US20060150628A1 - Method for controlling engine air/fuel ratio - Google Patents
Method for controlling engine air/fuel ratio Download PDFInfo
- Publication number
- US20060150628A1 US20060150628A1 US11/033,770 US3377005A US2006150628A1 US 20060150628 A1 US20060150628 A1 US 20060150628A1 US 3377005 A US3377005 A US 3377005A US 2006150628 A1 US2006150628 A1 US 2006150628A1
- Authority
- US
- United States
- Prior art keywords
- air
- engine
- compressor
- fuel ratio
- controlling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- 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
- F02B37/16—Control of the pumps by bypassing charging air
-
- 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
- F02D23/02—Controlling engines characterised by their being supercharged the engines being of fuel-injection type
-
- 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
- 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
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/024—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus
- F02D41/0245—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus by increasing temperature of the exhaust gas leaving the engine
-
- 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
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
- F02D41/0275—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a NOx trap or adsorbent
-
- 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
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/02—EGR systems specially adapted for supercharged engines
- F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
- F02M26/05—High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
-
- 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
- F01N2430/00—Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
- F01N2430/06—Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics by varying fuel-air ratio, e.g. by enriching fuel-air mixture
-
- 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
-
- 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
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B29/00—Engines characterised by provision for charging or scavenging not provided for in groups F02B25/00, F02B27/00 or F02B33/00 - F02B39/00; Details thereof
- F02B29/04—Cooling of air intake supply
- F02B29/0406—Layout of the intake air cooling or coolant circuit
-
- 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
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0047—Controlling exhaust gas recirculation [EGR]
- F02D41/0065—Specific aspects of external EGR control
-
- 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
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
-
- 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
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
- F02D41/029—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a particulate filter
-
- 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
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
- F02M26/22—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage
- F02M26/23—Layout, e.g. schematics
-
- 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 a method for controlling engine air/fuel ratio.
- LNT Lean NOx Traps
- After-treatment devices such as Lean NOx Traps (LNT) are being devised to adsorb NOx emissions from diesel engines in an effort to meet future emission standards.
- LNTs can be very effective in trapping NOx but need to be periodically cleaned through a regeneration process.
- a rich environment close to an air/fuel ratio of 14
- fuel injection in the combustion chamber and/or fuel injection in the exhaust stream can effectively reduce the exhaust air/fuel ratio, they both present some limitations in terms of how much fuel can be injected. Too much fuel injected in the combustion chamber after the main combustion event (late post injection) can result in wall wetting and engine damage or affect the engine torque curve when injected too early. Injecting large quantities of fuel in the exhaust stream could require large and bulky injectors.
- the invention comprehends bringing the air/fuel ratio down to an intermediate level through engine air flow management during the LNT regeneration process. More specifically, in a supercharged or turbocharged engine including a compressor at the intake, recirculating some air from the compressor discharge back to the compressor inlet reduces the engine air/fuel ratio. This approach alleviates much of the requirements on the fuel injection side that are typically associated with LNT regeneration. Further reduction of the air/fuel ratio can be achieved via fuel injection into the combustion chamber and/or fuel injection in the exhaust stream.
- this same method of recirculating some air from the compressor discharge back to the compressor inlet to reduce the engine air/fuel ratio can be used to increase the engine's exhaust temperature to promote regeneration of a diesel particulate filter (DPF).
- DPF diesel particulate filter
- this compressor recirculation can be used to increase the exhaust temperature.
- the amount of air being recirculated is selected as a function of the required exhaust temperature increase.
- this approach can be used to increase exhaust temperature for more rapid catalyst light off or move the exhaust temperature to a range where catalyst efficiency is higher.
- this approach can be used for optimization of turbocharger operation, by either moving the compressor operation away from the surge line (safety feature), or bringing it to a higher efficiency line (performance feature).
- FIG. 1 illustrates modulated compressor recirculation to control engine air/fuel ratio in accordance with a preferred embodiment of the invention
- FIG. 2 illustrates a method of the invention in the preferred embodiment.
- an engine 10 includes a plurality of cylinders fed by fuel injectors.
- the engine intake is indicated at 14 while the engine exhaust is indicated at 16 .
- the engine is equipped with an exhaust gas recirculation (EGR) system.
