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
Correct Answer :
D. All of these
Related Questions
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
In a Parson's turbine stage, blade velocity is 320 m/s at the mean radius and rotor blade exit angle is 30°. For minimum kinetic energy of the steam leaving the stage, the steam velocity at the exit of the rotor will be
160/3 m/s
320/3 m/s
640/3 m/s
640 m/s
The actual power generated in the engine cylinder is called
Indicated power
Brake power
Frictional power
None of these
The working pressure range for a LaMont boiler is
0.5 to 10 MN/m²
1 to 15 MN/m²
2.5 to 15 MN/m²
3.5 to 20 MN/m²
Carbonisation of coal is the process of
Pulverising coal in inert atmosphere
Heating wood in a limited supply of air at temperatures below 300°C
Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
Binding the pulverised coal into briquettes
Curtis turbine is a
Simple reaction turbine
Velocity compounded turbine
Pressure compounded turbine
Pressure-velocity compounded turbine
The fittings mounted on the boiler for its proper and safe functioning is a
Water level indicator
Pressure gauge
Safety valve
All of these
Steam exhaust from high pressure turbine is reheated in
Boiler drums
Superheater tubes
Economiser
A separate coil located in convection path.
Hard coke is used in
Cement industry
Thermal power plant
Blast furnace
Domestic use
The mechanical draught _________ with the amount of smoke.
Increases
Decreases
Does not effect
None of these
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
The biggest size of thermal power unit operating in India is
30 MW
60 MW
100 MW
500 MW
At which pressure the properties of water and steam become identical
0.1 kg/cm²
1 kg/cm²
100 kg/cm²
225.6 kg/cm²
A single stage impulse turbine with a diameter of 1.2 m runs at 3000 r.p.m. If the blade speed ratio is 0.42, then the inlet velocity of steam will be
79 m/s
188 m/s
450 m/s
900 m/s
The ratio of heat utilised to produce steam and the heat liberated in furnace is known as
Boiler effectiveness
Boiler evaporative capacity
Factor of evaporation
Boiler efficiency
In a uniflow engine
Steam enters and exhausts through the same port
Steam enters at one end and exhausts at the centre
Steam enters at the centre and exhausts at the other end
None of the above
The diameter of internal flue tubes of a Lancashire boiler is about _________ that of its shell.
One-fourth
One-third
Two-fifth
One-half
Fusible plug for boilers is made of fusible metal containing tin, lead, and
Bismuth
Copper
Aluminium
Nickel
The discharge of steam in a convergent-divergent nozzle __________ after the throat (i.e. in the divergent portion of the nozzle)
Remains constant
Decreases
Increases
None of these
Rateau turbine is
Simple reaction turbine
Velocity compounded turbine
Pressure compounded turbine
Pressure-velocity compounded turbine
In water wall furnace, the heat is transferred to the water walls by
Convection
Radiation
Conduction
Radiation and conduction
The expansion of steam in a nozzle follows
Carnot cycle
Rankine cycle
Joule cycle
Stirling cycle
The function of injector used in small steam plants is to
Create vacuum in furnace
Create vacuum at turbine exhaust
Pump feed water
Dose chemicals in feed water
When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as
Internally fired boiler
Externally fired boiler
Natural circulation boiler
Forced circulation boiler
If the critical pressure ratio for steam is 0.546, then the steam is initially
Wet steam
Dry saturated steam
Superheated steam
None of these
In a receiver type compound engine, the high pressure and low pressure cylinders
Have common piston rod
Are set at 90°
Have separate piston rods
Are set in V-arrangement
Cut-off 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
The impulse turbine rotor efficiency will have a maximum value of 0.5 cos 2α, where α is the nozzle exit flow angle, if the
Blades are equiangular
Blade velocity coefficient is unity
Blades are equiangular and frictionless
Blade solidity is 0.65
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
The fire tubes in a Scotch marine boiler are
Horizontal
Vertical
Inclined
None of these