柴油发动机和排放系统集成NOx吸附还原催化器

R“Systems Approach”策略改进region of interceptregion of interceptERICCONTROLSTOCK CONTROL5101520253035051015202530Design IntegrationStrategy Select PlatformSelect Emissions Solution/ Design systemTest PerformanceStudy EmissionCalibrate and TuneTest PerformanceLNCNOxNO x/PM ControlLNT Oxidation CatalystCombinationPMSolidsSOFSCRActive PassiveDPF(Diesel Particulate Filter) Integrated System6•Identify target technology8Lean NOx Traps (NOx Adsorbers)•Uses Same Onboard HC (Diesel Fuel)•Can Achieve High NOx Conversion-(90%+)•Active Temperature Range -250C to 450CAdvantages 优点•Extreme Sensitivity to Sulfur •Very Complex Controls •Uncertain Durability•Fuel Consumption Penalty -appears to be in 1.5-6% range, depending on sulfur Disadvantages 缺点Integration Needs:•Identify target technology•Highlighted Technology for this discussion:NAC for NOx•Identify technology specific needs •Determine component layout based on performance and installation constraints •Design Control Scheme•Set performance criteria•Temperature: Activity Window •Inlet Concentration: Capacity andBreakthrough •Regeneration: Periodic Rich Excursionto clean TrapTemperature Requirements •NO+1/2O2=> NO2Temperature Requirements•NO + 1/2O 2=> NO 2NO 2+ MO X => MNO 3Temperature RequirementsNO 2+ MO X => MNO 3•Temperature: Activity Window •Inlet Concentration: Capacity andBreakthrough •Regeneration: Periodic Rich Excursionto clean TrapAged NOx Adsorber Performance (tested at 30,000 s.v.)•Temperature: Activity Window •Inlet Concentration: Capacity andBreakthrough •Regeneration: Periodic Rich Excursionto clean TrapNAC Source: SAE Paper 2000-01-2911Integrate Mass of NO X Stored in NAC.A Target Mass is Set to Trigger Regeneration.RIntegrate Mass of NOX Stored in NAC.A Target Mass is Set to Trigger Regeneration.R ECS StrategyI IIIII EGR Controller NO x Mass ModelRegen StateDeterminationMass Reductant Regeneration Controller Burner Controller•Identify target technology•Highlighted Technology for this discussion:NAC for NOx•Identify technology specific needs •Determine component layout based on performance and installation constraints •Design Control Scheme•Set performance criteriaDPFNAC SFIOxi-CatDuramax Single In-LineNACOxi-CatsDPF NAC25DuramaxDPF NACSFI SFI BurnerNACRegenerating modeOxiNAC1NAC5CODesign IntegrationStrategySelect Platform Select EmissionsSolution/ Design systemTest PerformanceStudy EmissionCalibrate and TuneTest PerformanceSTOP!Carefully reviewDuramaxDPFNACNACSFIOxi-CatsDesign IntegrationStrategy Select PlatformSelect Emissions Solution/ Design systemTest PerformanceStudy EmissionCalibrate and TuneTest Performance4.5 g/mi Vehicle Test with Stock EGRVehicle Test with Stock EGRTarget (Tier 2, Bin 5)LD-FTP Engine-Out Emissions vs. Goals -NO X98.5%4.5 g/mi0.07 g/miFuel Economy Penalty NOx Reduction Efficiency Final Calibration RepeatsFACTORSThermal PenaltyEngine-Out NO X+ Regeneration Frequency+Emissions GoalThermal PenaltyEngine-Out NO X+Regeneration Frequency+Emissions Goal+Source of Thermal PenaltyToo Low:In Range:Too High:300°C -400°C163 °C Approach1:Approach2:Stock TemperatureBurner + EGR + IT Stock TemperaturePI + EGR + IT + HI + BYVehicle Speedm x cm x cη160300ΔT150200250300350DPF11"Oxi3- 1"NAC1-5"NAC2-5"Baseline LAFinal Hot LA CalIncrease of 165 deg C17.657.390.2Burner + EGRThermal PenaltyEngine-Out NO X+ Regeneration Frequency+Emissions GoalTemperature NOxCapacityNOxTemperature CapacitySystemConfigTargetMNO X* Mreductant MNO XMass Flow of Exhaust x %O2Mass O2RemainingMass O2 at low speed (idle) 14% O2 in exhaust Regeneration: 5 Second Durationm aEngineNACm em NACm exh2Importance of EGRNo EGRWith HP EGR34% Average Reduction in Space VelocityHLA-4 CycleEmissionsGoalEngine-outNOxNAC sizeRegenerationFrequencyOperatingTemperatureStorageCapacity。