AU2019222845B2 - System for controlling engine and method for controlling engine - Google Patents
System for controlling engine and method for controlling engine Download PDFInfo
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- AU2019222845B2 AU2019222845B2 AU2019222845A AU2019222845A AU2019222845B2 AU 2019222845 B2 AU2019222845 B2 AU 2019222845B2 AU 2019222845 A AU2019222845 A AU 2019222845A AU 2019222845 A AU2019222845 A AU 2019222845A AU 2019222845 B2 AU2019222845 B2 AU 2019222845B2
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- egr
- discharge amount
- decreased
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- 238000000034 method Methods 0.000 title claims abstract description 99
- 230000003247 decreasing effect Effects 0.000 claims abstract description 73
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims abstract description 66
- 230000008929 regeneration Effects 0.000 claims abstract description 58
- 238000011069 regeneration method Methods 0.000 claims abstract description 58
- 238000001816 cooling Methods 0.000 claims abstract description 37
- 239000013618 particulate matter Substances 0.000 claims abstract description 24
- 238000002347 injection Methods 0.000 claims description 131
- 239000007924 injection Substances 0.000 claims description 131
- 230000007423 decrease Effects 0.000 claims description 38
- 239000000446 fuel Substances 0.000 claims description 32
- 238000001514 detection method Methods 0.000 claims description 8
- 239000007789 gas Substances 0.000 description 66
- 238000002485 combustion reaction Methods 0.000 description 17
- 230000006866 deterioration Effects 0.000 description 7
- 230000001276 controlling effect Effects 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 230000032683 aging Effects 0.000 description 5
- 230000015654 memory Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000002411 adverse Effects 0.000 description 3
- 239000002826 coolant Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000000979 retarding effect Effects 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 238000010420 art technique Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000013400 design of experiment Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
Classifications
-
- 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
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust-Gas Circulating Devices (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
- Processes For Solid Components From Exhaust (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
A system for controlling an engine includes a sensor arranged on an exhaust passage
and configured to detect a discharge amount of nitrogen oxides and a controller. The
controller is configured to determine whether a cooling efficiency of an EGR cooler is
decreased based on the discharge amount of nitrogen oxides detected by the sensor. The
controller is configured to execute an EGR cooler regeneration process to remove particulate
matter from the EGR cooler when it is determined that the cooling efficiency of the EGR
cooler is decreased.
11654308_1 (GHMaers)P111876.AU
1/7
Fig.1 1
6200 {
ECU 13
110
116
144 1
108
142--, '118 '118 '118 118
100
140
10612
| Exhaust
125 124 131 104 122
102
Description
1/7
Fig.1 1
6200 {
ECU 13
110
116 144 1 108 142--, '118 '118 '118 118 100 140
10612
| 125 124 131 Exhaust 104 122
[0001] 1. Field
[0002] The present disclosure relates to a system for controlling an engine that includes an
exhaust gas recirculation (EGR) device. The present disclosure also relates to a method for
controlling the engine.
[0003] 2. Description of Related Art
[0004] A known engine includes an EGR pipe, which circulates a portion of exhaust from
the exhaust passage to the intake passage, and an EGR cooler, which cools the exhaust
(hereinafter, may also be referred to as "EGR gas") flowing through the EGR pipe. In such
an engine, particulate matter (PM) contained in the EGR gas may collect on a heat exchanger
of the EGR cooler and decrease the cooling efficiency of the EGR cooler. When the
cooling efficiency of the EGR cooler is decreased, the temperature of EGR gas recirculated
to the intake passage increases, and the combustion temperature in a cylinder increases. An
increase in the combustion temperature in the cylinder causes an increase in the amount of
nitrogen oxides NOx discharged from the engine.
[0005] For example, Japanese Laid-Open Patent Publication No. 2009-46982 discloses a
control system for limiting increases in the NOx discharge amount caused by a decrease in
the cooling efficiency of the EGR cooler. The control system executes a process on an
engine that includes an EGR pipe and an EGR cooler arranged on the EGR pipe. More
specifically, the control system estimates the cooling efficiency of the EGR cooler based on
the inlet gas temperature, the outlet gas temperature, and the coolant temperature of the EGR
cooler and increases the retardation amount of the fuel injection timing as the estimated
1 11654308_1 (GHMaers)P111876.AU cooling efficiency of the EGR cooler is decreased. The retardation of the fuel injection timing lowers the peak of the combustion temperature in a cylinder. Thus, even when the cooling efficiency of the EGR cooler is decreased, increases in the NOx discharge amount are limited.
[0006] In the above control system, increases in the NOx discharge amount caused by a
decrease in the cooling efficiency of the EGR cooler are limited by retardation of the fuel
injection timing. For example, the fuel injection timing may reach a retardation limit that is
determined by hard constraints or the like. More specifically, a situation in which the fuel
injection timing cannot be retarded any further to limit increases in the NOx discharge
amount may occur. Hence, the above control system may fail to appropriately limit the
NOx discharge amount.
[0007] It is an object of the present disclosure to appropriately limit increases in NOx
discharge amount of an engine that includes an EGR pipe and an EGR cooler arranged on
the EGR pipe when the cooling efficiency of the EGR cooler is decreased.
[0008] This Summary is provided to introduce a selection of concepts in a simplified form
that are further described below in the Detailed Description. This Summary is not intended
to identify key features or essential features of the claimed subject matter, nor is it intended
to be used as an aid in determining the scope of the claimed subject matter.
[0009] (1) An aspect of the present disclosure provides a system for controlling an engine.
The engine includes a cylinder connected to an intake passage and an exhaust passage, an
EGR pipe configured to recirculate a portion of exhaust from the exhaust passage to the
intake passage, and an EGR cooler arranged on the EGR pipe. The system includes a
sensor arranged on the exhaust passage and configured to detect a discharge amount of
nitrogen oxides and a controller. The controller is configured to determine whether a
2 11654308_1 (GHMaers)P111876.AU cooling efficiency of the EGR cooler is decreased based on the discharge amount of nitrogen oxides detected by the sensor. The controller is configured to execute an EGR cooler regeneration process to remove particulate matter from the EGR cooler when it is determined that the cooling efficiency of the EGR cooler is decreased.
