BOP Packages

7/30/2019 BOP Packages

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BOP PDevdatta Bha

MT, 2013


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Ag

BOP Packges

Cooling Water System

Main Condenser (Shell and Tube type)

Types of Cooling Wet, Dry, Indirect Dry

Cooling TowerCooling Tower Performance

Overview of Cooling Water Treatment


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Pacaccording to Central Electric Authority Spe

Coal Handling Plant

Ash Handling Plant

Fuel Oil Handling Plant

Water Treatment Plant

Circulating Water System

Fire Protection Detection and Alarm System

Electrical, Control and Instrumentation works

Civil Works


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Coal is the fuel used to heat up the water in the boiler to produce steam. The coal delivered to thestored in bunkers and delivered to the pulverizer by conveyor belts. The pulverized coal is further to the ball mill where its is converted into a powder form. This entire system is called the coal hansystem of the power plant.

Coal Handling System

Burnt coal produces bottom ash and fly ash. The bottom ash is falls through the grate of the furna

silo where it is mixed with water to produce ash slurry. This slurry is then pumped out of the boileinto an ash pond. The fly ash moves along with the flue gases and is trapped by an electrostatic prThe trapped ash is then pnuematically sent to the ash storage area.

Ash Handling System

Water for the power plant generally comes from a river, sea, lake reservoir or an STP plant of a citydistance of water source to the power plant may be quite large and hence a cross-country pipe linrequired along with a pumping station.

Water Pipeline

Pacfrom IPP developer po


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Water required by the power plant needs to be free of any suspened particles as well as dissolved salts. Hence the watepassed through a pre-treatment plant, RO plant and a De-mineralisation plant before being used in the boiler, turbine,

Water Treatment Plant

Cooling water is required to convert the exhausted steam from the turbine back into water to create back pressure andthermal efficieny of the plant.Hence cooling tower is required to cool the heated water passing through the condensor.

Cooling Tower

The electrical network where the power is transferred along different routes.

Switchyard

Coal needs to transferred from the coal mine to the power plant by means of a train. The train enters the power plantsthe coal into a underground bunker. Power plant owner needs to erect the railway tracks for the train to reach the pow

Railway Siding

The power needs to be evacuated by means of high voltage transmission line to the purchaser of power such as State EBoard.

Transmission Line

Pacfrom IPP developer po


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Cooling Water SS

Co

Cooling w

ProcessThe cooling water is extracted from a river and treated in the treatment plant. Subsequently, it is routed into the cooling circuit. pumps convey it to the main condenser. The condenser is a heat exchanger with integrated pipe system, through which the cooling

steam from the turbine condenses on the "cold" pipe walls of the condenser. The condensation heat is transferred to the cooling w

cooling and condensation of the steam, which leaves the low pressure part of the turbine. The warmed cooling water subseque

tower. In the cooling tower, often more than 100 m in height, the water is cooled. For this purpose it is routed to a height of bet

distribution pipes into the cooling tower from where it trickles through a plate system (trickler installation) to the bottom against the

process, a small portion evaporates and escapes as vapour into the atmosphere. The remaining cooling water is collected in cooling

it can be rerouted into the extraction waters (discharge operation) or else it is again rerouted into the cooling circuit. The volume o

power plant is substantial: per 100 kW power plant performance approximately 3 - 4 m3 water per second flow through the cond

approximately 75 000 m3/h cooling water.


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Condensing pr After condensing liquid water occupies

less than 0.1% that of saturated steam

at atmospheric pressure

To maintain this vacuum, the water

formed and other gases must be

continuously removed from the

condenser

Condensing pressure is estimated by

adding up the following temperatures to

get saturation temperature of turbine

exhaust steam and then using steam

tables to find corresponding pressure

Ambient Wet bulb temperature

Cooling tower approach temperature

TTD in condenser

Condenser approach temperature


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Main Condenser/Heat exch

In thermal power plants, the primary purpose of a surface

condenser is to condense the exhaust steam from a steam

turbine to obtain maximum efficiency and also to convert

the turbine exhaust steam into pure water (referred to as

steam condensate) so that it may be reused in the steam

generator or boiler as boiler feed water.

