CN114198216A

CN114198216A - Exhaust gas aftertreatment system, control system, program medium and corresponding control method

Info

Publication number: CN114198216A
Application number: CN202010979671.2A
Authority: CN
Inventors: 田威; 王文明; 韩晓梅; 秦岩; 李庆丰
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2020-09-17
Filing date: 2020-09-17
Publication date: 2022-03-18

Abstract

Disclosed is a method for controlling a diesel engine comprising an exhaust gas aftertreatment device including at least a selective catalytic reduction converter, comprising at least: acquiring a tail gas aftertreatment temperature condition parameter and an engine working parameter; processing temperature condition parameters and engine working parameters after the tail gas is processed and obtaining control signals; performing a first operating state adjusting operation for adjusting a first operating state of the diesel engine under a predetermined condition or based on at least the control signal; and performing a second operating state adjusting operation for adjusting a second operating state of the diesel engine based on at least the control signal, the first operating state adjusting operation having a higher priority than the second operating state adjusting operation, the first operating state being at least partially different from the second operating state, the second operating state adjusting operation including at least an operation related to adjusting a torque of the diesel engine. Overheating of the selective catalytic reduction converter can be avoided more reliably.

Description

Exhaust gas aftertreatment system, control system, program medium and corresponding control method

Technical Field

The present invention relates to a method for controlling a diesel engine, an exhaust gas aftertreatment system for a diesel engine, a vehicle control system and a computer-readable program medium.

Background

Diesel engines are widely used in small, heavy or large vehicles, ships, generators, military tanks, and other machines due to their characteristics of good reliability, high thermal efficiency, and large output torque. However, because of the high content of nitrogen oxides and other harmful components in the exhaust gas emitted from diesel engines, the exhaust gas needs to be treated by a special exhaust gas after-treatment system before being emitted into the atmosphere, so as to meet the increasingly strict environmental requirements.

In other words, aftertreatment of exhaust gas from diesel engines has become a standard outfit for diesel engines in order to reduce air pollution. For this reason, exhaust gas aftertreatment systems generally include functional units such as a diesel oxidation catalyst, a diesel particulate filter, and a selective catalytic reduction converter, which cooperate with each other by a physical method or a chemical reaction method to remove harmful components in exhaust gas.

Selective catalytic reduction converters are key to the control of nitrogen oxides in the exhaust of heavy duty diesel engines. Currently, a vanadium-based catalyst is widely used for a selective catalytic reduction converter because of its high nitrogen oxide conversion performance and sulfur resistance characteristics.

However, vanadium-based catalysts are not resistant to high temperatures. For this reason, emission regulations in some countries even prohibit inlet temperatures of selective catalytic reduction converters using vanadium-based catalysts above 550 ℃ to avoid harmful gas exposure.

For this reason, there is a strong need for improvements to existing exhaust after-treatment systems to improve their performance.

Disclosure of Invention

It is an object of the present invention to provide a method for controlling a diesel engine, an exhaust gas aftertreatment system for a diesel engine, a vehicle control system and a computer readable program medium.

According to a first aspect of the invention, a method for controlling a diesel engine is provided, wherein the diesel engine comprises an exhaust gas aftertreatment device comprising at least a selective catalytic reduction converter, the method comprising at least the steps of: obtaining an exhaust aftertreatment temperature condition parameter indicative of a temperature condition within the selective catalytic reduction converter and an engine operating parameter different from the exhaust aftertreatment temperature condition parameter; analyzing and processing the tail gas aftertreatment temperature condition parameters and the engine working parameters and obtaining control signals; performing a first operating state adjusting operation for adjusting a first operating state of the diesel engine under a predetermined condition or based on at least the control signal; and performing a second operating state adjusting operation for adjusting a second operating state of the diesel engine based on at least the control signal, wherein the first operating state adjusting operation has a higher execution priority than the second operating state adjusting operation, the first operating state being at least partially different from the second operating state, the second operating state adjusting operation including at least an operation related to adjusting a torque of the diesel engine.

