Skyactiv-X an Innovative Gasoline Engine with Compression Ignition
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ETH TAGUNGSREIHE „ASPEKTE DER INDIVIDUELLEN MOBILITÄT“ SKYACTIV-X AN INNOVATIVE GASOLINE ENGINE WITH COMPRESSION IGNITION Christian Schultze DIRECTOR RESEARCH & OPERATION EUROPEAN R&D CENTRE MAZDA MOTOR EUROPE 0. INTRODUCTION 1. SKYACTIV ROADMAP 2. CHALLENGES AND SOLUTIONS 3. SKYACTIV-X 4. CUSTOMER BENEFITS SUSTAINABLE ZOOM-ZOOM 2030 AT MAZDA, WE SEE IT AS OUR MISSION TO BRING ABOUT A BEAUTIFUL EARTH AND TO ENRICH PEOPLE’S LIVES AS WELL AS SOCIETY. WE WILL CONTINUE TO SEEK WAYS TO INSPIRE PEOPLE THROUGH THE VALUE FOUND IN CARS PEOPLE ENHANCE CUSTOMERS’ MENTAL WELL-BEING WITH THE SATISFACTION THAT COMES FROM PROTECTING THE EARTH AND CONTRIBUTING TO SOCIETY WITH A CAR THAT OFFERS TRUE DRIVING PLEASURE EARTH SOCIETY THROUGH CONSERVATION INITIATIVES, CREATE A REALIZE CARS AND A SOCIETY THAT OFFER SAFETY SUSTAINABLE FUTURE IN WHICH PEOPLE AND CARS AND PEACE OF MIND, AND CREATE A SYSTEM THAT COEXIST WITH A BOUNTIFUL, BEAUTIFUL EARTH ENRICHES LIVES BY OFFERING UNRESTRICTED MOBILITY TO PEOPLE EVERYWHERE MAZDA’S APPROACH TO ISSUES FACING THE EARTH APPROACH CO2 REDUCTION FROM A WELL-TO-WHEEL PERSPECTIVE TO REDUCE CO2 EMISSIONS THROUGHOUT THE VEHICLE’S LIFE CYCLE WELL-TO-WHEEL (FROM FUEL EXTRACTION TO DRIVING) TANK-TO-WHEEL COMBUSTION ENGINE REFINERY TANK WHEEL OIL WELL E EV/PHEV POWER TANK WHEEL GENERATION MATERIAL MANUFACTURE, ASSEMBLY, DISPOSAL LIFE CYCLE ASSESSMENT TARGETS FOR CO2 REDUCTION AIM TO REDUCE CORPORATE AVERAGE WELL-TO-WHEEL CO2 EMISSIONS TO 50% OF 2010 LEVELS BY 2030 -50% CORPORATE AVERAGE WELL-TO-WHEEL CO (G/KM) 2 -90% 2010 2030 2050 IMPORTANCE OF REDUCING CO2 FROM COMBUSTION ENGINES THE COMBUSTION ENGINE WILL HELP POWER THE MAJORITY OF VEHICLES GLOBALLY FOR MANY YEARS TO COME AND CAN MAKE THE BIGGEST CONTRIBUTION TO CO2 REDUCTION | 200 FUEL CELL ELECTRIC ELECTRICITY PLUG-IN HYBRID DIESEL PLUG-IN HYBRID GASOLINE 2035 DIESEL HYBRID | FUEL CELL VEHICLES (4.4％) 150 GASOLINE HYBRID (MILLIONS) CNG/LPG ELECTRIC VEHICLES (11.2％) DIESEL WHERE MAZDA WILL GASOLINE GASOLINE BE OPERATING DIESEL PLUG-IN HYBRIDS BY 2030-2035 | 100 SALES OF SALES GASOLINE DIESEL HYBRIDS | 50 NEW PASSENGER CARS CARS PASSENGER NEW GASOLINE DIESEL INTERNAL COMBUSTION CNG/LPG ENGINE (84.4％) | 0 | | | | | | 2000 2010 2020 2030 2040 2050 1. SKYACTIV ROADMAP 2. CHALLENGES AND SOLUTIONS 3. SKYACTIV-X 