EP3679235A1 - Verfahren zum betreiben eines gasmotors - Google Patents
Verfahren zum betreiben eines gasmotorsInfo
- Publication number
- EP3679235A1 EP3679235A1 EP18769112.6A EP18769112A EP3679235A1 EP 3679235 A1 EP3679235 A1 EP 3679235A1 EP 18769112 A EP18769112 A EP 18769112A EP 3679235 A1 EP3679235 A1 EP 3679235A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- phase
- dead center
- combustion chamber
- piston
- gaseous fuel
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
Classifications
-
- 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
- F02D41/0027—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures the fuel being gaseous
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D19/02—Controlling 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 gaseous fuels
- F02D19/021—Control of components of the fuel supply system
- F02D19/023—Control of components of the fuel supply system to adjust the fuel mass or volume flow
- F02D19/024—Control of components of the fuel supply system to adjust the fuel mass or volume flow by controlling fuel injectors
-
- 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
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
- F02D41/402—Multiple injections
-
- 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
- F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
- F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
- F02M21/0203—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels characterised by the type of gaseous fuel
- F02M21/0206—Non-hydrocarbon fuels, e.g. hydrogen, ammonia or carbon monoxide
-
- 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
- F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
- F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
- F02M21/0203—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels characterised by the type of gaseous fuel
- F02M21/0209—Hydrocarbon fuels, e.g. methane or acetylene
-
- 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
- F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
- F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
- F02M21/0218—Details on the gaseous fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
- F02M21/0248—Injectors
- F02M21/0275—Injectors for in-cylinder direct injection, e.g. injector combined with spark plug
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P15/00—Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 and combined with layout of ignition circuits
- F02P15/08—Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 and combined with layout of ignition circuits having multiple-spark ignition, i.e. ignition occurring simultaneously at different places in one engine cylinder or in two or more separate engine 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
- F02D41/30—Controlling fuel injection
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D2041/389—Controlling fuel injection of the high pressure type for injecting directly into the cylinder
-
- 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
- Y02T10/30—Use of alternative fuels, e.g. biofuels
Definitions
- the invention relates to a method for operating a gas engine, in particular a hydrogen engine, in particular for a motor vehicle, according to the preamble of patent claim 1.
- Such a method for operating a gas engine having at least one combustion chamber and designed, for example, as a hydrogen engine, in particular for a motor vehicle, can already be seen as known, for example, from DE 103 59 445 A1.
- a gaseous fuel, in particular hydrogen for operating the gas engine, in particular in its fired operation, injected directly into the combustion chamber, wherein the gaseous fuel is injected within a cycle of the gas engine during at least two phases spaced apart from each other directly into the combustion chamber ,
- EP 1 431 564 A2 discloses a method for a gas-fueled internal combustion engine, wherein the gas is injected via a blowing device into a combustion chamber and a layer charge is generated.
- DE 103 21 794 A1 discloses a method for operating a gas-operated, in particular hydrogen-operated, internal combustion engine.
- Object of the present invention is to develop a method of the type mentioned in such a way that a particularly advantageous operation of the gas engine can be realized. This object is achieved by a method having the features of claim 1.
- Advantageous embodiments with expedient developments of the invention are specified in the remaining claims.
- a gaseous fuel, in particular hydrogen, for operating the gas engine, in particular in its fired operation is blown directly into the combustion chamber, the gaseous fuel is blown directly into the combustion chamber within a working cycle of the gas engine during at least two phases spaced apart in time.
- the gaseous fuel, in particular the hydrogen is burned in the combustion chamber formed, for example, as a cylinder, at least together with air, whereby the gas engine, in particular in its fired operation, is operated.
- the combustion of the gaseous fuel with air causes the fired operation of the gas engine, with combustion processes taking place in the combustion chamber as part of the fired operation of the gas engine.
- the gas engine is in its train operation, in which, for example, the motor vehicle, which is designed for example as a commercial vehicle, is driven by the gas engine or driven.
- the gas engine is designed as a 4-stroke engine, so that the working cycle, in particular, has exactly four clocks.
- the four strokes are: intake or intake stroke; Compression and ignition or compression or compression stroke; Work or work cycle; Ejecting or exhaust stroke.
- the working cycle of the gas engine is considered in particular such that the first, occurring within the cycle cycle is the power stroke.
- the second occurring within the work cycle and subsequent to the power stroke clock is the exhaust stroke.
- the third occurring within the work cycle and join the Eject stroke subsequent stroke is the intake stroke, so that the fourth occurring within the working cycle and subsequent to the intake stroke clock is the compression stroke.
- a piston is movably received, for example, in the combustion chamber designed in particular as a cylinder.
