Urea Nozzle Injection Flow Control Method, Device, Equipment and Storage Medium

Abstract

The present application relates to a method, device, equipment and storage medium for controlling the injection flow rate of a urea nozzle in the field of exhaust gas treatment. The method for controlling the injection flow rate of the urea nozzle includes: obtaining the basic urea demand flow rate of the urea nozzle according to the basic opening degree of the urea nozzle; obtaining the current injection flow rate of the urea nozzle at the basic opening degree according to the basic opening degree; obtaining a compensation factor for the opening degree of the urea nozzle according to the basic urea demand flow rate and the current injection flow rate; and obtaining the actual driving opening degree to be output by the urea nozzle according to the compensation factor and the basic opening degree. The control method of the present application can achieve precise control of urea injection and meet the requirements for emissions.

Description

Technical Field

[0001] This application relates to the technical field of tail gas treatment, and in particular to a method, device, equipment and storage medium for controlling the injection flow rate of a urea nozzle. Background Technique

[0002] Urea nozzles are widely used in diesel engines. During the long-term operation of vehicles, the nozzles may become blocked due to factors such as impurities, crystallization, and rust, resulting in less urea injection and exceeding emissions standards. The nozzles may be corroded, causing the spray holes to become larger, resulting in excessive urea injection and a high risk of crystallization. Currently, the injection volume of urea demand is closed-loop regulated based on the NOx value downstream of the SCR (Selective Catalytic Reduction System). When the NOx downstream is high, the urea injection volume is increased. However, this regulation method reduces the regulation accuracy and is prone to causing urea waste or non-compliance with emissions standards. Summary of the Invention

[0003] In view of the problems existing in the background technique, this application provides a method for controlling the injection flow rate of a urea nozzle, which can achieve precise control of urea injection and meet the requirements for emissions.

[0004] According to the first aspect of the present invention, there is provided a method for controlling the injection flow rate of a urea nozzle, including: obtaining the basic urea demand flow rate of the urea nozzle according to the basic opening degree of the urea nozzle;

[0005] Obtaining the current injection flow rate of the urea nozzle at the basic opening degree according to the basic opening degree;

[0006] Obtaining a compensation factor for the opening degree of the urea nozzle according to the basic urea demand flow rate and the current injection flow rate;

[0007] Obtaining the driving opening degree that the urea nozzle actually needs to output according to the compensation factor and the basic opening degree.

[0008] In some embodiments of the present invention, the calculation of the driving opening degree includes:

[0009] a1 = Fac * a0; where Fac = Q sys / Q act ;

[0010] In the formula, a1 is the driving opening degree, Fac is the compensation factor, Q sys is the basic urea demand flow rate, Q act is the current injection flow rate, and a0 is the basic opening degree.

[0011] In some embodiments of the present invention, the acquisition of the basic urea demand flow rate of the urea nozzle includes:

[0012] The urea nozzle is in the initial use stage, the urea injection of the urea nozzle is stopped, the urea pump is stabilized to the set pump pressure, and the urea pump is fixed to the set rotational speed;

[0013] The urea nozzle is opened at the basic opening degree, a set volume of urea is consumed, the pump pressure at the opening moment and the closing moment of the urea nozzle are collected, and the average injection flow rate of the urea nozzle is calculated according to the change in the pump pressure of the urea pump;

[0014] Every time a set volume of urea is consumed, the average injection flow rate is calculated once, and a sequence of the average injection flow rate is obtained;

[0015] The basic urea demand flow rate of the urea nozzle is calculated according to the sequence of the average injection flow rate.

[0016] In some embodiments of the present invention, the obtaining of the current injection flow rate of the urea nozzle includes:

[0017] When the urea nozzle is in a subsequent use stage other than the initial use stage, the urea injection of the urea nozzle is stopped, the urea pump is stabilized to the set pump pressure, and the urea pump is fixed to the set rotational speed;

[0018] The urea nozzle is opened at the basic opening degree, a set volume of urea is consumed, the pump pressure at the opening moment and the closing moment of the urea nozzle are collected, and the average injection flow rate of the urea nozzle is calculated according to the change in the pump pressure of the urea pump;

[0019] Every time a set volume of urea is consumed, the average injection flow rate is calculated once, and a sequence of the average injection flow rate is obtained;

[0020] The current injection flow rate of the urea nozzle is calculated according to the sequence of the average injection flow rate.