[0010] In the above system, when it is determined that the cooling efficiency of the EGR
cooler is decreased based on the discharge amount of nitrogen oxides (NOx discharge
amount) detected by the sensor, the EGR cooler regeneration process is executed to remove
particulate matter from the EGR cooler. The EGR cooler regeneration process, for example,
increases the flow rate of the EGR gas, and the EGR gas blows off the particulate matter
collected on the EGR cooler. This may regain the cooling efficiency of the EGR cooler.
As a result, in the engine including the EGR cooler arranged on the EGR pipe, increases in
the discharge amount of nitrogen oxides caused by a decrease in the cooling efficiency of the
EGR cooler are appropriately limited.
[0011] (2) In an aspect of the present disclosure, the controller may be configured to
determine that the cooling efficiency of the EGR cooler is decreased and execute the EGR
cooler regeneration process when the discharge amount of nitrogen oxides is greater than a
threshold value.
[0012] When the cooling efficiency of the EGR cooler is decreased, the density of EGR gas
is lowered. This decreases an EGR gas amount, that is, an amount of EGR gas recirculated
into the cylinder. Decreases in the EGR gas amount cause the NOx discharge amount to
increase. Focusing on this point, in the above configuration, when the NOx discharge
amount is greater than the threshold value, it is determined that the cooling efficiency of the
EGR cooler is decreased, and the EGR cooler regeneration process is executed. Thus, after
appropriately determining whether the cooling efficiency of the EGR cooler is decreased
based on the NOx discharge amount, the EGR cooler regeneration process is executed.
3 11654308_1 (GHMaers)P111876.AU
[0013] (3) In an aspect of the present disclosure, the engine may be configured so that
multiple fuel injections are performed on the cylinder in one cycle. The multiple fuel
injections may include a pilot injection and amain injection. The controller maybe
configured to retard timing of the main injection by a predetermined amount when the
discharge amount of nitrogen oxides is greater than a threshold value. The controller may
be configured to determine that the cooling efficiency of the EGR cooler is decreased and
execute the EGR cooler regeneration process when timing of the main injection is retarded
and reaches a predetermined retardation limit.
[0014] In the above configuration, when the NOx discharge amount detected by the sensor
is greater than the threshold value, the main injection timing is retarded by the predetermined
amount. Thus, increases in the NOx discharge amount caused by a decrease in the cooling
efficiency of the EGR cooler are limited by retarding the main injection timing instead of
executing the EGR cooler regeneration process. This reduces the number of times the EGR
cooler regeneration process is executed as compared to when the EGR cooler regeneration
process is executed in accordance with the NOx discharge amount exceeding the threshold
value. When the NOx discharge amount is greater than the threshold value, the main
injection timing is retarded by the predetermined amount and may reach the retardation limit.
When the main injection timing reaches the retardation limit, it is determined that the EGR
cooler efficiency is decreased, and the EGR cooler regeneration process is executed. As a
result, increases in the NOx discharge amount are limited while reducing the number of
times the EGR cooler regeneration process is executed.
[0015] (4) In an aspect of the present disclosure, the cylinder may be one of cylinders.
The engine may be configured so that multiple fuel injections are performed on each of the
cylinders in one cycle. The multiple fuel injections may include a pilot injection and a
main injection. The controller may be configured to execute feedback control that
4 11654308_1 (GHMaers)P111876.AU increases and decreases a pilot injection amount by a feedback adjustment amount corresponding to each of the cylinders based on a detection result of the sensor so that the discharge amount of nitrogen oxides is equal among the cylinders. The controller may be configured to determine that the cooling efficiency of the EGR cooler is decreased and execute the EGR cooler regeneration process when the feedback adjustment amount corresponding to at least one of the cylinders is outside a predetermined adjustment range.
[0016] In the above configuration, feedback control is executed to increase and decrease
the pilot injection amounts of the cylinders so that the NOx discharge amounts are equal to
each other among the cylinders based on the detection result of the sensor. When the EGR
cooler efficiency is decreased, the density of the EGR gas is lowered, and the concentration
of the EGR gas becomes uneven. Uneven concentration of the EGR gas increases the
difference between the amount of EGR gas, or the EGR gas amount, flowing into a cylinder
and the amount of EGR gas, or the EGR gas amount, flowing into another cylinder and
increases the difference in the NOx discharge amount between the cylinders. Thus, when
the EGR cooler efficiency is decreased, the feedback adjustment amount of the pilot
injection amount is increased. The feedback adjustment amount refers to an increase or
decrease amount of the pilot injection amount that is adjusted by the feedback control.
Focusing on this point, in the above configuration, when at least one of the feedback
adjustment amounts of the pilot injection amounts of the cylinders is outside the
predetermined adjustment range, it is determined that the cooling efficiency of the EGR
cooler is decreased, and the EGR cooler regeneration process is executed. Thus, after
appropriately determining whether the cooling efficiency of the EGR cooler is decreased
based on the feedback adjustment amount of the pilot injection amount controlled in
accordance with the detection result of sensor, the EGR cooler regeneration process is
executed.
5 11654308_1 (GHMaers)P111876.AU
[0017] (5) In an aspect of the present disclosure, the EGR cooler regeneration process may
include a control that increases an intake air amount of the engine for a predetermined
amount of time.
[0018] It is assumed that a decrease in the cooling efficiency of the EGR cooler is mainly
caused by particulate matter in the EGR gas collecting on the surface of the heat exchanger
of the EGR cooler and inhibiting heat exchange. In the above configuration, the EGR
cooler regeneration process includes a control that increases the intake air amount of the
engine for the predetermined amount of time. As a result, the flow rate of the EGR gas is
increased, and the EGR gas blows off the particulate matter collected on the surface of the
heat exchanger of the EGR cooler. This allows the cooling efficiency of the EGR cooler to
be regained.
[0019] (6)An aspect of the present disclosure provides a method for controlling an engine.
The engine includes a cylinder connected to an intake passage and an exhaust passage, an
EGR pipe configured to recirculate a portion of exhaust from the exhaust passage to the
intake passage, and an EGR cooler arranged on the EGR pipe. The method includes
detecting a discharge amount of nitrogen oxides in the exhaust passage, determining whether
a cooling efficiency of the EGR cooler is decreased based on the detected discharge amount
of nitrogen oxides, and executing an EGR cooler regeneration process to remove particulate
matter from the EGR cooler when it is determined that the cooling efficiency of the EGR
cooler is decreased.
