Heating furnace combustion control method and system, medium and computer equipment

Abstract

The invention discloses a combustion control method and system for a heating furnace, a medium and computer equipment, and aims to create reaction conditions for SNCR (selective non-catalytic reduction) denitration by reducing furnace temperature set values of a preheating section and a first heating section, accurately controlling matching of the furnace temperature and a denitration reaction temperature window and reducing interference factors such as oxygen concentration and the like. And the regulation mode of'set period + fixed amplitude 'is adopted to avoid combustion condition disorder, closed-loop dynamic control is realized, the combustion atmosphere in the furnace can be accurately controlled, and the generation amount of nitrogen oxide is reduced from the source, so that the SNCR denitration efficiency is improved, and stable operation of the system is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgy, and in particular to a heating furnace combustion control method, system, medium and computer device. BACKGROUND

[0002] In the metallurgical industry, the heating furnace is the first process of the hot rolling production line, and the high-temperature combustion of the heating furnace generates nitrogen oxides. In order to reduce the content of nitrogen oxides in the heating furnace, the current heating furnace mainly introduces SNCR or SCR denitration process to meet the index requirements.

[0003] It is known that the SNCR denitration process requires a reaction temperature of 850-1050 DEG C, and too much oxygen and carbon monoxide in the reaction area will affect the denitration effect. However, the nitrogen oxide control technology and the combustion control technology in the heating furnace are controlled by two independent control systems, and the combustion control technology is not associated with the concentration of nitrogen oxides. Therefore, the current technical problem is that the combustion atmosphere in the furnace cannot be accurately controlled to reduce the generation of nitrogen oxides. SUMMARY

[0004] In order to solve or partially solve the technical problem that the combustion atmosphere in the furnace cannot be accurately controlled to reduce the generation of nitrogen oxides, the present application provides a heating furnace combustion control method, system, medium and computer device to improve the denitration efficiency of the SNCR denitration process.

[0005] To solve the above technical problems, the first aspect of the present application discloses a heating furnace combustion control method, the method comprising: detecting the concentration of nitrogen oxides in the flue gas; if the concentration of nitrogen oxides is greater than a first concentration threshold, and the opening degree of the coal gas regulating valve of the preheating section is greater than a first set opening threshold, gradually reducing the opening degree of the coal gas regulating valve according to a control logic of reducing a fixed opening degree every set period until the opening degree of the coal gas regulating valve is below the first set opening threshold; if the concentration of nitrogen oxides is greater than the first concentration threshold, and the first furnace temperature set value of the preheating section is higher than a reference temperature, gradually reducing the first furnace temperature set value according to a control logic of reducing a fixed temperature every set period until the first furnace temperature set value is within the reference temperature; if the concentration of nitrogen oxides is greater than the first concentration threshold, calculating a target furnace temperature reduction range of the first heating section, and controlling the second furnace temperature set value of the first heating section to be gradually reduced according to a control logic of reducing a fixed temperature proportion every set period until the reduction range of the second furnace temperature set value reaches the target furnace temperature reduction range; If the nitrogen oxide concentration is greater than a first concentration threshold, a target air-fuel ratio reduction amount is calculated, and a control logic that reduces the actual air-fuel ratio by a fixed air-fuel ratio ratio per set period is controlled to gradually reduce the actual air-fuel ratio until the reduction amount of the actual air-fuel ratio reaches the target air-fuel ratio reduction amount.

[0006] Optionally, the method further comprises: if the nitrogen oxide concentration is less than a second concentration threshold, restoring the original control logic.

[0007] Optionally, in the original control logic, the gas flow regulating valve is controlled to follow a gas flow set value.

[0008] Optionally, the gas flow set value is determined according to the following steps: detecting an air regulating valve opening degree; if the air regulating valve opening degree is less than a second set opening degree, adjusting the gas flow set value by using a furnace temperature control model; if the air regulating valve opening degree is greater than or equal to the second set opening degree, obtaining an actual air flow value, and calculating the gas flow set value according to a formula ; wherein, L denotes the gas flow set value, denotes the actual air flow value, K denotes the actual air-fuel ratio, A denotes an air excess coefficient.

[0009] Optionally, an upper limit value of the gas flow set value is set with reference to a rated output flow of a burner in a heating section.

[0010] Optionally, the target furnace temperature reduction amount of the first heating section is calculated according to a first proportion of a second furnace temperature set value.

