Urea injection amount calculation control method, device, electronic device and storage medium

Abstract

The embodiment of the present application provides a method for calculating and controlling the amount of urea injection, including: obtaining the engine operating conditions and the actual ammonia storage value; determining the minimum ammonia storage setting value and the maximum ammonia storage setting value according to the engine operating conditions; determining the urea injection state according to the minimum ammonia storage setting value and the maximum ammonia storage setting value, if the actual ammonia storage value reaches the maximum ammonia storage setting value, reducing the urea injection amount until the actual ammonia storage value drops to the minimum ammonia storage setting value, increasing the urea injection amount, and increasing the ammonia storage value, so that the ammonia storage value fluctuates within the range of the minimum ammonia storage setting value to the maximum ammonia storage setting value. This method allows the engine ammonia storage to fluctuate within the range of the minimum ammonia storage setting value to the maximum ammonia storage setting value, effectively improving the engine's ammonia storage capacity and greatly reducing the possibility of ammonia leakage.

Description

Technical Field

[0001] The present application relates to the field of engine technology, and in particular to a method for calculating and controlling a urea injection amount. Background Art

[0002] With the rapid economic development and the acceleration of urbanization, people are using more and more cars. The use of cars has greatly improved the convenience of our lives. However, while cars provide people with fast travel conditions, they also bring a series of disadvantages, especially environmental problems. Among them, automobile exhaust emissions are a very important factor, which not only seriously affects people's health, but also brings a series of irreversible damage to the earth's environment. Therefore, it is very important to control the emission of NOx from engines.

[0003] At present, most of the SCR systems in the post-treatment system are used to control the emission of NOx gas. The principle is to inject urea into the exhaust gas discharged from the engine, and use the urea to decompose and produce ammonia. Under the action of the catalyst, ammonia reacts with NOx, thereby reducing the emission of NOx. Among them, the SCR control strategy is mainly divided into two types: open-loop control strategy and closed-loop control strategy. However, in the face of strict emission regulations, the current open-loop SCR control strategy can no longer meet the requirements. At the same time, in the existing technology, although the traditional SCR closed-loop control strategy can form a closed-loop control system based on the downstream NOx sensor and realize a certain degree of precision control of the urea injection amount, in most closed-loop control strategies, the storage and control of ammonia decomposed by urea are still not perfect, and the ammonia storage value can only fluctuate within a very small range, resulting in poor storage and control of ammonia storage, which may lead to excessive ammonia emissions and still cause environmental problems.

[0004] Therefore, how to further achieve precise control of the SCR and precise control of ammonia emissions in the SCR so as to meet the NOx emission requirements and ensure that the ammonia leakage does not exceed the standard has become an urgent problem to be solved. Summary of the invention

[0005] The present application provides a method for calculating and controlling the amount of urea injection, in order to solve the problem that the SCR closed-loop control strategy in the prior art is still not perfect in terms of storage and control of ammonia decomposed by urea, and the ammonia storage value can only fluctuate within a very small range, resulting in poor ammonia storage capacity and control capability, which may lead to excessive ammonia emissions.

[0006] According to one aspect of the present application, a urea injection amount calculation control method is provided, comprising: obtaining an engine operating condition and an actual ammonia storage value; determining a minimum ammonia storage setting value and a maximum ammonia storage setting value according to the engine operating condition; determining a urea injection state according to the minimum ammonia storage setting value and the maximum ammonia storage setting value, if the actual ammonia storage value reaches the maximum ammonia storage setting value, reducing the urea injection amount until the actual ammonia storage value drops to the minimum ammonia storage setting value, increasing the urea injection amount, and increasing the ammonia storage value, so that the ammonia storage value fluctuates within the range of the minimum ammonia storage setting value to the maximum ammonia storage setting value.

