阅读说明：本技术 Dpf再生控制方法、尾气后处理系统及可读存储介质 (DPF regeneration control method, exhaust gas aftertreatment system and readable storage medium ) 是由 贾克斌 C·德林 严明 于 2018-08-28 设计创作，主要内容包括：本申请提供一种DPF再生程序中SCR温度的控制方法及系统,所述DPF设置于SCR的上游,包括所述DPF与SCR的尾气后处理系统持续获知SCR的温度T,通过判断SCR温度T是否大于或等于第一温度T1,如果T大于或等于T1持续一定时间,DPF退出再生程序,如果DPF退出再生程序后温度有效降低到第二温度T2并持续一定时间,则重新启动DPF再生程序。通过上述方式,可以解决现有技术中SCR催化剂基底温度过高的问题。(The application provides a control method and system of SCR temperature in DPF regeneration procedure, DPF sets up in the upper reaches of SCR, include DPF and SCR's exhaust aftertreatment system last learn SCR's temperature T, through judging SCR temperature T and being greater than or equal to first temperature T1, if T is greater than or equal to T1 lasts for a certain time, DPF withdraws from regeneration procedure, if DPF withdraws from regeneration procedure after the temperature effectively reduces to second temperature T2 and lasts for a certain time, the DPF regeneration procedure restarts. Through the mode, the problem that the temperature of the SCR catalyst substrate is too high in the prior art can be solved.)

1. A control method for DPF regeneration, which is provided in an exhaust gas aftertreatment system upstream of an SCR included in the exhaust gas aftertreatment system, the SCR having a catalyst, the control method comprising the steps of,

s0, starting a DPF regeneration program, wherein the real-time temperature (T) of the SCR is obtained by the exhaust aftertreatment system;

s1, judging whether the real-time temperature (T) is greater than or equal to a first temperature (T1);

s2, if the real-time temperature (T) is greater than or equal to a first temperature (T1), starting to time a first duration (T1) of the real-time temperature (T) being greater than or equal to the first temperature (T1);

s3, when the first duration (t1) reaches a first predetermined time (t2), the DPF exits the regeneration process;

s4, when the real-time temperature (T) is less than or equal to a second temperature (T2), starting timing a second duration (T3) in which the real-time temperature (T) is less than or equal to the second temperature (T2), the second temperature (T2) being less than or equal to the first temperature (T1);

s5, restarting the regeneration process of the DPF when the second duration (t3) reaches a second predetermined time (t 4).

2. The control method of claim 1, wherein the SCR is a vanadium-based SCR.

3. Control method according to claim 1 or 2, characterized in that the first temperature (T1) is less than 550 degrees, preferably 540 to 520 degrees, and/or the second temperature (T2) is less than 545 degrees, preferably 540 to 520 degrees.

4. Control method according to claim 1 or 2, characterized in that the first predetermined time (t2) is 3 seconds and/or the second predetermined time (t4) is 30 seconds.

5. The control method according to claim 1, characterized in that the SCR is a copper-based SCR, the first temperature (T1) is less than 650 degrees, preferably 630 degrees, and/or the second temperature (T2) is 620 degrees, the first predetermined time (T2) is set to 5 seconds and the second predetermined time (T4) is 45 seconds.

6. The control method according to claim 1 or 2, wherein the temperature of the catalyst of the SCR is known by a temperature sensor provided at the SCR, which is provided at an inlet of the SCR.

7. A control method according to claim 1 or 2, characterized in that the regeneration is an active regeneration or a passive regeneration.

8. An exhaust gas aftertreatment system (10) comprising a DPF (11), an SCR (12) and an ECU (13) capable of controlling the DPF (11) and the SCR (12), said DPF (11) being arranged upstream of said SCR (12) and being capable of regeneration, characterized in that said ECU is configured to carry out the control method according to any one of claims 1 to 7.

9. The exhaust aftertreatment system (10) of claim 7, wherein the exhaust aftertreatment system (10) reports an error if the event S3 occurs in two consecutive duty cycles, each power-up to power-down of the exhaust aftertreatment system (10) being one duty cycle, the exhaust aftertreatment system (10) reporting an error to a vehicle management system in which the exhaust aftertreatment system is located.

10. A non-transitory machine or computer readable storage medium storing executable instructions that when executed are capable of implementing the control method of any one of claims 1 to 6.

Technical Field

The present application relates to a DPF (Diesel particulate Filter) regeneration control method, an exhaust gas aftertreatment system and a readable storage medium, and more particularly, to a DPF regeneration control method for an exhaust gas aftertreatment system, an exhaust gas aftertreatment system and a readable storage medium capable of performing the DPF regeneration control method.

