BACKGROUND OF THE INVENTION
Field of the Invention
[0001] This invention relates to an exhaust gas treatment system for an internal combustion
engine, particularly to an exhaust gas treatment system for use in an internal combustion
engine equipped with an oxidation catalytic converter and a diesel particulate filter
(DPF) positioned downstream thereof to capture particulates or particulate matter,
and more particularly to an exhaust gas treatment system that enables regeneration
of the filter by supplying unburned fuel.
Description of the Related Art
[0002] The exhaust system of a diesel engine is equipped with a DPF that removes fine particulate
matter from the exhaust gas by capturing them in microporous trap. As the buildup
of captured fine particulate matter increases, the filter progressively clogs. Therefore,
as taught by
Japanese Laid-Open Patent Application Nos. Hei 4(1992) -019315 and
Hei 5(1993)-044434, the practice is to regenerate the DPF by burning the fine particulate matter using
fuel supplied through a fuel injector installed in the exhaust system.
[0003] The teaching of the first reference is to detect the exhaust gas temperature immediately
downstream of the DPF and control the fuel supply quantity to increase as the air
intake quantity increases and decrease as the detected exhaust gas temperature rises.
The teaching of the second reference is to calculate the fuel supply quantity based
on the air intake quantity and the exhaust gas temperature upstream of the DPF, and
conduct control for downwardly correcting the calculated fuel supply quantity using
the exhaust gas temperature on the downstream side of the DPF.
[0004] As explained, the prior art teachings of the first and second references calculate
the fuel supply quantity using as one factor the exhaust gas temperature(s) downstream
of or before and after the DPF, i.e., exhaust gas temperatures near the DPF. This
makes it difficult to achieve the fuel supply quantity required for regeneration with
good accuracy.
[0005] This is because the exhaust gas temperature changes rapidly with change in the fuel
injection quantity when the internal combustion engine is in transient operation.
In the prior art, the detected temperature is that near, e.g., immediately downstream
of, the DPF, so that the detected value is a value skewed by the combustion in the
DPF or the mass of the DPF. Moreover, when the exhaust gas temperature is high, the
temperature of the exhaust manifold becomes high, so that when unburned fuel is supplied
during post-injection, the unburned fuel self-ignites and bums to increase the exhaust
gas temperature still further.
[0006] Moreover, when an oxidation catalytic converter for oxidizing unburned exhaust gas
components is installed upstream of the DPF, the detected temperature similarly becomes
a value skewed by the combustion in the catalytic converter or the mass of the catalytic
converter.
[0007] In
US 2004/074225 A1 on which the preamble of claims 1 and 2 is based, the first of upstream exhaust gas
temperature is detected by a temperature sensor 191 upstream of the catalyst 115a,
and a second or downstream exhaust gas temperature TN is detected by a temperature
sensor 193 between the catalyst 115a and the downstream particulate filter 115b. The
temperature TN detected by the downstream sensor 193 is only used for ending or interrupting
the regeneration of the particulate filter 115b, by comparing this temperature TN
to a temperature upstream of the filter. If the temperature downstream of the filter
is greater than the temperature upstream of the filter, regeneration is done for correcting
the heat release of the filter during regeneration, especially heat radiation.
SUMMARY OF THE INVENTION
[0008] An object of this invention is therefore to overcome the aforesaid problems by providing
an exhaust gas treatment system for an internal combustion engine which, in a configuration
equipped with an oxidation catalytic converter upstream of the filter (DPF), detects
the exhaust gas temperature and corrects the unburned fuel supply quantity unaffected
by the filter (DPF) or the oxidation catalytic converter upstream thereof and conducts
regeneration treatment using the corrected unburned fuel supply quantity, thereby
achieving accurate supply of the unburned fuel quantity required for regeneration
and improving the regeneration efficiency of the filter (DPF).
