A method and device for adjusting air volume of a denitration reaction zone

Abstract

The present application relates to the technical field of denitration reaction, in particular to a kind of denitration reaction zone air volume adjustment method and equipment, comprising: step one: obtain the historical data of denitration reaction zone;Second step: according to the historical data, establish SNCR reaction model, according to the SNCR reaction model, ammonia water consumption, oxygen content, nitrogen oxide emission;Third step: according to the ammonia water consumption, oxygen content, nitrogen oxide emission in the SNCR reaction model determines the first corresponding relationship, second corresponding relationship and third corresponding relationship;Fourth step: according to the first corresponding relationship, the second corresponding relationship and the third corresponding relationship obtain first air volume interval;Step five: the first air volume interval is corrected, and second air volume interval is obtained, solves the phenomenon that oxygen content is excessively abundant and ammonia water consumption is excessive in the air volume adjustment improper in boiler operation, cannot effectively control nitrogen oxide compound emission, causes equipment failure and resource waste problem.

Description

Technical Field

[0001] This invention relates to the field of denitrification reaction technology, and more specifically, to a method and equipment for adjusting the air volume in a denitrification reaction zone. Background Technology

[0002] Coal-fired power plant boilers are a major source of nitrogen oxides (NOx) emissions in my country. NOx poses serious threats to human health and the ecological environment. To meet increasingly stringent national emission standards, most coal-fired power plant boilers currently require denitrification retrofitting to reduce NOx emissions to below 100 mg / Nm3.

[0003] The denitrification system employs SNCR (Selective Non-Catalytic Reduction), using 20% ​​ammonia water as a reducing agent injected into the boiler furnace to selectively react with NOx. No catalyst is required; therefore, the reducing agent must be added in the high-temperature zone. The reducing agent is injected into the furnace at a temperature of 850–1100℃, where it rapidly decomposes into NH3, which reacts with NOx in the flue gas to produce nitrogen, carbon dioxide, and water. The main reactions are as follows:

[0004] 4NO + 4NH3 + O2 → 4N2 + 6H2O

[0005] 6NO2 + 8NH3 → 7N2 + 12H2O

[0006] During the entire denitrification reaction, there have been instances where even with the ammonia injection rate adjusted to the maximum, nitrogen oxide emissions could not be effectively controlled. Furthermore, even when nitrogen oxide emissions reached the ideal emission level, the ammonia consumption remained excessive. This application proposes a method and equipment for adjusting the airflow in the denitrification reaction zone to address the issues of improper airflow adjustment during boiler operation, which leads to excessive oxygen levels and excessive ammonia consumption, resulting in ineffective control of nitrogen oxide emissions, equipment malfunctions, and resource waste. Summary of the Invention

[0007] This invention provides a method and equipment for adjusting the air volume in a denitrification reaction zone. By adjusting the air volume in the denitrification reaction zone, it solves the problems of excessive oxygen and ammonia consumption caused by improper air volume adjustment during boiler operation, which leads to ineffective control of nitrogen oxide emissions, equipment failure, and resource waste. The method includes:

[0008] Step 1: Obtain historical data for the denitrification reaction zone;

[0009] Step 2: Establish an SNCR reaction model based on the historical data, and obtain the ammonia water usage, oxygen content, and nitrogen oxide emissions based on the SNCR reaction model;

[0010] Step 3: Determine the first, second, and third correspondences based on the ammonia usage, oxygen content, and nitrogen oxide emissions within the SNCR reaction model;

[0011] Step 4: Obtain the first air volume range based on the first correspondence, the second correspondence, and the third correspondence;

[0012] Step 5: Correct the first airflow range to obtain the second airflow range;

[0013] Wherein, the first correspondence is the correspondence between the air volume in the reaction zone and the oxygen content, the second correspondence is the correspondence between the oxygen content and the ammonia water usage, and the third correspondence is the correspondence between the air volume in the reaction zone and the nitrogen oxide emissions.

[0014] In some embodiments of this application, in step three, determining the first correspondence specifically involves:

[0015] The first correspondence is the correspondence between the air volume of the reaction zone and the oxygen content. Based on the historical data, a preset air volume interval matrix A of the reaction zone is set, and A(A1, A2, A3, A4) is defined, where A1 is the first preset air volume interval, A2 is the second preset air volume interval, A3 is the third preset air volume interval, and A4 is the fourth preset air volume interval, and A1 < A2 < A3 < A4.

[0016] A preset oxygen content matrix B(B1, B2, B3, B4) is provided, where B1 is the first preset oxygen content, B2 is the second preset oxygen content, B3 is the third preset oxygen content, and B4 is the fourth preset oxygen content, and B1 < B2 < B3 < B4.

[0017] When the air volume in the reaction zone is adjusted to c, the oxygen content in the reaction zone is selected according to the relationship between the air volume in the reaction zone c and the preset air volume interval matrix A.

