A turbocharger is a turbine-driven device that increases an Internal Combustion Engine's Efficiency and Power Output by forcing extra air into the combustion chamber at higher pressure than atmospheric pressure.

1. Turbochargers: An
Introduction
Presented by
Muhammad Ahsan Hummayoun
Former Trainee Service Engr. MAN | PrimeServ

2. Turbocharger
A turbocharger is a turbine-driven device that increases an
Internal Combustion Engine's Efficiency and Power
Output by forcing extra air into the combustion chamber
at higher pressure than atmospheric pressure.

4. Applications
 They are used in Automobiles
for Better Fuel Efficiency.
 Trucks & Buses etc.

5. Applications (Contd.)
 Subsonic propeller driven aircrafts for increasing Air density at
high altitudes

6. Applications (Contd.)
 Used in stationary power plants for Additional Power/Cylinder
 MAN 18V48/60B uses Single stage Axial Turbocharger TCA-77
 MAN 18V48/60TS uses Two stage Axial Turbochargers; First
stage TCA-77 and Second stage TCA-88

7. Applications (Contd.)
 Used in Cruise Ships & naval vessels for
Additional Power/Cylinder

8. OEMs operating in Pakistan
 MAN
 ABB
 Napier Turbochargers

9. Working / Operation Principle
 A normal turbocharges work on the principle of Forced induction
 I.C Engine produce exhaust gases
 These exhaust gases drives TURBINE which drives
COMPRESSOR
 This draws extra air into combustion chamber at higher pressure
than atmospheric pressure resulting better fuel mixing

11. Design of Turbocharger: Basic view

12. Design of Turbocharger: Metallurgy
 Compressor wheels are made from high strength Aluminium alloys
 Turbine wheel is made from titanium alloys, stainless steel alloys
 Impurities during manufacturing of compressor wheel can weaken
the metal and can cause cracks so special care is required during
fabrication process
 This increase/ decrease of RPM creates cyclic loading or curved
blades therefore Blades must be designed to withstand these cyclic
bending loads and loading from compressing air.

13. Design of Turbocharger: Metallurgy

14. Design of Turbocharger: Lubricating system
 The lubrication system is critical for normal turbocharger
operation
 it performs three important functions: lubricating, cooling and
cleaning
 Interruptions of oil supply for only a few seconds can cause
disastrous results due to Excessive heat
 It is essential that sufficient quantity of oil continually flows
through the turbocharger to provide suspension and
stabilization of the full floating bearing system and to
remove heat

15. Design of Turbocharger: Lubricating system

16. Design of Turbocharger: Balancing
 Balancing of Turbocharger is critical as usual operating speed of
turbocharger ranges from 80,000-150,000 RPM
 If turbocharger is even slightly imbalanced, it creates immense
offset centrifugal force and causes repeated bearing failure or
Shaft failure
 Static and Dynamic balancing is done precisely
 ISO 1940-1(2003) is used as standard of guidelines for
balancing of rigid rotors

17. Design of Turbocharger: Balancing

18. Design of Turbocharger: Bearings
 The free-floating journal bearings
are usually made either from a
Brass or Bronze alloy
 Holes are drilled for lubrication
system which keeps them
suspended during normal
operation

19. Advantages
 Better combustion, better fuel efficiency
 Reduces Unburned Hydrocarbons and emissions
 Significant increase in Power output
 Flexibility of Down sizing of Engine for similar power output

20. Challenges
 Boost threshold is required for startup of turbine
 Turbolag
 Difficult to operate/Control: RPM (50,000-150,000); Bypass
valves and wastegate are required
 Periodic maintenance is required; Oil requirements
 Precise balancing (Static/Dynamic) is required for normal
operation

21. Turbochargers Vs Superchargers
Turbochargers
 It is driven by energy of exhaust gases
 No Mechanical load on Engine
 No instantaneous power due to Tarbolag
 Frequent maintenance & Oil change is
required
 High adiabatic efficiency
 place exhaust back pressure on engines
Superchargers
 It is driven by engine itself
 Puts Mechanical load on Engine
 Instantaneous power
 Little maintenance & Oil change is
needed
 Low adiabatic efficiency
 No back pressure on engine

22. Variants/Future technologies
 Twin turbos; These designs have two separate turbochargers
operating in either a sequence or in parallel. This setup
significantly reduces Turbolag
 Variable-geometry or variable-nozzle turbochargers use
moveable vanes to adjust the air-flow to the turbine
 Hybrid turbocharger is an electric turbocharger consisting of a
high speed turbine-generator and a high speed electric air
compressor
 The electrical motors run at speeds of 120,000 rpm and when
used as generator, which drives compressor and stores energy

23. Variants/Future technologies

24. Thankyou