[0011] Optionally, the target air-fuel ratio reduction amount is calculated according to a second proportion of the actual air-fuel ratio.

[0012] In a second aspect of the present application, a heating furnace combustion control system is disclosed, which comprises: a detection module configured to detect a nitrogen oxide concentration in flue gas; a first adjusting module configured to, if the nitrogen oxide concentration is greater than a first concentration threshold and a gas regulating valve opening degree of a preheating section is greater than a first set opening degree threshold, gradually reduce the gas regulating valve opening degree according to a control logic that reduces a fixed opening degree per set period until the gas regulating valve opening degree is below the first set opening degree threshold. a second adjusting module, configured to gradually reduce the first furnace temperature setting value according to the control logic of reducing the fixed temperature by a fixed amount every setting period, until the first furnace temperature setting value is within the reference temperature, if the nitrogen oxide concentration is greater than the first concentration threshold value and the first furnace temperature setting value of the preheating section is higher than the reference temperature; a third adjusting module, configured to calculate a target furnace temperature reduction range of the one-stage section, and control the control logic of gradually reducing the second furnace temperature setting value of the one-stage section according to the control logic of reducing the fixed temperature by a fixed proportion every setting period, until the reduction range of the second furnace temperature setting value reaches the target furnace temperature reduction range, if the nitrogen oxide concentration is greater than the first concentration threshold value. a fourth adjusting module, configured to calculate a target air-fuel ratio reduction range, and control the control logic of gradually reducing the actual air-fuel ratio according to the control logic of reducing the fixed air-fuel ratio by a fixed proportion every setting period, until the reduction range of the actual air-fuel ratio reaches the target air-fuel ratio reduction range, if the nitrogen oxide concentration is greater than the first concentration threshold value.

[0013] In a third aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the above method.

[0014] In a fourth aspect, the present application provides a computer device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the above method when executing the program.

[0015] The present application has the following advantages and benefits: The technical solution in the present application precisely adjusts the key factors of combustion from multiple dimensions: by reducing the preheating section and the one-stage section furnace temperature setting value, precisely controlling the matching of the furnace temperature and the denitration reaction temperature window, reducing the oxygen concentration and other interference factors, creating reaction conditions for SNCR denitration, and adopting the adjustment mode of "setting period + fixed amplitude / proportion" to avoid the disorder of combustion conditions, realizing closed-loop dynamic control, precisely controlling the combustion atmosphere in the furnace, reducing the generation of nitrogen oxides from the source, thereby improving the SNCR denitration efficiency and ensuring the stable operation of the system.

[0016] The above description is only a summary of the technical solutions of the present application, in order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0017] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments with reference made to the accompanying drawings. The drawings are for purposes of illustration only and are not intended to limit the present application thereto, as the present application can have application in forms other than those illustrated and described. Moreover, throughout the drawings, like reference numerals will be used to refer to like components. In the drawings: Figure 1 A flow chart of a heating furnace combustion control method according to an embodiment of the present application is shown; Figure 2 A schematic diagram of a heating furnace combustion control system according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0018] Exemplary embodiments of the present application will be described herein below with reference to the accompanying drawings. While exemplary embodiments of the present application are illustrated, it is to be understood that the present application is not limited to the embodiments described herein, but can be practiced with variation within the spirit and scope of the present application, as will be appreciated by those skilled in the art. Rather, the embodiments are presented as examples to more fully and completely convey the scope of the present application to those skilled in the art.

[0019] Exemplary embodiments of the present application will be described herein below with reference to the accompanying drawings. While exemplary embodiments of the present application are illustrated, it is to be understood that the present application is not limited to the embodiments described herein, but can be practiced with variation within the spirit and scope of the present application, as will be appreciated by those skilled in the art. Rather, the embodiments are presented as examples to more fully and completely convey the scope of the present application to those skilled in the art.

[0020] In a first aspect, embodiments of the present application provide a heating furnace combustion control method.

[0021] The heating furnace will be described first below.

[0022] The combustion system of the heating furnace is divided into a heat recovery section, a preheating section, a first heating section, a second heating section, and a soaking section. Except for the heat recovery section, the other heating sections are provided with a burner, and air flow and gas flow adjusting valves are provided to adjust the heat load supplied to the burner. The reactor of the SNCR denitration system is provided in the heat recovery section, and ammonia water is injected into the heat recovery section to reduce the nitrogen oxides generated by combustion.

