17-06-2014, 04:06 PM
CRDI Engine technology
CRDI Engine technology.ppt (Size: 560.5 KB / Downloads: 18)
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
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
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
Direct injector
A fuel injector is nothing but an electronically controlled valve
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
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