Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B41/00—Engines characterised by special means for improving conversion of heat or pressure energy into mechanical power
  • F02B41/02—Engines with prolonged expansion
  • F02B41/04—Engines with prolonged expansion in main cylinders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/04—Introducing corrections for particular operating conditions
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B47/00—Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines
  • F02B47/02—Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines the substances being water or steam
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
  • F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
  • F02D41/3017—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used
  • F02D41/3035—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used a mode being the premixed charge compression-ignition mode
  • F02D41/3041—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used a mode being the premixed charge compression-ignition mode with means for triggering compression ignition, e.g. spark plug
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
  • F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
  • F02D41/3064—Controlling fuel injection according to or using specific or several modes of combustion with special control during transition between modes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
  • F02M25/022—Adding fuel and water emulsion, water or steam
  • F02M25/025—Adding water
  • F02M25/03—Adding water into the cylinder or the pre-combustion chamber
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D41/0047—Controlling exhaust gas recirculation [EGR]
  • F02D41/006—Controlling exhaust gas recirculation [EGR] using internal EGR
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the present invention describes a method of operating an internal combustion engine, in particular for a reciprocating engine, for example for a gasoline direct injection engine in a motor vehicle, with NO x combustion -deficient (NAV).
• a reciprocating engine for example for a gasoline direct injection engine in a motor vehicle, with NO x combustion -deficient (NAV).
• NAV NO x combustion -deficient
• Downsizing means designing, deploying, and operating smaller displacement engines to achieve comparable or improved driveability values, unlike their previous large-displacement engines. By downsizing the fuel consumption can be reduced thereby reducing the C0 2 emissions. In addition, smaller displacement engines have lower absolute friction losses.
• cubic capacity engines are characterized by a lower torque, especially at low speeds, and thus lead to a poorer dynamic behavior of the vehicle, and thus for example to a poorer elasticity.
• operating method disadvantages which brings the downsizing of gasoline engines, at least largely be compensated.
• an operating method in which a lean fuel / exhaust gas / air mixture in the respective combustion chamber of the internal combustion engine is caused to autoignite. So that the compression ignition starts at the desired time, fuel is injected into the combustion chamber in the lean, homogeneous fuel / exhaust gas / air mixture with corresponding compression shortly before spark ignition, so that a more greasy mixture cloud is formed. Embedded in the lean, homogeneous fuel / exhaust gas / air mixture, this concentrated
• CONFIRMATION COPY mixed cloud as ignition initiator for the compression-ignited combustion in the combustion chamber.
• the characteristic area of the respective partial operating method can be expanded by means of water injection, the field of application of a pure RZV partial operating method is limited despite water injection.
• the present invention deals with the problem for an operating method for an internal combustion engine, in particular directly injected, having multiple combustion chambers an improved or at least provide an alternative embodiment, which is characterized in particular by a larger engine load and / or engine speed range, in which a Room ignition combustion can be practiced.
• the invention is thus based on the general idea, in an operating method for a, in particular directly injected, multiple combustion chambers having internal combustion engine, in particular for a directly injected gasoline engine, for example a motor vehicle, with at least partial low NO x combustion (NAV) and with several Part operating method to use the NAV partial operation method in which at least by means of injection water is injected into the respective combustion chamber, wherein in the NAV partial operation method at an ignition time (ZZP) a substantially homogeneous, lean fuel / exhaust gas / air mixture with a combustion air ratio of is externally ignited in the respective combustion chamber by means of an ignition device and the flame front combustion (FFV) started by the spark ignition passes into a room ignition combustion (RZV).
• ZZP ignition time
• FFV flame front combustion
• the NAV partial operating method can also be carried out to higher engine loads in comparison with the NAV partial operating method without water injection, and because of the at least partially occurring room ignition combustion (RZV), a reduction of the NO x emissions is possible.
• RZV room ignition combustion
• Such an injection of water is preferably carried out before an ignition point (ZZP) of a fuel / exhaust gas / air mixture arranged in the respective combustion chamber.
• ZZP ignition point
• a water injection is possible from the time of Close the exhaust valve to the ignition timing (ZZP).
• the amount of water can be introduced by means of single or multiple injection into the respective combustion chamber.
• a water injection during the intake stroke causes a uniform lowering of the mixture temperature.
• late injection of water during the compression stroke allows the formation of a thermal stratification and targeted utilization thereof.
• the injection of water during the intake or compression stroke is operating point dependent, load and / or speed to choose.
• An injection of water can be made immediately before a start of the room ignition combustion (RZV).