According to a second aspect of the invention, an exhaust gas aftertreatment system for a diesel engine is provided, wherein the exhaust gas aftertreatment system comprises an exhaust gas aftertreatment device and a controller configured for performing the method.

According to a third aspect of the invention, a vehicle control system is provided, wherein the vehicle control system comprises a controller configured to perform the method.

According to a fourth aspect of the invention, a computer-readable program medium is provided, wherein the computer-readable program medium stores program instructions which, when executed by a processor, perform the method.

According to the present invention, the overheating of the selective catalytic reduction converter can be prevented more reliably.

Drawings

The principles, features and advantages of the present invention may be better understood by describing the invention in more detail below with reference to the accompanying drawings. The drawings comprise:

fig. 1 shows a schematic composition diagram of an exhaust gas aftertreatment system for a diesel engine according to an exemplary embodiment of the invention.

Fig. 2 schematically shows a schematic block diagram of a vehicle control system according to an exemplary embodiment of the present invention.

Fig. 3 schematically shows a functional block diagram of a vehicle control system according to another exemplary embodiment of the present invention.

Fig. 4 schematically shows a functional block diagram of a vehicle control system according to another exemplary embodiment of the present invention.

Fig. 5 schematically shows a functional block diagram of a vehicle control system according to yet another exemplary embodiment of the present invention.

Fig. 6 shows a flowchart of a method for controlling a diesel engine according to an exemplary embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and exemplary embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of the invention.

As shown in fig. 1, the exhaust gas aftertreatment system comprises an exhaust gas aftertreatment device 1, and the exhaust gas aftertreatment device 1 may include: a diesel oxidation catalyst 2, a diesel particulate filter 3, and a selective catalytic reduction converter 4, wherein, the diesel oxidation catalyst 2 is mainly used for oxidizing products (including hydrocarbon and carbon monoxide) which are not completely combusted by the diesel engine into harmless gases such as carbon dioxide and water through oxidation reaction, on the other hand, when the diesel particulate filter 3 needs to be regenerated, the inlet temperature of the diesel particulate filter 3 is raised by oxidizing the fuel, thereby burning off the particulate matter trapped in the diesel particulate filter 3, the diesel particulate filter 3 is mainly used for physically trapping the particulate matter (e.g., soot) in the exhaust gas and then burning off at a proper time for regeneration treatment, and the selective catalytic reduction converter 4 is mainly used for selectively catalytically reducing nitrogen oxides by an exhaust gas treating agent such as an aqueous urea solution to convert into harmless gas such as nitrogen.

According to an exemplary embodiment of the present invention, the selective catalytic reduction converter 4 is a selective catalytic reduction converter using a vanadium-based catalyst.

The arrow 5 in fig. 1 indicates the flow direction of the exhaust gas. The exhaust gas preferably flows through the diesel oxidation catalyst 2, the diesel particulate filter 3 and the selective catalytic reduction converter 4 in this order and is finally discharged to the environment.

In order to monitor the operating state of the exhaust gas aftertreatment device 1, a first temperature sensor T1 is usually provided at the inlet of the diesel oxidation catalytic converter 2, a second temperature sensor T2 is provided at the inlet of the diesel particulate filter 3, a third temperature sensor T3 is provided at the inlet of the selective catalytic reduction converter 4, and a nitrogen oxide sensor 41 is provided at the outlet of the exhaust gas aftertreatment device 1, for example at the outlet of the selective catalytic reduction converter 4.

The operating state of the exhaust gas aftertreatment device 1 can be monitored by these sensors. To this end, the exhaust aftertreatment system may further include a controller 10. The signals of these sensors are transmitted to the controller 10, so that the controller 10 performs corresponding control, for example, control of the operating state of the engine, in accordance with one or more of these signals to ensure that the exhaust gas aftertreatment device 1 operates in a desired manner. The connection of the controller 10 to the various sensors is schematically shown in dashed lines in fig. 1.

