Turbine oil system OIL SUPP SUPPL LY A single oil supply line lubricates and cools the bearing, governs the m/c and operates the hydraulic actuators and saety and protective devices! "uring start#up $ shut#do%n, au& oil pump supplies the control oil! Once the turbine speed is more than '()* rpm, the main oil pump +!O!P- ta.es over! It dra%s oil rom main tan. !The lubricating oil passes through oil cooler, beore can be supplied to the bearing +Under emergency, lube oil can be supplied by a " oil pump-!0eore the turbine is turned or barred, barred, 1ac.ing 1ac.ing oil pump +' nos!- supplies high pressure oil to the 2ac. up the T3 shat to prevent boundary lubrication and also supplies high pressure oil to drive the hydraulic motor+turning gear-
'-Turbine lubricating oil system
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6! Provides a supply o oil to 2ournal bearings to give an oil %edge as the shat rotates! '! aintains the temperature o turbine bearings constant at the re7uired level! 8! Provides a medium or hydraulically operating the governor gear and controlling the steam admission valves! 9! Provides or hydrogen cooled generators a sealing medium to prevent hydrogen lea.ing out along the shat!
8-ain components 6- ain Oil Pump '-Au&iliary Oil Pump 8- :mergency Oil Pump 9- 1ac.ing Oil Pump )- ain Oil Tan. +OT;- entriugal
8!6- ain Oil Pump This pump is located at the ront bearing pedestal o the
8!'-Au&iliary Oil Pump Au&iliary Oil Pump can meet the re7uirements o lubrication system under emergency conditions One stage vertical centriugal pump driven by an A!! electric motor! It has radial impeller and volute casing! The pump automatically ta.es over under interloc. action %henever the oil pressure in the lubrication system ails belo% certain desired level!
8!8- :mergency Oil Pump :mergency oil pump has been oreseen by as a bac.#up protection to A driven standby oil pump! This is a centriugal pump, driven by " electric motor! This automatically cuts in %henever there is a ailure o A supply at po%er station
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ump5
1OP ensures that there is no metal contact bet%een a 2ournal and the bearing! Positive displacement pumps that provide high pressure supply o oil under strategic 2ournals o the turbo generator and oil lits the shat slightly! This greatly reduces the static riction and bearing %ear! The 1OP can be stopped ater the lubricating oil ilm is established bet%een the shat and bearings! Pressure produced is 6'* bars
8!)- ain oil tan. The oil used or lubrication is stored in the ain Oil Tan.! apacity #'*/8' m8! The ain Oil Tan. holds the oil inside the tan. or a period long enough to ensure liberation o air rom the oil! 4ilters are located inside the tan. to ilter the oil during its normal course! The oil tan. is supported on a ramed structure 2ust belo% the turbine loor at the let hand side o the turbine!
1ournal5The part o a shat or a&le that rests on bearings! A bearing is a machine element that constrains relative motion and reduces riction bet%een moving parts to only the desired motion!
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IAL PO=:? T?A>SISSIO> ":@I:S LASSI4IATIO>
"epending upon the direction o load to be supported5# 0ased on this criteria, the bearings may be categoried into! a- ?adial 0earings5#These are also .no%n as 1ournal 0earings! In these bearings the main load is perpendicular to the a&is o rotation o the moving element!
0earings and Lubrication T%o types o bearings are used to support and locate the rotors o steam turbines5 1ournal bearings are used to support the %eight o the turbine rotors! A 2ournal bearing consists o t%o hal# cylinders that enclose the shat and are internally lined %ith 0abbitt, a metal alloy usually consisting o tin, copper and antimonyB and Thrust bearings a&ially locate the turbine rotors! A thrust bearing is made up o a series o 0abbitt lined pads that run against a locating dis. attached to the turbine rotor!
Turning gear Large steam turbines are e7uipped %ith Cturning gearD to slo%ly rotate the turbines ater they have been shut do%n and %hile they are cooling! This evens out the temperature distribution around the turbines and prevents bo%ing o the rotors!
