WO2018041724A1 - Gas-operated internal combustion engine and method for the operation thereof - Google Patents

Gas-operated internal combustion engine and method for the operation thereof Download PDF

Info

Publication number
WO2018041724A1
WO2018041724A1 PCT/EP2017/071370 EP2017071370W WO2018041724A1 WO 2018041724 A1 WO2018041724 A1 WO 2018041724A1 EP 2017071370 W EP2017071370 W EP 2017071370W WO 2018041724 A1 WO2018041724 A1 WO 2018041724A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
amount
air mixture
injection
internal combustion
Prior art date
Application number
PCT/EP2017/071370
Other languages
German (de)
French (fr)
Inventor
Dino Imhof
German Weisser
Original Assignee
Abb Turbo Systems Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Abb Turbo Systems Ag filed Critical Abb Turbo Systems Ag
Publication of WO2018041724A1 publication Critical patent/WO2018041724A1/en

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/0025Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D41/0027Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures the fuel being gaseous
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D19/00Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D19/06Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
    • F02D19/08Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels
    • F02D19/10Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels peculiar to compression-ignition engines in which the main fuel is gaseous
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/30Controlling fuel injection
    • F02D41/38Controlling fuel injection of the high pressure type
    • F02D41/40Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
    • F02D41/402Multiple injections
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/30Controlling fuel injection
    • F02D41/38Controlling fuel injection of the high pressure type
    • F02D41/40Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
    • F02D41/402Multiple injections
    • F02D41/405Multiple injections with post injections
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/30Use of alternative fuels, e.g. biofuels
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/40Engine management systems

Definitions

  • the present disclosure relates to a method for operating internal combustion engines, in particular internal combustion engines with direct injection of a gaseous fuel.
  • Generic internal combustion engines are typically operated with internal mixture formation. It is customary to introduce the fuel, for example diesel or gas, under high pressure at the end of the compression stroke near top dead center (TDC) into the combustion chamber. A small amount of pilot fuel, for example diesel, or spark ignition, such as a spark plug, is used to ignite this gas jet. It is known that such internal combustion engines have a high thermal efficiency resulting from the high compression ratio. In internal combustion engines with direct injection of a gas into the combustion chamber, the gas is usually injected at about 250 to 500 bar. In dynamic processes, in fuel operation and in pure diesel operation, the behavior of such internal combustion engines is comparable to that of pure diesel engines with direct injection.
  • the fuel for example diesel or gas
  • TDC top dead center
  • the disadvantages of gas direct injection include high NO x emissions, since the gas introduced is primarily converted in a mixture-controlled combustion process. Furthermore, the significant energy expenditure which has to be applied to the injection pressure to compress the gas can be regarded as disadvantageous.
  • the object of the invention is to improve this opposite dependence on efficiency and emission formation and to reduce the required injection pressure.
  • CA 2838120 Al discloses a direct injection, gas powered engine that is ignited by autoignition of a pilot fuel. In the background of the prior art, there is a need for gas direct injection internal combustion engines and methods of operation having improved properties.
  • a method for combusting a gaseous fuel in the combustion chamber of an internal combustion engine.
  • the method comprises injecting a first amount of gas during the intake process, wherein the air ratio of the resulting gas-air mixture is in the lean range above the ignition limit; the compression of the gas-air mixture; injecting a second quantity of gas beginning during or at the end of the compression; the ignition of the gas-air mixture; the burning of the total amount of gas from the first amount of gas and the second amount of gas, wherein the first amount of gas is burned premixed, and the second amount of gas is reacted predominantly in a mischungskontro-connected combustion.
  • An advantage of the method is that the hybrid combustion concept - with a combination of premixed combustion and mixture-controlled combustion - enables operation with a high proportion of premixed combustion. This makes it possible to achieve low NO x emissions by a low proportion of mixing-controlled combustion of the injected gas stream, while the compression ratio and thus the thermal efficiency are approximately at the level of a direct-injection diesel engine.
  • FIG. 1 shows an injection scheme according to a method according to embodiments of the invention
  • FIG. 2 shows an internal combustion engine for carrying out a method according to embodiments. Detailed description
  • embodiments of the invention relate to a method of operating internal combustion engines with gas direct injection using a hybrid combustion process.
