Tail gas denitration method, device, equipment and medium

Abstract

The application discloses a tail gas denitration method, device, equipment and medium, relates to the technical field of tail gas emission, and comprises: a tail gas denitration device comprising a denitration equipment, a tail gas emission channel and an air injection channel, the output end of the injection channel is connected with the input end of the emission channel; the demand value of the oxygen mass flow of the denitration equipment is determined based on the current tail gas flow of the tail gas emission channel, the combustion mode of the engine corresponding to the device is determined according to the actual value and the demand value of the oxygen mass flow in the current tail gas flow; if it is the equivalent combustion mode, it is determined that the tail gas emission channel is in the air supplementing state, the current air supplementing mass flow of the tail gas emission channel is determined according to the current tail gas flow, the actual value, the target oxygen concentration required by the denitration equipment and the oxygen volume fraction; the external air is injected into the tail gas emission channel from the air injection channel according to the current air supplementing mass flow, and the denitration equipment is controlled to perform denitration treatment on the tail gas in the tail gas emission channel. The cost of engine tail gas emission is reduced.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas emission technology, and in particular to exhaust gas denitrification methods, apparatus, equipment and media. Background Technology

[0002] Lean combustion in an engine refers to the vigorous combustion of excess air and a suitable amount of fuel under high temperature and pressure, converting chemical energy into mechanical energy. The exhaust gases contain not only large amounts of nitrogen oxides but also a significant amount of oxygen. Equivalent combustion in an engine refers to the vigorous combustion of a suitable amount of air and a suitable amount of fuel; the exhaust gases contain large amounts of nitrogen oxides and very small amounts of oxygen.

[0003] When emissions contain a large amount of nitrogen oxides and oxygen, denitrification equipment is used to treat nitrogen oxides; when emissions contain a large amount of nitrogen oxides and very little oxygen, three-way catalytic converters are needed to treat nitrogen oxides. In other words, the equipment used to treat nitrogen oxides differs depending on the oxygen content in the exhaust gas. This means that in order to meet the bench test requirements of stationary source emission standards, engines need to be equipped with both denitrification equipment and three-way catalytic converters under both lean combustion and stoichiometric combustion modes, resulting in a waste of equipment.

[0004] In summary, how to reduce the cost of engine exhaust emissions is a problem that needs to be solved in this field. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method, apparatus, equipment, and medium for exhaust gas denitrification, thereby reducing the cost of engine exhaust emissions. The specific solution is as follows:

[0006] In a first aspect, this application discloses a method for exhaust gas denitrification, comprising:

[0007] Obtain the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device; wherein the exhaust gas denitrification device includes the exhaust gas emission channel and an air injection channel, and the output end of the air injection channel is connected to the input end of the exhaust gas emission channel;

[0008] The required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device is determined based on the current exhaust gas flow rate, and the current combustion mode of the engine in the exhaust gas denitrification device is determined based on the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required value of the oxygen mass flow rate; the current combustion mode is an equivalence combustion mode or a lean combustion mode.

[0009] If the current combustion mode is the equivalent combustion mode, the exhaust gas emission channel is determined to be in a state of needing to be replenished with air. The current mass flow rate of the air to be replenished in the exhaust gas emission channel is determined based on the current exhaust gas flow rate, the actual value, the target oxygen concentration required by the denitrification equipment, and the oxygen volume fraction.

[0010] According to the current mass flow rate of the air to be replenished, the external air is injected into the exhaust gas emission channel from the air injection channel, and then the denitrification equipment is controlled to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel.

[0011] Optionally, obtaining the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device includes:

[0012] The current exhaust gas flow rate of the exhaust gas emission channel is determined based on the theoretical air-fuel ratio, the upstream temperature of the denitrification equipment in the exhaust gas denitrification device, the actual air-fuel ratio of the exhaust gas emission channel in the exhaust gas denitrification device, the fuel consumption mass flow rate, and a preset correction coefficient.

[0013] Alternatively, the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device can be found in the MAP diagram based on the current engine speed and current torque in the exhaust gas denitrification device; wherein the MAP diagram is calibrated based on the engine's historical speed, historical torque and historical exhaust gas flow rate.

[0014] Optionally, determining the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device based on the current exhaust gas flow rate, and determining the current combustion mode of the engine in the exhaust gas denitrification device based on the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required oxygen mass flow rate, includes:

[0015] The required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device is determined based on the current exhaust gas flow rate, the nitrogen oxide concentration in the exhaust gas emission channel, the oxygen to nitrogen oxide molar ratio, the oxygen molar mass, and the nitrogen oxide molar mass.

[0016] The actual value of the oxygen mass flow rate in the current exhaust gas flow rate is determined based on the current exhaust gas flow rate and the actual oxygen concentration in the exhaust gas emission channel;

[0017] If the required oxygen mass flow rate is less than the actual oxygen mass flow rate, then the current combustion mode of the engine in the exhaust gas denitrification device is determined to be lean combustion mode.

[0018] If the required oxygen mass flow rate is greater than the actual oxygen mass flow rate, then the current combustion mode of the engine in the exhaust gas denitrification device is determined to be the stoichiometric combustion mode.

