Coordination control method, device and equipment for urea injection amount and medium

Abstract

The invention discloses a urea injection amount coordination control method, device, equipment and medium which are applied to a two-stage SCR aftertreatment system.The coordination control method comprises the steps that the first inlet temperature of a preceding-stage SCR, the second inlet temperature of a backward-stage SCR, the third inlet temperature of a DPF, the pressure difference of the two ends of the DPF, the exhaust mass flow and the original exhaust nitrogen oxide concentration are obtained firstly, and then the first inlet temperature of the preceding-stage SCR, the second inlet temperature of the backward-stage SCR, the third inlet temperature of the DPF and the pressure difference of the two ends of the DPF are obtained; then according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference between the two ends of the DPF, the exhaust mass flow and the original emission nitric oxide concentration, the first urea injection amount of the front-stage SCR and the second urea injection amount of the rear-stage SCR are determined, and finally the first urea injection amount is used for controlling a urea nozzle of the front-stage SCR to conduct urea injection. And controlling a urea nozzle of the post-stage SCR to perform urea injection by using the second urea injection amount. By means of the method, the conversion efficiency and emission control precision of nitric oxide can be improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of engine exhaust after-treatment, and in particular, to a method, device, equipment and medium for coordinated control of urea injection amount. Background Technique

[0002] In recent years, the requirements for diesel engine after-treatment emission control technology have been continuously updated. The current adopted after-treatment technical route is a combination of DOC (Diesel Oxidation Catalyst), DPF (Diesel Particulate Filter), SCR (Selective Catalytic Reduction) and ASC (Ammonia Slip Catalyst) to treat the emission pollutants in vehicle exhaust.

[0003] With the gradual implementation of the next-stage emission regulations, the emission limit requirements for pollutants such as nitrogen oxides are further improved. The after-treatment technical route needs to adopt a two-stage SCR scheme, that is, a combination of pre-stage SCR, DOC, DPF, and post-stage SCR. However, for a two-stage SCR after-treatment system, both the pre-stage SCR and the post-stage SCR can independently control urea injection. It is also necessary to reasonably coordinate and control the urea injection amount of the urea nozzle corresponding to the pre-stage SCR and the urea injection amount of the urea nozzle corresponding to the post-stage SCR, so that the nitrogen oxide conversion efficiency of the two-stage SCR after-treatment system reaches the optimum, so that the exhaust emission meets the requirements of relevant regulations. Summary of the Invention

[0004] The embodiments of the present invention provide a method, device, equipment and medium for coordinated control of urea injection amount, which reasonably coordinate and allocate the urea injection amount of the urea nozzle corresponding to the pre-stage SCR and the urea injection amount of the urea nozzle corresponding to the post-stage SCR, improve the conversion efficiency of nitrogen oxides, and improve the emission control accuracy of nitrogen oxides, so that the exhaust emission meets the requirements of the next-stage emission regulations.

[0005] In a first aspect, the embodiments of the present invention provide a method for coordinated control of urea injection amount, which is applied to a two-stage SCR after-treatment system. The two-stage SCR after-treatment system includes a pre-stage SCR, a post-stage SCR, and a DPF between the pre-stage SCR and the post-stage SCR;

[0006] The coordinated control method includes:

[0007] Obtain the first inlet temperature of the pre-stage SCR, the second inlet temperature of the post-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration;

[0008] Determine the first urea injection amount of the front-stage SCR and the second urea injection amount of the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration.

[0009] Control the urea nozzle of the front-stage SCR to inject urea using the first urea injection amount, and control the urea nozzle of the rear-stage SCR to inject urea using the second urea injection amount.

[0010] In a second aspect, an embodiment of the present invention further provides a coordinated control device for urea injection amounts, which is applied to a dual-stage SCR aftertreatment system. The dual-stage SCR aftertreatment system includes a front-stage SCR, a rear-stage SCR, and a DPF between the front-stage SCR and the rear-stage SCR.

[0011] The coordinated control device includes:

[0012] A data acquisition module, configured to acquire the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration.

[0013] An injection amount determination module, configured to determine the first urea injection amount of the front-stage SCR and the second urea injection amount of the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration.

[0014] An injection amount control module, configured to control the urea nozzle of the front-stage SCR to inject urea using the first urea injection amount, and control the urea nozzle of the rear-stage SCR to inject urea using the second urea injection amount.

[0015] In a third aspect, an embodiment of the present invention further provides a terminal device, including:

[0016] One or more processors;

[0017] A storage device, configured to store one or more programs;

[0018] When the one or more programs are executed by the one or more processors, the one or more processors implement the coordinated control method for urea injection amounts as described in any one of the first aspects.

[0019] Fourthly, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the urea injection amount coordination control method described in any one of the first aspect.

[0020] An embodiment of the present invention provides a urea injection amount coordination control method, device, equipment and medium, which are applied to a two-stage SCR after-treatment system. The two-stage SCR after-treatment system includes a front-stage SCR, a rear-stage SCR, and a DPF between the front-stage SCR and the rear-stage SCR. The coordination control method first obtains the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration. Then, according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration, it determines the first urea injection amount of the front-stage SCR and the second urea injection amount of the rear-stage SCR. Finally, it uses the first urea injection amount to control the urea nozzle of the front-stage SCR to inject urea, and uses the second urea injection amount to control the urea nozzle of the rear-stage SCR to inject urea. By using the above method, the urea injection amounts of the urea nozzles corresponding to the front-stage SCR and the rear-stage SCR are reasonably coordinated and distributed through the obtained multiple parameters. The first urea injection amount corresponding to the front-stage SCR and the second urea injection amount corresponding to the rear-stage SCR can be coordinately controlled. Also, the influence of the DPF state on the coordinated control of the urea injection amounts of the front-stage SCR and the rear-stage SCR is considered, so as to more effectively reduce the nitrogen oxide emissions for different real-time emission states, improve the conversion efficiency of nitrogen oxides, enhance the emission control accuracy of nitrogen oxides, achieve the efficient coordinated control of the urea injection amounts in the two-stage SCR after-treatment system, avoid the problem that the urea injection amounts of the front-stage SCR and the rear-stage SCR are limited by the engine working conditions, etc., and also make the tail gas emissions meet the requirements of the next-stage emission regulations, realizing the compliance of tail gas emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 is a schematic flowchart of a urea injection amount coordination control method provided by an embodiment of the present invention;

[0023] Figure 2 is a schematic structural diagram of a two-stage SCR after-treatment system provided by an embodiment of the present invention;

[0024] Figure 3 It is a schematic flowchart of another coordinated control method for urea injection amount provided by an embodiment of the present invention;

[0025] Figure 4 It is a schematic structural diagram of a coordinated control device for urea injection amount provided by an embodiment of the present invention;

[0026] Figure 5 It is a schematic structural diagram of a terminal device provided by an embodiment of the present invention. Specific embodiments

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of convenience of description, only parts related to the present invention are shown in the drawings rather than all structures.