  • hybrid combustion process refers to reacting a portion of the fuel in a premixed combustion and a portion in a mixture controlled combustion Basically, in accordance with embodiments of the invention, gas injection into the cylinder will occur in at least two The first gas injection takes place during the intake stroke, which allows an almost homogeneous mixing of this first gas quantity with air, whereby the air ratio lambda of the gas-air mixture thus formed remains above the lean range Ignition limit - based on the subsequent compression, that is, the mixture formed during the first injection is designed so that it would not auto-ignite in the subsequent compression even at top dead center is close to the top dead center then typically a liquid Pil injected ot fuel, and injected a second amount of gas.
  • the first amount of gas burns in a largely or ideally homogeneous, premixed combustion as a gas-air mixture.
  • the second amount of gas is converted in a mixture-controlled combustion. Since mixture-controlled combustion is generally associated with significantly higher NO x emissions than premixed combustion at the air ratios used herein, the engine's nitrogen oxide emissions are significantly reduced compared to pure direct injection operation, and the greater the greater the premixed first gas quantity is selected or adjusted in relation to the second quantity of gas.
  • the respective injection or injection quantities of the first and second gas quantities and the pilot fuel can be reduced individually, in some cases also reduced to zero, at least in the short term.
  • the processes of injecting the first amount of gas and / or the second amount of gas can in each case be further subdivided, that is to say subdivided into a plurality of individual phases.
  • Fig. 1 shows schematically the timing of a method according to embodiments of the invention. Shown is the injection of a first amount of gas 20 during the intake, wherein the air ratio of the resulting gas-air mixture is in the lean range above the ignition limit.
  • the gas-air mixture is compressed.
  • the resulting gas-air mixture is ignited, preferably by injection of a pilot fuel 40 already at the beginning of the injection of the second gas amount 30.
  • the compressed gas-air mixture is burned, wherein the first amount of gas 20 is premixed burned, and the second amount of gas is reacted predominantly in a mixture-controlled combustion.
  • the first gas quantity 20 and the second gas quantity 30 are varied as a function of the load.
  • This relates to the absolute quantities and in particular the ratio of the two gas quantities to each other.
  • the percentage of the second amount of gas (in the total amount of gas per cycle) can be reduced to lower loads.
  • This reduction in the case of partial load or low load can be made so far that the second gas amount 30 is completely eliminated, that is reduced to zero. Ignition also occurs in this case, typically by injecting the pilot fuel 40, as shown in FIG. 1, near top dead center. Since the entire amount of gas to be reacted then consists only of the first injected gas quantity 20, the entire injected gas burns in premixed combustion, that is to say under low nitrogen oxide formation.
  • the second amount of gas 30 can be increased and the first amount of gas 20 can be reduced.
  • the first amount of gas can also be reduced to zero in the short term. Since the second quantity of gas burns through mixed-cycle combustion under lower total hydrocarbon (THC) emissions, THC emission during load changes can be minimized in this way.
  • THC total hydrocarbon
  • the first amount of gas 20 can be reduced. This reduction can optionally be done to zero, so that only the second amount of gas 30 contributes to the combustion.
  • the pilot fuel 40 mentioned with reference to FIG. 1 is typically injected at the beginning of the injection of the second amount of gas 30.
  • the ignition of the gas-air mixture then occurs as a result of the self-ignition of the pilot fuel 40.
  • the pilot fuel is usually diesel, but may also include other liquid fuels such as biodiesel, rapeseed oil, etc.
  • the pilot fuel 40 can be injected earlier, namely even earlier during the compression. Preferably, this occurs at a time corresponding to about 50 degrees before TDC to about 90 degrees before TDC.
  • the ignition of the gas-air mixture can be done by applying a spark ignition, in particular by a spark plug, instead of by the pilot fuel.
  • a combustion engine 60 is shown schematically, which is suitable for carrying out a method according to embodiments.
  • This typically has a compression ratio of between about 14: 1 and 20: 1, similar to a direct injection diesel engine.
  • an injector 50 In addition to the typical basic components of a four-stroke engine - cylinder 78, cylinder head 70, piston 76, intake valve 72, exhaust valve 74, combustion chamber 77 - the engine according to embodiments, an injector 50.
  • the injector 50 may be embodied in various ways. As illustrated, the gas and pilot fuel feeds may be provided in a single injector housing. Such an injector is disclosed for example in DE102014014452 (B4).
  • the injectors for gas and diesel are each provided as a separate injection or Eindüsvorraumen in the cylinder head 70, and embodiments in which several injectors for gas are used.
  • the advantages of the described embodiments are above all in significantly reduced NOx emission values in comparison to conventional direct-injection gas-powered engines.
  • THC emissions are lower.
  • a correspondingly high degree of efficiency can be achieved by the compression ratio comparable to a diesel engine.
  • the lower required pressure level when injecting the first gas quantity, or the significantly lower mass fraction of the second gas quantity results in a significant energy saving in comparison with direct-injection gas-powered ones Engines that contribute to the increase in overall efficiency.

