A control method for prolonging the DPF on-road regeneration cycle of a dual-injection urea aftertreatment system and related equipment

Abstract

The application discloses a control method for prolonging a DPF on-road regeneration cycle of a double-injection urea aftertreatment system and related equipment, prolongs the DPF on-road regeneration cycle, slows down carbon accumulation growth of the DPF, reduces on-road regeneration frequency, and finally effectively reduces fuel consumption of a vehicle and comprehensively improves economic dynamic performance of the vehicle. The method comprises the following steps: monitoring engine information and aftertreatment state information of the engine in real time; judging whether the engine has DPF passive regeneration conditions according to the engine information and the aftertreatment state information of the engine; if yes, outputting a correction coefficient of two-stage urea in the double-urea aftertreatment system; controlling injection of urea in the double-urea aftertreatment system according to the correction coefficient; detecting whether NOx emission of the engine meets preset conditions; and if yes, performing injection of the first-stage urea and the second-stage urea according to the correction coefficient of the two-stage urea in the double-urea aftertreatment system.

Description

Technical Field

[0001] This application relates to the field of engine aftertreatment technology, and in particular to a control method and related equipment for extending the DPF regeneration cycle of a dual-injection urea aftertreatment system. Background Technology

[0002] The carbon buildup in a DPF (Diesel Particulate Filter) will react with NO2 at temperatures above 250°C to produce CO2, which is then emitted. This process is called passive DPF regeneration. As the carbon buildup in the DPF continues to increase until it affects the diesel engine's fuel consumption and power, the engine will change its combustion process and implement strong exhaust temperature thermal management while in operation, raising the temperature in front of the DPF to around 600°C. The carbon buildup in the DPF will then undergo a violent oxidation reaction with oxygen, thus removing the carbon buildup. This process is called DPF on-road regeneration.

[0003] To effectively meet extremely low NOx emission requirements, the industry generally considers the use of a dual-injection urea aftertreatment system essential. In this process, two stages of urea nozzles simultaneously inject urea, controlling NOx emissions to very low levels to meet the next stage of the China VII emission standard. However, after the first stage of urea injection, NOx emissions are significantly reduced, resulting in less NO2 flowing through the DPF. If NO2 is low, the DPF's passive regeneration capacity is weak, leading to rapid carbon buildup and frequent DPF regeneration during vehicle operation. This increases fuel consumption and reduces fuel economy and performance. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a control method and related equipment for extending the DPF regeneration cycle of a dual-injection urea aftertreatment system.

[0005] The technical solution provided in this application is described below:

[0006] The first aspect of this application provides a control method for extending the DPF (Dual Urea Filter) regeneration cycle in a dual urea aftertreatment system. The control method is applied to the dual urea aftertreatment system and includes:

[0007] Real-time monitoring of engine information and engine after-treatment status;

[0008] Based on the engine information and the engine after-processing status information, determine whether the engine has the conditions for DPF passive regeneration;

[0009] If so, output the correction coefficients for the two stages of urea in the dual urea after-treatment system;

[0010] The injection of urea in the dual urea aftertreatment system is controlled according to the correction coefficient.

[0011] The NOx emissions of the engine are checked to see if they meet preset conditions.

[0012] If so, the first-stage urea and the second-stage urea are injected according to the correction coefficients of the two-stage urea in the dual-urea aftertreatment system.

[0013] Optionally, determining whether the engine meets the conditions for DPF passive regeneration based on the engine information and the engine's aftertreatment status information includes:

[0014] A DPF passive regeneration model is established based on the engine information and the engine's after-processing status information;

[0015] Obtain the carbon loading of the DPF and the front temperature of the DPF;

[0016] After inputting the DPF carbon loading and DPF front-end temperature into the DPF passive regeneration model, correction coefficients a and b are output.

[0017] Obtain engine speed, exhaust flow rate, original NOx emission, NO2 ratio, and NOx tail emission;

[0018] The engine speed, exhaust flow rate, original NOx emission, NO2 ratio, and NOx tail emission are respectively input into the DPF passive regeneration model, and then the correction coefficients c, d, f, g, and h are output.

