This document describes the process of generating electricity from coal, beginning with coal mining and transport, processing the coal at the power plant, generating steam in boilers using the coal, producing work in turbines using the steam, and generating electricity using generators connected to the turbines. Key components and processes discussed include open-cast coal mines, transporting coal to the plant using a merry-go-round system, crushing and storing coal at the plant, pulverizing coal to a fine powder, burning the powdered coal in boilers to produce high-pressure steam, expanding the steam in a turbine to produce rotational work, and using generators connected to the turbines to convert the rotational work into electricity delivered to the power grid.

1. THERMODYNAMIC CYCLE
AND
COAL TO ELECTRICITY

2. Heat Input (Q1)
Work output (W1)
Work input (W2) Heat rejection (Q2)
Cycle efficiency=Net work output (W1-W2)/Heat input (Q1)

3. Adiabatic Expansion in
Turbine
Constant Pressure Heat
Rejection in Condenser
Pump Work
Sensible heat Addition in
Economizer
ENTROPY
T
E
M
P
E
R
A
T
U
R
E
Latent Heat Addition in
Evaporator (constt. Pressure) Super Heating
L + V
BASIC RANKINE CYCLE (SUB-CRITICAL)

5.  Steam power plants operate
on Rankine Cycle, DM water
as working fluid.
 Sensible heat is added in
economiser +furnace
 Steam generation takes
place in waterwall.
 Heat transfer in furnace and
enclosed superheater takes
place thru radiation.
condenser
CEP
LPH
BFP
HPH+Eco
w/w
SH
HPT
IPT
RH
LPT

6. HPT IPT LPT
EXC
GEN.
CEP
COND
LPH
1,2,3
DEARATOR
BFP
HPH
5,6
R Y B
ECO
LTSH
R
H
R
HS
H
S
H
BASIC WATER & STEAM CYCLE OF POWER
PLANT
BOILER

8. COAL TO ELECTRICITY
S W I T C H Y A R D / G R I D
G E N E R A T O R T R A N S F O R M E R
G E N E R A T O R
T U R B I N E
B O I L E R
P U L V E R I Z E R
B U N K E R
C R U S H E R
T R A C K H O P P E R
M G R
M I N E S
AIR
STEAM
FLUE GAS
CONDENSOR
COAL
PUMP

9. MINES
 MINES: GEVRA(SOUTH EASTERN COALFIELD LTD)
 TYPE: OPEN CAST MINES
 TYPE OF COAL: E& F GRADE
 COAL SIZE :<200MM

10. GRADING OF COAL
GRADE KCAL/KG
A >6200
B 5600-6200
C 4490-5600
D 4200-4490
E 3360-4200
F 2400-3360
G 1300-2400

11. MGR
(MERRY GO ROUND SYSTEM)
MINES END
NTPC
END
TRACK
HOPPERS
SILOS
TOTAL TRACK LENGTH: 34.80 KM
LENGTH OF LOAD LINE: 14.86
KM
LENGTH OF EMPTY LINE: 19.94
KM
RAIL TRACK

12. MGR
(MERRY GO ROUND SYSTEM)
 ONE WAGON CAPACITY: 60-65 TONS
 ONE RAKE : 34 WAGONS~ 2000 TONS
 TOTAL RAKES IN A DAY~ 19(APPROX)
 WAGON TYPE: BOTTOM DISCHARGE (PNEUMATIC)
 SPEED OF WAGONS DURING LOADING:0.8 KM/HR
TOTAL TIME FOR LOADING :35-40 MINUTES
TRAVEL TIME: 30 + 30 MINS

13. TRACK HOPPER
CRUSHE
R
TO BUNKERS
STACKYARD
CHP
COAL HANDLING PLANT
Coal size 20mm

14. TRACK HOPPERS
 UNDERGROUND HOPPER AT POWER STN END
FOR UNLOADING
 TRACK HOPPER 1&2 FOR ST-1(200MW) AND
ST-2 (500MW) RESPECTIVELY
 TRACK HOPPER –1 : 3000 TON
 TRACK HOPPER –2 : 3200 TON
WAGON UNLOADING:BY OPENING BOTTOM
DISCHARGE GATES
TOTAL UNLOADING TIME:25 MINS(APPROX)