[0023] In the present application, the concentration of nitrogen oxides in the flue gas needs to be controlled to be less than 50 , the SNCR denitration system controls the concentration of nitrogen oxides in the flue gas by controlling the flow of injected ammonia water. The required temperature range for the SNCR denitration reaction is 850-1050℃, and if the temperature is too high, the reducing agent is oxidized into NOx, and the content of NOx in the flue gas does not decrease but increases. In addition, the oxygen content also affects the reduction effect of nitrogen oxides, and a low oxygen content is beneficial to the denitration effect. Too much carbon monoxide content is also not conducive to the denitration effect. The high temperature of the heating furnace also sharply increases the generation of nitrogen oxides.

[0024] Based on the above reasons, the combustion control technology of the heating furnace is closely related to the denitration efficiency of the SNCR denitration system, and therefore, the present application is designed to optimize the combustion control technology to improve the denitration efficiency. When the actual operation process is in the state that the concentration of nitrogen oxides is higher than 50 , the combustion control strategy designed by the present application can be implemented.

[0025] As Figure 1 shown, the heating furnace combustion control method provided by the embodiment of the present application comprises the following steps: S101, detecting the concentration of nitrogen oxides in the flue gas.

[0026] Among them, the concentration of nitrogen oxides in the flue gas is detected by using a nitrogen oxide detection instrument arranged on the chimney of the heating furnace.

[0027] S102, if the concentration of nitrogen oxides is greater than a first concentration threshold, and the opening degree of the coal gas regulating valve of the preheating section is greater than a first set opening degree threshold, gradually reduce the opening degree of the coal gas regulating valve according to the control logic of reducing a fixed opening degree every set period, until the opening degree of the coal gas regulating valve is below the first set opening degree threshold.

[0028] Specifically, the first concentration threshold is set to 50 , and the opening degree of the coal gas regulating valve of the preheating section is usually detected by using a valve position feedback device.

[0029] If the concentration of nitrogen oxides is greater than 50 , and the opening degree of the coal gas regulating valve of the preheating section is greater than 15% of the first set opening degree threshold, the opening degree of the coal gas regulating valve needs to be reduced to reduce the excess input of fuel. For example, the opening degree of the coal gas regulating valve is controlled to be reduced according to the control logic of “reducing 5% of the opening degree every 20 seconds”, until the opening degree of the coal gas regulating valve is reduced to 15%.

[0030] S103, if the concentration of nitrogen oxides is greater than the first concentration threshold, and the first furnace temperature set value of the preheating section is higher than the reference temperature, gradually reduce the first furnace temperature set value according to the control logic of reducing a fixed temperature every set period, until the first furnace temperature set value is within the reference temperature.

[0031] Specifically, if the concentration of nitrogen oxides is greater than the first concentration threshold, and the operation of spraying ammonia water (for example, spraying ammonia water in the maximum amount) cannot reduce the concentration of nitrogen oxides, and the furnace temperature is relatively high, for example, the furnace temperature is higher than the set denitration reaction temperature zone, the operation of reducing the furnace temperature can be taken.

[0032] The reference temperature can ensure that the flue gas entering the denitration reaction temperature zone is in the optimal temperature range, for example, 950-1000°C. Therefore, the reference temperature can be set to 1040°C, and if the first furnace temperature set value is higher than 1040°C, the first furnace temperature set value is reduced. In the reduction strategy, the first furnace temperature set value is controlled according to the control logic of “reducing 7°C every 20 seconds” until the first furnace temperature set value is reduced to 1040°C or below, so that the subsequent denitration reaction temperature zone is kept in the optimal temperature range.

[0033] By jointly controlling the opening degree and temperature of the preheating section gas regulating valve, the preheating section can be quickly cooled, so as to accurately control the matching of the furnace temperature and the denitration reaction temperature window.

[0034] In S104, if the concentration of nitrogen oxides is greater than the first concentration threshold, a target furnace temperature reduction amplitude of the first stage is calculated, and the second furnace temperature set value of the first stage is gradually reduced according to the control logic of reducing a fixed temperature proportion every set period until the reduction amplitude of the second furnace temperature set value reaches the target furnace temperature reduction amplitude.

