Denitration ammonia spraying method and device based on flue gas pressure induction, electronic equipment and storage medium

Abstract

The invention discloses a denitration ammonia spraying method and device based on flue gas pressure induction, electronic equipment and a storage medium. The method comprises the following steps: for at least part of nozzle assemblies in a plurality of nozzle assemblies associated with an ammonia spraying pipeline, determining current flue gas pressure corresponding to each nozzle assembly; based on the current flue gas pressure corresponding to each nozzle assembly, the current injection coefficient of each nozzle assembly is determined, and the current injection coefficient is used for indicating the matching degree of the actual ammonia injection amount and the theoretical ammonia injection amount of the nozzle assembly at the current moment; and opening control is conducted on the nozzle assemblies based on the current spraying coefficient of each nozzle assembly, wherein the opening control is used for controlling and adjusting the ammonia spraying amount of the nozzle assemblies. According to the technical scheme, the flue gas pressure at the flue interface where the denitration ammonia spraying device is located can be sensed in real time, unit load changes are quickly responded through positive feedback so as to adjust the ammonia spraying amount of each nozzle assembly, the ammonia consumption of a denitration system is reduced, and tail flue blockage is relieved.

Description

Technical Field

[0001] The present invention relates to the technical field of selective catalytic reduction flue gas denitrification, and particularly to a denitrification ammonia injection method, device, electronic device, and storage medium based on flue gas pressure induction. Background Art

[0002] As one of the main energy production methods, coal-fired power plants emit nitrogen oxides (NOx) as one of the main pollutants, which can cause serious environmental problems such as acid rain and photochemical smog, posing great harm to the ecological environment and human health.

[0003] The selective catalytic reduction (SCR) flue gas denitrification technology has been widely used in coal-fired power plants due to its significant advantages such as high denitrification efficiency and mature technology. The principle of this technology is to inject reducing agents such as ammonia into the flue, and utilize the reduction characteristics of ammonia to nitrogen oxides. Under the action of a catalyst, the nitrogen oxides in the flue gas are converted into water and nitrogen, thereby effectively reducing nitrogen oxide emissions.

[0004] However, the ammonia injection volume of the denitrification ammonia injection device is affected by the total regulating valve of the ammonia injection pipeline, and is controlled according to stabilizing the nitrogen oxide concentration at the outlet of the denitrification system flue within the environmental protection standard. In the actual application process, the precise control of the denitrification ammonia injection volume has become a major problem. When the ammonia injection volume is too low, the nitrogen oxides cannot be fully reduced, resulting in excessive emissions and continued harm to the environment; when the ammonia injection volume is too high, the ammonia escape will increase, causing blockage and corrosion of equipment such as air preheaters and low-temperature economizers in the tail flue due to the deposition of ammonium bisulfate, seriously affecting the safe and stable operation of the equipment, and increasing the maintenance cost and shutdown risk. Summary of the Invention

[0005] The present invention provides a denitrification ammonia injection method, device, electronic device, and storage medium based on flue gas pressure induction to real-time sense the flue gas pressure at the interface of the flue where the denitrification ammonia injection device is located, and adjust the ammonia injection volume of each nozzle assembly through positive feedback to quickly respond to the change of the unit load, reduce the ammonia consumption of the denitrification system, and relieve the blockage of the tail flue.

[0006] According to the first aspect of the embodiments of the present invention, a denitrification ammonia injection method based on flue gas pressure induction is provided, which is applied to a denitrification ammonia injection device. The denitrification ammonia injection device is installed in the flue of the denitrification system. The denitrification ammonia injection device includes a plurality of ammonia injection pipelines, and each ammonia injection pipeline is configured with a plurality of nozzle assemblies. The ammonia injection pipeline is connected to the denitrification system pipeline. The ammonia injection pipeline is used to transport the ammonia-air mixture. The nozzle assembly is used to increase the flow rate of the ammonia-air mixture and then spray it out. The spraying direction of the nozzle of the nozzle assembly is opposite to the flue gas flow direction in the denitrification system flue. The method includes:

[0007] For at least some of the multiple nozzle assemblies associated with the ammonia injection pipeline, determine the current flue gas pressure corresponding to each nozzle assembly, where the current flue gas pressure is the flue gas pressure at the location of each nozzle assembly at the current moment;

[0008] Based on the current flue gas pressure corresponding to each nozzle assembly, determine the current injection coefficient of each nozzle assembly. The current injection coefficient is used to indicate the matching degree between the actual ammonia injection amount and the theoretical ammonia injection amount of the nozzle assembly at the current moment. The actual ammonia injection amount is the ammonia injection amount when the nozzle assembly ejects the ammonia-air mixture, and the theoretical ammonia injection amount is the ammonia injection amount required when the nozzle assembly ejects the ammonia-air mixture to fully react the nitrogen oxides and ammonia included in the flue gas in the denitration system flue. The theoretical ammonia injection amount is correlated with the nitrogen oxide content in the flue gas of the denitration system flue;

[0009] Based on the current injection coefficient of each nozzle assembly, perform opening control on the nozzle assembly, and the opening control is used to control and adjust the ammonia injection amount of the nozzle assembly.

[0010] According to the second aspect of the embodiments of the present invention, there is provided a denitration ammonia injection device based on flue gas pressure induction, configured in the denitration ammonia injection device. The denitration ammonia injection device is installed in the denitration system flue. The denitration ammonia injection device includes a plurality of ammonia injection pipelines, and a plurality of nozzle assemblies are arranged on each ammonia injection pipeline. The ammonia injection pipeline is connected to the denitration system pipeline. The ammonia injection pipeline is used to transport the ammonia-air mixture. The nozzle assembly is used to eject the ammonia-air mixture after increasing the flow rate. The ejection direction of the nozzle of the nozzle assembly is opposite to the flue gas flow direction in the denitration system flue. The device includes:

[0011] A first determination module, configured to determine the current flue gas pressure corresponding to each nozzle assembly for at least some of the multiple nozzle assemblies associated with the ammonia injection pipeline, where the current flue gas pressure is the flue gas pressure at the location of each nozzle assembly at the current moment;

[0012] A second determination module, configured to determine the current injection coefficient of each nozzle assembly based on the current flue gas pressure corresponding to each nozzle assembly. The current injection coefficient is used to indicate the matching degree between the actual ammonia injection amount and the theoretical ammonia injection amount of the nozzle assembly at the current moment. The actual ammonia injection amount is the ammonia injection amount when the nozzle assembly ejects the ammonia-air mixture, and the theoretical ammonia injection amount is the ammonia injection amount required when the nozzle assembly ejects the ammonia-air mixture to fully react the nitrogen oxides and ammonia included in the flue gas in the denitration system flue. The theoretical ammonia injection amount is correlated with the nitrogen oxide content in the flue gas of the denitration system flue;

[0013] A control module, configured to perform opening degree control on the nozzle assemblies based on the current injection coefficient of each nozzle assembly, where the opening degree control is used to control and adjust the ammonia injection amount of the nozzle assemblies.

[0014] According to a third aspect of an embodiment of the present invention, there is provided an electronic device, which includes:

[0015] At least one processor; and a memory communicatively connected to the at least one processor;

[0016] Wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor, so that the at least one processor can execute the denitration ammonia injection method based on flue gas pressure sensing according to any embodiment of the present invention.

[0017] According to a fourth aspect of an embodiment of the present invention, there is provided a computer-readable storage medium storing computer instructions for causing a processor to implement the denitration ammonia injection method based on flue gas pressure sensing according to any embodiment of the present invention when executed.

[0018] The technical solution of the embodiment of the present invention can accurately calculate the current injection coefficient by determining the current flue gas pressure at the location of each nozzle assembly, thereby judging the matching degree between the actual ammonia injection amount and the theoretical ammonia injection amount. The opening degree of the nozzle assemblies is controlled based on the injection coefficient, so as to quickly respond to the change of the unit load through positive feedback to adjust the ammonia injection amount of each nozzle assembly, so that the ammonia injection amount accurately matches the nitrogen oxide content, and the excessive injection of ammonia is avoided through accurate control of the ammonia injection amount, reducing the waste of ammonia and the use cost of the reducing agent. At the same time, it avoids equipment failures and increased maintenance costs caused by improper ammonia injection amounts, prevents blockage and corrosion of downstream equipment caused by ammonia escape, extends the service life of the equipment, and reduces the overall operation cost. At the same time, the flue gas pressure at the position of each nozzle assembly is monitored in real time, and the nozzle opening degree is dynamically adjusted accordingly, so that the denitration system can quickly adapt to the changes in operating conditions such as flue gas flow rate, temperature, and pressure in the denitration system flue, maintain stable denitration performance, and ensure that the system can operate efficiently under different operating conditions. And because the current flue gas pressure and injection coefficient are determined separately for each nozzle assembly, and then the opening degree control is performed, it changes the previous extensive mode of uniformly regulating the ammonia injection amount, and realizes refined ammonia injection management in the denitration ammonia injection process.