15. TRACK HOPPERS

16. CHP
COAL HANDLING PLANT
 TRANSPORTS COAL FROM TRACK HOPPERS TO
BUNKERS AT MAIN PLANT
 THROUGH PADDLE FEEDERS,CONVEYOR BELTS,
CRUSHERS ETC.(CRUSHED COAL SIZE <20 mm )
 ALSO STACKS THE COAL IN STACKYARD AND
RECLAIMS WHEN NEEDED

17. CHP
COAL HANDLING PLANT
BUNKERS
 6 BUNKERS (EACH 390 TON CAP) IN A 200 MW UNIT
 9 BUNKERS (EACH 900 TON CAP) IN A 500 MW UNIT
 TRIPPER CONVEYORS FOR TRANSFERING COAL FROM
CONVEYOR TO BUNKER

18. PULVERIZER
FEEDER
BUNKER
MAIN PLANT

19. MAIN PLANT
FEEDER
 TRANSFERS COAL FROM BUNKERS TO
MILL/PULVERIZER
 VARIABLE SPEED
 DC OR AC MOTOR DRIVEN

20. MAIN PLANT
MILL/PULVERIZER
 PULVERIZES COAL FROM 20 MM SIZE TO 200 MESH
SIZE i.e> 70% SHOULD PASS THRU 200 MESH(200
HOLES/SQ.INCH)~ 75 MICRON
 BOWL ROTATED BY MOTOR AND 3 ROLLERS AT 120
DEG APART (BOWL MILL)
 PULVERIZED COAL IS TAKEN TO BOILER BY
HOT+COLD PRIMARY AIR

21. Hot Air
Gate
Cold Air
Inspection Door CoalCoal
MillMill
Hot Air
Duct
Scraper
Housing
Hot Air Damper
Gear
Housing
Grinding
Chamber
Discharge
System
Classifying
System
Coal from bunker
Grinding
Rolls
Coal discharge
Air flow
Classification
of desired
fineness Coal
Pulverized Coal
Dropping of
undesired
coarse Coal
BOWL MILL

22. BOILER
(200 MW)
• Manufacturer: BHEL, CE Design
• Type: Natural circulation, Balance
draft, Corner fired, Tilting,
Tangential

23. MILL
BUNKER
FEEDER
ESP
ID FAN
APH
PA FAN
FD FAN
C
H
I
M
N
E
Y
BOILER
BOILER: AIR & FLUE GAS PATH

24. BOILER
P
S
H
R
H
R
H
F
S
H
LTSH
ECO
HPT

25. ASH GENERATION AND CLASSIFICATION
COAL
BUNKER
BOTTOM ASH COARSE ASH FLY ASH
CHIMNEY
ESP
HOPPERS
ECO /APH
HOPPERS
MILLING SYSTEM
BOILER

26. MAIN PLANT
TURBINE
THREE CYLINDER: HP,IP AND LP CYLINDER
ROTATES AT 3000 RPM (DECIDED BY GRID FREQ
AND GENERATOR POLE)
n=120f/P
n=speed, f=frequency of grid, P=no of poles of generator

27. TURBINE
• HP TURBINE (SINGLE FLOW)
• IP TURBINE( DOUBLE FLOW)
• LP TURBINE (DOUBLE FLOW)
NO OF STAGE
• HP TURBINE (25 STAGE)
• IP TURBINE( 20+20 STAGE)
• LP TURBINE(8+8 STAGE)

28. HP TURBINE
(SECTIONAL VIEW)

29. HP turbine rotor….

30. HP turbine innercasing….

31. IP rotor….

32. IP innercasing….

33. IP outercasing….

34. LP Turbine

35. CW system in condenser

36. NTPC Korba CW/CT system at a glance

37. MAIN PLANT
GENERATOR & GENERATOR TRANSFORMER
400 KV BUS IN
SWITCHYARD
GENERATOR
TRANSFORMER
GENERATOR
15.75 KV 400 KV
CIRCUIT BREAKER
OUTGOIN
G
LINE

38. GENERATOR

39. Generator Transformer

40. Switchyard

41. THANK YOU