The steam temperature with increase in load in case of a boiler fitted with radiation superheater
Increases
Decreases
Remain unaffected
First increases and then decreases
Correct Answer :
B. Decreases
Related Questions
Which of the following statement is correct?
A horizontal steam engine requires less floor area than a vertical steam engine
The steam pressure in the cylinder is not allowed to fall below the atmospheric pressure
The compound steam engines are generally non-condensing steam engines
All of the above
Benson boiler requires
No drum
One drum
Two drums
Three drums
The overall efficiency of thermal power plant is
Boiler efficiency, turbine efficiency, generator efficiency
All the three above plus gas cycle efficiency
Carnot cycle efficiency
Regenerative cycle efficiency
1 kg.m is equal to
9.81 Joules
102 Joules
427 Joules
None of these
The capacity of induced draft fan compared to forced draft fan in a boiler is
Same
More
Less
Less or more depending on size of boiler
Which of the following is steam dial?
Non-coking bituminous coal
Brown coal
Pulverised coal
Coking bituminous coal
For burning 1 kg of carbon to CO as per chemically correct combustion, amount of air required is
1 kg
4/3 kg
8/3 kg
2 kg
For the same diameter and thickness of tube, a water tube boiler has ________ heating surface as compared to fire tube boiler.
More
Less
Equal
None of these
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
The compounding of turbines is done in order to
Reduce speed of rotor
Improve efficiency
Reduce exit losses
All of these
The cylinder condensation or missing quantity may be reduced by
The efficient steam jacketing of the cylinder walls
Superheating the steam supplied to the engine cylinder
Keeping the expansion ratio small in each cylinder
All of the above
Which of the following coals has the highest calorific value?
Anthracite coal
Bituminous coal
Lignite
Peat
Steam in water tube boiler as compared to fire tube boiler
Can be raised rapidly
Is raised at slower rate
Is raised at same rate
Could be raised at fast/slow rate depending on design
In designing air preheaters, the important design consideration is that
Approach temperature should be as low as possible
Handling and maintenance should be easier
Heat transfer area should be optimum
Stack gases should not be cooled to the dew point
With increase in load, radiant superheater has
Drooping characteristic
Linear characteristic
Rising characteristic
Flat characteristic
Which of the following statement is wrong?
Locomotive boiler is a water tube boiler
Water tube boilers are internally fired
Lamont boiler is a low pressure water tube boiler
All of the above
Steam exhaust from high pressure turbine is reheated in
Boiler drums
Superheater tubes
Economiser
A separate coil located in convection path.
Green coal, in order to be burnt, must be
Heated sufficiently
Burnt in excess air
Heated to its ignition point
Burnt as powder
The function of a flywheel is
To convert reciprocating motion of the piston into rotary motion
To convert rotary motion of the crankshaft into to and fro motion of the valve rod
To prevent fluctuation of speed
To keep the engine speed uniform at all load conditions
Pick up wrong statement about desired properties of a good fuel
High calorific value
Produce minimum smoke and gases
Ease in storing
High ignition point
In order to reduce the rotor speed of an impulse turbine, the method employed is
Velocity compounding
Pressure compounding
Pressure-velocity compounding
All of these
In a reaction turbine
The steam is allowed to expand in the nozzle, where it gives a high velocity before it enters the moving blades
The expansion of steam takes place partly in the fixed blades and partly in the moving blades
The steam is expanded from a high pressure to a condenser pressure in one or more nozzles
The pressure and temperature of steam remains constant
The discharge is __________ at critical pressure.
Zero
Minimum
Maximum
None of these
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 size of a boiler drum in pulverised fuel fired boiler, as its size and capacity, (steam pressure and flow ratings) increase
Increases
Decreases
Remains unchanged
Increases/decreases depending on steam temperature requirements
At very low temperature, the melting and boiling temperatures become equal. This temperature is
373°K
273.16°K
303°K
0°K
The fire tubes in a Cochran boiler usually have _________ diameter.
6.25 mm
62.5 mm
72.5 mm
92.5 mm
A _________ in a boiler is used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit.
Blow off cock
Fusible plug
Stop valve
Safety valve
In locomotive boiler, maximum steam pressure is limited to
1 kg/cm²
5 kg/cm²
10 kg/cm²
18 kg/cm²
Which of the following statement is correct?
A fire tube boiler occupies less space than a water tube boiler, for a given power.
Steam at a high pressure and in large quantities can be produced with a simple vertical boiler.
A simple vertical boiler has one fire tube.
All of the above