JP2017129147A - Method for regenerating exhaust aftertreatment device and internal combustion engine device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform regeneration of an exhaust aftertreatment device including a particulate filter through a 2-stage regeneration process.SOLUTION: A regeneration process includes confirmation of whether or not a soot load of a particulate filter exceeds a predetermined value. After the confirmation, the regeneration process is executed in 2 stages in a manner that: keeps a temperature of exhaust gas passing through the particulate filter in a first temperature range TaNO2, preferably between 420°C and 550°C, until after predetermined time passes or the soot load of the particulate filter becomes lower than a certain value; and then increases the temperature of the exhaust gas passing through the particulate filter to a second temperature range TO2, exceeding 550°C, higher than the first temperature range.SELECTED DRAWING: Figure 4A

Description

  The present invention relates generally to a method and apparatus for regenerating an exhaust aftertreatment device, and more particularly to a method and apparatus for regenerating an exhaust aftertreatment device using two-stage regeneration.

  Due to environmental regulations, it is necessary to reinforce various exhaust aftertreatment devices in an exhaust aftertreatment system (EATS) for internal combustion engines. For example, a diesel engine generally includes a particle filter (usually called a diesel particle filter or DPF) in its EATS. Gasoline engines that inject fuel directly into the combustion chamber, especially direct injection gasoline engines, will also be equipped with such filters in the future. The EATS may include other components such as a NOx reduction device. In the case of a diesel engine, a NOx reduction catalyst (usually a selective catalytic reduction catalyst (SCR)) is usually upstream of the particulate filter and the filter or an oxidation catalyst (diesel oxidation catalyst (DOC) that forms part of the filter. ) Is also used downstream). The oxidation catalyst oxidizes CO and NO in the engine exhaust and converts them to CO2 and NO2. Other devices for providing an oxidation catalyst include uncoated DPF-equipped DOC (so-called CRT system), coated DPF-equipped DOC (so-called cCRT system), and coated DPF. .

The exhaust from the engine is typically at a temperature of about 250-350 ° C., and at these temperatures, a certain amount of so-called “passive” NO 2 regeneration of the particle filter 29 occurs, where the upstream of the particle filter or the Especially when promoted by an oxidation catalyst on the particle filter, the collected soot is oxidized and removed from the filter.
(1) C + 2NO2 → CO2 + 2NO
And / or (2) C + NO2 → CO + NO

  At low temperatures (<300 ° C.), NO 2 soot oxidation exhibits a fairly low rate, so the soot loading of the particle filter is in the case of extreme duty cycles where the exhaust gas temperature is below 200 ° C. (low temperature no load cycle) It increases fairly rapidly. Excessive soot on the particle filter degrades the functionality of the particle filter and engine. It is predetermined that the soot collected in the particle filter is burned out at approximately the same rate as it is oxidized by passive regeneration, thereby maintaining a balance where the soot loading in the particle filter remains within an acceptable level. Often over the duty cycle. However, in certain duty cycles, the soot load becomes too great and it is necessary to regenerate the particle filter through a specific active regeneration procedure.

In the past, it was common to perform regeneration by so-called “active” O 2 regeneration. Active O2 regeneration occurs through the following reaction.
(3) C + O2 → CO2
And / or (4) 2C + O2 → 2CO

  Active O2-based regeneration systems raise the temperature of the reactants through various methods to achieve and sustain the O2 / soot reaction. During active O2 regeneration, it is believed that substantially all soot is removed through reaction with O2.

  The problem with O2 regeneration is that the regeneration is usually performed at a high temperature of about 600-625 ° C. for the particle filter to be catalyzed. It is generally considered that if the reaction is highly exothermic and the soot loading level of the particle filter is too high, an unacceptable danger such as “runaway” or uncontrolled regeneration at temperatures above 550 ° C. will occur. It has been. For a given device, a safe high temperature regeneration soot load level that is lower than a level at which high temperature regeneration is assumed to be safe can be determined. Thereafter, it is believed that there is a risk of uncontrolled regeneration in the process of performing high temperature regeneration when the particle filter is loaded at a level greater than its safe high temperature soot loading level. In frequently used EATS devices, its safe hot soot loading level is believed to exceed about 2-8 grams of soot per liter of filter (herein expressed as gC / l filter). (The specific load level will vary depending on various factors such as filter type.) Therefore, because of the risk of uncontrolled regeneration at these soot loading levels, the particle filter and other components will have even higher soot loading. Even if the level is operating properly, active O2 regeneration is performed when the soot load level approaches that level. Each O2 regeneration includes the step of circulating the temperature of the exhaust gas in the filter or its particle filter to above about 600-625 ° C. This circulation tends to increase the wear of the particle filter and also tends to involve substantial use of exhaust gas or energy to heat the filter.

  In addition to regenerating the particle filter, it is necessary to “detoxify” EATS components such as oxidation catalysts or NOx reduction catalysts, or even other NOx reduction devices such as so-called NOx traps. Sometimes there are. Catalyst poisoning is usually removed by high heat treatment. In some specific cases (as S poisoning), regeneration (sometimes referred to as “detoxification”) requires a fairly high temperature, for example about 600 ° C. for a Cu-zeolite SCR catalyst. It is. In an aftertreatment system with an SCR downstream of the particle filter, it is only possible for the particle filter to reach 600 ° C. if the temperature is higher than 600 ° C. At that temperature, the filter is also regenerated (from soot) while the SCR is desulfated. Since regeneration at that temperature is active O2 regeneration, it is further necessary to pay special attention to the maximum soot loading of the particle filter. When trying to perform O2 regeneration, it was necessary to maintain the soot load at a level lower than the level at which uncontrolled regeneration would occur, so to prevent high heat generation effects in the filter, Or SCR desulfation appears to be quite frequent. This frequent regeneration caused higher fuel penalties and aging of the catalyst.

  安全 If the load level exceeds the safe high temperature load level considered to be an unacceptable risk of uncontrolled regeneration, or even if the load level is below that level, the risk of uncontrolled regeneration Therefore, O2 regeneration is normally performed only on the on-vehicle engine device when the vehicle is parked. This means that the vehicle is suspended every certain period in order to perform O2 regeneration.

  NO2 regeneration with enhanced effective NO2 supply in the middle temperature range between the standard exhaust temperature range where passive NO2 regeneration tends to occur and the temperature range of active O2 regeneration such as temperatures in the range of about 420-550 ° C It has recently been discovered that (hereinafter referred to as “enhanced NO2 regeneration”) occurs. It is assumed by reference that most of the remaining soot will react with NO2, but at temperatures of 450-550 ° C, two-thirds or less than half of the soot will be removed by reaction with O2. It is theorized in Patent Document 1 and Patent Document 2.

