25 March 2018

What is engine cooling system

In the engine during the process of converting thermal energy into mechanical energy, the high temperatures are produced in the cylinders of the engine as a result of the combustion process. A large portion of the heat from the gases is transferred to the cylinder head and walls, piston and valves. These parts are damaged and the engine will also be damaged unless heat is carried away so the adequate cooling must be required. 

A cooling system must be provided not only to prevent damage to the vital parts of the engine, but the temperature of these components must be maintained within certain limits in order to obtain maximum performance from the engine. Hence, a cooling system is needed to keep the engine from not getting so hot as to cause problems and yet to permit it to run hot enough to ensure maximum efficiency of the engine. 

The function of the cooling system :

The cooling system keeps the engine from getting not too hot but at the same time not to keep it too cool either. 

Characteristics of an efficient cooling system :
  • It should be capable of removing about 30% of the heat generated in the combustion chamber while maintaining the optimum temperature of the engine under all operating conditions of the engine. 
  • It should remove heat at a faster rate when the engine is hot. 
  • During the starting of the engine, the cooling should be minimum so that the working parts of the engine reach their operating temperatures in a short time. 
Types of the cooling system :

For cooling the engine a cooling medium is required. This can be either air or a liquid. 

According to that two types of the cooling system :
  1. Liquid or Indirect cooling system 
  2. Air or Direct cooling system 
In the liquid cooling system, there are five methods to cooled the engine. All five are listed below.
  1. Direct or non-return system 
  2. Thermosyphon system 
  3. Forced circulating cooling system 
  4. Evaporative cooling system 
  5. Pressure cooling system 
In the air cooling system, there are two methods to cooled the engine. These are listed below.
  1. Cooling fins 
  2. Baffles