Urea injection control method, device, medium and equipment for post-treatment device

Abstract

The present application discloses a urea injection control method, device, medium and equipment for a post-treatment device, which experimentally measures the ammonia storage limit value of a selective catalytic reducer under different operating conditions and the ammonia conversion rate of an ammonia slip catalyst; collects a first temperature and a first nitrogen oxide content at an inlet of the selective catalytic reducer and a second temperature at an outlet of the ammonia slip catalyst; queries the current ammonia storage limit value of the selective catalytic reducer; calculates the current ammonia storage amount of the selective catalytic reducer; if the current ammonia storage amount is greater than the current ammonia storage limit value, queries the current ammonia conversion rate of the ammonia slip catalyst; based on the current ammonia conversion rate, corrects the current urea injection amount, decouples the selective catalytic reducer and the ammonia slip catalyst, and thus can control the urea injection amount based on the respective characteristics of the selective catalytic reducer and the ammonia slip catalyst to improve control accuracy and reduce ammonia leakage.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle post-processing, and in particular to a urea injection control method, device, medium and equipment for a post-processing device. Background Art

[0002] Vehicles generally use SCR (Selective Catalytic Reduction, SCR) and ASC (Ammonia Slip Catalyst, ASC) post-processors to reduce NOx. Among them, urea injection control is the key. On the one hand, urea must reach a certain injection volume to ensure high-efficiency NOx conversion and make emissions meet the requirements of National VI emission regulations. On the other hand, from the perspective of economy and urea crystallization, the urea injection volume cannot be too much.

[0003] In the post-treatment electronic control system, the actual ammonia storage capacity of SCR and the ammonia leakage processing capacity of ASC are important parameters that affect urea injection. During the post-treatment calibration process, SCR exists in the form of SCR+ASC. When doing the SCR ammonia storage test, what is measured is the ultimate conversion capacity of SCR+ASC, not the individual characteristics of SCR and ASC. In this way, during the urea injection control process, the urea injection will stop too late, causing ammonia leakage. Summary of the invention

[0004] In order to solve the above technical problems, the present application is proposed. The embodiments of the present application provide a urea injection control method, device, medium and equipment for a post-treatment device.

[0005] According to one aspect of the present application, a urea injection control method for a post-treatment device is provided, which is applied to the post-treatment device, wherein the post-treatment device includes a selective catalytic reducer and an ammonia slip catalyst, wherein urea is injected into the selective catalytic reducer to consume nitrogen oxides in vehicle exhaust gas, and the ammonia slip catalyst is arranged at an outlet position of the selective catalytic reducer to consume ammonia discharged by the selective catalytic reducer; the urea injection control method for the post-treatment device comprises: experimentally measuring an ammonia storage limit value of the selective catalytic reducer under different operating condition information and an ammonia conversion rate of the ammonia slip catalyst; wherein the operating condition information includes temperature and exhaust flow rate; collecting a first temperature and a first nitrogen oxide content at an inlet of the selective catalytic reduction device, and a second temperature at an outlet of the ammonia slip catalyst; querying a current ammonia storage limit value of the selective catalytic reduction device based on the current exhaust flow rate and the first temperature; calculating a current ammonia storage amount of the selective catalytic reduction device based on the first nitrogen oxide content and a current urea injection amount; if the current ammonia storage amount is greater than the current ammonia storage limit value, querying a current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow rate and the second temperature; and correcting the current urea injection amount based on the current ammonia conversion rate.

[0006] In one embodiment, the correcting the current urea injection amount based on the current ammonia conversion rate includes: determining a correction ratio according to a range of the current ammonia conversion rate; wherein each ammonia conversion rate range corresponds to a correction ratio; and determining a corrected urea injection amount according to the correction ratio.

[0007] In one embodiment, determining the corrected urea injection amount according to the correction ratio includes: calculating the corrected urea injection amount according to the correction ratio; wherein a ratio between the corrected urea injection amount and the current urea injection amount is equal to the correction ratio.

[0008] In one embodiment, the calculating the current ammonia storage amount of the selective catalytic reducer based on the first nitrogen oxide content and the current urea injection amount includes: calculating, based on the current urea injection amount, an ammonia generation amount obtained by converting the current urea injection amount; calculating, based on the first nitrogen oxide content, an ammonia consumption amount required by the selective catalytic reducer to consume the first nitrogen oxide content; and calculating the current ammonia storage amount of the selective catalytic reducer based on the ammonia generation amount and the ammonia consumption.