[0018] When c < A1, select the first preset oxygen quantity B1 as the current oxygen quantity in the reaction zone;

[0019] When A1≤c<A2, select the second preset oxygen quantity B2 as the current oxygen quantity in the reaction zone;

[0020] When A2≤c<A3, select the third preset oxygen quantity B3 as the current oxygen quantity in the reaction zone;

[0021] When A3≤c<A4, the fourth preset oxygen quantity B4 is selected as the current oxygen quantity in the reaction zone.

[0022] In some embodiments of this application, in step three, determining the second correspondence specifically involves:

[0023] The second correspondence is the correspondence between the oxygen content and the ammonia usage. Based on the historical data, a matrix E of ammonia usage values ​​is preset, and E(E1, E2, E3, E4) is set, where E1 is the first preset ammonia usage value, E2 is the second preset ammonia usage value, E3 is the third preset ammonia usage value, and E4 is the fourth preset ammonia usage value, and E1 < E2 < E3 < E4.

[0024] When the current oxygen content in the reaction zone is the first preset oxygen content B1, the ammonia water usage in the reaction zone is determined to be the first preset ammonia water usage value E1.

[0025] When the current oxygen content in the reaction zone is detected to be the second preset oxygen content B2, the ammonia water usage in the reaction zone is determined to be the second preset ammonia water usage value E2.

[0026] When the current oxygen content in the reaction zone is detected to be the third preset oxygen content B3, the ammonia water usage in the reaction zone is determined to be the third preset ammonia water usage value E3.

[0027] When the current oxygen level in the reaction zone is detected to be the fourth preset oxygen level B4, the ammonia water usage in the reaction zone is determined to be the fourth preset ammonia water usage value E4.

[0028] In some embodiments of this application, step three further includes:

[0029] The boiler bed temperature is monitored in real time, and the ammonia dosage is corrected according to the boiler bed temperature. A preset ammonia dosage correction coefficient matrix α is set, α(α1, α2, α3, α4), where α1 is the first preset ammonia dosage correction coefficient, α2 is the second preset ammonia dosage correction coefficient, α3 is the third preset ammonia dosage correction coefficient, and α4 is the fourth preset ammonia dosage correction coefficient, and α1 < α2 < α3 < α4 < 1;

[0030] The preset boiler bed temperature matrix T is set as T(T1, T2, T3, T4), where T1 is the first preset boiler bed temperature, T2 is the second preset boiler bed temperature, T3 is the third preset boiler bed temperature, and T4 is the fourth preset boiler bed temperature, and T1 < T2 < T3 < T4.

[0031] When the preset ammonia dosage value is the i-th preset ammonia dosage value, i = 1, 2, 3, 4, the boiler bed temperature d is detected in real time, and the ammonia dosage value is corrected according to the relationship between the bed temperature d and the preset boiler bed temperature matrix.

[0032] When d < T1, the first preset ammonia dosage correction coefficient α1 is selected to correct the i-th preset ammonia dosage value, and the corrected ammonia dosage value is α1*Ei.

[0033] When T1≤d<T2, the second preset ammonia dosage correction coefficient α2 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α2*Ei.

[0034] When T2≤d<T3, the third preset ammonia dosage correction coefficient α3 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α3*Ei.

[0035] When T3≤d<T4, the fourth preset ammonia dosage correction coefficient α4 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α4*Ei.

[0036] In some embodiments of this application, step three further includes:

[0037] The boiler load is adjusted according to the ammonia water consumption. A preset boiler load matrix M is set, M(M1, M2, M3, M4), where M1 is the first preset boiler load, M2 is the second preset boiler load, M3 is the third preset boiler load, and M4 is the fourth preset boiler load, and M1 < M2 < M3 < M4.

[0038] When the ammonia water consumption is the first preset ammonia water consumption value E1, the boiler load is adjusted to the first preset boiler load M1.

[0039] When the ammonia water consumption is the second preset ammonia water consumption value E2, the boiler load is adjusted to the second preset boiler load M2.

[0040] When the ammonia water consumption is the third preset ammonia water consumption value E3, the boiler load is adjusted to the third preset boiler load M3.

[0041] When the ammonia water usage is the fourth preset ammonia water usage value E4, the boiler load is adjusted to the fourth preset boiler load M4.

[0042] In some embodiments of this application, in step three, determining the third correspondence specifically involves:

[0043] The third correspondence is the correspondence between the air volume of the reaction zone and the nitrogen oxide emissions. A nitrogen oxide emission matrix K is preset based on historical data, and K(K1, K2, K3, K4) is set, where K1 is the first preset nitrogen oxide emission, K2 is the second preset nitrogen oxide emission, K3 is the third preset nitrogen oxide emission, K4 is the fourth preset nitrogen oxide emission, and K4 < K3 < K2 < K1;

[0044] The nitrogen oxide emissions are determined based on the relationship between the air volume c in the reaction zone and the preset air volume interval matrix A.