[0019] The formula for calculating the passive regeneration coefficient is: η=a*b*(c+d+f+g+h), where η is the passive regeneration coefficient;

[0020] The engine is deemed to have the conditions for DPF passive regeneration based on the passive regeneration coefficient calculation formula.

[0021] Optionally, after determining whether the engine meets the DPF passive regeneration conditions based on the passive regeneration coefficient calculation formula, the method further includes:

[0022] When the passive regeneration coefficient η = 0, the engine does not meet the DPF passive regeneration condition;

[0023] When the passive regeneration coefficient η>0, the engine has the DPF passive regeneration condition.

[0024] Optionally, the method further includes outputting correction coefficients for the two stages of urea in the dual-urea after-treatment system:

[0025] Obtain the passive regeneration coefficient;

[0026] The injection correction coefficients for the first-stage urea and the second-stage urea are determined based on the passive regeneration coefficient.

[0027] Optionally, detecting whether the NOx emissions of the engine meet preset conditions includes:

[0028] Obtain the NOx sensor measurement value q and the engine exhaust energy k and power p;

[0029] Obtain the formula for calculating NOx cumulative emissions: m=∑(u*q*k) / ∑P, where m is the NOx cumulative emissions, u is the exhaust gas coefficient, q is the NOx sensor measurement value, k is the engine exhaust energy, and p is the engine power;

[0030] Determine the target preset value;

[0031] Detect whether the cumulative NOx emission ratio m is less than the target preset value.

[0032] Optionally, after detecting whether the cumulative NOx emission ratio m is less than the target preset value, the method further includes:

[0033] If not, then retrieve the original control coefficients of the dual urea aftertreatment system;

[0034] The injection of urea in the dual urea aftertreatment system is controlled according to the original control coefficient.

[0035] Optionally, controlling the injection of urea in the dual urea aftertreatment system according to the correction coefficient includes:

[0036] The injection of urea in the dual urea after-treatment system is controlled according to the injection correction coefficient of the first-stage urea and the injection correction coefficient of the second-stage urea. The injection correction coefficient of the first-stage urea is used to reduce the injection of the first-stage urea in the dual urea after-treatment system, and the injection correction coefficient of the second-stage urea is used to increase the injection of the second-stage urea in the dual urea after-treatment system.

[0037] The second aspect of this application provides a control system for extending the DPF (Dual Injection Urea) regeneration cycle of a dual-injection urea aftertreatment system, comprising:

[0038] The monitoring unit is used to monitor engine information and engine after-processing status information in real time.

[0039] The judgment unit is used to determine whether the engine has the conditions for passive regeneration of DPF based on the engine information and the engine after-processing status information.

[0040] The output unit is used to output the correction coefficients of the two stages of urea in the dual urea aftertreatment system when the judgment unit determines that the engine has the conditions for passive regeneration of DPF.

[0041] A control unit is configured to control the injection of urea in the dual urea aftertreatment system according to the correction coefficient, wherein the correction coefficient is used to reduce the injection of the first stage urea in the dual urea aftertreatment system and increase the injection of the second stage urea in the dual urea aftertreatment system.

[0042] The detection unit is used to detect whether the NOx emissions of the engine meet preset conditions;

[0043] An execution unit is configured to, when the detection unit determines that the engine's NOx emissions meet preset conditions,

[0044] The first and second stage urea are then injected according to the correction coefficients of the two stages of urea in the dual urea aftertreatment system.

[0045] A third aspect of this application provides a control device for extending the DPF (Dual Injection Urea) regeneration cycle of a dual-injection urea aftertreatment system, the device comprising:

[0046] Processor, memory, input / output units, and bus;

[0047] The processor is connected to the memory, the input / output unit, and the bus;

[0048] The memory stores a program, which the processor invokes to perform the method as described in the first aspect and any one of the first aspects.

[0049] A fourth aspect of this application provides a computer-readable storage medium on which a program is stored, which, when executed on a computer, performs the methods described in the first aspect and any one of the first aspects.

