The document discusses the increasing demand for power in India and the development of various power plants, including thermal, nuclear, and renewable sources. It provides an overview of thermal power plants, detailing their operation, components, and the principles behind energy conversion processes. Additionally, it highlights methods to enhance thermal efficiency, such as superheating steam, reheating, and utilizing regenerators.

1. STEAM POWER PLANT
Mohit Singhal, Lecturer, GPC Shajapur

2. RATIONALE
• The power demand in the country is increasing at a very fast
pace. In fact, power production is not able to keep pace with the
demand.
• More and more steam power plants are coming up in the public
sector.
• Nuclear Power plants and gas turbine power plants are also
being set up.
• Also industries in public and private sectors are being permitted
to establish their own captive steam and diesel power plants.
• This course is aimed at providing knowledge about the systems
of power generation, and the principles of the equipments.
Mohit Singhal, Lecturer, GPC Shajapur

3. POWER PLANT
STATION
ULTIMATE AIM OF POWER PLANT
Energy ( Heat / Nuclear/
Hydro / Wind ) Electrical Energy
Mohit Singhal, Lecturer, GPC Shajapur

4. Classification of Power Plant
Power plants using Non-conventional
(renewable) sources of energy
• Solar thermal power plant
• Wind powered generation (Aero Generation)
• Tidal power plant
• Geothermal power plant
• Bio-mass power plant
• Ocean thermal power plant
•Hydro-Electric power plant
Power plants using conventional
(non-renewable) sources of energy
• Steam power plant
• Nuclear (Atomic) power plant
• Diesel power plant
• Gas power plant
Mohit Singhal, Lecturer, GPC Shajapur

5. THERMAL
PLANT
STATION
ULTIMATE AIM OF THERMAL POWER PLANT
Heat Energy Electrical Energy
Mohit Singhal, Lecturer, GPC Shajapur

6. INTRODUCTION
• A Thermal (Steam) Power Plant converts the heat energy of
coal into Electrical Energy. Coal is burnt in a boiler which
converts water into steam. The expansion of steam in
turbine produces Mechanical Power which drives the
alternator coupled to the turbine. Thermal Power Plants
contribute maximum to the generation of Power for any
country.
• Thermal Power Plants constitute 66.2% of the total installed
captive and non-captive power generation in India.
• In thermal generating stations, coal, oil & natural gas etc. are
employed as primary sources of energy.
Mohit Singhal, Lecturer, GPC Shajapur

7. General Layout Of Thermal Power Plant
Mohit Singhal, Lecturer, GPC Shajapur

8. Main and Auxiliary Equipments
• Pulverizing plant
• Coal handling plant
• Draft fans
• Boiler
• Ash handling plant
• Turbine
• Condenser
• Cooling towers and ponds
• Feed water Pump
• Economizer
• Superheated and Reheated
• Air preheated
Mohit Singhal, Lecturer, GPC Shajapur

9. BOILER
Air
Fuel Boiler
DryerAir compressorAtmospheric Air
1. Water tube Boiler A boiler in which water circulates in tubes heated externally by the fire.
2. Fire tube Boiler Water is present in the drum inside the boiler and Hot air is circulated around
maintain the temperature.
Feed Water
(High Pressure & Low
Temperature ) Approx. 170 bar
Super Saturated
Steam ( High Pr.
& High Temp. )
Approx. 170 bar
& 550
Process in the Boiler
:- Heat Addition at
Constant Pressure
Mohit Singhal, Lecturer, GPC Shajapur

10. TURBINE
In a Thermal Power Plant generally 3 turbines are used to increase the efficiency.
• High Pressure Turbine(HPT): The superheated steam is directly fed to this turbine to rotate it.
• Intermediate Pressure Turbine(IPT): The out put from the HPT is reheated in a reheated(RH) and
used to rotate IPT .
• Low Pressure Turbine(LPT): The Exhausted steam from the IPT is directly fed to rotate the shaft of
LPT.
Condenser
HPT IPT LPT
RH
Super Heated Steam
Super
Heater
Generator
Steam
Shaft
Process in Steam Turbine :
Reversible Adiabatic
Expansion / Isentropic
Mohit Singhal, Lecturer, GPC Shajapur

11. CONDENSER
• Steam after rotating
steam turbine comes
to condenser.
Condenser refers
here to the shell and
tube heat exchanger
(or surface
condenser) installed
at the outlet of
steam turbine.
Process in Condenser :
Heat Rejection At Constant Pressure
Mohit Singhal, Lecturer, GPC Shajapur

