JP4367065B2 - Exhaust gas purification device for internal combustion engine - Google Patents

Description

  The present invention relates to an exhaust emission control device for an internal combustion engine provided with a fuel reformer for reforming fuel.

In an exhaust gas purification apparatus for an internal combustion engine that generates reformed gas containing hydrogen by reforming fuel and supplies the reformed gas to a NOx trap catalyst to reduce NOx trapped in the catalyst, NOx is reduced. There is known an exhaust emission control device that controls the supply of reformed gas to an exhaust system in accordance with the required amount of hydrogen and the amount of reformed gas retained in a buffer tank (see Patent Document 1). In addition, there are Patent Documents 2 to 4 as prior art documents related to the present invention.
JP 2002-161735 A Japanese Patent Laid-Open No. 11-210447 JP 2002-38925 A JP 2002-38926 A

  The properties of the reformed fuel such as reformed gas (reformed fuel) vary depending on the temperature and amount during reforming, the composition and properties of the fuel before reforming, and the like. Therefore, even if the reformed fuel is supplied to regenerate the function of the exhaust purification means such as the NOx trap catalyst, the exhaust purification means may not be properly regenerated depending on the properties of the reformed fuel.

  Accordingly, an object of the present invention is to provide an exhaust purification device for an internal combustion engine that can stably perform regeneration of the exhaust purification means even when the properties of the reformed fuel are not stable.

The exhaust gas purification apparatus for an internal combustion engine according to the present invention includes a fuel reforming means for reforming fuel of the internal combustion engine, a reformed fuel storage means for storing reformed fuel reformed by the fuel reforming means, and the modified A reformed fuel supply means for supplying the reformed fuel of the quality fuel storage means to the exhaust gas purification means of the internal combustion engine; and a property determination means for determining the properties of the reformed fuel stored in the reformed fuel storage means; The reformed fuel supply for controlling the reformed fuel supply means so that the amount of the reformed fuel supplied from the reformed fuel supply means is adjusted according to the property of the reformed fuel determined by the property determining means Control means, and the reformed fuel supply control means is 1 when the reformed fuel is supplied in a plurality of times when the reformed fuel is supplied and the reformed fuel is determined to be light. The time between the first supply and the last supply is a predetermined time Ri longer, the if the reformed fuel is determined to heavy by the time between the supply of the first to the last supply controls the reforming fuel supply means so as to be shorter than the predetermined time The problem described above is solved (claim 1).

  According to the exhaust emission control device of the present invention, the amount of reformed fuel to be supplied is adjusted according to the property of the reformed fuel. Therefore, even when the property of the reformed fuel is not stable, An appropriate amount of reformed fuel can be supplied. Therefore, the regeneration of the exhaust gas purification means can be executed stably. Note that the amount of reformed fuel here refers to the amount of reformed fuel supplied per unit time. Therefore, the adjustment of the reformed fuel amount includes adjusting the supply interval and the supply frequency.

  In the exhaust emission control device of the present invention, the fuel reforming means may reform the fuel by exhaust heat of the internal combustion engine (claim 2). By utilizing the exhaust heat of the internal combustion engine in this way, there is no need to provide another energy supply source for supplying energy for reforming the fuel. Thereby, cost can be reduced.

  In the exhaust emission control device of the present invention, the property determining means determines the high or low boiling point of the reformed fuel as the property of the reformed fuel, and the reformed fuel supply control means has a low boiling point of the reformed fuel. The amount of the reformed fuel may be reduced as much (claim 3).

  When the boiling point of the reformed fuel is low, the supplied reformed fuel is vaporized in a short time, so that the exhaust gas having a high reformed fuel concentration (rich in the air-fuel ratio) may be supplied to the exhaust purification unit at a time. There is. Therefore, a part of the reformed fuel may pass through the exhaust purification unit and be released to the atmosphere without being used for regeneration of the exhaust purification unit. On the other hand, when the boiling point of the reformed fuel is high, it takes time for the reformed fuel to vaporize. Therefore, there is a possibility that the exhaust gas having a predetermined air-fuel ratio necessary for regenerating the exhaust gas purification unit is not supplied to the exhaust gas purification unit.