Those skilled in the art will appreciate that the sensors listed herein are exemplary only, and in practice, the arrangement, type, and/or number of sensors may vary from case to case. However, in order to monitor and control the temperature in the selective-catalytic-reduction converter 4 (in particular in the case of a vanadium-based catalyst for the selective-catalytic-reduction converter 4), the exhaust gas aftertreatment device 1 is provided with at least one sensor, for example a third temperature sensor T3, which is adapted to characterizing the temperature conditions in the selective-catalytic-reduction converter 4.

It will also be understood by those skilled in the art that the controller 10 may be or be part of an electronic control unit of the vehicle, or may be a separate controller communicatively coupled to the electronic control unit of the vehicle. In some cases, the controller 10 may control not only the exhaust gas aftertreatment device 1, but also other devices of the vehicle, such as other components of the engine, to bring the vehicle into a desired operating state.

As shown in fig. 2, the vehicle control system 11 may comprise an engine operating state analyzing module 12 and an engine operating state adjusting module 13, wherein the engine operating state analyzing module 12 is configured to receive at least an exhaust gas aftertreatment temperature condition parameter 14 adapted to characterize a temperature condition within the selective catalytic reduction converter 4 of the exhaust aftertreatment device 1 and an engine operating parameter 15 different from the exhaust gas aftertreatment temperature condition parameter 14 and output a control signal 16 after being analyzed to the engine operating state adjusting module 13, the engine operating state adjusting module 13 is configured to execute a first operating state adjusting operation 17 for adjusting a first operating state of the engine and a second operating state adjusting operation 18 for adjusting a second operating state of the engine based on at least the control signal 16, wherein the first operating state adjusting operation 17 has a higher execution priority than the second operating state adjusting operation 18, the first operating state being at least partly different from the second operating state, i.e. the first operating state adjusting operation 17 is at least partly different from the second operating state adjusting operation 18, and the second operating state adjusting operation 18 at least comprises an operation related to adjusting the torque of the engine, in particular to reducing the torque of the engine. It is to be understood that the vehicle control system 11 is preferably implemented by the controller 10.

Here, as will be understood by those skilled in the art, the phrase "the first operating condition adjusting operation 17 has a higher execution priority than the second operating condition adjusting operation 18" means that the engine operating condition adjusting module 13 executes the first operating condition adjusting operation 17 when necessary, and then determines whether the second operating condition adjusting operation 18 needs to be executed again based on the temperature condition in the selective catalytic reduction converter 4 after the execution of the first operating condition adjusting operation 17. Furthermore, it will also be understood by those skilled in the art that adjusting the operation related to the torque of the engine may be, for example, adjusting the amount of fuel injected by the engine, which may be calculated, for example, by an electronic control unit of the vehicle based on the position of an accelerator pedal, etc.

Further, it will be appreciated that while the exhaust aftertreatment temperature condition parameter 14 and the engine operating parameter 15 are shown with only one arrow in FIG. 2, this does not mean that they each include only one parameter, but rather that they may include any number of parameters. Similarly, so does the control signal 16. This will be more readily understood from the following description.

According to an exemplary embodiment of the invention, the exhaust gas aftertreatment temperature regime parameter 14 may be or comprise a temperature at an inlet of the selective catalytic reduction converter 4 of the exhaust gas aftertreatment device 1. As shown in fig. 1, the temperature may be measured, for example, by a third temperature sensor T3. Preferably, the exhaust gas aftertreatment temperature condition parameter 14 may further comprise a temperature trend indicative quantity adapted to being indicative of a trend of change of the temperature at the inlet of the selective-catalytic-reduction converter 4. The temperature trend indicative quantity may be represented by a derivative of temperature, i.e. a temperature gradient. Those skilled in the art will appreciate that the temperature condition within the selective catalytic reduction converter 4 can be more reliably determined based on the temperature at the inlet of the selective catalytic reduction converter 4 in combination with the temperature trend indicative quantity, i.e., whether the temperature within the selective catalytic reduction converter 4 actually exceeds a predetermined temperature to adversely affect the selective catalytic reduction converter 4, such as to destroy the catalyst (particularly, a vanadium-based catalyst) within the selective catalytic reduction converter 4. For example, in a case where the temperature at the inlet of the selective catalytic reduction converter 4 is decreased in the tendency to change even if the temperature reaches a predetermined value, this means that the temperature in the selective catalytic reduction converter 4 does not tend to increase further, and therefore it can be judged that the selective catalytic reduction converter 4 is not adversely affected by the temperature.

