Control method and device of tail gas treatment equipment and vehicle

Abstract

The application provides a control method and device of tail gas treatment equipment and a vehicle. The tail gas treatment equipment comprises a first selective catalytic reduction device, an oxidative catalyst and a second selective catalytic reduction device. The tail gas treatment equipment is installed on a tail gas exhaust pipeline, so that the tail gas sequentially passes through the first selective catalytic reduction device, the oxidative catalyst and the second selective catalytic reduction device. The method comprises the following steps: obtaining a ratio of a first concentration and a second concentration. The first concentration is the concentration of NO2 in the tail gas at the outlet end of the oxidative catalyst. The second concentration is the concentration of NO in the tail gas at the outlet end of the oxidative catalyst. In the case that the ratio of the first concentration and the second concentration is greater than a predetermined threshold, the increased urea injection rate of the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device, thereby solving the problem of excessive N2O emission in the tail gas in the prior art. x ​

Description

Technical Field

[0001] This invention relates to the field of exhaust gas treatment technology, and more specifically, to a control method, apparatus, computer-readable storage medium, and vehicle for exhaust gas treatment equipment. Background Technology

[0002] Nitrogen oxides (N2O) are a typical strong greenhouse gas, with a thermal potential 298 times that of carbon dioxide (CO2). They are extremely stable in the atmosphere and have a strong destructive effect on the ozone layer. With increasingly stringent emission regulations, N2O has become a newly added pollutant subject to emission control.

[0003] Currently, the tightly coupled selective catalytic reduction (SCR) unit uses a closed-loop injection method with reduced injection, and the downstream SCR unit uses a closed-loop injection method to ensure NO... x Emissions. When the tightly coupled selective catalytic reduction unit enters reduced injection mode or stops injection, NO will pass through the oxidizing catalyst and particulate filter to generate NO2, increasing DeNOx emissions. x The formation of N2O as a byproduct. Summary of the Invention

[0004] The main objective of this application is to provide a control method, apparatus, computer-readable storage medium, and vehicle for exhaust gas treatment equipment, so as to at least solve the problem of excessive N2O emissions in exhaust gas in the prior art.

[0005] To achieve the above objectives, according to one aspect of this application, a control method for an exhaust gas treatment device is provided. The exhaust gas treatment device includes a first selective catalytic reduction (SCR) device, an oxidizing catalyst, and a second SCR device. The exhaust gas treatment device is installed on an exhaust gas pipeline, such that the exhaust gas sequentially passes through the first SCR device, the oxidizing catalyst, and the second SCR device. The method includes: obtaining a ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration of NO2; when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the urea injection rate of the first selective catalytic reduction device is increased to reduce the concentration of NO2 entering the second selective catalytic reduction device.

[0006] Optionally, the exhaust gas treatment device further includes a particulate filter located on the pipeline between the oxidizing catalyst and the second selective catalytic reduction device. Controlling the increased urea injection rate of the first selective catalytic reduction device includes: when the particulate filter does not meet the passive regeneration conditions, controlling the urea injection rate of the first selective catalytic reduction device to increase to the maximum urea injection rate.

[0007] Optionally, the exhaust gas treatment device further includes a particulate filter located on the pipeline between the oxidizing catalyst and the second selective catalytic reduction device. Controlling the increased urea injection rate of the first selective catalytic reduction device includes: when the particulate filter does not meet the passive regeneration conditions, controlling the particulate filter to actively regenerate and controlling the urea injection rate of the first selective catalytic reduction device to increase to a target urea injection rate, wherein the target urea injection rate is less than the maximum urea injection rate.

[0008] Optionally, the exhaust gas treatment device further includes a particulate filter located on the pipeline between the oxidizing catalyst and the second selective catalytic reduction device. Controlling the increased urea injection rate of the first selective catalytic reduction device includes: when the particulate filter meets the passive regeneration conditions, controlling the urea injection rate of the first selective catalytic reduction device to increase to a target urea injection rate, wherein the target urea injection rate is less than the maximum urea injection rate.

[0009] Optionally, when the particulate filter meets the passive regeneration conditions, controlling the urea injection rate of the first selective catalytic reduction device to increase to the target urea injection rate includes: when the particulate filter meets the passive regeneration conditions, obtaining the operating temperature of the particulate filter; and controlling the urea injection rate of the first selective catalytic reduction device to increase to the corresponding target urea injection rate according to the operating temperature, wherein the target urea injection rate is negatively correlated with the operating temperature.

[0010] Optionally, after obtaining the ratio of the first concentration to the second concentration, the method further includes: controlling the urea injection rate of the first selective catalytic reduction device to remain constant when the ratio of the first concentration to the second concentration is less than or equal to the predetermined threshold.

[0011] Optionally, obtaining the ratio of the first concentration to the second concentration includes: obtaining a first proportion, wherein the first proportion is the ratio of the NO2 concentration to the NO concentration in the exhaust gas at the outlet of the first selective catalytic reduction device. xThe ratio of NO2 concentration to NO2 concentration is calculated based on the equilibrium principle of the chemical reaction occurring in the first selective catalytic reduction device. A second ratio is calculated based on the first ratio and the first reaction factor. The second ratio is the ratio of the NO2 concentration to the NO2 concentration in the exhaust gas at the outlet of the oxidizing catalyst. x The ratio of the concentrations of the first and second concentrations is calculated based on the first reaction factor, which is determined according to the exhaust gas temperature at the inlet of the oxidizing catalyst and the exhaust flow rate of the oxidizing catalyst; the ratio of the first concentration to the second concentration is calculated based on the second proportion, the second reaction factor, and the third reaction factor, whereby the second reaction factor is determined according to the exhaust gas temperature at the inlet of the particulate filter and the exhaust flow rate of the particulate filter, and the third reaction factor is determined according to the carbon loading of the particulate filter.