[0009] In one embodiment, querying the current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow and the second temperature includes: calculating the current ammonia leakage into the ammonia slip catalyst based on the ammonia generation, the ammonia consumption and the current ammonia storage limit; querying the current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow, the second temperature and the current ammonia leakage.

[0010] In one embodiment, the urea injection control method of the post-treatment device further includes: collecting a second nitrogen oxide content at the outlet of the ammonia slip catalyst; calculating a current ammonia storage amount of the selective catalytic reducer based on the first nitrogen oxide content and the current urea injection amount includes: calculating the current ammonia storage amount of the selective catalytic reducer based on the first nitrogen oxide content, the second nitrogen oxide content and the current urea injection amount.

[0011] In one embodiment, the urea injection control method of the post-treatment device further includes: if the second nitrogen oxide content is greater than the first nitrogen oxide content, correcting the current urea injection amount.

[0012] According to another aspect of the present application, a urea injection control device for a post-treatment device is provided, which is arranged in the post-treatment device, wherein the post-treatment device includes a selective catalytic reducer and an ammonia slip catalyst, wherein urea is injected into the selective catalytic reducer to consume nitrogen oxides in vehicle exhaust gas, and the ammonia slip catalyst is arranged at the outlet position of the selective catalytic reducer, and is used to consume ammonia discharged by the selective catalytic reducer; the urea injection control device for the post-treatment device includes: an experimental data measurement module, which is used to measure the ammonia storage limit value of the selective catalytic reducer under different operating condition information and the ammonia conversion rate of the ammonia slip catalyst through experiments; wherein the operating condition information includes temperature and exhaust flow; an operating condition data acquisition module, which is used to acquire a first temperature and a first nitrogen oxide content at the inlet of the selective catalytic reducer, and a second temperature at the outlet of the ammonia slip catalyst; a storage limit calculation module, used to query the current ammonia storage limit value of the selective catalytic reducer based on the current exhaust flow rate and the first temperature; a storage quantity calculation module, used to calculate the current ammonia storage amount of the selective catalytic reducer based on the first nitrogen oxide content and the current urea injection amount; an ammonia conversion rate query module, used to query the current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow rate and the second temperature if the current ammonia storage amount is greater than the current ammonia storage limit value; a urea injection correction module, used to correct the current urea injection amount based on the current ammonia conversion rate.

[0013] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and the computer program is used to execute any of the above methods.

[0014] According to another aspect of the present application, an electronic device is provided, comprising: a processor; a memory for storing instructions executable by the processor; and the processor is used to execute any of the above-described methods.

[0015] The present application provides a urea injection control method, device, medium and equipment for a post-treatment device, which experimentally measures the ammonia storage limit value of a selective catalytic reducer and the ammonia conversion rate of an ammonia slip catalyst under different operating conditions; wherein the operating condition information includes temperature and exhaust flow; collects a first temperature and a first nitrogen oxide content at the inlet of the selective catalytic reducer, and a second temperature at the outlet of the ammonia slip catalyst; based on the current exhaust flow and the first temperature, queries the current ammonia storage limit value of the selective catalytic reducer; based on the first nitrogen oxide content and the current urea injection amount, calculates the current ammonia storage amount of the selective catalytic reducer; if the current ammonia storage amount is greater than the current ammonia storage limit value, then based on the current exhaust flow and the second temperature, query the current ammonia conversion rate of the ammonia slip catalyst; based on the current ammonia conversion rate, correct the current urea injection amount; that is, obtain the ammonia storage limit value of the selective catalytic reducer and the ammonia conversion rate of the ammonia slip catalyst under different operating conditions through experimental measurement, and in the actual processing process, query the ammonia storage limit value of the selective catalytic reducer by collecting the operating condition information, if the current ammonia storage amount is greater than the ammonia storage limit value, query the ammonia conversion rate of the ammonia slip catalyst, and correct the urea injection amount based on the ammonia conversion rate, decouple the selective catalytic reducer and the ammonia slip catalyst, so that the urea injection amount can be controlled based on the respective characteristics of the selective catalytic reducer and the ammonia slip catalyst, so as to improve the control accuracy and reduce ammonia leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0017] Figure 1 It is a structural diagram of a post-processing device provided by an exemplary embodiment of the present application.