Background

In order to reduce the content of NOx (nitrogen oxides) in the exhaust gas of a vehicle engine, a selective catalytic reduction system (SCR system) has been developed for injecting a reducing agent into the exhaust gas to reduce NOx in the exhaust gas into harmless components such as nitrogen, water, carbon dioxide, etc. by a selective catalytic reduction method. The catalyst system for SCR requires the use of a metal as a substrate for its catalyst, and the most commonly used catalysts in the art include copper-based SCR and vanadium-based SCR.

In an exhaust gas aftertreatment system in which a DPF is disposed upstream of an SCR to remove particulate matter contained in exhaust gas, a DPF used for a long time may be poisoned or failed by accumulation of particulate matter. Therefore, it is necessary to regenerate the DPF by raising the temperature of the exhaust gas to burn the particulate matter deposited on the DPF. The combustion of the particulate matter further raises the temperature of the DPF again.

However, if the temperature reaches a certain level during the regeneration of the DPF, it may cause the metal property as the substrate of the SCR to change or volatilize to cause air pollution.

Disclosure of Invention

The purpose of this application is to solve the problem that in the DPF regeneration process among the prior art, the base metal temperature as SCR catalyst is too high.

In order to achieve the above object, the present invention provides a method for controlling regeneration of a DPF provided in an exhaust gas aftertreatment system upstream of an SCR included in the exhaust gas aftertreatment system, the SCR having a catalyst, the method comprising the steps of,

s0, starting a DPF regeneration program, wherein the tail gas aftertreatment system knows the real-time temperature of the SCR;

s1, judging whether the real-time temperature is greater than or equal to a first temperature;

s2, if the real-time temperature is greater than or equal to a first temperature, starting to time a first duration time that the real-time temperature is greater than or equal to the first temperature;

s3, when the first duration reaches a first preset time, the DPF exits the regeneration process;

s4, when the real-time temperature is less than or equal to a second temperature, starting timing a second duration time that the real-time temperature is less than or equal to the second temperature, wherein the second temperature is less than or equal to the first temperature;

and S5, restarting the regeneration process of the DPF when the second duration reaches a second preset time.

The present application also features the SCR being a vanadium-based SCR.

The application is also characterized in that the first temperature is less than 550 degrees, preferably 540 to 520 degrees, and/or the second temperature is less than 545 degrees, preferably 540 to 520 degrees.

The present application is also characterized in that the first predetermined time is 3 seconds, and/or the second predetermined time is 30 seconds.

The present application is also characterized in that the SCR is a copper-based SCR, the first temperature is less than 650 degrees, preferably 630 degrees, and/or the second temperature is 620 degrees, the first predetermined time is set to 5 seconds and the second predetermined time is 45 seconds.

The present application also has features in which the temperature of the catalyst of the SCR is known by a temperature sensor disposed at the SCR, which is disposed at an inlet of the SCR.

The present application also features regeneration that is either active or passive.

In order to accomplish the above object, the present invention also provides an exhaust gas aftertreatment system including a DPF which is disposed upstream of the SCR and is capable of regeneration, an SCR, and an ECU capable of controlling the DPF and the SCR, wherein the ECU is configured to be capable of performing the control method described above.

The method is characterized in that if the S3 event occurs in two continuous working cycles, the tail gas aftertreatment system reports error information, each time the tail gas aftertreatment system is powered on and powered off, the tail gas aftertreatment system reports the error information to a vehicle management system where the tail gas aftertreatment system is located.

To achieve the above object, the present invention also provides a non-transitory machine or computer readable storage medium storing executable instructions that when executed enable the control method as described above.

By using the technical scheme provided by the application, the regeneration of the DPF is stopped when the SCR system is raised to a certain temperature, so that the problem that the temperature of the base metal of the catalyst in the SCR is too high is solved.

Drawings

Exemplary embodiments of the present application will be described in detail below with reference to the attached drawings, it being understood that the following description of the embodiments is only for the purpose of explanation and not limitation of the scope of the present application, and in the accompanying drawings:

FIG. 1 is a block diagram of the structure of one embodiment of an exhaust aftertreatment system of the present application;

FIG. 2 is a flow chart of one embodiment of a DPF regeneration control method of the present application;

FIG. 3 is a graph of the effectiveness of an embodiment of the DPF regeneration control method of the present application to show the effect of controlling the DPF regeneration process on the temperature of the SCR.

Detailed Description

It should be understood that the drawings are for purposes of illustration only and that the dimensions, proportions and number of parts are not to be construed as limiting the application.