[0009] In order to achieve the object, this invention provides a system for treating exhaust
gas produced by an internal combustion engine in accordance with claim 1 and a method
in accordance with claim 2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above and other objects and advantages of the invention will be more apparent
from the following description and drawings in which:
FIG. 1 is a schematic drawing showing the overall configuration of an exhaust gas
treatment system for an internal combustion engine according to an embodiment of the
invention;
FIG. 2 is a block diagram illustrating the operation of the system shown in FIG. 1;
FIG. 3 is a graph for explaining the tabulated characteristic of an injection quantity
correction factor with respect to an exhaust gas temperature TEX1, which is used in
the processing of FIG. 2; and
FIG. 4 is a graph for explaining the mapped characteristic of an exhaust gas temperature
correction weight (injection quantity correction factor correction value) with respect
to engine speed NE and a fuel injection quantity Q (exhaust gas flow rate), which
is used in the processing of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] An exhaust gas treatment system for an internal combustion engine according to an
embodiment of the present invention will now be explained with reference to the attached
drawings.
[0012] FIG. 1 is a schematic drawing showing the overall configuration of the exhaust gas
treatment system for an internal combustion engine according to this embodiment of
the invention.
[0013] The reference numeral 10 in FIG. 1 designates a four-cylinder internal combustion
engine, more specifically diesel engine (compression-ignition engine) and the reference
numeral 10a designates the main unit of the engine 10. Intake air sucked in through
an air cleaner 12 of the engine 10 flows through an air intake pipe (air intake passage)
14.
[0014] An intake shutter or intake air throttle 16 is installed at a suitable point in the
intake pipe 14. The intake shutter 16 includes a valve 16a and an electric motor or
other actuator 16b connected to the valve 16a. When the actuator 16b of the intake
shutter 16 is driven by a drive circuit (not shown) to rotate the valve 16a in the
closing direction, the opening of the intake pipe 14 is reduced to reduce the flow
rate of intake air through the intake pipe 14.
[0015] The air flowing through the intake pipe 14 passes through an intake manifold 20 installed
downstream of the intake shutter 16 and arrives at the individual cylinders to be
drawn into their combustion chambers (not shown) when the associated intake valve
(not shown) opens and the associated piston (not shown) descends. The inspired air
is compressed and reaches a high temperature when the piston ascends.
[0016] Fuel (kerosene) stored in a fuel tank (not shown) is supplied through a pump and
a common rail (neither shown) to fuel injectors 22 (only one shown) directed into
the combustion chambers of the individual cylinders. When each fuel injector 22 is
driven through a drive circuit (not shown), it injects fuel into the associated combustion
chamber and the injected fuel spontaneously ignites and burns upon coming in contact
with the compressed, high-temperature intake air. As a result, the piston is first
driven downward and thereafter ascends to discharge the exhaust gas into an exhaust
manifold 24 (of the exhaust system) upon opening of an associated exhaust valve (not
shown). The exhaust gas then flows into a downstream exhaust pipe 26 (of the exhaust
system).
[0017] An EGR pipe (Exhaust Gas Recirculation passage) 30 connected to the intake pipe 14
at one end is connected to the exhaust pipe 26 at the other end. The EGR pipe 30 is
equipped with an EGR valve 30a. When the EGR valve 30a is operated through a drive
circuit (not shown), the EGR pipe 30 is opened to return part of the exhaust gas to
the air intake system.
[0018] The turbine (not shown) of a turbocharger (illustrated as "T/C") 32 is installed
in the exhaust pipe 26 at a location downstream of the point at which the EGR pipe
30 is connected. The turbine is rotated by the exhaust gas to drive a compressor 32a
through a mechanical interconnection, thereby supercharging the engine 10 with intake
air from the air cleaner 12.
[0019] An oxidation catalytic converter (illustrated as "CAT") 34 utilizing platinum or
the like as catalyst is installed in the exhaust pipe 26 downstream of the turbocharger
32. The oxidation catalytic converter 34 oxidizes and removes unburned hydrocarbons
in the exhaust gas. The oxidization conducted in the oxidation catalytic converter
34 increases the exhaust gas temperature. This will be discussed in more detail later.