[0035] If the concentration of nitrogen oxides is greater than the first concentration threshold, the target furnace temperature reduction amplitude is calculated according to the first proportion of the second furnace temperature set value. For example, the target furnace temperature reduction amplitude is determined according to the proportion of ΔT2 = T2*4%, where ΔT2 represents the target furnace temperature reduction amplitude, and T2 represents the second furnace temperature set value.

[0036] In order to make the denitration reaction temperature zone reach the optimal temperature range, the second furnace temperature set value needs to be gradually reduced. In the process of reducing the temperature, the second furnace temperature set value T2 is gradually reduced according to the control logic of “reducing 0.5%*T2 every 20 seconds” until the reduction amplitude of the second furnace temperature set value T2 reaches the target furnace temperature reduction amplitude of T2*4%. Similarly, the second furnace temperature set value T2 is gradually reduced according to the control logic of “reducing 0.5%*T2 every 20 seconds” until the second furnace temperature set value T2 is reduced to T2-ΔT2, where ΔT2 = T2*4%.

[0037] It is known that the furnace temperature of the first stage is usually higher than the preset furnace temperature of the first stage. Considering that too low a temperature drop will affect the production rhythm, the furnace temperature of the first stage only needs to be slowly reduced and maintained stable. For example, the second furnace temperature set value of the first stage is 1100℃, and according to the above logic, the temperature drop amplitude of the first stage is 5.5° per 20 seconds. By adopting the control strategy of "controlling by period and amplitude", the second furnace temperature set value of the first stage is slowly reduced, so that the furnace temperature of the first stage slightly decreases.

[0038] In S105, if the nitrogen oxide concentration is greater than the first concentration threshold value, a target air-fuel ratio reduction amplitude is calculated, and the actual air-fuel ratio is gradually reduced according to the control logic of reducing the fixed air-fuel ratio proportion every set period until the reduction amplitude of the actual air-fuel ratio reaches the target air-fuel ratio reduction amplitude.

[0039] If the nitrogen oxide concentration is greater than the first concentration threshold value, the target air-fuel ratio reduction amplitude is calculated according to the second proportion of the actual air-fuel ratio. For example, the target air-fuel ratio reduction amplitude is determined according to the proportion of ΔK=K*8%; wherein ΔK represents the target air-fuel ratio reduction amplitude, and K represents the actual air-fuel ratio.

[0040] In this embodiment, the air-fuel ratio refers to the ratio of air flow to fuel flow when the fuel is burned. If the air-fuel ratio is large, it will cause the furnace temperature to rise rapidly and intensify the generation of NOx, so it is necessary to reduce the air-fuel ratio of the whole furnace to create an oxygen-deficient environment to inhibit the generation of NOx. In the process of reducing the air-fuel ratio, the actual air-fuel ratio is gradually reduced according to the control logic of "reducing K*1% every 20 seconds" until the reduction amplitude of the actual air-fuel ratio reaches the target air-fuel ratio reduction amplitude of K*8%. Similarly, the actual air-fuel ratio is gradually reduced according to the control logic of "reducing K*1% every 20 seconds" until the actual air-fuel ratio is reduced to K-ΔK, wherein ΔK=K*8%.

[0041] The above is a linkage control measure generated in the heating furnace. If the nitrogen oxide concentration is less than the second concentration threshold value, the original control logic is restored. The second concentration threshold value is less than the first concentration threshold value.

[0042] In the original control logic, the control gas flow regulating valve is adjusted according to the control gas flow set value.

[0043] Specifically, the control gas flow set value is determined according to the following steps: Detecting the air regulating valve opening; If the air regulating valve opening is less than the second set opening, the control gas flow set value is adjusted by using the furnace temperature control model. For example, when the air regulating valve opening is less than 80%, the control gas flow set value is adjusted by using the furnace temperature control model.

[0044] If the air regulating valve opening is greater than or equal to the second set opening, an actual air flow value is obtained, and the gas flow set value is calculated according to the formula , wherein, L represents the gas flow set value, represents the actual air flow value, K represents the actual air-fuel ratio, A represents the air excess coefficient. For example, when the air regulating valve opening is greater than or equal to 80%, the gas flow set value is calculated according to the formula.

[0045] In the control of the gas flow regulating valve, the gas flow set value and the actual gas flow detection value are compared by the PID controller, the deviation is calculated, and the control signal is output to the regulating valve actuator for closed-loop regulation.

