Method, system and equipment for adjusting ammonia spraying grid, medium and product

Abstract

The invention belongs to the technical field of ammonia spraying grids, and discloses an ammonia spraying grid adjusting method, system and equipment, a medium and a product. The method comprises the following steps: establishing a CFD model of a denitration reactor, and dividing a denitration flue boundary condition end face according to gridding; setting a measuring point in each grid of the denitration flue boundary condition of the denitration reactor model; reversely calculating a denitration flue boundary condition and an ammonia injection grid boundary condition; the ammonia spraying flow of each ammonia spraying grid partition is calculated with the minimum deviation of the remaining NO at a catalyst inlet as the target; and according to the ammonia spraying flow of each ammonia spraying grid subarea, the valve opening degree of each subarea is adjusted. The invention provides a method for correcting a numerical simulation boundary condition through an actual test result; on the basis, the opening degree of a branch pipe valve of each ammonia injection grid partition can be determined through numerical simulation, so that the number of times of adjusting the ammonia injection amount is greatly reduced, and the efficiency and accuracy of an ammonia injection optimization test are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of ammonia injection grids, and in particular relates to an adjustment method, system, equipment, medium and product of an ammonia injection grid. Background Art

[0002] Under the background of ultra-low emission of denitrification, the uniform distribution of ammonia nitrogen molar ratio at the denitrification inlet plays an important role in improving denitrification efficiency and reducing local ammonia escape high values. In actual operation, it is necessary to regularly optimize and adjust the ammonia spray grid to improve the uniformity of ammonia nitrogen distribution. Each adjustment of the existing technology needs to rely on the actual measurement results, and go through the repeated process of "test-adjustment-test", and the test adjustment takes a long time. Existing ammonia spray adjustment method: First, conduct on-site testing of the SCR system to obtain actual operating parameters, such as NOx concentration, ammonia escape rate, etc. Then, according to the test results, adjust the ammonia spray amount of the SCR system multiple times, and record the parameters such as denitrification efficiency and ammonia escape rate after each adjustment. The significance of ammonia spray grid adjustment: By optimizing the ammonia spray system, ammonia can react more fully with NOx in the flue gas, improve denitrification efficiency, and reduce NOx emissions.

[0003] In existing CFD (Computational Fluid Dynamics) numerical simulations, it is often assumed that the boundary conditions of the denitrification flue are ideal. In fact, the operating conditions of each unit under different loads vary greatly, and the critical positions such as the economizer outlet and the catalyst inlet cannot obtain accurate velocity and NO measurement results. The denitrification flue boundary conditions can only be inferred through the measurement points at the denitrification inlet and outlet. The calculation of boundary conditions includes two parts: the economizer outlet velocity and NO concentration distribution and the flow distribution of each partition of the ammonia injection grid. The acquisition of these boundary conditions is also beneficial for the operation analysis of the unit's ammonia injection system.

[0004] The Chinese patent publication number is CN107349786A, and the patent application titled Selective Catalytic Reduction Denitration Device and Ammonia Injection Optimization Method Thereof divides the ammonia injection grid into several sub-areas, and each ammonia injection partition corresponds to a butterfly valve to quantitatively adjust the ammonia injection amount. The area corresponding to the ammonia injection grid sub-area in the cross section above the catalyst is also divided into several sub-areas; based on the results of the uneven analysis of ammonia nitrogen distribution in the denitration device, the ammonia nitrogen concentrations in the cross section above the catalyst and in each sub-area of ​​the cross section are calculated, and the ratio of the difference between the ammonia nitrogen concentrations in each sub-area and the cross section above the catalyst to the ammonia nitrogen concentration in the cross section above the catalyst is used as a correction factor; the product of the correction factor and the ammonia injection port flow rate is used as the ammonia injection port flow rate for the next iterative calculation, and an iterative calculation is performed, and the above iterative calculation is performed for several sub-areas respectively; based on the results of the uneven analysis of ammonia nitrogen distribution in the denitration device, the ammonia nitrogen ratio in the cross section above the catalyst is calculated until the relative standard deviation coefficient of the ammonia nitrogen ratio in the cross section above the catalyst is less than or equal to 5%. This patent application does not objectively analyze the actual situation of on-site denitrification operation. 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 rates of the reactors on both sides of the same unit are different, and the distribution of nitrogen oxides is also different. Therefore, this patent application cannot adjust the boundary conditions according to the actual situation of each unit, which makes the final result prone to deviations. Summary of the invention