Why is it required?The steam turbine itself is a device to convert the heat in steam to mechanical power. The difference betwee

unit mass at the inlet to the turbine and the heat of steam per unit mass at the outlet to the turbine repres

converted to mechanical power. Therefore, the more the conversion of heat per pound or kilogram of steam t

the turbine, the better is its efficiency. By condensing the exhaust steam of a turbine at a pressure below atm

steam pressure drop between the inlet and exhaust of the turbine is increased, which increases the amou

conversion to mechanical power. Most of the heat liberated due to condensation of the exhaust steam

cooling medium (water or air) used by the surface condenser


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Wet CoComponents

Shell - The shell is the condenser's outermost body and

contains the heat exchanger tubes. The shell is

fabricated from carbon steel plates and is stiffened as

needed to provide rigidity for the shell

Vacuum System - the shell's internal vacuum is most

commonly supplied by and maintained by an external

steam jet ejector system

Tube Sheets - At each end of the shell, a sheet of

sufficient thickness usually made of stainless steel is

provided, with holes for the tubes to be inserted and

rolled

Tubes - the tubes are made of stainless steel, copper

alloys such as brass or bronze, cupro nickel, or titanium

depending on several selection criteria

Waterboxes - The tube sheet at each end with tube

ends rolled, for each end of the condenser is closed by

a fabricated box cover known as a waterbox, with

flanged connection to the tube sheet or condenser

shell. The waterbox is usually provided with man holes

on hinged covers to allow inspection and cleaning


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Dry cooling As the availability of water required for wet-cooling systems becomes more limited,modern power plants are increasinglyemploying indirect dry-cooling towers ordirect air-cooled steam condensers tocondense steam turbine exhaust.

Working Air-cooled steam condenser units are normally

arranged in multi-row or multistreet arrays. Eachstreet consists of three to five main condenserunits with a dephlegmator or secondary refluxcondenser

This inhibits the accumulation of non-condensable gases in the tubes that may lead tocorrosion, freezing or a reduction in the heattransfer capability of the system.


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Indirect Dry-Cooling System (H


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Cooling Com

Frame and Casing: structural frames th

exterior enclosures Fill: can be either of splash or film type

transfer by maximizing fluids contact

Cold Water Basin: located at or near th

tower, receives the cooled water that f

the tower and fill

Drift Eliminators: capture water drople

air stream that otherwise would be lost Air Inlet: point of entry for the air ente

Louvers: purpose is to equalize air flow

retain the water in tower

Nozzles: provide the water sprays to w

Fans: Generally, propeller fans are used

towers and both propeller and centrifu

forced draft towers


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Cooling Tower Perform Range is the difference between the cooling tower water inlet and outlet

temperature

Approach is the difference between the cooling tower outlet cold water

temperature and ambient wet bulb temperature.

Although, both range and approach should be monitored, the `Approach is

a better indicator of cooling tower performance

Cooling tower effectiveness (in percentage) is the ratio of range, to the

ideal range, i.e., difference between cooling water inlet temperature and

ambient wet bulb temperature, or in other words it is

= Range / (Range + Approach)

Cooling capacity is the heat rejected in kCal/hr or TR, given as product of

mass flow rate of water, specific heat and temperature difference

Liquid/Gas (L/G) ratio, of a cooling tower is the ratio between the water

and the air mass flow rates. Against design values, seasonal variations

require adjustment and tuning of water and air flow rates to get the best

cooling tower effectiveness through measures like water box loading

changes, blade angle adjustments


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Cooling Water Treat

Demineralisation

With demineralisation, all salts dissolvedin the water are removed through acombination of strongly acidic cationexchangers and strongly basic anionexchangers

Dosing to maintain pH

Biocide and algaecide treatment

pulsed technology

ultrasonic algae and biofilm control

chlorine dioxide generation systems


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Effects of Improper Treat


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Documents

BOP Packages