[0019] Optionally, before determining the actual value of the oxygen mass flow rate in the current exhaust gas flow rate based on the current exhaust gas flow rate and the actual oxygen concentration in the exhaust gas emission channel, the method further includes:

[0020] The initial oxygen concentration of the exhaust gas emission channel is collected using the upstream nitrogen oxide sensor of the denitrification equipment, and the actual oxygen concentration of the exhaust gas emission channel is determined based on the initial oxygen concentration, the molar mass of oxygen, and the molar mass of the current exhaust gas in the exhaust gas emission channel.

[0021] Optionally, the exhaust gas denitrification device further includes an air replenishment valve, which is located at the input end of the air injection channel and is used to adjust the air mass flow rate when external air is injected into the exhaust gas emission channel through the air injection channel.

[0022] Optionally, controlling the injection of external air from the air injection channel into the exhaust emission channel according to the current mass flow rate of the air to be replenished includes:

[0023] The current duty cycle of the air replenishment valve corresponding to the current mass flow rate of the air to be replenished is determined from the pulse spectrum curve; wherein, the pulse spectrum curve is calibrated based on each historical mass flow rate of the air to be replenished and each historical duty cycle of the air replenishment valve;

[0024] The opening degree of the air supply valve is controlled according to the current duty cycle to control the external air to be injected into the exhaust gas channel from the air injection channel.

[0025] Optionally, the exhaust gas denitrification device further includes a system controller, a urea pump, and a urea tank; controlling the denitrification device to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel includes:

[0026] The conversion efficiency of nitrogen oxides in the exhaust gas emission channel is determined based on the current exhaust gas flow rate and the upstream temperature of the denitrification equipment.

[0027] The system controller controls the urea pump to inject urea drawn from the urea tank into the denitrification equipment based on the conversion efficiency of the nitrogen oxides, so as to control the denitrification equipment to denitrify the exhaust gas in the exhaust gas emission channel.

[0028] Secondly, this application discloses a tail gas denitrification device, comprising:

[0029] The exhaust gas flow acquisition module is used to acquire the current exhaust gas flow in the exhaust gas emission channel of the exhaust gas denitrification device; wherein, the exhaust gas denitrification device includes the exhaust gas emission channel and the air injection channel, and the output end of the air injection channel is connected to the input end of the exhaust gas emission channel.

[0030] The combustion mode determination module is used to determine the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device based on the current exhaust gas flow rate, and to determine the current combustion mode of the engine in the exhaust gas denitrification device based on the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required value of the oxygen mass flow rate; the current combustion mode is an equivalence combustion mode or a lean combustion mode;

[0031] The replenishment flow determination module is used to determine that the exhaust gas emission channel is in a state of needing replenishment air if the current combustion mode is the equivalent combustion mode, and to determine the current mass flow rate of the air to be replenished in the exhaust gas emission channel based on the current exhaust gas flow rate, the actual value, the target oxygen concentration required by the denitrification equipment, and the oxygen volume fraction.

[0032] The exhaust gas denitrification module is used to control the external air to be injected into the exhaust gas emission channel from the air injection channel according to the current mass flow rate of the air to be replenished, and then control the denitrification equipment to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel.

[0033] Thirdly, this application discloses an electronic device, including:

[0034] Memory, used to store computer programs;

[0035] A processor is used to execute the computer program to implement the steps of the aforementioned disclosed exhaust gas denitrification method.

[0036] Fourthly, this application discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the steps of the aforementioned exhaust gas denitrification method.

[0037] The beneficial effects of this application are as follows: This application obtains the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device; wherein, the exhaust gas denitrification device includes the exhaust gas emission channel and an air injection channel, and the output end of the air injection channel is connected to the input end of the exhaust gas emission channel; based on the current exhaust gas flow rate, the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device is determined, and the current combustion mode of the engine in the exhaust gas denitrification device is determined according to the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required oxygen mass flow rate; the current combustion mode is an equivalence combustion mode or a lean combustion mode; if the current combustion mode is the equivalence combustion mode, the exhaust gas emission channel is determined to be in a state of needing supplemental air, and the current mass flow rate of the air to be supplemented in the exhaust gas emission channel is determined according to the current exhaust gas flow rate, the actual value, the target oxygen concentration required by the denitrification equipment, and the oxygen volume fraction; external air is controlled to be injected into the exhaust gas emission channel from the air injection channel according to the current mass flow rate of the air to be supplemented, and then the denitrification equipment is controlled to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel. Therefore, this application demonstrates several advantages. First, by accurately acquiring the current exhaust gas flow rate, it provides crucial foundational data for determining the subsequent oxygen mass flow rate requirement. Then, based on the current exhaust gas flow rate, it determines the oxygen mass flow rate requirement for the denitrification equipment and, combined with the actual value, identifies the engine's combustion mode. This enables precise identification of the combustion mode, preventing exhaust gas treatment failure due to misjudgment. When the combustion mode is determined to be equivalence combustion, the application calculates the required air mass flow rate based on parameters such as the target oxygen concentration needed by the denitrification equipment and precisely controls the air injection. This effectively increases the oxygen concentration in the exhaust gas under equivalence combustion mode, ensuring that the exhaust gas meets the operating conditions of the denitrification equipment. This eliminates the need for an additional three-way catalytic converter, reducing hardware investment costs for exhaust gas treatment equipment and saving labor costs associated with replacing aftertreatment equipment when the engine combustion mode changes. Furthermore, by precisely controlling the injected air mass flow rate, the application ensures that the denitrification equipment is always operating at high efficiency, guaranteeing that the exhaust gas under both combustion modes meets stationary source emission standards and improving the utilization rate of the exhaust gas treatment equipment. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0039] Figure 1 This is a flowchart of a tail gas denitrification method disclosed in this application;

