The two classifications of steam turbines include:
induction and extraction
condensing and non-condensing
impulse and reaction
compound and cross-compound
all of the above
The two types of steam turbines include
Impulse turbine blades
create considerable end thrust
convert heat energy into kinetic energy
are either bucket shape or nozzle shaped
convert kinetic energy into useful work
are typically used in the low pressure stages of a turbine
Reaction turbine blades
are nozzle shaped
are bucket shaped
are a combination of bucket and nozzle shaped
produce little end thrust
The pressure remains constant across the moving blades of an impulse turbine
The force applied to the blade is caused by changing the direction of the stream flow in an impulse turbine
Steam pressure drops across the moving blades of an impulse turbine
In a reaction turbine the steam pressure drops in both the stationary and rotating blades
In a reaction turbine the steam expands in the moving blades producing a reaction force
In a reaction turbine the velocity of the steam decreases in the stationary and moving blades
In a reaction turbine blade clearance between the rotor and the casing must be kept at a maximum to prevent rubbing.
Nozzles are used on steam turbines to
reduce the steam velocity to the blading
increase the enthalpy of the incoming steam
prevent moisture from entering the low pressure stages of the turbine
convert pressure energy into potential energy
The throttling effect of steam through a turbine nozzle
increased superheat, reduces pressure and increases the steam volume
reduced superheat, increases pressure and increase the steam volume
no change in superheat, reduces pressure and increases the steam volume
increased superheat, increased pressure, increased volume
heat loss, enthalpy gain and increase in velocity
In which type of turbine does the steam pressure drop in the nozzle and then remain constant through both the stationary and moving blades:
pressure compounding impulse turbine
reaction turbine
velocity compounded impulse turbine
non-condensing impulse turbine
none of the above
Steam velocity, blade velocity may be reduced in a multistage impulse turbine by: 1. Reducing turbine vacuum 2. pressure compounding 3. increasing blading length 4. velocity compounding
1,2
2,3
1,3
2,4
3,4
Compounding steam turbines is used primarily to: 1. counteract axial thrust 2. reduce turbine rotor speed 3. Reduce friction losses 4. reduce turbine blade erosion 5. reduce turbine noise
1,3,5
2,3,4
1,2,3,4,5
A dummy piston with balance pipe is used primarily on reaction turbines to:
reduce the clearance space between the blade tip and the casing
reduce turbine vibration
eliminate the use of a thrust bearing
offset the end thrust produced
A turbine thrust bearing is typically lined with a soft metal known as
brass
babbit
lead
carbon
inconel
The purpose of a thrust bearing on a steam turbine is to: 1. Absorb rotor axial thrust 2. Reduce turbine vibration 3. Prevent steam leakage 4. Reduce steam velocity 5. keep the rotor in place within the casing
1,2,5
1,2,3,4
2,3,4,5
1,5
Different types of steam turbine plants may be classified as:
compound and cross compound
SAGD and HRSG
Steam turbine and gas turbine
In addition to having a high thermal cycle efficiency, condensing steam plants have the following advantage.
a large amount of cooling water is required
low initial cost
little space is required
recovery of condensate is possible
This type of turbine acts like a pressure reducing valve.
Back pressure Turbine
Rateau Turbine
Extraction turbine
Induction turbine
Cross-compound Turbine
This type of steam turbine has a better overall efficiency than a purely condensing steam turbine.
gas turbine
cross-compounded
tandem double-flow
bleeder turbine
Another name for a condensing bleeder turbine would be referred to as
induction turbine
closed cycle steam turbine
extraction turbine
topping turbine
back pressure turbine
This type of turbine allows new high pressure boilers to provide steam to old lower pressure systems and could also be the back pressure turbine of a cross compound system
governing turbine
induction/extraction turbine
condensing turbine
reducing station turbine
The purpose of a coupling on a turbine is to:
A) compensate for axial expansion and contraction of the rotor
B) transmit power from one shaft to the other
C) keep the shaft from vibrating
D) both a and b
E) all of the above
The following pump is utilized on a turbine rotor while on barring gear to prevent rubbing inside the bearings
lifting oil pump
boilerfeed pump
hydraulic oil pump
jacking oil pump
