various types of Power plant engineering

1. BASIC CIVIL AND
MECHANICAL ENGINEERING

2. POWER PLANT ENGINEERING
A Power Plant or Power station is a machine or
assemblage of equipment's that produces and
delivers a flow of electrical energy.
Power plants are used for the generation of
electric power.
In India, there has been considerable increase in
power development under various power
plants
“Life without electric power is an unimaginable”

3. SELECTION OF POWER PLANT
• Availability of fuel and
water
• Availability of fuel storage
facility
• Transportation facility
• Availability of land
• Environmental conditions
• Requirement of labours
• Efficiency of the plant
• Capacity of the Plant
• Distance from the load
centre
• Life of the plant
• Availability of time period
for power production
• Cost of fuel used.
• Nature of losses
• Depending on noise of
vibration

4. TYPES OF POWER PLANT
Steam or Thermal power plant
Hydroelectric or Hydel power plant
 Nuclear power plant
Diesel power plant
Gas Turbine power plant

5. THERMAL POWER PLANT

6. THERMAL (OR) STEAM
POWER PLANT
Steam is used as working fluid.
The heat energy is converted into mechanical
energy by the steam turbine and that mechanical
energy is used for generating power with the help of
generator.
Heat energy Mechanical Energy Electrical Energy

7. THERMAL (OR) STEAM
POWER PLANT
• Boiler----- Turbine------ Generator
• Boiler – Fuel Heat Energy
• Turbine - Heat Energy Mechanical Energy
• Generator - Mechanical Energy Electrical Energy

8. THERMAL (OR) STEAM
POWER PLANT
• In consists of four main circuits
 Coal and Ash circuit
 Air and Flue gas circuit
 Feed water and steam circuit
 Cooling water circuit

9. THERMAL POWER PLANT
VIDEO

11. EQUIPMENTS
• Air preheater:
– to preheat the combustion air by means of exhaust gas
• Condenser:
– The main purposes of the condenser are to condense the
exhaust steam from the turbine for reuse in the cycle and to
maximize turbine efficiency by maintaining proper vacuum
• Economiser:
– It is used to preheat the water used for boiler by means of
exhaust gases escaping through chimney

12. CHARACTERISTICS
Low cost as compared with hydro power
plant
High efficiency
Reduced water requirement
Higher reliability and availability
Reduced environmental impact in terms of
air pollution

13. ADVANTAGES
Initial cost is low compared to hydel plant
Less space is required
Generation of power is continuous
The power plant can be located near load centre,
so the transmission cost and losses are
considerably reduced
The construction of thermal power plants are less
period of time

14. DISADVANTAGES
Maintenance and operating cost are High
Power generation cost is high compared with Hydel
power plant.
Life of the thermal power plant is hardly about (30-40
years) compared with the life of the hydel power plant
( 100- 125 years)
Transportation of fuel is a major problem in this type of
power plant.
Air pollution is the major problem

15. MAJOR PROBLEM
•Ash handling
•Air Pollution

16. SELECTION OF SITE FOR A
STEAM POWER PLANT
• The location of the plant should be at a minimum distance
from the load centre ( consumer) to avoid transmission losses.
• Availability of water is a desirable factor.
• The water should be preferably free from salt to reduce the
cost for water treatment.
• The soil should be satisfactory for a strong foundation.
• The site should be away from thickly populated areas to
reduce the effect of pollution ( such as smoke, Ash and heat
from the plant )
• Adequate transport facility is desirable.
• Space should be available to store Coal and disposal of Ash

17. THERMAL POWER PLANTS IN
TAMILNADU
Name of the power station capacity
• Neyveli - 2990 MW
• Tuticorin - 1,050 MW
• Ennore - 450 MW
• North Madras - 1830 MW
• Mettur - 1,440 MW

18. HYDEL POWER PLANT

19. HYDEL (OR) HYDROELECTRIC
POWER PLANT
• Hydro means water
• Water is used as working fluid
• The potential energy of water stored at
higher level in a dam is converted into
mechanical energy which is used for power
generation
Potential energy Mechanical Energy Electrical Energy

20. HYDEL (OR) HYDROELECTRIC
POWER PLANT
DEVICE ENERGY CONVERSION
• Dam – water Potential Energy
• Turbine - Potential Energy Mechanical Energy
• Generator - Mechanical Energy Electrical Energy