[0040] Figure 2This application discloses a specific exhaust gas flow control strategy diagram;

[0041] Figure 3 This is a schematic diagram of a specific air supply valve opening control strategy disclosed in this application;

[0042] Figure 4 This is a schematic diagram of a specific conversion efficiency control strategy disclosed in this application;

[0043] Figure 5 This is a schematic diagram of a specific exhaust gas denitrification device disclosed in this application;

[0044] Figure 6 This is a schematic diagram of the structure of a tail gas denitrification device disclosed in this application;

[0045] Figure 7 This is a structural diagram of an electronic device disclosed in this application. Detailed Implementation

[0046] The technical solutions of the embodiments of this 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 invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0047] Lean combustion in an engine refers to the vigorous combustion of excess air and a suitable amount of fuel under high temperature and pressure, converting chemical energy into mechanical energy. The exhaust gases contain not only large amounts of nitrogen oxides but also a significant amount of oxygen. Equivalent combustion in an engine refers to the vigorous combustion of a suitable amount of air and a suitable amount of fuel; the exhaust gases contain large amounts of nitrogen oxides and very small amounts of oxygen.

[0048] When emissions contain a large amount of nitrogen oxides and oxygen, denitrification equipment is used to treat nitrogen oxides; when emissions contain a large amount of nitrogen oxides and very little oxygen, three-way catalytic converters are needed to treat nitrogen oxides. In other words, the equipment used to treat nitrogen oxides differs depending on the oxygen content in the exhaust gas. This means that in order to meet the bench test requirements of stationary source emission standards, engines need to be equipped with both denitrification equipment and three-way catalytic converters under both lean combustion and stoichiometric combustion modes, resulting in a waste of equipment.

[0049] Therefore, this application provides a corresponding exhaust gas denitrification solution to reduce the cost of engine exhaust emissions.

[0050] See Figure 1 As shown in the embodiment of this application, a method for exhaust gas denitrification is disclosed, comprising:

[0051] Step S11: Obtain the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device; wherein, the exhaust gas denitrification device includes the exhaust gas emission channel and the air injection channel, and the output end of the air injection channel is connected to the input end of the exhaust gas emission channel.

[0052] In this embodiment, obtaining the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device includes: determining the current exhaust gas flow rate of the exhaust gas emission channel based on the theoretical air-fuel ratio, the upstream temperature of the denitrification equipment in the exhaust gas denitrification device, the actual air-fuel ratio of the exhaust gas emission channel in the exhaust gas denitrification device, the fuel consumption mass flow rate, and a preset correction coefficient; or, finding the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device in a MAP graph based on the current engine speed and current torque in the exhaust gas denitrification device; wherein the MAP graph is calibrated based on the engine's historical speeds, historical torques, and historical exhaust gas flow rates.

[0053] For example Figure 2 As shown, accurate measurement of the current exhaust gas flow is achieved through two complementary calculation paths. The first is to combine theoretical air-fuel ratio (DEFFC_rLam_C), upstream temperature (DEIn_tsnsrUp), actual air-fuel ratio (DEFFC_rLamclc), fuel consumption mass flow rate (DEIn_dmFuelEng), and preset correction coefficients (C1, C2) to perform formulaic calculations to obtain the calculated value (DEFFC_mfExhCalUs0). The second is to rely on a pre-calibrated engine speed (DEIn_nENG)-torque (DEIn_TrqENG)-historical exhaust gas flow MAP to perform operating condition matching queries to obtain the model value (DEFFC_mfExhMod0). That is, the model value (DEFFC_mfExhMod0) is obtained based on the MAP value with engine speed (DEIn_nENG) and torque (DEIn_TrqENG) as the horizontal and vertical axes. Next, the calculated or model value can be determined as the current exhaust gas flow rate of the exhaust gas emission channel by using the switch (DE_stEngType_C).

[0054] It should be noted that the exhaust gas denitrification device includes an exhaust gas emission channel, an air injection channel, and a denitrification device. The output end of the air injection channel is connected to the input end of the exhaust gas emission channel. Therefore, external air can be injected into the exhaust gas emission channel through the air injection channel to replenish the exhaust gas in the exhaust gas emission channel with fresh air. Furthermore, the output end of the exhaust gas emission channel is connected to the denitrification device, so that the exhaust gas from the exhaust gas emission channel is output to the denitrification device, which performs denitrification treatment on the exhaust gas.

[0055] Determining the calculated or modeled values ​​as the current exhaust gas flow rate in the exhaust gas emission channel ensures the accuracy and reliability of the exhaust gas flow rate value. This provides core basic data support for the subsequent calculation of oxygen mass flow rate requirements and actual values, accurate determination of combustion modes, and reasonable control of the air supply valve opening. In turn, it ensures the stable execution of the entire exhaust gas denitrification system control strategy, helps improve the denitrification equipment's adaptability to the treatment of exhaust gases from two combustion modes, and also reduces the errors that may occur with a single flow rate acquisition method. This lays a crucial data foundation for ultimately achieving a single denitrification equipment that can treat exhaust gases from two combustion modes, reducing equipment investment and labor replacement costs.