According to an exemplary embodiment of the invention, the engine operating parameter 15 may include at least one of an oil temperature, a coolant temperature, a fuel temperature, and an air temperature of the engine. It is more advantageous to include these four types at the same time.

According to an exemplary embodiment of the invention, the first operating state may comprise an operating state of a throttle valve of an air system of the engine and/or a post injection state of the engine. For example, in the case where it is judged that the temperature in the selective catalytic reduction converter 4 of the exhaust gas aftertreatment device 1 has exceeded the predetermined temperature or is about to exceed the predetermined temperature, the throttle valve may be operated toward the tendency of the orifice enlargement, for example, fully opened and/or the post-injection may be reduced, for example, the post-injection may be stopped, by the first operation state adjustment operation 17. Of course, those skilled in the art will appreciate that these operations are merely exemplary, and in practice, the first operating condition adjusting operation 17 may include other operating condition adjusting operations as appropriate, as long as it is advantageous to reduce the temperature within the selective catalytic reduction converter 4 or suppress the tendency to continue increasing, for example, reducing the temperature at the inlet of the selective catalytic reduction converter 4 or suppressing the tendency to continue increasing may have the effect of reducing the temperature within the selective catalytic reduction converter 4 or suppressing the tendency to continue increasing.

The embodiment shown in fig. 3 differs from that of fig. 2 in that the engine operating state analysis module 12 may include: a first engine operating state analysis submodule 121 configured to receive an exhaust aftertreatment temperature condition parameter 14 adapted to characterize a temperature condition within the selective catalytic reduction converter 4 and output a first control sub-signal 161, after analysis processing, to the engine operating state adjustment module 13; and a second engine operating condition analysis submodule 122 configured to receive the engine operating parameter 15 and output a second control sub-signal 162 to the engine operating condition adjustment module 13 after analysis processing.

The advantage of this embodiment is that the second engine operating condition analysis submodule 122 is typically already present in existing vehicle control systems, for which reason the vehicle control system of the invention can be further constructed directly with the existing modules. This not only saves time costs, but also eliminates the need to change the control logic within the existing module.

In this case, the engine operating parameters 15 may include the engine oil temperature, coolant temperature, fuel temperature, and air temperature of the engine, as described above. The second control sub-signal 162 may be a torque limiting factor of the engine. The torque limiting factor ranges from 0 to 1, with smaller factors indicating greater torque limitation of the engine. The following description and illustrations will be made with reference to more specific embodiments.

The portion of FIG. 4 that is generally enclosed by the dashed box may be considered the engine operating condition adjustment module 13.

In the present embodiment, the engine operating state adjusting module 13 may include a protection module 131 configured to receive the first control sub-signal 161 output by the first engine operating state analyzing sub-module 121 and the second control sub-signal 162 output by the second engine operating state analyzing sub-module 122 and output a protection control signal 163 based on the first control sub-signal 161 and the second control sub-signal 162, so that the engine operates more safely. At this time, the first control sub-signal 161 and the second control sub-signal 162 are preferably the same type of signal, for example, both torque limiting coefficients. When the first torque limiting factor, which is the first control sub-signal 161, is different from the second torque limiting factor, which is the second control sub-signal 162, it is indicated that the operating state adjustment desired to be performed by the first engine operating state analysis sub-module 121, as determined based on the exhaust gas aftertreatment temperature condition parameter 14, is inconsistent with the operating state adjustment desired to be performed by the second engine operating state analysis sub-module 122, as determined based on the engine operating parameter 15. For greater safety, a more safe torque limiting coefficient should be determined based on the first and second torque limiting coefficients to control the operation of the engine and thus the temperature within the selective catalytic reduction converter 4.

