Topics to be covered Fundamentals of Vibration • Fundamentals • Transducer operation and Selection • Machinery Protection and Management Management systems • Right Practices for Rotating Machineries
Vibration
What is vibration? Why care about vibration? What causes vibration? How do we measure vibration? Measuring vibration
Vibration What is vibration?
When an object moves back and forth repeatedly
Vibration can be fast or slow Vibration movement can be large or small Why care about vibration???
Machinery Vibration
What Causes Vibration?
Centrifugal Force = A force on an object when it swings in a circle
Bucket of water
Weight on a string
Centrifugal Force
Other objects that demonstrate rotating unbalance
Car tires
Ceiling fans
Measuring Vibration
We can measure vibration movement Amplitude = How far a vibrating object moves back and forth.
Machinery That Rotates
Vibrating Machinery
Vibrating Machinery
MACHINE DATA
Direct Measurements
Vibration and Position
Rotor Speed
Bearing Temperature
Indirect Data
Process Data
Performance Data
Operating Modes
A. Steady State :
Constant Machine Speed Process or Load Change
B. Transient :
Start Up Shut Down
C. Slow Roll D. Stopped
TRANSDUCER SYSTEMS
Transducer Operation
Three Parameter normally measured are : Displacement Velocity Acceleration
Transducer Operation
Types of Transducers Eddy Current Proximity Type Traditional Velocity Tx . Velomitor Velocity Tx. Acceleration Acceleromitor Transducer
Transducer Operation Proximity Transducer
Transducer Operation Proximity Transducer Measures distance between the target and the probe tip using eddy current principle. Generates a high frequency localized magnetic field around transducer tip The field causes Eddy current to flow out of the transducer Shaft movement is detected by the power loss occurs which converted in to DC voltage.
Transducer Operation Velocity Transducer
Measures time rate change of Displacement The construction is made of fixed magnet and coil assembly. Relative motion between coil an magnet creates current to flow proportional to the relative velocity between them.
Transducer Operation Velocity Transducer Disadvantages Disadvantages of Traditional Velocity Transducer Checking requires Shaker Table Poor Reliability : More moving parts Sensitive to Mounting Arrangement No slow roll information Cross Axis Sensitivity
Transducer Operation Velomitor Transducer Basically measures acceleration and integrates to velocity. Velomitor has no moving parts so more reliable than traditional velocity transducer A signal is generated by ceramic peizo electric crystal clamped between two masses.
Transducer Operation Velomitor Transducer This signal passes through the integral circuitry which conditions and integrates the signal that is proportional to the vibration velocity. Simple Bearing Housing Installations Good mid frequency response High Temperature ranges available. Very good reliability.
Transducer Operation Accelerometer Transducer
Works on the same principle of peizo electric charge. Force on peizo electric crystal directly gets converted into proportional acceleration signal. Reliable design Easy bearing housing installation Broad frequency response High temperature models available
Transducer Selection
You know the application but what about the proper Transducer Selection ??
Transducer Selection Criteria
Malfunction Based Machine Construction Based
Transducer Selection Criteria Machine Construction Based
API 670 Guidelines For Radial Shaft Vibration Probes : (Clause 4.1.1)
As per API 670 clause 4.1.1.1: Two radia radiall lly y or orie ient nted ed pro probe bess sh shal alll be pro provi vide ded d for each bearing. The two probes located at each bearing shall be copl coplan anar ar,, 90 90 deg degre rees es (+ or – 5 deg degre rees es ) apart and perpendicular to the shaft axi axis ( + or – 5 degr degree eess ). Th The e pr prob obes es shall be located 45 degrees from each side from the vertical center.
Condition Monitoring
Condition Monitoring
Why Shaft Relative Measureme Measurement? nt?
Vibration measurement Proximity Probes
Radial Proximity Probes
Sh ft Di Di
l
t & Be B
in lu i Ab Ab lute l te t Tr
sd
Inst Instal alla lati ti
API 670 Guidelines For Axial Position Probes:( Clause 4.1.2)
As per API 670 clause 4.1.2.1 : Two axially oriented probes shall be supplied for the thrust bearing end of each casing. Both probes shall sense the shaft itself or an integral axial surface installed within an axial distance of 300 mm from the thrust bearing or bearings. When specified, the standard optional arrangement shall be one probe sensing the shaft end and one probe sensing an integral thrust collar.
