this presentation covers principles of cooling system and different type of cooling system along with all the components and their functions

1. COOLING SYSTEM OF TRACTOR
Rashmi Bangale

2. Useful work
20%
Overcome friction
5%
Escaped through exhaust
gas
45%
Absorbed by cooling
system
28%
Overcome friction in
transmission
2%
FUEL ENERGY DISTRIBUTION IN THE ENGINE SYSTEM

3. Why 28 %
fuel energy
absorbed by
cooling
system??
???

4. High
Temperature
• Preignition
• Detonation
• Knocking
• Burning of piston
• Burning of valve
• Failure of lubrication
Low
Temperature
• Faster wear of parts
• More fuel consumption
• Condensation of water in
oil sump
Under
optimum
temperature
engine works
smoothly and
efficiently
Cooling
system
Best operating
temperature of
the engine lies
between 1400 to
2000 F

5. PURPOSE OF COOLING
 To maintain optimum temperature of engine for efficient
operation under all conditions.
To dissipate surplus heat for protection of engine
components like cylinder, cylinder head, piston, piston rings
and valves.
To maintain the lubricating property of the oil inside the
engine cylinder for normal functioning of the engine.

6. CLASSIFICATION OF COOLING SYSTEM
Cooling system
Air cooling
System
Water cooling
system
Thermo syphon
system
Impeller thermo
syphon system
Pump Circulation
system
Open system
Pressurized
system

7. AIR COOLING SYSTEM
• Air is made to come in contact with cylinder
block and head.
• This air takes away the excessive heat.
• Prerequisite of air cooling system
• More quantity of air
• More contact area

8. EFFICIENCY OF AIR COOLING SYSTEM
Area of fins
The speed and quantity of air touching the fins
Temperature of the engine
Fitting position of the engine
The conductivity of metal used for cylinder head and block

9. MAINTENANCE OF AIR COOLED ENGINE
• Keep fins of cylinder and head always clean of dust and oil
• Keep the ducts always properly positioned
• Keep the ducts always clean of dust and dirt
• Keep the blower belt always properly tensioned
• Ensure that there is no obstruction before the fan

10. ADVANTAGES OF AIR COOLED SYSTEM
• Engine weight is less as there is no radiator, water pump etc.
• Engine require less space
• It is simple in design and manufacturing as it is free from water jackets.
• Engine attains operating temperature quickly resulting in less wear of cylinder liner.
• Due to higher working temperature, fuel consumption and deposit of carbon are less.
• Air cooled engine can work efficiently if one or two fins are broken.
• Engine performance is good due to higher mean cylinder temperature.
• No topping of water
• No water freezing hazard in cold countries
• No maintenance of water pump, fan belt, hoses etc.

11. DISADVANTAGES OF AIR COOLING SYSTEM
• Air cooled engine produces more sound, as there is no water jacket to damp
down sound.
• The volumetric efficiency is less due to higher working temperature of cylinder
and head to cope up this big blowers or super charger are used.
• Air cooling is not suitable for multi cylinder engine as the air cannot reach all
parts effectively unless blowers are used.

12. WATER COOLING SYSTEM
Engines using water as a cooling medium is a water cooled engine.

13. THERMO SYPHON COOLING SYSTEM
Principle:
Water after getting heated up started
circulating by itself - water when heated up
becomes hot and light and the water at
top being cool and heavy settle down and
circulation starts.
Ex. Cooling system of Stationary Diesel Engine

14. Why thermosiphon system is not used in Automobile
engine?
For this system more quantity of water is required for that
heavy radiator is must.
Radiator should always remain filled up to its mouth otherwise
system will not work
Incase of damage or chocked hose pipe the complete system
will stop working.
For carrying more water and bigger radiator, dead weight of
vehicle increases.

15. IMPELLER THERMO SYPHON SYSTEM
 To reduce the volume and weight of radiator
and water in thermo syphon system, a fan is
placed behind the radiator so that small
radiator with less quantity of water in it could
be cooled with air current passing through it.
 Advantage: weight and volume were
reduced
 Disadvantage: keeping the radiator completely
full and also system will not work incase of
radiator hose chocking still persisted.
Not used in Automobile

16. PUMP CIRCULATION SYSTEM
 Most commonly used systems for cooling the
engine.
 In this system, a water pump is used which takes
its drive from the crankshaft, pumps water from
lower tank of radiator to the cylinder and cylinder
head through water jackets built around these.
 After having been moved around these hot areas
of the engine, hot water is pushed to the upper
tank of the radiator from where it drops down to the
lower tank of radiator through set of small pipes
known as radiator core.
 While it is being dropped, the air sucked by the fan
cools the pipes and water inside it.