4. CUSTOMER BENEFITS ROAD MAP TO IDEAL COMBUSTION GOAL: CONTROL GASOLINE ENGINES IDEAL DIESEL ENGINES FACTOR MZR SKYACTIV-G SKYACTIV-X ENGINE STILL SECRET SKYACTIV-D MZR-CD COMPRESSION WORLD’S HIGHEST EVEN HIGHER RATIO COMPRESSION COMPRESSION SPECIFIC MORE BETTER AIR/FUEL LEAN MIXTURE HEAT RATIO HOMOGENOUS MIXING COMBUSTION COMPRESSION PARTIAL PRE-MIX SPEED IGNITION COMBUSTION COMBUSTION DIRECT PRESSURE TDC TIMING MEASUREMENT COMBUSTION LOWER HEAT THERMAL TEMPERATURE, MANAGEMENT LOSSES ADIABATIC PUMPING MILLER CYCLE, CYLINDER LEAN MIXTURE LOSSES DE-ACTIVATION MECHANICAL FRICTION MORE FRICTION MORE FRICTION FRICTION FRICTION REDUCTION REDUCTION REDUCTION REDUCTION FAR << DISTANCE TO IDEAL STATE >> CLOSE GOAL: EXTREMELY LEAN COMBUSTION RICH MIXTURE STOICHIOMETRIC MIXTURE LEAN MIXTURE TOO MUCH FUEL, FUEL AND AIR MORE AIR THAN FUEL NOT ENOUGH AIR APPROPRIATELY MIXED UNBURNT FUEL WASTED AIR SIDE VIEW OF CYLINDER FUEL GOAL: LEAN COMBUSTION 1700 50 WHY IS EXTREMELY LEAN GOOD? NO EXTREMELY LEAN COMBUSTION IS COOLER 1600 40 . COOLER COMBUSTION MAKES LESS NOX . COOLER COMBUSTION WASTES LESS ENERGY HEATING 1500 30 UP THE ENGINE THE “UNUSED” AIR GETS PUT TO WORK v NO ppm 1400 20 . SURPLUS AIR ABSORBS COMBUSTION HEAT AND TURNS (K) TEMPERATURE IT INTO PRESSURE, PUSHING DOWN ON THE PISTON TEMPERATURE 1300 10 1200 0 0.8 0.9 1.0 1.1 1.2 1.3 AIR-FUEL RATIO, λ RICH STOICHIOMETRIC LEAN MIXTURE MIXTURE MIXTURE CHALLENGE: LEAN COMBUSTION IS UNRELIABLE BUT LEAN COMBUSTION IS NOT STABLE STOICHIOMETRIC MIXTURE (LAMBDA = 1) . NORMAL FLAME PROPAGATION CA= -4.3 CA= -0.7 CA= -2.9 CA= -6.5 (ACTUAL COMBUSTION AT 750 RPM) SUPER LEAN MIXTURE (LAMBDA = 2) . THE FUEL MOLECULES ARE SPACED SO FAR APART THAT A CHAIN REACTION ISN’T GUARANTEED FLAME CANNOT PROPAGATE CA= -4.0 CA= -0.4 CA= -3.2 CA= -6.8 CA = CRANK ANGLE BENEFIT: FASTER COMBUSTION IS MORE EFFICIENT TOP DEAD CENTER BOTTOM DEAD CENTER COMPRESSION IGNITION COMBUSTION IS FASTER . IDEAL COMBUSTION ENGINE BURNS ALL THE FUEL INSTANTLY COMPRESSION . REAL COMBUSTION TAKES TIME I G N I T I O N COMBUSTION . COMBUSTION ENERGY CAN ONLY BE SPARK IGNITION PARTLY USED CYLINDER PRESSURE >> COMBUSTION T I M E > > FASTER COMBUSTION GETS MORE WORK OUT OF THE SAME ENERGY POWER STROKE 1. SKYACTIV ROADMAP 2. CHALLENGES AND SOLUTIONS 3. SKYACTIV-X 4. CUSTOMER BENEFITS CHALLENGE CONTROLLING WHEN COMPRESSION IGNITION HAPPENS CHALLENGE: HCCI COMBUSTION TIMING IS UNCONTROLLED SPARK IGNITION