• 专利附录
  • 专利说明
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  • 同族专利
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    • 专利摘要:
    The present invention relates to a method for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine. The method comprises the step of keeping the pressure essentially constant in an inlet manifold of the gas engine, so that the pressure is not varying more than a pre-determined threshold. A first A. value is determined downstream the gas engine. The time period of gas injection into the inlet manifold is then changed. A second A. value downstream the gas engine is determined after the changing of the time period of gas injection into the inlet manifold. The specific gas constant and the stoichiometric air fuel ratio of the fuel gas is then determined based on the determined first and second A. value.The present invention also relates to a system for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine, a vehicle, a computer program, and a computer program product.(Fig. 3)
    公开号:SE1650387A1
    申请号:SE1650387
    申请日:2016-03-23
    公开日:2017-09-24
    发明作者:Wallengren Mårten
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    1A method and a system for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine TECHNICAL FIELD The present invention relates to a method and a system for determining the specific gasconstant and the stoichiometric air fuel ratio of a fuel gas for a gas engine. The presentrelation also relates to vehicle, to a computer program for determining the specific gasconstant and the stoichiometric air fuel ratio of a fuel gas for a gas engine and to a computer program product.
    BACKGROUND ART The exhaust aftertreatment of a spark ignited engine running stoichiometric consists often of athree-way catalytic converter in the exhaust system. A three-way catalytic converter must bein chemical balance to be able to reduce nitrogen-oxides emissions and oxidize carbon-monoxide and hydrocarbon emissions. A modern engine management system, EMS, adapts todifferent fuel qualities by adjusting the air-fuel ratio, AFR, until a so-called stoichiometric ratiocould be measured. This is usually done by means of a so-called lambda sensor situated in theexhaust pipe relatively close to the engine. The lambda sensor measures the ratio of actualAFR to stoichiometric AFR. This ration is usually denoted Å. The EMS then controls the fuelinjection by adding or reducing the fuel in relation to the air going in to the engine. This is done by a control algorithm called lambda controller.
    For petrol as the fuel this works very well and can compensate for different energy contents inthe fuel. lt also compensates for if some components like fuel injectors, air mass meters orother components involved in calculating air or fuel, are not nominal to their specification. Thevalue ofthe lambda controller is then saved as an adaptation in the flash memory of anelectronic control unit, ECU. This means that the value ofthe lambda controller can be usednext time engine is started. When fuel is stable and all components are functioning properly the adjustments made by the lambda controller are relatively small.
    For gaseous fuels a similar control is used.
    Problems relating to different fuel qualities of petrol are basically related to differentevaporation properties of the petrol. Functions of the EMS relating to different evaporation properties are of no need for gaseous fuels since gaseous fuels do not need to be evaporated.
    SUMMARY OF THE INVENTION Whereas the energy content of petrol usually only differs by i 1-2 MJ/kg, the energy contentof gaseous fuel can differ by around i 5 MJ/kg. Whereas the density of petrol usually onlydiffers with by a percent, the density of gaseous fuels can differ by up to 20%. As a result, thestoichiometric AFR of gaseous fuels can differ considerably. As an example, methane has astoichiometric AFR of 17.2, while some natural gas on the market has a stoichiometric AFR of13.1. As a further result, the specific gas constant can be different. While methane has aspecific gas constant of around 520 in the international system of units, Sl-units, said natural gas on the market has a specific gas constant of around 450 in Sl-units.
    The solution of using a similar EMS for gaseous fuels as for petrol, i.e. using basically thelambda controller for adjusting differences between different gases, has some drawbacks. Thedifference between different gases can be so large that it can be difficult to manage the adjustments between the limits of the lambda controller.
    The idea of having the standard fuel adaptation in the system is to correct for differences inthe hardware ofthe components involved in the fuel injection and lambda control, such asinjectors and lambda sensors. lf the fuel adaptation shall handle both quality differencesbetween gaseous fuels and hardware the risk of going outside the limits and getting an engine malfunction will be much higher.
    A further drawback of the solution is that the effect of the gas quality on the air masscalculation will be completely ignored. Even though Å will be correct the amount of aircalculated could be wrong. This affects the calculated torque and also the ignition angle used,which risks running the engine on an ignition angle which is not optimal and calculating an incorrect torque which could affect the drivability in a negative way. 3There is thus a need for determining the specific gas constant and the stoichiometric air fuelratio of a fuel gas for a gas engine in an advantageous way. This might then be used foradapting the control of the gas engine based on the determined specific gas constant and based on the determined stoichiometric air fuel ratio. lt is thus an object ofthe present invention to provide a method, a system, a vehicle, acomputer program and a computer program product for an advantageous determination of the specific gas constant and based on the determined stoichiometric air fuel ratio. lt is further an object of the present invention to provide an alternative method, a system avehicle, a computer program and a computer program product for determination of the specific gas constant and based on the determined stoichiometric air fuel ratio.
    At least parts of the objects are achieved by a method for determining the specific gasconstant and the stoichiometric air fuel ratio of a fuel gas for a gas engine. The methodcomprises the step of keeping the pressure essentially constant in an inlet manifold ofthe gasengine, so that the pressure is not varying more than a pre-determined threshold. The methodfurther comprises the step of determining a first Å value downstream the gas engine while theengine is operated at a first time period of gas injection into the inlet manifold. The methodcomprises changing the first time period of gas injection into the inlet manifold into a secondtime period of gas injection into the inlet manifold and determining a second Å valuedownstream the gas engine after the changing of the time period of gas injection into the inletmanifold. The method further comprises the step of determining the specific gas constant andthe stoichiometric air fuel ratio of the fuel gas based on the determined first and second Å value.
    This method presents a way of determining the specific gas constant and the stoichiometric airfuel ratio of the fuel gas. lt has the advantage that it can be performed in most existingvehicles without the need of additional components. The method can thus be employed assoftware updates to ECU of vehicles. lt is thus cost-efficient to implement the method.
