In a/an ______ turbine there is a difference in pressure across the _______ blades. Therefore the steam will tend to _____ around the periphery of the blades instead of passing through them. 1. impulse 2. moving 3. reaction 4. drip 5. stationary 6. Leak
1,2,4
3,5,6
3,2,6
1,5,4
1,5,6
A back-pressure turbine with exhaust steam going to an old boiler header that is supplying steam to an old lower pressure turbine is called a:
condensing-bleeder turbine
cross compound turbine
condensing turbine
Topping turbine
Mixed pressure turbine
A back-pressure turbine with exhaust steam going to an old boiler header that is supplying steam to an old lower pressure turbine is called a :
topping turbine
mixed pressure turbine
In a condensing-bleeder turbine up to 2 percent of the total steam flow may be bled off. What is the bleed-steam used for?
Building heating
Relieving pressure
Atomization of the fuel
To be reheated in boiler
Feed-water heating
In pressure compound steam turbines 1. The expansion of steam from boiler pressure to exhaust pressure is carried out in a number of steps or stages. 2. Each stage has a set of nozzles and a row of blades. 3. All of the velocity available is developed in one set of nozzles. 4. Rows of moving blades are separated by partitions or diaphragms into which nozzles have been installed.
1,2,3
2,3,4
1,3,4
3,4
The pressure at the outlet from the moving blades is the same as the pressure at the inlet to the moving blades in a/an ________ turbine
Topping
Reaction
Back pressure
Impulse
Extraction
When the exit pressure of a steam turbine nozzle is less than ________ times the inlet pressure then a _______ nozzle will be used.
0.757, convergent
0.577, convergent-divergent
0.757, convergent-divergent
0.757, convergents
0.577, convergent or convergent-divergent
A thrust adjusting gear
is found on impulse turbines
adjust the thrust generated by the turbine
positions the turbine rotor axially
compensates for steam pressure variations
is adjusted to provide minimum clearances on start up
In an impulse steam turbine nozzle the following events take place. 1. Steam pressure decreases. 2. Enthalpy of the steam decreases. 3. Velocity of the steam increases. 4. Volume of the steam increases.
1,2,3,4
In an impulse steam turbine nozzle the following events take place: 1. steam pressure decreases. 2. Enthalpy of the steam decreases 3. Velocity of the steam increases 4. volume of the steam increases
When disc rotors are assembled, the discs are heated until they are easily slid along the shaft and then located in the correct position on the shaft and shaft key. A small clearance between the discs prevents:
Noise
Slippage
Thermal stress in the shaft
Acceleration
Vibration
Proper expansion of steam through a turbine nozzle depends on what? 1. Operation at the design pressure 2. Operation at the design rotational speed 3. Operation at the design temperature 4. Selection of the proper nozzle material
1,2
2,3
1,3
2,4