Conventional Power Plants: How They Generate Electricity

1. UNIT 7 Vocabulary • Conventional Power Plants: • Thermal power plant • Nuclear power plant Grammar and functions • Describing processes: Method&purpose(U6) • Active vs. Passive • Revision of vb tenses (regular & irregular vbs) • Revision of grammar structures

2. DESCRIBING PROCESSES IMPORTANT EXPRESSIONS COMMON VERBS • Use of the PASSIVE • To carry out / develop a process • The process takes place / occurs / happens • This ALLOWS / CAUSES it TO occur (U5) • PREVENTSit FROM occurring (U5) METHOD (U6) (HOW?) • PASSIVE + BY = por • by means of ... / (by) using ... / With the help of ... Through … mediante, pormedio de, con …. • One method for /way of ... (+ verb –ING) .... is to .... PURPOSE (U6) (WHAT FOR?) In order to, so as to, to + INF = Para + Inf

3. TRANSLATION • GREAT/LARGE AMOUNTS OF ELECTRICITY CANNOT BE GENERATEDUNLESS ) a coilrotatesin a magneticfield • thatIS DONE BY MEANS OF/WITH A TURBINE (that is) connectedto a generator • The turbine converts the kinetic or thermal energy of a flowing fluid INTOuseful rotational energy • A generatorcontainsthestator, WHICH IS THE MAGNET and a rotor, WHICH IS THE COIL • WHEN/AS THE ROTOR TURNS the wires cut the lines of force in the magnetic field of the stator • PRODUCING AN ALTERNATING CURRENT • The enormous size of modern generators and the speed AT WHICH the rotor can turn mean that electric power of very high voltage can be produced • AS MUCH AS HALF A MILLION VOLTScan be transmitted over high voltage lines to substations • IN WHICH THE VOLTAGE IS REDUCED WITH / BY ( BY MEANS OF) / BY USING TRANSFORMERS

4. TRANSLATION • The rotor is turned BY/ BY MEANS OF / WITHa turbine, • a huge machine (that is ) movedby water or STEAM IN POWER PLANTS • ACCORDING TO/DEPENDING ON THE SOURCE OF ENERGY (that is)USEDtomovethe turbine • By far, the most important sources of power are those (sources) (which are) producedbyTHE CHEMICAL ENERGY OF/FROM FOSSIL FUELS, LIKE/SUCH AS OIL OR COAL , nuclear energy and thepotentialenergy of waterfalls. • Fossil-fueled power plants contain a boiler WHICH WORKS LIKE a big kettle. • AFTER BEING HEATED (UP) TO A CERTAIN TEMPERATURE, the steam is passed through small holes, increasing the speed of the water molecules • The fast moving molecules hit the blades of the turbine and MAKE IT (THEM) TURN / CAUSE THEM TO TURN.

5. VIDEO: Coal PP (Utube 0-1:50) • Where is half of world’s electricity generated? By coal power plants • How many are there in the world? Close to 3,000 large coal PP • How this controversial yet indispensable PP works, i.e. how to convert the energy storedinthe COAL to ELECTRICITY • Toincreaseburning efficiency a POWDERED COAL and air MIXTURE enters the furnace • During the burning process the chemical energy storedin the coal is releasedas heat to create high temperatures insidethe furnace. • This heat passes to the water inside the coils locatedin the furnace. • The hot water isthenforced to move to the boiler where it evaporates and generates high-pressure steam. • The high-pressure steam is taken tothe steam turbine • The energy inside the steam is converted into mechanical energy. • This mechanical energy isthentransferredto the generator where it will be convertedinto electricity • The generated electricity isfinally transferredto the grid through a transformer and is ready tobe consumed by the public

6. ACTIVE vs PASSIVE Passivevoice: Typical in TECNICAL ENGLISH, particularlywhendescribingprocesses. Thepyramidswerebuiltthousands of years ago. Thesampleswereanalysedin thelaboratory The mixture isfedintothepulveriser. NOTE: - SomeverbshaveNO PASSIVE (intransitive, impersonal) = e.g. RAIN, AGREE, APPEAR, ARRIVE, OCCUR, HAPPEN, BECOME, RISE, BELONG, CONSIST(of), DEPEND, EXIST, DIE, FALL, LIVE, WAIT, HAVE, modals(CAN, MAY, MUST) • Be carefulwithSpanishexpression “se + vb”: e.g. se lava las manos = he washeshishands; Polos opuestos se atraen = unlikepolesattracteachother Thereactionspreads outveryquickly AGENT => BY (por) = ThesystemwasdevelopedBYtheengineers of theplant • ifanobject = BY / BY MEANS OF / USING / WITH / THROUGH e.g. : ThesystemwasdevelopedBY / BY MEANS OF / USING a new technique