[0007] As an optional implementation, it also includes: obtaining a urea injection amount base value; obtaining an engine ammonia storage value state; determining an ammonia nitrogen ratio correction factor according to the engine operating condition; determining a urea injection amount adjustment value according to the ammonia nitrogen ratio correction factor and the engine operating condition; determining a correction coefficient according to the engine ammonia storage value state; determining a urea injection amount adjustment direction according to the correction coefficient; and determining an actual urea injection value according to the urea injection amount base value, the urea injection amount adjustment value and the urea injection amount adjustment direction.

[0008] As an optional implementation, determining the correction coefficient according to the engine ammonia storage value state includes: if the engine is in a state of increasing ammonia storage value, the correction coefficient is 1; if the engine is in a state of decreasing ammonia storage value, the correction coefficient is -1.

[0009] As an optional implementation, the engine operating condition acquisition includes: acquiring airspeed, average catalyst carrier temperature, catalyst volume, SCR inlet NO X At least one of concentration and exhaust mass flow rate.

[0010] As an optional implementation, determining the maximum ammonia storage setting value according to the engine operating condition includes: determining a unit volume ammonia storage setting value according to the air velocity and the average temperature of the catalyst carrier; determining the maximum ammonia storage setting value according to the unit volume ammonia storage setting value and the catalyst volume.

[0011] As an optional implementation, the determining of the urea injection amount adjustment amount according to the ammonia nitrogen ratio correction factor and the engine operating condition includes: determining the required ammonia nitrogen ratio according to the air velocity and the average temperature of the catalyst carrier; determining the required ammonia nitrogen ratio according to the required ammonia nitrogen ratio and the SCR inlet NO X The required ammonia concentration is determined according to the required ammonia concentration; a required ammonia mass flow base value is determined according to the required ammonia mass flow base value and the ammonia nitrogen ratio correction factor; and a required ammonia mass flow adjustment value is determined according to the required ammonia mass flow adjustment value.

[0012] As an optional implementation, determining the ammonia nitrogen ratio correction factor according to the engine operating condition includes: determining the ammonia nitrogen ratio correction factor according to the average temperature of the catalyst carrier.

[0013] According to another aspect of the present application, a urea injection amount calculation control device is provided, comprising: an acquisition module, for acquiring an engine operating condition and an actual ammonia storage value; a range determination module, for determining a minimum ammonia storage setting value and a maximum ammonia storage setting value according to the engine operating condition; a urea injection state determination module, for determining a urea injection state according to the minimum ammonia storage setting value and the maximum ammonia storage setting value, and if the actual ammonia storage value reaches the maximum ammonia storage setting value, reducing the urea injection amount until the actual ammonia storage value drops to the minimum ammonia storage setting value, increasing the urea injection amount, and increasing the ammonia storage value, so that the ammonia storage value fluctuates within the range from the minimum ammonia storage setting value to the maximum ammonia storage setting value.

[0014] According to another aspect of the present application, an electronic device is provided, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus, and the memory is used to store a computer program; and the processor is used to execute the steps of the urea injection amount calculation control method according to any one of claims 1 to 7 by running the computer program stored in the memory.

[0015] According to another aspect of the present application, a computer-readable storage medium is provided, in which a computer program is stored, wherein the computer program is configured to execute the steps of the urea injection amount calculation control method according to any one of claims 1 to 7 when running.

[0016] Due to the adoption of the above technical solution, the beneficial effects achieved by the present invention are as follows:

[0017] The present invention provides a method for calculating and controlling the amount of urea injection, including determining the maximum ammonia storage setting value according to the engine operating conditions, and if the actual ammonia storage value reaches the maximum ammonia storage setting value, reducing the amount of urea injection until the actual ammonia storage value drops to the minimum ammonia storage setting value, increasing the urea injection amount, and increasing the ammonia storage value. This method allows the engine ammonia reserve to fluctuate within the range of the minimum ammonia storage setting value to the maximum ammonia storage setting value, effectively improving the ammonia storage capacity of the engine and greatly reducing the possibility of ammonia leakage. At the same time, this method can set the minimum preset value to 0 so as to exhaust the ammonia storage, and at the same NO X The urea injection amount is reduced to a certain extent under the condition of low emission, which further realizes the precise control of SCR and the precise control of ammonia emission in SCR, thus ensuring that the ammonia leakage does not exceed the standard to the greatest extent while meeting the NOx emission requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] Figure 1 is a schematic flow chart of an optional urea injection amount calculation and control method according to an embodiment of the present application;

