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Power Plant Steam Generators
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Steam, The origin of Scientific & Industrial Civilization.
Trace the origin of steam.
Think about the impact of Steam on Science.
Enumerate the impact of steam on Technology.
Appreciate the role of steam in industrial world.
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The Philosophy of Steam -- Mill
There are many features which characterize thisprogressive economical movement of civilized nations.
The best of the best feature which excites attention
What is it?
This is the feature which intimately connected with thephenomena of production
This is the perpetual.
The unlimited growth of man's power over Nature so far
as human foresight can extend.
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Science of Cooking Methods
Camp fire
Wood Stove
Gas Stove
Micro Wave
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Science of Lighting
Wick lamp
Gas Lamp
Electric Lamp
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Science of Motive Power : Land
Horse Cart
Steam Wagon
Car
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Science of Motive Power : Sea
Man power Ship
Steam Engine Ship
Steamer
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Science of Motive Power : Air
Propeller aircraft
Turbojet Aircraft
Supersonic
aircraft
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Human being has ability to provide power,
set LIMITS to the rate of growth of
Civilization.
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The Philosophy of Steam -- Mill
Our knowledge of the properties and laws of physicalobjects shows no sign of approaching its ultimate
boundaries!!!!!
It is advancing more rapidly, and in a greater number of
directions at once, than in any previous age or generation. Affording such frequent glimpses of unexplored fields
beyond as to justify the belief that our acquaintance with
Nature is still almost in its infancy.
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Origin of Steam : Basis of Scientific & Technological Research
Denis Papin, while working at Huygens and ofBoyle, started to be interested in the vapor.
Several geniuses of science tried before him totry out an unspecified machine which would run on
the vapor, but their efforts were useless. It is into 1707 that Denis Papin made his first
great realization: the boat with vapor.
This superb invention brought much controversy
near the boatmen, who destroyed the ship.
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The Boiler
Boilers are accepted equipment of everyday life.
A prime device which connects natural resources and
human-made facilities.
A fire
A furnace.
A boiler ..
A Steam generator.
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The Steam Machines were in industrial use since 1712.
Establishment of the first and second laws of thermodynamics
by Clausius, Kelvin et al., occurred in 1855!!!
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This Led to Formulation of Greatest
Science .
Thermodynamics
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Thermodynamics-
A Science of Human Development
through Energy Utilities.
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Depth of Knowledge of Thermal
Sciences
isA Measure of Growth of
Technology & Civilization
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The Great Albert Einstein`sOpinion
A Theory is more impressive
the greater the simplicity of its premises is,
the more different kinds of things it relates,
and the more extended is its area of applicability.Therefore, the deep impression which Classical
Thermodynamics made upon me.
It is only physical theory of universal content
concerning which I am convinced that , Within theframework of the applicability of its basic
concepts, it will never be overthrown.
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Analysis of Power Plant Steam Generators
Available Resources (Energy, matter etc.,)
Engineering Design of Thermal processes,
devices and systems.
Is Design meeting Humans NEED?
YES
(task completed)
NO
Social Sciences and
Humanities
Thermodynamics
Laws and Information
Other Engineering Sciences
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Technology Vs Power
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Historical Development of Steam Generators
A Progressive development towards perfection!!!!!!!
A Quick Tour from Zero DOF to 4 DOF Technology !!!!!!
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Historical Eras of Technology
Historical Development in Steam Generators
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Historical Development in Steam Generators
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FIRE, FLAME and TORCH
Fire is a discovery rather thanan invention.
Homo erectus probably discoveredfire by accident.
Fire was most likely given to man as a'gift from the heavens' when a bolt oflightning struck a tree or a bush,
suddenly starting it on fire. The flaming touch and the campfire
probably constituted early man's firstuse of 'artificial' lighting.
As early as 400,000 BC, fire waskindled in the caves of Peking man.
Prehistoric man, used primitivelamps to illuminate his cave.
Various Oils were used as fuels.
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The Aelopile
In 130BC. Hero, a Greek
mathematician and scientist is
credited with inventing the first
practical application of steampower, the aelopile.
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Branca's Steam Engine
In 1629, Giovanni Branca,
of the Italian town ofLoretto, described, in awork' published at Rome,a number of ingeniousmechanical contrivances,
among which was asteam-engine in which thesteam, issuing from aboiler, impinged on thebasis of a horizontal well.
