CN115045738B - Control method and device of urea injection system, processor and urea injection system - Google Patents

Abstract

The application provides a control method and device of a urea injection system, a processor and the urea injection system. The method comprises the following steps: acquiring a first related parameter of a first selective catalytic conversion device; determining a first urea injection quantity of a first selective catalytic conversion device according to a first related parameter; obtaining a second phase Guan Canliang of a second selective catalytic conversion device; determining a second urea injection amount for a second selective catalytic conversion device based on the second phase Guan Canliang and the first related parameter; the first urea nozzle is controlled to inject urea based on the first urea injection amount, and the second urea nozzle is controlled to inject urea based on the second urea injection amount. The solution solves the problem that the urea injection quantity cannot be accurately determined in the prior art.

Description

Control method, device, processor and urea injection system of urea injection system

Technical field

The present application relates to the field of urea treatment, and specifically, to a control method, device, computer-readable storage medium, processor and urea injection system for a urea injection system.

Background technique

During the operation of the diesel engine, nitrogen oxides will be produced. In order to meet the emission requirements, the current diesel engine processing system will be equipped with an SCR (Selective Catalystic Reduction, selective catalytic reduction) device. The catalyst installed in the exhaust management The urea aqueous solution is sprayed to reduce nitrogen oxides into pollution-free nitrogen, thereby reducing emissions and meeting emission requirements. However, in the current solution, the urea injection amount cannot be accurately determined during the control process of the urea injection amount.

Contents of the invention

The main purpose of this application is to provide a control method, device, computer-readable storage medium, processor and urea injection system for a urea injection system, so as to solve the problem in the prior art that the urea injection amount cannot be accurately determined.

According to an aspect of an embodiment of the present invention, a method for controlling a urea injection system is provided. The urea injection system includes a first urea nozzle, a first selective catalytic conversion device, and a second urea nozzle sequentially distributed from upstream to downstream. and a second selective catalytic conversion device, the method including: obtaining a first relevant parameter of the first selective catalytic conversion device, the first relevant parameter being urea that will affect the first selective catalytic conversion device Parameters of the injection amount; determining the first urea injection amount of the first selective catalytic conversion device according to the first relevant parameters; obtaining second relevant parameters of the second selective catalytic conversion device; according to the first The two related parameters and the first related parameter determine the second urea injection amount of the second selective catalytic conversion device, and the second related parameter is the urea injection amount that will affect the second selective catalytic conversion device. parameters; the first urea nozzle is controlled to inject urea based on the first urea injection amount, and the second urea nozzle is controlled to inject urea based on the second urea injection amount.

Optionally, the urea injection system further includes a first nitrogen oxygen sensor, a first agitator, a first temperature sensor, an oxidation catalyst, a particulate matter trap and a second nitrogen oxygen sensor, the first nitrogen oxygen sensor is located Upstream of the first urea nozzle, the first agitator is located between the first urea nozzle and the first temperature sensor, and the first temperature sensor is located between the first agitator and the first Between the selective catalytic conversion device, the oxidation catalytic converter is located between the first selective catalytic conversion device and the particulate matter trap, and the second nitrogen and oxygen sensor is located between the particulate matter trap and the particulate matter trap. Between the second urea nozzles, the first relevant parameters include at least one of the following: first temperature, first air velocity, first gas flow rate, and second gas flow rate, where the first temperature is the first The temperature collected by the temperature sensor, the first space speed is the space speed between the first agitator and the first selective catalytic conversion device, the first space speed is the volume of ammonia gas and the volume of the catalyst The ratio of volumes, the first gas flow rate is the gas flow rate collected by the first nitrogen oxygen sensor, and the second gas flow rate is the gas flow rate collected by the second nitrogen oxygen sensor.

Optionally, after obtaining the first relevant parameters of the first selective catalytic conversion device, the method further includes: constructing according to the first temperature, the first space velocity and the first gas flow rate. a first model, and using the first model to determine a first predetermined ammonia gas storage amount of the first selective catalytic conversion device and a first predetermined conversion efficiency of the first selective catalytic conversion device, the first The predetermined conversion efficiency refers to the predetermined conversion rate of ammonia generated from urea into nitrogen oxides.

Optionally, determining the first urea injection amount of the first selective catalytic conversion device according to the first relevant parameter includes: according to the first temperature, the first gas flow rate and the first predetermined amount. Conversion efficiency, determine the first feedforward injection quantity of the first selective catalytic conversion device; perform ammonia storage correction according to the first predetermined ammonia gas storage quantity, determine the first ammonia gas correction injection quantity; according to the first predetermined ammonia gas storage quantity The first correction factor of the urea injection amount is determined based on the predetermined conversion efficiency, the first temperature and the first airspeed; based on the first feedforward injection amount, the first ammonia corrected injection amount and the third A correction factor determines the first urea injection amount of the first selective catalytic conversion device.

Optionally, determining a first feedforward injection amount of the first selective catalytic conversion device according to the first temperature, the first gas flow rate and the first predetermined conversion efficiency includes: obtaining the first feedforward injection amount. The product of a gas flow rate and the first predetermined conversion efficiency is used to obtain the first basic urea injection amount; the amount of ammonia oxidation gas obtained by oxidizing ammonia in the first selective catalytic conversion device is obtained; using the first The temperature performs ammonia storage correction on the ammonia oxidation gas amount to determine the first feedforward injection amount.

Optionally, performing ammonia storage correction based on the first predetermined ammonia gas storage amount and determining the first ammonia gas correction injection amount includes: obtaining a first actual ammonia gas based on the first temperature and the first airspeed. Storage amount; obtain the first difference between the first actual ammonia storage amount and the first predetermined ammonia storage amount; use the first difference to adjust the first actual ammonia storage amount until the If the difference between the first actual ammonia gas storage amount and the first predetermined ammonia gas storage amount is less than a first difference threshold, the first ammonia gas corrected injection amount is obtained.

Optionally, determining a first correction factor for the urea injection amount based on the first predetermined conversion efficiency, the first temperature and the first airspeed includes: based on the first temperature and the first airspeed. speed, determine the first correction proportional coefficient; obtain the first actual conversion efficiency, the first actual conversion efficiency refers to the real conversion rate of ammonia generated by urea into nitrogen oxide compounds; obtain the first predetermined conversion efficiency and The second difference of the first actual conversion efficiency; obtain the product of the first correction proportional coefficient and the second difference to obtain the first correction factor.

Optionally, the first urea injection amount of the first selective catalytic conversion device is determined based on the first feedforward injection amount, the first ammonia correction injection amount and the first correction factor, The method includes: obtaining the product of the first feedforward injection amount and the first correction factor to obtain an initial first urea injection amount; obtaining the initial first urea injection amount, the first feedforward injection amount and the The first ammonia gas correction amount is summed to obtain the first urea injection amount.

Optionally, the urea injection system further includes a second temperature sensor, a second agitator, an ammonia escape trap and a third nitrogen and oxygen sensor, the second temperature sensor is located between the first selective catalytic conversion device and the between the second urea nozzle, the second agitator is located between the second urea nozzle and the second selective catalytic conversion device, and the ammonia escape trap is located in the second selective catalytic conversion device between the third nitrogen oxygen sensor and the third nitrogen oxygen sensor located downstream of the ammonia escape trap, the second relevant parameter includes at least one of the following: a second temperature, a second airspeed and The third gas flow rate, wherein the second temperature is the temperature collected by the second temperature sensor, and the second space velocity is the distance between the first selective catalytic conversion device and the second agitator. Space speed, the second space speed is the ratio of the volume of ammonia gas to the volume of the catalyst, and the third gas flow rate is the gas flow rate collected by the third nitrogen and oxygen sensor.

Optionally, after obtaining the second relevant parameters of the second selective catalytic conversion device, the method further includes: constructing according to the second temperature, the second space speed and the second relevant parameters. a second model, and using the second model to determine a second predetermined ammonia storage amount of the second selective catalytic conversion device and a second predetermined conversion efficiency of the second selective catalytic conversion device, the second The predetermined conversion efficiency refers to the predetermined conversion rate of ammonia generated from urea into nitrogen oxides.

Optionally, determining the second urea injection amount of the second selective catalytic conversion device according to the second relevant parameter and the first relevant parameter includes: according to the second temperature, the second air Quickly sum the first relevant parameters to determine the second feedforward injection amount of the second selective catalytic conversion device; perform ammonia storage correction according to the second predetermined ammonia storage amount to determine the second corrected ammonia injection amount ; Determine the second urea injection amount of the second selective catalytic conversion device based on the second feedforward injection amount and the second ammonia correction injection amount.

Optionally, the first relevant parameter includes a second gas flow rate, and the second flow rate of the second selective catalytic conversion device is determined based on the second temperature, the second space speed and the first relevant parameter. The feedforward injection amount includes: determining the feedforward conversion efficiency according to the second temperature and the second airspeed, where the feedforward conversion efficiency is the ratio of the ammonia gas storage amount to the second gas flow rate; obtaining the The second feedforward injection amount is obtained by multiplying the feedforward conversion efficiency and the second gas flow rate.

Optionally, performing ammonia storage correction according to the second predetermined ammonia gas storage amount and determining a second ammonia gas correction injection amount includes: obtaining a second actual ammonia gas according to the second temperature and the second airspeed. Storage amount; obtain the third difference between the second actual ammonia storage amount and the second predetermined ammonia storage amount; use the third difference to adjust the second actual ammonia storage amount until the If the difference between the second actual ammonia gas storage amount and the second predetermined ammonia gas storage amount is less than a second difference threshold, the second ammonia gas corrected injection amount is obtained.

Optionally, determining the second urea injection amount of the second selective catalytic conversion device according to the second feedforward injection amount and the second ammonia correction injection amount includes: from the current moment to the history Within a predetermined period of time, determine the number of deviations between the third gas flow rate and the predetermined gas flow rate; when the number of deviations is less than the threshold number of deviations, use the first method to modify the second selective catalytic conversion device The urea injection amount is corrected to determine the second urea injection amount; when the number of deviations is greater than or equal to the deviation number threshold, the second method is used to adjust the urea injection amount of the second selective catalytic conversion device Correction is made to determine the second urea injection amount.

Optionally, when the number of deviations is less than a threshold number of deviations, the first method is used to correct the urea injection amount of the second selective catalytic conversion device, and the second urea injection amount is determined, including: Obtain the actual gas flow rate; obtain the fourth difference between the actual gas flow rate and the third gas flow rate; determine a second correction proportional coefficient according to the second temperature and the second airspeed; obtain the fourth The product of the difference and the second correction proportional coefficient is obtained to obtain the second correction factor; the product of the second correction factor and the basic injection volume is obtained to obtain the second urea injection volume, wherein the basic injection volume is It is determined based on the second temperature and the second airspeed.

