UD 4 ENGINES 3ºESO 15 16 INGLES
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(2) • 0.Introduction • I. Heat engines: – I.1 otto-diesel engine – I.2 jet engine – I.3 thermal fuels • II. Electrical engines – II.1 engine – II.2 electric batteries.. index. • III. Hybrid vehicle. • IV. Engines: Issues and expected developments. 2.
(3) 0-Introduction • Engines are machines that generate movement (kinetic energy) from another type of energy. • The movement is used by an element receiver (wheel, hammer, blade, crane ...). • In order to transmit the movement from the engine to the receiver element there is a mechanism, • With the mechanism you can also modify the movement: transform it from linear to rotative or the other way round or change its speed of strength.. INITIAL ENERGY. ENGINE. axis. axis Mechanism Receiver element. 3.
(4) I. heat engine The heat engine is a machine that converts the chemical energy of a fuel into kinetic energy (movement). When burnt the fuel, the high pressure of the combustion gases of the explotion is used to drive the engine.. Obtaining fuel (polluting process?) air. FUEL TANK. GAS. axis. HEAT ENGINE Mechanism SMOKE. Receptor element. 4.
(5) II. electric engine The electric engine is a machine that converts electrical energy into kinetic energy (movement). Electricity is generated in power plants and stored in a battery, from where it is released with the inverse process of storage. Be aware!: although the electric engine itself is clean , it can contaminate globally if the electric power is obtained by a polluting process. POWER PLANTS OR HYDROGEN PLANTS (Polluting process?). ELECTRIC BATTERY. Electric MOTOR. axis Mechanism. No smoke! The main problem of the electric engine is the autonomy and recharge of the battery. This problem is solved with the hydrogen, but it also tends to be produced by polluting processes.. Receptor element 5.
(6) types of engines HEAT ENGINES. ENGINES. External combustion engine Internal combustio n engine. steam engine. •Otto-diesel motor •jet engine. Direct corrent (DC) engine ELECTRIC ENGINES Alternating corrent (AC) engine. COMPRESSED AIR ENGINES 6.
(7) Heat engines. I. 7.
(8) I.1 otto and diesel engines • •. The heat engine or combution or thermal engine. It works putting inside the fuel + air (oxygen for combustion) in the cylinder. When the mix burns it explodes and explosion gases move the piston.. Admission valve. Device: plug or injector Exhaust valve. v. Combustion chamber piston cylinder. crankshaft. 8.
(9) plug. fuel. Fuel tank air. otto. SMOKE GAS. Spark!. fuel. Fuel tank air. diesel. injector SMOKE. GAS 8.
(10) Four stroke otto cycle. 1st time ADMISSION. GASOLINE + AIR. 2 nd time COMPRESSION. The intake valve opens to let air + gasoline to enter in. 3rd time EXPLOSION EXPANSION. 4th time ESCAPE. The spark gives an electric spark that explodes the mixture. the two valves are closed. The exhaust valve is opened and let he burnt gases to get out. SMO AIR + GASOLINE. AIR + GASOLINE. When raising the piston it compresses the air+gasoline mix. Combustion. The piston moves up by inertica and helps to expel gases. piston When lowering the piston a vacuum is made and causes de air+gasoline to enter in Valve Admissio n Exhaust Valve. The piston is driven down by the explosion gases. OPEN. Closed. closed. Closed. closed. Closed. Closed. OPEN. Off. Off. ON. off. Piston. Plug. 9.
(11) Activities 1.1 • What engine uses the car of your family, an otto or diesel one? • What are the differences between them? • What are the advantages of otto? • What are the advantages of diesel? • Explain in words how an otto engine works. • Draw and explain in words the pattern of the 4-stroke otto cycle.. 11.
(12) I.1 otto and diesel engines •. The combustion engine is a heat engine IGNITION.. Imagen: http://www.taringa.net/posts/autos-motos/9564312/Motor-a-explosion-Naftero.html.
(13) I.2 jet engine The jet engine is a heat engine. free of a piston, air and fuel get sprayed into the combustion chamber and explode. The burnt gases expand with great force and propel the vehicle forward. 12. • •. SMOKE. TURBINE. GAS. Highly compressed air. The expanding gases move in addition a turbine, which in turn drives a compressor to the inlet that comprisses the air in order to get a stronger explotion. COMPRESSOR. Fuel tank.
(14) Jet engine The jet engine was used in the aircraft and rockets from World War II.. fuel. air http://penerbangan-komersial.blogspot.com.es/2014/01/cara-kerjamesin-pesawat.html. SMOKE. 13.
(15) activities 1.2 • What is the difference between a jet engine and an ottodiesel engine? • Why the two are called "internal combustion” engines? • What vehicles use the jet engine? • What vehicles use the diesel engine?. 14.
(16) I.3 thermal fuels FORM OIL (Fossilized organic matter) -GASOLINE (petrol): liquid obtained from light fractions from petroleum. It is used in the OTTO -DIESEL Heavy liquid like gasoline, but less refined. Used in diesel engine. -KEROSENE: Intermediate weight liquid from petroleum Used in jet engines. -LIQUEFIED PETROLEUM-GAS (LPG or AUTOGAS): Gas oil for fuel from cars. -NATURAL-GAS: gas from fossilized matter different of petroleum BIOFUELS (Vegetable organic matter) that: -ETHANOL: -It is a liquid alcohol. -Obtained by fermentation of cereals, beet or sugar cane. -Could be equivalent to gasoline and can be used in otto engines. -BIODIESEL‘ -It's an oily organic liquid, -Is obtained by an esterification reaction of vegetable oils (sunflower, soybean, rapeseed, palm), oils or animal fats. -Could be equivalent to diesel and used in diesel engines. -BIOGAS: -It is a gas composed primarily of methane gas. -It is obtained from the decomposition of organic waste. 15.