  Even if the NO2 / NO ratio and thus the equilibrium-limited NO2 supply decreases, the effective supply is enhanced so that the soot removal effectiveness is enhanced compared to the effectiveness expected during normal NO2 regeneration. The concept of “effective NO 2 supply” is adopted by Patent Document 1 and Patent Document 2. Effective NO2 supply was defined as the amount of NO2 involved in soot oxidation. The NO2 involved may come directly from the equilibrium limited NO2 supply, from NO oxidized in the catalytic DPF, or directly from NO recirculation. The concept of soot removal capacity of NO2 reactant is also incorporated. Even if the enhanced NO2 regeneration can reduce the equilibrium-limited NO2 supply, the effective NO2 supply can be greatly increased at the same time, thereby increasing the soot removal capacity of the equilibrium-limited NO2 supply. This results in a significantly higher soot oxidation rate. Various conditions can be controlled. As a result, even if an amount of NO2 smaller than the amount under conventional conditions is supplied to the particle filter, the rate at which NO is converted to NO2 and NO2 reacts with soot inside the DPF Is greater than the rate under conventional conditions where more NO2 equilibrium limit would have been supplied to the DPF. It has been theorized that the NO is effectively "recirculated" usually two or more times through a catalytic reaction that in turn reacts with soot to form NO2 to form NO that is catalyzed again. Thus, under enhanced NO2 regeneration conditions, a specific amount of NOx in the engine exhaust is effective to oxidize more soot than an equilibrium limited NO2 supply.

In the NO2 regeneration test, the measurement of NO2 efficiency related to the reaction stoichiometry of NO2 and C is taken in, and the evaluation of the effectiveness of a specific method is described in US Pat. NO2 efficiency is clearly defined as the mass of C removed from a DPF divided by the mass of NO2 fed to that DPF, and is significant relative to the time required for effective regeneration of a substantially full DPF. But not over this time. Conventional wisdom for a conventional NO2-based regeneration, there is a NO2 efficiency is not greatly exceed ^{12.01gC / 46.01gNO2 = ~ 0.26gC / gNO2} . The unit “gC” is the mass of soot removed from the DPF, and the unit “gNO 2” is the mass of the cumulative equilibrium limited NO 2 supply. Nevertheless, at higher temperatures (near or slightly above the NO-NO2 conversion plateau), the gradually decreasing equilibrium limiting NO2 feed is not able to take advantage of the temperature rise, so the overall NO2 system It was estimated that the oxidative activity was greatly reduced. In other words, an increase in temperature simply lowers the NO2 supply, resulting in a more diffusion-limited reaction, thereby reducing the reaction rate and reducing the overall soot removal. Over a time that is significant but not exceeding the time required for effective regeneration of substantially full DPF, conventional passive NO2 regeneration is much less efficient than 0.52 gC / gNO2, more common Shows an efficiency lower than 0.26 gC / gNO2.

  By actively increasing the reactant temperature, NO2 efficiency well above 0.52 gC / gNO2, usually much higher than that of the prior art of NO2-based regeneration with an efficiency many times higher The achievement of the above is described in Patent Document 1 and Patent Document 2. This is achieved by increasing the NO2 soot removal capacity for the purpose of enhancing the effective NO2 supply (equilibrium limited NO2 supply is not necessarily required). Without being bound by theory, it is believed that the mechanism that increases the NO2 soot removal capacity is the NO recirculation mechanism. Within the catalytic DPF given a sufficiently long residence time and a sufficiently high temperature, the NO2 molecules that have reacted with soot to form NO molecules are then recycled to NO2 and then participate in another soot oxidation reaction. be able to. This process is repeated as many times as possible due to residence time, dynamic reaction rates of soot and NO oxidation, soot availability, oxygen availability, and catalyst availability.

US Patent Application Publication No. 2011/0000190 US Patent Application Publication No. 2010/0326055

According to one aspect of the invention, a process is provided for regenerating an exhaust gas aftertreatment device suitable for incorporation into an exhaust line of an internal combustion engine, the exhaust gas aftertreatment device being one of a particle filter and / or a NOx reduction catalyst. And the process is
a) setting the temperature of the exhaust gas in the particle filter within a first temperature range preferably comprised between 420 ° C. and 550 ° C .;
b) maintaining the temperature of the exhaust gas in the particle filter in a first temperature range during the first period;
and c) gradually increasing the temperature of the particle filter to a second temperature range exceeding 550 ° C. after the first period.

  If active O2 regeneration at high temperatures is to be performed, among other things, the first stage, called the active NO2 regeneration process, is performed at an intermediate temperature below the temperature at which there is a substantial risk of uncontrolled regeneration, By performing two-stage regeneration, the maximum soot load level of the DPF can be increased so that the safe hot regeneration soot load level is above that which is no longer considered safe for active O2 regeneration of the particle filter. The present inventors have discovered that this is possible. For example, some filters and engine devices continue to operate properly at a particulate filter dredging level of about 1.5 to 2 times higher than their safe hot regeneration dredging loading level, but the maximum loading level varies. It is thought that it fluctuates due to different factors. For example, this first stage of the regeneration process facilitates reducing frequent regeneration and reducing frequent interruptions in the use of the vehicle, including the engine and EATS. Nevertheless, in the second stage, the regeneration process, which is usually carried out at a high temperature above 550 ° C., preferably above 600 ° C., is an active that removes the residual particulate filter residue substantially completely during a limited time. A typical O2 regeneration process. If a NOx reduction device, such as a NOx reduction catalyst, is located downstream of the particle filter, the second stage of the process allows simultaneous detoxification of the NOx reduction device. Thus, the two-stage process according to the present invention makes it possible to reduce frequent regeneration while optimizing the time it takes for the particle filter with the soot loading level to return to the lowest level to reach substantially complete regeneration.