Optionally, when the number of deviations is greater than or equal to a threshold number of deviations, a second method is used to correct the urea injection amount of the second selective catalytic conversion device and determine the second urea injection amount, The method includes: obtaining the actual gas flow rate and the average actual gas flow rate, wherein the average actual gas flow rate is the average value of the actual gas flow rate obtained at multiple times within a predetermined time period from the current time to the historical time; obtaining the average actual gas flow rate. Three gas flow rates, wherein the average third gas flow rate is the third gas flow rate at multiple moments within the predetermined time period from the current moment to the historical moment obtained using the second model. average; obtain the fifth difference between the average actual gas flow and the average third gas flow; filter the fifth difference using EWMA filtering to obtain a third correction factor; obtain the second front The sum of the feed injection amount and the second ammonia corrected injection amount is obtained to obtain the initial second urea injection amount; the product of the third correction factor and the initial second urea injection amount is obtained to obtain the second urea injection amount. quantity.

According to another aspect of the embodiment of the present invention, a control device for a urea injection system is also provided. The urea injection system includes a first urea nozzle, a first selective catalytic conversion device, a second urea injection nozzle, and a second selective catalytic conversion device. Urea nozzle and second selective catalytic conversion device, the device includes a first acquisition unit, a first determination unit, a second acquisition unit, a second determination unit and a control unit: the first acquisition unit is used to acquire the first The first relevant parameter of the selective catalytic conversion device, the first relevant parameter is a parameter that will affect the urea injection amount of the first selective catalytic conversion device; the first determination unit is used to determine based on the first relevant parameter, Determine the first urea injection amount of the first selective catalytic conversion device; the second acquisition unit is used to obtain the second relevant parameters of the second selective catalytic conversion device, the second relevant parameters will affect the The parameter of the urea injection amount of the second selective catalytic conversion device; the second determination unit is used to determine the second urea injection amount of the second selective catalytic conversion device according to the second relevant parameter and the first relevant parameter. quantity; the control unit is configured to control the first urea nozzle to inject urea based on the first urea injection quantity, and control the second urea nozzle to inject urea based on the second urea injection quantity.

According to yet another aspect of the embodiment of the present invention, a computer-readable storage medium is also provided. The computer-readable storage medium includes a stored program, wherein the program executes any one of the methods described above.

According to yet another aspect of the embodiment of the present invention, a processor is also provided, the processor being configured to run a program, wherein the program executes any one of the methods described above when running.

According to another aspect of the embodiment of the present invention, a urea injection system is also provided, including a first nitrogen and oxygen sensor, a first urea nozzle, a first agitator, a first temperature sensor, a first temperature sensor, and a first nitrogen and oxygen sensor distributed in sequence from upstream to downstream. Selective catalytic conversion device, oxidation catalytic converter, particulate matter trap, second nitrogen and oxygen sensor, second temperature sensor, second urea nozzle, second agitator, second selective catalytic conversion device, ammonia escape trap , a third nitrogen oxygen sensor and a controller, the controller is respectively connected to the first nitrogen oxygen sensor, the first urea nozzle, the first agitator, the first temperature sensor, the first selection catalytic conversion device, the oxidation catalytic converter, the particulate matter trap, the second nitrogen oxygen sensor, the second temperature sensor, the second urea nozzle, the second agitator, the The second selective catalytic conversion device, the ammonia escape trap and the third nitrogen oxygen sensor communicate, and the controller is used to execute any one of the methods.

In the embodiment of the present invention, first the first relevant parameter of the first selective catalytic conversion device is obtained, and then the first urea injection amount of the first selective catalytic conversion device is determined based on the first relevant parameter, and then the second selectivity is obtained the second relevant parameter of the catalytic conversion device, and then determine the second urea injection amount of the second selective catalytic conversion device based on the second relevant parameter and the first relevant parameter, and finally control the first urea nozzle to inject urea based on the first urea injection amount , controlling the second urea nozzle to inject urea based on the second urea injection amount. In this solution, the urea injection system has a first selective catalytic conversion device and a second selective catalytic conversion device, as well as a first urea nozzle and a second urea nozzle, which are coordinated and controlled by the two selective catalytic conversion devices. Compared with The existing technology can emit nitrogen oxides more efficiently, and this solution can accurately determine the first urea injection amount of the first selective catalytic conversion device, and can also accurately determine the second urea injection amount of the second selective catalytic conversion device. quantity, the demand for high conversion rate of the selective catalytic conversion device can be achieved, thereby solving the problem of the inability to accurately determine the urea injection quantity in the existing technology, and this solution can accurately determine the urea injection quantity according to the first urea injection quantity and the second urea injection quantity. Controlling the urea injection volume of the first urea nozzle and the second urea nozzle improves the conversion rate of nitrogen oxides.

Description of the drawings

The description and drawings that constitute a part of this application are used to provide a further understanding of this application. The illustrative embodiments and their descriptions of this application are used to explain this application and do not constitute an improper limitation of this application. In the attached picture:

Figure 1 shows a schematic flow chart of a control method of a urea injection system according to an embodiment of the present application;

Figure 2 shows a schematic structural diagram of the urea injection system of the present application;

Figure 3 shows a schematic flow chart for determining the first urea injection amount of the first selective catalytic conversion device;

Figure 4 shows a schematic flow chart for determining the second urea injection amount of the second selective catalytic conversion device;

Figure 5 shows a schematic structural diagram of a control device of a urea injection system according to an embodiment of the present application.

Among them, the above-mentioned drawings include the following reference signs:

10. The first urea nozzle; 11. The first selective catalytic conversion device; 12. The second urea nozzle; 13. The second selective catalytic conversion device; 14. The first nitrogen and oxygen sensor; 15. The first agitator; 16 , first temperature sensor; 17. oxidation catalytic converter; 18. particulate matter trap; 19. second nitrogen and oxygen sensor; 20. second temperature sensor; 21. second agitator; 22. ammonia escape trap; 23 , the third nitrogen and oxygen sensor; 24. the third temperature sensor.

Detailed ways

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

In order to enable those in the technical field to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only These are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of protection of this application.

It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that data so used may be interchanged where appropriate for the embodiments of the application described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus that encompasses a series of steps or units and need not be limited to those explicitly listed. Those steps or elements may instead include other steps or elements not expressly listed or inherent to the process, method, product or apparatus.

It will be understood that when an element (such as a layer, film, region, or substrate) is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. Furthermore, in the specification and claims, when an element is described as being "connected" to another element, it can be "directly connected" to the other element, or "connected" to the other element through a third element.

For the convenience of description, some nouns or terms involved in the embodiments of this application are described below:

First selective catalytic conversion device: Pre-SCR (selectively catalytic reduction, referred to as preSCR). Urea is injected before the first selective catalytic conversion device to reduce nitrogen oxides in exhaust emissions. The first selective catalytic conversion device is separated from the first selective catalytic conversion device. The turbine distance of the system is the first distance;

Second selective catalytic conversion device: rear-mounted SCR (posSCR for short). Urea is injected before the second selective catalytic conversion device to reduce nitrogen oxides in exhaust emissions. The second selective catalytic conversion device is located away from the turbine of the system. is the second distance, and the first distance is smaller than the second distance;

The Diesel Particulate Filter (DPF) is used to capture particulate matter in the exhaust gas. When the quality of the captured particulate matter reaches a certain level, passive regeneration or active regeneration is required to restore the particulate matter trap's ability to control particulate matter. The collection ability mainly filters and captures particles in engine exhaust through diffusion, deposition and impact mechanisms. When the exhaust gas flows through the collector, the particles are captured in the filter element of the filter body, and the remaining cleaner exhaust gas is discharged into the atmosphere. Currently, wall-flow honeycomb ceramic filters are widely used. They are mainly used in construction machinery and city buses. They are characterized by simple operation and high filtration efficiency. However, there are problems with filter regeneration and sensitivity to sulfur components in fuel. question;

Diesel Oxidation Catalysis (DOC) is used to convert NO (nitric oxide) in the exhaust gas into NO ₂ (nitrogen dioxide), while increasing the temperature of the exhaust gas, assisting the particulate matter trap and selective catalytic conversion device The normal operation of the engine is to coat precious metal catalysts (such as Pt, etc.) on the honeycomb ceramic carrier. The purpose is to reduce the chemical reaction activation energy of HC, CO and SOF in the engine exhaust so that these substances can interact with the oxygen in the exhaust. The oxidation reaction proceeds at lower temperatures and is ultimately converted into CO ₂ and H ₂ O. The oxidation catalytic converter does not require a regeneration system and control device, has the characteristics of simple structure and good reliability, and has been widely used in modern small engines;

Ammonia Slip Catalyst (ASC), used to oxidize excess ammonia;

The basic working principle of the particulate matter trap is: when the engine exhaust flows through the oxidation catalytic converter (DOC), at a temperature of 200-600°C, CO and HC are first almost completely oxidized into CO ₂ and H ₂ O, and at the same time NO is converted into NO ₂ . After the exhaust gas comes out of the DOC and enters the particulate matter trap (DPF), the particles are captured in the filter element of the filter body, and the remaining cleaner exhaust gas is discharged into the atmosphere. The DPF's collection efficiency can reach more than 90%.

NO2 has a strong oxidizing ability on the captured particles. The generated _NO2 is used as an oxidant to remove particles in the particulate matter trap and generate _CO2 , and _NO2 is reduced to NO, thereby achieving the purpose of removing particles.

Reaction principle within DOC:

2NO+O ₂ →2NO ₂

2CO+O ₂ →2CO ₂

2CH+O ₂ →CO ₂ +H ₂ O

Reaction principle within DPF:

C+2NO ₂ →CO ₂ +2NO

There are two methods of filter regeneration: active regeneration and passive regeneration: Active regeneration refers to using external energy to increase the temperature inside the collector to cause the particles to ignite and burn. When the temperature in the filter reaches 550°C, the deposited particles will oxidize and burn. If the temperature does not reach 550°C, excessive sediment will clog the filter. At this time, external energy (such as an electric heater) will be needed. , changes in burner or engine operating conditions) to increase the temperature within the DPF, causing the particulate matter to oxidize and burn. Passive regeneration refers to the use of fuel additives or catalysts to reduce the ignition temperature of particles so that the particles can ignite and burn at normal engine exhaust temperatures. Additives (including cerium, iron and strontium) must be added to the fuel in a certain proportion. Too much additives will have little effect, but if there are too few, it will cause regeneration delay or increase the regeneration temperature.

The basic principle of SCR is to inject fuel into the exhaust or add additional reducing agents, and use a suitable catalyst to promote the reaction between the reducing agent and NOx, while inhibiting the non-selective oxidation reaction of the reducing agent and oxygen. Commonly used urea-SCR catalysts are V ₂ O ₅ /W ₂ O ₃ /TiO ₂ and metal oxide/zeolite. Vanadium-based catalysts have high selectivity for NOx and a wide high-efficiency temperature window. They also have high sulfur resistance. The disadvantage is that they are easily poisoned by phosphorus components in the lubricating oil and fail at high temperatures; zeolite-type catalysts are sensitive to NH ₃ Extremely strong adsorption capacity, but zeolite also has strong adsorption capacity for HC at low temperatures, and the adsorption of HC will affect the low-temperature performance of the catalytic converter. At the same time, zeolite has poor hydrothermal stability and sulfur resistance, so its actual use is limited. restrictions, requiring the use of low-sulfur content fuel.