[0021] Figure 2 is an optional urea injection amount calculation control logic diagram according to an embodiment of the present application;

[0022] Figure 3 is a schematic diagram of an optional urea injection amount calculation control device according to an embodiment of the present application;

[0023] Figure 4 It is a structural block diagram of an optional electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0025] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0026] In addition, in the description of the present invention, it should be understood that the orientations or positional relationships indicated by the terms "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the present invention, unless otherwise clearly specified and limited, the first feature "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0029] When the car is started and running, the engine will produce a large amount of NO X , and the emission of NOx brings great harm to human production and life as well as the natural environment. Its impact range has developed from local pollution to regional pollution, and even global pollution. Therefore, controlling the generation and emission of NOx is a very important issue. Now most of the SCR systems in the post-treatment system are used to control the emission of NOx gas. The principle is to inject urea into the exhaust gas discharged from the engine, use urea to decompose and produce ammonia, and react ammonia with NOx under the action of the catalyst, thereby reducing the emission of NOx. However, in the prior art (such as the invention patent with application number 201910646118.4), the SCR closed-loop control strategy can form a closed-loop control system based on the downstream NOx sensor and realize a certain precision control of the urea injection amount. However, in most closed-loop control strategies, the storage and control of ammonia decomposed by urea are still not perfect, and the ammonia storage value can only fluctuate within a very small range, which makes the ability to store ammonia and the control ability of ammonia storage poor, which may lead to the emission of excessive ammonia and still cause environmental problems.

[0030] Therefore, according to one aspect of the embodiment of the present application, Figure 1 As shown, a urea injection amount calculation control method is provided, comprising:

[0031] S201. Obtaining engine operating conditions and actual ammonia storage value;

[0032] S202. Determine a minimum ammonia storage setting value and a maximum ammonia storage setting value according to the engine operating condition;

[0033] S203. Determine the urea injection state according to the minimum ammonia storage setting value and the maximum ammonia storage setting value. If the actual ammonia storage value reaches the maximum ammonia storage setting value, reduce the urea injection amount until the actual ammonia storage value drops to the minimum ammonia storage setting value. Increase the urea injection amount and increase the ammonia storage value so that the ammonia storage value fluctuates within the range from the minimum ammonia storage setting value to the maximum ammonia storage setting value.

[0034] Specifically, when the engine is started, the engine emits nitrogen oxides. At the same time, the engine injects urea to decompose ammonia, and reacts ammonia with nitrogen oxides to generate nitrogen and water. In this process, nitrogen oxides and emissions do not always maintain the basic value. On this basis, the injection of urea may be too much or too little. When the amount of urea injected in real time exceeds the urea demand at that moment, part of the ammonia cannot react with nitrogen oxides. At this time, the engine needs to correct the amount of urea and store ammonia. At present, most of the methods using traditional closed-loop control strategies are used to correct the amount of urea and store ammonia, and the ammonia reserve can only fluctuate within a very small range. However, this method can determine the maximum ammonia storage setting according to the engine operating conditions, and by limiting the maximum ammonia storage setting, the control of the urea injection amount is achieved, that is, if the actual ammonia storage value reaches the maximum ammonia storage setting, the urea injection amount is reduced until the actual ammonia storage value drops to the minimum ammonia storage setting value, and the urea injection amount is increased, and the ammonia storage value increases. This method allows the engine ammonia storage to fluctuate within the range of the minimum ammonia storage setting to the maximum ammonia storage setting, effectively improving the engine's ammonia storage capacity, improving the controllability of urea injection, and greatly reducing the possibility of ammonia leakage. At the same time, this method can exhaust the ammonia storage. X The urea injection amount is reduced to a certain extent under the condition of low emission, which further realizes the precise control of SCR and the precise control of ammonia emission in SCR, thus ensuring that the ammonia leakage does not exceed the standard to the greatest extent while meeting the NOx emission requirements.