According to another aspect of the invention,
A controlled rate of temperature rise over time so as to further increase the safety of regeneration by further protecting against the risk of runaway reactions due to uncontrolled oxidation of excessive amounts of soot in the particle filter during step c) The temperature in the particle filter can be increased. As the temperature of the particle filter increases with time, it is equivalent to consider a controlled rate of temperature rise over time or to think that the controlled rate of temperature rise increases with the temperature itself.
-During step c), the temperature in the particle filter increases at a controlled rate of temperature rise over time, so that the rate can reach a better compromise between regeneration safety and its duration. It is controlled as a function of determining the soot load. In particular, it can be chosen whether the temperature in the particle filter increases with time and / or the rate of temperature increase with time, which decreases with the instantaneous temperature in the particle filter.
-During step c), the temperature in the particle filter may increase at a variable rate of temperature rise over time, for example, at the end of the first period, the variation in that rate is controlled as a function of determining the soot load of the particle filter Is done. This further enables optimization of the safety / period compromise. For example, during step c), the temperature in the particle filter may be increased in at least two substeps, these substeps being
A first sub-step c1) at a first rate of temperature rise;
-A second sub-step c2) at a second time-dependent temperature rise rate, wherein the second temperature rise rate is preferably lower than the first temperature rise rate.
-In some embodiments, during the second sub-step c2), if the soot load of the particle filter is estimated to be a lower value, the second temperature rise rate is implemented as a variable temperature rise rate implementation. Is adjusted to a higher value.
In some embodiments, for example, by using a dredging model for a particle filter, the dredging load of that particle filter can be an estimated dredging load because the reason is to perform in the operating environment This is because it is considered difficult and / or expensive to accurately measure the soot load. One parameter for estimating the soot load may be the duration of the first period of step b). For a more accurate estimation, the soot load may be estimated by the duration of the first period of step b) and the estimated soot load in step a). As an alternative or combination, the soot load may be estimated by the measured pressure difference between the inlet and outlet of the particle filter. As an alternative or combination, the soot load may be estimated by estimating soot oxidation in the particle filter based on engine soot emission models that estimate the soot discharged by the engine as a function of engine operating parameters and the operating conditions in the particle filter. The estimation may be performed using a reproduction model. Such a model leads to a more accurate estimation of the soot load.
-In some embodiments, the regeneration process may be used to detoxify the NOx reduction device. This process includes the step of detecting a regeneration trigger prior to step a), which includes estimating that the aforementioned NOx reduction device is poisoned.
-In some embodiments, the preferred first temperature range may be between 450C and 510C.
-In some embodiments, the step of gradually increasing the temperature in the particle filter to the second temperature range is above 600 ° C, for example from about 620 ° C to 625 ° C, or above 640 ° C. A step of raising the temperature in the particle filter may be included.
-In some embodiments, during the second period, the temperature in the particle filter may be maintained within the aforementioned second range.

  In accordance with another aspect of the present invention, a process is provided for regenerating an exhaust gas aftertreatment device in an exhaust line of an internal combustion engine device that includes a particulate filter, the process addressing the need for regeneration of the exhaust gas aftertreatment device. Detecting a triggering event, determining that the soot load of the particle filter exceeds a safe high temperature regeneration level, and until a predetermined period of time has elapsed, Setting and maintaining the temperature in the particle filter within a first temperature range for a first period of time, up to at least one, until it is determined that the temperature is below the high temperature regeneration level; After the period, the temperature of the particle filter is raised to a second temperature range higher than the first temperature range.

According to another aspect of the invention, there is provided a process for regenerating an exhaust gas aftertreatment device in an exhaust line of an internal combustion engine device that includes a particle filter, the process exhausting in the particle filter during a first time period. Maintaining the temperature of the gas within a first temperature range;
Raising the temperature of the exhaust gas in the particle filter within a second temperature range higher than the first temperature range after the first period;
After the first period, the step of raising the temperature in the particle filter to a second temperature range higher than the first temperature range is to increase the rate of temperature increase of the exhaust gas in the particle filter. There is a step of controlling from the first temperature range to the second temperature range described above.

According to another aspect of the present invention, an internal combustion engine device is provided,
The internal combustion engine device includes an internal combustion engine, an exhaust line that collects exhaust gas from the engine, and discharges the exhaust gas toward the atmosphere.
An exhaust aftertreatment system having at least one particle filter in the exhaust line;
Heating means arranged to increase the temperature in the particle filter;
A controller for controlling the heating means, the controller being arranged for performing the regeneration process described above.

  According to yet another aspect of the invention, there is provided a vehicle having an internal combustion engine device having any of the above features and / or arranged for performing a regeneration process according to the method defined above.

  The features and advantages of the present invention will be better understood when the following detailed description is read in conjunction with the drawings, in which like numerals indicate like elements.

1 is a schematic view of an internal combustion engine device according to an aspect of the present invention. It is a graph of the soot load SL with time t in different types of filter regeneration. 4 is a graph of the temperature T of a regenerating particle filter over time t according to an aspect of the present invention. 4 is a graph of particle filter temperature T versus time t for different regeneration strategies according to aspects of the present invention. 4 is a graph of particle filter temperature T versus time t for different regeneration strategies according to aspects of the present invention. 6 is a flowchart illustrating steps in a method according to an aspect of the present invention.

  An internal combustion engine device 21 according to an aspect of the present invention is shown in FIG. The internal combustion engine device 21 has an internal combustion engine 23 that includes an exhaust line 25 that collects exhaust gas from the engine and guides at least most of the exhaust gas to the atmosphere. The exhaust aftertreatment system (EATS) 27 is attached to the exhaust line 25 so that the exhaust gas guided to the atmosphere through the exhaust line 25 passes through various components of the EATS 27 before being exhausted to the atmosphere. . The EATS 27 includes a particle filter 29. In order to raise the temperature of the particle filter 29, a heating means is provided in the above-mentioned apparatus. Typically such heating means may include a heater 31 arranged to raise the temperature of the exhaust gas in the particle filter. The EATS 27 may have a NOx reduction device 33 (usually a so-called selective catalytic reduction catalyst (SCR) or NOx reduction catalyst such as a NOx trap) downstream of the particle filter 29. The EATS may have an oxidation catalyst 35 that is upstream of or forms part of the filter.

  Although the present invention has been described primarily in connection with an application with a diesel engine as the internal combustion engine 23, it will be understood that internal combustion engines other than diesel engines are provided. Instead of having an oxidation catalyst 35 (usually called diesel oxidation catalyst (DOC) in diesel engine devices) upstream of the particle filter 29 (usually called diesel particle filter (DPF) in diesel engine devices). Alternatively, or in addition, the particulate filter may include a catalyst that oxidizes CO and NO and converts these CO and NO to CO2 and NO2 (referred to herein as coated DPF). Other devices for providing an oxidation catalyst include uncoated DPF-equipped DOC (so-called CRT system), coated DPF-equipped DOC (so-called cCRT system), and coated DPF. . In general, at least a coated DPF is preferred.