[0012] According to another aspect of this application, a control device for an exhaust gas treatment equipment is provided. The exhaust gas treatment equipment includes a first selective catalytic reduction device, an oxidizing catalyst, and a second selective catalytic reduction device. The exhaust gas treatment equipment is installed on an exhaust gas pipeline, such that the exhaust gas passes sequentially through the first selective catalytic reduction device, the oxidizing catalyst, and the second selective catalytic reduction device. The device includes: a receiving unit for receiving the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration of NO2; a first control unit, configured to control the increased urea injection rate of the first selective catalytic reduction device to reduce the concentration of NO2 entering the second selective catalytic reduction device when the ratio of the first concentration to the second concentration is greater than a predetermined threshold.

[0013] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the methods described.

[0014] According to another aspect of this application, a vehicle is provided, comprising: an exhaust gas treatment device, one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of the methods described.

[0015] Applying the technical solution of this application, in the control method of the above-mentioned exhaust gas treatment equipment, firstly, the ratio of a first concentration to a second concentration is obtained, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration of NO2 is then adjusted; subsequently, if the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the increased urea injection rate in the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device. NO will be converted to NO2 via an oxidizing catalyst, and the NO2 / NO2 ratio will be adjusted accordingly. x A high percentage will lead to DeNO within the second SCR. x The amount of N2O generated during the reaction increases. This method monitors the ratio of the first concentration to the second concentration, i.e., NO2 / NO2. x When the ratio exceeds a predetermined threshold, the urea injection rate of the first SCR is increased to reduce NO through a catalytic reduction reaction. x By reducing the NO2 concentration entering the second SCR, the NO2 emission is reduced, thereby reducing the NO2 emission and solving the problem of excessive NO2 emission in exhaust gas in existing technologies. Attached Figure Description

[0016] Figure 1 A hardware structure block diagram of a mobile terminal for performing a control method for an exhaust gas treatment device according to an embodiment of this application is shown.

[0017] Figure 2 A schematic diagram of an exhaust gas treatment device according to an embodiment of this application is shown;

[0018] Figure 3 A schematic flowchart of a control method for an exhaust gas treatment device according to an embodiment of this application is shown.

[0019] Figure 4 A schematic flowchart of a control method for another exhaust gas treatment device provided according to an embodiment of this application is shown;

[0020] Figure 5 A structural block diagram of a control device for an exhaust gas treatment apparatus provided according to an embodiment of this application is shown.

[0021] The above figures include the following reference numerals:

[0022] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device; 01. Exhaust gas pipeline; 10. First selective catalytic reduction device; 20. Oxidizing catalyst; 30. Second selective catalytic reduction device; 40. Particulate trap; 50. Ammonia oxidation catalyst; 100. Acquisition unit; 200. First control unit. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] For ease of description, the following explains some of the nouns or terms used in the embodiments of this application:

[0027] DeNO x Lower NO x The reaction;

[0028] SCR: Selective Catalytic Reduction, used to remove NO x Reduced to N2 and H2O;

[0029] DOC: Oxidizing Catalyst, a device that treats engine exhaust through an oxidation reaction;

[0030] DPF: Particulate filter, used to reduce particulate matter in exhaust gas;

[0031] ASC: Ammonia Oxidation Catalyst, used to oxidize unreacted ammonia to ensure safe emissions meet standards.

[0032] As described in the background section, N2O emissions in exhaust gases exceed standards in the prior art. To address this issue, embodiments of this application provide a control method, apparatus, computer-readable storage medium, and vehicle for exhaust gas treatment equipment.

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a control method of an exhaust gas treatment device according to an embodiment of the present invention. (See diagram below.) Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0035] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the device information display method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0036] This embodiment provides a control method for exhaust gas treatment equipment operating on a mobile terminal, computer terminal, or similar computing device, such as... Figure 2 As shown, the exhaust gas treatment device includes a first selective catalytic reduction device 10, an oxidizing catalyst 20, and a second selective catalytic reduction device 30. The exhaust gas treatment device is installed on the exhaust gas pipeline 01, so that the exhaust gas passes through the first selective catalytic reduction device 10, the oxidizing catalyst 20, and the second selective catalytic reduction device 30 in sequence. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0037] Figure 3 This is a flowchart of a control method for an exhaust gas treatment device according to an embodiment of this application. Figure 3 As shown, the method includes the following steps:

[0038] Step S201: Obtain the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration;

[0039] Specifically, N2O, as a DeNOx byproduct of Cu-based SCR, is produced when the NO2 / NO ratio is high. x The proportion enters the selective catalytic reduction (SCR) unit for DeNOx production. x The amount of N2O produced during the reaction will increase. However, the NO2 / NO ratio in the untreated exhaust gas will increase. x The concentration of NO2 is relatively low, around 5% to 8%, and the resulting N2O byproduct generally does not exceed emission standards. However, as it enters the second selective catalytic reduction unit (second SCR), the oxidation of NO by the oxidizing catalyst (DOC) increases the formation of N2O byproduct. Therefore, monitoring the concentration of NO2 and NO in the exhaust gas at the outlet of the oxidizing catalyst is crucial. x To achieve real-time monitoring of NO2 / NO concentration. x Percentage.

[0040] In step S202, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the increased urea injection rate of the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device.

[0041] Specifically, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, i.e., NO2 / NO... x If the proportion exceeds the predetermined threshold, it may lead to excessive NO2 emissions. By controlling the increased urea injection rate of the first selective catalytic reduction device (first SCR), the first selective catalytic reduction device (first SCR) can remove as much NO2 as possible through the catalytic reduction reaction. x It is reduced to N2, thus decreasing the concentration of NO2 and lowering the NO2 / NO ratio. x Proportion, suppressing DeNO x The generation of N2O during the reaction ensures that N2O emissions meet standards.

