NOx equilibrium concentration adjusting method, system, equipment, medium and product

Abstract

The invention belongs to the technical field of coal-fired boiler denitration, and discloses a NOx equilibrium concentration adjusting method, system and equipment, a medium and a product, and a function relationship among NOx concentration, CO concentration and H2S concentration at a hearth outlet is established. On the basis, by limiting the uniform distribution degree of CO and H2S concentration, the NOx concentration and the critical value of CO concentration and H2S concentration, the opening degree of an over fire air door and the range of the over fire air volume are calculated, the NOx equilibrium concentration is obtained, and the hearth efficiency and the denitration economical efficiency are both considered.

Description

Technical Field

[0001] The present invention belongs to the technical field of denitration of coal-fired boilers, and in particular relates to a NOx equilibrium concentration adjustment method, system, equipment, medium and product. Background Art

[0002] For units that have implemented ultra-low NOx emissions, most units have air preheater ABS blockage problems. The direct cause of air preheater ABS blockage is excessive ammonia slip from SCR. For some units whose SCR denitrification efficiency has reached the upper limit, in order to control ammonia slip, measures can only be taken to control the coal powder combustion in the furnace to reduce the NOx concentration in the flue gas at the SCR inlet and increase the SCR denitrification efficiency margin. After adopting low-nitrogen combustion technology, the oxygen content of boiler operation is generally reduced. Low-oxygen operation will increase the CO content and fly ash combustible content in the flue gas while reducing NOx generation. In addition to CO generation, low-nitrogen combustion also causes a series of problems such as burnout, water-cooled wall corrosion, slagging, low steam temperature, and excessive cooling water, which unbalances the performance indicators of the boiler and reduces the overall safety and economy of the boiler. Therefore, the NOx generation concentration should be controlled during boiler combustion. Excessive NOx concentration will increase the burden of SCR and affect the economy and safety of SCR. Excessive NOx concentration will cause a series of problems in the boiler combustion system. It is necessary to seek a balance point of NOx generation concentration between combustion and SCR.

[0003] The Chinese patent publication number is CN112797439A, and the name is a patent application for a combustion optimization method based on CO online monitoring. It discloses a combustion optimization method based on CO online monitoring, which includes obtaining the nitrogen oxide concentration at the inlet of the boiler denitration system, obtaining the furnace CO concentration based on multiple CO detection points in the boiler furnace, and controlling the boiler operating oxygen and burnout air volume based on the furnace CO concentration and the nitrogen oxide concentration. This patent application cannot solve the problem of boiler combustion system caused by too low NOx concentration. Summary of the invention

[0004] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a NOx equilibrium concentration adjustment method, system, equipment, medium and product, by establishing a functional relationship between the NOx concentration, CO concentration and H2S concentration at the furnace outlet. On this basis, by limiting the uniformity of CO and H2S concentrations, the critical values ​​of NOx concentration, CO concentration and H2S concentration, the opening of the burnout air damper and the range of the burnout air volume are calculated, and the NOx equilibrium concentration is obtained, taking into account both the furnace efficiency and the denitration economy.

[0005] To achieve the above object, the technical solution adopted by the present invention is: In a first aspect, the present invention provides a method for adjusting NOx equilibrium concentration, comprising the following steps: S1: Real-time detection of CO concentration and H2S concentration in the combustion area; S2: Establish functional relationships between the NOx concentration at the furnace outlet, the CO concentration in the boiler combustion zone, the H2S concentration and their respective influencing factors; wherein the influencing factors include the opening of the burnout air damper at the sampling point and the burnout air volume; S3: Calculate the relative standard deviation of CO concentration in different areas and H2S concentration in different areas, solve the burnout air damper opening according to the relationship between the relative standard deviation of concentration and the mean concentration, and bring the burnout air damper opening into the functional relationship in step S2; S4: Take the critical values ​​of high temperature corrosion and incomplete combustion of fuel for CO concentration and H2S concentration respectively, and take the maximum value as the first limit of overburn air; and take the minimum critical value of NOx concentration where the SCR denitrification device cannot control NOx emissions to meet environmental protection standards as the second limit of overburn air; S5: comparing the first overburnt wind limit value and the second overburnt wind limit value, when the first overburnt wind limit value is greater than or equal to the second overburnt wind limit value, controlling the overburnt wind volume according to the first overburnt wind limit value; when the first overburnt wind limit value is less than the second overburnt wind limit value, controlling the overburnt wind volume according to the second overburnt wind limit value.