[0019] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0021] Figure 1 is a flowchart of a denitration ammonia injection method based on flue gas pressure induction provided according to an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of a distributed denitration ammonia injection device based on flue gas pressure induction provided according to an embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of the flue gas duct layout of a denitration system provided according to an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of the nozzle assembly layout provided according to an embodiment of the present invention;

[0025] Figure 5 is a schematic diagram of the nozzle assembly naming provided according to an embodiment of the present invention;

[0026] Figure 6 is a schematic flowchart of a denitration ammonia injection method based on flue gas pressure induction provided according to an embodiment of the present invention.

[0027] Figure 7 is a schematic structural diagram of a denitration ammonia injection device based on flue gas pressure induction provided according to an embodiment of the present invention;

[0028] Figure 8 is a schematic structural diagram of an electronic device for implementing the denitration ammonia injection method based on flue gas pressure induction in the embodiments of the present invention. Detailed implementation manners

[0029] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0031] Figure 1 FIG. is a schematic flow chart of a denitration ammonia injection method based on flue gas pressure induction provided by an embodiment of the present invention. The embodiment of the present invention is applicable to the situation of accurately regulating the ammonia injection amount according to the flue gas pressure induction in various industrial scenarios with strict requirements for nitrogen oxide emission control. The denitration ammonia injection method based on flue gas pressure induction can be executed by a denitration ammonia injection device based on flue gas pressure induction. The denitration ammonia injection device based on flue gas pressure induction can be implemented in the form of software and / or hardware, and is generally integrated on any electronic device with network communication function. The electronic device can be a mobile terminal, a PC or a server, etc.

[0032] As Figure 1 shown, the denitration ammonia injection method based on flue gas pressure induction in the embodiment of the present invention may include the following processes:

[0033] S110. For at least some of the multiple nozzle assemblies associated with the ammonia injection pipeline, determine the current flue gas pressure corresponding to each nozzle assembly. The current flue gas pressure is the flue gas pressure at the location of each nozzle assembly at the current moment.

[0034] Among them, the denitration ammonia injection device is installed in the denitration system flue. The denitration ammonia injection device includes a plurality of ammonia injection pipelines, and a plurality of nozzle assemblies are arranged on each ammonia injection pipeline. The ammonia injection pipeline is connected to the denitration system pipeline. The ammonia injection pipeline is used to transport the ammonia-air mixture. The nozzle assembly is used to spray the ammonia-air mixture after increasing the flow rate. The spraying direction of the nozzle of the nozzle assembly is opposite to the flue gas flow direction in the denitration system flue.

[0035] The application scenarios of this solution include, but are not limited to, the following: In coal-fired power plants, when boilers burn coal, a large amount of flue gas containing nitrogen oxides is generated. Therefore, it can be applied to its denitration system. By precisely controlling the ammonia injection volume, nitrogen oxides in the flue gas can be efficiently removed, ensuring that the flue gas discharged during the power generation process meets environmental protection standards, while reducing operating costs and ensuring the stable operation of the generator set. In the process of steel production, such as in the processes of blast furnace ironmaking and converter steelmaking, waste gas containing nitrogen oxides is discharged. Therefore, it can be applied to its denitration system, which can accurately adjust the ammonia injection volume according to the change in flue gas pressure generated in different production stages, denitrate the waste gas, and help steel enterprises save energy and reduce emissions and achieve green production.

[0036] See Figure 2 And Figure 3 , in this solution, the denitration ammonia injection device can include a nozzle assembly 1 and an ammonia injection pipeline 2. The ammonia injection pipeline 2 is connected to the denitration system pipeline. The denitration ammonia injection device can include multiple ammonia injection pipelines 2, and each ammonia injection pipeline 2 is configured with multiple nozzle assemblies 1. The denitration ammonia injection device is installed in the denitration system flue 7. The denitration ammonia injection device is used to inject ammonia-air mixture into the flue gas containing nitrogen oxides to achieve the denitration reaction. The ammonia injection pipeline 2 is connected to the denitration system pipeline. The ammonia injection pipeline 2 is responsible for transporting the ammonia-air mixture provided by the denitration system pipeline, providing the ammonia source required for the denitration reaction for the nozzle assembly 1, ensuring that ammonia can be stably transported to each nozzle assembly 1. The nozzle assembly 1 is installed on the ammonia injection pipeline 2 and can spray out after increasing the flow rate of the ammonia-air mixture, so that ammonia is fully mixed with the flue gas in the denitration system flue 7. The spraying direction of the nozzle of the nozzle assembly 1 is opposite to the flue gas flow direction, which helps to enhance the mixing effect and reaction efficiency.

[0037] In the related technical solutions, the ammonia injection volume of the nozzle assembly in the denitration ammonia injection device is affected by the main control valve of the ammonia injection pipeline. The opening degree of the main control valve of the ammonia injection pipeline is controlled according to the nitrogen oxide concentration at the outlet of the denitration system flue being stabilized within the environmental protection standards. It is impossible to control the ammonia injection volume of each nozzle assembly. Since the ammonia injection volume is related to the nitrogen oxide concentration and the nitrogen oxide volume, the denitration ammonia injection by controlling the nitrogen oxide concentration at the outlet of the denitration system flue is not accurate enough, and the negative feedback regulation method has a certain lag. Therefore, this solution selects to adaptively adjust the ammonia injection volume of each nozzle assembly respectively.

[0038] See Figure 3, the generation and conversion process of nitrogen oxides is usually accompanied by heat changes and gas volume changes. The change in the content of nitrogen oxides will change the average molar mass of the flue gas, thereby affecting the flue gas density, and thus affecting the flue gas pressure in the denitration system flue. The reaction between nitrogen oxides and ammonia in the denitration system flue is usually an exothermic reaction. If the nitrogen oxides react fully, more heat is released, which will cause the local flue gas temperature to rise. According to the principle of thermal expansion and contraction and the ideal gas state equation, the gas volume expands. When the flue volume is constant, it will lead to an increase in flue gas pressure; if the nitrogen oxides do not react fully and less heat is released, the effect of increasing the flue gas pressure is not obvious.

[0039] At the same time, due to the different flue gas flow velocities at different positions in the cross-section of the denitration system flue, it is inevitable that the residence times of the flue gas at different positions in the denitration system flue are different, and the corresponding nitrogen oxide concentrations at different positions also vary. By sensitively sensing the flue gas pressure at the location of the nozzle assembly through the flue gas pressure sensing sheet, the relative magnitude relationship between the nitrogen oxide concentrations and the amounts of nitrogen oxides at different positions can be obtained.

[0040] Based on the above situation, see Figure 2 , when adaptively adjusting the ammonia injection amounts of each nozzle assembly respectively, the flue gas pressure at the location of the nozzle assembly in the denitration system flue at the current moment can be considered. The flue gas pressure at the location of each nozzle assembly in the denitration system flue at the current moment can be sensed in real time, so as to detect whether the nitrogen oxides in the flue gas in the denitration system flue react fully. Once it is found that the flue gas pressure is abnormal, it may mean that the nitrogen oxides do not react fully, and a response can be made quickly to adjust the ammonia injection amount, realizing dynamic optimization and ensuring that the denitration system is always in an efficient operation state.

[0041] In an optional but non-limiting implementation solution, determining the current flue gas pressure corresponding to each nozzle assembly includes the following steps:

[0042] Sense the flue gas pressure at the location of each nozzle assembly at the current moment through the flue gas pressure sensing sheet in each nozzle assembly.

[0043] Among them, the flue gas pressure sensing sheet in the nozzle assembly is fixedly connected to the nozzle in the nozzle assembly. The first side of the flue gas pressure sensing sheet in the nozzle assembly faces the nozzle in the nozzle assembly, the second side of the flue gas pressure sensing sheet in the nozzle assembly faces the flue gas in the denitration system flue, and the area of the nozzle in the nozzle assembly is smaller than the area of the side of the flue gas pressure sensing sheet in the nozzle assembly.

