Transcript Slide 1

Overview
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Introduction
Principle
Working
Features
Scope for further development
Conclusion
Introduction
 The country among other things has
seen an enormous development in
engines used in cars also.
 The Diesel engines have also
undergone a sea change from the
time Rudolf Diesel invented it way
back in 1892.
 Today Common Rail Direct Injection
(CRDI) is the order of the day.
CRDI Engine
Principle
 Unlike in conventional diesel engines,
the fuel is fed into the common tube or
rail and high pressure is maintained.
 This allows fuel to combine with air
much more efficiently.
 It features high-pressure fuel rail
feeding individual solenoid valves as
opposed to low-pressure fuel pump
feeding injectors.
Layout of a CRDI Engine
Working
 Solenoid valves make possible fine
electronic control over the injection time
and amount, and the higher pressure
that the common rail technology makes
available provides better fuel
atomization. In order to lower engine
noise, the engine's electronic control
unit can inject a small amount of diesel
just before the main injection event
("pilot" injection), thus reducing its
explosiveness and vibration, as well as
optimizing injection timing and the
process continues
Features
Direct injector
Spiral-shaped intake port
Integrated port
Air flow metering
Multiple Pilot injection and
Post injection
 Powerful Microcomputer
 Newly-developed catalytic
converters
 Reduced noise levels
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Direct injector
A fuel injector is
nothing but an
electronically
controlled valve.
Spiral-shaped Intake port
Provides optimum
swirl and even
distribution of fuel.
Integrated port
Integrated port is used for exhaust gas
recycling. There are three advantages
to this system
• eliminates external pipes which are
subject to vibration
• quicker engine warm-up
• better combustion.
Air flow metering
 It gives exact analysis of the air-mass
that is being taken in.
 Due to this metering system, the
microcomputer that controls engine
timing receives precise data.
Multiple Pilot injection and
Post injection
 Pilot injections is small doses of fuel
made prior to the main injection which
help to smoothen the sharp combustion
character.
 Post injection is a similarly small dose of
fuel injected after the main injection to
reduce particulates.
Powerful Microcomputer
 The microcomputer regulates the
amount of time the valves stay open
and thus the amount of fuel injected,
depending on operating conditions and
how much output is needed.
Newly-developed catalytic
converters
 Besides electronically-controlled
exhaust-gas recycling which contributes
to lower nitrous oxide emissions, CRDI
engines are equipped with catalytic
converters near the motor and emission
control devices on the underbody. These
vouch for a high degree of efficiency.
Reduced Noise levels
 The Electronic control and multiple
injections reduced noise to a great
extent
Scope for further
development
 Use of different fuels for zero
emissions and better engine
performance
 By using different fuels and cetane
improvers, maximum torque can be
obtained
 Lowering the cost
 Closed-loop control injection with ion
sensing technology
Conclusion
CRDI technology revolutionized diesel
engines. It has changed the way one
looks as diesel cars by providing the
above said advantages.
Advantages
-More power is developed
-Increased fuel efficiency
-More stability
-Pollutants are reduced
-Particulates of exhaust are reduced
-Exhaust gas recirculation is enhanced
-Precise injection timing is obtained
-Pilot and post injection increase the
combustion quality
-The powerful microcomputer makes the
whole system more perfect
Manufacturers of CRDI engine
The car makers refer to their common
rail engines by their own brand
names. Some of them are
BMW's D-engines
Mahindra's CRDe
Tata's DICOR
Honda's i-CTDi
Hyundai-Kia's CRDi etc
References
 International Journal of Automotive
Technology
 Approaches to Automotive Emissions
Control
 Magazines: Auto week, Automobile India