Landscapes

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

Abstract

The invention relates to a method for the combustion of a gaseous fuel in the combustion chamber of an internal combustion engine with internal mixture formation. The method consists of injecting a first amount of gas during the drawing process wherein the air ratio of the thus formed gas-air mixture in the lean region is above the ignition limit; compressing the gas-air mixture; injecting a second amount of gas at the beginning, during or at the end of compression; igniting the gas-air mixture; and combusting the entire amount of gas from the first amount of gas and the second amount of gas, wherein the first amount of gas undergoes combustion prior to mixing, and the second amount of gas is predominantly converted in a mixing controlled combustion. The invention also relates to a corresponding internal combustion engine.

Description

GASBETRIEBENE BRENNKRAFTMASCHINE UND VERFAHREN  GAS-POWERED INTERNAL COMBUSTION ENGINE AND METHOD
ZU DEREN BETRIEB TO THEIR OPERATION
Technisches Gebiet Technical area
Die vorliegende Offenbarung betrifft ein Verfahren zum Betrieb von Brennkraftmaschinen, dabei insbesondere Verbrennungsmotoren mit Direkteindüsung eines gasförmigen Brennstoffs. The present disclosure relates to a method for operating internal combustion engines, in particular internal combustion engines with direct injection of a gaseous fuel.
Hintergrund der Erfindung Background of the invention
Gattungsgemäße Verbrennungsmotoren werden typischerweise mit innerer Gemischbildung betrieben. Dabei ist es üblich, den Brennstoff, zum Beispiel Diesel oder Gas, unter hohem Druck etwa zum Ende des Kompressionstaktes nahe dem oberen Totpunkt (OT) in den Brennraum einzubringen. Eine kleine Menge eines Pilot-Brennstoffs, zum Beispiel Diesel, oder eine Fremdzündung, zum Beispiel eine Zündkerze, wird eingesetzt, diesen Gasstrahl zu zünden. Es ist bekannt, dass solche Verbrennungsmotoren einen hohen thermischen Wirkungsgrad aufweisen, der aus dem hohen Verdichtungsverhältnis resultiert. In Verbrennungsmotoren mit direkter Eindüsung eines Gases in den Brennraum wird das Gas üblicherweise mit etwa 250 bis 500 bar eingedüst. Bei dynamischen Vorgängen, im Zwei- stoff-Betrieb und bei reinem Dieselbetrieb ist das Verhalten solcher Verbrennungsmotoren vergleichbar zu dem reiner Dieselmotoren mit Direkteinspritzung. Generic internal combustion engines are typically operated with internal mixture formation. It is customary to introduce the fuel, for example diesel or gas, under high pressure at the end of the compression stroke near top dead center (TDC) into the combustion chamber. A small amount of pilot fuel, for example diesel, or spark ignition, such as a spark plug, is used to ignite this gas jet. It is known that such internal combustion engines have a high thermal efficiency resulting from the high compression ratio. In internal combustion engines with direct injection of a gas into the combustion chamber, the gas is usually injected at about 250 to 500 bar. In dynamic processes, in fuel operation and in pure diesel operation, the behavior of such internal combustion engines is comparable to that of pure diesel engines with direct injection.
Zu den Nachteilen der Gas-Direkteindüsung gehören hohe NOx-Emissionen, da das einge- brachte Gas vor allem in einer mischungskontrollierten Verbrennung umgesetzt wird. Als nachteilig kann ferner der signifikante Energieaufwand angesehen werden, der zur Kompression des Gases auf den Eindüsungs-Druck aufgebracht werden muss. Aufgabe der Erfindung ist, diese gegenläufige Abhängigkeit von Effizienz und Emissionsbildung zu verbessern und den benötigten Eindüsungs-Druck zu senken. CA 2838120 AI offenbart einen direkteinspritzenden, gasbetriebenen Motor, der mittels Selbstzündung eines Pilot-Brennstoffs gezündet wird. Vor dem Hintergrund des Standes der Technik besteht Bedarf nach Verbrennungsmotoren mit Gas-Direkteindüsung und Verfahren zu deren Betrieb, die verbesserte Eigenschaften aufweisen. The disadvantages of gas direct injection include high NO x emissions, since the gas introduced is primarily converted in a mixture-controlled combustion process. Furthermore, the significant energy expenditure which has to be applied to the injection pressure to compress the gas can be regarded as disadvantageous. The object of the invention is to improve this opposite dependence on efficiency and emission formation and to reduce the required injection pressure. CA 2838120 Al discloses a direct injection, gas powered engine that is ignited by autoignition of a pilot fuel. In the background of the prior art, there is a need for gas direct injection internal combustion engines and methods of operation having improved properties.
Zusammenfassung der Erfindung Die Aufgabe der Erfindung wird gelöst durch ein Verfahren gemäß Anspruch 1 und einen Verbrennungsmotor gemäß Anspruch 10. Summary of the Invention The object of the invention is achieved by a method according to claim 1 and an internal combustion engine according to claim 10.
In einem ersten Aspekt der Erfindung wird ein Verfahren zur Verbrennung eines gasförmigen Brennstoffs im Brennraum eines Verbrennungsmotors mit innerer Gemischbildung bereitgestellt. Das Verfahren umfasst das Eindüsen einer ersten Gasmenge während des Ansaugvor- gangs, wobei die Luftzahl des dabei gebildeten Gas-Luft-Gemischs im mageren Bereich oberhalb der Zündgrenze liegt; die Kompression des Gas-Luft-Gemischs; das Eindüsen einer zweiten Gasmenge beginnend während oder am Ende der Kompression; das Zünden des Gas- Luft-Gemischs; das Verbrennen der Gesamt-Gasmenge aus erster Gasmenge und zweiter Gasmenge, wobei die erste Gasmenge vorgemischt verbrannt wird, und die zweite Gasmenge vorwiegend in einer mischungskontro liierten Verbrennung umgesetzt wird. In a first aspect of the invention, a method is provided for combusting a gaseous fuel in the combustion chamber of an internal combustion engine. The method comprises injecting a first amount of gas during the intake process, wherein the air ratio of the resulting gas-air mixture is in the lean range above the ignition limit; the compression of the gas-air mixture; injecting a second quantity of gas beginning during or at the end of the compression; the ignition of the gas-air mixture; the burning of the total amount of gas from the first amount of gas and the second amount of gas, wherein the first amount of gas is burned premixed, and the second amount of gas is reacted predominantly in a mischungskontro-connected combustion.
