LO- Main Turbine Lube Oil/Feedwater Pump Turbine Lube Oil Flashcards
What is the purpose of the Main Turbine LO system?
Provides lubricating oil to the Main Turbine and Generator bearings
Provides lubricating oil to the Bearing Lift Oil Pumps
Supplies oil to the Generator Seal Oil System
What is the heat sink for the Main Turbine LO coolers? What happens when this cooling source is lost?
Turbine Cooling Water
lube oil temp and bearing temp will increase
What system powers the Emergency Lube Oil Pump?
NK (NKN-M46)
The Main Turbine LO system is a backup oil supply for what system?
Generator Seal Oil system when both the Main and Emergency Seal Oil pumps fail
What system purifies the Main Turbine LO System?
OS system
What is the capacity of the LO Main Lube Oil Reservoir and what is the normal level?
Capacity of 11200 gallons
Normal level of 8550 gallons
Where is the Main Lube Oil reservoir in the LO system located?
140’ Turbine Building in the Lube Oil Room
What provides the motive force for the Main Shaft Oil Pump and where is it located?
Gear driven from the HP turbine shaft and is located in the HP turbine housing on the 176’ Turbine Building
What is the Main Shaft Oil Pump rated for?
1500 gpm and 235 psig at 3600 RPM
What is the motive force used to drive the LO Booster Pump?
Oil Driven Turbine, where a portion of the Main Shaft Oil Pump discharge is routed to the inlet of the turbine
The purpose of the LO turbine driven booster pump is to provide suction for the main shaft oil pump. What pump is used if the Booster Pump output is insufficient? Where are the Oil Driven turbine and booster pump located?
Motor Suction Pump will be used to supply the Main Shaft Oil Pump suction
in the main lube oil reservoir
What is the Booster Oil Pump rated for?
1500 gpm at a discharge pressure of 62 psig
What is the purpose of the Motor Suction Pump?
To provide the Main Shaft Driven Oil pump with a source of oil to its suction when the turbine speed is less than 90%
The Booster Pump will have sufficient capacity when turbine speed it greater than 90%
What is the Motor Suction Pump rated for? What powers this pump?
1500 gpm at 15 psig
480 VAC non-class
What is the purpose of the Turning Gear Oil Pump?
To provide bearing oil to the turbines bearings while the turbine is on the turning gear or when it is coming up to speed
What is the Turning Gear Oil Pump rated for? What powers it? Location?
1275 gpm at 43 psig
480VAC
main lube oil reservoir
What signals would cause an auto start of the Turning Gear Oil Pump?
Main shaft oil discharge pressure low @ 190 psig,
Bearing Oil Pressure Low @ 15 psig
Regarding the main turbine turning gear oil pump, how often is the Auto start tested and where are the pushbuttons for the tests?
Performed weekly
Four pushbuttons, two in the control room and two at the Main Lube Oil reservoir
What is the purpose of the Emergency Bearing Oil Pump?
To supply oil for shutting down the turbine should there be a simultaneous low discharge pressure on the Main Shaft Oil Pump and the Turning Gear Oil Pump
(caused by turbine trip or LOOP)
What is the Emergency Bearing Oil Pump rated for? Location? Power source?
110 gpm at 15 psig
main lube oil reservoir
NKN-M46
What would auto start the Emergency Bearing Oil Pump?
A low voltage on NGN-L14 (Power supply to the Turning Gear Oil Pump)
Main shaft oil discharge pressure low @ 180 psig,
AND
Turning Gear Oil Pump Discharge Pressure low @ 15 psig
How often is the EBOP auto start tested and where are the pushbuttons?
Performed weekly
One in the Control Room and one at the Lube Oil Reservoir
What flows on the shell side of the LO lube Oil Coolers? Tube side?
Oil
Turbine cooling water
How is Turbine Cooling Water flow controlled through the LO lube oil coolers?
Automatically at the cooler outlet by Turbine Cooling Water Control Valve (TCN-TV-183)
How is the “double handwheel” cooler inlet valve operated in the LO system?
Lower Handwheel is used to lock the valve stem into position and the Upper Handwheel is used to select which cooler is in service
(cooler inlet valve has a bypass around it to allow filling the standby cooler before being service)
How can I tell the LO lube oil cooler is full?
By opening the bypass valve and observing oil flow from a constant vent on the cooler that can be seen by lifting a hatch on the reservoir
What is the purpose of the MTLO Vapor Extractor?
Pulls air, oil vapor, hydrogen, and moisture from the Main Turbine Lube Oil Reservoir through the Lube Oil Mist Eliminator adjacent to the Vapor Extractor
The MTLO Vapor Extractor causes a small flow of cool air through the shaft bearing oil deflectors in order to prevent oil accumulation and carbonization in the deflector teeth and on the turbine shaft. How do we prevent oil vapor from leaking out past the bearing oil deflector?
Pressure on the pedestal side of the oil deflector is less than the outside
What is the LO Mist Eliminator comprised of? How effective are the fiberglass filters? Where is the removed oil directed to?
Five fiberglass filters mounted in parallel inside a cylindrical cylinder supported by a frame
removes virtually all oil vapor from the air
directs the oil to the OW system through a floor drain
Where are the MTLO Vapor Extractor and mist eliminator located?
176’ Outside the turbine building
Where do I operate the MTLO Vapor Extractor?
Handswitch located by the Vapor Extractor
What is the purpose of the Bearing Oil Lift Pumps in the LO system? Where do they inject oil into the bearings?
To reduce the torque requirements of the Turning Gear Motor
bearing lower half
Where are the LO Bearing Oil Lift Pumps located? How many are there?
176’ Turbine Building, on the turbine by the respective bearings
8 high pressure, positive displacement pumps
What would auto start a LO Bearing Lift Oil Pump?
