six stroke engine(presentation)

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BRUSH CROWER TYPE(WATER INJECTION) Prateek Kumar Das Trident Academy of Technology, Bhubaneswar

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BRUSH CROWER TYPE(WATER INJECTION)

Prateek Kumar DasTrident Academy of Technology, Bhubaneswar

CONTENTS INTRODUCTION

WORKING PRINCIPLE

THERMODYNAMIC ANALYSIS

AND COMPARISION WITH 4-STROKE

MODIFICATION REQUIRED

ADVANTAGES

DRAWBACKS

CONCLUSION

INTRODUCTION

The concept of six stroke engine was developed in mid 20th

century when pollution due to the conventional IC engineincreased.

The six stroke engine “Using water” was developed

By Brush Crower in 2006 and he patented his product at the end of2007.

Six stroke engine is a type of internal combustion enginebased on conventional four stroke engine, but it`s additional twostrokes make it more efficient and reduce the emission. The enginecaptures heat, which is lost from conventional four stroke cycle andadditional strokes use it to produce power by introducing waterinside the super heated cylinder.

WORKING PRINCIPLES

The working principles of six stroke engine is based on the concept of

four stroke engine but with some modification, another two strokes are added.

SUCTION STROKE

The piston moves from top dead center to the

Bottom dead center and creates vacuum pressure .

So the Air and fuel mixture is sucked in to the

Cylinder.

COMPRESSION STROKE

The piston moves from

Bottom dead center to top dead

center and compresses the

Mixture. The mixture is compressed

To high temperature and pressure.

POWER STROKE:

At the end of compression

stroke the fuel is ignited and

burnt. The pressure inside the

cylinder increases rapidly and

it pusses the piston down and

the power is transmitted from

piston to wheel.

EXHAUST STROKE:

The Burnt product is

pushed through the exhaust

valve by the upward movement

of the piston.

SECONDARY POWER STROKE:

At the end of the exhaust

stroke the cylinder temperature

becomes around 900-10000 C. At

this stage water is injected by an

Injector in the form of fine droplets.

The water turns in to vapour

increasing volume around 1600

times when it comes in contact

with the superheated cylinder.

The water turns into vapour

increasing volume around

1600 times when it comes in

contact with the superheated

cylinder.

SECONDARY EXHAUST STROKE:

In this stroke the water vapour

is exhausted by the upward

motion of the piston.

THERMODYNAMIC ANALYSISAND

COMPARISION WITH 4-STROKE ENGINE

Work obtained by six stroke is the sum of the both combustion work

and vaporization work. So that the break mean effective pressure will increase.

Pressure and volume diagram

Valve timing diagram of 6-stroke engine

IVO: Inlet Valve open

EVO: Exhaust Valve Open

IVC: Inlet Valve Close

EVC: Exhaust Valve Close

WC : Water Injection

Thermodynamic analysis of power strokes:Fuel power stroke:

Water injection 20

power stroke

In order to determine the engine parameters, in 2011 HONDA motors conducted the first simulation of the six stroke engine by using a modified Honda GC190 engine.

SIMULATION RESULTSPOWER AND TORQUE V/S ENGINE SPEED

Cycle analysis and Comparison

FUEL FLOW RATE:

The amount of fuel flow to the engine per unit time is known as fuel flow rate.

As the diagram shows the fuel flow rate of 6-stroke engine is 50% lesser than

the conventional 4-stroke engine.

THERMAL EFFICIENCY

The thermal efficiency of the engine is the power produced by the engine to the power available from fuel.

The thermal efficiency of the four stroke engine lies between 20-30%, where as

The thermal efficiency of six stroke engine lies between 40-50%.

BRAKE SPECIFIC FUEL CONSUMPTION

It is the ratio of fuel consumption per second to the brake power.

As from the diagram the brake specific fuel consumption of 6-stroke engine is much lower than the conventional six stroke engine.

Factors affecting the engine performance

Water injecting pump

Used fuel and lubrication

Valve timing of the engine

Temperature of the cylinder wall

MODIFICATIONS REQUIRED

FUELTANK:

The fuel tank should divided into two parts, as one part will contain fuel and theother part will contain water.

The water used should be neutral and distilled.

ENGINE COMPONENTS MATERIAL

The engine components like piston, cylinder , cam, crank, valves etc. aresubjected to severe thermal stress. The thermal stress developed due to the injectionof water into the very hot cylinder. The rapid temperature changes may cause microcrack and fractures in the engine components as the periodical compression andexpansion takes place.