According to an exemplary embodiment of the present invention, the smaller of the first torque limiting coefficient and the second torque limiting coefficient is selected to be output as the protection control signal 163. Of course, it will be understood by those skilled in the art that the protection control signal 163 may be determined based on the first and second torque limiting coefficients in other ways, such as selecting an average of the two. The present invention does not impose any limitation on this as long as a control signal that is relatively safe in terms of temperature inside the selective catalytic reduction converter 4 can be output based on the first control sub-signal 161 and the second control sub-signal 162. The determination method of the protection control signal 163 may be different according to the types of the first control sub-signal 161 and the second control sub-signal 162.

According to an exemplary embodiment of the invention, as shown in FIG. 4, the engine operating state adjustment module 13 may also include a decision module 132. The decision module 132 is configured to receive the protection control signal 163 from the protection module 131 while also receiving the second control sub-signal 162 from the second engine operating condition analysis sub-module 122. Furthermore, the engine operating state adjusting module 13 may further comprise a determining module 133, wherein the determining module 133 is configured to additionally determine whether the exhaust gas aftertreatment device 1 of the engine, in particular the selective catalytic reduction converter 4 thereof, actually has an overheating risk based on the exhaust gas aftertreatment operating state parameter adapted to characterize the operating state of the exhaust gas aftertreatment device 1, and to determine whether to perform the first operating state adjusting operation 17 according to the determination result, and to output a decision control signal 134 to the decision module 132 under a predetermined condition according to the determination result.

It will be understood by those skilled in the art that the exhaust gas aftertreatment operating state parameter is indicative of the operating state of the exhaust gas aftertreatment device 1, whereas as shown in fig. 1, the various main components of the exhaust gas aftertreatment device 1 are connected in series, and therefore the operating state of the other components indirectly reflects or predicts whether there is a risk of overheating of the selective catalytic reduction converter 4. Thus, it is possible to determine whether there is a risk of overheating the selective-catalytic-reduction converter 4 by means of the exhaust-gas aftertreatment operating state parameters.

According to an exemplary embodiment of the present invention, the exhaust aftertreatment operating state parameter may include the exhaust aftertreatment temperature condition parameter 14 or partially overlap the exhaust aftertreatment temperature condition parameter 14.

As shown in fig. 4, the determination module 133 may determine whether to perform the first operating state adjustment operation 17 based directly on the exhaust gas aftertreatment operating state parameter without considering the first control sub-signal 161, the second control sub-signal 162 and the protection control signal 163.

According to an exemplary embodiment of the invention, the exhaust aftertreatment operating state parameter may comprise at least one of: a first temperature measured by the first temperature sensor T1, a temperature trend indicative of the first temperature, a second temperature measured by the second temperature sensor T2, a temperature trend indicative of the second temperature, a third temperature measured by the third temperature sensor T3, and a temperature trend indicative of the third temperature. The third temperature is the temperature at the inlet of the selective-catalytic-reduction converter 4, and it can therefore be seen that the exhaust-gas aftertreatment operating state parameter may include the exhaust-gas aftertreatment temperature regime parameter 14 or partially overlap the exhaust-gas aftertreatment temperature regime parameter 14.

It will be appreciated by those skilled in the art that the temperature trend indicative quantity for each temperature may be a temperature derivative or a temperature gradient, as described above.

According to an exemplary embodiment of the present invention, the decision module 133 is configured to assume that the exhaust gas aftertreatment device 1, in particular the selective catalytic reduction converter 4 thereof, is at risk of overheating and at least the first operating state adjustment operation 17 needs to be performed when any one of the exhaust gas aftertreatment operating state parameters exceeds a respective threshold value.

Since the decision module 132 may also receive the second control sub-signal 162 from the second engine operating state analysis sub-module 122 as shown in fig. 4, the decision module 132 may be controlled accordingly based directly on the second control sub-signal 162 output by the second engine operating state analysis sub-module 122, which retains compatibility with existing control systems and increases flexibility of system configuration.

During the execution of the first operation state adjustment operation 17, the determining module 133 monitors in real time whether there is still an overheating risk in the exhaust gas aftertreatment device 1, and if there is still an overheating risk, outputs a decision control signal 134 to the decision module 132, so as to allow the decision module 132 to output a corresponding control signal based on the protection control signal 163 and the control quantity q to execute the second operation state adjustment operation 18, so as to further reduce the overheating risk of the exhaust gas aftertreatment device 1, in particular, the selective catalytic reduction converter 4 thereof.