[0028] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. It should be noted that the orientation terms such as "upper", "lower", "left", and "right" described in the embodiments of the present invention are described from the angles shown in the drawings, and should not be construed as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is formed "on" or "under" another element, it can not only be directly formed "on" or "under" another element, but also be indirectly formed "on" or "under" another element through an intermediate element. The terms "first", "second", etc. are only used for descriptive purposes, and do not indicate any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] The term "including" and its variants used in the present invention are open-ended, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment".

[0030] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish the corresponding contents, and are not used to limit the order or the interdependent relationship.

[0031] It should be noted that the modification of "one" and "multiple" mentioned in the present invention is illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly specified in the context, it should be understood as "one or more".

[0032] Figure 1FIG. 0 is a schematic flow chart of a coordinated control method for urea injection amount provided by an embodiment of the present invention. The coordinated control method is applicable to the coordinated control process of a dual-stage SCR after-treatment system for engine exhaust. The coordinated control method can be executed by a coordinated control device for urea injection amount. The coordinated control device for urea injection amount can be implemented in the form of hardware and / or software, and the coordinated control device for urea injection amount can be configured in a control board. The coordinated control method is applied to a dual-stage SCR after-treatment system. Figure 2 FIG. 1 is a schematic structural diagram of a dual-stage SCR after-treatment system provided by an embodiment of the present invention, as Figure 2 shown. The dual-stage SCR after-treatment system includes a front-stage SCR, a rear-stage SCR, and a DPF between the front-stage SCR and the rear-stage SCR; as Figure 1 shown, the coordinated control method includes:

[0033] S110. Obtain the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration.

[0034] First, it should be noted that the coordinated control method in this embodiment is applied to a dual-stage SCR after-treatment system. As Figure 2 visible from the schematic structural diagram of the dual-stage SCR after-treatment system shown, two upstream and downstream SCRs can be arranged respectively behind the turbine (i.e., the rear end of the turbine outlet) and behind the DPF. The upstream SCR can be understood as the front-stage SCR in this embodiment, and the downstream SCR can be understood as the rear-stage SCR in this embodiment. In other words, in a conventional DOC-DPF-SCR after-treatment system, an additional SCR can be added in front of the DOC to form the dual-stage SCR after-treatment system in this embodiment. The SCR in front of the DOC can be understood as the front-stage SCR in this embodiment, and the SCR behind the DOC can be understood as the rear-stage SCR in this embodiment. In addition, the corresponding ASC is not illustrated for the front-stage SCR and the rear-stage SCR in this embodiment. In the actual working process, the ASC can be set as needed. Exemplarily, the corresponding ASC can be set at the rear end of the front-stage SCR, and the corresponding ASC can also be set at the rear end of the rear-stage SCR. This embodiment does not make any limitations here.

[0035] Specifically, continue to refer to Figure 2, in this two-stage SCR aftertreatment system, the front-stage SCR, DOC, DPF, and rear-stage SCR are arranged in a "linear" order in sequence. Exemplarily, the front-stage SCR can be disposed closely behind the turbine. The first inlet temperature of the front-stage SCR can be understood as the temperature at the front end or inlet end of the front-stage SCR. The first inlet temperature of the front-stage SCR can be the current temperature value obtained by real-time detection or the average temperature value obtained by multiple detections. Exemplarily, a first temperature sensor 11 can be installed between the front-stage SCR and the turbine outlet, and the first temperature sensor 11 can be used to detect the first inlet temperature of the front-stage SCR. The second inlet temperature of the rear-stage SCR can be understood as the temperature at the front end or inlet end of the rear-stage SCR. The second inlet temperature of the rear-stage SCR can be the current temperature value obtained by real-time detection or the average temperature value obtained by multiple detections. Exemplarily, a second temperature sensor 12 can be installed between the rear-stage SCR and the DPF, and the second temperature sensor 12 can be used to detect the second inlet temperature of the rear-stage SCR.

[0036] The third inlet temperature of the DPF can be understood as the temperature at the front end or inlet end of the DPF. The third inlet temperature of the DPF can be the current temperature value obtained by real-time detection or the average temperature value obtained by multiple detections. Exemplarily, a third temperature sensor 13 can be installed between the DPF and the front-stage SCR, and the third temperature sensor 13 can be used to detect the third inlet temperature of the DPF. The pressure difference across the DPF can be understood as the pressure change before and after the DPF treats the exhaust gas. The pressure difference across the DPF can be the current pressure difference value obtained by real-time detection or the average pressure difference value obtained by multiple detections. Exemplarily, a differential pressure sensor 20 can be installed between the front end (or inlet end) and the rear end (or outlet end) of the DPF, and the differential pressure sensor 20 can be used to detect the pressure difference across the DPF.

[0037] Moreover, the original nitrogen oxide concentration can be understood as the nitrogen oxide concentration at the turbine outlet, that is, the nitrogen oxide concentration before being treated by the front-stage SCR and the rear-stage SCR. Exemplarily, a first nitrogen oxide concentration sensor 31 can also be installed between the front-stage SCR and the turbine outlet, and the first nitrogen oxide concentration sensor 31 can be used to detect the original nitrogen oxide concentration. In this embodiment, the positional relationship between the first temperature sensor 11 and the first nitrogen oxide concentration sensor 31 is not limited herein. Exemplarily, the first nitrogen oxide concentration sensor 31 can be disposed upstream of the first temperature sensor 11. In addition, exemplarily, a second nitrogen oxide concentration sensor 32 can be installed at the rear end of the rear-stage SCR, and the second nitrogen oxide concentration sensor 32 can be used to detect the nitrogen oxide concentration after being treated by the front-stage SCR and the rear-stage SCR, so as to facilitate subsequent analysis of the nitrogen oxide emission accuracy of this two-stage SCR aftertreatment system.

[0038] It should also be noted that the exhaust gas flow rates through the pre-stage SCR and the post-stage SCR are the same. Therefore, the exhaust mass flow rate is the exhaust gas flow rate through the pre-stage SCR and the post-stage SCR, and the unit of the exhaust mass flow rate can be kg / h. Exemplarily, an exhaust mass flow rate measurement unit ( Figure 2 not shown in

[0039] S120. Determine the first urea injection amount of the pre-stage SCR and the second urea injection amount of the post-stage SCR according to the first inlet temperature of the pre-stage SCR, the second inlet temperature of the post-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration.

