Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N9/00—Electrical control of exhaust gas treating apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
  • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
  • F01N3/206—Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
  • F01N3/36—Arrangements for supply of additional fuel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
  • F01N2560/06—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being a temperature sensor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
  • F01N2560/08—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being a pressure sensor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
  • F01N2560/14—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics having more than one sensor of one kind
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/03—Adding substances to exhaust gases the substance being hydrocarbons, e.g. engine fuel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/11—Adding substances to exhaust gases the substance or part of the dosing system being cooled
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
  • F01N2610/1433—Pumps
  • F01N2610/144—Control thereof
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
  • F01N2610/1446—Means for damping of pressure fluctuations in the delivery system, e.g. by puffer volumes or throttling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
  • F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
  • F01N2610/146—Control thereof, e.g. control of injectors or injection valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
  • F01N2610/1473—Overflow or return means for the substances, e.g. conduits or valves for the return path
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
  • F01N2900/06—Parameters used for exhaust control or diagnosing
  • F01N2900/14—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust gas
  • F01N2900/1404—Exhaust gas temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
  • F01N2900/06—Parameters used for exhaust control or diagnosing
  • F01N2900/16—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust apparatus, e.g. particulate filter or catalyst
  • F01N2900/1602—Temperature of exhaust gas apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
  • F01N2900/06—Parameters used for exhaust control or diagnosing
  • F01N2900/18—Parameters used for exhaust control or diagnosing said parameters being related to the system for adding a substance into the exhaust
  • F01N2900/1806—Properties of reducing agent or dosing system
  • F01N2900/1808—Pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
  • F01N3/025—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using fuel burner or by adding fuel to exhaust
  • F01N3/0253—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using fuel burner or by adding fuel to exhaust adding fuel to exhaust gases
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/103—Oxidation catalysts for HC and CO only
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
  • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
  • F01N3/2006—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating
  • F01N3/2033—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating using a fuel burner or introducing fuel into exhaust duct
• • 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
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
  • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• • 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
• • 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
  • Y02T10/40—Engine management systems

Definitions

• the present invention relates to a method pertaining to an HC (hydrocarbon) dosing system.
• the invention relates also to a computer programme product comprising programme code for a computer for implementing a method according to the invention.
• the invention relates also to an HC dosing system and a motor vehicle equipped with the HC dosing system.
• DPF diesel particulate filter
• a particle filter which is for example adapted to capturing diesel particles and soot.
• DOC oxidation catalyst
• active regeneration of the particle filter diesel fuel is supplied to an exhaust pipe downstream of an engine and is led into an oxidation catalyst, also called DOC.
• DOC oxidation catalyst
• active regeneration of the particle filter situated downstream of the oxidation catalyst may thus be achieved.
• DPF system comprises a container which holds diesel fuel.
• the DPF dosing system has also a pump arranged to draw said fuel from the container via a suction hose and supply it via a pressure hose to a dosing unit situated adjacent to an exhaust system of the vehicle, e.g. adjacent to an exhaust pipe of the exhaust system.
• the container may be the vehicle's fuel tank or a separate container belonging to the DPF system.
• the dosing unit is arranged to inject a necessary amount of diesel fuel into an exhaust sysem upstream of the particle filter according to operating routines which are stored in a control unit of the vehicle.
• the system comprises also a return hose running back to the container from a pressure side of the system.
• This configuration makes it possible to cool the dosing unit by means of said diesel fuel which while cooling flows from the container via the pump and the dosing unit back to the container.
• US2011174264 describes a device for injecting fuel in an exhaust system in order to generate heat for regenerating a filter in the exhaust system.
• the pressure of the fuel in a first fuel injector (22) is controlled by means of a fuel pressure regulator (24).
• the specification does not indicate the basis on which the pressure is controlled. In particular it states nothing about controlling the dosing unit's dosage by the pressure on the basis of a prevailing temperature of a surface in an exhaust pipe of the vehicle. Nor does it mention that the pressure is controlled by control of a rotation speed of said feed device.
• EP1291498 describes a device for controlling emissions from an engine by injecting fuel in an exhaust system.
• the fuel is injected in the form of drops of a certain size. Their diameter is determined on the basis of the temperature of the exhaust gases or on the basis of the temperature in the middle of the catalyst.
• an electronic control unit controls the amount of fuel which is to be added.
• US2010319325 describes a device for injecting fuel in an exhaust system.
• the dosing valve (14) is opened and closed a number of times in quick succession.
• the control unit (26) determines the amount of fuel to be injected and controls a regulating valve (22, 42).
• a dosing valve (14) situated after the regulating valve (22).
• the dosing valve (14) opens at a certain pressure.
• the pressure of the fuel in the dosing unit is regulated by the regulating valve (22, 42).