[0005] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide an adjustment method, system, equipment, medium and product for an ammonia injection grid, by obtaining the boundary conditions of numerical simulation, and correcting the boundary conditions according to the actual test results of the inlet and outlet measurement points of the on-site denitrification, so that the simulation results are closer to reality, thereby making the adjustment effect more accurate. By bringing the corrected boundary conditions into the CFD numerical simulation software, the valve opening of each branch pipe of the ammonia injection grid is determined according to theoretical calculations, thereby reducing the number of adjustments to the ammonia injection amount and improving the efficiency and accuracy of the ammonia injection optimization test.

[0006] 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 an ammonia injection grid, comprising the following steps: S1: Establish the CFD model of the denitrification reactor and divide the end surface of the denitrification flue boundary condition into grids; S2: Collect the on-site test data of the first actual measurement point of denitrification and the corresponding simulation data of the first simulated detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein, the first actual measurement point of denitrification is located at 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 of the first actual measurement point of denitrification are NO value and velocity value; S3: Collect the on-site test data of the second actual measurement point of denitrification and the corresponding simulation data of the second simulation detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein, the second actual measurement point of denitrification is located at the denitrification outlet flue, and the second simulation 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 value and NH3 escape value; S4: Set the calculated denitrification flue boundary conditions and ammonia injection grid boundary conditions, bring them into the CFD model calculation, and obtain the numerical simulation results; S5: According to the amount of residual nitrogen oxides at the catalyst inlet in the numerical simulation results, the ammonia injection flow rate of each ammonia injection grid partition is adjusted, and finally the valve opening of each partition is determined.

[0007] Optionally, in step S1, the denitrification reactor model includes an ash hopper outlet at the bottom of the economizer, a flue from the flue gas bypass to the denitrification reactor inlet, a flue from the denitrification reactor outlet to the air preheater inlet, and a denitrification reactor.

[0008] Optionally, in step S2, in the numerical simulation calculation model, an initial velocity value of the denitrification flue boundary condition is given, and a velocity simulation value of the first simulated detection surface of denitrification is obtained through simulation calculation. Taking the velocity test value of the first actual measuring point of denitrification as the target, an iterative calculation method is used to calculate the final velocity value of the denitrification flue boundary condition.

[0009] Optionally, in step S3, in the numerical simulation calculation model, an initial NO value of the denitrification flue boundary condition is given, and the NO value of the first simulated detection surface of denitrification is obtained by simulation calculation. Taking the NO test value of the first actual measuring point of denitrification as the target, an iterative calculation method is used to calculate the final NO value of the denitrification flue boundary condition.

[0010] Optionally, in step S5, in the numerical simulation calculation model, according to the initial ammonia injection amount of each partition under the given ammonia injection grid boundary condition, the NO value and NH3 test value of the second simulation detection surface of denitrification are obtained by simulation calculation, and the NO and NH3 test values ​​of the first actual measurement point of denitrification are taken as the target, and the iterative calculation method is adopted to calculate the final NO value of the denitrification flue boundary condition.

[0011] Optionally, in step S4, the calculated denitrification flue boundary conditions and ammonia injection grid boundary conditions are set, and the NO and NH3 simulation values ​​of the detection surface before the catalyst are obtained by numerical simulation. The flow rate of each partition of the ammonia injection grid is calculated with the goal of minimizing the residual NO deviation at the catalyst inlet.

