Navistar N13 - Inlet Air Heater System

ENGINESYSTEMS13
Airow
Airowsthroughtheairlterassemblyandenters
theLow-Pressure(LP)turbocharger.TheLP
turbochargerincreasesairpressureandtemperature
beforeenteringtheLowPressureChargeAirCooler
(LPCAC).Cooledandcompressedairthenowsfrom
theLPCACintotheHighPressure(HP)turbocharger
(compressorinlet).Hotandhighlycompressedair
owsfromtheHPturbocharger(compressoroutlet)
intotheHighPressureChargeAirCooler(HPCAC)
whereitiscooled,andintotheintakethrottleduct,
andcontinuesthroughtheEngineThrottleValve
(ETV).TheHPandLPturbochargerscanincrease
pressuresupto345kPa(50psi).
IftheExhaustGasRecirculationValve(EGRV)is
open,exhaustgasespassthroughtheEGRcooler
andintotheintakethrottleductwhereitismixedwith
lteredair.Thismixtureowsintotheintakemanifold,
andthenthecylinderhead.Theintakemanifoldisan
integralpartofthecylinderheadcasting.
Duringcoldweather,theInletAirHeatersystem
activatestheheaterelement,vaporizingandigniting
smallquantitiesoffuelintotheairinletduct.
Aftercombustion,exhaustgasesexitthroughthe
cylinderheadexhaustvalvesandports.Theexhaust
gasisforcedthroughtheexhaustmanifoldwhere,
dependingonEGRVposition,itissplitbetween
theEGRsystemandtheexitpaththroughtheHP
turbocharger,LPturbocharger,andExhaustBack
PressureValve(EBPV).
TheEBPVisoperatedbytheAirControlValve(ACV),
apneumaticactuator.WhentheACVisapplied,
theEBPVrestrictsowandincreasesexhaustback
pressure.OperationoftheEBPViscontrolledbythe
ECMusingtheACVandtheTurbocharger1Turbine
OutletPressure(TC1TOP)sensor.WhentheEBPV
isopened,exhaustbackpressureisreleased.
Exhaustgasesexitingtheengineowthroughthe
EBPV,thenthroughthevehicleAftertreatment(AFT)
system,andouttheexhausttailpipe.