Basic Mechanical Engineering
By
Nitin G Shekapure
Unit VI
Applied Thermal Engineering (L32)
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Unit VI
Applied Thermal Engineering
Power Plant Engineering: Conventional and non-conventional energy resources, Hydro-electric,
Thermal, Nuclear. Wind, Solar [with Block diagram].
Power Producing Devices: Boiler - Water tube and lire tube. Internal combustion engine - Two stroke
and four stroke (Spark ignition and compression ignition). Turbines - Impulse and reaction.
Power Absorbing Devices: Pump - Reciprocating and Centrifugal, Compressor - Single acting, single
stage reciprocating air compressor, Refrigeration - Vapour compression refrigeration process, House
hold refrigerator. Window air conditioner (Working with block diagrams).
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Power Absorbing Devices:-
Pump (Centrifugal & Reciprocating)
Compressor(Reciprocating – single stage, single acting)
Refrigerator (House hold)
Window Air Conditioner
Power Producing Devices:-
Turbines (Impulse & Reaction)
Internal Combustion Engines (Two stroke & Four stroke (CI & SI))
Boiler- Water Tube Boiler & Fire Tube Boiler
Power Plant Engineering:-
Thermal Power Plant
Hydro- Electric Power Plant
Nuclear Power Plant
Wind Power Plant
Solar Power Plant
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Boiler
A boiler is a closed vessel in which steam is produced from water by combustion of fuel.
 Purposes of Steam:
 For generating power in steam engines or steam turbines.
 In Sugar Mill, Chemical & many more.
 For heating the buildings in cold weather and for producing hot water for hot water
supply.
 Primary requirement of Steam:
 The water must be contained safely.
 The steam must be safely delivered in desired conditions (as regards its pressure,
temperature , quality and required rates).
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Simple Boiler
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• Steam is vapourized water. It is a transparent gas. At standard temperature and
pressure, pure steam (unmixed with air, but in equilibrium with liquid water)
occupies about 1,600 times the volume of an equal mass of liquid water.
• Saturated steam is steam at equilibrium with liquid water at the same pressure and
temperature.
• Superheated steam is steam at a temperature higher than its boiling point at a
given pressure
Steam
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Safety
• The boiler should be safe under operating conditions
Accessibility
• The various parts of the boiler should be accessible for repair and maintenance
Capacity
• Should be capable of supplying steam according to the requirements
Efficiency
• Should be able to absorb a maximum amount of heat produced due to burning of fuel in the furnace
Construction
• Simple in construction
Cost
• Its initial cost and maintenance cost should below
Boiler Requirements
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1. Depending upon the relative position of Water and Flue gases:
 Water Tube Boiler
 Smoke or Fire Tube Boiler
2. Depending upon the Position Furnace:
 Internally Fired Boiler
 Externally Fired Boiler
3. Depending upon the Position of Axis of the Boiler:
 Vertical Boiler
 Horizontal Boiler
4. Depending upon the Service:
 Stationary Boiler
 Portable Boiler
Classification of Boiler
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5. According to the Method of Circulation of Water and Steam:
 Natural Circulation
 Forced Circulation
6. According to the Pressure of Steam Generated:
 Low Pressure (pressure of steam below 20 bar)
 Medium Pressure( pressure of steam in range of 20-80 bar)
 High Pressure (80 bar &above pressure of steam )
7. According to Nature of Draught Employed
 Natural or Chimney Draught
 Artificial Draught
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Water Tube Boiler
• In these, the water flows in the tube and hot gases are
passed over the tubes.
• These type of boilers are useful for large amount of steam
generation at high pressures due to low water to high
flue gases ratio.
• Used for high steam demand and pressure requirements
• Capacity range of 4,500 – 120,000 kg/hour
• Combustion efficiency enhanced by induced draft
provisions
• Lower tolerance for water quality and needs water
treatment plant
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Babcock and Wilcox Boiler
• D - Drum
• DTH - Down take header
• WT - Water Tubes
• BP - Baffle Plates
• D - Doors
• G - Grate
• FD -Fire Door
• MC - Mud Collector
• WLI - Water Level Indicator
• PG - Pressure Gauge
• ST - Super heater Tubes
• SV - Safety Valve
• MSV - Main Stop Valve
• APP - Anti priming Pipe
• L - Lower Junction Box
• FV - Feed Valve
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• This is the one of the most important type of water tube boiler as shown in above figure.
• It consists of number of inclined water tubes connected between uptake header and downtake
header.
• Whole combustion chamber is divided into number of parts with the help of baffles so that hot gases
first move from the furnace upwards between the water tubes and then move downward and
upward between the baffles over the tubes and finally these are exhausted to the chimney through
the damper.
• The water near the uptake header are in contact with the hotter flue gases compared to portion near
the downtake header due to which the water in the uptake header rises due to decreased density and
enters the drum which is replaced by the cold water from the downtake header.
• Wet steam from the boiler drum enters in the outer tube, then passes into the superheated tubes and
during its passage it gets further heated up. Superheated steam now enters into the inner tubes and
from here it is withdrawn through a stop valve.
Babcock and Wilcox Boiler
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Fire Tube Boiler
• In these boilers, the flue gases pass through the tubes which are surrounded by water in
boiler shell.
• Relatively small steam capacities (12,000 kg/hour)
• Low to medium steam pressures (18 kg/cm2)
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Cochran Boiler
Salient features
• The dome shape of the furnace causes the hot gases to deflect
back and pass through the flue pipe. The un‐burnt fuel if any will
also be deflected back.
• Spherical shape of the top of the shell and the fire box gives
higher area by volume ratio.
• It occupies comparatively less floor area and is very compact.
• It is well suited for small capacity requirements.
 Very compact and requires minimum floor area
 Any type of fuel can be used with this boiler
 Well suited for small capacity requirements
 Gives about 70% thermal efficiency with coal firing and about 75%
with oil firing
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Lancashire Boiler
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• It is stationary, fire tube, internally fired, horizontal, natural circulation boiler.
• This is a widely used boiler because of its good steaming quality and its ability to
burn coal of inferior quality.
• These boilers have a cylindrical shell 2 m in diameters and its length varies from
8 m to 10 m.
• It has two large internal flue tubes having diameter between 80 cm to 100 cm in
which the grate is situated.
• This boiler is set in brickwork forming external flue so that the external part of
the shell forms part of the heating surface.
Lancashire Boiler
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Boiler Mountings:-
 Stop valve
 Safety Valve
 Water Level Indicators
 Pressure Gauge
 Fusible Plug
 Blow Off Cock, etc.