Sulfur oxides will form sulfates in copper-based SCR, reducing the catalyst active site, blocking small pores, and reducing the SCR's conversion efficiency of NOx. Therefore, when a certain amount of sulfur oxides are captured in the SCR, they need to be treated Desulfurization. There are two mechanisms for sulfur poisoning: (NH ₄ )SO ₄ , etc. are generated, which reduces the active site of the SCR catalyst and blocks the pores, thereby reducing the NOx conversion efficiency; SO ₂ and SO ₃ compete with NO _x for adsorption, reducing the adsorption of NO _x ;

The reaction principle of SCR technology:

Hydrolysis of urea into ammonia gas: (urea injection system)

(NH2) ₂ CO+H ₂ O→2NH ₃ +CO ₂

SCR post-treatment reaction: (SCR catalytic converter)

NO+NO ₂ +2NH ₃ →2N ₂ +3H ₂ O

4NO+O ₂ +4NH ₃ →4N ₂ +6H ₂ O

2NO ₂ +O ₂ +4NH ₃ →3N ₂ +6H ₂ O

The reducing agent that actually participates in the selective catalytic reduction reaction in SCR is ammonia (NH ₃ ). However, due to the high corrosiveness of ammonia, liquid ammonia and ammonia water are difficult to store and transport, so they cannot be directly used in vehicle-mounted SCR systems. Nowadays, urea aqueous solution is generally used as reducing agent. And because compared with urea aqueous solutions of other concentrations, 32.5% urea aqueous solution has the lowest freezing point of -11°C, so 32.5% urea aqueous solution is commonly used internationally as the standard reducing agent for SCR, and is named AdBlue.

In order to prevent the waste of reductant and secondary pollution caused by NH ₃ leakage after the SCR catalyst, the injection amount of the reductant must be dynamically controlled based on the actual _NOx emissions of the engine and the conversion efficiency of the SCR catalyst. Therefore, the injection strategy of the reductant is Hot spots and difficulties in SCR technology research. Since urea aqueous solution is only a carrier of NH ₃ , the process of decomposing urea aqueous solution into NH ₃ has an important impact on the performance of SCR.

As mentioned in the background art, the urea injection amount cannot be accurately determined in the prior art. In order to solve the above problems, in an embodiment of the present application, a control method, device, and computer-readable method of the urea injection system are provided. Storage media, processor and urea injection system.

According to an embodiment of the present application, a method for controlling a urea injection system is provided. The above-mentioned urea injection system includes a first urea nozzle, a first selective catalytic conversion device, a second urea nozzle and a second urea nozzle sequentially distributed from upstream to downstream. Selective catalytic conversion device.

Figure 1 is a flow chart of a control method of a urea injection system according to an embodiment of the present application. As shown in Figure 1, the method includes the following steps:

Step S101: Obtain the first relevant parameter of the above-mentioned first selective catalytic conversion device, the above-mentioned first relevant parameter is a parameter that will affect the urea injection amount of the above-mentioned first selective catalytic conversion device;

Step S102, determine the first urea injection amount of the first selective catalytic conversion device according to the first relevant parameter;

Step S103, obtain the second relevant parameters of the above-mentioned second selective catalytic conversion device;

Step S104: Determine the second urea injection amount of the second selective catalytic conversion device based on the second relevant parameter and the first relevant parameter. The second relevant parameter is the urea that will affect the second selective catalytic conversion device. Parameters of injection volume;

Step S105: Control the first urea nozzle to inject urea based on the first urea injection amount, and control the second urea nozzle to inject urea based on the second urea injection amount.

In the above method, first the first relevant parameters of the first selective catalytic conversion device are obtained, and then the first urea injection amount of the first selective catalytic conversion device is determined based on the first relevant parameters, and then the second selective catalytic conversion device is obtained. the second relevant parameter of the device, and then determine the second urea injection amount of the second selective catalytic conversion device based on the second relevant parameter and the first relevant parameter, and finally control the first urea nozzle to inject urea based on the first urea injection amount, based on The second urea injection amount controls the second urea nozzle to inject urea. In this solution, the urea injection system has a first selective catalytic conversion device and a second selective catalytic conversion device, as well as a first urea nozzle and a second urea nozzle, which are coordinated and controlled by the two selective catalytic conversion devices. Compared with The existing technology can emit nitrogen oxides more efficiently, and this solution can accurately determine the first urea injection amount of the first selective catalytic conversion device, and can also accurately determine the second urea injection amount of the second selective catalytic conversion device. quantity, the demand for high conversion rate of the selective catalytic conversion device can be achieved, thereby solving the problem of the inability to accurately determine the urea injection quantity in the existing technology, and this solution can accurately determine the urea injection quantity according to the first urea injection quantity and the second urea injection quantity. Controlling the urea injection volume of the first urea nozzle and the second urea nozzle improves the conversion rate of nitrogen oxides.

It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and, although a logical sequence is shown in the flowchart, in some cases, The steps shown or described may be performed in a different order than here.

In one embodiment of the present application, as shown in Figure 2, the above-mentioned urea injection system includes a first urea nozzle 10, a first selective catalytic conversion device 11, a second urea nozzle 12 and a second urea injection system sequentially distributed from upstream to downstream. Selective catalytic conversion device 13, the above-mentioned urea injection system also includes a first nitrogen oxygen sensor 14, a first agitator 15, a first temperature sensor 16, an oxidation catalyst 17, a particulate matter trap 18 and a second nitrogen oxygen sensor 19, The first nitrogen and oxygen sensor 14 is located upstream of the first urea nozzle 10 . The first agitator 15 is located between the first urea nozzle 10 and the first temperature sensor 16 . The first temperature sensor 16 is located between the first urea nozzle 10 and the first temperature sensor 16 . Between the agitator 15 and the first selective catalytic conversion device 11, the oxidation catalytic converter 17 is located between the first selective catalytic conversion device 11 and the particulate matter trap 18, and the second nitrogen oxygen sensor 19 is located above Between the particulate matter trap 18 and the above-mentioned second urea nozzle 12, the above-mentioned first relevant parameters include at least one of the following: a first temperature, a first air velocity, a first gas flow rate and a second gas flow rate, wherein the above-mentioned first The temperature is the temperature collected by the first temperature sensor 16, the first space speed is the space speed between the first agitator 15 and the first selective catalytic conversion device 11, and the first space speed is the air speed of ammonia gas. The ratio of the volume to the volume of the catalyst, the first gas flow rate is the gas flow rate collected by the first nitrogen oxygen sensor 14 , and the second gas flow rate is the gas flow rate collected by the second nitrogen oxygen sensor 19 . In this embodiment, the first temperature, the first air velocity, the first gas flow rate, and the second gas flow rate can be obtained. Subsequently, based on the first temperature, the first air velocity, the first gas flow rate, and the second gas flow rate, more information can be obtained. In order to accurately determine the first urea injection amount of the first selective catalytic conversion device.

In yet another embodiment of the present application, after obtaining the first relevant parameters of the first selective catalytic conversion device, the above method further includes: based on the above first temperature, the above first space velocity and the above first gas flow rate, Constructing a first model, and using the first model to determine the first predetermined ammonia gas storage amount of the above-mentioned first selective catalytic conversion device and the first predetermined conversion efficiency of the above-mentioned first selective catalytic conversion device, the above-mentioned first predetermined conversion efficiency It refers to the predetermined conversion rate of ammonia produced by urea into nitrogen oxides. In this embodiment, a first model is constructed, and the first predetermined ammonia storage amount and the first predetermined conversion efficiency determined by the first model can be used as standard values. Subsequently, the actual acquired data can be adjusted according to the standard values to further ensure The first urea injection amount is more accurate.

In another embodiment of the present application, determining the first urea injection amount of the first selective catalytic conversion device based on the above-mentioned first relevant parameters includes: based on the above-mentioned first temperature, the above-mentioned first gas flow rate and the above-mentioned first gas flow rate. Predetermined conversion efficiency, determine the first feedforward injection amount of the above-mentioned first selective catalytic conversion device; perform ammonia storage correction according to the above-mentioned first predetermined ammonia gas storage amount, determine the first ammonia gas correction injection amount; according to the above-mentioned first predetermined conversion efficiency, the above-mentioned first temperature and the above-mentioned first airspeed, determine the first correction factor of the urea injection amount; based on the above-mentioned first feedforward injection amount, the above-mentioned first ammonia gas correction injection amount and the above-mentioned first correction factor, determine the above-mentioned third The above-mentioned first urea injection amount of a selective catalytic conversion device. In this embodiment, the first urea injection amount has three influencing factors, which are the first feedforward injection amount, the first ammonia correction injection amount and the first correction factor. These three data are first determined respectively, and subsequently the first feedforward injection amount can be determined according to the first correction factor. The feedforward injection amount, the first ammonia correction injection amount and the first correction factor more accurately determine the first urea injection amount of the first selective catalytic conversion device.

In yet another embodiment of the present application, determining the first feedforward injection amount of the above-mentioned first selective catalytic conversion device according to the above-mentioned first temperature, the above-mentioned first gas flow rate and the above-mentioned first predetermined conversion efficiency includes: obtaining the above-mentioned The first basic urea injection amount is obtained by multiplying the first gas flow rate and the above-mentioned first predetermined conversion efficiency; obtaining the ammonia oxidation gas amount obtained by oxidizing ammonia in the above-mentioned first selective catalytic conversion device; using the above-mentioned first temperature to The above-mentioned ammonia oxidation gas amount is subjected to ammonia storage correction to determine the above-mentioned first feedforward injection amount. In this embodiment, the first feedforward injection amount of urea of the first selective catalytic conversion device can be further accurately determined, and then the first urea injection amount can be determined more accurately based on the accurate first feedforward injection amount. .

In a specific embodiment of the present application, performing ammonia storage correction based on the above-mentioned first predetermined ammonia gas storage amount and determining the first ammonia gas correction injection amount includes: obtaining the first ammonia gas injection amount based on the above-mentioned first temperature and the above-mentioned first airspeed. An actual ammonia gas storage capacity; obtain the first difference between the above-mentioned first actual ammonia gas storage capacity and the above-mentioned first predetermined ammonia gas storage capacity; use the above-mentioned first difference to adjust the above-mentioned first actual ammonia gas storage capacity until the above-mentioned The difference between the first actual ammonia gas storage amount and the first predetermined ammonia gas storage amount is less than the first difference threshold, and the above-mentioned first ammonia gas corrected injection amount is obtained. In this embodiment, the first corrected ammonia injection amount of urea in the first selective catalytic conversion device can be further accurately determined, and subsequently the first urea can be determined more accurately based on the accurate first corrected ammonia injection amount. Injection volume.

In one embodiment, the first actual ammonia gas storage amount of the first selective catalytic conversion device can also be determined through the following formula: Among them, θ represents the first actual ammonia storage amount, eta represents the first predetermined conversion efficiency, k represents the frequency factor, nox represents the gas flow rate collected by the first nitrogen and oxygen sensor, E represents the activation energy, the unit is J/mol, R Represents the unified gas constant, 8.3145, the unit is J/mol/k, T represents the first temperature, and sv represents the first space velocity.

