A method, system, device, medium and product for adjusting an ammonia injection grid

Abstract

The present application belongs to the technical field of ammonia injection grid, and discloses an adjusting method, system, device, medium and product of an ammonia injection grid. The method comprises the following steps: establishing a CFD model of a denitration reactor, dividing the end surface of the denitration flue boundary condition according to gridding; setting a measuring point in each grid of the denitration flue boundary condition of the denitration reactor model; reversely calculating the denitration flue boundary condition and the ammonia injection grid boundary condition; taking the minimum deviation of the residual NO at the catalyst inlet as the target, calculating the ammonia injection flow of each ammonia injection grid partition; and adjusting the opening degree of each partition valve according to the ammonia injection flow of each ammonia injection grid partition. The present application can provide a method for correcting the numerical simulation boundary condition through actual test results. On this basis, the opening degree of the valve of each branch pipe of the ammonia injection grid partition can also be determined through numerical simulation, so that the number of adjustments of the ammonia injection amount is greatly reduced, and the efficiency and accuracy of the ammonia injection optimization test are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ammonia injection lattices, and particularly relates to an ammonia injection lattice adjustment method, system, device, medium and product. BACKGROUND

[0002] Under the background of denitration ultra-low emission, uniform distribution of the molar ratio of ammonia nitrogen at the denitration inlet plays an important role in improving the denitration efficiency and reducing the local high value of ammonia escape. In actual operation, the ammonia injection lattice needs to be optimized and adjusted regularly to improve the uniformity of ammonia nitrogen distribution. The existing technology needs to rely on actual measurement results every time adjustment is made, and the test adjustment takes a long time. The existing ammonia injection adjustment method: first, the SCR system is tested on site to obtain actual operation parameters such as NOx concentration, ammonia escape rate, etc. Then, according to the test results, the SCR system is adjusted multiple times for ammonia injection amount, and parameters such as denitration efficiency and ammonia escape rate after each adjustment are recorded. The significance of ammonia injection lattice adjustment: through optimization of the ammonia injection system, ammonia gas can react more fully with NOx in flue gas, improving the denitration efficiency and reducing NOx emission.

[0003] In the existing CFD (Computational Fluid Dynamics) numerical simulation, the denitration flue boundary conditions are often assumed to be in an ideal state. The actual operation state of each unit under different loads is very different, and the speed and NO measurement results at the key positions such as the economizer outlet and the catalyst inlet cannot be obtained accurately. Only the denitration inlet and outlet measurement points can be used to calculate the denitration flue boundary conditions. The calculation of the boundary conditions includes two parts: the speed and NO concentration distribution at the economizer outlet and the flow distribution of each zone of the ammonia injection lattice. The acquisition of these boundary conditions is also beneficial to the operation analysis of the unit ammonia injection system.

[0004] The patent application with the Chinese patent publication number CN107349786A and the name of selective catalytic reduction denitration device and ammonia injection optimization method divides the ammonia injection grid into several sub-regions, each ammonia injection sub-region corresponds to a butterfly valve for quantitative adjustment of the ammonia injection amount, and the region above the catalyst section corresponding to the ammonia injection grid sub-region is also divided into several sub-regions; based on the analysis results of the non-uniformity of the ammonia-nitrogen distribution of the denitration device, the ammonia-nitrogen concentration of the catalyst section and each sub-region of the section is calculated, the difference between the ammonia-nitrogen concentration of each sub-region and the ammonia-nitrogen concentration of the catalyst section is taken as the correction factor, the product of the correction factor and the flow rate of the ammonia injection port is taken as the flow rate of the ammonia injection port for the next iteration calculation, and iteration calculation is performed, and the above iteration calculation is performed for several sub-regions; based on the analysis results of the non-uniformity of the ammonia-nitrogen distribution of the denitration device, the ammonia-nitrogen ratio of the catalyst section is calculated until the relative standard deviation coefficient of the ammonia-nitrogen ratio of the catalyst section is less than or equal to 5%. The patent application does not objectively analyze the actual situation of the actual denitration operation, the boundary conditions are crucial to the accuracy of numerical simulation, the boundary conditions of each unit are not the same, even the flue gas flow of the reactors on both sides of the same unit is not the same, and the distribution of nitrogen oxides is different, so the patent application cannot adjust the boundary conditions according to the actual situation of each unit, resulting in deviation of the final result. SUMMARY