[0035] In addition, it should be noted that the present application does not restrict the specific settings of the minimum ammonia storage setting and the maximum ammonia storage setting. Preferably, the minimum ammonia storage setting can be set to 0 so that the engine can exhaust the ammonia storage, thereby expanding the fluctuation range of the ammonia storage to the greatest extent.

[0036] As an optional implementation, it also includes: obtaining a urea injection amount base value; obtaining an engine ammonia storage value state; determining an ammonia nitrogen ratio correction factor according to the engine operating condition; determining a urea injection amount adjustment value according to the ammonia nitrogen ratio correction factor and the engine operating condition; determining a correction coefficient according to the engine ammonia storage value state; determining a urea injection amount adjustment direction according to the correction coefficient; and determining an actual urea injection value according to the urea injection amount base value, the urea injection amount adjustment value and the urea injection amount adjustment direction.

[0037] As an optional implementation, determining the correction coefficient according to the engine ammonia storage value state includes: if the engine is in a state of increasing ammonia storage value, the correction coefficient is 1; if the engine is in a state of decreasing ammonia storage value, the correction coefficient is -1.

[0038] Specifically, it is easy to understand that in the above method, since the engine may be in a state where the urea injection amount is reduced or in a state where the urea injection amount is increased, when the urea injection amount adjustment value is determined according to the ammonia nitrogen ratio correction factor and the engine operating condition, the urea amount adjustment value may be positive or negative. If the engine is in a state where the urea injection amount is reduced, the urea amount adjustment value is negative, and if the engine is in a state where the urea injection amount is increased, the urea amount adjustment value is positive. Based on this, the setting of the correction coefficient enables the method to accurately distinguish the urea injection amount state and perform precise calculation and control.

[0039] As an optional implementation, the engine operating condition acquisition includes: acquiring airspeed, average catalyst carrier temperature, catalyst volume, SCR inlet NO X At least one of concentration and exhaust mass flow rate.

[0040] Specifically, Figure 2 It is an optional urea injection amount calculation control logic diagram, such as Figure 2As shown, among them: ScrC_SvExh is the air velocity; ScrM_TScrMean is the average temperature of the catalyst carrier; ScrC_ConcNOxScrUs is the NOx concentration at the SCR inlet; ScrC_MfExh is the exhaust mass flow rate; SysG_VolScrCat_c is the catalyst volume; SysG_MmolNh3_c is the molar mass of NH3; SysG_MmolAir_c is the molar mass of air; ScrC_MfNh3Stdy is the basic value of NH3 mass flow rate; ScrC_MfNh3Dmd is the required final value of NH3 mass flow rate; ScrC_dmRdcAgDes is the actual urea injection amount; ScrC_RatNh3Dmd_M is the required ammonia nitrogen ratio MAP; ScrC_FacRatNh3Dmd is the ammonia nitrogen ratio correction factor; ScrC_LoadNh3Dmd_M: ammonia storage setting maximum value MAP.

[0041] As an optional implementation, determining the maximum ammonia storage setting value according to the engine operating condition includes: determining a unit volume ammonia storage setting value according to the air velocity and the average temperature of the catalyst carrier; determining the maximum ammonia storage setting value according to the unit volume ammonia storage setting value and the catalyst volume.

[0042] Specifically, the ammonia storage setting value per unit volume can be obtained by checking the ammonia storage setting value MAP, and the ammonia storage setting value per unit volume is multiplied by the catalyst volume to obtain the ammonia storage setting maximum value.