COMPRESSION IGNITION HCCI (GASOLINE) (DIESEL) (GASOLINE) COMBUSTION STARTS COMBUSTIONS STARTS COMBUSTION STARTS WITH A SPARK WHEN FUEL IS WHENEVER HEAT AND INJECTED PRESSURE ARE HIGH ENOUGH CHALLENGE: HCCI COMBUSTION TIMING IS UNCONTROLLED SPARK IGNITION IS STILL NEEDED . CONVENTIONAL HCCI COMBUSTION IS LIMITED IN IT’S RANGE OF APPLICATION . A PRACTICAL ENGINE NEEDS TO OPERATE IN DUAL MODES - HCCI AND SI SPARK IGNITION COMBUSTION . A SPARK PLUG IS REQUIRED . NEEDS TO SWITCH SMOOTHLY BETWEEN ENGINE LOAD (KPA) LOAD ENGINE OPERATING MODES CONVENTIONAL HCCI COMBUSTION RANGE ENGINE (RPM) BREAKTHROUGH SOLUTION SPARK CONTROLLED COMPRESSION IGNITION (SPCCI) THE BREAKTHROUGH: CONTROL COMPRESSION IGNITION WITH A SPARK! VERY LEAN MIXTURE START COMBUSTION SPARK CONTROLLED COMPRESSION VERY HIGH COMPRESSION WITH A SPARK IGNITION (SPCCI) SPCCI Farben VI ? Push… Farben VI? CI Farben? TIME DESIGN THE ENGINE TO RUN JUST EXPANDING FIREBALL COMPRESSION IGNITION IS BELOW THE THRESHOLD OF ADDS MORE HEAT AND TRIGGERED IN THE REST COMPRESSION IGNITION PRESSURE OF THE CYLINDER PUSHING CONDITIONS OVER THE THRESHOLD THE BREAKTHROUGH: SPCCI – COMPRESSION IGNITION WHEN YOU WANT IT HOW SPCCI WORKS 1. AIR AND FUEL ARE COMPRESSED TO NEAR SPARK IGNITED FIRE BALL FURTHER COMPRESSES COMPRESSION IGNITION CONDITIONS THE MIXTURE 2. THE SPARK PLUG INITIATES A SMALL FIREBALL SPCCI Farben VI ? 3. THE FIREBALL EXPANDS TO INCREASE TEMPERATURE AND PRESSURE UNTIL COMPRESSION IGNITION Push… Farben VI? CONDITIONS ARE MET CI Farben? 4. THE MAJORITY OF AIR AND FUEL IN THE CYLINDER IS GASSES THE MIXTURE COMBUSTED THROUGH COMPRESSION IGNITION Text mit click points 5. THE TIMING OF THE SPARK IGNITION CONTROLS WHEN COMPRESSION IGNITION WILL HAPPEN BASE COMPRESSION RATIO 16:1 CHALLENGE LIGHTING THE FIREBALL NEEDED FOR SPCCI SOLUTION: VARYING LOCAL FUEL DENSITY CONTROL FUEL DISTRIBUTION THROUGH TOP DOWN VIEW OF CYLINDER CYLINDER SWIRL AND FUEL INJECTION TIMING COMPRESSION SPARK PLUG IGNITION (CI) . SPCCI NEEDS DISTINCTLY DIFFERENT AIR FUEL RATIOS . A SLIGHTLY LESS LEAN REGION NEAR THE SPARK PLUG SPARK ALLOWS THE FIREBALL TO IGNITE PRESSURE WAVE TO INITIATE . THE MAJORITY OF THE MIXTURE INSIDE THE CYLINDER COMPRESSION IGNITION IN REMAINS VERY LEAN LEAN AREAS IT COMBUSTS WITH CI AIR/FUEL MIX SWIRL . SWIRLING THE AIR INSIDE THE CYLINDER AND GENERATING A VORTEX EFFECT KEEP IT VERY LEAN VERY LEAN REGION FOR COMPRESSION IGNITION LESS LEAN REGION