[0040] Specifically, continue to refer to Figure 2 . The first temperature sensor 11 can transmit the detected first inlet temperature of the pre-stage SCR to the relevant processor of the vehicle. The second temperature sensor 12 can transmit the detected second inlet temperature of the post-stage SCR to the relevant processor of the vehicle. The third temperature sensor 13 can transmit the detected third inlet temperature of the DPF to the relevant processor of the vehicle. The pressure difference sensor 20 can transmit the detected pressure difference across the DPF to the relevant processor of the vehicle. The exhaust mass flow rate measurement unit can transmit the detected exhaust mass flow rate to the relevant processor of the vehicle. The first nitrogen oxide concentration sensor 31 can transmit the detected original nitrogen oxide concentration to the relevant processor of the vehicle. After receiving the first inlet temperature of the pre-stage SCR, the second inlet temperature of the post-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration, the relevant processor of the vehicle can perform analog-to-digital conversion processing on these data, converting the analog signals of these data into digital signals to facilitate subsequent analysis of these data to respectively determine the first urea injection amount of the pre-stage SCR and the second urea injection amount of the post-stage SCR. In other words, the urea injection amounts of the pre-stage SCR and the post-stage SCR in this embodiment are associated with these detected data, and the pre-stage SCR and the post-stage SCR are adjusted accordingly as these detected data change. In a specific implementation, when these detected data change, the urea injection amount of the corresponding pre-stage SCR will change, and the urea injection amount of the post-stage SCR will also change. The determination of the urea injection amounts of the pre-stage SCR and the post-stage SCR is not limited by information such as the vehicle state or engine operating conditions.

[0041] Continue to refer to Figure 2 , a first urea nozzle 41 may also be installed between the pre-stage SCR and the turbine outlet. The first urea nozzle 41 can be used to perform urea injection required for injecting the pre-stage SCR, that is, the determined first urea injection amount. In a more understandable way, the first urea nozzle 41 can inject urea towards the pre-stage SCR, and the injection amount of urea is the determined first urea injection amount. In this embodiment, the positional relationship between the first temperature sensor 11, the first nitrogen oxide concentration sensor 31 and the first urea nozzle 41 is not limited herein. Exemplarily, the first urea nozzle 41 can be arranged upstream of the first temperature sensor 11, and the first nitrogen oxide concentration sensor 31 can be arranged upstream of the first urea nozzle 41. A second urea nozzle 42 may also be installed between the post-stage SCR and the DPF. The second urea nozzle 42 can be used to perform urea injection required for injecting the pre-stage SCR, that is, the determined second urea injection amount. In a more understandable way, the second urea nozzle 42 can inject urea towards the post-stage SCR, and the injection amount of urea is the determined second urea injection amount. In this embodiment, the positional relationship between the second temperature sensor 12 and the second urea nozzle 42 is not limited herein. Exemplarily, the second urea nozzle 42 can be arranged upstream of the second temperature sensor 12.

[0042] S130. Control the urea nozzle of the pre-stage SCR to perform urea injection by using the first urea injection amount, and control the urea nozzle of the post-stage SCR to perform urea injection by using the second urea injection amount.

[0043] Specifically, continue to refer to Figure 2, after determining the first urea injection amount, the relevant processor of the vehicle can control the urea nozzle corresponding to the front-stage SCR (exemplarily, the first urea nozzle 41) to inject urea. The urea nozzle corresponding to the front-stage SCR (exemplarily, the first urea nozzle 41) can inject the urea with the first urea injection amount into the front-stage SCR, so as to facilitate the front-stage SCR to treat the exhaust gas. After determining the second urea injection amount, the relevant processor of the vehicle can control the urea nozzle of the rear-stage SCR (exemplarily, the second urea nozzle 42) to inject urea. The urea nozzle of the rear-stage SCR (exemplarily, the second urea nozzle 42) can inject the urea with the second urea injection amount into the rear-stage SCR, so as to facilitate the rear-stage SCR to re-treat the exhaust gas. The first urea injection amount corresponding to the front-stage SCR and the second urea injection amount corresponding to the rear-stage SCR are reasonably coordinated and allocated through multiple obtained parameters. The first urea injection amount corresponding to the front-stage SCR and the second urea injection amount corresponding to the rear-stage SCR are determined by comprehensively considering the working state of the front-stage SCR, the working state of the rear-stage SCR, the working state of the DPF, the nitrogen oxide concentration, the gas flow rate, etc. When both the front-stage SCR and the rear-stage SCR are in an efficient exhaust gas purification state, the nitrogen oxide emissions can be reduced more effectively, the conversion efficiency of nitrogen oxides can be improved, the emission control accuracy of nitrogen oxides can be enhanced, and the exhaust gas emission compliance can be achieved.

[0044] In the technical solution of the embodiment of the present invention, the urea injection amounts of the urea nozzles corresponding to the front-stage SCR and the urea nozzles corresponding to the rear-stage SCR are reasonably coordinated and allocated through multiple obtained parameters. The first urea injection amount corresponding to the front-stage SCR and the second urea injection amount corresponding to the rear-stage SCR can be coordinately controlled. The influence of the DPF state on the coordinated control of the urea injection amounts of the front-stage SCR and the rear-stage SCR is also considered, so as to more effectively reduce the nitrogen oxide emissions for different real-time emission states, improve the conversion efficiency of nitrogen oxides, enhance the emission control accuracy of nitrogen oxides, achieve the efficient coordinated control of the urea injection amounts in the two-stage SCR post-treatment system, avoid the problem that the urea injection amounts of the front-stage SCR and the rear-stage SCR are limited by the engine working conditions, etc., and also make the exhaust gas emissions meet the requirements of the next-stage emission regulations, realizing the exhaust gas emission compliance.

[0045] Figure 3 It is a schematic flow chart of another method for coordinating and controlling the urea injection amount provided by the embodiment of the present invention. This embodiment is optimized on the basis of the above embodiment. Optionally, according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across both ends of the DPF, the exhaust gas mass flow rate, and the original nitrogen oxide concentration, determining the first urea injection amount of the front-stage SCR and the second urea injection amount of the rear-stage SCR includes:

[0046] Determine the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, and the exhaust gas mass flow rate;

[0047] Determine the regeneration process coordination factor of the DPF according to the third inlet temperature of the DPF, the pressure difference across the two ends of the DPF, and the exhaust gas mass flow rate;

[0048] Determine the total urea injection amount of the two-stage SCR aftertreatment system according to the exhaust gas mass flow rate and the original exhaust nitrogen oxide concentration;

[0049] Determine the first urea injection amount and the second urea injection amount according to the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR, the regeneration process coordination factor of the DPF, and the total urea injection amount of the two-stage SCR aftertreatment system.