[0012] In a second aspect, the present invention provides an adjustment system for an ammonia injection grid, comprising: The model building module is used to build the CFD model of the denitrification reactor and divide the end surface of the denitrification flue boundary conditions into grids; The first data acquisition module is used to collect the on-site test data of the first actual measurement point of denitrification and the corresponding simulation data of the first simulated detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein the first actual measurement point of denitrification is located at the denitrification inlet flue, and the first simulated detection surface of denitrification corresponds to the position of the first actual measurement point of denitrification; the on-site test data of the first actual measurement point of denitrification are NO value and speed value; The second data acquisition module is used to collect the on-site test data of the second actual measurement point of denitrification and the corresponding simulation data of the second simulation detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein the second actual measurement point of denitrification is located at the denitrification outlet flue, and the second simulation 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 value and NH3 escape value; The calculation module is used to set the boundary conditions of the denitrification flue and the ammonia injection grid, and bring them into the CFD model calculation to obtain the numerical simulation results; The regulating module is used to adjust the ammonia injection flow rate of each ammonia injection grid partition according to the residual nitrogen oxide amount at the catalyst inlet in the numerical simulation results, and finally determine the valve opening of each partition.

[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 method is implemented when the processor executes 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 the computer program implements the method when executed by a processor.

[0015] In a fifth aspect, the present invention provides a computer program product comprising a computer-readable medium, on which is embodied a computer-readable program code, wherein the program code executes the method.

[0016] Compared with the prior art, the present invention has the following beneficial effects: An adjustment method for an ammonia injection grid of the present invention applies a numerical simulation method in a field test, establishes a CFD model of a denitrification reactor, and can determine the valve opening of each ammonia injection grid partition branch pipe according to theoretical calculations. According to the ammonia injection flow rate of each ammonia injection grid partition, the valve opening of each partition is adjusted to achieve a target ammonia injection adjustment flow rate value, thereby greatly reducing the number of adjustments to the ammonia injection amount and improving the efficiency and accuracy of the ammonia injection optimization test. 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 This is a schematic diagram of the overall device of Example 2 of the present invention; Figure 2 This is a schematic diagram of a regulating valve in Example 2 of the present invention; Figure 3 This is a cloud diagram of the speed test value of the first actual measurement point of denitration in a single-side denitration reactor according to Example 2 of the present invention; Figure 4 This is a cloud diagram of the concentration test value at the first actual measurement point of denitration in a single-sided denitration reactor according to Example 2 of the present invention; Figure 5 It is a schematic diagram of the process of the present invention; Among them, 1. Denitrification flue boundary conditions; 2. The first actual measurement point of denitrification and the corresponding first simulated detection surface of denitrification; 3. Ammonia injection grid boundary conditions; 4. Catalyst inlet detection surface; 5. The second actual measurement point of denitrification and the corresponding second simulated detection surface of denitrification. 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. 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. The present invention is described in detail below with reference to the accompanying drawings.

[0022] A method for adjusting an ammonia injection grid comprises the following steps: S1: Establish the CFD model of the denitrification reactor and divide the end surface of the denitrification flue boundary condition into grids; S2: Collect the on-site test data of the first actual measurement point of denitrification and the corresponding simulation data of the first simulated detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein, the first actual measurement point of denitrification is located at 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 of the first actual measurement point of denitrification are NO value and velocity value; S3: Collect the on-site test data of the second actual measurement point of denitrification and the corresponding simulation data of the second simulation detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein, the second actual measurement point of denitrification is located at the denitrification outlet flue, and the second simulation 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 value and NH3 escape value; S4: Set the calculated denitrification flue boundary conditions and ammonia injection grid boundary conditions, bring them into the CFD (Computational Fluid Dynamics) model for calculation, and obtain the numerical simulation results; S5: According to the amount of residual nitrogen oxides at the catalyst inlet in the numerical simulation results, the ammonia injection flow rate of each ammonia injection grid partition is adjusted, and finally the valve opening of each partition is determined.