[0050] As can be seen from the above technical solutions, this application has the following advantages:

[0051] This application presents a control method for extending the DPF (Diesel Particulate Filter) regeneration cycle in a dual-urea aftertreatment system. This method first monitors engine information and engine aftertreatment status information in real time. Then, based on the engine information and engine aftertreatment status information, it determines whether the engine meets the conditions for passive DPF regeneration. When it is determined that the engine meets the conditions for passive DPF regeneration, the correction coefficients for the two stages of urea in the dual-urea aftertreatment system are output. Next, the injection of urea in the dual-urea aftertreatment system is controlled according to the correction coefficients. Finally, it checks whether the engine's NOx emissions meet preset conditions. If so, the injection of the first and second stages of urea is executed according to the correction coefficients for the two stages of urea in the dual-urea aftertreatment system.

[0052] Therefore, by determining whether the engine has the conditions for passive DPF regeneration, the correction coefficient of the two-stage urea in the dual urea aftertreatment system is output. Based on the correction coefficient, the injection of the first-stage urea is reduced and the injection of the second-stage urea is increased, thus extending the DPF regeneration cycle and improving the passive regeneration capability of the DPF. This slows down the carbon accumulation of the DPF and reduces the frequency of regeneration during driving, ultimately effectively reducing the vehicle's fuel consumption and comprehensively improving the vehicle's economic performance. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of an embodiment of the control method for extending the DPF regeneration cycle of the dual-injection urea aftertreatment system of this application;

[0055] Figure 2 This is a schematic diagram of another embodiment of the control method for extending the DPF regeneration cycle of the dual-injection urea aftertreatment system of this application;

[0056] Figure 3 A schematic diagram of an embodiment of the control system for extending the DPF travel regeneration cycle of the dual-injection urea aftertreatment system of this application;

[0057] Figure 4 This is a schematic diagram of an embodiment of the control device for extending the DPF regeneration cycle of the dual-injection urea aftertreatment system of this application. Detailed Implementation

[0058] In this application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and other terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to describe the relative positional relationship between the components or parts and do not specifically limit the specific installation orientation of each component or part.

[0059] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0060] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0061] Furthermore, the structures, proportions, sizes, etc., drawn in the accompanying drawings of this application are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0062] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0063] To effectively meet extremely low NOx emission requirements, the industry generally considers the use of a dual-injection urea aftertreatment system essential. In this process, two stages of urea nozzles simultaneously inject urea, controlling NOx emissions to very low levels to meet the next stage of the China VII emission standard. However, after the first stage of urea injection, NOx emissions are significantly reduced, resulting in less NO2 flowing through the DPF. If NO2 is low, the DPF's passive regeneration capacity is weak, leading to rapid carbon buildup and frequent DPF regeneration during vehicle operation. This increases fuel consumption and reduces fuel economy and performance.

[0064] Based on this, this application provides a control method and related equipment for extending the DPF regeneration cycle of a dual-injection urea aftertreatment system. By determining whether the engine has the conditions for passive DPF regeneration, the method outputs the correction coefficients of the two stages of urea in the dual-injection urea aftertreatment system. Based on the correction coefficients, the method controls the reduction of the injection of the first stage of urea and the increase of the injection of the second stage of urea, thereby extending the DPF regeneration cycle, improving the passive regeneration capability of the DPF, slowing down the carbon accumulation of the DPF, reducing the frequency of regeneration, and ultimately effectively reducing the vehicle's fuel consumption and comprehensively improving the vehicle's economic performance.

[0065] Please see Figure 1 , Figure 1A schematic diagram of an embodiment of the control method for extending the DPF regeneration cycle of a dual-injection urea aftertreatment system provided in the first aspect of this application. The control method is applied to a dual-urea aftertreatment system and includes:

[0066] 101. Real-time monitoring of engine information and engine after-treatment status information;

[0067] In this embodiment of the application, engine information, such as engine speed, engine exhaust flow rate, engine exhaust temperature, etc., and engine after-treatment status information, such as NOx emissions, DPF carbon accumulation, etc., are monitored in real time. By obtaining the above engine information and engine after-treatment status information, it is possible to understand the current state of the engine after-treatment, and then execute step 102.