[0050] For the content not detailed in this embodiment, please refer to the above embodiments, such as Figure 3 As shown, the coordinated control method includes:

[0051] S210. Obtain the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the two ends of the DPF, the exhaust gas mass flow rate, and the original exhaust nitrogen oxide concentration.

[0052] S220. Determine the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, and the exhaust gas mass flow rate.

[0053] Optionally, determining the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, and the exhaust gas mass flow rate includes: determining the exhaust gas space velocity flowing through the front-stage SCR according to the exhaust gas mass flow rate and the volume of the front-stage SCR, and determining the exhaust gas space velocity flowing through the rear-stage SCR according to the exhaust gas mass flow rate and the volume of the rear-stage SCR; according to the calculation formula Determine the actual ammonia storage amount N of the front-stage SCR 11 ; where, T1 represents the first inlet temperature of the front-stage SCR, V1 represents the exhaust gas space velocity flowing through the front-stage SCR, E1 represents the chemical reaction activation energy of the front-stage SCR, R represents the molar gas constant, a1 represents the first temperature correction coefficient, and b1 represents the first space velocity correction coefficient; according to the calculation formula Determine the actual ammonia storage amount N of the rear-stage SCR 21 ; where, T2 represents the second inlet temperature of the rear-stage SCR, V2 represents the exhaust gas space velocity flowing through the rear-stage SCR, E2 represents the chemical reaction activation energy of the rear-stage SCR, a2 represents the second temperature correction coefficient, and b2 represents the second space velocity correction coefficient; according to the calculation formula Determine the ammonia storage coordination factor α between the front-stage SCR and the rear-stage SCR; where N 10 represents the target ammonia storage of the front-stage SCR, and N 20 represents the target ammonia storage of the rear-stage SCR.

[0054] Specifically, continue to refer to Figure 2 , the unit of the exhaust gas mass flow rate can be kg / h. The exhaust gas volume flow rate flowing through the front-stage SCR can be determined according to the ratio of the exhaust gas mass flow rate to the air density. Exemplarily, the unit of the exhaust gas volume flow rate can be m 3 / h. And the exhaust gas space velocity flowing through the front-stage SCR can be determined according to the ratio of the exhaust gas volume flow rate flowing through the front-stage SCR to the volume of the front-stage SCR. Also, the unit of the exhaust gas mass flow rate can be kg / h. The exhaust gas volume flow rate flowing through the rear-stage SCR can be determined according to the ratio of the exhaust gas mass flow rate to the air density. Exemplarily, the unit of the exhaust gas volume flow rate can be m 3 / h. And the exhaust gas space velocity flowing through the rear-stage SCR can be determined according to the ratio of the exhaust gas volume flow rate flowing through the rear-stage SCR to the volume of the rear-stage SCR.

[0055] The actual ammonia storage N of the front-stage SCR 11 is related to the first inlet temperature T1 of the front-stage SCR and the exhaust gas space velocity V1 flowing through the front-stage SCR. The chemical reaction activation energy E1, the molar gas constant R, the first temperature correction coefficient a1, and the first space velocity correction coefficient b1 of the front-stage SCR can be understood as fixed values / constants and can be numerically set as needed. The actual ammonia storage N of the rear-stage SCR 21 is related to the second inlet temperature T2 of the rear-stage SCR and the exhaust gas space velocity V2 flowing through the rear-stage SCR. The chemical reaction activation energy E2, the molar gas constant R, the second temperature correction coefficient a2, and the second space velocity correction coefficient b2 of the rear-stage SCR can be understood as fixed values / constants and can be numerically set as needed. On this basis, the target ammonia storage N of the front-stage SCR 10 and the target ammonia storage N of the rear-stage SCR 20 can also be designed. According to the actual ammonia storage N of the front-stage SCR 11 , the target ammonia storage N of the front-stage SCR 10 , the actual ammonia storage N of the rear-stage SCR 21 and the target ammonia storage N of the rear-stage SCR 20 , calculate the ammonia storage coordination factor α between the front-stage SCR and the rear-stage SCR.

[0056] It should be noted that in the process of determining the ammonia storage coordination factor α between the front-stage SCR and the rear-stage SCR, it is first necessary to separately determine the exhaust gas space velocity V1 flowing through the front-stage SCR and the exhaust gas space velocity V2 flowing through the rear-stage SCR. In this embodiment, there are no specific requirements or special limitations on the determination order of the exhaust gas space velocity V1 flowing through the front-stage SCR and the exhaust gas space velocity V2 flowing through the rear-stage SCR. Exemplarily, the exhaust gas space velocity V1 flowing through the front-stage SCR and the exhaust gas space velocity V2 flowing through the rear-stage SCR can be determined successively, or the exhaust gas space velocity V1 flowing through the front-stage SCR and the exhaust gas space velocity V2 flowing through the rear-stage SCR can be determined simultaneously. After that, it is also necessary to separately determine the actual ammonia storage N 11 of the front-stage SCR and the actual ammonia storage N 21 of the rear-stage SCR. In this embodiment, there are no specific requirements or special limitations on the determination order of the actual ammonia storage N 11 of the front-stage SCR and the actual ammonia storage N 21 of the rear-stage SCR. Exemplarily, the actual ammonia storage N 11 of the front-stage SCR and the actual ammonia storage N 21 of the rear-stage SCR can be determined successively, or the actual ammonia storage N 11 of the front-stage SCR and the actual ammonia storage N 21 of the rear-stage SCR can be determined simultaneously. Finally, the required ammonia storage coordination factor α between the front-stage SCR and the rear-stage SCR can be calculated according to the determined actual ammonia storage N 11 of the front-stage SCR and the actual ammonia storage N 21 of the rear-stage SCR.

[0057] S230. Determine the regeneration process coordination factor of the DPF according to the third inlet temperature of the DPF, the pressure difference across the two ends of the DPF, and the exhaust gas mass flow rate.

[0058] Optionally, determining the regeneration process coordination factor of the DPF according to the third inlet temperature of the DPF, the pressure difference across the two ends of the DPF, and the exhaust gas mass flow rate includes: determining the exhaust gas volume flow rate flowing through the DPF according to the exhaust gas mass flow rate; determining the actual carbon loading M of the DPF according to the calculation formula 11 ; where, △P represents the pressure difference across the two ends of the DPF, Q represents the exhaust gas volume flow rate flowing through the DPF, c1 represents the first volume flow rate correction coefficient, and c2 represents the second volume flow rate correction coefficient; determining the regeneration process coordination factor β of the DPF according to the calculation formula ; where, M 10 represents the maximum carbon loading of the DPF, T3 represents the third inlet temperature of the DPF, T4 represents the target regeneration temperature of the DPF, and d1 represents the first carbon loading correction coefficient.