• US2009050109 describes a device for injecting fuel in an exhaust system. It comprises an injection nozzle (36). A control valve (39) is connected to the injection nozzle (36) via a feed valve (40). The pressure of the fuel dosed in the exhaust system via the injection nozzle is mainly determined by the pressure of the fuel in a "low pressure circuit" in the engine. A regulating valve (41 ) adjusts the pressure to the dosing device (36). The fuel dosage is controlled on the basis of load upon the engine and the speed range in which the engine is at the time.
• US2008245058 describes a device for injecting fuel in an exhaust system. It comprises inter alia a nozzle (12) which injects fuel in the exhaust system when the pressure difference across the nozzle exceeds a certain level. The pressure of the fuel in the dosing unit (10) is determined by means of a regulating valve (11 ) connected to a "low pressure circuit" in the engine and is controlled by a control unit (14).
• US2010050612 describes a device for injecting fuel in an exhaust system. It comprises inter alia a valve (11 ) adapted to injecting fuel in an exhaust system. A pressure of the fuel in the device when the valve (11 ) opens is determined. When said pressure has been determined, it is used to calculate the amount of fuel which is injected in the system.
• One object of the present invention is to propose a novel and advantageous method for improving the performance of an HC dosing system.
• Another object of the invention is to propose a novel and advantageous HC dosing system and a novel and advantageous computer programme for improving the performance of an HC dosing system.
• One object of the present invention is to propose a novel and advantageous method for reducing the amount of undesirable emissions from a combustion engine.
• a further object of the invention is to propose an alternative method pertaining to an HC dosing system, and an alternative computer programme pertaining to an HC dosing system and an alternative HC dosing system.
• One aspect of the invention proposes a method pertaining to HC dosing systems for a motor vehicle, comprising a feed device to feed fuel from a container to a dosing unit for supply of said fuel to an exhaust duct of the vehicle.
• the method comprises the step of controlling the dosing unit's dosage by means of a pressure at which fuel is dosed.
• One aspect of the invention proposes a method pertaining to HC dosing systems for a motor vehicle, comprising a feed device to feed fuel from a container to a dosing unit for supply of said fuel to an exhaust duct of the vehicle.
• the method comprises the step of controlling the dosing unit's dosage by means of a pressure at which fuel is dosed, which pressure is controlled by control of a rotation speed of said feed device.
• a relatively high working pressure of said fuel generally results in a drop size distribution with more smaller drops which can more readily be captured in an exhaust flow from the vehicle's engine.
• a relatively low working pressure of said fuel may generally result in a drop size distribution with more larger drops with a higher kinetic energy which are not affected by the exhaust flow in the same way as smaller drops.
• Smaller drops are advantageous in certain operating situations, e.g. at lower exhaust temperatures a smaller drop may vaporise relatively quickly in the exhaust flow.
• larger drops are advantageous in that they can for example be directed towards a surface of the exhaust system. This results in improved performance of the HC dosing system.
• the dosing unit may be configured to comprise an aperture and a needle.
• the needle covers the aperture when the dosing unit is not dosing fuel in the exhaust duct. For fuel dosing, the needle moves away from the aperture, allowing the fuel to be dosed in the exhaust duct.
• the needle may be used to adjust the degree of opening of the dosing unit.
• the dosing unit may alternatively comprise an aperture of adjustable size to be further able to control the fuel dosage.
• the aperture may be directionable for further potential control of the dosing of the fuel into the exhaust duct.
• the method may comprise the step of controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a surface or component of said exhaust duct.
• Controlling the dosing unit's dosage by means of the pressure at which fuel is dosed thus makes it possible to influence an associated drop size
• the method may comprise the step of controlling the pressure at which fuel is dosed by controlling a rotation speed of said feed device.
• the pressure may be varied during an opening phase of the dosing unit. This may be advantageous in that the drop size distribution of the fuel at the beginning and end of an opening phase of the dosing unit, with a constant pressure of the fuel, may differ from the drop size distribution during the remainder of the opening phase.
• the drop size distribution throughout the opening phase may be controlled by varying the pressure during it. In certain operating situations it is desirable to have a uniform drop size distribution throughout the opening phase, which may be achieved by applying a certain pressure at the beginning and end of an opening phase and a different pressure during the remainder of the opening phase. In certain operating situations it may be desirable for more larger or smaller drops of fuel to be dosed at the beginning than at the end of the opening phase.
• the pressure during an opening phase may be kept constant but vary between opening phases.
• the method may comprise the step of controlling the pressure at which fuel is dosed by controlling a displacement of a piston pump incorporated in said dosing unit.
• the dosing unit may take the form of any desired pump, e.g. a diaphragm pump or a gearwheel pump.
• the method may comprise the step of controlling the pressure by altering a constriction in a fuel feedback line from the dosing unit to said container.
• a pressure of said fuel may be controlled by controlling not only a rotation speed of said dosing unit but also a constriction in a fuel feedback line from the dosing unit to said container.
• the method may comprise the step of controlling the pressure by altering the configuration of the dosing unit, resulting in an accurate method pertaining to an HC dosing system according to one aspect of the invention.
• Said configuration may be altered with very great accuracy, making it also possible for a working pressure of the HC dosing system to be controlled with great accuracy. A robust method may thus reliably be achieved.