Dual Thrust Proximity Probes
Axial Position Measureme Measurements nts AXIAL (THRUST) POSITION Thrust Collar
12” Max
12” Max
DIFFERENTIAL EXPANSION
API 670 Guidelines
For Phase Reference Transducers : (Clause 4.1.3)
As per API 670 Clause 4.1.3.1 : A one – event – per revolution mark and a corresponding phase reference transducer shall be provided on the driver for each machinery train.
HOW TO MAKE PHASE MEASUREMENTS MEASU REMENTS
Deflection Shape
“A”
“B”
Once Per Turn Reference Pulse 0° -V ONE REVOLUTION
0°
ONE REVOLUTION
-V Video Clip
Process Parameters
V
THRUST
H
V
D
SP/A V
CE KØ™ KØ™ (Dual)
H
V
V
V
H V
V
V
H V
H V D V
V
V H
H D
V
V
H D
H D
H
H D V
H
V
D
EXC.
V
H
H D
D
D
H V
V
GEN. V
V
V
H
LP
D
SP/B
H DE V
HP/IP
ECC ECC
H
V
H D
THRUST BRG 1 ECC KØ™ ECC 0° 90° 90°
BRG 2
VERT 270°
BRG 3
BRG 4
HOR
VERT
D
D VERT
180° BRG 1-7 SHAFT Displ.
BRG 5
BRG 6
BRG 7
HOR V
HOR
COUPLINGS Mode Ident.
BRG 1-7 BEARING Vel.
CE - CASE EXPANSION
ECC - ECCENTRICITY
D - DISPLACEMENT
KØ™ - KEYPHASOR ®
DE - DI DIFFERENTIAL EXPANSION
SP
- SP SPEED
BRDRC
Fig. 3 - Advanced Advanced TSI TSI transducers transducers installat installation ion on Turbine-Gen Turbine-Generato eratorr
7
6 XX
WithMode ode Id Ident entificati cationProbes obes 23 XX
1
45 XX
An example of the application of Mode Identification Probes
Bearing Bearing Pedestal Pedestal Vibrations Vibrations alone do not provide provide sufficient sufficient information on large machines with sleeve / journal bearings.
It is very important to appreciate that application may demand use of bot both h Prox Proximi imity ty and Siesmi Siesmicc transd transduce ucers. rs. This This m must ust not be assumed to be ‘duplication’ of measurements.
Cond Co ndit itio ion n Moni Monito tori ring ng of of TG TGss Few more IMPORTANT & Correct MEASUREMENTS
Thrust Position Measurements must be Dual Redundant,
Case Expansion measurements must be made on both sides of the casing,
Redundant Phase measurement (Keyphasor R probes)
Redu Redund ndan antt Over Overspe speed ed Dete Detect ctio ion n Moni Monito tors rs..
HOW TO INTERPRET STARTUP AND SHUTDOWN PLOTS
INFORMATION AVAILABLE FROM TRANSIENT RESPONSE PLOTS
Slow Roll Speed
Slow Roll Runou nout Vector
Amplitude, Phase, and Frequency of Resonance
Synchronous Amplification Factor (API Method)
High / Heavy Spot Relationship
Structural and Split Resonance
Rotor Mode Shape / Deflection Shape
Preload Identification
Frequency Relationships
Orbit Plot Can Show Preloads (Misalignment) (No Resonance Near Twice Rotative Speed)
Rare
Common
Rare
Shaft Centerline Plot Can Show Misalignment
Turbine
Generator
Machine Characteristics Overall Amplitude Spectrum 1X, 2X, nX Amplitude 1X, 2X, nX Phase Not 1X Gap Voltage Vibration Shape Temperature Pressure Load
pp Amplitude Smax Vibration Transmitter
? Overall Amplitude
How can you MANAGE
your machine without complete information?
Machinery Management Uses Uses All All Of The The Too Tools ls Correlated Machine Information
Other (Gram Mole Weight, Density, Flow, etc.) n = 0.25, 0.5, 1, 2, 2, 3
Such as Bently Nevada’s DM2000 system
MACHINERY PROTECTION SYSTEMS
Systems that shutdown a machine or return it to a safe or nondestructive mode of operation without human intervention.