- the piston is received translationally movable in the combustion chamber.
- the piston is, in particular articulated, coupled to an output shaft designed, for example, as a crankshaft, wherein, for example, the gas engine is designed as an internal combustion engine in the form of a reciprocating piston engine.
- articulated coupling of the translationally recorded in the combustion chamber piston with the output shaft the translational movements of the piston are converted into a rotational movement of the output shaft.
- the gaseous fuel and the air form in the combustion chamber a fuel-air mixture, which is also referred to simply as a mixture.
- the mixture is ignited, for example, and then burned, whereby the mixture or combustion products resulting from the combustion expands or expand.
- the piston is driven and thereby moved, for example, from its top dead center to its bottom dead center.
- the output shaft is driven so that the gas engine can provide torques for driving the motor vehicle via the output shaft.
- spark ignition To burn the mixture of this is ignited, in particular by spark ignition, and burned in the sequence.
- spark ignition At least one ignition spark, in particular in the combustion chamber, is generated within the working cycle by means of a spark ignition spark plug, for example.
- the spark By means of the spark, the mixture is ignited and burned in the sequence.
- this combustion products or combustion resulting from the combustion expands, whereby the piston is driven.
- the piston moves, for example, starting from its top dead center or from his top dead center coming to its bottom dead center, then back to its top dead center, then to its bottom dead center and then back to its top dead center.
- the top dead center of the piston thus occurs exactly three times within the working cycle, while the bottom dead center of the piston occurs exactly twice within the working cycle.
- top dead centers A first of the types is the so-called upper Zündtotrete (ZOT), in whose area the mixture is ignited.
- ZOT so-called upper Zündtotrete
- LWOT top charge change dead center
- the piston carries out the exhaust stroke and the intake stroke and expels exhaust gas resulting from the combustion of the mixture from the combustion chamber and within the scope of the exhaust stroke. that is, in particular the aforementioned air, sucked into the combustion chamber.
- the upper charge change dead center lies between the bottom dead centers occurring within the work cycle, so that the first bottom dead center of the piston occurring within the work cycle lies between the upper ignition dead center (ZOT) and the upper charge cycle dead center (LWOT) ,
- the first bottom dead center occurring within the working cycle immediately follows the upper ignition dead center, with the upper charge reversal dead point directly following the first bottom dead center occurring within the working cycle.
- the second piston bottom dead center occurring within the work cycle is between the top charge cycle dead center and the top ignition dead center, so that the second bottom dead center occurring within the cycle directly or directly adjoins the top charge cycle dead center, and thus within the work cycle the top ignition dead center occurs immediately or directly connected to the second occurring within the working cycle bottom dead center.
- the first top dead center occurring within the work cycle in which - against the background of the above-described consideration of the work cycle - the work cycle begins, the upper Zündtotddling.
- the third top dead center occurring within the work cycle, in which the work cycle is against the background of the one described above Ending consideration is also the upper firing dead center so that the second top dead center of the piston occurring within the cycle is between the upper firing dead points and thus is the upper charge cycle dead center (LWOT).
- LWOT upper charge cycle dead center
- the first firing taking place within the working cycle is that of the several firings which are the very first firing take place within the described work cycle.
- the at least two or both phases begin and end in time before the first occurring within the work cycle ignition.
- a first quantity or a first subset of the gaseous fuel is blown directly into the combustion chamber.
- a second quantity or a second partial quantity of the gaseous fuel is injected directly into the combustion chamber. Since both phases begin and end before the first ignition, both partial quantities, in particular jointly, are burned in the combustion chamber by means of the first ignition or by means of combustion caused by the first ignition. In contrast to the prior art, it is thus not intended that at least one phase or subset of each separate, separate ignition and thus combustion is performed so that it is not provided in the context of the method according to the invention in contrast to the prior art that the respective subset is burned for itself or independently.
- first the first subset and then the second subset are each burned independently, but the subsets are burned together or simultaneously and are, for example, together by the first ignited within the working cycle ignition.
- the phases are temporally spaced from one another, it is to be understood in particular that a period of time is provided within the working cycle between the phases, in which an injection or introduction of the gaseous fuel into the combustion chamber is omitted.
- a period of time is provided within the working cycle between the phases, in which an injection or introduction of the gaseous fuel into the combustion chamber is omitted.
- the first phase ends before the second phase begins.
- the gaseous fuel is injected directly into the combustion chamber, is to be understood in particular that an internal mixture formation is provided or that the gas engine is operated with an internal mixture formation, in whose frame the air, which for example by means of the piston in the Combustion chamber is sucked, only within the combustion chamber and not already upstream of the combustion chamber, for example in an intake of the gas engine, is mixed with the gaseous fuel.