For example, in the case where the protection control signal 163 is a torque limit coefficient, the control amount q may be an injection amount, which may be calculated by other modules as described above. Preferably, the second operating condition adjusting operation 18 is executed by directly multiplying the torque limit coefficient by the fuel injection amount as the correction fuel injection amount at this time. It will be clear to the person skilled in the art that the invention is not restricted thereto, but that the protection control signal 163 and the control quantity q can also be other types of parameters, as long as finally a reduction of the risk of overheating of the exhaust gas aftertreatment device 1, in particular of the selective-catalytic-reduction converter 4 thereof, can be achieved by performing the second operating state adjustment operation 18.

Although the operation of the first engine operating condition analysis sub-module 121 has been described above by taking as an example the temperature at the inlet of the selective catalytic reduction converter 4 and its temperature trend representative, it is apparent that the present invention is not limited thereto, and the temperature condition within the selective catalytic reduction converter 4 may be determined based on the excess air ratio, for example. This will be described below.

It will be appreciated that the operating state of the selective catalytic reduction converter 4 is related to the temperature conditions therein, which are also reflected by the oxygen content in the exhaust gas finally emitted. Therefore, the temperature conditions within the selective catalytic reduction converter 4 can be determined by the oxygen content in the finally discharged exhaust gas. The oxygen content in the finally discharged exhaust gas is in turn related to the excess air factor. Therefore, the temperature condition in the selective catalytic reduction converter 4 can be judged by the control deviation of the excess air ratio.

Specifically, according to an exemplary embodiment of the present invention, the first excess air ratio may be obtained from an engine MAP, the second excess air ratio may be obtained in real time from the nox sensor 41, and in the case where the engine is operating at a steady state, it may be determined whether there is a risk of overheating the selective catalytic reduction converter 4 based on a deviation of the first excess air ratio from the second excess air ratio.

According to an exemplary embodiment of the present invention, in case the engine is operated in steady state, a corresponding control sub-signal may be generated as the first control sub-signal 161 based on a deviation of the first excess air factor from the second excess air factor.

As shown in fig. 5, the embodiment shown in fig. 5 differs from fig. 4 mainly in that the first engine operating state analysis sub-module 121 may include a first analysis and evaluation module 1211 based on the temperature at the inlet of the selective catalytic reduction converter 4 and a temperature trend indicative quantity thereof and a second analysis and evaluation module 1212 based on a control deviation of the excess air coefficient. At this time, the first analysis and evaluation module 1211 receives the temperature at the inlet of the selective catalytic reduction converter 4 and the temperature trend characteristic thereof as the first temperature condition parameter 141 and outputs a first corresponding control sub-signal 1611. Similarly, the second analysis evaluation module 1212 receives the first and second excess air coefficients at steady state engine operation as the second temperature condition parameter 142 and outputs a second corresponding control sub-signal 1612. In this exemplary embodiment, the first temperature situation parameter 141 and the second temperature situation parameter 142 are equivalent to jointly form the exhaust gas aftertreatment temperature situation parameter 14, while the first corresponding control subsignal 1611 and the second corresponding control subsignal 1612 are equivalent to jointly form the first control subsignal 161.

In this case, as shown in fig. 5, the first corresponding control sub-signal 1611 and the second corresponding control sub-signal 1612 may both be input to the protection module 131. However, the present invention is not limited to this, and only one corresponding control sub-signal may be output to the protection module 131 after being analyzed and processed in the first engine operating state analyzing sub-module 121.

Furthermore, it will be understood by those skilled in the art that although fig. 5 shows that the first analysis and evaluation module 1211 and the second analysis and evaluation module 1212 perform the analysis process based on the first temperature condition parameter 141 and the second temperature condition parameter 142 respectively and independently, the first engine operating state analysis submodule 121 as a whole may perform the analysis process in cooperation with the first temperature condition parameter 141 and the second temperature condition parameter 142.

