Why Engine Cooling System is important in any Vehicle?

 As we aware that every work producing system will produce heat.So it is necessary for the manufacturer to make sure that the heat produced should be controlled.So the first question that comes to our mind "why is engine cooling system needed?"

This task is accomplished by the Engine cooling system.As the work produced by engine is through the combustion of fuel. Out of which only 65-70 % is used and 30%-35% is lost as exhaust gases.The temperature of the gases being upto 500 degrees, Some of that heat gets transferred to the engine parts.If they get overheated it may reduce the life of the engine. So, engine life gets reduced.

After answering the first question in a simple way.. Let us see the "Types of Engine Cooling System"

They are basically classified into 2 types based on the type of Coolant used.

1. Air cooled system.
2. Water cooled system.

  1.  Air cooled System

As the name itself suggests the air is the cooling medium.As the cooling rate of this type of system is low it is used only for small capacity engines. The efficiency of  this type of engine can be improved by forced flow of air to the engine.

Its efficiency can also be increased by increasing the surface area and by providing Fins. These Fins will increase the heat transfer rate by 5-10 times the original value. It was used Air cooled aviation engine- continental C-85.

Water Cooled System:-In this type water is the cooling medium.It mainly has two types 

1. Natural Circulation System.
2. Forced Circulation System.
3. Cooling with Thermostatic Regulator

 1.Natural Circulation System: 

This is a passive heat exchange method in which heat exchange happens through natural convention and it does not use Mechanical pump. As you can see in the figure, the water is passed through the radiator, which is cooled by air which passes over radiator tubes via cooling fan. The cooled water is now raised to cylinder jacket,which takes the heat from cylinder wall. And this water is again entering the radiator head and the water is again cooled, and the process continues.The limitation is that the height of the Radiator should be above the engine to make sure natural circulation happens. This type of system was used in primitive models of cars.

2.Forced Circulation System:

The Natural circulation system was modified in this type.As you can see in the figure,

there is mechanical pump which overcomes the limitation of Natural circulation system.Even cooling happens in this type of cooling system. It can easily withstand load of engine. The limitation is that it may over cool the system as it is independent of temperatures.

3.Cooling With Thermostat Regulator: 

This is the important feature of the present day cars. It has an part called Thermostat. As you now that in forced circulation overcooling may happen to overcome that Thermostat is used.  Now the question arises..What is thermostat? It is a device whose task is to prevent the circulation of water through the radiator untill  the temperature about 75 degrees. 

By doing so, the engine gets warmer much more faster than usual rate. The main purpose of thermostat in cars is to regulate the flow of engine coolant to radiator.Coming to the arrangement of thermostat...It mainly has a valve attached to  bellow (flexible bag) which consists of volatile liquids. When this bellow is heated, the water vaporizes the  volatile liquid which expands the bellow which results in opening of valve. Thereby the cooling process happens.

You might have observed that if someone drives car for a long time, they pour water in the radiator tank it is to overcome the limitation that supply of water is necessary. I hope that this information has given a simple understanding on the engine cooling system and its importance.

Stay connected with this blog for further updates on bytes of information related to Automobile engineering..