Boiler Accessories:-
 Economizers
 Super heaters
 Air -Preheater
 Feed Pumps, etc.
Air preheater (APH) is a general term used to describe any device
designed to heat air before another process (for example,
combustion in a boiler) with the primary objective of increasing the
thermal efficiency of the process.
Economizers in steam power plants is to capture the waste heat
from boiler stack gases (flue gas) and transfer it to the boiler
feedwater. This raises the temperature of the boiler feedwater,
lowering the needed energy input, in turn reducing the firing rates
needed for the rated boiler output.
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Difference between Water Tube And Fire Tube Boiler:
Sr
No
Factors Water Tube Boiler Fire Tube Boiler
1 Position of water and flue
gases
Water flows inside tubes and flue
gases are circulated around the tubes
Flue gases are inside the tubes and
water is circulated around the tubes
2 Floor area for the same
power
It occupies less floor area It occupies more floor area
3 Rate of steam generation Higher Lesser
4 Construction Simple Difficult
5 Transportation Simpler Difficult
6 Shell diameter for the given
power
Less required Large
7 Treatment of water Not so much necessary More necessary
8 Requirement of skill It requires more skill as well as careful
attention
It requires less skill for efficient and
economic working
9 Accessibility of various
parts for cleaning, repair
and inspection
It has more accessibility The parts are not so easily accessible
11 Risk of bursting More (Steam Pressure) Less
12 Operating Pressure High Pressure (100bar) Less Pressure (16bar)
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Steam Turbines
A steam turbine is a thermo-mechanical device that extracts thermal energy from
pressurized steam, and converts it into rotary motion.
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Heat Engines
Any type of engine or machine which derives Heat Energy from the combustion of the
fuel or any other source and converts this energy into Mechanical Work is known as a
Heat Engine.
Classification :
1. External Combustion Engine (E. C. Engine) Combustion of fuel takes place outside the cylinder.
2. Internal Combustion Engine (I. C. Engine) Combustion of fuel takes place inside the cylinder.
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Advantages of External Combustion Engines over Internal Combustion Engines :
1. Starting Torque is generally high.
2. Due to external combustion, cheaper fuels can be used (even solid fuels !).
3. Due to external combustion, flexibility in arrangement is possible .
4. Self – Starting units.
Advantages of Internal Combustion Engines over External Combustion Engines :
1. Overall efficiency is high.
2. Greater mechanical simplicity.
3. Weight – to – Power ratio is low.
4. Easy Starting in cold conditions.
5. Compact and require less space.
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Steam Turbine
Gas Turbine
Steam Engine, etc.
Examples of External Combustion Engines
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Examples of Internal Combustion Engines
Road vehicles. Aircrafts. Locomotives
Construction
Equipment's
Pumping Sets
Generators for Hospitals,
Cinema Hall, and Public Places.
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Classification of I. C. Engines
IC engines may be classified on different bases. Some of the main classifications are
given below :
According to Fuel Used
(a) Petrol engine (b) Diesel engine
(c) LPG engine (d) CNG (Compressed Natural Gas)
According to Cycle of Operation
(a) Two stroke engines (b) Four stroke engines
According to Cycle of Combustion
(a) Otto cycle engines which work on Otto cycle.
(b) Diesel cycle engine which work on diesel cycle.
(c) Dual cycle engines which work on dual cycle.
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According to Method of Ignition
Spark Ignition (SI) Engines
These engines are petrol engines in which a spark plug is used to ignite the fuel-air
mixture.
Compression Ignition (CI) Engines
Diesel engines are CI engines in which air is compressed to such a high pressure and
temperature so that burning of fuel takes place as soon as it is injected into the
cylinder due to high temperature.
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Working of Four Stroke Petrol Engine
In four stroke engines, one cycle is completed with completion of four strokes. Main features of all the
strokes are discussed below and their sketch is given in Figure.
Suction or Intake Stroke (Induction Stroke)
• Initially the piston remains n top dead centre (TDC) position,
suction valve is open and exhaust valve remains closed.
• The piston now moves downward and the petrol and air
mixture (charge) enters into the cylinder.
• When piston reaches bottom dead centre (BDC). The cylinder
fills with the petrol air mixture.
• At this moment, suction valve closes.
• This completes one stroke. Crank turns by 180⁰, i.e. it
completes half revolution.
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Compression Stroke
• Both the valves (suction and exhaust) are closed. The piston
moves upwards from BDC to TDC position.
• The charge is compressed inside the cylinder, i.e. its pressure
increases and volume decreases.
• Along with pressure temperature also increases. The crank
completes next half of revolution.
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Working or Expansion or Power Stroke
When the piston reaches the TDC position spark plug generates
spark and the charge is ignited and combustion of mixture takes
place. Because of burning of fuel temperature and pressure of
gases increases tremendously., both the valves remain closed.
• The gases expand in the cylinder and push the piston
downward and therefore, work is done by the gases on the
piston.
• The crank revolves and completes next half revolution.
• The reciprocating motion of the piston is converted into rotary
motion of crank-shaft by piston rod and crank. During
expansion, volume of gases increases.
• All the power for running the engine is obtained during this
stroke
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Exhaust Stroke
• The suction valve remains closed but exhaust valve opens.
• The piston moves from BDC to TDC. The burnt gases are
pushed out of the cylinder due to movement of piston.
• The cylinder pressure falls down to little above
atmospheric pressure.
• This completes the next half revolution of the crank. By
this time, crank shaft completes two revolution and one
engine cycle is completed with the completion of four
strokes.
• After this the same process is repeated again and again.
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Working of Four Stroke Diesel Engine
The main features of all the four strokes in diesel engines are given below :
1. Suction or Intake Stroke
• Initially piston is at top dead centre (TDC), exhaust valve is closed but suction valve
opens.
• Piston moves downwards towards bottom dead centre (BDC).
• As suction valve is open, air enters into the cylinder. (It is important to note that only
air enters the cylinder during suction in case of diesel engines.)
• Cylinder is full of air when piston reaches BDC and suction stroke in completed.
• Crank shaft or crank rotates by 180o, i.e. it completes half revolution.
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2. Compression Stroke
• Both the valves (suction and exhaust) are closed, piston moves from BDC to TDC.
• Volume of air decreases and pressure and temperature increases. When the piston
reaches TDC, this stroke is completed and the crank completes next half revolution.
• By this time crank has rotated by 360⁰.
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3. Expansion or Power Stroke
• At the end of compression stroke, both the valve remains closed.
• The injector fitted in the cylinder head injects diesel fuel in the high temperature air.
• The temperature is so high that the fuel, i.e. diesel starts burning at constant pressure.