18. COMPONENTS OF WATER COOLING SYSTEM
• Radiator
• Radiator cap
• Fan
• Water pump
• Thermostat
• Hoses
• Water
• Radiator Cowal or
Radiator shroud

19. RADIATOR
 It mostly fitted in front of the engine.
 Function: Radiates the heat in the water through the air
current passing around its tube.
 It is made light to reduce dead weight on vehicle, yet
strong enough to withstand road shocks.
 Parts of the radiator
 Upper tank
 Radiator core
 Lower tank

20. • UPPER TANK:
Material used: Copper sheet, mild steel tinned steel
Parts:
Mouth: used for filling the radiator
Leak off pipe: Rubber or nylon pipe is brazed with a small pipe on
mouth to remove steam and the extra water.
• LOWER TANK:
Material used: same material as Upper tank
It has an outlet pipe soldered to it for taking connection for water
pump.
Drain plug is also provided with lower tank.

21. • RADIATOR CORE
It consists of a number of small brass pipes fixed in the fins so that
cooling area could be increased.
It is attached to upper tank at top and lower tank at bottom.
Types of radiator core:
Tubular Type Pressed Tube Type Honey Comb Type/ Cellular type

22. RADIATOR CAP
• Two spring loaded valves fitted in one cap.
• Small valve is vacuum and bigger one is
pressure valve.
• Pressure valve opens when the pressure in
the system increases more than 0.35 kg/sq cm
and allows the pressure to drop to safe limit. It
is a safety valve and protects the system from
getting over pressurized.
• When we stop the engine, the water
temperature and pressure drops causing a
partial vacuum in the system. At this stage
vacuum valve opens and allows air to come in.

23. FAN
• Fan is fitted behind radiator- it can have 4, 5, 6
blades.
• Fan is fixed on water pump shaft.
• Two type of fans: Suction type fans and blower
type fans
• In automobiles, suction type of fans are used
where the fresh cool air is sucked in through the
radiator core. While it is being passed from the
fins, it takes the heat from the radiator core.

24. WATER PUMP
• Centrifugal type water pump having an
impeller fixed to pump shaft is mostly
used.
• Shaft gets drive through a pulley fixed on
it with the help of v-belt from crankshaft
pulley.
• To seal the water pump body, bellow
type of seal is used on the shaft.
New Holland 6610 Tractor Water Pump, with Single Groove Pulley

25. THERMOSTAT
• Thermostats are such valves which
operates with the change in temperature
and cut off the water supply to radiator
from block if the engine is cold.
• When the engine regains its operating
temperature, it restores the supply.
• It is designed to start open at 700 to 750C
and then fully open at 820 for petrol
engine and 88-900C for diesel engine
• Types of thermostat valves used in
automobiles
• Bellows type
• Bimetallic type
BELLOWS TYPE BIMETALLIC TYPE

26. HOSES
• To connect the vibrating engine
to fixed radiator flexible hoses
are used
• The hoses are kept tight with the
help of hose clips.

27. WATER
• Used as cooling medium.
• Use only clean soft water
• Hard and dirty water may lead to scale
formation resulting in overheating.

28. RADIATOR COWAL OR RADIATOR SHROUD
• Main purpose of radiator shroud is to
deflect sucked air and direct it over the
engine, so that this air can take away part
of the heat from the engine block.
• The approximate distance between fan
blade and shroud is 20 mm.

29. ADVANTAGES OF WATER COOLING SYSTEM
• As water is in direct contact with cylinder walls and cylinder head, it takes away
heat quickly
• The water circulates freely between freezing and boiling points.
• The availability of water in water jackets damp down sound of engine to some
extent.
• Engine working temperature can be controlled easily.
• Engine with water cooled system can be fitted in any position in the vehicle.

30. DISADVANTAGES OF WATER COOLING SYSTEM
• It increases dead weight of the vehicle.
• Radiator usually fitted in front of the vehicle. Due to its presence in front
slope on bonnet cannot be given to avoid wind resistance.
• Water in water cooled system freezes at zero degree temperature.
• Water boils and evaporates easily at 1000C.
• Water corrodes the metal parts in the system
• In case of careless handling of water cooled engine, engine may overheat
soon and seize.

31. MAINTENANCE
• Check up water in radiator if dirty flush the system.
• Check up V-belt if loose tension it properly, if worn out replace with new one.
• Check up hoses for sharp bends cuts or deterioration. In case of slightest doubt,
replace it.
• Check water leakage from hose pipe, clips, radiator core, radiator and engine
drain cock – plug the leakage.
• Check up leakage of water from water pump.
• Check up the fan blade angle, if slightly bent repair it otherwise replace with new
one,
• Clean the radiator core by air/water under pressure from fan side.
• Clean the block- remove dust and oil.
• Check up for any blockage of air before radiator.
• Check up radiator shrouds for proper fitting
• Check up radiator cap for proper fitting and pressure holding

32. REFERENCES
• Tractors and their power units by John B. Liljedahl and others
• Farm Machines and Equipment by C. P. Nakra
• Principles of Agricultural Engineering Vol-1 by T. P. Ojha and A. M. Michael
• Elements of Agricultural Engineering by Dr. Jagdishwar Sahay
• YouTube
• Google
• Other electronic media