Denitration method, system and equipment for coke oven flue gas and storage medium

Abstract

The embodiment of the invention provides a denitration method, system and equipment for coke oven flue gas and a storage medium, and relates to the technical field of flue gas treatment. According to the specific implementation scheme, the top temperature of a regenerative chamber in a coke oven is obtained according to a first preset time interval; wherein the coke oven flue gas is subjected to SNCR denitration treatment in the heat storage chamber; the heat storage chamber is connected with a first end of a flue main pipe used for discharging flue gas, the flue main pipe is connected with a backflow pipeline used for backflow of the flue gas, and the other end of the backflow pipeline is connected with the heat storage chamber; a backflow valve is arranged at the joint of the flue main pipe and the backflow pipeline, and the induced draft fan is installed in the backflow pipeline and used for sucking flue gas into the heat storage chamber. If the currently obtained top temperature exceeds the first temperature threshold value, the valve opening degree of a return valve and / or the frequency of an induced draft fan are / is increased; and if the currently obtained top temperature is lower than the second temperature threshold value, the valve opening degree of the return valve and / or the frequency of the induced draft fan are / is turned down. According to the scheme, the denitration efficiency can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flue gas treatment, in particular to a coke oven flue gas denitration method, system, equipment and storage medium. BACKGROUND

[0002] Coke enterprises will produce a large amount of coke oven flue gas in the production process, coke oven flue gas contains a large amount of NO X (nitrogen oxides), with the increasingly stringent national environmental regulations, the ultra-low emission of NO X has become a challenge that coke enterprises must face.

[0003] At present, the SNCR (Selective Non-Catalytic Reduction) technology can be used for denitration treatment of coke oven flue gas, that is, by spraying the denitration reducing agent into the coke oven heat storage chamber, the active components in the denitration reducing agent and the nitrogen oxides in the coke oven flue gas are reacted to remove the nitrogen oxides in the coke oven flue gas.

[0004] However, due to the narrow optimal reaction temperature window of SNCR technology and the large temperature fluctuation of the heat storage chamber, the denitration efficiency is unstable. For example, the optimal reaction temperature window when using ammonia as a reducing agent is 850-1050℃, when the temperature in the heat storage chamber is not within the optimal reaction temperature window, the denitration efficiency is low.

[0005] Therefore, how to improve the denitration efficiency has become a technical problem to be solved. SUMMARY

[0006] The purpose of the embodiment of the present application is to provide a coke oven flue gas denitration method, system, equipment and storage medium to improve the denitration efficiency. The specific technical solutions are as follows:

[0007] In a first aspect, the present application provides a coke oven flue gas denitration method, which comprises:

[0008] obtaining the top temperature of the heat storage chamber in the coke oven according to a first preset time interval; wherein the coke oven flue gas is subjected to selective non-catalytic reduction SNCR denitration treatment in the heat storage chamber; the heat storage chamber is connected with a first end of a flue main for discharging flue gas, the flue main is connected with a reflux pipeline for refluxing flue gas, the other end of the reflux pipeline is connected with the heat storage chamber; a reflux valve is arranged at the connection between the flue main and the reflux pipeline, and an induced draft fan is installed in the reflux pipeline and used to draw flue gas into the heat storage chamber;

[0009] if the current obtained top temperature exceeds a first temperature threshold, the valve opening of the reflux valve and / or the frequency of the induced draft fan is increased;

[0010] If the current acquired top temperature is lower than the second temperature threshold, the valve opening of the reflux valve and / or the frequency of the air draft fan is reduced.

[0011] Optionally, a plurality of SNCR reaction zones are arranged in the regenerative chamber, and each SNCR reaction zone is connected with a branch flue for discharging flue gas, and each branch flue is connected with the first end of the flue main; the method further comprises:

[0012] Based on the concentration of nitrogen oxides in the specified branch flue acquired according to the second preset time interval, a first concentration is obtained;

[0013] It is determined whether the reducing agent flow rate of the reducing agent currently input into the regenerative chamber matches the first concentration currently acquired;

[0014] If not, the reducing agent flow rate matching the first concentration currently acquired is determined, and based on the determined reducing agent flow rate, the carrier gas flow rate of the carrier gas required to be input into the regenerative chamber is determined;

[0015] The valve opening of the current reducing agent delivery valve is adjusted according to the determined reducing agent flow rate, and the valve opening of the current carrier gas delivery valve is adjusted according to the determined carrier gas flow rate.

[0016] Optionally, a flue gas input pipeline of an SCR reactor is connected at the first position of the flue main, and a flue gas output pipeline of the SCR reactor is connected at the second position of the flue main, and an SCR valve is arranged at the connection between the flue main and the flue gas input pipeline of the SCR reactor;

[0017] The method further comprises:

[0018] If the second concentration of nitrogen oxides at the second end of the flue main is continuously acquired according to the third preset time interval and the number of times that the second concentration exceeds the preset concentration threshold reaches a specified number of times, the SCR valve is opened.

[0019] Optionally, the method further comprises:

[0020] The amount of ammonia escape at the second end of the flue main is acquired according to a fourth preset time interval;

[0021] If the current obtained ammonia escape amount exceeds the preset ammonia escape threshold value, the current valve opening of the reducing agent delivery valve and the current valve opening of the carrier gas delivery valve are obtained; according to the obtained valve opening of the reducing agent delivery valve and the valve opening of the carrier gas delivery valve, the ratio of the current reducing agent flow and the current carrier gas flow is calculated; if the calculated ratio is not within the preset interval, the valve opening of the carrier gas delivery valve is adjusted so that the ratio of the adjusted reducing agent flow and the carrier gas flow is within the preset interval; wherein when the ratio is within the preset interval, the reducing agent and the carrier gas can reach the preset atomization state;

[0022] and / or,

[0023] If the current obtained ammonia escape amount exceeds the preset ammonia escape threshold value, the top temperature of the regenerator is obtained; if the current obtained top temperature exceeds the first preset threshold value, the valve opening of the reflux valve and / or the frequency of the induced draft fan is increased.

[0024] Optionally, the method further comprises:

[0025] The current collected working condition parameters and the historically collected preset number of groups of working condition parameters are input into a prediction model to obtain a target temperature and a target ammonia nitrogen ratio; wherein each group of working condition parameters comprises the top temperature of the regenerator, a first concentration obtained based on the concentration of nitrogen oxides in the specified flue, the valve opening of the reducing agent delivery valve, the valve opening of the carrier gas delivery valve, and a first parameter, the first parameter comprising the valve opening of the reflux valve and / or the frequency of the induced draft fan;

[0026] The valve opening of the reflux valve and / or the frequency of the induced draft fan is adjusted according to the target temperature, and the valve opening of the reducing agent delivery valve and the valve opening of the carrier gas delivery valve are adjusted according to the target ammonia nitrogen ratio.

[0027] In a second aspect, the embodiments of the present application provide a coke oven flue gas denitration system, comprising a main control device, a temperature acquisition device and a reflux device, the reflux device comprising a reflux valve and / or an induced draft fan;

[0028] The temperature acquisition device is configured to acquire the top temperature of the regenerator in the coke oven; wherein the coke oven flue gas is subjected to selective non-catalytic reduction (SNCR) denitration treatment in the regenerator; the regenerator is connected with a first end of a flue main pipe for discharging flue gas, the flue main pipe is connected with a reflux pipeline for refluxing flue gas, the other end of the reflux pipeline is connected with the regenerator; the connection between the flue main pipe and the reflux pipeline is provided with the reflux valve, the induced draft fan is installed in the reflux pipeline, and the induced draft fan is configured to draw flue gas into the regenerator;

[0029] The master device is configured to acquire the top temperature collected by the temperature collection device according to a first preset time interval; if the current acquired top temperature exceeds a first temperature threshold, a first control instruction is sent to the reflux device; if the current acquired top temperature is lower than a second temperature threshold, a second control instruction is sent to the reflux device;

[0030] The reflux device is configured to, when the reflux valve is included, if the first control instruction is received, increase the valve opening degree of the reflux valve, and if the second control instruction is received, decrease the valve opening degree of the reflux valve; and / or, when the air induction fan is included, if the first control instruction is received, increase the frequency of the air induction fan, and if the second control instruction is received, decrease the frequency of the air induction fan.

[0031] Optionally, a plurality of SNCR reaction zones are arranged in the heat storage chamber, and each SNCR reaction zone is connected with a branch flue for discharging flue gas, and each branch flue is connected with the first end of the flue main pipe; the system further comprises a nitrogen oxide detection device, a reducing agent delivery valve and a carrier gas delivery valve;

[0032] The nitrogen oxide detection device is configured to collect the concentration of nitrogen oxides in a specified branch flue;

[0033] The master device is further configured to determine whether the reducing agent flow rate of the reducing agent currently input into the heat storage chamber matches the first concentration currently acquired by the nitrogen oxide detection device according to a second preset time interval; if not, determine the reducing agent flow rate matching the first concentration currently acquired, and determine the carrier gas flow rate of the carrier gas required to be input into the heat storage chamber based on the determined reducing agent flow rate; send a second control instruction to the reducing agent delivery valve for adjusting the determined reducing agent flow rate, and send a third control instruction to the carrier gas delivery valve for adjusting the determined carrier gas flow rate;

[0034] The reducing agent delivery valve is configured to adjust the valve opening degree according to the received second control instruction;

[0035] The carrier gas delivery valve is configured to adjust the valve opening degree according to the received third control instruction.

