Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
  • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
  • F02D41/1448—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an exhaust gas 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
  • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
• • 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
  • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
  • F01N11/002—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
  • F01N11/005—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus the temperature or pressure being estimated, e.g. by means of a theoretical model
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/12—Control of the pumps
  • F02B37/18—Control of the pumps by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B39/00—Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B39/00—Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00
  • F02B39/16—Other safety measures for, or other control of, pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D23/00—Controlling engines characterised by their being supercharged
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/0002—Controlling intake air
  • F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
• • 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
  • F01N2550/00—Monitoring or diagnosing the deterioration of exhaust systems
  • F01N2550/02—Catalytic activity of 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 for determining the temperature before entering a catalytic converter of a turbocharged engine.
• a catalyzed engine it is important to know the temperature at the level of the catalytic converter so as not to destroy it. This temperature is important for various functions: protection of the catalyst and its upstream oxygen sensor, detection of ready upstream oxygen sensor, heating of upstream oxygen sensor as well as heating of the catalyst. On some engines these four functions, or at least part of them, do not exist. On other motors, these functions are regulated in open loop. It is also known for the management of these functions to take into account less precise parameters than the temperature at the inlet of the catalytic converter.
• the object of the present invention is therefore to provide a method making it possible to reliably determine in a catalyzed turbocharged engine the inlet temperature of the exhaust gases into the catalytic converter, that is to say downstream of the turbocharger.
• a method for determining the temperature of the exhaust gases downstream of the turbine of the turbocharger in a turbocharged engine which comprises the following steps: - determination of the temperature upstream of the turbocharger turbine, - calculation of a corrective term from engine operating parameters, and - determination of the temperature downstream of the turbocharger turbine by subtracting the corrective term of the temperature upstream of the turbocharger turbine.
• This determination is very simple to perform, but as it has been shown, the determination of the temperature obtained by this process allows obtain temperatures substantially in line with those recorded using a temperature probe to confirm this process.
• the temperature upstream of the turbocharger turbine can be determined using a temperature sensor, but to minimize the cost of the corresponding engine it is preferably obtained by modeling.
• the corrective term is obtained first of all by a predetermined curve giving a temperature variation as a function of the engine speed and the air flow rate passing through the engine, then by the multiplication of this temperature variation by a adiabatic compression factor.
• the adiabatic compression factor is advantageously dependent on at least one physical quantity chosen from the assembly comprising the pressure at the engine exhaust, the difference between this pressure and the external pressure and the opening of a pressure relief valve of the turbocharger.
• FIG. 1 schematically represents the architecture of a turbocharged engine
• FIG. 2 is a diagram to explain the operation of a method according to the invention.
• Figure 1 very schematically shows an air supply and exhaust system of a turbocharged engine. This system makes it possible to supply fresh air to an engine in which at least one piston 2 moves in a cylinder 4.
• a valve 8 is in turn provided for the exhaust of the burnt gases out of the cylinder 4.
• the air supply system shown comprises, from upstream to downstream, an air inlet 10, a mass air flow meter 12 , a turbocharger 14, a chamber called an intercooler 16, a butterfly valve 18 disposed in a duct through which the air supplying the cylinders passes and making it possible to act on the air flow section of this duct, as well as a manifold d intake generally called manifold 20.
• the intake valves 6 are in direct connection with the intake manifold 20.
• the exhaust valves 8 are in turn in direct connection with an exhaust duct 22.
• this exhaust duct 22 is only shown at the cylinder outlet and at the level of the turbocharger 14.
• the latter comprises two turbines connected together by a shaft.
• a first turbine is disposed in the exhaust duct and is rotated by the burnt gases leaving the cylinders 4 by the exhaust valves 8.
• the second turbine is disposed, as indicated above, in the supply system for engine air and pressurizes the air in the intercooler 16.
• a turbocharger discharge valve 24 makes it possible to short-circuit the turbine placed in the exhaust duct 22.
• the exhaust gases pass through a catalytic converter 26 before being discharged into the open air. The method described below makes it possible to determine the temperature of the exhaust gases as they enter the catalytic converter 26.
• This catalytic converter 26 contains an upstream oxygen sensor (not shown) which gives indications to the engine management device to act on the richness of the fuel / oxidant mixture sent by the air supply system in the cylinders 4.
