No power loss (low flow resistance) No significant increase in FC Reduced HC/CO-emissions Reduced system effort
BMW Group Wolfgang Mattes DEER 2007 Page 16
Functions
Piezo Common-Rail
Fuel Injection
System
BMW Group Wolfgang Mattes DEER 2007 Page 8
BMW Diesel. Combustion.
Æ Central injector position Æ 4 valves per cylinder Æ Symetrical combustion chamber Æ Variable air control
Inline 6. Displacement Single Cylinder Displ. Bore / Stroke 2992 cm³ 499 cm³ 84/90 mm
Max. Combustion Pressure 180 bar
BMW Group Wolfgang Mattes DEER 2007 Page 9
BMW Diesel. TIER2 BIN5 Concept.
Modified
Combustion with 2­
stage Turbocharging
Diesel
Particulate Filter
Advanced
EGR-System
SCR-System
(Urea)
OBD
Sensors and
BMW Group Wolfgang Mattes DEER 2007 Page 18
BMW Diesel. CFD-Simulation of NH3-Distribution.
Targets Targets
• • • •
Improve Ammonia distribution → maximum conversion Reduce Ammonia slip, because of overloaded catalyst cells Best possible usage of mixing element Analysis of pressure drop and optimisation
TurbineBypass
Waste-Gate
Exhaust
BMW Group Wolfgang Mattes DEER 2007 Page 11
BMW Diesel. Variable Twin Turbo – even more powerfull.
630 560 490 420 Torque [Nm] 350 280 210 140 70 0 0 5000 1000
BMW Diesel. SCR System Overview.
Core Components:
• • • • • •
Urea Tank Dosing Module Mixer SCR-Catalyst NOx-Sensor Control Unit / ECU
Dosing Module
Urea Tank
Variable Twin Turbo 3,0 l : 560 Nm at 2000 min-1 200 kW at 4400 min-1 Base engine 3,0 l (MJ 05) : 500 Nm at 2000 min-1 160 kW at 4000 min-1
225 200 175 150 125 100 75 50 25 0 4000 Power [kW]
BMW Group Wolfgang Mattes DEER 2007 Page 15
BMW Diesel. Closed Coupled Particulate Filter.
Particles are filtered and burnt off in the ceramic filter with its catalytic coating.
2000
3000
Engine speed [min-1]
BMW Group Wolfgang Mattes DEER 2007 Page 12
BMW Diesel. Variable Twin Turbo – compact design.
small turbo turbine-bypass
compressor-bypass
• •
BMW typical fun to drive Fulfill 50 state legislations (Æ Tier2 Bin5)
• BMW Diesel Strengths:
- Low fuel-consumption
Æ 20-30% below comparable petrol cars Æ cost saving, sometimes supported by low fuel costs Æ high cruising range
BMW Group Wolfgang Mattes DEER 2007 Page 1
BMW Diesel. 13th DEER Conference, 13-16th August 2007 Detroit
The BMW Approach to Tier2 Bin5
Wolfgang Mattes BMW Group
NOx-Sensor
Oxi-Catalyst
DPF
Mixer
SCR-Catalyst
Source: Bosch
BMW Group Wolfgang Mattes DEER 2007 Page 17
BMW Diesel. SCR – Chemical Reactions.
Reduction
NO + NO2 + 2 NH3 Æ 2 N2 + 3 H2O
Æ combustion noise, driveability Æ New technologies are necessary Æ Robust, sustainable solutions are required
BMW Group Wolfgang Mattes DEER 2007 Page 4
BMW Diesel. Low Pressure EGR-System.
150 T22 [°C] [°C] 75 0
1500 min-1 / 6bar
T V57445809.217 T V57445809.219 HD-AGR ND-AGR
Effect of Low Pressure EGR:
• Reduced charge temperature
-
Fun to drive, outstanding torque characteristics Æ relaxed cruising Æ torque on demand Æ good NVH due to low engine speed
BMW Group Wolfgang Mattes DEER 2007 Page 7
260 BE [g/kWh] [g/kW.h] 250 240 230 220 210
fuel consumption
16 14 E_RUSS_A [g/h] 12 10 8
PM
PM [g/h]
6 4 2 0 0 10 20 30 40 50 60 70 80 PUM_Seid_MnoxAbgas [g/h] NOx [g/h] 90 100
BMW Group Wolfgang Mattes DEER 2007 Page 10
BMW Diesel. 2-Stage Turbocharger (Variable TwpressorBypass Small Turbo Big Turbo Air
Oxidation
NO + ½ O2 Æ NO2
4 NO + O2 + 4 NH3 Æ 4 N2 + 6 H2O 6 NO2 + 8 NH3 Æ 7 N2 + 12 H2O
(NH2)2CO Æ NH3 + HNCO Thermolysis HNCO + H2O Æ NH3 + CO2 Hydrolysis
BMW Group Wolfgang Mattes DEER 2007 Page 2
BMW Diesel. Contents.
• •
Challenges in the US market Tier2 Bin5 Concept Æ Internal Engine Measures Æ Aftertreatment: SCR System Æ OBD Summary
charge temperature
[mbar] P21 [mbar]
600 400 200
• Higher boost pressure (efficiency turbocharger) • Better fuel economy • 30% NOx-advantage
boost pressure
•
BMW Group Wolfgang Mattes
DEER 2007 Page 3
BMW Diesel. Challenges in the US-Market.
• Stringent emission legislation
Æ limits and test-procedures
• High requirements to OBD
Æ new engine control functions