- the invention is based in particular on the following finding: Hydrogen is the only fuel for internal combustion engines which has no carbon molecules. This results in the combustion of hydrogen no, or, for example, due to lubricating oil combustion, only very low pollutant emissions of the pollutant groups carbon monoxide, carbon dioxide, hydrocarbon compounds and particles.
- the inventive method is particularly advantageous for operating a hydrogen engine, but also to operate for other gas engines, which, for example, with natural gas such as CNG (compressed natural gas) or LPG (Liquefied Petroleum Gas).
- the gas engine is operated, for example, as a gasoline engine, so that the mixture is preferably ignited by spark ignition.
- a gaseous fuel in particular hydrogen
- a gaseous fuel has some physical properties that can make it difficult to adapt a conventional gasoline engine to the operation with hydrogen.
- One of these features is the low density of hydrogen compared to liquid fuel such as gasoline. Due to the low density, the hydrogen occupies a high volume fraction of the combustion mixture, which comprises at least air and the gaseous fuel as fuel. In particular, at a combustion air ratio of 1, the hydrogen occupies about one third of the volume of the mixture.
- the combustion air ratio is also referred to as lambda ( ⁇ ) and sets - as is well known - the actually available for each combustion mass of air in relation to the minimum necessary stoichiometric air mass, which is needed for complete combustion of the fuel.
- the hydrogen displaces air from the mixture.
- the displacement of air by hydrogen results in a low energy density of the mixture, from which - if no appropriate countermeasures are taken - results in a low power density of the gas engine, which is also referred to simply as an engine or internal combustion engine.
- a displacement-equal engine will have a much lower power-torque deployment in hydrogen operation than when operating with conventional, especially fossil fuels, if no appropriate countermeasures are taken.
- a time available for mixture formation is determined by the pressure increase in the combustion chamber during the compression stroke.
- a blowing device for example also called an injector
- the pressure at an inlet of the injector should always be more than twice the pressure at an outlet and thus be on an outlet side of the injector, since, for example, the pressure at the outlet or on the outlet side corresponds to the pressure prevailing in the combustion chamber internal pressure.
- the gaseous fuel is fed to the injector via the said inlet or the gaseous fuel is introduced into the injector.
- the gaseous fuel is discharged from the injector via said outlet, wherein in particular the injector injects the gaseous fuel via the outlet directly into the combustion chamber.
- the injector injects the gaseous fuel via the outlet directly into the combustion chamber.
- High inlet pressure at the injector and thus requires a limited usability of the gaseous fuel stored in compressed gas containers and thus a reduced range of the motor vehicle with hydrogen drive.
- high forces for opening and closing the injector, in particular a valve of the injector required what high demands on a particular electric drive, in particular for moving the valve, and at power amplifiers of an electronic control unit for driving the injector means.
- Another advantage of the internal mixture formation is the at least almost complete elimination of flashbacks in the intake tract of the gas engine. Since the hydrogen, for example, enters the combustion chamber only after the inlet valve has been closed, a spontaneous ignition of the mixture in the combustion chamber has no effect on the intake tract.
- a hydrogen engine is operated as the gas engine, wherein hydrogen is used as the gaseous fuel.
- Another embodiment is characterized in that initially a first of the phases begins and ends, whereupon the second phase following the first phase begins and ends.
- the phases are defined in a defined time interval.
- the gas engine has at least one piston, which is accommodated translationally movable in the example formed as a cylinder combustion chamber. It has been found to be particularly advantageous when the first phase begins after the top charge cycle dead center of the piston. As a result, for example, unwanted meshzünd bine be avoided in the intake of the gas engine, so that a particularly effective and efficient operation can be displayed.
- the first phase ends before the bottom dead center immediately following the upper charge reversal dead center, that is to say, for example, before the second bottom dead center occurring within the working cycle.
- degree of crank angle denotes a respective rotational position of the output shaft designed, for example, as a crankshaft, as is already well known from the general state of the art Working cycle occurring events such as the ignition, the phases, in particular their duration, beginning and end and respective opening and closing times, for example, each gas exchange valves, in particular intake valves and exhaust valves, open and close, are easily referenced to respective rotational positions of the output shaft.
- the second phase begins after the bottom dead center which adjoins directly at the upper charge reversal dead point. In this way, a sufficient time interval between the phases can be ensured, so that undesired displacement effects can be avoided or kept particularly low. As a result, a high power density can be easily realized.
- the second phase is connected directly to the bottom dead center which adjoins directly to the upper charge reversal dead center. As a result, a sufficiently large amount of fuel can be introduced into the combustion chamber.
