Diesel power plant: layout, components – Gas turbine power plant: open and closed cycles, gas turbine plant improvisation methods – Combined cycle power plants – Integrated gasifier based combined cycle systems.

1. UNIT-II
DIESEL, GAS TURBINE
AND COMBINED CYCLE
POWER PLANT

2. UNIT II DIESEL, GAS TURBINE AND
COMBINED CYCLE POWER PLANT
• Diesel power plant: layout,
components – Gas turbine power
plant: open and closed cycles, gas
turbine plant improvisation methods
– Combined cycle power plants –
Integrated gasifier based combined
cycle systems.

3. DIESEL POWER PLANT

5. Layout of Diesel Power Plant

6. Components of Diesel Power Plant
• Engine
• Air intake system
• Exhaust system
• Fuel system
• Cooling system
• Lubrication System

7. Engine

8. Air intake system

9. Exhaust system

10. Fuel system
Fuel Storage
Fuel Injection System
Common Rail
Individual Pump Injection
Distributor
Fuel Pump
Fuel Injector

11. Fuel Storage

12. TYPES OF FUELINJECTIONSYSTEM
Common rail injection system
Individual pump injection system
Distributor system

13. Common Rail injection system
Fuel Injection System

15. Fuel Injection System
Individual Pump Injection

16. Fuel Injection System
Rotary Distributor system

17. CAV Fuel Injection Pump

18. FUEL INJECTOR

19. Fuel Injector

20. Types of Lubrication System
There are three types of lubrication system
used in I.C. Engine:
 Wet sump
 Dry sump
 Mist lubrication

21. Lubrication allows
• Reduce friction (rubbing or deformation)
• Prevent pieces from wear
• Absorb/reduce shocks
• Protect from corrosion
• Isolate components from contamination
• Clean/get rid of contaminants.

22. Purpose of Lubrication System
• Reducing the friction: The primary function
of the lubrication is to reduce the friction
and wear and tear of the two rubbing parts.
• Cooling effect: The heat is generated by
piston, cylinder and bearings is removed by
lubricant to a great extent. Lubrication
creates cooling effect on the engine parts
and acts as coolant

23. Purpose of Lubrication System
• Sealing effect: The lubricant enters into
the gap between the cylinder liner, piston
and piston rings. Thus it acts as a seal
preventing the leakage of the gas.
• Cleaning effect: Lubrication keeps the
engine parts clean by removing dirt or
carbon from inside the engine

24. Wet Sump Lubrication System:
• The wet sump lubrication system, the lubricating oil
is drawn from the engine sump which contains the
oil. The oil is placed in the sump and it is drawn by
pump through the strainer. The sump contains the
lubricating oil and supplies continuously to system

25. There are three types of wet sump
lubrication systems used as below:
• (i) Splash lubrication system
• (ii) Pressure lubrication system
• (iii) Semi Pressure lubrication system

26. SPLASH LUBRICATION SYSTEM

27. Pressure lubrication system

28. Semi Pressure lubrication system

29. Dry sump lubrication system
In this system, the engine sump remains dry and the oil is placed in
the tank near to the sump. The oil is drawn from the tank and
supplied by pump to the lubrication system

30. COOLING SYSTEM
The cooling system serves three important
functions.
• First, it removes excess heat from the engine
• Second, it maintains the engine operating
temperature where it works most efficiently
• Finally, it brings the engine up to the right
operating temperature as quickly as possible

31. NECESSITY OF COOLING SYSTEM
The cooling system is provided in the IC engine for the
following reasons:
 The temperature of the burning gases in the engine cylinder reaches up to
1500 to 2000°C, which is above the melting point of the material of the
cylinder body and head of the engine. (Platinum, a metal which has one of
the highest melting points, melts at 1750 °C, iron at 1530°C and aluminium
at 657°C.) Therefore, if the heat is not dissipated, it would result in the
failure of the cylinder material.
 Due to very high temperatures, the film of the lubricating oil will get
oxidized, thus producing carbon deposits on the surface. This will result in
piston seizure.
 Due to overheating, large temperature differences may lead to a
distortion of the engine components due to the thermal stresses set up.
This makes it necessary for, the temperature variation to be kept to a
minimum.
 Higher temperatures also lower the volumetric efficiency of the engine.

32. TYPES OF COOLING SYSTEM
There are two types of cooling systems:
(i) Air cooling system and
(ii) Water-cooling system.

33. Cooling system
Air Cooling
Liquid Cooling
Thermosyphon Cooling
Forced or Pump Cooling
Cooling with thermostatic regulator
Pressurized Water Cooling
Evaporative Cooling

34. Thermosyphon Cooling

35. • Forced or Pump Cooling
Liquid Cooling
• Thermosyphon Cooling

36. Liquid Cooling
• Cooling with thermostatic regulator
A thermostat valve is used in the water cooling system to regulate the circulation of water in system to
maintain the normal working temperature of the engine parts during the operating conditions.