[0018] Figure 2 It is a flow chart of a urea injection control method for a post-treatment device provided by an exemplary embodiment of the present application.

[0019] Figure 3It is a logical schematic diagram of the change of ammonia content in a post-treatment device provided by an exemplary embodiment of the present application.

[0020] Figure 4 It is a schematic structural diagram of a urea injection control device of a post-treatment device provided by an exemplary embodiment of the present application.

[0021] Figure 5 It is a structural diagram of an electronic device provided by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0022] Below, the exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the exemplary embodiments described here.

[0023] Figure 1 is a structural diagram of a post-processing device provided by an exemplary embodiment of the present application. Figure 1 As shown, the post-treatment device includes a selective catalytic reducer (SCR) and an ammonia slip catalyst (ASC), urea is injected into the selective catalytic reducer to consume nitrogen oxides (NOx) in the vehicle exhaust, and the ammonia slip catalyst is arranged at the outlet position of the selective catalytic reducer to consume ammonia (NH3) discharged from the selective catalytic reducer; preferably, the present application arranges a first temperature sensor and a first nitrogen oxide sensor at the inlet of the SCR for collecting a first temperature and a first nitrogen oxide content at the inlet of the SCR, and arranges a second temperature sensor and a second nitrogen oxide sensor at the outlet of the ASC for collecting a second temperature and a second nitrogen oxide content at the outlet of the ASC.

[0024] Figure 2 1 is a flow chart of a urea injection control method for a post-treatment device provided by an exemplary embodiment of the present application. The urea injection control method for a post-treatment device is applied to the above-mentioned post-treatment device, such as Figure 2 As shown, the urea injection control method of the post-treatment device includes the following steps:

[0025] Step 210: Measure the ammonia storage limit value of the selective catalytic reduction device under different operating conditions and the ammonia conversion rate of the ammonia slip catalyst through experiments.

[0026] Among them, the operating condition information includes temperature and exhaust flow. The present application obtains the ammonia storage limit value of SCR and the ammonia conversion rate of ASC under different conditions such as temperature, exhaust flow rate (or air velocity) through experimental measurements such as small sample benches. Specifically, the present application can operate the post-treatment device at a certain experimental temperature (for example, 350°C) and air velocity (exhaust flow rate per unit time per unit area) at a specific value of ammonia nitrogen ratio (for example, 1.2) until NH3 leakage is detected at the outlet of ASC, and then it is considered that the SCR ammonia storage has reached the limit value; the present application can conduct physical and chemical experiments at different experimental temperatures, air velocities and ammonia concentrations to obtain the ammonia conversion rate of ASC, that is, to obtain the corresponding relationship between the ammonia conversion rate of ASC and temperature, exhaust flow rate, and ammonia concentration, wherein the ammonia conversion rate of ASC includes the ammonia conversion rate limit value at different ammonia concentrations.

[0027] Step 220: Collect a first temperature and a first nitrogen oxide content at an inlet of the selective catalytic reduction device, and a second temperature at an outlet of the ammonia slip catalyst.

[0028] After experimentally measuring the ammonia storage limit value of the SCR and the ammonia conversion rate of the ASC, the present application utilizes a first temperature sensor disposed at the inlet of the SCR, a first nitrogen oxide sensor, and a second temperature sensor disposed at the outlet of the ASC to respectively collect a first temperature and a first nitrogen oxide content at the inlet of the SCR, and a second temperature at the outlet of the ASC, thereby obtaining the operating condition information of the SCR and the ASC.

[0029] Step 230 : Based on the current exhaust gas flow rate and the first temperature, query the current ammonia storage limit value of the selective catalytic reduction device.

[0030] After obtaining the operating condition information of the SCR, the present application queries the current ammonia storage limit value of the SCR based on the operating condition information of the SCR to determine the limit value of ammonia that the SCR can store under the current operating condition.

[0031] Step 240 : Calculate the current ammonia storage amount of the selective catalytic reduction device based on the first nitrogen oxide content and the current urea injection amount.

