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 3-6 Types of Power Plants
IOT POLY ENGINEERING
3-6
Power Plants
Types of Power Plants
The engine, motor, and related parts
Supplies the motive power of a self-propelled object
Produces a kinetic energy output from a fuel source input
Electricity generating station
Typically what is referred to by “power plant”
Mechanical, heat, chemical, solar sources

3. Power Plants 3-6 Why Study Power Plants?
IOT POLY ENGINEERING
3-6
Power Plants
Why Study Power Plants?
Insight into the fundamental operation of most engineered technologies
Application of scientific and mathematical principles in real-world problem-solving situations

4. Power Plants – Engines 3-6 Terminology
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Terminology
Combustion – the burning of fuel with an oxidizer
Oxidizer – a chemical compound that transfers oxygen atoms – a typical oxidizer is ambient air
Ambient – surrounding, environmental, atmospheric
External combustion engine (ECE) – heat engine that derives heat from fuel consumed outside engine
Internal combustion engine (ICE) – heat engine that derives heat from combustion of fuel within engine, instead of in external furnace
Thermodynamics – physics that deals with the mechanical action or relations of heat

5. Power Plants – Engines 3-6 Types of Engines
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3-6
Types of Engines
Historically – engine referred to device that converted force into motion
Catapult, battering ram, and other siege weapons
Mills – grinding
Water mill, wind mill, horse mill, treadmill
al-Jazari – invented crankshaft and connecting rod, one of the most important mech. technologies after wheel
1698 – first practical steam powered engine – Thomas Savery

6. 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

7. Power Plants – Engines 3-6 Reciprocating Engines:
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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.

8. Power Plants – Engines 3-6 Steam Engine Steam
IOT POLY ENGINEERING
3-6
Types of Engines – E.C.E.
Steam Engine
Steam
Molecules of gases are further apart than molecules in liquids and solids
Vaporized water (steam) takes up more space than liquid water

9. Power Plants – Engines 3-6 Types of Engines – E.C.E.
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3-6
Types of Engines – E.C.E.
Steam Engine (continued)
History
75 C.E. Hero of Alexandria – mathematician
Presented plans for simple steam engine
1679 Denis Papin of France – pressure cooker
1698 Thomas Savery, English military engineer – Miner’s Friend pumped water out of coal mines
1712 Newcomen Engine, improved Savery’s design

10. Power Plants – Engines 3-6 Types of Engines – E.C.E.
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3-6
Types of Engines – E.C.E.
Steam Engine (cont.)
History (cont.)
1765 James Watt (Scotland) – mathematician, inventor, instrument maker, engineer
Modern steam engine credited to Watt
1804 Arthur Woolf (England) – compound steam engine
Increases the efficiency of the engine by reusing the steam in additional cylinders.

11. Power Plants – Engines 3-6 Steam Engine (cont) Steam Locomotive
IOT POLY ENGINEERING
3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Steam Locomotive
1770s – tracks laid for horses to pull carts
1804 – steam-powered engine
1820s – “Father of Railways” George Stephenson – civil and mechanical engineer Builds first public railway lines
Harnessing steam power made the Industrial Revolution possible

12. Power Plants – Engines 3-6 Types of Engines – E.C.E.
IOT POLY ENGINEERING
3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Operation – PISTON
High pressure steam enters
HP steam pushes piston
Valve rod shifts
HP steam pushes piston in reverse direction
Original steam, now cooled, exits through exhaust:
Choo-choo-choo-choo-choo

13. Power Plants – Engines 3-6 Types of Engines – E.C.E.
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3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Operation – PISTON
Coal Exhaust
Steam Exhaust

14. Power Plants – Engines 3-6 Types of Engines – E.C.E.
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3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Operation – BOILER
Coal burned in furnace
Hot gasses boil water
Steam moves to cylinder, gases exhaust through smokestack
Fire-tube Boiler (past)
Water-tube Boiler (modern)

15. Power Plants – Engines 3-6 Types of Engines – E.C.E.
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3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Operation – COMPOUND STEAM ENGINE
Engineers’ objective is to harness as much of the energy in the burning fuel as possible.
Compound steam engine reuses exhaust steam/fuel as much as possible (3 times below).