[0021] In some embodiments of the present invention, the calculation of the average injection flow rate of the urea nozzle includes:

[0022] Average injection flow rate Q dos =Q su -Q back wherein, Q su is the average supply flow rate of the urea pump, and Q back is the average flow rate of the urea pump return hole;

[0023] When the urea pump rotates at a set rotational speed, the pump pressure is stabilized to the set pump pressure and the urea nozzle does not inject, the average supply flow rate of the urea pump is balanced with the average flow rate of the return hole, that is, Q su is equal to Q back , and the system constant C b ;

[0024] Average injection flow rate Q dos =Cb *(P1)^ 1 / 2 -C b *[(P1 + P2) / 2]^ 1 / 2 。

[0025] In some embodiments of the present invention, if the compensation factor exceeds the set range, the compensation condition for the opening degree of the urea nozzle is satisfied, and the driving opening degree actually to be output by the urea nozzle is obtained according to the compensation factor and the basic opening degree; otherwise, the urea nozzle operates according to the basic opening degree.

[0026] According to a second aspect of the present invention, there is provided a urea nozzle injection flow control device, comprising:

[0027] A urea pump pump pressure acquisition module, configured to execute when the urea nozzle stops spraying urea, stabilize the urea pump to a set pump pressure, fix the urea pump to a set rotational speed, open the urea nozzle at a basic opening degree, consume a set volume of urea, and acquire the pump pressure at the opening moment and the pump pressure at the closing moment of the urea nozzle;

[0028] A determination module, configured to calculate the average injection flow rate of the urea nozzle according to the change in the pump pressure of the urea pump, obtain a sequence of average injection flow rates, and then calculate the basic urea demand flow rate or the current injection flow rate according to the sequence of average injection flow rates;

[0029] A control module, configured to obtain a compensation factor for the opening degree of the urea nozzle according to the basic urea demand flow rate and the current injection flow rate; and obtain the driving opening degree actually to be output by the urea nozzle according to the compensation factor and the basic opening degree, and adjust the actual opening degree of the urea nozzle to the driving opening degree.

[0030] In some embodiments of the present invention, the control device further comprises:

[0031] A storage module, configured to store the obtained basic urea demand flow rate if the operation time of the urea nozzle is within a preset time period at the factory.

[0032] According to a third aspect of the present invention, there is provided a urea nozzle injection flow control device, comprising: at least one processor and a memory;

[0033] The memory stores computer-executable instructions;

[0034] The at least one processor executes the computer-executable instructions stored in the memory, so that the at least one processor executes the above control method.

[0035] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer-executable instructions, and when a processor executes the computer-executable instructions, the above control method is implemented.

[0036] An embodiment of the present application provides a method for controlling the injection flow rate of a urea nozzle. When it is detected that the SCR efficiency is low for a long time, the current injection flow rate Q of the urea nozzle is evaluated act and the ratio relationship with the basic urea demand flow rate Q sys is used to calculate the compensation factor of the nozzle opening. Then, when the compensation factor exceeds the set range, the driving opening of the nozzle is calculated based on the supplementary factor and the basic opening, and the urea nozzle is closed-loop controlled to make the system demand urea injection amount equal to the actual injection amount of the nozzle, meet the precise control of urea injection, make the urea amount injected by the urea nozzle perfectly match the amount of tail gas to be treated, ensure the tail gas treatment effect while reducing the waste of urea, and meet the emission requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0038] Figure 1 is a schematic diagram of the urea injection system provided by the present invention.

[0039] Figure 2 is a flowchart of the method for controlling the injection flow rate of the urea nozzle provided by the embodiment of the present invention.

[0040] Figure 3 is a schematic diagram of the device for controlling the injection flow rate of the urea nozzle provided by the present invention.

[0041] Figure 4 is a schematic diagram of the hardware structure of the device for controlling the injection flow rate of the urea nozzle provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0043] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0044] In the description of this application, it should be understood that terms such as "first" and "second" are only for descriptive purposes and cannot be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances. In addition, in the description of this application, unless otherwise specified, "a plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the front and back associated objects.

[0045] The following will describe the urea nozzle injection flow control method, device, equipment, and storage medium provided by the embodiments of this application with reference to the accompanying drawings.

