A presentation i prepared on the Basics of Condition Monitoring, and with specifics to Vibration Analysis. A very simple on indeed! For people who wan...
Chapter- 8 MODAL ANALYSIS AND CONDITION MONITORING Syllabus: Signal analysis, dynamic testing of machines and structures, Experimental modal analysis, Machine condition monitoring and …Full description
Full description
Introduction guide to Vibration MonitoringFull description
Hints about turbine oil condition monitoring
John B. ReadeFull description
This presentation is a beginner's guide to Discourse Analysis. It introduces the key concepts in this field and develops a sound understanding of DA.Full description
400 pages, in english
A short introduction to the main concepts of TA. It is set out in 5 parts or chapters with a suggested activity to reinforce these conceptsFull description
Descripción: This presentation is a beginner's guide to Discourse Analysis. It introduces the key concepts in this field and develops a sound understanding of DA.
Hints about turbine oil condition monitoring
condition monitoring Turbine OA
Vibration Analysis for Power Plant Engineers
vibration analysis, vibrometer
Introduction to Condition Monitoring & Vibration Analysis
Today's Requirement
Low Maintenance Costs
Greater Machine Availability
Lesser Manpower Usage
Lesser Energy Consumption
Background
Imagine that the bearing or the blades of a steam turbine have been running for years in a power plant, and remain unattended and its condition not monitored. Without Without any monitoring system in place, it is tough to predict the reliability of the equipment, and predicting the potential failure mode of the same becomes almost impossible.
Poor Poor maintenance practices and no monitoring can be detrimental and lead to catastrophic failure failure and cause significant damage to life and property.
Maintenance Philosophies
Allow machinery to run to failure. Repair or replace damaged equipment when obvious problems occur.
Predictive Predictive Maintenance Main tenance
Schedule maintenance activities when mechanical or operational conditions warrant. Repair or replace damaged equipment before obvious problems occur.
Preventive Preventive Maintenance Mainten ance
Schedule maintenance activities at predetermined time intervals. Repair or replace damaged equipment before obvious problems occur.
Reactive Maintenance
Reliability Centered Cen tered Maintenance
Utilizes predictive/preventive predictive/preventive maintenance techniques with root cause failure analysis to detect and a nd pinpoint the precise problems, combined combined with advanced installation and repair techniques, including potential equipment redesign or modification to avoid or eliminate problems from occurring. occurring.
Case Study Comparison
A survey concluded that for a specific plant in consideration, the maintenance costs varied significantly if Maintenance Philosophies changed.
The use of condition monitoring allows maintenance to be scheduled, or other actions to be taken taken to avoid the consequences of failure, before the failure occurs.
Vibration Analysis
Why Monitor & Analyze A nalyze Vibrations?
Avoids Wastage of Energy
Avoids Premature Failure of Machine Components
Reduces Maintenance Costs
Lesser Maintenance Man-hours
Worst Case
Destruction of a Steam Turbine Driven Generator
Vibration?
Vibration is the physical movement or oscillation of a mechanical part about a reference reference position.
Terminology
Amplitude ◦
Frequency ◦
Magnitude of Vibration.
How many time does a machine vibrate in a specific unit of time.
Phase ◦
How is a machine ma chine vibrating with reference to a specific point.
Vibration Vs. Time Heavy Spot
Amplitude +
0
Time 360 degrees
Rotation 1 revolution 3600 rpm = 3600 cycles per minute 60 Hz = 60 cycles per second Order = One times turning speed
Amplitude
+
0
Time
1000 rpm
1 Revolution
4 blades = vibration occurs 4 times per revolution 4 x 1000 rpm = vibration occurs at 4000 cycles per minute = 4000 cpm
Amplitude + 12 tooth gear
0
Time
1 revolution
1000 rpm
12 teeth are meshing every revolution of the gear 12 x 1000 rpm = vibration occurs at 12,000 cycles per minute = 12,000 cpm
+ 0
Time
+ 0
Time
+ 0
-
Time
Complex Time Waveform Time Waveform contains all the different frequencies mixed together
+
0
Time
-
Complex Time Waveform Time Waveform contains all the different frequencies mixed together
From Time to Frequenc F requency y Waveform Frequen cy Amplitude
Offset, or Parall el – t he shafts are parallel to each other, but are not co-planar, or in the same plane. This can be bot bot h vert ical and horizontal. horizontal.
Angular – th e shafts are not in th e same plane, which causes a difference difference in m easurement easurement between m easurement easurement s m ade 180 degrees opposite opposite on the coupling faces.
Misalignment & Looseness
Bearing Faults–Potential Causes Funct ion of th e Geom Geom etr y of t he Bearing Bearing
Outer Race (BPFO) Inner Race (BPFI)
Cage (FTF)
Ball Spin (BSF)
Gear Faults–Potential Causes
Localised surface damage
Wear or inadequate lubrication
Tooth root cracks, missing tooth
Pitch error
Eccentricity
Motor Problems
Motor Problems Problems appear on the spectrums usually as line frequency or multiples of line frequency. Line Frequency Frequency is 3000CPM in our case.