[0042] In the control method of the aforementioned exhaust gas treatment equipment, firstly, the ratio of a first concentration to a second concentration is obtained, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration of NO2 is then adjusted; subsequently, if the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the increased urea injection rate in the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device. NO will be converted to NO2 via an oxidizing catalyst, and the NO2 / NO2 ratio will be adjusted accordingly. x A high proportion of NO2O leads to an increased amount of N2O generated during the DeNOx reaction in the second SCR. This method monitors the ratio of the first and second concentrations, i.e., NO2 / NO2. xWhen the ratio exceeds a predetermined threshold, the urea injection rate of the first SCR is increased to reduce NO through a catalytic reduction reaction. x By reducing the NO2 concentration entering the second SCR, the NO2 emission is reduced, thereby reducing the NO2 emission and solving the problem of excessive NO2 emission in exhaust gas in existing technologies.

[0043] In addition, such as Figure 2 As shown, each of the first selective catalytic reduction device 10 and the second selective catalytic reduction device 30 has an ammonia oxidation catalyst 50 downstream, which is used to treat the unreacted ammonia during the selective catalytic reduction reaction to ensure that safe emissions meet the standards.

[0044] To ensure that N2O emissions meet standards, one possible implementation method is as follows: Figure 2 As shown, the exhaust gas treatment equipment further includes a particulate filter 40, which is located in the pipeline between the oxidizing catalyst 20 and the second selective catalytic reduction device 30. Step S202 includes:

[0045] Step S2021: If the particulate trap does not meet the passive regeneration conditions, control the urea injection rate of the first selective catalytic reduction device to increase to the maximum urea injection rate.

[0046] Specifically, during the regeneration of the particulate filter (DPF), the reaction of carbon oxidizing particles can reduce some of the NO2, thereby reducing the NO2 / NO ratio. x According to the above-mentioned particulate filter (DPF), it does not meet the conditions for passive regeneration and cannot reduce NO2 / NO through passive regeneration. x The NO2 / NO ratio can only be reduced by reducing NO2 in the first selective catalytic reduction unit (first SCR) to lower the NO2 / NO2 ratio in the exhaust gas entering the second selective catalytic reduction unit (second SCR). x Therefore, the urea injection rate of the first selective catalytic reduction device (first SCR) is increased to the maximum urea injection rate to ensure that N2O emissions meet the standards.

[0047] To ensure that N2O emissions meet standards, one possible implementation method is as follows: Figure 2 As shown, the exhaust gas treatment equipment further includes a particulate filter 40, which is located in the pipeline between the oxidizing catalyst 20 and the second selective catalytic reduction device 30. Step S202 includes:

[0048] Step S2022: If the particulate trap does not meet the passive regeneration conditions, control the particulate trap to actively regenerate and control the urea injection rate of the first selective catalytic reduction device to increase to the target urea injection rate, wherein the target urea injection rate is less than the maximum urea injection rate.

[0049] Specifically, if the aforementioned particulate filter (DPF) does not meet the passive regeneration conditions, NO2 can also be reduced through active regeneration to decrease the NO2 / NO ratio in the exhaust gas entering the second selective catalytic reduction unit (second SCR). x Based on this ratio, the urea injection rate of the first selective catalytic reduction device (first SCR) can be increased to the target urea injection rate without increasing it to the maximum urea injection rate, thereby reducing urea consumption and lowering costs.

[0050] To reduce costs while ensuring N2O emissions meet standards, in one optional embodiment, the exhaust gas treatment equipment further includes a particulate filter located in the pipeline between the oxidizing catalyst and the second selective catalytic reduction device. Step S202 includes:

[0051] Step S2023: When the particulate trap meets the passive regeneration conditions, the urea injection rate of the first selective catalytic reduction device is controlled to increase to the target urea injection rate, which is less than the maximum urea injection rate.

[0052] Specifically, when the aforementioned particulate filter (DPF) meets the passive regeneration conditions, NO2 can be passively regenerated and reduced to reduce the NO2 / NO ratio in the exhaust gas entering the second selective catalytic reduction unit (second SCR). x Based on this ratio, the urea injection rate of the first selective catalytic reduction device (first SCR) can be increased to the target urea injection rate without increasing it to the maximum urea injection rate, thereby reducing urea consumption and lowering costs.

[0053] In order to reduce costs while ensuring that N2O emissions meet standards, in one optional implementation, step S2023 includes:

[0054] Step S20231: Under the condition that the particulate trap meets the passive regeneration conditions, obtain the operating temperature of the particulate trap.

[0055] Step S20232: Based on the above-mentioned operating temperature, the urea injection rate of the first selective catalytic reduction device is increased to the corresponding target urea injection rate, wherein the target urea injection rate is negatively correlated with the above-mentioned operating temperature.

[0056] Specifically, the higher the operating temperature of the particulate filter, the better the passive regeneration effect, the more carbon particles are oxidized, and thus the more NO2 is reduced. In other words, the higher the operating temperature of the particulate filter, the better the NO2 / NO2 ratio in the exhaust gas entering the second selective catalytic reduction unit (second SCR). x The lower the proportion, the smaller the increase in the urea injection rate of the first selective catalytic reduction device (first SCR). That is, by controlling the urea injection rate of the first selective catalytic reduction device (first SCR) to increase to the corresponding target urea injection rate, so that the target urea injection rate is negatively correlated with the operating temperature, N2O emissions can be guaranteed to meet the standards. Compared with increasing to the maximum urea injection rate, the consumption of urea is reduced and the cost is lowered.

[0057] To reduce costs while ensuring N2O emissions meet standards, in one optional implementation, after step S201, the method further includes:

[0058] Step S301: When the ratio of the first concentration to the second concentration is less than or equal to the predetermined threshold, the urea injection rate of the first selective catalytic reduction device is controlled to remain constant.

