08-10-2016, 11:01 AM
1458308129-783000409AirCarSeminarReport.docx (Size: 853.9 KB / Downloads: 4)
Abstract
TheAircarisacarcurrentlybeingdevelopedand,eventually,manufacturedbyMoteurDeveloppementInternational(MDI),founded bytheFrenchinventorGuyNègre.Itwillbesoldbythis companytoo,aswellasbyZevCat,aUScompany,basedinCalifornia.
Theaircarispoweredbyanairengine,specificallytailoredforthecar.Theusedairengineisbeing manufacturedbyCQFDAirsolution,acompanycloselylinkedtoMDI.
Theengineispoweredbycompressedair,storedinaglassorcarbon-fibretankat4500psi.Theengine hasinjectionsimilartonormalengines,butusesspecialcrankshaftsandpistons,whichremainattopdead centerforabout70%oftheengine'scycle;thisallowsmorepowertobedevelopedintheengine.
Thoughsomeconsiderthecartobepollution-free,itmustbetakenintoaccountthatthetanksare rechargedusingelectric(orgasoline)compressors,resultinginsomepollution,iftheelectricityusedto operatethecompressorscomesfrompollutingpowerplants(suchasgas-,orcoal-powerplants).Solar powercouldpossiblybeusedtopowerthecompressorsatfuelstation.
Introduction
AnAirCarisacarthatcanrunoncompressedairalonewithouttheuseofconventionalfuelsusedin presentdayautomobiles.Thecarispowered byanairengine.Theairengineisanemission-freepistonengineusingcompressedair.Theenginesaresimilartosteamenginesastheyusetheexpansionof externallysuppliedpressurisedgastoperformworkagainstapiston.
Forpracticalapplicationtotransportation,severaltechnicalproblemsmustbefirstaddressed:
• Asthepressurisedairexpands,itiscooled,whichlimitstheefficiency.Thiscoolingreducesthe amountofenergythatcanberecovered byexpansion,sopracticalenginesapplyambientheatto increasetheexpansion available.
• Conversely,thecompressionoftheairbypumps(topressurisethetanks)willheattheair.Ifthis heatisnotrecovereditrepresentsafurtherlossofenergyandsoreducesefficiency.
• Storageofairathighpressurerequiresstrongcontainers,whichifnotmadeofexoticmaterialswill beheavy,reducingvehicleefficiency,whileexoticmaterials(suchascarbonfibrecomposites)tend tobeexpensive.
• Energyrecoveryinavehicleduringbrakingbycompressingairalsogeneratesheat,whichmustbe conservedforefficiency.
• Itshouldbenotedthattheairengineisnottrulyemission-free,sincethepowertocompresstheair initiallyusuallyinvolves emissionsatthepointofgeneration.
Thismostrecentdevelopmentusingpressurizedairasfuelinanenginewasinvented byGuyNègre,aFrenchengineer.In1991theinventorGuyNègrestartedupMoteurDeveloppementInternational(MDI), Luxembourgandinventedadual-energyenginerunningonbothcompressedairasonregularfuel.From thismomentonhemanagedtocreateacompressedaironly-engine,andimprovedhisdesigntomakeit morepowerful.Inthe15 yearshe'sbeenworkingonthisengine,considerableprogresshasbeenmade:the engineisnowclaimedtobecompetitivewithmodernICEs.ItisprobablystillnotaspowerfulasanICE (althoughdependingonwhichmodelofairenginevsmodelICE).Proponentsclaimthatthisisoflittle importancesincethecarcansimplybemadelighter,orthetanksbeputonahigherpressure(psi-level), pushingtheenginetoaboveacomparable ICE-engine.
OtherpeoplethathavebeenworkingontheideaareArmandoRegusciandAngeloDiPietro.Theytoo havecompanies,RuguscistartedupRegusciAirandDiPietrostartedupEngineAir.Theyaresellingtheir engines.
2.EngineDesign
Itusestheexpansionofcompressedairtodrivethepistonsinamodifiedpistonengine.Efficiencyof operationisgainedthroughtheuseofenvironmentalheatatnormaltemperaturetowarmtheotherwisecold expandedairfromthestoragetank.Thisnon-adiabaticexpansionhasthepotentialtogreatlyincreasethe efficiencyofthemachine.Theonlyexhaustgasiscoldair(−15°C),whichmayalsobeusedforairconditioninginacar.Thesourceforairisapressurizedglassorcarbon-fibertankholdingairataround
3,000lbf/in²(20MPa).Airisdeliveredtotheengineviaaratherconventionalinjectionsystem.Unique crankdesignwithintheengineincreasesthetimeduringwhichtheairchargeiswarmedfromambient sourcesandatwostageprocessallowsimprovedheattransferrates.