[0044] See Figure 2, by providing a flue gas pressure sensing sheet 15 in each nozzle assembly 1, the flue gas pressure sensing sheet in each nozzle assembly can sense the change of the flue gas pressure around the position where each nozzle assembly 1 is located in real time and convert it into a measurable signal. The flue gas pressure sensing sheet 15 is fixedly connected to the nozzle 13 in the nozzle assembly 1. This connection method ensures the position stability of the flue gas pressure sensing sheet in the nozzle assembly 1, so that it will not be displaced due to factors such as flue gas erosion and vibration during long-term operation, ensuring the accuracy and reliability of pressure sensing. For example, in a high-flow flue gas environment, if the connection of the flue gas pressure sensing sheet is not stable, it may shake, resulting in deviation of the measured pressure data and affecting the control accuracy of the entire denitration system.

[0045] See Figure 2 , the first side of the flue gas pressure sensing sheet 15 faces the nozzle in the nozzle assembly. Such an orientation enables the flue gas pressure sensing sheet 15 to directly sense the pressure impact of the ammonia-air mixture ejected from the nozzle 13 on the flue gas pressure sensing sheet, and at the same time can monitor the change of the local pressure field formed near the nozzle 13 due to gas injection. The second side of the flue gas pressure sensing sheet 15 faces the flue gas in the denitration system flue. This side is mainly used to sense the pressure state of the mainstream flue gas in the flue. By comprehensively sensing the pressures on both sides, the complex pressure environment at the position where the nozzle assembly is located can be more comprehensively sensed.

[0046] See Figure 2 , combined with the setting that the area of the nozzle in the nozzle assembly is smaller than the side area of the flue gas pressure sensing sheet in the nozzle assembly, the larger-area flue gas pressure sensing sheet can receive the flue gas pressures from different directions in the flue more widely, improving the comprehensiveness of pressure sensing. At the same time, since the side area of the flue gas pressure sensing sheet is larger than the area of the nozzle 13 of the nozzle assembly, it can prevent the fly ash in the denitration system flue from entering the denitration ammonia injection device through the nozzle 13 of the nozzle assembly 1 and blocking the flow of the ammonia-air mixture.

[0047] In an alternative implementation, see Figure 2 , the nozzle assembly further includes a speed reduction sheet 14. The first side of the speed reduction sheet 14 faces the nozzle 13 in the nozzle assembly. The second side of the speed reduction sheet 14 is attached to the second side of the flue gas pressure sensing sheet 15, and the speed reduction sheet 14 in the nozzle assembly is fixedly connected to the nozzle 13 in the nozzle assembly.

[0048] See Figure 2, The nozzle assembly 1 is connected to the ammonia injection pipeline 2 and is used to increase the flow rate of the ammonia-air mixture and then spray it out from the nozzle 13 of the nozzle assembly 1. When the ammonia-air mixture is sprayed out from the nozzle of the nozzle assembly at a high speed, the excessive flow rate may cause the ammonia-air mixture to mix unevenly with the flue gas in the denitration system flue, affecting the adequacy of the denitration reaction. The flow rate reducing plate 14 can buffer and decelerate the ammonia-air mixture sprayed out at a high speed, so that the ammonia-air mixture enters the denitration system flue at a more appropriate speed, which is conducive to uniform mixing with the flue gas and improving the denitration efficiency.

[0049] See Figure 2 , The first side of the flow rate reducing plate 14 faces the nozzle 13 in the nozzle assembly and is fixedly connected to the nozzle 13. This fixed connection method ensures the stability of the position of the flow rate reducing plate, enabling it to continuously and effectively decelerate the gas sprayed out from the nozzle. At the same time, the setting facing the nozzle can ensure that the flow rate reducing plate contacts the ammonia-air mixture sprayed out at a high speed in the first time, maximizing the deceleration function.

[0050] In an alternative implementation, the nozzle assembly further includes a nozzle support. The nozzle support is used to support and fix the nozzle, the nozzle pipe, the flow rate reducing plate and the flue gas pressure sensing plate in the nozzle assembly.

[0051] In an alternative implementation, the nozzle pipe in the nozzle assembly is perpendicular to the first side of the flow rate reducing plate in the nozzle assembly, and the nozzle pipe in the nozzle assembly is perpendicular to the first side of the flue gas pressure sensing plate in the nozzle assembly.

[0052] See Figure 2 , The nozzle support 12 connects the nozzle pipe 11, the nozzle 13, the flow rate reducing plate 14 and the flue gas pressure sensing plate 15, playing a supporting role. The flow rate reducing plate 14 is perpendicularly connected to the nozzle pipe in the nozzle assembly, hindering the flow of the ammonia-air mixture sprayed out from the nozzle 13, capable of offsetting the flow rate of the ammonia-air mixture sprayed out from the nozzle 13, increasing the residence time of the ammonia-air mixture in the denitration system flue, and promoting the full mixing of the ammonia-air mixture with the flue gas in the denitration system flue.

[0053] In an alternative implementation, the flow area of the nozzle in the nozzle assembly is smaller than the flow area of the nozzle pipe in the nozzle assembly, and the flow area of the nozzle pipe in the nozzle assembly is smaller than the flow area of the ammonia injection pipeline to which the nozzle pipe in the nozzle assembly belongs.

[0054] See Figure 2 , The nozzle 13 of the nozzle assembly 1 is the final spraying part of the ammonia-air mixture. The nozzle pipe 11 of the nozzle assembly 1 is the component connecting the nozzle 13 and the ammonia injection pipeline 2, and the ammonia injection pipeline 2 is the channel providing the ammonia-air mixture for the entire nozzle assembly. These three are connected in sequence and jointly constitute the transmission path of the ammonia-air mixture.

[0055] See Figure 2,When the ammonia-air mixture in the nozzle 11 of the nozzle assembly 1 flows towards the nozzle orifice 13, due to the reduction in the flow area of the nozzle orifice, according to the continuity principle in the fluid mechanics of the ammonia-air mixture, when the ammonia-air mixture flows in the pipeline, the flow rate remains unchanged, and the flow velocity is inversely proportional to the flow area. Therefore, the gas flow velocity will increase. This can enable the ammonia-air mixture to be ejected from the nozzle orifice at a higher speed, which is beneficial for it to mix better with the flue gas in the flue of the denitration system. If the flow area of the nozzle orifice is the same as or larger than that of the nozzle, the gas flow velocity cannot be increased, which may cause the ejected ammonia-air mixture to fail to effectively penetrate the flue gas layer, thereby affecting the mixing effect and reaction efficiency with nitrogen oxides. That is to say, the flow area of the nozzle orifice 13 of the nozzle is smaller than the flow area of the nozzle 11, which plays a role in increasing the flow velocity of the ammonia-air mixture, preventing fly ash in the flue gas from entering the denitration ammonia injection device and blocking the flow of the ammonia-air mixture.

[0056] See Figure 2 ,When the ammonia injection pipeline transports the ammonia-air mixture to the nozzle, because the flow area of the nozzle of the nozzle assembly 1 becomes smaller, based on the continuity principle, the flow velocity of the gas in the nozzle will increase. At the same time, this design can maintain a relatively high pressure in the ammonia injection pipeline, providing sufficient power for the gas to enable it to pass through the nozzle smoothly and be ejected from the nozzle orifice. Moreover, the relatively large flow area of the ammonia injection pipeline can ensure sufficient supply of the ammonia-air mixture, meet the requirements of the denitration reaction, and avoid insufficient gas supply due to too small a flow area of the pipeline, which affects the denitration effect.

[0057] S120. Determine the current injection coefficient of each nozzle assembly based on the current flue gas pressure corresponding to each nozzle assembly. The current injection coefficient is used to indicate the matching degree between the actual ammonia injection amount and the theoretical ammonia injection amount of the nozzle assembly at the current moment. The actual ammonia injection amount is the ammonia injection amount when the nozzle assembly ejects the ammonia-air mixture, and the theoretical ammonia injection amount is the ammonia injection amount required when the nozzle assembly ejects the ammonia-air mixture to enable the nitrogen oxides and ammonia included in the flue gas in the flue of the denitration system to fully react. The theoretical ammonia injection amount is correlated with the nitrogen oxide content in the flue gas in the flue of the denitration system.

[0058] The current flue gas pressure can refer to the flue gas pressure value at the position of the nozzle orifice of the nozzle assembly in the flue of the denitration system sensed by the flue gas pressure sensing piece installed at the position of the nozzle orifice of the nozzle assembly at the current moment. This pressure value is affected by various factors such as the flue gas flow rate, flow velocity, and temperature in the flue, and will change dynamically as the denitration process progresses.