[0068] 102. Determine whether the engine has the conditions for DPF passive regeneration based on the engine information and the engine after-processing status information;

[0069] In this embodiment, it should be noted that passive DPF regeneration means that the accumulated carbon in the diesel engine particulate filter will react with NO2 at temperatures above 250°C to form CO2, which is then discharged. Passive DPF regeneration during operation means that as the accumulated carbon in the DPF continues to increase until it affects the diesel engine's fuel consumption and power, the engine will change its combustion process to implement strong exhaust temperature thermal management, raising the temperature before the DPF to around 600°C. The accumulated carbon in the DPF will then undergo a vigorous oxidation reaction with oxygen, thus removing the accumulated carbon. In practical applications, passive DPF regeneration is superior to passive DPF regeneration during operation. When the vehicle is in passive DPF regeneration mode, the accumulated carbon in the diesel engine particulate filter can react with NO2 to form CO2, which is then discharged. Furthermore, this process does not reduce engine power or fuel consumption. After obtaining engine information and engine aftertreatment status information, it is determined whether the engine meets the conditions for passive DPF regeneration. If so, step 103 is executed.

[0070] 103. Output the correction coefficients for the two stages of urea in the dual urea after-treatment system;

[0071] In this embodiment of the application, when it is determined that the vehicle has the conditions for passive regeneration of DPF, the correction coefficient of the two stages of urea in the dual urea aftertreatment system is output according to the vehicle's engine information and the engine's aftertreatment status information. There are two urea nozzles in the dual urea aftertreatment system, one urea nozzle in front of DPF and the other urea nozzle behind DPF. The output correction coefficient is used to adjust the urea injection amount of the two urea nozzles and control the amount of urea injection.

[0072] 104. Control the injection of urea in the dual urea aftertreatment system according to the correction coefficient;

[0073] In this embodiment, after obtaining the correction coefficient, the injection volume of one urea nozzle and another urea nozzle is controlled according to the correction coefficient. The injection volume of one urea nozzle is reduced, and the injection volume of the other urea nozzle is increased. In this way, the NOx removed in the first stage is reduced, the NO2 flowing through the DPF is increased, the passive regeneration capability of the DPF is improved, more carbon is passively regenerated, the carbon accumulation rate of the DPF is slowed down, and the regeneration cycle is extended. At the same time, the urea injection correction coefficient of the second stage is output to increase urea injection, ensuring that NOx emissions meet compliance.

[0074] 105. Check whether the NOx emissions of the engine meet the preset conditions;

[0075] In this embodiment, after controlling the injection of the two urea nozzles in the dual urea aftertreatment system according to the correction coefficient, further, to ensure that the emitted NOx meets preset conditions, that is, the emitted NOx meets emission standards and will not have an impact on the environment, it is necessary to detect the emitted NOx. When it is determined that the engine's NOx emissions meet the preset conditions, step 107 is executed.

[0076] 106. The first-stage urea and the second-stage urea are injected according to the correction coefficients of the two-stage urea in the dual-urea aftertreatment system.

[0077] In this embodiment, when the engine's NOx emissions meet preset conditions, it indicates that the injection volume of the two urea nozzles in the dual urea aftertreatment system meets the requirements. While reducing fuel consumption and ensuring economical power, the urea injection volume of the dual urea nozzles can be continuously controlled according to the output correction coefficient. When the engine's NOx emissions do not meet preset conditions, the injection of the two urea nozzles in the dual urea aftertreatment system is controlled according to the original control scheme. During this process, the urea injection correction coefficient is continuously adjusted. When the adjusted urea injection correction coefficient meets the NOx emission requirements, the urea injection volume is controlled according to the adjusted urea injection correction coefficient.

[0078] Please see Figure 2 , Figure 2 A schematic diagram of another embodiment of the control method for extending the DPF regeneration cycle of a dual-injection urea aftertreatment system provided in the second aspect of this application is shown. This control method is applied to a dual-urea aftertreatment system and includes:

[0079] 201. Real-time monitoring of engine information and engine after-treatment status information;

[0080] In this embodiment of the application, step 201 is similar to the aforementioned step 101, and will not be described again here.

