4Th Class Power Engineering Chapter 69

Front 1

Steam turbine lubrication oil:

1. Will be contaminated by water

2. Must be cooled

3. Lubricates the dummy piston

4. Can be used for the turbine governor

5. Lubricates the labyrinth gland

6. Must be filtered

1) 2, 4, 5, 6

2) 3, 4, 5

3) 1, 2, 3, 4, 5, 6

4) 2, 3, 4, 6

5) 1, 2, 4, 6

Back 1

5) 1, 2, 4, 6

Front 2

Turbine speed can be "fine tuned" with a device that will be limited to about 10% over the rated speed. This device is the:

1) Over-speed trip

2) Over-speed governor

3) Sentinel valve

4) Governor valve

5) Hand speed control

Back 2

5) Hand speed control

Front 3

Shaft sealing of steam turbines is done with:

1. Mechanical seals

2. Water sealed glands

3. Carbon rings

4. Labyrinth seals when the temperature and pressure of the steam is high

1) 3, 4

2) 2, 4

3) 1, 3, 4

4) 2, 3, 4

5) 1, 2, 3, 4

Back 3

4) 2, 3, 4

Front 4

Shaft sealing carbon glands are:

1) Metal sprayed components

2) Replaced monthly due to erosion

3) Self-lubricating

4) Lubricated by the main oil pump

5) Limited to a temperature of 250ºC

Back 4

3) Self-lubricating

Front 5

In an impulse turbine the:

1) Steam pressure is reduced in the nozzles

2) Steam pressure will drop across the blades

3) Exhaust steam is directed back to the boiler

4) Steam flow is reduced through the nozzles

5) Steam velocity is increased through the blades

Back 5

Steam pressure is reduced in the nozzles

Front 6

Turbine thrust bearings are fixed to the casing and prevent axial movement of the spindle by contacting a component on the shaft known as a:

1) Shaft sleeve

2) Diaphragm

3) Labyrinth

4) Shroud

5) Collar

Back 6

5) Collar

Front 7

Impulse turbines:

1. Have a velocity increase through the nozzles

2. Blades have the angle of inlet the same as the outlet

3. Could have more than one set of blades

4. Are used for low pressure steam only

5. May not require a thrust bearing

1) 1, 3, 4, 5

2) 2, 3, 4

3) 2, 3

4) 1, 2, 3, 5

5) 1, 2, 3, 4

Back 7

4) 1, 2, 3, 5