Seal oil Flashcards Preview

systems test 8 > Seal oil > Flashcards

Flashcards in Seal oil Deck (26):
1

STATE the functions of the SO system

Lubricates the generator seals.
Prevents hydrogen leaks from the generator to the atmosphere along the rotor shaft.
Minimizes the amount of air and moisture introduced into the generator
thereby maintaining hydrogen purity.

2

STATE the function of the following major component:
- SO Vacuum Tank (SOVT)

– a surge volume for the seal oil system.
– a suction source for the seal oil pumps.

3

STATE the function of the following major component:
H2 Detraining Tank

• Removes hydrogen that becomes entrained in the oil due to agitation at the seals.
• Provides a collection area for the hydrogen side of the shaft seals and allows entrained hydrogen to escape from the seal oil.

4

STATE the function of the following major component:
SO Vacuum Pump (SOVP)

– Maintains a vacuum of approximately 29” Hg in the SOVT to remove moisture and gases from the seal oil.
– Helps maintain the purity of the generator's hydrogen atmosphere.

5

STATE the function of the following major component:
H2 Float Trap

• Prevents hydrogen loss from the generator/detraining tank to the seal oil system.

6

STATE the function of the following major component:
Recirc. SO Pump (RSOP)

• continuously circulates the oil in the seal oil vacuum tank through a spray header.
Disassociates gases entrained in the oil

7

STATE the function of the following major component:
Seals

• Seals prevent the escape of hydrogen gas from the generator.

8

STATE the function of the following major component:
Main SO Pump (MSOP)

• circulates oil from the seal oil vacuum tank to the generator seals.

9

STATE the function of the following major component:
SO Filters

• Remove particulate contamination from the seal oil.

10

STATE the function of the following major component:
H2 Liquid Detector

• Liquid detector senses overflow conditions in the hydrogen detraining tank.
– Indicates a possible malfunction of the Hydrogen float.

11

STATE the function of the following major component:
Emerg. SO Pump (ESOP)

• supplies oil to the generator shaft seals if the main seal oil pump fails.

12

STATE the function of the following major component:
Press. Reg. Valve

• Maintains SO pressure approximately 8 psid higher than generator hydrogen pressure.
• Ensures sufficient driving head to overcome Hydrogen pressure and maintain flow through the seals.

13

STATE the function of the following major component:
Auxiliary Detraining Tank

• Collects oil from the air side of the generator seals and generator bearings 9 & 10.
• Removes air that becomes entrained in the oil due to agitation at the seals.
• Collects oil returning via the hydrogen float trap.

14

DESCRIBE the flowpath through the SO system:
During normal operation.

The MSOP takes suction from the SOVT. This gets sent to the filters and then to the generator. The Hydrogen side drains to the Hydrogen detraining tank. The air side is sent to the aux tank. The oil in the detraining tank goes to the aux tank and then back to the lube oil system where it is cooled. Make up is provided to the SOVT from the lube oil system. The SOVT is recirculated with the RSOP. A vacuum is maintained on the tank with the SOVP.

15

DESCRIBE the flowpath through the SO system:
When the ESOP is in operation (MSOP is not running).

When the ESOP is in operation (MSOP is not running).
The ESOP gets its supply from the lube oil system. The Hydrogen side drains to the Hydrogen detraining tank. The air side is sent to the aux tank. The oil in the detraining tank goes to the aux tank and then back to the lube oil system where it is cooled. The SOVT is recirculated with the RSOP. A vacuum is maintained on the tank with the SOVP. Make up is not vacuum treated and the SOVT may overheat.

16

DESCRIBE the flowpath through the SO system:
When the Lube Oil (LO) System is the sole source of SO pressure

LO provides flow to the seals. The Hydrogen side of the seals drains to the Hydrogen detraining tank. The air side is sent to the aux tank. The oil in the detraining tank goes to the aux tank and then back to the lube oil system where it is cooled. Makeup oil is NOT vacuum treated. Loaded operation in this configuration is not possible.

17

DESCRIBE the flowpath through the SO system:
When the SO system is in operation with the LO System shutdown.

The MSOP takes suction from the SOVT. This gets sent to the filters and then to the generator. The Hydrogen side drains to the Hydrogen detraining tank. The air side is sent to the aux tank. The oil in the detraining tank goes to the aux tank and then back to SOVT. There is no makeup or cooling provided to SOVT. The SOVT is recirculated with the RSOP. A vacuum is maintained on the tank with the SOVP.

18

STATE the three sources of SO pressure for the Main Generator

• MSOP (normal) – Can support full load operation. (75 psig H2 pressure in the generator).
• ESOP – Can support full load operation – with a caveat. (75 psig H2 pressure in the generator).
• LO bearing oil pressure – Cannot support loaded operation. (Based on 25 psig supplied by LO system. Maximum H2 pressure would be 8 psig less, or 17 psig H2 pressure in the generator – this is less than the 30 psig minimum H2 pressure for loaded operation).

19

EXPLAIN how SO is cooled.

• “Cool” Oil is supplied from the Main Turbine LO System via the Main Turbine LO Coolers.

20

STATE the normal at-power values for:
MSOP discharge pressure.
SOVT pressure and level.
Generator H2/SO differential pressure.
H2 Float Trap sight glass level.

MSOP discharge pressure.
Normal discharge pressure is approx 120 psig.
SOVT pressure and level.
1/2 on the lower sight glass
29” Hg
Generator H2/SO differential pressure.
8psid
H2 Float Trap sight glass level.
sight glass level is approx 1/2.

21

STATE the power supplies for the SOVP, the MSOP, the RSOP, and the ESOP.

SOVP is powered from MCC-131.
RSOP is powered from MCC-523
MSOP is powered from MCC-523
ESOP is powered from 12A

22

DESCRIBE the action to be taken if the MSOP starts to cavitate during the initial startup of the SO system.

• NSO required to open vent valve SO-V8032 to lower vacuum slightly until normal operating temperatures restored.

23

LIST the conditions that will start the ESOP.

• Auto start if MSOP pressure falls below 110 PSIG.

24

EXPLAIN why it is necessary to pre-fill an oil filter prior to placing it in service.

– Loss of flow when swapping filters.

25

DESCRIBE the indications of emulsified oil and what effects emulsified oil could have on SO system operation.

Emulsification is the homogenous mixing of oil and water and causes oil to appear cloudy.

Emulsified oil has poor sealing, lubricating, and pumping qualities.
can result in
Loss of generator hydrogen through the seals.
SOVP bearing damage.
MSOP discharge pressure fluctuations.

Emulsified oil would be evident at
SOVT sight glass.
SOVP Separator sight glass.

26

DESCRIBE the major effects of failure of each of the following active SO system components:
SOVP.
MSOP.
RSOP.

SOVP.
Loss of generator hydrogen purity.
MSOP.
ESOP starts
RSOP.
Loss of generator hydrogen purity