Transcript Slide 1

PROJECT : THERMAL POWER PLANTS
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PROJECT PROFILE OF EPGL
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APPROVED CAPACITY
LOCATION
FUEL SOURCE
FUEL REQUIREMENT
MODE OF TRANSPOR-TATION
DM WATER SOURCE
LAND REQUIREMENT
MAIN CONTRACTOR
POWER EVACUATION
BENEFICIARY STATE
: 1200 MW (2*600MW)
: SALAYA, JAMNAGAR
: IMPORTED COAL
: 4 MILLION TONNE/ANNUM
: BELT CONVEYERS
: DM PLANT
: 330 ACRES
: HARBIN POWER CHINA
: GETCO (400 kv LINE)
: GUJARAT
SUPPLIER OF MAIN EQUIPEMENT
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BOILER 1&2
TURBINE 1&2
GENERATOR
COOLING WATER
AHP
DM PLANT
ETP
E-BOP
: HARBIN BOILER GROUP
: HBC
: HBC
: SPIC, ITALY
: McNally INDIA
: THERMAX INDIA
:THERMAX INDIA
: AREVA
SCHEMATIC DIAGRAM OF COAL
BASED THERMAL POWER PLANT
MAIN COMPONENTS OF COAL BASED
THERMAL POWER PLANT
1.Cooling tower
2. Cooling water pump
3. Transmission line (3-phase)
4. Unit transformer (3-phase)
5. Electric generator (3-phase)
6. Low pressure turbine
7. Condensate extraction pump
8. Condenser
9. Intermediate pressure turbine
10. Steam governor valve
11. High pressure turbine
12. Deaerator
13. Feed heater
14. Coal conveyor
15. Coal hopper
16. Pulverised fuel mill
17. Boiler drum
18. Ash hopper
19. Super heater
20. Forced draught fan
21. Reheater
22. Air intake
23. Economiser
24. Air preheater
25. Precipitator
26. Induced draught fan
27. Chimney Stack
DESCRIPTION OF COMPONENTS OF
AIR AND FLUE GAS CIRCUIT
(A) PRIMARY AIR FAN
• PA Fan sucks the atmospheric air and sends it to the APH. This hot air goes to the
coal mill to provide sensible heat to the powdered coal and a medium to go to the
combustion chamber,
• Another link from the PA Fan sends
cooler air so that the temperature
of hotter air can be controlled.
(B) FORCED DRAFT FAN
• FD Fan sucks the atmospheric air and sends to the APH.
• This hot air enters combustion chamber providing oxygen which is required for
combustion process.
ID FAN
(C) INDUCED DRAFT FAN
• ID Fan sucks the flue gases and disposes it to the chimney.
(D) AIR PREHEATER
• The heat carried out with the flue gases coming out of economizer are further
utilized for preheating the air before supplying to the combustion chamber.
• It is a necessary equipment for supply of hot air for drying the coal in pulverized
fuel systems to facilitate grinding and satisfactory combustion of fuel in the
furnace
(E) ELECTRO-STATIC PRECIPITATORS
• From APH this flue gases (mixed with ash) goes to ESP.
• The precipitator has plate banks (A-F) which are insulated from each other
between which the flue gases are made to pass. The dust particles are ionized and
attracted by charged electrodes.
• Hammering is done to the plates
so that fly ash comes down and
collect at the bottom.
ESP
HOPPERS
MAIN CIRCUITS OF COAL BASED
THERMAL POWER PLANT
1.Feed water and steam circuit
2.Coal and ash circuit
3.Air and flue gas circuit
4.Cooling water circuit
1. FEED WATER CIRCUIT AND STEAM
CIRCUIT
ECONOMIZ-ER E
BCP
LOW
TEMP. SUPER
HEATER
DIVISIONAL
SH
ROOF TUBES
PENDANT SH
WATER
STEAM
FINAL SH
WATER WALL
BFP
WATER WALL
UPPER
HEADER
BOILER
N
DRUM
HP TURBINE
2. COAL CIRCUIT
BELT CONVEYERS
COAL BUNKER
FURNACE
PULVERISER
COAL FEEDER
AIR PREHEATER
PA FAN
BOTTOM
ASH
HOPPER
ASH CIRCUIT
FLY ASH
ECO.
HOPPERS
CLINKER
GRINDER
APH
HOPPERS
ESP
HOPPERS
I. SILO
JET PUMP
DEWATERING
TANK
MIXING
TANK
SETTLING
TANK
MAIN
SILO
ASH
WATER
TANK
TRUCK
TRUCK
ASH DISPOSAL AREA
3. AIR AND FLUE GAS CIRCUIT
FLUE GAS
AIR PREHEATER
PULVERIZER
ELECTROSTATIC
PRECIPITATORS
PA FAN
FD
FAN
ID
FAN
CHIMNEY
ECO. HOPPERS
COMBUSTION
CHAMBER
BOILER
• A boiler is defined as "a closed vessel in which water or other
liquid is heated, steam or vapor is generated, steam is
superheated, or any combination thereof, under pressure or
vacuum, for use external to itself, by the direct application of
energy from the combustion of fuels, from electricity or
nuclear energy."
• IBR Steam Boilers means any closed vessel exceeding 22.75
liters in capacity and which is used expressively for generating
steam under pressure and includes any mounting or other
fitting attached to such vessel, which is wholly, or partly under
pressure when the steam is shut off.
• TYPES OF BOILING
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NUCLEATE BOILING:As heat flux increases, the water temperature near the surface increases and
reaches saturation temperature , at this point a change from liquid to vapor
occurs.
As phase change occurs to vapor, small bubbles are formed and they rise to boiler
tubes. This is known as nucleate boiling.
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FILM BOILING:Beyond nucleate boiling, the bubbles form a film of steam inside heating surface.
This is known as film boiling.
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Nucleate boiling is used in all power plants because film boiling leads to excess
temperature in boiler tubes which can lead to failover of boiler tubes.
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The point at which this failover occurs is called DEVIATION FROM NUCLEATE
BOILING (DNP)
BASIC COMPONENTS OF RANKINE
CYCLE
BOILER
CONDENSER
WORKING OF RANKINE CYCLE
There are four processes in the Rankine cycle.
• Process 1-2: The working fluid is pumped from low to high
pressure. As the fluid is a liquid at this stage the pump requires little
input energy.
• Process 2-3: The high pressure liquid enters a boiler where it is
heated at constant pressure by an external heat source to become a
dry saturated vapour. The input energy required can be easily
calculated using mollier diagram or h-s chart or enthalpy-entropy
chart also known as steam tables.
• Process 3-4: The dry saturated vapour expands through a turbine,
generating power. This decreases the temperature and pressure of
the vapour, and some condensation may occur. The output in this
process can be easily calculated using the Enthalpy-entropy chart or
the steam tables.
• Process 4-1: The wet vapour then enters a condenser where it is
condensed at a constant temperature to become a saturated liquid.
• TYPES OF WATER CIRCULATION
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NATURAL CIRCULATION:In natural circulation boilers, circulation of water depends on the difference
between the density of an ascending mixture of hot water and steam and a
descending body of relatively cool and steam-free water.
Natural circulation may be free or accelerated.
Natural circulation boilers are of two types: (a) drum type
(b) header type
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FORCED CIRCULATION:Forced circulation boilers depend upon pumps, rather than upon natural
differences in density, for the circulation of water within the boiler.
Because forced circulation boilers are not limited by the requirements that hot
water and steam must be allowed to flow upward while the cooler water flows
downward, a great variety of arrangements may be found in forced circulation
boilers.
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Forced circulation is also known as positive circulation.
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