• An injection of water is preferably carried out as a function of the pressure prevailing in the respective combustion chamber.
• the temperature of the fuel / exhaust gas / air mixture can be controlled and controlled so that it becomes possible to use the NAV partial operation method even in engine load ranges that have no water injection due to the increased tendency to knock and the reduced Operational stability would not be suitable.
• a direct injection, multiple combustion chambers having internal combustion engine can be operated by various operating methods or with different partial operating methods. So several ottomotorische partial operating methods are possible.
• the stoichiometric, partial engine operating mode can be used throughout the engine load and / or engine speed range. It is preferably also used when other partial operating methods are used in the high engine load and / or engine speed range.
• An Otto engine partial operating method can also be carried out externally ignited with excess air and thus with a combustion air ratio ⁇ > 1.
• This partial operating method is usually also referred to as a DES partial operating method (direct injection layer), wherein a stratified, generally lean fuel / exhaust gas / air mixture is formed in the respective combustion chamber by means of a plurality of direct injections. Due to the layered design, at least idealized two partial areas with a different combustion air ratio ⁇ are arranged in the respective combustion chamber. This stratification is usually generated by multiple injections. In this case, a lean, homogeneous fuel / exhaust gas / air mixture in the respective combustion chamber can first be formed by one or more injections.
• a final injection which may be formed as a multiple injection, in the region of the ignition device, a mixture cloud, which is formed richer than the lean, homogeneous region.
• This method is commonly referred to as HOS (Homogeneous Layer). Due to the greasy mixture cloud in the region of the ignition device, the overall lean fuel / exhaust gas / air mixture in the combustion chamber can be ignited and converted by a flame front combustion (FFV).
• FFV flame front combustion
• the DES and HOS split modes are preferably used in a lower engine load and / or engine speed range.
• the DES and HOS sub-operations may also be compression-ignited and are then typically no longer referred to as DES, HOS sub-operations.
• the RZV partial operation method can be used, in which a lean, homogeneous fuel / exhaust gas / air mixture is started in the respective combustion chamber by space ignition combustion and thus compression ignited.
• a lean, homogeneous fuel / exhaust gas / air mixture is started in the respective combustion chamber by space ignition combustion and thus compression ignited.
• the fuel / exhaust gas / air mixture arranged in the respective combustion chamber begins to be ignited almost simultaneously in a plurality of regions of the respective combustion chamber, so that a room ignition combustion occurs.
• the RZV partial operating procedure has a significantly lower NO x emission compared with the partial engine operating modes and is characterized by a lower fuel consumption.
• the NAV partial operating method according to the invention can now be understood as a combination of a spark-ignited, Otto engine partial operating method and an RZV partial operating method.
• the NAV partial operating method involves a homogeneous, lean fuel / exhaust gas / air mixture which is externally ignited by means of an ignition device.
• FFV initial flame front combustion
• RZV room ignition combustion
• the NAV-part method of operation compared to the gasoline engine part operating method, due to the occurring homogeneous charge compression ignition (RZV) to a reduced fuel consumption and reduced NO x emissions.
• the combustion is externally ignited by an igniter.
• the operating stability of the mixture ignition and / or combustion is significantly improved.
• the homogeneous, lean fuel / exhaust gas / air mixture begins to burn in the manner of an internal combustion engine flame-retardant combustion (FFV), which then subsequently passes into a room-temperature combustion (RZV).
• FFV internal combustion engine flame-retardant combustion
• RZV room-temperature combustion
• the NAV fractional operation method combines the advantages of room ignition combustion (RZV) and gasoline engine, operational stable ignition of the fuel / exhaust gas / air mixture. It can be controlled by the provision of a correspondingly composed fuel / exhaust gas / air mixture in the respective combustion chamber, as well as controlled by the external ignition by means of an ignition at the right time of this invention NAV partial operation method can be performed.
• the NAV partial operation method is characterized by a low pressure gradient and a reduction in knock tendency. Consequently, by means of the NAV partial operation procedure, a room ignition combustion (RZV) in a higher engine load range feasible, in which the pure RZV partial operating method due to the increasing pressure gradient and because of irregular combustion conditions, in particular because of the increased tendency to knock, can no longer be carried out sufficiently stable operation.
• RZV room ignition combustion
• partial combustion engine room combustion (RZV) versus stoichiometric Otto engine combustion both have reduced fuel consumption and reduced NO x emission levels.
• the area of application can be extended by the NAV partial operating procedure with regard to the efficient combustion of room ignition.