  In the present invention, when the boiling point of the reformed fuel is low, the amount of the reformed fuel is reduced, so that the reformed fuel can be prevented from passing through the exhaust purification unit and being discharged to the atmosphere. On the other hand, when the reforming fuel has a high boiling point, the amount of the reforming fuel is increased, so that the air-fuel ratio exhaust gas required for regeneration of the exhaust purification means can be supplied to the exhaust purification means. In the present invention, the determination of “high or low boiling point” is a concept that includes both a case of directly judging from the detected value of the boiling point and a case of judging from the value detected by replacing the boiling point with a physical quantity that correlates with this.

  In the exhaust emission control device according to the present invention, the fuel reforming means reforms the fuel using the exhaust gas of the internal combustion engine, and the property judging means determines the reforming based on the temperature of the exhaust gas used for reforming. The quality of the quality fuel may be judged (claim 4). In this case, since the energy supply source for reforming the fuel is exhaust, the temperature when the fuel is reformed can be estimated from the temperature of the exhaust. Therefore, the property of the reformed fuel can be determined from the exhaust temperature.

  The exhaust emission control device according to the present invention acquires a fuel amount acquisition means for acquiring a fuel amount supplied to the fuel reforming means, and a reformed fuel amount sent from the fuel reforming means to the reformed fuel storage means. A reformed fuel amount acquiring means, wherein the property determining means is based on the fuel amount acquired by the fuel amount acquiring means and the reformed fuel amount acquired by the reformed fuel amount acquiring means. May be determined (claim 5). There is a correlation between the ratio of the amount of fuel to be reformed and the amount of reformed fuel recovered from this amount of fuel (reformed fuel recovery ratio) and the temperature at which the fuel is reformed It has been known. Therefore, since the temperature at the time of fuel reforming can be estimated from the reformed fuel recovery ratio, the property of the reformed fuel can be determined from the fuel amount and the reformed fuel amount.

  According to the present invention, since the amount of reformed fuel to be supplied is adjusted according to the property of the reformed fuel, the regeneration of the exhaust purification means can be stably performed even when the property of the reformed fuel is not stable. Can do.

  FIG. 1 shows a main part of an internal combustion engine to which an exhaust gas purification apparatus according to an embodiment of the present invention is applied. The internal combustion engine 1 is configured as a diesel engine. As is well known, an intake passage 2 and an exhaust passage 3 are connected to the internal combustion engine 1. The intake passage 2 is provided with a throttle valve 4 that adjusts the intake air amount, and a compressor 5a of the supercharger 5 that uses the exhaust energy to increase the intake pressure. In the exhaust passage 3, a turbine 5 b of the supercharger 5, an exhaust purification device 6 as exhaust purification means, an exhaust temperature sensor 7 that outputs a signal corresponding to the temperature of the exhaust, and a signal corresponding to the air-fuel ratio of the exhaust And an air-fuel ratio sensor 8 for outputting. The exhaust purification device 6 is a known device in which, for example, a NOx storage reduction catalyst material is supported on a filter base material for collecting particulates. The NOx occlusion is not limited as long as it can hold NOx.

  The internal combustion engine 1 includes a fuel tank 9 for storing fuel (light oil), a fuel pump 11 for supplying the fuel in the fuel tank 9 to the injector 10, and surplus fuel out of the fuel supplied by the fuel pump 11. And a return passage 12 returning to the tank 9.

  The internal combustion engine 1 is provided with a fuel reforming device 13 for reforming fuel and a reformed fuel supply device 14. The fuel reformer 13 includes a fractionation passage 15 as fuel reforming means, a flow rate control valve 16 for controlling the flow rate of fuel supplied from the return passage 12 to the fractionation passage 15, and a fractionation passage 15. A reformed fuel container 17 serving as a reformed fuel storage means for storing the reformed fuel for the light component, a level sensor 18 for outputting a signal corresponding to the amount of the reformed fuel stored in the reformed fuel container 17, It has. The reformed fuel supply device 14 is a reformed fuel supply injector 19 as a reformed fuel supply means for supplying reformed fuel to the exhaust gas purification device 6, and a reformed fuel in the reformed fuel container 17 is used for supplying reformed fuel. A feed pump 20 for feeding to the injector 19 is provided.

