In turbines, the fluid undergoes a continuous steady flow process and the speed of flow is
Low
Very low
High
Very high
Correct Answer :
D. Very high
Related Questions
Water tube boilers are those in which
Flue gases pass through tubes and water around it
Water passes through the tubes and flue gases around it
Work is done during adiabatic expansion
Change in enthalpy
By compounding the expansion of steam in two or more cylinders, the ratio of expansion
Does not change
Increases
Decreases
None of these
Which of the following is required for a steam condensing plant?
Condenser
Condensate pump
Air extraction pump
All of these
The specific heat of superheated steam in kcal/kg is generally of the order of
0.1
0.3
0.5
0.8
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
The flow through a nozzle is regarded as
Constant volume flow
Constant pressure flow
Isothermal flow
Isentropic flow
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
The balanced draft furnace is one using
Induced draft fan and chimney
Induced draft fan and forced draft fan
Forced draft fan and chimney
Any one of the above
Cut-off ratio is the ratio of
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
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
In turbines, the fluid undergoes a continuous steady flow process and the speed of flow is
Low
Very low
High
Very high
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
A single acting steam engine produces ________ power than that of double acting steam engine.
Equal
Half
Double
Four times
The effect of friction in the nozzle __________ dryness fraction of steam.
Has no effect on
Decreases
Increases
None of these
The diameter of fire tube of Cornish boiler compared to its shell is
One half
One third
One fourth
One fifth
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
The supersaturated flow of steam through a nozzle as compared to a stable flow, the available heat drop
Remains the same
Increases
Decreases
Is unpredictable
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
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 chimney draught varies with
Climatic conditions
Temperature of furnace gases
Height of chimney
All of these
Gusset stays in a boiler are provided to
Prevent the bulging of flat surfaces
Avoid explosion in furnace
Prevent leakage of hot flue gases
Support furnace freely from top
Which of the following statement is correct?
The expansion of steam in a nozzle follows Rankine cycle.
The friction in the nozzle increases the dryness fraction of steam.
The pressure of steam at throat is called critical pressure.
All of the above
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
Water and sediment in fuel oil can be removed by
Heating the oil in the settling tanks
Cooling the oil in the settling tanks
Burning the oil
Suspension
The maximum efficiency of a De-Laval turbine is (where α = Nozzle angle)
sin²α
cos²α
tan²α
cot²α
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
Which of the following varieties of coals is mostly used in steam boilers?
Non-coking bituminous coal
Brown coal
Peat
None of the above
The velocity of steam at throat of the nozzle is __________ the velocity of sound.
Equal to
Less than
More than
None of these
Which of the following coals has the highest calorific value?
Anthracite coal
Bituminous coal
Lignite
Peat
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