[0020] Other features and aspects will be apparent from the following detailed description,
the drawings, and the claims.
[0021] Fig. 1 is a schematic diagram showing an example of the entire configuration of an
6 11654308_1 (GHMaers)P111876.AU engine control system.
[0022] Fig. 2 is a graph schematically showing the correspondence relationship between
the EGR cooler efficiency and the NOx discharge amount.
[0023] Fig. 3 is a graph schematically showing an example of changes in NOx discharge
amount and intake air amount.
[0024] Fig. 4 is a (first) flowchart schematically showing a process executed by an ECU.
[0025] Fig. 5 is a graph schematically showing an example of changes in NOx discharge
amount, main injection timing, pilot injection amount, and intake air amount according to a
first modified example.
[0026] Fig. 6 is a (second) flowchart schematically showing a process executed by the
ECU in the first modified example.
[0027] Fig. 7 is a diagram showing an example of variations in pilot F/B adjustment
amount in four cylinders of the engine.
[0028] Fig. 8 is a (third) flowchart schematically showing a process executed by the ECU
in a second modified example.
[0029] Throughout the drawings and the detailed description, the same reference numerals
refer to the same elements. The drawings may not be to scale, and the relative size,
proportions, and depiction of elements in the drawings may be exaggerated for clarity,
illustration, and convenience.
[0030] This description provides a comprehensive understanding of the methods,
apparatuses, and/or systems described. Modifications and equivalents of the methods,
apparatuses, and/or systems described are apparent to one of ordinary skill in the art.
Sequences of operations are exemplary, and may be changed as apparent to one of ordinary
7 11654308_1 (GHMaers)P111876.AU skill in the art, with the exception of operations necessarily occurring in a certain order.
Descriptions of functions and constructions that are well known to one of ordinary skill in
the art may be omitted.
[0031] Exemplary embodiments may have different forms, and are not limited to the
examples described. However, the examples described are thorough and complete, and
convey the full scope of the disclosure to one of ordinary skill in the art.
[0032] Embodiments of the present disclosure will now be described with reference to the
drawings. The same reference characters are given to those elements that are the same as
or equivalent to the corresponding elements. Such elements will not be repeatedly
described.
[0033] Fig. 1 is a schematic diagram showing an example of the entire configuration of an
engine control system 1 according to the present embodiment. The engine control system 1
is installed in a vehicle, which is not shown in the drawings.
[0034] The engine control system 1 includes an engine 100 including multiple (four in the
example shown in Fig. 1) cylinders, multiple NOx sensors 121 respectively provided for the
cylinders, an exhaust temperature sensor 125, and an electronic controller 200 (hereinafter,
may also be referred to as "ECU"). The electronic controller 200 and its components may
be configured to be circuitry that includes 1) one or more processors that operate according
to a computer program (software), 2) one or more dedicated hardware circuits such as
application specific integrated circuits (ASICs) that execute at least some of various
processes, or 3) a combination of these. The processor includes a CPU and memories such
as a RAM and a ROM. The memories store program codes or commands configured to
cause the CPU to execute processes. The memories, or computer readable media, include
any type of media that are accessible by general-purpose computers and dedicated computers.
[0035] The engine 100 a common rail-type diesel engine including multiple (four in the
8 11654308_1 (GHMaers)P111876.AU example shown in Fig. 1) cylinders.
[0036] The engine 100 includes a fuel injection device 110, an intake passage that includes
an intake pipe 108 and an intake manifold 120, and an exhaust passage that includes an
exhaust manifold 130 and an exhaust pipe 131. The fuel injection device 110 includes a
supply pump 114, a common rail 116 (pressure accumulation chamber), and multiple
injectors 118 respectively provided for the cylinders.
[0037] Air drawn into the engine 100 is filtered by an air cleaner 102 and compressed by a
compressor 104 of a turbocharger. The compressed air is cooled by an intercooler 106 and
drawn into the combustion chamber of each cylinder through the intake pipe 108 and the
intake manifold 120.
[0038] Fuel that is pressurized by the supply pump 114 and stored in the common rail 116
is injected into the combustion chamber of each cylinder by the injector 118. Anair-fuel
mixture of the air and the fuel is burned in the combustion chamber to generate driving
power of the engine 100.
[0039] After the burned air-fuel mixture, or exhaust gas, is drawn into the exhaust manifold
130 and flows through a turbine 122 of the turbocharger, the air-fuel mixture is purified by a
catalyst 124 in the exhaust pipe 131 and discharged outside the vehicle.
[0040] The engine 100 further includes an EGR pipe 140, a water cooling-type EGR cooler
142 arranged on the EGR pipe 140, and an EGR valve 144. The EGR pipe 140 circulates a
portion of the exhaust from the exhaust passage (exhaust manifold 130 in the example
shown in Fig. 1) to the intake passage.
[0041] A portion of the exhaust discharged from each cylinder to the exhaust manifold 130
circulates to the intake passage through the EGR pipe 140. The EGR cooler 142 includes a
heat exchanger that performs heat exchange between the EGR gas flowing through the EGR
pipe 140 and the coolant so that the EGR gas is cooled. A metal having a high thermal
9 11654308_1 (GHMaers)P111876.AU conductivity is used in the heat exchanger of the EGR cooler 142.
[0042] The EGR gas cooled by the EGR cooler 142 is recirculated to the intake passage
through the EGR valve 144. The circulation amount of the EGR gas is adjusted in
accordance with the open degree of the EGR valve 144. The open degree of the EGR valve
144 is controlled by a control signal from the ECU 200.
[0043] Each NOx sensor 121 is arranged on a connecting portion of an exhaust port of the
corresponding cylinder and the exhaust manifold 130 to detect the NOx discharge amount of
the cylinder and transmit a signal indicating the detection result to the ECU 200.
[0044] The exhaust temperature sensor 125 detects the temperature of the exhaust flowing
through the exhaust pipe 131 and transmits a signal indicating the detection result to the
ECU 200.
[0045] The ECU 200 includes a central processing unit (CPU), a memory that stores
process programs or the like, input and output ports (not shown) that allow for input and
output of various signals. The ECU 200 executes a predetermined calculation process
based on information stored in the memory and information from each sensor. The ECU
200 controls, for example, the supply pump 114 and the injectors 118 based on the result of
the calculation process.