- EGR exhaust gas recirculation
- the EGR system recirculates a portion of the exhaust gases back to the engine intake 14 , as needed, to avoid excessively high combustion temperatures which cause NOx creation.
- EGR cooler 18 cools the recirculated exhaust gas prior to introduction at engine intake 14 .
- the engine is equipped with a turbocharger system 20 .
- System 20 includes turbine 22 driven by exhaust gases.
- Turbine 22 drives compressor 24 .
- Charge air cooler (CAC) 26 cools the charge air from compressor 24 prior to introduction at engine intake 14 .
- engine air flow management is utilized to reduce the engine air/fuel ratio. More specifically, a recirculation path 30 from the compressor discharge to the compressor inlet is provided, and a controllable valve 32 is located along this recirculation path 30 . A controller 33 is programmed to modulate controllable valve 32 to vary the airflow to the engine intake 14 , thereby varying the air/fuel ratio.
- a modulated compressor recirculation flow can, for instance, bring the engine air/fuel ratio from 25 down to 17 (arbitrary numbers selected as an example), and then fuel injection strategies may be employed to further lower the exhaust air/fuel ratio from 17 down to 14 where regeneration becomes effective.
- the Lean NOx Trap LNT
- the innovative approach of the invention involves recirculating some air flow (charge air) from the compressor outlet back into the compressor inlet. The amount of air available in each cylinder of engine 10 is reduced, resulting in richer fuel combustion in the engine. Exhaust gases reaching LNT 36 are fuel rich and promote the regeneration process. At the end of LNT regeneration, compressor recirculation is disabled, bringing the engine back to lean operating conditions where it runs most effectively.
- recirculation path 30 is composed of an external tube introduced between the compressor outlet and the compressor inlet of the turbocharger system 20 .
- the purpose of the tube is to recirculate compressed air from the compressor outlet back into the compressor inlet.
- the tube (recirculation passage) can also be directly incorporated into the compressor housing. Air will naturally flow from the compressor outlet (high pressure side) into the compressor inlet (low pressure side).
- Modulator valve 32 is capable of modulating the air flow, and is installed in the tube, creating a compressor bleed line.
- the amount of air going through the bypass tube is defined by the size of the tube and the valve position (full open, or modulated).
- the valve is electronically modulated by controller 33 to provide variable and controllable air/fuel ratio.
- controller 33 may be any suitable controller as understood by those of ordinary skill in the art of engine control systems. That is, controller 33 may be the engine controller or a different controller that controls one or more subsystems of the engine.
- bypass valve 32 When regeneration is required at LNT 36 (possibly defined by the NOx conversion rate of the LNT), bypass valve 32 is opened and high pressure air (charge air) circulates through the bypass tube and is fed back to the compressor inlet, thereby lowering the amount of air going into the engine intake 14 and the engine cylinders, thus creating rich combustion in the cylinders.
- the exhaust gases that are fed to the after-treatment devices that is, LNT 36 in FIG. 1 ) are fuel rich and contain high thermal mass. Such conditions promote LNT regeneration.
- the amount of air flow bled around compressor 24 can be modulated based on a targeted air/fuel ratio.
- bypass valve 32 is closed and the engine returns to normal lean operating conditions.
- Engine fueling and timing adjustments may be made during the regeneration phase to maintain the torque at the same level as under normal lean operating conditions, resulting in a minimum fuel economy penalty.
- the compressor pressure ratio and speed drop and the air mass flow rate displaced by the compressor increases. Those characteristics result in safe compressor operating conditions, as the operating point is moving away from the compressor surge line.
- fuel injection strategies will also be employed.
- the operation and strategy of these fuel injection strategies may vary depending on the implementation as understood by those of ordinary skill in the art of engine control systems.
- valve 32 can be electronically controlled by controller 33 based on LNT regeneration needs and engine operating conditions at that time. Bleed modulation, engine fueling and timing strategies can all be optimized to provide the required air/fuel ratio and exhaust temperature for LNT regeneration, while maintaining engine torque for good drivability and minimizing fuel economy impact.
- FIG. 1 illustrates a diesel particulate filter at 34 .
- FIG. 1 illustrates a diesel oxidation catalyst at 38 .
- Yet another application of the invention is the optimization of turbocharger operation, by either moving the compressor operation away from the surge line (safety feature), or bringing it to a higher efficiency line (performance feature).