[0032] When there is no leakage in the SCR, the present application calculates the current ammonia storage amount of the SCR in combination with the current urea injection amount after collecting the first nitrogen oxide content at the SCR inlet.

[0033] Step 250: If the current ammonia storage amount is greater than the current ammonia storage limit value, query the current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow rate and the second temperature.

[0034] If the calculated current ammonia storage amount of the SCR is greater than the current ammonia storage limit value, it means that the ammonia content stored in the SCR is full, that is, there is ammonia leakage in the SCR. At this time, the current ammonia conversion rate of the ASC is queried according to the operating condition information of the ASC to determine the ammonia conversion status of the ASC.

[0035] Step 260: Based on the current ammonia conversion rate, correct the current urea injection amount.

[0036] According to the current ammonia conversion rate, the current urea injection amount is corrected. Specifically, if the current ammonia conversion rate is low, it means that the ammonia leakage of the SCR is not much at this time, and the current urea injection amount can be left unchanged. If the current ammonia conversion rate is high, it means that the ammonia leakage of the SCR is large at this time, and the current urea injection amount can be reduced to reduce the ammonia leakage of the SCR.

[0037] The present application provides a urea injection control method for a post-treatment device, which measures the ammonia storage limit value of a selective catalytic reducer and the ammonia conversion rate of an ammonia slip catalyst under different operating conditions through experiments; wherein the operating condition information includes temperature and exhaust flow; collects a first temperature and a first nitrogen oxide content at the inlet of the selective catalytic reducer, and a second temperature at the outlet of the ammonia slip catalyst; based on the current exhaust flow and the first temperature, queries the current ammonia storage limit value of the selective catalytic reducer; based on the first nitrogen oxide content and the current urea injection amount, calculates the current ammonia storage amount of the selective catalytic reducer; if the current ammonia storage amount is greater than the current ammonia storage limit value, then calculates the current ammonia storage limit value based on the current exhaust flow and the second temperature. , query the current ammonia conversion rate of the ammonia slip catalyst; based on the current ammonia conversion rate, correct the current urea injection amount; that is, obtain the ammonia storage limit value of the selective catalytic reducer under different operating conditions and the ammonia conversion rate of the ammonia slip catalyst through experimental measurement. In the actual processing process, the operating condition information is collected to query the ammonia storage limit value of the selective catalytic reducer. If the current ammonia storage amount is greater than the ammonia storage limit value, query the ammonia conversion rate of the ammonia slip catalyst, and correct the urea injection amount based on the ammonia conversion rate. The selective catalytic reducer and the ammonia slip catalyst are decoupled, so that the urea injection amount can be controlled based on the respective characteristics of the selective catalytic reducer and the ammonia slip catalyst to improve the control accuracy and reduce ammonia leakage.

[0038] In one embodiment, the specific implementation method of the above step 260 may be: determining a correction ratio according to the interval range of the current ammonia conversion rate; wherein each ammonia conversion rate interval range corresponds to a correction ratio; and determining a corrected urea injection amount according to the correction ratio.

[0039] After obtaining the current ammonia conversion rate of the ASC through query, the present application determines the correction ratio according to the interval range of the current ammonia conversion rate; wherein each ammonia conversion rate interval range corresponds to a correction ratio; for example, the present application can divide multiple ammonia conversion rate intervals such as (90%, 100%], (80%, 90%], (70%, 80%], (0, 70%], etc., and set a correction ratio for each ammonia conversion rate interval. For example, when the current ammonia conversion rate is within the range of (80%, 90%], the correction ratio is determined to be 0.9, and when the current ammonia conversion rate is within the range of (70%, 80%], the correction ratio is determined to be 0.8. And the corrected urea injection amount is determined according to the correction ratio to avoid further increase in NH3 concentration, which causes the conversion capacity of the ASC to fail to meet the conversion requirement.

[0040] In one embodiment, the specific implementation of the above step 260 may be: calculating the corrected urea injection amount according to the correction ratio; wherein the ratio between the corrected urea injection amount and the current urea injection amount is equal to the correction ratio, that is, the corrected urea injection amount = the current urea injection amount × the correction ratio.

[0041] After the correction ratio is calculated, the present application corrects the current urea injection amount according to the correction ratio.