[0005] In order to overcome the problems existing in the prior art, the purpose of the present application is to provide an adjustment method, system, device, medium and product for an ammonia injection grid, by obtaining the boundary conditions through numerical simulation, correcting the boundary conditions according to the actual test results of the field denitration inlet and outlet measuring points, making the simulation results closer to the actual situation, and thus making the adjustment effect more accurate. By bringing the corrected boundary conditions into the CFD numerical simulation software, the valve opening of each ammonia injection grid partition branch is determined according to theoretical calculation, thereby reducing the number of adjustments of the ammonia injection amount and improving the efficiency and accuracy of the ammonia injection optimization test.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is:

[0007] In a first aspect, the present application provides an adjustment method for an ammonia injection grid, comprising the following steps:

[0008] S1: establishing a CFD model of the denitration reactor, and dividing the boundary condition end face of the denitration flue according to meshing;

[0009] S2: Collecting field test data of a first actual measurement point position of the denitration and corresponding simulation data of a first simulation detection surface of the denitration, and reversely calculating boundary conditions of the denitration flue; wherein the first actual measurement point position of the denitration is located at a denitration inlet flue, and the first simulation detection surface of the denitration corresponds to the first actual measurement point position; the field test data of the first actual measurement point position of the denitration is NO value and speed value;

[0010] S3: Collecting field test data of a second actual measurement point position of the denitration and corresponding simulation data of a second simulation detection surface of the denitration, and reversely calculating boundary conditions of the denitration flue; wherein the second actual measurement point position of the denitration is located at a denitration outlet flue, and the second simulation detection surface of the denitration corresponds to the second actual measurement point; the field test data of the second actual measurement point position of the denitration is NO value and NH3 escape value;

[0011] S4: Setting the calculated denitration flue boundary conditions and the ammonia injection grid boundary conditions, and bringing them into a CFD model for calculation to obtain a numerical simulation result;

[0012] S5: Adjusting ammonia injection flow of each ammonia injection grid partition according to residual nitrogen oxide amount at a catalyst inlet in the numerical simulation result, and finally determining valve opening degree of each partition.

[0013] Optionally, in step S1, the denitration reactor model comprises a coal economizer bottom ash hopper outlet, a flue with flue gas bypass to an inlet of the denitration reactor, a flue from an outlet of the denitration reactor to an inlet of an air preheater, and the denitration reactor.

[0014] Optionally, in step S2, in the numerical simulation calculation model, an initial speed value of the denitration flue boundary conditions is given, a speed simulation value of the first simulation detection surface of the denitration is obtained through simulation calculation, and an iterative calculation method is adopted to calculate a final speed value of the denitration flue boundary conditions, with the first actual measurement point speed test value as a target.

[0015] Optionally, in step S3, in the numerical simulation calculation model, an initial NO value of the denitration flue boundary conditions is given, an NO value of the first simulation detection surface of the denitration is obtained through simulation calculation, and an iterative calculation method is adopted to calculate a final NO value of the denitration flue boundary conditions, with the first actual measurement point NO test value as a target.

[0016] Optionally, in step S5, in the numerical simulation calculation model, an initial ammonia injection amount of each partition of the ammonia injection grid boundary conditions is given, an NO value and NH3 test value of the second simulation detection surface of the denitration are obtained through simulation calculation, and an iterative calculation method is adopted to calculate a final NO value of the denitration flue boundary conditions, with the first actual measurement point NO and NH3 test values as targets.

[0017] Optionally, in step S4, the calculated denitration flue boundary conditions and ammonia injection grid boundary conditions are set, the simulation values of the catalyst front detection surface NO and NH3 are calculated by numerical simulation, and the flow of each partition of the ammonia injection grid is calculated with the minimum deviation of the residual NO at the catalyst inlet as the target.

[0018] In a second aspect, the present application provides an adjustment system of an ammonia injection grid, comprising:

[0019] A model establishing module is configured to establish a CFD model of the denitration reactor, and divide the denitration flue boundary condition end surface according to meshing.

[0020] A first data acquisition module is configured to acquire field test data at a denitration first actual measurement point position and corresponding simulation data of a denitration first simulation detection surface, and reversely calculate the denitration flue boundary condition; wherein the denitration first actual measurement point position is located at a denitration inlet flue, and the denitration first simulation detection surface corresponds to the denitration first actual measurement point position; the field test data at the denitration first actual measurement point position includes NO value and velocity value.

[0021] A second data acquisition module is configured to acquire field test data at a denitration second actual measurement point position and corresponding simulation data of a denitration second simulation detection surface, and reversely calculate the denitration flue boundary condition; wherein the denitration second actual measurement point position is located at a denitration outlet flue, and the denitration second simulation detection surface corresponds to the denitration second actual measurement point; the field test data at the denitration second actual measurement point position includes NO value and NH3 escape value.