(17) Electric engines:. II. 16.
(18) II.1 electric engine. The electric engine uses the effects of repulsion and attraction of the magnets (like poles repel each other, oppsite poles attract). The magnets are actually electromagnets (you know that electric current flowing through coils of copper makes magnets). Through an efficient design and timing, we will make the rotor rotate inside the stator. Electric engines can be direct current (DC) or alternating current (AC). The AC engines can be single-phase or three-phase.. axis. brush. +. manifold. rotor. stator. + 17.
(19) http://upload.wikimedia.org/wikipedia/commons/c/ce/Schemat_ pracy_silnika_elektryczne_pr%C4%85du_sta%C5%82ego.gif. http://upload.wikimedia.org/wikiped ia/commons/c/ce/Schemat_pracy_ silnika_elektryczne_pr %C4%85du_sta%C5%82ego.gif. Electric engine http://apuntescientificos.org/motor-trifasico.html. 18.
(20) engine. II.2 ELECTRIC BATTERY DOWNLOAD In these cells, the anode element (XH) is separated as follows: XH X+ H+ + e• The electrons (e-) are used to run the engine • The positive ion (H+) migrates to the cathode through an intermediate membrane (electrolite) At the cathode, the positive ions and electrons are coupled with an element (Y) to form YH. Y + H + eYH. e-. e-. H+. discharge. H+. XH. Y X. YH. XH. YH. X. H+. RECHARGE. With the power of a electricity generator the process is reversed and the battery is ready to be used again. process. H+. Y. process Charging. eeanode (XH). TYPES: •Lithium ion battery (Li-Ion) •Battery Nickel-Metal Hydride (NiMH). cathode + (Y) 19.
(21) II.2 HYDROGEN BATTERY. engine. It's actually a subtype of electric batteries Download In these batteries, hydrogen (H2) is injected at the anode and desintegrated H2 H+ + H+ + e• The electrons (e-) are used to run the engine • The positive ion (H+) migrates to the cathode through an intermediate membrane. At the cathode, oxygen from air is taken and reacts with the positive ion H+ and electrons e- to form H2O. RECHARGE. Although in theory could have it, in practice has not a recharge process itself. Instead, more hydrogen and oxygen are injected.. eeO2. H2. H+. H2 = 2H+ + E-. O +2 H++ E-= H2 membrane. anode. H2O. cathode. 20.
(22) activities 2.1 • Whichs are the similiraties between an electric engine and a heat engine? • What's the difference? • Why magnets are made with electric wire? • What fuels used in internal combustion engines? • What is the device that generates electric power for the electric engine? • Explain in words how an electric battery works. • Wich is the main advantage and the main disavantage of 21 the hydrogen battery over the metal ion battery?.
(23) the hybrid vehicle. III. 22.
(24) III. hybrid vehicle The hybrid vehicle combines the two types of engines: Combined hybrid: In this case, any of the two engines can be used to propel the car with its own mechanical connection to the wheels. This is a very efficient but more complex mechanically and electronically. Obtaining fuel (contaminants?) air Fuel Tank. GAS. HEAT ENGINE. SMOKE. POWER PLANT! (Contaminants?). BATTERY POWER. Recharge when stopped. Electric MOTOR. axis Mechanism Receptor element. 23.
(25) III. hybrid vehicle Series hybrid: in this case the heat is only used to run electric generator in order to recharge the electric battery. It is the electric motor wich moves the wheels. .. Obtaining fuel (contaminants?) air Fuel Tank. GAS. SMOKE. HEAT ENGINE + ELECTRIC GENERATOR. BATTERY POWER. axis. Electric MOTOR. Mechanism Receptor element. 24.
(26) Activities 3.1 • Find out which models of commercial vehicles in Spain are hybrids. • Analyze your advertising (eg in web pages) What advantages over conventional contribute?. • What has advantages and disadvantages compared to a conventional vehicle? • And in front of an electric?. 25.
(27) Engines: expected problems and developments. V. 26.
(28) V.1 problems The heat engines are the most used and consume fossil fuels. The fossil fuels (oil, natural gas, coal ...) have 3 PROBLEMS: 1-CONTAMINATE with CO2 : -Greenhouse effect and climate change. 2-WILL BE DEPLETED. When finished an ENERGY CRISIS takes place. 3-ENERGY DEPENDENCE from other countries, some unstable and even competitors. The resources are in non-Western countries. So, look for cleaner fuels and engines that do not use them, such as electricity and compressed air.. 27.
(29) V.2 expected developments 1erSTEP: a) Using more eficient engines than squeeze every drop of fossil fuel -Diesel vehicles: use less fuel. -Hybrid vehicles: use electricity + heat. b) implement methods to reduce pollution. -Filters, catalysts. -Using biofuels. 2nd STEP : SUBSTITUTIVE TECHNOLOGIES FOR FOSSIL FUELS -A) Hydrogen Battery power. -B) metal electrical batteries. -C) Compressed air. 28.
(30) activities 5.1 • What are the problems of the fuels used in internal combustion engines' • What would you do to solve the problem? • Why do you think europe governments do not want to use gasoline? • Wich countries are in favour of use petrol? • In the first step of the previous slide, what would you choose a) or b)? • In the second step of the previous slide, what would you choose a), b) or c)?. 29.
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