In yet another specific embodiment of the present application, determining the first correction factor for the urea injection amount based on the above-mentioned first predetermined conversion efficiency, the above-mentioned first temperature and the above-mentioned first airspeed includes: based on the above-mentioned first temperature and the above-mentioned first airspeed The first airspeed determines the first correction proportional coefficient; obtains the first actual conversion efficiency, the above-mentioned first actual conversion efficiency refers to the real conversion rate of ammonia produced by urea into nitrogen oxide compounds; obtains the above-mentioned first predetermined conversion efficiency and the second difference between the above-mentioned first actual conversion efficiency; obtain the product of the above-mentioned first correction proportional coefficient and the above-mentioned second difference to obtain the above-mentioned first correction factor. In this embodiment, the first correction factor of urea of the first selective catalytic conversion device can be further accurately determined, and subsequently the first urea injection amount can be determined more accurately based on the accurate first correction factor.

In one embodiment, the first actual conversion efficiency may be collected by the second nitrogen and oxygen sensor.

In another specific embodiment of the present application, the first urea of the first selective catalytic conversion device is determined based on the first feedforward injection amount, the first ammonia correction injection amount and the first correction factor. The injection quantity includes: obtaining the product of the above-mentioned first feedforward injection quantity and the above-mentioned first correction factor to obtain the initial first urea injection quantity; obtaining the above-mentioned initial first urea injection quantity, the above-mentioned first feedforward injection quantity and the above-mentioned first first urea injection quantity. The sum of the ammonia gas correction amounts obtains the above-mentioned first urea injection amount. In this embodiment, the first urea injection amount can be determined more accurately based on the obtained first feedforward injection amount, the first ammonia corrected injection amount and the first correction factor.

Specifically, for the first predetermined conversion efficiency, if the second selective catalytic conversion device cannot meet the demand, the first correction factor can be used to correct the first urea injection amount of the first selective catalytic conversion device to improve the first urea injection amount. Conversion efficiency of the two-selective catalytic conversion device.

In a specific embodiment, the process of determining the first urea injection amount is shown in Figure 3:

The first step: construct a first model based on the first temperature, the first space velocity and the first gas flow rate, and use the first model to determine the first predetermined ammonia gas storage amount and the first predetermined conversion efficiency;

Second step: Calculate the product of the first gas flow rate and the first predetermined conversion efficiency to obtain the first basic urea injection amount, use the first temperature to perform ammonia storage correction on the ammonia oxidation gas amount, and then calculate the product with the first basic urea injection amount , obtain the above-mentioned first feedforward injection amount;

The third step: obtain the initial first actual ammonia gas storage amount based on the above-mentioned first temperature and the first airspeed, and obtain the reciprocal of the initial first actual ammonia gas storage amount through the inverse model, that is, the first actual ammonia gas storage amount, Use the first model to perform efficiency correction, calculate the first difference between the above-mentioned first actual ammonia gas storage amount and the above-mentioned first predetermined ammonia gas storage amount, perform ammonia storage correction through the first difference value, and obtain the first ammonia gas Correct injection volume;

The fourth step: obtain the first actual conversion efficiency, obtain the second difference between the first actual conversion efficiency and the first predetermined conversion efficiency, obtain the first corrected proportional coefficient, and calculate the product of the second difference and the first corrected proportional coefficient, Get the first correction factor;

Step 5: Calculate the product of the first feedforward injection amount and the first correction factor to obtain the initial first urea injection amount;

Step 6: Calculate the sum of the initial first urea injection amount, the first feedforward injection amount and the first ammonia gas correction amount to obtain the first urea injection amount.

In yet another specific embodiment of the present application, as shown in Figure 2, the above-mentioned urea injection system also includes a second temperature sensor 20, a second agitator 21, an ammonia escape trap 22 and a third nitrogen oxygen sensor 23, The second temperature sensor 20 is located between the first selective catalytic conversion device 11 and the second urea nozzle 12 , and the second agitator 21 is located between the second urea nozzle 12 and the second selective catalytic conversion device 13 , the above-mentioned ammonia escape trap 22 is located between the above-mentioned second selective catalytic conversion device 13 and the above-mentioned third nitrogen oxygen sensor 23, the above-mentioned third nitrogen oxygen sensor 23 is located downstream of the above-mentioned ammonia escape trap 22, the above-mentioned second The relevant parameters include at least one of the following: a second temperature, a second airspeed, and a third gas flow rate, wherein the second temperature is the temperature collected by the second temperature sensor 20 , and the second airspeed is the first selection. The space velocity between the catalytic conversion device 11 and the second agitator 21 , the second space velocity is the ratio of the volume of ammonia gas to the volume of the catalyst, and the third gas flow rate is collected by the third nitrogen oxygen sensor 23 gas flow rate. In this embodiment, the second temperature, the second air velocity, and the third gas flow rate can be obtained, and subsequently the third gas flow rate can be determined more accurately based on the second temperature, the second air velocity, the second gas flow rate, and the third gas flow rate. The second urea injection amount of the dual-selective catalytic conversion device.

In one embodiment, the urea injection system further includes a third temperature sensor 24 , and the third temperature sensor 24 is located between the oxidation catalyst 17 and the particulate matter trap 18 .

In an embodiment of the present application, after obtaining the second relevant parameters of the above-mentioned second selective catalytic conversion device, the above-mentioned method further includes: constructing according to the above-mentioned second temperature, the above-mentioned second space velocity and the above-mentioned second relevant parameters. The second model is used to determine the second predetermined ammonia storage capacity of the second selective catalytic conversion device and the second predetermined conversion efficiency of the second selective catalytic conversion device. The second predetermined conversion efficiency is Refers to the predetermined conversion rate of ammonia produced by urea into nitrogen oxides. In this embodiment, a second model is constructed, and the second predetermined ammonia storage amount and the second predetermined conversion efficiency determined by the second model can be used as standard values. Subsequently, the actually obtained data can be adjusted according to the standard values to further ensure The second urea injection amount is more accurate.

In yet another embodiment of the present application, determining the second urea injection amount of the above-mentioned second selective catalytic conversion device based on the above-mentioned second relevant parameter and the above-mentioned first relevant parameter includes: based on the above-mentioned second temperature, the above-mentioned second The airspeed and the above-mentioned first related parameter are used to determine the second feedforward injection amount of the above-mentioned second selective catalytic conversion device; the ammonia storage correction is performed according to the above-mentioned second predetermined ammonia gas storage amount to determine the second ammonia gas correction injection amount; according to The second feedforward injection amount and the second ammonia correction injection amount determine the second urea injection amount of the second selective catalytic conversion device. In this embodiment, the second urea injection amount has two influencing factors, namely the second feedforward injection amount and the second ammonia corrected injection amount. Subsequently, the second feedforward injection amount and the second ammonia corrected injection amount can be used. The second urea injection quantity of the second selective catalytic conversion device is determined more accurately.

In another embodiment of the present application, the above-mentioned first relevant parameter includes a second gas flow rate, and the above-mentioned second selective catalytic conversion device is determined based on the above-mentioned second temperature, the above-mentioned second space velocity and the above-mentioned first relevant parameter. The second feedforward injection amount includes: determining the feedforward conversion efficiency based on the above-mentioned second temperature and the above-mentioned second airspeed, the above-mentioned feedforward conversion efficiency being the ratio of the ammonia gas storage amount and the above-mentioned second gas flow rate; obtaining the above-mentioned feedforward conversion The product of the efficiency and the above-mentioned second gas flow rate obtains the above-mentioned second feedforward injection amount. In this embodiment, the second feedforward injection amount of the second selective catalytic conversion device can be further accurately determined, and subsequently the second urea injection amount can be determined more accurately based on the accurate second feedforward injection amount.

In yet another embodiment of the present application, performing ammonia storage correction based on the above-mentioned second predetermined ammonia gas storage amount and determining the second ammonia gas correction injection amount includes: obtaining a second ammonia gas storage amount based on the above-mentioned second temperature and the above-mentioned second airspeed. Actual ammonia storage amount; obtain the third difference between the above-mentioned second actual ammonia storage amount and the above-mentioned second predetermined ammonia storage amount; use the above-mentioned third difference to adjust the above-mentioned second actual ammonia storage amount until the above-mentioned third If the difference between the two actual ammonia gas storage amounts and the second predetermined ammonia gas storage amount is less than the second difference threshold, the above-mentioned second ammonia gas corrected injection amount is obtained. In this embodiment, the second corrected ammonia injection amount of the second selective catalytic conversion device can be further accurately determined, and then the second urea injection amount can be determined more accurately based on the accurate second ammonia corrected injection amount. .

In a specific embodiment of the present application, determining the second urea injection amount of the second selective catalytic conversion device based on the second feedforward injection amount and the second ammonia correction injection amount includes: at the current Within a predetermined time period from time to historical time, determine the number of deviations between the above-mentioned third gas flow rate and the predetermined gas flow rate; when the above-mentioned number of deviations is less than the threshold number of deviations, use the first method to modify the above-mentioned second selective catalytic conversion device The urea injection amount is corrected to determine the second urea injection amount; when the number of deviations is greater than or equal to the deviation number threshold, the second method is used to correct the urea injection amount of the second selective catalytic conversion device, The above-mentioned second urea injection amount is determined. In this embodiment, if an instantaneous deviation occurs, the first method is used to correct the urea injection amount of the second selective catalytic conversion device. If the deviation still exists after a period of time, the second method is used. In this way, the urea injection amount of the second selective catalytic conversion device is corrected, so that the second urea injection amount can be determined more accurately.

In one embodiment, the second actual conversion efficiency may be collected by the third nitrogen and oxygen sensor.

In another specific embodiment of the present application, when the number of deviations is less than the threshold number of deviations, the first method is used to correct the urea injection amount of the second selective catalytic conversion device, and the second urea injection amount is determined. The injection volume includes: obtaining the actual gas flow rate; obtaining the fourth difference between the above-mentioned actual gas flow rate and the above-mentioned third gas flow rate; determining the second correction proportional coefficient based on the above-mentioned second temperature and the above-mentioned second airspeed; obtaining the above-mentioned fourth The product of the difference and the above-mentioned second correction proportional coefficient is obtained to obtain the second correction factor; the product of the above-mentioned second correction factor and the basic injection amount is obtained to obtain the above-mentioned second urea injection amount, wherein the above-mentioned basic injection amount is based on the above-mentioned second temperature and the second airspeed above. In this embodiment, the deviated urea injection amount can be corrected more efficiently and accurately, so that the second urea injection amount can be determined more accurately.