[0036] Optionally, a flue gas input pipeline of an SCR reactor is connected at the first position of the flue main pipe, and a flue gas output pipeline of the SCR reactor is connected at the second position of the flue main pipe, and an SCR valve is arranged at the connection between the flue main pipe and the flue gas input pipeline; the system further comprises the SCR valve;

[0037] The master device is further configured to issue an opening instruction to the SCR valve if the second concentration of the nitrogen oxides at the second end of the flue main pipe is collected continuously for a third preset time interval and the number of times that the second concentration exceeds the preset concentration threshold reaches a specified number of times.

[0038] The SCR valve is configured to open the valve according to the received opening instruction.

[0039] Optionally, the system further comprises an ammonia escape monitoring device.

[0040] The ammonia escape monitoring device is configured to collect the amount of ammonia escape at the second end of the flue main pipe.

[0041] The master device is further configured to acquire the amount of ammonia escape collected by the ammonia escape monitoring device at a fourth preset time interval, acquire the valve opening degree of the reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve if the currently acquired amount of ammonia escape exceeds a preset ammonia escape threshold, calculate the ratio of the current reducing agent flow rate to the current carrier gas flow rate according to the acquired valve opening degree of the reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve, and send a fifth control instruction to the carrier gas delivery valve if the calculated ratio is not within a preset interval; the carrier gas delivery valve is configured to adjust the valve opening degree according to the received fifth control instruction, so that the ratio of the adjusted reducing agent flow rate to the carrier gas flow rate is within the preset interval.

[0042] and / or,

[0043] The master device is further configured to acquire the top temperature of the regenerative chamber if the currently acquired amount of ammonia escape exceeds the preset ammonia escape threshold, and send a first control instruction to the reflux device if the currently acquired top temperature exceeds a first preset threshold; the reflux device is configured to, when the reflux valve is included, adjust the valve opening degree of the reflux valve according to the received first control instruction, and / or, when the induced draft fan is included, adjust the frequency of the induced draft fan according to the received first control instruction.

[0044] Optionally, the master device is further configured to input the current collected working condition parameters and a preset number of groups of historical collected working condition parameters into a prediction model to obtain a target temperature and a target ammonia-nitrogen ratio; each group of working condition parameters comprises a top temperature of the regenerator, a first concentration of nitrogen oxides in the specified flue, a valve opening degree of the reducing agent delivery valve, a valve opening degree of the carrier gas delivery valve, and a first parameter comprising a valve opening degree of the reflux valve and / or a frequency of the induced draft fan; the valve opening degree of the reflux valve and / or the frequency of the induced draft fan are adjusted according to the target temperature, and the valve opening degree of the reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve are adjusted according to the target ammonia-nitrogen ratio.

[0045] In a third aspect, an electronic device is provided, comprising:

[0046] a memory configured to store a computer program;

[0047] a processor configured to execute the computer program stored in the memory to implement the coke oven flue gas denitration method of any one of the preceding aspects.

[0048] In a fourth aspect, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the coke oven flue gas denitration method of any one of the preceding aspects.

[0049] In a fifth aspect, a computer program product is provided, and the computer program product comprises executable instructions, and when the executable instructions are executed on a computer, the computer executes the coke oven flue gas denitration method of any one of the preceding aspects.

[0050] Advantages of the embodiments of the present application:

[0051] The scheme provided by the embodiment of the present application can improve the denitration efficiency when the temperature at the top of the regenerator exceeds the first temperature threshold or is lower than the second temperature threshold. The greater the valve opening of the backflow valve, the greater the proportion of flue gas that can backflow, and the greater the frequency of the induced draft fan, the faster the speed of flue gas backflow. Therefore, by increasing the valve opening of the backflow valve and / or the frequency of the induced draft fan, the flow of backflowing flue gas can be increased. Since the heat is continuously lost during the process of flue gas flowing out to the flue main and then backflowing to the regenerator through the backflow pipeline, the temperature of flue gas backflowing to the regenerator is relatively low. Therefore, when the temperature at the top of the regenerator is high, by increasing the valve opening of the backflow valve and / or the frequency of the induced draft fan, the temperature in the regenerator can be rapidly reduced, so that the temperature of the SNCR reaction region in the regenerator can rapidly approach the optimal reaction temperature window, thereby improving the denitration efficiency. Correspondingly, by decreasing the valve opening of the backflow valve and / or the frequency of the induced draft fan when the temperature is low, the temperature in the regenerator can be rapidly increased, so that the temperature of the SNCR reaction region in the regenerator can rapidly approach the optimal reaction temperature window, thereby improving the denitration efficiency.

[0052] Of course, implementing any of the products or methods of the present application does not necessarily require that all of the advantages described above be achieved simultaneously. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other embodiments can also be obtained by those skilled in the art based on these drawings.

[0054] Figure 1 The first flow chart of the coke oven flue gas denitration method provided by the embodiment of the present application;

[0055] Figure 2 The second flow chart of the coke oven flue gas denitration method provided by the embodiment of the present application;

[0056] Figure 3 The third flow chart of the coke oven flue gas denitration method provided by the embodiment of the present application;

[0057] Figure 4 The fourth flow chart of the coke oven flue gas denitration method provided by the embodiment of the present application;

[0058] Figure 5 The schematic diagram of one specific example of the coke oven flue gas denitration method provided by the embodiment of the present application;

[0059] Figure 6A structural schematic diagram of a coke oven flue gas denitration system provided by an embodiment of the present application is provided.

[0060] Figure 7 A block diagram of an electronic device for implementing the coke oven flue gas denitration method provided by an embodiment of the present application is provided. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0062] The coke oven flue gas denitration method provided by an embodiment of the present application is applied to a master control device, which can be various electronic devices, such as a PLC (Programmable Logic Controller), a personal computer, a server, and other devices with data processing capabilities. In addition, it can be understood that the coke oven flue gas denitration method provided by the embodiment of the present application can be realized by software, hardware, or a combination of software and hardware.

[0063] As shown in FIG. 1, the coke oven flue gas denitration method provided by the embodiment of the present application includes steps S101-S103: Figure 1

[0064] S101, the top temperature of the regenerator in the coke oven is obtained according to a first preset time interval; wherein the coke oven flue gas is subjected to SNCR denitration treatment in the regenerator; the regenerator is connected with a first end of a flue main for discharging flue gas, the flue main is connected with a reflux pipeline for refluxing flue gas, the other end of the reflux pipeline is connected with the regenerator; a reflux valve is arranged at the connection between the flue main and the reflux pipeline, and an induced draft fan is installed in the reflux pipeline and used to draw flue gas into the regenerator.

[0065] S102, if the current obtained top temperature exceeds a first temperature threshold, the valve opening of the reflux valve and / or the frequency of the induced draft fan is increased.

[0066] S103, if the current obtained top temperature is lower than a second temperature threshold, the valve opening of the reflux valve and / or the frequency of the induced draft fan is decreased.

[0067] ​In practical application, the coke oven chamber is located below the combustion chamber in the coke oven, and the coke oven flue gas generated by the combustion chamber is discharged into the coke oven chamber for SNCR denitration treatment. The coke oven chamber is connected with the first end of the flue main for discharging flue gas, and the second end of the flue main is connected with the chimney. The flue gas treated by SNCR denitration in the coke oven chamber is discharged to the flue main, and flows to the chimney through the flue main, and is finally discharged into the atmosphere through the end of the chimney.

[0068] Exemplarily, the probe of the temperature collection device can be inserted into the coke oven chamber through the temperature measuring hole at the top of the coke oven chamber to collect the top temperature of the coke oven chamber in real time. The electronic device for performing the coke oven flue gas denitration method provided by the embodiment of the present application can obtain the top temperature collected currently from the temperature collection device according to the first preset time interval. Exemplarily, the temperature collection device can be an optical pyrometer or a thermocouple, etc. The type of the temperature collection device is not limited by the embodiment of the present application. The first preset time interval can be 1 minute or 2 minutes, etc.

[0069] In practical application, the coke oven flue gas is subjected to SNCR denitration treatment in the SNCR reaction area in the coke oven chamber. In the optimal reaction temperature window corresponding to the reducing agent, the reducing agent can effectively react with the nitrogen oxides in the coke oven flue gas to generate nitrogen and water, thereby achieving the purpose of denitration. When the temperature of the SNCR reaction area is not in the optimal reaction temperature window corresponding to the reducing agent, the denitration efficiency is significantly reduced. Different types of reducing agents correspond to different optimal temperature reaction windows. For example, when urea is used as the reducing agent, the optimal reaction temperature window corresponding thereto is 950-1150℃, and when ammonia water is used as the reducing agent, the optimal reaction temperature window corresponding thereto is 850-1050℃.

[0070] Since the top temperature of the coke oven chamber is usually 200-300 degrees higher than the temperature of the SNCR reaction area in the coke oven chamber, the first temperature threshold can be determined according to the upper limit of the optimal reaction temperature window corresponding to the reducing agent used and the preset difference between the top temperature and the temperature of the reaction area. For example, if ammonia water is used as the reducing agent, and the preset top temperature is 250℃ higher than the temperature of the reaction area, 1300℃ can be used as the first temperature threshold.

[0071] Then, if the top temperature exceeds the first temperature threshold, the temperature of the SNCR reaction area exceeds the upper limit of the optimal reaction temperature window, and at this time, the denitration efficiency is low.

[0072] In this embodiment, a backflow pipeline is arranged between the flue main and the regenerator, that is, one end of the backflow pipeline is connected to the flue main and the other end is connected to the regenerator. For example, a hole is formed in the sidewall of the flue main, and one end of the backflow pipeline is connected to the hole, and a backflow valve is arranged at the connection. When the backflow valve is in the closed state, the flue gas in the flue main flows normally to the downstream of the flue main, and when the backflow valve is in the open state, part of the flue gas in the flue main flows normally to the downstream of the flue main, and the other part of the flue gas flows to the regenerator through the backflow pipeline.

