1. UNIT 3 – ENERGY AND POWER 3-6 UNIT 3 Topics Covered
IOT POLY ENGINEERING
3-6
UNIT 3 – ENERGY AND POWER
UNIT 3
Topics Covered
Energy Sources – Fuels and Power Plants
Trigonometry and Vectors
Classical Mechanics:
Force, Work, Energy, and Power
Impacts of Current Generation and Use

2. Power Plants – Engines 3-6 Reciprocating Engines:
IOT POLY ENGINEERING
3-6
Types of Engines
Reciprocating Engines:
Reciprocate: to move forward and backward alternately
Pistons move linearly, forward and backward, in reciprocating engines.
A crank converts linear motion into rotational motion.

3. Types of Engines and Uses
Power Plants – Engines
IOT POLY ENGINEERING
3-6
Types of Engines and Uses
External Combustion (EC) Engines:
Steam – steam locomotives; turbines in electricity stations
Internal Combustion (IC) Engines:
Four-stroke: cars, trucks, motorcycles, construction machinery, airplanes
Two-stroke: moped, dirt bike, chainsaw, trimmer, motor boat, lawnmowers, go-karts
Diesel: 50% new cars in europe, submarines, ships, locomotives, large trucks/machinery
Gas Turbine Engines:
Power plants and airplanes

4. Power Plants – Engines 3-6 Types of Engines – IC
IOT POLY ENGINEERING
3-6
Types of Engines – IC
Spark Ignition – FOUR STROKE
Otto Engine / Otto Cycle
Nicolaus Otto first to develop functioning 4-stroke engine – 1877
Uses spark plugs to ignite fuel/air mixture

5. Power Plants – Engines 3-6 Types of Engines – IC
IOT POLY ENGINEERING
3-6
Types of Engines – IC
Spark Ignition – FOUR STROKE
Cycle begins at Top Dead Center (TDC)
Intake – fuel and air enter cylinder
Compression – fuel mixture under pressure
Combustion – causes expansion against piston
Exhaust – cooled combustion products exhausted
Cylinders fire once every other revolution

6. Power Plants – Engines 3-6 Types of Engines – IC 7
IOT POLY ENGINEERING
3-6
Types of Engines – IC 7
Spark Ignition I.C.E. – FOUR STROKE
Identify the following components:
Piston
Connecting rod
Crankshaft
Valves
Spark plug
Cams
Cam shaft
Cylinder Block
Crank Case
Oil Galleries 6 6 5 4 4 10 1 8 2 9 3

7. Power Plants – Engines Engines – Cylinders
Typically, the larger the number of cylinders, the more powerful the engine.
Engine power is determined by volumetric displacement
The combined volume of all cylinders
Example: 5 Liters, 308 Cubic Inches, cc’s, etc.
W / “3-bank”
Straight/inline 4 V Flat 4

8. Power Plants – Engines Engines – Cams
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Power Plants – Engines
Engines – Cams
Cam – lobe that forces open valves
Camshaft – cylindrical rod that runs length of cylinder bank
Explain valve operation:

9. Power Plants – Engines 3-6 Gasoline
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Gasoline
Petroleum-derived liquid mixture, primarily fuel in internal combustion engines
Enhanced with additives to tune performance and reduce emissions
Enhanced with isooctane to prevent engine “knocking”
“same” 8
hydrocarbon

10. Power Plants – Engines 3-6 Gasoline – Octane Rating
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Gasoline – Octane Rating
Engine Knocking – when combustion occurs in the cylinder at the wrong time
Not due to spark plug igniting incorrectly
Due to pressure exploding fuel before plug ignites
Octane Rating – the higher the rating, the less knocking
High performance cars operate at higher pressures – require higher octane.
Standard performance cars – higher octane is a waste of $

11. Power Plants – Engines 3-6 Engine Oil Lubricates moving parts
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Engine Oil
Lubricates moving parts
Creates separating film between surfaces
Minimizes direct contact between parts
Decreases friction, wear, excess heat
Prevents the waste of useful power and the degradation of the engine, and increases efficiency
Cleans and inhibits corrosion – metallic parts and sludge carried out of engine to oil filter

12. Power Plants – Engines 3-6 Engine Oil
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Engine Oil
Improves sealing – keeps fuel and combustion in the right place
Cools the engine – carries heat away from moving parts
Oil Galleries:
Small passages in cylinder block
Allow oil to flow to moving parts