[0045] When c < A1, the first preset nitrogen oxide emission K1 is determined to be the current nitrogen oxide emission of the reaction zone;

[0046] When A1≤c<A2, the second preset nitrogen oxide emission K2 is determined to be the current nitrogen oxide emission of the reaction zone;

[0047] When A2≤c<A3, the fourth preset nitrogen oxide emission K4 is determined to be the current nitrogen oxide emission of the reaction zone;

[0048] When A3≤c<A4, the third preset nitrogen oxide emission K3 is determined as the current nitrogen oxide emission of the reaction zone.

[0049] In some embodiments of this application, step three further includes:

[0050] Real-time detection of nitrogen oxide emissions n, and determination of the relationship between nitrogen oxide emissions n and preset nitrogen oxide emission value B:

[0051] When n≥B, continue to increase the air volume in the reaction zone;

[0052] When n < B, it indicates that the nitrogen oxide emission n has reached the preset nitrogen oxide emission value B, and the nitrogen oxide emission n continues to decrease until the nitrogen oxide emission n increases, at which point the increase in the air volume of the reaction zone stops.

[0053] In some embodiments of this application, in step five, the first airflow range is modified to obtain a second airflow range, specifically as follows:

[0054] The flue temperature in the denitrification reaction zone is monitored in real time, and the first air volume range is corrected according to the flue temperature. The preset air volume range correction coefficient is β, and β(β1, β2, β3, β4) is set, where β1 is the first preset air volume range correction coefficient, β2 is the second preset air volume range correction coefficient, β3 is the third preset air volume range correction coefficient, β4 is the fourth preset air volume range correction coefficient, and β1 < β2 < β3 < β4 < 1;

[0055] The preset flue temperature matrix is ​​P, and P(P1, P2, P3, P4) is set, where P1 is the first preset flue temperature, P2 is the second preset flue temperature, P3 is the third preset flue temperature, and P4 is the fourth preset flue temperature, and P1 < P2 < P3 < P4.

[0056] The first airflow range is set as Q, and the first airflow range is corrected according to the relationship between the real-time detected flue temperature t and the preset flue temperature matrix:

[0057] When t < P1, the first preset air volume interval correction coefficient β1 is selected to correct the first preset air volume interval Q, and the second air volume interval is Q*β1 after correction.

[0058] When P1≤t<P2, the second preset air volume interval correction coefficient β2 is selected to correct the first preset air volume interval Q, and the second air volume interval is Q*β2 after correction.

[0059] When P2≤t<P3, the third preset air volume interval correction coefficient β3 is selected to correct the first preset air volume interval Q, and the second air volume interval is Q*β3 after correction.

[0060] When P3≤t<P4, the fourth preset air volume range correction coefficient β4 is selected to correct the first preset air volume range Q, and the second air volume range is obtained as Q*β4 after correction.

[0061] In some embodiments of this application, the method further includes:

[0062] In the SNCR reaction model, the boiler combustion performance indicators are monitored in real time. When the boiler combustion performance indicators exceed the preset indicators, an early warning signal is issued. The boiler combustion performance indicators include pulverized coal burnout rate, fly ash carbon content, and lower furnace outlet temperature.

[0063] In some embodiments of this application, a denitrification reaction zone airflow adjustment device is also included, specifically:

[0064] The historical data storage module is used to store historical data from the denitrification reaction zone;

[0065] The SNCR reaction model establishment module is used to adjust the air volume in the reaction zone according to the SNCR reaction model and to detect the ammonia water usage, oxygen content, and nitrogen oxide emissions in the SNCR reaction model in real time.

[0066] The central control module is used to determine the first, second, and third correspondences based on the ammonia water usage, oxygen content, and nitrogen oxide emissions in the SNCR reaction model, and to obtain the first air volume interval based on the first, second, and third correspondence intervals.

[0067] The correction module is used to correct the first air volume range to obtain the second air volume range.

[0068] The central control module, the correction module, the historical data storage module, and the SNCR reaction model establishment module are electrically connected.

[0069] Compared with the prior art, the embodiments of this application bring the following beneficial effects:

[0070] This invention provides a method and device for adjusting the airflow in a denitrification reaction zone, comprising: Step 1: acquiring historical data of the denitrification reaction zone; Step 2: establishing an SNCR reaction model based on the historical data, and obtaining ammonia water usage, oxygen content, and nitrogen oxide emissions based on the SNCR reaction model; Step 3: determining a first correspondence, a second correspondence, and a third correspondence based on the ammonia water usage, oxygen content, and nitrogen oxide emissions within the SNCR reaction model; Step 4: obtaining a first airflow range based on the first correspondence, the second correspondence, and the third correspondence; Step 5: correcting the first airflow range to obtain a second airflow range; wherein, the first correspondence is the correspondence between the airflow in the reaction zone and the oxygen content, the second correspondence is the correspondence between the oxygen content and the ammonia water usage, and the third correspondence is the correspondence between the airflow in the reaction zone and the nitrogen oxide emissions. This method collects historical data on denitrification reactions, constructs an SNCR reaction model based on the historical data, adjusts the air volume in the reaction zone, and obtains the corresponding relationship between the air volume in the reaction zone, the ammonia water consumption, the oxygen content, and the nitrogen oxide emissions. Based on the corresponding relationship, the first air volume range is determined. This method solves to some extent the problem of excessive oxygen and excessive ammonia water consumption caused by improper air volume adjustment during boiler operation, which leads to equipment failure and resource waste. Attached Figure Description

