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I.C. ENGINE WITH HOMOGENEOUS COMBUSTION IN A POROUS MEDIUM 1
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Homogeneous Combustion in a Porous Medium

Nov 18, 2014

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ABDUL SHAFI M

Homogeneous Combustion in a Porous Medium
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Page 1: Homogeneous Combustion in a Porous Medium

I.C. ENGINE WITH HOMOGENEOUS COMBUSTION IN A POROUS MEDIUM

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Page 2: Homogeneous Combustion in a Porous Medium

A new concept that fulfills the requirements to

perform the homogeneous combustion in IC

engine.

Internal heat recuperation, fuel injection and

vaporization, mixing with air, homogenization,

3D thermal self-ignition followed by a

homogeneous combustion.

BACKGROUND

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Page 3: Homogeneous Combustion in a Porous Medium

IMPLICATION EXPECTATIONS

Very low emissions level due to homogeneous

combustion and controlled temperature in the PM-

combustion zone (e.g. NOx between 100 and 300

mg/kWh for the (A/F) ratio from 1 to 5); CO can be

reduced by several times (almost eliminated soot

formation).

Theoretically higher cycle efficiency due to similarity to

the Carnot cycle. Very low combustion noise due to

significantly reduced pressure peaks. Nearly constant

and homogeneous combustion temperature field in the

PM volume. Very fast combustion. 3

Page 4: Homogeneous Combustion in a Porous Medium

HOMOGENEOUS COMBUSTION

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Homogeneous combustion in an IC engine is defined as a process characterized by a 3D-ignition of the homogeneous charge with simultaneous volumetric combustion, ensuring a homogeneous temperature field.

Three steps of the mixture formation and combustion may be selected that define the ability of a given combustion system to operate as a homogeneous combustion system.

Homogenization of charge.Ignition conditions.Combustion process and temperature field.

Page 5: Homogeneous Combustion in a Porous Medium

FOUR DIFFERENT IGNITION TECHNIQUES

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•Local ignition (e.g. spark plug)

•Thermal self-ignition (e.g. compression ignition)

•Controlled auto-ignition (e.g. low temperature chemical ignition)

•3D thermal PM self-ignition (e.g. 3D-grid-structure of a high temperature)

•The 3D-structure of the porous medium is a large number of “hot spots” homogeneously distributed throughout the combustion chamber volume.

Page 6: Homogeneous Combustion in a Porous Medium

HOMOGENEOUS CHARGE WITH LOCAL IGNITION

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HOMOGENOUS

CHARGE

SPARK

IGNITION

NON-HOMOGENEOUS

COMBUSTION

HOMOGENEOUS CHARGE WITH COMPRESSION IGNITION

HOMOGENOUS

CHARGE

COMPRESSION

IGNITION

QUASI

HOMOGENEOUS

COMBUSTION

Page 7: Homogeneous Combustion in a Porous Medium

HOMOGENEOUS CHARGE WITH CONTROLLED IGNITION

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HOMOGENOUS

CHARGE

CONTROLLED-AUTO

IGNITION

QUASI

HOMOGENEOUS

COMBUSTION

HOMOGENEOUS CHARGE WITH 3D THERMAL SELF-IGNITION IN PM-VOLUME

HOMOGENOUS

CHARGE

3D -THERMAL—PM IGNITION

HOMOGENEOUS

COMBUSTION

Page 8: Homogeneous Combustion in a Porous Medium

POROUS MEDIUM TECHNOLOGY

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•Heat capacity• Specific surface area,• Heat transport properties (radiation, conductivity), transparency for fluid flow,• Spray and flame propagation, pore sizes,• Pore density, •Pore structure•Thermal resistance of the material,• Mechanical resistance and •Mechanical properties under heating and cooling conditions

Page 9: Homogeneous Combustion in a Porous Medium

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PRINCIPLE OF THE PM-ENGINE

•An internal combustion engine with the following processes realized in a porous medium: •Internal heat recuperation• Fuel injection• Fuel vaporization• Mixing with air• Homogenization of charge• 3D-thermal self-ignition followed by a homogeneous combustion

Page 10: Homogeneous Combustion in a Porous Medium

PM-ENGINE WITH CLOSED CHAMBER

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Page 11: Homogeneous Combustion in a Porous Medium

PM-ENGINE WITH OPEN CHAMBER

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Page 12: Homogeneous Combustion in a Porous Medium

(THERMODYNAMIC MODEL AND THEORETICAL CONSIDERATIONS)

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It is assumed that no time elapses during the thermal coupling (i.e. heat exchange), and the heat capacitor has a very large heat capacitance in comparison with that of gas in the cylinder.

This allows the modeling of the condition that the temperature remains constant during the heat exchange between the heat capacitor and the cylinder content.

Page 13: Homogeneous Combustion in a Porous Medium

EFFICIENCY RESULTS

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The cycle efficiency for the ideal CV cycle (Otto) 1-2-3-4-1 is

η(constant volume) = 1 - Qout = 1- CV (T4-T1) Qin CV (T3-T2)

Page 14: Homogeneous Combustion in a Porous Medium

For the idealized PM-engine cycle 1-a-3’’-4’-1, the efficiency is

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η(PM)(i) = 1 - Qout = 1- CV(T4-T1)

Qin RT3 ln (V3”/Va)

For a more realistic PM-engine cycle with periodic

contact of gas with PM material 1-2’-3’-3’’-4’-1, the efficiency is

η (PM)(Periodic) = 1 - Qout = 1- CV(T4’-T1) Qin CV (T3’-T2’)+RT3 ln (V3”/V3’)

Page 15: Homogeneous Combustion in a Porous Medium

For a more realistic PM-engine cycle with permanent contact of gas with PM

material 1-2’’-3’-3’’-4’-1, the efficiency is

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η(PM)(Permanent) = 1-Qout = 1-CV(T4’-T1) Qin CV (T3’-T2”)+RT3 ln (V3”/V3’)

Page 16: Homogeneous Combustion in a Porous Medium

STUDY RESULTS

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The significantly constant temperature distribution over the cycle and corresponding cylinder pressure distribution for the PM engine is responsible for the higher cycle efficiency and very low combustion noise as compared to conventional DI engines.

The multifuel properties of the PM-engine cycle permits a wide application range and offers new engine concepts to be realized. The PM engine may use all components known in conventional engines, and only optimization of injection nozzle is required.

Page 17: Homogeneous Combustion in a Porous Medium

queries

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Page 18: Homogeneous Combustion in a Porous Medium

THANK YOU

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