[0059] See Figure 2 And Figure 3, the current injection coefficient can be a parameter used to measure the accuracy of the ammonia injection amount of the nozzle assembly at the current moment, reflecting the matching degree between the ammonia injection amount in the ammonia-air mixture actually ejected by the nozzle assembly and the ammonia injection amount theoretically expected to fully react nitrogen oxides and ammonia. The current injection coefficient is a relative value, and through the current injection coefficient, the difference between the actual ammonia injection amount and the theoretical ammonia injection amount of the nozzle assembly at the current moment can be intuitively understood.

[0060] The actual ammonia injection amount can refer to the actual ejection amount of ammonia contained in the ammonia-air mixture when the nozzle assembly ejects it into the flue gas duct of the denitration system. The actual ammonia injection amount can be measured by relevant equipment (such as a flow meter, etc.) and is affected by various factors such as the structure of the nozzle assembly, the size of the nozzle orifice, the injection pressure, and the control system. The theoretical ammonia injection amount can be calculated according to the content of nitrogen oxides in the flue gas in the flue gas duct of the denitration system based on the stoichiometric relationship of chemical reactions. It is the amount of ammonia in the ammonia-air mixture that the nozzle assembly needs to eject when it is expected to fully react nitrogen oxides and ammonia. The theoretical ammonia injection amount is an ideal value set based on chemical principles and the denitration reaction target, which is directly related to the content of nitrogen oxides in the flue gas and usually needs to be dynamically adjusted according to the real-time monitored content of nitrogen oxides.

[0061] Since there is a certain correlation between the flue gas pressure and the denitration reaction process, for example, the change of the flue gas pressure may affect the mixing effect and reaction rate of the ammonia-air mixture and the flue gas, etc., so the working state of the nozzle assembly and the injection situation of the ammonia-air mixture can be inferred by analyzing the current flue gas pressure. By establishing a mathematical model or empirical formula between the flue gas pressure and the injection coefficient, and using the currently obtained flue gas pressure data, the current injection coefficient of each nozzle assembly can be calculated. For example, if the flue gas pressure is higher than a certain threshold, it may mean that the ammonia injection amount of the ammonia-air mixture is insufficient, and the actual ammonia injection amount may be less than the theoretical ammonia injection amount, resulting in the current injection coefficient being greater than 1; conversely, if the flue gas pressure is too low, there may be an over-injection situation, and the current injection coefficient may be less than 1.

[0062] As a quantitative index, the value of the current injection coefficient directly reflects the relationship between the actual ammonia injection amount and the theoretical ammonia injection amount. When the current injection coefficient is equal to 1, it means that the actual ammonia injection amount and the theoretical ammonia injection amount are completely matched, which is the most ideal state. At this time, nitrogen oxides and ammonia in the denitration system can fully react according to the expected stoichiometric relationship, and the denitration efficiency is the highest. When the current injection coefficient is greater than 1, it indicates that the actual ammonia injection amount is less than the theoretical ammonia injection amount, meaning that the ammonia injection amount of the ammonia-air mixture is insufficient, and nitrogen oxides may not be fully reduced, which will affect the denitration effect; when the current injection coefficient is less than 1, it indicates that the actual ammonia injection amount is greater than the theoretical ammonia injection amount, which may cause waste of ammonia in the ammonia-air mixture and may also lead to problems such as ammonia slip.

[0063] In an optional but non-limiting implementation, based on the current flue gas pressure corresponding to each nozzle assembly, determining the current injection coefficient of each nozzle assembly includes the following steps A1 - A2:

[0064] Step A1: Determine the current denitration parameter information of the denitration system at the current moment. The denitration parameter information includes the concentration of nitrogen oxides at the inlet of the denitration system flue corresponding to the denitration system, the concentration of nitrogen oxides at the outlet of the denitration system flue corresponding to the denitration system, the ammonia flow rate of the denitration system, the operating coal quantity of the denitration system, and the operating air volume of the denitration system.

[0065] Step A2: Based on the current flue gas pressure corresponding to each nozzle assembly and the current denitration parameter information, determine the current injection coefficient of each nozzle assembly.

[0066] The denitration parameter information can be a set of key data used to describe the operating state of the denitration system, specifically as follows: The concentration of nitrogen oxides at the inlet of the denitration system flue can refer to the content of nitrogen oxides in the flue gas entering the denitration system flue, usually expressed in units such as milligrams per cubic meter. This concentration is an important indicator for measuring the denitration system's processing task volume. The higher the concentration, the more nitrogen oxides need to be processed, and the higher the requirement for the denitration system's processing capacity. The concentration of nitrogen oxides at the outlet of the denitration system flue can be the content of nitrogen oxides in the flue gas discharged from the flue after being processed by the denitration system, directly reflecting the denitration effect of the denitration system. It is a key parameter for evaluating whether the denitration system meets the environmental protection emission standards and its operating efficiency. The ammonia flow rate of the denitration system can refer to the flow rate of ammonia introduced into the denitration system during the denitration process, generally measured in units such as cubic meters per hour. Ammonia is a key substance that reacts chemically with nitrogen oxides to achieve denitration, and the size of its flow rate directly affects the progress of the denitration reaction. The operating coal quantity of the denitration system can represent the amount of coal burned by equipment such as boilers served by the denitration system at the current moment, usually in units such as tons per hour. The operating coal quantity is closely related to the amount of flue gas generated and the initial content of nitrogen oxides in the flue gas. Generally speaking, the larger the coal quantity, the corresponding increase in the amount of flue gas and the content of nitrogen oxides. The operating air volume of the denitration system can refer to the air flow rate participating in the system operation during the denitration process, and the unit is often cubic meters per hour. The air volume has an important impact on the denitration reaction. It affects the flow rate of the flue gas in the flue, the mixing effect with ammonia, and the reaction temperature, etc., thereby affecting the denitration efficiency.

[0067] See Figure 2 And Figure 3, the current flue gas pressure corresponding to each nozzle assembly can reflect the flow state and pressure change of the flue gas at that position, while the current denitration parameter information describes the operating condition of the denitration system as a whole. By establishing a mathematical model containing multiple parameters or adopting an experience-based algorithm, the current flue gas pressure and various denitration parameter information are comprehensively considered. For example, the progress of the denitration reaction can be judged based on the concentration difference of nitrogen oxides at the inlet and outlet of the flue duct. Combining parameters such as ammonia flow rate, operating coal quantity, and operating air volume, the theoretical ammonia injection quantity required by the current system can be analyzed. Then, by combining this theoretical ammonia injection quantity with the actual ammonia injection capacity of each nozzle assembly reflected by the current flue gas pressure, the current injection coefficient of each nozzle assembly is calculated to accurately grasp the matching degree between the ammonia injection quantity of each nozzle assembly and the actual demand.

[0068] See Figure 2 And Figure 3 , input the NOx concentration at the inlet of the denitration system flue duct, the NOx concentration at the outlet of the denitration system flue duct, the nozzle flue gas pressure value, the ammonia mass flow rate of the denitration system, the unit operating air volume of the denitration system, and the unit operating coal quantity of the denitration system at the current moment, and calculate the injection coefficient K of each nozzle assembly according to the injection coefficient calculation formula of each nozzle assembly. Among them, the calculation formula for the injection coefficient K of the nozzle assembly at the current moment is as follows:

[0069]

[0070] Where: c NOx,in , c NOx,out , Q m,gas , Q m,coal And Are all unit operating parameters. c NOx,in Is the nitrogen oxide concentration at the inlet of the denitration system, c NOx,out Is the nitrogen oxide concentration at the inlet of the denitration system, Q m,gas Is the unit operating air volume at the current moment, Q m,coal Is the unit operating air volume at the current moment, Q m,NH3,in Is the ammonia flow rate of the unit denitration system at the current moment; F (i,j) And ∑F (i,j) Are the induction parameters of the flue gas pressure sensing sheet of the nozzle assembly at the current moment. F (i,j) Is the flue gas pressure sensed by the (i, j) nozzle assembly at the current moment, ∑F (i,j) Is the sum of the flue gas pressures sensed by all nozzle assemblies at the current moment.

