WO2023000166A1

WO2023000166A1 - Exhaust after-treatment system, operating method thereof and computer program product

Info

Publication number: WO2023000166A1
Application number: PCT/CN2021/107331
Authority: WO
Inventors: Ming Yan
Original assignee: Robert Bosch Gmbh
Priority date: 2021-07-20
Filing date: 2021-07-20
Publication date: 2023-01-26
Also published as: CN117751231A

Abstract

The invention provides an exhaust after-treatment system (2) for a diesel engine (1), comprising an injection device (21) for injecting exhaust gas treatment agent and a controller (23) for controlling the injection device (21), wherein the controller (23) is provided to select different strategies for determining an injection limit value of the exhaust gas treatment agent depending on whether the diesel engine (1) has a demand for revolution increase within a predetermined period of time, and to keep an injection amount of the injection device (21) below the injection limit value. The invention also provides a method for operating the exhaust after-treatment system (2) and a corresponding computer program product. With the invention, different strategies can be selected for determining the injection limit value of the exhaust gas treatment agent depending on whether the diesel engine has the demand for revolution increase within the predetermined period of time, so that over-injection of the exhaust gas treatment agent can be reduced and, in particular, crystallization of the exhaust gas treatment agent can be avoided.

Description

Exhaust after-treatment system, operating method thereof and computer program product

Technical Field

The invention relates to an exhaust after-treatment system for a diesel engine, a method for operating the exhaust after-treatment system and a corresponding computer program product.

Background Art

Diesel engines are widely used in small, heavy or large vehicles, ships, generators and military tanks because of their reliability, high thermal efficiency and high output torque. However, due to a high content of nitrogen oxides (NOx) and other harmful components in exhaust gas of the diesel engine, the exhaust gas needs to be treated by a specific exhaust gas after-treatment system before it is released into the atmosphere to meet the increasingly stringent environmental requirements.

Treatment for the exhaust gas is now generally carried out by a selective catalytic reduction method, wherein a reducing agent (usually an aqueous urea solution) is injected in a form of aerosol into a tailpipe and harmful gas in the exhaust gas is turned through a selective catalytic reduction reaction into harmless gas and discharged into the atmosphere, so that damage to the environment is reduced. For this purpose, an exhaust after-treatment system usually includes an injection device for injecting exhaust gas treatment agent, particularly liquid reducing agent, and a controller for controlling functions.

Obviously, an injection amount of the exhaust gas treatment agent injected into the tailpipe affects exhaust gas treatment effect. The controller can calculate the required injection amount of the exhaust gas treatment agent based on an exhaust gas emission flow of the diesel engine and a concentration of NOx in the exhaust gas, and control the injection device to operate in accordance with the injection amount. However, in practice, the calculated injection amount is often too excessive for the exhaust after-treatment system to adequately convert and consume the exhaust gas treatment agent, resulting in waste of the exhaust gas treatment agent and even crystallization of the exhaust gas treatment agent in the exhaust after-treatment system.

For this reason, there is an urgent need to further develop the existing exhaust after-treatment system to improve its performance.

Summary of invention

An object of the present invention is to provide an exhaust after-treatment system for a diesel engine, a method for operating the exhaust after-treatment system and a corresponding computer program product.

According to a first aspect of the present invention, an exhaust after-treatment system for a diesel engine is proposed, which exhaust after-treatment system comprises an injection device for injecting exhaust gas treatment agent and a controller for controlling the injection device, wherein the controller is provided to select different strategies for determining an injection limit value of the exhaust gas treatment agent depending on whether the diesel engine has a demand for revolution increase within a predetermined period of time, and to keep an injection amount of the injection device below the injection limit value.

According to a second aspect of the present invention, a method for operating the exhaust after-treatment system according to the present invention is proposed, wherein the method includes at least the following steps: a strategy selection step, in which different strategies are selected for determining the injection limit value of the exhaust gas treatment agent depending on whether the diesel engine has the demand for revolution increase within the predetermined time period; and a control step, in which the injection amount of the injection device is kept below the injection limit value.

According to a third aspect of the present invention, a computer program product is proposed, which comprises computer program instructions, wherein the computer program instructions enable one or more processors to execute the method according to the present invention when executed by the processors.