[0071] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0072] Figure 1 This is a schematic flowchart of a method for adjusting the air volume in a denitrification reaction zone according to an embodiment of the present invention;

[0073] Figure 2 This is a schematic diagram of the structure of a denitrification reaction zone airflow adjustment device in an embodiment of this application. Detailed Implementation

[0074] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0075] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0076] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0077] like Figure 1 As shown, an embodiment of the present invention provides a method for adjusting the air volume in a denitrification reaction zone, comprising:

[0078] Step 1 S101: Obtain historical data of the denitrification reaction zone;

[0079] Step 2 S102: Establish an SNCR reaction model based on the historical data, and obtain the ammonia water usage, oxygen content, and nitrogen oxide emissions based on the SNCR reaction model;

[0080] Step 3 S103: Determine the first, second, and third correspondences based on the ammonia water usage, oxygen content, and nitrogen oxide emissions within the SNCR reaction model;

[0081] Step 4 S104: Obtain the first air volume range based on the first correspondence, the second correspondence, and the third correspondence;

[0082] Step 5 S105: Correct the first air volume range to obtain the second air volume range.

[0083] In some embodiments of this application, in step three S103, determining the first correspondence relationship specifically involves:

[0084] The first correspondence is the correspondence between the air volume of the reaction zone and the oxygen content. Based on the historical data of the denitrification reaction zone, a preset air volume interval matrix A is set, and A(A1, A2, A3, A4) is defined, where A1 is the first preset air volume interval, A2 is the second preset air volume interval, A3 is the third preset air volume interval, and A4 is the fourth preset air volume interval, and A1 < A2 < A3 < A4.

[0085] A preset oxygen content matrix B(B1, B2, B3, B4) is provided, where B1 is the first preset oxygen content, B2 is the second preset oxygen content, B3 is the third preset oxygen content, and B4 is the fourth preset oxygen content, and B1 < B2 < B3 < B4.

[0086] When the air volume in the reaction zone is adjusted to c, the oxygen content in the reaction zone is selected according to the relationship between the air volume in the reaction zone c and the preset air volume interval matrix A.

[0087] When c < A1, select the first preset oxygen quantity B1 as the current oxygen quantity in the reaction zone;

[0088] When A1≤c<A2, select the second preset oxygen quantity B2 as the current oxygen quantity in the reaction zone;

[0089] When A2≤c<A3, select the third preset oxygen quantity B3 as the current oxygen quantity in the reaction zone;

[0090] When A3≤c<A4, the fourth preset oxygen quantity B4 is selected as the current oxygen quantity in the reaction zone.

[0091] In this embodiment, the change in oxygen content is obtained by adjusting the air volume. The air volume is detected by the air volume detection module. When the air volume gradually increases, it has an inhibitory effect on the generation of nitrogen oxides. When the air volume increases to a certain extent, the oxygen content detection module detects the oxygen content in the reaction zone in real time. It is found that the oxygen content in the denitrification reaction zone is too high, but it will promote the emission of nitrogen oxides. At the same time, the ammonia water usage detection module detects that the ammonia water usage has also increased.

[0092] In some embodiments of this application, in step three S103, determining the second correspondence specifically involves:

[0093] The second correspondence is the correspondence between the oxygen content and the ammonia water usage. Based on the historical data of the denitrification reaction zone, a matrix E of ammonia water usage values ​​is preset, and E(E1, E2, E3, E4) is set, where E1 is the first preset ammonia water usage value, E2 is the second preset ammonia water usage value, E3 is the third preset ammonia water usage value, and E4 is the fourth preset ammonia water usage value, and E1 < E2 < E3 < E4.

[0094] When the current oxygen content in the reaction zone is the first preset oxygen content B1, the ammonia water usage in the reaction zone is determined to be the first preset ammonia water usage value E1.

[0095] When the current oxygen content in the reaction zone is detected to be the second preset oxygen content B2, the ammonia water usage in the reaction zone is determined to be the second preset ammonia water usage value E2.

[0096] When the current oxygen content in the reaction zone is detected to be the third preset oxygen content B3, the ammonia water usage in the reaction zone is determined to be the third preset ammonia water usage value E3.

[0097] When the current oxygen level in the reaction zone is detected to be the fourth preset oxygen level B4, the ammonia water usage in the reaction zone is determined to be the fourth preset ammonia water usage value E4.