[0046] For example, when running the engine 100, the ECU 200 may perform multiple fuel
injections on each cylinder in one cycle. The multiple fuel injections include a pilot
injection and amain injection. More specifically, the ECU 200 sends amain injection
instruction corresponding to requested power to the injector 118 at a predetermined time
point. As a result, the "main injection," in which fuel corresponding to the main injection
instruction is injected from the injector 118, is performed. Additionally, the ECU 200 sends
a pilot injection instruction to the injector 118 prior to the main injection instruction so that a
very small amount of fuel is injected to reduce combustion noise and purify the exhaust.
10 11654308_1 (GHMaers)P111876.AU
As a result, the "pilot injection," in which a very small amount of fuel corresponding to the
pilot injection instruction is injected from the injector 118, is performed prior to the main
injection. The multiple fuel injections performed on each cylinder in one cycle may
include an injection other than the pilot injection and the main injection.
EGR Cooler Regeneration
[0047] As described above, the engine 100 of the present embodiment includes the EGR
pipe 140 and the EGR cooler 142. When EGR gas containing a greater amount of
components having a high heat capacity ratio than fresh air (intake air before combustion) is
mixed with fresh air, increases in the combustion temperature in the cylinders are limited,
and nitrogen oxides NOx are reduced in the exhaust. Additionally, the EGR gas is cooled
by the EGR cooler 142. This lowers the initial combustion temperature in the cylinders as
compared to when the EGR gas is not cooled. Decreases in the initial combustion
temperature limit increases in the combustion temperature in the cylinders. Thus, a greater
amount of nitrogen oxides NOx is reduced. Additionally, when the EGR gas is cooled by
the EGR cooler 142, volumetric expansion of the EGR gas is limited. This allows a greater
amount of the EGR gas to be supplied to the cylinders. More specifically, the EGR gas
amount, which is an amount of EGR gas recirculated into the cylinders, is increased. Thus,
a greater amount of nitrogen oxides NOx is reduced.
[0048] However, when PM (particulate matter) in the EGR gas collects on a metal surface
of the heat exchanger of the EGR cooler 142, heat exchange between the EGR gas and the
coolant in the heat exchanger of the EGR cooler 142 is inhibited. Thus, the cooling
efficiency of the EGR cooler 142 (hereinafter, may simply be referred to as the "EGR cooler
efficiency") is decreased. Decreases in the EGR cooler efficiency increase the temperature
of the EGR gas circulated to the intake passage. This increases the combustion temperature
in the cylinders and results in increases in the NOx discharge amount.
11 11654308_1(GHMaters) P111876.AU
[0049] Fig. 2 is a graph schematically showing the correspondence relationship between
the EGR cooler efficiency and the NOx discharge amount. When the EGR cooler 142 is in
an initial state, PM is not collected on the metal surface of the heat exchanger. Thus, as
shown in Fig. 2, the initial value CO of the EGR cooler efficiency is high. Accordingly, the
initial value E0 of the NOx discharge amount is limited to a low value. However, as the
EGR cooler efficiency is decreased due to aging deterioration caused by collection of PM,
the NOx discharge amount is increased.
[0050] There is a prior art technique that assumes that the EGR cooler efficiency is
decreased to a predetermined value C1 due to aging deterioration caused by collection of PM
and determines properties of the EGR cooler 142 so that when the EGR cooler efficiency is
decreased to the predetermined value C1, a NOx discharge amount El will not exceed a
regulatory value. This technique allows the NOx discharge amount to increase to a value
close to the regulatory value and cannot limit increases in the NOx discharge amount. For
the future, there is a need for developing a technique that limits increases in the NOx
discharge amount by maintaining the EGR cooler efficiency at a value close to the initial
value CO.
[0051] In this regard, the ECU 200 of the present embodiment determines whether the
EGR cooler efficiency is decreased based on the NOx discharge amount detected by the
NOx sensors 121. When it is determined that the EGR cooler efficiency is decreased, the
ECU 200 executes an EGR cooler regeneration process to remove PM from the EGR cooler
142. The process will now be described in detail.
EGR Cooler Efficiency Decrease Determination Process
[0052] The present embodiment of a process for determining a decrease in the EGR cooler
efficiency will now be described. When the EGR cooler efficiency is decreased, the
density of the EGR gas is lowered. This decreases the EGR gas amount, that is, the amount
12 11654308_1 (GHMaers)P111876.AU of EGR gas recirculated into the cylinders. Decreases in the EGR gas amount improve the ignition performance of fuel in the cylinders. More specifically, an ignition delay period decreases. Improvement in the fuel ignition performance increases the combustion temperature in the cylinders. Thus, the NOx discharge amount is increased. More specifically, decreases in the EGR cooler efficiency result in increases in the NOx discharge amount.
[0053] The ECU 200 determines whether the EGR cooler efficiency is decreased by
detecting an increase in the NOx discharge amount. More specifically, the ECU 200
determines whether the NOx discharge amount detected by at least one of the NOx sensors
121 is greater than a threshold value Eth. In this determination, the threshold value Eth
may be compared to each of NOx discharge amounts detected by two or more of the NOx
sensors 121. Alternatively, the threshold value Eth may be compared to the NOx discharge
amount detected by only a specified one of the NOx sensors 121.
[0054] The ECU 200 may perform this determination through two or more of the NOx
sensors 121 or only one of the NOx sensors 121. More specifically, the engine control
system 1 may include multiple NOx sensors 121 or may include only one NOx sensor 121.
For example, the engine may include one NOx sensor 121 arranged in the exhaust passage at
the downstream side of the exhaust manifold 130. The threshold value Eth may be
compared to a NOx discharge amount detected by the NOx sensor 121.
[0055] When the NOx discharge amount detected by the NOx sensor 121 is greater than the
threshold value Eth, the ECU 200 determines that the EGR cooler efficiency is decreased to
below a reference value Cth (refer to Fig. 2 described above).
[0056] In the prior art, the EGR cooler efficiency is estimated by assigning an inlet gas
temperature TGin, an outlet gas temperature TGout, and an inlet water temperature TW of
the EGR cooler in equation (1) shown below.