21. CLASSIFICATION OF HYDEL
POWER PLANT
S.No HEAD TYPE OF POWER
PLANT
TYPE OF
TURBINE
1 Above 100 m High head Pelton wheel
2 30 to 100 m Medium Head Francis turbine
3 Below 30 m Low Head Kaplan (or)
Francis turbine

22. HYDEL POWER PLANT VIDEO

23. HYDEL POWER PLANT VIDEO

25. COMPONENTS OF HYDEL POWER
PLANT
 Water reservoir
 Dam
 Spillway
 Gate
 Pressure tunnel
 Surge tank
 Penstock
 Hydraulic turbine
 Inlet valve
 Draft tube
 Tail race level
 Head race level
 Catchment area

26. Availability of water
Water storage capacity
Available water head
Accessibility of the site
Distance from the load centre
Type of the land of the site
SELECTION OF SITE FOR A
HYDROELECTRIC POWER PLANT

27. ADVANTAGES
• Water is the cheapest source of energy
• Hydel power plant is highly reliable
• Life of the plant is very long
• Running cost of plant is low
• No fuel transportation problem
• Maintenance and operation charges are very low
• No ash disposal problem
• Easy operation

28. DISADVANTAGES
• Initial cost of plant is very high and more time is
required for erection
• Transmission losses are more and cost is high
• Power generation depends on quantity of water
available which in turn depends on rainfall
• It takes considerably longer time for its installation,
compared to thermal power plants

29. DIESEL POWER PLANT

30. DIESEL POWER PLANT
• Diesel power plant depend upon the diesel
engine
• Capacity – 2 to 50 MW
• Diesel power plant is suitable for small and
medium outputs
• Diesel power plants can be used as stand-by
plants to hydro-electric power plants and
steam power plants for emergency service.

32. COMPONENTS OF DIESEL
POWER PLANT
• Diesel engine
• Air filter and super charger
• Engine starting system
• Fuel system
• Lubrication system
• Cooling system
• Governing system
• Exhaust system

33. DIESEL POWER PLANT

34. DIESEL POWER PLANT

35. DIESEL POWER PLANT

36. DIESEL POWER PLANT

37. ADVANTAGES
• Fuel handling is easier
• The plant is smaller in size than steam or
thermal power plant
• There is no problem of ash disposal exists
• Diesel power plants operate at high overall
efficiency than steam power plant
• It requires minimum labour
• Plant layout is simple

38. DISADVANTAGES
• The repair and maintenance costs are high
• Diesel fuel is much more expensive than coal
• The lubrication costs are high
• The capacity of the diesel engine is
considerably lower than thermal power plant
• Life of the diesel power plants are low when
compared with thermal power plants

39. APPLICATIONS
• It is quite suitable for mobile power
generation
• It is used as peak load plants in combined
with thermal or hydro plants
• It is used as stand by plants for emergency
service

40. GAS TURBINE POWER PLANT

41. GAS TURBINE POWER PLANT
• Natural gas is used as fuel.
• Air is compressed to a high pressure and
heated by means of the flue gases.
• Natural gas burns in the stream of hot air
and the gases coming out are used to run
the turbine
Heat energy
Pressure
energy
Mechanical
energy
Electrical
energy

42. GAS TURBINE POWER PLANT
• The working medium for transforming
thermal energy into rotating mechanical
energy is the hot combustion gas, hence the
term “GAS TURBINE”
• Gas turbines are also referred to as
Combustion Turbines (or) Combustion gas
turbines

43. GAS TURBINE POWER PLANT
DEVICE ENERGY CONVERSION
Compressor - Air Pressure energy
Combustion Chamber - Pressure energy Heat energy
(Air+fuel)
Turbine - Heat energy Mechanical energy
Generator - Mechanical energy Electrical energy

45. COMPONENTS OF GAS TURBINE
POWER PLANT
Low pressure Air compressor ( LPC)
Intercooler
High pressure Air compressor (HPC)
Regenerator
Combustion Chamber ( CC)
High pressure turbine ( HPT)
Low pressure turbine ( LPT)
Reheating combustion chamber ( RCC)

46. ADVANTAGES
• Natural gas is a very suitable for gas turbine
plant and is easily available and cheap
• Gas turbine plant is smaller in size and less
weight compared to steam plant
• Initial cost is low
• Less maintenance cost
• Simple in construction and does not require
heavy foundation and buildings