For discussion purposes, the present invention will be described in connection with the apparatus described below.
The temperature of the exhaust gas that stimulates the warm diesel engine is typically in the range of about 250-350 ° C. At such temperatures, the “passive” NO 2 of the particle filter, especially by utilizing a DOC or catalyzed particle filter, including most of the reaction between NO 2 and C to form NO and CO 2. Regeneration can occur. Usually, in order to have a remarkable reaction rate (2NO2 + C = CO2 + 2NO), a minimum of 250 ° C. and 20 NOx / soot (preferably 50) are required. The average exhaust temperature generally depends on the application type. For example, the exhaust temperature of buses in the city center seems to be below 200 ° C, but the exhaust temperature of long-distance transport trucks is usually above 300 ° C. In order to bring the temperature in the range of 250-350 ° C., the engine may be operated in “heat mode”, but in general, engine heat mode is not always used. In general, if the temperature of the exhaust gas is below 250 ° C., the passive regeneration is very low, and if the temperature of the exhaust gas is below 200 ° C., there is virtually no passive regeneration.
• More rapid “active” NO 2 regeneration occurs at generally higher temperatures, such as temperatures in the range of about 420-550 ° C., preferably between 450-510 ° C. The “enhanced” NO2 regeneration that is theorized in US Pat. Nos. 6,057,058 and 6,037,086, incorporated by reference, is believed to form a higher family of active NO2 regeneration. In general, it is believed that "active" NO2 regeneration according to the present invention is achieved with or without the use of a catalyst coated particle filter. Nevertheless, in that temperature range, the “active” NO2 regeneration defined in the present invention has greatly benefited from the use of a catalyst-coated filter by increasing the reaction rate of soot and NO2. Therefore, it is believed that the reproduction efficiency has been greatly increased. The optimized regeneration temperature can be selected in view of the way in which the energy required to heat the exhaust is created. If hydrocarbon oxidation in DOC is used to generate exotherm, then NO2 production may be affected by effects that are highly dependent on the amount of oxidized hydrocarbon (NO oxidation to DOC and hydrocarbon oxidation). Competition between). Therefore, in general, it is necessary to make a trade-off from the viewpoints of regeneration temperature, NO 2 formation, and carbon oxidation. With respect to the amount of NOx generated in the engine, it can be said that the active NO2 regeneration according to the present invention can be performed without fluctuations in engine operating conditions. Of course, active NO2 regeneration may still be performed with varying engine operating conditions, especially considering increased NOx production in the engine.
A more rapid “active” O2 regeneration that substantially removes all soot in reaction with O2 occurs at temperatures above about 600 ° C., typically between 600-625 ° C. At that time, if it is necessary or preferred to remove all soot in a rapid event, a temperature usually above 600 ° C. is required. However, starting from about 550 ° C., when using a catalyzed filter, there is a tendency to have a significant rate of carbon oxidation due to enhanced oxygen. O2 regeneration is usually more than 500 ° C, with a significant increase rate of O2 regeneration at temperatures higher than 550 ° C, and a final temperature at T> 600 ° C, in order to remove all soot, especially in short-term events Start at a higher temperature (while active NO2 regeneration is also taking place).
Especially for uncontrolled regeneration or “runaway” regeneration of the filter at temperatures above about 550 ° C. and even at lower temperatures such as 500 ° C. when the filter dredging load is higher than the safe high temperature regeneration level. There is a substantial risk. Thus, for example, during parking of a vehicle equipped with the engine device described above, it is preferable not to perform active regeneration with a dredging load exceeding the safe high temperature regeneration level, or only under highly controlled conditions.
• Regular particle filters continue to operate properly at drought load levels approximately 1.5 to 2 times the safe hot regeneration level.

  Of course, the specific temperatures and soot loading levels described above are merely exemplary and are used here for discussion. It should be emphasized that the soot load level is simply too high because of the risk of uncontrolled regeneration due to O2 regeneration or not all filters, but due to the maximum load on some filters. The actual load value of a particular filter may vary substantially and may depend on factors such as the material from which the filter is made (cordierite, silicon carbide, etc.) It may also depend on the application. Passive regeneration, active regeneration and active regeneration in different temperature ranges may be performed with different engine devices and EATS, and the dredging load level considered to be a substantial risk of runaway regeneration, Or it will be understood that the soot loading levels at which the performance of the particle filter is compromised may be different.

The internal combustion engine device 21 also includes a controller 37 arranged to control the heating means or heater 31. The heater 31 can include any suitable combination of many different structural types or structures and methods as described below. However, it is not limited to the following.
-Fuel is injected into the combustion chamber (not shown), but the fuel does not burn or burns completely in the combustion chamber that oxidizes the fuel by heat regeneration and the oxidation catalyst (for example, a particle filter with DOC or coated catalyst) In addition, a regular fuel injection device (not shown) that is controlled to inject fuel during the exhaust stroke of the engine or after the power stroke.
Control of specific engine operating parameters such as intake throttle and injection timing for raising the temperature of gas from the combustion chamber (not shown) of the engine 23.
In these cases, the heater or heating means is directly connected to the internal combustion engine itself. In other cases described below, the heater or heating means may be a component of EATS and may include:
• Dedicated fuel injectors (not shown) in oxidation catalysts (DOC or coated catalyst particle filters) that oxidize fuel by exhaust line and heat regeneration ("post-treatment hydrocarbon injector" (AHI), "No. 7 "or" fuel delivery device ").
A fuel burner in the exhaust line that directs fuel and air to create a flame.
An electric heater in front of and / or around the particle filter and / or in the particle filter.
A microwave device that directs microwaves to the particle filter.
The heater or heating means may include some combination of the structures and methods described above.

  For illustrative purposes, the heater 31 is illustrated as a separate component located in the exhaust line upstream of the oxidation catalyst 35 and the particle filter 29, but the heater includes several components that work together. It will be understood that the structure may also be accompanied by a structure or a structure disposed at a location other than that illustrated.

  The controller 37 is typically part of an electronic control unit, including one on the electronic control units (ECUs) or several electronic control units. The controller may be a controller dedicated to the heating means or to control other components of the engine device, or may be separated between physical entities. This controller may be an open loop controller or preferably a closed loop controller with feedback at a temperature sensor.

  Typically, the engine device 21 is activated so that the exhaust from the engine 23 is at a temperature of about 250-350 ° C. and is passively promoted by the upstream oxidation catalyst 35 or the oxidation catalyst 35 on the particle filter, which is usually promoted. Regeneration occurs. At low temperatures (<300 ° C.), soot oxidation with NO 2 shows a fairly low rate, so it appears that soot loading increases fairly rapidly in the case of extreme duty cycles (low temperature no-load cycle).

  The soot load may be stabilized with respect to the operating temperature or duty cycle, i.e. an equilibrium point may be reached. This is highly dependent on the operating temperature and the soot load can be more or less high. As can be seen from line A in FIG. 2, this balance or level of equilibrium may be a soot loading level below a level considered safe for active O2 regeneration of the particle filter, ie a safe hot regeneration level SL. It may be SHT. In some duty cycles of the engine system, the soot load can be reduced by just passive NO2 regeneration for a given time and / or stays below its safe level, for example, to perform high temperature regeneration. It can vary. However, as can be seen in lines B and C in FIG. 2, after the operating period, the soot load of the particle filter performs at least the above-mentioned safety level SL SHT, which performs high temperature regeneration, ie active O2 regeneration of the particle filter. It often rises above the level of drought considered safe.

  In such a case as can be seen from line B, the soot load level rises to a level higher than the aforementioned safety level SL SHT for high temperature regeneration, after which the soot collected with time is removed by passive regeneration. Stable to be more or less equal to the amount of dredging. In these cases, it is unnecessary to perform active regeneration of the particle filter unless the temperature of the EATS 27 is required to be increased for other purposes such as “detoxification” of the components such as the NOx reduction catalyst 33. possible.

  In other cases, as seen by line C, the soot load continues to rise. That is, the equilibrium or equilibrium is not reached, or the particle filter reaches the target maximum soot load SL MAX (typically 1.5-2 times higher than the safe hot regeneration level) and at the point of that target maximum soot load. , The soot accumulation reaches a level where the risk of filter damage due to increased soot load is considered significant, or the impact on the engine of increased back pressure begins to increase. If passive regeneration cannot keep the dredging load below this level, active measures are needed to remove the dredging.