[0071] In an alternative implementation, each nozzle assembly included in the denitration ammonia injection device is respectively configured to be installed at the center of the reference rectangular area corresponding to each nozzle assembly. The reference rectangular areas corresponding to each nozzle assembly are rectangular areas generated by dividing the rectangular cross-section of the denitration system flue where the denitration ammonia injection device is located, and the difference between the area sizes of the reference rectangular areas corresponding to each nozzle assembly is less than a preset difference.

[0072] See Figure 4 , a schematic diagram of the layout of each nozzle assembly 1 in the denitration system flue. The length of the cross-section of the denitration system flue where each nozzle assembly 1 is located is W, and the width is D. m nozzle assemblies are arranged in the length direction of the cross-section of the denitration system flue. The distance from the first nozzle assembly to the left wall surface of the denitration system flue is W / 2m, the distance from the second nozzle assembly to the first nozzle assembly is W / m, and so on. The distance from the mth nozzle assembly to the (m - 1)th nozzle assembly is W / m; n of the said nozzle assemblies are arranged in the width direction of the flue cross-section. The distance from the first nozzle assembly to the upper wall surface of the denitration system flue is W / 2n, the distance from the second nozzle assembly to the first nozzle assembly is W / n, and so on. The distance from the nth nozzle assembly to the (n - 1)th nozzle assembly is W / n. Generally speaking, the warp and weft divide the rectangular flue cross-section where each nozzle assembly 1 is located into several reference rectangles with equal areas and close to squares, and the intersection point of the diagonals of each small rectangle is the position where the nozzle assembly 1 is located.

[0073] See Figure 5 , a naming schematic diagram of each nozzle assembly 1. The length of the cross-section of the denitration system flue where each nozzle assembly 1 is located is W, and the width is D. m nozzle assemblies are arranged in the length direction of the cross-section of the denitration system flue, and n of the said nozzle assemblies are arranged in the width direction of the flue cross-section. Counting from the left wall surface of the denitration system flue, the first column of nozzle assemblies in the length direction is denoted as column 1, the i-th column of nozzle assemblies in the length direction is denoted as column i, and the m-th column of nozzle assemblies in the length direction is denoted as column m; counting from the upper wall surface of the denitration system flue, the first row of nozzle assemblies in the width direction is denoted as row 1, the j-th row of nozzle assemblies in the width direction is denoted as row j, and the n-th row of nozzle assemblies in the width direction is denoted as row n. Then, one nozzle assembly is formed by column 1 in the length direction and row 1 in the width direction, denoted as (1,1); one nozzle assembly is formed by column i in the length direction and row j in the width direction, denoted as (i,j); one nozzle assembly is formed by column m in the length direction and row n in the width direction, denoted as (m,n). Correspondingly, the flue gas pressure on the flue gas pressure sensor corresponding to the nozzle assembly (i,j) is denoted as F (i,j) , the area of the cross-section area of the denitration system flue where each nozzle assembly is located is W / m * D / n.

[0074] In an alternative implementation, each nozzle assembly included in the denitration ammonia injection device is at the same horizontal height in the denitration system flue.

[0075] See Figure 2 and Figure 3 , the nozzle assembly 1 includes parts such as a nozzle tube 11, a nozzle orifice support 12, a nozzle orifice 13, a speed reduction piece 14, a flue gas pressure sensing piece 15, a micro actuator 16, and a nozzle throat piece 17. Each nozzle assembly 1 is at the same horizontal height, and the jetting direction of the nozzle orifice 13 in the nozzle assembly 1 is opposite to the flowing direction of the flue gas in the denitration system flue.

[0076] S130. Perform opening control on the nozzle assembly based on the current injection coefficient of each nozzle assembly, and the opening control is used to control and adjust the ammonia injection amount of the nozzle assembly.

[0077] See Figure 2 and Figure 3 , the opening control can refer to adjusting the opening size of the nozzle assembly, thereby changing the ejection amount of the ammonia-air mixture, that is, the ammonia injection amount. The opening size of the nozzle directly affects the ammonia injection amount. The larger the opening, the more ammonia-air mixture is ejected per unit time, and the larger the ammonia injection amount; conversely, the smaller the opening, the smaller the ammonia injection amount.

[0078] See Figure 6 , after calculating the current injection coefficient of each nozzle assembly, compare the value of the current injection coefficient with 1 to determine how to adjust the nozzle opening. When the current injection coefficient is greater than 1, it indicates that the actual injection amount is less than the theoretical injection amount. At this time, it is necessary to increase the ammonia injection amount to ensure that there is enough ammonia to fully react with nitrogen oxides and improve the denitration efficiency. By increasing the opening of the nozzle assembly, more ammonia-air mixture can be ejected from the nozzle, thereby increasing the ammonia injection amount. When the current injection coefficient is less than 1, it means that the actual injection amount exceeds the theoretical injection amount. Excessive ammonia not only causes waste but may also lead to problems such as ammonia slip. Therefore, it is necessary to reduce the ammonia injection amount, correspondingly reduce the opening of the nozzle assembly, and reduce the ejection amount of the ammonia-air mixture. When the current injection coefficient is equal to 1, it indicates that the actual injection amount perfectly matches the theoretical injection amount. At this time, keep the opening of the nozzle assembly unchanged, maintain the current ammonia injection amount, and make the denitration system operate continuously and stably.

[0079] When performing opening control based on the current injection coefficient, it is possible to accurately adjust the ammonia injection amount according to the actual situation of each nozzle assembly, avoid the error caused by unified regulation, and ensure that nitrogen oxides at each position can be fully treated. Precise control of the ammonia injection amount makes the reaction between ammonia and nitrogen oxides more sufficient, thereby effectively improving the denitration efficiency, reducing the emission of nitrogen oxides, avoiding excessive injection of ammonia, reducing waste of ammonia, and reducing the use cost of the denitration agent. At the same time, it reduces problems such as corrosion and blockage of equipment caused by ammonia slip, and reduces the equipment maintenance cost.

[0080] In an optional but non-limiting implementation, the opening degree of the nozzle assembly is controlled based on the current injection coefficient of each nozzle assembly, including the following steps B1 - B3:

[0081] Step B1: If it is determined according to the current injection coefficient of each nozzle assembly that the ammonia gas ejected by the nozzle assembly at the current moment cannot fully react with the nitrogen oxides contained in the flue gas in the denitration system flue, then control the nozzle assembly to perform a first opening operation, and the first opening operation is used to increase the ammonia injection amount of the nozzle assembly.

[0082] Step B2: If it is determined according to the current injection coefficient of each nozzle assembly that the ammonia gas ejected by the nozzle assembly at the current moment can fully react with the nitrogen oxides contained in the flue gas in the denitration system flue and the remaining amount of ammonia gas meets the preset remaining amount requirement, then no opening degree control is performed on the nozzle assembly.

[0083] Step B3: If it is determined according to the current injection coefficient of each nozzle assembly that the ammonia gas ejected by the nozzle assembly at the current moment can fully react with the nitrogen oxides contained in the flue gas in the denitration system flue and the remaining amount of ammonia gas does not meet the preset remaining amount requirement, then control the nozzle assembly to perform a second opening operation, and the second opening operation is used to reduce the ammonia injection amount of the nozzle assembly.

[0084] See Figure 6 , determine whether the current injection coefficient K of the nozzle assembly at the current moment is equal to 1. If the current injection coefficient K is equal to 1, it indicates that the ammonia gas ejected by the nozzle assembly at the current moment can fully react with the nitrogen oxides contained in the flue gas in the denitration system flue and the remaining amount of ammonia gas is not much. At this time, the opening degree control of the nozzle assembly at the next moment is entered. If the current injection coefficient K is not equal to 1, determine whether the current injection coefficient K is greater than 1. If the current injection coefficient K is greater than 1, it indicates that the ammonia gas ejected by the nozzle assembly at the current moment cannot fully react with the nitrogen oxides contained in the flue gas in the denitration system flue, and there is a problem of insufficient ammonia gas volume. Then the opening degree of the nozzle assembly is increased, and the NOx concentration at the inlet of the denitration system, the NOx concentration at the outlet of the denitration system, the nozzle flue gas pressure value, the ammonia mass flow rate, the unit operation air volume, and the unit operation coal amount are re-measured, and steps 2 and 3 are repeated until the injection coefficient K is equal to 1; if K is less than 1, then the nozzle throat piece is closed, and the NOx concentration at the inlet of the denitration system, the NOx concentration at the outlet of the denitration system, the nozzle flue gas pressure value, the ammonia mass flow rate, the unit operation air volume, and the unit operation coal amount are re-measured, the injection coefficient is recalculated and it is determined whether the injection coefficient is equal to 1 until the injection coefficient K is equal to 1.