[0022] A calculation module is configured to set the calculated denitration flue boundary condition and ammonia injection grid boundary condition, and input the CFD model for calculation to obtain a numerical simulation result.

[0023] An adjustment module is configured to adjust the ammonia injection flow of each partition of the ammonia injection grid according to the residual nitrogen oxide amount at the catalyst inlet in the numerical simulation result, and finally determine the opening degree of each partition valve.

[0024] In a third aspect, the present application 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 executes the computer program to implement the method.

[0025] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program, wherein the computer program is executable on a processor to implement the method.

[0026] In a fifth aspect, the present application provides a computer program product comprising a computer readable medium, wherein the computer readable medium comprises computer readable program code, and the program code executes the method.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] The adjustment method of the ammonia injection grid in the present application can greatly reduce the number of times of adjusting the ammonia injection amount and improve the efficiency and accuracy of the ammonia injection optimization test by applying the numerical simulation method to the field test, establishing the CFD model of the denitration reactor, determining the opening degree of each branch valve of the ammonia injection grid partition according to the theoretical calculation, and adjusting the opening degree of each partition valve according to the ammonia injection flow of each partition of the ammonia injection grid to reach the target ammonia injection adjustment flow value. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.

[0030] In the drawings:

[0031] Figure 1 It is a schematic diagram of the overall device of embodiment 2 of the present application.

[0032] Figure 2 It is a schematic diagram of the adjusting valve of embodiment 2 of the present application.

[0033] Figure 3 It is a velocity test value cloud chart of the denitration first actual measuring point of a unilateral denitration reactor of embodiment 2 of the present application.

[0034] Figure 4 It is a concentration test value cloud chart of the denitration first actual measuring point of a unilateral denitration reactor of embodiment 2 of the present application.

[0035] Figure 5 It is a flowchart of the method of the present application.

[0036] Among them, 1 is the denitration flue boundary condition; 2 is the denitration first actual measuring point and the corresponding denitration first simulation detection surface; 3 is the ammonia injection grid boundary condition; 4 is the catalyst inlet detection surface; 5 is the denitration second actual measuring point and the corresponding denitration second simulation detection surface. DETAILED DESCRIPTION

[0037] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] It is to be noted that in the claims the verb "comprise" and its conjugations do not exclude other elements or steps than those recited therein. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. It is further to be noted that claims can be drafted to exclude any or all combinations of features. It is the intention, therefore, to be bound only by the claims and their equivalents.

[0040] Furthermore, the terms "first", "second", and the like, do not denote any order, quantity, or importance, but rather are used to identify individual features, states, and / or actions of the application and are used for description only and are not limiting. The features of the application defined with the terms "first" and "second" can include one or both of those features unless otherwise specified. In the description of the application, the meaning of "a", "an", and "the" includes singular and plural referents unless otherwise specifically defined.

[0041] The application will now be described in detail with reference to the drawings.

[0042] A method for adjusting an ammonia injection grid, comprising the following steps:

[0043] S1: establishing a CFD model of a denitration reactor, and dividing the end face of a denitration flue boundary condition according to meshing;

[0044] S2: collecting field test data of a denitration first actual measuring point position and corresponding simulation data of a denitration first simulation detection surface, and reversely calculating the denitration flue boundary condition; wherein the denitration first actual measuring point position is located at a denitration inlet flue, and the denitration first simulation detection surface corresponds to the denitration first actual measuring point position; the field test data of the denitration first actual measuring point position are NO value and speed value;

[0045] S3: collecting field test data of a denitration second actual measuring point position and corresponding simulation data of a denitration second simulation detection surface, and reversely calculating the denitration flue boundary condition; wherein the denitration second actual measuring point position is located at a denitration outlet flue, and the denitration second simulation detection surface corresponds to the denitration second actual measuring point; the field test data of the denitration second actual measuring point position are NO value and NH3 escape value;

[0046] S4: Set the calculated denitration flue boundary conditions and ammonia injection grid boundary conditions, bring into the CFD (Computational Fluid Dynamics) model calculation, and obtain the numerical simulation results;

[0047] S5: According to the residual amount of nitrogen oxides at the catalyst inlet in the numerical simulation results, adjust the ammonia injection flow rate of each ammonia injection grid partition, and finally determine the valve opening degree of each partition.

