Improvement of anti-knocking characteristics of Diesel engine fuels

May 3 • General • 7236 Views • 3 Comments on Improvement of anti-knocking characteristics of Diesel engine fuels

Improvement of anti-knocking characteristics of Diesel engine fuels

Internal Structure of Diesel Engine

Knocking:

Knocking is also called knock, detonation, spark knock, pinging or pinking in spark-ignition internal combustion engines occurs when air/fuel mixture combustion of the in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode when present outside the envelope of the normal combustion front.

The fuel-air charge is ignited by the spark plug only, and at a precise time in the piston’s stroke cycle. When the peak of the combustion process no longer occurs at the optimum moment for the four- stroke cycle knock occurs. The shock wave makes the characteristic metallic “pinging” sound, and cylinder pressure increases dramatically. Effects of engine knocking range from inconsequential to completely destructive nature.

Anti-Knocking:

Diesel Anti-Knock is a combination of additives with cleaning, dispersing and material-protecting characteristics and cetan-number increasing properties,which are made to match the present-day engines, automotive fluids and operating conditions. The fuel shows better combustion behavior when the engine is cold and the pollution from odors in the exhaust gases is reduced,when ignition performance is increased.

                                                                                                                                Diesel Anti-Lock product

Knock detection and Anti- Knocking improvement methods:

Due to the greater variation in fuel quality, a large number of engines now contain mechanisms to detect knocking and adjust timing or boost pressure accordingly in order to offer improved performance on high octane fuels whereas reducing the risk of engine damage caused by knock while running on low octane fuels.Various monitoring devices are commonly utilized by tuners as a method of seeing and listening to the engine in order to ascertain if a tuned vehicle is safe under load or used to re-tune a vehicle safely which is knocked.

Knock prediction

As the avoidance of knocking combustion is so important to development engineers, a variety of simulation technologies have been developed which can identify engine design or operating conditions in which knock might be expected to occur through anti-knocking mechanisms. This enables engineers to design ways to mitigate knocking combustion while maintaining a high thermal efficiency of the system.As the onset of knock is sensitive to the in-cylinder pressure, temperature and auto-ignition chemistry  have proven most effective in determining knock operating limits which enables engineers to determine the most appropriate operating strategy.

                       RELATED QUESTIONS AND ANSWERS

Q1. WHEN KNOCKING OCCURS?

Ans. Knocking in spark-ignition internal combustion engines occurs when air/fuel mixture combustion of the in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode when present outside the envelope of the normal combustion front.

Q2. WHAT IS DIESEL ANTI-LOCK?

Ans. Diesel Anti-Knock is a combination of additives with cleaning, dispersing and material-protecting characteristics and cetan-number increasing properties,which are made to match the present-day engines, automotive fluids and operating conditions.

Q3. HOW IS KNOCK DETECTED?

Ans. Reducing the risk of engine damage caused by knock while running on low octane fuels by various monitoring devices are commonly utilized by tuners as a method of seeing and listening to the engine in order to ascertain if a tuned vehicle is safe under load or used to re-tune a vehicle safely which is knocked.

Q4. WHAT ARE ANTI-LOCKING METHODS?

Ans. Various monitoring devices are commonly utilized by tuners as a method of seeing and listening to the engine in order to ascertain if a tuned vehicle is safe under load or used to re-tune a vehicle safely which is knocked.

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