    Especially no sensors for analysing the gas composition are needed. ln one example the method comprises the step of determining at least one out of a temperature value in the inlet manifold of the gas engine and a pressure value in the inlet 4 manifold of the gas engine. The determining ofthe specific gas constant and thestoichiometric air fuel ratio of the fuel gas is then based on the at least one out of thedetermined temperature value in the inlet manifold of the gas engine and the determinedpressure value in the inlet manifold of the gas engine. Sensors for determining temperatureand/or pressure in the inlet manifold are often present at nowadays vehicles. lt also provides away of determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine with relatively low computational complexity. ln one example the method further comprises the step of determining a flow of air into thegas engine and/or determining a mass of air in a cylinder ofthe gas engine. The determining ofthe specific gas constant and the stoichiometric air fuel ratio is then based on the determinedflow of air into the gas engine and/or the determined mass of air in the cylinder of the gasengine. Sensors for determining a flow of air into the gas engine and/or determining a mass ofair in a cylinder ofthe gas engine are often present at nowadays vehicles. lt also provides away of determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine with relatively low computational complexity. ln one example the method is performed while the load on the gas engine is essentiallyconstant, so that the load on the gas engine is not varying more than a pre-determinedthreshold. This provides a way of using fewer variables when determining the specific gasconstant and the stoichiometric air fuel ratio of a fuel gas for a gas engine. Having fewervariables lowers the sources of errors. Further, keeping the load constant makes it easier tocontrol the pressure in the inlet manifold, thus lowering the complexity when implementing the method. ln one example the method is performed repeatedly and a resulting specific gas constantand/or a resulting stoichiometric air fuel ratio is calculated based on the repeatedlydetermined specific gas constants and/or the repeatedly determined air fuel ratios. This increases the accuracy of the specific gas constant and/or the air fuel ratio.
    At least parts of the objects are achieved by a system for determining the specific gas constantand the stoichiometric air fuel ratio of a fuel gas for a gas engine. The system comprises meansfor keeping the pressure essentially constant in an inlet manifold of the gas engine, so that the pressure is not varying more than a pre-determined threshold. The system further comprises means for determining a first Å value downstream the gas engine while the engine is operatedat a first time period of gas injection into the in|et manifold and means for changing the firsttime period of gas injection into the in|et manifold into a second time period of gas injectioninto the in|et manifold. The system even further comprises means for determining a second Åvalue downstream the gas engine after the changing ofthe time period of gas injection intothe in|et manifold. The system also comprises means for determining the specific gas constantand the stoichiometric air fuel ratio of the fuel gas based on the determined first and second Å value. ln one embodiment the system comprises means for determining at least one out of atemperature value in the in|et manifold of the gas engine and a pressure value in the in|etmanifold of the gas engine. The means for determining the specific gas constant and thestoichiometric air fuel ratio of the fuel gas is then arranged for basing the determining on theat least one out of the determined temperature value in the in|et manifold of the gas engine and the determined pressure value in the in|et manifold of the gas engine. ln one example the system further comprises means for determining a flow of air into the gasengine and/or determining a mass of air in a cylinder of the gas engine. The means fordetermining the specific gas constant and the stoichiometric air fuel ratio is then arranged forbasing the determining on the determined flow of air into the gas engine and/or the determined mass of air in the cylinder of the gas engine. ln one embodiment the system further comprises means for performing the determining ofthe specific gas constant and the stoichiometric air fuel ratio ofthe fuel gas for the gas enginewhile the load on the gas engine is essentially constant, so that the load on the gas engine is not varying more than a pre-determined threshold. ln one embodiment the system further comprises means for determining a resultingstoichiometric air fuel ratio and/or a resulting stoichiometric air fuel ratio, wherein the meansfor determining a resulting stoichiometric air fuel ratio and/or a resulting stoichiometric airfuel ratio are arranged for determining the resulting specific gas constant and/or the resultingstoichiometric air fuel ratio based on repeatedly determined specific gas constants and/or repeatedly determined air fuel ratios. 6At least parts of the objects are achieved by a vehicle comprising a system for determining thespecific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine according to the present invention.
    At least parts of the objects are achieved by a computer program for determining the specificgas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine. The computerprogram comprises program code for causing an electronic control unit or a computerconnected to the electronic control unit to perform the steps of the method for determiningthe specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine according to the present invention.
    At least parts of the objects are achieved by a computer program product containing aprogram code stored on a computer-readable medium for performing the method steps of themethod for determining the specific gas constant and the stoichiometric air fuel ratio of a fuelgas for a gas engine according to the present invention. The computer program is run on an electronic control unit or a computer connected to the electronic control unit.
    The system, the vehicle, the computer program and the computer program product havecorresponding advantages as have been described in connection with the corresponding examples of the method according to this disclosure.
    Further advantages of the present invention are described in the following detailed description and/or will arise to a person skilled in the art when performing the invention.
    BRIEF DESCRIPTION OF THE DRAWINGS For a more detailed understanding of the present invention and its objects and advantages,reference is made to the following detailed description which should be read together withthe accompanying drawings. Same reference numbers refer to same components in the different figures. ln the following, Fig. 1 shows, in a schematic way, a vehicle according to one embodiment of the present invention; 7Fig. 2 shows, in a schematic way, a system according to one embodiment ofthe present invention; Fig. 3 shows, in a schematic way, a flow chart over an example of a method according to the present invention; Fig. 4 shows, in a schematic way, a device which can be used in connection with the present invention.
    DETAILED DESCRIPTION Fig. 1 shows a side view of a vehicle 100. ln the shown example, the vehicle comprises atractor unit 110 and a trailer unit 112. The vehicle 100 can be a heavy vehicle such as a truck.ln one example, no trailer unit is connected to the vehicle 100. The vehicle 100 comprises agas engine. The vehicle 100 comprises a system 299, se Fig. 2a. The system 299 can be arranged in the tractor unit 110. ln one example, the vehicle 100 is a bus. The vehicle 100 can be any kind of vehicle comprisinga gas engine. Other examples of vehicles comprising a gas engine are boats, passenger cars,construction vehicles, and locomotives. The present invention can also be used in connectionwith any other platform than vehicles, as long as such a platform comprises a gas engine. One example is a power plant with a gas engine.
    The innovative method and the innovative system according to one aspect of the inventionare also well suited to, for example, systems which comprise industrial engines and/or engine- powered industrial robots.
    Although in the following mainly described in connection with engines being operated at a stoichiometric AFR, the present invention is also suitable for engines operated at a lean AFR.
