This document discusses the technology and operation of turbochargers. It describes the key parts of a turbocharger including the turbine, compressor, and bearing system. It explains how a turbocharger works by using the engine's exhaust gases to drive a turbine which spins a compressor to force more air into the engine, allowing for more power. It covers turbocharger sizing and response time, boost control methods like wastegates, potential failures, and the effects on engine performance and emissions.

1. TURBOCHARGER
PRESENTED BY:
AVINASH MISRA
2011UME1480
MECH. ENGG.

2. INDEX
 Technology behind
 Parts of a Turbocharger
 Design of Turbocharger
 Turbocharger Size and Response Time
 Boost Control
 The effects of turbocharger on the performance and exhaust emissions of
a diesel engine fuelled with biodiesel.
 Maintenance/Problems
 Conclusion
 References

3. TECHNOLOGY BEHIND
 Turbocharger is a turbine driven air compressor
and a forced induction device powered by
exhaust gases from the internal combustion
engine.
 Here, air is compressed twice once during
induction into the engine and secondly during
compression stroke of the engine
FIGURE 1: A turbocharger uses some of the
heat energy that would normally be
wasted.

4. PARTS of a Turbocharger
 Turbine
 Compressor
 Bearing system
 Manifold
 Hot lines
 Cold lines
 Lubrication Lines
Figure 2:
Parts of a Turbocharger

5. TURBOCHARGERS
Turbocharger Design and Operation
 A turbocharger
consists of two
chambers connected
by a center housing.
 The two chambers
contain a turbine
wheel and a
compressor wheel
connected by a shaft
which passes
through the center
housing.
FIGURE 3. The exhaust drives the turbine wheel on the left,
which is connected to the impeller wheel on the right
through a shaft. The bushings that support the shaft are
lubricated with engine oil under pressure.

6. TURBOCHARGERS
Turbocharger Size and Response Time
 Turbocharger response time is directly related to the size of the turbine and compressor wheels.
 Small wheels accelerate rapidly; large wheels accelerate slowly.
 While small wheels would seem to have an advantage over larger ones, they may not have
enough airflow capacity for an engine.
 To minimize turbo lag, the intake and exhaust breathing capacities of an engine must be
matched to the exhaust and intake airflow capabilities of the turbocharger.

7. BOOST CONTROL
 Both supercharged and turbocharged systems are designed to provide a
pressure greater than atmospheric pressure in the intake manifold.
 This increased pressure forces additional amounts of air into the
combustion chamber over what would normally be forced in by
atmospheric pressure.
 This increased charge increases engine power.

8. BOOST CONTROL
Wastegate
• A turbocharger uses exhaust gases to increase boost,
which causes the engine to make more exhaust gases,
which in turn increases the boost from the
turbocharger.
• To prevent overboost and severe engine damage, most
turbocharger systems use a wastegate.
• A wastegate is a valve similar to a door that can open
and close.
• The wastegate is a bypass valve at the exhaust inlet to
the turbine.
• It allows all of the exhaust into the turbine, or it can
route part of the exhaust past the turbine to the
exhaust system.
FIGURE 4. A wastegate is
used in the diesel to
control maximum boost
pressure.

9. BOOST CONTROL
Relief Valves
 A relief valve vents pressurized air from the
connecting pipe between the outlet of the
turbocharger and the throttle whenever the
throttle is closed during boost, such as during
shifts.
FIGURE 5. A blow-off valve is
used in some turbocharged
systems to relieve boost
pressure during deceleration.

10. TURBOCHARGER FAILURES
 When turbochargers fail to function correctly, a drop in power is noticed.
 To restore proper operation, the turbocharger must be rebuilt, repaired, or
replaced.
 It is not possible to simply remove the turbocharger, seal any openings,
and still maintain decent drivability.

11. The effects of turbocharger on the
performance and exhaust emissions of a diesel
engine fuelled with biodiesel.
Figure 6. Variation of Brake power
with engine speed for Naturally
aspirated (NA) and Turbo Charged
engine
Figure 7. Variation of Brake Specific Fuel Consumption
with engine speed for Naturally aspirated (NA) and Turbo
Charged engine

12. The effects of turbocharger on the
performance and exhaust emissions of a diesel
engine fuelled with biodiesel.
Figure 8. Variation of Torque with engine speed for
Naturally aspirated (NA) and Turbo Charged engine
Figure 9. Variation of Thermal Efficiency with engine
speed for Naturally aspirated (NA) and Turbo Charged
engine

13. Maintenance / Problem
 LACK OF OIL
 DIRTY OIL
 MECHANICAL DAMAGE OF VANE WHEELS
 WASTEGATE CONTROL PROBLEMS
 OIL CAKING

14. Conclusion
 It’s a forced induction device
 Increasing the efficiency of an engine
 Too much boost can result into preignition and knocking
 Half's the fuel consumption in an engine

15. Reference
 www.wikepedia.org
 www.superchevy.com
 www.explara.com
 www.turbobygarrett.com
 The effects of turbocharger on the performance and exhaust emissions of a
diesel engine fuelled with biodiesel.
Murat Karabektas* Department of Mechanical Education, Sakarya
University, 54187 Sakarya, Turkey