  As shown in FIG. 2, the fractionation passage 15 includes a fractionation section 15a disposed in the exhaust passage 3 while being inclined with respect to the horizontal direction, and a light fuel evaporated by exhaust heat in the fractionation section 15a. The gas phase passage 15b for guiding the fuel to the reformed fuel container 17, the liquid phase passage 15c for guiding the heavy fuel that has not evaporated due to the exhaust heat to the fuel tank 9, and the branching of the gas phase passage 15b and the liquid phase passage 15c And a temperature sensor 21 (see FIG. 1) that outputs a signal corresponding to the temperature of the point 15d. The liquid phase passage 15c may be directly connected to the fuel tank 7, or may be connected to the return passage 12 on the downstream side of the position where the fractionation passage 15 is connected. As described above, the fractionation passage 15 uses the exhaust gas of the internal combustion engine 1 to reform the fuel into a light reformed fuel.

  The operating state of the internal combustion engine 1 is controlled by an engine control unit (ECU) 22. The ECU 22 is configured as a computer in which a microprocessor and peripheral devices such as ROM and RAM necessary for its operation are combined. The ECU 22 controls the operation of the reformed fuel supply injector 19 with reference to, for example, a signal from the air-fuel ratio sensor 8 and supplies the reformed fuel to the exhaust passage 3 to make the air-fuel ratio of the exhaust stoichiometric or rich. A process for regenerating the function of the exhaust emission control device 6 is performed. In addition to the sensors described above, the ECU 22 is connected to an outside air temperature sensor 23 that outputs a signal corresponding to the temperature of the outside air, a fuel temperature sensor 24 that outputs a signal corresponding to the temperature of the fuel, and the like. The ECU 22 controls the flow rate control valve 16 and the like in addition to the reformed fuel supply injector 19.

  The quality of the reformed fuel changes depending on the exhaust temperature of the internal combustion engine 1. For example, when the exhaust temperature is high, heavy fuel with a high boiling point is also evaporated and guided to the reformed fuel container 17. Therefore, the reformed fuel becomes heavy, has low volatility, and has a high boiling point. On the other hand, when the exhaust temperature is low, only the low boiling point fuel is led to the reformed fuel container 17 among the lighter fuels. Therefore, the reformed fuel is light, highly volatile, and has a low boiling point.

  The ECU 22 adjusts the amount of reformed fuel supplied from the reformed fuel supply injector 19 to the exhaust purification device 6 in accordance with the properties of the reformed fuel. FIG. 3 shows a reformed fuel supply amount control routine executed by the ECU 22 to adjust the reformed fuel amount. By executing the control routine of FIG. 3, the ECU 22 functions as a property determination unit and a reformed fuel supply control unit. The control routine of FIG. 3 is repeatedly executed at a predetermined cycle during the operation of the internal combustion engine 1.

  In the control routine of FIG. 3, the ECU 22 first determines in step S11 whether or not the property of the reformed fuel in the reformed fuel container 17 is a property (proper property) suitable for being supplied by normal addition control. To do. If it is determined that the property is appropriate, the process proceeds to step S12, and the ECU 22 causes the reforming fuel supply injector 19 to perform normal supply control. Thereafter, the current control routine is terminated. FIG. 4 shows an example of a reformed fuel supply pattern during normal supply control. As is clear from FIG. 4, the reformed fuel is supplied four times by the supply amount q within the supply time T.

  Whether or not the reformed fuel is appropriate is determined, for example, based on the boiling point of the reformed fuel. The boiling point of the reformed fuel can be estimated from the temperature history of the temperature sensor 21, for example. When the temperature of the branch portion 15d is higher than a predetermined temperature range (for example, a temperature range around 220 degrees) where the reformed fuel having proper properties is recovered, it is determined that the boiling point of the reformed fuel is high. On the other hand, when the temperature is lower than the predetermined temperature range, it is determined that the boiling point of the reformed fuel is low.

  On the other hand, if it is determined that the reformed fuel does not have proper properties, the process proceeds to step S13, and the ECU 22 changes the reformed fuel supply pattern in accordance with the properties of the reformed fuel. Thereafter, the current control routine is terminated. FIG. 5 shows an example of the relationship between the properties of the reformed fuel used when the ECU 22 changes the supply pattern and the number of reformed fuel supplies. As is apparent from FIG. 5, the ECU 22 increases the number of times of supply as the reformed fuel becomes lighter (lower boiling point). Further, the ECU 22 reduces the amount of reformed fuel (added amount) supplied from the reformed fuel supply injector 19 at a time as the number of times of supply is increased. An example of a supply pattern when the reformed fuel is determined to be light is shown in FIG. 6, and an example of a supply pattern when the reformed fuel is determined to be heavy is shown in FIG.

