Abstract:
A method to control the combustion of a compression ignition engine (1) having the steps of: establishing, for each combustion cycle, a fuel quantity (Q) to be injected into the cylinder (2); injecting a first fraction (Fl) of the fuel quantity (Q); heating a second fraction (F2) of the fuel quantity (Q), which is equal to the remaining fraction of the fuel quantity (Q), to an injection temperature (T) higher than 100°C; injecting the second fraction (F2) of the fuel quantity (Q) heated to the injection temperature (T) into the cylinder (2) at the end of the compression stroke and at no more than 60° from the top dead centre (PMS); and decreasing the injection temperature (T) and the ratio between the second fraction (F2) and the first fraction (Fl) as the internal combustion engine (1) increases and as the rotation speed of the internal combustion engine (1) increases.
Abstract:
Die Erfindung betrifft ein Verfahren zum Betreiben einer Brennkraftmaschine, bei dem mit einem Dual-Fuel-Injektor ein gasförmiger Brennstoff über mehrere kreisförmig angeordnete Einblasöffnungen (1) unter Hochdruck in einen Brennraum (2) der Brennkraftmaschine eingeblasen wird, wobei Gasstrahlen (3) erzeugt werden, die mittels einer zuvor eingespritzten Flüssigkraftstoff-, insbesondere Dieselkraftstoff-Piloteinspritzung gezündet und verbrannt werden. Durch den Dual-Fuel-Injektor wird beim Einspritzen der Flüssigkraftstoff-Piloteinspritzung ein Hohlkegelstrahl (4) erzeugt, mittels dessen die Gasstrahlen (3) gezündet werden.
Abstract:
An optimized port plus direct injection (PFI+DI) fueling system for reducing DI-generated particulates from a spark ignition gasoline engine is disclosed. It uses information from a computational model that includes piston wetting. Means for DI particulate reduction include control of DI timing and duration as a function of various parameters. Illustrative computational results for decreasing particulates in various drive cycles are presented. These calculations illustrate large potential particulate reductions (e.g. 95%) that can be obtained relative to DI operation alone. The optimized PFI+DI system could provide DI generated particulate reduction, efficiency and cost advantages relative to operation of a DI alone engine with a gasoline particulate filter (GPF). Alternatively, it could be used in combination with a GPF to ease GPF operation requirements and provide additional particulate reduction. Techniques for reducing piston wetting generation of particles from use of DI alone are also described.
Abstract:
Methods are provided for managing forcing function frequency profiles during operation of a multi-cylinder engine. A first stroke mode for a first cylinder is selected and comprises at least a sequential deactive operation of the opening and the closing of a first intake valve and a first exhaust valve during at least two reciprocations of a first reciprocating piston. The first stroke mode is operated on the first cylinder, a second stroke mode is operated on a second cylinder, and a third stroke mode is operated on the remaining cylinders to meet or exceed a required torque output and to form a first aggregate of forcing function frequency profiles that comprises primary forcing function frequency profiles that are less than or approximate in amplitude and less than or approximate in frequency value to one of the respective baseline of primary forcing function frequency profiles.
Abstract:
The present invention relates to the technology of gasoline direct injection (GDI) in automotive engines. In this context, the present invention provides a method for maximizing the formation of deposits in injector nozzles of GDI engines, said method comprising at least one test cycle, each test cycle comprising at least one testing step in which a predetermined condition of speed and load of the GDI engine is maintained for a specified period of time, wherein, in said cycle, in at least one testing step, the engine speed is maintained between 1300 and 3700 rpm, the engine load is maintained between 10 and 80% and the specified period of time is from 10 to 200 minutes. Thus, the method of the present invention is able to reproduce severe conditions of deposition of material in a few days, so that, in a short period of time, the test fuel can be assessed for tendency to form deposits.
Abstract:
Die Erfindung betrifft ein Verfahren zum Betreiben einer wenigstens einen Brennraum, wenigstens ein dem Brennraum zugeordnetes Einlassventil und wenigstens ein dem Brennraum zugeordneten Injektor aufweisenden Verbrennungskraftmaschine, bei welchem Kraftstoff zum Betreiben der Verbrennungskraftmaschine mittels des Injektors direkt in den Brennraum eingespritzt wird, wobei der Kraftstoff in den Brennraum eingespritzt wird, indem wenigstens ein Teilhub (TH) des Injektors durchgeführt wird, während das Einlassventil geöffnet ist.
Abstract:
Ein Verfahren zum Einspritzen eines gasförmigen Kraftstoffs (108) für eine Brennkraftmaschine (110) mit einem Brennraum (101) und einem dem Brennraum (101) zugeordneten Einlassventil (102) umfasst : - Ermitteln einer Drehmomentabgabe (TQ_ist_cyl_x) des Brennraums (101), - Vorgeben eines Vergleichswerts (TQ_mid) für die Drehmomentabgabe (TQ_ist_cyl_x), - Ermitteln einer Differenz (D_TQ_x) der Drehmomentabgabe (TQ_ist_cyl_x) und des Vergleichswerts, - wenn die Differenz (D_TQ_x) kleiner als ein vorgegebener Schwellenwert ist: Reduzieren einer ersten Einspritzmenge des gasförmigen Kraftstoffs (108) in Abhängigkeit von der ermittelten Differenz (D_TQ_x), die zeitlich vor einem Schließen des Einlassventils (103) eingespritzt wird, und - wenn die Differenz (D_TQ_x) größer als der vorgegebener Schwellenwert ist: Erhöhen der ersten Einspritzmenge des gasförmigen Kraftstoffs (108) in Abhängigkeit von der ermittelten Differenz (D_TQ_x). Weiterhin ist eine Vorrichtung beschreiben, die das Verfahren ausführen kann.
Abstract:
An assembly at least comprising a fuel injector for dual fuel operation of an internal combustion engine. The assembly includes a nozzle holder defining a fuel circuit and provided with a nose adapted in use to be in connection with a combustion space of an internal combustion engine, and first and second nozzles in communication with the fuel circuit in the nozzle holder for directly injecting liquid fuel into the combustion space of the internal combustion engine for ignition of a combustible mixture present in the combustion space. The first and second nozzles adjacent to the nose of the nozzle holder are interconnected by a cooling channel. At each actuation of a fuel pump upstream of the first and second nozzles, substantially a full volume of fuel pumped during actuation of the fuel pump is allowed to flow through the cooling channel and via the first and second nozzles, to provide cooling thereof. The assembly further comprises a spill valve in the fuel circuit. Opening and closing of the spill valve controls the amount of liquid fuel to be delivered to the first and second nozzles.