INTERNATIONAL Diesel Engine Emissions Requirements & Technology

Transcription

1 INTERNATIONAL 2010 Diesel Engine Emissions Requirements & Technology Independent Armored Car Operators Association, Inc Annual Convention Monday, June 23, 2008

2 2007 EPA Emissions Standards PPM (6/93) 5.0 Electronic fuel control % reduction in NOx NOx (g/hp-hr) hr) EGR Increased EGR w / DPF 2010 EGR w/urea injection PM (g/hp PM 0.01 (g/hp-hr) hr) 0.10 ULSD 15 PPM (6/06) SULFUR Content In Fuel % reduction in Particulate matter

3 Emissions Technology Hardware Strategies VG Turbo CAC EGR DOC DPF

4 International Exhaust Configurations DPF Temperature Sensor T3 Temperature Sensor T1 DOC Temperature Sensor T2 3 Bolt Flange Pressure Differential Sensor

5 Challenge for 2010 Particulate matter challenge met in 2007 No technology change required NOx emissions 83% reduction 2007 rule allows certification of engines below 2.5 g, but half of engines must be measured against 0.20 g standard De facto 2007 NOx limit of 1.2 g/bhp*hr Full implementation of NOx rule for 2010 at 0.20 g/bhp*hr Banking and trading of credits still allowed, but engines must be certified at or below 0.5 g Technology change required to meet the NOx standard

6 After-Treatment Approaches NOx Catalysts Selective Catalytic Reduction NOx Adsorbers Combination Aftertreatment Systems Common Goal: Separate the N from the O NO X N 2

7 Passive NOx Catalysts Passive NOx Catalysts which require no urea or fuel injection do exist, but their effectiveness is not high enough for them to be a stand alone solution for Simple pass-through device NOx reduction 20% or less Need additional help to meet 2010 goals Diesel Engine Tail pipe De-NOx Catalyst Exhaust System (DPF and DOC Deleted)

8 Selective Catalytic Reduction SCR is probably the simplest NOx reduction technique NH 3 + NO x N 2 + H 2 0 Ammonia reacts with NO and NO 2 in presence of a catalyst forming N 2 gas and water

9 Selective Catalytic Reduction SCR system on a vehicle Urea Tank Diesel Engine Urea Injector Tail pipe Ammonia Slip Catalyst SCR Catalyst Diesel Particulate Filter Diesel Oxidation Catalyst Diesel Exhaust System

10 Selective Catalytic Reduction Issues with SCR When Urea tank runs dry, vehicle is in violation of the EPA ruling and must be shut down Engines will require Urea in the amount of 1.5 percent of total fuel volume per gm of NOx reduction Space for tanks and catalysts on short wheel base vehicles and specialty truck bodies Urea solutions freeze at +12 F and evaporate at +112 F Logistics of Urea supply for on-road consumption SCR catalysts are sensitive to contamination

11 NOx Adsorbers A NOx adsorber (sometimes called a NOx trap) is a device which captures NOx on the surface of a catalyst and periodically regenerates conceptually similar to DPF The NOx is captured during normal lean Air-Fuel Ratio conditions NO NO 2 NO NO 2 CO 2 H O 2 O 2 CO 2 O 2 O 2 NO NO 2 NO NO NO 2 NO 2 CO 2 O 2 NO O 2 CO H 2 NO 2 O 2 2 ONO2 NO NO 2 NO NO 2 NOx is regenerated during rich A/F conditions (abnormal for diesel engines) N 2 NO 2 CO 2 H 2 O N NO 2 NO 2 CO HC H 2 2 O H N 2 CO CO N 2 H 2 NO 2 O HC HC 2 HC 2 2 O NO NO 2

12 NOx Adsorbers NOx Adsorber system on a vehicle Fuel Tank Tail pipe Fuel Injector Diesel Engine NOx Adsorber Exhaust System (DOC and DPF Deleted)

13 NOx Adsorbers Pros No extra fluid tanks required or any of the other issues associated with SCR systems Weight and space savings compared with SCR Cons Frequent regeneration required More complicated to control than SCR systems Fuel consumed in regeneration

14 Hybrid Aftertreatment Approaches SCR catalysts that use diesel fuel as reductant instead of urea These are only effective in limited temperature ranges, so they are matched with a NOx adsorber to provide a complete solution Pros Cons Advantages of SCR without the need for urea storage More expensive overall exhaust system Packaging of multiple aftertreatment stages

15 On-Engine Approaches to 2010 NOx Control EGR Rates Turbocharging Strategies Fuel Injection Strategies Homogenous Charge Compression Ignition

16 EGR Rates g/bhphr NOx At high enough rates of Exhaust Gas Recirculation it is possible to meet the 2010 NOx requirements Precise engine controls required Difficult to achieve at high load conditions High particulate matter generation EGR rate strategy will vary Reduced EGR Requires more aftertreatment and urea or fuel dosing Increased EGR Less need for urea or fuel dosing 0% 10% 20% 30% 40% 50% 60% EGR Rate

17 Turbocharging Strategies Trend towards 2-stage turbocharging will continue More controls (wastegates, VGT, by-pass) Supercharging in conjunction with turbos Alternate uses for turbine energy (compounding) Turbo strategies may largely depend on engine-out vs. aftertreatment NOx emissions strategies

18 Fuel Injection Strategies 9 shot capable fuel systems To better control combustion and engine out emissions, fuel system suppliers are working on injection systems that are capable of 9 shots per cycle 3 shots prior to main injection NOx control Noise reduction 3 shots to replace the current one main injection event Precise control of combustion 3 shots post main injection Particulate matter clean up Post dosing 9 Injections Per Cycle Crank Angle

19 Homogenous Charge Compression Ignition HCCI the Holy Grail of Diesel combustion Well mixed (homogenous) air and fuel charge Compression Ignition delayed until the piston is at the top of its stroke. Diesel efficiency Gasoline emissions levels Theoretically this is achievable and could result in Diesel engines that meet the 2010 standard without need for aftertreatment devices

20 2010 Technology Summary Big challenge to meet NOx standard (83% reduction) No change for particulates, but DPFs will stay NOx aftertreatment strategies De-NOx Catalysts Selective Catalytic Reduction (Urea injection) NOx Adsorbers Hybrid SCR/Adsorber Technologies On-Engine approaches EGR systems Turbo and supercharging Fuel systems Homogenous Charge Compression Ignition

21 2010 Emissions Methods EGR Solution Same configuration as today SCR Method Electronics Injection Metering Monitored Urea tank Heated/cooled Monitored Ammonia Slip Catalyst Monitored

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23 THANK YOU!! Questions?