  Previously, due to the risk of uncontrolled regeneration at a drought load level above the aforementioned safety level SL SHT for high temperature regeneration, it is considered that active O2 regeneration was done when the drought load level approached that level. . This is still true even if the particle filter was operating properly and even if there was no current demand to raise the temperature at EATS above that at the unacceptable uncontrolled regeneration risk. This means that it was necessary to frequently perform O2 regeneration. This is indicated by line D in FIG. Each O2 regeneration involved a step of circulating the temperature of the exhaust gas in the filter or particle filter to about 600 to 625 ° C or higher. This circulation increased the wear of the particle filter and also tended to involve substantial energy use to heat the exhaust gas or filter.

  According to one aspect of the present invention, frequent O2 regeneration requirements can be reduced or avoided, and if the only way to regenerate the filter is via O2 regeneration, the soot load level is substantially less than reasonable. Can be maintained at a very high level. According to this aspect of the present invention, if the soot load of the particle filter 29 exceeds a predetermined level, a level that is considered to be unacceptable uncontrolled regeneration risk may be identified. After exceeding this level, if a level exceeding passive regeneration is required, the controller 37 is arranged to control the heater 31 to maintain the temperature at the particle filter within the first temperature range, i.e. The temperature range in which active NO2 regeneration occurs is the temperature range considered by the inventors to be about 420-550 ° C., preferably 450-510 ° C. in the engine device embodiment described. This of course involves a first step of raising the temperature to its first range. The controller 37 controls the heater 31 to maintain this first temperature range until it is determined that the soot load on the particle filter 29 is below a safe level for high temperature regeneration. Unless otherwise noted, references to the expression "temperature in the particle filter" or "temperature of the exhaust gas in the filter" are used regardless of the temperature of the exhaust gas, such as when the heater heats the particle filter rather than the exhaust gas. It is clearly defined here not only as the meaning of the temperature of the exhaust gas at the inlet to the normal particle filter, but also as the meaning to be interpreted more broadly, in particular to cover the temperature of the particle filter itself. The temperature can be measured at the temperature inlet, or it can be considered as the average temperature of the filter or gas passing through the filter.

  After the temperature at that filter is maintained within the first temperature range and the second determination is made (the soot load is below the level considered to be unacceptable uncontrolled regeneration risk), controller 37 then For example, in order to raise the temperature of the exhaust gas to a second temperature range higher than the first temperature range, that is, a temperature range in which O2 regeneration occurs, the heater is controlled to further raise the temperature in the particle filter 29. . The inventors consider that the second temperature range is above 550 ° C. Usually, the upper limit of this range is a general upper limit for the safe operating temperature range of various EATS components. In this second temperature range, the particle filter 29 can be regenerated and carried out normally until there is virtually no soot load. In addition to, or as an alternative to, regeneration until substantially free of soot loads, in particular, detoxification of the diesel oxidation catalyst 35 and / or NOx reduction catalyst 33 may cause regeneration of other EATS components, A controller 37 may be arranged to control the heater 31 to maintain the second temperature range.

  Typically, some form of trigger signal is provided to the controller 31 when more than passive regeneration is required or required. In response to a trigger event that implies the need for regeneration of the exhaust gas aftertreatment device in the exhaust aftertreatment system, the trigger signal is provided to the controller 31 to bring the temperature of the exhaust gas into the first temperature range. Various means may be provided to initiate the ascent. The trigger event may be, for example, a determination that the particle filter has reached a target maximum soot load. Alternatively or incidentally, the trigger event may be a determination that the oxidation catalyst 35 and / or the NOx reduction device 33 is poisoned. Alternatively or incidentally, the trigger event is a determination that a cumulative engine operating parameter after a previous regeneration has exceeded a threshold, such as a certain period of time for operating the engine device 21 has elapsed. There may be.

  The trigger event is a specific decision as to whether the soot load level exceeds a safe high temperature regeneration level that is considered unacceptable uncontrolled regeneration risk, especially when the NOx reduction device 33 is poisoned. It may be interesting to do. If the soot load exceeds that level, then the controller is in a two-stage active regeneration followed by an active NO2 regeneration followed by a hot regeneration where the exhaust gas is preferably at a level above 600 ° C in the particle filter. Proceed as above. In this second stage, the gas received at the NOx reduction device should be at a temperature high enough to detoxify the NOx reduction device. At the same time, residual soot in the particle filter is also oxidized. If the trigger event is a determination that the soot load level in the particle filter is lower than its safe hot soot load level, then the temperature is directly controlled by a controlled method, preferably by a controlled method. By raising the range, it seems that the controller can control the heater so that only the second stage regeneration is performed directly.

  Determining the load, especially when the load is above or above the safe high temperature regeneration load level or beyond the safe high temperature regeneration level, i.e., unacceptable uncontrolled regeneration risk The level to be applied can be, for example, an estimation by modeling. Typically, a model includes a series of equations, maps, charts, and tables for calculating an estimated value without actually measuring the value (here, the soot load of the particle filter). The model typically receives as input a number of variables, such as engine device operating parameters that can be measured through sensors or acquired by the model based on what has been calculated. A preferred model may be based on an engine soot emission model that predicts soot that the engine emits as a function of factors such as engine speed, torque, and temperature (engine operation). In addition, passive and / or active NO2 regeneration and / or O2 regeneration can be considered for these engine operating points (temperature, flow rate). In this way, the soot load tends to increase due to engine soot emissions and tends to decrease due to soot NO2 oxidation (and O2 oxidation at temperatures above 500 ° C.). Such a model determines the soot load as a theoretical prediction of how the filter is loaded at any engine operating point and what the soot load of the particle filter at a point in time is. Is done. Such a soot model can be combined with other triggers / parameters, such as a model based on differential pressure over time from previous regenerations, DPF, fuel consumption, and / or time. The soot model can also be determined when the maximum soot load is to be reached, and at that time or when a similar determination is made, can trigger a so-called first stage regeneration, ie, active NO2 regeneration. The decision in the dredging model that the dredging load level should be reached below a level that is considered safe for performing the O2 regeneration then triggers a second stage regeneration, called O2 regeneration. be able to.

  Alternatively, the simple model may include only the total fuel consumption after the last full regeneration, the elapsed time of operation after the last regeneration, and / or the pressure drop in the particle filter 29, and / or combinations thereof. . For example, modeling such as a model based on the pressure drop in the particle filter makes a determination that the soot load is at or above the target maximum soot load. As another example, after maintaining the temperature of the exhaust gas in the particle filter in the first temperature range in which active NO2 regeneration occurs, there is a risk of uncontrolled regeneration in which the soot load in the particle filter 29 is unacceptable. The determination that the temperature has fallen below a predetermined level is made by modeling, such as a model based on the length of time that the temperature is maintained within that temperature range. More complex models may also be provided, but the foregoing is only an example of a model configuration that would be used to determine the saddle load for different purposes.