    The term ”link” refers herein to a communication link which may be a physical connectionsuch as an opto-electronic communication line, or a non-physical connection such as a wireless connection, e.g. a radio link or microwave link. 8Fig. 2 shows schematically an embodiment of a system 299 for determining the specific gasconstant and the stoichiometric air fuel ratio of a fuel gas for a gas engine according to thepresent invention. The system 299 comprises a gas engine 210. The gas engine 210 can bearranged to propel a vehicle. The gas engine 210 comprises at least one cylinder. Each cylinderhas a corresponding volume of the cylinder, VCW. ln the following it is assumed that thevolumes of the cylinders are equal. However, it should be understood that the presentinvention easily could be adapted to cylinders of different volumes by defining differentvolumes Vcy|_,, for a specific cylinder n. The value Vcy| relates to a volume in the cylinder inwhich air and/or fuel can be injected at a pre-determined position of a piston in the cylinder.ln one example, the value Vcy| relates to the maximum possible volume of the cylinder, forexample when the position of the piston is in its least extended position. The value Vcy| is pre- determined for a given gas engine and can be stored in a first control unit 200.
    Said first control unit 200 is arranged to control operation of said gas engine 210. Said firstcontrol unit 200 is arranged for communication with said gas engine 210 via a link L210. Said first control unit 200 is arranged to receive information from said gas engine 210.
    Said system 299 comprises an air inlet 241. The possible flowing direction of air into the airinlet is indicated by the white arrow. The air then passes a throttle 260 before entering aninlet manifold 230. Said throttle 260 is arranged for controlling the flow of air into said inlet manifold 230. Said throttle 260 is, for example, controlled by said first control unit 200.
    Said first control unit 200 is arranged to control operation of said throttle 260. Said firstcontrol unit 200 is arranged for communication with said throttle 260 via a link L260. Said first control unit 200 is arranged to receive information from said throttle 260.
    Said system 299 further comprises a tank 220. Said tank 220 is arranged for storing the fuelgas of the vehicle. The fuel gas can, for example, be compressed natural gas, CNG. lt should,however, be noted that the invention is not limited to CNG but could use any suitable gaswhich can act as a fuel gas for the gas engine 210. The tank 220 is connected via connectingmeans 243 to a gas injector arrangement 270. Said connecting means 243 can comprise pipes,tubes, or the like. Said connecting means 243 are arranged for transporting the fuel gas from the tank 220 to the gas injector arrangement 270. 9Said gas injector arrangement 270 is arranged for injecting gas from the connecting means 243into the inlet manifold 230. The gas is injected during a time period tim- per working cycle. Saidgas injector arrangement 270 comprises at least one gas injector. Each of said at least one gasinjectors has an effective cross-sectional area, ACD, of its injector nozzle. ACD can be stored in said first control unit 200.
    Said first control unit 200 is arranged to control operation of said gas injector arrangement270. Said first control unit 200 is arranged for communication with said gas injectorarrangement 270 via a link L270. Said first control unit 200 can be arranged to receive information from said gas injector arrangement 270.
    Said first control unit 200 can, for example, be arranged to control tim-_ ln one example, tim- iscalculated by said first control unit 200. ln one example, tim- is measured at the gas injector 270. tim- can be stored in said first control unit 200.
    Said system 299 further comprises an exhaust pipe 240. Said exhaust pipe 240 is connected tothe gas engine 210 and arranged to transport exhausts from the gas engine 210 into theenvironment as indicated by the white arrow. lt should be understood that means for treatingthe exhaust (not shown) can be arranged along the exhaust pipe. Such means are for example catalytic means for exhaust treatment.
    Said system 299 further comprises means for determining a Å value downstream the gasengine. Said means for determining a first Å value downstream the gas engine can comprise alambda sensor arrangement 250. Said lambda sensor arrangement 250 is provideddownstream said gas engine. Said lambda sensor arrangement 250 is provided at said exhaustpipe 240. Said lambda sensor arrangement 250 comprises at least one lambda sensor. Said lambda sensor arrangement 250 is arranged to perform a measurement of Å, i.e. the ratio between actual air-fuel ratio, AFR, and stoichiometric air-fuel ratio, AFRS.
    Said first control unit 200 is arranged to control operation of said lambda sensor arrangement250. Said first control unit 200 is arranged for communication with said lambda sensorarrangement 250 via a link L250. Said first control unit 200 can be arranged to receive information from said lambda sensor arrangement 250.
    The system 299 is arranged to determine Å values at different times. The system is arranged todetermine at least a first Å value, Ål, and a second Å value, ÅZ. The system is arranged todetermine ÅZ at a different time than Ål. The system is arranged to measure Ål in connectionwith a first time period, tim-l, of gas injection and ÅZ at a second time period, tim-Z, of gas injection, wherein tim-land tim-Z have different lengths.
    Said system 299 further comprises means for determining a temperature value in the in|etmanifold 230 of the gas engine 210. Said means for determining a temperature value in thein|et manifold 230 of the gas engine 210 can comprise a temperature sensor arrangement252. Said temperature sensor arrangement can comprise at least one temperature sensor.Said temperature sensor arrangement 252 is arranged at the in|et manifold 230. Saidtemperature sensor arrangement 252 is arranged to measure the temperature Tin in the in|et manifold 230..
    Said first control unit 200 is arranged to control operation of said temperature sensorarrangement 252. Said first control unit 200 is arranged for communication with saidtemperature sensor arrangement 252 via a link L252. Said first control unit 200 can be arranged to receive information from said temperature sensor arrangement 252.
    Said system 299 further comprises means for determining a pressure value in the in|etmanifold 230 of the gas engine 210. Said means for determining a pressure value in the in|etmanifold 230 of the gas engine 210 can comprise a pressure sensor arrangement 253. Saidpressure sensor arrangement 253 can comprise at least one pressure sensor. Said pressuresensor arrangement 253 is arranged at the in|et manifold 230. Said pressure sensor arrangement 253 is arranged to measure the pressure pan in the in|et manifold 230.
    Said first control unit 200 is arranged to control operation of said pressure sensorarrangement 253. Said first control unit 200 is arranged for communication with said pressuresensor arrangement 253 via a link L253. Said first control unit 200 can be arranged to receive information from said pressure sensor arrangement 253.
    Said system 299 further comprises means for determining a flow of air into the gas engine and/or means for determining a mass of air in a cylinder of the gas engine. 11ln one example, said means for determining a flow of air into the gas engine and/or means fordetermining a mass of air in a cylinder of the gas engine comprise a mass air flow sensorarrangement, I/IAF-sensor arrangement, 251. Said I/IAF-sensor arrangement 251 can comprisea hot film air mass sensor, HFI/I-sensor. Said I/IAF-sensor arrangement 251 is arranged for measuring an air mass flow in the air inlet 241.