FOR FIREBALL IGNITION CHALLENGE PREVENTING UNCONTROLLED AUTO-IGNITION CHALLENGE: COMPRESSION IGNITION ONLY WHEN WE WANT IT A HIGHER COMPRESSION RATIO INCREASES THE POTENTIAL FOR KNOCK . KNOCK IS THE SPONTANEOUS COMBUSTION OF AIR AND FUEL UNDER HIGH TEMPERATURES AND PRESSURES . COMPRESSION IGNITION IS KNOCK! . VERY HIGH COMPRESSION CAN ALSO INCREASES UNWANTED AUTO IGNITION WHICH CAN SEVERELY DAMAGE AN ENGINE . DURING THE COMPRESSION STROKE WE NEED TO PREVENT COMPRESSION IGNITION BUT RETAIN A HIGH COMPRESSION RATIO SOLUTION: SPLIT FUEL INJECTION STRATEGY REDUCE TIME TO HEAT UP THE FUEL MIX AUTO-IGNITION TEMPERATURE . CI CAN OCCUR PREMATURELY WHEN THE MIXTURE IS HEATED ABOVE ITS AUTO-IGNITION TEMPERATURE A/F MIX A/F . IF ALL FUEL IS INJECTED EARLY DURING THE INTAKE STROKE TEMPERATURE SMALL INJECTION OF FUEL TOO LEAN TO IT WILL HEAT UP DURING THE COMPRESSION STROKE HIGH-PRESSURE AUTO IGNITE FUEL SPRAY . IF ONLY A PORTION OF FUEL IS INITIALLY INJECTED ALL FUEL UNDESIRED INJECTED PRE-IGNITION THE MIXTURE IS KEPT TOO LEAN TO AUTO-IGNITE AT ONCE PROLONGED TIME TO COMPRESS & HEAT AIR-FUEL MIXTURE SPARK LESS TIME TO HEAT MIXTURE . IF REMAINING FUEL IS INJECTED LATER IN THE COMPRESSION IGNITION STROKE LESS HEAT UP TIME INCREASE ATOMIZATION AND MIXING INTAKE COMPRESSION STROKE STROKE BY UPGRADED FUEL SYSTEM CHALLENGE KEEPING TRACK TO MAINTAIN RELIABILITY CHALLENGE: CONSTANT CONTROL OF SPCCI IDEAL SPCCI COMBUSTION PROFILE MAINTAINING THE IDEAL TIMING TOP DEAD CENTER AND PRESSURE RISE COMPRESSION IGNITION PRESSURE RISE . LEAN COMPRESSION IGNITION SHOULD HAPPEN SHORTLY AFTER TOP DEAD CENTER COMPRESSION IGNITION MUST BE INITIATED BY SPARK INITIATED . FIREBALL A PRESSURE RISE FROM THE SPARK-INITIATED PRESSURE RISE COMPRESSION-IGNITION FIREBALL THRESHOLD PRESSURE . FIREBALL GENERATED PRESSURE ALSO CHANGES WITH VARIOUS AMBIENT CONDITIONS SPARK CYLINDER PRESSURE CYLINDER IGNITION TO KEEP SAME CI TIMING THE SPARK OFF TIMING NEEDS TO BE MODIFIED COMPRESSION STROKE EXPANSION STROKE SOLUTION: ADAPTIVE SPARK TIMING CONTROL ADJUST IGNITION TIMING FOR DIFFERENT CONDITIONS INDIVIDUAL CYLINDER PRESSURE TOP DEAD CENTER MONITORING AND FEEDBACK INTAKE AIR TEMPERATURE CONTROL OF SPARK TIMING 1500rpm, 500kPa o 156,1 C . BY CHANGING THE TIMING OF THE SPARK INITIATED FIREBALL, SPCCI MAINTAINS THE 141,1286oFo C IDEAL CI TIMING oo COMPRESSION-IGNITION 125257 FC . IN-CYLINDER PRESSURE SENSORS MONITOR THRESHOLD PRESSURE EACH