Ein Vorteil des Verfahrens besteht darin, dass das hybride Verbrennungskonzept - mit einer Kombination aus vorgemischter Verbrennung und mischungskontrollierter Verbrennung - einen Betrieb mit einem hohen Anteil an vorgemischter Verbrennung ermöglicht. Dies ermöglicht die Erzielung niedriger NOx-Emissionen durch einen geringen Anteil an mischungs- kontrollierter Verbrennung des eingedüsten Gasstroms, während das Verdichtungsverhältnis und damit der thermische Wirkungsgrad etwa auf dem Niveau eines direkteinspritzenden Dieselmotors liegen. An advantage of the method is that the hybrid combustion concept - with a combination of premixed combustion and mixture-controlled combustion - enables operation with a high proportion of premixed combustion. This makes it possible to achieve low NO x emissions by a low proportion of mixing-controlled combustion of the injected gas stream, while the compression ratio and thus the thermal efficiency are approximately at the level of a direct-injection diesel engine.
Weitere Merkmale und Vorteile der vorliegenden Erfindung werden in der folgenden ausführlichen Beschreibung von bevorzugten Ausführungsformen des Systems vorgestellt. Kurze Beschreibung der Figuren Further features and advantages of the present invention are presented in the following detailed description of preferred embodiments of the system. Brief description of the figures
Weitere Merkmale und Vorteile der vorliegenden Erfindung werden für den Fachmann anhand der ausführlichen Beschreibung in Verbindung mit den angehängten Figuren ersichtlich. Dabei zeigen: Fig. 1 zeigt ein Eindüsungsschema gemäß einem Verfahren nach Ausführungsformen der Erfindung; Other features and advantages of the present invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the appended drawings. Showing: Fig. 1 shows an injection scheme according to a method according to embodiments of the invention;
Fig. 2 zeigt einen Verbrennungsmotor zum Ausführen eines Verfahrens gemäß Ausführungsformen. Detaillierte Beschreibung FIG. 2 shows an internal combustion engine for carrying out a method according to embodiments. Detailed description
Auch wenn bevorzugte Ausführungsformen beschrieben werden, ist der Schutzbereich der Erfindung nicht auf die dargestellten Ausführungsformen beschränkt, sondern umfasst auch für den Fachmann naheliegende Ausführungsformen. Although preferred embodiments are described, the scope of the invention is not limited to the illustrated embodiments, but also includes embodiments obvious to those skilled in the art.
Grundsätzlich betreffen Ausführungsformen der Erfindung ein Verfahren zum Betrieb von Verbrennungsmotoren mit Gas-Direkteinspritzung, wobei ein hybrides Verbrennungsverfahren zur Anwendung kommt. Gemäß der hierin verwendeten Bedeutung bezieht sich„hybrides Verbrennungsverfahren" darauf, dass ein Teil des Brennstoffs in einer vorgemischten Verbrennung und ein Teil in einer mischungskontrollierten Verbrennungumgesetzt wird. Grundsätzlich wird dazu, gemäß Ausführungsbeispielen der Erfindung, die Gas-Eindüsung in den Zylinder in mindestens zwei zeitlich voneinander getrennte bzw. beabstandete Vorgänge aufgeteilt. Die erste Gaseindüsung geschieht während des Einlass-Taktes, wodurch eine nahezu homogene Durchmischung dieser ersten Gasmenge mit Luft ermöglicht wird. Dabei bleibt die Luftzahl Lambda des so gebildeten Gas-Luft-Gemischs im mageren Bereich oberhalb der Zündgrenze - bezogen auf die darauffolgende Kompression, das heißt, das während der ersten Eindüsung gebildete Gemisch ist derart ausgelegt, dass es bei der nachfolgenden Kompression auch im oberen Totpunkt noch nicht selbstzünden würde. Nahe dem oberen Totpunkt wird dann typischerweise ein flüssiger Pilot-Brennstoff eingespritzt, sowie eine zweite Gasmenge eingedüst. Die erste Gasmenge verbrennt in einer weitgehend bzw. idealerweise homogenen, vorgemischten Verbrennung als Gas-Luft-Gemisch. Die zweite Gasmenge wird dagegen in einer mischungskontrollierten Verbrennung umgesetzt. Da eine mischungskontrollierte Verbrennung grundsätzlich mit signifikant höheren NOx-Emissionen als eine vorgemischte Verbrennung bei den hier zur Anwendung kommenden Luftzahlen verbunden ist, ist der Stickoxid-Ausstoß des Motors deutlich reduziert im Vergleich zum reinen Direkteinspritzungs- Betrieb, und zwar umso stärker, je größer die vorgemischt verbrennende erste Gasmenge im Verhältnis zur zweiten Gasmenge gewählt bzw. eingestellt ist. In einigen Ausführungsbeispielen, die im Folgenden noch genauer ausgeführt werden, können zumindest kurzfristig die jeweiligen Eindüs- oder Einspritzmengen der ersten und zweiten Gasmenge sowie des Pilot-Brennstoffs individuell reduziert werden, in einigen Fällen auch bis auf null reduziert werden. Auch können generell die Vorgänge des Eindüsens der ersten Gasmenge und/oder der zweiten Gasmenge jeweils weiter unterteilt, das heißt in mehrere Einzelphasen aufgeteilt vorgenommen werden. Basically, embodiments of the invention relate to a method of operating internal combustion engines with gas direct injection using a hybrid combustion process. As used herein, "hybrid combustion process" refers to reacting a portion of the fuel in a premixed combustion and a portion in a