[0085] In an optional implementation, a nozzle throat piece is provided in the nozzle assembly. The nozzle throat piece is located inside the nozzle tube in the nozzle assembly, and the opening degree of the nozzle throat piece supports being adjusted larger and smaller. The opening degree of the nozzle throat piece is used to adjust the ammonia injection amount of the nozzle assembly.

[0086] See Figure 2 and Figure 3 , nozzle throats 17 are arranged in the nozzle assembly 1. The nozzle throats 17 are located inside the nozzle pipe 11 and can be opened wider or closed smaller according to the actuator movement. See Figure 3 , a schematic layout of the denitration system flue. The denitration ammonia injection device is installed in the denitration system flue 7. The denitration system is provided with a nozzle assembly 1, an ammonia injection pipeline 2, a denitration catalyst 3, a denitration inlet NOx measuring point 4, a denitration outlet NOx measuring point 5, a control cabinet 6, and a denitration system flue 7.

[0087] In an alternative implementation, a micro actuator 16 is provided on the nozzle pipe 11 in the nozzle assembly. When the micro actuator 16 performs an adjustment action, it is used to increase and decrease the opening degree of the nozzle throat 17.

[0088] See Figure 2 and Figure 3 , the micro actuator 16 is a device capable of performing fine movement adjustments and usually has the characteristics of high precision and precise control. The micro actuator 16 is provided on the nozzle pipe 11, and its main function is to adjust the opening degree of the nozzle throat 17. The micro actuator can be an electric, pneumatic or other type of drive device and can accurately perform corresponding actions according to the instructions of the control system.

[0089] See Figure 2 and Figure 3 , the nozzle throat 17 is located at a position close to the nozzle in the nozzle assembly and is a key component for controlling the injection volume and injection state of the ammonia-air mixed gas. The opening degree of the nozzle throat 17 directly determines parameters such as the flow rate and flow velocity of the ammonia-air mixed gas ejected from the nozzle. When the opening degree of the nozzle throat 17 increases, the channel area through which the ammonia-air mixed gas passes becomes larger, and the amount of ammonia-air mixed gas ejected per unit time increases; conversely, when the opening degree decreases, the amount of ammonia-air mixed gas ejected decreases.

[0090] See Figure 2 and Figure 3, when it is necessary to increase the injection amount of ammonia-air mixed gas such as the ammonia injection amount, the control system will send an instruction to the micro actuator 16. After receiving the instruction, the micro actuator 16, through its internal driving mechanism, precisely pushes or pulls the nozzle throat piece 17 to move it in the direction of increasing the opening degree. For example, if the micro actuator is electric, it may drive a screw-nut mechanism through a motor to convert the rotational motion of the motor into a linear motion, thereby pushing the nozzle throat piece 17 to open, increasing the opening degree, so that more ammonia-air mixed gas can flow through the nozzle throat piece to the nozzle outlet and be ejected. Contrary to increasing the opening degree, when it is necessary to reduce the injection amount of ammonia-air mixed gas such as the ammonia injection amount, a corresponding instruction will be sent to the micro actuator 16. The micro actuator 16 also makes the nozzle throat piece 17 move in the direction of reducing the opening degree through its driving mechanism, restricting the passage area for the ammonia-air mixed gas to pass through, thereby reducing the amount of ammonia-air mixed gas ejected from the nozzle per unit time.

[0091] In an alternative solution, refer to Figure 2 and Figure 3 , the ammonia injection pipeline 2 is connected to the main ammonia injection pipeline of the denitration system and is arranged in the denitration system flue 7. The control cabinet 6 integrates the control system and related hardware of the denitration ammonia injection device, connects the flue gas pressure sensing piece 15, the nozzle throat piece 17 of the nozzle assembly 1, and the unit DCS system, calculates the injection coefficient K by processing the flue gas pressure signal sensed by the flue gas pressure sensing piece 15 in real time, and controls the opening degree of the nozzle throat piece 17 accordingly.

[0092] The technical solution of the embodiment of the present invention can accurately calculate the current injection coefficient by determining the current flue gas pressure at the location of each nozzle assembly, thereby judging the matching degree between the actual ammonia injection amount and the theoretical ammonia injection amount. The opening degree of the nozzle assembly is controlled according to the injection coefficient, so as to quickly respond to the change of the unit load through positive feedback to adjust the ammonia injection amount of each nozzle assembly, so that the ammonia injection amount can accurately match the nitrogen oxide content, and the excessive injection of ammonia can be avoided by accurately controlling the ammonia injection amount, reducing ammonia waste and the use cost of the reducing agent. At the same time, it avoids equipment failures and increased maintenance costs caused by improper ammonia injection amount, prevents blockage and corrosion of downstream equipment caused by ammonia escape, extends the service life of the equipment, and reduces the overall operation cost. At the same time, the flue gas pressure at the location of each nozzle assembly is monitored in real time, and the nozzle opening degree is dynamically adjusted accordingly, so that the denitration system can quickly adapt to the changes in working conditions such as flue gas flow rate, temperature, and pressure in the denitration system flue, maintain stable denitration performance, and ensure that the system can operate efficiently under different operating conditions. And because the current flue gas pressure and injection coefficient are determined separately for each nozzle assembly, and then the opening degree is controlled, it changes the previous extensive mode of uniformly regulating the ammonia injection amount, realizes refined ammonia injection management in the denitration ammonia injection process, quickly responds to the change of the unit load through flue gas pressure perception, and adjusts the ammonia injection amount of each nozzle assembly in a positive feedback regulation manner, which can reduce the ammonia consumption of the denitration system and alleviate the risk of blockage and corrosion of the tail flue.

[0093] Figure 7 This is a schematic structural diagram of a denitration ammonia injection device based on flue gas pressure induction provided by an embodiment of the present invention. The embodiment of the present invention is applicable to the situation of accurately regulating the ammonia injection amount according to the flue gas pressure induction in various industrial scenarios with strict requirements for nitrogen oxide emission control. The denitration ammonia injection device based on flue gas pressure induction can be implemented in the form of software and / or hardware, and is generally integrated on any electronic device with network communication functions. The electronic device can be a mobile terminal, a PC terminal or a server, etc.

[0094] As Figure 7 shown, the denitration ammonia injection device based on flue gas pressure induction in the embodiment of the present invention may include the following:

[0095] A first determination module, configured to determine the current flue gas pressure corresponding to each of at least some of the multiple nozzle assemblies associated with the ammonia injection pipeline, where the current flue gas pressure is the flue gas pressure at the location of each nozzle assembly at the current moment;

[0096] Wherein, the denitration ammonia injection device is installed in the denitration system flue. The denitration ammonia injection device includes a plurality of ammonia injection pipelines, and each ammonia injection pipeline is configured with a plurality of nozzle assemblies. The ammonia injection pipeline is connected to the denitration system pipeline. The ammonia injection pipeline is used to transport the ammonia-air mixture. The nozzle assembly is used to spray the ammonia-air mixture after increasing the flow rate. The spraying direction of the nozzle of the nozzle assembly is opposite to the flue gas flow direction in the denitration system flue;

[0097] A second determination module, configured to determine the current injection coefficient of each nozzle assembly based on the current flue gas pressure corresponding to each nozzle assembly. The current injection coefficient is used to indicate the matching degree between the actual ammonia injection amount and the theoretical ammonia injection amount of the nozzle assembly at the current moment. The actual ammonia injection amount is the ammonia injection amount when the nozzle assembly sprays the ammonia-air mixture. The theoretical ammonia injection amount is the ammonia injection amount that needs to be sprayed when the nozzle assembly sprays the ammonia-air mixture when it is desired to make the nitrogen oxides and ammonia in the flue gas in the denitration system flue react fully. The theoretical ammonia injection amount is correlated with the nitrogen oxide content in the flue gas in the denitration system flue;

[0098] A control module, configured to perform opening control on the nozzle assembly based on the current injection coefficient of each nozzle assembly, and the opening control is used to control and adjust the ammonia injection amount of the nozzle assembly.

[0099] On the basis of the above embodiment, optionally, determining the current flue gas pressure corresponding to each nozzle assembly includes:

[0100] Perceiving the flue gas pressure at the location of each nozzle assembly at the current moment through the flue gas pressure sensing sheet in each nozzle assembly;

[0101] Among them, the flue gas pressure sensing piece in the nozzle assembly is fixedly connected to the nozzle in the nozzle assembly. The first side of the flue gas pressure sensing piece in the nozzle assembly faces the nozzle in the nozzle assembly, and the second side of the flue gas pressure sensing piece in the nozzle assembly faces the flue gas in the denitration system flue. The area of the nozzle in the nozzle assembly is smaller than the area of the side of the flue gas pressure sensing piece in the nozzle assembly.