- FIG. 2 illustrates a method of the invention in the preferred embodiment.
- a recirculation path extending from the compressor discharge to the compressor inlet is provided (block 50 ).
- a controllable valve is provided at a location along the recirculation path (block 52 ).
- the valve is controlled to vary the air flow to the engine intake, thereby controlling the air/fuel ratio (block 54 ).
- the method may be utilized for a variety of different applications.
Abstract
Description
- This invention was made with Government support under Contract No. DE-FC02-99EE50575. The Government may have certain rights to this invention.
- 1. Field of the Invention
- The invention relates to a method for controlling engine air/fuel ratio.
- 2. Background Art
- After-treatment devices such as Lean NOx Traps (LNT) are being devised to adsorb NOx emissions from diesel engines in an effort to meet future emission standards. LNTs can be very effective in trapping NOx but need to be periodically cleaned through a regeneration process. A rich environment (close to an air/fuel ratio of 14) is required to regenerate the trap. While fuel injection in the combustion chamber and/or fuel injection in the exhaust stream can effectively reduce the exhaust air/fuel ratio, they both present some limitations in terms of how much fuel can be injected. Too much fuel injected in the combustion chamber after the main combustion event (late post injection) can result in wall wetting and engine damage or affect the engine torque curve when injected too early. Injecting large quantities of fuel in the exhaust stream could require large and bulky injectors.
- For the foregoing reasons, there is a need for an improved method for controlling engine air/fuel ratio.
- It is an object of the invention to provide an improved method for controlling engine air/fuel ratio.
- The invention comprehends bringing the air/fuel ratio down to an intermediate level through engine air flow management during the LNT regeneration process. More specifically, in a supercharged or turbocharged engine including a compressor at the intake, recirculating some air from the compressor discharge back to the compressor inlet reduces the engine air/fuel ratio. This approach alleviates much of the requirements on the fuel injection side that are typically associated with LNT regeneration. Further reduction of the air/fuel ratio can be achieved via fuel injection into the combustion chamber and/or fuel injection in the exhaust stream.
- Further, in accordance with the invention, this same method of recirculating some air from the compressor discharge back to the compressor inlet to reduce the engine air/fuel ratio can be used to increase the engine's exhaust temperature to promote regeneration of a diesel particulate filter (DPF). For example, if the DPF is full of exhaust particles and requires regeneration, this compressor recirculation can be used to increase the exhaust temperature. The amount of air being recirculated is selected as a function of the required exhaust temperature increase.
- Similarly, this approach can be used to increase exhaust temperature for more rapid catalyst light off or move the exhaust temperature to a range where catalyst efficiency is higher.
- Further, this approach can be used for optimization of turbocharger operation, by either moving the compressor operation away from the surge line (safety feature), or bringing it to a higher efficiency line (performance feature).
-
FIG. 1 illustrates modulated compressor recirculation to control engine air/fuel ratio in accordance with a preferred embodiment of the invention; and -
FIG. 2 illustrates a method of the invention in the preferred embodiment. - With reference to
FIG. 1 , anengine 10 includes a plurality of cylinders fed by fuel injectors. The engine intake is indicated at 14 while the engine exhaust is indicated at 16. In the illustrated preferred embodiment, the engine is equipped with an exhaust gas recirculation (EGR) system. The EGR system recirculates a portion of the exhaust gases back to theengine intake 14, as needed, to avoid excessively high combustion temperatures which cause NOx creation. EGRcooler 18 cools the recirculated exhaust gas prior to introduction atengine intake 14. - As shown, the engine is equipped with a
turbocharger system 20.System 20 includesturbine 22 driven by exhaust gases. Turbine 22drives compressor 24. Charge air cooler (CAC) 26 cools the charge air fromcompressor 24 prior to introduction atengine intake 14. - According to the invention, engine air flow management is utilized to reduce the engine air/fuel ratio. More specifically, a