[0073] In addition, an induced draft fan is arranged at the end of the backflow pipeline close to the regenerator. When the induced draft fan is turned on, it can ensure that the flue gas in the backflow pipeline flows to the regenerator, and by adjusting the frequency of the induced draft fan, the flow rate of the flue gas flowing back to the regenerator in the backflow pipeline can be adjusted.

[0074] It can be understood that in the process of flowing out to the flue main and then flowing back to the regenerator through the backflow pipeline, the heat of the flue gas is continuously lost, so that the temperature of the flue gas flowing back to the regenerator is relatively low. Therefore, by flowing the flue gas in the flue main back to the regenerator, the temperature in the regenerator can be reduced, and the temperature of the SNCR reaction region in the regenerator will be reduced, that is, the temperature of the SNCR reaction region approaches the optimal reaction temperature window, thereby improving the denitration efficiency.

[0075] Since the connection between the flue main and the backflow pipeline is provided with a backflow valve, the larger the opening degree of the backflow valve, the greater the proportion of the flue gas that can flow back, and the greater the frequency of the induced draft fan, the faster the flow rate of the backflow. Therefore, by increasing the opening degree of the backflow valve and / or the frequency of the induced draft fan, the flow rate of the backflow can be increased. Thus, the temperature at the top of the regenerator can be quickly reduced.

[0076] Therefore, if the top temperature exceeds the first preset threshold, the opening degree of the backflow valve and / or the frequency of the induced draft fan can be increased to cool the regenerator, thereby improving the denitration efficiency.

[0077] For example, the second preset threshold can be determined according to the lower limit of the optimal reaction temperature window corresponding to the reducing agent used and the preset difference between the top temperature and the SNCR reaction region temperature. For example, if ammonia water is used as the reducing agent, and the preset top temperature is 250℃ higher than the SNCR reaction region temperature, 1100℃ can be used as the second temperature threshold. Then, if the top temperature is lower than the second temperature threshold, the temperature of the SNCR reaction region is lower than the lower limit of the optimal reaction temperature window, and at this time, the denitration efficiency is low.

[0078] It can be understood that, as the valve opening of the backflow valve and / or the frequency of the induced draft fan is reduced, the flow of the low-temperature flue gas backflowing in the regenerator is reduced, and heat is released in the denitration reaction process, so that the temperature in the regenerator is increased. Therefore, by reducing the valve opening of the backflow valve and / or the frequency of the induced draft fan, the temperature in the regenerator is gradually increased, thereby improving the denitration efficiency.

[0079] For example, the present embodiment can take the top temperature as a controlled variable, and the valve opening of the backflow valve and / or the frequency of the induced draft fan as a control variable, and perform closed-loop control, so that the top temperature is maintained within a temperature range in which the SNCR reaction region can stably denitrate.

[0080] For example, the above-mentioned way of increasing or reducing the valve opening of the backflow valve and / or the frequency of the induced draft fan can be to increase or reduce the valve opening of the backflow valve and / or the frequency of the induced draft fan by a predetermined step, for example, increasing the valve opening by 10% or increasing the operating frequency of the induced draft fan by 1 Hz. Alternatively, a PID (Proportional, Integral, Derivative) algorithm can be used to adjust the valve opening of the backflow valve and / or the frequency of the induced draft fan. In this case, a target value to which the top temperature is to be adjusted can be preset, and the PID algorithm calculates the difference (error) between the target value and the current value, and then adjusts the valve opening of the backflow valve and / or the frequency of the induced draft fan according to the error, so as to reduce the error. Alternatively, a fuzzy control algorithm can be used to adjust the valve opening of the backflow valve and / or the frequency of the induced draft fan. The present embodiment is not limited to the way of increasing or reducing the valve opening of the backflow valve and / or the frequency of the induced draft fan.

[0081] In addition, in another embodiment, if the temperature of the SNCR reaction region in the regenerator can be measured, the temperature of the SNCR reaction region can be directly monitored, and if the temperature of the SNCR reaction region is not within the optimal reaction temperature window corresponding to the reducing agent, the temperature of the SNCR reaction region can be adjusted according to the above-mentioned control method, so that the temperature of the SNCR reaction region is maintained within a temperature range in which the SNCR reaction region can stably denitrate, thereby improving the denitration efficiency.

[0082] In another embodiment of the present application, a plurality of SNCR reaction regions are provided in the regenerator, and each SNCR reaction region is connected with a branch flue for discharging flue gas, and each branch flue is connected with the first end of the flue main. Figure 1 Based on the embodiment shown in Figure 2 The above-mentioned denitration method can further include steps S201-S204:

[0083] S201, obtaining a first concentration based on the concentration of nitrogen oxides in the specified branch flue obtained at the second preset time interval;

[0084] In this embodiment, multiple SNCR reaction zones are designed in the regenerative chamber, and flue gas after denitration treatment in each SNCR reaction zone flows out to the flue gas main through the branch flue.

[0085] For example, the specified branch flue can be one or more. If the specified branch flue is one, the concentration of nitrogen oxides obtained in the specified branch flue is the first concentration. If the specified branch flue is multiple, the average concentration of nitrogen oxides in each specified branch flue can be taken as the first concentration. It can be understood that in actual application, since each SNCR reaction zone is uniformly controlled in the same control mode, that is, the working conditions in each SNCR reaction zone are basically the same, the average concentration of nitrogen oxides in each specified branch flue can represent the overall denitration situation in the regenerative chamber, and therefore the average concentration of nitrogen oxides in each specified branch flue can be taken as the first concentration to determine the required reducing agent flow and carrier gas flow in the regenerative chamber.

[0086] For example, if there are a large number of SNCR reaction zones in the regenerative chamber, in order to reduce system complexity and cost, five branch flues can be selected as specified branch flues. The selection of specified branch flues can be equidistant selection or selection by relevant technical personnel according to experience, which is reasonable. Of course, if there are fewer SNCR reaction zones in the regenerative chamber, each branch flue can also be taken as a specified branch flue, which is reasonable.

[0087] For example, a monitoring hole can be arranged in the specified branch flue, and the probe of the nitrogen oxide detection device is inserted into the specified branch flue through the monitoring hole to monitor the concentration of nitrogen oxides in the specified branch flue in real time. In actual application, an instantaneous concentration measurement method can be used, that is, the flow of nitrogen oxides in the specified branch flue per unit time is taken as the concentration of nitrogen oxides in the specified branch flue. The nitrogen oxide detection device can use CEMS (Continuous Emissions Monitoring System) or an electrochemical sensor, etc., and the type of the nitrogen oxide detection device is not limited in the embodiments of the present application. The nitrogen oxide detection device can upload the currently collected concentration of nitrogen oxides in the specified branch flue to the electronic device executing the denitration method provided in the embodiments of the present application according to a second preset time interval. The second preset time interval can be the same as or different from the above-mentioned first preset time interval. For example, the second time interval can be 30 seconds or 1 minute, etc.

[0088] S202, determining whether the reducing agent flow of the reducing agent currently input into the regenerative chamber matches the first concentration currently obtained;

[0089] It can be understood that, when the SNCR denitration treatment is performed, in order to maintain a high denitration efficiency, the injection amount of the reducing agent needs to be increased when the concentration of the nitrogen oxide is increased, but too much reducing agent will lead to ammonia escape and thus reduce the denitration efficiency. Therefore, in order to maintain a high denitration efficiency, the appropriate reducing agent flow rate needs to be determined. In the embodiment, the reducing agent flow rate matched with the first concentration is the reducing agent flow rate that can achieve a high denitration efficiency.

[0090] In an implementation manner, if the reducing agent is ammonia water, the molar flow rate ratio of NH3 to NO X is between 1.3 and 1.8, the reducing agent flow rate matched with the first concentration is the reducing agent flow rate that can achieve a high denitration efficiency.

[0091] In another implementation manner, the reducing agent flow rate matched with the first concentration is the reducing agent flow rate that can achieve a preset denitration efficiency, which can be 80%, 90%, etc. For example, in actual application, the proportional relationship between the reducing agent flow rate and the first concentration when the denitration efficiency of 80% is achieved can be determined according to analysis of historical data, and thus the range of the reducing agent flow rate that can achieve the denitration efficiency of 80% is determined as the range of the reducing agent flow rate matched with the first concentration.

[0092] It can be understood that, in actual application, the reducing agent and the carrier gas are supplied to the regenerator through a delivery main pipe, one end of the delivery main pipe is connected to the reducing agent delivery pipe and the carrier gas delivery pipe, and the other end is connected to the injection device in the regenerator. The delivery main pipe and the reducing agent delivery pipe are provided with a reducing agent delivery valve for controlling the flow rate of the reducing agent input into the regenerator, and the delivery main pipe and the carrier gas delivery pipe are provided with a carrier gas delivery valve for controlling the flow rate of the carrier gas input into the regenerator. When the reducing agent is ammonia water and the carrier gas is air, the other end of the reducing agent delivery pipe is connected to an ammonia water tank, and the other end of the carrier gas delivery pipe is connected to a compressed air tank.

[0093] For example, the current valve opening degree of the reducing agent delivery valve can be obtained, and the current reducing agent flow rate can be determined according to the current valve opening degree of the reducing agent delivery valve. The larger the valve opening degree, the larger the flow rate of the reducing agent passing through the valve. The relationship between the valve opening degree and the flow rate of the reducing agent is related to the type of the valve, and different types of valves have different flow characteristics (such as linear type and percentage type), that is, different types of valves correspond to different relationships between the opening degree and the flow rate, and the specific type of the reducing agent delivery valve used in the embodiment is not limited.

