Turbine Lub Oil System

TURBINE LUB OIL SYSTEM OF 200 MW

CONTENTS WHY LUB OIL SYSTEM IS NECESSARY COMPONENTS OF LUB OIL SYSTEM FLOW DIAGRAM OF LUB OIL SYSTEM FUNCTIONS OF INDIVIDUAL COMPONENTS OIL FLOW TO DIFFERENT BRANCHES FIRE PROTECTIONS CONTROL OIL

WHY LUB OIL IS NECESSARY LUBRICATION : SUPPLIES OIL TO JOURNAL BEARRINGS TO GIVE AN OIL WEDGE AS THE SHAFT ROTATES MAINTAINS THE TEMP OF BEARINGS H2 COOLED GEN : SEALING MEDIUM TO PREVENT H2 LEAKING OUT ALONG THE SHAFT MEDIUM FOR HYDRAULCALLY OPERATING THE GOVERNOR GEAR DRIVING THE TURNING GEAR JACKING UP THE SHAFT AT SLOW SPEED

COMPONENTS AUXILLARY OIL PUMP JACKING OIL PUMP EMERGENCY OIL PUMP MAIN OIL PUMP EMERGENCY SHUT OFF OIL MAIN OIL COOLERS MOT CENTRIFUGE MOT VAPOUR EXTRACTOR

LUB OIL SYSTEM

HP

IP

LP

GEN

SOST OIL TANK

OIL COOLER

AUXILLARY OIL PUMP AOP-Two in numbers Specifications – Capacity-78 L/S Discharge pr-6.8 Ksc Speed - 1480 rpm Drive - A.C. Motor Motor power-11 KW Rated Current-53 Amp During start up & shut down AOP supplies the control oil. When turbine speed is less than 2800 rpm it supplies oil to governing system as well as lubrication system

SLC AOP Command goes to switch ON AOP-1 when : SLC AOP-1 IS ON and AOP-2 trips OR Oil pressure <4.8 ksc  Command goes to switch ON AOP-2 When: SLC AOP-2 IS ON and AOP-1 trips OR Oil pressure < 4.5 ksc

JACKING OIL PUMP Use to lift the shaft during start up/shut down JOP- Two in numbers SpecificationsCapacity- 1.26 L/S Discharge pr- 120 ksc Speed-2980 rpm Drive-A.C .Motor

SLC JOP  SLC JOP-1 ON If speed < 510 rpm JOP-1 gets on command If speed> 540 rpm JOP-1 gets off command  SLC JOP-2 ON If JOP-1 trips OR JOP pr<120 ksc When speed <510 rpm with delay of 5 second command goes to ON JOP-2 OFF JOP-1 OFF SLC JOP-1

EMERGENCY OIL PUMP Provided as back up protection Cuts in whenever there is AC failure or the power in the lubrication system falls less than 1.1 Ksc SpecificationsCapacity-30L/S Discharge pr-2.3 ksc Speed-1460 rpm Drive-D.C Motor Motor power-27.6 kw

SLC EOP EOP ON Command goes when SLC EOP is on and Lub oil pressure< 1.1 ksc

MAIN OIL PUMP Pump mounted in front Brg pedestal Coupled with turbine rotor through a coupling When speed is more than 2800 rpm then desired quality of oil goes to governing system(12 Ksc) & to the lubricating oil system Two injectors are arranged in series SpecificationsCapacity- 139 L/S Discharge pr-8.2 ksc Speed -3000 rpm Drive- Turbine

EMERGENCY SHUT OFF OIL FUNCTION: Shut off oil during emergency like when oil catches fire , it saves the equipment from further damage Operated from local LOCATION MOT ROOM NEAR MAIN OIL PUMP

I

EMERGENCY SHUT OFF OIL MOP

Lub oil header

filter

To lub oil cooler

Gate valve 2 Shut off Control valve

Gate valve 1

drain

Control oil

MAIN OIL COOLERS  Purpose is to cool the oil , Water is inside the tube and oil flows in outer shell  Maximum lubricating oil temperature at cooler outlet restricted to 47 deg  Bearing metal temperature alarm- 90 deg shut down-120 deg  Three way control valve -Electrically driven & has the function of regulating lubricating oil temperature

CENTRIFUGE  Draws oil from turbine oil tank mainly DOT , after removing any water & entrained solid matter oil is returned back to oil tank  Centrifuge does two functions: o Clarification-Sludge seperation in which the machine is used for seperating off particles normally solid o Purification-Liquid (oil)–Liquid (water) separating two intermixed liquids which are insoluable in each other & have different sp gravities. Solids with sp gr higher than those of liquid can be seperated of at the same time

MOT VAPOUR EXTRACTOR Mounted on top of main oil tank Function is to produce slight negative pressure in main oil tank and in the bearing casing and thus draws off oil vapour Oil vapour before exhausting to atm is passed through oil catcher

TURNING GEAR Consist of two rows of moving blades mounted on coupling between IP & LP turbine Oil supplied by AOP strikes against hydraulic turbine blades & rotates the shaft at 110 rpm Provision for manual bearing in event of failure of TG SLC TURNING GEAR ON Speed < 210 rpm opens TG Speed > 240 rpm closes TG

OIL FLOW TO DIFFERENT BRANCHES Lube oil Turnning gear

MOP

Oil cooler

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AOP1

Thrust brg

AOP2 Shut off valve

EOP

CONTROL OIL

CONTROL OIL Control oil is used in governing System Control oil generates several oil like Trip oil : stop v/v , sec oil ckt Aux trip oil :turbine protn device Start up oil : Resetting stop v/v Aux start up oil :Resetting . protection devices