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1. Steam Generation Philosophy

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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.asp
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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


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