• the method may comprise the step of controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a surface in the exhaust system. It may comprise the step of controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a surface in the exhaust system where fuel dosed vaporises. It may comprise the step of controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a suitable surface in the exhaust system. It may comprise the step of controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a suitable component of the exhaust system, e.g. a
• Said surface may comprise various parts of the exhaust system where the fuel vaporises. It may for example be a surface towards which the dosing unit's nozzle is directed in the exhaust system. It may also be a surface downstream of the dosing unit where fuel is carried by the exhaust flow. It may be a surface of a vaporisation unit situated downstream of the dosing unit in the exhaust system. It may be a surface which fuel dosed encounters.
• the temperature of said surface or component may be detected by means of a temperature sensor situated at or close to said surface where the fuel vaporises.
• the temperature of said surface or component may be detected by a temperature sensor situated on or in the immediate vicinity of said surface where the fuel vaporises.
• this temperature is that of an inside surface of the exhaust system.
• the temperature of said inside surface may be calculated on the basis of a measured temperature of the outside surface.
• a prevailing temperature of said inside surface may be calculated on the basis of other parameters, e.g. prevailing temperature of an exhaust flow from an engine, prevailing mass flow of exhaust gases from an engine, amount of fuel dosed and the characteristics and state of the fuel, e.g. its chemical composition and prevailing temperature at the time of dosing.
• the method may comprise the step of controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of an exhaust flow from an engine and/or a prevailing mass flow of exhaust gases from an engine. Improved performance of the HC dosing system may thus be achieved. A versatile method pertaining to an HC dosing system is thus also achieved, since alternative versions are possible.
• a prevailing mass flow of the exhaust gases may be calculated by a control unit of the vehicle, e.g. using the engine's air intake and fuel intake as parameters. Alternatively, the mass flow of the exhaust gases may be measured by means of a mass flow sensor. As temperature sensors are relatively inexpensive, a cost-effective method is also achieved according to one aspect of the invention.
• the method may comprise the step of controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of air surrounding the vehicle. This entails having to install temperature sensors on the vehicle in a suitable way if none has already been installed.
• the method may comprise the step of controlling the dosing unit's dosage by means of the pressure on the basis of previous operating situations of the vehicle. This entails a control unit of the vehicle using calculations according to a stored model as a basis for controlling the dosing unit's dosage in a suitable way by means of the pressure.
• the method may comprise the step of controlling the dosing unit's dosage by means of the pressure and a dosing cycle rate, resulting in a method pertaining to an HC dosing system with improved performance.
• Combined control of the dosing unit's dosage by means of the pressure of the fuel during dosing and making changes to a prevailing cycle rate of the HC dosing system makes it possible to achieve an optimised spray pattern of said fuel dosed.
• the cycle rate may for example be within a range of [1 , 10] Hz.
• the dosing unit's opening period may be determined to regulate the amount of fuel dosed during said cycle. The amount of undesirable emissions from the vehicle's engine may thus be advantageously reduced.
• the method may comprise the step of varying the pressure of the fuel within a range of [5, 15] bar. In one version the method may comprise the step of varying the pressure of the fuel within a range of [7, 13] bar. In one version the method may comprise the step of varying the pressure of the fuel within a range of [10, 50] bar. In one version the method may comprise the step of varying the pressure of the fuel within a range of [100, 300] bar. In one version the method may comprise the step of varying the pressure of the fuel within any suitable range. The result is a robust method whereby a working range is defined beforehand, eliminating risks of undesirable spray patterns caused by too low or too high working pressure.
• An operationally safe and reliable method pertaining to an HC dosing system is thus achieved according to one aspect of the present invention.
• the method may comprise the step of varying the pressure of the fuel steplessly during said control of the dosing unit's dosage, thus achieving a method whereby a desired spray pattern of said fuel may be set in a well- defined way.
• a method for an HC dosing system whereby a desired mixture of exhaust gases and fuel may be set with very great accuracy is thus advantageously achieved .
• the method may further comprise the step of varying the pressure of the fuel, in discrete steps during said control of the dosing unit's dosage, resulting in a method for an HC dosing system which involves relatively simple
• the method may comprise the step of altering a dosing cycle rate steplessly, resulting in a method whereby a desired spray pattern of said fuel may be set in a well-defined way.
• a method pertaining to an HC dosing system whereby a desired mixture of exhaust gases and fuel may be set with very great accuracy is thus advantageously achieved.
• the method may comprise the step of altering a dosing cycle rate in discrete steps during said control of the dosing unit's dosage. Providing control of the dosing unit's dosage on the basis of discrete settable steps of the cycle rate makes it possible for a rotation speed of the feed device to be directed towards predetermined set-point values, affording the advantage of data processing which involves fewer calculations.
• the method may comprise the step of controlling the dosing unit's dosage by means of the pressure and a dosing cycle rate on the basis of a prevailing exhaust temperature and/or a prevailing mass flow of exhaust gases from an engine of the vehicle. It should be noted that the method may incorporate one or more of the above features in suitable combinations.