In another specific embodiment of the present application, when the number of deviations is greater than or equal to the threshold number of deviations, a second method is used to correct the urea injection amount of the second selective catalytic conversion device to determine the number of deviations. The diurea injection amount includes: obtaining the actual gas flow rate and the average actual gas flow rate, where the above-mentioned average actual gas flow rate is the average value of the above-mentioned actual gas flow rate obtained at multiple times within a predetermined time period from the current time to the historical time; Obtain the average third gas flow rate, wherein the average third gas flow rate is the average of the third gas flow rate at multiple times during the predetermined time period from the current time to the historical time obtained using the second model; Obtain the fifth difference between the above-mentioned average actual gas flow rate and the above-mentioned average third gas flow rate; use the EWMA filtering method to filter the above-mentioned fifth difference value to obtain the third correction factor; obtain the above-mentioned second feedforward injection amount, the above-mentioned second The sum of the ammonia gas correction injection amounts is obtained to obtain the initial second urea injection amount; the product of the above-mentioned third correction factor and the above-mentioned initial second urea injection amount is obtained to obtain the above-mentioned second urea injection amount. In this embodiment, the deviated urea injection amount can be corrected more efficiently and accurately, so that the second urea injection amount can be determined more accurately.

In a specific embodiment, the process of determining the second urea injection amount is as shown in Figure 4:

The first step: construct a second model based on the second temperature, the second space velocity and the second gas flow rate, and use the second model to determine the second predetermined ammonia gas storage amount and the second predetermined conversion efficiency;

The second step: determine the feedforward conversion efficiency according to the second temperature and the second airspeed, calculate the product of the feedforward conversion efficiency and the second gas flow rate, and obtain the second feedforward injection amount;

The third step: obtain the second actual ammonia gas storage amount according to the second temperature and the second airspeed, calculate the third difference between the second actual ammonia gas storage amount and the second predetermined ammonia gas storage amount, and use the third difference value , perform ammonia storage correction to obtain the second corrected ammonia injection amount;

The fourth step: After determining that the first method is used to correct the urea injection amount of the second selective catalytic conversion device, obtain the actual gas flow, calculate the fourth difference between the third gas flow and the actual gas flow, and obtain The second correction proportional coefficient calculates the product of the fourth difference and the second correction proportional coefficient to obtain the second correction factor, uses the first temperature and the second correction factor to perform efficiency correction on the second actual conversion efficiency, and calculates the second correction factor The product of the basic injection quantity is the second urea injection quantity;

Step 5: After determining that the second method is used to correct the urea injection amount of the second selective catalytic conversion device, obtain the average actual gas flow rate and the average third gas flow rate, and calculate the average actual gas flow rate and the average third gas flow rate. For the fifth difference in gas flow, use the EWMA filtering method to filter the fifth difference to obtain the third correction factor. Obtain the sum of the second feedforward injection amount and the second ammonia correction injection amount, and then combine it with the third correction factor Perform a product operation to obtain the second urea injection amount.

The embodiment of the present application also provides a control device for the urea injection system. It should be noted that the control device of the urea injection system of the embodiment of the present application can be used to perform the control for the urea injection system provided by the embodiment of the present application. method. The control device of the urea injection system provided by the embodiment of the present application is introduced below.

Figure 5 is a schematic diagram of a control device of a urea injection system according to an embodiment of the present application. As shown in Figure 5, the device includes:

The first acquisition unit 100 is used to acquire the first relevant parameter of the above-mentioned first selective catalytic conversion device, where the above-mentioned first relevant parameter is a parameter that will affect the urea injection amount of the above-mentioned first selective catalytic conversion device;

The first determination unit 200 is used to determine the first urea injection amount of the first selective catalytic conversion device according to the first relevant parameter;

The second acquisition unit 300 is used to acquire the second relevant parameter of the above-mentioned second selective catalytic conversion device. The above-mentioned second relevant parameter is a parameter that will affect the urea injection amount of the above-mentioned second selective catalytic conversion device;

The second determination unit 400 is used to determine the second urea injection amount of the above-mentioned second selective catalytic conversion device according to the above-mentioned second relevant parameter and the above-mentioned first relevant parameter;

The control unit 500 is configured to control the first urea nozzle to inject urea based on the first urea injection amount, and control the second urea nozzle to inject urea based on the second urea injection amount.

In the above device, the first acquisition unit acquires the first relevant parameter of the first selective catalytic conversion device, the first determination unit determines the first urea injection amount of the first selective catalytic conversion device according to the first relevant parameter, and the second The acquisition unit acquires the second relevant parameter of the second selective catalytic conversion device, the second determination unit determines the second urea injection amount of the second selective catalytic conversion device based on the second relevant parameter and the first relevant parameter, and the control unit determines the second urea injection amount of the second selective catalytic conversion device based on the second relevant parameter. A urea injection amount controls the first urea nozzle to inject urea, and the second urea nozzle controls the second urea injection amount to inject urea. In this solution, the urea injection system has a first selective catalytic conversion device and a second selective catalytic conversion device, as well as a first urea nozzle and a second urea nozzle, which are coordinated and controlled by the two selective catalytic conversion devices. Compared with The existing technology can emit nitrogen oxides more efficiently, and this solution can accurately determine the first urea injection amount of the first selective catalytic conversion device, and can also accurately determine the second urea injection amount of the second selective catalytic conversion device. quantity, the demand for high conversion rate of the selective catalytic conversion device can be achieved, thereby solving the problem of the inability to accurately determine the urea injection quantity in the existing technology, and this solution can accurately determine the urea injection quantity according to the first urea injection quantity and the second urea injection quantity. Controlling the urea injection volume of the first urea nozzle and the second urea nozzle improves the conversion rate of nitrogen oxides.

In one embodiment of the present application, as shown in Figure 2, the above-mentioned urea injection system includes a first urea nozzle 10, a first selective catalytic conversion device 11, a second urea nozzle 12 and a second urea injection system sequentially distributed from upstream to downstream. Selective catalytic conversion device 13, the above-mentioned urea injection system also includes a first nitrogen oxygen sensor 14, a first agitator 15, a first temperature sensor 16, an oxidation catalyst 17, a particulate matter trap 18 and a second nitrogen oxygen sensor 19, The first nitrogen and oxygen sensor 14 is located upstream of the first urea nozzle 10 . The first agitator 15 is located between the first urea nozzle 10 and the first temperature sensor 16 . The first temperature sensor 16 is located between the first urea nozzle 10 and the first temperature sensor 16 . Between the agitator 15 and the first selective catalytic conversion device 11, the oxidation catalytic converter 17 is located between the first selective catalytic conversion device 11 and the particulate matter trap 18, and the second nitrogen oxygen sensor 19 is located above Between the particulate matter trap 18 and the above-mentioned second urea nozzle 12, the above-mentioned first relevant parameters include at least one of the following: a first temperature, a first air velocity, a first gas flow rate and a second gas flow rate, wherein the above-mentioned first The temperature is the temperature collected by the first temperature sensor 16, the first space speed is the space speed between the first agitator 15 and the first selective catalytic conversion device 11, and the first space speed is the air speed of ammonia gas. The ratio of the volume to the volume of the catalyst, the first gas flow rate is the gas flow rate collected by the first nitrogen oxygen sensor 14 , and the second gas flow rate is the gas flow rate collected by the second nitrogen oxygen sensor 19 . In this embodiment, the first temperature, the first air velocity, the first gas flow rate, and the second gas flow rate can be obtained. Subsequently, based on the first temperature, the first air velocity, the first gas flow rate, and the second gas flow rate, more information can be obtained. In order to accurately determine the first urea injection amount of the first selective catalytic conversion device.

In another embodiment of the present application, the above-mentioned device further includes a first construction unit, and the first construction unit is used to, after obtaining the first relevant parameters of the above-mentioned first selective catalytic conversion device, according to the above-mentioned first temperature, the above-mentioned third A space velocity and the above-mentioned first gas flow rate are used to construct a first model, and the above-mentioned first model is used to determine the first predetermined ammonia gas storage amount of the above-mentioned first selective catalytic conversion device and the first predetermined amount of ammonia gas of the above-mentioned first selective catalytic conversion device. Predetermined conversion efficiency, the above-mentioned first predetermined conversion efficiency refers to the predetermined conversion rate of ammonia generated from urea into nitrogen oxide compounds. In this embodiment, a first model is constructed, and the first predetermined ammonia storage amount and the first predetermined conversion efficiency determined by the first model can be used as standard values. Subsequently, the actual acquired data can be adjusted according to the standard values to further ensure The first urea injection amount is more accurate.

In another embodiment of the present application, the first determination unit includes a first determination module, a second determination module, a third determination module and a fourth determination module, and the first determination module is used to determine the temperature according to the above-mentioned first temperature, the above-mentioned first The gas flow rate and the above-mentioned first predetermined conversion efficiency are used to determine the first feedforward injection amount of the above-mentioned first selective catalytic conversion device; the second determination module is used to perform ammonia storage correction according to the above-mentioned first predetermined ammonia gas storage amount to determine the first The ammonia gas corrects the injection amount; the third determination module is used to determine the first correction factor of the urea injection amount according to the above-mentioned first predetermined conversion efficiency, the above-mentioned first temperature and the above-mentioned first airspeed; the fourth determination module is used to determine the first correction factor of the urea injection amount according to the above-mentioned first predetermined conversion efficiency, the above-mentioned first temperature and the above-mentioned first airspeed. A feedforward injection amount, the first ammonia correction injection amount and the first correction factor determine the first urea injection amount of the first selective catalytic conversion device. In this embodiment, the first urea injection amount has three influencing factors, which are the first feedforward injection amount, the first ammonia correction injection amount and the first correction factor. These three data are first determined respectively, and subsequently the first feedforward injection amount can be determined according to the first correction factor. The feedforward injection amount, the first ammonia correction injection amount and the first correction factor more accurately determine the first urea injection amount of the first selective catalytic conversion device.

In yet another embodiment of the present application, the first determination module includes a first acquisition sub-module, a second acquisition sub-module and a first determination sub-module. The first acquisition sub-module is used to acquire the above-mentioned first gas flow rate and the above-mentioned first gas flow rate. The product of the predetermined conversion efficiency is used to obtain the first basic urea injection amount; the second acquisition sub-module is used to obtain the ammonia oxidation gas amount obtained by oxidizing ammonia in the above-mentioned first selective catalytic conversion device; the first determination sub-module is used to obtain The above-mentioned first temperature is used to perform ammonia storage correction on the above-mentioned ammonia oxidation gas amount to determine the above-mentioned first feedforward injection amount. In this embodiment, the first feedforward injection amount of urea of the first selective catalytic conversion device can be further accurately determined, and then the first urea injection amount can be determined more accurately based on the accurate first feedforward injection amount. .

In a specific embodiment of the present application, the second determination module includes a third acquisition sub-module, a fourth acquisition sub-module and a second determination sub-module. The third acquisition sub-module is used to determine the temperature according to the above-mentioned first temperature and the above-mentioned first temperature. airspeed, to obtain the first actual ammonia gas storage amount; the fourth acquisition sub-module is used to obtain the first difference between the above-mentioned first actual ammonia gas storage amount and the above-mentioned first predetermined ammonia gas storage amount; the second determination sub-module is used to obtain Using the first difference, adjust the first actual ammonia storage amount until the difference between the first actual ammonia storage amount and the first predetermined ammonia storage amount is less than the first difference threshold, to obtain the first ammonia storage amount. Air correction injection volume. In this embodiment, the first corrected ammonia injection amount of urea in the first selective catalytic conversion device can be further accurately determined, and subsequently the first urea can be determined more accurately based on the accurate first corrected ammonia injection amount. Injection volume.