[0046] The embodiments of this application disclose a urea nozzle injection flow control method. Figure 1 It is a schematic diagram of the urea injection system provided by the present invention. As Figure 1 shown, the urea injection system 100 includes a urea tank 101, a urea pump 102, a urea pressure pipe 103, and a urea nozzle 104; among them, the urea pump 102 is responsible for supplying urea solution to the urea nozzle 104, and the motor is responsible for driving the urea pump 102 to transport the urea solution from the urea tank 101 to the urea pressure pipe 103. A part of the urea solution is used for injection, and the other part returns to the urea tank 101 through the return hole.

[0047] The specific working process of the urea injection system is divided into three stages: pressure building, injection, and back suction.

[0048] Pressure building: After the vehicle runs, when the exhaust gas temperature reaches 180 °C, the urea injection system starts to operate to build pressure. When the pressure reaches 9 bar, the urea pump 102 stops rotating, and the urea nozzle 104 opens for a trial injection once to diagnose the mechanical jamming of the urea nozzle 104; then, the pressure fluctuation range is monitored for a period of time to determine whether there is a leak in the pipeline. If the pressure building fails due to a leak, the urea injection system will stop operating.

[0049] Injection: When the exhaust gas temperature is higher than a certain value, the urea nozzle 104 starts to inject urea solution, and the opening degree and opening duration of the urea nozzle 104 are controlled by the ECU according to the engine working conditions.

[0050] Back suction: After the engine is turned off, the steering valve of the urea injection system opens to back suck the residual urea solution in the pipeline into the urea tank 101 to prevent the urea from freezing and bursting the pipeline and the urea pump 102 in winter.

[0051] As Figure 1 shown, Q dos is the average injection flow rate of the urea nozzle 104, Q backis the average flow rate of the urea pump return hole, Q su is the average supply flow rate of the urea pump, P p is the urea pump pressure,

[0052] Q dos = Q su - Q back (1)

[0053] As shown in formula (1), the injection flow rate of the urea nozzle 104 is equal to the reduced return flow rate. When the urea pump 102 operates at a set speed N and stabilizes the pump pressure to the set pump pressure P0 and the urea nozzle 104 does not inject, the average supply flow rate Q of the urea pump 102 su is balanced with the average flow rate Q of the return hole, that is, Q back is equal to Q su and Q back are equal, and the system constant C can be calculated b ; thus, it can be obtained that

[0054] Q dos = C b *(P1) ^1 / 2 - C b *((P1 + P2) / 2) ^1 / 2 (2)

[0055] In the formula, P1 is the pump pressure at the start of injection, and P2 is the pump pressure at the end of injection. The average injection flow rate of the urea nozzle 104 can be calculated based on the change in the pump pressure when the urea nozzle 104 is opened and closed.

[0056] The execution subject of the urea nozzle injection flow rate control method in this embodiment can be the electronic control unit ECU.

[0057] When the operating time of the urea nozzle 104 is within the factory preset time period, that is, the urea nozzle 104 is in the initial use stage, and the SCR (Selective Catalytic Reduction System) efficiency is normal and there is no ammonia leakage during this stage, it is considered that the urea nozzle 104 is in a normal state at this time. The opening degree of the urea nozzle 104 that just meets the required injection volume of urea in this stage is set as the basic opening degree a0. On the basis of this basic opening degree a0, in the subsequent use stages other than the initial use stage of the urea nozzle 104, the opening degree of the urea nozzle 104 is adjusted to obtain the actual driving opening degree a1 to be output by the urea nozzle 104.

[0058] Specifically, in this embodiment, the operating time of the urea nozzle 104 within the factory preset time period can be understood as the normal operation state stage of a new vehicle or the start operation state stage after the urea pump 102, urea pressure pipe 103, and urea nozzle 104 are replaced later.

[0059] The urea nozzle injection flow control method of this embodiment is mainly completed by obtaining the flow mean value of the injection average flow of the urea nozzle 104. This control method divides the flow mean value of the urea nozzle 104 into the urea basic demand flow Q sys and the current injection flow Q act . The calculation methods of the urea basic demand flow Q sys and the current injection flow Q act are the same, only different in the time sequence of acquisition. Among them, the urea basic demand flow Q sys is obtained prior to all the current injection flows Q act .