[0098] In this embodiment, when the air volume increases and the oxygen content is too high, the ammonia water dosage increases accordingly. However, even when the ammonia water dosage is adjusted to the maximum, nitrogen oxide emissions cannot be effectively controlled, resulting in a decrease in denitrification efficiency.

[0099] In some embodiments of this application, step three S103 further includes:

[0100] The boiler bed temperature is monitored in real time, and the ammonia dosage is corrected according to the boiler bed temperature. A preset ammonia dosage correction coefficient matrix α is set, α(α1, α2, α3, α4), where α1 is the first preset ammonia dosage correction coefficient, α2 is the second preset ammonia dosage correction coefficient, α3 is the third preset ammonia dosage correction coefficient, and α4 is the fourth preset ammonia dosage correction coefficient, and α1 < α2 < α3 < α4 < 1;

[0101] The preset boiler bed temperature matrix T is set as T(T1, T2, T3, T4), where T1 is the first preset boiler bed temperature, T2 is the second preset boiler bed temperature, T3 is the third preset boiler bed temperature, and T4 is the fourth preset boiler bed temperature, and T1 < T2 < T3 < T4.

[0102] When the preset ammonia dosage value is the i-th preset ammonia dosage value, i = 1, 2, 3, 4, the boiler bed temperature d is detected in real time, and the ammonia dosage value is corrected according to the relationship between the bed temperature d and the preset boiler bed temperature matrix.

[0103] When d < T1, the fourth preset ammonia dosage correction coefficient α4 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α4*Ei.

[0104] When T1≤d<T2, the third preset ammonia dosage correction coefficient α3 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α3*Ei.

[0105] When T2≤d<T3, the second preset ammonia dosage correction coefficient α2 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α2*Ei.

[0106] When T3≤d<T4, the first preset ammonia dosage correction coefficient α1 is selected to correct the i-th preset ammonia dosage value, and the corrected ammonia dosage value is α1*Ei.

[0107] In this embodiment, the ammonia dosage is adjusted by the boiler bed temperature. Adjusting the air volume has a cooling effect on the boiler bed temperature. A correction coefficient for the ammonia dosage is set based on historical data on the influence of boiler bed temperature on ammonia dosage. When the boiler bed temperature is higher, the ammonia dosage will be appropriately reduced.

[0108] In some embodiments of this application, step three S103 further includes:

[0109] The boiler load is adjusted according to the ammonia water consumption. A preset boiler load matrix M is set, M(M1, M2, M3, M4), where M1 is the first preset boiler load, M2 is the second preset boiler load, M3 is the third preset boiler load, and M4 is the fourth preset boiler load, and M1 < M2 < M3 < M4.

[0110] When the ammonia water consumption is the first preset ammonia water consumption value E1, the boiler load is adjusted to the first preset boiler load M1.

[0111] When the ammonia water consumption is the second preset ammonia water consumption value E2, the boiler load is adjusted to the second preset boiler load M2.

[0112] When the ammonia water consumption is the third preset ammonia water consumption value E3, the boiler load is adjusted to the third preset boiler load M3.

[0113] When the ammonia water usage is the fourth preset ammonia water usage value E4, the boiler load is adjusted to the fourth preset boiler load M4.

[0114] In this embodiment, excessive ammonia injection at low load will aggravate ash accumulation and corrosion in the air preheater, seriously affecting the economy and safety of boiler operation; while ammonia consumption is too high at medium and high loads. By monitoring ammonia consumption in real time, the boiler load is adjusted to maintain the economy and safety of boiler operation.

[0115] In some embodiments of this application, in step three S103, determining the third correspondence relationship specifically involves:

[0116] The third correspondence is the correspondence between the air volume of the reaction zone and the preset nitrogen oxide emission. Based on historical data, a preset nitrogen oxide emission matrix K is set, and K(K1, K2, K3, K4) is defined, where K1 is the first preset nitrogen oxide emission, K2 is the second preset nitrogen oxide emission, K3 is the third preset nitrogen oxide emission, K4 is the fourth preset nitrogen oxide emission, and K4 < K3 < K2 < K1.

[0117] The nitrogen oxide emissions are determined based on the relationship between the air volume c in the reaction zone and the preset air volume interval matrix A.

[0118] When c < A1, the first preset nitrogen oxide emission K1 is determined to be the current nitrogen oxide emission of the reaction zone;

[0119] When A1≤c<A2, the second preset nitrogen oxide emission K2 is determined to be the current nitrogen oxide emission of the reaction zone;

[0120] When A2≤c<A3, the fourth preset nitrogen oxide emission K4 is determined to be the current nitrogen oxide emission of the reaction zone;

[0121] When A3≤c<A4, the third preset nitrogen oxide emission K3 is determined as the current nitrogen oxide emission of the reaction zone.

[0122] In this embodiment, the air volume is detected by the air volume detection module. When the air volume gradually increases, it has an inhibitory effect on the generation of nitrogen oxides. When the air volume increases to a certain extent, it will promote the emission of nitrogen oxides and reduce the denitrification efficiency.