[0020] A DPF (Diesel Particulate Filter) 36 is installed downstream of the oxidation catalytic
converter 34 for capturing particulates entrained by the exhaust gas. The DPF 36 comprises
a ceramic honeycomb filter internally provided with exhaust gas passages whose upstream
ends are closed and downstream ends are opened arranged alternately with exhaust gas
passages whose upstream ends are opened and downstream ends are closed. Microporous
walls formed with numerous holes of around 10 µm diameter are provided between adjacent
passages. Particulates contained in the exhaust gas are captured in these holes.
[0021] The DPF 36 experiences clogging owing to gradual buildup of the so-captured particulates.
In this embodiment, the DPF 36 is a catalyzed soot filter (CSF) in which the temperature
at which the particulates can be burned is reduced by the action of a catalyst carried
on the filter and the particulates captured from the exhaust gas are burned at the
reduced temperature.
[0022] After passing through the DPF 36, the exhaust gas passes through a silencer, tailpipe
and the like (none of which are shown) to be discharged to outside the engine 10.
[0023] A crank angle sensor 40 including multiple sets of magnetic pickups is installed
near the crankshaft (not shown) of the engine 10. The crank angle sensor 40 produces
outputs indicative of a cylinder identification signal, a TDC signal at or near the
TDC of each of the four cylinders, and a crank angle signal every prescribed crank
angle.
[0024] A coolant temperature sensor 42 installed near a coolant passage (not shown) of the
engine 10 produces an output or signal indicative of the engine coolant temperature
TW. An intake air temperature sensor 44 is installed in the intake pipe 14 at a point
near the air cleaner 12. The intake air temperature sensor 44 outputs a signal indicative
of the temperature of intake air sucked into the engine 10 (the intake air temperature
or outside air temperature).
[0025] An accelerator position sensor 50 is installed near an accelerator pedal 46 located
on the floor near the driver's seat (not shown) of the vehicle in which the engine
10 is installed. The accelerator position sensor 50 produces an output or signal indicative
of the accelerator position or opening θAP, which is indicative of the engine load.
A wheel speed sensor 52 installed at a suitable part of a wheel (not shown) produces
an output or signal every predetermined angle of rotation of the wheel indicative
of a travel speed of the vehicle.
[0026] A first exhaust gas temperature sensor 54 is installed in the exhaust system of the
engine 10 at a suitable location downstream of the turbocharger 32 and upstream of
the oxidation catalytic converter 34. The first exhaust gas temperature sensor 54
produces an output indicative of the exhaust gas temperature TEX1 on the upstream
side of the oxidation catalytic converter 34 (temperature of the exhaust gas flowing
into the oxidation catalytic converter 34). A second exhaust gas temperature sensor
56 is installed downstream of the oxidation catalytic converter 34 and upstream of
the DPF 36 (immediately before the DPF 36). The second exhaust gas temperature sensor
56 produces an output indicative of the exhaust gas temperature TEX2 on the upstream
side of the DPF 36 (temperature of the exhaust gas flowing into the DPF 36).
[0027] The DPF 36 is provided with a differential pressure sensor 60 that produces an output
indicative of the differential pressure PDIF between the pressure of the exhaust gas
flowing into the DPF 36 and the pressure of the exhaust gas flowing out of the DPF
36, i.e., the differential pressure PDIF between the inlet side and outlet side pressures
of the DPF 36.
[0028] The outputs of the foregoing sensors are sent to an ECU (Electronic Control Unit)
62. The ECU 62 is constituted as a microcomputer comprising a CPU, ROM, RAM and input/output
circuit. The ECU 62 detects or calculates the engine speed NE of the engine 10 by
using a counter to count the crank angle signals outputted by the crank angle sensor
40 and detects or calculates the vehicle speed by using a counter to count the signals
outputted by the wheel speed sensor 52.
[0029] The ECU 62 is housed in a case (not shown) and installed at an appropriate location
near the driver's seat of the vehicle. An atmospheric pressure sensor 64 accommodated
in the case sends the ECU 62 an output indicative of the atmospheric pressure at the
current location of the engine 10.