INTRODUCTION TO MACHINERY MANAGEMENT
Bently Nevada’s mission is to help you protect and manage your machinery. This Course Focuses on Machinery Management. Supported by the effective use of “Diagnostic Principals and Practices.”
MACHINERY MANAGEMENT SYSTEMS
Use of systems that provide data and information that is interpreted and applied by people to correctly operate, maintain, and assess the condition of their machinery.
System 1 Single Platform for all your Management Needs !!
Machinery Monitoring
Monitoring System Sensors
Sensors
Machinery Monitoring
Machinery Protection Distributed Control System
Control System
Protection System Sensors
Level 1
Sensors
Machinery Protection
Trigger relay if all four channels indicate “Danger”
3500 SERIES MONITORING SYSTEM
Basic Features * Dual Redundant Power Supply * Flexible Flexible Cards - Reduced Reduced Spares Spares * Programmable Relays * Software Software Configu Configurable rable - Less Installation & Maint. Cost. * Redundant Gateway * More data for better analysis.
Inputs 28 Vibration / Axial Inputs 2 speed inputs Two 7200 Racks included in the same rack of 3500.
LCD DISPLAY FOR 3500 SERIES SYSTEM
Enhanced Operator Interface Improved Operator Information Set ♦
The Informative Data Set Overall Amplitude Probe Gap Voltage 1X Amplitude and Phase 2X Amplitude and Phase Not 1X Amplitude
Alarm Event List ♦ System Event List ♦
Windows™ Based Operator Display Software
Enhanced Operator Interface
Data Where you need it X Station
BENTLY NEVADA SCREENS
OPERATOR
Plant
DCS Modbus Gateway RS 232 / RS 422
TCP / IP XProtocol
LINK
PLANTWIDE ETHERNET
MODBUS LINK
OPERATOR DISPLAY SOFTWARE
3500
Net DDE TCP / IP
SYSTEM
10
10
0
0
0
PLANT MGR
MAINT. MGR
MACHINE SPEC.
0
REMOTE DISPLAY
Vibration Data at the Machine Skid COMMUNICATION GATEWAY
3500 SYSTEM
MODBUS LINK
10
10
0
0
MACHINE REMOTE DISPLAY
3500 Ethernet Communication
PLANTWIDE ETHERNET
OPERATOR DISPLAY SOFTWARE
RS 232 / RS 422 LINK
3500 SYSTEM
TCP / IP Net DDE
OPERATOR DISPLAY SOFTWARE
PLANT MGR
MAINT. MGR
MACHINE SPEC.
Don’t Forget Data for The Maintenance People TDM2
RS232
MAINTENANCE PERSONNEL
TDIX
DDIX STATIC & DYNAMIC DATA
MACHINE
3500 SYSTEM
Reduced Installation & Maintenance Costs Lower Cabling Costs Mount at the Machine Downward Compatibility Easy to Configure Reduced Spare Parts
Machinery Data Analysis Data Review
Level 2
Data Acquisition and Display
Remote Access Protection System
Control System Sensors
Level 1
Sensors
System 1 MMS System
Machinery Management Level 3
Decision Support
Level 2
Data Acquisition and Display
Remote Access Protection System
Control System Sensors
Level 1
Sensors
Where Where
Data DataAvailable? Available?
How HowSerious? Serious? Serious?
What Whatisisit? it?
Audit Result Informa Information tion - Fluid Induced Induced Instabilit Instability y - Whip Summary Supporting Evidence Details
Notes
A bou t
Severity: Malfunction: Location: Date/Time:
When When
Note:
Fluid Fluid Induced Instabili Instability ty - Whip
Steam Turbine Turbine Genera Generator tor 2 - LP! - Bearing Bearing 6 12-Aug-97 2:09:22 PM Audit performed with sufficient data
Bently Nevada Corporation Recommended Actions: A) Increase or decrease oil supply temperature +/- 10F(5C) B) Increase the oil supply pressure 10 psi C) If there are no improvements from steps A and B, the Unit should be removed from service
Print...
What Whatdo doIIdo? do?
Close
Audit Results Display from Machinery Management System
Data Display and Automated Notification Win95 or NT and advisories available both Local and Process Variables Remote Plant Information Network (PIN) Advisories/Data
Plant DCS Remote
BNC
Display and Notification
Serve
System 1 Expert System
r
Ethernet (Dedicated or PIN) TDXnet Comm Processor (s)