According to the present invention, different strategies can be selected for determining the injection limit value of the exhaust gas treatment agent depending on whether the diesel engine has the demand for revolution increase within the predetermined period of time, and the injection amount of the injection device can be kept below the injection limit value, so that over-injection of the exhaust gas treatment agent can be reduced and, in particular, crystallization of the exhaust gas treatment agent in the exhaust after-treatment system can be avoided.

Brief Description of the Drawings

The disclosure and advantages thereof will be further understood by reading the following detailed description of some preferred exemplary embodiments with reference to the drawings in which:

FIG. 1 shows a schematic component diagram of an exhaust after-treatment system for a diesel engine according to an exemplary embodiment of the present invention;

FIG. 2 shows a schematic diagram of how a required injection amount of an exhaust gas treatment agent changes in relation to a NOx emission amount;

FIG. 3 schematically shows injection limit values determined with different strategies in an exemplary embodiment according to the present invention; and

FIG. 4 schematically shows a flow chart of a method for operating the exhaust after-treatment system according to an exemplary embodiment of the present invention.

Detailed Description of the Embodiments

The present invention will be further described in detail below in conjunction with the accompanying drawings and exemplary embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of the invention.

It should be understood that in the context, expressions "first" , "second" , etc. are used merely for descriptive purposes and should not be interpreted as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, the feature defined with "first" and "second" may explicitly or implicitly include at least one such feature.

FIG. 1 shows a schematic component diagram of an exhaust after-treatment system 2 for a diesel engine 1 according to an exemplary embodiment of the present invention. As shown in FIG. 1, the exhaust after-treatment system 2 comprises: an injection device 21, an SCR catalyst 22 and a controller 23. The injection device 21 is used to inject an exhaust gas treatment agent into a tailpipe of the diesel engine 1. The exhaust gas treatment agent is preferably a liquid reducing agent, such as an aqueous urea solution (AdBlue) . The SCR catalyst 22 is arranged downstream of the injection device 21 in the tailpipe. The exhaust gas in the tailpipe is mixed with the exhaust gas treatment agent injected by the injection device 21 and reacted in the SCR catalyst 22, thereby converting a harmful component of the exhaust gas, such as NOx, into a harmless gas, such as nitrogen. Although the exhaust after-treatment system 2 that reduces a content of NOx in the exhaust gas by a selective catalytic reduction method is used as an example in this embodiment, it will be appreciated by those skilled in the art that it does matter which principle is used to treat the exhaust gas in the exhaust after-treatment system 2 as long as a content of the harmful component in the exhaust gas is reduced by the injected exhaust gas treatment agent.

The controller 23 is used to control components of the exhaust after-treatment system 2 including the injection device 21. The controller 23 may also receive an operation status or detection data of corresponding components, such as some sensors, via a communication line for monitoring or controlling an operation of the exhaust after-treatment system 2 of the diesel engine 1. For example, the controller 23 may be connected to a temperature sensor 24 for detecting the exhaust gas emission temperature of the diesel engine 1 and receive a detection result of the temperature sensor 24. The controller 23 may be an electronic control unit of the diesel engine 1 or a separate component to the electronic control unit of the diesel engine 1. In the case that the controller 23 is the separate component, it may preferably be in communication with the electronic control unit of the diesel engine 1 to receive data from the electronic control unit and transmit data to the electronic control unit.

During an operation of the diesel engine 1, its NOx emission amount will change as an operating condition of the diesel engine 1 changes. An amount of the required exhaust gas treatment agent for converting the NOx will also change accordingly. Generally, the controller 23 may calculate a required injection amount of the required exhaust gas treatment agent based on the current operating condition of the diesel engine 1, for example based on an exhaust gas emission flow of the diesel engine 1 and a concentration of the NOx in the exhaust gas, etc. Then, the controller 23 controls the injection device 21 to inject the exhaust gas treatment agent in accordance with the required injection amount.

