?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F152%2F&rft.title=Spot-on%3A+Safe+Fuel%2FAir+Compression&rft.creator=Banks%2C+Jeffrey&rft.creator=Fehribach%2C+Joseph&rft.creator=Fitt%2C+Alistair&rft.creator=Hart%2C+Robert&rft.creator=Hughes%2C+Kevin&rft.creator=Ockendon%2C+John&rft.creator=Please%2C+Colin&rft.creator=Schwendeman%2C+Don&rft.creator=Tilley%2C+Burt&rft.creator=Weekes%2C+Suzanne&rft.subject=Transport+and+Automotive&rft.subject=Energy+and+utilities&rft.description=The+emission+of+fuel+vapors+into+the+atmosphere+from+underground+storage+tanks+at+filling+stations+is+a+common+occurrence+in+many+parts+the+world.+The+conditions+of+the+vapor+in+the+tanks+vary+significantly+over+a+24+hour+period+such+that+evaporation+and+excess+air+ingestion+during+the+refueling+process+can+cause+tank+over+pressurization+and+subsequent+emissions.+At+other+times+during+a+24+hour+cycle%2C+pressures+can+fall+below+atmospheric+pressure.+The+state+of+California+has+recognized+this+emissions+problem+and+has+enacted+regulations+to+address+it.%0ADue+to+these+low-emission+environmental+requirements+in+California%2C+solutions+must+be+implemented+that+do+not+entail+release+of+these+vapors+into+the+atmosphere.+One+solution+requires+that+the+vapors+fill+a+balloon+during+the+appropriate+times.+However%2C+the+size+of+the+balloon+at+typical+inflation+rates+requires+a+significant+amount+of+physical+space+(approximately+1000-2000+liters)%2C+which+may+not+necessarily+be+available+at+filling+stations+in+urban+areas.+Veeder-Root+has+a+patent+pending+for+a+system+to+compress+the+vapors+that+are+released+to+a+10%3A1+ratio%2C+store+this+compressed+vapor+in+a+small+storage+tank%2C+and+then+return+the+vapors+to+the+original+underground+fuel+tank+when+the+conditions+are+thermodynamically+appropriate+(see+Figure+1+for+the+schematic+representation+of+this+system).%0AThe+limitation+of+the+compressor%2C+however%2C+is+that+the+compression+phase+must+take+place+below+the+ignition+temperature+of+the+vapor.+For+a+10%3A1+compression+ratio%2C+however%2C+the+adiabatic+temperature+rise+of+a+vapor+would+be+above+the+ignition+temperature.+Mathematical+modeling+is+necessary+here+to+estimate+the%0Aperformance+of+the+compressor%2C+and+to+suggest+paths+in+design+for+improvement.%0AThis+report+starts+with+a+mathematical+formulation+of+an+ideal+compressor%2C+and+uses+the+anticipated+geometry+of+the+compressor+to+state+a+simplified+set+of+partial+differential+equations.+The+adiabatic+case+is+then+considered%2C+assuming+that+the+temporary+storage+tank+is+kept+at+a+constant+temperature.+Next%2C+the%0Aheat+transfer+from+the+compression+chamber+through+the+compressor+walls+is+incorporated+into+the+model.%0AFinally%2C+we+consider+the+case+near+the+valve+wall%2C+which+is+subject+to+the+maximum+temperature+rise+over+the+estimated+10%2C000+cycles+that+will+be+necessary+for+the+process+to+occur.+We+find+that+for+adiabatic+conditions%2C+there+is+a+hot+spot+close+to+the+wall+where+the+vapor+temperature+can+exceed+the+wall+temperature.+Lastly%2C+we+discuss+the+implications+of+our+analysis%2C+and+its+limitations.&rft.date=2003-12-09&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F152%2F1%2FVR_final_num.pdf&rft.identifier=++Banks%2C+Jeffrey+and+Fehribach%2C+Joseph+and+Fitt%2C+Alistair+and+Hart%2C+Robert+and+Hughes%2C+Kevin+and+Ockendon%2C+John+and+Please%2C+Colin+and+Schwendeman%2C+Don+and+Tilley%2C+Burt+and+Weekes%2C+Suzanne++(2003)+Spot-on%3A+Safe+Fuel%2FAir+Compression.++%5BStudy+Group+Report%5D+++++