[0059] Specifically, continue to refer to Figure 2 , the unit of the exhaust gas mass flow rate can be kg / h. The exhaust gas volume flow rate flowing through the DPF can be determined according to the ratio of the exhaust gas mass flow rate to the air density. Exemplarily, the unit of the exhaust gas volume flow rate can be m 3 / h. The actual carbon loading M of the DPF 11 is related to the differential pressure ΔP across the DPF and the exhaust gas volume flow rate Q flowing through the DPF. The first volume flow rate correction factor c1 and the second volume flow rate correction factor c2 can be understood as fixed values / constants and can be numerically set as needed. On this basis, the maximum carbon loading M of the DPF 10 , the target regeneration temperature T4 of the DPF, and the first carbon loading correction factor d1 can also be designed. According to the third inlet temperature T3 of the DPF, the actual carbon loading M of the DPF 11 , the maximum carbon loading M of the DPF 10 , the target regeneration temperature T4 of the DPF, and the first carbon loading correction factor d1, the regeneration process coordination factor β of the DPF is calculated. Exemplarily, the target regeneration temperature T4 of the DPF can be designed as 500 °C. It can be understood that when the DPF is in the regeneration process, since the regeneration temperature of the DPF increases, the temperature of the post-stage SCR will be too high, resulting in a decrease in the conversion efficiency of the post-stage SCR. Therefore, at this time, the urea injection amount of the post-stage SCR needs to be reduced. To ensure that the nitrogen oxide emissions meet the relevant regulatory requirements, the urea injection amount of the pre-stage SCR also needs to be increased at this time. In addition, it should also be noted that when the DPF is in the non-regeneration process, the regeneration process coordination factor β of the DPF = 1.

[0060] S240. Determine the total urea injection amount of the dual-stage SCR after-treatment system according to the exhaust gas mass flow rate and the original exhaust nitrogen oxide concentration.

[0061] Optionally, determining the total urea injection amount of the dual-stage SCR after-treatment system according to the exhaust gas mass flow rate and the original exhaust nitrogen oxide concentration includes: determining the total urea injection amount U0 of the dual-stage SCR after-treatment system according to the calculation formula ; where L represents the exhaust gas mass flow rate, represents the original exhaust nitrogen oxide concentration, and f represents the conversion coefficient constant.

[0062] Specifically, continue to refer to Figure 2 , the total urea injection amount U0 of the dual-stage SCR after-treatment system is related to the obtained exhaust gas mass flow rate L and the original exhaust nitrogen oxide concentration Regarding this, the conversion coefficient constant f can be understood as a fixed value / constant, and its numerical value can be set as needed. Moreover, the total urea injection amount U0 of the two-stage SCR after-treatment system is equal to the sum of the first urea injection amount U1 corresponding to the front-stage SCR and the second urea injection amount U2 corresponding to the rear-stage SCR. Subsequently, according to the ammonia storage coordination factor α between the front-stage SCR and the rear-stage SCR and the regeneration process coordination factor β of the DPF, the total urea injection amount U0 of the two-stage SCR after-treatment system can be reasonably coordinated and distributed so that both the front-stage SCR and the rear-stage SCR are in an efficient exhaust gas purification state. In other words, this embodiment essentially comprehensively considers the ammonia storage amounts of the front-stage SCR and the rear-stage SCR and the carbon loading amount of the DPF to determine the first urea injection amount corresponding to the front-stage SCR and the second urea injection amount corresponding to the rear-stage SCR.

[0063] It should also be noted that S220 is the step of determining the ammonia storage coordination factor α between the front-stage SCR and the rear-stage SCR, S230 is the step of determining the regeneration process coordination factor β of the DPF, and S240 is the step of determining the total urea injection amount U0 of the two-stage SCR after-treatment system. In this embodiment, no specific requirements or special limitations are imposed on the execution order of S220, S230, and S240. Exemplarily, S220, S230, and S240 can be executed successively (the order of S220, S230, and S240 can be arbitrarily selected), or S220, S230, and S240 can be executed simultaneously.

[0064] S250. Determine the first urea injection amount and the second urea injection amount according to the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR, the regeneration process coordination factor of the DPF, and the total urea injection amount of the two-stage SCR after-treatment system.

[0065] Optionally, determining the first urea injection amount and the second urea injection amount according to the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR, the regeneration process coordination factor of the DPF, and the total urea injection amount of the two-stage SCR after-treatment system includes: determining the first urea injection amount U1 according to the calculation formula U1 = U0×[k1 - k2×(α - 1)]×β; where U0 represents the total urea injection amount of the two-stage SCR after-treatment system, α represents the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR, β represents the regeneration process coordination factor of the DPF, k1 represents the basic urea injection proportion coefficient of the front-stage SCR, and k2 represents the first ammonia storage coordination factor correction coefficient.

[0066] Specifically, continue to refer to Figure 2, the first urea injection amount U1 corresponding to the pre-stage SCR is related to the total urea injection amount U0 of the calculated two-stage SCR after-treatment system, the ammonia storage coordination factor α between the pre-stage SCR and the post-stage SCR, and the DPF regeneration process coordination factor β. The urea injection basic proportional coefficient k1 of the pre-stage SCR and the first ammonia storage coordination factor correction coefficient k2 can be understood as fixed values / constants and can be numerically set as needed.

[0067] Optionally, according to the ammonia storage coordination factor between the pre-stage SCR and the post-stage SCR, the DPF regeneration process coordination factor, and the total urea injection amount of the two-stage SCR after-treatment system, determine the first urea injection amount and the second urea injection amount, including: determining the second urea injection amount U2 according to the calculation formula U2 = U0 × [k3 + k2 × (α - 1)] × β; where U0 represents the total urea injection amount of the two-stage SCR after-treatment system, α represents the ammonia storage coordination factor between the pre-stage SCR and the post-stage SCR, β represents the DPF regeneration process coordination factor, k2 represents the first ammonia storage coordination factor correction coefficient, and k3 represents the urea injection basic proportional coefficient of the post-stage SCR.