Turning Gear Pump discharge pressure high signal is received
What would stop the Bearing Lift Oil pump?
Lift Pump suction pressure low or electrical protection signal
What is the interlock associated with bearings 7 and 10 and the Lift pumps? Purpose?
- When the following conditions are met, the lift pumps for these bearings will stop:
- Bearing oil lift pump hand switch in the Control Room is in Auto
- Turning Gear Motor is running
- Turbine Rotor Speed is less than 2 rpm
Prevents the turbine gear from disengaging during turbine shaft pulses
(with those pumps running, there isn’t enough friction to keep the turbine from rolling off the shaft turning gear)
What portions of the header supply use pipe-within-pipe arrangement? Why?
Piping in vicinity of hot turbine parts
in the case of a supply header rupture, the high-pressure oil will spray into the drain header
(portions of the supply header not in the vicinity of hot turbine parts do not use pipe-within-a-pipe arrangement)
What bearing header pressure would trip the Main Turbine? What main shaft oil pump discharge pressure will trip the main turbine?
Below 12 psig
below 100 psig
What is the purpose of the Feedwater Pump/Turbine Lube Oil System?
Provides lubricating oil to the bearings of the Feedwater Pump and Turbine
Supplies control oil to the Feedwater Pump Turbine Control system
What provides the cooling medium to the Main Feed Pump/turbine oil system?
Turbine Cooling Water
What pressure is maintained in the LO Low Pressure Oil Header?
55 psig
What happens if I lose the AC powered, FWPT LO main oil pumps?
Emergency pump discharges directly into the pump and turbine bearing oil supply lines, bypassing the oil coolers and filters
What are the regulators for the FWPT LO bearing headers set to?
12 psig to the turbine
there are two regulators due to original design having them at different pressures
What powers the MFWPT main oil pumps?
NH
What powers the MFWP/T LO Vapor Extractor Blowers?
NH
What does NK power in the MFW lube oil system?
MFW emergency oil pumps
What system purifies the Main Feedwater pump lube oil and transfers lube oil to and from the reservoir?
Lube Oil Storage, Transfer and Purification System (OS)
What is the capacity of FW pump lube oil reservoir? Location?
1000 gallons
In front of the turbine and extends under the governor casing
Where are the Feedwater Pump/Turbine Main Oil pumps located? How many are there?
In the lube oil reservoir with the pump motors mounted on top of the reservoir
two
What is the pressure of the low pressure discharge from the 1st stage of the Feedwater Pump/Turbine Main Oil pumps? What is that pressure reduced to for the MFW pump/turbine bearings?
60-65 psig
12 psig
What is the pressure of the high pressure discharge from the 4th stage of the Feedwater Pump/Turbine Main Oil pumps?
220 psig
Under normal operations, how many Feedwater Pump/Turbine Main Oil pumps are running?
One, the other one in standby
When would the standby Feedwater Pump/Turbine Main Oil pump auto start?
Low oil header pressure of 195 psig (oil header monitored is the high pressure oil header)
What is the purpose of the TEST push button for the FWPT lube oil pumps and where is that switch normally operated from?
To test the auto start feature of the Main Lube Oil pumps
Normally done from the Control Room
What is the discharge pressure of the FWPT Emergency Lube Oil pump? Where is it powered from? Where are the test buttons located for this pump?
12 psig
NK
control room and local panel
When will the FWPT Emergency Lube Oil pump auto start? What is it meant for?
Upon a receipt of a pump and turbine bearing low oil pressure of 37 psig
Only provides lubrication for coastdown since it doesn’t supply control oil or trip headers
Where are the two FWPT Lube Oil Coolers located? What is their capacity? What is provided with the coolers?
110’ Turbine Building, at the end of their respective Feed Pumps
100%
transfer valve, filling valves and vents to allow cleaning of one cooler with the other is in service
Where are the two FWPT Vapor Extractors located? How often do the vapor extractor blowers run?
140’ of the Turbine building, above ‘B’ Feed Pump
continuously while the turbine is operating
What is the purpose of the FWPT Vapor Extractors?
To create negative pressure in the oil reservoir, which will cause an inward flow of air through the bearings oil deflectors in the bearing housing that will eliminate leakage of oil out through the oil deflectors
What else does the FWPT Vapor Extractor do for us? What is the oil separator at the oil reservoir upstream of the intake of the vapor extractor for?
Removes explosive gasses and air moisture inside the MFWP oil reservoirs
mesh type oil demister that separates oil from the vapor prior to entering the vapor extractor.
What would be the adverse effect of too much vacuum in the MFWP oil reservoirs? Too little vacuum?
Can draw excessive contamination into the system and oil out the vent line
oil leaks
What would be the adverse effect of losing Feedwater Pump/Turbine Lube Oil?
standby oil pump will start on low oil header pressure and losing both oil pumps activates the emergency pump and only supply the bearings while the feedwater pumps coast down
Loss of one feedwater pump, results in a Reactor Cutback
Loss of two feedwater pumps, results in a Reactor Trip and Aux feed will be used to fill the S/Gs
How is the FWPT Lube oil system affected by a loss of TC?
If lost for an extended period of time, the plant will have to be shut down and the feed water pumps stopped
What penetrations are in the LO Main lube oil reservoir?
LO coolers, motor suction pump, EBOP, turning gear oil pump, supply and return purification, level sensing equipment and visual inspection
What is the purpose of the two parallel FWPT lube oil filters? Where are they located? What are these filter elements equipped with?
remove impurities for system reliability
downstream of the lube oil coolers
transfer valve between them to transfer use without interrupting flow, and a relief valve allowing to bypass the filters upon clogging of filters