    Said first control unit 200 is arranged to control operation of MAF-sensor arrangement 251.Said first control unit 200 is arranged for communication with said I/IAF-sensor arrangement251 via a link L251. Said first control unit 200 can be arranged to receive information from said I/IAF-sensor arrangement 251. ln one example, said means for determining a flow of air into the gas engine and/or means fordetermining a mass of air in a cylinder of the gas engine comprise means for determining aflow through the throttle 260. Said means for determining a flow through the throttle 260 can,for example, comprise a pressure sensor at the air inlet 241 and a temperature sensor at theair inlet 241 (not shown). Said means for determining a flow through the throttle 260 can alsocomprise means for determining an effective area of the throttle. Said effective area relates toan effective area through which the air can flow from the air inlet 241 through the throttle.Said means for determining an effective area of the throttle can comprise a sensor fordetermining an angle of a throttle flap. The first control unit 200 can then be arranged tocalculate the flow of air mass through the throttle based on the measurement results of atleast one of said temperature sensor at the air inlet, said pressure sensor at the air inlet and said sensor for determining an angle of the throttle flap. ln one example, the mass of air in a cylinder of the gas engine, maii, can be determined by saidfirst control unit 200. This can, for example, be done based on the determined angle of the throttle flap and/or based on measurement results from said MAF-sensor arrangement 251.
    The first control unit 200 can also be arranged to determine a volumetric efficiency, VE, of thecylinder. The volumetric efficiency can be determined based on piii and/or Tiii. ln one examplethe volumetric efficiency is determined via the equation VE=maii*Tiii*Raii/(piifivcyi), where Raiidenotes the specific gas constant of air. ln one example, the first control unit 200 is arrangedto determine a first volumetric efficiency, VE1, of the cylinder in connection with a first time period, tiiiil, of gas injection, and a second volumetric efficiency, VEZ, of the cylinder in 12 connection with a second time period, tim-Z, of gas injection, wherein tim-l and tim-Z have different lengths. Values for the volumetric efficiency might be stored in said first control unit 200.
    The system 299 is further arranged for keeping the pressure in the in|et manifold 230essentially constant. The term essentially constant refers to the fact that the pressure is notvarying more than a pre-determined threshold. Such a pre-determined threshold can, forexample, be 1%, 2%, 3%, 5%, 7%, 10% or 15%. The threshold can be chosen in such a way thatconsideration is given to control uncertainties in the throttle 260 or to measurementuncertainties in the I/IAF-sensor arrangement 251, the temperature sensor arrangement 252,the pressure sensor arrangement 253, or in any other sensor arrangements which might bepresent in the system 299. ln one example the first control unit 200 keeps the pressure in thein|et manifold 230 constant by controlling the throttle 260, for example the angle of the throttle flap.
    A change in the pressure in the in|et manifold 230 can be caused by changing the time periodof gas injection. Changing the time period of gas injection will result in more or less fuel gasinjected into the in|et manifold, where the increase or decrease in the amount of gas willhigher or lower the pressure in the in|et manifold 230, respectively. By controlling the throttle260 the effect of an increased or decreased amount of fuel gas in the in|et manifold 230 canbe compensated with a lower or higher amount of air, respectively, which passes the throttle230 so as to keep the resulting pressure in the in|et manifold 230 constant. The pressuresensor arrangement 253 can be used for checking any changes of the pressure in the in|etmanifold 230. ln another example, the pressure in the in|et manifold is controlled without thepressure sensor arrangement 253. This can, for example, be achieved by making a calculationof the pressure based on the time period of gas injection and the amount of air passing the throttle 260.
    Said first control unit 200 is arranged for determining, during operation of the gas engine 210,the specific gas constant of a fuel gas for the gas engine 210. A way of doing this is described in relation to Fig. 3 and 4.
    Said first control unit 200 is arranged for determining the stoichiometric air fuel ratio of the fuel gas for the gas engine 210. A way of doing this is described in relation to Fig. 3 and 4. 13ln one example, said first control unit 200 is arranged for adapting the control of the gasengine 210 based on the determined specific gas constant and the determined stoichiometricair fuel ratio. Said adapting the control of the gas engine 210 can comprise adapting theamount of fuel injected into the gas engine 210. This is in one example done by adapting tinj.Said adapting the control of the gas engine 210 can comprise adapting the amount of airinjected into the gas engine 210. This is in one example done by adapting the amount of airwhich can pass the throttle 260. This is in one example done by controlling the throttle flap.Said adapting the control of the gas engine 210 can comprise adapting the control of anexhaust gas recirculation, EGR (not shown). Said adapting the control of the gas engine 210can comprise adapting a time of ignition in a cylinder of the gas engine 210. A person skilled inthe art will realise that the control of a gas engine can relate to other parameters then those named here.
    Adapting the control of the gas engine 210 based on the stoichiometric air fuel ratio and thespecific gas constant of the fuel gas allows minimising fuel consumption and emissions. lt alsoallows increasing drivability of the gas engine 210. A further advantage of system 299 is thatmost or all of its components present in nowadays vehicles. The present invention can thus beapplied to present vehicles via software updates, without the need of any new hardware alTaHgemeHtS. lt should also be understood that one or more of the measured parameters which aredescribed in this application can instead be estimated or pre-determined. This is especiallyuseful when the component of the system 299 which corresponds to measuring theparameter is not present at a present vehicle. Said estimation can, for example, be performedby said first control unit 200. Said estimation can, for example, be based on measurementresults from the remaining sensors arrangement and/or a model of the fuel/air/engine system in the corresponding vehicle.
    A second control unit 205 is arranged for communication with the first control unit 200 via alink L205 and may be detachably connected to it. lt may be a control unit external to thevehicle 100. lt may be adapted to conducting the innovative method steps according to theinvention. The second control unit 205 may be arranged to perform the inventive method steps according to the invention. lt may be used to cross-load software to the first control unit 14200, particularly software for conducting the innovative method. lt may alternatively bearranged for communication with the first control unit 200 via an internal network on boardthe vehicle. lt may be adapted to performing substantially the same functions as the firstcontrol unit 200, such as adapting engine control of a gas engine in a vehicle. The innovativemethod may be conducted by the first control unit 200 or the second control unit 205, or by both of them. ln Fig. 3 a flowchart of an example of a method 300 for determining the specific gas constantand the stoichiometric air fuel ratio of a fuel gas for a gas engine is schematically illustrated.The method starts with step 310. lt should be emphasised that the steps of the method 300not necessarily have to be performed in the order at which they are presented. The order ofthe steps is only limited in so far as one step might need the result of another step as input.Where this is not the case, the steps might be performed in any order, or in parallel, as long as not explicitly stated otherwise. ln step 310 the pressure in an inlet manifold of the gas engine is kept essentially constant. Theterm essentially constant relates to the fact that the pressure is not varying more than a pre-determined threshold. The pre-determined threshold can be set as discussed in relation to Fig.2. ln general, the lower the threshold the better the more reliable the results for the specificgas constant and the stoichiometric air fuel ratio of the fuel gas will be. However,measurement uncertainties of sensors and controlling accuracy of the throttle usually give areasonable lowest value of the threshold. The pre-determined threshold might thus beadapted to the specific components of the system 299 which is used for performing themethod. The pressure in the inlet manifold is kept essentially constant at least whileperforming the steps 320, 330, 340, 360, 365, and 370. This means that said pressure in theinlet manifold is essentially the same while performing the steps 320, 330, 340, 360, 365, and370.