[0043] As an optional implementation, the determining of the urea injection amount adjustment amount according to the ammonia nitrogen ratio correction factor and the engine operating condition includes: determining the required ammonia nitrogen ratio according to the air velocity and the average temperature of the catalyst carrier; determining the required ammonia nitrogen ratio according to the required ammonia nitrogen ratio and the SCR inlet NO X The required ammonia concentration is determined according to the required ammonia concentration; a required ammonia mass flow base value is determined according to the required ammonia mass flow base value and the ammonia nitrogen ratio correction factor; and a required ammonia mass flow adjustment value is determined according to the required ammonia mass flow adjustment value.

[0044] Specifically, Figure 2 As shown, the required ammonia nitrogen ratio is obtained by looking up the ammonia nitrogen ratio MAP according to the air velocity and the average temperature of the catalyst carrier; the required ammonia nitrogen ratio is multiplied by the NOx concentration at the SCR inlet to obtain the required ammonia concentration, the required ammonia concentration is calculated with the exhaust mass flow rate, the molar mass of ammonia, and the molar mass of air to obtain the basic value of the required ammonia mass flow rate, the basic value of the required ammonia mass flow rate is multiplied by the ammonia nitrogen ratio correction factor and the correction coefficient to obtain the required ammonia mass flow rate adjustment; the required ammonia mass flow rate adjustment is multiplied by 5.425 to obtain the urea injection amount adjustment.

[0045] As an optional implementation, determining the ammonia nitrogen ratio correction factor according to the engine operating condition includes: determining the ammonia nitrogen ratio correction factor according to the average temperature of the catalyst carrier.

[0046] Specifically, the ammonia nitrogen ratio correction factor is obtained by checking the ammonia nitrogen ratio correction factor curve according to the average temperature of the catalyst carrier.

[0047] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM (Read-Only Memory, Read-Only Memory) / RAM (Random Access Memory, Random Access Memory), a magnetic disk, or an optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute a urea injection amount calculation control method described in each embodiment of the present application.

[0048] According to another aspect of the embodiment of the present application, a urea injection amount calculation control device is also provided. Figure 3 is a schematic diagram of a urea injection amount calculation control device according to an embodiment of the present application, such as Figure 3 As shown, the device may include:

[0049] An acquisition module 502 is used to acquire engine operating conditions and actual ammonia storage value;

[0050] A range determination module, 504, determines a minimum ammonia storage setting value and a maximum ammonia storage setting value according to the engine operating condition;

[0051] The urea injection state determination module 506 determines the urea injection state according to the minimum ammonia storage setting value and the maximum ammonia storage setting value. If the actual ammonia storage value reaches the maximum ammonia storage setting value, the urea injection amount is reduced until the actual ammonia storage value drops to the minimum ammonia storage setting value. The urea injection amount is increased and the ammonia storage value is increased so that the ammonia storage value fluctuates within the range from the minimum ammonia storage setting value to the maximum ammonia storage setting value.

[0052] Figure 3 is a structural block diagram of an optional electronic device according to an embodiment of the present application, such as Figure 3 As shown, it includes a processor 602, a communication interface 604, a memory 606 and a communication bus 608, wherein the processor 602, the communication interface 604 and the memory 606 communicate with each other through the communication bus 608, wherein,

[0053] Memory 606, used to store computer programs;

[0054] The processor 602 is used to implement the following steps when executing the computer program stored in the memory 606:

[0055] Obtain engine operating conditions and actual ammonia storage value;

[0056] Determining a minimum ammonia storage setting value and a maximum ammonia storage setting value according to the engine operating condition;

[0057] The urea injection state is determined according to the minimum ammonia storage setting value and the maximum ammonia storage setting value. If the actual ammonia storage value reaches the maximum ammonia storage setting value, the urea injection amount is reduced until the actual ammonia storage value drops to the minimum ammonia storage setting value. The urea injection amount is increased and the ammonia storage value increases, so that the ammonia storage value fluctuates within the range from the minimum ammonia storage setting value to the maximum ammonia storage setting value.