[0094] S203, if not matched, determining the reducing agent flow rate matched with the first concentration currently obtained, and determining the carrier gas flow rate of the carrier gas needed to be input into the regenerator based on the determined reducing agent flow rate;

[0095] In the embodiment, if the current reducing agent flow rate does not match the current acquired first concentration, a product of a preset ratio and the current first concentration can be determined as the reducing agent flow rate of the reducing agent matching the current first concentration. The preset ratio is a ratio between the amount of reducing agent used to achieve the preset denitration efficiency and the first concentration. For example, the preset ratio can be 1.5 or 1.6, etc.

[0096] After the reducing agent and the carrier gas are mixed, the reducing agent and the carrier gas are injected into the SNCR reaction region designed in the regenerator through injection devices (e.g., injection guns) distributed in the regenerator. Under a suitable temperature window, the reducing agent reacts with NOx in the coke oven flue gas to generate N2 and H2O. X The non-catalytic reduction reaction occurs, and N2 and H2O are generated.

[0097] It can be understood that, due to improper mixing ratio of the reducing agent and the carrier gas, the atomization is not uniform or the atomized particle size is too large, which causes the reducing agent to not fully contact with the coke oven flue gas, thereby reducing the denitration efficiency. Therefore, if it is determined in step S202 that the current reducing agent flow rate does not match the current acquired first concentration, after the reducing agent flow rate matching the current acquired first concentration is determined, the carrier gas flow rate of the carrier gas can be determined according to the determined reducing agent flow rate, so that the carrier gas flow rate can be adjusted following the reducing agent flow rate, thereby keeping the reducing agent flow rate and the carrier gas flow rate within a suitable ratio range to ensure the atomization effect.

[0098] In an implementation manner, in order to improve the atomization effect, the amount of reducing agent and the amount of carrier gas are mixed and atomized according to a preset ratio, and the preset ratio is in a range of 1 / 3-2.

[0099] In step S204, the valve opening of the current reducing agent delivery valve is adjusted according to the determined reducing agent flow rate, and the valve opening of the current carrier gas delivery valve is adjusted according to the determined carrier gas flow rate.

[0100] In an implementation manner, the reducing agent is ammonia water, the ammonia water tank and the delivery pump are used to supply the reducing agent into the regenerator, the carrier gas is air, and the compressed air tank is used to supply the air into the regenerator. For example, an electric proportional regulating valve is installed at a connection between the output pipeline (reducing agent delivery pipeline) of the delivery pump and the delivery main pipe as the reducing agent delivery valve, and the ammonia water supply amount (i.e., the reducing agent flow rate) is controlled by adjusting the valve opening of the reducing agent delivery valve. An electric proportional regulating valve is installed at a connection between the carrier gas delivery pipeline through which the carrier gas is delivered into the regenerator and the delivery main pipe as the carrier gas delivery valve, and the air supply amount (i.e., the carrier gas flow rate) is controlled by adjusting the valve opening of the carrier gas delivery valve.

[0101] The embodiment is not limited to the types of the reducing agent and the carrier gas. For example, urea can be used as the reducing agent, and other inert gases such as nitrogen can be used as the carrier gas. In addition, the embodiment is not limited to the types of the reducing agent delivery valve and the carrier gas delivery valve. For example, pneumatic diaphragm control valves or V-shaped ball valves can be used as the reducing agent delivery valve or the carrier gas delivery valve.

[0102] It can be understood that, since different types of valves have different flow characteristics, that is, different types of valves have different relationships between valve opening and flow, the valve opening of the reducing agent delivery valve required to reach the determined reducing agent flow and the valve opening of the carrier gas delivery valve required to reach the determined carrier gas flow can be calculated according to the relationship between the valve opening and the flow corresponding to the type of the valve used, and then the current valve opening of the reducing agent delivery valve and the current valve opening of the carrier gas delivery valve can be adjusted according to the calculated two valve openings.

[0103] For example, a PID algorithm can be used to perform closed-loop adjustment with the reducing agent flow as the controlled variable and the valve opening of the reducing agent delivery valve as the control variable. In addition, the valve opening of the carrier gas delivery valve and the valve opening of the reducing agent delivery valve are linked in a set ratio. The set ratio can be in the range of 1 / 3-2.

[0104] It can be seen that, when the concentration of nitrogen oxides in the flue main fluctuates, the embodiment can adjust the reducing agent flow and the carrier gas flow according to the current first concentration, so that the reducing agent flow matches the current first concentration, and the carrier gas flow is linked with the reducing agent flow in a set ratio to ensure the atomization effect of the reducing agent, thereby improving the denitration efficiency.

[0105] In an implementation manner, the denitration method can further include steps A1-A2.

[0106] A1, input the current collected working condition parameters and the preset number of groups of historical collected working condition parameters into a prediction model to obtain a target temperature and a target ammonia nitrogen ratio; wherein each group of working condition parameters includes a top temperature of the regenerator, a first concentration obtained based on the concentration of nitrogen oxides in the specified flue, a valve opening of the reducing agent delivery valve, a valve opening of the carrier gas delivery valve, and a first parameter including a valve opening of the reflux valve and / or a frequency of the induced draft fan;

[0107] A2, adjust the valve opening of the reflux valve and / or the frequency of the induced draft fan according to the target temperature, and adjust the valve opening of the reducing agent delivery valve and the valve opening of the carrier gas delivery valve according to the target ammonia nitrogen ratio.

[0108] For example, the preset number can be 10, 20, etc.

[0109] In the present implementation, each training sample for training the initial prediction model includes multiple sets of historical working condition parameters. For example, a training sample includes a set of working condition parameters collected at a historical time T1, and the previous 10 sets of working condition parameters of the working condition parameters at the time T1. Each set of working condition data includes the temperature at the top of the regenerator, the first concentration based on the concentration of nitrogen oxides in the specified flue, the valve opening of the reducing agent delivery valve, the valve opening of the carrier gas delivery valve, and the first parameter including the valve opening of the backflow valve and / or the frequency of the induced draft fan. The label of each training sample includes the temperature and ammonia-nitrogen ratio that can improve the denitration efficiency under the current working condition.

[0110] The initial prediction model can adopt a transformer model architecture, and the output is the predicted temperature and ammonia-nitrogen ratio. The loss value between the predicted output of the model and the label is calculated, and the model parameters are adjusted through the back propagation method of minimizing the loss value until the model converges, to obtain the trained prediction model.

[0111] After obtaining the trained prediction model, the currently collected working condition parameters and the preset number of sets of historical collected working condition parameters are input into the prediction model, to obtain the target temperature and target ammonia-nitrogen ratio output by the model. The preset number of sets of historical collected working condition parameters are the previous preset number of sets of working condition parameters of the current working condition parameters.

[0112] After obtaining the target temperature and target ammonia-nitrogen ratio by the model prediction, the valve opening of the backflow valve and / or the frequency of the induced draft fan can be adjusted according to the target temperature by using the PID algorithm, so that the temperature at the top of the regenerator is reduced to the target temperature. The valve opening of the reducing agent delivery valve and the valve opening of the carrier gas delivery valve are adjusted according to the target ammonia-nitrogen ratio, so that the ratio of the reducing agent and the carrier gas reaches the target ammonia-nitrogen ratio.

[0113] By the present scheme, the AI (Artificial Intelligence) model can periodically recommend more optimal operating parameters based on historical data and real-time working conditions to maintain high denitration efficiency.

[0114] In one implementation, each SNCR reaction region is provided with a branch pipe, one end of each branch pipe is connected to a delivery main pipe for inputting a mixture of reducing agent and carrier gas into the regenerator, the other end of each branch pipe is connected to a spraying device for spraying the mixture into the SNCR reaction region, and a branch pipe distribution valve is arranged at the connection between each branch pipe and the delivery pipe; the other end of the delivery main pipe is connected to a reducing agent delivery pipe and a carrier gas delivery pipe, a reducing agent delivery valve is arranged at the connection between the reducing agent delivery pipe and the delivery main pipe, and a carrier gas delivery valve is arranged at the connection between the carrier gas delivery pipe and the delivery main pipe.

[0115] In one implementation, the branch pipe distribution valves are uniformly regulated, i.e. the branch pipe distribution valves maintain the same valve opening degree, so as to facilitate the overall control of the system.

[0116] In another implementation, after the concentration of nitrogen oxides in the specified flue is obtained according to the second preset time interval, it is further determined whether the mixture flow rate currently injected into the SNCR reaction region to which the specified flue belongs matches the currently obtained concentration of nitrogen oxides in the specified flue. If not, the mixture flow rate matching the currently obtained concentration of nitrogen oxides in the specified flue is determined, and the valve opening degree of the branch pipe distribution valve corresponding to the SNCR reaction region to which the specified flue belongs is adjusted according to the determined mixture flow rate.

[0117] It can be understood that when multiple SNCR reaction regions are designed in the regenerative chamber, the injection device distributed in the regenerative chamber is provided with an injection port in each SNCR reaction region. That is, each SNCR reaction region is provided with a branch pipe, the delivery main pipe for inputting the mixture of reducing agent and carrier gas into the regenerative chamber is connected to each branch pipe, and a branch pipe distribution valve is arranged at the connection between the delivery main pipe and each branch pipe for distributing the mixture flow rate flowing to the branch pipe. The other end of each branch pipe is connected to the injection device in the SNCR reaction region, and the injection device is used to atomize and inject the mixture in the branch pipe.