    The pressure can be kept constant by controlling the throttle 260. lf a change in pressurewould occur due to other reasons, the throttle can adapt the amount of air which is allowed to flow into the inlet manifold. This can then compensate for the change in pressure which otherwise would occur. Examples have been discussed in relation to Fig. 2. After step 310 an optional step 320 is performed. ln the optional step 320 at least one out of a temperature value in the in|et manifold of thegas engine and a pressure value in said in|et manifold of the gas engine are determined.Preferably the temperature value in the in|et manifold of the gas engine is determined.Preferably step 320 is performed before step 350. The determined temperature value in thein|et manifold of the gas engine from step 320 will in the following be denoted as a first temperature value Tinl. The first temperature value can for example be determined by the temperature sensor arrangement 252. The first temperature value is determined during a first time period for the gas injection tim-l. lf a pressure value is determined this pressure value fromstep 320 will be denoted first pressure value pinl. The first pressure value can for example be determined by the pressure sensor arrangement 253. The first pressure value is determined during a first time period for the gas injection tim-l. ln one example said first pressure and/or said first temperature value are determined without the help of the temperature sensorarrangement 252 and/or the pressure sensor arrangement 253. Said first temperature and/orsaid first pressure value can for example be determined by a model of the system 299 or partsthereof and other determined values. ln one example, said other determined values comprisevalues determined by the I/IAF-sensor arrangement 241, by the throttle 260, and/or by the gas injector 270. .After the optional step 320 an optional step 330 is performed. ln the optional step 330 a flow of air into the gas engine is determined and/or a mass of air ina cylinder of the gas engine is determined. ln one example this is done based on measuringthe mass air flow with the I/IAF-sensor arrangement 251. ln one example this is done viadetermining the effective area of the throttle. This has been described in more detail above, inrelation to Fig. 2. The mass of air in the cylinder of the gas engine determined in step 330 will in the following be determined as a first air mass, mairl. Preferably, the first air mass isdetermined during the first time period for the gas injection tim-l. The method continues with step 340. ln step 340 a first Å value, Ål, is determined downstream the gas engine. This can be done with the help of the lambda sensor arrangement 250. Said first Å value is determined during a time 16when the engine is operated with said first time period of gas injection. The method continues with step 350. ln step 350 the time period of gas injection into the in|et manifold is changed. This change imp|ies preferably that the first time period of gas injection, tim-l, is changed to a second timeperiod of gas injection, tim-Z. Said changing can be an increase or a decrease relative to the firsttime period tim-l. ln one example, tim-Z is increased or decreased by 5% in relation to tim-l. Said change in tim- imp|ies usually a change in pin. Since, however, step 310 demands that thepressure in the in|et manifold is kept constant, this change in pan has to be avoided. This isdescribed in more detail in relation to step 310. After step 350 an optional step 360 is performed. ln the optional step 360 at least one out of a temperature value in the in|et manifold of thegas engine and a pressure value in said in|et manifold of the gas engine are determined.Preferably the temperature value in the in|et manifold of the gas engine is determined. Thedetermined temperature value in the in|et manifold of the gas engine from step 360 will in the following be denoted as a second temperature value Tinz. The second temperature value can for example be determined by the temperature sensor arrangement 252. The secondtemperature value is determined during a time while the engine is operated with the second time period for the gas injection tim-Z . lf a pressure value is determined this pressure valuefrom step 360 will be denoted second pressure value pinz. The second pressure value can for example be determined by the pressure sensor arrangement 253. The second pressure valueis determined during a time while the engine is operated with the second time period for the gas injection tim-Z. After the optional step 360 an optional step 365 is performed. ln the optional step 365 (not shown in Fig. 3) a flow of air into the gas engine is determinedand/or a mass of air in a cylinder of the gas engine is determined. This is done in the same wayas described in relation to step 330. The mass of air in the cylinder of the gas engine determined in step 365 will in the following be determined as a second air mass, mairz.
    Preferably, the second air mass is determined during the second time period for the gas injection tim-Z. The method continues with step 370. 17ln step 370 a second Å value, ÅZ, is determined downstream the gas engine. This can be donewith the help of the lambda sensor arrangement 250. Said second Å value is determinedduring a time while the engine is operated with said second time period of gas injection. The method continues with step 380. ln step 380 the specific gas constant of the fuel gas, RPG, and the stoichiometric air fuel ratio ofthe fuel gas, AFRS, are determined based on said determined first and second Å value, Ål andÅZ. ln one example said determination of RPG and AFRS is based on a determined temperaturevalue in the inlet manifold of the gas engine and/or a determined pressure value in said inletmanifold of the gas engine. ln one example said determination of RPG and AFRS is based on said first and second temperature value, Tinl and Tinz . ln one example said determination of RPG and AFRS is based on said determined flow of air into the gas engine and/or said determined mass of air in the cylinder ofthe gas engine, ma”.
    As an example, one can first determine a ratio of RPG and AFRS according to the following equation:1_E2íRFG I VEZ R-AFRS VEI _: alr- lt should be noted that the first and second volumetric efficiencies only appear as a ratio inthe above equation. lt is therefore not necessary to determine the volumetric efficiencies themselves. |nstead the ratio VE1/VE2 can be determined as (maPr1*TPn1)/(maPr2*TPn2).