[0059] Specifically, when the ratio of the first concentration to the second concentration is less than or equal to the predetermined threshold, i.e., NO2 / NO x If the proportion is less than or equal to a predetermined threshold, it indicates that the second selective catalytic reduction unit (second SCR) has deNOx. x The N2O generated during the reaction will not exceed the emission standards. Therefore, it is sufficient to keep the urea injection rate of the first selective catalytic reduction device (first SCR) constant, thereby reducing the consumption of urea and lowering the cost.

[0060] In order to monitor NO2 / NO in real time x In one optional implementation, the above step S201 includes:

[0061] Step S2011: Obtain the first proportion, wherein the first proportion is the ratio of the NO2 concentration to the NO concentration in the exhaust gas at the outlet of the first selective catalytic reduction device. x The ratio of the concentrations of the first proportion is calculated based on the equilibrium principle of the chemical reaction occurring in the first selective catalytic reduction device.

[0062] Step S2012: A second proportion is calculated based on the first proportion and the first reaction factor. The second proportion is the ratio of the NO2 concentration to the NO concentration in the exhaust gas at the outlet of the oxidizing catalyst. xThe ratio of the concentrations of the first reaction factor is determined based on the exhaust gas temperature at the inlet of the oxidizing catalyst and the exhaust flow rate of the oxidizing catalyst.

[0063] Step S2013: The ratio of the first concentration to the second concentration is calculated based on the second proportion, the second reaction factor and the third reaction factor. The second reaction factor is determined based on the exhaust gas temperature at the inlet of the particulate filter and the exhaust flow rate of the particulate filter. The third reaction factor is determined based on the carbon loading of the particulate filter.

[0064] Specifically, the first selective catalytic reduction unit undergoes a catalytic reduction reaction and some side reactions. By detecting the concentrations of other components involved in the reaction in the exhaust gas at the inlet of the first selective catalytic reduction unit, the concentrations of NO2 and NO2 after the reaction can be calculated using the principle of chemical reaction equilibrium. x The ratio of the concentrations can be used to obtain the first proportion 'a' and the second proportion 'b' = a + (1 - a). facA, where facA is the first reaction factor, can be obtained by referring to the corresponding MAP table based on the exhaust gas temperature at the inlet of the oxidizing catalyst and the exhaust flow rate of the oxidizing catalyst. The ratio of the first concentration to the second concentration is c = [b + (1-b)]. facB] facC, where facB is the second reaction factor, which can be obtained by referring to the corresponding MAP table based on the exhaust gas temperature at the inlet of the particulate filter and the exhaust flow rate of the particulate filter; facC is the third reaction factor, a correction factor determined based on the carbon loading of the particulate filter. The amount of carbon loading is closely related to the reduction of NO2. Since the sensor cannot distinguish between NO2 and other NO... x Therefore, it is impossible to directly detect the concentration of NO2 and NO through sensors. x Only by using the above method can the ratio of the first concentration to the second concentration be calculated.

[0065] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the control method of the exhaust gas treatment device of this application will be described in detail below with reference to specific embodiments.

[0066] This embodiment relates to a specific control method for exhaust gas treatment equipment, such as... Figure 4 As shown, it includes the following steps:

[0067] Step S1: First, establish a calculation model for gas components, which can calculate the various gas components before each component through chemical reaction kinetic equations, and calculate the various gas components downstream of the DPF.

[0068] Step S2: When the calculated NO2 / NOx ratio downstream of the DPF exceeds a threshold, if it does not, the first SCR maintains its injection rate; otherwise, it depends on whether the DPF can undergo passive regeneration. If the DPF requires passive regeneration, the urea injection rate of the first SCR can be controlled according to the required DPF conditions (temperature, NO2 content, carbon loading). For example, the higher the temperature, the less the urea injection rate of the first SCR increases. If the DPF does not meet the conditions for passive regeneration, the tightly coupled SCR enters a closed-loop control mode, i.e., the higher the NO2 / NOx ratio, the faster the urea injection rate of the first SCR, using the first SCR to reduce NO2 / NOx and thus reduce N2O generation.

[0069] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0070] This application also provides a control device for an exhaust gas treatment device. It should be noted that the control device for the exhaust gas treatment device in this application can be used to execute the control method for the exhaust gas treatment device provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0071] The control device of the exhaust gas treatment equipment provided in the embodiments of this application is described below.

[0072] Figure 5 This is a structural block diagram of the control device of the exhaust gas treatment equipment according to an embodiment of this application. Figure 5 As shown, the device includes:

[0073] The acquisition unit 100 is used to acquire the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration;

[0074] Specifically, N2O, as a DeNOx byproduct of Cu-based SCR, is produced when the NO2 / NO ratio is high. x The proportion enters the selective catalytic reduction (SCR) unit for DeNOx production. x The amount of N2O produced during the reaction will increase. However, the NO2 / NO ratio in the untreated exhaust gas will increase. xThe concentration of NO2 is relatively low, around 5% to 8%, and the resulting N2O byproduct generally does not exceed emission standards. However, as it enters the second selective catalytic reduction unit (second SCR), the oxidation of NO by the oxidizing catalyst (DOC) increases the formation of N2O byproduct. Therefore, monitoring the concentration of NO2 and NO in the exhaust gas at the outlet of the oxidizing catalyst is crucial. x To achieve real-time monitoring of NO2 / NO concentration. x Percentage.

[0075] The first control unit 200 is configured to control the increased urea injection rate of the first selective catalytic reduction device when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, so as to reduce the concentration of NO2 entering the second selective catalytic reduction device.

[0076] Specifically, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, i.e., NO2 / NO... x If the proportion exceeds the predetermined threshold, it may lead to excessive NO2 emissions. By controlling the increased urea injection rate of the first selective catalytic reduction device (first SCR), the first selective catalytic reduction device (first SCR) can remove as much NO2 as possible through the catalytic reduction reaction. x It is reduced to N2, thus decreasing the concentration of NO2 and lowering the NO2 / NO ratio. x Proportion, suppressing DeNO x The generation of N2O during the reaction ensures that N2O emissions meet standards.