[0118] The reducing agent flow rate determined through the above steps S201-S204 is the total flow rate of reducing agent required in the regenerative chamber, and the reducing agent and the carrier gas mixed after the flow rate of the reducing agent and the flow rate of the carrier gas are determined are injected into each SNCR reaction region through each injection port. It can be understood that the mixture flow rate in the SNCR reaction region to which the specified flue belongs can be calculated according to the above determined flow rate of the reducing agent and the flow rate of the carrier gas and the valve opening degree of each branch pipe distribution valve. For example, if the valve opening degrees of each branch pipe distribution valve are the same, and there are a total of 10 branch pipe distribution valves, the above reducing agent flow rate is uniformly distributed to each SNCR reaction region, and the mixture flow rate in the SNCR reaction region to which the specified flue belongs is one tenth of the total amount of the above reducing agent flow rate and the carrier gas flow rate.

[0119] It can be understood that since the reducing agent and the carrier gas are mixed in proportion, according to the reducing agent flow rate matching the concentration of nitrogen oxides in the specified flue, the mixture flow rate matching the concentration of nitrogen oxides in the specified flue can be determined. For example, if the reducing agent flow rate matching the concentration of nitrogen oxides in the specified flue is 0.3 m 3 / min, and the reducing agent and the carrier gas are mixed in a ratio of 3:1, then the mixture flow rate matching the concentration of nitrogen oxides in the specified flue is 0.4 m 3 / min. The determination of the flow rate of the reducing agent matching the concentration of the nitrogen oxides in the specified flue duct can refer to the above description of the determination of the flow rate of the reducing agent matching the first concentration, which will not be repeated here.

[0120] Since different types of valves have different flow characteristics, the valve opening of the branch distribution valve corresponding to the SNCR reaction region to which the specified flue duct belongs required to reach the determined mixture flow rate can be calculated according to the relationship between the valve opening and the flow of the branch distribution valve of the type of valve used, and then the valve opening of the branch distribution valve of the SNCR reaction region to which the specified flue duct belongs is adjusted according to the calculated valve opening.

[0121] It can be understood that adjusting the valve opening of the branch distribution valve of the SNCR reaction region to which the specified flue duct belongs according to the concentration of the nitrogen oxides in each specified flue duct can make the flow rate of the reducing agent injected into the SNCR reaction region to which each specified flue duct belongs match the concentration of the nitrogen oxides in the SNCR reaction region, thereby improving the denitration efficiency in the SNCR reaction region to which the specified flue duct belongs. In this way, the flow rate of the reducing agent in each SNCR reaction region can be adaptively adjusted according to the differences between the actual working conditions in each SNCR reaction region, thereby improving the overall denitration efficiency.

[0122] In another embodiment of the present application, a flue gas input pipe of an SCR (Selective Catalytic Reduction) reactor is connected to the flue main at a first position, and a flue gas output pipe of the SCR reactor is connected to the flue main at a second position, and an SCR valve is arranged at the connection between the flue main and the flue gas input pipe. The first position is an upstream position of the second position, that is, in the flue main, flue gas flows from the first position to the second position.

[0123] In one implementation, the connection between the return pipe and the flue main is downstream of the second position, that is, after the SCR valve is opened, the flue gas after SNCR denitration treatment in the regenerator flows through the flue main, part of which flows to the SCR reactor, and the flue gas after SCR denitration treatment in the SCR reactor continues to flow downstream of the flue main and returns to the regenerator through the return pipe downstream. The present embodiment does not limit the positional relationship between the connection between the return pipe and the flue main and the second position, for example, in another implementation, the connection between the return pipe and the flue main is upstream of the second position.

[0124] In Figure 1 Based on the embodiment shown in Figure 3 The above method for denitration of coke oven flue gas can further include step S104:

[0125] S104, if the second concentration of the nitrogen oxides at the second end of the flue main is continuously collected for a third preset time interval and exceeds the preset concentration threshold for a specified number of times, then the SCR valve is opened.

[0126] In this embodiment, the specified number of times can be 5, 10, etc. The preset concentration threshold can be set according to the emission standard of nitrogen oxides, for example, if the emission standard is that the concentration of nitrogen oxides is less than 100 mg / m 3 , then the preset concentration threshold can be 100 mg / m 3 , exceeding the preset concentration threshold means that the emission exceeds the standard; or the preset concentration threshold can be 95 mg / m 3 , at this time, exceeding the preset concentration threshold means that the emission is about to exceed the standard. Exemplarily, the third preset time interval can be 1 minute or 2 minutes, etc.

[0127] In actual application, the second end of the flue main is connected with the chimney, and the flue gas after denitration treatment is finally discharged from the end of the chimney. Exemplarily, a monitoring hole can be arranged near the second end of the flue main, and the probe of the nitrogen oxide detection device is inserted into the specified flue through the monitoring hole to monitor the second concentration of the nitrogen oxides at the second end of the flue main in real time. Moreover, the nitrogen oxide detection device can upload the currently collected second concentration to the electronic device for performing the denitration method of the coke oven flue gas provided in the embodiment of the present application at the third preset time interval.

[0128] It can be understood that if the second concentration exceeding the preset concentration threshold is continuously collected for a specified number of times, it means that the denitration treatment of the coke oven flue gas according to the current denitration method is still difficult to reach the emission standard, at this time the SCR valve can be opened to enable the SCR reactor to perform SCR denitration treatment.

[0129] When the SCR valve is opened, the flue gas after SNCR denitration treatment in the above regenerator flows into the SCR reactor through the flue main, and under the action of the catalyst in the SCR reactor, the reducing agent reacts with the remaining nitrogen oxides in the flue gas at a lower temperature (about 300-400°C) to form nitrogen and water.

[0130] Correspondingly, if the second concentration is continuously collected for a preset number of times and is lower than the specified threshold, the SCR valve is closed. Exemplarily, the specified threshold can be much smaller than the concentration of nitrogen oxides required by the emission standard, for example, if the emission standard is that the concentration of nitrogen oxides is less than 100 mg / m 3 , then the specified threshold can be a concentration of 10 mg / m 3 , which is one order of magnitude lower than the emission standard. Exemplarily, the preset number of times can be 5 or 10, etc.

[0131] It can be understood that, since the SCR denitration treatment needs to use a catalyst and is high in cost, if the second concentration is continuously and repeatedly collected to be low, it indicates that the current denitration efficiency is high, at which time the SCR valve can be closed to save the denitration cost.

[0132] In another embodiment of the present application, as shown in Figure 4 The denitration method can further include steps S401-S403.

[0133] S401, collecting the ammonia escape amount at the second end of the flue main pipe according to a fourth time interval;

[0134] In the embodiment, the fourth preset time interval can be 30s or 1 minute, etc. In actual application, the second end of the flue main pipe is connected with the chimney, and the flue gas is finally discharged from the end of the chimney after the denitration treatment.

[0135] Exemplarily, the ammonia escape monitoring hole can be arranged at a position close to the second end of the flue main pipe, and the probe of the ammonia escape monitoring device is inserted into the flue main pipe through the monitoring hole to collect the ammonia escape amount in real time. Moreover, the ammonia escape monitoring device can upload the currently collected ammonia escape amount to the electronic device for executing the denitration method of the coke oven flue gas provided in the embodiment of the present application according to the fourth preset time interval.

[0136] Exemplarily, the ammonia escape monitoring device can adopt a tunable semiconductor laser absorption spectrum analyzer or a wall-mounted ammonia escape monitoring system, etc., and the present embodiment is not limited to the specific type of the ammonia escape monitoring device.

[0137] S402, if the currently collected ammonia escape amount exceeds the preset ammonia escape threshold value, the valve opening degree of the reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve are collected; the ratio of the current reducing agent flow rate to the current carrier gas flow rate is calculated according to the collected valve opening degree of the reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve; if the calculated ratio is not within the preset interval, the valve opening degree of the carrier gas delivery valve is adjusted so that the ratio of the adjusted reducing agent flow rate to the carrier gas flow rate is within the preset interval; wherein when the ratio is within the preset interval, the reducing agent and the carrier gas can reach the preset atomization state;

[0138] and / or,

[0139] S403, if the currently collected ammonia escape amount exceeds the preset ammonia escape threshold value, the top temperature of the regenerator is collected; if the currently collected top temperature exceeds the first preset threshold value, the valve opening degree of the reflux valve and / or the frequency of the induced draft fan is increased.

[0140] Exemplarily, the ammonia escape threshold value can be 8mg / m 3or 10 mg / m 3 or 10 mg / m

[0141] In this embodiment, if the ammonia escape amount exceeds the ammonia escape threshold, the atomization effect of the SNCR or the temperature of the SNCR reaction region can be detected first to reduce the ammonia escape amount by improving the denitration efficiency.

[0142] It can be understood that, since the valve opening degree is used to control the flow through the valve, by obtaining the valve opening degree of the current reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve, the reducing agent flow can be determined according to the obtained valve opening degree of the reducing agent delivery valve, and the carrier gas flow can be determined according to the valve opening degree of the carrier gas delivery valve, so that the ratio of the reducing agent flow and the carrier gas flow can be calculated.

[0143] For example, if the reducing agent delivery valve and the carrier gas delivery valve are the same type of valve, i.e. have the same flow characteristics, and the valve opening degree of the reducing agent delivery valve is 20% and the valve opening degree of the carrier gas delivery valve is 60%, the ratio of the reducing agent flow and the carrier gas flow is 1:3.

[0144] For example, the above-mentioned preset interval can be [1 / 3, 2]. When the ratio of the reducing agent flow and the carrier gas flow is within the preset interval, the reducing agent and the carrier gas can reach a preset atomization state, at which time the reducing agent can be fully atomized, i.e. can be uniformly atomized and have a small atomized particle size, so that the atomized reducing agent can fully contact the coke oven flue gas, thereby improving the denitration efficiency. In practical applications, the preset interval can be set by relevant technical personnel according to experience. It can be understood that, since the reducing agent can be fully atomized when the ratio of the reducing agent flow and the carrier gas flow is within the preset interval, the denitration efficiency is improved, so that the proportion of the reducing agent participating in the SNCR denitration treatment among the reducing agent input into the regenerative chamber can be increased, thereby reducing the ammonia escape amount.

