Volvo EPA2007 D13F - Operational Mode

ENGINECOMPONENTANDLOCATION113
ExhaustAftertreatmentSystem
New,stringentstandardsforexhaustemissioncontrolbeginwiththe2007modelyear.
TheExhaustAftertreatmentSystem(EATS)hasbeendevelopedtoactincombination
withUltraLowSulfurDiesel(ULSD)fuelandtheEGRsystemtoreducenoxious
emissionstomeettherequirement.Thisnewsystemtreatstheexhaustafteritleaves
theturbochargeronitswaytotheatmosphere.
ExhaustGasRecirculation
Nitrousoxide(NOx)emissionlevelsincreasewithcombustionchambertemperatures.
TheprimaryfunctionoftheExhaustGasRecirculation(EGR)systemistocool
exhaustgasandrecirculateexhaustgasesbacktothecombustionchambertolower
thecombustiontemperature,therebyreducingnitrousoxide(NOx)emissions.
Reducingthequantityofnoxiouscompoundstoanacceptablelevelbeginninginthe
year2007requiresalteringtheirchemicalcomposition.Directingtheowofexhaust
gasthroughcatalyticandparticulateltersmakesthishappen.
ParticulateMatter
ThecompoundsremainingintheexhaustafterpassingthroughtheEGRsystem
containextremelysmallparticlesofsootandashcalledParticulateMatter(PM).When
theseparticlescontactcertainmetalsunderhightemperature,theyarechemically
transformed.Themetalsthatcausethistransformationarecalledcatalysts.