[0048] Fluid flow has a corresponding relationship, and the nitrogen oxide content in the inlet gas flow has a corresponding relationship with the nitrogen oxide content of the outlet detection surface.

[0049] The non-uniformity of the nitrogen oxide content of the outlet detection surface is caused by the non-uniformity of the nitrogen oxide content of the inlet gas flow, and the local high nitrogen oxide content of the outlet corresponds to the local high nitrogen oxide content of the inlet. Similarly, the ammonia gas distribution also has similar rules.

[0050] Example 1

[0051] According to the existing boiler general layout, SCR inlet and outlet flue diagram, economizer general layout, reactor diagram, ammonia injection grid diagram, flue internal component diagram, and operation data of flue gas volume and flue gas components of the economizer outlet, a CFD model of the denitration reactor is established.

[0052] Specifically, the denitration reactor model has: an economizer bottom ash hopper outlet, a flue with a smoke guide plate, an ammonia injection grid (AIG), and a smoke rectification grid, which bypasses to the SCR reactor inlet.

[0053] As shown in Figure 1 , the denitration flue boundary condition grid surface 1, the denitration inlet actual measurement point and the corresponding detection surface 2, the ammonia injection grid boundary condition 3, the catalyst inlet detection surface 4, and the denitration outlet actual measurement point and the corresponding detection surface 5 of the present embodiment.

[0054] As shown in Figure 2 , the SCR denitration device of the present embodiment has a regulating valve 6 and a main pipe 7.

[0055] The flue gas at the economizer outlet passes through the inlet flue, is fully mixed with the ammonia gas injected by the ammonia injection grid, enters the reactor, and undergoes a reduction reaction under the action of the catalyst, and finally the flue gas passes through the denitration reactor outlet flue and enters the air preheater after passing through the SCR outlet flue.

[0056] Set the denitration flue boundary conditions (grid surface velocity and NO value), the ammonia injection grid boundary conditions (ammonia injection flow rate of each partition), and adjust the ammonia injection amount according to the simulation results, so that the 3x7 detection points are stably controlled at the target emission value, and the steps are as follows:

[0057] Set the de-NOx flue boundary conditions and ammonia injection grid boundary conditions as the calculated values, and calculate the simulated residual NO value at the 3x7 detection points = simulated NO value - simulated NH3 value.

[0058] Compare the deviation rate at each detection point = residual NO value at each detection point - target residual NO value at each detection point / target NO value at each detection point. If the deviation rate is less than 5%, proceed to calculate the second detection point deviation rate. The deviation rate of the NO simulation value and the actual value during iteration is the NO deviation rate. The deviation rate of the residual NO simulation value and the actual value during iteration is the velocity deviation rate.

[0059] Otherwise, divide the nozzles of the ammonia injection grid into 3x7 sub-regions. Calculate the theoretical ammonia injection amount correction coefficient for each region, and the theoretical ammonia injection amount = inlet NO value - simulated NO value.

[0060] According to the theoretical ammonia injection amount of each region, calculate the corrected flow rate of each region nozzle, nozzle corrected flow rate = nozzle original design data flow rate * nozzle theoretical ammonia injection amount correction coefficient. Then repeat steps 2 and 3.

[0061] Until the deviation rate at each point is less than 5%, indicating that through the adjustment of the 3x7 sub-regions of the nozzles, the simulated values at the 3x7 detection points can approach the target values.

[0062] Record the ammonia injection adjustment flow rate of each sub-region.

[0063] Simulate the valve and flow distribution process of the ammonia injection grid, establish the ammonia injection grid model, and include the actual opening of each branch valve. According to the target ammonia injection adjustment flow rate of the 3x7 sub-regions, adjust the opening of the branch valve to achieve the target ammonia injection adjustment flow rate value.

[0064] Optionally, simulate the valve and flow distribution process of the ammonia injection grid through a linear empirical relationship between the ammonia injection grid valve and the flow distribution.

[0065] Record the opening of the branch valve, adjust the opening of the field valve, and verify the outlet nitrogen oxides.

[0066] Example 2

[0067] According to the actual test results on site, determine the flow field simulation boundary conditions.

[0068] As Figure 1As shown, the denitration flue boundary conditions correspond to the number tuoxiaoyandao of 4x3, a total of 12 areas; ammonia injection grid boundary conditions correspond to the number penangeshan of 7x3, a total of 21 areas; the first denitration actual measuring point corresponds to the first simulation detection surface number cedianA of 4x3, a total of 12 points; the second denitration actual measuring point corresponds to the second simulation detection surface number cedianB of 7x3, a total of 21 points; the denitration catalyst inlet detection surface number cuihuajirukou is 7x3, a total of 21 points.

