The ultimate analysis of fuel lists
Various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as percents by volume
Various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as percents by weight
Fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash
Fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash
Correct Answer :
B. Various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as percents by weight
Related Questions
The efficiency of a boiler is defined as
Ratio of heat actually used in producing steam to the heat liberated in the furnace
Ratio of the mass of steam produced to the mass of total water supplied in a given time
Ratio of the heat liberated in the furnace to the heat actually used in producing steam
None of the above
Heating of dry steam above saturation temperature is known as
Enthalpy
Superheating
Super saturation
Latent heat
Heating wet steam at constant temperature is heating it at constant
Volume
Pressure
Entropy
Enthalpy
The fittings mounted on the boiler for its proper and safe functioning is a
Water level indicator
Pressure gauge
Safety valve
All of these
In a boiler, feed water supplied per hour is 205 kg while coal fired per hour is 23 kg. The net enthalpy rise per kg of water is 145 kJ. If the calorific valve of the coal is 2050 kJ/kg, then the boiler efficiency will be
56 %
63 %
74 %
78 %
The critical pressure gives the velocity of steam at the throat
Equal to the velocity of sound
Less than the velocity of sound
More than the velocity of sound
None of these
A nozzle is said to be a divergent nozzle
When the cross-section of the nozzle increases continuously from entrance to exit
When the cross-section of the nozzle decreases continuously from entrance to exit
When the cross-section of the nozzle first decreases from entrance to throat and then increases from its throat to exit
None of the above
In regenerative air preheaters, the heat is transferred
From a metal wall from one medium to another
From heating an intermediate material and then heating the air from this material
By direct mixing
Heat is transferred by bleeding some gas from furnace
It is required to produce large amount of steam at low pressure. Which boiler should be used?
Pulverised fuel fired boiler
Cochran boiler
Lancashire boiler
Babcock and Wilcox boiler
In case of condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the atmospheric pressure.
Equal to
Lower than
Higher than
None of these
The diameter of internal flue tubes in a Lancashire boiler compared to its shell is
One-half
One-third
Two-fourth
Two-fifth
Which of the following is a fire tube boiler?
Lancashire boiler
Babcock and Wilcox boiler
Yarrow boiler
None of these
The maximum discharge through a chimney occurs when the height of chimney is
Infinitely long
Around 200 meters
Equal to the height of the hot gas column producing draught
Outside temperature is very low
In a compound steam engine, the first stage of expansion is carried out in a high pressure cylinder whereas the last expansion is completed in low pressure cylinder. The diameter of high pressure cylinder is _________ the low pressure cylinder.
Equal to
Less than
More than
None of these
In a throttling process
Steam temperature remains constant
Steam pressure remains constant
Steam enthalpy remains constant
Steam entropy remains constant
For a Parson's reaction turbine, if α₁ and α₂ are fixed blade angles at inlet and exit respectively and β₁ and β₂ are the moving blade angles at entrance and exit respectively, then
α₁ = α₂ and β₁ = β₂
α₁ = β₁ and α₂= β₂
α₁ < β₁ and α₂ > β₂
α₁ = β₂ and β₁ = α₂
A safety valve usually employed with stationary boilers is
Lever safety valve
Dead weight safety valve
High steam and low water safety valve
All of these
Which of the following is a fire tube boiler?
Locomotive boiler
Babcock and Wilcox boiler
Stirling boiler
All of the above
The diameter of tubes for natural circulation boiler as compared to controlled circulation boilers is
More
Less
Same
Could be more or less depending on other factors
In forced circulation steam boilers, the force is applied
To draw water
To circulate water
To drain off the water
All of these
Thermal efficiency of well maintained boiler will be of the order
40 %
50 %
75 %
90 %
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 amount of water evaporated in kg per kg of fuel burnt is called
Evaporative capacity of a boiler
Equivalent evaporation from and at 100° C
Boiler efficiency
None of these
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 pressure of feed water has to be raised before its entry into the boiler. The pressure is raised by a device known as
Feed pump
Injector
Feed check valve
Pressure gauge
The effect of bleeding is that
It increases the thermodynamic efficiency of the turbine
Boiler is supplied with hot water
It decreases the power developed by the turbine
All of the above
Bomb calorimeter is used to determine
Higher calorific value at constant volume
Lower calorific value at constant volume
Higher calorific value at constant pressure
Lower calorific value at constant pressure
The function of a piston in a steam engine is
To guide motion of the piston rod and to prevent it from bending
To transfer motion from the piston to the crosshead
To convert heat energy of the steam into mechanical work id) to exhaust steam from the cylinder at proper moment
None of these
Spontaneous combustion is a phenomenon in which
All the fuel burns instantaneously producing high energy release
Fuel burns with less air
Coal bursts into flame without any external ignition source but by itself due to gradual increase in temperature as a result of heat released by combination of oxygen with coal
Explosion in furnace
Steam engine operates on
Carnot cycle
Joule cycle
Stirling cycle
Brayton cycle