• The pressure and temperature increases further due to combustion of fuel.
• The gases in the cylinder push the piston downwards from TDC to BDC and expansion process takes
place.
• The volume of gases increases and work is obtained in this process.
• The reciprocating motion of piston is converted into rotary motion of crank shaft through piston rod
and crank.
• Expansion process is completed when piston reaches BDC. The crank rotates by next half revolution.
• This stroke is called power stroke because power of work is obtained in this stroke.
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4. Exhaust Stroke
• After completion of expansion stroke, the piston starts moving upwards from BDC
to TDC. Suction valve is close, exhaust valve is open.
• As the piston moves, it pushes the burnt gases through the exhaust vale. Thus,
exhaust takes place.
• The cylinder becomes empty as the piston reaches TDC.
• The exhaust stroke is completed.
• Crank has now completed two revolutions and all the four strokes are now
completed. This completes one engine cycle.
• These cycles are repeated as engine continues to run.
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Working of Two Stroke Petrol Engine
The two stroke engine employs the crankcase as well as
the cylinder to achieve all the elements of the cycle in
only two strokes of the piston.
360 degrees rotation of crankshaft completes the cycle.
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Intake & Compression stroke
Intake:
The fuel/air mixture is first drawn into the crankcase by the
vacuum created during the upward stroke of the piston
through the reed valve.
Compression:
The piston then rises, driven by flywheel momentum, and
compresses the fuel mixture. (At the same time, another
intake stroke is happening beneath the piston).
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Power & Exhaust/Transfer Stroke
Power:
At the top of the stroke the spark plug ignites the fuel mixture.
The burning fuel expands, driving the piston downward.
Exhaust/Transfer:
Toward the end of the stroke, the piston exposes the intake port,
allowing the compressed fuel/air mixture in the crankcase to escape
around the piston into the main cylinder.
This expels the exhaust gasses out the exhaust port, usually located on
the opposite side of the cylinder.
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(a) For the same power output the design of two stroke engine is simple where as a four stroke engine is
complex in design for manufacturer.
(b) A two stroke engine gives on working stroke for each revolution of the crank shaft whereas a four
stroke engine gives one power stroke per two revolutions of crank shaft.
(c) Two stroke engines have suction and exhaust ports whereas four stroke engines have suction and
exhaust valves and valve mechanism.
(d) Two stroke engines lighter in weight but four stroke engines are heavier.
(e) The initial cost of two stroke engines is less than that of four stroke engines.
(f) Thermal efficiency of two stroke engines is less than that of four stroke engines.
(g) Four stroke engines are used where efficiency is important, e.g. in cars, busses, etc. Whereas two stroke
engines are used where lower cost is required in two wheelers, e.g. scooters and motorcycles.
Main Differences Between Two and Four Stroke Engines
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Important Terms
Cylinder
The cylinder is that part in which air-fuel mixture is sucked, compressed, ignited and expanded.
Cylinder Block
Cylinder block is made by casting and is used to support the cylinder in position.
Piston
Piston reciprocates inside the cylinder.
Combustion Chamber
The space enclosed between cylinder and upper part of the cylinder forms the combustion
chamber where fuel-air mixture burns.
Piston Rings
Piston rings are provided on the piston. These are used to seal the high pressure side (cylinder)
and low pressure side (crank case), i.e. to prevent leakage of gases. There is one oil ring also
which is used to scrap the lubricating oil at the cylinder surface so that it returns to crank case.
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Important Terms
Spark Plug
A spark plug is put near the top of the cylinder or in the cylinder head. It is used to ignite the fuel-air
mixture by generating a spark in petrol engines.
Fuel Injector
Fuel injector is used in diesel engines in place of spark plug.
Piston Rod
Piston rod or connecting rod connects the piston and crank.
Valve Mechanism
A mechanism to open and close the suction and exhaust valves is also provided in four stroke engines.
Top Dead Centre (TDC)
Top dead center is the upper most position upto which piston moves.
Bottom Dead Centre (BDC)
BDC is the lower most position upto which piston comes down.
Bore (D)
Bore is the diameter of piston on cylinder.
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Stroke (L)
The nominal distance through which the piston moves from one extreme position (say TDC) to other
extreme position (say BDC).
Suction Manifold
Suction or intake manifold is the pipe through which air and petrol mixture enters the cylinder (through
suction valve).
Exhaust Manifold
Exhaust manifold is the pipe through which burnt gases pass from cylinder (through exhaust valve) to the
silencer of the engine.
Stroke Volume
The volume of the cylinder between TDC and BDC is known as stroke volume.
Clearance Volume
It is the volume of cylinder left above TDC, i.e. between TDC and top of cylinder.
Important Terms
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Power Absorbing Devices
 Compressor
 Pumps
 Refrigerator
 Air Conditioner N
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Compressor
 Compressor – A device which takes a definite quantity of fluid ( usually gas, and most
often air ) and deliver it at a required pressure.
 Air Compressor- are used to compress the atmospheric air to high pressure.
 Air Compressor –1) Takes in atmospheric air,
2) Compresses it, and
3) Delivers it to a storage vessel ( i.e. Reservoir )
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Uses of Compressed Air:
• Inflating tyres /tubes
• In spray Paintings
• For cleaning purposes in garages along with water for washing cars etc.
• Gas turbines
• Diesel Engines
• Air Brakes
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Compressed Air
Powering portable
small Engines
Drills and Hammers
in road building
Excavating
Tunneling
and MiningStarting the
Diesel engines
Operating Brakes for
buses, trucks and trains
Uses of Compressed Air
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Air Compressors
Reciprocating Rotary
Single – Acting
Double - Acting
No. of Sides of Piston
in operation
No. of Stages
for Compression
Centrifugal
Single – stage
Multi - stage
Classification
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Reciprocating Compressor - Working
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Refrigeration
Refrigeration – Science of producing and maintaining temperature below that of
surrounding / atmosphere.
Refrigeration – Cooling of or removal of heat from a system.
Refrigerating System – Equipment employed to maintain the system at a low temperature.
Refrigerated System – System which is kept at lower temperature.
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Refrigeration Circuit
Evaporator
Compressor
CondenserExpansion
Valve
Refrigeration Circuit
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Compressor
Condenser
Evaporator
Expansion
Valve
Wnet, in
Surrounding Air
Refrigerated Space
QH
QL
High Temp
Source
Low Temp
Sink
QH
QL
Wnet, in
Refrigeration - Elements
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Vapor Compression Cycle
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1. Ice making.