[0042] In one embodiment, the specific implementation method of the above step 240 may be: based on the current urea injection amount, calculating the ammonia generation amount obtained by converting the current urea injection amount; based on the first nitrogen oxide content, calculating the ammonia consumption required for the selective catalytic reduction device to consume the first nitrogen oxide content; based on the ammonia generation amount and the ammonia consumption amount, calculating the current ammonia storage amount of the selective catalytic reduction device.

[0043] The present application collects the current urea injection amount according to the sensor, and calculates the ammonia generated by urea conversion according to the current urea injection amount, that is, the ammonia amount entering the SCR, and calculates the ammonia consumption required by the SCR to consume the NOx of the first nitrogen oxide content according to the first nitrogen oxide content collected at the SCR inlet, and finally calculates the current ammonia storage amount of the SCR according to the ammonia generation amount and the ammonia consumption. The specific calculation formula is: current ammonia storage amount of the SCR = ammonia content converted from the current urea injection amount - ammonia content required to consume the first nitrogen oxide content.

[0044] It should be understood that when the SCR operates under the same operating conditions for a period of time, the corresponding temperature and exhaust flow rate are basically the same. At this time, the SCR will reach a steady state, that is, the ammonia storage amount in the SCR is the ammonia storage limit value of the SCR under the current operating conditions.

[0045] In one embodiment, the specific implementation method of the above step 250 can be: based on the ammonia generation, ammonia consumption and the current ammonia storage limit value, calculate the current ammonia leakage entering the ammonia slip catalyst; based on the current exhaust flow, the second temperature and the current ammonia leakage, query the current ammonia conversion rate of the ammonia slip catalyst.

[0046] After the SCR reaches a steady state, the present application calculates the current ammonia leakage entering the ASC based on the calculated ammonia generation, ammonia consumption and current ammonia storage limit of the SCR, and inquires the current ammonia conversion rate of the ASC based on the current operating conditions (current exhaust flow, second temperature) and ammonia concentration (calculated based on the current ammonia leakage). The present application decouples the SCR and the ASC and calculates the characteristic parameters of the SCR and the ASC respectively, so as to control the urea injection amount to maintain the current ammonia storage amount of the SCR near the current ammonia storage limit to meet the NOx consumption demand, and at the same time, avoids the excessive urea injection amount, which causes the ASC to convert in an untimely manner and causes ammonia to be discharged into the air.

[0047] In one embodiment, the urea injection control method of the above-mentioned post-treatment device may further include: collecting a second nitrogen oxide content at the outlet of the ammonia slip catalyst; correspondingly, the specific implementation method of the above-mentioned step 240 may be: calculating the current ammonia storage amount of the selective catalytic reducer based on the first nitrogen oxide content, the second nitrogen oxide content and the current urea injection amount.

[0048] like Figure 3 As shown, the NH3 at the SCR inlet is x 、NH3 at the SCR outlet is y 、NH3 at the ASC outlet is z 、The NH3 content consumed by the reaction between SCR inlet and NOx is t 、The current ammonia storage capacity of SCR is m The ammonia conversion rate of ASC is k .

[0049] For SCR: y=xmt;

[0050] After the ammonia nitrogen ratio of the SCR is determined, the NH3 at the SCR inlet gradually changes with the set ammonia nitrogen ratio adjustment, and the NH3 at the SCR outlet also gradually changes.

[0051] For ASC: z=y ×(1- k );

[0052] The NH3 at the ASC outlet will change with the change of the NH3 at the ASC inlet (i.e., the NH3 at the SCR outlet).

[0053] Based on the above formula, we can get: z= ( xmt )×(1- k );

[0054] Among them, the NH3 at the SCR inlet and the NH3 at the ASC outlet can be collected by sensors, the NH3 content consumed by the SCR inlet and NOx reaction can be calculated based on the NOx content at the SCR inlet, and the ammonia conversion rate of the ASC can be obtained by looking up the table based on the operating conditions. According to this formula, the current ammonia storage capacity of the SCR can be calculated.

[0055] In one embodiment, the urea injection control method of the post-treatment device may further include: if the second nitrogen oxide content is greater than the first nitrogen oxide content, correcting the current urea injection amount.

