UNIT 111
1) Define power plant.
Power plant is an
industrial system composed of machinery, equipment and structures designed to
convert various energy resources into electricity on a large scale.
2) Mention some of renewable sources of energy.
Hydro power, solar energy,
wind energy and tidal or wave energy.
3) Mention some of the non renewable sources of energy.
Non renewable
sources of energy are different types of fuels which include solid, liquid and
gaseous fuels.
4) What is water hammer?
When water passes
through the penstock of the hydro electric power plant, there may be sudden
rise in pressure in the penstock due to the backflow of water from turbine.
This sudden rise in pressure causes the water to knock the walls of the
penstock and it is known as water hammer.
5) State the principle of hydro electric power plant.
Water stored in the
dam is allowed to flow under pressure to run the turbine. The turbine is
coupled with the generator, it generates electric power
6) What is a solar pond?
A solar pond is
nothing but a water pond which consists of water heated with the help of solar
radiations.
7) Define positive displacement pump.
Positive
displacement pump is a pump which uses the reciprocating motion exerted on the
fluid, to move the fluid from lower pressure to higher pressure.
8) What is priming?
Priming is the
operation of filling up water in the suction pipe, casing and a portion of
delivery valve to remove the air present inside.
9) What is cavitation?
When the suction lift is high for centrifugal
pump, a large vacuum is created at the pump inlet. The vacuum pressure falls
below the vapour pressure of water forming vapour bubbles. This is called
cavitation.
10) What is an impulse turbine?
If at the inlet of
the turbine, the energy available is only kinetic energy, then the turbine is
called as impulse turbine.
11) What is a Reaction turbine?
If at the inlet of
the turbine, the energy available is kinetic energy and pressure energy, then
the turbine is called as reaction turbine.
12) What is a draft tube?
Draft tube is a
pipe or passage which leads the water exhausted from the turbine into the tail race.
Its cross section increases gradually towards the outlet. The bottom enlarged
end is submerged in tail race water level.
13) What is a function of hydraulic brake in a turbine?
When the turbine
has to be brought t6o rest by closing the inlet valve of the turbine, the
runner generally a very long time to come to rest due to its inertia. To bring
it to rest quickly, a small brake nozzle is provided which directs a jet of
water to bring the revolving runner quickly to rest.
14) What are factors to be considered ion a selection of a
turbine.
a)Specific speed
b) Head of water
c) Load operations
15) Define pump.
A pump is a
mechanical device which is used for moving fluids, either by physical lifting
or by the force of compression.
16) State the working principle of nuclear power plant.
Nuclear fission is
the principle used in nuclear power plant which is the splitting up the nucleus
of an atom into parts where enormous amount of energy is released and this
energy is used to generate power.
17) State the principle of solar power plant.
Solar radiations
received on the earth surface can be converted directly or indirectly in the
form of energy such as heat and electricity.
18) Mention the types of solar collectors.
a)Flat plate
collector
b)Parabolic
Concentric collectors
19) What are the advantages of steam power plant.
a) Power plant can
be located near the load centre to avoid huge transportation of coal
b) Power can be
generated continuously
c) Power plant can
withstand the varying load.
20) State the working principle of Gas turbine power plant.
Natural gas burnt
with with the compressed air supplies the necessary combustion gases to run the
turbine. The turbine is coupled with the generator to produce electric power.
UNIT IV
1) Define Heat engine?
Heat engine is a
device that converts heat energy into work by exploiting the temperature
gradient between a hot source and a cold sink. Heat is transferred from the
source to the sink and ion this process some amount of heat is converted into
work.
2) Define an Internal combustion engine.
In this type of
engine combustion of fuel takes place within the cylinder. This type of engine
includes gas engines, petrol engines and diesel engines.
3) Define stroke.
Distance traveled by
the piston while moving from T.D.C to the B.D.C is called Stroke.
4) Define power.
Power is the work
done in a given period of time. For doing the same amount of work in a less
period of time more power would be required.
5) Define scavenging.
Scavenging is the
process of forcing out the burnt exhaust gases from the cylinder by admitting
the fresh charge into the cylinder. This action takes place in two stroke cycle
engines.
6) Define carburetion.
In petrol engine,
a mixture of air and petrol is taken in the engine cylinder during suction stroke.
This process of mixing the air with petrol by vaporizing is known as
carburetion.
7) Define an ignition system.
Ignition system is
used to ignite the air fuel mixture at the end of compression stroke of the
petrol engine.
