1. APPLIED THERMAL ENGINEERING
Prof. kiran gore

2. Contents Power producing devices Boiler Internal combustion engine
Turbines
b) Power absorbing devices
Pump
Compressor
Refrigeration
Window air conditioner

3. Contents c) Power plant engineering
Conventional & non-conventional energy resources
Thermal power plant
Hydro-electric power plant
Nuclear power plant
Wind power plant
Solar power plant

4. Power producing devices
Boiler
Internal combustion engine
Turbines

5. Boiler or steam generator
*FUNCTION – It converts the water in to steam by application of heat energy.
*The heat energy required for generation of steam is produced by burning of fuel in closed furnace.

6. STEAM POWER PLANT

7. Classification of boiler
According to relative position of boiler
Fire Tube Boiler
Water Tube Boiler

8. Classification of boiler
B) According to water circulation arrangement
Natural circulation
Forced circulation
C) According to use
Stationary boilers
Mobile boilers

9. Classification of boiler
D) According to position of furnace
Internally fired
2)Externally fired
E) According to position of boiler
Horizontal boiler
Vertical boiler
Inclined boiler

10. Classification of boiler
F) According to pressure of steam generation
Low pressure boiler (15-20 bar)
Medium pressure boiler (20-80bar)
High pressure boiler ( more than 80 bar)
Super critical boiler (more than 150 bar)

11. Water Tube Boiler
Water is flowing through the tube which surrounded by hot combustion gases

12. Examples of Water Tube Boiler
Babcock-wilcox
Stirling & package boilers

13. Fire Tube Boiler
Hot combustion gases flow through tube which surrounded by water

14. Examples of Fire Tube Boiler
Cochron
Lancashire
Locomotive & package boiler

15. CRITERIA FOR SELECTION OF BOILER:
Floor area available
Rate of steam generation
Working pressure required
Quality of steam required
Fuel & water available
Repair , operating & maintains cost

16. Internal combustion engine

17. Classification of I.C. engine
According to number of stroke
Two stroke engine
Four stroke engine
b) According to cycle of combustion
Otto cycle engine
Diesel cycle engine
Dual cycle engine

18. Classification of I.C. engine
c) According to fuel used
Petrol engine
Gas engine
Diesel engine
d) According to method of ignition
S.I. engine
C.I. engine

19. Classification of I.C. engine
e) According cooling system
Air cooled engine
2.Water cooled engine

20. Classification of I.C. engine
f) According to speed of engine
Low speed engine
Medium speed engine
High speed engine

21. Classification of I.C. engine
g) According to arrangement of cylinder
Horizontal engine
2. Vertical engine
4. Radial engine
3. V-type engine

22. Classification of I.C. engine
h) According to number of cylinder
Single cylinder engine
2. Multicylinder engine

23. Classification of I.C. engine
I) According to their used
Stationary engine
Marine engine
Automobile engine
Aero engine

24. construction of I.C. engine
A. Parts common to both Petrol and Diesel engine: 1.Cylinder, 2.Cylinder head, 3. Piston, 4.Piston rings, 5.Gudgeon pin, 6.Connecting rod, 7.Crankshaft, 8.Crank, 9.Engine bearing, 10.Crank case. 11.Flywheel, 12.Governor, 13. Valves and valve operating mechanism.

25. B. Parts for Petrol engines only:
1.Spark plug,
2. Carburetor,
C. Parts for Diesel engine only :
1. Fuel pump,
2. Injector.

26. Parts of I.C. engine
Cylinder
Piston

27. Cylinder
It is heart of the engine, in which the piston reciprocates (moves to and fro) in order to develop power. It is made of C.I.
Piston
It is reciprocating member of an I.C. engine. Main function is to transmit the force exerted by the burning of charge to the connecting rod. The piston are generally made of aluminum alloys which are light in weight.