[0145] Furthermore, if the currently obtained ammonia escape amount exceeds the ammonia escape threshold, the top temperature of the regenerative chamber can also be obtained, and if the currently obtained top temperature exceeds a first preset threshold, the valve opening degree of the reflux valve and / or the frequency of the induced draft fan can be increased. The way of increasing the valve opening degree of the reflux valve and / or the frequency of the induced draft fan can refer to the related description of step S102 above.

[0146] It can be understood that, by adjusting the top temperature of the regenerative chamber, the SNCR reaction region can perform SNCR treatment within the optimal reaction temperature window, which can increase the proportion of the reducing agent participating in the SNCR denitration treatment among the reducing agent input into the regenerative chamber, thereby reducing the ammonia escape amount.

[0147] As can be seen, in this embodiment, when ammonia slip exceeds the standard, the atomization effect and the temperature of the SNCR reaction zone are first checked. If they are not suitable, the atomization effect and the temperature of the SNCR reaction zone are adjusted to reduce ammonia slip by improving denitrification efficiency. Of course, if the atomization effect and the temperature of the SNCR reaction zone are suitable, the valve opening of the reducing agent delivery valve can be directly reduced to decrease the reducing agent flow rate, thereby reducing ammonia slip.

[0148] It is evident that this solution effectively suppresses ammonia escape, avoids secondary pollution, and achieves green and environmentally friendly practices throughout the entire process.

[0149] To better understand the solutions provided in the embodiments of this application, a method for denitrification of coke oven flue gas provided in the embodiments of this application is described below with reference to a specific example.

[0150] like Figure 5 As shown, this example mainly consists of four parts: an in-furnace SNCR denitrification subsystem, an external SCR denitrification subsystem, a low-temperature flue gas recirculation subsystem, and a measurement, sensing, and central control system.

[0151] (1) In-furnace SNCR denitrification subsystem.

[0152] Working principle: Ammonia and other reducing agents (dosage equal to NO) are used to reduce NO. X Content-related, for example, NH3 and NO X The molar flow rate ratio should be between 1.3 and 1.8. The reducing agent is mixed with compressed air at a recommended ratio (gas-liquid mass ratio 0.5:1~3:1), atomized, and then injected into the designed SNCR reaction zone of the coke oven regenerator through injection devices distributed throughout the regenerator. Under suitable temperature conditions (850-1050℃), the reducing agent reacts with NO in the flue gas. X A non-catalytic reduction reaction occurs, producing nitrogen and water.

[0153] The main equipment in the in-furnace SNCR denitrification subsystem includes:

[0154] The in-furnace denitrification agent supply unit includes an ammonia tank and a transfer pump. The total ammonia supply is controlled by a proportional regulating valve (main pipe regulating valve V1, corresponding to the reducing agent transfer valve mentioned above).

[0155] The in-furnace carrier gas supply unit includes a compressed air tank. The total air volume is controlled by a proportional regulating valve (main pipe regulating valve V2, corresponding to the carrier gas delivery valve mentioned above), and is proportionally linked to the ammonia water volume.

[0156] The regulating and distributing valve group consists of a main regulating valve (V1, V2) and multiple branch distributing valves (KV).

[0157] Control logic: According to the working conditions of each SNCR reaction zone in the regenerator, the central control system adjusts the flow distribution of each branch through control instructions to ensure that the reducing agent injected into each point matches the local NO X concentration.

[0158] (2) Low-temperature flue gas back blending subsystem.

[0159] Working principle: A portion of low-temperature flue gas is drawn from the end of the flue gas emission unit pipeline and back blended into the SNCR reaction zone in the coke oven regenerator through the induced draft fan and regulating valve group. By using the mixing effect of low-temperature flue gas, the actual temperature of the SNCR reaction zone can be adjusted within a certain range (mostly reduced) to fall within the optimal reaction temperature window of SNCR (adjusted in combination with the top temperature of the regenerator).

[0160] The main equipment in the low-temperature flue gas back blending system includes:

[0161] Low-temperature flue gas supply unit: including induced draft fan, supply pipeline. The fan parameters (mainly frequency) can be adjusted by the central control system to control the overall back blending capacity.

[0162] Low-temperature flue gas regulating valve group (V3, corresponding to the backflow valve in the above): receives the flow adjustment instructions from the central control system to accurately control the instantaneous flow of back blended flue gas. Its valve opening is mainly dynamically adjusted according to the top temperature of the regenerator (T1).

[0163] (3) Off-site SCR denitration subsystem.

[0164] Working principle: When the flue gas after in-furnace denitration still does not meet the standard, the off-site SCR denitration system is started. Under the action of the catalyst, the reducing agent (usually gaseous ammonia) reacts with the remaining NO X in the flue gas at a lower temperature (about 300-400°C) to occur catalytic reduction reaction.

[0165] The main equipment in the off-site SCR denitration system includes: denitrating agent supply unit, dilution air supply unit, nitrogen supply unit, and SCR reaction unit. The dilution air supply unit is used to supply air.

[0166] Control logic: receives the ON / OFF (on / off) control instructions from the central control system. Its own reducing agent adjustment is closed-loop controlled according to the NO X concentration at the end of the chimney (C2) and the ammonia escape concentration (M1).

[0167] (4) Central control system

[0168] Working principle: All key measurement parameters are collected, and the optimal control instructions are calculated through the built-in intelligent decision-making module and adaptive optimization module, and sent to each execution unit.

[0169] The measurement parameters include:

[0170] Process parameters: Regenerator top temperature (T1); Branch pipe line flow rate (F1, F2…), atomization pressure (P1, P2…).

[0171] Emission parameters: Coke oven flue NOx content (C1, corresponding to the first concentration above), stack end NOx content (C2, corresponding to the second concentration above), stack end ammonia escape amount (M1), wherein the NOx content is measured under the O2 content benchmark required by the national standard. X X X X

[0172] Control logic:

[0173] A) The data acquisition and monitoring unit receives data collected by all measurement sensors in real time.

[0174] B) The intelligent decision-making module (core controller) first takes T1 and C1 as the primary feedback, generates control instructions for V3 (flue gas recirculation) and V1, V2 (ammonia water / carrying gas) through PID or fuzzy control algorithms, and prioritizes optimizing the denitration performance of the in-furnace SNCR denitration system.

[0175] C) The adaptive parameter optimization module (advanced function) can periodically recommend more optimal operating parameter set points (such as the optimal temperature set value and the optimal ammonia nitrogen ratio) based on historical data and real-time working conditions through an AI model (such as a reinforcement learning model), and issue them to the intelligent decision-making module for execution, achieving continuous optimization of system energy efficiency.

[0176] D) The system continuously monitors C2. When the in-furnace SNCR denitration subsystem is running under optimal parameters, but C2 still exceeds the set limit, the intelligent decision-making module will issue a “ON” control instruction to the out-of-furnace SCR denitration subsystem to start the out-of-furnace denitration as the final safeguard.

[0177] The following describes the various functional modules in combination with a specific processing flow.

[0178] (1) System startup and initial operation.

[0179] The coke oven is in normal production, and the flue gas flows through the regenerator. The central control system first starts only the in-furnace SNCR denitration subsystem.

[0180] ​​​​The central control system reads T1 (the temperature at the top of the regenerator T1 = the temperature in the reaction zone + 200-300℃), and if T1 is higher than a certain temperature (the temperature range of the optimal reaction temperature window of SNCR is learned and summarized through the content of flue gas NOx, such as 1150-1300℃), the central control system issues a control instruction 2 to the low-temperature back-mixing subsystem, and the low-temperature back-mixing subsystem automatically opens and adjusts the low-temperature flue gas adjusting valve V3 upon receiving the control instruction 2 to adjust the flow of back-mixed flue gas, and can adjust the parameters of the fan to gradually reduce T1 to an appropriate temperature range, and monitor the change of the NOx concentration of the flue gas in the flue main pipe (whether it decreases and the decrease amplitude). The low-temperature flue gas is transported to the regenerator reaction unit (corresponding to the SNCR reaction zone in the foregoing) through the low-temperature flue gas supply pipeline (corresponding to the backflow pipeline in the foregoing).

[0181] At the same time, the central control system calculates the required amount of ammonia water according to C1, adjusts V1 and V2 in proportion, and sprays the ammonia water into the regenerator through the distribution valve group KV. The adjustment of the amount of ammonia water is made in proportion to the amount of NOx that needs to be reduced in the flue gas, and the carrier gas is adjusted in proportion to the adjustment amount of the ammonia water. Specifically, the central control system issues a control instruction 1 to the in-furnace SNCR denitration subsystem, and the in-furnace denitration agent supply unit adjusts the valve opening of the reducing agent delivery valve group (corresponding to the reducing agent delivery valve in the foregoing) in proportion according to the received control instruction 1, and the in-furnace carrier gas supply unit adjusts the valve opening of the carrier gas delivery valve group (corresponding to the carrier gas delivery valve in the foregoing) in proportion according to the received control instruction 1.

[0182] (2) Optimization adjustment of the in-furnace SNCR denitration subsystem.

[0183] The adjustment content includes:

[0184] Temperature adjustment: T1 is the controlled variable, and V3 is the control variable, and PID closed-loop adjustment is performed. When T1 exceeds the first temperature threshold, the central control system issues a control instruction 3 to the out-of-furnace SCR denitration subsystem, and the SCR denitration subsystem opens the SCR valve according to the received control instruction 3. The flue gas after the SCR reaction is transported to the low-temperature flue gas supply unit by the flue gas discharge unit.