2. Transportation of food items above and below freezing.
2. Industrial Air – Conditioning.
4. Comfort Air – Conditioning.
5. Chemical and related industries.
6. Medical and Surgical instruments.
7. Processing food products and beverages.
8. Oil Refining. 9. Synthetic Rubber Manufacturing.
10. Manufacture and treatment of metals.
11. Freezing food products.
12. Manufacturing Solid Carbon Dioxide.
13. Production of extremely low temperatures (Cryogenics)
14. Plumbing.
15. Building Construction.
Refrigeration - Applications
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Window Air Conditioner
Air conditioning is the simultaneous control of temperature, humidity, motion, and purity of
atmosphere of confined space.
Application of Air conditioning:-
• Industrial applications
 Food Industry
 Printing Industry
• Hospital Air conditioning
• Transport Air conditioning
 Automobile Air conditioning
 Train Air conditioning
 Air craft Air conditioning
 Ship Air conditioning
• Air conditioning of Computer centers
• Air conditioning of television centers
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Block diagram of Window Air conditioner
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Sources of Energy
Non-Conventional
Energy Sources
• Solar
• Wind
• Ocean
• Geo-thermal
Conventional
Energy Sources
• Coal
• Water
• Nuclear Energy
• Petroleum Products
• Natural Gas
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Non-Conventional Energy Sources
ADVANTAGES
Easily available in nature.
Available in large quantity.
Not pollutant.
Less maintenance cost.
DIS-ADVANTAGES
Available in Low intensity.
Available in particular period only.
Less efficiency of power plant.
High initial cost.
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ADVANTAGES
Thermal Efficiency is more
Initial cost is less.
Intensities are high.
DIS-ADVANTAGES
Running and maintenance cost is
high
Pollution in atmosphere.
Conventional Energy Sources
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Coal
57%
Hydro
electricity
19%
Renewable
energy source
12%
Gas
9%
Nuclear
2%
Oil
1%
Energy sources in India
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Power Plants
• Thermal/ Steam Power plants
• Hydroelectric Power Plant
• Solar Power System
• Wind Power Plant
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Thermal Power Plant
 Thermal power is the largest source of power in India. About 75% of electricity consumed
in India are generated by Thermal power plants. There are different types of Thermal power
plants based on the fuel used to generate the steam such as coal, gas, diesel etc.
 Coal-fired plants account for 56% of India's installed electricity capacity.
 The thermal energy available in the steam is converted into mechanical energy and is used
for driving steam turbines. Steam turbines is coupled to generator and hence power is
produced whenever turbine is rotated.
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Prime factors for starting a steam power plant
• Availability of fuel, Coal
• Availability of water
• Availability of strong foil foundation
• Availability of transport facility
• Availability of labors and engineers
• Availability of sufficient space for power plant equipment's, space for disposing
ash, space for storing coal etc.
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Working principle of Steam power plant
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Advantages
• Fuel is cheaper
• Less space is required as compared with Hydro-electric power plant
• Cheaper in production cost and initial cost compared with diesel power plant
• Transmission Costs are reduced as these plants can be set up near the industry.
Disadvantages
• The Cost of plant is increases with the increase in temperature and pressure.
• Maintenance and operating cost is high.
• Long Time is required for erecting and put in action.
• Large quantity of water is required.
• Coal and ash handling poses a serious problem.
• Pollution causes health problem to workers and habitants near the thermal power plant
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• In Hydro Power Plant the water is utilized to move the turbines which in turn run the electric
generator’s.
• The Potential energy of the water stored in the dam gets converted into the Kinetic Energy of
the moving water in the penstock. And this Kinetic Energy gets converted into the Electrical
Energy with the help of Turbine & Generator (T-G) combination.
• Hydro Power Plant was invented by H.F. Rogers
• Hydro Power Plant fulfills the 30% of the total energy needs of the world.
• Total hydro potential of the world = 5000 GW
Hydro-Electric Power Plant
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Hydro-Electric Power Plant
Working principle
• Potential energy is the energy which a substance
has due to its position or state. The water behind a
dam has potential energy because of its position.
The water can fall from this position and exert a
force over a distance and therefore do work.
• In a Hydro-electric power plant the force is used to
drive a turbine, which inturn drives the electric
generator.
• Because gravity provides the force which makes the
water fall, the energy stored in the water is called
gravitational potential energy.
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Advantages
• Water is a renewable energy source.
• Maintenance and operation charges are very low.
• The efficiency of the plant does not change with age.
• In addition to power generation, hydro-electric power plants are also useful for flood control, irrigation
purposes, fishery and recreation.
• Have a longer life(100 to 125 years) as they operate at atmospheric temperature.
• Water stored in the hydro-electric power plants can also be used for domestic water supply.
• Since hydro-electric power plants run at low speeds(300 to 400 rpm) there is no requirement of special
alloy steel construction materials or specialised mechanical maintenance.
Disadvantages
• The initial cost of the plant is very high.
• Since they are located far away from the load centre, cost of transmission lines and transmission losses
will be more.
• During drought season the power production may be reduced or even stopped due to insufficient water
in the reservoir.
• Water in the reservoir is lost by evaporation.
Hydro-Electric Power Plant
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Three Gorges Dam China
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Solar Power Plant
• The intensity of solar radiation are weather dependent.
On cloudy days , the intensity is very low.
• Average power available is only 1 kW/m2 in hottest regions. Thus large collection area
is required.
• It is intermittent source of energy since it is not available in night.
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Working Principle of Solar Power Plant
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Gujarat Solar Park the largest solar park in the India. It's the biggest solar farm in
the world, covering 2,000 hectare (4900 acres) of northern Gujarat, India, and it
has the capacity to generate 600 MW of power.
600 MW of solar panels will save around 8 million tonnes of carbon dioxide from
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Wind Power
 The wind power can be generated where the wind
velocities are more than 8 kmph.
 Such winds are available along the sea coast and at high altitudes in hilly region.
 The wind power is clean and non-polluting
 It has low maintenance cost and low power generation cost of about Rs.
2.25/kWh.
 It needs high capital cost of about 3.5crores/MW.
N
itin
Shekapure
Advantages:-
• Non polluting.
• No fuel is required.
• The cost of generation is low.
Disadvantages:-
• More noisy.
• Weight of system is high.
• Does not provide constant output due
to velocity fluctuations
Wind Power
N
itin
Shekapure

Applied Thermal Engineering

  • 1.
    Basic Mechanical Engineering By NitinG Shekapure Unit VI Applied Thermal Engineering (L32) N itin Shekapure
  • 2.