[0060] Under the condition of the basic opening a0 of the urea nozzle 104, the urea basic demand flow Q sys and the current injection flow Q act are obtained. The corresponding current injection flow Q act is calculated with the urea basic demand flow Q sys to obtain the compensation factor Fac of the opening of the urea nozzle 104. Then, according to the compensation factor Fac and the basic a0 opening, the actual driving opening a1 to be output by the urea nozzle 104 is obtained.

[0061] Figure 2 is the flow chart of the urea nozzle injection flow control method provided by the embodiment of the present invention. As Figure 2 shown, the urea nozzle injection flow control method of this embodiment includes the following steps:

[0062] 1) Obtain the current injection flow of the urea nozzle

[0063] During the vehicle operation, when it is detected that the SCR efficiency is lower than the set efficiency for a long time, the evaluation nozzle flow function is activated. When the evaluation nozzle flow meets the release condition, the injection system is actively controlled to evaluate the current flow of the nozzle at the basic opening a0 according to the urea pump pressure to obtain the current injection flow Q act .

[0064] First, obtain the sequence of the injection average flow of the urea nozzle 104; the sequence of the injection average flow is divided into n first sequences, and the n first sequences are respectively obtained within n driving cycles, where n≥1.

[0065] Specifically, within each driving cycle, m injection average flows of the urea nozzle 104 are respectively obtained. The m injection average flows of the urea nozzle 104 are the first sequences. Among them, m>1. The calculation of the m injection average flows of the urea nozzle 104 respectively includes the following processes:

[0066] First, stop injecting urea from the urea nozzle 104, stabilize the pump pressure of the urea pump 102 to the set pump pressure P0, and fix the rotational speed of the urea pump to the set rotational speed N; then open the urea nozzle 104 at the basic opening a0, consume the set volume V of urea, collect the pump pressure P1 at the opening moment of the urea nozzle 104 and the pump pressure P2 at the closing moment, and use the system constant C obtained in advance above b , according to formula (2), calculate the average injection flow rate of the urea nozzle 104, and obtain the average injection flow rate Q of the urea nozzle 104 at the basic opening a0 dos ; Repeat the above process until a first sequence for one driving cycle is obtained, and then calculate the first mean value of the first sequence.

[0067] Repeat the above process until n first mean values Q dos1 、Q dos2 、Q dos3 、Q dos4 、…、Q dosn are obtained for n driving cycles.

[0068] After that, calculate the second mean value of the n first mean values,

[0069]

[0070] This second mean value is the current injection flow rate Q of the urea nozzle 104 act .

[0071] If it is detected that the SCR efficiency is at the set efficiency, or when it is evaluated that the nozzle flow rate does not meet the release condition, then the urea nozzle 104 still injects according to the normal process, and the urea injection system still undergoes the working process of pressure building, injection, and reverse pumping to treat the tail gas.

[0072] 2) Compensation factor calculation

[0073] Before obtaining the current injection flow rate Q act of the urea nozzle 104, when the running time of the urea nozzle 104 is within the factory preset time period, the basic urea demand flow rate Q sys has been obtained in advance and the obtained basic urea demand flow rate Q sys is stored; The specific establishment process of the basic urea demand flow rate Q sys includes:

[0074] When the running time of the urea nozzle 104 is within the factory preset time period, and the SCR efficiency is normal and there is no ammonia leakage at this stage, it is considered that the urea nozzle 104 is in a normal state, and the opening of the nozzle that just meets the required injection volume of urea at this stage is set as the basic opening a0.

[0075] First, obtain the sequence of the average injection flow rate of the urea nozzle 104; the sequence of the average injection flow rate is divided into n' first sequences, and the n' first sequences are obtained within n' driving cycles respectively, where n'≥1.

