A.B. Hopkins Generating StationSeal Oil and Hydrogen System
August 1 2014Test Bank of Questions Unit 2 HPA
Test Bank of Questions
Seal Oil and Hydrogen SystemHOPKINS REPOWERING PROJECT
UNIT HP2A
1.TH-HOP-14Seal Oil and Hydrogen System
Why is hydrogen used for cooling generators?
- Hydrogen has a better heat removal capacity than air
- Hydrogen is safer than carbon dioxide
- Hydrogen is more ecologically sound
- Hydrogen is readily available
2.TH-HOP-14Seal Oil and Hydrogen System
When is the removable link installed in the hydrogen manifold?
- When hydrogen is purged from the generator
- When hydrogen is added to air in the generator
- When hydrogen is added to the generator
- When connecting the backup hydrogen supply
3.TH-HOP-14Seal Oil and Hydrogen System
What is the purpose of the defoaming tank?
- Removes carbon dioxide from seal oil
- Allows hydrogen in the seal oil to vent back into the generator
- Cools seal oil as it drains from the gland seals
- Removes foam from water leaving the seal oil coolers
4.TH-HOP-14Seal Oil and Hydrogen System
Which system supplies cooling water to the seal oil coolers?
- Circulating water
- Service water
- Feedwater
- Condensate water
5.TH-HOP-14Seal Oil and Hydrogen System
What do gland seals do?
- Seal hydrogen in the generator casing
- Regulate the supply of water to the generator casing
- Expand to keep oil out of the generator casing
- Lubricate the generator shaft
6.TH-HOP-14Seal Oil and Hydrogen System
The differential pressure regulator maintains air side seal pressure at what level?
- 12 psi below hydrogen pressure in the generator casing
- 12 psi above seal oil pressure in the generator casing
- 12 psi above hydrogen pressure in the generator casing
- 12 psi above ambient air outside the generator casing
7.TH-HOP-14Seal Oil and Hydrogen System
What controls are associated with the generator bearing oil drain tank?
- None
- Hydrogen control panel
- Seal oil control panel
- 480 VAC breaker on MCC2-2
8.TH-HOP-14Seal Oil and Hydrogen System
What color does the activated alumina in the gas dryer turn to when it is completely dry?
- Gray
- Yellow
- Green
- Blue
9.TH-HOP-14Seal Oil and Hydrogen System
Of the gases used in the generator, which is the lightest?
- Air
- Helium
- Hydrogen
- Carbon dioxide
10.TH-HOP-14Seal Oil and Hydrogen System
Where does the major flowpath of the hydrogen seal oil system begin?
- Hydrogen side drain regulator
- Lube oil reservoir
- Generator bearing oil drain line loop seal tank
- Hydrogen side seal oil cooler
11.TH-HOP-14Seal Oil and Hydrogen System
What gas is used to purge the generator of hydrogen?
- Service Air
- Carbon dioxide
- Ammonia
- Instrument Air
12.TH-HOP-14Seal Oil and Hydrogen System
What is the result when hydrogen and air are combined?
- Condensation
- Carbon dioxide
- An explosive mixture
- An inert mixture
13.TH-HOP-14Seal Oil and Hydrogen System
What are the safe purity levels for hydrogen in the generator?
- Below 4.1% and above 74.2%
- Above 74.2% only
- Between 4.1% and 72.4%
- 100% only
14.TH-HOP-14Seal Oil and Hydrogen System
What is the purpose of the gas dryer?
- Remove moisture from hydrogen in the hydrogen side seal oil cooler
- Remove moisture from air in the generator
- Remove moisture from the gland seals
- Remove moisture from hydrogen in the generator
15.TH-HOP-14Seal Oil and Hydrogen System
At which end of the rotor does cooling gas enter the rotor?
- Turbine end
- Exciter end
- Both ends
- Cooling gas does not enter the rotor directly
16.TH-HOP-14Seal Oil and Hydrogen System
In a gland seal where is the hydrogen side seal located?
- Between the generator and the air side seal
- Adjacent to the air side seal
- Turbine end of the generator shaft
- Exciter end of the generator shaft
17.TH-HOP-14Seal Oil and Hydrogen System
Which is NOT a function of the generator bearing oil drain tank?
- Serves as generator seal oil reservoir
- Removes any hydrogen entrained in the air side seal oil
- Removes condensate entrained in the seal oil draining from the gland seals
- Provides a liquid loop seal between the generator seal oil and turbine lube oil systems
18.TH-HOP-14Seal Oil and Hydrogen System
What is the purpose of the vapor extractor?
- Removes unwanted gases from the loop seal tank
- Removes moisture from the generator casing
- Extracts vapor from the seal oil coolers
- Removes moisture from the hydrogen manifold
19.TH-HOP-14Seal Oil and Hydrogen System
Where is the Hydrogen Control Panel located?
- In the generator casing
- In the control room
- Next to the turning gear
- Adjacent to the operator room on the pump room floor
20.TH-HOP-14Seal Oil and Hydrogen System
When placing the seal oil system in service, which pump is started first?
- Air side seal oil pump
- Air side seal oil backup pump
- Hydrogen side seal oil pump
- Hydrogen side seal oil backup pump
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