[0030] The operation of the exhaust gas treatment system shown in FIG. 1 will now be explained.
[0031] FIG. 2 is a block diagram illustrating the operation. The diagram comprises functional
blocks representing the processing operations of the ECU 62. The operation of the
system will be explained with reference to these blocks.
[0032] First, in block 62a, the basic (post-injection) fuel injection quantity (basic supply
quantity of unburned fuel) required for regenerating the DPF 36 is determined or calculated
based on the engine speed NE and the ordinary, i.e., not post-injection fuel injection
quantity Q. The fuel injection quantity Q is determined in another processing step
(not shown) by using the accelerator position θAP to retrieve a value from an appropriate
characteristic and correcting the retrieved value based on other operating parameters.
[0033] The fuel injection quantity Q is determined as the valve open time of the injector
22. Every time each cylinder of the engine 10 is about to shift from the intake stroke
to the compression stroke, the associated injector 22 injects fuel into the combustion
chamber of the cylinder in a quantity equal to the determined fuel injection quantity
Q.
[0034] As pointed out above, the fuel injected into the combustion chamber spontaneously
ignites and bums to drive down the piston upon coming into contact with the intake
air raised to a high temperature by compression. The exhaust gas produced by the combustion
is discharged into the exhaust system, i.e., exhaust manifold 24 and exhaust pipe
26 when the exhaust valve opens during the exhaust stroke.
[0035] Post-injection is performed after the combustion of the fuel injected by ordinary
combustion at about the time power stroke is shifting from the expansion stroke to
the exhaust stroke during low or medium load operation of the engine 10 by injecting
fuel through the injector 22 based on the post-injection quantity. Most of the fuel
injected by the post-injection does not burn because no compressed air is present.
It is therefore discharged into the exhaust system as unburned fuel. Almost all of
the unburned fuel components are hydrocarbons (HC). The block 62a thus functions as
basic supply quantity calculating means for calculating the basic supply quantity
of unburned fuel based on an operating condition of the engine 10.
[0036] In block 62b, the engine speed NE and fuel injection quantity Q are used to determine
or calculate a corrected fuel injection quantity (corrected supply quantity of the
unburned fuel) for correcting the calculated basic (post-injection) fuel injection
quantity. A correction factor for correcting the calculated corrected fuel injection
quantity is also determined or calculated in block 62b.
[0037] Specifically, the exhaust gas temperature TEX1 (exhaust gas temperature on the upstream
side of the oxidation catalytic converter 34) is read in block 62b1 and then, in block
62b2, the read exhaust gas temperature TEX1 is used to determine or calculate the
corrected fuel injection quantity by retrieval from a tabulated characteristic determined
beforehand and stored in ROM.
[0038] FIG. 3 is a graph for explaining the tabulated characteristic. As shown, the corrected
fuel injection quantity is determined or defined to decrease with increasing exhaust
gas temperature TEX1. This is because the required (post-injection) fuel injection
quantity decreases with increasing exhaust gas temperature TEX1.
[0039] Thus, the blocks 62b1 and 62b2 function as corrected supply quantity calculating
means for calculating the corrected supply quantity of the unburned fuel to correct
the basic supply quantity based on the exhaust gas temperature TEX1 at a location
upstream of the oxidation catalytic converter 34.
[0040] Next, in block 62b3, the engine speed NE and (ordinary) fuel injection quantity Q
are used to determine or calculate an exhaust gas temperature correction weight (correction
value of the corrected supply quantity of the unburned fuel) by retrieval from a mapped
characteristic determined and stored in ROM beforehand.
[0041] FIG. 4 is a graph for explaining the mapped characteristic. The exhaust gas flow
rate or exhaust gas volume depends on the engine speed NE and fuel injection quantity
Q, namely, it increases as they increase. The foregoing therefore means that the exhaust
gas temperature correction weight is calculated based on the exhaust gas flow rate
in accordance with the mapped characteristic.