  FIG. 6A shows a supply pattern when the addition amount is reduced and the supply frequency is increased. By thus changing the supply pattern, the reformed fuel can be distributed and supplied to the exhaust passage 3. Accordingly, it is possible to prevent exhaust gas rich in the air-fuel ratio from being supplied to the exhaust gas purification device 6 at a time. Note that the supply pattern when the reformed fuel is determined to be light is not limited to the supply pattern shown in FIG. For example, the supply pattern shown in FIGS. 6B and 6C may be changed. FIG. 6B shows the supply pattern when the addition amount is the same as the supply pattern of FIG. 4 (the supply amount q remains unchanged) and the supply interval is increased. FIG. 6C shows a supply pattern when the supply frequency is increased while the addition amount is reduced and the supply interval is further expanded. By changing the supply pattern in this way, the reformed fuel can be distributed and supplied to the exhaust passage 3.

  On the other hand, FIG. 7A shows a supply pattern when the addition amount is increased and the number of times of supply is reduced. By changing the supply pattern in this way and increasing the amount of reformed fuel to be vaporized, the exhaust gas having a rich air-fuel ratio sufficient and sufficient to regenerate the exhaust purification device 6 even with heavy reformed fuel having a high boiling point. Can be supplied. The supply pattern when the reformed fuel is determined to be heavy is not limited to the supply pattern shown in FIG. For example, the supply pattern shown in FIGS. 7B and 7C may be changed. FIG. 7B shows a supply pattern when the addition amount is the same as the supply pattern of FIG. 4 (the supply amount q remains unchanged) and the supply interval is reduced. FIG. 7C shows a supply pattern in the case where the number of times of supply is reduced while the addition amount is increased and the supply interval is further reduced. By changing in this way, the same effect as in FIG. 7A can be obtained.

  By executing the control routine of FIG. 3 in this way, the reforming fuel supply pattern can be changed according to the properties of the reforming fuel.

  In step S11 of FIG. 3, the property of the reformed fuel can be determined from a physical quantity other than the temperature of the branch portion 15d. For example, the property is judged from the ratio (reformed fuel recovery ratio) of the amount of fuel supplied from the flow control valve 16 to the fractionation passage 15 and the increase in the level sensor 18 when this amount of fuel is fractionated. Can do. FIG. 8 shows the relationship between the temperature of the branch portion 15d and the reformed fuel recovery ratio. As is clear from FIG. 8, since there is a correlation between the temperature of the branching portion 15d and the reformed fuel recovery ratio, the property of the reformed fuel can be determined from the reformed fuel recovery ratio. Since the flow control valve 16 is controlled by the ECU 22, the amount of fuel supplied to the fractionation passage 15 is acquired by the ECU 22. In this case, the ECU 22 functions as a fuel amount acquisition unit, and the level sensor 18 functions as a reformed fuel amount acquisition unit.

  Further, since the fuel is reformed using the heat of the exhaust gas in the diversion passage 15, the temperature of the branching portion 15d can be estimated from the exhaust gas temperature. Therefore, the property of the reformed fuel can be determined from the exhaust temperature. By referring to the fuel temperature at the time of fuel reforming and the amount of fuel supplied to the diversion passage 15 together with the exhaust gas temperature, the temperature of the branch portion 15d can be estimated with higher accuracy.

  Further, the ECU 22 may change the supply pattern with reference to the signal of the air-fuel ratio sensor 8. 9 to 12 show examples of supply patterns that are changed by the ECU 22 with reference to the signal from the air-fuel ratio sensor 8. 9C to 12C show supply patterns during normal supply control as comparative examples.