FIG. 2 shows a schematic diagram of how the required injection amount of the exhaust gas treatment agent changes in relation to the NOx emission amount. In Fig. 2, a horizontal axis represents the time T, a left vertical axis represents the NOx emission amount E _NOx of the diesel engine 1, and a right vertical axis represents the required injection amount I _T of the exhaust gas treatment agent. A dashed curve illustrates that the NOx emission amount of the diesel engine 1 changes with time during the operation of the diesel engine 1, and a solid curve illustrates that the required injection amount of the exhaust gas treatment agent changes accordingly. As shown in FIG. 2, the required injection amount of the exhaust gas treatment agent is relatively high when the NOx emission amount is relatively high and the required injection amount of the exhaust gas treatment agent is relatively low when the NOx emission amount is relatively low. It will be appreciated by those skilled in the art that the required injection amount of the exhaust gas treatment agent may also be influenced by other parameters, such as the exhaust gas emission temperature, an ammonia storage content of the SCR catalyst 22, etc., and the present invention is not limited in this regard.

In practice, the required injection amount is often overestimated (i.e. being calculated as an excessive amount) , which not only leads to waste of the exhaust gas treatment agent, but also leads to crystallization of the exhaust gas treatment agent in the exhaust after-treatment system. The crystallization of the exhaust gas treatment agent will affect the SCR conversion efficiency, increase an exhaust resistance, and even affect fuel consumption and emission of the engine, resulting in an improper operation of the engine. It will be appreciated by those skilled in the art that "excessive injection amount" or "over-injection" of the exhaust gas treatment agent represents the case that the injected exhaust gas treatment agent is not fully consumed by the exhaust after-treatment system due to insufficient mixing or insufficient conversion capacity of the SCR catalysts, etc.

In order to avoid over-injection of the exhaust gas treatment agent due to the overestimated required injection amount, the controller 23 may set an injection limit value and keep the injection amount of the injection device 21 below the injection limit value. In other words, the controller 23 controls the injection device 21 to inject the exhaust gas treatment agent in accordance with the smaller one of the required injection amount and the injection limit value. As shown in FIG. 2, if the injection limit value is set to a relatively small value, for example a first injection limit value L1, the injection limit value will lead to insufficient injection of the exhaust gas treatment agent when the NOx emission amount is at the peak shown in FIG. 2, such that the NOx in the exhaust gas cannot be converted sufficiently into the harmless gas. If the injection limit value is set to a relatively large value, for example a second injection limit value L2, the injection limit value cannot limit the injection amount effectively when the NOx emission amount is at a low level.

Thus, the controller 23 is provided to select different strategies for determining the injection limit value of the exhaust gas treatment agent depending on whether the diesel engine 1 has a demand for revolution increase within a predetermined period of time, and to keep the injection amount of the injection device 21 below the injection limit value. As a result, the injection limit value can be determined in an optimized manner. When the diesel engine 1 has the demand for revolution increase within the predetermined time period, its NOx emission amount increases, the amount of the required exhaust gas treatment agent increases, and the exhaust after-treatment system 2 has a higher capacity to consume the exhaust gas treatment agent; while the fact that the diesel engine 1 does not have the demand for revolution increase within the predetermined time period means that the diesel engine 1 runs in a steady state, its NOx emission amount will remain at a relatively low level, the amount of the required exhaust gas treatment agent is reduced and the capacity of the exhaust after-treatment system 2 to consume the exhaust gas treatment agent decreases. In these two situations, respectively setting different strategies to determine the injection limit value can make the injection limit value more suitable for the dynamically changing operating condition of the diesel engine 1.

For example, after an accelerator pedal controlling the diesel engine 1 is pressed, revolution of the diesel engine 1 increases and its NOx emission amount will increase rapidly and may peak in a short period of time. At this stage, the exhaust after-treatment system 2 requires a large amount of the exhaust gas treatment agent for converting the NOx in the exhaust gas. When the diesel engine 1 is running steadily, its NOx emission amount will decrease and remain stable at a relatively low level. Accordingly, less exhaust gas treatment agent is required and the capacity of the exhaust after-treatment system 2 to consume the exhaust gas treatment agent decreases, such that the exhaust gas treatment agent is more likely to crystallize. Since the controller 23 selects different strategies for determining the injection limit value of the exhaust gas treatment agent depending on whether the diesel engine 1 has the demand for revolution increase within the predetermined time period, the injection limit value can be determined in an optimized manner. This approach takes into account the operation of the diesel engine 1 within the predetermined time period, making the injection limit value more suitable for the dynamically changing operating condition of the diesel engine 1.