13 11654308_1 (GHMaers)P111876.AU
[0057] EGR Cooler Efficiency = (TGin-TGout)/(TGin-TW) ... (1)
[0058] However, when the EGR cooler efficiency is estimated using equation (1) shown
above, at least three temperature sensors, that is, a temperature sensor detecting the inlet gas
temperature TGin of the EGR cooler, a temperature sensor detecting the outlet gas
temperature TGout of the EGR cooler, and a temperature sensor detecting the inlet water
temperature TW of the EGR cooler, are necessary. This may increase the cost and cause
trouble with mounting the sensors.
[0059] In this regard, in the present embodiment, the EGR cooler efficiency is estimated
using at least one NOx sensor 121. This may solve the issues of the cost increase and
mounting described above.
EGR Cooler Regeneration Process
[0060] The process for regenerating the EGR cooler will now be described. As described
above, it is assumed that a decrease in the EGR cooler efficiency is mainly caused by PM in
the EGR gas collecting on the metal surface of the heat exchanger of the EGR cooler 142
and inhibiting heat exchange.
[0061] Thus, when the above-described decrease determination process determines that the
EGR cooler efficiency is decreased to below the reference value Cth, the ECU 200 increases
the flow rate of the EGR gas to remove the PM from the metal surface of the heat exchanger
of the EGR cooler 142. For example, the ECU 200 continues the EGR cooler regeneration
process for a predetermined amount of time TI (e.g., a few minutes). TheEGRcooler
regeneration process includes a process of increasing the amount (main injection amount) of
fuel injected into each cylinder while maintaining the open state of the EGR valve 144 so
that the intake air amount is set to a predetermined value G Ithat is greater than a normal
intake air amount, which is used during a normal operation (when it is determined that the
EGR cooler efficiency is not decreased).
14 11654308_1 (GHMaers)P111876.AU
[0062] The EGR cooler regeneration process increases the flow rate of the EGR gas, and
the EGR gas blows off the PM collected on the metal surface of the heat exchanger of the
EGR cooler 142. This allows the EGR cooler efficiency to regain to a value close to the
initial value (refer to Fig. 2 described above). As a result, the NOx discharge amount is
also decreased to a value close to the initial value EO.
[0063] Fig. 3 is a graph schematically showing an example of changes in NOx discharge
amount and intake air amount when executing the EGR cooler efficiency decrease
determination process and the EGR cooler regeneration process. As the EGR cooler
efficiency is decreased due to aging deterioration caused by collection of PM, the NOx
discharge amount is gradually increased from the initial value EO.
[0064] At time tl, when the NOx discharge amount reaches the threshold value Eth, the
ECU 200 determines that the EGR cooler efficiency is decreased. For the sake of
convenience, Fig. 3 shows a relatively short period as the period from time tO, at which the
NOx discharge amount starts to increase from the initial value E0 due to aging deterioration,
to time tl, at which the NOx discharge amount reaches the threshold value Eth. However,
it is assumed that the actual period is relatively long, for example, a few months or a few
years.
[0065] When it is determined that the EGR cooler efficiency is decreased at time tl, at
which the NOx discharge amount reaches the threshold value Eth, the ECU 200 executes the
EGR cooler regeneration process. The intake air amount is increased to the predetermined
value GI for the predetermined amount of time TI (e.g., a few minutes) from time tI to time
t2. Consequently, the flow rate of the EGR gas is increased, and the EGR gas blows off the
PM collected on the EGR cooler 142. This allows the EGR cooler efficiency to regain to a
value close to the initial value CO. As a result, the NOx discharge amount is decreased to a
value close to the initial value EO.
15 11654308_1 (GHMaers)P111876.AU
[0066] Fig. 4 is a flowchart schematically showing a process executed by the ECU 200
when executing the EGR cooler efficiency decrease determination process and the EGR
cooler regeneration process described above. The flowchart is repeated whenever a
predetermined condition is satisfied (e.g., in a predetermined cycle) while the engine 100 is
running.
[0067] The ECU 200 obtains a NOx discharge amount detected by the NOx sensors 121
(step S10) and determines whether the NOx discharge amount is greater than the threshold
value Eth (step S12). Instep S12, as described above, the threshold value Eth maybe
compared to each of NOx discharge amounts detected by two or more of the NOx sensors
121. Alternatively, the threshold value Eth maybe compared to the NOx discharge amount
detected by only a specified one of the NOx sensors 121.
[0068] When it is determined that the NOx discharge amount is not greater than the
threshold value Eth (step S12: NO), the ECU 200 skips the subsequent process and proceeds
to RETURN.
[0069] When it is determined that the NOx discharge amount is greater than the threshold
value Eth (step S12: YES), the ECU 200 determines that the EGR cooler efficiency is
decreased to below the reference value Cth (step S14). The ECU 200 executes the EGR
cooler regeneration process, which increases the main injection amount so that the intake air
amount is set to the predetermined value G1 for the predetermined amount of time Ti (step
S18).
[0070] As described above, when the NOx discharge amount detected by the NOx sensors
121 is greater than the threshold value Eth, the ECU 200 of the present embodiment
determines that the EGR cooler efficiency is decreased. Then, the ECU 200 executes the
EGR cooler regeneration process, which increases the main injection amount to increase the
flow rate of the EGR gas. The EGR gas blows off the PM collected on the heat exchanger
16 11654308_1 (GHMaers)P111876.AU of the EGR cooler 142. As a result, the EGR cooler efficiency is recovered from the age deterioration, and the NOx discharge amount is decreased.
First Modified Example
[0071] In the above embodiment, when the NOx discharge amount is greater than the
threshold value Eth, it is determined that the EGR cooler efficiency is decreased, and the
EGR cooler regeneration process is executed. However, since the EGR cooler regeneration
process includes a process for increasing the main injection amount, frequent execution of
the EGR cooler regeneration process may adversely affect fuel economy.
[0072] In this regard, in a first modified example, when the NOx discharge amount exceeds
the threshold value Eth, the ECU 200 retards the main injection timing of each cylinder by a
predetermined amount a. As shown in Fig. 5, after the main injection timing is retarded by
the predetermined amount a, if the NOx discharge amount again exceeds the threshold value
Eth, the main injection timing is again retarded by the predetermined amount a. Thus,
increases in the NOx discharge amount caused by decreases in the EGR cooler efficiency are
limited by retarding the main injection timing instead of executing the EGR cooler
regeneration process. In the first modified example, the retardation of the main injection
timing is repeated whenever the NOx discharge amount exceeds the threshold value Eth.