  FIG. 9 shows that when the air-fuel ratio sensor 8 detects the exhaust gas having an air-fuel ratio richer than the air-fuel ratio necessary for regenerating the exhaust gas purification device 6 when the exhaust gas purification device 6 is regenerated, the next exhaust gas purification device 6 is used. The example of the supply pattern which ECU22 changes at the time of reproduction | regeneration of is shown. FIG. 9A shows an example of a supply pattern in the case where exhaust richer than a predetermined air-fuel ratio is detected for a long time when a reformed fuel of supply amount q is supplied as an addition amount. If rich exhaust gas is detected for a long time when the reformed fuel is supplied at the supply amount q, it is estimated that the reformed fuel has a low boiling point and a large amount of reformed fuel has evaporated at once. Therefore, the reformed fuel is dispersed and supplied to the exhaust purification device 6 by increasing the addition interval. FIG. 9B shows an example of a supply pattern when the air-fuel ratio sensor 8 detects rich exhaust gas immediately after the reformed fuel is supplied. Also in this case, since the boiling point of the reformed fuel is estimated to be low, the reformed fuel is dispersed and supplied to the exhaust emission control device 6 by increasing the number of times of supply while reducing the amount of addition once. Can do.

FIG. 10 (a), when that supply reformed fuel by reforming the fuel supply injector 19, when the rich exhaust is detected than the air-fuel ratio required for regeneration of the exhaust gas purification device 6, at the time of supply The example of the supply pattern which ECU22 changes is shown. In FIG. 10 (a), the reformed fuel is dispersed and supplied to the exhaust purification device 6 by expanding the third and fourth supply intervals. In addition, FIG.10 (b) has shown the reference example of the supply pattern when it is judged that reformed fuel is light. In this reference example, an excessive amount of reformed fuel is prevented from being supplied to the exhaust purification device 6 by reducing the amount of addition for the fourth time.

  FIG. 11 shows an example of a supply pattern that the ECU 22 changes when the exhaust purification device 6 is regenerated next time when exhaust gas having a stoichiometric or rich air-fuel ratio is not detected during the regeneration of the exhaust purification device 6. If stoichiometric or rich air-fuel ratio exhaust is not detected even when the reformed fuel is supplied, it is estimated that the reformed fuel has a heavy property with a high boiling point. Therefore, in FIG. 11A, the supply interval at the next supply is reduced, and the amount of reformed fuel to be vaporized within a predetermined time is increased to make the air-fuel ratio of the exhaust stoichiometric or rich. Further, in FIG. 11B, the air-fuel ratio of the exhaust is made stoichiometric or rich by increasing the addition amount at the next regeneration of the exhaust purification device 6. In the supply pattern of FIG. 11B, the number of times of supply may be reduced.

12 (a) is an exhaust gas purification device 6 is not detected exhaust stoichiometric or rich air-fuel ratio at the time of reproduction (which is a heavy high boiling point of the reformed fuel), the supply pattern of changing the ECU22 at the reproduction An example is shown. Figure 12 (a) in is the air-fuel ratio of exhaust to stoichiometric or rich by reducing the supply interval of the third and fourth. In addition, FIG.12 (b) has shown the reference example of the supply pattern when it is judged that reformed fuel is heavy. In this reference example, the air-fuel ratio of the exhaust is made stoichiometric or rich by increasing the amount of addition for the fourth time.

  In this way, by changing the supply pattern with reference to the air-fuel ratio of the exhaust, the amount of reformed fuel supplied to the exhaust purification device 6 can be adjusted with higher accuracy. In addition, after changing to the supply pattern shown in FIG. 9, FIG. 10, when the exhaust of air fuel ratio richer than a predetermined air fuel ratio is no longer detected, it returns to the supply pattern at the time of normal supply control. Further, after changing to the supply pattern shown in FIGS. 11 and 12, when the air-fuel ratio richer than the predetermined air-fuel ratio is detected, the supply pattern is returned to the normal supply control.

  For the functional regeneration of the NOx storage reduction catalyst which is the exhaust gas purification device 6, NOx regeneration for releasing the stored NOx by setting the air-fuel ratio of the inflowing exhaust to stoichiometric or rich, and the air-fuel ratio of the inflowing exhaust gas is stoichiometric. Alternatively, it is set to rich, and the S regeneration for releasing the sulfur content (S) by raising the temperature of the exhaust gas higher than the NOx regeneration, and the PM for burning the adhering particulate matter (PM) by raising the temperature of the NOx catalyst. There is playback. Since reformed fuel is supplied to the exhaust passage 3 in any of NOx regeneration, S regeneration, and PM regeneration, the amount of reformed fuel is adjusted at any of these regenerations.