[0023] Fluid flow has correspondence, and there is a corresponding relationship between the nitrogen oxide content in the inlet airflow and the nitrogen oxide content on the outlet detection surface.

[0024] The uneven nitrogen oxide content at the outlet detection surface is caused by the uneven nitrogen oxide content at the inlet airflow, and the local high nitrogen oxide content at the outlet corresponds to the high nitrogen oxide content at the inlet. Similar ammonia distribution also has similar rules.

[0025] Example 1 The CFD model of the denitrification reactor is established based on the existing boiler general diagram, SCR inlet and outlet flue diagram, economizer general diagram, reactor diagram, ammonia injection grid diagram, flue internal component diagram, and operating data of economizer outlet flue gas volume and flue gas composition.

[0026] Specifically, the denitration reactor model has: an economizer bottom ash hopper outlet, a flue gas bypass to an SCR reactor inlet including a flue gas guide plate, an ammonia injection grid (AIG) and a flue gas rectifying grid.

[0027] like Figure 1 As shown, the denitrification flue boundary condition grid surface 1, the actual measurement point of the denitrification inlet and the corresponding detection surface 2, the ammonia injection grid boundary condition 3, the catalyst inlet detection surface 4 and the actual measurement point of the denitrification outlet and the corresponding detection surface 5 of this embodiment.

[0028] like Figure 2 As shown, the SCR denitration device of this embodiment has a regulating valve 6 and a main pipe 7.

[0029] The flue gas at the economizer outlet passes through the inlet flue, is fully mixed with the ammonia injected from the ammonia injection grid, and then enters the reactor. Under the action of the catalyst, a reduction reaction occurs. Finally, the flue gas passes through the outlet flue of the denitrification reactor and enters the air preheater after passing through the SCR outlet flue.

[0030] Set the denitrification flue boundary conditions (grid surface velocity and NO value) and the ammonia grid boundary conditions (ammonia injection flow rate in each partition) according to the simulation results. Adjust the ammonia injection amount so that 3×7 detection points are stably controlled at the target emission value. The steps are as follows: The boundary conditions of the denitrification flue and the ammonia injection grid were set as estimated values, and the simulated residual NO value of 3×7 detection points in the model was calculated = simulated NO value - simulated NH3 value.

[0031] Compare the deviation rate of each detection point = the remaining NO value of each detection point - the target remaining NO value of each detection point / the target NO value of each detection point. If the deviation rate is less than 5%, the second detection point deviation rate calculation is performed. During iteration, the deviation rate between the NO simulation value and the actual value is the NO deviation rate. During iteration, the deviation rate between the remaining NO simulation value and the actual value is the speed deviation rate.

[0032] Otherwise, the nozzles of the ammonia injection grid are divided into 3×7 sub-areas. The theoretical ammonia injection amount correction coefficient of the nozzles in each area is calculated, and the theoretical ammonia injection amount = inlet NO value - simulated NO value.

[0033] According to the theoretical ammonia spraying amount in each area, calculate the nozzle correction flow rate in each area. The nozzle correction flow rate = nozzle original design data flow rate * nozzle theoretical ammonia spraying amount correction coefficient. Then repeat steps 2 and 3.

[0034] Until the deviation rate of each point is less than 5%, it means that by adjusting the 3×7 sub-areas of the nozzle, the simulated values ​​of the 3×7 detection points can be made close to the target values.

[0035] Record the ammonia injection adjustment flow rate for each sub-area.

[0036] The ammonia injection grid valve and flow distribution process is simulated, and the ammonia injection grid model is established, including the actual opening of each branch valve. According to the target ammonia injection adjustment flow of 3×7 sub-areas, the branch valve opening is adjusted to achieve the target ammonia injection adjustment flow value.

[0037] Optionally, the ammonia injection grid valve and flow distribution process is simulated by a linear empirical relationship between the ammonia injection grid valve and the flow distribution.

[0038] Record the branch valve opening, adjust the on-site valve opening, and export nitrogen oxides for verification.

