Main Turbine Lube Oil System

Question 1

which pump supplies the oil system during normal turbine operations?

Answer 1

the main shaft oil pump

Question 2

What is the motive force for the main shaft oil pump?

Answer 2

the main turbine shaft

Question 3

which pump supplies oil to the bearings of the turbine generator shaft?

Answer 3

main shaft oil pump

Question 4

which pump normally supplies oil to the suction of the main turbine shaft oil pump?

Answer 4

booster oil pump located in the oil reservoir

Question 5

What provides the motive force for the booster pump?

Answer 5

the oil driven turbine which receives force from the discharge of the main turbine shaft oil pump

pressure is reduced by the booster nozzle and baffler valves

Question 6

which oil pump provides oil to the turbine while it is on the turning gear?

Answer 6

turning gear oil pumps

Question 7

which oil pumps provides oil pressure during emergency situations or while coming up to speed?

Answer 7

the emergency bearing oil pumps

Question 8

how many lube oil coolers are there?

Answer 8

2

Question 9

what provides the cooling medium for the lube oil coolers?

Answer 9

turbine cooling water

Question 10

how is rate of cooling controlled in the lube oil coolers?

Answer 10

water flow rate is automatically adjusted to maintain temperature.

Question 11

what provides suction for the shaft oil pump until the turbine reaches 90% speed?

Answer 11

suction pump until the booster oil pump takes over at 90%

Question 12

what controls the oil flow through or around the oil driven turbine?

Answer 12

two baffler valves

Question 13

what controls oil flow through the oil driven turbine?

Answer 13

the booster nozzle baffler valve

Question 14

what controls flow around the oil driven turbine?

Answer 14

the booster bypass baffler valve

Question 15

what is the main shaft oil pump suction to be maintained at?

Answer 15

15 psig

Question 16

what maintains the bearing header pressure at 25 psig?

Answer 16

bearing oil header relief valve auto adjusts

Question 17

what is the power source for the emergency oil pump?

Answer 17

NKN-M46

Question 18

what provides purification for the main lube oil and feed pump lube oil system?

Answer 18

centrifuge

Question 19

how is oil transferred to/from the storage tanks/reservoirs

Answer 19

transfer pump

Question 20

where is the lube oil reservoir located?

Answer 20

in the LO room in the 140’ of the turbine building

Question 21

where is the main shaft oil pump located?

Answer 21

it is a gear driven pump from the HP turbine shaft. located in the HP turbine housing on the 176’ of the turbine building

Question 22

what is the power source for the motor driven centrifugal suction pump used while turbine speed is increased?

Answer 22

NH

Question 23

describe the turning gear oil pump

Answer 23

centrifugal with a flexible coupling

Question 24

what causes the turning gear oil pump to start when the switch is auto?

Answer 24

when the main shaft oil pump discharge pressure is low (190 psig) or the bearing oil pressure low signal (15 psig)

Question 25

what is the purpose of the emergency bearing oil pumps?

Answer 25

supplies for for shutting down in the event of a simultaneous low discharge pressure on the main shaft and turning gear oil pump

Question 26

describe the location of the Lube Oil Coolers

Answer 26

vertically mounted inside the LO reservoir

U-tube design

Question 27

what side of the HX is the turbine cooling water on?

Answer 27

tube side

Question 28

How is the cooling water flow controlled?

Answer 28

automatically controlled at the cooler outlet by throttling the turbine cooling water control valve (TIC-32)

Question 29

What is the purpose of the “double handwheel” cooler inlet valve?

Answer 29

one wheel selects the cooler to be placed in service (upper wheel) the other is for locking the valve stem in place (lower wheel)

Question 30

Where is the vapor that is extracted with the oil in the vapor extractor directed?

Answer 30

to the oily waste system through a floor drain.

discharges the filtered air to atmosphere

Question 31

where is the vapor extractor and oil mist eliminator located?

Answer 31

176’ of the turbine building

Question 32

how is the vapor extractor controlled?

Answer 32

a local handswitch

Question 33

which bearings have an interlock to stop the lift oil pumps if the control room switch is in AUTO and the turning gear motor is running.

Answer 33

bearing 7 and 10

Question 34

describe the bearing oil headers?

Answer 34

high pressure oil inside the low pressure drain header

Question 35

what happens to the plant in the event of a loss of the LO system?

Answer 35

the main turbine will trip when the main shaft oil pumps drop below 110 psig
also trips when the bearing header pressure drops below 12 psig

Question 36

what must the control room do if the main turbine LO is 110F or more?

Answer 36

they must ensure the turning gear is in “PULL TO LOCK”