- the gaseous fuel is blown into the combustion chamber by means of the aforementioned injector, wherein the second phase is preferably ended before the compression pressure in the combustion chamber has reached or reached a value which is within a range of 40%. up to 60%, in particular from 45% to 55% and preferably from 48% to 52% of a before the injector, in particular at its inlet prevailing injection pressure, with which For example, the gaseous fuel in the injector, in particular via the inlet, introduced and / or is blown by means of the injector directly into the interior, is located.
- the second phase is terminated before the compression pressure in the combustion chamber has reached a value which is about 50% of the injection pressure.
- the compression pressure is to be understood as meaning a pressure prevailing in the combustion chamber, the compression pressure being caused by the compression stroke, that is to say that the piston, as part of its compression stroke, moves from its bottom dead center toward its top dead center and in particular toward the top dead center moves while compacting the mixture.
- a sufficiently high total amount of the fuel can be injected into the combustion chamber, and this in a particularly advantageous manner, since the second phase can be sufficiently long, however, not carried out for an excessively long time.
- a further embodiment is characterized in that the first phase, in particular at least predominantly or completely, takes place during a movement phase of the piston in which the piston moves at such a piston speed in the direction of its bottom dead center - in particular when the inlet valve is open Return flow of the gaseous fuel from the combustion chamber into the intake tract of the gas engine, in particular completely, is omitted.
- the first phase in particular at least predominantly or completely, takes place during a movement phase of the piston in which the piston moves at such a piston speed in the direction of its bottom dead center - in particular when the inlet valve is open
- the first phase begins after opening at least one inlet valve assigned to the combustion chamber, via which at least air is supplied to the combustion chamber. If, for example, a plurality of inlet valves are assigned to the combustion chamber, it is preferably provided that the first phase begins after a respective opening of the or of all inlet valves, via which at least air is supplied to the combustion chamber.
- the second phase begins before closing or closing the inlet valve or intake valves.
- the closing of the inlet valve is to be understood in particular as meaning a point in time at which the inlet valve, in particular completely, is closed, that is to say reaches its closed position.
- the second phase begins before the inlet valve is closed, that is, before the inlet valve reaches its closed position and thus, for example, while the inlet valve is moving in the direction of its closed position.
- the time at which the inlet valve reaches its closed position coincides with the beginning of the second phase.
- the second phase begins before ES, or the second phase begins with ES.
- the gaseous fuel can be particularly advantageously introduced into the combustion chamber, so that an efficient and effective operation can be represented.
- a first of the conditions is that the air which has flowed into the combustion chamber, in particular via the inlet valve or via the inlet valves, cools the combustion chamber to such an extent that ignition of the inflowing fuel is precluded.
- the second condition is that a speed at which the piston moves, in particular in the direction of its bottom dead center and thereby in particular in the direction of the second occurring within the working cycle bottom dead center, is so high that by a suction effect of the piston, in particular a bottom of the piston, an inflow of air into the combustion chamber is not or only slightly hindered and a back flow of hydrogen is excluded in the intake tract.
- the first phase is terminated when the second condition is no longer satisfied, for example, by reducing the above-mentioned speed, also referred to as piston speed, in the region of top dead center.
- the second phase may begin when the inlet valve is physically closed.
- the second phase is completed, for example, when the required or intended hydrogen, that is, when the predetermined or desired total amount of the gaseous fuel was injected.
- the injection of the fuel should be completed when the ratio of pressure prevailing in the cylinder to the pressure of the gaseous fuel prevailing at the inlet of the injector and thus before the injector exceeds 0.5.
- the following advantages can be realized by means of the method according to the invention: It can be realized a particularly high injection time, during which a sufficiently high amount of gaseous fuel can be injected into the combustion chamber. Compared to conventional methods, thus an increase in injection time can be realized. By this gain in injection time, for example, the pressure prevailing in front of the injector and / or a Cross-sectional area of the injector can be reduced, wherein the gaseous fuel flows in particular during injection through the cross-sectional area.
- At least a portion of the gaseous fuel can be injected into a turbulent air flow, in particular during the intake stroke.
- the division of the fuel injection into the two phases makes it possible, in particular for an engine application of the gas engine, to create additional freedom for optimizing the engine behavior in each characteristic map. Taking into account the parameters operating safety, pollutant emission and efficiency.
- any resulting impairment of the service life of the injector can be counteracted, for example, by introducing the gaseous fuel into the combustion chamber by means of exactly one phase within the working cycle in at least one operating region of the gas engine, for example in a partial and low-load operating region, so that within the working cycle preferably exactly one phase takes place, during which the gaseous fuel is injected by means of the injector directly into the combustion chamber.