• the method is easy to implement in existing motor vehicles.
• Software pertaining to an HC dosing system according to the invention may be installed in a control unit of the vehicle during the manufacture of the vehicle.
• a purchaser of the vehicle may thus have the possibility of selecting the function of the method as an option.
• Software which comprises programme code for an HC dosing system according to the invention will be easy to update or replace. Moreover, different parts of the software which contain the programme code may be replaced independently of one another. This modular configuration is advantageous from a maintenance perspective.
• One aspect of the invention proposes an HC dosing system for a motor vehicle, comprising a feed device to feed fuel from a container to a dosing unit for supply of said fuel to an exhaust duct of the vehicle, comprising means for controlling the dosing unit's dosage by means of a pressure at which fuel is dosed, and means for controlling the pressure by control of a rotation speed of said feed device.
• One aspect of the invention proposes an HC dosing system for a motor vehicle, comprising a feed device to feed fuel from a container to a dosing unit for supply of said fuel to an exhaust duct of the vehicle.
• the HC dosing system comprises means for controlling the dosing unit's dosage by means of a pressure at which fuel is dosed.
• the HC dosing system may further comprise means for controlling the pressure by control of a rotation speed of said feed device.
• the HC dosing system may comprise means for controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a surface or component of said exhaust duct.
• the HC dosing system may comprise means for determining a prevailing temperature of a surface or component of said exhaust duct.
• the HC dosing system may comprise means for controlling the pressure by altering a constriction in a fuel feedback line from the dosing unit to said container.
• the HC dosing system may comprise means for controlling the pressure by altering the configuration of the dosing unit.
• the HC dosing system may comprise means for controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a surface in the exhaust system.
• the HC dosing system may further comprise means for detecting a prevailing temperature of a surface in the exhaust system. It may comprise means for determining a prevailing temperature of a surface in the exhaust system. It may comprise means for determining a prevailing temperature of a surface in an exhaust duct which is provided to lead exhaust gases from an engine to the surroundings.
• the HC dosing system may comprise means for determining a prevailing temperature of a silencer of an exhaust system. It may comprise means for determining a prevailing temperature of a suitable component of a silencer of an exhaust system.
• the HC dosing system may comprise means for calculating a prevailing temperature of a suitable surface in the exhaust system. It may comprise means for calculating a prevailing temperature of a surface in the exhaust system where fuel dosed at least partly vaporises. Said calculation may be based on specified parameters, e.g. exhaust mass flow and exhaust temperature.
• the HC dosing system may comprise means for controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of an exhaust flow from an engine and/or a prevailing mass flow of exhaust gases from an engine.
• the HC dosing system may further comprise means for controlling the dosing unit's dosage by means of the pressure and a dosing cycle rate.
• the HC dosing system may further comprise means for varying the pressure of the fuel within a range of [5, 15] bar.
• the HC dosing system may comprise means for varying the pressure of the fuel steplessly during said control of the dosing unit's dosage.
• the HC dosing system may comprise means for varying the pressure of the fuel in discrete steps during said control of the dosing unit's dosage.
• the HC dosing system may comprise means for altering a dosing cycle rate steplessly or in discrete steps during said control of the dosing unit's dosage.
• the HC dosing system may comprise means for controlling the dosing unit's dosage by means of the pressure and a dosing cycle rate on the basis of a prevailing exhaust temperature and/or a prevailing mass flow of exhaust gases from an engine of the vehicle.
• the above objects are also achieved with a motor vehicle which is provided with the HC dosing system.
• the vehicle may be a truck, bus or car.
• One aspect of the invention is a proposed computer programme for an HC dosing system, which programme comprises programme code stored on a computer-readable medium for causing an electronic control unit or another computer connected to the electronic control unit to perform steps according to any one of claims 1-8.
• One aspect of the invention is a proposed computer programme for an HC dosing system, which programme comprises programme code for causing an electronic control unit or another computer connected to the electronic control unit to perform steps according to any one of claims 1-8.
• One aspect of the invention is a proposed computer programme product comprising a programme code stored on a computer-readable medium for performing method steps according to any one of claims 1-8 when said computer programme is run on an electronic control unit or another computer connected to the electronic control unit.
• FIG. 1 schematically illustrates a vehicle according to an embodiment of the invention
• Figure 2 schematically illustrates a subsystem for the vehicle depicted in Figure 1 , according to an embodiment of the invention
• Figure 3a is a schematic flowchart of a method according to an embodiment of the invention
• Figure 3b is a more detailed schematic flowchart of a method according to an embodiment of the invention.
• Figure 4 schematically illustrates a computer according to an embodiment of the invention.
• FIG. 1 depicts a side view of a vehicle 100.
• the vehicle here exemplified comprises a tractor unit 110 and a trailer 112.
• the vehicle may be a heavy vehicle, e.g. a truck or a bus. It may alternatively be a car.