recirculation path 30 from the compressor discharge to the compressor inlet is provided, and acontrollable valve 32 is located along thisrecirculation path 30. Acontroller 33 is programmed to modulatecontrollable valve 32 to vary the airflow to theengine intake 14, thereby varying the air/fuel ratio. - In more detail, a modulated compressor recirculation flow can, for instance, bring the engine air/fuel ratio from 25 down to 17 (arbitrary numbers selected as an example), and then fuel injection strategies may be employed to further lower the exhaust air/fuel ratio from 17 down to 14 where regeneration becomes effective. In
FIG. 1 , the Lean NOx Trap (LNT) is indicated at 36. The innovative approach of the invention involves recirculating some air flow (charge air) from the compressor outlet back into the compressor inlet. The amount of air available in each cylinder ofengine 10 is reduced, resulting in richer fuel combustion in the engine. Exhaust gases reaching LNT 36 are fuel rich and promote the regeneration process. At the end of LNT regeneration, compressor recirculation is disabled, bringing the engine back to lean operating conditions where it runs most effectively. - The invention is applicable to supercharged or turbocharged engines. In the preferred embodiment illustrated in
FIG. 1 ,recirculation path 30 is composed of an external tube introduced between the compressor outlet and the compressor inlet of theturbocharger system 20. The purpose of the tube is to recirculate compressed air from the compressor outlet back into the compressor inlet. The tube (recirculation passage) can also be directly incorporated into the compressor housing. Air will naturally flow from the compressor outlet (high pressure side) into the compressor inlet (low pressure side). -
Modulator valve 32 is capable of modulating the air flow, and is installed in the tube, creating a compressor bleed line. The amount of air going through the bypass tube is defined by the size of the tube and the valve position (full open, or modulated). The valve is electronically modulated bycontroller 33 to provide variable and controllable air/fuel ratio. It is appreciated thatcontroller 33 may be any suitable controller as understood by those of ordinary skill in the art of engine control systems. That is,controller 33 may be the engine controller or a different controller that controls one or more subsystems of the engine. - When regeneration is required at LNT 36 (possibly defined by the NOx conversion rate of the LNT),
bypass valve 32 is opened and high pressure air (charge air) circulates through the bypass tube and is fed back to the compressor inlet, thereby lowering the amount of air going into theengine intake 14 and the engine cylinders, thus creating rich combustion in the cylinders. The exhaust gases that are fed to the after-treatment devices (that is, LNT 36 inFIG. 1 ) are fuel rich and contain high thermal mass. Such conditions promote LNT regeneration. - The amount of air flow bled around
compressor 24 can be modulated based on a targeted air/fuel ratio. Once regeneration is achieved,bypass valve 32 is closed and the engine returns to normal lean operating conditions. Engine fueling and timing adjustments may be made during the regeneration phase to maintain the torque at the same level as under normal lean operating conditions, resulting in a minimum fuel economy penalty. Under recirculation conditions, the compressor pressure ratio and speed drop and the air mass flow rate displaced by the compressor increases. Those characteristics result in safe compressor operating conditions, as the operating point is moving away from the compressor surge line. - To get air fuel ratios of 14 (in the example), fuel injection strategies will also be employed. The operation and strategy of these fuel injection strategies may vary depending on the implementation as understood by those of ordinary skill in the art of engine control systems.
- With continuing reference to
FIG. 1 , the primary application of this modulated compressor recirculation arrangement is to provide a targeted air/fuel ratio for LNT regeneration. The operation ofvalve 32 can be electronically controlled bycontroller 33 based on LNT regeneration needs and engine operating conditions at that time. Bleed modulation, engine fueling and timing strategies can all be optimized to provide the required air/fuel ratio and exhaust temperature for LNT regeneration, while maintaining engine torque for good drivability and minimizing fuel economy impact. - Another application of the invention is the temporary increase of engine exhaust temperature to promote diesel particulate filter regeneration.
FIG. 1 illustrates a diesel particulate filter at 34. - Another application of the invention is to increase exhaust temperature to promote faster catalyst light off or to increase exhaust temperature to a level where catalyst efficiency is higher, resulting in overall lower tailpipe emissions.
FIG. 1 illustrates a diesel oxidation catalyst at 38. - Yet another application of the invention is the optimization of turbocharger operation, by either moving the compressor operation away from the surge line (safety feature), or bringing it to a higher efficiency line (performance feature).