[0058] According to another aspect of the embodiment of the present application, an electronic device for implementing the above-mentioned urea injection amount calculation control method is also provided. The electronic device may be a server, a terminal, or a combination thereof.

[0059] Optionally, in this embodiment, the communication bus may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. The communication bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0060] The communication interface is used for communication between the above electronic device and other devices.

[0061] The memory may include RAM, or may include non-volatile memory, such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0062] It may also include but is not limited to other module units in the above-mentioned urea injection amount calculation control device, which will not be repeated in this example.

[0063] The above-mentioned processor can be a general-purpose processor, which can include but not be limited to: CPU (Central Processing Unit), NP (Network Processor), etc.; it can also be DSP (Digital Signal Processing), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0064] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0065] It can be understood by those skilled in the art that Figure 4 The structure shown is for illustration only. The device for implementing the above-mentioned urea injection amount calculation and control method may be a terminal device, which may be a smart phone (such as an Android phone, an IOS phone, etc.), a tablet computer, a PDA, a mobile Internet device (Mobile Internet Devices, MID), a PAD, and other terminal devices. Figure 4 It does not limit the structure of the above electronic device. For example, the terminal device may also include Figure 4 More or fewer components (such as network interfaces, display devices, etc.) shown in, or having Figure 4 Different configurations shown.

[0066] A person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a computer-readable storage medium, which can include: a flash drive, ROM, RAM, a magnetic disk or an optical disk, etc.

[0067] According to another aspect of the embodiment of the present application, a storage medium is also provided. Optionally, in this embodiment, the storage medium can be used to execute the program code of the urea injection amount calculation control method.

[0068] Optionally, in this embodiment, the storage medium may be located on at least one network device among a plurality of network devices in the network shown in the above embodiment.

[0069] Optionally, in this embodiment, the storage medium is configured to store program codes for executing the following steps:

[0070] Obtain engine operating conditions and actual ammonia storage value;

[0071] Determining a minimum ammonia storage setting value and a maximum ammonia storage setting value according to the engine operating condition;

[0072] The urea injection state is determined according to the minimum ammonia storage setting value and the maximum ammonia storage setting value. If the actual ammonia storage value reaches the maximum ammonia storage setting value, the urea injection amount is reduced until the actual ammonia storage value drops to the minimum ammonia storage setting value, the urea injection amount is increased, and the ammonia storage value is increased, so that the ammonia storage value fluctuates within the range from the minimum ammonia storage setting value to the maximum ammonia storage setting value. The specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated in this embodiment.

[0073] Optionally, in this embodiment, the storage medium may include, but is not limited to, various media that can store program codes, such as a USB flash drive, a ROM, a RAM, a mobile hard disk, a magnetic disk, or an optical disk.

[0074] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0075] If the integrated units in the above embodiments are implemented in the form of software functional units and sold or used as independent products, they can be stored in the above computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling one or more electronic devices (such as personal computers, servers, or network devices) to perform all or part of the steps of the methods described in the various embodiments of the present application.

[0076] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0077] In the several embodiments provided in the present application, it should be understood that the disclosed client can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0078] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution provided in this embodiment.