• the invention is suitable for application in any suitable HC dosing system and is therefore not confined to DPF systems of motor vehicles.
• the innovative method and the innovative device according to one aspect of the invention are well suited to other platforms which comprise an HC dosing system than motor vehicles, e.g. watercraft.
• the watercraft may be of any kind, e.g. motorboats, steamers, ferries or ships.
• the innovative method and the innovative HC dosing system according to one aspect of the invention are for example also well suited to systems which comprise industrial engines and/or engine-powered industrial robots.
• the innovative method and the innovative HC dosing system according to one aspect of the invention are also well suited to various kinds of power plants, e.g. an electric power plant provided with a diesel generator.
• the innovative method and the innovative HC dosing system are well suited to any engine system which comprises an engine and an HC dosing system, e.g. on a locomotive or some other platform.
• the innovative method and the innovative device are well suited to any system which comprises a particle generator (e.g. a combustion engine) and an HC dosing system.
• the innovative method and the innovative device are well suited to any system comprising a device which generates exhaust gases with particles and a filter which can store particles, which particles are burnt during regeneration of said filter, particularly during its active regeneration.
• the HC dosing system may be any HC dosing system, although it is here exemplified as an HC dosing system pertaining to a DPF system for a vehicle.
• the feed device may be any feed device and need not be a diaphragm pump such as herein described.
• the fuel of the HC dosing system may be any suitable fuel, such as oil, e.g. lubricating oil, diesel fuel or some other hydrocarbon-based fuel, e.g. petrol, ethanol or methane, etc.
• link refers herein to a communication link which may be a physical connection such as an opto-electronic communication line, or a non-physical connection such as a wireless connection, e.g. a radio link or microwave link.
• the term "line” refers herein to a passage for holding and conveying a fluid, e.g. fuel in liquid form.
• the line may be a pipe of any size and be made of any suitable material, e.g. plastic, rubber or metal.
• fuel refers herein to an agent used for active regeneration of a particle filter of an HC dosing system.
• said fuel is diesel fuel.
• Other kinds of hydrocarbon-based fuels may of course be used.
• Diesel fuel is herein indicated as an example of a fuel but one skilled in the art will appreciate that the innovative method and the innovative device are feasible with other types of fuels, subject to necessary adjustments, e.g. adjustments to appropriate boiling points for fuels chosen, in control algorithms for executing software code in accordance with the innovative method.
• cycle rate refers herein to a rate defined by the number of dosing periods, also called dosing cycles, per second. It should however be noted that at least one active dose of fuel from the dosing unit may take place during a dosing cycle.
• pressure of the fuel refers herein to a pressure at which said fuel is dosed from a dosing unit of the innovative HC dosing system.
• the pressure at which said fuel is dosed, and the working pressure Pr, are herein used synonymously.
• FIG. 2 depicts a subsystem 299 of the vehicle 100.
• the subsystem 299 is situated in the tractor unit 110 and may be part of an HC dosing system. It comprises in this example a container 205 arranged to hold a fuel.
• the container is adapted to holding a suitable amount of fuel and also to being replenishable as necessary.
• the container may be a fuel tank with which the vehicle is already provided.
• a first line 271 is provided to lead the fuel to a pump 230 from the container 205.
• the pump 230 may be any suitable pump. It may be a diaphragm pump with at least one filter. It may be arranged to be driven by an electric motor (not depicted).
• the pump is adapted to drawing the fuel from the container 205 via the first line 271 and supplying it via a second line 272 to a dosing unit 250.
• the dosing unit comprises an electrically controlled dosing device by means of which a flow of fuel added to the exhaust system can be controlled.
• the dosing unit comprises an electrically controlled dosing valve by means of which a flow of fuel added to the exhaust system can be controlled.
• the pump is adapted to pressurising the fuel in the second line 272.
• the dosing unit is provided with a throttle unit, which may also be called throttle valve, against which said pressure of the fuel may build up in the subsystem 299.
• This pressure is herein referred to as the working pressure Pr of the HC dosing system.
• Said throttle unit may be of a fixed or adjustable type.
• the dosing unit 250 is adapted to supplying said fuel to an exhaust system of the vehicle 100. More specifically, it is adapted to supplying a suitable amount of fuel in a controlled way to an exhaust duct 290 of the vehicle 00.
• an oxidation catalyst (not depicted) is situated downstream of a location in the exhaust system where the supply of fuel takes place. The amount of fuel supplied in the exhaust system is intended to be used in the oxidation catalyst to achieve active regeneration.
• the dosing unit 250 may be situated adjacent to said exhaust duct 290 which is provided to lead exhaust gases from a combustion engine (not depicted) of the vehicle to the oxidation catalyst and thence to the vehicle's surroundings.
• a third line 273 running between the dosing unit 250 and the container 205 is adapted to leading back to the container a certain amount of the fuel fed to the dosing valve 250. This configuration results in advantageous cooling of the dosing unit 250.
