Types of Engine:
Any
device which can convert heat energy of fuel into mechanical energy is known as
engine or heat engine.
Engine
is widely used in automobile industries or we can say that engine is the heart
of an automobile.
Basically
engines are classified into 2 types
- External Combustion Engines &
- Internal Combustion Engines
1. External combustion (E.C.) Engine
It is an engine in which combustion of fuel take place outside of the
engine.
In this type of engine, the heat which is generated by burning of fuel is
use to convert the water or other low boiling temperature fluid into steam.
This high pressure steam used to rotate a turbine.
In this engine we can use all solid, liquid and gases fuel.
These engines are generally used in driving locomotive, ships, generation
of electric power etc.
Advantages of E.C. engine:
- In these engines starting torque is generally high.
- Because of external combustion we can use cheaper fuels as well as solid fuel.
- They are more flexible compare to internal combustion engines.
2. Internal Combustion (I.C.) Engine
It is an engine in which combustion of fuel take place inside the engine.
When the fuel burns inside the engine cylinder, it generates a high
temperature and pressure.
This high pressure force is exerted on the piston (A device which is free
to move inside the cylinder and transmit the pressure force to crank by use of
connecting rod), which used to rotate the wheels of vehicle.
In these engines we can use only gases and high volatile fuel like
petrol, diesel.
These engines are generally used in automobile industries, generation of
electric power etc.
Advantages of I.C. engine:
- It has overall high efficiency over E.C. engine.
- These engines are compact and required less space.
- Initial cost of I.C. engine is lower than E.C. engine.
- This engine easily starts in cold because of it uses high volatile fuel.
Types of I.C. Engine
*I.C. engine is widely used in automobile industries so it is also known as
automobile engine.
An automobile engine may be classified in many manners.
According to number of stroke:
1. Two stroke engine
In a
two stroke engine a piston moves one time up and down inside the cylinder and
complete one crankshaft revolution during single time of fuel burn.
This
type of engine has high torque compare to four stroke engine.
These
are generally used in scooters, pumping sets etc.
2. Four stroke engine
In a
four stroke engine piston moves two times up and down inside the cylinder and
complete two crankshaft revolutions during single time of fuel burn.
This
type of engines has high average compare to two stroke engine.
These
are generally used in bikes, cars, truck etc.
According to design of engine:
1. Reciprocating engine (piston engine)
In
reciprocating engine the pressure force generate by combustion of fuel is
exerted on the piston.
So the
piston starts reciprocating motion (to and fro motion).
This
reciprocating motion converts into rotary motion by use of crank shaft.
So the
crank shaft starts to rotate and rotate the wheels of vehicle.
These
are generally used in all automobile.
2. Rotary engine (Wankel engine)
In
rotary engine there is a rotor which frees to rotate.
The
pressure force generate by burning of fuel is exerted on this rotor so the
rotor rotate and starts to rotate the wheels of vehicle.
This
engine is developed by Wankel in 1957.
This
engine is not used in automobile in present days.
According to fuel used:
1. Diesel engine
These engines use diesel as the fuel.
These are used in trucks, buses, cars etc.
2. Petrol engine
These engines use petrol as the fuel.
These are used in bikes, sport cars, luxury cars etc.
3. Gas engine
These engines use CNG and LPG as the fuel.
These are used in some light motor vehicles.
4. Electric engine
It is eco-friendly engine.
It doesn’t use any fuel to burn.
It uses electric energy to rotate wheel.
According to method of ignition:
1. Compression ignition engine
In these types of engines, there is no extra equipment to burn the fuel.
In these engines burning of fuel starts due to temperature rise during
compression of air.
So it is known as compression ignition engine.
2. Spark ignition engine
In these types of engines, ignition of fuel start by the spark, generate
inside the cylinder by some extra equipment.
So it is known as spark ignition engine.
According to number of cylinder:
1. Single cylinder engine
In this type of engines have only one cylinder and one piston connected to
the crank shaft.
2. Multi-cylinder engine
In this type of engines have more than one cylinder and piston connected to
the crank shaft.
According to air intake process:
1. Naturally aspirated
In this types of engine intake of air into cylinder occur by the
atmospheric pressure.
2. Supercharged engine
In this type of engine air intake pressure is increased by the compressor which
is driven by the engine crankshaft.
3. Turbocharged engine
In this type of engine intake air pressure is increase by use of turbine
compressor which is driven by the exhaust gases of burning fuel.
According to arrangement of cylinder:
1. In-line engine
In this type of engines, cylinders are positioned in a straight line one
behind the other along the length of the crankshaft.
2. V-type engine
An engine with two cylinder banks inclined at an angle to each other and
with one crankshaft known as V-type engine.
3. Opposed cylinder engine
An engine with two cylinders banks opposite to each other on a single
crankshaft (V-type engine with 180o angle between banks).
4. W-type engine
An engine same as V-type engine except with three banks of cylinders on the
same crankshaft known as W-type engine.
5. Opposite piston engine
In this type of engine there are two pistons in each cylinder with the
combustion chamber in the center between the pistons.
In this engine a single combustion process causes two power strokes, at the
same time.
6. Radial engine
It is an engine with pistons positioned in circular plane around the
central crankshaft. The connecting rods of pistons are connected to a master
rod which, in turn, connected to the crankshaft.