    Unit VI Applied ThermalEngineering Power Plant Engineering: Conventional and non-conventional energy resources, Hydro-electric, Thermal, Nuclear. Wind, Solar [with Block diagram]. Power Producing Devices: Boiler - Water tube and lire tube. Internal combustion engine - Two stroke and four stroke (Spark ignition and compression ignition). Turbines - Impulse and reaction. Power Absorbing Devices: Pump - Reciprocating and Centrifugal, Compressor - Single acting, single stage reciprocating air compressor, Refrigeration - Vapour compression refrigeration process, House hold refrigerator. Window air conditioner (Working with block diagrams). N itin Shekapure
  • 3.
    Power Absorbing Devices:- Pump(Centrifugal & Reciprocating) Compressor(Reciprocating – single stage, single acting) Refrigerator (House hold) Window Air Conditioner Power Producing Devices:- Turbines (Impulse & Reaction) Internal Combustion Engines (Two stroke & Four stroke (CI & SI)) Boiler- Water Tube Boiler & Fire Tube Boiler Power Plant Engineering:- Thermal Power Plant Hydro- Electric Power Plant Nuclear Power Plant Wind Power Plant Solar Power Plant N itin Shekapure
  • 4.
    Boiler A boiler isa closed vessel in which steam is produced from water by combustion of fuel.  Purposes of Steam:  For generating power in steam engines or steam turbines.  In Sugar Mill, Chemical & many more.  For heating the buildings in cold weather and for producing hot water for hot water supply.  Primary requirement of Steam:  The water must be contained safely.  The steam must be safely delivered in desired conditions (as regards its pressure, temperature , quality and required rates). N itin Shekapure
  • 5.
  • 6.
    • Steam isvapourized water. It is a transparent gas. At standard temperature and pressure, pure steam (unmixed with air, but in equilibrium with liquid water) occupies about 1,600 times the volume of an equal mass of liquid water. • Saturated steam is steam at equilibrium with liquid water at the same pressure and temperature. • Superheated steam is steam at a temperature higher than its boiling point at a given pressure Steam N itin Shekapure
  • 7.
    Safety • The boilershould be safe under operating conditions Accessibility • The various parts of the boiler should be accessible for repair and maintenance Capacity • Should be capable of supplying steam according to the requirements Efficiency • Should be able to absorb a maximum amount of heat produced due to burning of fuel in the furnace Construction • Simple in construction Cost • Its initial cost and maintenance cost should below Boiler Requirements N itin Shekapure
  • 8.
    1. Depending uponthe relative position of Water and Flue gases:  Water Tube Boiler  Smoke or Fire Tube Boiler 2. Depending upon the Position Furnace:  Internally Fired Boiler  Externally Fired Boiler 3. Depending upon the Position of Axis of the Boiler:  Vertical Boiler  Horizontal Boiler 4. Depending upon the Service:  Stationary Boiler  Portable Boiler Classification of Boiler N itin Shekapure
  • 9.
    5. According tothe Method of Circulation of Water and Steam:  Natural Circulation  Forced Circulation 6. According to the Pressure of Steam Generated:  Low Pressure (pressure of steam below 20 bar)  Medium Pressure( pressure of steam in range of 20-80 bar)  High Pressure (80 bar &above pressure of steam ) 7. According to Nature of Draught Employed  Natural or Chimney Draught  Artificial Draught N itin Shekapure
  • 10.
    Water Tube Boiler •In these, the water flows in the tube and hot gases are passed over the tubes. • These type of boilers are useful for large amount of steam generation at high pressures due to low water to high flue gases ratio. • Used for high steam demand and pressure requirements • Capacity range of 4,500 – 120,000 kg/hour • Combustion efficiency enhanced by induced draft provisions • Lower tolerance for water quality and needs water treatment plant N itin Shekapure
  • 11.
    Babcock and WilcoxBoiler • D - Drum • DTH - Down take header • WT - Water Tubes • BP - Baffle Plates • D - Doors • G - Grate • FD -Fire Door • MC - Mud Collector • WLI - Water Level Indicator • PG - Pressure Gauge • ST - Super heater Tubes • SV - Safety Valve • MSV - Main Stop Valve • APP - Anti priming Pipe • L - Lower Junction Box • FV - Feed Valve N itin Shekapure
  • 12.
    • This isthe one of the most important type of water tube boiler as shown in above figure. • It consists of number of inclined water tubes connected between uptake header and downtake header. • Whole combustion chamber is divided into number of parts with the help of baffles so that hot gases first move from the furnace upwards between the water tubes and then move downward and upward between the baffles over the tubes and finally these are exhausted to the chimney through the damper. • The water near the uptake header are in contact with the hotter flue gases compared to portion near the downtake header due to which the water in the uptake header rises due to decreased density and enters the drum which is replaced by the cold water from the downtake header. • Wet steam from the boiler drum enters in the outer tube, then passes into the superheated tubes and during its passage it gets further heated up. Superheated steam now enters into the inner tubes and from here it is withdrawn through a stop valve. Babcock and Wilcox Boiler N itin Shekapure
  • 13.
    Fire Tube Boiler •In these boilers, the flue gases pass through the tubes which are surrounded by water in boiler shell. • Relatively small steam capacities (12,000 kg/hour) • Low to medium steam pressures (18 kg/cm2) • Operates with oil, gas or solid fuelsN itin Shekapure
  • 14.
    Cochran Boiler Salient features •The dome shape of the furnace causes the hot gases to deflect back and pass through the flue pipe. The un‐burnt fuel if any will also be deflected back. • Spherical shape of the top of the shell and the fire box gives higher area by volume ratio. • It occupies comparatively less floor area and is very compact. • It is well suited for small capacity requirements.  Very compact and requires minimum floor area  Any type of fuel can be used with this boiler  Well suited for small capacity requirements  Gives about 70% thermal efficiency with coal firing and about 75% with oil firing N itin Shekapure
  • 15.
  • 16.
    • It isstationary, fire tube, internally fired, horizontal, natural circulation boiler. • This is a widely used boiler because of its good steaming quality and its ability to burn coal of inferior quality. • These boilers have a cylindrical shell 2 m in diameters and its length varies from 8 m to 10 m. • It has two large internal flue tubes having diameter between 80 cm to 100 cm in which the grate is situated. • This boiler is set in brickwork forming external flue so that the external part of the shell forms part of the heating surface. Lancashire Boiler N itin Shekapure
  • 17.
    Boiler Mountings:-  Stopvalve  Safety Valve  Water Level Indicators  Pressure Gauge  Fusible Plug  Blow Off Cock, etc. Boiler Accessories:-  Economizers  Super heaters  Air -Preheater  Feed Pumps, etc. Air preheater (APH) is a general term used to describe any device designed to heat air before another process (for example, combustion in a boiler) with the primary objective of increasing the thermal efficiency of the process. Economizers in steam power plants is to capture the waste heat from boiler stack gases (flue gas) and transfer it to the boiler feedwater. This raises the temperature of the boiler feedwater, lowering the needed energy input, in turn reducing the firing rates needed for the rated boiler output. N itin Shekapure
  • 18.