8) Define lubrication.
Lubrication is the
process of applying the lubricant between the surfaces of contact of the two
moving parts.
9) Define a boiler.
The function of a
boiler is to evaporate water into steam at a pressure higher than the
atmospheric pressure.
10) What are piston rings?
Piston rings are those,
fitted into the grooves of the piston to maintain good seal between the piston
and the cylinder wall.
11) Mention the classification of boilers.
a)Fire tube boiler
b)Water tube
boiler
12) Define fire tube boiler.
In fire tube
boilers, hot gases from the furnace pass through the tubes which are surrounded
by water
13) What is water tube boilers.
In water tube boilers,
water circulates inside the tubes which are surrounded by the hot gases from
the furnace.
14) Mention the classification of steam.
Wet steam,dry
steam,Super heated steam.
15) What is the difference between IC engine and steam
engines?
In IC engines
combustion of fuel takes place within the cylinder but in steam engine
combustion of fuel takes place outside the cylinder.
16) What is the purpose of lubrication system in an IC
engine?
a)To reduce
friction between the moving parts.
b)To minimize the
vibration
c)To reduce the
wear and tear
17) What are the types of
fuel lift pumps?
a)Mechanical fuel
pump
b)Electrical fuel
pump
18) What is a carburetor?
Carburetor is a
device used for atomizing and vaporizing petrol and mixing it with air in
different proportions according to the operation of the engine.
19) Define swept volume.
The volume swept
by the piston in moving from TDC to BDC is called swept volume
20) Mention some of the applications of Internal combustion
engines.
IC engines are
generally used for road vehicles,locomotives,aircraft and for other industrial
applications.
UNIT V
1) Define refrigeration.
Refrigeration is the
process of removing heat from an enclosed space or from a substance, under
controlled conditions and moving the heat to an unobjectionable place.
2) State the second law of thermodynamics.
It states that
heat will not pass from a cold region to a warm one without the aid of external
agent.
3) What is refrigeration?
The process of
removing heat from an area or a substance and is usually done by an artificial
means of lowering the temperature.
4) Define Ton of refrigeration.
One Ton of
refrigeration is defined as the quantity of heat removed i.e., amount of
refrigeration required to freeze one ton of water at 00C into ice at
00C in 24 hours.
1 ton of
refrigeration=3.5 KJ/sec
5) Define COP of a refrigerator?
The purpose of the
refrigerator is to remove heat from the cold region while requiring as little external work as possible
COP=Heat
exerted/Work supplied
6) What are the types of refrigeration systems?
a)Vapour compression system
b)Vapour absorption
system
7) Define air conditioning.
Air conditioning is
the process of controlling the temperature and humidity of air by heating or cooling,
humidifying or dehumidifying, and filtering the atmospheric air, and thus
creating a healthy and comfortable condition for human beings
8) Define moisture.
Moisture denotes the
water vapour present in the air.
9) Define humidity.
It is a measure of
amount of water vapour in air
10) Define relative humidity.
It is the ratio of
water vapour present in the given amount of air to the mass of water vapour
present in the same volume under the same temperature conditions.
11) Define psychrometry.
Psychrometry is
the science which deals with the study of
the behavior of air and water vapour mixture.
12) Define Dry Bulb Temperature(DBT).
It is the
temperature of air measured by an ordinary thermometer
13) Define Wet Bulb Temperature.
It is the
temperature of air measured by thermometer when its bulb is covered with a wet
cloth and is exposed to atmospheric air.
14) Define Dew point temperature.
It is the
temperature at which the moisture present in the air begins to condense.It
corresponds to the saturation temperature of water vapour in the mixture of air
and water vapour.
15) What are the types of air conditioner?
a)Window air
conditioner
b)Package air
conditioner
c)Centralised air
conditioner.
16) Mention the function of a compressor.
The most important
part in a refrigerator is compressor. It draws low pressure low temperature
refrigerant vapour and converts into a high pressure, high temperature vapour.
17) State the main components of a refrigeration system.
Compressor,Condensor,Throttle valve and expansion valve.
18) Define convection.
In convection, the
heat transfer is caused by molecular motion(in fluids)
19) Define radiation.
Radiation is the
transfer of heat without any medium. By radiation heat can transfer through
space.
20) Define Specific heat.
Specific heat is
the amount of heat required to raise the temperature of one pound of the
material through one degree Fahrenheit.
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