- the parameters of operational safety, pollutant emission and efficiency must also be taken into account.
- the gas engine is designed as a hydrogen engine in the embodiment illustrated in the figure, so that the gas engine, in particular in its fired operation, is operated by means of hydrogen as a gaseous fuel.
- the gas engine is also referred to as internal combustion engine, internal combustion engine, internal combustion engine or engine and has at least one combustion chamber designed in particular as a cylinder, in which a piston is received in a translationally movable manner.
- the cylinder is formed for example by a motor housing of the gas engine.
- At least indirectly designed as a crankshaft output shaft of the gas engine is rotatably mounted on the motor housing, so that the crankshaft can rotate about an axis of rotation relative to the motor housing.
- the piston is pivotally connected to a connecting rod, which in turn is pivotally connected to the crankshaft.
- the translational movements of the piston can be converted into a rotational movement of the crankshaft about its axis of rotation.
- the cylinder is associated with a plurality of intake valves and a plurality of exhaust valves, wherein the intake valves and the exhaust valves are collectively referred to as gas exchange valves.
- the respective gas exchange valve is movable between a closed position and at least one open position, in particular translationally. On its way from the closed position to the open position or from the open position to the closed position, the respective gas exchange valve executes a stroke, which is also referred to as a valve lift.
- a respective time at which the opening of the respective inlet valve is started is also referred to as inlet opening (E ⁇ ).
- a respective point in time at which the respective inlet valve reaches its closed position is also referred to as inlet closing (ES).
- a respective time at which the opening of the respective outlet valve is started is also referred to as outlet opening (A ⁇ ).
- a respective time at which the respective exhaust valve its Closed position is also referred to as outlet closes (AS).
- the respective gas exchange valve is, for example, by means of a camshaft, in particular by means of a respective cam, operated and thereby moved from the respective closed position to the respective open position.
- a return device in particular a spring, tensioned by means of which the respective gas exchange valve can be moved back from the closed position to the open position and held in the closed position.
- the camshaft is driven by the output shaft.
- a respective rotation of the crankshaft by one degree is also referred to as the degree of crank angle (° CA).
- degree of crank angle thus characterizes a path or a distance by which the crankshaft rotates.
- the gas engine is designed as a four-stroke engine, so that the respective working cycle has four clocks. These four bars are: work cycle; Exhaust stroke; intake; Compression stroke. Furthermore, the cycle includes two complete revolutions of the crankshaft and thus 720 degrees crank angle. It is applied to the respective abscissa 18 exactly one cycle of the gas engine.
- the respective valve lift is plotted on the ordinate 20 of the diagram 14, wherein a curve 22 entered in the diagram 14 opens the movement of the respective outlet valve from the outlet to the outlet and thus illustrates it from the closed position to the open position and back again into the closed position , Accordingly, a plot 24 plotted in the chart 14 illustrates the movement of the respective intake valve from the intake opens to the intake and thus from the closed position to the open position and back to the closed position.
- the curves 22 and 24 are also referred to as valve lift curves, wherein the respective times at which the gas exchange valves are opened and closed, collectively referred to as the timing.
- the working cycle is now considered such that the first cycle taking place or occurring within the working cycle is the working cycle.
- the second occurring within the cycle or occurring clock is the subsequent to the power stroke exhaust stroke.
- the third occurring within the work cycle and subsequent to the second clock or to the exhaust stroke third clock is the intake stroke.
- the fourth occurring within the work cycle clock or the compression stroke which follows the intake stroke.
- the piston is translatable between a bottom dead center (UT) and a top dead center (TDC) in the cylinder.
- UT bottom dead center
- TDC top dead center
- LWOT upper charge cycle dead center
- ZOT Zündtotrete
- This mixture comprises hydrogen as gaseous fuel, by means of which the gas engine is operated in its fired operation.
- the mixture comprises air, which is the combustion chamber, in particular the inlet valves supplied.
- the respective inlet valve is assigned to an inlet channel, via which, when the respective inlet valve releases the respectively assigned inlet channel in the open position, the air can flow into the combustion chamber.
- the fuel-air mixture is, in particular by means of spark ignition, ignited and thereby burned, resulting in exhaust gas of the gas engine.
- the respective outlet valve is assigned a respective outlet channel.
- the exhaust gas can flow out of the combustion chamber via the outlet channel.
- the exhaust gas can then flow in an exhaust tract of the gas engine.
- the air is guided by means of an intake tract of the gas engine to the and in particular into the cylinder.
- the respective inlet valve of the respectively associated inlet channel blocks fluidically, wherein the respective outlet valve fluidly obstructs the respectively associated outlet channel in the closed position.