-
FIG. 2 illustrates a method of the invention in the preferred embodiment. According to the method for controlling engine air/fuel ratio, a recirculation path extending from the compressor discharge to the compressor inlet is provided (block 50). A controllable valve is provided at a location along the recirculation path (block 52). According to the method, the valve is controlled to vary the air flow to the engine intake, thereby controlling the air/fuel ratio (block 54). The method may be utilized for a variety of different applications. - While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.
Claims (12)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/033,770 US7080511B1 (en) | 2005-01-12 | 2005-01-12 | Method for controlling engine air/fuel ratio |
DE102005061643A DE102005061643A1 (en) | 2005-01-12 | 2005-12-22 | A method of controlling the air / fuel ratio in an engine |
GB0600434A GB2422209A (en) | 2005-01-12 | 2006-01-11 | Controlling air/fuel ratio in supercharged or turbocharged i.c. engines |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/033,770 US7080511B1 (en) | 2005-01-12 | 2005-01-12 | Method for controlling engine air/fuel ratio |
Publications (2)
Publication Number | Publication Date |
---|---|
US20060150628A1 true US20060150628A1 (en) | 2006-07-13 |
US7080511B1 US7080511B1 (en) | 2006-07-25 |
Family
ID=35911651
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/033,770 Expired - Fee Related US7080511B1 (en) | 2005-01-12 | 2005-01-12 | Method for controlling engine air/fuel ratio |
Country Status (3)
Country | Link |
---|---|
US (1) | US7080511B1 (en) |
DE (1) | DE102005061643A1 (en) |
GB (1) | GB2422209A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080092861A1 (en) * | 2006-10-23 | 2008-04-24 | Duffy Kevin P | Exhaust gas recirculation in a homogeneous charge compression ignition engine |
US20080098723A1 (en) * | 2006-10-30 | 2008-05-01 | Carlill Thomas W | Self-sustaining oxy-exothermal filter regeneration system |
WO2008056242A3 (en) * | 2006-11-10 | 2008-11-06 | Toyota Jidosha Kabushiki Kaisy | Internal combustion engine and internal combustion engine control method |
US20120203434A1 (en) * | 2011-01-06 | 2012-08-09 | Cummins Intellectual Property, Inc. | Supervisory thermal management system and method for engine system warm up and regeneraton |
EP2074296A4 (en) * | 2006-10-02 | 2016-08-17 | Mack Trucks | Engine with charge air recirculation and method |
CN112282899A (en) * | 2019-07-22 | 2021-01-29 | 卡特彼勒公司 | Regeneration control system for regeneration of oxidation catalyst in internal combustion engine |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE528620C2 (en) * | 2005-05-18 | 2006-12-27 | Scania Cv Ab | Arrangements for the recirculation of exhaust gases of a supercharged internal combustion engine |
DE102005030276A1 (en) * | 2005-06-21 | 2006-12-28 | Pilz Gmbh & Co. Kg | Safety switching device for e.g. safe shutdown of consumer unit in automated installation has analog signal combiner, which is designed to superimpose analog test signal on analog input signal to form analog combination signal |
JP4787330B2 (en) * | 2006-01-13 | 2011-10-05 | マック トラックス インコーポレイテッド | Exhaust and intake gas temperature control |
US20080163855A1 (en) * | 2006-12-22 | 2008-07-10 | Jeff Matthews | Methods systems and apparatuses of EGR control |
US8001778B2 (en) * | 2007-09-25 | 2011-08-23 | Ford Global Technologies, Llc | Turbocharged engine control operation with adjustable compressor bypass |
US8371120B2 (en) * | 2008-01-15 | 2013-02-12 | Southwest Research Institute | HCCI combustion timing control with decoupled control of in-cylinder air/EGR mass and oxygen concentration |
US8136357B2 (en) | 2008-08-27 | 2012-03-20 | Honda Motor Co., Ltd. | Turbocharged engine using an air bypass valve |
US10196993B2 (en) * | 2009-09-08 | 2019-02-05 | Ge Global Sourcing Llc | System and method for operating a turbocharged engine |
EP2546506B1 (en) * | 2010-03-09 | 2015-12-16 | Toyota Jidosha Kabushiki Kaisha | Control device for internal combustion engine |