    Difference between WaterTube And Fire Tube Boiler: Sr No Factors Water Tube Boiler Fire Tube Boiler 1 Position of water and flue gases Water flows inside tubes and flue gases are circulated around the tubes Flue gases are inside the tubes and water is circulated around the tubes 2 Floor area for the same power It occupies less floor area It occupies more floor area 3 Rate of steam generation Higher Lesser 4 Construction Simple Difficult 5 Transportation Simpler Difficult 6 Shell diameter for the given power Less required Large 7 Treatment of water Not so much necessary More necessary 8 Requirement of skill It requires more skill as well as careful attention It requires less skill for efficient and economic working 9 Accessibility of various parts for cleaning, repair and inspection It has more accessibility The parts are not so easily accessible 11 Risk of bursting More (Steam Pressure) Less 12 Operating Pressure High Pressure (100bar) Less Pressure (16bar) N itin Shekapure
  • 19.
    Steam Turbines A steamturbine is a thermo-mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. N itin Shekapure
  • 20.
    Heat Engines Any typeof engine or machine which derives Heat Energy from the combustion of the fuel or any other source and converts this energy into Mechanical Work is known as a Heat Engine. Classification : 1. External Combustion Engine (E. C. Engine) Combustion of fuel takes place outside the cylinder. 2. Internal Combustion Engine (I. C. Engine) Combustion of fuel takes place inside the cylinder. N itin Shekapure
  • 21.
    Advantages of ExternalCombustion Engines over Internal Combustion Engines : 1. Starting Torque is generally high. 2. Due to external combustion, cheaper fuels can be used (even solid fuels !). 3. Due to external combustion, flexibility in arrangement is possible . 4. Self – Starting units. Advantages of Internal Combustion Engines over External Combustion Engines : 1. Overall efficiency is high. 2. Greater mechanical simplicity. 3. Weight – to – Power ratio is low. 4. Easy Starting in cold conditions. 5. Compact and require less space. N itin Shekapure
  • 22.
    Steam Turbine Gas Turbine SteamEngine, etc. Examples of External Combustion Engines N itin Shekapure
  • 23.
    Examples of InternalCombustion Engines Road vehicles. Aircrafts. Locomotives Construction Equipment's Pumping Sets Generators for Hospitals, Cinema Hall, and Public Places. N itin Shekapure
  • 24.
    Classification of I.C. Engines IC engines may be classified on different bases. Some of the main classifications are given below : According to Fuel Used (a) Petrol engine (b) Diesel engine (c) LPG engine (d) CNG (Compressed Natural Gas) According to Cycle of Operation (a) Two stroke engines (b) Four stroke engines According to Cycle of Combustion (a) Otto cycle engines which work on Otto cycle. (b) Diesel cycle engine which work on diesel cycle. (c) Dual cycle engines which work on dual cycle. N itin Shekapure
  • 25.
    According to Methodof Ignition Spark Ignition (SI) Engines These engines are petrol engines in which a spark plug is used to ignite the fuel-air mixture. Compression Ignition (CI) Engines Diesel engines are CI engines in which air is compressed to such a high pressure and temperature so that burning of fuel takes place as soon as it is injected into the cylinder due to high temperature. N itin Shekapure
  • 26.
    Working of FourStroke Petrol Engine In four stroke engines, one cycle is completed with completion of four strokes. Main features of all the strokes are discussed below and their sketch is given in Figure. Suction or Intake Stroke (Induction Stroke) • Initially the piston remains n top dead centre (TDC) position, suction valve is open and exhaust valve remains closed. • The piston now moves downward and the petrol and air mixture (charge) enters into the cylinder. • When piston reaches bottom dead centre (BDC). The cylinder fills with the petrol air mixture. • At this moment, suction valve closes. • This completes one stroke. Crank turns by 180⁰, i.e. it completes half revolution. N itin Shekapure
  • 27.
    Compression Stroke • Boththe valves (suction and exhaust) are closed. The piston moves upwards from BDC to TDC position. • The charge is compressed inside the cylinder, i.e. its pressure increases and volume decreases. • Along with pressure temperature also increases. The crank completes next half of revolution. N itin Shekapure
  • 28.
    Working or Expansionor Power Stroke When the piston reaches the TDC position spark plug generates spark and the charge is ignited and combustion of mixture takes place. Because of burning of fuel temperature and pressure of gases increases tremendously., both the valves remain closed. • The gases expand in the cylinder and push the piston downward and therefore, work is done by the gases on the piston. • The crank revolves and completes next half revolution. • The reciprocating motion of the piston is converted into rotary motion of crank-shaft by piston rod and crank. During expansion, volume of gases increases. • All the power for running the engine is obtained during this stroke N itin Shekapure
  • 29.
    Exhaust Stroke • Thesuction valve remains closed but exhaust valve opens. • The piston moves from BDC to TDC. The burnt gases are pushed out of the cylinder due to movement of piston. • The cylinder pressure falls down to little above atmospheric pressure. • This completes the next half revolution of the crank. By this time, crank shaft completes two revolution and one engine cycle is completed with the completion of four strokes. • After this the same process is repeated again and again. N itin Shekapure
  • 30.
    Working of FourStroke Diesel Engine The main features of all the four strokes in diesel engines are given below : 1. Suction or Intake Stroke • Initially piston is at top dead centre (TDC), exhaust valve is closed but suction valve opens. • Piston moves downwards towards bottom dead centre (BDC). • As suction valve is open, air enters into the cylinder. (It is important to note that only air enters the cylinder during suction in case of diesel engines.) • Cylinder is full of air when piston reaches BDC and suction stroke in completed. • Crank shaft or crank rotates by 180o, i.e. it completes half revolution. N itin Shekapure
  • 31.
    2. Compression Stroke •Both the valves (suction and exhaust) are closed, piston moves from BDC to TDC. • Volume of air decreases and pressure and temperature increases. When the piston reaches TDC, this stroke is completed and the crank completes next half revolution. • By this time crank has rotated by 360⁰. N itin Shekapure
  • 32.
