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Internal Combustion Engines. Engine. “A machine for converting energy into mechanical force and motion.”. Heat Engine. An engine which uses heat to convert the chemical energy of a fuel into mechanical force and motion. Two general categories based on design. External combustion engine. - PowerPoint PPT Presentation
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Internal Internal Combustion Combustion EnginesEngines
EngineEngine• ““A machine for converting A machine for converting
energy into mechanical force energy into mechanical force and motion.”and motion.”
Heat EngineHeat Engine
An engine which uses heat to An engine which uses heat to convert the chemical energy of a convert the chemical energy of a
fuel into mechanical force and fuel into mechanical force and motionmotion
Two general categories based on Two general categories based on design.design.
External combustion engine
Internal combustion engine
Engine SizeEngine Size•Largest:Largest:
•The Wartsila-Sulzer RTA96-C The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is turbocharged two-stroke diesel engine is the most powerful and most efficient the most powerful and most efficient prime-mover in the world today.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.
Engine Size--cont.Engine Size--cont.
•Smallest: Smallest:
•Not much bigger than a stack of Not much bigger than a stack of pennies, the "mini engine" is the pennies, the "mini engine" is the first engine of its size to deliver first engine of its size to deliver power on a continuous basis.power on a continuous basis.
•Currently will produce 2.5 watts Currently will produce 2.5 watts of electricity (0.00335 hp).of electricity (0.00335 hp).
•Uses 1/2 fluid ounce of fuel per Uses 1/2 fluid ounce of fuel per hourhour
Engines are further classified by Engines are further classified by ignition, number of strokes, ignition, number of strokes,
cylinder design/orientation and cylinder design/orientation and cooling system. cooling system.
IgnitionIgnition
• Spark ignitionSpark ignition
Compression ignition
Number of Number of StrokesStrokes
• Four strokeFour stroke
Two stroke
Cylinder Design-Cylinder Design-cont.cont.
V
Horizontally opposed
In-line
Three common cylinder configuration in multiple cylinder engines:
• When fuel is oxidized (burned) heat is When fuel is oxidized (burned) heat is produced.produced.
• Only approximately 30% of the energy Only approximately 30% of the energy released is converted into useful work.released is converted into useful work.
• The remaining (70%) must be removed The remaining (70%) must be removed from the engine to prevent the parts from the engine to prevent the parts from melting.from melting.
Excess heat is removed by:Excess heat is removed by:
• Cooling systemCooling system
• Exhaust systemExhaust system
• Lubrication systemLubrication system
• Radiation Radiation
Additional heat is also Additional heat is also generated by friction generated by friction between the moving parts.between the moving parts.
•This heat This heat must also be must also be removed.removed.
Energy Conversion PrincipleEnergy Conversion Principle
• ““All internal combustion engines exhibit All internal combustion engines exhibit and convert different forms of energy.”and convert different forms of energy.”
• ““Energy is the resource that provides Energy is the resource that provides the capacity to do work”.the capacity to do work”.
• The two forms of energy used in The two forms of energy used in engines are potential and kinetic. engines are potential and kinetic.
Potential Energy Potential Energy
•““Stored energy a body has due Stored energy a body has due to its position, chemical state, or to its position, chemical state, or condition.”condition.”
Examples of Potential Examples of Potential EnergyEnergy
•Fuels have potential Fuels have potential energy based on their energy based on their chemical state.chemical state.
A compressed spring has potential energy due to its mechanical condition.
Water behind a dam has potential energy due to difference in elevation.
Kinetic EnergyKinetic Energy
• FlywheelFlywheel
Water falling over a dam.
A speeding automobile
ForceForce
• In engines the In engines the amount of force amount of force exerted on the top of a exerted on the top of a piston is determined piston is determined by the cylinder by the cylinder pressure during the pressure during the combustion process.combustion process.
P r e s s u r e
A r e a
TorqueTorque
• ““A force acting on A force acting on the perpendicular the perpendicular radial distance from radial distance from a point of rotation.”a point of rotation.”
To (lb-ft) = Force x Radius
LeverLever
•““A lever is a simple machine that A lever is a simple machine that consists of a rigid bar”,consists of a rigid bar”, which pivots on a fulcrum with both resistance and effort applied. Applied force
Resultant force
•Power is the rate of doing workPower is the rate of doing work
P=WT
P=F x D
T
.
HorsepoweHorsepowerr
• 1 Hp = 33,000 ft-lb/min1 Hp = 33,000 ft-lb/min
• A unit of power developed by James A unit of power developed by James Watt to provide a basis for comparing Watt to provide a basis for comparing the amount of power produced by the amount of power produced by horses and other engines. horses and other engines.