In an exemplary embodiment according to the present invention, the different strategies are implemented by means of different injection limit value maps. Mappings between the exhaust gas emission flow as well as the exhaust gas emission temperature of the diesel engine 1 and the injection limit value can be stored in the injection limit value maps. The injection limit value maps may be pre-calibrated and stored in the controller 23 or in a memory connected to the controller 23. When the diesel engine 1 is operating, the corresponding injection limit value map is selected depending on whether the diesel engine 1 has a demand for revolution increase within the predetermined time period, and then the injection limit value of the exhaust gas treatment agent can be obtained by looking up the corresponding injection limit value map according to the exhaust gas emission flow and the exhaust gas emission temperature of the diesel engine 1. The injection limit value may also be determined based on other parameters, such as the revolution, fuel injection amount and so on of the diesel engine 1.

FIG. 3 schematically shows the injection limit values determined with different strategies in an exemplary embodiment according to the present invention. In FIG. 3, a horizontal axis represents the time T and a vertical axis represents the required injection amount I _T of the exhaust gas treatment agent. A dashed curve illustrates a variation curve of the required injection amount of the exhaust gas treatment agent during the operation of the diesel engine 1. A solid curve illustrates the injection limit value determined by the controller 23, wherein the injection limit value ST1 is determined according to a first strategy in the case that the diesel engine 1 has the demand for revolution increase within the predetermined time period and the injection limit value ST2 is determined according to a second strategy different from the first strategy in the case that the diesel engine 1 does not have the demand for revolution increase within the predetermined time period.

For example, at a first time T1, the diesel engine 1 has the demand for revolution increase within the predetermined time period, e.g., at a previous time T0, so the injection limit value ST1 is determined by the controller 23 with the first strategy at the first time T1. At a second time T2, the diesel engine 1 does not have the demand for revolution increase within the predetermined time period, so the injection limit value ST2 is determined by the controller 23 with the second strategy at the second time T2.

The predetermined time period may include a time period prior to the current point in time and/or a time period after the current point in time. In other words, the predetermined time period is a time period before the current point in time or a time period after the current point in time, or the predetermined time period is a time period that spans the current point in time. Optionally, duration of the predetermined time period is less than 10 minutes, in particular between 2 and 8 minutes, particularly between 3 and 5 minutes.

The first strategy may be particularly a strategy that preferentially ensures effectiveness of exhaust gas treatment, and the second strategy may be particularly a strategy that preferentially avoids the crystallization of the treatment agent. In the case that the other parameters affecting the injection limit values are the same, the injection limit value determined with the first strategy is no less than the injection limit value determined with the second strategy. When the diesel engine 1 has the demand for revolution increase, it is expected that the NOx emission amount will increase rapidly, in which case the first strategy, which ensures the effectiveness of exhaust gas treatment, will enable the harmful components of the exhaust gas to be adequately converted into harmless components. When the diesel engine 1 is running steadily, it is expected that the capacity of the exhaust after-treatment system to consume exhaust gas treatment agent will decrease, in which case the exhaust gas treatment agent is likely to crystallize if the injected exhaust gas treatment agent is excessive, for example, exceeds the conversion capacity of the SCR catalytic converter 22. For this reason, the second strategy, which avoids the crystallization of the treatment agent, can be used and a lower injection limit value is set appropriately. In particular, the second strategy can be provided to achieve a balance between effect of the exhaust gas treatment and conversion rate of the exhaust gas treatment agent.

Now back to FIG. 1. As shown in FIG. 1, the diesel engine 1 may include an exhaust gas recirculation (EGR) device 11, which EGR device 11 is provided to direct a portion of the exhaust gas emitted from the diesel engine 1 back into an intake pipe of the diesel engine 1 to reduce an oxygen content of an intake gas into the diesel engine 1, so that a combustion temperature of the diesel engine 1 and the NOx emission amount are reduced. The EGR device 11 comprises at least an EGR passage 111 connecting the intake pipe and the exhaust pipe of the diesel engine 1 and an EGR valve 112 for opening and closing the EGR passage 111.

When an ambient temperature is low, the EGR device 11 will be closed to protect its components such as the EGR valve 112. Obviously, the NOx emission amount of the diesel engine 1 will increase when the EGR device 11 is closed compared to the case when the EGR device 11 is open. This increase in NOx emission amount is even more significant when the diesel engine 1 is running steadily, and may even be as much as several times. The required injection amount of the exhaust gas treatment agent will increase accordingly. However, the exhaust after-treatment system 2 has a limited conversion capacity for the exhaust gas treatment agent. For example, since the exhaust gas treatment agent cannot mix sufficiently with the exhaust gas due to the low exhaust amount of diesel engine 1 and thus cannot decompose sufficiently, some of the exhaust gas treatment agent does not react with the NOx in the exhaust gas.