[0077] In the control device of the aforementioned exhaust gas treatment equipment, the acquisition unit acquires the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the aforementioned oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the aforementioned oxidizing catalyst. x The concentration of NO2 entering the second selective catalytic reduction device is determined by the first control unit. When the ratio of the first concentration to the second concentration exceeds a predetermined threshold, the first control unit increases the urea injection rate of the first selective catalytic reduction device to reduce the NO2 concentration entering the second selective catalytic reduction device. NO will be converted to NO2 by the oxidizing catalyst, and the NO2 / NO2 ratio will be calculated. x A high percentage will lead to DeNO within the second SCR. x As the amount of N2O generated during the reaction increases, the device monitors the ratio of the first concentration to the second concentration, i.e., NO2 / NO. x When the ratio exceeds a predetermined threshold, the urea injection rate of the first SCR is increased to reduce NO through a catalytic reduction reaction. x By reducing the NO2 concentration entering the second SCR, the NO2 emission is reduced, thereby reducing the NO2 emission and solving the problem of excessive NO2 emission in exhaust gas in existing technologies.

[0078] In addition, such as Figure 2 As shown, each of the first selective catalytic reduction device 10 and the second selective catalytic reduction device 30 has an ammonia oxidation catalyst 50 downstream, which is used to treat the unreacted ammonia during the selective catalytic reduction reaction to ensure that safe emissions meet the standards.

[0079] To ensure that N2O emissions meet standards, one possible implementation method is as follows: Figure 2 As shown, the exhaust gas treatment equipment further includes a particulate filter 40, which is located in the pipeline between the oxidizing catalyst 20 and the second selective catalytic reduction device 30. The first control unit includes:

[0080] The first control module is used to control the urea injection rate of the first selective catalytic reduction device to increase to the maximum urea injection rate when the particulate trap does not meet the passive regeneration conditions.

[0081] Specifically, during the regeneration of the particulate filter (DPF), the reaction of carbon oxidizing particles can reduce some of the NO2, thereby reducing the NO2 / NO ratio. x According to the above-mentioned particulate filter (DPF), it does not meet the conditions for passive regeneration and cannot reduce NO2 / NO through passive regeneration. x The NO2 / NO ratio can only be reduced by reducing NO2 in the first selective catalytic reduction unit (first SCR) to lower the NO2 / NO2 ratio in the exhaust gas entering the second selective catalytic reduction unit (second SCR). x Therefore, the urea injection rate of the first selective catalytic reduction device (first SCR) is increased to the maximum urea injection rate to ensure that N2O emissions meet the standards.

[0082] To ensure that N2O emissions meet standards, one possible implementation method is as follows: Figure 2 As shown, the exhaust gas treatment equipment further includes a particulate filter 40, which is located in the pipeline between the oxidizing catalyst 20 and the second selective catalytic reduction device 30. The first control unit includes:

[0083] The second control module is used to control the particulate trap to actively regenerate and increase the urea injection rate of the first selective catalytic reduction device to a target urea injection rate when the particulate trap does not meet the passive regeneration conditions. The target urea injection rate is less than the maximum urea injection rate.

[0084] Specifically, if the aforementioned particulate filter (DPF) does not meet the passive regeneration conditions, NO2 can also be reduced through active regeneration to decrease the NO2 / NO ratio in the exhaust gas entering the second selective catalytic reduction unit (second SCR).x Based on this ratio, the urea injection rate of the first selective catalytic reduction device (first SCR) can be increased to the target urea injection rate without increasing it to the maximum urea injection rate, thereby reducing urea consumption and lowering costs.

[0085] To reduce costs while ensuring N2O emissions meet standards, in one optional embodiment, the exhaust gas treatment equipment further includes a particulate filter located on the pipeline between the oxidizing catalyst and the second selective catalytic reduction device. The first control unit includes:

[0086] The third control module is used to control the urea injection rate of the first selective catalytic reduction device to increase to a target urea injection rate when the particulate trap meets the passive regeneration conditions. The target urea injection rate is less than the maximum urea injection rate.

[0087] Specifically, when the aforementioned particulate filter (DPF) meets the passive regeneration conditions, NO2 can be passively regenerated and reduced to reduce the NO2 / NO ratio in the exhaust gas entering the second selective catalytic reduction unit (second SCR). x Based on this ratio, the urea injection rate of the first selective catalytic reduction device (first SCR) can be increased to the target urea injection rate without increasing it to the maximum urea injection rate, thereby reducing urea consumption and lowering costs.

[0088] To reduce costs while ensuring N2O emissions meet standards, in one optional implementation, the third control module includes:

[0089] The first control submodule is used to obtain the operating temperature of the particle trap when the particle trap meets the passive regeneration conditions.

[0090] The second control submodule is used to control the urea injection rate of the first selective catalytic reduction device to increase to the corresponding target urea injection rate according to the operating temperature, wherein the target urea injection rate is negatively correlated with the operating temperature.

[0091] Specifically, the higher the operating temperature of the particulate filter, the better the passive regeneration effect, the more carbon particles are oxidized, and thus the more NO2 is reduced. In other words, the higher the operating temperature of the particulate filter, the better the NO2 / NO2 ratio in the exhaust gas entering the second selective catalytic reduction unit (second SCR). xThe lower the proportion, the smaller the increase in the urea injection rate of the first selective catalytic reduction device (first SCR). That is, by controlling the urea injection rate of the first selective catalytic reduction device (first SCR) to increase to the corresponding target urea injection rate, so that the target urea injection rate is negatively correlated with the operating temperature, N2O emissions can be guaranteed to meet the standards. Compared with increasing to the maximum urea injection rate, the consumption of urea is reduced and the cost is lowered.