[0102] On the basis of the above embodiment, optionally, the nozzle assembly further includes a speed reduction piece. The first side of the speed reduction piece faces the nozzle in the nozzle assembly, the second side of the speed reduction piece is attached to the second side of the flue gas pressure sensing piece, and the speed reduction piece in the nozzle assembly is fixedly connected to the nozzle in the nozzle assembly.

[0103] On the basis of the above embodiment, optionally, the nozzle assembly further includes a nozzle support. The nozzle support is used to support and fix the nozzle in the nozzle assembly, the nozzle pipe in the nozzle assembly, the speed reduction piece in the nozzle assembly, and the flue gas pressure sensing piece in the nozzle assembly.

[0104] On the basis of the above embodiment, optionally, the nozzle pipe in the nozzle assembly is perpendicular to the first side of the speed reduction piece in the nozzle assembly, and the nozzle pipe in the nozzle assembly is perpendicular to the first side of the flue gas pressure sensing piece in the nozzle assembly.

[0105] On the basis of the above embodiment, optionally, the flow-through area of the nozzle in the nozzle assembly is smaller than the flow-through area of the nozzle pipe in the nozzle assembly, and the flow-through area of the nozzle pipe in the nozzle assembly is smaller than the flow-through area of the ammonia injection pipeline to which the nozzle pipe in the nozzle assembly belongs.

[0106] On the basis of the above embodiment, optionally, each of the nozzle assemblies included in the denitration ammonia injection device is respectively configured and installed at the center of the reference rectangular area corresponding to each nozzle assembly. The reference rectangular areas corresponding to each nozzle assembly are rectangular areas generated by dividing the rectangular cross-section of the denitration system flue where the denitration ammonia injection device is located, and the difference between the areas of the reference rectangular areas corresponding to each nozzle assembly is less than a preset difference.

[0107] On the basis of the above embodiment, optionally, each of the nozzle assemblies included in the denitration ammonia injection device is at the same horizontal height in the denitration system flue.

[0108] On the basis of the above embodiment, optionally, determining the current injection coefficient of each nozzle assembly based on the current flue gas pressure corresponding to each nozzle assembly includes:

[0109] Determine the current denitration parameter information of the denitration system at the current moment. The denitration parameter information includes the nitrogen oxide concentration at the inlet of the denitration system flue corresponding to the denitration system, the nitrogen oxide concentration at the outlet of the denitration system flue corresponding to the denitration system, the ammonia flow rate of the denitration system, the operating coal quantity of the denitration system, and the operating air volume of the denitration system;

[0110] Based on the current flue gas pressure corresponding to each nozzle assembly and the current denitration parameter information, determine the current injection coefficient of each nozzle assembly.

[0111] On the basis of the above embodiments, optionally, the opening control of the nozzle assembly is performed based on the current injection coefficient of each nozzle assembly, including:

[0112] If it is determined according to the current injection coefficient of each nozzle assembly that the ammonia gas ejected by the nozzle assembly at the current moment cannot fully react with the nitrogen oxides included in the flue gas in the denitration system flue, then control to perform a first opening operation on the nozzle assembly, and the first opening operation is used to increase the ammonia injection amount of the nozzle assembly;

[0113] If it is determined according to the current injection coefficient of each nozzle assembly that the ammonia gas ejected by the nozzle assembly at the current moment can fully react with the nitrogen oxides included in the flue gas in the denitration system flue and the remaining ammonia amount meets the preset remaining amount requirement, then no opening control is performed on the nozzle assembly;

[0114] If it is determined according to the current injection coefficient of each nozzle assembly that the ammonia gas ejected by the nozzle assembly at the current moment can fully react with the nitrogen oxides included in the flue gas in the denitration system flue and the remaining ammonia amount does not meet the preset remaining amount requirement, then control to perform a second opening operation on the nozzle assembly, and the second opening operation is used to reduce the ammonia injection amount of the nozzle assembly.

[0115] On the basis of the above embodiments, optionally, a nozzle throat piece is provided in the nozzle assembly. The nozzle throat piece is located inside the nozzle tube in the nozzle assembly, and the opening of the nozzle throat piece supports being enlarged and reduced. The opening of the nozzle throat piece is used to adjust the ammonia injection amount of the nozzle assembly.

[0116] On the basis of the above embodiments, optionally, a micro actuator is provided on the nozzle tube in the nozzle assembly. When the micro actuator performs an adjustment action, it is used to enlarge and reduce the opening of the nozzle throat piece.

[0117] The technical solution of the embodiment of the present invention can accurately calculate the current injection coefficient by determining the current flue gas pressure at the location of each nozzle assembly, so as to judge the matching degree between the actual ammonia injection amount and the theoretical ammonia injection amount. According to the injection coefficient, the opening degree of the nozzle assembly is controlled to realize the rapid response to the unit load change through positive feedback to adjust the ammonia injection amount of each nozzle assembly, so that the ammonia injection amount accurately matches the nitrogen oxide content, realizing the accurate control of the ammonia injection amount to avoid excessive ammonia injection, reducing ammonia waste and the use cost of the reducing agent. At the same time, it avoids equipment failures and increased maintenance costs caused by improper ammonia injection amounts, prevents blockage and corrosion of downstream equipment caused by ammonia escape, extends the service life of the equipment, and reduces the overall operation cost. At the same time, by real-time monitoring the flue gas pressure at the location of each nozzle assembly and dynamically adjusting the nozzle opening degree accordingly, the denitration system can quickly adapt to changes in working conditions such as flue gas flow rate, temperature, and pressure in the denitration system flue, maintain stable denitration performance, and ensure that the system can operate efficiently under different operating conditions. Moreover, since the current flue gas pressure and injection coefficient are determined separately for each nozzle assembly and then the opening degree is controlled, it changes the previous extensive mode of uniformly regulating the ammonia injection amount, realizing refined ammonia injection management during the denitration ammonia injection process.

[0118] The denitration ammonia injection device based on flue gas pressure induction provided by the embodiment of the present invention can execute the denitration ammonia injection method based on flue gas pressure induction provided by any embodiment of the present invention, and has corresponding functional modules and beneficial effects for executing the denitration ammonia injection method based on flue gas pressure induction.

[0119] It should be noted that the various units and modules included in the above device are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of the embodiments of the present invention.

[0120] Figure 8 FIG. 10 shows a schematic structural diagram of an electronic device 10 that can be used to implement the embodiments of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are only examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0121] As Figure 8As shown, the electronic device 10 includes at least one processor 11 and a memory communicatively connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc. Among them, the memory stores a computer program executable by the at least one processor 11, and the computer program is executed by the at least one processor 11 so that the at least one processor 11 can execute the method provided by the present invention.

[0122] The processor 11 can execute various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. The input / output (I / O) interface 15 is also connected to the bus 14.

[0123] Multiple components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disc, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0124] The processor 11 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include but are not limited to a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the denitration ammonia injection method based on flue gas pressure induction.

[0125] In some embodiments, the denitration ammonia injection method based on flue gas pressure sensing can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the denitration ammonia injection method based on flue gas pressure sensing described above can be executed. Alternatively, in other embodiments, the processor 11 can be configured to execute the denitration ammonia injection method based on flue gas pressure sensing by any other suitable means (e.g., by means of firmware).

[0126] The various embodiments of the systems and techniques described above in this document can be implemented in digital electronic circuitry, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard parts (ASSPs), systems on chip (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special-purpose or general-purpose programmable processor that receives data and instructions from a storage system, at least one input device, and at least one output device, and transmits the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0127] The computer programs for implementing the methods of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer programs are executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer programs can be executed entirely on the machine, partially on the machine, as a stand-alone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0128] In the context of the present invention, a computer-readable storage medium stores computer instructions, and the computer instructions are used to implement the denitration ammonia injection method based on flue gas pressure induction provided by the present invention when executed by a processor.

[0129] The present invention also provides a computer program product, the computer program product includes a computer program, and the computer program implements the denitration ammonia injection method based on flue gas pressure induction provided by the embodiments of the present invention when executed by a processor.