37. Liquid Cooling
• Pressurized Water Cooling
• Evaporative Cooling

38. Exhaust system

39. GAS TURBINE POWER PLANT

40. Open Cycle Gas Turbine Power Plant

41. Open cycle gas turbine
• The most basic gas turbine unit is one operating on the
basis of open cycle in which a rotary compressor and
turbine are mounted on a common shaft.
• Air is drawn from the atmosphere into the compressor
and it is compressed to a pressure of 300 to 400
kN/m².
• The compressed air is then entered into the
combustion chamber where the energy is supplied by
spraying the fuel into the air and it is ignited to
produce hot gases.
• The hot gases expand through the turbine to produce
the mechanical power. Then, the burnt gases are
exhausted to the atmosphere.

42. Closed Cycle Gas Turbine Power Plant

43. Closed cycle gas turbine
• In a closed cycle gas turbine, the air is
isentropically compressed in air compressor to a
required pressure and then it is passes through a
combustion chamber where the fuel injects to
the air and ignited.
• The high temperature air from combustion
chamber expands through a gas turbine where
the heat energy is converted into mechanical
energy.
• Then, the exhaust gas from the gas turbine is
passed through a pre-cooler where it is cooled at
constant pressure with the help of circulating
water to its original pressure.

44. COMBINED POWER CYCLES
• The maximum steam temperature in a power
cycle exceeds 600°C but the pulverized coal
furnace temperature is about 1300°C.
• So, there is a lot of energy wasted in the power
plant.
• To increase the efficiency and reduce the
fuel consumption, the combined power
cycles are introduced by superimposing a
high temperature power plant as a topping unit
and the low temperature power plant as a
bottoming unit.

45. COMBINED POWER CYCLES
1.Gas turbine-steam turbine
power plant
2.MHD-Thermionic steam
power plant
3.Thermo electric-steam
power plant
4.MHD-steam power plant

46. Improvisation of Gas Turbine Power
Plant
Intercooler
Regenerator
Re-heater

47. GAS TURBINE WITH INTER COOLING

48. GAS TURBINE WITH REGENERATION

49. GAS TURBINE WITH REHEATER

50. GAS TURBINE WITH INTER COOLER, REHEATER & REGENERATION

51. COMBINED POWER PLANT

52. Types of Combined Power Cycles
• Gas Turbine – Steam Turbine
• Thermionic – Steam Power Plant
• Thermo Electric – Steam Power Plant
• M.H.D – Steam Power Plant
• Nuclear – Steam Combined Power Plant

53. Gas Turbine – Steam Turbine Plant

54. Thermionic – Steam Power Plant

55. Thermo Electric – Steam Power Plant

57. MHD– Steam Combined Power Plant

58. Nuclear – Steam Combined Power
Plant

59. Integrated Gasification Combined
Cycle

60. INTEGRATED GASIFICATION
COMBINED CYCLE (IGCC)

61. • Gasification of coal is the cleanest way
of utilizing the coal for the combined cycle
power generation towards the highest
efficiency.
• The integration of gasification combined
cycle permits the power plant for very low
emissions and efficiencies of the order
of 44-48%.
• In this cycle, a gas turbine is driven by the
combusted syngas from the gasifier and
the exhaust gases exchange its heat to
wet or dry steam to generate the

62. The coal is gasified in a gasifier in the
presence of steam and oxygen.
The fuel gas is composed of hydrogen and
carbon monoxide.
The fuel gas is cleaned to remove
impurities and it is expanded in a gas
turbine to produce electricity.
At the same time, by-products are formed
such as carbon dioxide and water vapour.
The waste heat from the gasification
process is utilized to generate steam
which drives a steam turbine for further

63. Construction of IGCC
(1) ASU (Air Separation Unit):
• ASU supplies oxygen and steam required for
gasification.
(2) Gasification system:
• This unit has a coal gasifier where the conversion
of solid fuel into combustible syngas takes place.
(3) Gas clean-up:
• It filters the impurities in syngas.
(4) Combined power block:
• It consists of a steam turbine and gas turbine for
power production.

64. First, coal is gasified either partially or fully in a
gasifier.
 Here, the coal and limestone are fed and the
coal is gasified by oxygen and steam.
The synthetic gas is produced. Then, it is
cleaned.
The ash and limestone are formed unwanted
waste which is removed as a molten slag by
discharging it.
In the combustion chamber, the synthetic gas is
burnt by using natural gas as fuel.
The synthetic gas is expanded in the gas
turbine.
The exhaust gas from gas turbine is recovered

65. Advantages
(i) Higher efficiencies and lower emissions
are produced.
(ii) Improvements in efficiency ultimately
reduce emissions from coal combustion.
Increasing the efficiency from 35% to 40%
reduces carbon dioxide emissions by over
10%.
(iii) IGCC power plants use less coal than
conventional power plants.
(iv) It increases the process temperatures

66. Thank
you