• the dosing unit is thus cooled by a flow of the fuel when it is pumped through it from the pump 230 to the container 205.
• a first control unit 200 is arranged for communication with a pressure sensor 220 via a link 221.
• This pressure sensor is adapted to detecting a prevailing pressure Pr of the fuel at the location where the sensor is fitted.
• the sensor is situated adjacent to the second line 272 to measure the working pressure Pr of the fuel downstream of the pump 230.
• it is situated in the dosing unit 250 to measure the working pressure Pr of the fuel downstream of the pump. It is adapted to continuously sending signals via the link 221 to the first control unit 200 which contain information about a prevailing pressure Pr of the fuel.
• the first control unit 200 is arranged for communication with the pump 230 via a link 231 and is adapted to controlling the operation of the pump.
• the first control unit is adapted to controlling the pump by means of an electric motor.
• the first control unit is adapted to influencing the working pressure Pr in the second line 272, which may be achieved in various suitable ways.
• the first control unit 200 may be adapted to influencing the pressure Pr by controlling a change in the stroke length of a piston or a diaphragm of the pump 230.
• the pressure Pr may be varied while maintaining a substantially constant speed RPM of the pump.
• the pressure may thus for example be influenced by altering a stroke length of pistons or diaphragms of the pump.
• the first control unit 200 is arranged for communication with a first temperature sensor 240 via a link 241.
• This sensor is adapted to detecting a prevailing temperature T1 of an exhaust flow from the vehicle's engine.
• this first sensor is situated immediately downstream of the vehicle's engine and upstream of a dosing unit 250. It is adapted to continuously detecting a prevailing temperature T1 of the exhaust flow and sending signals which contain information about said prevailing temperature to the first control unit via the link 241.
• the first control unit 200 is arranged for communication with a second temperature sensor 260 via a link 261.
• This sensor is adapted to detecting a prevailing temperature T2 of a surface in the exhaust system where the fuel vaporises.
• this second sensor is situated directly downstream of a dosing unit 250.
• it is situated in a vaporisation unit 270 downstream of the dosing unit.
• the second sensor is associated with an oxidation catalyst downstream of the dosing unit 250.
• This second temperature sensor is adapted to continuously detecting a prevailing temperature T2 of a surface and sending signals which contain information about said temperature to the first control unit via the link 261.
• the first control unit 200 is arranged for communication with the dosing unit 250 via a link 251 and is adapted to controlling the operation of the dosing unit, e.g. in order to regulate the supply of fuel to the vehicle's exhaust system.
• the dosing unit 250 may be provided with a nozzle to dose the fuel for mixing with exhaust gases in an exhaust system of the vehicle.
• a geometry of said nozzle may be variable, making it possible to control the pressure Pr of the fuel.
• the first control unit 200 is adapted to altering said variable configuration of the dosing unit in order to control the pressure Pr of the fuel.
• the first control unit 200 is adapted in one version to using the signals received from the pressure sensor 220 which contain information about a prevailing pressure of the fuel as a basis for running said pump 230 in a manner in accordance of one aspect of the innovative method. Feedback control of the working pressure Pr is thus achieved.
• the first control unit 200 is adapted to calculating an exhaust mass flow MF of the exhaust gases from the vehicle's engine. It is adapted to continuously determining an exhaust mass flow MF of the exhaust gases from the vehicle's engine. This may be achieved in any suitable way.
• the subsystem comprises a mass flow sensor (not depicted) adapted to continuously measuring a prevailing exhaust mass flow from the vehicle's engine. Said sensor is adapted to continuously sending signals which contain information about a prevailing exhaust mass flow to the first control unit via a link.
• the first control unit 200 is adapted to controlling the dosage of the dosing unit 250 by means of a pressure Pr at which fuel is dosed. It may be adapted to controlling the pressure Pr by control of the speed RPM of the pump 230. It may be adapted to controlling the pressure Pr by altering a constriction in the line 273 for fuel from the dosing unit 250 to the container 205. In one alternative, the first control unit is adapted to controlling the pressure Pr by altering a constriction of fuel flow in the dosing unit 250, which flow is intended to lead to the container 205. It may be adapted to controlling the pressure Pr by altering the configuration of the dosing device of the dosing unit.
• It may adapted to controlling the dosing unit's dosage by means of the pressure Pr on the basis of a prevailing temperature T of an exhaust flow from an engine and/or a prevailing mass flow MF of exhaust gases from an engine. It may be adapted to controlling the dosing unit's dosage by means of the pressure Pr of the fuel and a dosing cycle rate CF. It may be adapted to varying the pressure Pr of the fuel within a range of [5, 15] bar. It may be adapted to varying the pressure Pr of the fuel steplessly during said control of the dosing unit's dosage. It may be adapted to varying the pressure Pr of the fuel in discrete steps during said control of the dosing unit's dosage.
• It may be adapted to altering a dosing cycle rate CF steplessly or in discrete steps during said control of the dosing unit's dosage. It may adapted to controlling the dosing unit's dosage by means of the pressure Pr of the fuel and a dosing cycle rate CF on the basis of a prevailing exhaust temperature T and/or a prevailing exhaust mass flow MF of exhaust gases from an engine of the vehicle.