[0130] The computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0131] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device for displaying information to the user (e.g., a cathode ray tube (CRT) or a liquid crystal display (LCD) monitor); and a keyboard and a pointing device (e.g., a mouse or a trackball), by which the user can provide input to the electronic device. Other kinds of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and the input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0132] The systems and techniques described herein can be implemented in a computing system including backend components (e.g., as a data server), or a computing system including middleware components (e.g., an application server), or a computing system including frontend components (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described herein), or a computing system including any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected to each other by digital data communication in any form or medium (e.g., a communication network). Examples of communication networks include: Local Area Network (LAN), Wide Area Network (WAN), blockchain network, and the Internet.

[0133] A computing system can include a client and a server. The client and the server are generally far from each other and typically interact through a communication network. The client-server relationship is created by computer programs running on respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, solving the defects of difficult management and weak business scalability existing in traditional physical hosts and Virtual Private Server (VPS) services.

[0134] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps recited in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0135] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A denitrification and ammonia injection method based on flue gas pressure sensing, characterized in that: The invention is applied to a denitration ammonia spraying device, which is installed in a flue of a denitration system, comprises a plurality of ammonia spraying pipelines and a plurality of nozzle assemblies are arranged on each ammonia spraying pipeline, the ammonia spraying pipeline is connected to a pipeline of a denitration system, the ammonia spraying pipeline is used to transport ammonia-air mixed gas, the nozzle assembly is used to increase the flow rate of the ammonia-air mixed gas and then spray it out, and the nozzle spraying direction of the nozzle assembly is opposite to the flow direction of the flue gas in the flue of the denitration system, and the method comprises: For at least some of the multiple nozzle assemblies associated with the ammonia injection pipeline, determine the current flue gas pressure corresponding to each nozzle assembly, where the current flue gas pressure is the flue gas pressure at the location of each nozzle assembly at the current moment; Based on the current flue gas pressure corresponding to each nozzle assembly, the current injection coefficient of each nozzle assembly is determined, the current injection coefficient is used to indicate the matching degree between the actual ammonia injection amount of the nozzle assembly at the current moment and the theoretical ammonia injection amount, the actual ammonia injection amount is the ammonia injection amount when the nozzle assembly sprays the ammonia-air mixed gas, the theoretical ammonia injection amount is the ammonia injection amount that needs to be sprayed when the nozzle assembly sprays the ammonia-air mixed gas when the nitrogen oxides included in the flue gas in the flue of the denitrification system are expected to fully react with ammonia, and the theoretical ammonia injection amount is correlated with the nitrogen oxide content of the flue gas in the flue of the denitrification system; The opening of each nozzle assembly is controlled based on the current injection coefficient of the nozzle assembly, and the opening control is used to control and adjust the ammonia injection amount of the nozzle assembly.

2. The method according to claim 1, characterized in that Determine the current flue gas pressure for each nozzle assembly, including: The smoke pressure at the location of each nozzle assembly is sensed at the current moment through the smoke pressure sensing sheet in each nozzle assembly; Among them, the flue gas pressure sensing sheet in the nozzle assembly is fixedly connected to the nozzle in the nozzle assembly, the first side of the flue gas pressure sensing sheet in the nozzle assembly faces the nozzle in the nozzle assembly, the second side of the flue gas pressure sensing sheet in the nozzle assembly faces the flue gas in the flue of the denitrification system, and the nozzle area in the nozzle assembly is smaller than the side area of ​​the flue gas pressure sensing sheet in the nozzle assembly.

3. The method according to claim 2, characterized in that The nozzle assembly also includes a speed-eliminating plate, the first side of which faces the nozzle in the nozzle assembly, the second side of which is in contact with the second side of the smoke pressure sensing plate, and the speed-eliminating plate in the nozzle assembly is fixedly connected to the nozzle in the nozzle assembly.

4. The method according to claim 2, characterized in that: The flow area of ​​the nozzle in the nozzle assembly is smaller than the flow area of ​​the nozzle pipe in the nozzle assembly, and the flow area of ​​the nozzle pipe in the nozzle assembly is smaller than the flow area of ​​the ammonia injection pipeline to which the nozzle pipe in the nozzle assembly belongs.

5. The method according to claim 2, characterized in that: Each of the nozzle assemblies included in the denitrification ammonia injection device is respectively configured and installed at the center of a reference rectangular area corresponding to each of the nozzle assemblies. The reference rectangular area corresponding to each of the nozzle assemblies is a rectangular area generated by dividing the rectangular cross-section of the flue of the denitrification system in which the denitrification ammonia injection device is located, and the difference between the area areas of the reference rectangular areas corresponding to each of the nozzle assemblies is less than a preset difference.

6. The method according to claim 1, characterized in that Based on the current flue gas pressure corresponding to each nozzle assembly, the current injection coefficient of each nozzle assembly is determined, including: Determine current denitration parameter information of the denitration system at the current moment, the denitration parameter information including the nitrogen oxide concentration at the flue inlet of the denitration system corresponding to the denitration system, the nitrogen oxide concentration at the flue outlet of the denitration system corresponding to the denitration system, the ammonia flow of the denitration system, the operating coal volume of the denitration system, and the operating air volume of the denitration system; Based on the current flue gas pressure and current denitrification parameter information corresponding to each nozzle assembly, the current injection coefficient of each nozzle assembly is determined.

7. The method according to claim 1, characterized in that The opening degree of each nozzle assembly is controlled based on the current injection coefficient of each nozzle assembly, including: If it is determined according to the current injection coefficient of each nozzle assembly that the ammonia gas sprayed by the nozzle assembly at the current moment cannot fully react the nitrogen oxides included in the flue gas in the flue of the denitrification system, the nozzle assembly is controlled to perform a first opening operation, and the first opening operation is used to increase the ammonia spray amount of the nozzle assembly; If it is determined according to the current injection coefficient of each nozzle assembly that the ammonia gas sprayed by the nozzle assembly at the current moment can fully react the nitrogen oxides included in the flue gas in the flue of the denitrification system and the remaining amount of ammonia gas meets the preset remaining amount requirement, the opening degree of the nozzle assembly is not controlled; If it is determined based on the current injection coefficient of each nozzle assembly that the ammonia gas sprayed by the nozzle assembly at the current moment can fully react the nitrogen oxides included in the flue gas in the flue of the denitrification system and the remaining amount of ammonia gas does not meet the preset remaining amount requirement, the nozzle assembly is controlled to perform a second opening operation, and the second opening operation is used to reduce the amount of ammonia sprayed by the nozzle assembly.

8. A denitrification and ammonia injection device based on flue gas pressure sensing, characterized in that: The denitration ammonia spraying device is configured, and the denitration ammonia spraying device is installed in the flue of the denitration system. The denitration ammonia spraying device includes a plurality of ammonia spraying pipelines and a plurality of nozzle assemblies are configured on each ammonia spraying pipeline. The ammonia spraying pipeline is connected to the pipeline of the denitration system. The ammonia spraying pipeline is used to transport the ammonia-air mixed gas. The nozzle assembly is used to increase the flow rate of the ammonia-air mixed gas and then spray it out. The nozzle spraying direction of the nozzle assembly is opposite to the flow direction of the flue gas in the flue of the denitration system. The device includes: A first determination module is used to determine, for at least some of the multiple nozzle assemblies associated with the ammonia injection pipeline, a current flue gas pressure corresponding to each nozzle assembly, wherein the current flue gas pressure is the flue gas pressure at the location of each nozzle assembly at the current moment; A second determination module is used to determine a current injection coefficient of each nozzle assembly based on a current flue gas pressure corresponding to each nozzle assembly, wherein the current injection coefficient is used to indicate a matching degree between an actual ammonia injection amount and a theoretical ammonia injection amount of the nozzle assembly at a current moment, wherein the actual ammonia injection amount is an ammonia injection amount when the nozzle assembly sprays an ammonia-air mixture, and the theoretical ammonia injection amount is an ammonia injection amount required to be sprayed when the nozzle assembly sprays an ammonia-air mixture when the nitrogen oxides included in the flue gas in the flue of the denitrification system are expected to fully react with ammonia, and the theoretical ammonia injection amount is correlated with the nitrogen oxide content of the flue gas in the flue of the denitrification system; A control module is used to control the opening of each nozzle assembly based on the current injection coefficient of the nozzle assembly, and the opening control is used to control and adjust the ammonia injection amount of the nozzle assembly.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the denitrification and ammonia injection method based on flue gas pressure sensing as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the denitrification and ammonia injection method based on flue gas pressure sensing as described in any one of claims 1 to 7 when executed.

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