Those skilled in the art will appreciate that the temperature conditions within the selective catalytic reduction converter 4 may be better determined by a combination of the first and second

temperature condition parameters

141 and 142, such as using the first and second

analytical evaluation modules

1211 and 1212 in combination as shown in FIG. 5.

The basic idea and some exemplary embodiments of the present invention are described above, and a person skilled in the art may also conceive of other exemplary embodiments in combination with some exemplary embodiments under the guidance of the basic idea. For example, it may be determined in various ways, such as experimentally and/or simulation, how the first engine operating state analysis sub-module 121 determines the first control sub-signal 161 based specifically on the exhaust aftertreatment temperature condition parameter 14 adapted to characterize the temperature condition within the selective catalytic reduction converter 4. The invention is not limited in this regard.

From the above description, it is clear that the invention also discloses a method for controlling a diesel engine, for example of a vehicle. Fig. 6 shows a flowchart of a method for controlling a diesel engine according to an exemplary embodiment of the present invention.

As shown in fig. 6, in step S1, an exhaust aftertreatment temperature condition parameter 14 adapted to characterize a temperature condition within the selective catalytic reduction converter 4 of the exhaust aftertreatment device 1 and an engine operating parameter 15 different from the exhaust aftertreatment temperature condition parameter 14 are obtained; analyzing and processing the exhaust aftertreatment temperature condition parameters 14 and the engine operating parameters 15 and obtaining control signals 16 at step S2; in step S3, a first operating state adjusting operation 17 for adjusting a first operating state of the engine and a second operating state adjusting operation 18 for adjusting a second operating state of the engine are executed under a predetermined condition or at least based on the control signal 16, wherein the first operating state adjusting operation 17 has a higher execution priority than the second operating state adjusting operation 18, the first operating state is at least partially different from the second operating state, and the second operating state adjusting operation 18 includes at least an operation related to adjusting the torque of the engine.

The method may also include other steps that are apparent by reference to the description above in connection with the vehicle control system and are not repeated herein for clarity.

The invention also relates to a controller configured to perform the method. Furthermore, a computer-readable program medium is provided, which stores program instructions that, when executed by a processor, implement the method.

Although specific embodiments of the invention have been described herein in detail, they have been presented for purposes of illustration only and are not to be construed as limiting the scope of the invention. Various substitutions, alterations, and modifications may be devised without departing from the spirit and scope of the present invention.

List of reference numerals

1 exhaust gas after-treatment device

2 diesel oil oxidation catalyst

3 diesel particulate filter

4 selective catalytic reduction converter

5 arrow head

T1 first temperature sensor

T2 second temperature sensor

T3 third temperature sensor

10 controller

41 nitrogen oxide sensor

11 vehicle control system

12 engine working state analysis module

13 engine working state adjusting module

14 exhaust aftertreatment temperature Condition parameter

15 operating parameters of the engine

16 control signal

17 first operation state adjustment operation

18 second operating condition adjustment operation

121 first engine working state analysis submodule

122 second engine operating condition analysis submodule

161 first control sub-signal

162 second control sub-signal

131 protective module

132 decision module

133 judging module

134 decision control signal

163 protection control signal

q control quantity

141 first temperature condition parameter

142 second temperature condition parameter

1211 first analysis and evaluation module

1212 second analysis and evaluation module

1611 first corresponding control sub-signal

1612 second corresponding control sub-signal

Claims

1. A method for controlling a diesel engine, wherein the diesel engine comprises an exhaust gas aftertreatment device (1), the exhaust gas aftertreatment device (1) comprising at least a selective catalytic reduction converter (4), the method comprising at least the steps of:

-acquiring an exhaust gas aftertreatment temperature condition parameter (14) adapted to characterize a temperature condition within the selective-catalytic-reduction converter (4) and an engine operating parameter (15) different from the exhaust gas aftertreatment temperature condition parameter (14);

analyzing and processing the exhaust aftertreatment temperature condition parameters (14) and the engine operating parameters (15) and obtaining control signals (16);

performing a first operating state adjusting operation (17) for adjusting a first operating state of the diesel engine under predetermined conditions or at least based on the control signal (16); and

performing a second operating state adjusting operation (18) for adjusting a second operating state of the diesel engine based on at least the control signal (16),

wherein the first operating state adjusting operation (17) has a higher execution priority than the second operating state adjusting operation (18), the first operating state being at least partially different from the second operating state, the second operating state adjusting operation (18) including at least an operation of adjusting a torque related to a diesel engine.