[0042] The exhaust gas flow rate affects the fuel supply quantity (i.e., the exhaust gas
temperature) required for regeneration of the DPF 36, and the amount of heat needed
to heat the DPF 36 to the temperature required for regeneration increases (or decreases)
as the exhaust gas flow rate increases (or decreases). Therefore, as shown in FIG.
4, the exhaust gas temperature correction weight is determined or defined to increase
with increasing engine speed NE and fuel injection quantity Q and decrease with decreasing
engine speed NE and fuel injection quantity Q, i.e., so as to increase and decrease
as the exhaust gas flow rate increases and decreases.
[0043] The exhaust gas temperature correction weight is calculated as a multiplier coefficient
such as 1.1 or 1.2. The corrected injection quantity is multiplied by the exhaust
gas temperature correction weight in block 62b4, thereby correcting the corrected
fuel injection quantity. Thus, the blocks 62b3, 62b4 function as corrected supply
quantity correction value calculating means for calculating the correction value of
the corrected supply quantity based on a flow rate of the exhaust gas produced by
the engine 10 such that the correction value increases with increasing flow rate of
the exhaust gas.
[0044] In block 62c, the corrected fuel injection quantity is added to the basic (post-injection)
fuel injection quantity. As a result, the basic (post-injection) fuel injection quantity
is corrected by the exhaust gas temperature TEX1 on the upstream side of the oxidation
catalytic converter 34 and, in addition, the corrected fuel injection quantity is
corrected by the flow rate of the exhaust gas discharged from the engine 10 so as
to increase with increasing exhaust gas flow rate.
[0045] Next, in block 62d, a correction amount for the temperature feedback correction by
the temperature sensor at the inlet of the DPF (the second exhaust gas temperature
sensor 56) is calculated. Specifically, the amount of change (increase or decrease)
in the manipulated variable (injection quantity) that will make the exhaust gas temperature
TEX2 detected by the second exhaust gas temperature sensor 56 equal to a desired temperature,
e.g., 600 °C, is calculated in response to the error or deviation between exhaust
gas temperature TEX2 and the desired temperature using a PI control term (or PID control
term). The calculated change is added to the sum of the basic (post-injection) fuel
injection quantity and the corrected fuel injection quantity in block 62e.
[0046] Next, in block 62f, the final (post-injection) fuel injection quantity (unburned
fuel supply quantity) is determined or calculated in terms of the valve opening time
of the injector 22 based on the basic (post-injection) fuel injection quantity, corrected
fuel injection quantity and temperature feedback correction amount, and the aforesaid
post-injection (unburned fuel supply) is executed based on the calculated final (post-injection)
fuel injection quantity.
[0047] Thus, the blocks 62c to 62f function as fuel supply executing means for calculating
the final supply quantity of the unburned fuel based on the calculated basic supply
quantity and corrected supply quantity and for executing supply of the unburned fuel
based on the calculated final supply quantity of the unburned fuel to the engine 10
such that the filter (DPF 36) is regenerated.
[0048] The injected fuel flows through the exhaust system to the oxidation catalytic converter
34 to give rise to an oxidization reaction (i.e., combustion). The exhaust gas heated
by the combustion flows into the DPF 36 located downstream to burn the accumulated
particulates captured by the DPF 36. As a result, the DPF 36 is unclogged and regenerated.