  Moreover, the model which determines the soot load of a particle filter was able to consider the effect | action of the other structural part of an engine apparatus, for example, the effect | action of DOC. For example, the soot model has a special equation / map that takes into account additional factors such as the effect of the amount of hydrocarbons emitted in NO2 formation (eg, for heating DOC if AHI is used). It may be further improved by introducing it. Hydrocarbon oxidation (exothermic) and NO oxidation to NO2 compete in the DOC. This means that if there is a low temperature cycle (low exhaust temperature), in order to reach high temperatures, more hydrocarbons need to be injected into the DOC to form high temperatures. Thus, less NO2 is formed, which leads to lower efficiency NO2 active regeneration, causing a higher soot load at 4 points. This effect of HC can make the soot model more accurate, especially when fuel administration devices such as AHI and the seventh injection device are used. That is, the soot load may be estimated in consideration of the speed and / or efficiency at which NO is converted to NO2 in the catalyst upstream of the particle filter.

  Exhaust from the first temperature range to the second temperature range in addition to controlling the heater 31 to raise the temperature of the exhaust gas to a specific temperature range or to maintain the gas temperature in the specific temperature range The controller 37 may be arranged so as to control a heater that controls the rising rate of the gas temperature. This is useful to allow optimization of fuel consumption during O2 regeneration and to reduce the risk of uncontrolled regeneration. For example, as can be seen in FIG. 3, after controlling the heater 31 to heat the exhaust gas to a temperature TaNO2 at which passive NO2 regeneration occurs, for example, from a temperature TpNO2 that can be a standard exhaust temperature at which passive NO2 regeneration can occur, The controller 37 may be arranged so as to control the heater that heats the exhaust gas to the temperature TO2 where the active O2 regeneration is the first regeneration mechanism. Simply trying to reach the temperature target may not be able to control the heating of TaNO2 to TO2, but on the other hand, the controller may, for example, verify that the temperature over time in the particle filter follows a predetermined line or curve, Alternatively, it is preferable to be able to control the rate of temperature rise over time in the particle filter by making sure it stays at least within certain boundaries around such lines or curves. In a simple form, the controller may control the temperature rise in the particle filter, for example, at a predetermined rate along a straight line, ie, a straight line representing a linear increase in temperature versus time.

  Preferably, the controller 37 controls the temperature increase rate as an effect of the soot load of the particle filter 29. For example, the controller may be arranged to control the rate of temperature rise as a function of soot loading of the particle filter 29 as determined at the end of the first stage regeneration as described above. For example, if the soot load of the particle filter is below the safe hot soot load level, but near the safe hot soot load level, the decision will allow a lower soot load at the end of the first stage. The controller may be arranged to control the rate of temperature rise in the particle filter at a generally slower rate than would be the case.

  In addition, or in combination with the above, for example, by controlling the heater 31 such that the temperature in the particle filter is increased at a rate of temperature rise with time and the rate decreases with time and / or instantaneous temperature in the particle filter, for example, A controller 37 may be arranged to control the temperature rise rate of the exhaust gas. For example, first, after the temperature of the exhaust gas is raised to the transient temperature Tt, for example, 570 ° C., at the first rising speed (speed R1), the second is different from the first rising speed described above. The controller may be arranged to raise the temperature of the exhaust gas at a rising speed (speed R2), wherein the second rising speed is lower than the first rising speed. Each of the first speed and the second speed showing two consecutive linear increases can vary with a constant or with time. The rising speed is changed several times by, for example, further reducing the rising speed to a lower speed (speed R3 indicated by the broken line) than the second rising speed at a higher transient temperature Tt ′, eg 600 ° C. Alternatively, the rate of increase may be varied continuously so that the temperature follows a curve along at least a portion of the temperature increase process.

  Currently, it is usually considered desirable to reduce the rate of temperature rise to reach higher temperatures and reduce the risk of uncontrolled regeneration, for example at temperatures above about 550 ° C., so that O2 regeneration is more efficient. Yes. However, the temperature of the exhaust gas is increased at the first rising speed (speed R1) lower than the second rising speed (speed R2 ′ shown by the broken line) in the subsequent portion of the temperature rise to TO2 by controlling the heater 31. It is possible to arrange the controller 37 to increase the speed. For example, it may be possible to increase the temperature more rapidly to achieve fuel savings, especially when the soot load is low enough that the risk of uncontrolled regeneration is minimal. Although FIG. 3 shows the temperature increasing along a straight line, the temperature rise need not be along the straight line. In other words, it will be understood that the aforementioned line may be bent so that the temperature increases at a rate of decrease from one temperature level to the next (or ascending rate if necessary). In addition, like the counter-control process, the measured temperature seems to deviate slightly from the theoretical control target.

  Preferably, the temperature at the particle filter is increased from the first range to a second stage temperature at a controlled rate of temperature rise over time with a controlled rate of temperature rise over time. Equivalently, the temperature control rate increases with time because the temperature in the particle filter increases with time, or the temperature control rate increases with temperature itself. For example, at the end of the first stage regeneration, it is preferable to control the aforementioned control speed as a function of determining the soot load of the particle filter. It is preferred that the aforementioned rate decreases with time and / or with the instantaneous temperature in the particle filter.

  The methods and apparatus of the present invention are themselves suitable for various wrinkle reduction strategies. According to a first strategy according to one aspect of the invention illustrated in FIG. 4A, for example, the heater 31 is controlled, typically in the range of 420 ° C. to 550 ° C., preferably between 450 ° C. and 510 ° C., for example at 490 ° C. For active NO2 regeneration (point 1), also referred to herein as first stage regeneration, the maximum soot load level is achieved by a suitable soot model that triggers the controller 37 to raise the exhaust gas temperature in the filter to the temperature range TaNO2. Can be determined. The soot model may continue to assess the soot load, and if it is determined that the soot load has fallen and the second trigger has been reached, the soot load level is active O2 regeneration (eg, 2-8 gC / 1 filter) is preferably below a level that is considered safe to perform, after which heating to a temperature range for active NO2 regeneration ends (point 2). At point 2, the controller 37 controls the heater 31 to raise the temperature in the filter to the temperature range TO2 for active O2 regeneration, also referred to herein as second stage regeneration. In other words, an increasing or substantially increased active O2 regeneration at a temperature higher than 550 ° C with the second stage with TO2> 600 ° C. In the first phase, a temperature rise rate R1 (rapid temperature rise such as a temperature rise of 0.4 ° C./second to 5 ° C./second) may be used, and the temperature is preferably 550 ° C. to 600 ° C. When entering a transient temperature range, eg, 570 ° C., where the risk of uncontrolled regeneration is increased (risk to filter integrity increased), the rate of temperature rise is It changes to R2 (temperature increase 2 to 20 times, preferably 5 to 15 times slower than the first speed R1). Then, the temperature rise gradient R2 may be used until it reaches a flat part, typically TO2> 600 ° C., and held at that level for a predetermined period or at the second stage. Then, it is considered that the second stage reproduction is completed and the reproduction is successful.

