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LATEST TREND IN SPARK IGNITION 

Seminar Presentationby

Methuku Sai Krishna( B14ME044)

 

Under the Guidance of

Ms.G.Kavyasree

Department of Mechanical EngineeringKAKATIYA INSTITUTE OF TECHNOLOGY& SCIENCE WARANGAL

(An Autonomous Institute under Kakatiya University, Warangal)SEPTEMBER 2016

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Content

1. Spark plug Anatomy2. Spark plug performance requirements3. Working Principle of DTS-i System 4. Importance of DTS-I5. Advantages and disadvantages of DTS-I6. Triple spark ignition

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The Spark Plug

The spark plug:

Typical spark plug components:

Ribbed insulator

Terminal

Insulator nose

Centre electrode

Ground electrode

Shell

Conductive seal

Ignites the air and fuel mixture.

Removes heat from the combustion chamber.

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The Steel Shell

The shell is threaded so it can be screwed into the cylinder head.

To minimize corrosion, its surface is electroplated with nickel.

Thread

It is machined with a hexagonal section, for plug removal and fitting.

Hex

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Purpose:

The Ceramic Insulator

It is made from aluminium oxide and glazed to discourage dirt.

Ribs increase the surface area of the insulator to reduce flashover to ground. Nose

Ribs To prevent high voltages

from shorting to ground.

To remove heat from the combustion chamber.

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Electrodes are made from nickel alloy or platinum.

Ground and Centre Electrodes

The ground electrode is welded to the shell.

They must be resistant to high temperatures and corrosion.

The centre electrode has a machined tip.

Ground electrode

Centre electrode

Spark erosion

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Spark Plug Dimensions

Thread Diameter

Spark gap

Thread diameter

ReachSpark Gap

Spark Plugs are made in 10, 12, 14, and 18 mm thread diameters.

The gap must be correct.

If it is too small, a weak spark is produced.

If it is too large, the mixture will burn inefficiently due to misfiring.

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Spark Plug Temperature

Ideal spark plug tip temperature = 500 to 850°C.

If temperature = low, carbon and combustion chamber deposits will not be burnt off.

If temperature = high, the plug may overheat, damaging the electrodes.

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100%Fresh air

Heat Dissipation

The combustion process produces heat.

20% is absorbed by intake stroke fresh air.

Dissipation occurs as follows:

58% is absorbed by the cylinder head walls.

20% is absorbed by the insulator and spark plug side walls.

2% is absorbed by spark plug wires.

2%

10%

10%

58%

20%

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Spark Plug Heat Range

Heat range = spark plug's ability to remove combustion chamber heat.

Determined by:

Insulator nose length = distance from tip of insulator to where it meets the metal shell.

Insulator nose length

Insulator nose length.

Gas volume around the insulator nose.

Composition of the insulator and the centre electrode.

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Spark Plug Heat Range

Hot Plug:

Long insulator nose, exposing a large surface area to combustion gases.

Cold Plug:

Shorter insulator nose, minimizing surface area exposed to combustion gases.

Dissipates heat slowly.

Firing end heats up quickly.

Dissipates heat quickly.

Firing end heats up slower.

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Other Types of Spark Plugs

Some spark plugs have multiple ground electrodes.

They provide multiple spark paths which reduces spark erosion.

This surface discharge plug can be used with CDI systems.

It provides good sparking, even when fouled.

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Spark plug ground electrode evolution

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SPARK PLUG PERFORMANCE REQUIREMENTS

• High voltage• Withstand Severe pressure• Sustain high temperature• Make air tight seal• Radio interference• Consistent performance• Durability

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In digital twin spark ignition system two spark plugs Are used, controlled digitally; by a micro processor.These spark plugs ignite the fuel more efficiently at The end of compression stroke .

Working Principle of DTS-i System

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Combustion Process In SI engine

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In 4-stroke petrol engine at time of ignition the air and fuel mixture does not burn completely. But when DTS-i system is used in engine the rich mixture is completely burnt and the ignition time decrease. And power of engine increases.

Importance of DTS-i in 4-stroke Petrol Engine

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Ignition time decreases. The rich mixture (air and fuel) completely burns in combustion

chamber. Power produced by DTS-i more compared to single spark

ignition system. Less vibrations and noise. Decrease in the specific fuel consumption. Higher fuel efficiency Less emission causing less pollution

Disadvantages of DTS-i system The engine tends to overheat and loose power at higher speeds as compared

to a single spark plug engine.

Advantages of DTS-i system

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Revolution in DTS-I Technology-Triple spark plug –

“DTS-I Triple” spark technology that Bajaj employs on the new “Pulsar 200NS”.The “Pulsar 200NS” an engine that has the world’s only first 3 spark plugs for its single cylinder. The 3 spark plugs make for efficient burning of the “air + fuel ” mixture which benefits and enhances.The master plug takes the center place and the two slave plugs opposition across the lateral axis of the engine head. (Over square configuration).

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Comparison

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SINGLE VS TWIN VS TRIPLE PLUG

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Summary Spark Plug Construction Perfect Combustion in Internal Combustion engine is not possible due to

the various losses. So for the instantaneous burning of fuels in I.C. engine, Digital Spark Ignition system can be used which produces twin or triple sparks at regular intervals that can help to complete the combustion to the maximum possible extent.

Combustion process in triple spark engine takes place 27% faster than twin spark and 50% than single spark engine due to faster flame propagation.

Brake thermal efficiency of twin spark engine is 5.1% higher and BTE of triple spark engine is about 13% higher than single spark engine

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REFERENCES: 1) Autolite Training Manual, WWW.Autolite.com./media2) BERU Technical Information,BERU.FEDERALMOGUL.COM3) www.Bajajauto.com4) John b. Heywood, Internal Combustion Engine Fundamentals, McGraw-Hill Book Co., New Delhi, 20015) http://research.omicsgroup.org/index.php/Spark_plug.html6) Narasimha Bailkeri, Krishna Prasad, Shrinivasa Rao B.R, International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976- ISSN 0976 – 6499(Online) Volume 4, Issue 5, July – August (2013), © IAEME 7) Karthik Dhayakar, G.Vijay, J. Gowtham Kumar, T. Kamalahar and C. Preetham "Effect of Twin Sparkplug in Two Stroke IC Engine" International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Volume 4 Issue 2, February 2015.

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Thank you