[0006] Optionally, in step S1, the CO concentration and H2S concentration values ​​in the combustion area are obtained by installing online analysis meters for CO and H2S behind the sampling tube in the combustion area of ​​the boiler.

[0007] Optionally, in step S2, factors affecting the NOx concentration at the furnace outlet, the CO concentration and the H2S concentration in the boiler combustion zone also include unit load and coal feed rate.

[0008] Optionally, in step S2, principal component analysis or multivariate linear fitting method is used to establish functional relationships between the furnace outlet NOx concentration, boiler combustion zone CO concentration, H2S concentration and their respective influencing factors.

[0009] Optionally, in step S3, the calculation formula of the relative standard deviation of concentration is:

[0010] in, is the mean CO concentration, is the relative standard deviation of CO concentration in different regions, is the mean CO concentration, is the relative standard deviation of H2S concentration in different areas.

[0011] Optionally, in step S3, the minimum relative standard deviation of CO concentration in different regions and the minimum relative standard deviation of H2S concentration in different regions are solved, and then the average value of the two minimum values ​​is calculated as the burnout air damper opening.

[0012] In a second aspect, the present invention provides a NOx equilibrium concentration adjustment system, comprising: Data acquisition module, used to detect the CO concentration and H2S concentration values ​​in the combustion area in real time; A function establishment module is used to establish functional relationships between the NOx concentration at the furnace outlet, the CO concentration in the boiler combustion zone, the H2S concentration and their respective influencing factors; wherein the influencing factors include the burnout air damper opening at the sampling point and the burnout air volume; A calculation module is used to calculate the relative standard deviation of CO concentration in different areas and H2S concentration in different areas, solve the burnout air damper opening according to the relationship between the relative standard deviation of the concentration and the mean concentration, and bring the burnout air damper opening into the functional relationship in step S2; The experience value setting module is used to respectively take the critical values ​​of high temperature corrosion and incomplete combustion of fuel of CO concentration and H2S concentration, and take the maximum value as the first limit of burnout air; and take the minimum critical value of NOx concentration where the SCR denitrification device cannot control NOx emission to meet environmental protection standards as the second limit of burnout air; The comparison module is used to compare the first limit value of the overburned wind and the second limit value of the overburned wind. When the first limit value of the overburned wind is greater than or equal to the second limit value of the overburned wind, the overburned wind volume is controlled according to the first limit value of the overburned wind; when the first limit value of the overburned wind is less than the second limit value of the overburned wind, the overburned wind volume is controlled according to the second limit value of the overburned wind.

[0013] In a third aspect, the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the NOx equilibrium concentration adjustment method when executing the computer program.

[0014] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the NOx equilibrium concentration adjustment method is implemented.

[0015] In a fifth aspect, the present invention provides a computer program product including a computer-readable medium, wherein the computer-readable medium contains a computer-readable program code, and the program code executes the NOx equilibrium concentration adjustment method.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention detects the CO concentration and H2S concentration values ​​in the combustion zone of the boiler in real time, and establishes the functional relationship between the NOx concentration, CO concentration and H2S concentration at the furnace outlet through mathematical methods. On this basis, by limiting the uniform distribution of CO and H2S concentrations, the opening of the burnout air damper can be calculated. The range of the burnout air volume is further limited by the critical values ​​of NOx concentration, CO concentration and H2S concentration, and the NOx equilibrium concentration is obtained. Through the present invention, it is possible to achieve a reasonable opening of the burnout air damper, and no areas with locally high CO concentration and H2S concentration appear. At the same time, a reasonable burnout air volume is achieved, ensuring that the NOx concentration is at a low level under the premise that the boiler efficiency is not reduced and high-temperature corrosion does not occur in the furnace, and both the furnace efficiency and the denitrification economy can be taken into account. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0018] In the attached picture: Figure 1 It is a schematic diagram of the NOx equilibrium concentration prediction feedforward adjustment method of the present invention. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0021] It should be noted that in the claims, any reference signs placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present application may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] The present invention is described in detail below with reference to the accompanying drawings.