• Knowledge of the temperature upstream of the catalytic converter 26, and downstream of the turbocharger 14, makes it possible to protect the catalyst and the upstream oxygen sensor from excessively high temperatures. When an excessively high temperature is detected, it is possible to act on the engine supply in order to reduce the temperature of the exhaust gases leaving the cylinders 4. Conversely, the catalyst and the probe must also be corresponding upstream oxygen are at a relatively high temperature to be able to function perfectly.
• Knowing the temperature at the inlet of the catalytic converter 26 therefore makes it possible to know whether the upstream oxygen sensor is ready and therefore whether the information which it provides must be taken into consideration. It is also possible to provide for heating of the upstream oxygen sensor and of the catalyst when the temperature thereof is not sufficient.
• an atmospheric or turbocharged engine it is known to a person skilled in the art to model the temperature in the exhaust duct at the outlet of the cylinders 4. Many parameters are used to determine this temperature, for example, and not exclusively, the engine speed, the air flow, the richness of the fuel / oxidizer mixture sent into the cylinders, the ignition advance, etc.
• the present invention proposes to calculate the temperature at the inlet of the catalytic converter 26, that is to say at the outlet of the turbocharger, from the temperature (modeled) upstream of the turbocharger. To do this, it proposes to subtract from the basic mapping determining the temperature before the turbocharger 14 a mapping dependent on the engine speed and the air flow rate passing through the engine multiplied by an adiabatic compression factor depending on a parameter such as the pressure at the exhaust and / or the opening of the discharge valve of the turbocharger 24.
• FIG. 2 illustrates a diagram explaining how the temperature downstream of the turbocharger 14, at the inlet of the catalytic converter 26, is determined according to l 'invention. In this FIG. 2, there is a three-dimensional curve shown diagrammatically in a first window 28.
• An orthogonal coordinate system is also shown diagrammatically in this window 28.
• the curve represented diagrammatically gives a variation in temperature TC determined from the engine speed N and of the MAF air flow measured by the flow meter 12.
• one axis of the reference corresponds to the engine speed N
• the third axis indicates the value of the temperature variation TC.
• Under window 28 is a second window 30 inside which are represented a curve and a two-axis orthogonal coordinate system.
• the abscissa axis corresponds to a parameter while the ordinate axis corresponds to a multiplicative factor ⁇ .
• the parameter on the abscissa can be the pressure at the PE exhaust measured in the exhaust duct 22 at the outlet of the cylinders 4. It can also be the pressure difference between this PE exhaust pressure and the atmospheric pressure prevailing outside the engine. Finally, it may be the opening (in degree or in percentage) of the discharge valve of the turbocharger 24. This opening is called WG in FIG. 2. It is considered that the temperature in the exhaust duct 22 upstream of the catalytic converter 26 takes the value T am have- Similarly, downstream of the turbocharger 14, the temperature takes a value T ava ⁇ . So then
• the values TCo and TCi found correspond to an opening of the discharge valve of the turbocharger 24 corresponding to a value WG 0 .
• the curve of window 30 is produced.
• the value of the parameter WG is then varied.
• FIG. 2 the obtaining of two points of the curve of window 30 with the values of the parameter WG being equal to WGi and WG 2 .
• the temperature upstream of the turbocharger 14 is first of all determined in a known manner. This function is already known and performed on certain engines.
• the same means can determine the temperature downstream of this turbocharger using a method according to the invention.
• the additional cost linked to the determination of this temperature at the inlet of the catalytic converter 26 is therefore very low while bringing great advantages with regard to the lifetime of the catalyst and of the upstream oxygen sensor which equips it.
• a numerical example is indicated below. It is generally considered that the inlet temperature of the exhaust gases into the turbocharger should not exceed approximately 1000 ° C. With regard to the upstream oxygen sensor, it is preferable not to exceed temperatures of the order of 750 ° C.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Supercharger (AREA)
• Exhaust Gas After Treatment (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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• 2003
  • 2003-09-05 FR FR0310516A patent/FR2859501B1/fr not_active Expired - Fee Related
• 2004
  • 2004-08-18 JP JP2006525060A patent/JP4575379B2/ja not_active Expired - Fee Related
  • 2004-08-18 WO PCT/EP2004/009235 patent/WO2005024198A1/fr active Search and Examination
  • 2004-08-18 KR KR1020067004569A patent/KR20060090663A/ko not_active Application Discontinuation
  • 2004-08-18 EP EP04764223A patent/EP1664500A1/fr not_active Withdrawn
  • 2004-08-18 MX MXPA06002538A patent/MXPA06002538A/es active IP Right Grant
  • 2004-08-18 US US10/570,504 patent/US7261095B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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