In one embodiment, the first actual ammonia gas storage amount of the first selective catalytic conversion device can also be determined through the following formula: Among them, θ represents the first actual ammonia storage amount, eta represents the first predetermined conversion efficiency, k represents the frequency factor, nox represents the gas flow rate collected by the first nitrogen and oxygen sensor, E represents the activation energy, the unit is J/mol, R Represents the unified gas constant, 8.3145, the unit is J/mol/k, T represents the first temperature, and sv represents the first space velocity.

In yet another specific embodiment of the present application, the third determination module includes a third determination sub-module, a fifth acquisition sub-module, a sixth acquisition sub-module and a seventh acquisition sub-module. The third determination sub-module is used according to the above The first temperature and the above-mentioned first airspeed determine the first correction proportional coefficient; the fifth acquisition sub-module is used to obtain the first actual conversion efficiency. The above-mentioned first actual conversion efficiency refers to the conversion of ammonia produced by urea into nitrogen oxide compounds. The real conversion rate; the sixth acquisition sub-module is used to obtain the second difference between the above-mentioned first predetermined conversion efficiency and the above-mentioned first actual conversion efficiency; the seventh acquisition sub-module is used to obtain the above-mentioned first corrected proportion coefficient and the above-mentioned second second difference The product of the differences yields the above-mentioned first correction factor. In this embodiment, the first correction factor of urea of the first selective catalytic conversion device can be further accurately determined, and subsequently the first urea injection amount can be determined more accurately based on the accurate first correction factor.

In one embodiment, the first actual conversion efficiency may be collected by the second nitrogen and oxygen sensor.

In another specific embodiment of the present application, the fourth determination module includes an eighth acquisition sub-module and a ninth acquisition sub-module. The eighth acquisition sub-module is used to acquire the above-mentioned first feedforward injection amount and the above-mentioned first correction factor. to obtain the initial first urea injection amount; the ninth acquisition sub-module is used to obtain the sum of the above-mentioned initial first urea injection amount, the above-mentioned first feedforward injection amount and the above-mentioned first ammonia gas correction amount, to obtain the above-mentioned first urea injection amount Injection volume. In this embodiment, the first urea injection amount can be determined more accurately based on the obtained first feedforward injection amount, the first ammonia corrected injection amount and the first correction factor.

Specifically, for the first predetermined conversion efficiency, if the second selective catalytic conversion device cannot meet the demand, the first correction factor can be used to correct the first urea injection amount of the first selective catalytic conversion device to improve the first urea injection amount. Conversion efficiency of the two-selective catalytic conversion device.

In yet another specific embodiment of the present application, as shown in Figure 2, the above-mentioned urea injection system also includes a second temperature sensor 20, a second agitator 21, an ammonia escape trap 22 and a third nitrogen and oxygen sensor 23, The second temperature sensor 20 is located between the first selective catalytic conversion device 11 and the second urea nozzle 12 , and the second agitator 21 is located between the second urea nozzle 12 and the second selective catalytic conversion device 13 , the above-mentioned ammonia escape trap 22 is located between the above-mentioned second selective catalytic conversion device 13 and the above-mentioned third nitrogen oxygen sensor 23, the above-mentioned third nitrogen oxygen sensor 23 is located downstream of the above-mentioned ammonia escape trap 22, the above-mentioned second The relevant parameters include at least one of the following: a second temperature, a second airspeed, and a third gas flow rate, wherein the second temperature is the temperature collected by the second temperature sensor 20 , and the second airspeed is the first selection. The space velocity between the catalytic conversion device 11 and the second agitator 21, the second space velocity is the ratio of the volume of ammonia gas to the volume of the catalyst, and the third gas flow rate is collected by the third nitrogen oxygen sensor 23 gas flow rate. In this embodiment, the second temperature, the second air velocity, and the third gas flow rate can be obtained, and subsequently the third gas flow rate can be determined more accurately based on the second temperature, the second air velocity, the second gas flow rate, and the third gas flow rate. The second urea injection amount of the dual-selective catalytic conversion device.

In one embodiment, the urea injection system further includes a third temperature sensor 24 , and the third temperature sensor 24 is located between the oxidation catalyst 17 and the particulate matter trap 18 .

In an embodiment of the present application, the above-mentioned device further includes a second construction unit, and the second construction unit is configured to, after obtaining the second relevant parameters of the above-mentioned second selective catalytic conversion device, according to the above-mentioned second temperature, the above-mentioned second The airspeed and the above-mentioned second related parameters are used to construct a second model, and the above-mentioned second model is used to determine the second predetermined ammonia storage amount of the above-mentioned second selective catalytic conversion device and the second predetermined amount of the above-mentioned second selective catalytic conversion device. Conversion efficiency, the above-mentioned second predetermined conversion efficiency refers to the predetermined conversion rate of ammonia generated from urea into nitrogen oxides. In this embodiment, a second model is constructed, and the second predetermined ammonia storage amount and the second predetermined conversion efficiency determined by the second model can be used as standard values. Subsequently, the actually obtained data can be adjusted according to the standard values to further ensure The second urea injection amount is more accurate.

In yet another embodiment of the present application, the second determination unit includes a fifth determination module, a sixth determination module, and a seventh determination module, and the fifth determination module is configured to determine according to the above-mentioned second temperature, the above-mentioned second airspeed, and the above-mentioned third A related parameter to determine the second feedforward injection amount of the above-mentioned second selective catalytic conversion device; the sixth determination module is used to perform ammonia storage correction according to the above-mentioned second predetermined ammonia gas storage amount and determine the second ammonia gas correction injection amount; The seventh determination module is configured to determine the second urea injection amount of the second selective catalytic conversion device based on the second feedforward injection amount and the second ammonia correction injection amount. In this embodiment, the second urea injection amount has two influencing factors, namely the second feedforward injection amount and the second ammonia corrected injection amount. Subsequently, the second feedforward injection amount and the second ammonia corrected injection amount can be used. The second urea injection quantity of the second selective catalytic conversion device is determined more accurately.

In another embodiment of the present application, the above-mentioned first relevant parameter includes the second gas flow rate, the fifth determination module includes a fourth determination sub-module and a tenth acquisition sub-module, and the fourth determination sub-module is used to determine the second temperature according to the above-mentioned second temperature. and the above-mentioned second airspeed to determine the feed-forward conversion efficiency, which is the ratio of the ammonia storage amount to the above-mentioned second gas flow rate; the tenth acquisition sub-module is used to obtain the above-mentioned feed-forward conversion efficiency and the above-mentioned second gas flow rate The product of the flow rate obtains the above-mentioned second feedforward injection amount. In this embodiment, the second feedforward injection amount of the second selective catalytic conversion device can be further accurately determined, and subsequently the second urea injection amount can be determined more accurately based on the accurate second feedforward injection amount.

In yet another embodiment of the present application, the sixth acquisition module includes an eleventh acquisition sub-module, a twelfth acquisition sub-module and a fifth determination sub-module. The eleventh acquisition sub-module is used to calculate the temperature according to the above-mentioned second temperature and the above-mentioned The second airspeed is to obtain the second actual ammonia gas storage amount; the twelfth acquisition sub-module is used to obtain the third difference between the above-mentioned second actual ammonia gas storage amount and the above-mentioned second predetermined ammonia gas storage amount; the fifth determiner The module is configured to use the third difference to adjust the second actual ammonia storage amount until the difference between the second actual ammonia storage amount and the second predetermined ammonia storage amount is less than the second difference threshold to obtain the above The second ammonia gas corrected injection amount. In this embodiment, the second corrected ammonia injection amount of the second selective catalytic conversion device can be further accurately determined, and then the second urea injection amount can be determined more accurately based on the accurate second ammonia corrected injection amount. .

In a specific embodiment of the present application, the seventh determination module includes a sixth determination sub-module, a seventh determination sub-module and an eighth determination sub-module. The sixth determination sub-module is used to determine the predetermined time from the current moment to the historical moment. Within the section, determine the number of deviations between the above-mentioned third gas flow rate and the predetermined gas flow rate; the seventh determination sub-module is used to use the first method to modify the above-mentioned second selective catalytic conversion device when the above-mentioned number of deviations is less than the threshold number of deviations. The urea injection amount is corrected to determine the above-mentioned second urea injection amount; the eighth determination sub-module is used to use the second method to adjust the above-mentioned second selective catalytic conversion device when the above-mentioned number of deviations is greater than or equal to the deviation number threshold. The urea injection amount is corrected to determine the above-mentioned second urea injection amount. In this embodiment, if an instantaneous deviation occurs, the first method is used to correct the urea injection amount of the second selective catalytic conversion device. If the deviation still exists after a period of time, the second method is used. In this way, the urea injection amount of the second selective catalytic conversion device is corrected, so that the second urea injection amount can be determined more accurately.

In one embodiment, the second actual conversion efficiency may be collected by the third nitrogen and oxygen sensor.

In another specific embodiment of the present application, the seventh determination sub-module is also used to obtain the actual gas flow rate; obtain the fourth difference between the above-mentioned actual gas flow rate and the above-mentioned third gas flow rate; according to the above-mentioned second temperature and the above-mentioned third gas flow rate 2 airspeed, determine the second correction proportional coefficient; obtain the product of the above-mentioned fourth difference and the above-mentioned second correction proportional coefficient, obtain the second correction factor; obtain the product of the above-mentioned second correction factor and the basic injection volume, obtain the above-mentioned second Urea injection amount, wherein the above-mentioned basic injection amount is determined based on the above-mentioned second temperature and the above-mentioned second airspeed. In this embodiment, the deviated urea injection amount can be corrected more efficiently and accurately, so that the second urea injection amount can be determined more accurately.

In another specific embodiment of the present application, the eighth determination sub-module is also used to obtain the actual gas flow rate and the average actual gas flow rate, wherein the above-mentioned average actual gas flow rate is the number of actual gas flow rates within a predetermined time period from the current time to the historical time. The average value of the above-mentioned actual gas flow rate obtained at each time; obtain the average third gas flow rate, wherein the above-mentioned average third gas flow rate is within the above-mentioned predetermined time period from the above-mentioned current time to the above-mentioned historical time obtained using the above-mentioned second model, The average value of the above-mentioned third gas flow rate at multiple times; obtain the fifth difference between the above-mentioned average actual gas flow rate and the above-mentioned average third gas flow rate; use EWMA filtering method to filter the above-mentioned fifth difference value to obtain the third correction factor ; Obtain the sum of the above-mentioned second feedforward injection quantity and the above-mentioned second ammonia correction injection quantity to obtain the initial second urea injection quantity; Obtain the product of the above-mentioned third correction factor and the above-mentioned initial second urea injection quantity to obtain the above-mentioned second second urea injection quantity. Urea injection volume. In this embodiment, the deviated urea injection amount can be corrected more efficiently and accurately, so that the second urea injection amount can be determined more accurately.

The control device of the above-mentioned urea injection system includes a processor and a memory. The above-mentioned first acquisition unit, first determination unit, second acquisition unit, second determination unit and control unit are all stored in the memory as program units and executed by the processor. The above program units stored in the memory implement corresponding functions.