[0056] Since NH3 contains nitrogen, if there is a large amount of ammonia leakage in the SCR, it will also cause the second nitrogen oxide content collected by the second nitrogen oxide sensor set at the outlet of the ASC to be high. Therefore, the present application determines that there is a large amount of ammonia leakage in the SCR when the second nitrogen oxide content is greater than the first nitrogen oxide content, and the current urea injection amount can be directly corrected at this time. Optionally, the present application can determine the correction ratio between the corrected urea injection amount and the current urea injection amount according to the difference between the second nitrogen oxide content and the first nitrogen oxide content, wherein the difference between the second nitrogen oxide content and the first nitrogen oxide content is inversely correlated with the correction ratio.

[0057] Optionally, the present application may also select a controller that supports an offline storage function to implement offline storage of ammonia storage capacity to ensure that data is not lost after power failure.

[0058] Figure 4 is a schematic diagram of the structure of a urea injection control device of a post-treatment device provided by an exemplary embodiment of the present application. The urea injection control device of the post-treatment device is arranged in the post-treatment device, such as Figure 4As shown, the urea injection control device 40 of the post-treatment device includes: an experimental data measurement module 41, which is used to measure the ammonia storage limit value of the selective catalytic reducer and the ammonia conversion rate of the ammonia slip catalyst under different operating conditions through experiments; wherein the operating condition information includes temperature and exhaust flow; an operating condition data acquisition module 42, which is used to collect the first temperature and the first nitrogen oxide content at the inlet of the selective catalytic reducer, and the second temperature at the outlet of the ammonia slip catalyst; a storage limit calculation module 43, which is used to query the current ammonia storage limit value of the selective catalytic reducer based on the current exhaust flow and the first temperature; a storage quantity calculation module 44, which is used to calculate the current ammonia storage amount of the selective catalytic reducer based on the first nitrogen oxide content and the current urea injection amount; an ammonia conversion rate query module 45, which is used to query the current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow and the second temperature if the current ammonia storage amount is greater than the current ammonia storage limit value; a urea injection correction module 46, which is used to correct the current urea injection amount based on the current ammonia conversion rate.

[0059] The present application provides a urea injection control device for a post-treatment device, wherein an experimental data measurement module 41 measures the ammonia storage limit value of a selective catalytic reducer and the ammonia conversion rate of an ammonia slip catalyst under different operating conditions through experiments; wherein the operating condition information includes temperature and exhaust flow; an operating condition data acquisition module 42 acquires a first temperature and a first nitrogen oxide content at an inlet of the selective catalytic reducer, and a second temperature at an outlet of the ammonia slip catalyst; a storage limit calculation module 43 queries a current ammonia storage limit value of the selective catalytic reducer based on the current exhaust flow and the first temperature; a storage quantity calculation module 44 calculates a current ammonia storage amount of the selective catalytic reducer based on the first nitrogen oxide content and the current urea injection amount; if the current ammonia storage amount is greater than the current ammonia storage limit value, the ammonia conversion rate The query module 45 queries the current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow rate and the second temperature; the urea injection correction module 46 corrects the current urea injection amount based on the current ammonia conversion rate; that is, the ammonia storage limit value of the selective catalytic reducer under different operating conditions and the ammonia conversion rate of the ammonia slip catalyst are obtained through experimental measurement. In the actual processing process, the operating condition information is collected to query the ammonia storage limit value of the selective catalytic reducer. If the current ammonia storage amount is greater than the ammonia storage limit value, the ammonia conversion rate of the ammonia slip catalyst is queried, and the urea injection amount is corrected based on the ammonia conversion rate, so as to decouple the selective catalytic reducer and the ammonia slip catalyst, so that the urea injection amount can be controlled based on the respective characteristics of the selective catalytic reducer and the ammonia slip catalyst to improve the control accuracy and reduce ammonia leakage.

[0060] In one embodiment, the urea injection correction module 46 may be further configured to: determine a correction ratio according to a current ammonia conversion rate interval; wherein each ammonia conversion rate interval corresponds to a correction ratio; and determine a corrected urea injection amount according to the correction ratio.

[0061] In one embodiment, the urea injection correction module 46 may be further configured to: calculate a corrected urea injection amount according to a correction ratio; wherein a ratio between the corrected urea injection amount and the current urea injection amount is equal to the correction ratio.

