Throttle governing of steam engines is a method of controlling the engine output by varying
Volume of intake steam
Pressure of intake steam
Temperature of intake steam
All of these
Correct Answer :
B. Pressure of intake steam
Related Questions
The change in internal energy in steam engines equals to
Work done during the Rankine cycle
Work done during compression
Work done during adiabatic expansion
Change in enthalpy
The flow of steam is supersonic
At the entrance to the nozzle
At the throat of the nozzle
In the convergent portion of the nozzle
In the divergent portion of the nozzle
The behaviour of coal in a furnace is determined by
The content of sulphur
The content of ash and heating value
The proximate analysis
The exact analysis
Which of the following is correct? (Where pa = Actual mean effective pressure, pm = Theoretical mean effective pressure, and K = Diagram factor)
pa = pm/K
pa = pm × K
pa = K/pm
pa = pm + K
The reheat factor is the ratio of the
Cumulative heat drop to the isentropic heat drop
Isentropic heat drop to the heat supplied
Total useful heat drop to the total isentropic heat drop
None of the above
The ratio of total useful heat drop to the total isentropic heat drop, is called
Stage efficiency
Internal efficiency
Rankine efficiency
None of these
The velocity of whirl at outlet for an axial discharge turbine is
Minimum
Maximum
Zero
None of these
1 kg.m is equal to
9.81 Joules
102 Joules
427 Joules
None of these
The selection of type and size of a steam boiler depends upon
The power required and working pressure
The geographical position of the power house
The fuel and water available
All of the above
Expanding steam to a very low pressure (high vacuum) in steam engines is
Desirable
Economical
Essential
Uneconomical
Willians line for the steam engine is a straight line relationship between the steam consumption per hour and
Indicated power
Brake power
Efficiency
Pressure of steam
A device used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit, is called
Blow off cock
Stop valve
Superheater
None of these
Which of the following substance will have same percentage in both proximate and ultimate analysis?
Ash
Volatile matter
Moisture
Hydrogen
Willian's law states that the steam consumption per hour provided with a throttled governor is proportional to (where I.P. = Indicated power)
1/(I.P)
1/(I.P)²
I.P.
(I.P.)²
The fire tubes in a Cochran boiler usually have _________ diameter.
6.25 mm
62.5 mm
72.5 mm
92.5 mm
Steam exhaust from high pressure turbine is reheated in
Boiler drums
Superheater tubes
Economiser
A separate coil located in convection path.
Caking coals are those which
Form lumps or masses of coke
Burn freely
Show little or no fusing action
Burn completely
For maximum discharge through a chimney, the condition is that height of hot gas column producing the draught should be
One-half the height of chimney
Equal to the height of chimney
Two times the height of chimney
Four times the height of chimney
Blow off cock in a boiler is used to
Control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required
Empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler
Put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit
Increase the temperature of saturated steam without raising its pressure
The length of shell of a Locomotive boiler is
1 m
2 m
3 m
4 m
The process of draining steam from the turbine, at certain points during its expansion and using this steam for heating the feed water in feed water heaters and then supplying it to the boiler is known as
Regenerative heating
Reheating of steam
Bleeding
None of these
A wet vapour can be completely specified by
Pressure only
Temperature only
Dryness fraction only
Pressure and dryness fraction
A condenser where circulating water flows through tubes which are surrounded by steam, in known as
Surface condenser
Jet condenser
Barometric condenser
Evaporative condenser
The rate of discharge through the nozzle __________ when the exit pressure is gradually reduced.
Remains same
Decreases
Increases
None of these
The effect of super-saturation is that the
Mass of the steam discharged increases
Entropy and specific volume of the steam increases
Exit velocity of steam reduces
All of these
The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam.
More
Less
Same
None of these
An economiser is generally placed between
Last superheater or reheater and air preheater
Induced draft fan and forced draft fan
Air preheater and chimney
None of the above
In a Woolf type compound engine, the high pressure and low pressure cylinders
Have common piston rod
Are set at 90°
Have separate piston rod
Are set in V-arrangement
When the speed of the engine is controlled by means of a valve in a steam pipe, which regulates the pressure of steam entering the engine, then the governing is known as
Throttle governing
Cut-off governing
By-pass governing
None of these
The function of a valve rod is
To provide reciprocating motion to the slide valve
To convert reciprocating motion of the piston into rotary motion of the crank
To convert rotary motion of the crankshaft into to and fro motion of the valve rod
To provide simple harmonic motion to the D-slide valve