Purdom Generating StationSeal Oil and Hydrogen System

August 1 2014Test Bank of Questions Unit 8

Test Bank of Questions

Seal Oil and Hydrogen System
Purdom Generating Station
UNIT 8

1. TH-PUR-14 Seal Oil and Hydrogen System

Why is hydrogen used for cooling generators?

  1. Hydrogen has a better heat removal capacity than air
  2. Hydrogen is safer than carbon dioxide
  3. Hydrogen is more ecologically sound
  4. Hydrogen is readily available

2. TH-PUR-14 Seal Oil and Hydrogen System

When is the removable link installed in the hydrogen manifold?

  1. When hydrogen is purged from the generator
  2. When hydrogen is added to air in the generator
  3. When hydrogen is added to the generator
  4. When connecting the backup hydrogen supply

3. TH-PUR-14 Seal Oil and Hydrogen System

What is the purpose of the defoaming tank?

  1. Removes carbon dioxide from seal oil
  2. Allows hydrogen in the seal oil to vent back into the generator
  3. Cools seal oil as it drains from the gland seals
  4. Removes foam from water leaving the seal oil coolers

4. TH-PUR-14 Seal Oil and Hydrogen System

Which system supplies cooling water to the seal oil coolers?

  1. Circulating water
  2. Service water
  3. Feedwater
  4. Condensate water

5. TH-PUR-14 Seal Oil and Hydrogen System

What do gland seals do?

  1. Seal hydrogen in the generator casing
  2. Regulate the supply of water to the generator casing
  3. Expand to keep oil out of the generator casing
  4. Lubricate the generator shaft

6. TH-PUR-14 Seal Oil and Hydrogen System

The differential pressure regulator maintains air side seal pressure at what level?

  1. 12 psi below hydrogen pressure in the generator casing
  2. 12 psi above seal oil pressure in the generator casing
  3. 12 psi above hydrogen pressure in the generator casing
  4. 12 psi above ambient air outside the generator casing

7. TH-PUR-14 Seal Oil and Hydrogen System

What controls are associated with the generator bearing oil drain tank?

  1. None
  2. Hydrogen control panel
  3. Seal oil control panel
  4. 480 VAC breaker on MCC2-2

8. TH-PUR-14 Seal Oil and Hydrogen System

What color does the activated alumina in the gas dryer turn to when it is completely dry?

  1. Gray
  2. Yellow
  3. Green
  4. Blue

9. TH-PUR-14 Seal Oil and Hydrogen System

Of the gases used in the generator, which is the lightest?

  1. Air
  2. Helium
  3. Hydrogen
  4. Carbon dioxide

10. TH-PUR-14 Seal Oil and Hydrogen System

Where does the major flowpath of the hydrogen seal oil system begin?

  1. Hydrogen side drain regulator
  2. Lube oil reservoir
  3. Generator bearing oil drain line loop seal tank
  4. Hydrogen side seal oil cooler

11. TH-PUR-14 Seal Oil and Hydrogen System

What gas is used to purge the generator of hydrogen?

  1. Service Air
  2. Carbon dioxide
  3. Ammonia
  4. Instrument Air

12. TH-PUR-14 Seal Oil and Hydrogen System

What is the result when hydrogen and air are combined?

  1. Condensation
  2. Carbon dioxide
  3. An explosive mixture
  4. An inert mixture

13. TH-PUR-14 Seal Oil and Hydrogen System

What are the safe purity levels for hydrogen in the generator?

  1. Below 4.1% and above 74.2%
  2. Above 74.2% only
  3. Between 4.1% and 72.4%
  4. 100% only

14. TH-PUR-14 Seal Oil and Hydrogen System

What is the purpose of the gas dryer?

  1. Remove moisture from hydrogen in the hydrogen side seal oil cooler
  2. Remove moisture from air in the generator
  3. Remove moisture from the gland seals
  4. Remove moisture from hydrogen in the generator

15. TH-PUR-14 Seal Oil and Hydrogen System

At which end of the rotor does cooling gas enter the rotor?

  1. Turbine end
  2. Exciter end
  3. Both ends
  4. Cooling gas does not enter the rotor directly

16. TH-PUR-14 Seal Oil and Hydrogen System

In a gland seal where is the hydrogen side seal located?

  1. Between the generator and the air side seal
  2. Adjacent to the air side seal
  3. Turbine end of the generator shaft
  4. Exciter end of the generator shaft

17. TH-PUR-14 Seal Oil and Hydrogen System

Which is NOT a function of the generator bearing oil drain tank?

  1. Serves as generator seal oil reservoir
  2. Removes any hydrogen entrained in the air side seal oil
  3. Removes condensate entrained in the seal oil draining from the gland seals
  4. Provides a liquid loop seal between the generator seal oil and turbine lube oil systems

18. TH-PUR-14 Seal Oil and Hydrogen System

What is the purpose of the vapor extractor?

  1. Removes unwanted gases from the loop seal tank
  2. Removes moisture from the generator casing
  3. Extracts vapor from the seal oil coolers
  4. Removes moisture from the hydrogen manifold

19. TH-PUR-14 Seal Oil and Hydrogen System

Where is the Hydrogen Control Panel located?

  1. In the generator casing
  2. In the control room
  3. Next to the turning gear
  4. Adjacent to the operator room on the pump room floor

20. TH-PUR-14 Seal Oil and Hydrogen System

When placing the seal oil system in service, which pump is started first?

  1. Air side seal oil pump
  2. Air side seal oil backup pump
  3. Hydrogen side seal oil pump
  4. Hydrogen side seal oil backup pump

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