[0024] like Figure 1 As shown, a method for adjusting NOx equilibrium concentration of the present invention comprises the following steps: S1: Real-time detection of CO concentration and H2S concentration in the combustion area; S2: Establish functional relationships between the NOx concentration at the furnace outlet, the CO concentration in the boiler combustion zone, the H2S concentration and their respective influencing factors; wherein the influencing factors include the opening of the burnout air damper at the sampling point and the burnout air volume; S3: Calculate the relative standard deviation of CO concentration in different areas and H2S concentration in different areas, solve the burnout air damper opening according to the relationship between the relative standard deviation of concentration and the mean concentration, and bring the burnout air damper opening into the functional relationship in step S2; S4: Take the critical values ​​of high temperature corrosion and incomplete combustion of fuel for CO concentration and H2S concentration respectively, and take the maximum value as the first limit of overburn air; and take the minimum critical value of NOx concentration where the SCR denitrification device cannot control NOx emissions to meet environmental protection standards as the second limit of overburn air; S5: comparing the first overburnt wind limit value and the second overburnt wind limit value, when the first overburnt wind limit value is greater than or equal to the second overburnt wind limit value, controlling the overburnt wind volume according to the first overburnt wind limit value; when the first overburnt wind limit value is less than the second overburnt wind limit value, controlling the overburnt wind volume according to the second overburnt wind limit value.

[0025] Since NOx concentration, local CO concentration and H2S concentration are related to the overburnt air volume and the overburnt air damper opening. Among them, the total overburnt air volume affects the overall level of the three. The larger the overburnt air volume, the lower the NOx generation concentration, but the CO concentration and H2S concentration increase, further leading to unburned coal powder, reduced boiler efficiency, and high-temperature corrosion problems. The smaller the overburnt air volume, the lower the CO concentration and H2S concentration, and the degree of incomplete combustion in the furnace is weakened, but the NOx generation concentration increases, affecting the economy of denitrification. At the same time, there are multiple overburnt air dampers, representing the distribution of overburnt air. The damper opening corresponds to the size of the overburnt air volume in the area. The size of the overburnt air volume in the area affects the CO concentration and H2S concentration in the corresponding area. When the overburnt air damper is unreasonable, even if the total amount of overburnt air is reasonable, the CO concentration and H2S concentration in the local area may still be too high. Under ideal conditions, the opening of the overburnt air damper is reasonable, and there are no areas with locally high CO and H2S concentrations. At the same time, the overburnt air volume is reasonable, ensuring that the NOx concentration is as low as possible without reducing the boiler efficiency and preventing high-temperature corrosion in the furnace. At this time, both furnace efficiency and denitrification economy can be taken into account.

[0026] Therefore, the NOx equilibrium concentration adjustment method of the present invention detects the CO concentration and H2S concentration values ​​in the boiler combustion zone in real time, and establishes the functional relationship between the NOx concentration, CO concentration and H2S concentration at the furnace outlet by mathematical methods. On this basis, by limiting the uniform distribution of CO and H2S concentrations, the opening of the burnout air damper can be calculated. Further, the range of the burnout air volume is limited by the critical values ​​of NOx concentration, CO concentration and H2S concentration, and the NOx equilibrium concentration is obtained.

[0027] Example 1 Combine the following Figure 1 The specific implementation modes of the present invention are further described.

[0028] like Figure 1 As shown, a flow chart of a NOx equilibrium concentration prediction feedforward adjustment method proposed by the present invention is as follows Figure 1 The present invention mainly includes the following steps: establishing a functional relationship; solving the optimal burnout air damper opening; solving the range of burnout air volume; and determining the NOx equilibrium concentration.

[0029] Step 1: Establish a functional relationship: Coal-fired power plant units are usually equipped with a NOx concentration meter at the furnace outlet, and some units are equipped with an online analysis meter for CO. Usually, there are no online analysis meters for CO and H2S in the boiler combustion area, but there are sampling tubes.

[0030] The present invention requires that an online analysis meter for CO and H2S be installed behind the sampling tube in the combustion area of ​​the boiler to detect the CO concentration and H2S concentration values ​​in the combustion area in real time.

[0031] For different burner arrangements, the number of sampling tubes is different. Taking the four-corner tangential burner as an example, there are usually 4 to 6 sampling tubes, which means that the CO and H2S concentration values ​​of 4 to 6 areas can be obtained.

[0032] On this basis, combined with the DCS operating parameters of the unit, the functional relationship between the NOx concentration at the furnace outlet and its influencing factors is established, and the functional relationship between the CO concentration and H2S concentration in the boiler combustion zone and their influencing factors is established to predict the values ​​of the NOx concentration at the furnace outlet, the CO concentration and the H2S concentration in the boiler combustion zone when the unit is running.