[0039] Example 2 According to the actual test results on site, the boundary conditions of flow field simulation are determined.

[0040] like Figure 1 As shown, the boundary conditions of the denitrification flue gas duct correspond to the numbering of tuoxiaoyandao, which is 4×3, with a total of 12 areas; the boundary conditions of the ammonia injection grid correspond to the numbering of penangeshan, which is 7×3, with a total of 21 areas; the first actual measurement point of denitrification corresponds to the first simulation detection surface, which is numbered cedianA, which is 4×3, with a total of 12 points; the second actual measurement point of denitrification corresponds to the second simulation detection surface, which is numbered cedianB, which is 7×3, with a total of 21 points; the denitrification catalyst inlet detection surface is numbered cuihuajirukou, which is 7×3, with a total of 21 points.

[0041] The mass flow value of the denitrification flue boundary condition is calculated through the measured value of the velocity distribution at the first actual measuring point of denitrification, and the NO value of the denitrification flue boundary condition is calculated through the measured value of NO at the first actual measuring point of denitrification.

[0042] 1) Determination of the mass flow value of the denitrification flue boundary condition The test speed results of the first actual measurement point of denitrification are shown in Table 1 below: Table 1

[0043] The denitrification flue boundary condition adjustment process is shown in Table 2 (the initial value of the boundary condition and the boundary condition setting value after iteration): Table 2

[0044] According to Table 2, the boundary conditions are adjusted three times to obtain the boundary conditions shown in Table 3 below (final boundary condition setting values).

[0045] Table 3

[0046] The specific adjustment and calculation process is as follows: The statistical results of the first simulated detection surface velocity simulation value and the first actual measurement point velocity test value are shown in Table 4 below: Table 4

[0047] Among them, the deviation rate s=(xi-xi test) / xi test Among them, xi is the speed simulation value of the first simulated detection surface 4×3, a total of 12 points; xi measure is the speed test value of the first actual measurement point 4×3, a total of 12 points, and the deviation rate reflects the degree to which the simulation value deviates from the actual value.

[0048] According to the deviation rate, adjust the mass flow value of the denitrification flue boundary condition, so as to reduce the deviation rate through multiple iterations. For example, under the initial working condition, the deviation rate between the velocity simulation value and the velocity measured value of the detection surface cedianA-1-1 is s=10.4%, so the boundary condition velocity boundary condition setting value of tuoxiaoyandao1-3 is adjusted accordingly; calculated according to the method of yi= yi / (1+s).

[0049] yi is the boundary condition mass flow rate, which is updated in each iteration.

[0050] For example, in the data of cedianA-1-1 in Table 4, xi=15.68m / s; ximeasured=14.20 m / s, according to s=(xi-ximeasured) / ximeasured, s=10.4% is deduced. The data in Table 2 are tuoxiaoyandao1-3, the initial boundary condition is yi=27.1 kg / s; calculated according to the method of yi= yi / (1+s), the boundary condition after the first adjustment after iteration is yi=24.5kg / s; Based on the deviation rate s of the velocity simulation result of the detection surface from the target test value, the model boundary condition yi = yi / (1+s) corresponding to the detection surface is adjusted. When the absolute value of the deviation rate between all detection surfaces and the target is less than 10%, the calculation is stopped. The corresponding relationship is shown in Table 5 below: Table 5

[0051] The statistical results of the operating conditions of a single-side denitrification reactor after the first, second and third adjustments are shown in Table 6 below: Table 6

[0052] 2) Determination of the boundary condition concentration of the denitrification flue The measured concentration results of the first actual measurement point of denitrification are shown in Table 7 below: Table 7

[0053] The denitrification flue boundary condition adjustment process is shown in Table 8 below: Table 8

[0054] According to Table 8 above, the boundary conditions are adjusted once to obtain the content in Table 9 under the boundary conditions: Table 9

[0055] The specific adjustment and calculation process is as follows: The statistical results of the first simulated detection surface are shown in Table 10 below: Table 10

[0056] Among them, the deviation rate s=(xi-xi test) / xi test Among them, xi is the NO simulation value of the first simulated detection surface 4×3 with a total of 12 points; xi test is the NO test value of the first actual measurement point 4×3 with a total of 12 points, and the deviation rate reflects the degree to which the simulation value deviates from the actual value.