[0068] Specifically, continue to refer to Figure 2 , the second urea injection amount U2 corresponding to the post-stage SCR is related to the total urea injection amount U0 of the calculated two-stage SCR after-treatment system, the ammonia storage coordination factor α between the pre-stage SCR and the post-stage SCR, and the DPF regeneration process coordination factor β. The first ammonia storage coordination factor correction coefficient k2 and the urea injection basic proportional coefficient k3 of the post-stage SCR can be understood as fixed values / constants and can be numerically set as needed.

[0069] It can be seen from the calculation formulas of the first urea injection amount U1 corresponding to the pre-stage SCR and the second urea injection amount U2 corresponding to the post-stage SCR that when the ammonia storage coordination factor α between the pre-stage SCR and the post-stage SCR > 1, it indicates that the actual ammonia storage amount N inside the pre-stage SCR 11 is sufficient, and the urea injection amount corresponding to the pre-stage SCR can be appropriately reduced, and the urea injection amount corresponding to the post-stage SCR can be appropriately increased. And when the ammonia storage coordination factor α between the pre-stage SCR and the post-stage SCR < 1, it indicates that the actual ammonia storage amount N inside the post-stage SCR 21If it is sufficient, the urea injection amount corresponding to the post-stage SCR can be appropriately reduced, and the urea injection amount corresponding to the pre-stage SCR can be appropriately increased. When the DPF is in the non-regeneration process, the DPF does not affect the urea injection amount corresponding to the pre-stage SCR and the urea injection amount corresponding to the post-stage SCR. Moreover, when the DPF is in the regeneration process, since the regeneration temperature of the DPF increases, it will cause the temperature of the post-stage SCR to be too high, resulting in a decrease in the conversion efficiency of the post-stage SCR. Therefore, at this time, the urea injection amount of the post-stage SCR can be appropriately reduced, and the urea injection amount of the pre-stage SCR can be appropriately increased. In this way, in the dual-stage SCR after-treatment system, the pre-stage SCR and the post-stage SCR can achieve coordinated control according to their respective actual ammonia storage amounts, and fully consider the influence of the DPF regeneration process on the SCR conversion efficiency. The urea injection compensation during the regeneration process is achieved through the regeneration process coordination factor β of the DPF, improving the conversion efficiency of nitrogen oxides, enhancing the emission control accuracy of nitrogen oxides, and achieving compliance with tail gas emissions.

[0070] S260. Control the urea nozzle of the pre-stage SCR to inject urea using the first urea injection amount, and control the urea nozzle of the post-stage SCR to inject urea using the second urea injection amount.

[0071] Figure 4 It is a schematic structural diagram of a coordinated control device for urea injection amount provided by an embodiment of the present invention. This coordinated control device is applicable to the coordinated control process of the dual-stage SCR after-treatment system for engine exhaust. This coordinated control device can be implemented in the form of hardware and / or software and is generally configured in the control board. This coordinated control device is applied to the dual-stage SCR after-treatment system. As Figure 2 shown, this dual-stage SCR after-treatment system includes a pre-stage SCR, a post-stage SCR, and a DPF between the pre-stage SCR and the post-stage SCR; as Figure 4 shown, this coordinated control device includes:

[0072] A data acquisition module 310, configured to acquire the first inlet temperature of the pre-stage SCR, the second inlet temperature of the post-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration; an injection amount determination module 320, configured to determine the first urea injection amount of the pre-stage SCR and the second urea injection amount of the post-stage SCR according to the first inlet temperature of the pre-stage SCR, the second inlet temperature of the post-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original nitrogen oxide concentration; an injection amount control module 330, configured to control the urea nozzle of the pre-stage SCR to inject urea using the first urea injection amount, and control the urea nozzle of the post-stage SCR to inject urea using the second urea injection amount.

[0073] In the technical solution of the embodiment of the present invention, by reasonably coordinating and distributing the urea injection amount of the urea nozzle corresponding to the front-stage SCR and the urea injection amount of the urea nozzle corresponding to the rear-stage SCR through the obtained multiple parameters, the first urea injection amount corresponding to the front-stage SCR and the second urea injection amount corresponding to the rear-stage SCR can be coordinately controlled. The influence of the DPF state on the coordinated control of the urea injection amounts of the front-stage SCR and the rear-stage SCR is also considered, so as to more effectively reduce the nitrogen oxide emissions for different real-time emission states, improve the conversion efficiency of nitrogen oxides, enhance the emission control accuracy of nitrogen oxides, realize the efficient coordinated control of the urea injection amounts in the two-stage SCR aftertreatment system, avoid the problem that the urea injection amounts of the front-stage SCR and the rear-stage SCR are limited by the engine working conditions, etc., and also make the tail gas emissions meet the requirements of the next-stage emission regulations, realizing the compliance of tail gas emissions.

[0074] Based on the above technical solution, optionally, the injection amount determination module 320 may specifically include a first coordination factor determination unit, a second coordination factor determination unit, a total injection amount determination unit, and a front and rear stage injection amount determination unit. The first coordination factor determination unit is used to determine the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, and the exhaust mass flow rate; the second coordination factor determination unit is used to determine the regeneration process coordination factor of the DPF according to the third inlet temperature of the DPF, the pressure difference across the DPF, and the exhaust mass flow rate; the total injection amount determination unit is used to determine the total urea injection amount of the two-stage SCR aftertreatment system according to the exhaust mass flow rate and the original nitrogen oxide concentration; the front and rear stage injection amount determination unit is used to determine the first urea injection amount and the second urea injection amount according to the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR, the regeneration process coordination factor of the DPF, and the total urea injection amount of the two-stage SCR aftertreatment system.

[0075] Optionally, the first coordination factor determination unit may specifically include an exhaust gas space velocity determination subunit, a front-stage ammonia storage determination subunit, a rear-stage ammonia storage determination subunit, and a first coordination factor determination subunit. The exhaust gas space velocity determination subunit is used to determine the exhaust gas space velocity flowing through the front-stage SCR according to the exhaust mass flow rate and the volume of the front-stage SCR, and determine the exhaust gas space velocity flowing through the rear-stage SCR according to the exhaust mass flow rate and the volume of the rear-stage SCR; the front-stage ammonia storage determination subunit is used to determine the actual ammonia storage amount N of the front-stage SCR according to the calculation formula ; where, T1 represents the first inlet temperature of the front-stage SCR, V1 represents the exhaust gas space velocity flowing through the front-stage SCR, E1 represents the chemical reaction activation energy of the front-stage SCR, R represents the molar gas constant, a1 represents the first temperature correction coefficient, and b1 represents the first space velocity correction coefficient; the rear-stage ammonia storage determination subunit is used to determine according to the calculation formula 11 of the front-stage SCR; Determine the actual ammonia storage amount N of the subsequent SCR 21 ; Wherein, T2 represents the second inlet temperature of the rear SCR, V2 represents the exhaust gas velocity flowing through the rear SCR, E2 represents the chemical reaction activation energy of the rear SCR, a2 represents the second temperature correction coefficient, and b2 represents the second air velocity correction coefficient; the first coordination factor determination subunit is used to calculate the formula Determine the ammonia storage coordination factor α between the front SCR and the rear SCR; where N 10 Indicates the target ammonia storage capacity of the front-stage SCR, N 20 Indicates the target ammonia storage amount of the post-stage SCR.

