03-07-2012, 03:13 PM
TURBOCHARGERS AND SUPERCHARGERS
A TURBOCHARGERS.pptx (Size: 869.06 KB / Downloads: 105)
INTRODUCTION:
A turbocharger is a centrifugal compressor powered by a turbine that
is driven by engine’s exhaust gases. Its benefit lies with the
compressor increasing the mass of air entering the engine, thereby
resulting in greater engine performance. They are preferably used
with I.C. engines (e.g.- 4 stroke engines like otto or diesel cycle)
The term turbocharger is derived by shortening
the term turbosupercharger. This term specifies that turbocharger are
a specific type of supercharger one that is driven by turbine.
A supercharger, also called a blower, is a gas
compressor used to pump air into the cylinder of an I.C. engine. In
petrol engine, the charge is petrol/air mixture.
HISTORY:-
Turbocharger was invented by Swiss Engineer Alfred Buchi, who
received a patent in 1905 for using a compressor driven by exhaust
gases to force air into a piston engine. During World War-1 French
Engineer Auguste Rateau fitted turbocharger to Renault engines
powering french fighters, ships, and locomotives equipped with
turbocharged diesel engines began appearing in 1920’s.
The world’s first functional , actually tested engine
superchager was made by Dugald Clerk, who used it for the first 2
stroke engine in 1878. Gottlieb Daimler received a German patent for
supercharging an I.C. engine in 1885. An early supercharged car was
by Lee Chadwick of Pottstown, Pennysylvania in 1908, which, it was
reported, reached a speed of 100 mph (160 km/h).
TYPES OF SUPERCHARGERS:-
Generally, They are of three types
Centrifugal type
Root’s type
Vane type
Centrifugal Type:- This is most common type. It is run from the engine pulley by means of a V-belt. The air/fuel mixture
enters the impeller at the center and after passing through the
impeller and diffuser vanes, it enters the volute casing, where a
part of its kinetic energy is recovered and mixture at supercharged
pressure goes out of the casing to the engine.
They have to run at very high speeds (80000 r.p.m.) , so made of duralumin, or alloy steels.
OTHER TWO TYPES
2. Roots Type:- This type has two long rotors which spin inside the
housing. Each rotor has two or three lobes that are either straight or
helical. The rotors are geared together and driven by a belt or chain
from the engine crankshaft. In case of diesel engine , the air fills the
space between the rotor lobes and housing. The spinning rotors carry
the trapped air around the housing and meshing rotors force the air
out and into the intake manifold.
3. Vane Type:- In this type, a no. of vanes are mounted on the drum
in such a way that they can slide in or out against the spring force. It
is seen that spaces between the body and the drum goes on dec. from
the inlet to outlet side as drum rotates. Thus the mixture entrapped
between two vanes experience decrease of volume and hence increase
of pressure as it reaches the outlet.
WORKING OF TURBOCHARGER:-
The turbocharger includes a turbine and a centrifugal compressor
coupled together . The exhaust gases from the engine enter the
turbocharger and run the turbine, which further derives the
compressor . The atmospheric air enters the compressor and raises its
pressure about 0.5 bar (50 kPa ), which means about 50% more air by
weight , which should increase the power by 50% from the same
engine. In practice, we obtain about 30 to 40% increase in power.
It is seen that advanced engine management lets turbocharged
engines deliver pumped-up power in low rpm range, called
“over boost”. This over boost period provides extra turbo pressure
at lower speeds for period of time long enough to accelerate the
vehicle to highway speed, which means turbocharged engine provide
muscular response . The purpose of inter-cooler is to cool the mixture
as to increase its volumetric efficiency.
A TURBOCHARGERS.pptx (Size: 869.06 KB / Downloads: 105)
INTRODUCTION:
A turbocharger is a centrifugal compressor powered by a turbine that
is driven by engine’s exhaust gases. Its benefit lies with the
compressor increasing the mass of air entering the engine, thereby
resulting in greater engine performance. They are preferably used
with I.C. engines (e.g.- 4 stroke engines like otto or diesel cycle)
The term turbocharger is derived by shortening
the term turbosupercharger. This term specifies that turbocharger are
a specific type of supercharger one that is driven by turbine.
A supercharger, also called a blower, is a gas
compressor used to pump air into the cylinder of an I.C. engine. In
petrol engine, the charge is petrol/air mixture.
HISTORY:-
Turbocharger was invented by Swiss Engineer Alfred Buchi, who
received a patent in 1905 for using a compressor driven by exhaust
gases to force air into a piston engine. During World War-1 French
Engineer Auguste Rateau fitted turbocharger to Renault engines
powering french fighters, ships, and locomotives equipped with
turbocharged diesel engines began appearing in 1920’s.
The world’s first functional , actually tested engine
superchager was made by Dugald Clerk, who used it for the first 2
stroke engine in 1878. Gottlieb Daimler received a German patent for
supercharging an I.C. engine in 1885. An early supercharged car was
by Lee Chadwick of Pottstown, Pennysylvania in 1908, which, it was
reported, reached a speed of 100 mph (160 km/h).
TYPES OF SUPERCHARGERS:-
Generally, They are of three types
Centrifugal type
Root’s type
Vane type
Centrifugal Type:- This is most common type. It is run from the engine pulley by means of a V-belt. The air/fuel mixture
enters the impeller at the center and after passing through the
impeller and diffuser vanes, it enters the volute casing, where a
part of its kinetic energy is recovered and mixture at supercharged
pressure goes out of the casing to the engine.
They have to run at very high speeds (80000 r.p.m.) , so made of duralumin, or alloy steels.
OTHER TWO TYPES
2. Roots Type:- This type has two long rotors which spin inside the
housing. Each rotor has two or three lobes that are either straight or
helical. The rotors are geared together and driven by a belt or chain
from the engine crankshaft. In case of diesel engine , the air fills the
space between the rotor lobes and housing. The spinning rotors carry
the trapped air around the housing and meshing rotors force the air
out and into the intake manifold.
3. Vane Type:- In this type, a no. of vanes are mounted on the drum
in such a way that they can slide in or out against the spring force. It
is seen that spaces between the body and the drum goes on dec. from
the inlet to outlet side as drum rotates. Thus the mixture entrapped
between two vanes experience decrease of volume and hence increase
of pressure as it reaches the outlet.
WORKING OF TURBOCHARGER:-
The turbocharger includes a turbine and a centrifugal compressor
coupled together . The exhaust gases from the engine enter the
turbocharger and run the turbine, which further derives the
compressor . The atmospheric air enters the compressor and raises its
pressure about 0.5 bar (50 kPa ), which means about 50% more air by
weight , which should increase the power by 50% from the same
engine. In practice, we obtain about 30 to 40% increase in power.
It is seen that advanced engine management lets turbocharged
engines deliver pumped-up power in low rpm range, called
“over boost”. This over boost period provides extra turbo pressure
at lower speeds for period of time long enough to accelerate the
vehicle to highway speed, which means turbocharged engine provide
muscular response . The purpose of inter-cooler is to cool the mixture
as to increase its volumetric efficiency.