To this end, in an exemplary embodiment according to the present invention, the injection limit value determined with the second strategy is pre-calibrated, at least in part, to be lower than a theoretical injection amount of treatment agent required to completely treat the exhaust gas emitted from the diesel engine 1 with the exhaust gas recirculation device of the diesel engine 1 closed.

In an exemplary embodiment according to the present invention, the controller 23 is provided to receive a throttle opening signal, which indicates a throttle opening of the diesel engine 1, wherein the demand for revolution increase of the diesel engine 1 is determined depending on the throttle opening signal. For example, when the throttle opening signal indicates an increase in throttle opening, it may be determined that the diesel engine 1 has the demand for revolution increase.

Alternatively or additionally, the controller 23 is provided to receive a pedal position signal, which indicates a position of the accelerator pedal capable of controlling the diesel engine 1, wherein the demand for revolution increase of the diesel engine 1 is determined depending on the pedal position signal. For example, the position of the accelerator pedal may be detected by a pedal position sensor and the corresponding pedal position signal may be sent to the controller 23. When the pedal position signal indicates an increase of displacement of the accelerator pedal, it may be determined that the diesel engine 1 has the demand for revolution increase.

In an exemplary embodiment according to the present invention, the diesel engine 1 is equipped on a vehicle and the demand for revolution increase of the diesel engine 1 is determined by performing a predictive analysis of the demand for revolution increase of the diesel engine 1 based on data from the Internet of vehicles (IoV) used by the diesel engine 1. In this case, the controller 23 may be a main electronic control unit of the vehicle or a separate component to the main electronic control unit of the vehicle. For the Internet of vehicles, the main electronic control unit of the vehicle generally obtains driving data of the vehicle, such as vehicle position, vehicle speed and route and so on, by various detection devices, and then transmits the driving data through a connectivity control unit (CCU) of the vehicle via wireless communication technology, such as a 4G network, to a central processor, such as a cloud processor, which can analyze and process the driving data.

For example, a user's driving habits may be analyzed based on previous driving data of the vehicle and then a future driving behavior of the vehicle, in particular the demand for revolution increase of the diesel engine 1 of the vehicle, may be predicted based on the current driving data. For example, the user may be accustomed to accelerating on a particular roadway and/or slowing down on another particular roadway. As a result, the demand for revolution increase of the diesel engine 1 can be predicted relatively reliably. This analysis and prediction can be done automatically in the background with a big data analysis capability of the Internet of vehicles.

As another example, the demand for revolution increase of the diesel engine 1 may be predicted based on real-time navigation data in the case that a navigation system is used for real-time navigation. The real-time navigation data includes at least one of the following: a type of road being driven, real-time road conditions, and navigation route. When the vehicle is driving on the highway and the road is clear without congestion, the vehicle will drive steadily and the revolution of the diesel engine 1 will remain stable. When the vehicle is driving in the city, operations such as acceleration and deceleration are often demanded. For example, the demand for revolution increase of the diesel engine 1 may be predicted based on the navigation route and a position and status of a traffic light ahead.

FIG. 4 schematically shows a flow chart of a method for operating the exhaust after-treatment system 2 according to an exemplary embodiment of the present invention. The method includes at least the following steps: a strategy selection step, in which different strategies are selected for determining the injection limit value of the exhaust gas treatment agent depending on whether the diesel engine 1 has the demand for revolution increase within the predetermined period of time; and a control step, in which the injection amount of the injection device 21 is kept below the injection limit value.

Particularly, the method may include the following sub-steps:

S1, the different strategies are selected depending on whether the diesel engine 1 has the demand for revolution increase within the predetermined time period;

S2, the injection limit value of the exhaust gas treatment agent is determined depending on the first strategy if the diesel engine 1 has the demand for revolution increase within the predetermined time period;

S3, the injection limit value of the exhaust gas treatment agent is determined depending on the second strategy if the diesel engine 1 does not have the demand for revolution increase within the predetermined time period;

S4, the injection amount of the injection device 21 is kept below the injection limit value.