12. Boiler Feed Water Pump
Cross-Sectional View of PumpProcess in Feed Water Pump:
Reversible Adiabatic Compression /
Isentropic Compression
Mohit Singhal, Lecturer, GPC Shajapur

13. Simple Rankine / Simple Vapor Power Cycle
T
2 3
41
P
v
1
2 3
4
Boiler
Turbine
Compressor
(pump)
Heat exchanger
(Condenser)
1
2 3
4
Qout
Qin
Wout
Win
SMohit Singhal, Lecturer, GPC Shajapur

14. Limitation Of Simple Rankine Cycle
1. To avoid transporting and compressing two-phase fluid:
• We can try to condense all fluid exiting from the turbine into
saturated liquid before compressed it by a pump.
1. When the saturated vapor enters the turbine, as its temperature and
pressure decreases, condensation occurs, leading to liquid. These liquid
droplets can significantly damage the turbine blades due to corrosion
and/or erosion.
• One possible solution: superheating the vapor.
• It can also increase the thermal efficiency of the cycle (since TH ).
Mohit Singhal, Lecturer, GPC Shajapur

15. Modified Rankine cycle
T
s
3
41
2
Boiler
Turbine(pump)
Heat exchanger
(Condenser)
1
2 3
4
Qout
Qin
Wout
Win
Mohit Singhal, Lecturer, GPC Shajapur

16. Ideal Rankine Cycle - Energy analysis
• Assumptions: steady flow process, No heat generation due to friction,
neglect KE and PE changes for all four devices,
• Apply First Law of Thermodynamics in each process:
(Net heat transfer ) = (Net work out) + (Net Energy flow)
 (qout - qin) = (Wout - Win) + (hout - hin)
• 1-2: Pump (q=0)
 Wpump = h2 - h1 = v(P2-P1)
• 2-3: Boiler (W=0)  qin = h3 - h2
• 3-4: Turbine (q=0)  Wout = h3 - h4
• 4-1: Condenser (W=0)  qout = h4 - h1
Thermal efficiency h = Wnet/qin = 1 - qout/qin = 1 - (h4-h1)/(h3-h2)
Wnet = Wout - Win = (h3-h4) - (h2-h1)
T
s
3
41
2
Mohit Singhal, Lecturer, GPC Shajapur

17. Thermal Efficiency – How to enhance it?
Thermal efficiency can be improved by manipulating the temperatures and/or pressures in
various components
(a) Lowering the condensing pressure (lowers TL, but decreases quality, x4 )
(b) Superheating the steam to a higher temperature (increases TH but requires
higher temp. materials)
(c) Increasing the boiler pressure (increases TH but requires higher temp. & high
pressure bearable materials)
T
s
1
2
3
4
(a) lower pressure(temp)
s
T
1
2
(b) Superheating
(c) increase pressure
s
T
1
2
3
4
Low quality
high moisture content
1
2
4
Red area = increase in W net
Blue area = decrease in W net
Mohit Singhal, Lecturer, GPC Shajapur

18. Reheating
• The optimal way of increasing the boiler pressure without increasing the
moisture content in the exiting vapor is to reheat the vapor after it exits from
a first-stage turbine and redirect this reheated vapor into a second turbine.
boiler
high-P
turbine
Low-P
turbine
pump
condenser
1
2
3
4
5
6
T
s
1
2
3 5
6
4
high-P
turbine
low-P
turbine
4
Mohit Singhal, Lecturer, GPC Shajapur

19. Regeneration
• From 2-2’, the average temperature is very low, therefore, the heat
addition process is at a lower temperature and therefore, the thermal
efficiency is lower. Why?
• Use a regenerator to heat the liquid (feedwater) leaving the pump before
sending it to the boiler. This increases the average temperature during
heat addition in the boiler, hence it increases efficiency.
T
s
1
2
2’
3
4
Lower temp.
heat addition
T
s
1
2
3
4
5
6
7
Use regenerator to heat up the feedwater
higher temp.
heat addition
Extract steam @ 6
From turbine to provide
heat source in the
regenerator
Mohit Singhal, Lecturer, GPC Shajapur

20. Mohit Singhal, Lecturer, GPC Shajapur

21. Mohit Singhal, Lecturer, GPC Shajapur