US9174637B2 (en) * | 2013-08-13 | 2015-11-03 | Ford Global Technologies, Llc | Methods and systems for torque control |
US10161300B2 (en) * | 2013-12-19 | 2018-12-25 | Volvo Truck Corporation | Internal combustion engine system |
US9611793B2 (en) | 2014-08-04 | 2017-04-04 | Caterpillar Inc. | Method for thermal control of exhaust aftertreatment |
US11053834B2 (en) | 2015-09-29 | 2021-07-06 | Carrier Corporation | Transportation refrigeration system comprising a refrigeration unit and a diesel engine |
US10100719B2 (en) * | 2016-07-18 | 2018-10-16 | Delphi Technologies Ip Limited | GDCI intake air temperature control system and method |
Citations (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4282713A (en) * | 1977-05-26 | 1981-08-11 | Nissan Motor Company, Limited | Control for supercharger turbines |
US4489702A (en) * | 1982-09-27 | 1984-12-25 | The Garrett Corporation | Supercharged diesel engine air flow control system |
US4515136A (en) * | 1982-09-27 | 1985-05-07 | The Garrett Corporation | Supercharged diesel engine air inflow control system |
US4817387A (en) * | 1986-10-27 | 1989-04-04 | Hamilton C. Forman, Trustee | Turbocharger/supercharger control device |
US4873961A (en) * | 1987-04-02 | 1989-10-17 | Mazda Motor Corporation | Air-fuel ratio control for supercharged automobile engine |
US5526645A (en) * | 1995-07-26 | 1996-06-18 | Powerhouse Diesel Services, Inc. | Dual-fuel and spark ignited gas internal combustion engine excess air control system and method |
US6055967A (en) * | 1997-05-16 | 2000-05-02 | Ishikawajma-Harima Heavy Industries Co., Ltd. | Screw supercharger for vehicle |
US6327856B1 (en) * | 1999-02-26 | 2001-12-11 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Control apparatus and method for premixed compression ignition type internal combustion engines |
US6378506B1 (en) * | 2001-04-04 | 2002-04-30 | Brunswick Corporation | Control system for an engine supercharging system |
US20020195086A1 (en) * | 1997-12-16 | 2002-12-26 | Beck N. John | Cylinder pressure based optimization control for compression ignition engines |
US20030000507A1 (en) * | 2000-05-24 | 2003-01-02 | Nobuhiro Kobayashi | Device and method for exhaust gas circulation of internal combustion engine |
US6675579B1 (en) * | 2003-02-06 | 2004-01-13 | Ford Global Technologies, Llc | HCCI engine intake/exhaust systems for fast inlet temperature and pressure control with intake pressure boosting |
US6681171B2 (en) * | 2001-12-18 | 2004-01-20 | Detroit Diesel Corporation | Condensation control for internal combustion engines using EGR |
US6701710B1 (en) * | 2002-09-11 | 2004-03-09 | Detroit Diesel Corporation | Turbocharged engine with turbocharger compressor recirculation valve |
US6732507B1 (en) * | 2002-12-30 | 2004-05-11 | Southwest Research Institute | NOx aftertreatment system and method for internal combustion engines |
US20040237509A1 (en) * | 2003-05-29 | 2004-12-02 | Detroit Diesel Corporation | System and method for supplying clean pressurized air to diesel oxidation catalyst |
US20050103013A1 (en) * | 2003-11-17 | 2005-05-19 | Dennis Brookshire | Dual and hybrid EGR systems for use with turbocharged engine |
US6983597B2 (en) * | 2002-06-07 | 2006-01-10 | Robert Bosch Gmbh | Method and arrangement for controlling an internal combustion engine |
US6988361B2 (en) * | 2003-10-27 | 2006-01-24 | Ford Global Technologies, Llc | Method and system for controlling simultaneous diesel particulate filter regeneration and lean NOx trap desulfation |
US6990814B2 (en) * | 2003-12-18 | 2006-01-31 | Caterpillar Inc. | Engine turbocharger control management system |
US7010914B1 (en) * | 2005-03-04 | 2006-03-14 | Southwest Research Institute | Method for controlling boost pressure in a turbocharged diesel engine |
-
2005
- 2005-01-12 US US11/033,770 patent/US7080511B1/en not_active Expired - Fee Related
- 2005-12-22 DE DE102005061643A patent/DE102005061643A1/en not_active Withdrawn
-
2006
- 2006-01-11 GB GB0600434A patent/GB2422209A/en not_active Withdrawn