    A so-called Wobbe index WG can be defined for the fuel gas according to the equation AFRS / RFG ' Rair, where kl is a constant which can be empirically determined and which is essentially the same WÛFG = kl for all relevant fuel gases. For each gas engine a reference Wobbe index, Woref, can be defined for an arbitrary reference gas. This reference gas will then have a certain reference time period of gas injection, tPnJ-reyfor which a Å value of 1 will be achieved downstream the gas engine. The time period of gas injection for the actual fuel gas to achieve a Å value of 1 18 downstream the gas engine is denoted tim-FG. These two time periods are related via the relation tinJ-FG=kFG* tim-ref, wherein the constant kFG can be denoted fuel factor. ln one example, the first control unit 200 is arranged to determine tim-FG. This can be done by waiting until a Å value of 1 is reached during propulsion of the vehicle. The fuel factor kFG can then be stored in the first control unit 200. tim-ref can be determined based on AFRSref, the specific gas constant for the reference gas, Rref, and mair. From kFG it is then possible to determine tim-FG. The determination of tim-FG can be done before the method 300 is started. ln one example, the system 299 is actively controlled to reach a Å value of 1 so as to determine tin- . Rref and/or AFRS can be pre-determined and stored in the first control unit 200. FromJFG ref this the fuel factor can be determined.
    The fuel factor relates also to the Wobbe index of the fuel gas and the reference gas via WOFG=kFG* Woref. The Wobbe index for the reference can be pre-determined and stored in the first control unit 200. From this the Wobbe index for the fuel gas can be determined.
    Having determined the Wobbe index for the fuel gas and the ratio of RFG and AFRS, the specific gas constant can then be determined via the equation From the determined RFG and the determined ratio of RFG and AFRS the stoichiometric air fuel ratio of the fuel gas can be determined. lt should be understood that the above equations are only an enabling example of how step380 can be implemented. This example is not intended to limit the claims as there aredifferent ways to determine RFG and AFRS. As an example, it is not necessary to achieve a Å value of 1 with the fuel gas so as to determine tim-FG. Any other Å value for tim- will work as well.
    This will introduce further correction terms in the subsequent calculations, but one can arriveat RFG and AFRS as well. lt is neither necessary to perform all the above calculations. ln one example, the above calculations are combined to final equations for RFG and AFRS. ln one 19example, step 380 is performed by the first control unit 200. After step 380 the method 300 ends. ln one example method 300 can be used as a step in a method for adapting the control of thegas engine. ln this case the specific gas constant and the stoichiometric air fuel ratio of a fuelgas for a gas engine are first determined according to method 300. Afterwards the control ofthe gas engine is adapted based on the determined specific gas constant and based on the determined stoichiometric air fuel ratio.
    Said adaption of the control of the gas engine comprises in one example adapting the amountof fuel injected into the gas engine. Said adapting of the control of the gas engine comprises inone example adapting tinj. Said adapting of the control of the gas engine comprises in oneexample adapting the amount of air injected into the gas engine. This is in one example doneby controlling the throttle flap. Said adapting of the control of the gas engine can compriseadapting the control of an exhaust gas recirculation, EGR. Said adapting the control of the gasengine can comprise adapting a time of ignition in a cylinder of the gas engine. Depending onthe design of the gas engine there are other parameters as well which can be adapted. Aperson skilled in the art will be aware of which other parameters are present at a specific gasengine. Some advantages of the adaptions based on AFRS and RFG are lower fuel consumptionand/or lower amount of certain exhausts from the gas engine. lf the optional step 390 is performed ln one example, the method 300 is performed while the load on the gas engine is essentiallyconstant, so that the load on the gas engine is not varying more than a pre-determinedthreshold. The load is preferably at least essentially constant while performing steps 320, 330,340, 360, 365, and 370. This has the advantage that no corrections for different loads of theengine have to be introduced in the equations used in connection with step 380. ln oneexample, said load is essentially constant during 1, 2, 3, 5, 7, or 10 seconds. This is in oneexample the case when a driver of the vehicle is not accelerating with the vehicle. This is inone example the case when the vehicle is driving with constant speed. ln another example thisis the case when the driver is standing still with the vehicle, for example due to traffic lights. lngeneral, situations with constant load will naturally appear during operation of the vehicle.
    Performing the method 300 as these situations naturally appear has the advantage of not affecting the driveability of the vehicle while the method 300 is performed. ln an alternativeexample, the gas engine 210 and/or other components in the system 299 can be actively controlled so as to keep the load of the gas engine constant. ln one example, the method 300 is performed repeatedly. Thus AFRS and RFG are determinedrepeatedly. A resulting specific gas constant and/or a resulting stoichiometric air fuel ratio isthen calculated based on the repeatedly determined specific gas constants and/or therepeatedly determined air fuel ratios. This calculation is in one example an arithmetic mean ofthe repeatedly determined specific gas constants and/or the repeatedly determined air fuelratios. ln one example the repeatedly determined specific gas constants and/or the repeatedlydetermined air fuel ratios are weighted when calculating the resulting specific gas constantand/or the resulting stoichiometric air fuel ratio. The weighting can be based on how accurateeach determined air fuel ratio and/or specific gas constant is. The accurateness relates in oneexample to errors or uncertainties in the lambda sensor arrangement 250, the I/IAF-sensorarrangement 251, the temperature sensor arrangement 252, the pressure sensorarrangement 253, the throttle 260, or the gas injector 270. ln one example the accuratenessrelates to how well the pressure in the inlet manifold 230 and/or the load of the gas engine 210 can be kept constant. Performing the method 300 repeatedly results in higher accuracy of ÅFRS and RPG.
    The method 300 can also be combined with the method disclosed in the Swedish patentapplication 1650386-4, entitled ”A method and a system for adapting engine control of a gasengine in a vehicle” (same applicant and filing date as the present patent application), to lHCFeaSe aCCUFaCy.
    Figure 4 is a diagram of one version of a device 500. The control units 200 and 205 describedwith reference to Figure 2 may in one version comprise the device 500. The device 500comprises a non-volatile memory 520, a data processing unit 510 and a read/write memory550. The non-volatile memory 520 has a first memory element 530 in which a computerprogram, e.g. an operating system, is stored for controlling the function of the device 500. Thedevice 500 further comprises a bus controller, a serial communication port, I/O means, an A/D converter, a time and date input and transfer unit, an event counter and an interruption 21controller (not depicted). The non-volatile memory 520 has also a second memory element 540.
    The computer program comprises routines for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine.
    The computer program P may comprise routines for keeping the pressure essentially constantin an inlet manifold of the gas engine, so that the pressure is not varying more than a pre-determined threshold. This may at least partly be performed by means of said first control unit 200 controlling operation of the throttle 260.