[0049] This embodiment is thus configured to have a system for treating exhaust gas produced
by an internal combustion engine (10) having an oxidation catalytic converter (34)
installed in an exhaust system (exhaust manifold 24, exhaust pipe 26) for oxidizing
and removing unburned hydrocarbons in the exhaust gas and a filter (DPF 36) installed
downstream of the oxidation catalytic converter for capturing particulates entrained
by the exhaust gas, characterized by: basic supply quantity calculating means (ECU
62, block 62a) for calculating a basic supply quantity of unburned fuel (basic (post-injection)
fuel injection quantity) based on an operating condition of the engine, more specifically
based on the engine speed NE and fuel injection quantity Q; corrected supply quantity
calculating means (ECU 62, blocks 62b1, 62b2) for calculating a corrected supply quantity
of the unburned fuel (corrected fuel injection quantity) to correct the basic supply
quantity based on an exhaust gas temperature at a location upstream of the oxidation
catalytic converter; and fuel supply executing means (ECU 62, blocks 62c, 62f) for
calculating a final supply quantity of the unburned fuel (final (post-injection) fuel
injection quantity) based on the calculated basic supply quantity and corrected supply
quantity and for executing supply of the unburned fuel based on the calculated final
supply quantity of the unburned fuel to the engine such that the filter is generated.
[0050] Thus the detected exhaust gas temperature TEX1 is not affected by the combustion
in the DPF 36 or the mass of the DPF 36, nor is it affected by the combustion in the
oxidation catalytic converter 34 or the mass thereof, so that the fuel supply quantity
required for regeneration can be achieved with good accuracy, thereby improving the
regeneration efficiency of the DPF 36.
[0051] In addition, the system further includes: corrected supply quantity correction value
calculating means (ECU 62, blocks 62b3, 62b4) for calculating a correction value of
the corrected supply quantity (exhaust gas temperature correction weight) based on
a flow rate of the exhaust gas produced by the engine. Therefore, by calculating and
injecting the post-injection quantity also taking into account the exhaust gas flow
rate which has an effect on the unburned fuel supply quantity (exhaust gas temperature)
required for regenerating the DPF 36, it becomes possible to achieve the fuel supply
quantity required for regenerating the DPF 36 without excess or deficiency, thereby
further enhancing the regeneration efficiency of the DPF 36.
[0052] Further, the corrected supply quantity correction value calculating means calculates
the correction value such that the correction value increases with increasing flow
rate of the exhaust gas, more specifically, with increasing engine speed NE and fuel
injection quantity Q. Therefore, when the fuel supply quantity required for regeneration
increases (or decreases) with increasing (or decreasing) exhaust gas flow rate, i.e.,
with increase (or decrease) in the amount of heat needed to heat the DPF 36 to the
required temperature, the required heat can be supplied accordingly without excess
or deficiency, thereby further enhancing the regeneration efficiency of the DPF 36.
[0053] In the foregoing, it is explained that the injection quantity correction factor (supply
quantity correction factor) is calculated as an addition value (addition term) and
the injection quantity correction factor correction value is calculated as a multiplier
coefficient (multiplier term). However, it is instead possible to calculate both as
addition terms or both as multiplier terms.
[0054] In the foregoing embodiment, the unburned fuel is supplied by conducting post-injection
through the injectors 22, but is possible instead to supply the unburned fuel through
an exhaust injector provided in the exhaust system.
[0055] Although the foregoing explanation is made taking application of the invention to
a vehicle engine as an example, the invention can also be applied to an engine for
a boat propulsion system such as an outboard motor having a vertically oriented crankshaft.
[0056] In an exhaust gas treatment system for an internal combustion engine, a basic (post-injection)
fuel injection quantity is calculated at block 62a based on an operating condition
of the engine, a corrected fuel injection quantity is calculated at blocks 62b1, 62b2
to correct the basic supply quantity based on an exhaust gas temperature TEX1 at a
location upstream of the oxidation catalytic converter, and a final (post-injection)
fuel injection quantity is calculated in blocks 62c to 62f based on the calculated
quantities and injected into the engine 10. Thus the detected exhaust gas temperature
TEX1 is not affected by the combustion in the DPF or the mass thereof, nor is it affected
by the combustion in the converter or the mass thereof, so that the fuel supply for
regeneration can be achieved with good accuracy, thereby improving the DPF regeneration
efficiency.
