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

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 http://inventors.about.com/library/inventors/blotto.htm

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 http://en.wikipedia.org/wiki/Internal_combustion_engine#Two-stroke

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 http://upload.wikimedia.org/wikipedia/commons/f/f7/Four_stroke_cycle_compression.jpg 1 8 2 9 3

Power Plants – Engines 3-6 Types of Engines – IC IOT POLY ENGINEERING 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) http://en.wikipedia.org/wiki/Two-stroke_engine

Power Plants – Engines 3-6 Types of Engines – IC IOT POLY ENGINEERING 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” http://www.keveney.com/twostroke.html

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 http://www.keveney.com/twostroke.html

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

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

Power Plants – Engines 3-6 Types of Engines – IC Diesel Engine IOT POLY ENGINEERING 3-6 Types of Engines – IC Diesel Engine No spark plug 4-stroke engine Air intake Compression Fuel injection / Combustion Exhaust http://www.keveney.com/twostroke.html

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, 250 cc’s, etc. W / “3-bank” http://www.ul.ie/~kirwanp/linkstoanimations.htm http://auto.howstuffworks.com/engine2.htm http://en.wikipedia.org/wiki/W_engine Straight/inline 4 V6 Flat 4

Power Plants – Engines Engines – Cams IOT POLY ENGINEERING Power Plants – Engines Engines – Cams Cam – lobe that forces open valves Camshaft – cylindrical rod that runs length of cylinder bank Explain valve operation: http://www.ul.ie/~kirwanp/linkstoanimations.htm http://en.wikipedia.org/wiki/Camshaft

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” http://www.eia.doe.gov/kids/energyfacts/sources/non-renewable/naturalgas.html#HOWWEGETIT “same” 8 hydrocarbon

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 $ http://www.eia.doe.gov/kids/energyfacts/sources/non-renewable/naturalgas.html#HOWWEGETIT

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 http://www.eia.doe.gov/kids/energyfacts/sources/non-renewable/naturalgas.html#HOWWEGETIT

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 http://www.eia.doe.gov/kids/energyfacts/sources/non-renewable/naturalgas.html#HOWWEGETIT

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 http://www.kic-oil.com/images/Engine%20Oil%20Bible%20(Tech%20Article)_html_m36ab91ab.jpg http://images.google.com/imgres?imgurl=http://www.installuniversity.com/install_university/installu_graphics/freshman_year/engine_oil_change/engine_oil_filler_cap.jpg&imgrefurl=http://www.installuniversity.com/install_university/installu_pages/freshman_year/engine_oil_change.htm&usg=__xhl7DieY85ai1H6-R3Ffe4Tw3SU=&h=432&w=576&sz=59&hl=en&start=13&um=1&tbnid=hn78IIkX-WMLKM:&tbnh=101&tbnw=134&prev=/images%3Fq%3Dengine%2Boil%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DN

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 http://www.installuniversity.com/install_university/installu_pages/freshman_year/engine_oil_change.htm Oil Pan Drain Bolt Images: www.installuniversity.com