This allows the main injection timing to reach a retardation limit that is determined by hard
constraints or the like. When the main injection timing reaches the retardation limit, the
ECU 200 determines that the EGR cooler efficiency is decreased to a level at which the
decrease in the EGR cooler efficiency cannot be hindered by the retardation of the main
injection and executes the EGR cooler regeneration process. Asa result, increases in the
NOx discharge amount are limited while reducing the number of times the EGR cooler
regeneration process is executed.
[0073] Fig. 5 is a graph schematically showing an example of changes in the NOx
17 11654308_1 (GHMaers)P111876.AU discharge amount, the main injection timing, the pilot injection amount, and the intake air amount when executing the EGR cooler efficiency decrease determination process and the
EGR cooler regeneration process in the first modified example. Fig. 5 shows an example in
which the initial value of the main injection timing is set to a retardation side of the time at
which the piston reaches top dead center (TDC).
[0074] When the EGR cooler efficiency is decreased due to aging deterioration caused by
collection of PM, the NOx discharge amount is increased. At time t3, when the NOx
discharge amount exceeds the threshold value Eth, the ECU 200 retards the main injection
timing by the predetermined amount a. This lowers the peak of the combustion
temperature in the cylinder. Thus, the NOx discharge amount is decreased.
[0075] Retardation of the main injection timing by the predetermined amount a adversely
affects the ignition performance of fuel in the cylinder. In the first modified example, the
ECU 200 increases the pilot injection amount by a predetermined value P to limit the adverse
effect on the fuel ignition performance. Thus, as compared to when the pilot injection
amount is not increased, the ignition performance is assured, and increases in the NOx
discharge amount are further limited.
[0076] After the NOx discharge amount is temporarily decreased by retardation of the main
injection timing and increase in the pilot injection amount, if the EGR cooler efficiency is
further decreased by collection of PM, the NOx discharge amount is again increased. At
time t4, when the NOx discharge amount again exceeds the threshold value Eth, the ECU
200 further retards the main injection timing by the predetermined amount a and further
increases the pilot injection amount by the predetermined value. The same process is
performed at time t5.
[0077] At time t6, the NOx discharge amount is again increased and exceeds the threshold
value Eth by a further decrease in the EGR cooler efficiency. At time t6, when the main
18 11654308_1 (GHMaers)P111876.AU injection timing is further retarded by the predetermined amount a, the main injection timing reaches a predetermined retardation limit. The retardation limit is a value determined by hard constraints or the like. The retardation limit may be set to a limit value. For example, unless the main injection timing reaches the retardation limit, retardation of the main injection timing will not cause performance degradation and lubrication impurity of the engine 100.
[0078] In the first modified example, when the main injection timing reaches the
retardation limit at time t6, the ECU 200 determines that the EGR cooler efficiency is
decreased to a level at which the decrease in the EGR cooler efficiency cannot be inhibited
by the retardation of the main injection and executes the EGR cooler regeneration process.
As a result, the EGR cooler efficiency is recovered from the age deterioration, and the NOx
discharge amount is decreased to a value close to the initial value EO.
[0079] In the first modified example, when the EGR cooler regeneration process is
executed, the ECU 200 initializes the main injection timing and the pilot injection amount.
More specifically, the main injection timing and the pilot injection amount are each returned
to the initial value.
[0080] Fig. 6 is a flowchart schematically showing a process executed by the ECU 200
when executing the EGR cooler efficiency decrease determination process and the EGR
cooler regeneration process described above in the first modified example. The process of
steps S10, S12, and S18 shown in Fig. 6 is the same as the process of steps S10, S12, and
S18 shown in Fig. 4.
[0081] The ECU 200 obtains a NOx discharge amount detected by the NOx sensors 121
(step S10) and determines whether the NOx discharge amount is greater than the threshold
value Eth (step S12).
[0082] When it is determined that the NOx discharge amount is not greater than the
19 11654308_1 (GHMaers)P111876.AU threshold value Eth (step S12: NO), the ECU 200 skips the subsequent process and proceeds to RETURN.
[0083] When it is determined that the NOx discharge amount is greater than the threshold
value Eth (step S12: YES), the ECU 200 retards the present main injection timing by the
predetermined amount a to calculate main injection timing after retardation (step S20).
[0084] Then, the ECU 200 determines whether the calculated main injection timing after
retardation reaches the retardation limit (step S22).
[0085] When the calculated main injection timing after retardation does not reach the
retardation limit (step S22: NO), the ECU 200 retards the main injection timing (step S24)
and increases the pilot injection amount (step S28). More specifically, the ECU 200 retards
the main injection timing by the predetermined amount a from the present main injection
timing and increases the pilot injection amount by the predetermined value# from the
present pilot injection amount.
[0086] When the calculated main injection timing after retardation reaches the retardation
limit (step S22: YES), the ECU 200 determines that the EGR cooler efficiency is decreased
to a level at which the decrease in the EGR cooler efficiency cannot be hindered by the
retardation of the main injection (step S14A) and executes the EGR cooler regeneration
process (step S18). After executing the EGR cooler regeneration process, the ECU 200
initializes the main injection timing (step S30) and the pilot injection amount (step S32).
[0087] As described above, in the first modified example, whenever the NOx discharge
amount exceeds the threshold value Eth, the ECU 200 retards the main injection timing by
the predetermined amount a. When the retardation is repeated and the main injection
timing reaches the retardation limit, the ECU 200 determines that the EGR cooler efficiency
is decreased and executes the EGR cooler regeneration process. As a result, increases in
the NOx discharge amount are limited while reducing the number of times the EGR cooler
20 11654308_1 (GHMaers)P111876.AU regeneration process is executed.
Second Modified Example
[0088] In the above embodiment, when the NOx discharge amount is greater than the
threshold value Eth, it is determined that the EGR cooler efficiency is decreased, and the
EGR cooler regeneration process is executed. In the first modified example, whenever the
NOx discharge amount exceeds the threshold value Eth, the main injection timing is retarded
by the predetermined amount a. When the main injection timing reaches the retardation
limit, it is determined that the EGR cooler efficiency is decreased, and the EGR cooler
regeneration process is executed.
[0089] In a second modified example, the ECU 200 executes feedback control that
increases and decreases the pilot injection amounts of multiple cylinders so that the NOx
discharge amounts are equal to each other among the cylinders. The ECU 200 adjusts the
pilot injection amount of each cylinder by a corresponding feedback adjustment amount.