[0056] Step S12: Determine the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device based on the current exhaust gas flow rate, and determine the current combustion mode of the engine in the exhaust gas denitrification device according to the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required oxygen mass flow rate; the current combustion mode is an equivalence combustion mode or a lean combustion mode.

[0057] In this embodiment, determining the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device based on the current exhaust gas flow rate, and determining the current combustion mode of the engine in the exhaust gas denitrification device based on the actual oxygen mass flow rate in the current exhaust gas flow rate and the required oxygen mass flow rate, includes: determining the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device based on the current exhaust gas flow rate, the nitrogen oxide concentration in the exhaust gas emission channel, the oxygen to nitrogen oxide molar ratio, the oxygen molar mass, and the nitrogen oxide molar mass; determining the actual oxygen mass flow rate in the current exhaust gas flow rate based on the current exhaust gas flow rate and the actual oxygen concentration in the exhaust gas emission channel; if the required oxygen mass flow rate is less than the actual oxygen mass flow rate, then the current combustion mode of the engine in the exhaust gas denitrification device is determined to be a lean combustion mode; if the required oxygen mass flow rate is greater than the actual oxygen mass flow rate, then the current combustion mode of the engine in the exhaust gas denitrification device is determined to be an equivalence combustion mode.

[0058] For example Figure 3As shown, when determining the current combustion mode of the engine in the exhaust gas denitrification device, it is necessary to first determine the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device and the actual oxygen mass flow rate in the exhaust gas emission channel. Then, based on the relationship between the required value and the actual value, the current combustion mode of the engine in the exhaust gas denitrification device can be determined. Specifically, it is as follows: 1) Determine the required oxygen mass flow rate of the denitrification equipment (DEFFC_dmdeO2Us): Combine the current exhaust gas flow rate (DEFFC_mfExhUs), the nitrogen oxide concentration in the exhaust gas emission channel (DEFFC_ppmNOx), the oxygen to nitrogen oxide molar ratio (DiO2NOxmol_C), the oxygen molar mass (MO2Mol_C), the nitrogen oxide molar mass (MNOxMol_C), and the preset oxygen correction coefficient (facO2_C) to calculate the required oxygen mass flow rate of the denitrification equipment. 2) Determine the actual oxygen mass flow rate (DEFFC_dmO2Us): Calculate the actual oxygen mass flow rate (DEFFC_dmO2Us) based on the current exhaust gas flow rate (DEFFC_mfExhUs0) and the actual oxygen concentration in the exhaust gas emission channel (DEFFC_ratPrcO2Us). 3) Determine the current combustion mode: Determine the combustion mode by comparing the required value and the actual value. When the actual value is greater than the required value, it indicates a lean combustion mode (more air, less fuel). When the actual value is less than the required value, it indicates an equivalence combustion mode (moderate air and fuel). It is evident that the system achieves accurate calculation of oxygen mass flow rate requirements and scientific determination of combustion modes, providing crucial information for determining whether the supplementary gas valve needs to be opened and for precise control of the supplementary gas volume. This ensures the orderly implementation of the entire exhaust gas treatment control strategy and effectively guarantees that the denitrification equipment has suitable oxygen concentration conditions under different combustion modes. This helps achieve the goal of treating exhaust gas from two combustion modes with a single denitrification system, improving the accuracy and stability of exhaust gas treatment, avoiding equipment waste and substandard exhaust gas treatment caused by misjudgment of combustion modes, and saving the cost of additional three-way catalytic converter equipment and the labor cost of equipment replacement.

[0059] In this embodiment, before determining the actual value of the oxygen mass flow rate in the current exhaust gas flow based on the current exhaust gas flow rate and the actual oxygen concentration in the exhaust gas emission channel, the method further includes: collecting the initial oxygen concentration in the exhaust gas emission channel using the upstream nitrogen oxide sensor of the denitrification equipment, and determining the actual oxygen concentration in the exhaust gas emission channel based on the initial oxygen concentration, the oxygen molar mass, and the current exhaust gas molar mass in the exhaust gas emission channel.

[0060] Before determining the actual oxygen mass flow rate in the current exhaust gas flow, it is necessary to first determine the actual oxygen concentration (DEFFC_ratPrcO2Us0) in the exhaust gas emission channel. Specifically, the initial oxygen concentration (DEFFC_ratO2Us) in the exhaust gas emission channel is collected using a nitrogen oxide sensor upstream of the denitrification equipment. This initial oxygen concentration, unit conversion (TransUnit_C), oxygen molar mass (O2M_C), and the current molar mass of the exhaust gas in the emission channel (ExhM_C) are then used to perform a conversion, yielding the actual oxygen concentration in the exhaust gas emission channel. This professional conversion of the initial oxygen concentration collected by the sensor provides accurate actual oxygen concentration data, offering a reliable foundation for the accurate calculation of the subsequent actual oxygen mass flow rate. This ensures the effectiveness of comparing the actual oxygen mass flow rate with the required value, thereby improving the accuracy of combustion mode determination. This lays a solid data foundation for subsequent injection valve control and stable operation of the denitrification equipment, helping to achieve the goal of treating exhaust gases from two combustion modes with a single denitrification system, reducing equipment investment and labor costs, and avoiding exhaust gas treatment failures due to data errors.