[0123] In some embodiments of this application, step three S103 further includes:

[0124] Real-time detection of nitrogen oxide emissions n, and determination of the relationship between nitrogen oxide emissions n and the preset nitrogen oxide emission value B:

[0125] When n≥B, continue to increase the air volume in the reaction zone;

[0126] When n < B, it indicates that the nitrogen oxide emission n has reached the preset nitrogen oxide emission value B, and the nitrogen oxide emission n continues to decrease until the nitrogen oxide emission n increases, at which point the increase in the air volume of the reaction zone stops.

[0127] In this embodiment, the preset nitrogen oxide emission value is set according to the ultra-low emission standard in the "Emission Standard of Air Pollutants for Coal-fired Power Plants". When the nitrogen oxide emission changes from decreasing to increasing, the air volume in the reaction zone is stopped from being adjusted.

[0128] In some embodiments of this application, in step five S105, the first air volume range is modified to obtain a second air volume range, specifically as follows:

[0129] The flue temperature in the denitrification reaction zone is monitored in real time, and the first air volume range is corrected according to the flue temperature. The preset air volume range correction coefficient is β, and β(β1, β2, β3, β4) is set, where β1 is the first preset air volume range correction coefficient, β2 is the second preset air volume range correction coefficient, β3 is the third preset air volume range correction coefficient, β4 is the fourth preset air volume range correction coefficient, and β1 < β2 < β3 < β4 < 1;

[0130] The preset flue temperature matrix is ​​P, and P(P1, P2, P3, P4) is set, where P1 is the first preset flue temperature, P2 is the second preset flue temperature, P3 is the third preset flue temperature, and P4 is the fourth preset flue temperature, and P1 < P2 < P3 < P4.

[0131] The first airflow range is set as Q, and the first airflow range is corrected according to the relationship between the real-time detected flue temperature t and the preset flue temperature matrix:

[0132] When t < P1, the first preset air volume interval correction coefficient β1 is selected to correct the first preset air volume interval Q, and the second air volume interval is Q*β1 after correction.

[0133] When P1≤t<P2, the second preset air volume interval correction coefficient β2 is selected to correct the first preset air volume interval Q, and the second air volume interval is Q*β2 after correction.

[0134] When P2≤t<P3, the third preset air volume interval correction coefficient β3 is selected to correct the first preset air volume interval Q, and the second air volume interval is Q*β3 after correction.

[0135] When P3≤t<P4, the fourth preset air volume range correction coefficient β4 is selected to correct the first preset air volume range Q, and the second air volume range is obtained as Q*β4 after correction.

[0136] In this embodiment, the first air volume range is the air volume range of the reaction zone that satisfies the dual conditions of low ammonia water consumption and low nitrogen oxide emissions. The first air volume range is corrected according to the air volume range correction coefficient. The air volume range correction coefficient is selected based on the relationship between the real-time flue temperature and the preset flue temperature matrix to correct the first air volume range.

[0137] In some embodiments of this application, the method further includes:

[0138] During the denitrification reaction zone simulation process, the boiler combustion performance indicators are monitored in real time. When the boiler combustion performance indicators exceed the preset indicators, an early warning signal is issued. The boiler combustion performance indicators include pulverized coal burnout rate, fly ash carbon content, and lower furnace outlet temperature.

[0139] Through the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented in hardware or by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) and includes several instructions to cause a computer device (such as a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0140] In some embodiments of this application, such as Figure 2 As shown, it also includes a denitrification reaction zone airflow adjustment device, specifically:

[0141] Historical data storage module 201 is used to store historical data of the denitrification reaction zone;

[0142] The SNCR reaction model establishment module 202 is used to adjust the air volume in the reaction zone according to the SNCR reaction model and to detect the ammonia water usage, oxygen content, and nitrogen oxide emissions in the SNCR reaction model in real time.

[0143] The central control module 203 is used to determine a first correspondence, a second correspondence, and a third correspondence based on the ammonia water consumption, oxygen consumption, and nitrogen oxide emissions in the SNCR reaction model, and to obtain a first air volume interval based on the first correspondence interval, the second correspondence interval, and the third correspondence interval.

[0144] The correction module 204 is used to correct the first air volume range to obtain the second air volume range.

[0145] The central control module 203, the correction module 204, the historical data storage module 201, and the SNCR reaction model establishment module 202 are electrically connected.