16. Power Plants – Engines 3-6 Types of Engines – E.C.E.
IOT POLY ENGINEERING
3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Explain what you see…

17. Power Plants – Engines 3-6 Types of Engines – E.C.E.
IOT POLY ENGINEERING
3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Explain what you see…

18. Power Plants – Engines 3-6 Types of Engines – E.C.E.
IOT POLY ENGINEERING
3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Explain what you see…

19. Power Plants – Engines 3-6 Types of Engines – E.C.E.
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3-6
Types of Engines – E.C.E.
Steam Engine (cont)
Explain what you see…

20. Power Plants – Engines 3-6 Reciprocating Engines:
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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.

21. 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

22. Power Plants – Engines 3-6 Types of Engines – IC
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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

23. Power Plants – Engines 3-6 Types of Engines – IC
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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

24. Power Plants – Engines 3-6 Types of Engines – IC 7
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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

25. Power Plants – Engines 3-6 Types of Engines – IC
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3-6
Types of Engines – IC
Spark Ignition – TWO STROKE
Does not have valves – simplifies construction and lowers weight
Fire once every revolution, instead of every other (4-stroke) – power boost
Work in any physical orientation (4-stroke limited due to oil flow)

26. Power Plants – Engines 3-6 Types of Engines – IC
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3-6
Types of Engines – IC
Spark Ignition – TWO STROKE
Expansion/Transfer/Exhaust
Spark ignition
Intake port exposed
Exhaust forced out
Compression/Charging
Compression of air/fuel/oil mixture
Fuel pulled into crankcase by vacuum – “charging”

27. Returns unused fuel to cylinder, and charges cylinder
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Types of Engines – IC
Spark Ignition – TWO STROKE
Can you identify the strokes?
Notice in this animation the “return positive pressure”
What purpose does it fulfill?
Returns unused fuel to cylinder, and charges cylinder

28. Compression Ignition – not spark ignition
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Types of Engines – IC
Diesel Ignition
Compression Ignition – not spark ignition
Spark ignition –
Piston compresses air/fuel mixture, spark ignites combustion.
Amount of pressure is limited (early combustion bad)
Compression ignition –
Piston compresses air (fuel is not mixed)
Fuel injected into hot compressed air – initiates combustion

29. Power Plants – Engines 3-6 Types of Engines – IC
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Types of Engines – IC
Diesel Ignition (cont.)
Early gasoline engines very inefficient
Greater power and efficiency available at higher pressures
Rudolf Diesel – patented engine by 1892
Student of Polytechnic High School of Germany
Fuel has higher energy density than gasoline
Fuel emits fewer greenhouse gases
Fuel emits greater N-gases and soot

30. Power Plants – Engines 3-6 Types of Engines – IC Diesel Engine
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3-6
Types of Engines – IC
Diesel Engine
No spark plug
4-stroke engine
Air intake
Compression
Fuel injection / Combustion
Exhaust

31. 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

32. 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:

33. 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
(not external combustion or gas turbine engines)
Enhanced with additives to tune performance and reduce emissions
Enhanced with isooctane to prevent engine “knocking”
“same” 8
hydrocarbon

34. 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 $

35. 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

36. 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

37. Oil starts in the sump/pan Pump sends oil through filter
Oil enters galleries
Oil lubricates main bearings and camshaft bearings
Lubricates crankshaft and rods
Seals piston rings

38. Power Plants – Engines 3-6 Engine Oil Filler Cap Oil Pan Drain Bolt
IOT POLY ENGINEERING
3-6
Power Plants – Engines
Engine Oil
Filler Cap
Oil Pan
Drain Bolt
Images:

39. POWER-TO-WEIGHT RATIO:
Power Plants – Engines
IOT POLY ENGINEERING
3-6
Types of Engines – Aircraft Engines
In-line engine
Early aircraft, including Wright Brothers’.
Advantage: narrow frontal area for low drag
Disadvantage: Poor power-to-weight ratio (heavy crankcase and crankshaft)
In ALL engines, we want a high power-to-weight ratio.
POWER-TO-WEIGHT RATIO:
amount of power you get out of the engine compared to the weight of the engine itself
P Wt