TheArmandoRegusci'sversionoftheairenginehasseveraladvantagesovertheoriginalGuyNègre's one.IntheinitialGuyNègre'sairengine,onepistoncompressesairfromtheatmosphere,holdingitona smallcontainerthatfeedsthehighpressureairtankswithasmallamountofair.Thenthatportionoftheair issenttothesecondpistonwhereitworks.Duringcompressionforheatingitup,thereisalossofenergy duetothefactthatitcannotreceiveenergyfromtheatmosphereastheatmosphereislesswarmthanit. Also,ithastoexpandasithasthecrank.TheGuyNègre'sairengineworkswithconstanttorque,andthe onlywaytochangethetorquetothewheelsistouseapulleytransmissionofconstantvariation,losing efficiency.IntheRegusci'sversion,thetransmissionsystemisdirecttothewheel,andhasvariabletorque fromzerotothemaximumwithalltheefficiency.Whenvehicleisstopped,GuyNègre'senginehas tobe
onandworking,losingenergy,whiletheRegusci'sversionhasnot.
InJuly2004,GuyNègreabandonedhisoriginaldesign,andshowedlateranewdesignwherehestated tohaveitinventedbackinyear2001,buthisnewdesignisidenticaltotheArmandoRegusci'sairengine whichwaspatentedbackin1989(Uruguay)withthepatentnumber22976,andbackin1990(Argentina). Inthosesamepatents,itismentionedtheuseofelectricalmotorstocompressairinthetanks.
3.Usesofairengine
TheNègreengineisusedtopoweranurbancarwithroomforfivepassengersandaprojectedrangeof about100to200miles(160to320km),dependingontrafficconditions.Themainadvantagesare:no roadsideemissions,lowcosttechnology,engineusesfoodoilforlubrication(justabout1liter,changes
onlyevery30,000miles(50,000km))andintegratedairconditioning.Rangecouldbequicklytripled,since therearealreadycarbonfibertankswhichhavepassedsafetystandardsholdinggasat10,000lbf/in²(70
MPa).
Thetanksmayberefilledinaboutthreeminutesataservicestation,orinafewhoursathomeplugging thecarintotheelectricgridviaanon-boardcompressor.However,theairengineandrefuelingsystem, consideredasasystem,arenotpollutionfreeexceptinspecialcases,astheelectricpowergenerationwould haveitsownenvironmentalcosts.Oneofthespecialcasesiswhereanoperatorofsuchavehicleinstalls photovoltaicorwinddriveelectricpowergeneration.
4.MDICAT’s(Compressedairtechnologycars)
MDIpreparestointroducecompressedairvehiclestothemarket. MDIhasdevelopedahigh performancecompressedairtechnology.Whenitiscomparedtotraditionalgasolinepoweredengines, MDI
´sengineisfarsuperiorintermsofenergyusedandthermodynamics.
Anoverview oftheaircar
ThetechnologythatMDIvehiclesuseisnotnew,infactithadbeenaroundforyears.Compressedair technologyallowsforenginesthatarebothnonpollutingandeconomical.Aftertenyearsofresearchand development,MDIispreparedtointroduceitscleanvehiclesontothemarket.Unlikeelectricorhydrogen poweredvehicles,MDIvehiclesarenotexpensiveanddonothavealimiteddrivingrange. MDIcarsare affordableandhaveaperformanceratethatstands uptocurrentstandards.Tosumitup,theyarenon- expensivecarsthatdonotpolluteandareeasytogetaroundcitiesin.
Twotechnologieshavebeendevelopedtomeetdifferentneeds: Singleenergycompressedairengines
Dualenergycompressedairplusfuelengines
ThesingleenergyengineswillbeavailableinbothMinicatsandCitycats. Theseengineshavebeen conceivedforcityuse,wherethemaximumspeedis50km/handwhereMDIbelievespollutingwillsoon beprohibited.
Thedualenergyengine,ontheotherhand,hasbeenconceivedasmuchforthecityastheopenroadand willbeavailableinallMDIvehicles.Theengineswillworkexclusivelywithcompressedairwhileitis runningunder50km/hinurbanareas.Butwhenthecarisusedoutsideurbanareasatspeedsover50km/h, theengineswillswitchtofuelmode.Theenginewillbeabletousegasoline,gasoil,biodiesel,gas, liquidizedgas,ecologicalfuel,alcohol,etc.
Bothengineswillbeavailablewith2,4and6cylinders,Whentheairtanksareemptythedriverwillbe abletoswitchtofuelmode byusingthecar’sonboardcomputer.Thevehiclesdonothavenormalspeed gauges.Instead,theywillhaveasmallcomputerscreenthatshowsthespeedandenginerevolutions.The systemallowsforinfinitepossibilitiessuchasGSMtelephonesystems,GPSsatellitetrackingsystems, programs for delivery people, emergency systems, internet connections, voice recognitions, map presentation,trafficinformation...inthreewords:thefutureisnow.
Unlikethemajorityoftraditionalcarsonthemarket,MDI´svehicle'shavefibreglassbodieswhich makesthemlight,silenturbancar.Thecar'sbodyistubular,lightweight,andisheldtogetherusing aerospacetechnology.