2. The method of claim 1, wherein at least one of the following features is included:

the first operating state adjusting operation (17) being at least partially different from the second operating state adjusting operation (18); and/or

The second working state adjustment operation (18) is only performed after the first working state adjustment operation (17) is performed and still meets the predetermined condition; and/or

The operation related to the torque of the diesel engine is an operation of reducing the torque of the diesel engine.

3. The method of claim 1 or 2,

the exhaust aftertreatment temperature condition parameter (14) comprises a temperature at an inlet of the selective catalytic reduction converter (4) and a temperature trend indicative thereof; and/or

The exhaust aftertreatment temperature condition parameter (14) comprises a first excess air factor determined based on a MAP of the diesel engine and a second excess air factor determined based on an oxygen content in exhaust gas emitted from the selective catalytic reduction converter (4) at steady state operation of the diesel engine; and/or

The engine operating parameter (15) includes at least one of an oil temperature, a coolant temperature, a fuel temperature, and an air temperature of the diesel engine.

4. The method of any one of claims 1-3,

the first working state comprises a working state of a throttle valve of an air system of the diesel engine and/or a post-injection state of the diesel engine; and/or

The second operating state includes a fuel injection state of the diesel engine.

5. The method of claim 4, wherein,

the first operating condition adjusting operation (17) comprises a tendency operation of causing the throttle valve to expand toward the throttle orifice and/or a reduction in post-injection; and/or

The second operating condition adjusting operation (18) includes reducing an amount of fuel injected from the diesel engine.

6. The method of any one of claims 1-5,

the predetermined condition comprises determining that the exhaust gas aftertreatment device (1) is at risk of overheating based on an exhaust gas aftertreatment operating state parameter adapted to characterizing an operating state of the exhaust gas aftertreatment device (1).

7. The method of claim 6, wherein,

the exhaust gas aftertreatment device (1) further comprising a diesel particulate filter (3) upstream of the selective-catalytic-reduction converter (4) and a diesel oxidation catalyst (2) upstream of the diesel particulate filter (3), the exhaust gas aftertreatment operating state parameters comprising at least one of: the temperature at the inlet of the diesel oxidation catalyst (2), the temperature trend characteristic of the temperature at the inlet of the diesel oxidation catalyst (2), the temperature at the inlet of the diesel particulate filter (3), the temperature trend characteristic of the temperature at the inlet of the diesel particulate filter (3), the temperature at the inlet of the selective catalytic reduction converter (4), and the temperature trend characteristic of the temperature at the inlet of the selective catalytic reduction converter (4).

8. The method of any one of claims 1-7,

-generating a first control sub-signal (161) based on the exhaust aftertreatment temperature condition parameter (14), -generating a second control sub-signal (162) based on the engine operating parameter (15), -generating a protection control signal (163) based on the first and second control sub-signals (161, 162), -performing the second operating state adjustment operation (18) based on at least the protection control signal (163).

9. The method of claim 8, wherein,

the first control sub-signal (161) is a first torque limit coefficient, the second control sub-signal (162) is a second torque limit coefficient, and the protection control signal (163) is determined based on the lesser of the first torque limit coefficient and the second torque limit coefficient.

10. An exhaust gas aftertreatment system for a diesel engine, wherein the exhaust gas aftertreatment system comprises an exhaust gas aftertreatment device (1) and a controller (10) configured for performing the method according to any one of claims 1-9.

11. A vehicle control system, wherein the vehicle control system comprises a controller (10) configured for performing the method according to any one of claims 1-9.

12. A computer-readable program medium, wherein the computer-readable program medium stores program instructions that, when executed by a processor, perform the method according to any one of claims 1-9.