This it was proposed toapply to many usefulpurposes
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Newcomen Engine
In 1712 Thomas Newcomen
developed a Steam engine called
Atmospheric engine.
a
b
d
ef
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1720 Haycock : Shell-type boiler made of copper plates
http://nla.gov.au/apps/pictureaustralia?action=PADisplay&mode=go&url=http%3A%2F%2Fwww.prov.vic.gov.au%2Fimages%2F12800%2F12800-00001-000157-050.asp7/28/2019 1. Steam Generation Philosophy
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The Theory of Producing Steam
Water and steam are typically used as heat carriers in heating systems.
It is well known that water boils and evaporates at 100C under
atmospheric pressure.
By higher pressure, water evaporates at higher temperature - e.g. a
pressure of 10 bar equals an evaporation temperature of 184C.
During the evaporation process, pressure and temperature are constant,
and a substantial amount of heat are use for bringing the water from
liquid to vapour phase.
When all the water is evaporated, the steam is called dry saturated.
In this condition the steam contains a large amount of latent heat.
This latent heat in the dry saturated steam can efficiently be utilised to
different processes requiring heat. The steam boiler or steam generator is connected to the consumers
through the steam and condensate piping.
When the steam is provided to the consumers, it condensate.
It can then be returned to the feed water tank.
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Water Tube Boilers: The Steam Generators
As industry developed during 19th century, so the use of
boilers for raising steam became widespread.
Disastrous explosions sometimes occurred.
Boilers of that period consisted of heated pressure vessels
of large diameter.
These are subject to internal pressure which is tensile
stresses in the walls of the enclosure.
The value of stress, known as hoop stress is given by
T
Dpf
2
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Steam generator versus steam boiler
Opposite the principle of the steam boilers, the water in the steamgenerators evaporates inside the tube winded up into serial connected
tube coils. The feed water is heated up to the evaporation temperature and then
evaporated.
The intensity of the heat, the feed water flow and the size/length of thetube are adapted, so that the water is exactly fully evaporated at the exitof the tube.
This ensures a very small water and steam volume (content of thepressure vessel).
Thus there are no buffer in a steam generator, and is it temporaryoverloaded.
The advantages using a steam generator compare to conventional steam
boilers: Easy to operate - normally no requirement for boiler authorisation
Rapid start-up and establishing full steam pressure Compact and easy toadapt in the existing machinery arrangement
Price attractive - especially at low steam rates.
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The water tube boiler
As you can see, the Water Tube
Boiler (below) looks verycomplicated.
Thousands of tubes are placed instrategic location to optimize theexchange of energy from the heat to
the water in the tubes. These types of boilers are most
common because of their ability todeliver large quantities of steam.
The large tube like structure at thetop of the boiler is called the steam
drum.
The hundreds of tube start andeventually end up at the steam drum.
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Steam Theory
Within the boiler, fuel and air are
force into the furnace by theburner.
There, it burns to produce heat.
From there, the heat (flue gases)travel throughout the boiler.
The water absorbs the heat, andeventually absorb enough tochange into a gaseous state -steam.
To the left is the basic theoreticaldesign of a modern boiler.
Boiler makers have developedvarious designs to squeeze themost energy out of fuel and tomaximized its transfer to the water.
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Water enters the boiler, preheated, at the top.
The hot water naturally circulates through the tubes down to thelower area where it is hot.
The water heats up and flows back to the steam drum where thesteam collects.
Not all the water gets turn to steam, so the process starts again.
Water keeps on circulating until it becomes steam.
Meanwhile, the control system is taking the temperature of the steamdrum, along with numerous other readings, to determine if it should
keep the burner burning, or shut it down. As well, sensors control the amount of water entering the boiler, this
water is know as feedwater.
Feedwater is not our regular drinking water.
It is treated with chemicals to neutralize various minerals in the water,
which untreated, would cling to the tubes clogging or worst, rustingthem.
This would make the boiler expensive to operate because it would notbe very efficient.
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On the fire side of the boiler, carbon deposit resulting from impropercombustion or impurities in the fuel can accumulate on the outersurface of the water tube.
This creates an insulation which quickly decrease the energy transferfrom the heat to the water.
To remedy this problem the engineer will carry out soot blowing. At aspecified time the engineer uses a long tool and insert it into the fireside of the boiler.
This device, which looks like a lance, has a tip at the end which "blows"steam.
This blowing action of the steam "scrubs" the outside of the water
tubes, cleaning the carbon build up. Water tube boilers can have pressures from 7 bar to as high as 250
bar. The steam temperature's can vary between saturated steam, 100
degrees Celsius steam with particle of water, or be as high as 600 -650 degrees Celsius, know as superheated steam or dry steam
The performance of boiler is generally referred to as tons of steamproduced in one hour.