[0061] Step S13: If the current combustion mode is the equivalent combustion mode, then the exhaust gas emission channel is determined to be in a state of needing to be replenished with air. The current mass flow rate of the air to be replenished in the exhaust gas emission channel is determined based on the current exhaust gas flow rate, the actual value, the target oxygen concentration required by the denitrification equipment, and the oxygen volume fraction.

[0062] When the program determines that the engine in the exhaust gas denitrification device is in stoichiometric combustion mode, indicating that there is more air and less fuel, the exhaust gas emission channel is determined to be in a state where air needs to be added. When the program determines that the engine in the exhaust gas denitrification device is in lean combustion mode, indicating that there is an appropriate amount of air and fuel, the exhaust gas emission channel is determined to be in a state where air does not need to be added.

[0063] Understandably, if the current combustion mode is stoichiometric combustion, it is necessary to determine the current mass flow rate of the air to be added to the exhaust gas passage so that the oxygen concentration in the exhaust gas passage increases, allowing the denitrification equipment to perform denitrification treatment on the exhaust gas. For example... Figure 3 As shown, the current mass flow rate of the exhaust gas to be replenished (DEFFC_dmAirDes) is determined based on the current exhaust gas flow rate (DEFFC_mfExhUs0), the actual value (DEFFC_dmO2Us), the target oxygen concentration required by the denitrification equipment (DEFFC_ratPrcO2targ_C), and the oxygen volume fraction (ratO2Air).

[0064] Step S14: Control the external air to be injected into the exhaust gas emission channel from the air injection channel according to the current mass flow rate of the air to be replenished, and then control the denitrification equipment to denitrify the exhaust gas in the exhaust gas emission channel.

[0065] In this embodiment, the exhaust gas denitrification device further includes an air replenishment valve, which is located at the input end of the air injection channel and is used to adjust the air mass flow rate when external air is injected into the exhaust gas emission channel through the air injection channel.

[0066] It is important to note that the exhaust gas denitrification device is equipped with an air replenishment valve, which is located at the input end of the air injection channel. Its core function is to regulate the mass flow rate of external air injected into the exhaust gas emission channel through the air injection channel. By precisely controlling the amount of fresh air supplied to the exhaust gas emission channel through the air replenishment valve, the oxygen concentration of the exhaust gas in the stoichiometric combustion mode can be increased to the target range required by the denitrification equipment. This allows a single denitrification device to simultaneously adapt to both stoichiometric combustion and lean combustion modes for exhaust gas treatment, eliminating the need for additional three-way catalytic converters. This reduces the hardware investment cost of exhaust gas treatment and saves the labor cost of replacing aftertreatment equipment when switching combustion modes. At the same time, precise air replenishment control ensures that the denitrification equipment is always in a highly efficient denitrification state, ensuring that exhaust gas emissions meet relevant standards, improving equipment utilization, and solving the problems of equipment waste and inconvenient replacement in traditional solutions.

[0067] In this embodiment, controlling the injection of external air from the air injection channel into the exhaust gas emission channel according to the current mass flow rate of the air to be injected includes: determining the current duty cycle of the air injection valve corresponding to the current mass flow rate of the air to be injected from the pulse spectrum curve; wherein, the pulse spectrum curve is calibrated based on each historical mass flow rate of the air to be injected and each historical duty cycle of the air injection valve; controlling the opening of the air injection valve according to the current duty cycle to control the injection of external air from the air injection channel into the exhaust gas emission channel.

[0068] When controlling the external air injection into the exhaust gas channel according to the current mass flow rate of the air to be injected, the current duty cycle of the air injection valve that matches the current mass flow rate of the air to be injected is first determined from a pre-calibrated calibrated calibrated curve (CUR) containing the correspondence between the historical mass flow rates of the air to be injected and the historical duty cycles of the air injection valve. The on / off control of the air injection valve is filtered and delayed by tFiltering_C, and then the opening degree of the air injection valve is precisely adjusted according to the current duty cycle, thereby achieving flow control of the external air injected into the exhaust gas channel through the air injection channel. The calibrated calibrated curve enables precise conversion of the mass flow rate of the air to be injected into the air injection valve duty cycle. By adjusting the opening degree of the air injection valve through the duty cycle, the amount of fresh air injected can be finely controlled, ensuring that the oxygen concentration in the exhaust gas under stoichiometric combustion mode is stably increased to the target range required by the denitrification equipment, thus ensuring that the denitrification equipment can carry out denitrification work efficiently even under stoichiometric combustion mode. For example... Figure 3 As shown, the opening degree of the air replenishment valve is obtained based on the CUR value with the air mass flow rate as the horizontal axis. The required fresh air mass flow rate (DEFFC_dmAirDes) is converted into the duty cycle of the air replenishment valve in the program, thereby controlling its opening degree and thus accurately controlling the required fresh air intake.

[0069] In this embodiment, the exhaust gas denitrification device further includes a system controller, a urea pump, and a urea tank; controlling the denitrification device to denitrify the exhaust gas in the exhaust gas emission channel includes: determining the conversion efficiency of nitrogen oxides in the exhaust gas emission channel based on the current exhaust gas flow rate and the upstream temperature of the denitrification device; and controlling the urea pump to inject urea drawn from the urea tank into the denitrification device based on the conversion efficiency of nitrogen oxides, so as to control the denitrification device to denitrify the exhaust gas in the exhaust gas emission channel.