    3. Expansion orPower Stroke • At the end of compression stroke, both the valve remains closed. • The injector fitted in the cylinder head injects diesel fuel in the high temperature air. • The temperature is so high that the fuel, i.e. diesel starts burning at constant pressure. • The pressure and temperature increases further due to combustion of fuel. • The gases in the cylinder push the piston downwards from TDC to BDC and expansion process takes place. • The volume of gases increases and work is obtained in this process. • The reciprocating motion of piston is converted into rotary motion of crank shaft through piston rod and crank. • Expansion process is completed when piston reaches BDC. The crank rotates by next half revolution. • This stroke is called power stroke because power of work is obtained in this stroke. N itin Shekapure
  • 33.
    4. Exhaust Stroke •After completion of expansion stroke, the piston starts moving upwards from BDC to TDC. Suction valve is close, exhaust valve is open. • As the piston moves, it pushes the burnt gases through the exhaust vale. Thus, exhaust takes place. • The cylinder becomes empty as the piston reaches TDC. • The exhaust stroke is completed. • Crank has now completed two revolutions and all the four strokes are now completed. This completes one engine cycle. • These cycles are repeated as engine continues to run. N itin Shekapure
  • 34.
    Working of TwoStroke Petrol Engine The two stroke engine employs the crankcase as well as the cylinder to achieve all the elements of the cycle in only two strokes of the piston. 360 degrees rotation of crankshaft completes the cycle. N itin Shekapure
  • 35.
    Intake & Compressionstroke Intake: The fuel/air mixture is first drawn into the crankcase by the vacuum created during the upward stroke of the piston through the reed valve. Compression: The piston then rises, driven by flywheel momentum, and compresses the fuel mixture. (At the same time, another intake stroke is happening beneath the piston). N itin Shekapure
  • 36.
    Power & Exhaust/TransferStroke Power: At the top of the stroke the spark plug ignites the fuel mixture. The burning fuel expands, driving the piston downward. Exhaust/Transfer: Toward the end of the stroke, the piston exposes the intake port, allowing the compressed fuel/air mixture in the crankcase to escape around the piston into the main cylinder. This expels the exhaust gasses out the exhaust port, usually located on the opposite side of the cylinder. N itin Shekapure
  • 37.
    (a) For thesame power output the design of two stroke engine is simple where as a four stroke engine is complex in design for manufacturer. (b) A two stroke engine gives on working stroke for each revolution of the crank shaft whereas a four stroke engine gives one power stroke per two revolutions of crank shaft. (c) Two stroke engines have suction and exhaust ports whereas four stroke engines have suction and exhaust valves and valve mechanism. (d) Two stroke engines lighter in weight but four stroke engines are heavier. (e) The initial cost of two stroke engines is less than that of four stroke engines. (f) Thermal efficiency of two stroke engines is less than that of four stroke engines. (g) Four stroke engines are used where efficiency is important, e.g. in cars, busses, etc. Whereas two stroke engines are used where lower cost is required in two wheelers, e.g. scooters and motorcycles. Main Differences Between Two and Four Stroke Engines N itin Shekapure
  • 38.
    Important Terms Cylinder The cylinderis that part in which air-fuel mixture is sucked, compressed, ignited and expanded. Cylinder Block Cylinder block is made by casting and is used to support the cylinder in position. Piston Piston reciprocates inside the cylinder. Combustion Chamber The space enclosed between cylinder and upper part of the cylinder forms the combustion chamber where fuel-air mixture burns. Piston Rings Piston rings are provided on the piston. These are used to seal the high pressure side (cylinder) and low pressure side (crank case), i.e. to prevent leakage of gases. There is one oil ring also which is used to scrap the lubricating oil at the cylinder surface so that it returns to crank case. N itin Shekapure
  • 39.
    Important Terms Spark Plug Aspark plug is put near the top of the cylinder or in the cylinder head. It is used to ignite the fuel-air mixture by generating a spark in petrol engines. Fuel Injector Fuel injector is used in diesel engines in place of spark plug. Piston Rod Piston rod or connecting rod connects the piston and crank. Valve Mechanism A mechanism to open and close the suction and exhaust valves is also provided in four stroke engines. Top Dead Centre (TDC) Top dead center is the upper most position upto which piston moves. Bottom Dead Centre (BDC) BDC is the lower most position upto which piston comes down. Bore (D) Bore is the diameter of piston on cylinder. N itin Shekapure
  • 40.
    Stroke (L) The nominaldistance through which the piston moves from one extreme position (say TDC) to other extreme position (say BDC). Suction Manifold Suction or intake manifold is the pipe through which air and petrol mixture enters the cylinder (through suction valve). Exhaust Manifold Exhaust manifold is the pipe through which burnt gases pass from cylinder (through exhaust valve) to the silencer of the engine. Stroke Volume The volume of the cylinder between TDC and BDC is known as stroke volume. Clearance Volume It is the volume of cylinder left above TDC, i.e. between TDC and top of cylinder. Important Terms N itin Shekapure
  • 41.
    Power Absorbing Devices Compressor  Pumps  Refrigerator  Air Conditioner N itin Shekapure
  • 42.
    Compressor  Compressor –A device which takes a definite quantity of fluid ( usually gas, and most often air ) and deliver it at a required pressure.  Air Compressor- are used to compress the atmospheric air to high pressure.  Air Compressor –1) Takes in atmospheric air, 2) Compresses it, and 3) Delivers it to a storage vessel ( i.e. Reservoir ) N itin Shekapure
  • 43.
    Uses of CompressedAir: • Inflating tyres /tubes • In spray Paintings • For cleaning purposes in garages along with water for washing cars etc. • Gas turbines • Diesel Engines • Air Brakes N itin Shekapure
  • 44.
    Compressed Air Powering portable smallEngines Drills and Hammers in road building Excavating Tunneling and MiningStarting the Diesel engines Operating Brakes for buses, trucks and trains Uses of Compressed Air N itin Shekapure
  • 45.
    Air Compressors Reciprocating Rotary Single– Acting Double - Acting No. of Sides of Piston in operation No. of Stages for Compression Centrifugal Single – stage Multi - stage Classification N itin Shekapure
  • 46.
    Reciprocating Compressor -Working N itin Shekapure
  • 47.
    Refrigeration Refrigeration – Scienceof producing and maintaining temperature below that of surrounding / atmosphere. Refrigeration – Cooling of or removal of heat from a system. Refrigerating System – Equipment employed to maintain the system at a low temperature. Refrigerated System – System which is kept at lower temperature. N itin Shekapure
  • 48.
  • 49.
    Compressor Condenser Evaporator Expansion Valve Wnet, in Surrounding Air RefrigeratedSpace QH QL High Temp Source Low Temp Sink QH QL Wnet, in Refrigeration - Elements N itin Shekapure
  • 50.
  • 51.