[0069] The denitration flue boundary condition mass flow value is calculated by the denitration first actual measuring point speed distribution measured value, and the denitration flue boundary condition NO value is calculated by the denitration first actual measuring point NO measured value.

[0070] 1) Determination of denitration flue boundary condition mass flow value

[0071] The denitration first actual measuring point test speed results are shown in Table 1 as follows:

[0072] Table 1

[0073]

[0074] The denitration flue boundary condition adjustment process is shown in Table 2 (boundary condition initial value and boundary condition set value after iteration) as follows:

[0075] Table 2

[0076]

[0077] According to Table 2, the boundary condition is adjusted three times to obtain the boundary condition as shown in Table 3 (final boundary condition set value).

[0078] Table 3

[0079]

[0080] The specific adjustment and calculation process is as follows:

[0081] The first simulation detection surface speed simulation value and the first actual measuring point speed test value statistical results are shown in Table 4 as follows:

[0082] Table 4

[0083]

[0084] Wherein, the deviation rate s=(xi-xi measured) / xi measured

[0085] Wherein, xi is the first analog detection surface 4x3 a total of 12 points of the speed simulation value; xi measured is the first actual measuring point 4x3 a total of 12 points of the speed test value, the deviation rate reflects the degree of deviation of the simulation value from the actual value.

[0086] According to the deviation rate, the boundary condition mass flow value of the denitration flue is adjusted, so as to reduce the deviation rate by multiple iterations. For example, the deviation rate s of the speed simulation value and the speed test value of the detection surface cedianA-1-1 under the initial working condition is 10.4%, and the boundary condition speed boundary condition setting value of tuoxiaoyandao1-3 is adjusted; the method of yi= yi / (1+s) is used for calculation.

[0087] Yi is the boundary condition mass flow, which is updated each time the iteration is calculated.

[0088] For example, the data cedianA-1-1 in table 4, xi=15.68 m / s; xi measured=14.20 m / s, according to s=(xi-xi measured) / xi measured, s=10.4% is obtained

[0089] The data tuoxiaoyandao1-3 in table 2, the initial boundary condition yi=27.1 kg / s; according to the method of yi= yi / (1+s), the boundary condition yi=24.5 kg / s after the first adjustment after iteration is calculated;

[0090] Based on the deviation rate s of the speed simulation result of the detection surface deviating from the target test value, the model boundary condition yi= yi / (1+s) corresponding to the detection surface is adjusted, and when the absolute value of the deviation rate of all detection surfaces is less than 10%, the calculation is stopped, and the corresponding relationship is shown in the following table 5:

[0091] Table 5

[0092]

[0093] The statistical results of the first, second and third adjustment working conditions of the denitration single reactor are shown in the following table 6:

[0094] Table 6

[0095]

[0096] 2) Determination of the concentration of the denitration flue boundary condition

[0097] The concentration test value results of the first actual measuring point of denitration are shown in the following table 7:

[0098] Table 7

[0099]

[0100] The adjustment process of the denitration flue boundary condition is shown in Table 8 as follows:

[0101] Table 8

[0102]

[0103] According to the above Table 8, the boundary condition is adjusted once to obtain the content in Table 9 below:

[0104] Table 9

[0105]

[0106] The specific adjustment and calculation process is as follows:

[0107] The first simulation detection surface statistical result is shown in Table 10 as follows:

[0108] Table 10

[0109]

[0110] Among them, the deviation rate s=(xi-xi measured) / xi measured

[0111] Among them, xi is the NO simulation value of the first simulation detection surface 4x3, a total of 12 points; xi measured is the NO test value of the first actual detection point 4x3, a total of 12 points, and the deviation rate reflects the degree of deviation of the simulation value from the actual value.

[0112] According to the deviation rate, the concentration value of the denitration flue boundary condition is adjusted, so as to reduce the deviation rate through multiple iterations. For example, the concentration simulation value of the detection surface cedianA-1-1 under the initial working condition deviates from the concentration actual value by 5.7%, and the boundary condition concentration of tuoxiaoyandao1-3 is adjusted to the boundary condition set value; according to the method of yi=yi / (1+s).

[0113] For example, in Table 10, the data cedianA-1-1, xi=0.00019606 mol / mol; xi measured=0.00018547 mol / mol, according to s=(xi-xi measured) / xi measured, s=5.7% is obtained.