7. PASSIVE VOICE TO BE (changing verb) + Past Part of MAIN VERB. + DEVELOPED The system ….. • PRESENT = IS • PRESENT CONT= IS BEING • PAST = WAS (WERE) • PRESENT PERFECT = HAS (HAVE) BEEN • PAST PERFECT = HAD BEEN • WITH MODAL VB = CAN/MUSTBE • WILL / SHOULD = BE • GERUND = BEING • PAST PARTICIPLE = BEEN

8. PASSIVE VOICE FOR = PREPOSITION (+ NOUN)= usuallyPARA • indicating a goal: para, de, por thefoodfortheparty, clothesforchildren, to studyfor a test cure forcancerfor more information, call… time fordinner to travelforpleasure • indicatinga recipient:paraa giftforyou • Indicating cause = because of:porforfear of • en beneficio de : por he foughtforhis country I diditforyou • indicatingduration:por, durante he'sgoingfortwoyears • indicatinga particular time:para, por theweddingisplannedforAprilthat'senoughfornow • indicatingamountorvalue:por, dea checkfor $100 • EXPRESSIONS: FORexample; FORinstance, responsibleFOR…, suitableFOR….., needFOR…, reasonFOR… FOR IS NOT USED TO INTRODUCE THE AGENT in THE PASSIVE

9. PASSIVE VOICE POR • Por causa de => because of, dueto I arrived late because of thetraffic • Transito por un lugar = by, alongthroughwewentthroughthecity center I stoppedbyyourhouse; alongthecoast • durante ( tiempo) => for, duringtheystayedtherefor a week • por medio de => bymeansof Voltageischangedbymeans of transformers • a través de => throughWaterflowsthroughthe pipes • AGENT OF THE PASSIVE=> BYThepyramidswerebuiltbytheEgipcians PARA: PARA + NOUN (usuallyFOR) • Forsomebody=> fora presentforyou • Forsomepurpose => forthefoodisforthepartywhatfor? • indicatingcomparison=> forit'sgoodforwhatitcosts • Time => for, by, aroundanappointmentforMondayit’ll be readybyApril • Direction => to, towardsthey'reheadingtowardstheriver to theright/left • PARA + INFINITIVO (Purpose) = To, In order to, so as to + INFINITIVE he doesit to annoyyou ; in ordernot to be seentooyoung to understand • PARA QUE+ SENTENCE (Purpose) = so that Position the test tube so thatthe metal isbelowthe wáter

10. VERB TENSES Nuclear energy is the energy (that is)RELEASED through the fission or fusion of atomic nuclei. In the process (that is)KNOWNAS nuclear fusion two light atoms join together UNDER conditions of extreme HEAT and PRESSURE (at LEAST 50,000,000 degrees Celsius) until they merge, forming a new nucleus WHOSE mass is only slightly smaller THAN the total masses of the nuclei that FUSE together. The opposite process is nuclear FISSION which MEANS “splitting apart” or “dividing”. If either nuclear fusion or fission TAKES place quickly, the result is a sudden release of ENERGY but so far the only one THAT can BESLOWEDdown and CONTROLLED is fission.

11. VERB TENSES • However, only A FEW elements are suitable FOR use. • When one of THESE elements is STRUCK/STRIKEN by a free neutron, ITSPLITS / BREAKS/ IS BROKENdown INTO two lighter nuclei, WHICH fly apart AT high speeds, colliding WITH surrounding atoms. • This kinetic energy ISCONVERTEDINTOheat. • AT the same time, two or three more neutrons ARERELEASED and one of THEM enters the nucleus of a neighbouring atom, causing fission TOOCCURagain,…. • The reaction SPREADS very quickly with more and more energy (that is)RELEASED. • This IS REFERREDto as A “chain” reaction because the splitting of each nucleus ISLINKEDto another.

12. VERB TENSES • If this reaction ISUNCONTROLLED, the result is an atomic explosion like THAT (the explosion) (which was) CAUSEDby the atomic bombs of Hiroshima and Nagasaki. • However, the reaction can BESLOWEDdown and that is WHAT happens in a nuclear reactor or pile. • Here the highly fissile material ISSURROUNDEDBYa substance that is non-fissile, FOR instance, graphite. • This material IS CALLEDA moderator. • The neutrons LOSE some of THEIR energy through COLLIDING with the atoms of the moderator and no expansion ISPRODUCED. • by SLOWING down the speed of the free neutrons, IT makes it …. collide WITH the nucleus of a neighbouring atom to continue the chain REACTION

13. VERB TENSES • The major advantage of nuclear energy is that it DOES NOTDEPENDON any local factors. • A nuclear reactor, UNLIKE conventional power plants, DOES not have TOBEBUILTnear a fossil-fuel source, nor does it depend ON a large flow of water WHICH may BEREDUCEDduring some seasons of the year.