In water tube boilers that could be as low as 1.5 t/hr to as high as2500 t/hr.
Water Tube Boiler
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Water Tube Boiler
A. Smoke uptake
B. EconomizerA heat exchanger that transfersheat from Boiler Flue Gases toBoiler Feedwater.
C. SteamOutletSaturated steam from theSteamDrum to the Superheater
D. CycloneA device inside the drum that isused to prevent water and solids
from passing over with thesteamoutlet.
E. Stay tubefor superheater
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F. Superheated steam outlet
G. Superheater
A bank of tubes, in the exhaust gas duct
after the boiler, used to heat the steam
above the saturation temperature.H. Superheater Headers
Distribution and collecting boxes for the
superheater tubes.
I. WaterDrum
J. BurnerK. Waterwall Header
Distribution box for waterwall and
downcomers.
L. Foting
M. Waterwall
Tubes welded together to form a wall.
N. Waterwall Header
Distribution box for waterwall and
downcomers.
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O. Back side waterwall
P. Boiler hood
Q. Waterwall Header
Collecting box for waterwall and risers.
R. RiserTubes in which steam is generated due
to high convection or radiant heat. The
water-steam emulsion rises in these
tubes toward the steamdrum.
S. Downcomer
A tube through which water flows
downward. These tubes are normally
not heated, and the boiler water flows
through them to supply the generating
tubes.
T. SteamDrumSeparates the steam from the water.
U. Economizer Header
Distribution box for the economizer
tubes.
water tube steam boiler V2M8
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water tube steam boiler V2M8
with regenerative air preheater
A Vertical Boiler whose major design
features are the gastight waterwall
furnace and the vertical in-line invertedU-loop superheater.
The boiler shown is top-fired with
resulting improved gas distribution over
the entire superheater furnace.
Both the main-bank tubes andsuperheater elements are in-line for
improved tube cleaning.
Normally, soot-blowing equipment
includes retractable blowers in the
superheater and rotary blowers in themain bank and economizer.
The combustion air preheater, on the
top of the boiler, heats the inlet
combustion air to the burners by means
of the flue cases and improves the
efficiency of the boiler.
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Water and steam flow diagram
Blue: the downcomers lead the
water from the steam drum to the
water drum and the waterwalls
headers.Red and blue: the evaporation
tubes and the water walls lead the
water and steam emulsion back to
the steam drum.
Red: the steam passes through the
superheater before it leaves theboiler for the consumers
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One large V2M8 boiler is
installed in a ship at a shipyard
and one other boiler is still
suspended in the crane-hook.
When the boilers are placed and
secured then the engine room
will be built around them.
water tube steam boiler V2M9
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water tube steam boiler V2M9
with regenerative air preheater
The most outstanding feature of the V2M9
is the combustion.
The boiler is a vertical two-drum dropped-
furnace boiler.
A burner is located at each of the four
corners of the furnace and the burners are
aligned to be tangential to a circle in the
center of the furnace. This arrangement gives a rotary motion to
the combustion gases within the furnace,
with improved turbulence and air/fuel
mixing.
This lengthens the fuel-particle residence
time in the furnace and allows combustion
to be completed before the gases pass
into the convection generating bank and
superheaters
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Water and steam flow diagram
Blue: the downcomers lead thewater from the steam drum to
the water drum and the water
walls headers.
Red and blue: the evaporation
tubes and the waterwalls lead thewater and steam emulsion back
to the steam drum.
Red: the steam passes through
the superheater before it leaves
the boiler for the consumers.
Eckrohr Steam Boilers
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Eckrohr Steam Boilers
Eckrohr-Boiler (Corner Tube Boiler)is a boiler for all kinds of fuel.
Originally it got its name because it
has downcomers in the four corners. It is a natural water circulation single
drum boiler and it needs nocirculation pump.
Downcomers, headers andwaterwalls are welded together to a
gas-tight tube cage.
The Eckrohr-Boiler is self-supportingand needs no supporting structure.
It stands on its own downcomers.
Due to the cage structure with
downcomers, headers and overheadpipes the Eckrohr-Boiler isearthquake safe (more than 550boilers installed in Japan, many ofthem for municipal waste).
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Eckrohr Boilers water and steam flow diagram
1. Unheated return tubes
2. Header
3. Mixture tubes4. Riser tubes (evaporator)
5. Overflow tubes
6. Unheated steam drum
7. Unheated downcomers
The water-steam mixture flows upwards throughthe riser tubes (4).
