The expansion of steam, as it flows over the blades in reaction turbine, represents
Isothermal process
Isentropic process
Throttling process
Free expansion process
Correct Answer :
B. Isentropic process
Related Questions
Feed water conditioning in thermal power plants in done to
Reduce hardness and for removal of solids
Increase efficiency of thermal power plant
Increase heat transfer rate
Increase steam parameters
The fire tubes in a Cochran boiler are
Horizontal
Vertical
Inclined
None of these
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
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
The ratio of the workdone on the blades to the energy supplied to the blades, is called
Blading efficiency
Nozzle efficiency
Gross or stage efficiency
Mechanical efficiency
The feed check valve is used in order to
Regulate flow of boiler water
Check level of water in boiler drum
Recirculate unwanted feed water
Allow high pressure feed water to flow to drum and not allow reverse flow to take place
Lancashire boiler is of
Stationary < fire tube type
Horizontal type
Natural circulation type
All of the above
The ratio of the volume at cut-off to the swept volume is called
Cut-off ratio
Expansion ratio
Clearance ratio
None of these
Which of the following boiler is best suited to meet the fluctuating demand of steam?
Locomotive boiler
Lancashire boiler
Cornish boiler
Babcock and Wilcox boiler
When the cross-section of a nozzle increases continuously from entrance to exit, it is called a
Divergent nozzle
Convergent nozzle
Convergent-divergent nozzle
None 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
Parson's turbine is a
Simple impulse turbine
Simple reaction turbine
Impulse-reaction turbine
None of these
In accelerated circulation type boiler
Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
Feed pump is employed to supplement natural circulation in water wall type furnace
Water is converted into steam in one pass without any recirculation
Fusible plug for boilers is made of fusible metal containing tin, lead, and
Bismuth
Copper
Aluminium
Nickel
A single acting steam engine produces ________ power than that of double acting steam engine.
Equal
Half
Double
Four times
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 efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine.
Same
Less
More
None of these
The power of a boiler may be defined as
The ratio of heat actually used in producing the steam to the heat liberated in the furnace
The amount of water evaporated or steam produced in kg per kg of fuel burnt
The amount of water evaporated from and at 100° C into dry and saturated steam
The evaporation of 15.653 kg of water per hour from and at 100° C
The value of diagram factor depends upon
Initial conditions of steam
Back pressure
Initial pressure of steam
All of these
The pressure at which latent heat of vaporisation of water is zero, is
Below atmospheric pressure
1 kg/cm²
100 kg/cm²
225.6 kg/cm²
The draught may be produced by a
Mechanical fan
Chimney
A steam jet
All of these
The diameter of Cornish boiler varies from
0.5 to 1 m
1 to 2 m
1.25 to 2.5 m
2 to 3 m
Which of the following is not a boiler mounting?
Blow off cock
Feed check valve
Economiser
Fusible plug
The process of maintaining the speed of the turbine constant for various load conditions, is known as
Bleeding
Reheating
Governing
None of these
The diameter of a cylindrical shell of a Scotch marine boiler varies from
1.5 to 2 m
2.5 to 3.5 m
3.5 to 4.5 m
None of these
The numbers of fire tubes in a Cochran boiler are
75
115
165
225
In cross compounding, the cylinders are arranged
Side by side and each cylinder has common piston, connecting rod and crank
Side by side and each cylinder has separate piston, connecting rod and crank
At 90° and each cylinder has common piston, connecting rod and crank
At 90° and each cylinder has separate piston, connecting rod and crank
The biggest size of thermal power unit operating in India is
30 MW
60 MW
100 MW
500 MW
The proximate 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
The fire tubes in a Scotch marine boiler are
Horizontal
Vertical
Inclined
None of these