[0092] To reduce costs while ensuring N2O emissions meet standards, in one optional embodiment, the above-mentioned device further includes:

[0093] The second control unit is configured to, after obtaining the ratio of the first concentration and the second concentration, control the urea injection rate of the first selective catalytic reduction device to remain constant when the ratio of the first concentration and the second concentration is less than or equal to the predetermined threshold.

[0094] Specifically, when the ratio of the first concentration to the second concentration is less than or equal to the predetermined threshold, i.e., NO2 / NO x If the proportion is less than or equal to a predetermined threshold, it indicates that the second selective catalytic reduction unit (second SCR) has deNOx. x The N2O generated during the reaction will not exceed the emission standards. Therefore, it is sufficient to keep the urea injection rate of the first selective catalytic reduction device (first SCR) constant, thereby reducing the consumption of urea and lowering the cost.

[0095] In order to monitor NO2 / NO in real time x In one optional implementation, the acquisition unit includes:

[0096] The acquisition module is used to acquire a first proportion, wherein the first proportion is the concentration of NO2 in the exhaust gas at the outlet of the first selective catalytic reduction device and the concentration of NO2 in the exhaust gas. x The ratio of the concentrations of the first proportion is calculated based on the equilibrium principle of the chemical reaction occurring in the first selective catalytic reduction device.

[0097] The first calculation module is used to calculate a second proportion based on the first proportion and the first reaction factor, wherein the second proportion is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst and the NO concentration. x The ratio of the concentrations of the first reaction factor is determined based on the exhaust gas temperature at the inlet of the oxidizing catalyst and the exhaust flow rate of the oxidizing catalyst.

[0098] The second calculation module is used to calculate the ratio of the first concentration to the second concentration based on the second proportion, the second reaction factor, and the third reaction factor. The second reaction factor is determined based on the exhaust gas temperature at the inlet of the particulate filter and the exhaust flow rate of the particulate filter. The third reaction factor is determined based on the carbon loading of the particulate filter.

[0099] Specifically, the first selective catalytic reduction unit undergoes a catalytic reduction reaction and some side reactions. By detecting the concentrations of other components involved in the reaction in the exhaust gas at the inlet of the first selective catalytic reduction unit, the concentrations of NO2 and NO2 after the reaction can be calculated using the principle of chemical reaction equilibrium. x The ratio of the concentrations can be used to obtain the first proportion 'a' and the second proportion 'b' = a + (1 - a). facA, where facA is the first reaction factor, can be obtained by referring to the corresponding MAP table based on the exhaust gas temperature at the inlet of the oxidizing catalyst and the exhaust flow rate of the oxidizing catalyst. The ratio of the first concentration to the second concentration is c = [b + (1-b)]. facB] facC, where facB is the second reaction factor, which can be obtained by referring to the corresponding MAP table based on the exhaust gas temperature at the inlet of the particulate filter and the exhaust flow rate of the particulate filter; facC is the third reaction factor, a correction factor determined based on the carbon loading of the particulate filter. The amount of carbon loading is closely related to the reduction of NO2. Since the sensor cannot distinguish between NO2 and other NO... x Therefore, it is impossible to directly detect the concentration of NO2 and NO through sensors. x Only by using the above method can the ratio of the first concentration to the second concentration be calculated.

[0100] The control device of the aforementioned exhaust gas treatment equipment includes a processor and a memory. The aforementioned acquisition unit and first control unit are all stored as program units in the memory, and the processor executes the aforementioned program units stored in the memory to realize the corresponding functions. All of the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0101] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and adjusting kernel parameters can address the problem of excessive N2O emissions in exhaust gases in existing technologies.

[0102] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0103] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the control method of the exhaust gas treatment device.

[0104] Specifically, the control methods for exhaust gas treatment equipment include:

[0105] Step S201: Obtain the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration;

[0106] Specifically, N2O, as a DeNOx byproduct of Cu-based SCR, is produced when the NO2 / NO ratio is high. x The proportion enters the selective catalytic reduction (SCR) unit for DeNOx production. x The amount of N2O produced during the reaction will increase. However, the NO2 / NO ratio in the untreated exhaust gas will increase. x The concentration of NO2 is relatively low, around 5% to 8%, and the resulting N2O byproduct generally does not exceed emission standards. However, as it enters the second selective catalytic reduction unit (second SCR), the oxidation of NO by the oxidizing catalyst (DOC) increases the formation of N2O byproduct. Therefore, monitoring the concentration of NO2 and NO in the exhaust gas at the outlet of the oxidizing catalyst is crucial. x To achieve real-time monitoring of NO2 / NO concentration. x Percentage.

[0107] In step S202, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the increased urea injection rate of the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device.

[0108] Specifically, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, i.e., NO2 / NO... x If the proportion exceeds the predetermined threshold, it may lead to excessive NO2 emissions. By controlling the increased urea injection rate of the first selective catalytic reduction device (first SCR), the first selective catalytic reduction device (first SCR) can remove as much NO2 as possible through the catalytic reduction reaction. x It is reduced to N2, thus decreasing the concentration of NO2 and lowering the NO2 / NO ratio. x Proportion, suppressing DeNO x The generation of N2O during the reaction ensures that N2O emissions meet standards.

[0109] This invention provides a processor for running a program, wherein the program executes the control method of the exhaust gas treatment device.

[0110] Specifically, the control methods for exhaust gas treatment equipment include:

[0111] Step S201: Obtain the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration;

[0112] Specifically, N2O, as a DeNOx byproduct of Cu-based SCR, is produced when the NO2 / NO ratio is high. x The proportion enters the selective catalytic reduction (SCR) unit for DeNOx production. x The amount of N2O produced during the reaction will increase. However, the NO2 / NO ratio in the untreated exhaust gas will increase. x The concentration of NO2 is relatively low, around 5% to 8%, and the resulting N2O byproduct generally does not exceed emission standards. However, as it enters the second selective catalytic reduction unit (second SCR), the oxidation of NO by the oxidizing catalyst (DOC) increases the formation of N2O byproduct. Therefore, monitoring the concentration of NO2 and NO in the exhaust gas at the outlet of the oxidizing catalyst is crucial. x To achieve real-time monitoring of NO2 / NO concentration. x Percentage.