[0114] In Table 8, the data tuoxiaoyandao1-3, the initial boundary condition yi=0.0001960 mol / mol; according to the method of yi=yi / (1+s), the first adjusted boundary condition yi=0.0001854 mol / mol after iteration is calculated.

[0115] Based on the concentration simulation results of the detection surface deviate from the target test value of the deviation rate s, the detection surface corresponding to the model boundary conditions yi= yi / (1+s), when all detection surface and target deviation rate absolute value <5% stop calculation, the corresponding relationship is shown in Table 11:

[0116] Table 11

[0117]

[0118] 3) Determination of the flow rate of the ammonia injection grid boundary conditions

[0119] The NO value and NH3 escape results of the second actual measurement point test are shown in Table 12:

[0120] Table 12

[0121]

[0122] The adjustment process of the ammonia injection grid boundary conditions is shown in Table 13:

[0123] Table 13

[0124]

[0125] According to Table 8 above, the boundary conditions are obtained after one adjustment of the boundary conditions in Table 14:

[0126] Table 14

[0127]

[0128] The specific adjustment and calculation process is as follows:

[0129] The second simulation detection surface statistical results are shown in Table 15:

[0130] Table 15

[0131]

[0132] Wherein, the deviation rate s=(xi-xi measured) / xi measured

[0133] Wherein, xi is the residual NO simulation value of the second simulation detection surface 7x3, a total of 21 points; xi measured is the residual NO test value of the second actual measurement point 7x3, a total of 21 points, and the deviation rate reflects the degree of deviation of the simulation value from the actual value.

[0134] Second simulation detection surface residual NO simulation value=second simulation detection surface NO simulation value-second simulation detection surface NH3 simulation value

[0135] Second actual measurement point residual NO simulation value=second actual measurement point NO simulation value-second actual measurement point NH3 simulation value.

[0136] Based on the deviation rate, adjust the boundary condition values ​​of the ammonia injection grid, iterating multiple times to reduce the deviation rate. For example, if the deviation rate s = 0.8% between the simulated and measured values ​​of the remaining NO on the detection surface cedianB-1-1 under the initial working condition, adjust the boundary condition velocity boundary condition setting value of penangeshan1-3 accordingly; calculate according to the method yi = yi / (1+s).

[0137] For example, in Table 15, the data cedianB-1-1 has an xi = 16.2 mg / m³. 3 xi measurement = 15.2 mg / m³ 3 Based on s=(xi-ximeasured) / ximeasured, we can deduce that s=0.8%.

[0138] The data in Table 13, penangeshan1-3, has an initial boundary condition of yi = 5 m / s; calculated using the method yi = yi / (1+s), the boundary condition after the first adjustment following iteration is yi = 4.68 m / s.

[0139] Based on the deviation rate s of the remaining NO simulation results of the detection surface from the target test value, the model boundary conditions yi = yi / (1+s) corresponding to the detection surface are adjusted. The calculation stops when the absolute value of the deviation rate between all detection surfaces and the target is <10%. The corresponding relationship is shown in Table 16 below:

[0140] Table 16

[0141]

[0142] 4) Determining the opening degree of the ammonia injection grid valve

[0143] The detection points at the inlet of the denitrification catalyst are numbered 7×3, totaling 21 points.

[0144] The ammonia injection grid has 21 points in total, with each section numbered 7×3.

[0145] The simulated residual NO value at the inlet detection surface of the denitrification catalyst was obtained based on numerical simulation. The simulated residual NO = simulated NO concentration - simulated NH3 concentration. The results are shown in Table 17 below.

[0146] Table 17

[0147]

[0148] The nozzle flow rate is calculated based on the simulated and target values ​​of the remaining NO concentration, and the calculation is stopped when the relative standard deviation rate of the remaining NO concentration no longer decreases.

[0149] V after adjustment = V before adjustment × target molar value of ammonia / simulated molar value of ammonia. The results are shown in Table 18 below.

[0150] Table 18

[0151]

[0152] The specific adjustment and calculation process is as follows:

[0153] The initial working condition detection surface statistical results and data processing of the denitration single-sided reactor are shown in the following table 19.

[0154] Table 19

[0155]

[0156] Among them, the remaining NO target value is set, and the control of the remaining 40mg unit is shown in the following table 20:

[0157] Table 20

[0158]

[0159] The ammonia target molar value = NO simulation value mol-remaining NO target value mol.

[0160] Vadjusted = Vbefore adjustment x ammonia target molar value / ammonia simulation molar value.