- the working cycle starts and ends at the upper ignition dead center as a result of the described consideration, so that the first top dead center of the piston occurring within the work cycle and the third or last piston top dead center occurring within the work cycle is the upper ignition dead center ZOT.
- the second top dead center occurring within the work cycle is the upper charge cycle dead point LWOT which lies between the first and the third top dead center of the work cycle.
- the first bottom dead center UT occurring within the working cycle is directly or directly connected to the first top dead center occurring within the working cycle and directly or directly anticipates the second top dead center occurring within the working cycle, so that the first bottom dead center between the first top dead center and the upper charge cycle dead center.
- the second bottom dead center occurring within the cycle end immediately or directly adjoins the top dead center and directly precedes the top dead center so that the second bottom dead center occurring within the cycle is between the top dead center and the top dead center. Including that the respective bottom dead center directly or directly to the respective top dead center adjoins or anticipates this, it is to be understood that between the respective bottom dead center and the respective top dead center no other further dead center of the piston.
- the piston On its way from the respective top dead center into the respective bottom dead center or vice versa from the respective bottom dead center into the respective top dead center, the piston carries out a stroke, which is also referred to as piston stroke.
- the piston stroke is plotted on the ordinate 26 of the diagram 10, so that a graph 28 recorded in the diagram 10 illustrates the piston stroke, in particular its course, within the working cycle.
- the piston moves from the respective top dead center into the respective bottom dead center or from the respective bottom dead center into the respective top dead center with a piston speed, also referred to as piston speed Velocity plotted on the ordinate 30 of the graph 12.
- a curve 32 entered in the diagram 12 illustrates the piston speed or its course within the working cycle, wherein, for example, the piston speed is specified in the unit of millimeter per degree crank angle. It can be seen in particular from FIGS. 10 and 12 that the piston speed is zero in the respective bottom dead center and in the respective top dead center.
- a total amount of the gaseous fuel formed as hydrogen is introduced into the cylinder within the working cycle and thereby, in particular by means of an injector, blown directly into the cylinder.
- This total amount is now divided into exactly two subsets, so that the total quantity or the gaseous fuel is injected directly into the cylinder during the working cycle during at least two temporally spaced-apart and successive phases P1 and P2.
- a first of the subset is injected directly into the cylinder by means of the injector.
- the second phase P2 which is temporally separated from the first phase P1 and follows the first phase P1 in terms of time, the second subset is injected directly into the cylinder by means of the injector.
- the injector has, for example, a valve element, which is also referred to as a valve or injector valve.
- the valve element is, for example, between a closed position and an open position, in particular translationally, movable. In the closed position, for example, the valve element obstructs at least one or more injection openings of the injector. In the open position, the valve element releases the injection opening or the injection openings, for example, so that the hydrogen can be blown directly into the combustion chamber via the injection openings.
- the injection opening or blowing-in openings is or are arranged, for example, at an outlet and thus on an outlet side of the injector, the hydrogen issuing from the outlet discharged to the injector.
- the injector further has an inlet and thus an inlet side, via which the hydrogen injected directly into the cylinder by means of the injector is introduced into the injector.
- At the inlet prevails, for example, a first pressure, in particular of the hydrogen, wherein the first pressure, for example, is a blowing pressure, with which the hydrogen is injected directly into the cylinder.
- a second pressure prevails, which is, for example, a pressure prevailing in the cylinder and also referred to as cylinder internal pressure.
- the in-cylinder pressure is a compression pressure which occurs, for example, during the compression stroke or is effected by the same.
- valve element On its way from the closed position to the open position or vice versa, the valve element, for example, sets a path or carries out a stroke, which is also referred to as a valve element lift.
- This Ventilelementhub is plotted, for example, on the ordinate 34, so that a recorded in the diagram 16 History 36 illustrates the Ventilelementhub or its course within the working cycle.
- the subsets mentioned sum in total the total amount that is injected directly into the cylinder within the working cycle. Thus, only or exclusively the total amount is injected directly into the cylinder, especially within the working cycle.
- the aforementioned first ignition taking place within the working cycle is exactly one ignition. If, for example, within the work cycle several, spaced apart and consecutive ignitions performed, so is the first mentioned above, the ignition taking place within the work cycle, such as the ignition, which is performed by the multiple ignitions as the very first ignition. As part of the ignition, for example, by means of a spark ignition device designed as a spark ignition at least one spark generated by means of which the mixture is ignited and burned in the sequence.
- the subsets are not burned separately or independently, but together or together in the context of the ignition or the combustion caused by the ignition. As a result, a particularly high power density can be realized in a simple manner.
- the first phase P1 first begins and ends, whereupon the second phase P2 following the first phase P1 begins and ends.