[0146] Those skilled in the art will understand that the modules in the system of the implementation scenario can be distributed throughout the system of the implementation scenario as described, or they can be modified to reside in one or more systems different from this implementation scenario. The modules of the above-mentioned implementation scenario can be merged into one module, or they can be further divided into multiple sub-modules.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for adjusting the air volume in a denitrification reaction zone, characterized in that, include: Step 1: Obtain historical data for the denitrification reaction zone; Step 2: Establish an SNCR reaction model based on the historical data, and obtain the ammonia water usage, oxygen content, and nitrogen oxide emissions based on the SNCR reaction model; Step 3: Determine the first, second, and third correspondences based on the ammonia usage, oxygen content, and nitrogen oxide emissions within the SNCR reaction model; Step 4: Obtain the first air volume range based on the first correspondence, the second correspondence, and the third correspondence; Step 5: Correct the first airflow range to obtain the second airflow range; Wherein, the first correspondence is the correspondence between the air volume in the reaction zone and the oxygen content, the second correspondence is the correspondence between the oxygen content and the ammonia water usage, and the third correspondence is the correspondence between the air volume in the reaction zone and the nitrogen oxide emissions; In step three, the first correspondence is determined, specifically as follows: The first correspondence is the correspondence between the air volume of the reaction zone and the oxygen content. Based on the historical data, a reaction zone air volume interval matrix A is preset, and A (A1, A2, A3, A4) is set, where A1 is the first preset air volume interval, A2 is the second preset air volume interval, A3 is the third preset air volume interval, A4 is the fourth preset air volume interval, and A1 < A2 < A3 < A4. A preset oxygen content matrix B (B1, B2, B3, B4) is provided, where B1 is the first preset oxygen content, B2 is the second preset oxygen content, B3 is the third preset oxygen content, and B4 is the fourth preset oxygen content, and B1 < B2 < B3 < B4. When the air volume in the reaction zone is adjusted to c, the oxygen content in the reaction zone is selected according to the relationship between the air volume in the reaction zone c and the preset air volume interval matrix A. When c < A1, select the first preset oxygen quantity B1 as the current oxygen quantity in the reaction zone; When A1≤c<A2, select the second preset oxygen quantity B2 as the current oxygen quantity in the reaction zone; When A2≤c<A3, select the third preset oxygen quantity B3 as the current oxygen quantity in the reaction zone; When A3≤c<A4, select the fourth preset oxygen quantity B4 as the current oxygen quantity in the reaction zone; In step three, the second correspondence is determined, specifically as follows: The second correspondence is the correspondence between the oxygen content and the ammonia usage. Based on the historical data, a matrix E of ammonia usage values ​​is preset, and E (E1, E2, E3, E4) is set, where E1 is the first preset ammonia usage value, E2 is the second preset ammonia usage value, E3 is the third preset ammonia usage value, and E4 is the fourth preset ammonia usage value, and E1 < E2 < E3 < E4. When the current oxygen content in the reaction zone is detected to be the first preset oxygen content B1, the ammonia water usage in the reaction zone is determined to be the first preset ammonia water usage value E1. When the current oxygen content in the reaction zone is detected to be the second preset oxygen content B2, the ammonia water usage in the reaction zone is determined to be the second preset ammonia water usage value E2. When the current oxygen content in the reaction zone is detected to be the third preset oxygen content B3, the ammonia water usage in the reaction zone is determined to be the third preset ammonia water usage value E3. When the current oxygen content in the reaction zone is detected to be the fourth preset oxygen content B4, the ammonia water usage in the reaction zone is determined to be the fourth preset ammonia water usage value E4. Step three also includes: The boiler bed temperature is monitored in real time, and the ammonia dosage is corrected according to the boiler bed temperature. A preset ammonia dosage correction coefficient matrix α is set, α (α1, α2, α3, α4), where α1 is the first preset ammonia dosage correction coefficient, α2 is the second preset ammonia dosage correction coefficient, α3 is the third preset ammonia dosage correction coefficient, and α4 is the fourth preset ammonia dosage correction coefficient, and α1 < α2 < α3 < α4 < 1; A preset boiler bed temperature matrix T is defined as T(T1, T2, T3, T4), where T1 is the first preset boiler bed temperature, T2 is the second preset boiler bed temperature, T3 is the third preset boiler bed temperature, and T4 is the fourth preset boiler bed temperature, and T1 < T2 < T3 < T4. When the preset ammonia dosage is the i-th preset ammonia dosage value, i=1, 2, 3, 4, the boiler bed temperature d is detected in real time, and the ammonia dosage value is corrected according to the relationship between the bed temperature d and the preset boiler bed temperature matrix. When d < T1, the first preset ammonia dosage correction coefficient α1 is selected to correct the i-th preset ammonia dosage value, and the corrected ammonia dosage value is α1. Ei; When T1≤d<T2, the second preset ammonia dosage correction coefficient α2 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α2. Ei; When T2≤d<T3, the third preset ammonia dosage correction coefficient α3 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α3. Ei; When T3≤d<T4, the fourth preset ammonia dosage correction coefficient α4 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α4. Ei; In step three, the third correspondence is determined, specifically as follows: The third correspondence is the correspondence between the air volume of the reaction zone and the nitrogen oxide emissions. A nitrogen oxide emission matrix K is preset based on historical data, and K (K1, K2, K3, K4) is set, where K1 is the first preset nitrogen oxide emission, K2 is the second preset nitrogen oxide emission, K3 is the third preset nitrogen oxide emission, K4 is the fourth preset nitrogen oxide emission, and K4 < K3 < K2 < K1; The nitrogen oxide emissions are determined based on the relationship between the air volume c in the reaction zone and the preset air volume interval matrix A. When c < A1, the first preset nitrogen oxide emission K1 is determined to be the current nitrogen oxide emission of the reaction zone; When A1≤c<A2, the second preset nitrogen oxide emission K2 is determined to be the current nitrogen oxide emission of the reaction zone; When A2≤c<A3, the fourth preset nitrogen oxide emission K4 is determined to be the current nitrogen oxide emission of the reaction zone; When A3≤c<A4, the third preset nitrogen oxide emission K3 is determined as the current nitrogen oxide emission of the reaction zone.