  The present invention is not limited to the above-described embodiments, and may be implemented in various forms. For example, the air-fuel ratio of the exhaust gas is not limited to the air-fuel ratio sensor, and an oxygen concentration sensor may be used.

The figure which shows the principal part of the internal combustion engine to which the exhaust gas purification apparatus which concerns on one Embodiment of this invention is applied. The figure which expands and shows a part of fuel reformer of FIG. The figure which shows the reformed fuel quantity control routine which ECU of FIG. 1 performs in order to adjust the reformed fuel quantity. The figure which shows an example of the supply pattern at the time of normal addition of a reformed fuel. The figure which shows the relationship between the property of a reformed fuel, and the frequency | count of reformed fuel supply. The figure which shows the example of the supply pattern of reformed fuel when it is judged that reformed fuel is light. The figure which shows the example of the supply pattern of reformed fuel when it is judged that reformed fuel is heavy. The figure which shows the relationship between the temperature of the branch part of FIG. 2, and a reformed fuel recovery ratio. The figure which shows the example of the supply pattern of the reformed fuel changed at the time of reproduction | regeneration of the next exhaust gas purification apparatus when it is judged that the reformed fuel is light. The figure which shows the example of the supply pattern of the reformed fuel changed at the time of the reproduction | regeneration of the exhaust gas purification device of the time when it is judged that the reformed fuel is light. The figure which shows the example of the supply pattern of the reformed fuel changed at the time of reproduction | regeneration of the next exhaust gas purification apparatus when it is judged that reformed fuel is heavy. The figure which shows the example of the supply pattern of the reformed fuel changed at the time of the reproduction | regeneration of the exhaust purification apparatus of the time when it is judged that reformed fuel is heavy.

Explanation of symbols

1 Internal combustion engine 6 Exhaust purification device (exhaust purification means)
15 Fractionation passage (fuel reforming means)
17 Reformed fuel container (reformed fuel storage means)
18 Level sensor (reforming fuel quantity acquisition means)
19 Reformed fuel supply injector (reformed fuel supply means)
22 Engine control unit (property determination means, reformed fuel supply control means, fuel amount acquisition means)

Claims (5)

Fuel reforming means for reforming the fuel of the internal combustion engine, reformed fuel storage means for storing the reformed fuel reformed by the fuel reforming means, and the reformed fuel of the reformed fuel storage means for the reformed fuel Reformed fuel supplying means for supplying to the exhaust gas purifying means of the internal combustion engine, property determining means for determining the property of the reformed fuel stored in the reformed fuel storing means, and the reforming determined by the property determining means Reformed fuel supply control means for controlling the reformed fuel supply means so that the amount of reformed fuel supplied from the reformed fuel supply means is adjusted according to the properties of the fuel ,
The reformed fuel supply control means supplies the reformed fuel in a plurality of times when the reformed fuel is supplied, and if the reformed fuel is determined to be light, the reformed fuel supply control means supplies the reformed fuel from the first supply to the last supply. When the reformed fuel is judged to be heavy, the reforming time is shorter than the predetermined time when the reformed fuel is judged to be heavy. An exhaust purification device for an internal combustion engine, characterized by controlling a fuel supply means .   The exhaust gas purification apparatus for an internal combustion engine according to claim 1, wherein the fuel reforming means reforms the fuel by exhaust heat of the internal combustion engine. The property determining means determines the level of the boiling point of the reformed fuel as the property of the reformed fuel,
The exhaust gas purification apparatus for an internal combustion engine according to claim 1 or 2, wherein the reformed fuel supply control means reduces the reformed fuel amount as the boiling point of the reformed fuel is lower. The fuel reforming means reforms the fuel using the exhaust gas of the internal combustion engine,
The exhaust gas purification of an internal combustion engine according to any one of claims 1 to 3, wherein the property determining means determines the property of the reformed fuel based on the temperature of exhaust gas used for reforming. apparatus. Fuel amount acquisition means for acquiring the amount of fuel supplied to the fuel reforming means; reformed fuel amount acquisition means for acquiring the amount of reformed fuel sent from the fuel reforming means to the reformed fuel storage means; With
The property determining means determines the property of the reformed fuel based on the fuel amount acquired by the fuel amount acquiring means and the reformed fuel amount acquired by the reformed fuel amount acquiring means. Item 5. An exhaust emission control device for an internal combustion engine according to any one of Items 1 to 4.

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