The processor contains a core, which retrieves the corresponding program unit from the memory. One or more cores can be set, and the problem of being unable to accurately determine the urea injection amount in the prior art can be solved by adjusting the core parameters.

Memory may include non-permanent memory in computer-readable media, random access memory (RAM) and/or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). The memory includes at least one memory chips.

Embodiments of the present invention provide a computer-readable storage medium on which a program is stored. When the program is executed by a processor, the control method of the urea injection system is implemented.

An embodiment of the present invention provides a processor. The processor is configured to run a program. When the program is run, the control method of the urea injection system is executed.

An embodiment of the present invention provides a device. The device includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements at least the following steps:

Embodiments of the present application also provide a urea injection system, including a first nitrogen and oxygen sensor, a first urea nozzle, a first agitator, a first temperature sensor, a first selective catalytic conversion device, and are distributed in sequence from upstream to downstream. Oxidation catalytic converter, particulate matter trap, second nitrogen oxygen sensor, second temperature sensor, second urea nozzle, second agitator, second selective catalytic conversion device, ammonia escape trap, third nitrogen oxygen sensor and a controller, the controller is respectively connected with the first nitrogen oxygen sensor, the first urea nozzle, the first agitator, the first temperature sensor, the first selective catalytic conversion device, the oxidation catalytic converter, the above Particulate matter trap, the above-mentioned second nitrogen oxygen sensor, the above-mentioned second temperature sensor, the above-mentioned second urea nozzle, the above-mentioned second agitator, the above-mentioned second selective catalytic conversion device, the above-mentioned ammonia escape trap and the above-mentioned third nitrogen Oxygen sensor communication, the above-mentioned controller is used to perform any one of the above-mentioned methods.

In the above system, since it includes any one of the above methods, in this method, the first relevant parameter of the first selective catalytic conversion device is first obtained, and then the first relevant parameter of the first selective catalytic conversion device is determined based on the first relevant parameter. The urea injection amount, and then obtain the second relevant parameter of the second selective catalytic conversion device, and then determine the second urea injection amount of the second selective catalytic conversion device based on the second relevant parameter and the first relevant parameter, and finally based on the first The first urea nozzle is controlled to inject urea based on the urea injection amount, and the second urea nozzle is controlled to inject urea based on the second urea injection amount. In this solution, the urea injection system has a first selective catalytic conversion device and a second selective catalytic conversion device, as well as a first urea nozzle and a second urea nozzle, which are coordinated and controlled by the two selective catalytic conversion devices. Compared with The existing technology can emit nitrogen oxides more efficiently, and this solution can accurately determine the first urea injection amount of the first selective catalytic conversion device, and can also accurately determine the second urea injection amount of the second selective catalytic conversion device. quantity, the demand for high conversion rate of the selective catalytic conversion device can be achieved, thereby solving the problem of the inability to accurately determine the urea injection quantity in the existing technology, and this solution can accurately determine the urea injection quantity according to the first urea injection quantity and the second urea injection quantity. Controlling the urea injection volume of the first urea nozzle and the second urea nozzle improves the conversion rate of nitrogen oxides.

Step S101: Obtain the first relevant parameter of the above-mentioned first selective catalytic conversion device, the above-mentioned first relevant parameter is a parameter that will affect the urea injection amount of the above-mentioned first selective catalytic conversion device;

Step S102, determine the first urea injection amount of the first selective catalytic conversion device according to the first relevant parameter;

Step S103, obtain the second relevant parameters of the above-mentioned second selective catalytic conversion device;

Step S104: Determine the second urea injection amount of the second selective catalytic conversion device based on the second relevant parameter and the first relevant parameter. The second relevant parameter is the urea that will affect the second selective catalytic conversion device. Parameters of injection volume;

Step S105: Control the first urea nozzle to inject urea based on the first urea injection amount, and control the second urea nozzle to inject urea based on the second urea injection amount.

The devices in this article can be servers, PCs, PADs, mobile phones, etc.

This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program initialized with at least the following method steps:

Step S101: Obtain the first relevant parameter of the above-mentioned first selective catalytic conversion device, the above-mentioned first relevant parameter is a parameter that will affect the urea injection amount of the above-mentioned first selective catalytic conversion device;

Step S102, determine the first urea injection amount of the first selective catalytic conversion device according to the first relevant parameter;

Step S103, obtain the second relevant parameters of the above-mentioned second selective catalytic conversion device;

Step S104: Determine the second urea injection amount of the second selective catalytic conversion device based on the second relevant parameter and the first relevant parameter. The second relevant parameter is the urea that will affect the second selective catalytic conversion device. Parameters of injection volume;

Step S105: Control the first urea nozzle to inject urea based on the first urea injection amount, and control the second urea nozzle to inject urea based on the second urea injection amount.

In the above-mentioned embodiments of the present invention, each embodiment is described with its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the above-mentioned units can be a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated. to another system, or some features can be ignored, or not implemented. On the other hand, the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the units or modules may be in electrical or other forms.

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

In addition, each functional unit in various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or software functional units.

If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or contributes to the existing technology or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to cause a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the above methods in various embodiments of the present invention. The aforementioned storage media include: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program code. .

From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

1). The control method of the urea injection system of the present application first obtains the first relevant parameters of the first selective catalytic conversion device, and then determines the first urea injection amount of the first selective catalytic conversion device based on the first relevant parameters, Then, the second relevant parameter of the second selective catalytic conversion device is obtained, and then the second urea injection amount of the second selective catalytic conversion device is determined based on the second relevant parameter and the first relevant parameter, and finally the second urea injection amount is controlled based on the first urea injection amount. The first urea nozzle injects urea, and the second urea nozzle is controlled to inject urea based on the second urea injection amount. In this solution, the urea injection system has a first selective catalytic conversion device and a second selective catalytic conversion device, as well as a first urea nozzle and a second urea nozzle, which are coordinated and controlled by the two selective catalytic conversion devices. Compared with The existing technology can emit nitrogen oxides more efficiently, and this solution can accurately determine the first urea injection amount of the first selective catalytic conversion device, and can also accurately determine the second urea injection amount of the second selective catalytic conversion device. quantity, the demand for high conversion rate of the selective catalytic conversion device can be achieved, thereby solving the problem of the inability to accurately determine the urea injection quantity in the existing technology, and this solution can accurately determine the urea injection quantity according to the first urea injection quantity and the second urea injection quantity. Controlling the urea injection volume of the first urea nozzle and the second urea nozzle improves the conversion rate of nitrogen oxides.

2) In the control device of the urea injection system of the present application, the first acquisition unit acquires the first relevant parameters of the first selective catalytic conversion device, and the first determination unit determines the first relevant parameters of the first selective catalytic conversion device based on the first relevant parameters. The first urea injection amount, the second acquisition unit acquires the second relevant parameter of the second selective catalytic conversion device, and the second determination unit determines the second relevant parameter of the second selective catalytic conversion device according to the second relevant parameter and the first relevant parameter. The control unit controls the first urea nozzle to inject urea based on the first urea injection amount, and controls the second urea nozzle to inject urea based on the second urea injection amount. In this solution, the urea injection system has a first selective catalytic conversion device and a second selective catalytic conversion device, as well as a first urea nozzle and a second urea nozzle, which are coordinated and controlled by the two selective catalytic conversion devices. Compared with The existing technology can emit nitrogen oxides more efficiently, and this solution can accurately determine the first urea injection amount of the first selective catalytic conversion device, and can also accurately determine the second urea injection amount of the second selective catalytic conversion device. quantity, the demand for high conversion rate of the selective catalytic conversion device can be achieved, thereby solving the problem of the inability to accurately determine the urea injection quantity in the existing technology, and this solution can accurately determine the urea injection quantity according to the first urea injection quantity and the second urea injection quantity. Controlling the urea injection volume of the first urea nozzle and the second urea nozzle improves the conversion rate of nitrogen oxides.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application.

Claims (17)

1. A control method of a urea injection system, characterized in that the urea injection system comprises a first urea nozzle, a first selective catalytic conversion device, a second urea nozzle and a second selective catalytic conversion device, which are distributed in order from upstream to downstream, the method comprising:

acquiring a first related parameter of the first selective catalytic conversion device, wherein the first related parameter is a parameter which can influence the urea injection quantity of the first selective catalytic conversion device;

determining a first urea injection quantity of the first selective catalytic conversion device according to the first related parameter;

obtaining a second phase Guan Canliang of the second selective catalytic conversion device;

determining a second urea injection amount of the second selective catalytic conversion device according to the second phase Guan Canliang and the first related parameter, wherein the second related parameter is a parameter which can influence the urea injection amount of the second selective catalytic conversion device;

Controlling the first urea nozzle to inject urea based on the first urea injection amount, and controlling the second urea nozzle to inject urea based on the second urea injection amount;

the urea injection system further comprises a first nitrogen-oxygen sensor, a first stirrer, a first temperature sensor, an oxidation catalyst, a particulate matter trap and a second nitrogen-oxygen sensor, wherein the first nitrogen-oxygen sensor is positioned upstream of the first urea nozzle, the first stirrer is positioned between the first urea nozzle and the first temperature sensor, the first temperature sensor is positioned between the first stirrer and the first selective catalytic conversion device, the oxidation catalyst is positioned between the first selective catalytic conversion device and the particulate matter trap, the second nitrogen-oxygen sensor is positioned between the particulate matter trap and the second urea nozzle, and the first related parameters comprise at least one of the following: the device comprises a first temperature, a first airspeed, a first gas flow and a second gas flow, wherein the first temperature is the temperature acquired by the first temperature sensor, the first airspeed is the airspeed between the first stirrer and the first selective catalytic conversion device, the first airspeed is the ratio of the volume of ammonia to the volume of a catalyst, the first gas flow is the gas flow acquired by the first nitrogen-oxygen sensor, and the second gas flow is the gas flow acquired by the second nitrogen-oxygen sensor;

After acquiring the first relevant parameter of the first selective catalytic conversion device, the method further includes:

constructing a first model according to the first temperature, the first airspeed and the first gas flow, and determining a first preset ammonia storage amount of the first selective catalytic conversion device and a first preset conversion efficiency of the first selective catalytic conversion device by adopting the first model, wherein the first preset conversion efficiency refers to a preset conversion rate of ammonia gas generated by urea into nitrogen oxides;

determining a first urea injection amount of the first selective catalytic conversion device according to the first related parameter, including:

determining a first feed-forward injection amount of the first selective catalytic conversion device based on the first temperature, the first gas flow rate, and the first predetermined conversion efficiency;

performing ammonia storage correction according to the first preset ammonia storage amount, and determining a first ammonia correction injection amount;

determining a first correction factor for the urea injection quantity according to the first predetermined conversion efficiency, the first temperature and the first airspeed;

and determining the first urea injection quantity of the first selective catalytic conversion device according to the first feedforward injection quantity, the first ammonia correction injection quantity and the first correction factor.