28. Parts of I.C. engine
Piston Ring
Piston

29. Piston Ring
Generally, there are two sets of rings mounted for the piston.
The function of the upper rings is to provide air tight seal to prevent leakage of the burnt gases into the lower portion.
Similarly, the function of the lower rings is to provide effective seal to prevent leakage of the oil into the engine cylinder

30. Cylinder head
Fuel Injector
Cylinder Head

31. Cylinder head
It is fitted on one end of the cylinder, while other end is open to crank case.
The cylinder head contains inlet and exit valves for admitting fresh charge and exhausting the burnt gases

32. Connecting Rod
Gudgeon Pin
Connecting Rod
Crank-Shaft

33. Connecting Rod It is a link between the piston and crankshaft.
whose main function is to transmit force from the piston to the crankshaft.
Moreover, it converts reciprocating motion of the piston into circular motion of the crankshaft.

34. Gudgeon Pin Gudgeon pin is used to connect piston and connecting rod

35. Crank & crank shaft
Crank-Shaft

36. Crank shaft It is considered as the backbone of an I.C. engine.
The power developed by the engine is transmitted outside by this shaft.

37. Valves
Inlet valve
Exhaust valve
Cam-Shafts
Valve Spring

38. Valves
Inlet valve
Exhaust valve

39. Valves Inlet valve Exhaust valve Exhaust Cam & Valve Inlet Cam & Valve
Spring
Inlet Passage
Exhaust Passage

40. Valves – Two types of valves are used in I.C engine
1) Inlet valve :- This valve is used to admit charge into cylinders.
2) Outlet valve :- This valve is used to remove exhaust gases from the cylinder.

41. Flywheel
Crank-Shaft

42. Flywheel It is a big wheel, mounted on the crankshaft.
It is done by storing excess energy during power stroke, which is returned during other stroke.

43. Parts for Petrol engines only
carburetor

44. Carburetor
– Main function of carburetor is to supply limited quantity of fuel to engine

45. Parts for Petrol engines only
Spark plug

46. Spark plug It is provided on petrol engine.
Main function is ignite air fuel mixture by producing spark at the end of compression stroke

47. Parts for diesel engines only
Fuel Injector
Nozzle tip with several small holes for fuel spray

48. Fuel Injector It is provided on Diesel Engine.
Its function is to inject diesel at the end of compression stroke at very high pressure

49. Parts for diesel engines only
Fuel pump
It is used in diesel engine
It forces the fuel at high pressure through fuel injector in to the cylinder at the end of compression stroke.

50. i.C engine terminology

51. 1.Bore
The inside diameter of the cylinder is called bore.

52. 2. Top dead centre (TDC)
The top most position of piston towards the cylinder head is called “top dead centre”.

53. 3. Bottom dead centre (BDC)
The Lowest position of piston towards the crank case is called “bottom dead centre”.

54. 4.Stroke
The maximum distance travel by the piston during its motion from TDC to BDC is called stroke.

55. 5. Clearance volume
The volume contained in the cylinder above the top of the piston, when the piston is at top dead centre, is called the clearance volume.

56. Four Stroke petrol Engine (S.I. Engine)
The four strokes of a internal combustion engine are:
Intake
Compression
Power
Exhaust
Each stroke = 180˚ of
crankshaft revolution.
Each cycle requires two revolutions
of the crankshaft (720˚ rotation), and
one revolution of the camshaft to complete (360˚ rotation).

57. Intake Stroke First Stroke The piston moves down the cylinder
from TDC (Top Dead Center) to BDC
(Bottom Dead Center).
This movement of piston causes low
air pressure in the cylinder (vacuum)
Mixture of Air and Fuel in the ratio
of 14.7 : 1 (air : fuel) is drawn into
the cylinder.
Intake valve stays open and the
Exhaust valve stays closed during
this stroke.

58. Compression stroke Second stroke The piston moves from BDC to TDC
Intake and exhaust valves stay closed
Air and fuel mixture is compressed
8:1 to 12:1
The pressure in the cylinder is raised

59. Power stroke Third stroke At the end of compression stroke
the sparkplug fires, igniting the air/fuel mixture.
Both the valves stay closed in
this stroke.
The expanding gases from the
combustion in the cylinder
(with no escape) push the piston
down.
The piston travels from TDC to BDC.