mixture controlled combustion Basically, in accordance with embodiments of the invention, gas injection into the cylinder will occur in at least two The first gas injection takes place during the intake stroke, which allows an almost homogeneous mixing of this first gas quantity with air, whereby the air ratio lambda of the gas-air mixture thus formed remains above the lean range Ignition limit - based on the subsequent compression, that is, the mixture formed during the first injection is designed so that it would not auto-ignite in the subsequent compression even at top dead center is close to the top dead center then typically a liquid Pil injected ot fuel, and injected a second amount of gas. The first amount of gas burns in a largely or ideally homogeneous, premixed combustion as a gas-air mixture. By contrast, the second amount of gas is converted in a mixture-controlled combustion. Since mixture-controlled combustion is generally associated with significantly higher NO x emissions than premixed combustion at the air ratios used herein, the engine's nitrogen oxide emissions are significantly reduced compared to pure direct injection operation, and the greater the greater the premixed first gas quantity is selected or adjusted in relation to the second quantity of gas. In some embodiments, which are explained in more detail below, the respective injection or injection quantities of the first and second gas quantities and the pilot fuel can be reduced individually, in some cases also reduced to zero, at least in the short term. In general, the processes of injecting the first amount of gas and / or the second amount of gas can in each case be further subdivided, that is to say subdivided into a plurality of individual phases.
Fig. 1 zeigt schematisch den zeitlichen Ablauf eines Verfahrens gemäß Ausführungsbeispie- len der Erfindung. Gezeigt ist das Eindüsen einer ersten Gasmenge 20 während des Ansaugvorgangs, wobei die Luftzahl des dabei gebildeten Gas-Luft-Gemischs im mageren Bereich oberhalb der Zündgrenze liegt. In der folgenden Kompression wird das Gas-Luft-Gemisch komprimiert. Gegen Ende der Kompression, d.h. nahe des oberen Totpunkts (OT), wird eine zweite Gasmenge 30 eingedüst. Das so entstandene Gas-Luft-Gemisch wird gezündet, vor- zugsweise durch Einspritzung eines Pilot-Brennstoffs 40 bereits zu Beginn der Eindüsung der zweiten Gasmenge 30. Das komprimierte Gas-Luft-Gemisch wird verbrannt, wobei die erste Gasmenge 20 vorgemischt verbrannt wird, und die zweite Gasmenge vorwiegend in einer mischungskontrollierten Verbrennung umgesetzt wird. Zur Lastregelung werden in Ausführungsbeispielen die erste Gasmenge 20 und die zweite Gasmenge 30 als Funktion der Last variiert. Dies betrifft die absoluten Mengen und insbesondere auch das Verhältnis der beiden Gasmengen zueinander. So kann etwa der prozentuale Anteil der zweiten Gasmenge (an der Gesamt-Gasmenge pro Zyklus) zu niedrigeren Lasten hin reduziert werden. Diese Reduzierung im Fall von Teillast bzw. niedriger Last kann soweit vorgenommen werden, dass die zweite Gasmenge 30 ganz wegfällt, also auf null reduziert wird. Die Zündung geschieht auch in diesem Fall typischerweise durch Einspritzung des Pilot-Brennstoffs 40, wie in Fig. 1 dargestellt, nahe des oberen Totpunkts. Da die gesamte umzusetzende Gasmenge dann nur aus der ersten eingedüsten Gasmenge 20 besteht, verbrennt das gesamte eingedüste Gas in vorgemischter Verbrennung, das heißt unter geringen Stick- oxid-Bildung. Lediglich der Pilot-Brennstoff 40 verbrennt in diesem Fall in einer mischungskontrollierten Verbrennung. Im Fall von dynamischen Lasterhöhungen kann in Ausführungsbeispielen die zweite Gasmenge 30 erhöht werden und die erste Gasmenge 20 reduziert werden. Die erste Gasmenge kann dabei optional auch kurzfristig bis auf null abgesenkt werden. Da die zweite Gasmenge durch die mischungskontroUierte Verbrennung unter geringeren Gesamt-Kohlenwasserstoff (total hydrocarbon - THC)-Emissionen verbrennt, lässt sich auf diese Weise die THC- Emission bei Lastwechseln minimieren. Ebenso kann bei dynamischen Lastabsenkungen vor allem die erste Gasmenge 20 reduziert werden. Diese Reduzierung kann optional bis auf null erfolgen, so dass nur noch die zweite Gasmenge 30 zur Verbrennung beiträgt. Fig. 1 shows schematically the timing of a method according to embodiments of the invention. Shown is the injection of a first amount of gas 20 during the intake, wherein the air ratio of the resulting gas-air mixture is in the lean range above the ignition limit. In the following compression, the gas-air mixture is compressed. Towards the end of the compression, ie near top dead center (TDC), a second amount of gas 30 is injected. The resulting gas-air mixture is ignited, preferably by injection of a pilot fuel 40 already at the beginning of the injection of the second gas amount 30. The compressed gas-air mixture is burned, wherein the first amount of gas 20 is premixed burned, and the second amount of gas is reacted predominantly in a mixture-controlled combustion. For load control, in embodiments the first gas quantity 20 and the second gas quantity 30 are varied as a function of the load. This relates to the absolute quantities and in particular the ratio of the two gas quantities to each other. For example, the percentage of the second amount of gas (in the total amount of gas per cycle) can be reduced to lower loads. This reduction in the case of partial load or low load can be made so far that the second gas amount 30 is completely eliminated, that is reduced to zero. Ignition also occurs in this case, typically by injecting the pilot fuel 40, as shown in FIG. 1, near top dead center. Since the entire amount of gas to be reacted then consists only of the first injected gas quantity 20, the entire injected gas burns in premixed combustion, that is to say under low nitrogen oxide formation. Only the pilot fuel 40 burns in this case in a mixture-controlled combustion. In the case of dynamic load increases, in embodiments, the second amount of gas 30 can be increased and the first amount of gas 20 can be reduced. Optionally, the first amount of gas can also be reduced to zero in the short term. Since the second quantity of gas burns through mixed-cycle combustion under lower total hydrocarbon (THC) emissions, THC emission during load changes can be minimized in this way. Likewise, with dynamic load decreases, especially the first amount of gas 20 can be reduced. This reduction can optionally be done to zero, so that only the second amount of gas 30 contributes to the combustion.