1. System zum Behandeln von von einem Verbrennungsmotor (10) erzeugtem Abgas, das einen
in einem Auspuffsystem (24, 26) angebrachten Oxidationskatalysator (34) aufweist,
um unverbrannte Kohlenwasserstoffe in dem Abgas zu oxidieren und zu beseitigen, sowie
einen Filter (36), der stromab des Oxidationskatalysators angebracht ist, um vom Abgas
mitgenommene Partikel aufzufangen, umfassend:
Basiszufuhrmengenberechnungsmittel (62, 62a) zum Berechnen einer Basiszufuhrmenge
von unverbranntem Kraftstoff basierend auf einem Betriebszustand des Motors;
Korrigierte-Zufuhrmengen-Berechnungsmittel (62, 62b1, 62b2) zum Berechnen einer korrigierten
Zufuhrmenge des unverbrannten Kraftstoffs zum Korrigieren der Basiszufuhrmenge basierend
auf einer Abgastemperatur an einer Stelle stromauf des Oxidationskatalysators; und
Kraftstoffzufuhrausführungsmittel (62, 62c bis 62f) zum Berechnen einer End-Zufuhrmenge
des unverbrannten Kraftstoffs basierend auf der berechneten Basiszufuhrmenge und der
korrigierten Zufuhrmenge und zum Ausführen der Zufuhr des unverbrannten Kraftstoffs
basierend auf der berechneten End-Zufuhrmenge des unverbrannten Kraftstoffs zu dem
Motor derart, dass der Filter regeneriert wird,
gekennzeichnet durch
Bestimmungsmittel (62, 62b3, 62b4) zum Bestimmen eines Abgastemperaturkorrekturgewichts,
das mit zunehmender Motordrehzahl (NE) und Kraftstoffeinspritzmenge (Q) zunimmt und
mit abnehmender Motordrehzahl (NE) und Kraftstoffeinspritzmenge (Q) abnimmt, so dass
es zunimmt und abnimmt, wenn die Abgasströmungsrate zunimmt und abnimmt, und
Korrekturmittel zum Korrigieren der korrigierten Zufuhrmenge durch Multiplizieren der korrigierten Zufuhrmenge mit dem Abgastemperaturkorrekturgewicht.
2. Verfahren zum Behandeln von von einem Verbrennungsmotor (10) erzeugtem Abgas, der
einen in einem Auspuffsystem (24, 26) angebrachten Oxidationskatalysator (34) aufweist,
um unverbrannte Kohlenwasserstoffe in dem Abgas zu oxidieren und zu beseitigen, sowie
einen Filter (36), der stromab des Oxidationskatalysators angebracht ist, um vom Abgas
mitgenommene Partikel aufzufangen, welches die Schritte umfasst:
Berechnen (62, 62a) einer Basiszufuhrmenge von unverbranntem Kraftstoff basierend
auf einem Betriebszustand des Motors;
Berechnen (62, 62b1, 62b2) einer korrigierten Zufuhrmenge des unverbrannten Kraftstoffs
zum Korrigieren der Basiszufuhrmenge basierend auf einer Abgastemperatur an einer
Stelle stromauf des Oxidationskatalysators; und
Berechnen (62, 62c bis 62f) einer End-Zufuhrmenge des unverbrannten Kraftstoffs basierend
auf der berechneten Basiszufuhrmenge und der korrigierten Zufuhrmenge und zum Ausführen
der Zufuhr des unverbrannten Kraftstoffs basierend auf der berechneten End-Zufuhrmenge
des unverbrannten Kraftstoffs zu dem Motor derart, dass der Filter regeneriert wird,
gekennzeichnet durch die Schritte:
Bestimmen eines Abgastemperaturkorrekturgewichts, das mit zunehmender Motordrehzahl
(NE) und Kraftstoffeinspritzmenge (Q) zunimmt und mit abnehmender Motordrehzahl (NE)
und Kraftstoffeinspritzmenge (Q) abnimmt, so dass es zunimmt und abnimmt, wenn die
Abgasströmungsrate zunimmt und abnimmt, und zum Korrigieren der korrigierten Zufuhrmenge
durch Multiplizieren der korrigierten Zufuhrmenge mit dem Abgastemperaturkorrekturgewicht.