60. Exhaust stroke Fourth and last stroke The momentum created by the
Counter-weights on the crankshaft,
move the piston from BDC to TDC.
The exhaust valve opens and
the burned gases escape into the
exhaust system.
Intake valve remains closed.

61. Four strokes
All four strokes
Suction
Compression
Power
Exhaust

62. Four Stroke Diesel Engine (C.I. Engine)
The only difference between diesel engine and a four-stroke gasoline engine is:
No sparkplug on Diesel engine.
Has a higher compression ratio(14:1 to 25:1)
Better fuel mileage.

63. Diesel Engine Intake Stroke:
Piston moves from TDC to BDC creating vacuum in the cylinder
Intake valve opens allowing only air to enter the cylinder and exhaust valve remains closed

64. Diesel Engine Compression Stroke Both valves stay closed
Piston moves from BDC to TDC,
compressing air to 22:1
Compressing the air to this extent
increases the temperature inside the
cylinder to above 1000 degree F.

65. Diesel Engine Power Stroke Both valves stay closed
When the piston is at the end of
compression stroke(TDC) the injector
sprays a mist of diesel fuel into the
cylinder.
When hot air mixes with diesel fuel
an explosion takes place in the cylinder.
Expanding gases push the piston
from TDC to BDC

66. Diesel Engine Exhaust Stroke Piston moves from BDC to TDC
Exhaust valve opens and the
exhaust gases escape
Intake valve remains closed

67. Diesel Engine Operation
Stroke 3 (power) diesel is injected, high air temperature ignites diesel.
Stroke 1 (intake) only air enters cylinder.
Stroke 2 (compression) air is compressed to high extent, raising its temperature.
Stroke 4 (exhaust) burnt gases are expelled from the engine.

68. Diesel Engine
Four Strokes of Diesel Engine

69. Operation of two-stroke engine
The two stroke engine employs the crankcase as
well as the cylinder to achieve all the elements of
the cycle in only two strokes of the piston.
360 degrees rotation of crankshaft
completes the cycle.

70. Intake & Compression stroke
Intake.  The fuel/air mixture is first drawn into the crankcase by the vacuum created during the upward stroke of the piston through the reed valve.
Compression. The piston then rises, driven by flywheel momentum, and compresses the fuel mixture.  (At the same time, another intake stroke is happening beneath the piston).  

71. Power & Exhaust/Transfer Stroke
Power. At the top of the stroke the
spark plug ignites the fuel mixture.
The burning fuel expands, driving
the piston downward.
Exhaust/Transfer : Toward the end of the stroke,
the piston exposes the intake port, allowing the
compressed fuel/air mixture in the crankcase to
escape around the piston into the main cylinder. 
This expels the exhaust gasses out the exhaust
port, usually located on the opposite side of the
cylinder. 

72. Operation of Two-stroke engine

73. Operation of Two-stroke engine

74. PETROL ENGINE (S.I. ENGINE) DIESEL ENGINE (C.I. ENGINE)
Sr. no.
PETROL ENGINE (S.I. ENGINE)
DIESEL ENGINE (C.I. ENGINE) 01
Based on Otto cycle
Based on diesel cycle 02
Petrol used as fuel.
Diesel used as fuel . 03
For ignition Spark plug is required.
Spark plug is not required. 04
In these engine, air – fuel mixture is sucked during suction stroke.
In these engine, only air is sucked during suction stroke.

75. PETROL ENGINE (S.I. ENGINE) DIESEL ENGINE (C.I. ENGINE)
Sr. no.
PETROL ENGINE (S.I. ENGINE)
DIESEL ENGINE (C.I. ENGINE) 05
Compression ratio is low (about 6 to 12)
Compression ratio is high (about 14 to 22) 06
Light in weight.
Heavier in weight. 07
Due to light in weight threes engines can rotate at high speed.
Due to heavy in weight threes engines can not rotate at high speed 08
The operation of these engine is silent
The operation of these engine is noisy. 09
Initial cost is low.
Initial cost is high. 10
These engines are used in light duty vehicle like motor cycle, scooters, cars etc.
These engines are used heavy duty vehicle like buses, trucks etc.

