Main Generator Seal Oil

Question 1

What is Main Generator Seal Oil used for ?

Answer 1

-Used to keep hydrogen inside generating casing during operation
-Also used to keep CO2 or service air during startup,shutdown,or testing

Question 2

What should be in service before pressurizing the Main Generator with Hydrogen, CO2, or Service Air ?

Answer 2

Seal oil should be in service before pressuring generator

Question 3

What pumps use 480VAC MCC(NH) ?

Answer 3

-Main Seal Oil Pump
-Recirculating Seal Oil Pump
-Seal Oil Vacuum Pump

Question 4

What does 125VDC Control Power(NK) provide power to ?

Answer 4

-Emergency Seal Oil Pump
-Generator hydrogen & stator cooling cabinet annunciator
-Local circuit isolation switch for ESOP

Question 5

What does Main Turbine Lube Oil provide for Main Generator Seal Oil ?

Answer 5

Main turbine LO supplies lube oil to the Seal Oil system

Question 6

Where does drainage from the Seal Oil Separator directed to ?

Answer 6

Directed to Turbine Building Oily Waste Sump

Question 7

What is the Seal Oil Vacuum Tank used for ?

Answer 7

Contains & treats Main Generator Seal Oil prior to being used for generator

Question 8

What does the Seal Oil Vacuum Tank float valve do ?

Answer 8

Regulates flow as required by total seal oil flow demand

Question 9

What’re the SOVT inlet spray nozzles used for ?

Answer 9

Separates oil into small droplets, this increases surface air. This removes gasses & moisture from oil

Question 10

What is the SOVT Recirulation line used for ?

Answer 10

-Draws oil from bottom & sprays out on top to remove more moisture & gasses
-Also minimizes foaming in tank

Question 11

Why is the SOVT important for the hydrogen inside the Generator Casing ?

Answer 11

-SOVT removes gasses & moisture which could effect dilute hydrogen purity
-SOVT automatically maintains satisfactory hydrogen purity without having to add hydrogen

Question 12

What does the Seal Oil Vacuum Pump do ?

Answer 12

Maintains vacuum in SOVT, which aids in removing gasses & moisture from seal oil

Question 13

Where does the SOVP takes it suction from & where does it discharge to ?

Answer 13

-Takes suction from gas space in the SOVT
-Discharges to the Separator Tank

Question 14

Where does the SOVP receive its sealing & lubrication oil from ?

Answer 14

-Separator Tank supplies oil to SOVP via solenoid operator valve
-Solenoid operated valve opens when SOVP starts, closes when SOVP stops

Question 15

What is the Seal Oil Separator used for ?

Answer 15

Separates gases & moisture withdrawn from SOVT

Question 16

How does Seal Oil Separator work?where do gasses vent to ?

Answer 16

-Contains baffles with separates liquid from gasses
-Gasses are exhausted out top of separator, towards outside turbine building

Question 17

What happens to water inside separator when oil/water level reaches 50%?

Answer 17

Water will flow out through water overflow pipe

Question 18

What level in the Separator will supply oil to SOVP ?

Answer 18

25% level will have collected oil directed to SOVP

Question 19

What does the Recirc. Seal Oil Pump do ?

Answer 19

Circulates main generator seal oil & discharges to spray nozzles removing gasses & moisture from seal oil

Question 20

Where does the Recirc Seal Oil Pump take its suction from ? Where does it discharge to ?

Answer 20

Takes suction from bottom of SOVT & discharges to SOVT Spray Nozzles

Question 21

Where is the Recirc. Seal Oil Pump operated from ?

Answer 21

Operated from control room

Question 22

What are advantages for positive displacement pump compared to Centrifugal pump ?

Answer 22

-High flow rates in viscous liquid with steady discharge pressure
-Constant flow even with back pressure changes
-Self Priming
-High tolerance for entrained air &
gasses