40. Types of Engines – Aircraft Engines
Power Plants – Engines
IOT POLY ENGINEERING
3-6
Types of Engines – Aircraft Engines
Rotary engine i.c.e.
Early WWI
Cylinders around crankcase, crankshaft bolted to airframe
Entire engine rotates with the propeller
Advantages: Lightweight, powerful, cheap, easy to manufacture
Disadvantage: Difficult to fly, spread oil over plane

41. Types of Engines – Aircraft Engines
Power Plants – Engines
IOT POLY ENGINEERING
3-6
Types of Engines – Aircraft Engines
Radial engine i.c.e.
Post WWI
Cylinders around crankcase, bolted to airframe
Propeller rotates with crankshaft
Advantages: Good P/W ratio, cools evenly, runs smoothly
Disadvantage: blunt and aerodynamically inefficient profile

42. Types of Engines – Gas Turbine
Power Plants – Engines
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3-6
Types of Engines – Gas Turbine
Gas Turbine
1934: first “free-piston engine”

43. Types of Engines – Gas Turbine
Power Plants – Engines
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3-6
Types of Engines – Gas Turbine
Compressor
Compresses incoming air to high pressure (up to 30 times)
2) Combustion Area
Burns fuel and produces high pressure, high velocity gas
3) Turbine
Extracts energy from combustion

44. Types of Engines – Gas Turbine
Power Plants – Engines
IOT POLY ENGINEERING
3-6
Types of Engines – Gas Turbine
Gas Turbine (cont.)
Advantages:
High power-to-weight ratio
Smaller than reciprocating engines of same power
Disadvantages:
Expensive
High speeds and temperatures – materials
More fuel while “idling”

45. Types of Engines – Gas Turbine
Power Plants – Engines
IOT POLY ENGINEERING
3-6
Types of Engines – Gas Turbine
Gas Turbine (cont.)
Uses:
Jet Engines
Electrical Generation
Other Vehicles
Tanks
Naval Vessels
Automobiles

46. Types of Engines – Gas Turbine
Power Plants – Engines
Types of Engines – Gas Turbine
Gas Turbine (cont.)
Turbine Jet Engine
THRUST

47. Types of Engines – Gas Turbine
Power Plants – Engines
Types of Engines – Gas Turbine
Gas Turbine (continued)
Turbofan
THRUST

48. Types of Engines – Other Types
Power Plants – Engines
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3-6
Types of Engines – Other Types
Other types of engines
Bourke
Wankel
Sterling
Carnot Heat Engine
Controlled Combustion
IRIS Engine
Five-stroke
Six-stroke

49. Non-Renewable Fuels – Petroleum
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3-2
Petroleum
Distillation

50. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Background

51. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Background
What electricity is used for:
Heating, cooking, cooling, light, sound, computers, communication, entertainment…
Distribution grid:
Our focus

52. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Typical Operation
Fuel is used to produce heat energy
Water is heated and boiled to steam
High pressure steam enters and spins turbines
(Turbines convert steam into mechanical energy)
Turbines turn electrical generator (electricity is created)
Electricity is transmitted via cables through power grid 2 1 5 3 4

53. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Power Plants – Power Stations
Alternative Operation
Alternative energy source (e.g. water, wind) spins turbines
Turbines turn electrical generator
Electricity is transmitted via cables through power grid 1 3 2

54. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Non-renewable
Fossil Fuel Power Plant – Coal
Prime mover is steam turbine
Flue gas exhausted to atmosphere
Waste heat released to atmosphere – cooling towers
2nd law of thermodynamics – not all heat can be converted into mechanical form to do work, some heat will be wasted
A power plant cannot be 100% efficient

55. Power Plants – Power Stations
Types of Power Stations – Non-renewable
Fossil Fuel Power Plant – Coal (cont.)
Flue 7 5 4 1 3 6 2
Waste Heat

56. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Power Plants – Power Stations
Types of Power Stations – Non-renewable
Fossil Fuel Power Plant – Petroleum and Natural Gas
Prime mover is gas turbine