[0057] According to the deviation rate, adjust the concentration value of the denitrification flue boundary condition, so as to reduce the deviation rate through multiple iterations. For example, under the initial working condition, the deviation rate between the simulated concentration value and the measured concentration value of the detection surface cedianA-1-1 is s=5.7%, so the boundary condition concentration boundary condition setting value of tuoxiaoyandao1-3 is adjusted accordingly; calculated according to the method of yi= yi / (1+s).

[0058] For example, in the data of cedianA-1-1 in Table 10, xi=0.00019606mol / mol; xitest=0.00018547mol / mol, according to s=(xi-xitest) / xitest, s=5.7% is deduced. For the data tuoxiaoyandao1-3 in Table 8, the initial boundary condition yi=0.0001960 mol / mol; calculated according to the method of yi=yi / (1+s), the boundary condition after the first adjustment after iteration is yi=0.0001854 mol / mol; Based on the deviation rate s of the concentration simulation results of the detection surface from the target test value, the model boundary condition yi = yi / (1+s) corresponding to the detection surface is adjusted. When the absolute value of the deviation rate between all detection surfaces and the target is less than 5%, the calculation is stopped. The corresponding relationship is shown in Table 11 below: Table 11

[0059] 3) Determination of the boundary condition flow rate of the ammonia injection grid The results of NO value and NH3 escape at the second actual measurement point of denitrification are shown in Table 12 below: Table 12

[0060] The adjustment process of the boundary conditions of the ammonia injection grid is shown in Table 13: Table 13

[0061] According to Table 8 above, the boundary conditions are adjusted once to obtain the content in Table 14 under the boundary conditions: Table 14

[0062] The specific adjustment and calculation process is as follows: The statistical results of the second simulated detection surface are shown in Table 15 below: Table 15

[0063] Among them, the deviation rate s=(xi-xi test) / xi test Among them, xi is the residual NO simulation value of the second simulated detection surface 7×3, a total of 21 points; xi measure is the residual NO test value of the second actual measurement point 7×3, a total of 21 points, and the deviation rate reflects the degree to which the simulation value deviates from the actual value.

[0064] Remaining NOx simulation value of the second simulation detection surface = NOx simulation value of the second simulation detection surface - NH3 simulation value of the second simulation detection surface The residual NO simulation value at the second actual measuring point = the NO simulation value at the second actual measuring point - the NH3 simulation value at the second actual measuring point.

[0065] According to the deviation rate, adjust the boundary condition value of the ammonia injection grid, and iterate multiple times to reduce the deviation rate. For example, under the initial working condition, the deviation rate between the simulated value of residual NOx of the detection surface cedianB-1-1 and the measured value of residual NOx is s=0.8%, so the boundary condition velocity boundary condition setting value of penangeshan1-3 is adjusted accordingly; it is calculated according to the method of yi= yi / (1+s).

[0066] For example, in the data of cedianB-1-1 in Table 15, xi=16.2 mg / m 3 ; xi measurement = 15.2mg / m 3 According to s=(xi-xitest) / xitest, we can infer that s=0.8%.

[0067] The data penangeshan1-3 in Table 13, the initial boundary condition yi=5m / s; calculated according to the method of yi= yi / (1+s), the boundary condition yi=4.68m / s after the first adjustment after iteration; Based on the deviation rate s of the residual NO simulation result of the detection surface from the target test value, the model boundary condition yi = yi / (1+s) corresponding to the detection surface is adjusted. When the absolute value of the deviation rate between all detection surfaces and the target is less than 10%, the calculation is stopped. The corresponding relationship is shown in Table 16 below: Table 16

[0068] 4) Determination of the opening of the ammonia injection grid valve The denitrification catalyst inlet detection surface number cuihuajirukou is 7×3, with a total of 21 points.