[0046] In an optional embodiment, the upper limit value of the gas flow set value is set with reference to the rated output flow of the burner in the heating section. For example, the upper limit value of the gas flow set value is set at 1.05xQ to prevent the burner from overloading; wherein Q is the rated output flow capacity of all burners. This operation can not only avoid the overloading of the burner to increase the generation of nitrogen oxides, but also avoid the detection distortion caused by the gas flow value exceeding the upper limit of the gas flow meter.

[0047] In the original control logic, a two-stage furnace temperature calculation model is used to determine the furnace temperature set value. Specifically, the furnace temperature set value is determined by minimizing NOx emissions and energy consumption as the optimization target with reference to the process requirements of the slab in the furnace, the temperature feedback of the thermocouple, the heat load distribution, the slab weight, and other information. Further, in the original control logic, the air-fuel ratio is calculated according to the gas calorific value. For example, the gas calorific value is detected in real time by an online gas calorific value analyzer, or the gas calorific value is calculated according to the gas composition, and then the air-fuel ratio is calculated using the gas calorific value.

[0048] In the present technical solution, the key factors of combustion are precisely adjusted in a step-by-step manner from multiple dimensions: by reducing the preheating section and the first stage furnace temperature set value, the furnace temperature is precisely controlled to match the denitration reaction temperature window, the oxygen concentration and other interference factors are reduced, the reaction conditions are created for SNCR denitration, and the "set period + fixed amplitude / ratio" adjustment method is used to avoid combustion condition disorder, realize closed-loop dynamic control, and precisely control the combustion atmosphere in the furnace, thereby reducing the generation of nitrogen oxides from the source, improving the SNCR denitration efficiency, and ensuring stable operation of the system.

[0049] In a second aspect, based on the same inventive concept as the heating furnace combustion control method provided in the foregoing first aspect embodiment, the present embodiment also provides a heating furnace combustion control system. Referring to Figure 2 , the system comprises: The detection module 201 is configured to detect the concentration of nitrogen oxides in flue gas. The first adjustment module 202 is configured to gradually reduce the opening of the gas adjustment valve of the preheating section according to a control logic of reducing a fixed opening every setting period until the opening of the gas adjustment valve is below the first setting opening threshold, if the concentration of nitrogen oxides is greater than the first concentration threshold and the opening of the gas adjustment valve of the preheating section is greater than the first setting opening threshold. The second adjustment module 203 is configured to gradually reduce the first furnace temperature setting value of the preheating section according to a control logic of reducing a fixed temperature every setting period until the first furnace temperature setting value is within the reference temperature, if the concentration of nitrogen oxides is greater than the first concentration threshold and the first furnace temperature setting value of the preheating section is higher than the reference temperature. The third adjustment module 204 is configured to calculate a target furnace temperature reduction range of a first heating section and control a control logic of reducing a fixed temperature ratio every setting period until the second furnace temperature setting value of the first heating section reaches the target furnace temperature reduction range. The fourth adjustment module 205 is configured to calculate a target air-fuel ratio reduction range and control a control logic of reducing a fixed air-fuel ratio ratio every setting period until the actual air-fuel ratio reaches the target air-fuel ratio reduction range.

[0050] It should be noted that the specific manner in which each module performs the operation in the heating furnace combustion control system provided by the embodiments of the present application has been described in detail in the method embodiments provided in the first aspect above, and the specific implementation process can be referred to the method embodiments provided in the first aspect above, which will not be described in detail here.

[0051] In a third aspect, based on the same inventive concept as the heating furnace combustion control method provided in the first aspect above, the embodiments of the present application further disclose a computer readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0052] In a fourth aspect, based on the same inventive concept as the heating furnace combustion control method provided in the first aspect above, the embodiments of the present application further disclose a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of any of the methods described above when executing the program.

[0053] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the present application.

[0054] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the application can be practiced otherwise than as specifically described herein.

