DIFFERENCE B/W INTERNAL COMBUSTION(IC ENGINE) AND EXTERNAL COMBUSTION ENGINE(EC ENGINE)

IC Engine(internal combustion engine)	EC Engine(external combustion engine)
Combustion of fuel takes place inside engine cylinder.	Working fluid (steam) is produce in a boiler which is outside the power producing unit.
Higher thermal efficiency (35-40%)	Low thermal efficiency (10-15%)
The product of combustion after doing useful work is exhausted in the atmosphere.	The steam after doing useful work is rejected to a condenser where steam is reused.
Very easy to start as can be started simultaneously.A starting motor is used in automobiles.	First boiler has to be fired, then steam is raised and then steam engines are started.
Have  single acting cylinders	Have double acting cylinders Exception- atmospheric engines & beam engines
Advantages- power to weight ratio high,  Higher thermal efficiency, Less space required, Start instantly.	Advantages- low emission, Low noise and vibration, Potentially long life, Easy availability of fuel, Huge power generation.
Disadvantages – fuel used is very costly,  Exhaust gases are toxic, Not suitable for large scale power generation, An engine produces noises due to detonation or knocking.	Disadvantages- Leakage of working fluid, Size of engine is very big, Overall working temperature is high so Maintenance and spl. Building materials are required, Not suitable for low power requirements

               IC ENGINE                                                        EC ENGINE