- the first phase P1 begins after the upper charge change dead point LWOT of the piston.
- the first phase P1 ends before the bottom dead center UT immediately following the upper charge reversal dead point LWOT, so that the first phase P1 ends in time before the second bottom dead center occurring within the working cycle.
- the time interval Z thus begins before the second bottom dead center and extends to the bottom dead center.
- the first phase P1 extends from 400 degrees crank angle to the upper Zündtot Vietnamese to 500 degrees crank angle to the upper Zündtot Vietnamese.
- the first phase P1 extends over 100 degrees crank angle, whereby a sufficiently high amount of fuel can be injected.
- the second phase P2 begins, for example, before or with ES and thus closes, for example, before or with the immediately following to the upper charge exchange dead center LWOT inlet.
- ES This means that the second phase P2 begins after the second bottom dead center occurring during the work cycle.
- the Beginning of the second phase P2 may, in particular in the case of a high fuel requirement, alternatively begin before the inlet closes ES, in particular when it is precluded that fuel can enter the intake tract through the opened inlet valve.
- the pressure increase in the cylinder caused by the amount of fuel injected until the inlet closes ES should be limited to a value below the pressure in the intake tract. This means that the fuel mass inflatable before inlet closes is limited.
- the second phase P2 is immediately followed by the bottom dead center immediately following the upper charge reversal dead center LWOT, so that, for example, a distance between the second phase P2, in particular between its beginning and the second within the Working cycle occurring bottom dead center is less than 50 degrees crank angle, in particular less than 20 degrees crank angle, in particular less than 10 degrees crank angle and preferably less than 5 degrees crank angle.
- the second phase P2 is ended before the compression pressure in the cylinder reaches a value in the range of 40% to 60%, in particular 45% to 55%, of the pressure prevailing in front of the injector A blaserucks lies.
- the second phase P2 is terminated before the compression pressure is about 50% of the injection pressure.
- the first phase P1 preferably takes place at least predominantly or completely during a movement phase of the piston in which the piston moves with a piston speed in the direction of its bottom dead center, that a return flow of the gaseous fuel from the cylinder into the intake tract of the gas engine, in particular completely, omitted.
- the first phase P1 opens after the inlet and preferably closes after the outlet closes and ends before the inlet immediately adjacent to the inlet opens subsequent inlet.
- the first phase P1 is completely opened between the inlet and closes the inlet.
- the second phase P2 closes after the inlet or starts during the closing of the inlet valve. In the embodiment illustrated in the figure, the second phase P2 begins before the inlet closes and ends after the inlet closes.
- the gaseous fuel flows through the injector during injection in such a way that the gaseous fuel has a supercritical flow when injected at the narrowest cross section of the injector through which the gaseous fuel can flow.
- a flow rate and thus a flow rate of the hydrogen flowing through the injector from the inlet to the outlet is independent of the cylinder internal pressure prevailing on the outlet side or at the outlet, which is of particular advantage since that at the outlet prevailing cylinder internal pressure can not be known precisely.
- the narrowest cross section through which the hydrogen can flow is also referred to as the Laval cross section of the injector.
- the supercritical flow at the narrowest cross section means that the velocity of sound of the hydrogen is set at the narrowest cross section, which is also referred to as the design cross section.
- Performing the first phase P1 allows a particularly good homogenization of the mixture.
- the time interval Z is a pause, by which excessive displacement effects can be avoided.
- Performing the second phase P2 makes it possible to introduce a sufficiently large amount of hydrogen into the cylinder. It is preferably provided that the second subset, which is injected directly into the combustion chamber during the second phase P2, is greater than the first subset, which is blown into the combustion chamber during the first phase P1.
- the end of the second phase P2 is determined, for example, by the internal cylinder pressure or by a pressure ratio of injection pressure prevailing at the inlet of the injector and cylinder internal pressure, as described above.