[0062] In one embodiment, the storage quantity calculation module 44 may be further configured to: calculate the ammonia generation amount obtained by converting the current urea injection amount based on the current urea injection amount; calculate the ammonia consumption amount required for the selective catalytic reducer to consume the first nitrogen oxide content based on the first nitrogen oxide content; and calculate the current ammonia storage amount of the selective catalytic reducer based on the ammonia generation amount and the ammonia consumption amount.

[0063] In one embodiment, the ammonia conversion rate query module 45 may be further configured as follows: based on the ammonia generation amount, the ammonia consumption amount and the current ammonia storage limit value, calculate the current ammonia leakage amount entering the ammonia slip catalyst; based on the current exhaust flow rate, the second temperature and the current ammonia leakage amount, query the current ammonia conversion rate of the ammonia slip catalyst.

[0064] In one embodiment, the urea injection control device 40 of the above-mentioned post-treatment device can be further configured to: collect the second nitrogen oxide content at the outlet of the ammonia slip catalyst; correspondingly, the above-mentioned storage quantity calculation module 44 can be further configured to: calculate the current ammonia storage amount of the selective catalytic reducer based on the first nitrogen oxide content, the second nitrogen oxide content and the current urea injection amount.

[0065] In one embodiment, the urea injection control device 40 of the post-treatment device may be further configured to correct the current urea injection amount if the second nitrogen oxide content is greater than the first nitrogen oxide content.

[0066] Below, reference Figure 5 The electronic device according to the embodiment of the present application is described. The electronic device may be any one or both of the first device and the second device, or a stand-alone device independent of them, and the stand-alone device may communicate with the first device and the second device to receive the collected input signal from them.

[0067] Figure 5 A block diagram of an electronic device according to an embodiment of the present application is illustrated.

[0068] like Figure 5 As shown, the electronic device 10 includes one or more processors 11 and a memory 12 .

[0069] The processor 11 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 10 to perform desired functions.

[0070] The memory 12 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 11 may run the program instructions to implement the methods of the various embodiments of the present application described above and / or other desired functions. Various contents such as input signals, signal components, noise components, etc. may also be stored in the computer-readable storage medium.

[0071] In one example, the electronic device 10 may further include: an input device 13 and an output device 14 , and these components are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0072] When the electronic device is a stand-alone device, the input device 13 may be a communication network connector, which is used to receive the collected input signals from the first device and the second device.

[0073] In addition, the input device 13 may also include, for example, a keyboard, a mouse, and the like.

[0074] The output device 14 can output various information to the outside, including the determined distance information, direction information, etc. The output device 14 can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto, and the like.

[0075] Of course, to simplify, Figure 5 Only some of the components related to the present application in the electronic device 10 are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, according to specific application situations, the electronic device 10 may also include any other appropriate components.

[0076] In addition to the above-mentioned methods and devices, an embodiment of the present application may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the method according to various embodiments of the present application described in the above-mentioned "Exemplary Method" section of this specification.

[0077] The computer program product may be written in any combination of one or more programming languages ​​to write program codes for performing the operations of the embodiments of the present application, including object-oriented programming languages, such as Java, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0078] In addition, an embodiment of the present application may also be a computer-readable storage medium on which computer program instructions are stored. When the computer program instructions are executed by a processor, the processor executes the steps of the method according to various embodiments of the present application described in the above "Exemplary Method" section of this specification.

[0079] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, 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 disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0080] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0081] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0082] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0083] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0084] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A urea injection control method for a post-treatment device, characterized in that: Applicable to a post-treatment device, the post-treatment device includes a selective catalytic reducer and an ammonia slip catalyst, urea is injected into the selective catalytic reducer to consume nitrogen oxides in vehicle exhaust gas, and the ammonia slip catalyst is arranged at the outlet position of the selective catalytic reducer to consume ammonia discharged from the selective catalytic reducer; The urea injection control method of the post-treatment device includes: Measuring the ammonia storage limit value of the selective catalytic reduction device and the ammonia conversion rate of the ammonia slip catalyst under different operating condition information by experiments; wherein the operating condition information includes temperature and exhaust gas flow rate; collecting a first temperature and a first nitrogen oxide content at an inlet of the selective catalytic reduction device, and a second temperature at an outlet of the ammonia slip catalyst; querying a current ammonia storage limit value of the selective catalytic reduction device based on a current exhaust gas flow rate and the first temperature; calculating a current ammonia storage amount of the selective catalytic reduction device based on the first nitrogen oxide content and a current urea injection amount; If the current ammonia storage amount is greater than the current ammonia storage limit value, querying a current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow rate and the second temperature; The current urea injection amount is corrected based on the current ammonia conversion rate.