[0070] The exhaust gas denitrification device is also equipped with a system controller, a urea pump, and a urea tank, for example... Figure 4As shown, the efficiency of nitrogen oxide conversion in the denitrification equipment is a crucial factor in calculating the urea injection rate. Therefore, when controlling the denitrification equipment to treat the exhaust gas in the exhaust emission channel, the conversion efficiency of nitrogen oxides in the exhaust emission channel is first obtained using the current exhaust gas flow rate (DEFFC_mfExhUs0) and the upstream temperature of the denitrification equipment (DEIn_tsnsrUp) as the MAP values ​​on the horizontal and vertical axes. The upstream temperature of the denitrification equipment can be obtained by using the upstream temperature sensor value (DEIn_tsnsrUp) via the switch (DEFFC_swtTempSensSeln_C) or by taking the average of the temperature values ​​measured by the upstream and downstream temperature sensors (DEFFC_mfExhMod0). Then, the system controller, in conjunction with this nitrogen oxide conversion efficiency, controls the urea pump to extract the corresponding amount of urea from the urea tank and inject it into the denitrification equipment, thereby achieving the denitrification treatment of the exhaust gas in the exhaust emission channel. By accurately determining the nitrogen oxide conversion efficiency based on the current exhaust gas flow rate and upstream temperature, a scientific basis is provided for controlling the urea injection quantity. With the coordinated work of the system controller, urea pump, and urea tank, the precise control of the urea injection quantity can be achieved. This allows the denitrification equipment to maintain high denitrification reaction efficiency under different combustion modes, ensuring the full conversion of nitrogen oxides in the exhaust gas and guaranteeing that exhaust gas emissions meet relevant standards. At the same time, it achieves the goal of treating exhaust gas from two combustion modes with one denitrification equipment.

[0071] The beneficial effects of this application are as follows: This application obtains the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device; wherein, the exhaust gas denitrification device includes the exhaust gas emission channel and an air injection channel, and the output end of the air injection channel is connected to the input end of the exhaust gas emission channel; based on the current exhaust gas flow rate, the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device is determined, and the current combustion mode of the engine in the exhaust gas denitrification device is determined according to the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required oxygen mass flow rate; the current combustion mode is an equivalence combustion mode or a lean combustion mode; if the current combustion mode is the equivalence combustion mode, the exhaust gas emission channel is determined to be in a state of needing supplemental air, and the current mass flow rate of the air to be supplemented in the exhaust gas emission channel is determined according to the current exhaust gas flow rate, the actual value, the target oxygen concentration required by the denitrification equipment, and the oxygen volume fraction; external air is controlled to be injected into the exhaust gas emission channel from the air injection channel according to the current mass flow rate of the air to be supplemented, and then the denitrification equipment is controlled to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel. Therefore, this application demonstrates several advantages. First, by accurately acquiring the current exhaust gas flow rate, it provides crucial foundational data for determining the subsequent oxygen mass flow rate requirement. Then, based on the current exhaust gas flow rate, it determines the oxygen mass flow rate requirement for the denitrification equipment and, combined with the actual value, identifies the engine's combustion mode. This enables precise identification of the combustion mode, preventing exhaust gas treatment failure due to misjudgment. When the combustion mode is determined to be equivalence combustion, the application calculates the required air mass flow rate based on parameters such as the target oxygen concentration needed by the denitrification equipment and precisely controls the air injection. This effectively increases the oxygen concentration in the exhaust gas under equivalence combustion mode, ensuring that the exhaust gas meets the operating conditions of the denitrification equipment. This eliminates the need for an additional three-way catalytic converter, reducing hardware investment costs for exhaust gas treatment equipment and saving labor costs associated with replacing aftertreatment equipment when the engine combustion mode changes. Furthermore, by precisely controlling the injected air mass flow rate, the application ensures that the denitrification equipment is always operating at high efficiency, guaranteeing that the exhaust gas under both combustion modes meets stationary source emission standards and improving the utilization rate of the exhaust gas treatment equipment.

[0072] The following is based on Figure 5This application will now be described. The exhaust gas denitrification device includes an engine, an electronic control unit (ECU), a supplemental air valve, a nitrogen oxide sensor, a temperature sensor, a urea pump, denitrification equipment, a urea tank, a system controller, and a controller assembly. The engine is located upstream and in the input direction of the denitrification equipment. Therefore, the temperature sensor between the engine and the denitrification equipment is the upstream temperature sensor of the denitrification equipment, and the temperature value measured by the upstream temperature sensor is the upstream temperature of the denitrification equipment. Similarly, the nitrogen oxide sensor located between the engine and the denitrification equipment is the upstream nitrogen oxide sensor. The channel between the engine and the denitrification equipment is the exhaust gas emission channel, and the channel between the supplemental air valve and the exhaust gas emission channel is the air injection channel. It can be understood that the output direction of the denitrification equipment is the downstream direction of the denitrification equipment, and the temperature sensor located in the downstream direction is the downstream temperature sensor. The temperature value measured by the downstream temperature sensor is the downstream temperature, and the nitrogen oxide sensor located in the downstream direction is the downstream nitrogen oxide sensor.