[0113] In step S202, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the increased urea injection rate of the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device.

[0114] Specifically, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, i.e., NO2 / NO... x If the proportion exceeds the predetermined threshold, it may lead to excessive NO2 emissions. By controlling the increased urea injection rate of the first selective catalytic reduction device (first SCR), the first selective catalytic reduction device (first SCR) can remove as much NO2 as possible through the catalytic reduction reaction. x It is reduced to N2, thus decreasing the concentration of NO2 and lowering the NO2 / NO ratio. x Proportion, suppressing DeNO x The generation of N2O during the reaction ensures that N2O emissions meet standards.

[0115] This invention provides a vehicle, which includes an exhaust gas treatment device, a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps:

[0116] Step S201: Obtain the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration;

[0117] Specifically, N2O, as a DeNOx byproduct of Cu-based SCR, is produced when the NO2 / NO ratio is high. x The proportion enters the selective catalytic reduction (SCR) unit for DeNOx production. x The amount of N2O produced during the reaction will increase. However, the NO2 / NO ratio in the untreated exhaust gas will increase. x The concentration of NO2 is relatively low, around 5% to 8%, and the resulting N2O byproduct generally does not exceed emission standards. However, as it enters the second selective catalytic reduction unit (second SCR), the oxidation of NO by the oxidizing catalyst (DOC) increases the formation of N2O byproduct. Therefore, monitoring the concentration of NO2 and NO in the exhaust gas at the outlet of the oxidizing catalyst is crucial. x To achieve real-time monitoring of NO2 / NO concentration. x Percentage.

[0118] In step S202, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the increased urea injection rate of the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device.

[0119] Specifically, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, i.e., NO2 / NO... x If the proportion exceeds the predetermined threshold, it may lead to excessive NO2 emissions. By controlling the increased urea injection rate of the first selective catalytic reduction device (first SCR), the first selective catalytic reduction device (first SCR) can remove as much NO2 as possible through the catalytic reduction reaction. x It is reduced to N2, thus decreasing the concentration of NO2 and lowering the NO2 / NO ratio. x Proportion, suppressing DeNO x The generation of N2O during the reaction ensures that N2O emissions meet standards.

[0120] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0121] Step S201: Obtain the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration;

[0122] Specifically, N2O, as a DeNOx byproduct of Cu-based SCR, is produced when the NO2 / NO ratio is high. x The proportion enters the selective catalytic reduction (SCR) unit for DeNOx production. x The amount of N2O produced during the reaction will increase. However, the NO2 / NO ratio in the untreated exhaust gas will increase. x The concentration of NO2 is relatively low, around 5% to 8%, and the resulting N2O byproduct generally does not exceed emission standards. However, as it enters the second selective catalytic reduction unit (second SCR), the oxidation of NO by the oxidizing catalyst (DOC) increases the formation of N2O byproduct. Therefore, monitoring the concentration of NO2 and NO in the exhaust gas at the outlet of the oxidizing catalyst is crucial. x To achieve real-time monitoring of NO2 / NO concentration. x Percentage.

[0123] In step S202, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the increased urea injection rate of the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device.

[0124] Specifically, when the ratio of the first concentration to the second concentration is greater than a predetermined threshold, i.e., NO2 / NO... x If the proportion exceeds the predetermined threshold, it may lead to excessive NO2 emissions. By controlling the increased urea injection rate of the first selective catalytic reduction device (first SCR), the first selective catalytic reduction device (first SCR) can remove as much NO2 as possible through the catalytic reduction reaction. x It is reduced to N2, thus decreasing the concentration of NO2 and lowering the NO2 / NO ratio. x Proportion, suppressing DeNO x The generation of N2O during the reaction ensures that N2O emissions meet standards.

[0125] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0126] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0127] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0128] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0129] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0130] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0131] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0132] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0133] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0134] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0135] 1) In the control method of the exhaust gas treatment equipment of this application, firstly, the ratio of a first concentration and a second concentration is obtained, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration of NO2 is then adjusted; subsequently, if the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the increased urea injection rate in the first selective catalytic reduction device is controlled to reduce the concentration of NO2 entering the second selective catalytic reduction device. NO will be converted to NO2 via an oxidizing catalyst, and the NO2 / NO2 ratio will be adjusted accordingly. x A high proportion of NO2O leads to an increased amount of N2O generated during the DeNOx reaction in the second SCR. This method monitors the ratio of the first and second concentrations, i.e., NO2 / NO2. x When the ratio exceeds a predetermined threshold, the urea injection rate of the first SCR is increased to reduce NO through a catalytic reduction reaction. x By reducing the NO2 concentration entering the second SCR, the NO2 emission is reduced, thereby reducing the NO2 emission and solving the problem of excessive NO2 emission in exhaust gas in existing technologies.

[0136] 2) In the control device of the exhaust gas treatment equipment of this application, the acquisition unit acquires the ratio of a first concentration and a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration of NO2 entering the second selective catalytic reduction device is determined by the first control unit. When the ratio of the first concentration to the second concentration exceeds a predetermined threshold, the first control unit increases the urea injection rate of the first selective catalytic reduction device to reduce the NO2 concentration entering the second selective catalytic reduction device. NO will be converted to NO2 by the oxidizing catalyst, and the NO2 / NO2 ratio will be calculated. x A high percentage will lead to DeNO within the second SCR. x As the amount of N2O generated during the reaction increases, the device monitors the ratio of the first concentration to the second concentration, i.e., NO2 / NO. x When the ratio exceeds a predetermined threshold, the urea injection rate of the first SCR is increased to reduce NO through a catalytic reduction reaction. x By reducing the NO2 concentration entering the second SCR, the NO2 emission is reduced, thereby reducing the NO2 emission and solving the problem of excessive NO2 emission in exhaust gas in existing technologies.