When the feedback adjustment amount corresponding to at least one of the cylinders is
outside an adjustment range, the ECU 200 determines that the EGR cooler efficiency is
decreased and executes the EGR cooler regeneration process. This point will now be
described in detail.
[0090] When the EGR cooler efficiency is decreased, the density of the EGR gas is
lowered, which decreases the amount of the EGR gas circulated into the cylinders. Thus,
the concentration of the EGR gas in the intake manifold 120 becomes significantly uneven.
This increases the difference between the amount of EGR gas flowing into a cylinder and the
amount of EGR gas flowing into another cylinder and may cause variations in the ignition
performance between the cylinders. Variations in the ignition performance between
cylinders increase the difference in the NOx discharge amount between the cylinders.
More specifically, when the EGR cooler efficiency is decreased, the difference in the amount
21 11654308_1 (GHMaers)P111876.AU of EGR gas flowing to cylinders increases between the cylinders, and the difference in the
NOx discharge amount increases between the cylinders.
[0091] Taking this point into consideration, in the second modified example, the ECU 200
executes feedback control that increases and decreases the pilot injection amount of each of
the cylinders so that the NOx discharge amounts are equal to each other among the cylinders.
In a cylinder containing a large amount of EGR gas, the ignition performance degrades, and
the combustion temperature is lowered. Hence, the NOx discharge amount tends to
decrease. Thus, for a cylinder in which the NOx discharge amount is decreased, the ECU
200 decreases the pilot injection amount from a base injection amount (average injection
amount of cylinders) so that the NOx discharge amount is increased. When the pilot
injection amount is decreased from the base injection amount, the main injection timing may
also be advanced by a predetermined amount.
[0092] In a cylinder having a small amount of EGR gas, the ignition performance improves,
and the combustion temperature is increased. Hence, the NOx discharge amount tends to
increase. Thus, for a cylinder in which the NOx discharge amount is increased, the ECU
200 increases the pilot injection amount from the base injection amount so that the NOx
discharge amount is decreased. When the pilot injection amount is increased from the base
injection amount, the main injection timing may also be retarded by a predetermined amount.
[0093] The difference in the EGR gas amount (difference in the NOx discharge amount)
from one cylinder to another cylinder may be recognized by detection values of the NOx
sensors 121 respectively provided for the cylinders. Alternatively, the design of
experiments may be used to recognize the difference in the EGR gas amount (difference in
the NOx discharge amount) under a specified load. When the design of experiments is used,
the difference in the EGR gas amount may be recognized using detection values of the
exhaust temperature sensor 125 and a NOx sensor arranged in the exhaust pipe 131 in which
22 11654308_1 (GHMaers)P111876.AU the exhaust is collected from the cylinders.
[0094] The feedback control is executed as described above. The amount of the pilot
injection amount that is increased or decreased from the base injection amount (hereafter,
may also be referred to as "pilot F/B adjustment amount") has an adjustment limit. In the
second modified example, when at least one of the pilot F/B adjustment amounts of the
cylinders is outside a predetermined adjustment range (range from adjustment lower limit
value to adjustment upper limit value), the ECU 200 determines that the EGR cooler
efficiency is decreased and executes the EGR cooler regeneration process.
[0095] Fig. 7 is a diagram showing an example of variations in the pilot F/B adjustment
amount in four cylinders (#1, #2, #3, #4) of the engine 100. In the example shown in Fig. 7,
pilot F/B adjustment amounts corresponding to when the pilot injection amount is increased
from the base injection amount are shown in the cylinders #1 and #4, and pilot F/B
adjustment amounts corresponding to when the pilot injection amount is decreased from the
base injection amount are shown in the cylinders #2 and #3.
[0096] In the example shown in Fig. 7, the pilot F/B adjustment amount of the cylinder #4
is outside the adjustment range, and more specifically, exceeds the adjustment upper limit
value. In such a state, the ECU 200 determines that the EGR cooler efficiency is decreased
and executes the EGR cooler regeneration process.
[0097] Fig. 8 is a flowchart schematically showing a process executed by the ECU 200
when executing the EGR cooler efficiency decrease determination process and the EGR
cooler regeneration process described above in the second modified example.
[0098] The ECU 200 obtains the NOx discharge amount of each cylinder from the
corresponding one of the NOx sensors 121 (step S50).
[0099] The ECU 200 uses the NOx discharge amount of each cylinder obtained in step S50
to calculate the pilot F/B adjustment amount of the cylinder so that the EGR gas amounts of
23 11654308_1 (GHMaers)P111876.AU the cylinders are equal to each other (step S52).
[0100] The ECU 200 determines whether any one of the pilot F/B adjustment amounts of
the cylinders is outside the predetermined adjustment range (i.e., greater than the adjustment
upper limit value or less than the adjustment lower limit value) (step S60).
[0101] When there is no pilot F/B adjustment amount that is outside the predetermined
adjustment range (step S60: NO), the ECU 200 sets the pilot injection amount of each
cylinder to a value added by the pilot F/B adjustment amount corresponding to the base
injection amount (step S62).
[0102] When there is a pilot F/B adjustment amount that is outside the predetermined
adjustment range (step S60: YES), the ECU 200 determines that the EGR cooler efficiency is
decreased (step S14B) and executes the EGR cooler regeneration process (step S18).
[0103] As described above, in the second modified example, the ECU 200 executes
feedback control that increases and decreases the pilot injection amounts of multiple
cylinders so that the NOx discharge amounts are equal to each other among the cylinders
based on the NOx discharge amounts detected by the NOx sensors 121. When at least one
of the pilot F/B adjustment amounts of the cylinders is outside the predetermined adjustment
range, the ECU 200 determines that the EGR cooler efficiency is decreased and executes the
EGR cooler regeneration process. Thus, after appropriately determining whether the
cooling efficiency of the EGR cooler is decreased based on the feedback adjustment amount
of the pilot injection amount controlled in accordance with the NOx discharge amount
detected by the NOx sensors 121, the EGR cooler regeneration process is executed.