• the first control unit 200 may be adapted to controlling the dosing unit's dosage by means of a pressure at which fuel is dosed, which pressure is controlled by control of a speed of said feed device.
• the first control unit 200 may be adapted to controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a surface or component of said exhaust duct.
• a second control unit 210 is arranged for communication with the first control unit 200 via a link 201.
• This second control unit may be detachably connected to the first control unit. It may be a control unit external to the vehicle. It may be adapted to conducting the innovative method steps according to the invention. It may be used to cross-load software to the first control unit, particularly software for applying the innovative method. It may alternatively be arranged for communication with the first control unit via an internal network of the vehicle. It may be adapted to performing functions substantially similar to the first control unit, e.g. controlling the dosing unit's dosage by means of a pressure Pr at which fuel is dosed.
• the innovative method may be conducted by the first control unit 200 or the second control unit 210 or by both of them.
• the working pressure Pr may be controlled by the first control unit 200 in various different operating situations of the vehicle 100.
• Example 1 A change from a reference state to a state with higher exhaust temperature and greater exhaust mass flow MF (e.g. T>400 degrees C and MF>1000 kg/h) is here determined.
• the working pressure Pr is thus lowered (e.g. from 9 to 5 bar) to achieve dosage in larger drops of fuel which may be directed better in the large exhaust flow and encounter desired warm surface in the vehicle's exhaust system. Controlled wall encounter is thus advantageously achieved.
• Example 2 A change from a reference state to a state with higher exhaust temperature T and smaller mass flow (e.g. T>400 degrees C and MF ⁇ 1000 kg/h) is here determined.
• the working pressure Pr is thus raised (e.g. from 9 to 15 bar) to achieve dosage in smaller drops of fuel which may vaporise immediately in the exhaust flow before they encounter a surface in the vehicle's exhaust system. Improved vaporisation of fuel before wall encounter is thus advantageously achieved.
• Example 3 A change from a reference state to a state with lower exhaust temperature T and greater exhaust mass flow MF (e.g. T ⁇ 250 degrees C and MF>1000 kg/h) is here determined.
• the working pressure Pr may here be kept at a reference level (e.g.
• Example 4 A change from a reference state to a state with lower exhaust temperature T and smaller exhaust mass flow MF (e.g. T ⁇ 250 degrees C and MF ⁇ 1000 kg/h) is here determined.
• the working pressure Pr may here be raised to achieve small drops which may vaporise more quickly on the surfaces encountered in the exhaust system or may actually vaporise in the exhaust flow.
• the method may be supplemented so that control is based on a preceding operating situation.
• the vehicle's exhaust system may still be warm despite a prevailing exhaust mass flow and a prevailing exhaust temperature both being low at the time.
• a corresponding earlier prevailing working pressure may thus with advantage continue to be utilised for an appropriate period of time.
• the working pressure Pr may be controlled on the basis of a change in a detected exhaust backpressure of the vehicle.
• the working pressure may with advantage be raised in a suitable way to maintain a desired spray pattern of fuel dosed.
• the working pressure Pr may be controlled on the basis of a prevailing temperature of air surrounding the vehicle. In a situation where the temperature of the surrounding air is below 0 degrees C the working pressure may be raised as appropriate, e.g. by 2 bar, to alter the drop size distribution towards smaller drops and thus potentially facilitate vaporisation of fuel dosed. In one aspect of the invention the working pressure Pr may be controlled on the basis of a prevailing temperature of the fuel in the vehicle's HC dosing system.
• FIG. 3a is a schematic flowchart of a method pertaining to HC dosing systems for a motor vehicle, comprising a feed device to feed fuel from a container to a dosing unit for supply of said fuel to an exhaust duct of the vehicle, according to an embodiment of the invention.
• the method comprises a first step s301 comprising the step of controlling the dosing unit's dosage by means of a pressure at which fuel is dosed.
• the method ends after step s301.
• Figure 3b is a schematic flowchart of a method pertaining to HC dosing systems for a motor vehicle, comprising a feed device to feed fuel from a container to a dosing unit for supply of said fuel to an exhaust duct of the vehicle, according to an embodiment of the invention.
• the method comprises a first step s310 comprising the step of determining a prevailing temperature T of exhaust gases from the engine of the vehicle 100. This may be effected by means of the temperature sensor 240.
• Step s310 is followed by a step s320.
• Method step s320 comprises the step of determining a prevailing mass flow MF of said exhaust gases. This exhaust mass flow may in one example be calculated by the first control unit 200. Alternatively it may be detected by means of suitable sensors or equipment.
• Step s320 is followed by a step s330.
• Method step s330 comprises the step of controlling the dosage of the dosing unit 250 by means of a pressure Pr at which fuel is dosed.
