What is cooling system? - Some other methods of cooling - Air cooling - Water cooling - Liquid cooling

If we want to make a cooling system, we have to distribute fuel for some necessities like loss in friction, loss in exhaust gases, loss to the cylinder walls and useful work at the crankshaft. However, cooling beyond optimum limits is not desirable, because it decreases the overall efficiency due to the following reasons:

Thermal efficiency is decreased due to more loss of heat to the cylinder walls.

The vaporization of the fuel is less; this results in a fall in combustion efficiency.

Low temperatures increase the viscosity of lubricant and hence more piston friction is encountered, thus decreasing the mechanical efficiency.

Some other methods of cooling

Air cooling

Water cooling

Liquid cooling

Air cooling

The basic principle involved in this method is to have a current of air flowing continuously over the heated metal surface from where the heat is to be removed. The heat dissipated depends upon some factors.

Air-cooled engines are lighter because of the absence of the radiator, the cooling jackets and the coolant. They can be operated in extreme climates, where the water may freeze. In certain areas where there is a scarcity of cooling water, the air-cooled engine is an advantage. Air-cooled engines get warmed up earlier than the water-cooled engines.

Water cooling

In a water cooling system, the cylinders of the engine are surrounded by water jackets through which the cooling water flows. Heat flows from the cylinder walls into water which goes to the radiator where it loses its heat to the air.

Liquid cooling

        Sometimes instead of water, other liquids having higher boiling points are used for engine cooling. Examples are glycerin and ethylene glycerol. A higher boiling point increases the capacity of the liquid to carry heat and consequently weight of the coolant and hence that of the radiator is decreased.