• the smoothness in the NAV combustion process compared to the partial operation method with space ignition is improved.
• the combustion air ratio is a dimensionless physical quantity describing a mixture composition of a fuel-ZAbgas-ZLuftgemisches.
• the mixture composition of the fuel / exhaust gas / air mixture can be specified by the charge dilution. Regardless of whether there is a lean or a rich or stoichiometric fuel / exhaust / air mixture, the charge dilution indicates how much fuel has been positioned in relation to the other components of the fuel / exhaust / air mixture in the respective combustion chamber.
• the charge dilution is the quotient of the mass of fuel and the total mass of fuel / exhaust gas / air mixture present in the respective combustion chamber.
• a charge dilution of 0.03 to 0.05 is set.
• the ignition timing plays an essential role in the NAV partial operation method, it is preferable to arrange the ignition timing at a crank angle (KWW) of -45 to -10 ° KWW.
• the crankshaft angle is understood to mean a movement of the piston in the respective cylinder or combustion chamber that is divided into degrees.
• a four-stroke cycle in which an intake stroke transits into a compression stroke and then into an expansion stroke and subsequently into an exhaust stroke, usually the top dead center of the piston retracted into the respective combustion chamber becomes between the compression stroke and the expansion stroke with the crankshaft angle of zero ° referenced. Starting from this top dead center at 0 ° KWW, the crankshaft angle decreases in the direction of the expansion stroke and exhaust stroke, and in the direction of the compression stroke and intake stroke.
• the intake stroke is arranged in this division between - 360 ° KWW and - 180 ° KWW, the compression stroke between -180 ° KWW and 0 ° KWW, the Expansion cycle between 0 ° KWW and 180 ° KWW and the exhaust stroke between 180 ° KWW and 360 ° KWW.
• a homogeneous, lean fuel / exhaust gas / air mixture which is distributed substantially homogeneously in the respective combustion chamber.
• an exactly homogeneous design is present.
• small inhomogeneities may occur, but they have no significant influence on the respective partial operating procedure.
• Such a homogeneous, lean fuel / exhaust gas / air mixture can be generated by single or multiple injection.
• the injections or the multiple injections are made load-dependent and / or speed-dependent.
• the NAV partial operation method is performed at an engine speed of 5% to 70% of the maximum engine speed of the internal combustion engine.
• the NAV partial operation method is performed at an engine load of 10% to 70% of the maximum engine load of the internal combustion engine.
• an internal exhaust gas recirculation can be carried out.
• This exhaust gas recirculation can be carried out as exhaust gas recirculation and / or exhaust gas retention.
• exhaust gas is supplied to the respective combustion chamber by ejecting the exhaust gas into the intake tract and / or in the exhaust tract with subsequent sucking back.
• an exhaust gas retention can be carried out, in which a part of the exhaust gas is retained in the respective combustion chamber.
• an external exhaust gas recirculation can be carried out, wherein the externally recirculated exhaust gas can also be cooled.
• the NAV partial operation method may be performed in combination with and / or in addition to a spark-ignited stratified DES partial operation method.
• the ignition timing (ZZP) and / or a center of gravity of the combustion conversion may be positioned at such a crankshaft angle, which corresponds to the crank angle of the ignition timing (ZZP) and / or the center of gravity of a spark-ignited, stratified DES partial operation method.
• the NAV partial operating method is preferably also carried out in an engine speed range and / or an engine load range, in which a spark-ignited, stratified DES partial operating mode is also possible.
• the NAV partial operating method is carried out in combination with and / or in addition to an RZV partial operating method with pure space ignition transfer (RZV), switching between the two partial operating methods if the respective other partial operating method has a lower operational stability.
• RZV space ignition transfer
• FIG. 2 a comparison of valve lifts of an RZV, NAV and DES operating method
• FIG. 3 a graphic representation of a map area of the RZV and NAV
• Fig. 4 Setting conditions of the RZV and NAV operating method.
• a combustion course diagram 1 of a NAV partial operating method shown in FIG. 1 the crankshaft angle in degrees KWW is plotted on an abscissa 2, while a combustion curve in Joules is plotted on an ordinate 3.
• the combustion process of the NAV partial operation method is represented by a curve 4.
• One in the respective burning space arranged fuel / exhaust gas / air mixture is externally ignited to an ignition timing 5 at a crankshaft angle of - 30 ° +/- 5 ° KWW.
• the combustion chamber arranged in the respective fuel / exhaust gas / air mixture burns with a ottomisches flame front combustion (FFV).