Patent Citations (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4282713A (en) * | 1977-05-26 | 1981-08-11 | Nissan Motor Company, Limited | Control for supercharger turbines |
US4489702A (en) * | 1982-09-27 | 1984-12-25 | The Garrett Corporation | Supercharged diesel engine air flow control system |
US4515136A (en) * | 1982-09-27 | 1985-05-07 | The Garrett Corporation | Supercharged diesel engine air inflow control system |
US4817387A (en) * | 1986-10-27 | 1989-04-04 | Hamilton C. Forman, Trustee | Turbocharger/supercharger control device |
US4873961A (en) * | 1987-04-02 | 1989-10-17 | Mazda Motor Corporation | Air-fuel ratio control for supercharged automobile engine |
US5526645A (en) * | 1995-07-26 | 1996-06-18 | Powerhouse Diesel Services, Inc. | Dual-fuel and spark ignited gas internal combustion engine excess air control system and method |
US6055967A (en) * | 1997-05-16 | 2000-05-02 | Ishikawajma-Harima Heavy Industries Co., Ltd. | Screw supercharger for vehicle |
US20020195086A1 (en) * | 1997-12-16 | 2002-12-26 | Beck N. John | Cylinder pressure based optimization control for compression ignition engines |
US6327856B1 (en) * | 1999-02-26 | 2001-12-11 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Control apparatus and method for premixed compression ignition type internal combustion engines |
US20030000507A1 (en) * | 2000-05-24 | 2003-01-02 | Nobuhiro Kobayashi | Device and method for exhaust gas circulation of internal combustion engine |
US6378506B1 (en) * | 2001-04-04 | 2002-04-30 | Brunswick Corporation | Control system for an engine supercharging system |
US6681171B2 (en) * | 2001-12-18 | 2004-01-20 | Detroit Diesel Corporation | Condensation control for internal combustion engines using EGR |
US6983597B2 (en) * | 2002-06-07 | 2006-01-10 | Robert Bosch Gmbh | Method and arrangement for controlling an internal combustion engine |
US6701710B1 (en) * | 2002-09-11 | 2004-03-09 | Detroit Diesel Corporation | Turbocharged engine with turbocharger compressor recirculation valve |
US6732507B1 (en) * | 2002-12-30 | 2004-05-11 | Southwest Research Institute | NOx aftertreatment system and method for internal combustion engines |
US6675579B1 (en) * | 2003-02-06 | 2004-01-13 | Ford Global Technologies, Llc | HCCI engine intake/exhaust systems for fast inlet temperature and pressure control with intake pressure boosting |
US20040237509A1 (en) * | 2003-05-29 | 2004-12-02 | Detroit Diesel Corporation | System and method for supplying clean pressurized air to diesel oxidation catalyst |
US6988361B2 (en) * | 2003-10-27 | 2006-01-24 | Ford Global Technologies, Llc | Method and system for controlling simultaneous diesel particulate filter regeneration and lean NOx trap desulfation |
US20050103013A1 (en) * | 2003-11-17 | 2005-05-19 | Dennis Brookshire | Dual and hybrid EGR systems for use with turbocharged engine |
US6990814B2 (en) * | 2003-12-18 | 2006-01-31 | Caterpillar Inc. | Engine turbocharger control management system |
US7010914B1 (en) * | 2005-03-04 | 2006-03-14 | Southwest Research Institute | Method for controlling boost pressure in a turbocharged diesel engine |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2074296A4 (en) * | 2006-10-02 | 2016-08-17 | Mack Trucks | Engine with charge air recirculation and method |
US20080092861A1 (en) * | 2006-10-23 | 2008-04-24 | Duffy Kevin P | Exhaust gas recirculation in a homogeneous charge compression ignition engine |
US7377270B2 (en) * | 2006-10-23 | 2008-05-27 | Caterpillar Inc. | Exhaust gas recirculation in a homogeneous charge compression ignition engine |
US20080098723A1 (en) * | 2006-10-30 | 2008-05-01 | Carlill Thomas W | Self-sustaining oxy-exothermal filter regeneration system |
US7805931B2 (en) | 2006-10-30 | 2010-10-05 | Perkins Engines Company Limited | Self-sustaining oxy-exothermal filter regeneration system |
WO2008056242A3 (en) * | 2006-11-10 | 2008-11-06 | Toyota Jidosha Kabushiki Kaisy | Internal combustion engine and internal combustion engine control method |