[0079] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0080] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0081] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for calculating and controlling the amount of urea injection, characterized in that: include: Obtain engine operating conditions and actual ammonia storage value; Determining a minimum ammonia storage setting value and a maximum ammonia storage setting value according to the engine operating condition; Determine the urea injection state according to the ammonia storage setting minimum value and the ammonia storage setting maximum value, if the actual ammonia storage value reaches the ammonia storage setting maximum value, reduce the urea injection amount until the actual ammonia storage value drops to the ammonia storage setting minimum value, increase the urea injection amount, and increase the ammonia storage value, so that the ammonia storage value fluctuates within the range from the ammonia storage setting minimum value to the ammonia storage setting maximum value; Also includes: Get the basic value of urea injection amount; Get the engine ammonia storage value status; determining an ammonia nitrogen ratio correction factor according to the engine operating conditions; determining a urea injection amount adjustment value according to the ammonia nitrogen ratio correction factor and the engine operating condition; determining a correction factor according to the engine ammonia storage value state; determining a urea injection amount adjustment direction according to the correction coefficient; The actual urea injection value is determined according to the urea injection amount basic value, the urea injection amount adjustment value and the urea injection amount adjustment direction.

2. The urea injection amount calculation and control method according to claim 1, characterized in that: Determining the correction coefficient according to the engine ammonia storage value state includes: If the engine is in a state of increasing ammonia storage value, the correction factor is 1; If the engine is in a state where the ammonia storage value is reduced, the correction factor is -1.

3. A urea injection amount calculation and control method as claimed in claim 2, characterized in that: The obtaining of the engine operating condition comprises: Obtain space velocity, average catalyst carrier temperature, catalyst volume, SCR inlet NO X At least one of concentration and exhaust mass flow rate.

4. A urea injection amount calculation and control method as claimed in claim 3, characterized in that: Determining the maximum ammonia storage setting value according to the engine operating condition comprises: Determining a set value of ammonia storage per unit volume according to the space velocity and the average temperature of the catalyst carrier; The maximum ammonia storage setting value is determined according to the unit volume ammonia storage setting value and the catalyst volume.

5. The urea injection amount calculation and control method according to claim 3, characterized in that: Determining the urea injection amount adjustment value according to the ammonia nitrogen ratio correction factor and the engine operating condition includes: Determining the required ammonia nitrogen ratio according to the space velocity and the average temperature of the catalyst carrier; According to the required ammonia nitrogen ratio and the SCR inlet NO X Concentration determines the required ammonia concentration; Determining a required ammonia mass flow base value according to the required ammonia concentration and the exhaust mass flow; Determining a required ammonia mass flow adjustment value according to the required ammonia mass flow basic value and the ammonia nitrogen ratio correction factor; The urea injection amount adjustment value is calculated according to the required ammonia mass flow adjustment value.

6. A urea injection amount calculation and control method as claimed in claim 3, characterized in that: Determining the ammonia nitrogen ratio correction factor according to the engine operating condition comprises: The ammonia nitrogen ratio correction factor is determined according to the average temperature of the catalyst carrier.

7. A urea injection amount calculation control device, characterized in that: Applied to the urea injection amount calculation control method according to any one of claims 1 to 6, the urea injection amount calculation control device comprises: An acquisition module, used to acquire engine operating conditions and actual ammonia storage value; A range determination module, which determines a minimum ammonia storage setting value and a maximum ammonia storage setting value according to the engine operating condition; The urea injection state determination module determines the urea injection state according to the minimum ammonia storage setting value and the maximum ammonia storage setting value. If the actual ammonia storage value reaches the maximum ammonia storage setting value, the urea injection amount is reduced until the actual ammonia storage value drops to the minimum ammonia storage setting value, and the urea injection amount is increased, and the ammonia storage value increases, so that the ammonia storage value fluctuates within the range from the minimum ammonia storage setting value to the maximum ammonia storage setting value.

8. An electronic device comprising a processor, a communication interface, a memory and a communication bus, wherein: The processor, the communication interface and the memory communicate with each other via the communication bus, wherein: The memory is used to store computer programs; The processor is configured to execute the steps of the urea injection amount calculation control method according to any one of claims 1 to 6 by running the computer program stored in the memory.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, wherein the computer program is configured to execute the steps of the urea injection amount calculation control method according to any one of claims 1 to 6 when running.

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