14. VERBS (regular&irregular) • TO DRAW • DREWDRAWN • TO SPREAD • SPREADSPREAD • TO RAISE • RAISED • TO BUILD • BUILTBUILT • TO SPEND • SPENTSPENT • TO FIND • FOUNDFOUND • TO MAKE • MADEMADE • TO SUPPLY • SUPPLIED • TO THROW • THREWTHROWN • TO WRITE • WROTEWRITTEN • TO RISE • ROSERISEN • TO HOLD • HELDHELD • TO BREAK • BROKEBROKEN • TO PUT • PUT PUT • TO BRING • BROUGHTBROUGHT • TO GIVE • GAVE GIVEN

15. VERBS (regular&irregular) TO KNOW KNEWKNOWN TO SHOW SHOWEDSHOWN TO LEAVE LEFTLEFT TO STRIKE STRUCKSTRUCK/STRIKEN TO LET LETLET TO SEE SAWSEEN TO CUT CUTCUT TO LEAD LEDLED • TO TAKE • TOOKTAKEN • TO SPLIT • SPLITSPLIT • TO WIND • WOUNDWOUND • TO FEED • FEDFED • TO SET • SETSET • TO DRIVE • DROVEDRIVEN • TO ALLOW • ALLOWED • TO FLOW • FLOWED

16. VIDEO: Nuclear reactor • URANIUM • the exact SIZE that is USED in the fuel rods. • This TINY pellet CONTAINS more ENERGY than 6 car loads of coal. • We have 20 MILLION of these pellets INSIDE the reactor vessel. • We call it the CORE. • Around the core, of course, there is WATER. • WATER is used as a COOLANT. • Now, … another set of rods called the CONTROL RODS. • These rods actually control the NUCLEAR REACTION. • What happens is this: …. that is when it is ACTIVATED, • with them gone, the NUCLEAR FUEL sets up a CHAIN REACTION • that PRODUCES a tremendous AMOUNT of HEAT, • that BOILS the WATER, • that turns to STEAM, • that TURNS the TURBINE, • that turns the GENERATOR, that PRODUCES ELECTRICITY.

17. GRAMMAR REVISION: THE NUCLEAR REACTOR • … place IN which a fission NUCLEAR reaction TAKES place. • It contains …in THE form of rods to produce the appropriate result. • The reactor consists OF a fuel, a moderator and A cooling system. • An instrument …neutron WHICH strikes the nucleus of an atom of U-235. • The nucleus … which collide WITH other nuclei and split, and so on. • However, if no explosion occurs IT is because …is moderated BY a non-fissionable material such AS graphite or heavy water. • This absorbs most OF the free neutrons and prevents them FROM splitting too MANY nuclei too quickly. • The process releases great AMOUNTS of energy in the form of heat. • This heat ….produced can be USED to generate electric power. • As the fuel … during ITS use inside the reactor, when IT is taken …, IT is stored in the fuel pools, …, in general more THAN a year, before sending IT to the processing plant.

18. LISTENING: comparison of fuels • about different fuels and processes. We’ve been told that nuclear power is more efficient than conventional fossil fuels and we know that fossil fuels are limited. • -Conventional fossil fuels, i.e., oil, coal and gas, and nuclear fuels, i.e., uranium and plutonium. • -different nuclear reactors and different conventional processes. • -Say a bucket holds 10 kg • Let’s look at the 2 million Kw power station. • 2 million kw make 2,000 megawatts • That’s nuclear fuel • which converts all the matter in this fuel into energy. • it may last 8 ½ years. In fact, ….. with the hydrogen fusion reactor. • Only two weeks • - The next process is a fast reactor. …. natural uranium. • After three days. Now let’s look at conventional fossil fuels, shall we? …. One hour? • -it will last 1/18th of a second. And the same goes with coal. • -In Europe, France, and then West Germany.

19. EXTRA VIDEO: HOW POWER PLANTS WORKhttp://www.youtube.com/watch?v=GI7AhajfhWE • Most power plants produce what? Heat in order to generate steam to drive turbines that generate electricity • Which are the main fuels? Nuclear fission, natural gas and coal • Which fuel is used in W C plant? Coal to produce heat • Furnace boiler: How does the system capture the heat? Usinga system of circulating water and steam • Process: Step 1 • Which process takes place in the boiler? Combustion • Step 2: pulverized COAL is injected with a stream of AIRinto the FURNACEthrough a BURNER • Step 3: Burners IGNITE THE COAL-AIR MIXTURE -> maximum possible heat = AS MUCH AS 1500ºC • The steam turbine generator: converts THE HEAT captured BY THE STEAM INTO ELECTRICIAL ENERGY • Intense HEAT coming FROM THE FURNACE turns WATER RUNNING THROUGH THE PIPESaround the boiler INTO STEAM • Steam travels THROUGH MORE PIPES toTHE TURBINE causing it TO SPIN and turn the shaft of A GENERATOR, which CREATES ELECTRICITY • Another series of pipes ALLOWS THE STEAM TO COOL condensing back INTO WATER heading back to THE BOILER where THE PROCESS BEGINS AGAIN in a continuous cycle