[0076] Optionally, the second coordination factor determination unit may specifically include an exhaust volume flow determination subunit, a DPF carbon load determination subunit, and a second coordination factor determination subunit, wherein the exhaust volume flow determination subunit is used to determine the exhaust volume flow flowing through the DPF according to the exhaust mass flow rate; the DPF carbon load determination subunit is used to determine the exhaust volume flow flowing through the DPF according to the calculation formula Determine the actual carbon load M of the DPF 11 ; Wherein, △P represents the pressure difference between the two ends of the DPF, Q represents the exhaust volume flow rate flowing through the DPF, c1 represents the first volume flow correction coefficient, and c2 represents the second volume flow correction coefficient; the second coordination factor determination subunit is used to determine the second volume flow correction coefficient according to the calculation formula Determine the DPF regeneration process coordination factor β; where M 10 represents the maximum carbon load of DPF, T3 represents the third inlet temperature of DPF, T4 represents the target regeneration temperature of DPF, and d1 represents the first carbon load correction coefficient.

[0077] Optionally, the total injection amount determination unit may specifically include a total injection amount determination subunit, which is used to determine the total injection amount according to the calculation formula Determine the total urea injection amount U0 of the dual-stage SCR aftertreatment system; where L represents the exhaust mass flow rate, represents the original nitrogen oxide concentration, and f represents the conversion coefficient constant.

[0078] Optionally, the front-stage and rear-stage injection quantity determination unit may specifically include a front-stage injection quantity determination subunit, which is used to determine the first urea injection quantity U1 according to the calculation formula U1=U0×[k1-k2×(α-1)]×β; wherein U0 represents the total urea injection quantity of the two-stage SCR after-treatment system, α represents the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR, β represents the DPF regeneration process coordination factor, k1 represents the urea injection basic proportional coefficient of the front-stage SCR, and k2 represents the first ammonia storage coordination factor correction coefficient.

[0079] Optionally, the front and rear stage injection amount determination unit may specifically include a rear stage injection amount determination subunit, which is configured to determine the second urea injection amount U2 according to the calculation formula U2 = U0 × [k3 + k2 × (α - 1)] / β; where U0 represents the total urea injection amount of the two-stage SCR post-treatment system, α represents the ammonia storage coordination factor between the front stage SCR and the rear stage SCR, β represents the regeneration process coordination factor of the DPF, k2 represents the first ammonia storage coordination factor correction coefficient, and k3 represents the basic urea injection proportion coefficient of the rear stage SCR.

[0080] The urea injection amount coordination control device provided by the embodiments of the present invention can execute the urea injection amount coordination control method provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0081] Figure 5 It is a schematic structural diagram of a terminal device provided by an embodiment of the present invention. The terminal device is intended to represent various forms of digital computers, such as, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The terminal device can also represent various forms of mobile devices, such as, personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0082] As Figure 5 shown, the terminal device 100 includes one or more processors 110, and a storage device, the storage device is communicatively connected to the processor 110, and the storage device is such as a read-only memory (ROM) 120, a random access memory (RAM) 130, etc. Among them, the storage device stores a computer program executable by one or more processors, and the processor 110 can execute various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 120 or the computer program loaded from the storage unit 180 into the random access memory (RAM) 130. In the RAM 130, various programs and data required for the operation of the terminal device 100 can also be stored. The processor 110, the ROM 120, and the RAM 130 are connected to each other through a bus 140. The input / output (I / O) interface 150 is also connected to the bus 140.

[0083] Multiple components in the terminal device 100 are connected to the I / O interface 150, including: an input unit 160, such as a keyboard, a mouse, etc.; an output unit 170, such as various types of displays, speakers, etc.; a storage unit 180, such as a disk, an optical disc, etc.; and a communication unit 190, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 190 allows the terminal device 100 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0084] The processor 110 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 110 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 110 executes the various methods and processes described above, such as the coordinated control method of the urea injection amount.

[0085] In some embodiments, the coordinated control method of the urea injection amount can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as the storage unit 180. In some embodiments, part or all of the computer program can be loaded and / or installed onto the terminal device 100 via the ROM 120 and / or the communication unit 190. When the computer program is loaded into the RAM 130 and executed by the processor 110, one or more steps of the coordinated control method of the urea injection amount described above can be executed. Alternatively, in other embodiments, the processor 110 can be configured to execute the coordinated control method of the urea injection amount in any other suitable manner (e.g., by means of firmware).

[0086] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGA), application-specific integrated circuits (ASIC), application-specific standard products (ASSP), system-on-a-chip systems (SOC), complex programmable logic devices (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, the programmable processor can be a special or general programmable processor, and can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0087] A computer program for implementing the method of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, a special purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowchart and / or block diagram to be implemented. The computer programs can be executed entirely on the machine, partially on the machine, as a stand-alone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0088] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include an electrical connection based on one or more wires, 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), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0089] In order to provide interaction with a user, the systems and techniques described herein can be implemented on a terminal device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the terminal device. Other kinds of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, speech input, or tactile input).

[0090] The systems and techniques described herein can be implemented in a computing system including backend components (e.g., as a data server), or a computing system including middleware components (e.g., an application server), or a computing system including frontend components (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described herein), or a computing system including any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected to each other by digital data communication in any form or medium (e.g., a communication network). Examples of communication networks include: local area network (LAN), wide area network (WAN), blockchain network, and the Internet.

[0091] A computing system can include a client and a server. The client and the server are generally remote from each other and typically interact through a communication network. The client-server relationship is created by computer programs running on respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, and solves the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0092] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps recited in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and this is not limited herein.

[0093] Note that the above is only a preferred embodiment of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A coordinated control method for urea injection amount, characterized in that Applied to a two-stage SCR aftertreatment system, the two-stage SCR aftertreatment system includes a front-stage SCR, a rear-stage SCR, and a DPF between the front-stage SCR and the rear-stage SCR; The coordinated control method includes: Obtaining a first inlet temperature of the front-stage SCR, a second inlet temperature of the rear-stage SCR, a third inlet temperature of the DPF, a pressure difference across the DPF, an exhaust mass flow rate, and an original exhaust nitrogen oxide concentration; Determining a first urea injection amount of the front-stage SCR and a second urea injection amount of the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original exhaust nitrogen oxide concentration; Controlling the urea nozzle of the front-stage SCR to inject urea using the first urea injection amount, and controlling the urea nozzle of the rear-stage SCR to inject urea using the second urea injection amount.