• FFV ottomisches flame front combustion
• the fuel / exhaust gas / air mixture which has been heated further by the flame front combustion (FFV) and is pressurized more intensely, begins to be converted into a room ignition combustion.
• FFV flame front combustion
• a temperature necessary for the space ignition and a sufficiently high pressure are built up by the progressive flame front combustion (FFV).
• the NAV-Teil ists vide is subdivided into a phase I of the homogeneous flame front combustion (FFV) and a phase II of the homogeneous Kunststoffzündverbrennung (RZV), wherein both phases ⁇ , ⁇ are limited by the boundary line 6.
• the crankshaft angle in degrees KWW is plotted on an abscissa 8
• the cylinder pressure in bar or the valve lift in millimeters is plotted on the ordinates 9, 9 '.
• the curves 10, 10 ', 10 "respectively refer to the cylinder pressure curves of the DES, RZV, and NAV partial operating modes. For these curves, the cylinder pressure graduation of the ordinate 9 applies.
• a map 15 for the RZV partial operating method and a map 16 for the NAV partial operating method are shown in a motor glass engine speed diagram 14.
• the speed is plotted on the abscissa 17, while on the ordinate 18, the engine load is removed.
• a limit curve 19 limits that engine load or engine speed range in which the engine can be operated.
• the engine load / engine speed region 20 which is not taken up by the map 15 of the RZV partial operation method and also not by the map 16 of the NAV partial operation method, a partial engine operating method can be performed.
• An adjustment condition diagram 21, shown in FIG. 4, schematically illustrates adjustment conditions for the RZV partial operation method and for the NAV partial operation method.
• the charge dilution is decreased, decreasing in the direction of the abscissa 22, visualized by a decreasing bar 30.
• the engine load increases in the direction of the abscissa 22.
• an ordinate 23 of the crankshaft angle of the ignition (ZZP) is removed, which also decreases in orientation of the ordinate 23, visualized by a decreasing bar 30 '.
• the operation areas 24, 25, 26, 27, 28, 29 are shown.
• the operating area 24 identifies a possible operating range of the RZV partial operating method.
• the RZV partial operating method can be used in this operating region 24.
• both the RZV partial operating method and the NAV partial operating method can be carried out in the operating region 25.
• the NAV partial operation method can be shifted by means of the ignition timing, the center of gravity of the combustion conversion to an earlier crankshaft angle.
• the operating range 26 in which the RZV partial operating method can be carried out is reached, but in this charge dilution range the RZV partial operating method has a higher tendency to knock and is characterized by a correspondingly high pressure rise.
• the RZV partial operation method in this charge dilution region suffers from an increased operational instability, which can be improved by, for example, an external exhaust gas recirculation.
• This operating range 26 can be skipped by the NAV partial operating method, in which case the center of gravity of the combustion conversion can likewise be shifted towards a low crankshaft angle by the appropriate selection of the ignition point (ZZP).
• the NAV partial operating method is preferably to be used.
• an Otto engine partial operation method can be applied.
• neither the RZV, NAV or DES partial operation method can be used in the operation area 29.
• the compression ratio of the internal combustion engine is correspondingly designed to be advantageous. More specifically, the NAV partial operation method is performed at a compression ratio ⁇ of 10 to 13.
• the compression ratio ⁇ is the quotient of a compression volume of the combustion chamber at a position of the piston at its top dead center and the sum of the compression volume and the stroke volume of the combustion chamber at a position of the piston in its bottom dead center.
• the compression ratio ⁇ When changing from the RZV partial operating method to the NAV partial operating method, the compression ratio ⁇ is lowered. Due to the lowered compression ratio ⁇ the tendency to knock is significantly reduced and given an earlier center of gravity of the combustion conversion, as well as a resulting increased operational stability of the NAV partial operating procedure. When changing from the NAV partial operation method to the RZV partial operation method, the compression ratio ⁇ is raised.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Combustion Methods Of Internal-Combustion Engines (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

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• 2011
  • 2011-03-31 DE DE102011015628.3A patent/DE102011015628B4/de active Active
  • 2011-10-06 EP EP11778510.5A patent/EP2625410A2/de not_active Withdrawn
  • 2011-10-06 JP JP2013532072A patent/JP5877840B2/ja active Active
  • 2011-10-06 WO PCT/EP2011/004977 patent/WO2012045452A2/de active Application Filing
• 2013
  • 2013-04-03 US US13/856,088 patent/US20130297183A1/en not_active Abandoned

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