[0069] The partition numbers of the ammonia spray grid are 7×3, with a total of 21 points.

[0070] The simulated residual NO value at the inlet detection surface of the denitration catalyst is obtained by numerical simulation, where simulated residual NO = simulated NO concentration - simulated NH3 concentration. The results are shown in Table 17 below.

[0071] Table 17

[0072] The nozzle flow rate is calculated based on the simulated value and target value of the residual NO, and the calculation is stopped when the relative standard deviation rate of the residual NO concentration does not decrease.

[0073] V after adjustment = V before adjustment × target molar value of ammonia gas / simulated molar value of ammonia gas. The results are shown in Table 18 below.

[0074] Table 18

[0075] The specific adjustment and calculation process is as follows: The statistical results and data processing of the initial operating condition detection surface of a single-side denitrification reactor are shown in Table 19 below.

[0076] Table 19

[0077] Among them, the residual NO target value is set, and optionally, the unit with 40mg is controlled as shown in Table 20 below: Table 20

[0078] Target molar value of ammonia = simulated value of NO, mol - target value of remaining NO, mol.

[0079] V after adjustment = V before adjustment × target molar value of ammonia / simulated molar value of ammonia.

[0080] The statistical results of the operating condition detection surface after the first adjustment on one side of the denitrification reactor are shown in Table 21 below: Table 21

[0081] The statistical results of the operating condition detection surface after the second adjustment on one side of the denitrification reactor are shown in Table 22 below: Table 22

[0082] The statistical results of the operating condition detection surface after the third adjustment on one side of the denitrification reactor are shown in Table 23 below: Table 23

[0083] The corresponding relationship is shown in Table 24 below: Table 24

[0084] Use numerical simulation to adjust. According to the nitrogen oxide target value, determine the nozzle flow rate, and thus determine the valve opening.

[0085] Table 25

[0086] Taking 7.7m / s of penzui-6-1 as the benchmark, the opening k = nozzle flow rate v / 7.7.

[0087] Table 26

[0088] 5) Unit conversion formula NO value mg / m 3 Conversion with mol / mol: NO mg / m 3 =NOmol / mol×30mg / mol×1000000 / 22.4 Remaining NO mol / mol = NO mol / mol - NH 3 mol / mol NH3ppm= NH3×1000000 mol / mol Example 3 Based on the method for adjusting an ammonia injection grid in Example 1, an ammonia injection grid adjustment system is disclosed, comprising: The model building module is used to build the CFD model of the denitrification reactor and divide the end surface of the denitrification flue boundary conditions into grids; The first data acquisition module is used to collect the on-site test data of the first actual measurement point of denitrification and the corresponding simulation data of the first simulation detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein the first actual measurement point of denitrification is located at the denitrification inlet flue, and the first simulation detection surface of denitrification corresponds to the position of the first actual measurement point of denitrification; the on-site test data of the first actual measurement point of denitrification are NO value and velocity value; The second data acquisition module is used to collect the on-site test data of the second actual measurement point of denitrification and the corresponding simulation data of the second simulation detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein the second actual measurement point of denitrification is located at the denitrification outlet flue, and the second simulation 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 value and NH3 escape value; The calculation module is used to set the boundary conditions of the denitrification flue and the ammonia injection grid, and bring them into the CFD model calculation to obtain the numerical simulation results; The regulating module is used to adjust the ammonia injection flow rate of each ammonia injection grid partition according to the residual nitrogen oxide amount at the catalyst inlet in the numerical simulation results, and finally determine the valve opening of each partition.

[0089] Example 4 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 method for adjusting the ammonia injection grid when executing the computer program.

[0090] Example 5 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, the method for adjusting the ammonia injection grid is implemented.

[0091] Example 6 The purpose of this embodiment is to provide a computer program product comprising a computer-readable medium, on which a computer-readable program code is contained, and the program code executes the method for adjusting the ammonia injection grid.