76. One power stroke is obtained in each revolution of crank shaft.
SR. NO.
TWO STRKE ENGINE
FOUR STROKE ENGINE 1
The cycle is completed in two stroke of piston or one revolution of crank shaft.
The cycle is completed in four stroke of piston or two revolution of crank shaft. 02
One power stroke is obtained in each revolution of crank shaft.
One power stroke is obtained in every two revolution of crank shaft 03
2- stroke engine have port mechanism.
4- stroke engine have valve mechanism. 04
The piston head has crown shape.
The piston head is flat.

77. Construction is simple. Construction is complicated.
SR. NO.
TWO STRKE ENGINE
FOUR STROKE ENGINE 05
Engine is lighter.
Engine is heavier. 06
Construction is simple.
Construction is complicated. 07
Initial cost is less.
Initial cost is high. 08
Efficiency is low
Efficiency is high.

78. Two-stroke engines have three important advantages over four-stroke engines:
Two-stroke engines do not have valves, which simplifies their construction and lowers their weight.
Two-stroke engines fire once every revolution, while four-stroke engines fire once every other revolution. This gives two-stroke engines a significant power boost.
Two-stroke engines can work in any orientation, which can be important in something like a chainsaw. A standard four-stroke engine may have problems with oil flow unless it is upright, and solving this problem can add complexity to the engine.

79. Two Stroke Advantages
These advantages make two-stroke engines lighter, simpler and less expensive to manufacture.
Two-stroke engines also have the potential to pack about twice the power into the same space because there are twice as many power strokes per revolution.
The combination of light weight and twice the power gives two-stroke engines a great power-to-weight ratio compared to many four-stroke engine designs.
You don't normally see two-stroke engines in cars, however. That's because two-stroke engines have a couple of significant disadvantages that will make more sense once we look at how it operates.

80. You can see that the piston is really doing three different things in a two-stroke engine:
On one side of the piston is the combustion chamber, where the piston is compressing the air/fuel mixture and capturing the energy released by the ignition of the fuel.
On the other side of the piston is the crankcase, where the piston is creating a vacuum to suck in air/fuel from the carburetor through the reed valve and then pressurizing the crankcase so that air/fuel is forced into the combustion chamber.
Meanwhile, the sides of the piston are acting like valves, covering and uncovering the intake and exhaust ports drilled into the side of the cylinder wall.

81. Oil Requirements
It's really pretty neat to see the piston doing so many different things! That's what makes two-stroke engines so simple and lightweight.
If you have ever used a two-stroke engine, you know that you have to mix special two-stroke oil in with the gasoline.

82. Now that you understand the two-stroke cycle you can see why.
In a four-stroke engine, the crankcase is completely separate from the combustion chamber, so you can fill the crankcase with heavy oil to lubricate the crankshaft bearings, the bearings on either end of the piston's connecting rod and the cylinder wall.
In a two-stroke engine, on the other hand, the crankcase is serving as a pressurization chamber to force air/fuel into the cylinder, so it can't hold a thick oil. Instead, you mix oil in with the gas to lubricate the crankshaft, connecting rod and cylinder walls.
If you forget to mix in the oil, the engine isn't going to last very long!

83. Two-Strokes Usage
You can now see that two-stroke engines have two important advantages over four-stroke engines: They are simpler and lighter, and they produce about twice as much power. So why do cars and trucks use four-stroke engines?

84. There are four main reasons:
Two-stroke engines don't last nearly as long as four-stroke engines. The lack of a dedicated lubrication system means that the parts of a two-stroke engine wear a lot faster.
Two-stroke oil is expensive, and you need about 4 ounces of it per gallon of gas. You would burn about a gallon of oil every 1,000 miles if you used a two-stroke engine in a car.
Two-stroke engines do not use fuel efficiently, so you would get fewer miles per gallon.
Two-stroke engines produce a lot of pollution -- so much, in fact, that it is likely that you won't see them around too much longer. The pollution comes from two sources. The first is the combustion of the oil. The oil makes all two-stroke engines smoky to some extent, and a badly worn two-stroke engine can emit huge clouds of oily smoke.