2. The coordinated control method according to claim 1, wherein Determining the first urea injection amount of the front-stage SCR and the second urea injection amount of the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original exhaust nitrogen oxide concentration includes: Determining an ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, and the exhaust mass flow rate; Determining a regeneration process coordination factor of the DPF according to the third inlet temperature of the DPF, the pressure difference across the DPF, and the exhaust mass flow rate; Determining a total urea injection amount of the two-stage SCR aftertreatment system according to the exhaust mass flow rate and the original exhaust nitrogen oxide concentration; Determining the first urea injection amount and the second urea injection amount according to the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR, the regeneration process coordination factor of the DPF, and the total urea injection amount of the two-stage SCR aftertreatment system.

3. The coordinated control method according to claim 2, characterized in that, Determining the ammonia storage coordination factor between the front-stage SCR and the rear-stage SCR according to the first inlet temperature of the front-stage SCR, the second inlet temperature of the rear-stage SCR, and the exhaust mass flow rate includes: Determining an exhaust gas space velocity flowing through the front-stage SCR according to the exhaust mass flow rate and the volume of the front-stage SCR, and determining an exhaust gas space velocity flowing through the rear-stage SCR according to the exhaust mass flow rate and the volume of the rear-stage SCR; According to the calculation formula Determine the actual ammonia storage amount N of the pre-stage SCR 11 ; where, T1 represents the first inlet temperature of the pre-stage SCR, V1 represents the exhaust gas space velocity flowing through the pre-stage SCR, E1 represents the chemical reaction activation energy of the pre-stage SCR, R represents the molar gas constant, a1 represents the first temperature correction coefficient, and b1 represents the first space velocity correction coefficient; According to the calculation formula determine the actual ammonia storage amount N of the post-stage SCR 21 ; where T2 represents the second inlet temperature of the post-stage SCR, V2 represents the exhaust gas space velocity flowing through the post-stage SCR, E2 represents the chemical reaction activation energy of the post-stage SCR, a2 represents the second temperature correction coefficient, and b2 represents the second space velocity correction coefficient; According to the calculation formula determine the ammonia storage coordination factor α between the pre-stage SCR and the post-stage SCR; where N 10 represents the target ammonia storage of the pre-stage SCR, and N 20 represents the target ammonia storage of the post-stage SCR.

4. The coordination control method according to claim 2, characterized in that Determining the regeneration process coordination factor of the DPF according to the third inlet temperature of the DPF, the pressure difference across the DPF, and the exhaust mass flow rate includes: Determining an exhaust gas volume flow rate flowing through the DPF according to the exhaust mass flow rate; According to the calculation formula to determine the actual carbon loading M of the DPF 11 ; where, △P represents the differential pressure across the two ends of the DPF, Q represents the exhaust gas volume flow rate flowing through the DPF, c1 represents the first volume flow rate correction coefficient, and c2 represents the second volume flow rate correction coefficient; According to the calculation formula to determine the regeneration process coordination factor β of the DPF; where M 10 represents the maximum carbon loading of the DPF, T3 represents the third inlet temperature of the DPF, T4 represents the target regeneration temperature of the DPF, and d1 represents the first carbon loading correction coefficient.

5. The coordination control method according to claim 2, wherein Determining the total urea injection amount of the two-stage SCR aftertreatment system according to the exhaust mass flow rate and the original exhaust nitrogen oxide concentration includes: According to the calculation formula Determine the total urea injection amount U0 of the double-stage SCR post-treatment system; where L represents the exhaust gas mass flow rate, represents the original nitrogen oxide concentration, and f represents the conversion coefficient constant.

6. The coordinated control method according to claim 2, wherein Determine the first urea injection amount and the second urea injection amount according to the ammonia storage coordination factor between the pre-stage SCR and the post-stage SCR, the regeneration process coordination factor of the DPF, and the total urea injection amount of the two-stage SCR post-treatment system, including: Determine the first urea injection amount U1 according to the calculation formula U1 = U0×[k1 - k2×(α - 1)]×β; where U0 represents the total urea injection amount of the two-stage SCR post-treatment system, α represents the ammonia storage coordination factor between the pre-stage SCR and the post-stage SCR, β represents the regeneration process coordination factor of the DPF, k1 represents the basic urea injection proportion coefficient of the pre-stage SCR, and k2 represents the first ammonia storage coordination factor correction coefficient.

7. The coordination control method according to claim 2, characterized in that Determine the first urea injection amount and the second urea injection amount according to the ammonia storage coordination factor between the pre-stage SCR and the post-stage SCR, the regeneration process coordination factor of the DPF, and the total urea injection amount of the two-stage SCR post-treatment system, including: Determine the second urea injection amount U2 according to the calculation formula U2 = U0×[k3 + k2×(α - 1)]×β; where U0 represents the total urea injection amount of the two-stage SCR post-treatment system, α represents the ammonia storage coordination factor between the pre-stage SCR and the post-stage SCR, β represents the regeneration process coordination factor of the DPF, k2 represents the first ammonia storage coordination factor correction coefficient, and k3 represents the basic urea injection proportion coefficient of the post-stage SCR.

8. A coordinated control device for urea injection amount, characterized in that Applied to a two-stage SCR post-treatment system, the two-stage SCR post-treatment system includes a pre-stage SCR, a post-stage SCR, and a DPF between the pre-stage SCR and the post-stage SCR; The coordination control device includes: A data acquisition module for acquiring the first inlet temperature of the pre-stage SCR, the second inlet temperature of the post-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original exhaust nitrogen oxide concentration; An injection amount determination module for determining the first urea injection amount of the pre-stage SCR and the second urea injection amount of the post-stage SCR according to the first inlet temperature of the pre-stage SCR, the second inlet temperature of the post-stage SCR, the third inlet temperature of the DPF, the pressure difference across the DPF, the exhaust mass flow rate, and the original exhaust nitrogen oxide concentration; An injection amount control module for controlling the urea nozzle of the pre-stage SCR to inject urea using the first urea injection amount, and controlling the urea nozzle of the post-stage SCR to inject urea using the second urea injection amount.

9. A terminal device, characterized in that, Includes: One or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the coordinated control method of urea injection amount as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the coordinated control method of urea injection amount as described in any one of claims 1-7.

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