[0185] Ammonia injection adjustment: C1 is the controlled variable, and V1 is the control variable, and PID closed-loop adjustment is performed. V2 is linked with V1 in a set proportion.

[0186] Distribution adjustment: If the working conditions of each regenerator are uneven, the system can finely adjust the opening of each branch pipe distribution valve KV to achieve precise ammonia injection.

[0187] During this period, the adaptive optimization module starts running, which through analyzing the relationship between denitration efficiency, ammonia water consumption and temperature for a period of time, may suggest to fine-tune the SNCR optimal temperature set point from 950℃ to 930℃, and the central control system automatically adopts and executes.

[0188] (3) Intervention and linkage of the external SCR denitration subsystem.

[0189] After the above optimization adjustment, the central control system continues to monitor C2. Assuming that the national emission standard is 100 mg / m³ (the O2 content under the national standard requirement), when the central control system detects that C2 is continuously higher than 90 mg / m³ and has an upward trend, the intelligent decision module judges that SNCR has approached its capacity limit.

[0190] At this time, the central control system issues an "ON" control instruction to the external SCR system, and starts the external SCR denitration subsystem.

[0191] After the external SCR denitration subsystem is started, its own controller accurately controls the ammonia injection amount according to C2 and M1, to ensure that the final emission C2 is stably below 50 mg / m³, and M1 is lower than 8 mg / m³.

[0192] (4) Whole-process safety and economic monitoring.

[0193] During the whole process, the central control system monitors M1 in real time. If M1 is over-standard, the system will preferentially check the atomization effect (adjust V2) or reaction temperature (adjust V3) of the internal SNCR denitration subsystem, rather than simply reducing ammonia injection, so as to control ammonia slip under the premise of ensuring denitration efficiency.

[0194] Through this set of control process, the central control system ensures that only low-cost SNCR is used in most of the time, and only starts SCR in peak load or when the working condition fluctuates sharply, so as to achieve the best economic benefit.

[0195] It can be seen that the scheme provides a denitration system of deep coupling of SNCR in the furnace and SCR outside the furnace. The advantages of the two technologies are complementary through intelligent regulation and control, the reaction temperature of SNCR in the furnace can be accurately and actively regulated, and the SNCR is ensured to always operate in the efficient reaction range. Through the establishment of an intelligent decision-making logic with economic operation as the goal, the front-end and rear-end denitration loads are dynamically adjusted in real time according to the end emission index, which can significantly reduce the comprehensive operation cost. Through accurate proportioning and adjustment of the reducing agent and carrier gas, optimization of the atomization and mixing effect, the denitration efficiency can be improved while the ammonia slip is strictly controlled. While ensuring that NOx stably reaches the ultra-low emission standard, the operation time of the SCR system, the reducing agent and the catalyst consumption are greatly reduced by preferentially using the low-cost SNCR technology, and the comprehensive operation cost is significantly lower than that of single SCR technology. The low-temperature flue gas backflow system effectively widens the adaptability of SNCR to the coke oven working conditions, and the intelligent regulation and control ensures the denitration stability of the system under complex conditions such as load fluctuation and coal type change. The whole system realizes unmanned automatic regulation and control, automatically adjusts the operation parameters and automatically starts and stops the SCR system according to the real-time emission data, thereby reducing the burden of the operator and improving the automation degree. Through accurate proportioning and multi-link control, the ammonia slip is effectively inhibited, secondary pollution is avoided, and green environmental protection is realized in the whole process.

[0196] Corresponding to the method embodiments, the embodiments of the present application also provide a denitration system for coke oven flue gas, as shown in Figure 6 The system comprises a temperature acquisition device 610, a master control device 620 and a backflow device 630. The backflow device comprises a backflow valve and / or an induced draft fan.

[0197] The temperature acquisition device 610 is configured to acquire the top temperature of the regenerator of the coke oven. The coke oven flue gas is subjected to selective non-catalytic reduction (SNCR) denitration treatment in the regenerator. The regenerator is connected with a first end of a flue main for discharging flue gas. A backflow pipeline for backflow of flue gas is connected to the flue main. The other end of the backflow pipeline is connected with the regenerator. A backflow valve is arranged at the connection between the flue main and the backflow pipeline. An induced draft fan is installed in the backflow pipeline, and the induced draft fan is configured to draw flue gas into the regenerator.

[0198] The master control device 620 is configured to acquire the top temperature acquired by the temperature acquisition device 610 at a first preset time interval. If the currently acquired top temperature exceeds a first temperature threshold, a first regulation and control instruction is sent to the backflow device 630. If the currently acquired top temperature is lower than a second temperature threshold, a second regulation and control instruction is sent to the backflow device 630.

[0199] A backflow device 630, when including a backflow valve, is configured to increase the valve opening of the backflow valve if the first control instruction is received, and decrease the valve opening of the backflow valve if the second control instruction is received; and / or, when including an induced draft fan, is configured to increase the frequency of the induced draft fan if the first control instruction is received, and decrease the frequency of the induced draft fan if the second control instruction is received.

[0200] Optionally, a plurality of SNCR reaction zones are arranged in the regenerative chamber, and each SNCR reaction zone is connected with a sub-flue for discharging flue gas, and each sub-flue is connected with the first end of the flue main; the system further comprises a nitrogen oxide detection device, a reducing agent delivery valve and a carrier gas delivery valve;

[0201] The nitrogen oxide detection device is configured to collect the concentration of nitrogen oxides in a specified sub-flue;

[0202] The master control device 620 is further configured to determine whether the reducing agent flow rate of the reducing agent currently input into the regenerative chamber matches the first concentration currently obtained based on the concentration collected by the nitrogen oxide detection device according to the second preset time interval; if not, determine the reducing agent flow rate matching the first concentration currently obtained, and determine the carrier gas flow rate of the carrier gas required to be input into the regenerative chamber based on the determined reducing agent flow rate; send a second control instruction adjusted to the determined reducing agent flow rate to the reducing agent delivery valve, and send a third control instruction adjusted to the determined carrier gas flow rate to the carrier gas delivery valve;

[0203] The reducing agent delivery valve is configured to adjust the valve opening according to the received second control instruction;

[0204] The carrier gas delivery valve is configured to adjust the valve opening according to the received third control instruction.

[0205] Optionally, a flue gas input pipeline of an SCR reactor is connected at the first position of the flue main, and a flue gas output pipeline of the SCR reactor is connected at the second position of the flue main, and an SCR valve is arranged at the connection between the flue main and the flue gas input pipeline; the system further comprises the SCR valve;

[0206] The master control device 620 is further configured to send an opening instruction to the SCR valve if the second concentration of nitrogen oxides at the second end of the flue main is collected continuously according to the third preset time interval and the number of times that the second concentration exceeds the preset concentration threshold reaches a specified number of times;

[0207] The SCR valve is configured to open the valve according to the received opening instruction.

[0208] Optionally, the system further comprises an ammonia escape monitoring device;

[0209] The ammonia escape monitoring device is configured to collect the amount of ammonia escape at the second end of the flue main pipe;

[0210] The master control device 620 is further configured to acquire the amount of ammonia escape collected by the ammonia escape monitoring device according to a fourth preset time interval, acquire the valve opening degree of the reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve if the current acquired amount of ammonia escape exceeds a preset ammonia escape threshold, calculate the ratio of the current reducing agent flow rate to the current carrier gas flow rate according to the acquired valve opening degree of the reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve, and send a fifth control instruction to the carrier gas delivery valve if the calculated ratio is not within a preset interval; the ratio is within the preset interval, and the reducing agent and the carrier gas can reach a preset atomization state; and the carrier gas delivery valve is configured to adjust the valve opening degree according to the received fifth control instruction, so that the ratio of the adjusted reducing agent flow rate to the carrier gas flow rate is within the preset interval.

[0211] and / or,

[0212] The master control device 620 is further configured to acquire the top temperature of the regenerator if the current acquired amount of ammonia escape exceeds the preset ammonia escape threshold, and send a first control instruction to the reflux device if the current acquired top temperature exceeds a first preset threshold; the reflux device is configured to increase the valve opening degree of the reflux valve according to the received first control instruction when the reflux valve is included, and / or increase the frequency of the induced draft fan according to the received first control instruction when the induced draft fan is included.

[0213] Optionally, the master control device 620 is further configured to input the currently collected working condition parameters and a preset number of groups of historically collected working condition parameters into a prediction model to obtain a target temperature and a target ammonia-nitrogen ratio; each group of working condition parameters includes the top temperature of the regenerator, the first concentration of nitrogen oxides in the specified flue, the valve opening degree of the reducing agent delivery valve, the valve opening degree of the carrier gas delivery valve, and a first parameter including the valve opening degree of the reflux valve and / or the frequency of the induced draft fan; the valve opening degree of the reflux valve and / or the frequency of the induced draft fan is adjusted according to the target temperature, and the valve opening degree of the reducing agent delivery valve and the valve opening degree of the carrier gas delivery valve is adjusted according to the target ammonia-nitrogen ratio.

[0214] It can be understood that the specific functions of each device involved in the system embodiment can be referred to the related description of the above method embodiment, which will not be described here. For example, the above each control instruction can carry a target value to be adjusted to, and each device adjusts according to the target value carried in the received control instruction.

[0215] The embodiment of the present application also provides an electronic device, such as Figure 7 As shown in the figure, the electronic device comprises a processor 701, a communication interface 702, a memory 703 and a communication bus 704, wherein the processor 701, the communication interface 702 and the memory 703 complete mutual communication through the communication bus 704.

[0216] The memory 703 is used for storing a computer program.

[0217] The processor 701 is used for executing the program stored in the memory 703, and realizes the steps of the coke oven flue gas denitration method.