Der in Bezug auf Fig. 1 erwähnte Pilot-Brennstoff 40 wird typischerweise zu Beginn des Eindüsens der zweiten Gasmenge 30 eingespritzt. Das Zünden des Gas-Luft-Gemisches geschieht dann als Folge des Selbstzündens des Pilot-Brennstoffs 40. Der Pilot-Brennstoff ist üblicherweise Diesel, kann aber auch andere flüssige Brennstoffe wie Biodiesel, Rapsöl, etc. umfassen. The pilot fuel 40 mentioned with reference to FIG. 1 is typically injected at the beginning of the injection of the second amount of gas 30. The ignition of the gas-air mixture then occurs as a result of the self-ignition of the pilot fuel 40. The pilot fuel is usually diesel, but may also include other liquid fuels such as biodiesel, rapeseed oil, etc.
Wird, wie oben mit Bezug auf Teillast bzw. niedrige Lasten angeführt, bei niedrigen Lasten die zweite Gasmenge 30 weitgehend oder ganz bis auf null reduziert, so kann der Pilot- Brennstoff 40 bereits früher, nämlich noch früh während der Kompression eingespritzt werden. Bevorzugt geschieht dies zu einem Zeitpunkt entsprechend etwa 50 Grad vor OT bis etwa 90 Grad vor OT. If, as stated above with respect to partial load or low loads, the second gas quantity 30 is reduced substantially or completely to zero at low loads, the pilot fuel 40 can be injected earlier, namely even earlier during the compression. Preferably, this occurs at a time corresponding to about 50 degrees before TDC to about 90 degrees before TDC.
In einigen Ausführungsbeispielen kann die Zündung des Gas-Luft-Gemisches statt durch den Pilot-Brennstoff auch durch Anwenden einer Fremdzündung geschehen, insbesondere durch eine Zündkerze. In some embodiments, the ignition of the gas-air mixture can be done by applying a spark ignition, in particular by a spark plug, instead of by the pilot fuel.
In Fig. 2 ist schematisch ein Verbrennungsmotor 60 dargestellt, der zur Ausführung eines Verfahrens gemäß Ausführungsbeispielen geeignet ist. Dieser weist typischerweise ein Verdichtungsverhältnis zwischen etwa 14: 1 und 20: 1 auf, ähnlich einem direkteinspritzenden Dieselmotor. Neben den typischen Grundbestandteilen eines Viertaktmotors - Zylinder 78, Zylinderkopf 70, Kolben 76, Einlassventil 72, Auslassventil 74, Brennraum 77 - weist der Motor gemäß Ausführungsbeispielen einen Injektor 50 auf. In Ausführungsbeispielen kann der Injektor 50 auf verschiedene Weise ausgeführt sein. Wie dargestellt, können die Zuführungen für Gas und Pilot-Brennstoff in einem einzelnen Injektorgehäuse vorgesehen sein. Ein solcher Injektor wird beispielsweise in der DE102014014452 (B4) offenbart. Möglich sind auch baulich getrennte Ausführungen, wobei die Injektoren für Gas und Diesel jeweils als eigene Einspritz- bzw. Eindüsvorrichtungen im Zylinderkopf 70 bereitgestellt sind, sowie Ausführungen bei denen mehrere Injektoren für Gas zur Anwendung kommen. Die Vorteile der beschriebenen Ausführungsformen liegen vor allem in erheblich reduzierten NOx-Emissionswerten im Vergleich zu herkömmlichen direkt-eindüsenden gasbetriebenen Motoren. Zudem sind die THC-Emissionen im Vergleich zu herkömmlichen, im Magerbetrieb betriebenen Gasmotoren geringer. Beim Umstellen auf reinen Dieselbetrieb kann durch das mit einem Dieselmotor vergleichbare Verdichtungsverhältnis ein entsprechend hoher Wirkungsgrad erzielt werden Durch das geringere erforderliche Druckniveau beim Eindüsen der ersten Gasmenge, bzw. den deutlich geringeren Massenanteil der zweiten Gasmenge, ergibt sich eine signifikante Energieeinsparung im Vergleich zu direkteinspritzenden gasbetriebenen Motoren, die zur Steigerung des Gesamtwirkungsgrades beiträgt. 2, a combustion engine 60 is shown schematically, which is suitable for carrying out a method according to embodiments. This typically has a compression ratio of between about 14: 1 and 20: 1, similar to a direct injection diesel engine. In addition to the typical basic components of a four-stroke engine - cylinder 78, cylinder head 70, piston 76, intake valve 72, exhaust valve 74, combustion chamber 77 - the engine according to embodiments, an injector 50. In embodiments, the injector 50 may be embodied in various ways. As illustrated, the gas and pilot fuel feeds may be provided in a single injector housing. Such an injector is disclosed for example in DE102014014452 (B4). Possible are also structurally separate versions, the injectors for gas and diesel are each provided as a separate injection or Eindüsvorrichtungen in the cylinder head 70, and embodiments in which several injectors for gas are used. The advantages of the described embodiments are above all in significantly reduced NOx emission values in comparison to conventional direct-injection gas-powered engines. In addition, compared to conventional lean-burn gas engines, THC emissions are lower. When switching to pure diesel operation, a correspondingly high degree of efficiency can be achieved by the compression ratio comparable to a diesel engine. The lower required pressure level when injecting the first gas quantity, or the significantly lower mass fraction of the second gas quantity, results in a significant energy saving in comparison with direct-injection gas-powered ones Engines that contribute to the increase in overall efficiency.