2. The urea injection control method for a post-treatment device according to claim 1, characterized in that: The correcting the current urea injection amount based on the current ammonia conversion rate includes: Determine the correction ratio according to the interval range of the current ammonia conversion rate; wherein each ammonia conversion rate interval range corresponds to a correction ratio; The corrected urea injection amount is determined according to the correction ratio.

3. The urea injection control method of the post-treatment device according to claim 2, characterized in that: Determining the corrected urea injection amount according to the correction ratio includes: The corrected urea injection amount is calculated according to the correction ratio; wherein the ratio between the corrected urea injection amount and the current urea injection amount is equal to the correction ratio.

4. The urea injection control method for a post-treatment device according to claim 1, characterized in that: The calculating the current ammonia storage amount of the selective catalytic reduction device based on the first nitrogen oxide content and the current urea injection amount comprises: Based on the current urea injection amount, calculating an ammonia generation amount obtained by converting the current urea injection amount; calculating, based on the first nitrogen oxide content, an ammonia consumption required by the selective catalytic reduction device to consume the first nitrogen oxide content; A current ammonia storage amount of the selective catalytic reduction device is calculated based on the ammonia generation amount and the ammonia consumption amount.

5. The urea injection control method for a post-treatment device according to claim 4, characterized in that: The querying the current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow and the second temperature comprises: Calculating a current ammonia leakage amount entering the ammonia slip catalyst based on the ammonia generation amount, the ammonia consumption amount and the current ammonia storage limit value; Based on the current exhaust gas flow rate, the second temperature and the current ammonia slip amount, a current ammonia conversion rate of the ammonia slip catalyst is queried.

6. The urea injection control method of the post-treatment device according to claim 1, characterized in that: The urea injection control method of the post-treatment device also includes: collecting a second nitrogen oxide content at an outlet of the ammonia slip catalyst; Calculating the current ammonia storage amount of the selective catalytic reduction device based on the first nitrogen oxide content and the current urea injection amount includes: A current ammonia storage amount of the selective catalytic reduction device is calculated based on the first nitrogen oxide level, the second nitrogen oxide level, and the current urea injection amount.

7. The urea injection control method for a post-treatment device according to claim 6, characterized in that: The urea injection control method of the post-treatment device also includes: If the second nitrogen oxide content is greater than the first nitrogen oxide content, the current urea injection amount is corrected.

8. A urea injection control device for a post-treatment device, characterized in that: The post-treatment device includes a selective catalytic reducer and an ammonia slip catalyst. Urea is injected into the selective catalytic reducer to consume nitrogen oxides in vehicle exhaust gas. The ammonia slip catalyst is arranged at the outlet of the selective catalytic reducer to consume ammonia discharged from the selective catalytic reducer. The urea injection control device of the post-treatment device includes: An experimental data measurement module, used to measure the ammonia storage limit value of the selective catalytic reduction device and the ammonia conversion rate of the ammonia slip catalyst under different operating conditions through experiments; wherein the operating condition information includes temperature and exhaust gas flow; An operating condition data acquisition module, used for acquiring a first temperature and a first nitrogen oxide content at an inlet of the selective catalytic reduction device, and a second temperature at an outlet of the ammonia slip catalyst; a storage limit calculation module, configured to query a current ammonia storage limit value of the selective catalytic reduction device based on a current exhaust gas flow rate and the first temperature; a storage quantity calculation module, configured to calculate a current ammonia storage quantity of the selective catalytic reduction device based on the first nitrogen oxide content and a current urea injection quantity; an ammonia conversion rate query module, configured to query a current ammonia conversion rate of the ammonia slip catalyst based on the current exhaust flow rate and the second temperature if the current ammonia storage amount is greater than the current ammonia storage limit value; The urea injection correction module is configured to correct the current urea injection amount based on the current ammonia conversion rate.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is used to execute the method described in any one of claims 1 to 7.

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