    The computer program P may comprise routines for determining a first Å value downstreamthe gas engine. This may at least partly be performed by means of said first control unit 200controlling operation of the lambda sensor arrangement 250. Said first Å value may be stored in said non-volatile memory 520.
    The computer program P may comprise routines for changing the time period of gas injectioninto the inlet manifold. This may at least partly be performed by means of said first control unit 200 controlling operation of said gas injector 270.
    The computer program P may comprise routines for determining a second Å valuedownstream the gas engine after said changing of the time period of gas injection into theinlet manifold. This may at least partly be performed by means of said first control unit 200controlling operation of the lambda sensor arrangement 250. Said second Å value may be stored in said non-volatile memory 520.
    The computer program P may comprise routines for determining the specific gas constant andthe stoichiometric air fuel ratio of the fuel gas based on said determined first and second Å value.
    The computer program P may comprise routines for determining at least one out of atemperature value in the inlet manifold of the gas engine and a pressure value in said inletmanifold of the gas engine. This may at least partly be performed by means of said firstcontrol unit 200 controlling operation of the temperature sensor arrangement 252 and/or thepressure sensor arrangement 253. Said temperature value and/or pressure value may be stored in said non-volatile memory 520. 22The computer program P may comprise routines for determining a flow of air into the gasengine and/or determining a mass of air in a cylinder ofthe gas engine. This may at least partlybe performed by means of said first control unit 200 controlling operation of any of the massair flow sensor arrangement 251, and/or the throttle 260. The result of said determined flowof air into the gas engine and/or the determined mass of air in a cylinder of the gas engine may be stored in said non-volatile memory 520.
    The computer program P may comprise routines for determining the specific gas constant andthe stoichiometric air fuel ratio of the fuel gas for the gas engine repeatedly. The repeatedlydetermined specific gas constants and the repeatedly determined stoichiometric air fuel ratiosof the fuel gas for the gas engine may be stored in said non-volatile memory. The computerprogram P may comprise routines for determining a resulting specific gas constant and/or aresulting stoichiometric air fuel ratio based on the repeatedly determined specific gas constant and/or the repeatedly determined air fuel ratio.
    The computer program P may comprise routines for determining a flow of air into the gas engine 210 and/or for determining a mass of air in a cylinder ofthe gas engine 210.
    The program P may be stored in an executable form or in compressed form in a memory 560 and/or in a read/write memory 550.
    Where it is stated that the data processing unit 510 performs a certain function, it means thatit conducts a certain part of the program which is stored in the memory 560 or a certain part of the program which is stored in the read/write memory 550.
    The data processing device 510 can communicate with a data port 599 via a data bus 515. Thenon-volatile memory 520 is intended for communication with the data processing unit 510 viaa data bus 512. The separate memory 560 is intended to communicate with the dataprocessing unit via a data bus 511. The read/write memory 550 is arranged to communicatewith the data processing unit 510 via a data bus 514. The links L205, L210, L250-255, and L270, for example, may be connected to the data port 599 (see Figure 2).
    When data are received on the data port 599, they can be stored temporarily in the secondmemory element 540. When input data received have been temporarily stored, the data processing unit 510 can be prepared to conduct code execution as described above. 23Parts of the methods herein described may be conducted by the device 500 by means of thedata processing unit 510 which runs the program stored in the memory 560 or the read/write memory 550. When the device 500 runs the program, methods herein described are executed.
    The foregoing description of the preferred embodiments of the present invention is providedfor i|ustrative and descriptive purposes. lt is neither intended to be exhaustive, nor to limitthe invention to the variants described. I/|any modifications and variations will obviouslysuggest themselves to one skilled in the art. The embodiments have been chosen anddescribed in order to best explain the principles ofthe invention and their practicalapplications and thereby make it possible for one skilled in the art to understand the inventionfor different embodiments and with the various modifications appropriate to the intended USS.
    权利要求:
    Claims (13)
    [1] 1.
    [2] 2.
    [3] 3.
    [4] 4. A method (300) for determining the specific gas constant and the stoichiometric airfuel ratio of a fuel gas for a gas engine, the method comprising the steps of: - keeping (310) the pressure essentially constant in an inlet manifold of the gasengine, so that the pressure is not varying more than a pre-determinedthreshold; - determining (340) a first Å value downstream the gas engine while the engine isoperated at a first time period of gas injection into the inlet manifold; - changing (350) said first time period of gas injection into the inlet manifold intoa second time period of gas injection into the inlet manifold; - determining (370) a second Å value downstream the gas engine after saidchanging of the time period of gas injection into the inlet manifold; and - determining (380) the specific gas constant and the stoichiometric air fuel ratioof the fuel gas based on said determined first and second Å value. The method according to claim 1, further comprising the step of - determining (320; 360) at least one out of a temperature value in the inletmanifold of the gas engine and a pressure value in said inlet manifold of the gasengine, wherein said determining (380) of the specific gas constant and the stoichiometric airfuel ratio of the fuel gas is based on said at least one out of the determinedtemperature value in the inlet manifold of the gas engine and the determined pressurevalue in said inlet manifold of the gas engine. The method according to claim 1 or 2, further comprising the step of - determining (330) a flow of air into the gas engine and/or determining a mass of air in a cylinder ofthe gas enginewherein said determining (380) of the specific gas constant and the stoichiometric airfuel ratio is based on said determined flow of air into the gas engine and/or saiddetermined mass of air in the cylinder of the gas engine.The method according to any of the previous claims, wherein the method is performedwhile the load on the gas engine is essentially constant, so that the load on the gas engine is not varying more than a pre-determined threshold.
    [5] 5. The method according to any of the previous claims, wherein the method is performed repeatedly and a resulting specific gas constant and/or a resulting stoichiometric air fuel ratio is calculated based on the repeatedly determined specific gas constants and/or the repeatedly determined air fuel ratios.
    [6] 6. A system (299) for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine (210), the system comprising: means (260, 200) for keeping the pressure essentially constant in an inletmanifold (230) of the gas engine (210), so that the pressure is not varying morethan a pre-determined threshold; means (250) for determining a first Å value downstream the gas engine whilethe engine is operated at a first time period of gas injection into the inletmanifold; means (270, 200) for changing said first time period of gas injection into theinlet manifold (230) into a second time period of gas injection into the inletmanifold (230); means (250) for determining a second Å value downstream the gas engine (210)after said changing of the time period of gas injection into the inlet manifold(230); and means (200) for determining the specific gas constant and the stoichiometric air fuel ratio of the fuel gas based on said determined first and second Å value.
