compound vortex controlled combustion (cvcc)

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COMPOUND VORTEX CONTROLLED COMBUSTION

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A presentation about the Honda's Compound Vortex Controlled Combustion (CVCC).

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Page 1: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

COMPOUND VORTEX CONTROLLED COMBUSTION

Page 2: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

CONTENTS

• INTRODUCTION• CONSTRUCTION & OPERATION• EARLY DESIGN FLAW• ADVANTAGES• CVCC EQUIPED ENGINES• CONCLUSION

Page 3: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

INTRODUCTION

• CVCC - Compound Vortex Controlled Combustion• CVCC is a trademark by the Honda Motor

Company for an engine with reduced automotive emissions

• The first mention of Honda developed CVCC technology was done by Mr. Soichiro Honda February 12, 1971

Page 4: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

CVCC engine for Honda Civic

• The CVCC engine debuted in 1975 and had a head design that allowed for more efficient combustion.

• CVCC system did not require a catalytic converter or unleaded fuel.

Page 5: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Construction and operation• Honda CVCC engines have normal inlet and

exhaust valves, plus a small auxiliary inlet valve which provides a relatively rich air–fuel mixture to a volume near the spark plug.

• The remaining air–fuel charge, drawn into the cylinder through the main inlet valve, is leaner than normal.

• Upon ignition flame fronts emerge from the perforations and ignite the remainder of the air–fuel charge.

Page 6: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Construction & Operation Contd…

• The remaining engine cycle is as per a standard four stroke engine.

• The volume near the spark plug is contained by a small perforated metal plate.

• Rich mixture (near spark plug)+ lean mixture (in the cylinder) = Stable running

• Yet complete combustion of fuel, thus reducing CO (carbon monoxide) and hydrocarbon emissions.

Page 7: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Fig: Schematic diagram of CVCC engine

Page 8: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Suction Stroke

• A large amount of very lean mixture is drawn through the main intake valve into the main combustion chamber.• A very small amount of rich mixture is drawn through the auxiliary intake valve into the pre-chamber

Page 9: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Compression Stroke

• A rich mixture is present in the pre-chamber• A moderate mixture is formed in the main combustion chamber near the pre-chamber outlet • A very lean mixture is present in the remainder of the main combustion chamber.

Page 10: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Ignition

• When the spark plug fires, the rich mixture in the pre-chamber is easily ignited.

Page 11: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Expansion Stroke

• The flame from the pre-chamber ignites the moderate mixture• This, in turn, ignites the lean mixture in the main combustion chamber. • The formation of carbon monoxide is minimized because of this lean mixture.

Page 12: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Bottom Dead Center

• The stable and slow burning in the main combustion chamber has two desired effects. • The peak temperature stays low enough to minimize the formation of oxides of nitrogen. • The mean temperature is maintained high

enough and long enough to substantially reduce hydrocarbon emissions.

Page 13: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Exhaust Stroke

• The hot gases exit through the exhaust valve, and oxidation continues in the manifold.

Page 14: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Early design flaw

• Early CVCC engines had a problem with the auxiliary valves retaining collars vibrating loose.

• Once unscrewed, engine oil would leak from the valve train into the pre-combustion chamber, causing a sudden loss of power and massive amounts of smoke to emanate from the exhaust pipe.

Page 15: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Early design flaw contd…

• The condition simulated a blown engine, even though the needed repair was quite simple.

• Honda eventually came up with a fix involving metal retaining rings that slipped over the collars and prevented them from backing out of their threads

Page 16: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

Advantages• Able to use carburettors.• Did not rely on intake swirl• Previous versions of stratified charge engines

needed costly fuel injection systems• Previous engines tried to increase the velocity

and swirl of the intake charge in keeping the rich and lean mixtures separated.

• Able to keep the charges adequately separated by combustion chamber shape.

Page 17: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

CVCC EQUIPED ENGINES• The ED series introduced the CVCC

technology. • This group displaced 1,487 cc. • Uses a SOHC 8-valve design. • Output with a 3 barrel carburetor was 52 hp

(39 kW) @ 5000 rpm

Page 18: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

CVCC EQUIPED ENGINES cntd…• ED1– 1975- Honda Civic CVCC

• ED2– 1975- Honda Civic Wagon

• ED3– 1976-1979 Honda Civic CVCC

• ED4– 1976-1979 Honda Civic Wagon

Page 19: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

CONCLUSION

The CVCC reduce carbon monoxide and hydrocarbon emissions by the creation of an additional auxiliary inlet valve that allowed an engine to run smoothly with a lean air/fuel mixture in the cylinder area and a rich air/fuel mixture at the spark plug.

Page 20: COMPOUND VORTEX CONTROLLED COMBUSTION (CVCC)

For Seminar ReportVisit: http://mexmate.blogspot.in/