  For example, the maximum duration of the first stage can be set to save fuel and / or avoid regeneration that is too long (point 3 in FIG. 4A). If point 3 arrives prior to point 2, the maximum duration of first stage regeneration prior to point 2, ie, the point at which the soot load is below the level considered safe for active O2 regeneration This means that the soot load on the filter is probably higher than the level considered safe for active O2 regeneration. If it occurs and heating to the second stage begins and a heating rate ramp of R1 and R2 is used, there is a substantial risk of filter cracking. The regeneration is interrupted to maintain the integrity of the filter and is considered a failed regeneration. The soot model in this case prevents performing a second stage active O2 regeneration to protect the filter from damage.

  As a variant, the reference for converting from the first temperature range TaNO2 to the second temperature range TO2 can also be set to a sufficiently long first stage maximum period, so that probabilistically if that period If so, it can be determined without further estimation that the soot loading level in the particle filter is below the safe hot soot loading level. In such cases, playback can proceed to the second stage playback based solely on the fact that this maximum period has been reached.

  A second strategy according to one aspect of the invention is an improvement over the first strategy described above and is illustrated in FIG. 4A. Abandoned regeneration generally leads to fuel loss by repeated regeneration trials, each performing not only active NO2 regeneration but also accelerated aging, which also requires regeneration during parking there is a possibility. Instead of suspending regeneration with the first strategy, according to the second strategy, if point 3 is reached (maximum duration of the first stage regeneration) and the load is safe to perform O2 regeneration If it is not determined that it has been reduced to a level (point 2), the regeneration continues, but another ramp is used to raise the temperature at a slow rate. For example, the temperature may be increased at a first rate along a gradient R1 (dashed line) during normal regeneration, but the temperature is increased at a higher temperature along the gradient R′2 (dashed line). Raised at low speed. However, R′2 is the speed that was used when it was considered that the dredging load had fallen to a level considered safe for O2 regeneration or below that level. Below R2. A different temperature rise rate R'2 may be set as an effect of the soot load determination when point 3 is reached.

  The temperature in the particle filter may be increased at a variable rate of temperature rise over time, and the variation is controlled as a function of determining the soot load of the particle filter. This determination may be made at the end of the first period, ie at the end of the first stage of playback. Due to the fluctuation of the rising speed, when the temperature rises from the first range to the second range, the temperature rises with time which is not linear.

  In this second strategy, it takes longer to reach the temperature range for O2 regeneration in the second stage, but in the end it is considered a successful regeneration and active NO2 regeneration along the first stage. Can be avoided repeatedly.

  The second strategy is in the case of detoxification without SCR delay (desulfurization), in other words, when the regeneration trigger event is a regeneration trigger that includes the step of estimating the NOx reduction device poisoning. It is particularly useful. When the detoxification usually requires T> 600 ° C., regeneration in the second stage is essential. If Strategy 1 is used, there is a risk that the SCR will begin to have a significant efficiency drop due to delays in desulfurization, so there may be a need for regeneration during parking or inspection regeneration where vehicle immobilization is required. is there.

  According to a third strategy, a fixed period for the first stage active NO2 regeneration may be provided as illustrated in FIG. 4B. When the soot model determines that a trigger such as maximum soot load has been reached, then the temperature is raised to TaNO2 for active NO2 regeneration or the first stage regeneration is started (point 1). Active NO2 regeneration is a fixed period corresponding to point 4 in FIG. 4B. When point 4 is reached (after a fixed period), then the kite model can calculate the kite load on the filter. Based on the soot load determined at point 4, the temperature can be raised to TO2 for active O2 regeneration or second stage regeneration along different slopes. In other words, different temperature rise rates can be used. The initial temperature rise rate R1 appears to be maintained at the same rate up to the transient temperature Tt regardless of the dredging load (eg, the same as the rate R1 in FIG. 3a), but the subsequent temperature rise rate up to TO2 is different. It may have the value R2 or R′2 or R ″ 2. For example, if the soot load is low at point 4, the next highest temperature rise rate will be used (R2). If it is high at 4, then it is desirable to use the next slower rate of temperature rise (R′2 or R ″ 2). Of course, a different number of arbitrary temperature rise rates may be provided after R1. Of course, different gradients may be applied to the overall gradient from TaNO2 to TO2, including the first partial velocity R1, as the effect of soot loading. According to this third measure, since regeneration is normally performed to the end, fuel consumption can be optimized and aging can be minimized. The filter integrity can be improved, and the temperature ramp rate gradient can be developed to accommodate any particular level of drought.

  The steps in the process of regenerating the exhaust gas aftertreatment device in the exhaust line are shown in FIG. 5 and described in connection with the internal combustion engine device 21 of FIG. The processing device may then be a device such as a particle filter 29, NOx reduction catalyst 33, and / or oxidation catalyst 35.

  According to the optional step 200 of the method, which can be used when a regeneration trigger event is associated with detoxification of the NOx reduction device, the soot load of the particle filter 29 is unacceptable for a predetermined level, usually uncontrolled regeneration. It can be determined that it is above the level considered to be dangerous, usually above about 2-8 g C / l filter.

  If step 200 is performed and it is determined that the particle filter soot load is above a predetermined level, then controller 37 determines in step 400 that the particle filter soot load is below a predetermined level. Until determined, the temperature of the exhaust gas in the particle filter is maintained at a temperature between 420 ° C. and 550 ° C. in the first stage (FIG. 3) or temperature range, typically active NO 2 regeneration occurs (step 300). The heater 31 may be controlled. After it is determined that the temperature of the exhaust gas is maintained within the first temperature range and the soot load of the particle filter 29 is below a predetermined level, the controller 37 sets the temperature of the exhaust gas in the particle filter to the first temperature range. The heater 37 is controlled to rise to a second temperature range above the temperature range, typically in step 500, to the second stage (FIG. 3) in the range above 550 ° C. where active O 2 regeneration occurs.

  If it is desired to regenerate an aftertreatment device such as a NOx reduction device in EATS 27 and it is determined in step 200 that the soot load is below a safe high temperature regeneration level, the controller 37 may check the exhaust gas in the particle filter. The heater 31 can be controlled so that the temperature directly rises to a temperature at which active O 2 regeneration occurs, in other words, directly skips from step 200 to step 500 and exceeds 550 ° C.

  The temperature of the exhaust gas can be raised within the first temperature range in response to a trigger event, step 100, indicating the need for regeneration of the exhaust gas aftertreatment device. The temperature of the exhaust gas in the particle filter 29 is raised from a typical exhaust temperature range, usually about 250-350 ° C., the temperature at which passive regeneration is likely to occur. The trigger event may be a determination that the soot load on the particle filter 29 is at or above the target maximum soot load at which regeneration of the particle filter is forced. Alternatively or additionally, the trigger event may be a determination that the NOx reduction catalyst 33 or the oxidation catalyst 35 is poisoned. The trigger event may be a determination that the cumulative engine operating parameter from the previous regeneration has exceeded a threshold such as the length of time from the previous regeneration or the fuel consumption from the previous regeneration.

