The cylinder condensation or missing quantity may be reduced by
The efficient steam jacketing of the cylinder walls
Superheating the steam supplied to the engine cylinder
Keeping the expansion ratio small in each cylinder
All of the above
Correct Answer :
D. All of the above
Related Questions
The fire tubes in a Locomotive boiler has _________ diameter.
4.75 mm
5.47 mm
7.45 mm
47.5 mm
The aim of a compound steam engine is
To reduce the ratio of expansion in each cylinder
To reduce the length of stroke
To reduce the temperature range in each cylinder
All of the above
A safety valve in a locomotive starts leaking. The leaking medium will be
Water
Dry steam
Wet steam
Super heated steam
The coal requirement per kW hour generation in the thermal power plant is of the order of
0.1 to 0.2 kg
0.2 to 0.4 kg
0.6 to 0.8 kg
1.0 to 1.5 kg
A throttle governed steam engine develops 15 kW with 280 kg per hour of steam and 35 kW with 520 kg per hour of steam. The steam consumption in kg per hour when developing 20 kW will be nearly
150 kg/h
210 kg/h
280 kg/h
340 kg/h
Which of the following varieties of coals is mostly used in steam boilers?
Non-coking bituminous coal
Brown coal
Peat
None of the above
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
Clearance ratio is the ratio of
Clearance volume to the swept volume
Clearance volume to the volume at cut-off
Volume at cut-off to the swept volume
Swept volume to the clearance volume
The ratio of heat actually used in producing the steam to the heat liberated in the furnace, is known as
Equivalent evaporation
Factor of evaporation
Boiler efficiency
Power of a boiler
Lancashire boiler is used where working pressure and power required are
Low
Moderate
High
None of these
In a throttling process
Heat transfer takes place
Work is done by the expanding steam
Internal energy of steam changes
None of the above
Which of the following gases has the highest calorific value?
Producer gas
Coal gas
Water gas
Blast furnace gas
The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ numbers of stages are required.
More
Less
Equal
None of these
De-Laval turbines are mostly used
Where low speeds are required
For small power purposes and low speeds
For large power purposes
For small power purposes and high speeds
For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has
More heating surface
Less heating surface
Equal heating surface
Heating surface depends on other parameters
In a nozzle, the effect of super-saturation is to
Decrease dryness fraction of steam
Decrease specific volume of steam
Increase the entropy
Increase the heat drop
The saturation temperature of steam with increase in pressure increases
Linearly
Rapidly first and then slowly
Slowly first and then rapidly
Inversely
Boiler parameters are expressed by
Tonnes/hr. of steam
Pressure of steam in kg/cm²
Temperature of steam in °C
All of the above
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 maximum steam pressure in a Locomotive boiler is limited to
0.18 MN/m²
1.8 MN/m²
18 MN/m²
180 MN/m²
Thermal efficiency of well maintained boiler will be of the order
40 %
50 %
75 %
90 %
The actual vacuum in a condenser is equal to
Barometric pressure + actual pressure
Barometric pressure - actual pressure
Gauge pressure + atmospheric pressure
Gauge pressure - atmospheric pressure
The economiser is used in boilers to
Increase thermal efficiency of boiler
Economise on fuel
Extract heat from the exhaust flue gases
Increase flue gas temperature
Vacuum for reciprocating steam engines compared to steam turbines is
More
Equal
Less
Could be more or less depending on the size of plant
The variation of steam pressure in the nozzle depends upon
Velocity of steam
Specific volume of steam
Dryness fraction of steam
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
The clearance in the engine cylinder
Increases the mean effective pressure
Increases the workdone
Decreases the efficiency of the engine
All of these
Which of the following statement is correct for a compound steam engine?
The cost of the engine, for the same power and economy, is more than that of a simple steam engine.
The forces in the working parts are increased as the forces are distributed over more parts.
The ratio of expansion is reduced, thus reducing the length of stroke.
The temperature range per cylinder is increased, with corresponding increase in condensation.
There is always some steam left in the clearance space from the previous stroke. This steam left in the clearance space is called
Wet steam
Saturated steam
Superheated steam
Cushion steam
The diameter of flue tube in a Cornish boiler is _________ that of the shell.
One-fourth
One-third
Two-fifth
Three-fifth