The features and advantages described above for the exhaust gas after-treatment system 2 are also applicable to the method for operating the exhaust after-treatment system 2.

The present invention also relates to a computer program product comprising computer program instructions, wherein the computer program instructions enable one or more processors to execute the method according to the present invention when executed by the processors. The computer program instructions may be stored in a computer readable storage medium. The computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (anon-exhaustive list) of the computer readable storage medium include the following: a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context, the computer readable storage medium may be any tangible medium that contains or stores program instructions that may be used by or in conjunction with an instruction execution system, apparatus or device. The processor may be a Central Processing Unit (CPU) , but may also be other general purpose processors, Digital Signal Processors (DSP) , Application Specific Integrated Circuit (ASIC) , Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The above method when being executed by the processor can be implemented by hardware or by hardware executing the corresponding software.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

List of Reference Numbers

1 diesel engine

11 EGR device

111 EGR passage

112 EGR valve

2 exhaust after-treatment system

21 injection device

22 SCR catalyst

23 controller

24 temperature sensor

Claims

An exhaust after-treatment system (2) for a diesel engine (1) , comprising:

an injection device (21) for injecting exhaust gas treatment agent; and

a controller (23) for controlling the injection device (21) ,

wherein the controller (23) is provided to select different strategies for determining an injection limit value of the exhaust gas treatment agent depending on whether the diesel engine (1) has a demand for revolution increase within a predetermined period of time, and to keep an injection amount of the injection device (21) below the injection limit value.
The exhaust after-treatment system (2) according to claim 1, wherein the controller (23) is provided to

determine the injection limit value with a first strategy, which ensures exhaust gas treatment effectiveness, when the diesel engine (1) has the demand for revolution increase within the predetermined time period;

determine the injection limit value with a second strategy, which avoids crystallization of the treatment agent, when the diesel engine (1) does not have the demand for revolution increase within the predetermined period of time.
The exhaust after-treatment system (2) according to claim 2, wherein the injection limit value determined with the second strategy is at least partially pre-calibrated to be lower than a theoretical injection amount of the treatment agent required to completely treat the exhaust gas from the diesel engine (1) with an exhaust gas recirculation device (11) of the diesel engine (1) closed.
The exhaust after-treatment system (2) according to any one of claims 1-3, wherein

the different strategies are implemented by means of different injection limit value maps;

in at least one of the different strategies, the injection limit value is determined depending on an exhaust gas emission flow and an exhaust gas emission temperature of the diesel engine (1) .
The exhaust after-treatment system (2) according to any one of claims 1-4, wherein

the predetermined time period is a time period before or after the current point in time, or the predetermined time period is a time period that spans the current point in time;

duration of the predetermined time period is between 3 and 5 minutes.
The exhaust after-treatment system (2) according to any one of claims 1-5, wherein

the controller (23) is further provided to receive a throttle opening signal, which indicates a throttle opening of the diesel engine (1) , wherein the demand for revolution increase of the diesel engine (1) is determined depending on the throttle opening signal; or

the controller (23) is further provided to receive a pedal position signal, which indicates a position of an accelerator pedal capable of controlling the diesel engine (1) , wherein the demand for revolution increase of the diesel engine (1) is determined depending on the pedal position signal.
The exhaust after-treatment system (2) according to any one of claims 1-6, wherein the demand for revolution increase of the diesel engine (1) is determined by performing a predictive analysis of the demand for revolution increase of the diesel engine (1) based on data from the Internet of vehicles used by the diesel engine (1) .
The exhaust after-treatment system (2) according to claim 7, wherein the predictive analysis of the demand for revolution increase of the diesel engine (1) comprises:

an analysis of real-time navigation data, wherein the real-time navigation data includes at least one of the following: a type of road being driven, a real-time road condition, and a navigation route; and/or

a big data analysis of driving habits.
A method for operating the exhaust after-treatment system (2) according to any one of claims 1-8, wherein the method includes at least the following steps:

a strategy selection step, in which different strategies are selected for determining the injection limit value of the exhaust gas treatment agent depending on whether the diesel engine (1) has the demand for revolution increase within the predetermined time period; and

a control step, in which the injection amount of the injection device (21) is kept below the injection limit value.
A computer program product comprising computer program instructions, wherein the computer program instructions enable one or more processors to execute the method according to claim 9 when executed by the processors.