The document discusses engine cooling systems. It explains that only 20% of the engine's heat is used to power the crankshaft, with 35% transmitted to the cylinder walls, causing inefficiencies. Cooling systems must remove this excess heat to prevent damage. It describes air and liquid cooling systems. Air cooling relies on fins and fans for heat dissipation but has limitations with many cylinders. Liquid cooling uses water jackets and a cooling system involving a water pump, radiator, thermostat, and antifreeze solution to efficiently cool the engine.

1. ENGINE COOLING

2. NEED FOR COOLING
ONLY ABOUT 20% OF HEAT IS USED AS
POWER AT CRANK SHAFT
35% OF HEAT IS TRASMITTED TO THE
CYLINDER WALLS WHICH CONSTITUTES
POWER LOSS
THE HEAT SHOULD BE PREVENTED FROM
BEING TRANSFERRED TO CYLINDER
WALLS AS IT CAUSES PREIGNITION OF
CHARGE

3. LUBRICANT MIGHT ALSO BE BURNED
BECAUSE OF EXCESSIVE HEAT
THE BURNING OF LUBRICANT LEAD TO
SEIZURE OF THE PISTON
WHILE ENGINE IS RUNNING HEAT MUST BE
REMOVED CONTINOUSLY FROM THE ENGINE

4. TYPES OF COOLING
 DIRECT COOLING OR COOLING BY AIR
INDIRECT COOLING OR LIQUID
COOLING

5. AIR COOLING
Air cooling is a method of dissipating
heat
It works by making the object to be
cooled have a larger surface area or have
an increased flow of air over its surface,
or both.

6. An example of the former is to add fins to
the surface of the object, either by making
them integral or by attaching them tightly to
the object's surface (to ensure efficient heat
transfer).
In the case of the latter it is done by using a
fan blowing air into or onto the object one
wants to cool.

7. In many cases the addition of fins adds to the
total surface area making a heatsink that
makes for greater efficiency in cooling.
In all cases, the air has to be cooler than the
object or surface from which it is expected to
remove heat.

10. ADVANTAGES
NO NEED OF RADIATOR COOLANT AND
WATER PUMP
LESS WEIGHT AND LOW COST
IN DESERTS AIR COOLING IS THE
PREFFERABLE METHOD
IN COLD COUNTRIES AIR COOLING IS
UTILIZED FOR THE VEHICLES AS WATER
FREEZES INSIDE THE SYSTEM

11. DISADVANTAGES
The cooling tends to be uneven and
leads to cylinder distortion. Even though
this has been remedied by placing the
fins in a different manner, it is a problem
nonetheless.
It is almost impossible to manage with
air-cooling if the number of cylinders
increases beyond two.
The fins vibrate sometimes leading
to a lot of noise

12. LIQUID COOLING
IN WATER COOLING SYSTEMS, WATER
JACKETS ARE PROVIDED IN THE
CYLINDER BLOCK AND THE CYLINDER
HEAD.
WATER FILLS UP THESE JACKETS AND
THE HEAT IS TRANSFERRED TO THE
WATER IN THE WATER JACKETS THUS
COOLING THE CYLINDER

13. TYPES OF LIQUID COOLING
SYSTEMS
THERMOSIPHON SYSTEM
PUMP COOLING

14. THERMOSIPHON SYSTEM
 Thermosiphon refers to a method of passive heat
exchange based on natural convection which
circulates liquid without the necessity of a
mechanical pump.
 Its intended purpose is to simplify the pumping of
liquid and/or heat transfer ,by avoiding the cost and
complexity of a conventional liquid pump

16. PUMP COOLING SYSTEM
 A water pump is an important part of the engine
cooling system. It provides circulation of the
engine coolant (antifreeze) through the cooling
system.
 A water pump pushes the coolant through the
passages (water jackets) in the engine cylinder
block and cylinder head and then out into the
radiator.
 This helps to keep the engine from overheating;
the hot coolant passes through the radiator
where it cools down and then returns back to the
engine.

19. Water pump problems
Typical water pump problems include
coolant leaks, noisy or defective bearing,
damaged or corroded impeller.
Faulty water pump might cause the
engine to overheat, which can result in
serious engine damage. If defective, a
water pump is replaced as a unit.

20. THERMOSTAT
 -Any liquid-cooled car engine has a small
device called the thermostat that sits
between the engine and the radiator
 Its job is to block the flow of coolant to the
radiator until the engine has warmed up.
 When the engine is cold, no coolant flows
through the engine. Once the engine reaches
its operating temperature (generally about 95
degrees C), the thermostat opens.
 By letting the engine warm up as quickly as
possible, the thermostat reduces engine wear,
deposits and emissions.

22. RADIATOR
 -A radiator is a type of heat exchanger.
 It is designed to transfer heat from the hot
coolant that flows through it to the air blown
through it by the fan.
 These radiators are made by brazing thin
aluminum fins to flattened aluminum tubes.
 The coolant flows from the inlet to the outlet
through many tubes mounted in a parallel
arrangement. The fins conduct the heat from
the tubes and transfer it to the air flowing
through the radiator.

25. RADIATOR CAP
 It keeps the cooling system sealed from
outside contaminants.
By keeping pressure on the cooling
system, it raises the boiling point.
It contains pressure valve and the
vaccum valve.

27. ANTI FREEZE SOLUTION
 A fluid, such as methanol or ethylene glycol,
which is added to vehicle engine coolant or
used in solar heating system heat transfer
fluids, to protect the system from freezing.
 The expansion of water exerts high pressure
inside the cooling system and causes serious
damage to the pipe in the cooling system

28. SCALES AND CORROSION
 Scale formation and corrosion or rust are the
most common problems encountered in the
cooling systems of engines
 The composition of the water used for cooling
leads to scale formation
 The impurities present in water combine with
air sucked into the cooling systemthrough the
water pump to produce rust.

29. CORROSION AND SCALE
PREVENTION
 A special rust inhibitor is addedwith water in
the cooling system to prevent the formation
of rust.
 Alkalies and acids are added to prevent scale
formation.
 Kerosene and alkalies like washing soda
reduce oil or grease in the cooling system.

30. THANK YOU