Claims

Patentansprüche claims
1. Verfahren zur Verbrennung eines gasförmigen Brennstoffs im Brennraum eines Verbrennungsmotors (60) mit innerer Gemischbildung, umfassend: A method of combusting a gaseous fuel in the combustion chamber of an internal combustion engine (60) comprising:
Eindüsen einer ersten Gasmenge (20) während des Ansaugvorgangs, wobei die Luftzahl des dabei gebildeten Gas-Luft-Gemischs im mageren Bereich oberhalb der Zündgrenze liegt;  Injecting a first amount of gas (20) during the intake process, wherein the air ratio of the resulting gas-air mixture is in the lean range above the ignition limit;
Kompression des Gas-Luft-Gemischs;  Compression of the gas-air mixture;
Eindüsen einer zweiten Gasmenge (30) beginnend während oder am Ende der Kompression;  Injecting a second amount of gas (30) beginning during or at the end of the compression;
Zünden des Gas-Luft-Gemischs;  Igniting the gas-air mixture;
- Verbrennen der Gesamt-Gasmenge aus erster Gasmenge und zweiter Gasmenge, wobei die erste Gasmenge vorgemischt verbrannt wird, und die zweite Gasmenge vorwiegend in einer mischungskontrollierten Verbrennung umgesetzt wird.  - Burning the total amount of gas from the first amount of gas and second amount of gas, wherein the first amount of gas is burned premixed, and the second amount of gas is converted predominantly in a mixture-controlled combustion.
2. Verfahren nach Anspruch 1, wobei die erste Gasmenge (20) und die zweite Gasmenge (30) als Funktion der Last variiert werden, insbesondere der Anteil der zweiten Gasmenge (30) zu niedrigeren Lasten hin reduziert wird, optional bis auf null. 2. The method of claim 1, wherein the first amount of gas (20) and the second amount of gas (30) are varied as a function of the load, in particular the proportion of the second amount of gas (30) is reduced towards lower loads, optionally down to zero.
3. Verfahren nach Anspruch 1 oder 2, wobei bei dynamischen Lasterhöhungen die zweite Gasmenge (30) erhöht wird, und die erste Gasmenge (20) reduziert wird, optional bis auf null, und bei dynamischen Lastabsenkungen vor allem die erste Gasmenge (20) reduziert wird, optional bis auf null. 3. The method of claim 1 or 2, wherein at dynamic load increases the second amount of gas (30) is increased, and the first amount of gas (20) is reduced, optionally to zero, and reduced in dynamic load decreases, especially the first amount of gas (20) will, optionally to zero.
4. Verfahren nach einem der vorhergehenden Ansprüche, wobei zu Beginn des Eindüsens der zweiten Gasmenge (30) ein Pilot-Brennstoff (40) eingespritzt wird, und wo- bei das Zünden des Gas-Luft-Gemisches durch Selbstzünden des Pilot-Brennstoffs (40) geschieht. 4. The method according to any one of the preceding claims, wherein at the beginning of the injection of the second amount of gas (30) a pilot fuel (40) is injected, and where in the ignition of the gas-air mixture by spontaneous ignition of the pilot fuel (40).
Verfahren nach Anspruch 2, wobei bei niedrigen Lasten die zweite Gasmenge (30) bis auf null reduziert wird und der Pilot-Brennstoff (40) bereits früh während der Kompression eingespritzt wird, bevorzugt zu einem Zeitpunkt entsprechend 50 Grad vor OT bis 90 Grad vor OT. The method of claim 2, wherein at low loads, the second amount of gas (30) is reduced to zero and the pilot fuel (40) is injected early during compression, preferably at a time equal to 50 degrees BTDC to 90 degrees BTDC ,
Verfahren nach einem der Ansprüche 1 bis 3, wobei die Zündung des Gas-Luft- Gemisches durch Fremdzündung geschieht. Method according to one of claims 1 to 3, wherein the ignition of the gas-air mixture is done by spark ignition.
Verfahren gemäß einem der vorhergehenden Ansprüche, wobei zwischen dem Ende des Eindüsens der ersten Gasmenge (20) und dem Beginn des Eindüsens der zweiten Gasmenge (30) ein Abstand von mindestens etwa 150 Grad Kurbelwinkel besteht. A method according to any one of the preceding claims, wherein there is a distance of at least about 150 degrees crank angle between the end of injection of the first quantity of gas (20) and the beginning of the injection of the second quantity of gas (30).
Verfahren nach einem der vorhergehenden Ansprüche, wobei der Verbrennungsmotor (60) ein Verdichtungsverhältnis zwischen etwa 14: 1 und 20: 1 aufweist. The method of any one of the preceding claims, wherein the internal combustion engine (60) has a compression ratio between about 14: 1 and 20: 1.
Verfahren nach einem der vorhergehenden Ansprüche, wobei das Eindüsen der ersten Gasmenge (20) und/oder der zweiten Gasmenge (30) in mindestens zwei Einzelphasen aufgetrennt ist. Method according to one of the preceding claims, wherein the injection of the first amount of gas (20) and / or the second amount of gas (30) is separated into at least two individual phases.
10. Ein Verbrennungsmotor (60), der zur Anwendung eines Verfahrens gemäß einem der Ansprüche 1 bis 9 ausgelegt ist. An internal combustion engine (60) adapted to use a method according to any one of claims 1 to 9.
PCT/EP2017/071370 2016-08-29 2017-08-24 Gas-operated internal combustion engine and method for the operation thereof WO2018041724A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102016116040.7 2016-08-29
DE102016116040.7A DE102016116040A1 (en) 2016-08-29 2016-08-29 Gas powered combustion engine and method of operation therefor

Publications (1)

Publication Number Publication Date
WO2018041724A1 true WO2018041724A1 (en) 2018-03-08

Family

ID=59799351

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2017/071370 WO2018041724A1 (en) 2016-08-29 2017-08-24 Gas-operated internal combustion engine and method for the operation thereof

Country Status (2)