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102017120512.8A DE102017120512B4 (de) | 2017-09-06 | 2017-09-06 | Verfahren zum Betreiben eines Wasserstoffmotors für ein Kraftfahrzeug |
PCT/EP2018/073819 WO2019048454A1 (de) | 2017-09-06 | 2018-09-05 | Verfahren zum betreiben eines gasmotors |
Publications (1)
Publication Number | Publication Date |
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EP3679235A1 true EP3679235A1 (de) | 2020-07-15 |
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ID=63557441
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP18769112.6A Pending EP3679235A1 (de) | 2017-09-06 | 2018-09-05 | Verfahren zum betreiben eines gasmotors |
Country Status (6)
Country | Link |
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US (1) | US11268460B2 (de) |
EP (1) | EP3679235A1 (de) |
JP (1) | JP7288433B2 (de) |
CN (1) | CN111601959B (de) |
DE (1) | DE102017120512B4 (de) |
WO (1) | WO2019048454A1 (de) |
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DE102019007221A1 (de) * | 2019-10-17 | 2021-04-22 | Man Truck & Bus Se | Verfahren zum Betreiben einer Brennkraftmaschine |
DE102021121214A1 (de) | 2021-08-16 | 2023-02-16 | Keyou GmbH | Verfahren zum Betrieb einer fremdzündenden Verbrennungskraftmaschine und Steuereinrichtung zur Durchführung des Verfahrens |
CN114017178B (zh) * | 2021-11-01 | 2022-11-01 | 浙江吉利控股集团有限公司 | 一种稀薄燃烧控制方法、控制装置及氢气发动机系统 |
GB2622271A (en) * | 2022-09-12 | 2024-03-13 | Jaguar Land Rover Ltd | Control system and method for hydrogen fuelled internal combustion engine |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
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JP3075685B2 (ja) * | 1995-09-04 | 2000-08-14 | 本田技研工業株式会社 | 気体燃料エンジンの燃料噴射方法 |
US6675748B2 (en) * | 2000-02-11 | 2004-01-13 | Westport Research Inc. | Method and apparatus for fuel injection into an internal combustion engine |
AT7202U1 (de) | 2002-12-19 | 2004-11-25 | Avl List Gmbh | Verfahren zum betreiben einer mit gas betriebenen brennkraftmaschine |
DE10321794A1 (de) | 2003-05-14 | 2004-12-09 | Bayerische Motoren Werke Ag | Verfahren zum Betreiben einer Brennkraftmaschine |
US6983732B2 (en) | 2003-07-01 | 2006-01-10 | General Motors Corporation | Injection strategy for operating a direct-injection controlled auto-ignition four-stroke internal combustion engine |
DE10341089A1 (de) * | 2003-09-05 | 2005-04-28 | Siemens Ag | Verfahren zur Steuerung der Direkteinspritzung von Autogas in einen Zylinder einer Brennkraftmaschine sowie Vorrichtung |
DE10359445A1 (de) | 2003-12-17 | 2005-07-28 | Enginion Ag | Wasserstoff-Verbrennungsmotor |
JP4547665B2 (ja) * | 2004-05-25 | 2010-09-22 | トヨタ自動車株式会社 | ガス燃料直噴エンジンの燃焼制御方法 |
JP2008291726A (ja) * | 2007-05-24 | 2008-12-04 | Suzuki Motor Corp | 6サイクルエンジン |
CA2799952C (en) * | 2012-12-20 | 2014-04-29 | Westport Power Inc. | Mid-cycle fuel injection strategies |
DE102013013755A1 (de) * | 2013-08-17 | 2015-02-19 | Daimler Ag | Verfahren zum Betreiben einer Verbrennungskraftmaschine |
DE102013016503A1 (de) * | 2013-10-04 | 2014-08-14 | Daimler Ag | Verfahren zum Betreiben einer Hubkolben-Verbrennungskraftmaschine |
DE102015009898A1 (de) * | 2015-07-30 | 2017-02-02 | Daimler Ag | Verfahren zum Betreiben einer Hubkolben-Verbrennungskraftmaschine |
DE102015015343A1 (de) * | 2015-11-26 | 2017-06-01 | Man Diesel & Turbo Se | Verfahren und Steuerungseinrichtung zum Betreiben eines Motors |
JP2017137853A (ja) * | 2016-02-04 | 2017-08-10 | 本田技研工業株式会社 | ガスエンジン |
-
2017
- 2017-09-06 DE DE102017120512.8A patent/DE102017120512B4/de active Active
-
2018
- 2018-09-05 WO PCT/EP2018/073819 patent/WO2019048454A1/de unknown
- 2018-09-05 US US16/644,045 patent/US11268460B2/en active Active
- 2018-09-05 JP JP2020514535A patent/JP7288433B2/ja active Active
- 2018-09-05 EP EP18769112.6A patent/EP3679235A1/de active Pending
- 2018-09-05 CN CN201880071787.7A patent/CN111601959B/zh active Active
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CN111601959B (zh) | 2024-02-06 |
US20200277907A1 (en) | 2020-09-03 |
CN111601959A (zh) | 2020-08-28 |
WO2019048454A1 (de) | 2019-03-14 |
JP7288433B2 (ja) | 2023-06-07 |
DE102017120512B4 (de) | 2022-09-29 |
DE102017120512A1 (de) | 2019-03-07 |
JP2020532681A (ja) | 2020-11-12 |
US11268460B2 (en) | 2022-03-08 |
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