[0137] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A control method for an exhaust gas treatment device, characterized in that, The exhaust gas treatment equipment includes a first selective catalytic reduction device, an oxidizing catalyst, and a second selective catalytic reduction device. The equipment is installed on the exhaust gas pipeline, such that the exhaust gas sequentially passes through the first selective catalytic reduction device, the oxidizing catalyst, and the second selective catalytic reduction device. The method includes: Obtain the ratio of a first concentration to a second concentration, where the first concentration is the NO2 concentration in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the NO2 concentration in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration; When the ratio of the first concentration to the second concentration is greater than a predetermined threshold, the urea injection rate of the first selective catalytic reduction device is increased to reduce the concentration of NO2 entering the second selective catalytic reduction device. The exhaust gas treatment equipment also includes a particulate filter, which is located on the pipeline between the oxidizing catalyst and the second selective catalytic reduction device. Controlling the increased urea injection rate of the first selective catalytic reduction device includes: when the particulate filter does not meet the passive regeneration conditions, controlling the urea injection rate of the first selective catalytic reduction device to increase to the maximum urea injection rate. Obtaining the ratio of the first concentration to the second concentration includes: obtaining a first proportion, where the first proportion is the ratio of the NO2 concentration to the NO concentration in the exhaust gas at the outlet of the first selective catalytic reduction device. x The ratio of NO2 concentration to NO2 concentration is calculated based on the equilibrium principle of the chemical reaction occurring in the first selective catalytic reduction device. A second ratio is calculated based on the first ratio and the first reaction factor. The second ratio is the ratio of the NO2 concentration to the NO2 concentration in the exhaust gas at the outlet of the oxidizing catalyst. x The ratio of the concentrations of the first and second concentrations is calculated based on the first reaction factor, which is determined according to the exhaust gas temperature at the inlet of the oxidizing catalyst and the exhaust flow rate of the oxidizing catalyst; the ratio of the first concentration to the second concentration is calculated based on the second proportion, the second reaction factor, and the third reaction factor, whereby the second reaction factor is determined according to the exhaust gas temperature at the inlet of the particulate filter and the exhaust flow rate of the particulate filter, and the third reaction factor is determined according to the carbon loading of the particulate filter.

2. The method according to claim 1, characterized in that, Controlling the increased urea injection rate of the first selective catalytic reduction device includes: When the particulate trap meets the passive regeneration conditions, the urea injection rate of the first selective catalytic reduction device is controlled to increase to the target urea injection rate, which is less than the maximum urea injection rate.

3. The method according to claim 2, characterized in that, When the particulate trap meets the passive regeneration conditions, controlling the urea injection rate of the first selective catalytic reduction device to increase to the target urea injection rate includes: Under the condition that the particulate trap meets the passive regeneration conditions, the operating temperature of the particulate trap is obtained; The urea injection rate of the first selective catalytic reduction device is increased to the corresponding target urea injection rate based on the operating temperature, wherein the target urea injection rate is negatively correlated with the operating temperature.

4. The method according to any one of claims 1 to 3, characterized in that, After obtaining the ratio of the first concentration to the second concentration, the method further includes: When the ratio of the first concentration to the second concentration is less than or equal to the predetermined threshold, the urea injection rate of the first selective catalytic reduction device is controlled to remain constant.

5. A control device for an exhaust gas treatment equipment, characterized in that, The exhaust gas treatment equipment includes a first selective catalytic reduction (SCR) device, an oxidizing catalyst, and a second SCR device. The equipment is installed on the exhaust gas pipeline, such that the exhaust gas sequentially passes through the first SCR device, the oxidizing catalyst, and the second SCR device. The equipment includes: The acquisition unit is used to acquire the ratio of a first concentration to a second concentration, wherein the first concentration is the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst, and the second concentration is the concentration of NO in the exhaust gas at the outlet of the oxidizing catalyst. x The concentration; A first control unit is configured to control the increased urea injection rate of the first selective catalytic reduction device to reduce the concentration of NO2 entering the second selective catalytic reduction device when the ratio of the first concentration to the second concentration is greater than a predetermined threshold. The exhaust gas treatment equipment also includes a particulate filter, which is located on the pipeline between the oxidizing catalyst and the second selective catalytic reduction device. The first control unit includes a first control module, which is used to control the urea injection rate of the first selective catalytic reduction device to increase to the maximum urea injection rate when the particulate filter does not meet the passive regeneration conditions. The acquisition unit includes: an acquisition module, used to acquire a first proportion, wherein the first proportion is the concentration of NO2 in the exhaust gas at the outlet of the first selective catalytic reduction device and the concentration of NO2 in the exhaust gas. x The ratio of the concentrations of NO2 and NO3, wherein the first ratio is calculated based on the equilibrium principle of the chemical reaction occurring in the first selective catalytic reduction device; the first calculation module is used to calculate a second ratio based on the first ratio and the first reaction factor, wherein the second ratio is the ratio of the concentration of NO2 in the exhaust gas at the outlet of the oxidizing catalyst to the concentration of NO3. x The ratio of the concentrations of the first and second concentrations is calculated based on the first reaction factor, which is determined according to the exhaust gas temperature at the inlet of the oxidizing catalyst and the exhaust flow rate of the oxidizing catalyst; the second calculation module is used to calculate the ratio of the first concentration to the second concentration based on the second ratio, the second reaction factor, and the third reaction factor, whereby the second reaction factor is determined according to the exhaust gas temperature at the inlet of the particulate filter and the exhaust flow rate of the particulate filter, and the third reaction factor is determined according to the carbon loading of the particulate filter.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 4.

7. A vehicle, characterized in that, include: An exhaust gas treatment device, one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of claims 1 to 4.

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