Country Link
DE (1) DE102016116040A1 (en)
WO (1) WO2018041724A1 (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6202601B1 (en) * 2000-02-11 2001-03-20 Westport Research Inc. Method and apparatus for dual fuel injection into an internal combustion engine
WO2001059285A2 (en) * 2000-02-11 2001-08-16 Westport Research Inc. Method and apparatus for gaseous fuel introduction and controlling combustion in an internal combustion engine
US20040118557A1 (en) * 2000-12-26 2004-06-24 Richard Ancimer Method and apparatus for pilot fuel introduction and controlling combustion in gaseous-fuelled internal combustion engine
US20120325180A1 (en) * 2011-06-21 2012-12-27 Caterpillar, Inc. Dual Fuel Injection Compression Ignition Engine And Method Of Operating Same
CA2838120A1 (en) 2013-12-23 2014-03-14 Westport Power Inc. Method and apparatus for fuel injection and dynamic combustion control
US20150285178A1 (en) * 2014-04-02 2015-10-08 Caterpillar Inc. Reactivity controlled compression ignition engine and method of combustion phasing control
DE102014014452B4 (en) 2014-09-26 2016-07-14 L'orange Gmbh Dual-fuel injector, method of execution with it, as well as dual-fuel fuel injection system

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4472932B2 (en) 2003-02-07 2010-06-02 いすゞ自動車株式会社 Engine combustion control device
US7044103B2 (en) 2004-08-16 2006-05-16 Dresser, Inc. Fuel quantity modulation in pilot ignited engines
DE102008001606B4 (en) 2008-05-07 2019-11-21 Robert Bosch Gmbh Method and device for operating an internal combustion engine
DE102012222368A1 (en) 2012-12-06 2014-06-12 Schaeffler Technologies Gmbh & Co. Kg Engine control unit for an ignition jet engine and method for operating a Zündstrahlmotors
US9399968B2 (en) 2013-09-05 2016-07-26 Ford Global Technologies, Llc Engine control for a liquid petroleum gas fueled engine

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6202601B1 (en) * 2000-02-11 2001-03-20 Westport Research Inc. Method and apparatus for dual fuel injection into an internal combustion engine
WO2001059285A2 (en) * 2000-02-11 2001-08-16 Westport Research Inc. Method and apparatus for gaseous fuel introduction and controlling combustion in an internal combustion engine
US20040118557A1 (en) * 2000-12-26 2004-06-24 Richard Ancimer Method and apparatus for pilot fuel introduction and controlling combustion in gaseous-fuelled internal combustion engine
US20120325180A1 (en) * 2011-06-21 2012-12-27 Caterpillar, Inc. Dual Fuel Injection Compression Ignition Engine And Method Of Operating Same
CA2838120A1 (en) 2013-12-23 2014-03-14 Westport Power Inc. Method and apparatus for fuel injection and dynamic combustion control
US20150285178A1 (en) * 2014-04-02 2015-10-08 Caterpillar Inc. Reactivity controlled compression ignition engine and method of combustion phasing control
DE102014014452B4 (en) 2014-09-26 2016-07-14 L'orange Gmbh Dual-fuel injector, method of execution with it, as well as dual-fuel fuel injection system

Also Published As

Publication number Publication date
DE102016116040A1 (en) 2018-03-01

Similar Documents

Publication Publication Date Title
DE10147529B4 (en) Method for operating an internal combustion engine operated with auto-ignitable fuel
DE112006003590B4 (en) Compression ignition induction device and internal combustion engine using the same
DE102014115142B4 (en) Double antechamber combustion system
DE112005001363B4 (en) Method for medium load operation of auto-ignition combustion
DE102005044544B4 (en) Method for operating a spark-ignited 4-stroke internal combustion engine
DE112011103649T5 (en) Prechamber combustion system with turbulent ignition jet for gasoline engines
AT516490B1 (en) Method for operating a spark-ignited internal combustion engine
AT516289B1 (en) Method for operating an auto-ignition internal combustion engine
DE112011104585T5 (en) Stratified charge engine with intake manifold injection and method therefor
EP2446133A1 (en) Method for operating an internal combustion engine
DE102018000706A1 (en) Method for operating an internal combustion engine for a motor vehicle
DE112019004367T5 (en) Split direct injection for reactivated cylinders of an internal combustion engine
DE2615643A1 (en) PROCEDURE FOR OPERATING AN EXTERNAL IGNITION ENGINE AND COMBUSTION ENGINE FOR CARRYING OUT THIS PROCEDURE
EP3872330A1 (en) Large diesel engine and method for operating a large diesel engine
DE102009040795A1 (en) Eight-stroke engine cycle
DE102016221979A1 (en) Apparatus for controlling a gasoline-diesel complex internal combustion engine and method for controlling a gasoline-diesel complex internal combustion engine
DE102012202080A1 (en) Lifting cylinder combustion engine for car, has fuel injector that is provided with first and second apertures such that fuel is passed into first combustion chamber by first aperture and into second chamber by second aperture
DE102011015626B9 (en) Operating method for a direct-injection gasoline engine with low-NOx combustion (NAV)
EP1055061B1 (en) Method of producing a mixture in the combustion chamber of an internal combustion engine
AT5135U1 (en) METHOD FOR OPERATING A FUEL-LIKE FUEL, IN PARTICULAR GASOLINE, OPERATING COMBUSTION ENGINE
EP2116707A1 (en) Method for cold start of an internal combustion engine
DE102017219583A1 (en) Multi-injection gas engine and method of operating a gas engine
WO2018041724A1 (en) Gas-operated internal combustion engine and method for the operation thereof
EP4028659A1 (en) Method for operating an internal combustion engine
EP4028655A1 (en) Device for fuel injection for internal combustion engines

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17762069

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17762069

Country of ref document: EP

Kind code of ref document: A1