that is, in the presence of the minor bad, especially in the horizontal direction exciter does not exist in the points lead to big vibration. In May 2003 and November respectively on the unit for repair, have not completely solve the problem of misalignment. To run the unit in March 2004, the value of the vibration individual points a slight increase in the spectrum of significant changes in the unit concluded that the diagnosis of serious friction fault movement, in the same year in May in the repair, this conclusion has been verified.
     First, the use of standards and monitoring equipment
     1. Vibration standards
     Data monitoring and evaluation in the light of the standard ISO10816-3 "in the non-rotating parts on the machine vibration measurement and evaluation unit over the past few years combined with the actual operation condition, the unit set an alarm for the value of 4.5mm / s, the value of the secondary alarm To 7.1mm / s.
     2. Monitoring the basic system configuration
     An acceleration sensor EDL, a data collector PM, a 586 computer software to monitor a printer, the acceleration sensor model E322A01, sensitivity factor of 102mV / g, data acquisition model for DATALINE-F.
     Second, to monitor the process analysis
     1. Unit parameters and layout of the measuring point (see Figure 1)
     Unit parameters: P = 15MW power
     Speed n = 3000r/min

     2. Map data and analysis
     Various points since 2003, 11 months after the repair of Statistics found that vibration data, the four points in 4-watt level and horizontal vibration exciter greater value, especially in the horizontal direction exciter points more than 2 times the value of alarm 7.1mm / s. 4-watt level on March 18 from the direction of the future value of the vibration was gradually on the rise, but still less than the alarm level, the value of 4.5mm / s.

     February 8, 2004 and before the spectrum, all the main points is 2 octave frequency components and frequency, the crew Misalignment for the performance of the major and minor movement of friction. March 18, we can see the spectrum, there have been scores of rich and harmonic frequency components, although some of the points of a slight increase in the value of vibration, but the alarm level is less than the value of 4.5mm / s. Vibration spectrum of mutations have taken place in that unit's operating conditions have changed.

According to the movement of the fault rub characteristics of the response times should be synchronized with the harmonic spectrum. Collisions serious friction, the harmonic spectrum of the more abundant. Combined with the unit of measurement point there is a serious movement rubbing, and the operation of the historical characteristics of the unit, the unit may be judged not in a state of extreme positions in the journal so that the entire rotor deflection, and bearing journal rubbing occurred.
Third, the results of overhaul
May 2004 carried out a repair, demolition of the Bearing Inspection found: (1) l, 2,3-watt gap of more than the required standard, which is due to the journal bearing and movement caused by friction; (2) 4 pieces of tile on the tile Babbit loose and crack down after falling Babbit, the exciter may be wrong, the value of the excessive vibration, so that the journal bearing and cause rubbing.
At that time, had a bearing on the restoration, as the unit as a whole can not be renewed, the boot still does not, the value of the vibration measuring point on the rise, the harmonic spectrum of rich, but scores less frequency components, the unit There is still a slight movement of friction. In strengthening the monitoring on the basis of the unit to run rural issues left to be resolved overhaul.