seal oil system t
DESCRIPTION
This system consists of three main parts1)Seal liner2)Seal body3)Rotor collerTRANSCRIPT
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Powerpoint Templates
GeneratorSeal Oil System
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Need of Sealing -
In Hydrogen Cooled Generator .
Where ?
To Prevent escape of Hydrogen from Generator casing along the rotor shaft.
Why ?
How ?
By Providing radial and axial oil film.
Oil pressure = higher than hydrogen gas.
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1) Thrust type seals (LMW)
2) Ring type seals (KWU)
Types of Seals -
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Oil supply to seals through an injector in normal operation.
Automatic taking over of oil supply by pumps.(A.C. and D.C.)
Cools and filters the oil before supplying to seals.
Always maintain a constant differential pressure between the seal oil pressure and hydrogen pressure at varying casing pressure.
Drain out effectively the oil flowing towards the hydrogen side without allowing any hydrogen to escape.
Functions -
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IN ORDER TO PREVENT THE ESCAPE OF HYDROGEN FROM GENERATOR, SEALS
ARE USED ON EITHER ENDS OF THE MACHINE
WHERE THE ROTOR COMES OUT OF THE STATOR.
• GENERATOR SEALS
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• The shaft seal consists of seal liner with• babbitted surface pressing against the • collar of the rotor and is suitable mounted • in a seal body so as to be able to follow • the rotor free in the axial direction.• Oil under pressure is supplied to an • annular chamber in the seal body from • where it is led to the space between the • seal liner and rotor collar through several• canals distributed uniformly along the
periphery.
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• This oil under pressure and under the • influence of rotation and configuration of • the seal linar surface , forms a continuous• hydrodynamic film between the collar and • liner which prevents the escape of • hydrogen from inside the machine.
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GENERATOR SEAL
• THE SHAFT SEAL CONSISTS OF --------
• 1) SEAL LINER
• 2) ROTOR COLLAR
• 3)SEAL BODY
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Seal Oil System For Thrust Type Seals (LMW)-
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Oil injector – 1 no.
Seal oil pump coupled to AC motor – 1 no.
Seal oil pump coupled to DC motor – 1 no.
Oil coolers - 2 X 100% capacity
Mechanical filter – 2 X 100 % capacity
Differential Pressure Regulator - 1 no.
Pressure Oil Regulator - 1 no.
Damper tank - 1 no.
Hydraulic seal oil tank - 1 no.
Seal Oil System Consist of -
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Differential Pressure Regulator (DPR) -
To Damper Tank
Seal Oil Inlet
Seal Oil Press. FeedbackSeal Oil Outlet
Sensing Line of Hydrogen Pressure
Bypass Vlalve
Seal Oil Supply
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From Damper Tank
Press Oil Regulator (POR) -
Inlet to POR
Bypass Valve
EE
Feedback Line of Thrust Oil
Outlet of POR
TE
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Outlet
H2 Feedback to DPR
Drain from Exciter side
Feedback connection between hyd. Seal & damper tank
Overflow from Damper tank
Hydraulic Seal oil tank-
Drain from turbine side
MOT
H2 press connection from casing
Bypass drain valve
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Damper tank -
From DPR Outlet
H2 Feedback
Seal Oil to Shaft Seal
Spill Over to hyd. Seal oil tank
Vent
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H2 pressure - 3.5 kg/cm2 (for 210 MW)
Seal Oil Pressure - 4.1 to 4.4 kg/cm2
Seal Oil Temperature - 40 °C.
Quantity of seal oil - 80 lit / min (For Seal)
Quantity of seal oil
flowing towards H2 side - 1 to 2 lit / min.
Pressure of Thrust Oil - 1.5 to 2.2 kg/cm2
Qty of Seal Oil - 4000 lit.
to fill the system
Injector Outlet Pressure- 10 kg/cm2.
A.C. SOP start at - 6.5 kg/cm2.
D.C. SOP start at - 5.5 kg/cm2.
DPR - Inlet Press of oil - 10 to12 kg/cm2.
POR - Inlet Press of oil - 10 to12 kg/cm2.
Technical Particulars (Thrust Type) -
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AC SEAL OIL PUMP
SPECIFICATION OF PUMP
• TYPE: -MULTISTAGE, VERTICAL SPLIT• CENTRIFUGAL PUMP • DISCHARGE: ------- 3.6 litre/sec
• HEAD: --120 M OF WATER COLUMN
• SPEED: -------------- 1465 RPM
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DC SEAL OIL PUMP
• SPECIFICATION OF PUMP
• TYPE: MULTISTAGE, VERTICAL SPLIT
• CENTRIFUGAL PUMP • • DISCHARGE: ------- 3.6 litre/sec
• HEAD: ----120 M W C•
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SEAL OIL COOLER
• NO. OF COOLERS: --- TWO• TYPE: DOUBLE PASS, VERTICAL
INLET OIL TEMP: -- ----------- 400 C• OUTLET OIL TEMP: ------------ 500 C
• INLET PRESS. ------------ 10 KG/CM2
• PRESS. DROP OF OIL: ---- 5MWC
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• OIL FILTERS
• TYPE:------ WIRE MESH DISC TYPE
• MATERIAL OF FILTER: ---- BRASS
• PRESS. DROP :---------- 0.4KG/CM2• ACROSS FILTER
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DIFF. PRESS. REGULATOR (DPR)
• TYPE: -------------- PLUNGER TYPE
• INLET OIL PRESS.:----- 10-12 KG/CM2
• DIFF. PRESS. -----0.6 TO 0.9 KG/CM2
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DAMPER TANK
DPR
PORHYDRAULIC SEAL OIL TANK
TO EXCITER END
HEADER
EXE. ENDTUR. END
LUB OIL OUTLET HDR
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Seal Oil pressure low .
Thrust Oil pressure low
Differential Pressure between oil and hydrogen is low .
Differential Pressure between oil and hydrogen is high
Pressure of cooling water to seal oil coolers low
Oil Level in damper tank too low
Oil level in hydraulic seal oil tank low .
Oil level in hydraulic seal oil tank high .
Pressure of cooling water to seal oil cooler low
Annuciations (Thrust Type) -
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Seal oil pressure
Gas pressure inside generator casing
Thrust oil pressure
Differential pressure between hydrogen and seal oil
Presence of liquid inside the machine
Oil level in hydraulic seal
Oil level in damper tank
Pressure drop across the filter
Pressure at the outlet of the injector or pumps
Cooling water temperature, pressure at inlet and outlet of coolers
Operational Checks -
Hourly Checks
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Very little quantity of seal oil flows towards H2 side
thus making a lesser effect on H2 purity during operation.
Advantages & Disadvantages -
Advantages -
A separate collar has to be provided on the rotor shaft.
Restricts the flexibility in rotor shaft expansions, rotor collar
movement, is limited to the allowances available in the seal
body.
Excessive thrust on the seal ring or sudden impact of rotor
may damage the babbit surface of the seal ring and it may
require machining of the rotor collar also, due to mechanical
rubbing between seal ring and rotor collar.
Disadvantages -