[0073] Engines developed on test benches can be either stoichiometric or lean-burn engines, and their exhaust compositions differ accordingly. Stoichiometric engines produce exhaust containing large amounts of nitrogen oxides (NOx) and very little oxygen (O2), requiring a three-way catalytic converter to treat this gas composition. Lean-burn engines, on the other hand, produce exhaust containing large amounts of both NOx and O2, requiring a denitrification system. This embodiment first automatically determines the engine's combustion mode based on a control strategy. Then, by measuring the NOx and oxygen concentrations using an upstream NOx sensor, it calculates whether fresh air needs to be added to the exhaust pipe, and the required mass flow rate of fresh air. With a denitrification system (eliminating the need for a three-way catalytic converter), urea injection ensures that the exhaust gases from both stoichiometric and lean-burn engines meet emission regulations.

[0074] See Figure 6 As shown in the figure, this application discloses a tail gas denitrification device, including:

[0075] The exhaust gas flow acquisition module 11 is used to acquire the current exhaust gas flow in the exhaust gas emission channel of the exhaust gas denitrification device; wherein, the exhaust gas denitrification device includes the exhaust gas emission channel and the air injection channel, and the output end of the air injection channel is connected to the input end of the exhaust gas emission channel.

[0076] Combustion mode determination module 12 is used to determine the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device based on the current exhaust gas flow rate, and to determine the current combustion mode of the engine in the exhaust gas denitrification device based on the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required oxygen mass flow rate; the current combustion mode is an equivalence combustion mode or a lean combustion mode;

[0077] The replenishment flow determination module 13 is used to determine that the exhaust gas emission channel is in a state of needing replenishment air if the current combustion mode is the equivalent combustion mode, and to determine the current mass flow rate of the exhaust gas emission channel to be replenished based on the current exhaust gas flow rate, the actual value, the target oxygen concentration required by the denitrification equipment, and the oxygen volume fraction.

[0078] The exhaust gas denitrification module 14 is used to control the external air to be injected into the exhaust gas emission channel from the air injection channel according to the current mass flow rate of the air to be replenished, and then control the denitrification equipment to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel.

[0079] Furthermore, embodiments of this application also provide an electronic device. Figure 7 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content of the diagram should not be construed as limiting the scope of this application.

[0080] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Specifically, it may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the exhaust gas denitrification method performed by the electronic device disclosed in any of the foregoing embodiments.

[0081] In this embodiment, the power supply 23 is used to provide operating voltage for various hardware devices on the electronic device; the communication interface 24 can create a data transmission channel between the electronic device and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0082] The processor 21 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 21 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 21 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 21 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 21 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0083] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored on it include operating system 221, computer program 222 and data 223, etc., and the storage method can be temporary storage or permanent storage.

[0084] The operating system 221 manages and controls the various hardware devices and computer programs 222 on the electronic device to enable the processor 21 to perform calculations and processing on the massive amounts of data 223 in the memory 22. The operating system can be Windows, Unix, Linux, etc. The computer program 222, in addition to including a computer program capable of performing the exhaust gas denitrification method executed by the electronic device as disclosed in any of the foregoing embodiments, may further include computer programs capable of performing other specific tasks. The data 223 may include data received by the electronic device from external devices, as well as data collected by its own input / output interface 25.

[0085] Furthermore, this application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the aforementioned exhaust gas denitrification method. Specific steps of this method can be found in the corresponding content disclosed in the foregoing embodiments, and will not be repeated here.

[0086] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0087] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application. The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly in hardware, software modules executed by a processor, or a combination of both. The software module may be located in random access memory (RAM), memory, read-only memory (ROM), electrically programmable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), register, hard disk, removable disk, CD-ROM (Compact Disc Read-Only Memory), or any other form of storage medium known in the art.

[0088] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 a process, method, article, or apparatus. Without further limitations, 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 said element.