In the upper mixture tube (3) steam is alreadyseparated from water and a part of the waterflows through unheated return tubes (1) to theheader (2).
The separated steam flows through the overflowtube (5) to the steam space of the drum (6).
The remaining mixture runs through mixturetube (3) into the drum.
The final separation of water and steam takesplace in the drum, the water flows through thedowncomers (7) to the headers (2).
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Composite steam boiler
Composite boilers that mixes
the diesel engines exhaust
gases and the flue gases from
the fuel oil burner have existed,
and may still exist.
Using the diesel engines
exhaust gases as combustion
air for the fuel oil burner is
quite economically although it
makes a rather complicated
unit.
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Steam Generator Design
Steam generators can be delivered in horizontal execution (with low
height), or in vertical execution (occupying limited floor space). They are delivered as insulated with stainless steel cover sheets and
complete with burner, armatures, instrumentation, safeties and a
control panel.
The steam generators heaters are made with coils made of seamless
tubes, where the feed water is preheated and evaporated during theflow through these.
The heat is transferred to the water/steam mixture as radiant heat in
the combustion chamber, where the inner cylindrical tube coil
and a flat tube coil forms the chamber wall and the bottom
respectively. Consequently refractory concrete is avoided.
The combustion gasses are hereafter cooled in the outer convection
part, as the gasses pass the space between the two tube coils.
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The thermal design ensures a modest volume of steam relative to the
size of the heater, and allows unlimited thermal expansion due to the
high temperatures. Beside the standard execution the steam generators can be
delivered in following variations:
Electrical heated, including EX-design if required
Material in stainless steel
Complete skid-mounted with tanks and pretreatment equipment.
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Classification of Boilers
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Classification of Boilers
Packaged Boilers : Small in capacity.
Preassembled units.
Shell type or watertube Shell type: Domestic hot water boilers are most common example.
Low Thermal efficiency 50 -- 65%.
Water-tube Type: Packaged water-tube boilers are built incapacity up to 25 kg/s
Pressure up to 73 bar and temperature up to 440 C.
furnace operates under positive pressure. Designed for compactness.
Operated with a very high volumetric heat release rate.
Marine or Naval Boilers : Extremely compact.
Built to maximize the power-to-weight and power-to-volume ratio.
High heat release rates: up to 10 MW per cubic meter in Naval vessels and up to 1Mw per cubic meter in merchant vessels.
Generally oil fired.
Modern ships using diesel engine or gas turbine power use a waste heat recovery
boiler or auxiliary pakage boiler.
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Power Generation Boilers
Pulverised coal combustion.
Fluidized Bed Combustion.
Solid Waste Fired Boilers
Biomass Fired Boilers
Waste Heat Recovery Boilers.
Nuclear Steam Generators.
Classification of Boilers
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Classification of Boilers
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MECHANICAL DESIGN
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Boiler.
Furnace.
Turbine.
Super Heater & Re- Heater.
PA,FD & ID Fan.Cooling Tower
MECHANICAL DESIGN
FUNCTION HELD IN PLANT
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FUNCTION HELD IN PLANT
1.COAL FLOW
2.STEAM FLOW
3.WATER FLOW
4.ASH HANDLING
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OPERATIONAL FEATURES
INSIDE THE POWER PLANT
HR
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BOILER
DRUM
2
3
5
1
6
4
LPHDEARATOR
HPHAPH
COAL
OIL
FURNACE
DRAFT
SH RH
ECONO-
MISOR
BF
P
CRH
CEP
CHIMNEY
FD FAN
H
GENERATOR
CONDENSOR
HP
T
LP
T
IPT
HOT SEC AIR
COLD AIR
TO PA FANS
ID FAN
PA FAN MILL
STEAM FLOW
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S.HEATER
R.H.
I.P L.P
condenser
H.P
STEAM FLOW
WATER FLOW
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WATER FLOW
D.M.PLANT ECONOMIZER
BOILER CO
NDENSER
HOT WATER
COOL WATER
B.F.P
STEAM
COOLINGTOWER
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FEED WATER SYSTEM
HIGH PRESSURE HEATERS
BOILER FEED PUMP (BFP)
FEED REGULATING STATIOIN
DRIP & DRAIN SYSTEM
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BOILER & ITS ACCESSORIES
BOILER DRUM
SUPER HEATERS
AIR HEATERSSUPRING LOADED SAFETY VALVES
PRIMARY AIR CYCLE
IGNITERSECONOMIZER
SUPER HEATERS