[0076] Specifically, within each driving cycle, obtain the average injection flow rates of m' urea nozzles 104 respectively. The average injection flow rates of the m' urea nozzles 104 are the first sequences. Where m'>1, the calculation of the average injection flow rates of the m' urea nozzles 104 respectively includes the following processes:

[0077] First, stop the urea injection of the urea nozzle 104, stabilize the pump pressure of the urea pump 102 to the set pump pressure P0, and fix the rotation speed of the urea pump 102 to the set rotation speed N; then open the urea nozzle 104 at the basic opening a0, consume the set volume V of urea, collect the pump pressure P'1 at the opening moment of the urea nozzle 104 and the pump pressure P'2 at the closing moment, and from the system constant C obtained in advance above b , according to formula (2), calculate the average injection flow rate of the urea nozzle 104, and obtain the average injection flow rate Q' at the opening a of the urea nozzle 104 dos ; repeat the above process until the first sequence of a driving cycle is obtained, and then calculate the first mean value of the first sequence.

[0078] Repeat the above process until the n' first mean values Q dos1 ', Q dos2 ', Q dos3 ', Q dos4 ', …, Q dosn ' of the n' driving cycles are obtained.

[0079] After that, calculate the second mean value of the n' first mean values,

[0080]

[0081] This second mean value is the basic urea demand flow rate Q sys of the urea nozzle 104, and store the obtained basic urea demand flow rate Q sys .

[0082] When both the basic urea demand flow rate Q sys and the current injection flow rate Q act are known, calculate the compensation factor Fac,

[0083] Fac = Q sys / Q act (5)

[0084] Thus, according to the basic urea demand flow rate and the current injection flow rate, obtain the compensation factor Fac of the opening of the urea nozzle.

[0085] Obtain the current injection flow rate Q of the urea nozzle 104 act Same as the control method for obtaining the basic urea demand flow rate Q of the urea nozzle 104 sys where n' and n, m' and m can be the same numbers or different numbers respectively. Specifically, according to different stages of vehicle use, the number of the first sequence and the number of driving cycles can be selected to ensure the accuracy of the flow rate average value calculation of the urea nozzle 104.

[0086] 3) Drive opening calculation

[0087] When the compensation factor Fac exceeds the set range, it is determined that the compensation condition is met, and the drive opening is calculated

[0088] a1 = Fac * a0 (6)

[0089] Multiply the compensation factor by the basic opening a0, and use the obtained opening value as the final drive opening a1; the urea nozzle 104 will operate according to the drive opening a1, and the urea nozzle 104 will continue to spray according to the normal process. The urea injection system still works in the processes of pressure building, spraying and reverse pumping to treat the tail gas.

[0090] For example, when the compensation factor Fac exceeds the set range and the current injection flow rate Q act relative to the basic urea demand flow rate Q sys increases, the compensation factor Fac is less than 1. At this time, the calculated drive opening a1 will be less than the basic opening a0; when the compensation factor Fac exceeds the set range and the current injection flow rate Q act relative to the basic urea demand flow rate Q sys decreases, the compensation factor Fac is greater than 1. At this time, the calculated drive opening a1 will be greater than the basic opening a0.

[0091] If the compensation factor does not exceed the set range, the compensation condition for the opening of the urea nozzle is not met, and the urea nozzle will operate according to the basic opening a0. The urea nozzle 104 will continue to spray according to the normal process. The urea injection system still works in the processes of pressure building, spraying and reverse pumping to treat the tail gas.

[0092] Specifically, the set range of the compensation factor in this embodiment can be 0.5 - 1.5, or other intervals including 1 within the range of 0.5 - 1.5, such as: 0.6 < Fac < 1.4, 0.7 < Fac < 1.3, 0.8 < Fac < 1.2, etc.

[0093] By using the urea nozzle injection flow rate control method in this technical solution, when it is detected that the SCR efficiency is low for a long time, by evaluating the difference between the current flow rate of the urea nozzle and the normal nozzle flow rate, that is, the current injection flow rate Qact The proportional relationship with the basic demand flow rate Q of urea sys to calculate the compensation factor of the nozzle opening degree, and then when the compensation factor exceeds the set range, calculate the driving opening degree of the nozzle according to the supplementary factor and the basic opening degree, and perform closed-loop control on the urea nozzle, so that the system demand urea injection amount is equal to the actual injection amount of the nozzle, meeting the precise control of urea injection, making the urea amount injected by the urea nozzle perfectly match the amount of tail gas to be treated, ensuring the tail gas treatment effect while reducing the waste of urea, thereby meeting the emission requirements.