  Prediction of soot discharged by the engine as a function of speed, torque, etc., and modeling such as a model for predicting soot consumed by passive or active NO2 regeneration or O2 regeneration, etc. You may decide that you are above. Other simpler models may be based on factors such as fuel consumption, time since last regeneration, or pressure drop in particle filter 29. Similarly, the soot load of the particle filter 29 is increased by a model as described above, or by a model based on the length of time that the temperature of the exhaust gas in the particle filter is maintained within the first range. A determination may be made that the level has dropped below a predetermined level.

  When the temperature is increased from step 300 to step 500, the controller 37 can control the heater 31 so as to control the temperature increase rate of the exhaust gas from the first temperature range to the second temperature range. The temperature rise rate of the temperature of the exhaust gas can be controlled, for example, as an effect of soot loading on the particle filter to minimize the risk of uncontrolled regeneration. The rate of ascent may be controlled selectively or additionally to optimize fuel consumption.

  Even if the temperature of the gas in the particle filter 29 is increased at the first speed of the first rising portion (speed 1 in FIG. 3) and at the second low speed of the second rising portion (speed 2 in FIG. 3). Good. However, the first speed and the second speed may correspond to a straight line or a curve, in other words, may correspond to a linear increase or a non-linear increase with time. In other situations, the first ascending portion may increase at a first speed (speed 1) and then the second ascending portion may increase at a second high speed, the increase being along a straight line or curve. Also good. The rising speed from the first temperature range to the second temperature range may be changed a plurality of times, such as by further reducing the rising speed to a speed (speed R3) lower than the second speed (speed R2), or During the time period during which the temperature is increased from the first temperature range to the second temperature range or during a part of the time period, the rate of increase may be continuously changed.

  The above method is typically carried out in an internal combustion engine device, particularly a vehicle mounted engine device. The two-stage regeneration process according to the present invention can be performed while the vehicle is running and can be performed even when the initial soot load at the start of the regeneration process exceeds a safe hot soot load level.

  In this application, the use of a term such as “including” means non-limiting and has the same meaning as a term such as “comprising”, but other It does not exclude the presence of structure, material, or action. Similarly, use of terms such as “can” or “may” is intended to be non-limiting and to indicate that no structure, material, or action is required. However, the use of such terms is not intended to indicate that a structure, material, or action is essential. As long as the structure, material, or action is considered essential at present, they are so specified.

  Although the invention has been illustrated and described according to preferred embodiments, it will be appreciated that modifications and changes can be made without departing from the invention as set forth in the claims.

Claims (20)

A regeneration process of an exhaust gas aftertreatment device suitable for incorporation into an exhaust line of an internal combustion engine device, the exhaust line comprising a particulate filter,
Detecting a trigger event indicating the need for regeneration of the exhaust gas aftertreatment device;
Determining that the soot loading of the particle filter exceeds a safe high temperature regeneration level;
The first temperature range during the first period until a predetermined period has elapsed and at least one until the particle filter determines that the soot load is below the safe hot regeneration level. Setting and maintaining the temperature in the particle filter within,
After the first period, raising the temperature in the particle filter to a second temperature range higher than the first temperature range;
A regeneration process for an exhaust gas aftertreatment device.   The process of claim 1, wherein the first temperature range is between 420 ° C and 550 ° C.   The process of claim 2, wherein the second temperature range is 550 ° C or higher.   The process of claim 1, wherein the exhaust gas aftertreatment device is at least one of a particle filter, a diesel oxidation catalyst, and a NOx reduction device.   The exhaust gas aftertreatment device is the particle filter, and the trigger event is a determination that the soot load of the particle filter is a target maximum soot load of the particle filter. The process described in   The process of claim 1, wherein the trigger event is a determination that a cumulative engine operating parameter from a previous regeneration has exceeded a threshold.   The determination that the soot load of the particle filter is below the safe high temperature regeneration level is a function of the length of time that the temperature of the exhaust gas is maintained within the first temperature range. The process of claim 1.   The process of claim 1, wherein the exhaust gas aftertreatment device comprises at least one of a diesel oxidation catalyst and at least one catalyzed portion of the particle filter.   The process according to claim 1, further comprising the step of performing passive NO2 regeneration before maintaining the temperature of the exhaust gas in the particle filter within the first temperature range. Performing passive NO2 regeneration until the soot loading of the particle filter is at a second predetermined level; and
After the soot load of the particle filter reaches a second predetermined level, the temperature of the exhaust gas in the particle filter is raised to the first temperature range; and the soot load of the particle filter is a safe high temperature regeneration level 2. The process of claim 1, further comprising maintaining the temperature of the exhaust gas in the particle filter within the first temperature range until a determination is made that the value is below.   The process of claim 10, wherein the second predetermined level is 1.5 and 2 times the safe hot regeneration level.   The process of claim 1, wherein the safe high temperature regeneration level is between 2-8 gC / l filter. An internal combustion engine device,
An internal combustion engine;
An exhaust line for collecting exhaust gas from the engine and discharging the exhaust gas toward the atmosphere;
An exhaust aftertreatment system having at least one particle filter in the exhaust line;
Heating means arranged to increase the temperature in the particle filter;
A controller for controlling the heating means,
An internal combustion engine device, wherein the controller is arranged to perform a regeneration process of the exhaust gas aftertreatment device according to any one of claims 1 to 12.   A trigger signal to start raising the temperature of the exhaust gas in the particle filter into a first temperature range in response to a trigger event indicating the need for regeneration of the exhaust gas aftertreatment device in the exhaust aftertreatment system; 14. The internal combustion engine device according to claim 13, further comprising means for providing to the controller.   The internal combustion engine device according to claim 14, wherein the exhaust gas aftertreatment device is at least one of a particle filter, a diesel oxidation catalyst, and a NOx reduction catalyst.   The controller is arranged to control the heating means for controlling the rate of temperature rise in the particle filter from the first temperature range to the second temperature range. An internal combustion engine device according to claim 1.   The internal combustion engine apparatus according to claim 13, further comprising means for estimating a soot load of the particle filter.   The controller is arranged to control the heater such that soot on the particle filter is oxidized by passive NO2 regeneration until the soot load on the particle filter is at a second predetermined level, and After the soot load of the particle filter reaches the second predetermined level, the heater is controlled to raise the temperature of the exhaust gas in the particle filter to the first temperature range, and the soot of the particle filter 14. The internal combustion engine of claim 13, wherein the temperature of the exhaust gas in the particle filter is maintained within the first temperature range until a second determination is made that a load is below the predetermined level. engine.   A vehicle having an internal combustion engine device arranged to perform a regeneration process of the exhaust gas aftertreatment device according to any one of claims 1 to 12.   A vehicle comprising the internal combustion engine device according to any one of claims 13 to 19.

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