A Heat engine is a device which transforms the
chemical energy of a fuel into
thermal energy and uses this energy to produce
mechanical work.
Heat engines are classified into two broad types:
* External Combustion(EC) Engines
* Internal Combustion(IC) Engines
In an external combustion engine, the products of combustion of air and fuel transfer
the heat generated to a
second fluid which is the working fluid of the cycle
( like water is for a steam engine, where the heat is used to generate steam from water,
which in turn is used to power the piston or a turbine).
Another good example of an External Combustion Engine is a
closed Cycle gas turbine
wherein the heat generated from a closed furnace is transferred to gas, usually air,
which is then used in the gas turbine.
In an Internal Combustion Engine, the products of combustion would directly move the piston of the engine.
Gasoline, Diesel, Wankel engines and
open gas turbines are all examples of an Internal Combustion Engine.
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Components of Engines
Stages in Engines
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Advantages of IC Engines over EC Engines
* The IC engines are generally simpler and offer much greater mechanical simplicity
compared to the EC engines.
* The IC engines have a lower weight -to-output ratio due to the absence of auxiliary units
like boilers and condensers that are required for an External Combustion Engine.
* The cost of manufacturing an IC engine is much lesser owing to the ease and standardization
in production and
* Higher overall efficiency in operations as compared to the EC Engines because most of it
is within the engine and not much energy produced is lost.
* EC engines cannot be used for smaller requirements like in transportation. But IC engines
can be used due to their compact size.
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For more details on 2-Stoke & 4-Stoke Engines, follow the link given below-
2-Stroke & 4-Stroke IC Engines