[0033] Optionally, the functional relationship between the NOx concentration at the furnace outlet and its influencing factors, as well as the functional relationship between the CO concentration and H2S concentration in the boiler combustion zone and their influencing factors are established by principal component analysis or multivariate linear fitting method.

[0034] Principal component analysis is a mathematical analysis method. It is a statistical analysis method to grasp the main contradictions of things. It can analyze the main influencing factors from multivariate things, reveal the essence of things, and simplify complex problems. The purpose of calculating the principal component is to project high-dimensional data into a lower-dimensional space. The new mapping space is composed of a linear combination of the original data variables, which greatly reduces the dimension of the projection space. Because the statistical eigenvectors of the projection space are orthogonal to each other, the correlation between variables is eliminated, which greatly simplifies the complexity of the original process characteristic analysis.

[0035] Taking four sampling points as an example, i=1,2,3,4, the functional relationship is as follows:

[0036] In the formula, , , They are the NOx concentration at the furnace outlet, CO concentration in the boiler combustion zone, and H2S concentration; are the burnout air damper openings at the four sampling points respectively; For burnout air volume, For the unit load, It is the coal feeding amount, and there are other parameters not listed, which are determined according to the specific conditions of the unit.

[0037] Step 2: Calculate the optimal burnout air damper opening: On this basis, calculate the relative standard deviation of CO concentration in different areas and the relative standard deviation of H2S concentration in different areas.

[0038] The calculation formula for the relative standard deviation of CO concentration and H2S concentration is as follows:

[0039] In the formula, is the mean CO concentration, for The relative standard deviation, is the mean CO concentration, for The relative standard deviation of .

[0040] The simplified functional relationship between the relative standard deviation of CO concentration and H2S concentration is as follows. At this time, the main influencing factors in the formula are ,and , All are fixed values. is eliminated during the calculation:

[0041] In mathematical terms, the smaller the CV value, the closer the CO concentration and H2S concentration in these areas are to the average value, that is, the more evenly distributed the concentration is.

[0042] Solve at this time , The minimum value of , we get two sets of damper openings: , , that is, in The CO concentration distribution is most uniform under the opening degree. The H2S concentration distribution is most uniform under the opening. The optimal burnout air damper opening is the average of the two groups of damper openings.

[0043] The measured results show that the distribution patterns of CO concentration and H2S concentration are similar, that is, if the CO concentration in this area is low, the H2S concentration is also low, so the two groups of damper openings are close, and it is feasible to solve the average damper opening.

[0044] The meaning of relative standard deviation is the level of deviation of data from the average value, and the effect of overburnt air on CO / H2S at four points affects its absolute value, but does not affect the relative value. When the overburnt air is turned up, all CO / H2S will increase, but at the same proportion, the calculated CV value will remain unchanged.

[0045] The control factor is the CV value of two values, and the only variable involved is , the others are fixed or eliminated, the damper at this time, solve the optimal burnout air damper opening, that is, solve the minimum value of the two functions, at this time Still need to meet , , , , can be solved.

[0046] Substitute the calculated results into the functional relationship of NOx concentration, CO concentration and H2S concentration. At this time, the results of the three concentrations are mainly related to the burnout air volume.

[0047] Step 3: Solve the range of burnout air volume: Set the critical values ​​(empirical values) of CO concentration and H2S concentration. Above this value, high-temperature corrosion and incomplete combustion of fuel may occur in this area, and further derive the maximum value of the burnout air volume.

[0048] The formula is as follows:

[0049] It can be concluded that

[0050] A critical value of NOx concentration (design value of the denitrification device) is set. If the value is higher than this value, it will be difficult for the SCR denitrification device to control NOx emissions to meet environmental protection standards, and further the minimum value of the burnout air volume can be obtained.

[0051] The formula is as follows:

[0052] It can be concluded that

[0053] It follows from this .

[0054] Step 4: Determine the NOx equilibrium concentration: Compare these two values. 燃尽风限值1 ≥Q 燃尽风限值2 , then according to Q 燃尽风限值1 Control, at this time, both high temperature corrosion and denitrification economy are taken into account. When Q 燃尽风限值1 <Q 燃尽风限值2 , indicating that the boiler cannot meet these two requirements at the same time, At this time, according to Q 燃尽风限值2 Control, that is, environmental emission requirements must be met.