[0081] 202. Establish a DPF passive regeneration model based on the engine information and the engine's after-processing status information;

[0082] 203. Obtain the DPF carbon loading and DPF front-end temperature;

[0083] 204. Input the DPF carbon loading and DPF front-end temperature into the DPF passive regeneration model and output correction coefficients a and b respectively;

[0084] 205. Obtain engine speed, exhaust flow rate, original NOx displacement, NO2 ratio, and NOx tail discharge;

[0085] 206. Input the engine speed, exhaust flow rate, original NOx displacement, NO2 ratio, and NOx tail displacement into the DPF passive regeneration model and output correction coefficients c, d, f, g, and h respectively;

[0086] 207. Obtain the formula for calculating the passive regeneration coefficient: η=a*b*(c+d+f+g+h), where η is the passive regeneration coefficient;

[0087] 208. Determine whether the engine meets the conditions for DPF passive regeneration based on the passive regeneration coefficient calculation formula;

[0088] In this embodiment, after establishing the DPF passive regeneration model, the DPF carbon load and DPF front exhaust temperature are further obtained. The DPF carbon load and DPF front exhaust temperature are primary influencing factors. Then, the DPF carbon load and DPF front exhaust temperature are input into the DPF passive regeneration model, and correction coefficients a and b are output. After obtaining correction coefficients a and b, the engine speed, exhaust flow rate, original NOx emission, NO2 ratio, and NOx tail emission are further input into the DPF passive regeneration model, and correction coefficients c, d, f, g, and h are output. The passive regeneration coefficient is calculated using the passive regeneration coefficient calculation formula: η = a*b*(c+d+f+g+h). When the passive regeneration coefficient η = 0, the engine does not meet the conditions for DPF passive regeneration; when the passive regeneration coefficient η > 0, the engine meets the conditions for DPF passive regeneration. If the engine is determined to have the conditions for passive regeneration of DPF according to the passive regeneration coefficient calculation formula, then proceed to step 209; if the engine is determined not to have the conditions for passive regeneration of DPF according to the passive regeneration coefficient calculation formula, then proceed to step 217.

[0089] 209. Output the correction coefficients for the two stages of urea in the dual urea after-treatment system;

[0090] 210. Control the injection of urea in the dual urea aftertreatment system according to the correction coefficient;

[0091] In this embodiment of the application, the injection of urea in the dual urea after-treatment system is controlled according to the injection correction coefficient of the first-stage urea and the injection correction coefficient of the second-stage urea. The injection correction coefficient of the first-stage urea is used to reduce the injection of the first-stage urea in the dual urea after-treatment system, and the injection correction coefficient of the second-stage urea is used to increase the injection of the second-stage urea in the dual urea after-treatment system.

[0092] 211. Obtain the NOx sensor measurement value q and the engine exhaust energy k and power p;

[0093] 212. Obtain the formula for calculating cumulative NOx emissions: m=∑(u*q*k) / ∑P, where m is the cumulative NOx emissions, u is the exhaust gas coefficient, q is the NOx sensor measurement value, k is the engine exhaust energy, and p is the engine power;

[0094] 213. Determine the target preset value;

[0095] 214. Detect whether the cumulative NOx emission ratio m is less than the target preset value;

[0096] 215. If so, the first-stage urea and the second-stage urea shall be injected in accordance with the correction coefficients of the two-stage urea in the dual-urea aftertreatment system.

[0097] 216. If not, retrieve the original control coefficients of the dual urea aftertreatment system;

[0098] 217. Control the injection of urea in the dual urea aftertreatment system according to the original control coefficient.

[0099] In this embodiment, after controlling the injection of urea in the dual urea aftertreatment system according to the correction coefficient, it is further necessary to ensure that the NOx emitted meets the standards. Specifically, firstly, the NOx sensor measurement value q, engine exhaust energy k, and power p are obtained. Then, the NOx cumulative emission ratio calculation formula is obtained: m=∑(u*q*k) / ∑P, where m is the NOx cumulative emission ratio, u is the exhaust gas coefficient, q is the NOx sensor measurement value, k is the engine exhaust energy, and p is the engine power. The NOx cumulative emission ratio is calculated according to the above calculation formula, and the NOx cumulative emission ratio is calculated based on the preset emission standard value and the NOx cumulative emission ratio. When comparing the cumulative NOx emissions, if the cumulative NOx emissions m are less than the target preset value, the injection of the first and second stage urea is performed according to the correction coefficient of the two stages of urea in the dual urea aftertreatment system. If the cumulative NOx emissions m are greater than the target preset value, it means that the cumulative NOx emissions m cannot be controlled by the correction coefficient. In this case, in order to ensure that the emissions meet the standards, the original control coefficient of the dual urea aftertreatment system will be retrieved, and the injection of urea in the dual urea aftertreatment system will be controlled according to the original control coefficient, thereby reducing NOx emissions and making NOx emissions meet the standards.