Referring to FIG. 1, a block diagram of an embodiment of an exhaust aftertreatment system according to the present application is shown. One embodiment of the exhaust aftertreatment system 10 of the present application includes a DPF11, SCR12, the DPF11 may be regenerated, including active regeneration and passive regeneration. The DPF11 is disposed upstream of the SCR12 and is connected to the SCR12 through an exhaust pipe, and the upstream refers to the flow of exhaust gas from the DPF11 to the SCR 12. In some embodiments, including this embodiment, the SCR12 is a vanadium-based SCR, and in other embodiments the SCR12 may be a copper-based or other type of substrate. In addition, the exhaust gas after-treatment system 10 further includes an ECU13(Electronic Control Unit) for controlling the DPF11 and the SCR12, and the ECU13 may be an ECU dedicated to the exhaust gas after-treatment system 10 or an ECU of the entire vehicle or a cloud processing system.

The SCR12 is provided with a temperature sensor 121 for detecting the temperature of the SCR12 and communicating with the ECU13, and the temperature sensor 121 is provided at the inlet of the SCR12 for testing the real-time temperature T of the inlet of the SCR 12. For accuracy of temperature detection, the temperature sensor 121 may be as close to the substrate of the SCR catalyst as possible.

With continued reference to fig. 2, the present application provides a control method for DPF regeneration, which is used in an exhaust gas aftertreatment system having a DPF and an SCR, wherein the DPF is disposed upstream of the SCR, the exhaust gas aftertreatment system can continuously obtain a real-time temperature T of the SCR, and the real-time temperature T can be obtained through a temperature sensor disposed in the SCR or data in a usage system. In some embodiments, including this embodiment, the SCR is a vanadium-based SCR, i.e., a V-SCR. In step S0, the DPF regeneration process is started, and then, in step S1, it is determined whether the V-SCR temperature T reaches or exceeds a first temperature T1, the first temperature T1 being less than 550 degrees, in some embodiments including this embodiment, the first temperature T1 is between 540 degrees and 520 degrees, and in this embodiment, the first temperature T1 is set to 540 degrees. In the step S2, if the live temperature T is greater than or equal to the first temperature T1, the ECU starts timing a first duration T1 in which the live temperature T is greater than or equal to the first temperature T1. Next, in step S3, after the first duration t1 reaches the preset first predetermined time t2, the system controls the DPF to exit the regeneration process. After the regeneration process is exited, the temperature of the SCR can be effectively reduced, and in this way, the volatilization degree of the vanadium groups can be controlled. If the shorter on-time temperature T of the first duration T1 falls below the first temperature T1, the DPF regeneration process continues without stopping. In the present embodiment, the first predetermined time t2 is set to 3 seconds. It will be appreciated by those skilled in the art that in other embodiments, the first predetermined time T2 can be adjusted according to the setting of the first temperature T1, and the lower the setting of the first temperature T1, the longer the first predetermined time T2 can be set.

After the DPF regeneration process is terminated, in step S4, the real-time temperature T of the SCR is continuously known, and if the real-time temperature T is less than or equal to the second temperature T2, a second duration T3 is started in which the real-time temperature T is less than or equal to the second temperature T2, and the second temperature T2 is less than or equal to the first temperature T1. In step S5, when the second duration t3 reaches the second predetermined time t4, the current temperature is considered to be relatively safe for SCR, and the DPF regeneration process is restarted. In some embodiments including the present embodiment, the second temperature T2 is set to the same 540 degrees as the first temperature T1, and the second predetermined time T4 is set to 30 seconds.

The temperature setting in the above embodiments is exemplified by vanadium-based SCR, and in other different-based SCR systems, the temperature setting may be adjusted as needed, for example, in copper-based SCR catalysts, the first temperature T1 may be less than 650 degrees, in some embodiments 630 degrees, the second temperature T2 may be 620 degrees, the first predetermined time T2 may be set to 5 seconds, and the second predetermined time T4 may be set to 45 seconds.

The control method and control system of the present application may also include an enhanced solution where the exhaust aftertreatment system 10 reports an error message if an S3 event occurs in both consecutive duty cycles. The exhaust gas aftertreatment system 10 is powered on to powered off each time, that is, the exhaust gas aftertreatment system is restarted each time, which is a work cycle. The exhaust aftertreatment system 10 reports error information to the vehicle management system in which it is located. After the vehicle management system receives the error report, the early warning system of the vehicle fault can be started.

The present application also provides a non-transitory machine or computer readable storage medium storing executable instructions that when executed enable the aforementioned method. The readable storage medium may be an ECU in an exhaust aftertreatment system or an ECU of a vehicle management system, or other readable storage medium.

Please refer to fig. 3, which is a graph illustrating the SCR temperature control effect of an embodiment of the SCR temperature control method for controlling the DPF regeneration effect on the SCR temperature. Wherein the lower curve shows the regeneration process of the PDF and the upper curve shows the temperature profile of the SCR. It is known that the temperature of the substrate of the SCR can be effectively controlled within a certain range using the technique of the present application.