[0094] The embodiment of the present application also provides a urea nozzle injection flow rate control device. This control device corresponds to the above method embodiment and uses the above urea nozzle injection flow rate control method to adjust the injection flow rate of the urea nozzle 104. Figure 3 It is a schematic diagram of the urea nozzle injection flow rate control device provided by the present invention. As Figure 3 shown, this control device 200 includes:

[0095] A urea pump pump pressure acquisition module 201, which is used to execute when the urea nozzle stops injecting urea, stabilize the urea pump to the set pump pressure, fix the urea pump to the set rotational speed, open the urea nozzle at the basic opening degree, consume the set volume of urea, and acquire the pump pressure at the moment when the urea nozzle opens and the pump pressure at the moment when it closes.

[0096] A determination module 202, which calculates the average injection flow rate of the urea nozzle according to the change in the pump pressure of the urea pump, obtains a sequence of average injection flow rates, and then calculates the basic demand flow rate of urea or the current injection flow rate Q according to the sequence of average injection flow rates act ;

[0097] A storage module 203, which is used to store the obtained basic demand flow rate Q of urea if the operation time of the urea nozzle is within the preset time period at the factory. sys .

[0098] A control module 204, which obtains the compensation factor of the opening degree of the urea nozzle according to the basic demand flow rate of urea and the current injection flow rate; and obtains the driving opening degree that the urea nozzle actually needs to output according to the compensation factor and the basic opening degree, and adjusts the actual opening degree of the urea nozzle to the driving opening degree.

[0099] The embodiment of the present application also provides a urea nozzle injection flow rate control device. Figure 4 It is a schematic diagram of the hardware structure of the urea nozzle injection flow rate control device provided by the embodiment of the present invention. As Figure 4 shown, the urea nozzle injection flow rate control device 300 of this embodiment includes: a processor 301 and a memory 302; where:

[0100] The memory 302 is used to store computer execution instructions;

[0101] A processor 301 for executing computer-executable instructions stored in a memory to implement the respective steps performed by the ECU in the above embodiments; for details, reference may be made to the relevant descriptions in the foregoing method embodiments.

[0102] In a possible design, the memory 302 can be either independent or integrated with the processor 301.

[0103] When the memory 302 is independently provided, the urea nozzle injection flow control device further includes a bus 303 for connecting the memory 302 and the processor 301.

[0104] An embodiment of the present application also proposes a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above urea nozzle injection flow control method.

[0105] In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of modules is only a logical function division, and there may be other division methods in actual implementation. For example, multiple modules can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of devices or modules can be in electrical, mechanical or other forms.

[0106] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0107] In addition, in each embodiment of the present invention, the various functional modules can be integrated in a processing unit, or each module can exist physically alone, or two or more modules can be integrated in one unit. The units formed by the above modules can be implemented in the form of hardware or in the form of a combination of hardware and software functional units.

[0108] The above integrated modules implemented in the form of software functional modules can be stored in a computer-readable storage medium. The above software functional modules are stored in a storage medium and include several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) to execute some steps of the methods in the various embodiments of the present application.

[0109] It should be understood that the above-mentioned processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly embodied as being executed and completed by a hardware processor, or by a combination of hardware and software modules in the processor.

[0110] The memory may include high-speed RAM memory, and may also include non-volatile storage NVM, such as at least one disk memory, and may also be a USB flash drive, a mobile hard disk, a read-only memory, a magnetic disk, or an optical disc, etc.

[0111] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience in representation, the buses in the accompanying drawings of this application are not limited to only one bus or one type of bus.

[0112] The above-mentioned storage medium may be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic memory, flash memory, a magnetic disk, or an optical disc. The storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0113] An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and the storage medium may be located in an Application Specific Integrated Circuit (ASIC). Of course, the processor and the storage medium may also exist as discrete components in an electronic device or a master control device.

[0114] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps including the above method embodiments; and the foregoing storage medium includes: various media such as ROM, RAM, magnetic disk, or optical disc that can store program codes.