[0100] Please see Figure 3 , Figure 3 A schematic diagram of an embodiment of the control system for extending the DPF (Dual Injection Urea) regeneration cycle of the dual-injection urea aftertreatment system provided in the second aspect of this application, including:

[0101] The monitoring unit 301 is used to monitor engine information and engine after-processing status information in real time.

[0102] The judgment unit 302 is used to determine whether the engine has the conditions for passive regeneration of DPF based on the engine information and the engine after-processing status information.

[0103] Output unit 303 is used to output the correction coefficients of the two-stage urea in the dual urea aftertreatment system when the judgment unit determines that the engine has the conditions for passive regeneration of DPF.

[0104] Control unit 304 is used to control the injection of urea in the dual urea after-treatment system according to the correction coefficient, wherein the correction coefficient is used to reduce the injection of the first stage urea in the dual urea after-treatment system and increase the injection of the second stage urea in the dual urea after-treatment system.

[0105] The detection unit 305 is used to detect whether the NOx emissions of the engine meet preset conditions;

[0106] The execution unit 306 is used to execute the injection of the first-stage urea and the second-stage urea according to the correction coefficient of the two-stage urea in the dual urea aftertreatment system when the detection unit determines that the NOx emission of the engine meets the preset conditions.

[0107] Please see Figure 4 , Figure 4 A schematic diagram of an embodiment of the control device for extending the DPF regeneration cycle of a dual-injection urea aftertreatment system provided in the third aspect of this application includes:

[0108] Processor 401, memory 402, input / output unit 403, and bus 404;

[0109] The processor 401 is connected to the memory 402, the input / output unit 403 and the bus 404;

[0110] The memory 402 stores a program, which the processor 401 invokes to perform the method as described in the first aspect and any one of the first aspects.

[0111] A fourth aspect of this application provides a computer-readable storage medium on which a program is stored, which, when executed on a computer, performs the methods described in the first aspect and any one of the first aspects.

[0112] It should be noted that the above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for extending the DPF (Dual Injection Urea) regeneration cycle in a dual-injection urea aftertreatment system, characterized in that, The control method is applied to a dual urea aftertreatment system, and the method includes: Real-time monitoring of engine information and engine after-treatment status; A DPF passive regeneration model is established based on the engine information and the engine's after-processing status information; Obtain the carbon loading of the DPF and the front temperature of the DPF; After inputting the DPF carbon loading and DPF front-end temperature into the DPF passive regeneration model, correction coefficients a and b are output. Obtain engine speed, exhaust flow rate, original NOx emission, NO2 ratio, and NOx tail emission; The engine speed, exhaust flow rate, original NOx emission, NO2 ratio, and NOx tail emission are respectively input into the DPF passive regeneration model, and then the correction coefficients c, d, f, g, and h are output. The formula for calculating the passive regeneration coefficient is: η=a*b*(c+d+f+g+h), where η is the passive regeneration coefficient; Determine whether the engine meets the conditions for DPF passive regeneration based on the passive regeneration coefficient calculation formula; If so, output the correction coefficients for the two stages of urea in the dual urea after-treatment system; The injection of urea in the dual urea aftertreatment system is controlled according to the correction coefficient. The NOx emissions of the engine are checked to see if they meet preset conditions. If so, the first-stage urea and the second-stage urea are injected according to the correction coefficients of the two-stage urea in the dual-urea aftertreatment system.

2. The control method for extending the DPF regeneration cycle of the dual-injection urea aftertreatment system according to claim 1, characterized in that, After determining whether the engine meets the DPF passive regeneration conditions based on the passive regeneration coefficient calculation formula, the method further includes: When the passive regeneration coefficient η = 0, the engine does not meet the DPF passive regeneration condition; When the passive regeneration coefficient η>0, the engine has the DPF passive regeneration condition.