47. DISADVANTAGES
Major part of the work (i.e.,66%) developed in
the turbine is used to drive the compressor.
Therefore net work output of the plant is
low. Therefore, overall efficiency is low
Special cooling methods are required
Poor part load efficiency

48. APPLICATIONS
Gas turbine power plants are used to supply
peak loads in steam or Hydel power plants
It is used as standby unit for Hydel power
plants
It is used in aircraft and ships

49. NUCLEAR POWER PLANT

50. NUCLEAR POWER PLANT
• Uranium is used as nuclear fuel
• The principle involved is nuclear fission
Nuclear fission :
• It is a process of splitting up the nucleus of
fissionable material like uranium into two or
more fragments with release of enormous
amount of energy

51. NUCLEAR FISSION
• When the nucleus of uranium 235 is
bombarded with high energy neutrons.
• The atom splits up into two fragments
thereby releasing 2.5 neutrons and
enormous amount of energy
U235 + 0n1 Ba141 + Kr 92 + 2.5 0n1 + 200 MeV

52. NUCLEAR FISSION

53. NUCLEAR FISSION

56. 0n1
Ba141
Kr92
Ba141
CHAIN REACTIONS

58. Nuclear reactor
• Nuclear reactor is the heart of the nuclear
plant
• It is a device used to produce heat
• It is similar to a boiler in steam power plant
• Heat is produced in the reactor due to
nuclear fission of the fuel U235
• Pressure equalizer is used to maintain a
constant pressure

59. COMPONENTS
• Reactor core
• fuel rod & Control rod
• Moderator
• Coolant
• Radiation Shielding
• Steam generator
• Turbine
• Condenser
• Feed pump

60. REACTOR CORE
• Nuclear fission reaction takes place in
reactor core.
• It is in the shape of right circular cylinder and
consists of fuel elements, control rods,
coolant and moderator

61. FUEL RODS & CONTROL ROD
• Fuel rod of a nuclear reactor should be a
fissionable material
• Fuel rods of the reactor can be one or all of the
following : U233 , U235 , Pu239
• Control rods are used to regulate the rate of
chain reaction.
• They are used to absorb the excess neutrons.
• Control rods are made of boron or cadmium

62. MODERATORS
• Moderator is used to slow down the fast
moving neutrons.
• The process of slowing down is called
moderation or thermalizing.
• Materials containing light weight atoms,
Hydrogen, graphite,beryllium
• Specially hydrogen are found to be most
effective as moderators

63. COOLANT
• Coolant is used to remove the intense heat
produced in the reactor
• Water is used as coolant and sometimes
liquid sodium is also used

64. SHIELDING
• Among the nuclear radiations produced in a
reactor the α and ᵝ particles, fast neutrons,
slow neutrons and ƴ rays are the harmful
ones must be shielded against
• Thermal shield is provided through steel
lining of the reactor vessel and another
shield is made of thick concrete surrounding
the reactor. This is called as radiation
shielding

65. STEAM GENERATOR
• Hot coolant water leaves the reactor at the
top. It flows into steam generator ( Boiler )
in the secondary circuit and transfers the
heat to the feed water in the steam
generator.
• The feed water evaporates to become steam

66. TURBINE
The steam produced in the steam generator is
passed to the turbine. Work is done by the
expansion of steam in the turbine.
The turbine shaft is coupled to the generator
and electricity is produced

67. • Condenser :
– The steam coming from the turbine is passed to
condenser. Steam is converted into water by
circulating cold water around the condenser
tubes.
• Feed pump :
– The feed pump pumps the condensed water
from the condenser to the steam generator

68. ADVANTAGES
• Nuclear power plant needs less space
• Fuel consumption is very small
• Less fuel transportation cost
• Not affected by adverse weather conditions
• Operation of the plant is more reliable
• Less workmen is required

69. DISADVANTAGES
• Capital cost is high
• Maintenance cost is high
• Radioactive wastes, if not disposed carefully
have adverse effects on environment
• Not suitable for varying load conditions

70. SELECTING SUITABLE SITE FOR
NUCLEAR POWER PLANT
• Distance from the load center
• Availability of cooling water
• Distance from populated area
• Radioactive waste disposal facility

74. PUMPS AND TURBINES

75. PUMPS
• Pump is a hydraulic machine driven by a motor
• The pump converts the mechanical energy
developed by reciprocating or rotation
motion of the pump into hydraulic energy.
• The hydraulic energy is in the form of pressure
energy.This pressure energy is converted into
potential energy, as the liquid is lifted from a
lower level to higher level