[0115] As described above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for controlling the injection flow rate of a urea nozzle, characterized in that, including: obtaining a basic urea demand flow rate of the urea nozzle according to a basic opening degree at which the urea nozzle can meet a required injection volume during an initial use stage; obtaining a current injection flow rate of the urea nozzle at the basic opening degree according to the basic opening degree; obtaining the basic urea demand flow rate or the current injection flow rate of the urea nozzle includes: when the urea nozzle is in an initial use stage or a subsequent use stage other than the initial use stage, the urea nozzle stops injecting urea, the urea pump is stabilized to a set pump pressure, and the urea pump is fixed to a set rotational speed; the urea nozzle is opened at the basic opening degree, a set volume of urea is consumed, the pump pressure at the opening moment and the closing moment of the urea nozzle are collected, and according to the change in the pump pressure of the urea pump, the average injection flow rate of the urea nozzle is calculated; the average injection flow rate is calculated once for each consumption of the set volume of urea, and a sequence of the average injection flow rates is obtained; the basic urea demand flow rate or the current injection flow rate of the urea nozzle is calculated according to the sequence of the average injection flow rates; obtaining a compensation factor for the opening degree of the urea nozzle according to the basic urea demand flow rate and the current injection flow rate; obtaining an actual driving opening degree to be output by the urea nozzle according to the compensation factor and the basic opening degree; 2. The urea nozzle injection flow rate control method according to claim 1, characterized in that, the calculation of the driving opening degree includes: a1 = Fac * a0; where Fac = Q sys / Q act ; Wherein, a1 is the driving opening degree, Fac is the compensation factor, and Q sys is the basic urea demand flow rate, and Q act is the current injection flow rate, and a0 is the basic opening degree.

3. The urea nozzle injection flow rate control method according to claim 1, wherein the calculation of the average injection flow rate of the urea nozzle includes: Average injection flow rate Q dos = Q su - Q back , where Q su is the average supply flow rate of the urea pump, and Q back is the average flow rate of the urea pump return hole; When the urea pump operates at a set rotational speed and stabilizes the pump pressure to the set pump pressure and the urea nozzle does not spray, the average supply flow rate of the urea pump is balanced with the average flow rate of the return hole, i.e., Q su is equal to Q back and the system constant C is calculated b ; Average injection flow rate Q dos = C b *(P1)^ 1 / 2 - C b *[(P1 + P2) / 2]^ 1 / 2 ; wherein, P1 is the pump pressure at the start moment of injection, and P2 is the pump pressure at the end moment of injection.

4. The urea nozzle injection flow rate control method according to claim 1 or 2, characterized in that, If the compensation factor exceeds a set range, the compensation condition for the opening degree of the urea nozzle is satisfied, and an actual driving opening degree to be output by the urea nozzle is obtained according to the compensation factor and the basic opening degree, otherwise the urea nozzle operates at the basic opening degree.

5. A urea nozzle injection flow control device, characterized in that, including: a urea pump pump pressure acquisition module configured to, when the urea nozzle stops injecting urea, stabilize the urea pump to a set pump pressure, fix the urea pump to a set rotational speed, open the urea nozzle at a basic opening degree, consume a set volume of urea, and collect the pump pressure at the opening moment and the closing moment of the urea nozzle, wherein the basic opening degree is the opening degree of the nozzle that can meet the required injection volume when the urea nozzle is in an initial use stage; a determination module configured to, when the urea nozzle is in an initial use stage or a subsequent use stage other than the initial use stage, calculate the average injection flow rate of the urea nozzle according to the change in the pump pressure of the urea pump, obtain a sequence of average injection flow rates, and then calculate the basic urea demand flow rate or the current injection flow rate according to the sequence of the average injection flow rates; a control module configured to obtain a compensation factor for the opening degree of the urea nozzle according to the basic urea demand flow rate and the current injection flow rate; and obtain an actual driving opening degree to be output by the urea nozzle according to the compensation factor and the basic opening degree, and adjust the actual opening degree of the urea nozzle to the driving opening degree.

6. The urea nozzle injection flow control device according to claim 5, characterized in that, The control device further includes: a storage module configured to store the obtained basic urea demand flow rate if the operation time of the urea nozzle is within a preset time period at the factory.

7. A urea nozzle injection flow control device, characterized in that, including: at least one processor and a memory; the memory stores computer-executable instructions; The at least one processor executes the computer-executable instructions stored in the memory, such that the at least one processor executes the control method according to any one of claims 1-4.

8. A computer-readable storage medium, characterized in that, Computer-executable instructions are stored in the computer-readable storage medium, and when the processor executes the computer-executable instructions, the control method according to any one of claims 1-4 is implemented.

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