[0161] The statistical results of the working condition detection surface after the first adjustment of the denitration reactor on one side are shown in the following table 21:

[0162] Table 21

[0163]

[0164] The statistical results of the working condition detection surface after the second adjustment of the denitration reactor on one side are shown in the following table 22:

[0165] Table 22

[0166]

[0167] The statistical results of the working condition detection surface after the third adjustment of the denitration reactor on one side are shown in the following table 23:

[0168] Table 23

[0169]

[0170] The corresponding relationship is shown in the following table 24:

[0171] Table 24

[0172]

[0173] Adjustment by numerical simulation. According to the nitrogen oxide target value, the nozzle flow rate is determined, thereby determining the valve opening degree.

[0174] Table 25

[0175]

[0176] The opening degree k = nozzle flow rate v / 7.7 is based on 7.7 m / s of penzui-6-1.

[0177] Table 26

[0178]

[0179] 5) Unit conversion formula

[0180] NO value mg / m 3 Conversion with mol / mol:

[0181] NO mg / m 3 = NO mol / mol x 30 mg / mol x 1000000 / 22.4

[0182] Remaining NO mol / mol = NO mol / mol - NH3 mol / mol

[0183] NH3 ppm = NH3 x 1000000 mol / mol

[0184] Example 3

[0185] Based on the adjustment method of the ammonia injection grid of Example 1, an adjustment system of the ammonia injection grid is disclosed, comprising:

[0186] A model establishing module is configured to establish a CFD model of the denitration reactor, and divide the denitration flue boundary condition end face according to meshing;

[0187] A first data acquisition module is configured to acquire field test data at a denitration first actual measurement point position and corresponding simulation data of a denitration first simulation detection surface, and reversely calculate the denitration flue boundary condition; wherein the denitration first actual measurement point position is located at a denitration inlet flue, and the denitration first simulation detection surface corresponds to the denitration first actual measurement point position; the field test data at the denitration first actual measurement point position includes NO value and velocity value;

[0188] A second data acquisition module is configured to acquire field test data at a denitration second actual measurement point position and corresponding simulation data of a denitration second simulation detection surface, and reversely calculate the denitration flue boundary condition; wherein the denitration second actual measurement point position is located at a denitration outlet flue, and the denitration second simulation detection surface corresponds to the denitration second actual measurement point; the field test data at the denitration second actual measurement point position includes NO value and NH3 escape value;

[0189] a calculation module configured to set calculated flue gas boundary conditions and ammonia injection grid boundary conditions, and to input the CFD model calculation, to obtain a numerical simulation result;

[0190] an adjustment module configured to adjust the ammonia injection flow rate of each ammonia injection grid zone according to the amount of residual nitrogen oxides at the catalyst inlet in the numerical simulation result, and to finally determine the valve opening degree of each zone.

[0191] Embodiment 4

[0192] An object of the present 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, the processor implementing the adjustment method of the ammonia injection grid when executing the computer program.

[0193] Embodiment 5

[0194] An object of the present embodiment is to provide a computer-readable storage medium storing a computer program, the computer program being executable by a processor to implement the adjustment method of the ammonia injection grid.

[0195] Embodiment 6

[0196] An object of the present embodiment is to provide a computer program product comprising a computer-readable medium having computer-readable program code embodied thereon, the program code implementing the adjustment method of the ammonia injection grid.

[0197] The steps and methods involved in the above embodiments 3, 4, 5, and 6 correspond to embodiment 1, and the specific implementation can refer to the relevant description of embodiment 1.

[0198] Those skilled in the art will appreciate that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0199] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks. Figure 1 one or more flow or blocks.

[0200] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flow or blocks. Figure 1 one or more flow or blocks.

[0201] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks. Figure 1 one or more flow or blocks.

[0202] In the above embodiments, the working modes or control modes involved are the conventional working modes or control modes in the field unless otherwise specified.

[0203] Although the preferred embodiments of the application have been described, those skilled in the art behind the basic inventive concept can make additional changes and modifications to the embodiments. 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 application.

[0204] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the application but not to limit the application. Other modifications or equivalent replacements to the technical solutions of the application made by those skilled in the art should be covered in the scope of the claims of the application as long as they do not depart from the spirit and scope of the application.