[0055] Example 2 After a large amount of data was obtained from the test, the influencing factors of CO concentration and H2S concentration in the boiler combustion area were obtained by principal component analysis. The results are as follows:

[0056] Taking CO1 concentration as an example, after fitting, this value is mainly related to k1, k2, , The CO concentration and H2S concentration in other boiler combustion zones can be deduced by analogy. Based on this, the functional expression of the relative standard deviation of CO concentration and H2S concentration is obtained:

[0057] Solve the minimum values ​​of the two relative standards respectively, and the calculation results are as follows: ,

[0058] At this point, the results of each parameter are shown in the following table:

[0059] At this time, under normal opening (100 / 100 / 100 / 100), , are both too high. After fitting and solving, we get , Minimum value, that is, when the opening is 100 / 70 / 50 / 100, Minimum, when the opening is 100 / 80 / 50 / 90, Minimum.

[0060] Then the optimal overburn air damper opening is:

[0061] Substituting this formula into the functional relationship of NOx concentration, CO concentration and H2S concentration, the results of the three concentrations are mainly related to the burnout air volume.

[0062] The critical value of CO concentration is set to 1000μL / L, and the critical value of H2S concentration is set to 100μL / L. Above this value, high-temperature corrosion and incomplete combustion of fuel may occur in this area, and the maximum value of the burnout air volume is further obtained, for example .

[0063] The critical value of NOx concentration is set at 300 mg / m 3 , higher than this value, it is difficult for the SCR denitrification device to control NOx emissions to meet environmental standards, and further derive the minimum value of the burnout air volume, for example

[0064] It follows from this .

[0065] The burnout wind should be Control, that is , at this time, high temperature corrosion does not occur and NOx emissions can be controlled.

[0066] Example 3 The previous steps are similar to those in Example 1, and the obtained optimal burnout air damper opening is substituted into the functional relationship among NOx concentration, CO concentration and H2S concentration.

[0067] The critical value of CO concentration is set to 1000 μL / L, and the critical value of H2S concentration is set to 100 μL / L, and the maximum value of the burnout air volume is obtained, for example .

[0068] The critical value of NOx concentration is set at 300 mg / m 3 , and further obtain the minimum value of the burnout air volume, such as

[0069] It follows from this .

[0070] The burnout wind should be Control, that is At this time, the boiler cannot meet these two requirements at the same time. Control, that is, environmental emission requirements must be met.

[0071] Example 4 Based on the NOx equilibrium concentration adjustment method of Example 1, a NOx equilibrium concentration adjustment system is disclosed, comprising: Data acquisition module, used to detect the CO concentration and H2S concentration values ​​in the combustion area in real time; A function establishment module is used to establish functional relationships between the NOx concentration at the furnace outlet, the CO concentration in the boiler combustion zone, the H2S concentration and their respective influencing factors; wherein the influencing factors include the burnout air damper opening at the sampling point and the burnout air volume; A calculation module is used to calculate the relative standard deviation of CO concentration in different areas and H2S concentration in different areas, solve the burnout air damper opening according to the relationship between the relative standard deviation of the concentration and the mean concentration, and bring the burnout air damper opening into the functional relationship in step S2; The experience value setting module is used to respectively take the critical values ​​of high temperature corrosion and incomplete combustion of fuel of CO concentration and H2S concentration, and take the maximum value as the first limit of burnout air; and take the minimum critical value of NOx concentration where the SCR denitrification device cannot control NOx emission to meet environmental protection standards as the second limit of burnout air; The comparison module is used to compare the first limit value of the overburned wind and the second limit value of the overburned wind. When the first limit value of the overburned wind is greater than or equal to the second limit value of the overburned wind, the overburned wind volume is controlled according to the first limit value of the overburned wind; when the first limit value of the overburned wind is less than the second limit value of the overburned wind, the overburned wind volume is controlled according to the second limit value of the overburned wind.

[0072] Example 5 The purpose of this embodiment is to provide an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the NOx equilibrium concentration adjustment method when executing the computer program.

[0073] Example 6 The purpose of this embodiment is to provide a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, a method for adjusting the NOx equilibrium concentration is implemented.

[0074] Example 7 The purpose of this embodiment is to provide a computer program product including a computer-readable medium, on which a computer-readable program code is contained, and the program code executes the NOx equilibrium concentration adjustment method.

[0075] The steps involved in the devices of the above embodiments 4, 5, 6 and 7 correspond to the method embodiment 1. The specific implementation methods can refer to the relevant description part of embodiment 1.

[0076] It should be understood by those skilled in the art that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0077] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0078] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0079] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0080] Unless otherwise specified, the working modes or control modes involved in the above embodiments are all conventional working modes or control modes in the art.