Claims

1. A method of combustion control for a heating furnace, characterized by, The method comprises: detecting the concentration of nitrogen oxides in flue gas; if the concentration of nitrogen oxides is greater than a first concentration threshold value and the opening degree of a gas regulating valve of a preheating section is greater than a first set opening degree threshold value, gradually reducing the opening degree of the gas regulating valve according to control logic of reducing a fixed opening degree every set period until the opening degree of the gas regulating valve is below the first set opening degree threshold value; if the concentration of nitrogen oxides is greater than the first concentration threshold value and a first furnace temperature set value of the preheating section is higher than a reference temperature, gradually reducing the first furnace temperature set value according to control logic of reducing a fixed temperature every set period until the first furnace temperature set value is within the reference temperature; if the concentration of nitrogen oxides is greater than the first concentration threshold value, calculating a target furnace temperature reduction range of a first heating section and controlling gradual reduction of a second furnace temperature set value of the first heating section according to control logic of reducing a fixed temperature proportion every set period until the reduction range of the second furnace temperature set value reaches the target furnace temperature reduction range; if the concentration of nitrogen oxides is greater than the first concentration threshold value, calculating a target air-fuel ratio reduction range and controlling gradual reduction of an actual air-fuel ratio according to control logic of reducing a fixed air-fuel ratio proportion every set period until the reduction range of the actual air-fuel ratio reaches the target air-fuel ratio reduction range.

2. The method of claim 1, wherein, The method further comprises: if the concentration of nitrogen oxides is less than a second concentration threshold value, restoring original control logic.

3. The method of claim 2, wherein, In the original control logic, a gas flow regulating valve is controlled to follow a gas flow set value.

4. The method of claim 3, wherein, The gas flow set value is determined according to the following steps: detecting the opening degree of an air regulating valve; if the opening degree of the air regulating valve is less than a second set opening degree, adjusting the gas flow set value by using a furnace temperature control model; If the air regulating valve opening is greater than or equal to the second set opening, an actual air flow value is obtained, and the coal gas flow set value is calculated according to the formula wherein, L represents the coal gas flow set value, represents the actual air flow value, K represents the actual air-fuel ratio, A represents the air excess coefficient.

5. The method of claim 4, wherein, the upper limit value of the gas flow set value is set by referring to the rated output flow of a burner in the heating section.

6. The method of claim 1, wherein, The calculation of the target furnace temperature reduction range of the first heating section specifically comprises: calculating the target furnace temperature reduction range according to a first proportion of the second furnace temperature set value.

7. The method of claim 1, wherein, The calculation of the target air-fuel ratio reduction range specifically comprises: calculating the target air-fuel ratio reduction range according to a second proportion of the actual air-fuel ratio.

8. A furnace combustion control system characterized by, The system comprises: a detection module configured to detect the concentration of nitrogen oxides in flue gas; a first adjusting module configured to, if the concentration of nitrogen oxides is greater than a first concentration threshold value and the opening degree of a gas regulating valve of a preheating section is greater than a first set opening degree threshold value, gradually reduce the opening degree of the gas regulating valve according to control logic of reducing a fixed opening degree every set period until the opening degree of the gas regulating valve is below the first set opening degree threshold value; a second adjusting module configured to, if the concentration of nitrogen oxides is greater than the first concentration threshold value and a first furnace temperature set value of the preheating section is higher than a reference temperature, gradually reduce the first furnace temperature set value according to control logic of reducing a fixed temperature every set period until the first furnace temperature set value is within the reference temperature; a third adjusting module configured to, if the concentration of nitrogen oxides is greater than the first concentration threshold value, calculate a target furnace temperature reduction range of a first heating section and control gradual reduction of a second furnace temperature set value of the first heating section according to control logic of reducing a fixed temperature proportion every set period until the reduction range of the second furnace temperature set value reaches the target furnace temperature reduction range; and a fourth adjusting module configured to, if the concentration of nitrogen oxides is greater than the first concentration threshold value, calculate a target air-fuel ratio reduction range and control gradual reduction of an actual air-fuel ratio according to control logic of reducing a fixed air-fuel ratio proportion every set period until the reduction range of the actual air-fuel ratio reaches the target air-fuel ratio reduction range. a third adjusting module, configured to calculate a target furnace temperature reduction range of the first stage if the nitrogen oxide concentration is greater than the first concentration threshold, and control a control logic of reducing the second furnace temperature setting value of the first stage by a fixed temperature proportion in each setting period until the reduction range of the second furnace temperature setting value reaches the target furnace temperature reduction range; a fourth adjusting module, configured to calculate a target air-fuel ratio reduction range if the nitrogen oxide concentration is greater than the first concentration threshold, and control a control logic of reducing the actual air-fuel ratio by a fixed air-fuel ratio proportion in each setting period until the reduction range of the actual air-fuel ratio reaches the target air-fuel ratio reduction range.

9. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program, when executed by a processor, implements the steps of the method of any one of claims 1-7.

10. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor, when executing the program, implements the steps of the method of any one of claims 1-7.

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