[0104] Various changes in form and details may be made to the examples above without
departing from the spirit and scope of the claims and their equivalents. The examples are
for the sake of description only, and not for purposes of limitation. Descriptions of features
in each example are to be considered as being applicable to similar features or aspects in
24 11654308_1 (GHMaers)P111876.AU other examples. Suitable results may be achieved if sequences are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined differently, and/or replaced or supplemented by other components or their equivalents. The scope of the disclosure is not defined by the detailed description, but by the claims and their equivalents. All variations within the scope of the claims and their equivalents are included in the disclosure.
[0105] In this specification, the terms "comprise", "comprises", "comprising" or
similar terms are intended to mean a non-exclusive inclusion, such that a system, method or
apparatus that comprises a list of elements does not include those elements solely, but may
well include other elements not listed.
[0106] The reference to any prior art in this specification is not, and should not be taken as,
an acknowledgement or any form of suggestion that the prior art forms part of the common
general knowledge in Australia.
25 11654308_1 (GHMaers)P111876.AU
Claims (6)
1. A system for controlling an engine, the engine including a cylinder
connected to an intake passage and an exhaust passage, an EGR pipe configured to
recirculate a portion of exhaust from the exhaust passage to the intake passage, and an EGR
cooler arranged on the EGR pipe, the system comprising:
a sensor arranged on the exhaust passage and configured to detect a discharge
amount of nitrogen oxides; and
a controller, wherein
the controller is configured to determine whether a cooling efficiency of the EGR
cooler is decreased based on the discharge amount of nitrogen oxides detected by the sensor,
and
the controller is configured to execute an EGR cooler regeneration process to
remove particulate matter from the EGR cooler when it is determined that the cooling
efficiency of the EGR cooler is decreased.
2. The system according to claim 1, wherein the controller is configured to
determine that the cooling efficiency of the EGR cooler is decreased and execute the EGR
cooler regeneration process when the discharge amount of nitrogen oxides is greater than a
threshold value.
3. The system according to claim 1, wherein
the engine is configured so that multiple fuel injections are performed on the
cylinder in one cycle,
the multiple fuel injections include a pilot injection and a main injection,
26 11654308_1 (GHMaers)P111876.AU the controller is configured to retard timing of the main injection by a predetermined amount when the discharge amount of nitrogen oxides is greater than a threshold value, and the controller is configured to determine that the cooling efficiency of the EGR cooler is decreased and execute the EGR cooler regeneration process when timing of the main injection is retarded and reaches a predetermined retardation limit.
4. The system according to claim 1, wherein
the cylinder is one of cylinders,
the engine is configured so that multiple fuel injections are performed on each of
the cylinders in one cycle,
the multiple fuel injections include a pilot injection and a main injection,
the controller is configured to execute feedback control that increases and decreases
a pilot injection amount by a feedback adjustment amount corresponding to each of the
cylinders based on a detection result of the sensor so that the discharge amount of nitrogen
oxides is equal among the cylinders, and
the controller is configured to determine that the cooling efficiency of the EGR
cooler is decreased and execute the EGR cooler regeneration process when the feedback
adjustment amount corresponding to at least one of the cylinders is outside a predetermined
adjustment range.
5. The system according to any one of claims 1 to 4, wherein the EGR cooler
regeneration process includes a control that increases an intake air amount of the engine for a
predetermined amount of time.
27 11654308_1 (GHMaers)P111876.AU
6. A method for controlling an engine, the engine including a cylinder
connected to an intake passage and an exhaust passage, an EGR pipe configured to
recirculate a portion of exhaust from the exhaust passage to the intake passage, and an EGR
cooler arranged on the EGR pipe, the method comprising:
detecting a discharge amount of nitrogen oxides in the exhaust passage;
determining whether a cooling efficiency of the EGR cooler is decreased based on
the detected discharge amount of nitrogen oxides; and
executing an EGR cooler regeneration process to remove particulate matter from the
EGR cooler when it is determined that the cooling efficiency of the EGR cooler is decreased.
28 11654308_1 (GHMaers)P111876.AU
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018-165586 | 2018-09-05 | ||
| JP2018165586A JP2020037912A (en) | 2018-09-05 | 2018-09-05 | Control system of engine |
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| AU2019222845A1 AU2019222845A1 (en) | 2020-03-19 |
| AU2019222845B2 true AU2019222845B2 (en) | 2020-11-12 |
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| JP (1) | JP2020037912A (en) |
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Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8056544B2 (en) * | 2008-08-27 | 2011-11-15 | Ford Global Technologies, Llc | Exhaust gas recirculation (EGR) system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3998861B2 (en) * | 1999-06-16 | 2007-10-31 | 株式会社小松製作所 | Exhaust gas recirculation device and control method thereof |
| JP3835241B2 (en) * | 2001-10-15 | 2006-10-18 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engine |
| JP2005133580A (en) * | 2003-10-28 | 2005-05-26 | Denso Corp | Exhaust gas heat exchanger |
| JP4449816B2 (en) * | 2005-05-13 | 2010-04-14 | 株式会社日立製作所 | EGR gas flow rate detection device and engine control method |
| JP4525544B2 (en) * | 2005-09-28 | 2010-08-18 | トヨタ自動車株式会社 | Internal combustion engine with a supercharger |
| JP4849052B2 (en) * | 2007-10-25 | 2011-12-28 | 日産自動車株式会社 | Exhaust gas recirculation device for internal combustion engine |
| US8250865B2 (en) * | 2008-11-05 | 2012-08-28 | Ford Global Technologies, Llc | Using compressed intake air to clean engine exhaust gas recirculation cooler |
| JP2012154244A (en) * | 2011-01-26 | 2012-08-16 | Toyota Motor Corp | Internal combustion engine control device |
| JP5141807B1 (en) * | 2011-08-31 | 2013-02-13 | 株式会社豊田自動織機 | Combustion control device |
| JP2013113217A (en) * | 2011-11-29 | 2013-06-10 | Suzuki Motor Corp | Apparatus for removing unburned deposits in egr flow passage of vehicle |
| FR2986565B1 (en) * | 2012-02-06 | 2014-01-24 | Renault Sa | METHOD AND SYSTEM FOR DIAGNOSING THE INTAKE OF AIR IN AN INTERNAL COMBUSTION ENGINE OF A MOTOR VEHICLE |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8056544B2 (en) * | 2008-08-27 | 2011-11-15 | Ford Global Technologies, Llc | Exhaust gas recirculation (EGR) system |
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| AU2019222845A1 (en) | 2020-03-19 |
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