Classifications

• • 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
  • F02D19/12—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 non-fuel substances or with anti-knock agents, e.g. with anti-knock fuel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the invention relates to supplying internal combustion engines with liquid fuels.
• It relates more specifically to a method for monitoring the injection of an additive into a fuel system for an internal combustion engine.
• Additives that give good results are those sold under the tradenames Eolys® and Infmeum; these are ceria-based compounds developed by Rhodia and Infmeum, which lower the natural combustion temperature of the particulates to 350°C instead of 600°C, i.e. around 250°C lower than their natural combustion temperature.
• Eolys Powerflex® and Infmeum are ceria-based compounds developed by Rhodia and Infmeum, which lower the natural combustion temperature of the particulates to 350°C instead of 600°C, i.e. around 250°C lower than their natural combustion temperature.
• Infmeum F7995 grades give good results in practice. In order to remove the risk of insufficient additive addition into the diesel for a vehicle equipped with a particulate filter, it may be necessary to monitor the amount of additive actually injected into the fuel tank. However, this type of compound is viscous, especially at low temperature, which makes the usual flow rate or pressure measurements difficult or even impossible, or too slow. Another parameter which makes these conventional measurements unusable in practice is the fact that the injectors that are available commercially exhibit considerable dispersion (which may range up to 10% of the absolute value of the pressure) and that therefore using "absolute" values (such as the pressure or the average flow rate) does not make it possible to develop a universal and reliable diagnostic method.
• the invention relates to a method for monitoring the injection of an additive into a fuel system for an internal combustion engine operating with a liquid fuel and comprising a fuel tank, an additive tank, an additive pump, an injector for injecting the additive into the fuel tank and a feed line connecting the pump and the injector, according to which the pressure in the feed line is measured continuously, during the injection of the additive, and is compared to a reference pressure.
• the fuel system is a set of elements that are intended to be incorporated into an automotive vehicle or into a stationary power plant and that have the main role of storing, purifying, measuring or transporting a fuel intended for supplying an internal combustion engine.
• the automotive vehicle may be a motor vehicle (a car, lorry, motorcycle, river boat, sea-going ship, or aeroplane for example) or a vehicle constrained to run on a track (for example a railway locomotive).
• the stationary power plant may for example be the engine of an electric power generator or the motor of a machine tool.
• fuel is understood to mean a hydrocarbon suitable for powering internal combustion engines.
• liquid hydrocarbon denotes a hydrocarbon that, under the standard operating conditions of the engine, is in the liquid state in the fuel tank of the fuel system.
• volatile liquid hydrocarbon denotes a liquid hydrocarbon (according to the aforementioned definition) that has a saturation vapour pressure of greater than 1 bar at 293 K (20°C).
• Volatile liquid hydrocarbons commonly used for powering internal combustion engines of motor vehicles are those sold commercially under the name “petrol” and intended for spark-ignition internal combustion engines.
• heavy liquid hydrocarbon denotes a liquid hydrocarbon that has a saturation vapour pressure of less than 1 bar at 293 K (20°C).
• Heavy liquid hydrocarbons commonly used for powering the internal combustion engines of motor vehicles are those sold commercially under the names “diesel” or “gasoil” and intended for self-ignition internal combustion engines operating on the diesel cycle.
• the metering system In the case where the metering system has the role of dispensing the additive into the fuel tank, it does this for example in an amount that is a mathematical function (usually, but not necessarily, a proportional function) of the instantaneous fuel consumption of the engine. This amount is generally calculated by an on-board computer or a specific control unit. Alternatively, the metering operation may take place in a single step, just after the filling operation, as a function of the amount of fuel introduced during the filling operation. In this case, the computer or control unit can be connected to a device that makes it possible to detect the opening and closing of the fuel filling system.
• a mathematical function usually, but not necessarily, a proportional function
• Such a device may comprise a magnet linked to a moving part (typically a cap or any other manual or automatic closure system) and a sensor able to detect the presence/absence of the magnet. This presence/absence is detected by the on- board computer which stores the content of the tank at the moment when it is informed thereof. If the position of the cap when it is closed corresponds to a rest condition for the control unit, it is able to calculate a difference in volume of fuel introduced, between the moment when the system is activated and the moment when it stabilizes. This volume serves as a basis for the calculation (carried out after closure of the cap) of the amount that needs to be metered out in order to maintain a constant additive concentration.
• the computer or control unit can receive a signal from a level gauge measuring dynamically the fuel level in the tank so that it can calculate the amount of fuel introduced into the tank and hence, calculate the amount of additive to be metered.
• the method comprises the steps consisting in:
• This signal analysis may be carried out by:
• a warning is sent to the CPU (central processing unit or on-board computer) and/or to the instrument panel of the vehicle.
• a new (second) injection trial may be performed before sending such a warning.
• Figure 1 comparison of the increase in pressure at the start of a metering operation, respectively with a defective pump and/or in the presence of air (bubbles) in the system, and with a "normal” pump and a system free of air (bubbles).
• Figure 2 comparison of the pressure during metering, respectively with a defective pump (for example: having an incomplete piston stroke, with internal leaks, etc.) and with a "normal" pump.
• Figure 4 comparison of the increase in pressure at the start of metering, respectively with a system where the injector has got stuck after drying of additive residues, and with a "normal" system.
• Figure 5 pressure evolution during metering with a system where the injector is stuck because of dry additive residues.
• Figure 6 comparison of the pressure signal, respectively with a system where the feed line is pinched and/or partially clogged, and with a "normal" system.
• Figure 7 comparison of the pressure signal, respectively with a system where the feed line is split or disconnected, and with a "normal" system.
• Figure 8 pressure evolution during metering with a system where the pump gets unprimed
• Figure 9 pressure evolution with a system where the pump is priming.
• FIG. 1 An example of malfunction detection based on the pressure increase gradient at the start of metering is illustrated in Figure 1 appended to the present document.
• the left-hand graph illustrates a loss of efficiency of the pump or the presence of an air bubble whereas the right-hand graph represents the reference (normal) operation. It can be seen in this figure that it is possible to detect an insufficient flow rate during this operating phase by calculating the pressurization gradient (gradient of the pressure increase).
• the following figures (2 to 9) respectively illustrate:
• the present invention has the following advantages: reduction in the risk of the particulate filter overheating, which risk may lead to the outbreak of fire;

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

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• 2011
  • 2011-04-05 EP EP11713748A patent/EP2561202A1/de not_active Withdrawn
  • 2011-04-05 WO PCT/EP2011/055290 patent/WO2011124579A1/en not_active Ceased

Non-Patent Citations (1)

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