3. The control method for extending the DPF regeneration cycle of the dual-injection urea aftertreatment system according to claim 1, characterized in that, The method further includes outputting correction coefficients for the two stages of urea in the dual-urea after-treatment system. Obtain the passive regeneration coefficient; The injection correction coefficients for the first-stage urea and the second-stage urea are determined based on the passive regeneration coefficient.

4. The control method for extending the DPF regeneration cycle of the dual-injection urea aftertreatment system according to claim 1, characterized in that, The detection of whether the NOx emissions of the engine meet the preset conditions includes: Obtain the NOx sensor measurement value q and the engine exhaust energy k and power p; Obtain the formula for calculating NOx cumulative emissions: m=∑(u*q*k) / ∑P, where m is the NOx cumulative emissions, u is the exhaust gas coefficient, q is the NOx sensor measurement value, k is the engine exhaust energy, and p is the engine power; Determine the target preset value; Detect whether the cumulative NOx emission ratio m is less than the target preset value.

5. The control method for extending the DPF regeneration cycle of the dual-injection urea aftertreatment system according to claim 4, characterized in that, After detecting whether the cumulative NOx emission ratio m is less than the target preset value, the method further includes: If not, then retrieve the original control coefficients of the dual urea aftertreatment system; The injection of urea in the dual urea aftertreatment system is controlled according to the original control coefficient.

6. The control method for extending the DPF regeneration cycle of the dual-injection urea aftertreatment system according to claim 3, characterized in that, The step of controlling the injection of urea in the dual urea aftertreatment system according to the correction coefficient includes: The injection of urea in the dual-urea aftertreatment system is controlled according to the injection correction coefficient of the first-stage urea and the injection correction coefficient of the second-stage urea. The injection correction coefficient of the first-stage urea is used to reduce the injection of the first-stage urea in the dual-urea aftertreatment system, and the injection correction coefficient of the second-stage urea is used to increase the injection of the second-stage urea in the dual-urea aftertreatment system.

7. A control system for extending the DPF (Dual Injection Urea) regeneration cycle in a dual-injection urea aftertreatment system, characterized in that, include: The monitoring unit is used to monitor engine information and engine after-processing status information in real time. The judgment unit is used to establish a DPF passive regeneration model based on the engine information and the engine aftertreatment status information; and to obtain the DPF carbon load and DPF front exhaust temperature. The DPF carbon load and DPF front exhaust temperature are input into the DPF passive regeneration model, and correction coefficients a and b are output. Engine speed, exhaust flow rate, original NOx emission, NO2 ratio, and NOx tail emission are obtained. The engine speed, exhaust flow rate, original NOx emission, NO2 ratio, and NOx tail emission are input into the DPF passive regeneration model, and correction coefficients c, d, f, g, and h are output. The passive regeneration coefficient calculation formula is obtained: η = a * b * (c + d + f + g + h), where η is the passive regeneration coefficient. Based on the passive regeneration coefficient calculation formula, it is determined whether the engine meets the conditions for DPF passive regeneration. The output unit is used to output the correction coefficients of the two stages of urea in the dual urea aftertreatment system when the judgment unit determines that the engine has the conditions for passive regeneration of DPF. A control unit is configured to control the injection of urea in the dual urea aftertreatment system according to the correction coefficient, wherein the correction coefficient is used to reduce the injection of the first stage urea in the dual urea aftertreatment system and increase the injection of the second stage urea in the dual urea aftertreatment system. The detection unit is used to detect whether the NOx emissions of the engine meet preset conditions; The execution unit is used to inject the first-stage urea and the second-stage urea according to the correction coefficient of the two-stage urea in the dual urea aftertreatment system when the detection unit determines that the NOx emission of the engine meets the preset conditions.

8. A control device for extending the DPF (Dual Injection Urea) regeneration cycle in a dual-injection urea aftertreatment system, characterized in that, The device includes: Processor, memory, input / output units, and bus; The processor is connected to the memory, the input / output unit, and the bus; The memory stores a program, which the processor invokes to perform the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a program stored thereon, the program performing the method as described in any one of claims 1 to 6 when executed on a computer.

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