• This pressure may be altered by influencing a speed of the pump 230. It may alternatively or in combination be altered by acting upon a constriction in the line 273. It may alternatively or in combination be altered by altering the configuration of the dosing unit's dosing device.
• the dosage of the dosing unit 250 is controlled by means of the pressure Pr on the basis of said prevailing temperature T determined of the exhaust flow and/or on the basis of said prevailing exhaust mass flow MF determined.
• Step s330 is followed by a step s340.
• Method step s340 comprises the step of controlling the dosage of the dosing unit 250 by means of a cycle rate of the HC dosing system.
• said control of the dosing unit's dosage is by means of the pressure Pr at which fuel is dosed, at the same time as said control of the dosing unit's dosage by means of a cycle rate of the HC dosing system.
• the dosage of the dosing unit 250 is controlled by means of the pressure Pr of the fuel and by means of a dosing cycle rate CF at the same time on the basis of a said prevailing exhaust temperature T determined and/or said prevailing exhaust mass flow MF determined.
• step s340 ends after step s340.
• FIG 4 is a diagram of one version of a device 400.
• the control units 200 and 210 described with reference to Figure 2 may in one version comprise the device 400.
• the device 400 comprises a non-volatile memory 420, a data processing unit 410 and a read/write memory 450.
• the non-volatile memory has a first memory element 430 in which a computer programme, e.g. an operating system, is stored for controlling the function of the device 400.
• the device 400 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 controller (not depicted).
• the non-volatile memory has also a second memory element 440.
• a proposed computer programme P comprises routines for controlling the dosage of the dosing unit 250 by means of a pressure Pr at which fuel is dosed.
• the programme comprises routines for controlling the pressure Pr by control of the speed RPM of the pump 230.
• the programme comprises routines for controlling the pressure Pr by altering a constriction in the line 273 for fuel from the dosing unit 250 to the container 205.
• the programme comprises routines for controlling the pressure Pr by altering a constriction of fuel flow in the dosing unit, which flow is intended to lead to the container.
• the programme comprises routines for controlling the pressure Pr by altering the configuration of the dosing device of the dosing unit.
• the programme comprises routines for controlling the dosing unit's dosage by means of the pressure Pr on the basis of a prevailing temperature T of an exhaust flow from an engine and/or a prevailing mass flow MF of exhaust gases from an engine.
• the programme comprises routines for controlling the dosing unit's dosage by means of the pressure Pr of the fuel and a dosing cycle rate CF.
• the programme comprises routines for varying the pressure Pr of the fuel within a range of [5, 15] bar.
• the programme comprises routines for varying the pressure Pr of the fuel steplessly during said control of the dosing unit's dosage.
• the programme comprises routines for varying the pressure Pr of the fuel in discrete steps during said control of the dosing unit's dosage.
• the programme comprises routines for altering a dosing cycle rate CF steplessly or in discrete steps during said control of the dosing unit's dosage.
• the programme comprises routines for controlling the dosing unit's dosage by means of the pressure Pr of the fuel and a dosing cycle rate CF on the basis of a prevailing exhaust temperature T and/or a prevailing exhaust mass flow MF of exhaust gases from an engine of the vehicle.
• the programme P may comprise routines for controlling the dosing unit's dosage by means of a pressure at which fuel is dosed, which pressure is controlled by control of a rotation speed of said feed device 230.
• the programme P may comprise routines for controlling the dosing unit's dosage by means of the pressure on the basis of a prevailing temperature of a surface or component of said exhaust duct.
• the programme P may be stored in an executable form or in compressed form in a memory 460 and/or in a read/write memory 450.
• the data processing unit 410 is described as performing a certain function, it means that the data processing unit conducts a certain part of the programme stored in the memory 460, or a certain part of the programme stored in the read/write memory 450.
• the data processing device 410 can communicate with a data port 499 via a data bus 415.
• the non-volatile memory 420 is intended for communication with the data processing unit 410 via a data bus 412.
• the separate memory 460 is intended to communicate with the data processing unit 410 via a data bus 411.
• the read/write memory 450 is adapted to communicating with the data processing unit via a data bus 414.
• the data port 499 may for example have the links 201 , 221 , 231 , 241 and 251 connected to it (see Figure 2).
• signals received on the data port 499 contain information about a prevailing working pressure Pr of the fuel in the HC dosing system.
• signals received on the data port contain information about a prevailing temperature T of the exhaust gases in an exhaust system of the vehicle.
• signals received on the data port contain information about a prevailing mass flow MF of the exhaust gases in an exhaust system of the vehicle.
• the signals received on the data port 499 may be used by the device 400 to apply the herein innovative method.
• Parts of the methods herein described may be conducted by the device 400 by means of the data processing unit 410 which runs the programme stored in the memory 460 or the read/write memory 450. When the device 400 runs the programme, methods herein described are executed.

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• 2012
  • 2012-12-12 SE SE1251410A patent/SE1251410A1/sv not_active Application Discontinuation
  • 2012-12-12 WO PCT/SE2012/051379 patent/WO2013089626A1/en active Application Filing

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