[0081] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in the field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for adjusting NOx equilibrium concentration, characterized in that: The following steps are involved: S1: Real-time detection of CO concentration and H2S concentration in the combustion area; S2: Establish functional relationships between the NOx concentration at the furnace outlet, the CO concentration in the boiler combustion zone, the H2S concentration and their respective influencing factors; wherein the influencing factors include the opening of the burnout air damper at the sampling point and the burnout air volume; S3: Calculate the relative standard deviation of CO concentration in different areas and H2S concentration in different areas, solve the burnout air damper opening according to the relationship between the relative standard deviation of concentration and the mean concentration, and bring the burnout air damper opening into the functional relationship in step S2; S4: Take the critical values ​​of high temperature corrosion and incomplete combustion of fuel for CO concentration and H2S concentration respectively, and take the maximum value as the first limit of overburn air; and take the minimum critical value of NOx concentration where the SCR denitrification device cannot control NOx emissions to meet environmental protection standards as the second limit of overburn air; S5: comparing the first overburnt wind limit value and the second overburnt wind limit value, when the first overburnt wind limit value is greater than or equal to the second overburnt wind limit value, controlling the overburnt wind volume according to the first overburnt wind limit value; when the first overburnt wind limit value is less than the second overburnt wind limit value, controlling the overburnt wind volume according to the second overburnt wind limit value.

2. A method for adjusting NOx equilibrium concentration according to claim 1, characterized in that: In step S1, the CO concentration and H2S concentration values ​​in the combustion area are obtained by installing online analysis meters for CO and H2S behind the sampling tube in the combustion area of ​​the boiler.

3. A method for adjusting NOx equilibrium concentration according to claim 1, characterized in that: In step S2, factors affecting the NOx concentration at the furnace outlet, the CO concentration and the H2S concentration in the boiler combustion zone also include unit load and coal feed rate.

4. A method for adjusting NOx equilibrium concentration according to claim 1, characterized in that: In step S2, principal component analysis or multivariate linear fitting method is used to establish functional relationships between the NOx concentration at the furnace outlet, the CO concentration in the boiler combustion zone, the H2S concentration and their respective influencing factors.

5. A method for adjusting NOx equilibrium concentration according to claim 1, characterized in that: In step S3, the calculation formula of the relative standard deviation of concentration is: in, is the mean CO concentration, is the relative standard deviation of CO concentration in different regions, is the mean CO concentration, is the relative standard deviation of H2S concentration in different areas.

6. A method for adjusting NOx equilibrium concentration according to claim 1, characterized in that: In step S3, the minimum relative standard deviation of CO concentration in different regions and the minimum relative standard deviation of H2S concentration in different regions are solved, and then the average value of these two minimum values ​​is calculated as the opening of the burnout air damper.

7. A NOx equilibrium concentration adjustment system, characterized in that: include: Data acquisition module, used to detect the CO concentration and H2S concentration values ​​in the combustion area in real time; A function establishment module is used to establish functional relationships between the NOx concentration at the furnace outlet, the CO concentration in the boiler combustion zone, the H2S concentration and their respective influencing factors; wherein the influencing factors include the burnout air damper opening at the sampling point and the burnout air volume; A calculation module is used to calculate the relative standard deviation of CO concentration in different areas and H2S concentration in different areas, solve the burnout air damper opening according to the relationship between the relative standard deviation of the concentration and the mean concentration, and bring the burnout air damper opening into the functional relationship in step S2; The experience value setting module is used to respectively take the critical values ​​of high temperature corrosion and incomplete combustion of fuel of CO concentration and H2S concentration, and take the maximum value as the first limit of burnout air; and take the minimum critical value of NOx concentration where the SCR denitrification device cannot control NOx emission to meet environmental protection standards as the second limit of burnout air; The comparison module is used to compare the first limit value of the overburned wind and the second limit value of the overburned wind. When the first limit value of the overburned wind is greater than or equal to the second limit value of the overburned wind, the overburned wind volume is controlled according to the first limit value of the overburned wind; when the first limit value of the overburned wind is less than the second limit value of the overburned wind, the overburned wind volume is controlled according to the second limit value of the overburned wind.

8. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the NOx equilibrium concentration regulating method according to any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for adjusting the NOx equilibrium concentration according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer readable medium, characterized in that The computer-readable medium contains a computer-readable program code, and the program code executes the NOx equilibrium concentration adjustment method according to any one of claims 1 to 6.

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