[0218] The communication bus mentioned in the above electronic device can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or only one type of bus.

[0219] The communication interface is used for communication between the above electronic device and other devices.

[0220] The memory can comprise a random access memory (RAM) and can also comprise a non-volatile memory (NVM), for example at least one disk memory. Optionally, the memory can also be at least one storage device located away from the aforementioned processor.

[0221] The processor mentioned above can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component.

[0222] In yet another embodiment provided by the present application, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program. The computer program is executed by a processor to implement the steps of any of the above coke oven flue gas denitration methods.

[0223] In yet another embodiment provided by the present application, a computer program product containing instructions, which when executed on a computer, causes the computer to perform any of the above coke oven flue gas denitration methods.

[0224] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium, or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transferred from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (for example, floppy disk, hard disk, magnetic tape), optical media (for example, DVD), or semiconductor media (for example, Solid State Disk (SSD)) and the like.

[0225] It should be noted that, in this document, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0226] The various embodiments in the specification are described in a related manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments. In particular, for system, electronic device and computer readable storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiment.

[0227] The above only describes the preferred embodiments of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for denitrifying coke oven flue gas, characterized in that, The method includes: The top temperature of the regenerator in the coke oven is obtained according to a first preset time interval; wherein, the coke oven flue gas undergoes selective non-catalytic reduction (SNCR) denitrification treatment in the regenerator; the regenerator is connected to a first end of a main flue pipe for discharging flue gas, and a return pipe for returning flue gas is connected to the main flue pipe, the other end of the return pipe being connected to the regenerator; a return valve is provided at the connection between the main flue pipe and the return pipe, and an induced draft fan is installed in the return pipe, and the induced draft fan is used to draw flue gas into the regenerator; If the current top temperature exceeds the first temperature threshold, then increase the valve opening of the reflux valve and / or the frequency of the induced draft fan. If the currently obtained top temperature is lower than the second temperature threshold, then reduce the valve opening of the reflux valve and / or the frequency of the induced draft fan.

2. The method according to claim 1, characterized in that, The heat storage chamber is provided with multiple SNCR reaction zones, each SNCR reaction zone is connected to a branch flue for exhausting flue gas, and each branch flue is connected to the first end of the main flue pipe; the method further includes: The first concentration is obtained based on the concentration of nitrogen oxides in a designated flue gas duct obtained at a second preset time interval; Determine whether the current flow rate of the reducing agent input into the heat storage chamber matches the currently obtained first concentration; If there is no match, determine the reducing agent flow rate that matches the currently obtained first concentration, and determine the carrier gas flow rate that needs to be input into the heat storage chamber based on the determined reducing agent flow rate. The valve opening of the current reducing agent delivery valve is adjusted according to the determined reducing agent flow rate, and the valve opening of the current carrier gas delivery valve is adjusted according to the determined carrier gas flow rate.

3. The method according to claim 1, characterized in that, The flue gas inlet pipe of the SCR reactor is connected to the first position of the main flue pipe, and the flue gas outlet pipe of the SCR reactor is connected to the second position of the main flue pipe. An SCR valve is provided at the connection between the main flue pipe and the flue gas inlet pipe. The method further includes: If, according to the third preset time interval, the number of times the second concentration of nitrogen oxides at the second end of the flue gas duct exceeds the preset concentration threshold is collected reaches a specified number of times, then the SCR valve is opened.

4. The method according to claim 2, characterized in that, The method further includes: The ammonia escape amount at the second end of the flue main is obtained according to the fourth preset time interval; If the currently acquired ammonia slip exceeds a preset ammonia slip threshold, then the current valve opening of the reducing agent delivery valve and the valve opening of the carrier gas delivery valve are acquired; based on the acquired valve openings of the reducing agent delivery valve and the carrier gas delivery valve, the ratio of the current reducing agent flow rate to the current carrier gas flow rate is calculated; if the calculated ratio is not within a preset range, the valve opening of the carrier gas delivery valve is adjusted so that the adjusted ratio of the reducing agent flow rate to the carrier gas flow rate is within the preset range; wherein, when the ratio is within the preset range, the reducing agent and the carrier gas can reach a preset atomization state; And / or, If the currently acquired ammonia escape amount exceeds the preset ammonia escape threshold, then the top temperature of the heat storage chamber is acquired; if the currently acquired top temperature exceeds the first preset threshold, then the valve opening of the reflux valve and / or the frequency of the induced draft fan are increased.

5. The method according to claim 2, characterized in that, The method further includes: The currently collected operating parameters and a preset number of historically collected operating parameters are input into the prediction model to obtain the target temperature and the target ammonia-nitrogen ratio. Each set of operating parameters includes the top temperature of the heat storage chamber, a first concentration based on the concentration of nitrogen oxides in the designated flue, the valve opening of the reducing agent delivery valve, the valve opening of the carrier gas delivery valve, and a first parameter, which includes the valve opening of the return valve and / or the frequency of the induced draft fan. The valve opening of the reflux valve and / or the frequency of the induced draft fan are adjusted according to the target temperature, and the valve opening of the reducing agent delivery valve and the carrier gas delivery valve are adjusted according to the target ammonia-nitrogen ratio.

6. A denitrification system for coke oven flue gas, characterized in that, It includes a main control device, a temperature acquisition device, and a reflux device, wherein the reflux device includes a reflux valve and / or an induced draft fan; The temperature acquisition device is used to acquire the top temperature of the regenerator in the coke oven; wherein, the coke oven flue gas undergoes selective non-catalytic reduction (SNCR) denitrification treatment in the regenerator; the regenerator is connected to a first end of a main flue pipe for discharging flue gas, and a return pipe for returning flue gas is connected to the main flue pipe, the other end of the return pipe being connected to the regenerator; a return valve is installed at the connection between the main flue pipe and the return pipe, and an induced draft fan is installed in the return pipe, and the induced draft fan is used to draw flue gas into the regenerator; The main control device is used to acquire the top temperature collected by the temperature acquisition device at a first preset time interval; if the currently acquired top temperature exceeds a first temperature threshold, a first control command is sent to the return flow device; if the currently acquired top temperature is lower than a second temperature threshold, a second control command is sent to the return flow device. The reflux device is configured to, when including the reflux valve, increase the valve opening of the reflux valve if a first control command is received, and decrease the valve opening of the reflux valve if a second control command is received; and / or, when including the induced draft fan, increase the frequency of the induced draft fan if a first control command is received, and decrease the frequency of the induced draft fan if a second control command is received.

7. The system according to claim 6, characterized in that, The heat storage chamber is equipped with multiple SNCR reaction zones, each of which is connected to a branch flue for emitting flue gas. Each branch flue is connected to the first end of the main flue. The system also includes nitrogen oxide detection equipment, reducing agent delivery valve, and carrier gas delivery valve. The nitrogen oxide detection device is used to collect the concentration of nitrogen oxides in a designated flue gas duct; The main control device is also used to determine whether the reducing agent flow rate of the reducing agent currently input into the heat storage chamber matches the currently obtained first concentration, based on the concentration collected by the nitrogen oxide detection device at a second preset time interval; If there is a mismatch, a reducing agent flow rate that matches the currently obtained first concentration is determined, and a carrier gas flow rate that needs to be input into the heat storage chamber is determined based on the determined reducing agent flow rate; a second control command to adjust the determined reducing agent flow rate is sent to the reducing agent delivery valve, and a third control command to adjust the determined carrier gas flow rate is sent to the carrier gas delivery valve. The reducing agent delivery valve is used to adjust the valve opening according to the received second control command; The carrier gas delivery valve is used to adjust the valve opening according to the received third control command.

8. The system according to claim 6, characterized in that, The flue gas inlet pipe of the SCR reactor is connected to the first position of the main flue pipe, and the flue gas outlet pipe of the SCR reactor is connected to the second position of the main flue pipe. An SCR valve is provided at the connection between the main flue pipe and the flue gas inlet pipe; the system also includes the SCR valve. The main control device is also used to issue an opening command to the SCR valve if the number of times the second concentration of nitrogen oxides at the second end of the flue main exceeds the preset concentration threshold is collected continuously at a specified number of times according to the third preset time interval. The SCR valve is used to open the valve according to the received opening command.

9. The system according to claim 6, characterized in that, The system also includes ammonia escape monitoring equipment; The ammonia escape monitoring device is used to collect the amount of ammonia escape at the second end of the flue gas duct. The main control device is further configured to acquire the ammonia escape amount collected by the ammonia escape monitoring device according to a fourth preset time interval; if the currently acquired ammonia escape amount exceeds a preset ammonia escape threshold, then acquire the current valve opening of the reducing agent delivery valve and the valve opening of the carrier gas delivery valve; calculate the ratio of the current reducing agent flow rate to the current carrier gas flow rate based on the acquired valve openings of the reducing agent delivery valve and the carrier gas delivery valve; if the calculated ratio is not within a preset range, then send a fifth control command to the carrier gas delivery valve; wherein, when the ratio is within the preset range, the reducing agent and the carrier gas can reach a preset atomization state; the carrier gas delivery valve is configured to adjust the valve opening according to the received fifth control command, so that the adjusted ratio of the reducing agent flow rate to the carrier gas flow rate is within the preset range; And / or, The main control device is further configured to acquire the top temperature of the heat storage chamber if the currently acquired ammonia escape amount exceeds a preset ammonia escape threshold; and to send a first control command to the reflux device if the currently acquired top temperature exceeds a first preset threshold. The reflux device is configured to increase the valve opening of the reflux valve according to the received first control command when the reflux valve is included, and / or to increase the frequency of the induced draft fan according to the received first control command when the induced draft fan is included.

10. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the steps of the method described in any one of claims 1-5.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method described in any one of claims 1-5.

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