Claims

1. A method for adjusting an ammonia-injected grid, characterized in that, Includes the following steps: S1: Establish a CFD model of the denitrification reactor and divide the boundary condition end face of the denitrification flue into a grid. S2: Collect on-site test data at the first actual measurement point of the denitrification process and corresponding simulation data at the first simulated detection surface of the denitrification process, and reverse-calculate the boundary conditions of the denitrification flue. This includes: in the CFD model, given the initial NO value of the denitrification flue boundary conditions, obtaining the simulated NO value of the first simulated detection surface of the denitrification process through simulation calculation; using the NO test value and velocity test value of the first actual measurement point of the denitrification process as the target, and employing an iterative calculation method to calculate the final NO boundary value and velocity boundary value of the denitrification flue boundary conditions; wherein, the first actual measurement point of the denitrification process is located in the denitrification inlet flue, and the first simulated detection surface of the denitrification process corresponds to the location of the first actual measurement point of the denitrification process; the on-site test data at the location of the first actual measurement point of the denitrification process are the NO test value and velocity test value; S3: Collect on-site test data at the second actual measurement point of the denitrification system and corresponding simulation data at the second simulated detection surface of the denitrification system, and reverse-calculate the boundary conditions of the ammonia injection grid. This includes: in the CFD model, based on the initial ammonia injection rate of each zone given the boundary conditions of the ammonia injection grid, obtaining the simulated NO and NH3 values ​​of the second simulated detection surface of the denitrification system through simulation calculation; using the NO and NH3 test values ​​at the second actual measurement point of the denitrification system as targets, calculating the NH3 boundary value of the boundary conditions of the ammonia injection grid using an iterative calculation method; wherein, the second actual measurement point of the denitrification system is located in the denitrification outlet flue, and the second simulated detection surface of the denitrification system corresponds to the second actual measurement point of the denitrification system; the on-site test data at the second actual measurement point of the denitrification system are the NO and NH3 test values; S4: Set the boundary conditions of the denitrification flue and the ammonia injection grid obtained from the calculation, and input them into the CFD model to obtain the numerical simulation results; S5: Adjust the ammonia injection flow rate of each ammonia injection grid zone according to the amount of residual nitrogen oxides at the catalyst inlet in the numerical simulation results, and finally determine the valve opening of each zone.

2. The method for adjusting an ammonia injection grid according to claim 1, characterized in that, In step S1, the CFD model of the denitrification reactor includes the economizer bottom ash hopper outlet, the flue gas bypass to the denitrification reactor inlet, the flue gas outlet to the air preheater inlet, and the denitrification reactor.

3. The method for adjusting an ammonia injection grid according to claim 1, characterized in that, In step S4, the boundary conditions of the denitrification flue and the boundary conditions of the ammonia injection grid are set. The simulated values ​​of NO and NH3 at the catalyst inlet detection surface are obtained through numerical simulation. The flow rate of each zone of the ammonia injection grid is calculated with the goal of minimizing the deviation of the simulated value of the remaining NO at the catalyst inlet.

4. An adjustment system for an ammonia injection grid using the adjustment method of any one of claims 1-3, characterized in that, include: The model building module is used to build a CFD model of the denitrification reactor and divide the boundary condition end face of the denitrification flue into a grid. The first data acquisition module is used to collect on-site test data at the first actual measurement point of denitrification and the corresponding simulated data of the first simulated detection surface of denitrification, and to reverse-calculate the boundary conditions of the denitrification flue. The first actual measurement point of denitrification is located in the denitrification inlet flue, and the first simulated detection surface of denitrification corresponds to the first actual measurement point of denitrification. The on-site test data at the first actual measurement point of denitrification are NO test values ​​and velocity test values. The second data acquisition module is used to collect on-site test data of the second actual measurement point of denitrification and the corresponding simulation data of the second simulated detection surface of denitrification, and to reverse-calculate the boundary conditions of the ammonia injection grid; wherein, the second actual measurement point of denitrification is located in the denitrification outlet flue, and the second simulated detection surface of denitrification corresponds to the second actual measurement point of denitrification; the on-site test data of the second actual measurement point of denitrification are NO test values ​​and NH3 test values; The calculation module is used to set the boundary conditions of the denitrification flue and the ammonia injection grid obtained from the calculation, input them into the CFD model, and obtain the numerical simulation results. The adjustment module is used to adjust the ammonia injection flow rate of each ammonia injection grid zone based on the amount of residual nitrogen oxides at the catalyst inlet in the numerical simulation results, and finally determine the valve opening of each zone.

5. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method of any one of claims 1-3.

6. 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 method of any one of claims 1-3.

7. A computer program product comprising a computer-readable medium, characterized in that, The computer-readable medium contains computer-readable program code that performs the method according to any one of claims 1-3.

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