Prsentation on Internal Combustion Engine

8/8/2019 Prsentation on Internal Combustion Engine

1/38

Small GasolineEngines


2/38

Engine

A machine for converting energy

into mechanical force and motion.


3/38

Heat Engine

An engine which uses heat to convert

the chemical energy of a fuel intomechanical force and motion


4/38

Two general categories based on design.

External combustion engine

Internal combustion engine


5/38

Engine SizeLargest:The Wartsila-Sulzer RTA96-C

turbocharged two-stroke diesel engine isthe most powerful and most efficient

prime-mover in the world today.

The cylinder bore is just under

38" and the stroke is just over

98".

Each cylinder displaces

111,143 cubic inches (1,820

liters) and produces 7,780

horsepower.Total displacement comes out to 1,556,002 cubic

inches (25,480 liters) for the fourteen cylinder

version.


6/38

Engine Size--cont.

Smallest:

Not much bigger than a stack ofpennies, the "mini engine" is thefirst engine of its size to deliverpower on a continuous basis.

Currently will produce 2.5 watts

of electricity (0.00335 hp). Uses 1/2 fluid ounce of fuel per

hour


7/38

Small Engine

Industry definition: A small engine is

an internal combustion engine

generally rated up to 25 horsepower.


8/38

Small engines are further classified by

ignition, number of strokes, cylinder design,

shaft orientation and cooling system.

(pg. 2 & 3)


9/38

Ignition

Spark ignition

Compression ignition


10/38

Number of Strokes

Four stroke

Two stroke


11/38

Cylinder Design

Small engines usually have one or two cylinders,

but may have as many as four.

Three Common Cylinder Orientations For

Single Cylinder Engines

Vertical Horizontal

Slanted


12/38

Cylinder Design-cont.

V

Horizontally opposed

In-line

Three common cylinder configuration in multiple cylinder

engines:


13/38

Horizontal

Vertical

Small gas engines use three crankshaft orientations:

Cylinder Design-cont.

Multi-position


14/38

When fuel is oxidized (burned) heat is

produced.

Only approximately 30% of the energy

released is converted into useful work.

The remaining (70%) must be removed fromthe engine to prevent the parts from

melting.


15/38

Excessh

eat is removed by:

Cooling system

Exhaust system

Lubrication system

Radiation


16/38

Additional heat is also generated by

friction between the moving parts.

This heat mustalso be

removed.


17/38

Small Engine Development

(pg 5)Year Engine De signer/developer

1680 Gunpowder Christian Huygens

1698 Sa very Pump Thomas Saverly

1712 NewcomenSteam Thomas Newcomen

1763 Watt Double-actingsteam James Watt

1801 Coalgas/electric ignition E ugeneLebon

1802 High pressuresteam RichardTrevithick

1859 Pre-mixedfuelandair E tienneLenoir

1862 Gasoline Nikolaus Otto

1876 Fourcyclegasoline Nikolaus Otto1892 Diesel RudolfDiesel

1953 Die-cast aluminum B&S


18/38

Energy Conversion Principle

All internal combustion engines exhibit andconvert different forms of energy.

Energy is the resource that provides thecapacity to do work.

The two forms of energy used in engines arepotential and kinetic.


19/38

Potential Energy

Stored energy a body has due to its

position, chemical state, or condition.


20/38

Examples of Potential Energy

Fuels have potentialenergy based on theirchemical state.

A compressed spring

has potential energy due

to its mechanical

condition.

Water behind a dam has

potential energy due to

difference in elevation.


21/38

Kinetic Energy


22/38

FlywheelFlywheelWater falling over a dam.

A speeding automobile


23/38

Internal combustion engines operate utilizing

the principles of nine (9) physical phenomena.

Heat

Chemistry

Temperature

Force

Power

Pressure

LeverTorque

Horsepower


24/38

HeatKinetic energy caused

by atoms and

molecules in motion

within a substance.


25/38

In a small engine, as the air-fuel

charge is compressed, internal energy

increases, producing heat.

When the charge is ignited and the burninggases expand, internal energy decreases and

heat is given up.

Engines use heat in two ways


26/38

Heat Transfer

Heat is always transferred from an object of

higher heat to one with lower heat.

Transfer is by conduction, convection,

and radiation


27/38

Temperature

Temperature

Temperature (oF) is theintensity of heat.

The amount of heat ismeasured in BTUs.


28/38

BritishThermal Unit

(BTU)

The amount ofheat required to

raise thetemperature of

1 pound ofwater1oF.


29/38

Force

A force can result in

pressure, torque or work,

depending on how it is

applied.

Anything that changes or tends to change

the state of rest or motion of a body.


30/38

PRESSURE

The cylinder pressure is not

constant. It is highest rightafter combustion, as much as2,000 psi, and decreases as

the piston moves away fromthe cylinderhead.

P

Ti

A force acting on a unit of area.


31/38

Force

In engines the amount offorce exerted on the top of apiston is determined by the

cylinder pressure during thecombustion process.

r e s s u r e

A r e a


32/38

Torque

A force acting on the

perpendicular radialdistance from a point

of rotation.

To (lb-ft) = Force x Radius


33/38

Lever

A lever is a simple machine thatconsists of a rigid bar, which pivots on

a fulcrum with both resistance andeffort applied.

Applied force

Resultant force


34/38

Power is the rate of doing work

P =WT

P =F x D

T


35/38

Horsepower

1 Hp = 33,000 ft-lb/min

A unit of power developed by James Watt to

provide a basis for comparing the amount of

power produced by horses and other engines.


36/38

ChemistryAll internal combustion

engines utilize some

form of fossil fuel.

A fossil fuel is composed of carbon and hydrogen.

When the hydrocarbon is ignited in the

presence of air, the oxygen causes an

exchange of elements which release heat

energy.


37/38

PERFECTCOMBUSTION

EQUATION

C8H 18 + 121

2O 2 + 47N 2 = 8CO 2 + 9H 2 O + 47N 2 + HEAT

Unfortunately, combustion is not perfect---the result is

many unwanted gasses and compounds.


38/38

The End

Prsentation on Internal Combustion Engine

Documents