2. The method of claim 1, wherein determining a first feed-forward injection amount of the first selective catalytic conversion device based on the first temperature, the first gas flow rate, and the first predetermined conversion efficiency comprises:

obtaining the product of the first gas flow and the first preset conversion efficiency to obtain a first basic urea injection quantity;

obtaining the amount of oxidized ammonia obtained by oxidizing ammonia in the first selective catalytic conversion device;

and carrying out ammonia storage correction on the ammonia oxidation amount by adopting the first temperature, and determining the first feedforward injection amount.

3. The method according to claim 1, wherein performing ammonia storage correction based on the first predetermined ammonia storage amount, determining a first ammonia correction injection amount, comprises:

acquiring a first actual ammonia storage amount according to the first temperature and the first airspeed;

acquiring a first difference value between the first actual ammonia storage amount and the first preset ammonia storage amount;

and adjusting the first actual ammonia storage amount by adopting the first difference value until the difference value between the first actual ammonia storage amount and the first preset ammonia storage amount is smaller than a first difference value threshold value, so as to obtain the first ammonia correction injection amount.

4. The method of claim 1, wherein determining a first correction factor for the urea injection quantity based on the first predetermined conversion efficiency, the first temperature, and the first airspeed comprises:

determining a first modified scaling factor from the first temperature and the first airspeed;

obtaining a first actual conversion efficiency, wherein the first actual conversion efficiency refers to the actual conversion rate of ammonia gas generated by urea into oxynitride;

acquiring a second difference between the first predetermined conversion efficiency and the first actual conversion efficiency;

and obtaining the product of the first correction proportionality coefficient and the second difference value to obtain the first correction factor.

5. The method of claim 1, wherein determining the first urea injection amount of the first selective catalytic conversion device based on the first feed-forward injection amount, the first ammonia correction injection amount, and the first correction factor comprises:

obtaining the product of the first feedforward injection quantity and the first correction factor to obtain an initial first urea injection quantity;

and obtaining the sum of the initial first urea injection quantity, the first feedforward injection quantity and the first ammonia correction injection quantity to obtain the first urea injection quantity.

6. The method of claim 1, wherein the urea injection system further comprises a second temperature sensor located between the first selective catalytic conversion device and the second urea nozzle, a second agitator located between the second urea nozzle and the second selective catalytic conversion device, an ammonia slip trap located between the second selective catalytic conversion device and the third nitrogen sensor, and a third nitrogen oxygen sensor located downstream of the ammonia slip trap, the second related parameter comprising at least one of: the system comprises a first temperature sensor, a first space velocity and a second space velocity, wherein the first temperature is acquired by the first temperature sensor, the first space velocity is the space velocity between the first selective catalytic conversion device and the first stirrer, the first space velocity is the ratio of the volume of ammonia to the volume of a catalyst, and the second gas flow is acquired by the second nitrogen-oxygen sensor.

7. The method according to claim 6, further comprising, after acquiring the second related parameter of the second selective catalytic conversion device:

A second model is constructed based on the second temperature, the second space velocity, and the second phase Guan Canliang, and a second predetermined ammonia storage amount for the second selective catalytic conversion device and a second predetermined conversion efficiency for the second selective catalytic conversion device, which is a predetermined conversion rate of ammonia gas produced from urea to nitrogen oxides, are determined using the second model.

8. The method of claim 7, wherein determining a second urea injection amount for the second selective catalytic conversion device based on the second phase Guan Canliang and the first related parameter comprises:

determining a second feed-forward injection amount of the second selective catalytic conversion device based on the second temperature, the second airspeed, and the first related parameter;

performing ammonia storage correction according to the second preset ammonia storage amount, and determining a second ammonia correction injection amount;

and determining the second urea injection quantity of the second selective catalytic conversion device according to the second feedforward injection quantity and the second ammonia correction injection quantity.

9. The method of claim 8, wherein the first related parameter comprises a second gas flow rate, and determining a second feed-forward injection amount for the second selective catalytic conversion device based on the second temperature, the second space velocity, and the first related parameter comprises:

Determining feed-forward conversion efficiency according to the second temperature and the second airspeed, wherein the feed-forward conversion efficiency is the ratio of the ammonia storage amount to the second gas flow;

and obtaining the product of the feedforward conversion efficiency and the second gas flow to obtain the second feedforward injection quantity.

10. The method of claim 8, wherein performing ammonia storage correction based on the second predetermined ammonia storage amount, determining a second ammonia correction injection amount, comprises:

acquiring a second actual ammonia storage amount according to the second temperature and the second airspeed;

acquiring a third difference value between the second actual ammonia storage amount and the second preset ammonia storage amount;

and adjusting the second actual ammonia storage amount by adopting the third difference value until the difference value between the second actual ammonia storage amount and the second preset ammonia storage amount is smaller than a second difference value threshold value, so as to obtain the second ammonia correction injection amount.

11. The method of claim 8, wherein determining the second urea injection amount of the second selective catalytic conversion device based on the second feed-forward injection amount and the second ammonia correction injection amount comprises:

Determining the deviation times of the third gas flow and the preset gas flow in a preset time period from the current time to the historical time;

when the deviation times is smaller than a deviation times threshold value, correcting the urea injection quantity of the second selective catalytic conversion device in a first mode to determine the second urea injection quantity;

and when the deviation times is greater than or equal to a deviation times threshold value, correcting the urea injection quantity of the second selective catalytic conversion device in a second mode to determine the second urea injection quantity.

12. The method according to claim 11, wherein, in the case where the number of deviations is smaller than a threshold number of deviations, correcting the urea injection quantity of the second selective catalytic conversion device in the first manner, determining the second urea injection quantity includes:

acquiring actual gas flow;

acquiring a fourth difference value between the actual gas flow and the third gas flow;

determining a second modified scaling factor from the second temperature and the second airspeed;

obtaining the product of the fourth difference value and the second correction proportionality coefficient to obtain a second correction factor;

And obtaining the product of the second correction factor and a basic injection quantity to obtain the second urea injection quantity, wherein the basic injection quantity is obtained by determining according to the second temperature and the second airspeed.

13. The method according to claim 11, wherein, in the case where the number of deviations is greater than or equal to a threshold number of deviations, correcting the urea injection quantity of the second selective catalytic conversion device in a second manner, determining the second urea injection quantity includes:

acquiring actual gas flow and average actual gas flow, wherein the average actual gas flow is an average value of the actual gas flow acquired at a plurality of moments in a preset time period from the current moment to the historical moment;

obtaining an average third gas flow, wherein the average third gas flow is an average value of the third gas flows at a plurality of moments in the preset time period from the current moment to the historical moment, which are obtained by adopting the second model;

obtaining a fifth difference between the average actual gas flow and the average third gas flow;

filtering the fifth difference value by adopting an EWMA filtering mode to obtain a third correction factor;

Obtaining the sum of the second feedforward injection quantity and the second ammonia correction injection quantity to obtain an initial second urea injection quantity;

and obtaining the product of the third correction factor and the initial second urea injection quantity to obtain the second urea injection quantity.

14. A control device of a urea injection system, characterized in that the urea injection system comprises a first urea nozzle, a first selective catalytic conversion device, a second urea nozzle and a second selective catalytic conversion device, which are distributed in sequence from upstream to downstream, the device comprising:

a first obtaining unit, configured to obtain a first related parameter of the first selective catalytic conversion device, where the first related parameter is a parameter that affects a urea injection amount of the first selective catalytic conversion device;

the first determining unit is used for determining a first urea injection quantity of the first selective catalytic conversion device according to the first related parameter;

a second obtaining unit, configured to obtain a second phase Guan Canliang of the second selective catalytic conversion device, where the second related parameter is a parameter that affects an urea injection amount of the second selective catalytic conversion device;

A second determining unit configured to determine a second urea injection amount of the second selective catalytic conversion device based on the second phase Guan Canliang and the first related parameter;

a control unit for controlling the first urea nozzle to inject urea based on the first urea injection amount and controlling the second urea nozzle to inject urea based on the second urea injection amount;

the urea injection system further comprises a first nitrogen-oxygen sensor, a first stirrer, a first temperature sensor, an oxidation catalyst, a particulate matter trap and a second nitrogen-oxygen sensor, wherein the first nitrogen-oxygen sensor is positioned upstream of the first urea nozzle, the first stirrer is positioned between the first urea nozzle and the first temperature sensor, the first temperature sensor is positioned between the first stirrer and the first selective catalytic conversion device, the oxidation catalyst is positioned between the first selective catalytic conversion device and the particulate matter trap, the second nitrogen-oxygen sensor is positioned between the particulate matter trap and the second urea nozzle, and the first related parameters comprise at least one of the following: the device comprises a first temperature, a first airspeed, a first gas flow and a second gas flow, wherein the first temperature is the temperature acquired by the first temperature sensor, the first airspeed is the airspeed between the first stirrer and the first selective catalytic conversion device, the first airspeed is the ratio of the volume of ammonia to the volume of a catalyst, the first gas flow is the gas flow acquired by the first nitrogen-oxygen sensor, and the second gas flow is the gas flow acquired by the second nitrogen-oxygen sensor;

A first construction unit, configured to construct a first model according to the first temperature, the first space velocity and the first gas flow rate after acquiring a first related parameter of the first selective catalytic conversion device, and determine a first predetermined ammonia storage amount of the first selective catalytic conversion device and a first predetermined conversion efficiency of the first selective catalytic conversion device by using the first model, where the first predetermined conversion efficiency refers to a predetermined conversion rate of ammonia gas generated by urea into nitrogen oxide;

the first determining unit comprises a first determining module, a second determining module, a third determining module and a fourth determining module, wherein the first determining module is used for determining a first feed-forward injection quantity of the first selective catalytic conversion device according to the first temperature, the first gas flow and the first preset conversion efficiency; the second determining module is used for carrying out ammonia storage correction according to the first preset ammonia storage quantity and determining a first ammonia correction injection quantity; the third determining module is used for determining a first correction factor of the urea injection quantity according to the first preset conversion efficiency, the first temperature and the first airspeed; the fourth determining module is configured to determine the first urea injection amount of the first selective catalytic conversion device according to the first feed-forward injection amount, the first ammonia correction injection amount, and the first correction factor.

15. A computer readable storage medium, characterized in that the computer readable storage medium comprises a stored program, wherein the program performs the method of any one of claims 1 to 13.

16. A processor for running a program, wherein the program when run performs the method of any one of claims 1 to 13.

17. A urea injection system, comprising: a first nitrogen-oxygen sensor, a first urea nozzle, a first agitator, a first temperature sensor, a first selective catalytic conversion device, an oxidation catalytic converter, a particulate trap, a second nitrogen-oxygen sensor, a second temperature sensor, a second urea nozzle, a second agitator, a second selective catalytic conversion device, an ammonia slip trap, a third nitrogen-oxygen sensor, and a controller in communication with the first nitrogen-oxygen sensor, the first urea nozzle, the first agitator, the first temperature sensor, the first selective catalytic conversion device, the oxidation catalytic converter, the particulate trap, the second nitrogen-oxygen sensor, the second temperature sensor, the second urea nozzle, the second agitator, the second selective catalytic conversion device, the ammonia slip trap, and the third nitrogen-oxygen sensor, respectively, in order from upstream to downstream, the controller being configured to perform the method of any one of claims 1-13.