So the engine components should be designed with high thermal resistivemetal alloys to withstand the stress and prevent failure of engine.

The materials that can be used are…

Silicon Nitride(Si3N4)

Silicon Carbide(SiC)

Zirconia(ZrO2)

Alumina-Tungsten alloy etc.

CAM-SHAFT DESIGN AND VALVE TIMING

The valve control of the 6-stroke engine can be done in two ways.

by mechanically cam controlled

by solenoid valve controlled.

The mechanically cam controlled valve is based on the four strokedesign.

In four stroke original angular speed of camshaft is one half of the crankshaft. Thecrankshaft rotates once for every two revolution of the crank shaft.

In six stroke engine the camshaft has been designed to turn one revolutionfor every three revolution of the crankshaft.

Since camshaft is geared directly to the crankshaft, this makes it impossible tochange the number of teeth on each shaft to achieve the correct speed due to thesize constraint.

To overcome this a third shaft is to be installed with double reduction gearingsystem.

(a)Gear reduction in 4-stroke . (b)Gear reduction in 6-stroke.

The camshaft of 6-stroke engine contains three cams.

Intake cam

Exhaust cam

Water injector cam

Cam follower modification

The bottom shape of regular follower has the flat pattern, which issuitable with the normal camshaft for four stroke engine. The shape of thefollower must be roller or spherical shape. In this case a spherical shape is chosenas it’s contact area is less .

Flat and Spherical follower

Solenoid valve

Solenoid valve with engine control unit is used in place of mechanically

driven cam for accurate injection and exhaust operation. The solenoids have then been attached to the bracket system using 1/4-28 threaded rod and plates. This allows for fairly fine adjustment of the valve to throw water. The original cores of the valves have made from one inch diameter cold rolled steel. Each core

has been designed to act as the

stop when the valve is completely open.

The valves have been attached to the

pushrods using universal joints. The

push rod is Connected with solenoid coil

Which energized and DE energized by

Electric current to open and close the valve.

Water Injection:

The water injection is done by the help of water injector which is

operated by the cam. This thing can be done more effectively by the use of

Water metering pump or by the progressive cavity pump.

Water metering Pump:

A positive displacement pump capable of driving a fixed quantity of water into the cylinder at regular intervals, independent of the back pressure applied.

Progressive cavity pump:

It is a screw pump positive displacement variant. In this the working fluid passes

through series of discrete cavities as rotor is turned.

The pump is to be synchronized with the output shaft of the engine with a reduction gear of 3:1 ratio.

ADVANTAGES: Uses rejected heat from engine

Fuel economy increases to 60% of conventional engine

Power output per stroke is more

Exhaust gas emission is low

High thermal Efficiency

Drawbacks: Early engine starting problem:

As the engine is not sufficiently hot at the starting the water injection stroke cannot be taken place. So a prime mover is used to run the engine for some cycle and after heating of the cylinder it is cut out.

Running problem in cold region:

As the temperature in cold region is low there might be problem in case of water injection stroke as the cylinder temperature is low.

Requirement of neutral water:

As the steam is generated in 20

power stroke, if the water is not neutralized itmay react with the cylinder wall and with the piston top which resultscavitation and distortion of the metal. It causes the uneven heat transferbetween the water droplets and the cylinder wall which may decrease theperformance of the engine. And it is difficult to carry neutral water all thetimes.

CONCLUSIONSix stroke engine has many advantages like high thermal efficiency, low fuel

consumption, high break mean effective pressure, low emission. However drawbacks likeinitial starting problem, availability of water are also associated. The starting problem can be

Can be eliminated by using heater or glow plug and coupling a dc motor as prime mover tothe engine. Now a days research and experiments are going on to modify the engine furtherand to make it for practical purpose.

REFERENCES : 15th International Conference on Applied Mechanics and Mechanical Engineering, 29-31

May, 2012,report by M. M. Gasim, L. G. Chui and K. A. Bin Anwar

Project report on Six stroke engine, Calvin College, ENGR 340

Thermodynamic analysis testing and validation of six stroke engine Report,

University of Northern Ireland.

Conklina J. C. and Szybist J. P., "A Highly Efficient Six-Stroke Internal Combustion Engine Cycle with Water Injection for In-Cylinder Exhaust Heat Recovery", Energy, Volume 35, Issue 4, pp. 1658-1664 (2010).

Andrew De Jong, team 6 stroke, https://knightvision.calvin.edu (accessed14/2/2012).

THANK YOU