[0092] The steps involved in the devices of the above embodiments 3, 4, 5 and 6 correspond to those of the method embodiment 1. For the specific implementation methods, please refer to the relevant description part of embodiment 1.

[0093] 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. 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. 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. 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.

[0094] 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.

[0095] 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. 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 an ammonia injection grid, characterized in that: The following steps are involved: S1: Establish the CFD model of the denitrification reactor and divide the end surface of the denitrification flue boundary condition into grids; S2: Collect the on-site test data of the first actual measurement point of denitrification and the corresponding simulation data of the first simulated detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein, the first actual measurement point of denitrification is located at 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 of the first actual measurement point of denitrification are NO value and velocity value; S3: Collect the on-site test data of the second actual measurement point of denitrification and the corresponding simulation data of the second simulation detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein, the second actual measurement point of denitrification is located at the denitrification outlet flue, and the second simulation 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 value and NH3 escape value; S4: Set the calculated denitrification flue boundary conditions and ammonia injection grid boundary conditions, bring them into the CFD model calculation, and obtain the numerical simulation results; S5: According to the amount of residual nitrogen oxides at the catalyst inlet in the numerical simulation results, the ammonia injection flow rate of each ammonia injection grid partition is adjusted, and finally the valve opening of each partition is determined.

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

3. The method for adjusting an ammonia injection grid according to claim 1, characterized in that: In step S2, in the numerical simulation calculation model, the initial velocity value of the denitrification flue boundary condition is given, and the velocity simulation value of the first simulated detection surface of denitrification is obtained through simulation calculation. Taking the velocity test value of the first actual measuring point of denitrification as the target, the iterative calculation method is used to calculate the final velocity value of the denitrification flue boundary condition.

4. The method for adjusting an ammonia injection grid according to claim 1, characterized in that: In step S3, in the numerical simulation calculation model, the initial NO value of the denitrification flue boundary condition is given, and the NO value of the first simulated detection surface of denitrification is obtained through simulation calculation. The NO test value of the first actual measurement point of denitrification is taken as the target, and the iterative calculation method is used to calculate the final NO value of the denitrification flue boundary condition.

5. The method for adjusting an ammonia injection grid according to claim 1, characterized in that: In step S5, in the numerical simulation calculation model, according to the initial ammonia injection amount of each partition under the given ammonia injection grid boundary conditions, the NO value and NH3 test value of the second simulation detection surface of denitrification are obtained through simulation calculation. Taking the NO and NH3 test values ​​of the first actual measurement point of denitrification as the target, the iterative calculation method is used to calculate the final NO value of the denitrification flue boundary conditions.

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

7. An adjustment system for an ammonia injection grid, characterized in that: include: The model building module is used to build the CFD model of the denitrification reactor and divide the end surface of the denitrification flue boundary conditions into grids; The first data acquisition module is used to collect the on-site test data of the first actual measurement point of denitrification and the corresponding simulation data of the first simulated detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein the first actual measurement point of denitrification is located at the denitrification inlet flue, and the first simulated detection surface of denitrification corresponds to the position of the first actual measurement point of denitrification; the on-site test data of the first actual measurement point of denitrification are NO value and speed value; The second data acquisition module is used to collect the on-site test data of the second actual measurement point of denitrification and the corresponding simulation data of the second simulation detection surface of denitrification, and reversely calculate the boundary conditions of the denitrification flue; wherein the second actual measurement point of denitrification is located at the denitrification outlet flue, and the second simulation 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 value and NH3 escape value; The calculation module is used to set the boundary conditions of the denitrification flue and the ammonia injection grid, and bring them into the CFD model calculation to obtain the numerical simulation results; The regulating module is used to adjust the ammonia injection flow rate of each ammonia injection grid partition according to the residual nitrogen oxide amount at the catalyst inlet in the numerical simulation results, and finally determine the valve opening of each partition.

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 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 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 method according to any one of claims 1 to 6.

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