[0089] The above provides a detailed description of the exhaust gas denitrification method, apparatus, equipment, and medium provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only intended to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for denitrification of exhaust gas, characterized in that, include: Obtain the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device; wherein the exhaust gas denitrification device includes the exhaust gas emission channel and an air injection channel, and the output end of the air injection channel is connected to the input end of the exhaust gas emission channel; The required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device is determined based on the current exhaust gas flow rate, and the current combustion mode of the engine in the exhaust gas denitrification device is determined based on the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required value of the oxygen mass flow rate; the current combustion mode is an equivalence combustion mode or a lean combustion mode. If the current combustion mode is the equivalent combustion mode, the exhaust gas emission channel is determined to be in a state of needing to be replenished with air. The current mass flow rate of the air to be replenished in the exhaust gas emission channel is determined based on the current exhaust gas flow rate, the actual value, the target oxygen concentration required by the denitrification equipment, and the oxygen volume fraction. According to the current mass flow rate of the air to be replenished, the external air is controlled to be injected into the exhaust gas emission channel from the air injection channel, and then the denitrification equipment is controlled to denitrify the exhaust gas in the exhaust gas emission channel. The step of determining the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device based on the current exhaust gas flow rate, and determining the current combustion mode of the engine in the exhaust gas denitrification device based on the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required oxygen mass flow rate, includes: Based on the current exhaust gas flow rate, the nitrogen oxide concentration in the exhaust gas emission channel, the oxygen to nitrogen oxide molar ratio, the oxygen molar mass, and the nitrogen oxide molar mass, the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device is determined; based on the current exhaust gas flow rate and the actual oxygen concentration in the exhaust gas emission channel, the actual value of the oxygen mass flow rate in the current exhaust gas flow rate is determined; if the required oxygen mass flow rate is less than the actual oxygen mass flow rate, the current combustion mode of the engine in the exhaust gas denitrification device is determined to be lean combustion mode; if the required oxygen mass flow rate is greater than the actual oxygen mass flow rate, the current combustion mode of the engine in the exhaust gas denitrification device is determined to be stoichiometric combustion mode. The exhaust gas denitrification device also includes an air replenishment valve, which is located at the input end of the air injection channel and is used to adjust the air mass flow rate when external air is injected into the exhaust gas emission channel through the air injection channel. The step of controlling external air to be injected into the exhaust emission channel from the air injection channel according to the current mass flow rate of the air to be replenished includes: The current duty cycle of the air replenishment valve corresponding to the current mass flow rate of the air to be replenished is determined from the pulse spectrum curve; wherein, the pulse spectrum curve is calibrated based on each historical mass flow rate of the air to be replenished and each historical duty cycle of the air replenishment valve; the opening of the air replenishment valve is controlled according to the current duty cycle to control the external air to be injected into the exhaust gas emission channel from the air injection channel; The exhaust gas denitrification device also includes a system controller, a urea pump, and a urea tank; controlling the denitrification device to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel includes: The conversion efficiency of nitrogen oxides in the exhaust gas emission channel is determined based on the current exhaust gas flow rate and the upstream temperature of the denitrification equipment. The system controller controls the urea pump to inject urea drawn from the urea tank into the denitrification equipment based on the nitrogen oxide conversion efficiency, so as to control the denitrification equipment to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel. The upstream temperature of the denitrification equipment is the value of the upstream temperature sensor or the average value of the temperature value measured by the upstream temperature sensor and the temperature value measured by the downstream temperature sensor.

2. The exhaust gas denitrification method according to claim 1, characterized in that, The acquisition of the current exhaust gas flow rate in the exhaust gas emission channel of the exhaust gas denitrification device includes: The current exhaust gas flow rate of the exhaust gas emission channel is determined based on the theoretical air-fuel ratio, the upstream temperature of the denitrification equipment in the exhaust gas denitrification device, the actual air-fuel ratio of the exhaust gas emission channel in the exhaust gas denitrification device, the fuel consumption mass flow rate, and a preset correction coefficient. Alternatively, the current exhaust gas flow rate of the exhaust gas emission channel in the exhaust gas denitrification device can be found in the MAP diagram based on the current engine speed and current torque in the exhaust gas denitrification device; wherein the MAP diagram is calibrated based on the engine's historical speed, historical torque and historical exhaust gas flow rate.

3. The exhaust gas denitrification method according to claim 1, characterized in that, Before determining the actual value of the oxygen mass flow rate in the current exhaust gas flow rate based on the current exhaust gas flow rate and the actual oxygen concentration in the exhaust gas emission channel, the method further includes: The initial oxygen concentration of the exhaust gas emission channel is collected using the upstream nitrogen oxide sensor of the denitrification equipment, and the actual oxygen concentration of the exhaust gas emission channel is determined based on the initial oxygen concentration, the molar mass of oxygen, and the molar mass of the current exhaust gas in the exhaust gas emission channel.

4. A tail gas denitrification device, characterized in that, The steps for implementing the exhaust gas denitrification method as described in any one of claims 1 to 3 include: The exhaust gas flow acquisition module is used to acquire the current exhaust gas flow in the exhaust gas emission channel of the exhaust gas denitrification device; wherein, the exhaust gas denitrification device includes the exhaust gas emission channel and the air injection channel, and the output end of the air injection channel is connected to the input end of the exhaust gas emission channel. The combustion mode determination module is used to determine the required oxygen mass flow rate of the denitrification equipment in the exhaust gas denitrification device based on the current exhaust gas flow rate, and to determine the current combustion mode of the engine in the exhaust gas denitrification device based on the actual value of the oxygen mass flow rate in the current exhaust gas flow rate and the required value of the oxygen mass flow rate; the current combustion mode is an equivalence combustion mode or a lean combustion mode; The replenishment flow determination module is used to determine that the exhaust gas emission channel is in a state of needing replenishment air if the current combustion mode is the equivalent combustion mode, and to determine the current mass flow rate of the air to be replenished in the exhaust gas emission channel based on the current exhaust gas flow rate, the actual value, the target oxygen concentration required by the denitrification equipment, and the oxygen volume fraction. The exhaust gas denitrification module is used to control the external air to be injected into the exhaust gas emission channel from the air injection channel according to the current mass flow rate of the air to be replenished, and then control the denitrification equipment to perform denitrification treatment on the exhaust gas in the exhaust gas emission channel.

5. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the steps of the exhaust gas denitrification method as described in any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that, Used to store a computer program; wherein, when the computer program is executed by a processor, it implements the steps of the exhaust gas denitrification method as described in any one of claims 1 to 3.

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