    [7] 7. The system according to claim 6, further comprising: means (252, 253) for determining at least one out of a temperature value in theinlet manifold (230) of the gas engine (210) and a pressure value in said inlet manifold (230) of the gas engine (210), wherein said means (200) for determining the specific gas constant and the stoichiometric air fuel ratio of the fuel gas is arranged for basing said determining on said at least one out of the determined temperature value in the inlet manifold of the gas engine and the determined pressure value in said inlet manifold ofthe gas engine.
    [8] 8. The system according to claim 6 or 7, further comprising: means (251, 260, 200) for determining a flow of air into the gas engine (210) and/or determining a mass of air in a cylinder ofthe gas engine (210)
    [9] 9. 26 wherein said means (200) for determining the specific gas constant and thestoichiometric air fuel ratio is arranged for basing said determining on said determinedflow of air into the gas engine and/or said determined mass of air in the cylinder of thegas engine. The system according to any of the claims 6-8, further comprising means (200) forperforming the determining of the specific gas constant and the stoichiometric air fuelratio of the fuel gas for the gas engine (210) while the load on the gas engine isessentially constant, so that the load on the gas engine is not varying more than a pre- determined threshold.
    [10] 10.The system according to any of the claims 6-9, further comprising means (200) for determining a resulting stoichiometric air fuel ratio and/or a resulting stoichiometricair fuel ratio, wherein said means for determining a resulting stoichiometric air fuelratio and/or a resulting stoichiometric air fuel ratio are arranged for determining theresulting specific gas constant and/or the resulting stoichiometric air fuel ratio basedon repeatedly determined specific gas constants and/or repeatedly determined air fuel ratios.
    [11] 11. A vehicle (100) comprising a system (299) according to any of claims 6-10.
    [12] 12.A computer program (P) for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine, wherein said computerprogram (P) comprises program code for causing an electronic control unit (200; 500)or a computer (205; 500) connected to the electronic control unit (200; 500) to perform the steps according to any of the claims 1-5.
    [13] 13.A computer program product containing a program code stored on a computer- readable medium for performing method steps according to any of claims 1-5, whensaid computer program is run on an electronic control unit (200; 500) or a computer (205; 500) connected to the electronic control unit (200; 500).
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    同族专利:
    公开号 | 公开日
    US20190101067A1|2019-04-04|
    CN108779721A|2018-11-09|
    SE540143C2|2018-04-10|
    EP3433479A1|2019-01-30|
    BR112018015323A2|2018-12-18|
    KR102086021B1|2020-03-06|
    KR20180118227A|2018-10-30|
    EP3433479A4|2019-11-06|
    WO2017164801A1|2017-09-28|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US6295808B1|1999-06-29|2001-10-02|Hereaus Electro-Nite International N.V.|High driveability index fuel detection by exhaust gas temperature measurement|
    KR100538844B1|2001-09-19|2005-12-23|박용성|An automobile driving fuel economy acquisition method and display device|
    JP3824983B2|2002-09-04|2006-09-20|本田技研工業株式会社|An air-fuel ratio control device for an internal combustion engine that stops the operation of the identifier during lean operation|
    JP2006029239A|2004-07-16|2006-02-02|Toyota Motor Corp|Exhaust emission control filter overheat prevention device|
    DE102004038122B4|2004-08-05|2006-07-20|Siemens Ag|Method and device for controlling an internal combustion engine|
    DE102006022357B3|2006-05-12|2007-10-11|Siemens Ag|Fuel tank gas composition determination for motor vehicle, involves determining actual composition of gas mixture under consideration of fuel consumption during dropping of vapor pressure of integral part of gas mixture in tank|
    DE102006050357A1|2006-10-25|2008-05-08|Siemens Ag|Method and apparatus for determining the gas composition in a tank|
    JP4989523B2|2008-03-06|2012-08-01|日立オートモティブシステムズ株式会社|Variable valve system for internal combustion engine and control device for internal combustion engine|
    DE102008054796A1|2008-12-17|2010-06-24|Ford Global Technologies, LLC, Dearborn|Stoichiometric air/fuel ratio determining method for internal combustion engine i.e. diesel engine, of vehicle, involves determining air/fuel ratio based on gas quantity in cylinder, injected fuel quantity, and exhaust residual percentage|
    JP2012229666A|2011-04-27|2012-11-22|Denso Corp|Internal combustion engine control device|
    JP2013092083A|2011-10-25|2013-05-16|Yanmar Co Ltd|Gas engine, gas heat pump device and cogeneration device using gas engine, and gas engine control method|
    EP2772627B1|2011-10-26|2018-03-21|Toyota Jidosha Kabushiki Kaisha|Fuel property determination system for vehicle|
    CN103375287B|2012-04-19|2016-01-13|北京易康泰科汽车电子有限公司|The air fuel ratio learning method of natural gas engine|
    US9909514B2|2013-05-07|2018-03-06|Ford Global Technologies, Llc|Direct injection of diluents or secondary fuels in gaseous fuel engines|RU2766103C1|2018-02-28|2022-02-07|ЕКОНТРОЛЗ, ЭлЭлСи|Mass flow throttle for large engines on natural gas|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1650387A|SE540143C2|2016-03-23|2016-03-23|A method and a system for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine|SE1650387A| SE540143C2|2016-03-23|2016-03-23|A method and a system for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine|
    CN201780015331.4A| CN108779721A|2016-03-23|2017-03-22|A kind of method and system for determining the specific gas constant and stoichiometric air-fuel ratio of the fuel gas for gas engine|
    US16/085,967| US20190101067A1|2016-03-23|2017-03-22|A method and a system for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine|
    PCT/SE2017/050274| WO2017164801A1|2016-03-23|2017-03-22|A method and a system for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine|
    EP17770712.2A| EP3433479A4|2016-03-23|2017-03-22|A method and a system for determining the specific gas constant and the stoichiometric air fuel ratio of a fuel gas for a gas engine|
    KR1020187029521A| KR102086021B1|2016-03-23|2017-03-22|Method and system for determining non-gas constant and stoichiometric air-fuel ratio of fuel gas for gas engine|
    BR112018015323A| BR112018015323A2|2016-03-23|2017-03-22|method and system for determining the specific gas constant and stoichiometric air-fuel ratio of a fuel gas to a gas engine|
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