57. Power Plants – Power Stations
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3-7
Power Plants – Power Stations
Waste heat (options):
Cooling Towers: Released to atmosphere
Combined Cycle: Recycled in secondary boiler

58. Power Plants – Power Stations
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3-7
TERTIARY LOOP
SECONDARY LOOP
PRIMARY LOOP
Cooling water from outside source; gets hot as it condenses steam
Released in cooling tower
Nuclear Power Plant
Closed-loop reactor
Control rods inserted to decrease chain reaction (control rods absorb neutrons, which slows reaction)
Heated reactor water boils secondary loop of water in boiler (steam generator)
Steam spins turbine
Electricity generated to grid

59. Containment Structure
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3-7
Steam Turbine
Generator
Condenser
Cooling Tower
Containment Structure
Reactor
Boiler
Nuclear Power Plant (continued)

60. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant
Total solar energy absorbed by earth in 1 hour is more than world uses in a year
1 year of solar energy is as much as twice the amount of energy derived from all non-renewables on Earth
All renewables (except geothermal) derive energy from the Sun (e.g., wind, biomass, hydro, wave…)
Sun’s warmth and light
Passive collection – capturing warmth and light through design
Active collection – using technology to transform solar energy into electricity

61. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – PASSIVE COLLECTION
Architecture – designing structures
Face buildings south
Solar water heating

62. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – PASSIVE COLLECTION (cont.)
Agriculture – growing food
Fruit walls (trap heat and accelerate ripening)
Timed planting cycles
Drying chicken manure
Greenhouses

63. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – PASSIVE COLLECTION (cont.)
Other Uses
Water treatment – UV filter
Cooking – focuses heat directly or creates steam

64. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – ACTIVE COLLECTION
Photovoltaics (PV)
Photovoltaic Effect – converts light into electric current
1880s – first solar cell
1958 – first significant application – Vanguard I satellite
1960s – PV established power source for satellites
Hamau Solar Park, Germany

65. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – ACTIVE COLLECTION (cont.)
Concentrating Solar Power (CSP)
Use lenses, mirrors, trackers to focus large area of sunlight into small beam
Solar troughs – most cost-effective
Parabolic reflector – most efficient

66. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Solar Power Plant – ACTIVE COLLECTION (cont.)
Concentrating Solar Power (CSP)
Solar tower – traps heat, creates steam for turbines
Solar updraft tower – combines chimney, greenhouse, wind turbine

67. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Wind Power Plant
Sun influences weather processes that create wind
Converts wind energy into electricity using turbines
History
>5,500 yrs ago – sailboats and natural ventilation
600s, Afghanistan – vertical shaft mills grind grain
1100s, Europe – horizontal shaft mills grind wheat
U.S. – used for irrigation

68. Sketch and label this diagram
Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Wind Power Plant (cont.)
Blades – propellers mounted on masts are pitched (angled)
Gear Box – connects low-speed shaft to high-speed shaft to increase rpm from ~50 to ~1200
Generator – converts mechanical energy of high-speed shaft to electrical energy
Sketch and label this diagram
Mast

69. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Hydroelectric Power Plant
Gravitational force of falling water converted into electricity using turbines
History
>2000 yrs ago, Rome and Greece – grinding wheat into flour
1700/1800s – powered textile and industrial mills
1882, Wisconsin – first hydroelectric plant

70. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Hydroelectric Power Plant (cont.)
Dam stores water in reservoir
Energy generation depends on head – height difference from top of reservoir to top of river – and volume
Spillway releases excess water
Gate releases dam water into penstock – screen prevents objects from damaging turbines
Penstock is piping – pressure of water increases

71. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Hydroelectric Power Plant (cont.)

72. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Hydroelectric Power Plant (cont.)

73. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Geothermal Power Plant
Harnessing energy generated from heat stored in Earth
History
Hot springs used for centuries for bathing and heating
1911, Italy – world’s first and only plant until 1958

74. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Geothermal Power Plant (cont.)
Steam or hot water pumped from underground to turn turbines
Waste steam/water returned to ground or reused

75. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Tidal Power Plants

76. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Wave Power Plants – 2 types
Linear Generator