present vibration
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VibrationVibrationVibrationSystem
VibrationSystemSystemSystem
แผนกวศวกรรมเครองมอวด และ ระบบควบคมไฟฟา กองวศวกรรมระบบควบคมโรงไฟฟา
The Rathbone Chart,The Rathbone Chart,
Introduced by a UL agent named T. C. Rathbone in 1939(measured in Inch Per Second-IPS))
ISO 10816ISO 10816
Released in August 2000, establishes the general conditions and procedures for theestablishes the general conditions and procedures for the measurement and evaluation of vibrations using measurements made on the non-rotating parts of machines
Zone A Green: Vibration values from machines just put into operation.
Zone B Yellow: Continuous operation without any restrictions
Z C O C diti i t bl l f li it d i d f tiZone C Orange: Condition is acceptable only for a limited period of time.
Zone D Red: Dangerous vibration values – damage could occur at any time.
API 670 (American Petroleum Institute) API 670 (American Petroleum Institute)
The standard details the following measuring techniques
Casing VibrationRadial Shaft VibrationRadial Shaft VibrationShaft Axial PositionSh f R i l S dShaft Rotational SpeedPhase ReferenceOverspeedCritical Machinery TemperaturesCritical Machinery Temperatures
Two out of three majority voting for turbine overspeed protectionTwo out of three majority voting for turbine overspeed protection
SensorsSensors
SensorsSensorsSensorsSensors
ProximityProximity VelocityVelocity AccelerometerAccelerometerProximityProximity yy
Eddy CuttentEddy Cuttent
Eddy current probes are non-contact sensors primarily used to y p p ymeasure shaft vibration , shaft rotor position and clearance .
Piezoelectric AccelerometersPiezoelectric Accelerometers
A crystal generates a low voltage or charge when stressed as for example during compression.
Keyphaser Probe for Speed & Phase MeasurementKeyphaser Probe for Speed & Phase Measurement
Mounted on the shaft of the driver machine. The target notch t i h ld b it bl t t th t i lor protrusion should be suitable to generate the correct signal
at all machine states
0°
-VONE
REVOLUTION
0°
-V
ONEREVOLUTION
Overspeed ProtectionOverspeed Protection
API 670, 4th edition, calls for a segregated electronic 6 0, ed t o , ca s o a seg egated e ect o coverspeed detection system with three independent sensors, monitors and relays, with a 40-millisecond
Probe A Probe A
response time.
Probe BProbe B obeProbe B
Probe C Probe C
Trust TransducersTrust Transducers
Two non-contact proximity displacement transducers in a dual voting configuration to be installed in accordancedual-voting configuration to be installed in accordance with API 670 4th edition
For SIL 3 applications, three probes shall be installed, connected to triple modular redundant monitors.
Thrust Collar 12” Max12 Max
12” Max12 Max
Radial VibrationRadial Vibration
Two orthogonally mounted shaft-relative non-contact proximity transducers (XY) shall be installed at each radial bearing, using a mounting position directly
f d t th b ireferenced to the bearing.
R t
“X” ProximityProbe
“Y” ProximityProbe
Rotor
Bearing
Casing VibrationCasing Vibration
In some fluid film bearing machines, the casing can exhibit a high degree of compliance. In this case seismic vibration g g ptransducers should be installed. Two orthogonal casing mounted piezo-velocity transducers shall be installed at each Turbine bearing housing. Where possible, the tansducersTurbine bearing housing. Where possible, the tansducers should be aligned with the internally mounted proximity probes in conjunction with non-contacting proximity probes, to monitor machine integrity
machine integrity.
BearingHousingRotor Housing
Journal Bearingg
Shaft Differential ExpansionShaft Differential Expansion
Differential expansion is the measurement of the axial position of the rotor with respect to the machine casing at some distance from the thrust bearing.
Shaft Differential ExpansionShaft Differential Expansion
There are two types of Shaft Differential Expansion , Ramp shaft Direction and Normal shaft Diff ExpensionRamp shaft Direction and Normal shaft Diff.Expension
EccentricityEccentricity
Eccentricity is the measurement of shaft bow at slow-rollEccentricity is the measurement of shaft bow at slow-roll speed.
Gas TurbineGas Turbine
Shaft Position/ Speed/
Gas Turbine Gearbox Centrifugal Compressor
S d/Casing
Vibration PhaseReference
Speed/Load
Vibration
Thrust Position
Keyphaser AxialPosition
Thrust PositionExcentricity
Steam TurbineSteam Turbine
Dual Thrust
X/Y Displacement sensors
Dual ThrustPosition
Speed/PhasePhaseReference
EccentricityDifferentialExpansiony
SensorExpansionSensorCase
ExpansionSensorSensor
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