Relative percentage of heat absorbed through the heat transfer of (i) Furnace water wall (ii) Boiler tank (iii) Superheater (iv) Economiser (v) Air-heater of a typical boiler of 200 MW capacity would be of the order of
48 : 20 : 15 : 7 : 10
10 : 7 : 15 : 20 : 48
20 : 48 : 7 : 15 : 10
7 : 15 : 20 : 10 : 48
Correct Answer :
A. 48 : 20 : 15 : 7 : 10
Related Questions
A regenerative steam cycle renders
Increased work output per unit mass of steam
Decreased work output per unit mass of steam
Increased thermal efficiency
Decreased work output per unit mass of steam as well as increased thermal efficiency
For water, at pressures below atmospheric;
Melting point rises slightly and boiling point drops markedly
Melting point rises markedly and boiling point drops markedly
Melting point drops slightly and boiling point drops markedly
Melting point drops slightly and boiling point drops slightly
The safety valve on boiler drum compared to safety valve on superheater is set at
Same value
Higher value
Lower value
Lower/higher depending on steam flow
A stage, in reaction turbine, is represented by
Number of casing
Number of entries of steam
Number of exits of steam
Each row of blades
A single acting steam engine produces ________ power than that of double acting steam engine.
Equal
Half
Double
Four times
Reheating of steam in a turbine
Increases the workdone through the turbine
Increases the efficiency of the turbine
Reduces wear on the blades
All of these
Fire tube boilers are limited to a maximum working pressure of
0.17 MN/m²
1.7 MN/m²
17 MN/m²
170 MN/m²
A nozzle is said to be a convergent 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
Cut-off governing as compared to throttle governing is
Less efficient and less economical
Less efficient and more economical
More efficient and less economical
More efficient and more economical
Hard coke is produced by carburisation of coal at
Atmospheric temperature
500-600°C
700-850°C
950-1100°C
All steam engines work on
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
None of these
Heating of dry steam above saturation temperature is known as
Enthalpy
Superheating
Super saturation
Latent heat
The value of the reheat factor varies from
1.02 to 1.06
1.08 to 1.10
1.2 to 1.6
1.6 to 2
The diameter of fire tubes in Cochran boiler is of the order of
2 cm
6 cm
8 cm
12 cm
Which of the following gases has the highest calorific value?
Producer gas
Coal gas
Water gas
Blast furnace gas
In water tube boilers
Water passes through the tubes which are surrounded by flames and hot gases
The flames and hot gases pass through the tubes which are surrounded by water
Forced circulation takes place
None of these
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
The fire tubes in a Cochran boiler are
Horizontal
Vertical
Inclined
None of these
The three Ts for good combustion are
Temperature, time, and turbulence
Total air, true fuel, and turbulence
Thorough mixing, total air and temperature
Total air, time, and temperature
In which of the following boilers, the draught in furnace is increased by utilising exhaust steam from engine
Lancashire boiler
Locomotive boiler
Babcock and Wilcox boiler
Benson boiler
In forced circulation steam boilers, the force is applied
To draw water
To circulate water
To drain off the water
All of these
The high pressure and low pressure cylinders in a receiver type compound engine are regarded as having cranks
180° to each other
90° to each other
0° to each other
None of these
A steam turbine, in which a part of the steam after partial expansion, is used for process heating and the remaining steam is further expanded for power generation, is known as
Back pressure turbine
Pass out turbine
Low pressure turbine
Impulse turbine
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
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0.18 MN/m²
1.8 MN/m²
18 MN/m²
180 MN/m²
A supercritical boiler is one that operates above the pressure and temperature of following values
100 kg/cm² and 540°C
1 kg/cm² and 100°C
218 kg/cm² abs and 373°C
218 kg/cm² abs and 540°C
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Swept volume to the volume at cut-off
Volume at cut-off to the clearance volume
Volume at cut-off to the swept volume
Clearance volume to the volume at cut-off
The discharge is __________ at critical pressure.
Zero
Minimum
Maximum
None of these
The diameter of Cornish boiler is of the order of
12 m
1.52.5 m
23 m
2.53.5 m
Over fire burning is the phenomenon of
Supply of excess, air
Supply of excess coal
Burning CO and unburnts in upper zone of furnace by supplying more air
Fuel bed firing