    1. Ice making. 2.Transportation of food items above and below freezing. 2. Industrial Air – Conditioning. 4. Comfort Air – Conditioning. 5. Chemical and related industries. 6. Medical and Surgical instruments. 7. Processing food products and beverages. 8. Oil Refining. 9. Synthetic Rubber Manufacturing. 10. Manufacture and treatment of metals. 11. Freezing food products. 12. Manufacturing Solid Carbon Dioxide. 13. Production of extremely low temperatures (Cryogenics) 14. Plumbing. 15. Building Construction. Refrigeration - Applications N itin Shekapure
  • 52.
    Window Air Conditioner Airconditioning is the simultaneous control of temperature, humidity, motion, and purity of atmosphere of confined space. Application of Air conditioning:- • Industrial applications  Food Industry  Printing Industry • Hospital Air conditioning • Transport Air conditioning  Automobile Air conditioning  Train Air conditioning  Air craft Air conditioning  Ship Air conditioning • Air conditioning of Computer centers • Air conditioning of television centers N itin Shekapure
  • 53.
    Block diagram ofWindow Air conditioner N itin Shekapure
  • 54.
    Sources of Energy Non-Conventional EnergySources • Solar • Wind • Ocean • Geo-thermal Conventional Energy Sources • Coal • Water • Nuclear Energy • Petroleum Products • Natural Gas N itin Shekapure
  • 55.
    Non-Conventional Energy Sources ADVANTAGES Easilyavailable in nature. Available in large quantity. Not pollutant. Less maintenance cost. DIS-ADVANTAGES Available in Low intensity. Available in particular period only. Less efficiency of power plant. High initial cost. N itin Shekapure
  • 56.
    ADVANTAGES Thermal Efficiency ismore Initial cost is less. Intensities are high. DIS-ADVANTAGES Running and maintenance cost is high Pollution in atmosphere. Conventional Energy Sources N itin Shekapure
  • 57.
  • 58.
    Power Plants • Thermal/Steam Power plants • Hydroelectric Power Plant • Solar Power System • Wind Power Plant N itin Shekapure
  • 59.
    Thermal Power Plant Thermal power is the largest source of power in India. About 75% of electricity consumed in India are generated by Thermal power plants. There are different types of Thermal power plants based on the fuel used to generate the steam such as coal, gas, diesel etc.  Coal-fired plants account for 56% of India's installed electricity capacity.  The thermal energy available in the steam is converted into mechanical energy and is used for driving steam turbines. Steam turbines is coupled to generator and hence power is produced whenever turbine is rotated. N itin Shekapure
  • 60.
    Prime factors forstarting a steam power plant • Availability of fuel, Coal • Availability of water • Availability of strong foil foundation • Availability of transport facility • Availability of labors and engineers • Availability of sufficient space for power plant equipment's, space for disposing ash, space for storing coal etc. N itin Shekapure
  • 61.
    Working principle ofSteam power plant N itin Shekapure
  • 62.
    Advantages • Fuel ischeaper • Less space is required as compared with Hydro-electric power plant • Cheaper in production cost and initial cost compared with diesel power plant • Transmission Costs are reduced as these plants can be set up near the industry. Disadvantages • The Cost of plant is increases with the increase in temperature and pressure. • Maintenance and operating cost is high. • Long Time is required for erecting and put in action. • Large quantity of water is required. • Coal and ash handling poses a serious problem. • Pollution causes health problem to workers and habitants near the thermal power plant N itin Shekapure
  • 63.
    • In HydroPower Plant the water is utilized to move the turbines which in turn run the electric generator’s. • The Potential energy of the water stored in the dam gets converted into the Kinetic Energy of the moving water in the penstock. And this Kinetic Energy gets converted into the Electrical Energy with the help of Turbine & Generator (T-G) combination. • Hydro Power Plant was invented by H.F. Rogers • Hydro Power Plant fulfills the 30% of the total energy needs of the world. • Total hydro potential of the world = 5000 GW Hydro-Electric Power Plant N itin Shekapure
  • 64.
    Hydro-Electric Power Plant Workingprinciple • Potential energy is the energy which a substance has due to its position or state. The water behind a dam has potential energy because of its position. The water can fall from this position and exert a force over a distance and therefore do work. • In a Hydro-electric power plant the force is used to drive a turbine, which inturn drives the electric generator. • Because gravity provides the force which makes the water fall, the energy stored in the water is called gravitational potential energy. N itin Shekapure
  • 65.
    Advantages • Water isa renewable energy source. • Maintenance and operation charges are very low. • The efficiency of the plant does not change with age. • In addition to power generation, hydro-electric power plants are also useful for flood control, irrigation purposes, fishery and recreation. • Have a longer life(100 to 125 years) as they operate at atmospheric temperature. • Water stored in the hydro-electric power plants can also be used for domestic water supply. • Since hydro-electric power plants run at low speeds(300 to 400 rpm) there is no requirement of special alloy steel construction materials or specialised mechanical maintenance. Disadvantages • The initial cost of the plant is very high. • Since they are located far away from the load centre, cost of transmission lines and transmission losses will be more. • During drought season the power production may be reduced or even stopped due to insufficient water in the reservoir. • Water in the reservoir is lost by evaporation. Hydro-Electric Power Plant N itin Shekapure
  • 66.
    Three Gorges DamChina N itin Shekapure
  • 67.
    Solar Power Plant •The intensity of solar radiation are weather dependent. On cloudy days , the intensity is very low. • Average power available is only 1 kW/m2 in hottest regions. Thus large collection area is required. • It is intermittent source of energy since it is not available in night. N itin Shekapure
  • 68.
    Working Principle ofSolar Power Plant N itin Shekapure
  • 69.
    Gujarat Solar Parkthe largest solar park in the India. It's the biggest solar farm in the world, covering 2,000 hectare (4900 acres) of northern Gujarat, India, and it has the capacity to generate 600 MW of power. 600 MW of solar panels will save around 8 million tonnes of carbon dioxide from being released into the atmosphere and save around 900,000 tonnes of coal & Natural gas per year.N itin Shekapure
  • 70.
    Wind Power  Thewind power can be generated where the wind velocities are more than 8 kmph.  Such winds are available along the sea coast and at high altitudes in hilly region.  The wind power is clean and non-polluting  It has low maintenance cost and low power generation cost of about Rs. 2.25/kWh.  It needs high capital cost of about 3.5crores/MW. N itin Shekapure
  • 71.
    Advantages:- • Non polluting. •No fuel is required. • The cost of generation is low. Disadvantages:- • More noisy. • Weight of system is high. • Does not provide constant output due to velocity fluctuations Wind Power N itin Shekapure