US20100071658A1 (en) * | 2006-11-10 | 2010-03-25 | Toyota Jidosha Kabushiki Kaisha | Internal combustion engine and internal combustion engine control method |
US8051835B2 (en) | 2006-11-10 | 2011-11-08 | Toyota Jidosha Kabushiki Kaisha | Internal combustion engine and internal combustion engine control method |
US20120203434A1 (en) * | 2011-01-06 | 2012-08-09 | Cummins Intellectual Property, Inc. | Supervisory thermal management system and method for engine system warm up and regeneraton |
US8577568B2 (en) * | 2011-01-06 | 2013-11-05 | Cummins Intellectual Property, Inc. | Supervisory thermal management system and method for engine system warm up and regeneration |
US8818659B2 (en) | 2011-01-06 | 2014-08-26 | Cummins Intellectual Property, Inc. | Supervisory thermal management system and method for engine system warm up and regeneration |
CN112282899A (en) * | 2019-07-22 | 2021-01-29 | 卡特彼勒公司 | Regeneration control system for regeneration of oxidation catalyst in internal combustion engine |
Also Published As
Publication number | Publication date |
---|---|
DE102005061643A1 (en) | 2006-07-20 |
US7080511B1 (en) | 2006-07-25 |
GB0600434D0 (en) | 2006-02-15 |
GB2422209A (en) | 2006-07-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7080511B1 (en) | Method for controlling engine air/fuel ratio | |
US11598277B2 (en) | System and method for reducing engine knock | |
US10502166B2 (en) | EGR system with particle filter and wastegate | |
US7010914B1 (en) | Method for controlling boost pressure in a turbocharged diesel engine | |
US7640731B2 (en) | Method for controlling exhaust gas flow and temperature through regenerable exhaust gas treatment devices | |
RU2569410C2 (en) | Engine intake manifold forced aspiration | |
US7104048B2 (en) | Low emission diesel particulate filter (DPF) regeneration | |
US20100043428A1 (en) | Engine With Exhaust Temperature Control and Method of Controlling Engine Exhaust Gas Temperature and Engine Intake Temperature | |
US20070089400A1 (en) | Fast warm-up of diesel aftertreatment system during cold start | |
US20070199320A1 (en) | Flexible engine cooling and exhaust gas temperature controls for diesel after-treatment regeneration and engine performance improvement | |
US20090271094A1 (en) | Engine with charge air recirculation and method | |
US20070056266A1 (en) | System and method for regenerating a NOx storage and conversion device | |
US8069650B2 (en) | Method for internal combustion engine with exhaust recirculation | |
US20140007851A1 (en) | Method of controlling an after-treatment system warm-up | |
WO2006091374A2 (en) | Slectively by passing a dpf in hybrid hccii combustion engine | |
AU2007362594A1 (en) | Engine cooling and exhaust gas temperature controls for diesel after-treatment regeneration | |
RU2569397C2 (en) | Operation of supercharged gas engine (versions) and gas engine | |
GB2507061A (en) | Method of two-stage turbocharger matching for supporting cylinder deactivation. | |
US10167792B2 (en) | Engine system and control method of using the engine system | |
EP3428415B1 (en) | Pollutant abatement system of an internal combustion engine, internal combustion engine comprising the abatement system and method for the pollutant abatement | |
JP3743232B2 (en) | White smoke emission suppression device for internal combustion engine | |
US20160186634A1 (en) | Exhaust after-treatment system for an internal combustion engine | |
CN114076053B (en) | Exhaust gas recirculation regeneration method and device and vehicle | |
JP4760697B2 (en) | Control device for internal combustion engine | |
EP1770252B1 (en) | Internal combustion engine with an exhaust emission aftertreatment device for reducing nitrogen oxides (NOx) emissions and method for controlling such an engine |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: DETROIT DIESEL CORPORATION, MICHIGAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SISKEN, KEVIN DEAN;GROSMOUGIN, ANNE-LISE;REEL/FRAME:016393/0538;SIGNING DATES FROM 20041103 TO 20041110 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.) |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20180725 |