76. USES OF PUMPS
• Used to feed the water into the boiler
( called feed pump) in power plants
• Used to circulate water in the condenser
( called condensate pump) for condensing
steam in power plants
• Used to force the lubricating oil into the
moving parts or rotating parts of I.C engines

77. There are two main categories of pump:
 Rotodynamic pumps.
 Positive displacement pumps.
Diaphragm
Piston
Plunger
Reciprocating
Rotary
Mixed flow
Gear
Lobe
Sliding Vane
Screw
Axial flow
Centrifugal
Rotodynamic
Turbine
Positive displacement
PUMP
2

78. Centrifugal pump
• Centrifugal pump is a hydraulic machine with
a rotating part called impeller.
• In this pump, mechanical energy is
converted into pressure energy by means of
centrifugal force acting on the liquid.
• The liquid enters the pump at the peripheral
hub and leaves the casing radially

80. VOLUTE CASING

81. VORTEX CASING

82. DIFFUSER CASING

83. RECIPROCATING PUMP
• Pumps are used to increase the energy level of
water by virtue of which it can be raised to a higher
level.
• Reciprocating pumps are positive displacement
pump, i.e. initially, a small quantity of liquid is taken
into a chamber and is physically displaced and
forced out with pressure by a moving mechanical
elements.
• The use of reciprocating pumps is being limited
these days and being replaced by centrifugal
pumps

84. Main components
• A reciprocation pumps consists of a plunger or a piston that
moves forward and backward inside a cylinder with the
help of a connecting rod and a crank. The crank is rotated
by an external source of power.
• The cylinder is connected to the sump by a suction pipe and
to the delivery tank by a delivery pipe.
• At the cylinder ends of these pipes, non-return valves are
provided. A non-return valve allows the liquid to pass in
only one direction.
• Through suction valve, liquid can only be admitted into the
cylinder and through the delivery valve, liquid can only be
discharged into the delivery pipe.

85. Single acting reciprocating pump

86. Single acting reciprocating pump

87. Double acting reciprocating
pump

88. Double acting reciprocating
pump

89. Double acting reciprocating
pump

90. Comparison of Centrifugal and Reciprocating Pumps
Centrifugal Pumps Reciprocating Pumps
1. Steady and even flow 1. Intermittent and pulsating flow
2. For large discharge, small heads 2. For small discharge, high heads.
3. Can be used for viscous fluids e.g. oils,
muddy water.
3. Can handle pure water or less viscous liquids
only otherwise valves give frequent trouble.
4. Low initial cost 4. High initial cost.
5. Can run at high speed. Can be coupled
directly to electric motor.
5. Low speed. Belt drive necessary.
6. Low maintenance cost. Periodic check up
sufficient.
6. High maintenance cost. Frequent replacement
of parts.
7. Compact less floors required. 7. Needs 6-7 times area than for centrifugal
pumps.
8. Low head pumps have high efficiency 8. Efficiency of low head pumps as low as 40
per cent due to the energy losses.
9. Uniform torque 9. Torque not uniform.
10. Simple constructions. Less number of spare
parts needed
10. Complicated construction. More number of
spare parts needed.

91. Air vessels

92. Purposes of Air vessels
(i) The flow fluctuation is reduced and a
uniform flow is obtained.
(ii) The friction work is reduced.
(iii) The acceleration head is reduced
considerably.
(iv) Enables the use of higher speeds.

93. STEAM TURBINES
• A steam turbine is a mechanical device that
extracts thermal energy from pressurised
steam and converts it into useful mechanical
work.
• A steam turbine is a prime mover which
converts heat energy in the steam into
mechanical work.
• The main parts of a steam turbine are
nozzle, rotor and rotor blades

94. PRINCIPLE
• The enthalpy of the steam is first converted
into kinetic energy in nozzles.
• The high velocity steam impinges on the
curved blades and the direction of flow of
steam is changed.
• The change in flow direction of steam exerts
a force on the blades fixed on the rotor and
the rotor starts rotating producing power

95. Classification of steam turbines
• Impulse turbine
• Reaction turbine

96. Impulse turbine
• In impulse turbines, the steam coming out at
a very high velocity through the nozzle
impinges on the blades fixed on the
periphery of the rotor
• The blades change the direction of steam
flow without changing its pressure.
• The resulting force causes the rotation of
the turbine shaft.

97. Impulse turbine

98. Reaction turbine

99. Reaction turbine