2. The method for adjusting the air volume in the denitrification reaction zone as described in claim 1, characterized in that, Step three also includes: Adjust the boiler load according to the ammonia water consumption, preset the boiler load matrix M, set M (M1, M2, M3, M4), where M1 is the first preset boiler load, M2 is the second preset boiler load, M3 is the third preset boiler load, M4 is the fourth preset boiler load, and M1 < M2 < M3 < M4. When the ammonia water consumption is the first preset ammonia water consumption value E1, the boiler load is adjusted to the first preset boiler load M1. When the ammonia water consumption is the second preset ammonia water consumption value E2, the boiler load is adjusted to the second preset boiler load M2. When the ammonia water consumption is the third preset ammonia water consumption value E3, the boiler load is adjusted to the third preset boiler load M3. When the ammonia water usage is the fourth preset ammonia water usage value E4, the boiler load is adjusted to the fourth preset boiler load M4.

3. The method for adjusting the air volume in the denitrification reaction zone as described in claim 1, characterized in that, Step three also includes: Real-time detection of nitrogen oxide emissions n, and determination of the relationship between nitrogen oxide emissions n and preset nitrogen oxide emission value B: When n≥B, continue to increase the air volume in the reaction zone; When n < B, it indicates that the nitrogen oxide emission n has reached the preset nitrogen oxide emission value B, and the nitrogen oxide emission n continues to decrease until the nitrogen oxide emission n increases, at which point the increase in the air volume of the reaction zone stops.

4. The method for adjusting the air volume in the denitrification reaction zone as described in claim 1, characterized in that, In step five, the first airflow range is corrected to obtain the second airflow range, specifically as follows: The flue temperature in the denitrification reaction zone is monitored in real time, and the first air volume range is corrected according to the flue temperature. The preset air volume range correction coefficient is β, and β (β1, β2, β3, β4) is set, where β1 is the first preset air volume range correction coefficient, β2 is the second preset air volume range correction coefficient, β3 is the third preset air volume range correction coefficient, β4 is the fourth preset air volume range correction coefficient, and β1 < β2 < β3 < β4 < 1; The preset flue temperature matrix is ​​P, and P(P1, P2, P3, P4) is set, where P1 is the first preset flue temperature, P2 is the second preset flue temperature, P3 is the third preset flue temperature, and P4 is the fourth preset flue temperature, and P1 < P2 < P3 < P4. The first airflow range is set as Q, and the first airflow range is corrected according to the relationship between the real-time detected flue temperature t and the preset flue temperature matrix: When t < P1, the first preset air volume interval correction coefficient β1 is selected to correct the first preset air volume interval Q. After correction, the second air volume interval is obtained as Q. β1; When P1≤t<P2, the second preset airflow range correction coefficient β2 is selected to correct the first preset airflow range Q. After correction, the second airflow range is obtained as Q. β2; When P2≤t<P3, the third preset airflow range correction coefficient β3 is selected to correct the first preset airflow range Q. After correction, the second airflow range is obtained as Q. β3; When P3≤t<P4, the fourth preset air volume interval correction coefficient β4 is selected to correct the first preset air volume interval Q. After correction, the second air volume interval is obtained as Q. β4.

5. The method for adjusting the air volume in the denitrification reaction zone as described in claim 1, characterized in that, The method further includes: In the SNCR reaction model, the boiler combustion performance indicators are monitored in real time. When the boiler combustion performance indicators exceed the preset indicators, an early warning signal is issued. The boiler combustion performance indicators include pulverized coal burnout rate, fly ash carbon content, and lower furnace outlet temperature.

6. A denitrification reaction zone airflow adjustment device, characterized in that, include: The historical data storage module is used to store historical data of the denitrification reaction zone; The SNCR reaction model establishment module is used to adjust the air volume in the reaction zone according to the SNCR reaction model and to detect the ammonia water usage, oxygen content, and nitrogen oxide emissions in the SNCR reaction model in real time. The central control module is used to determine the first, second, and third correspondences based on the ammonia water usage, oxygen content, and nitrogen oxide emissions in the SNCR reaction model, and to obtain the first air volume interval based on the first, second, and third correspondence intervals. The correction module is used to correct the first air volume range to obtain the second air volume range; The central control module, the correction module, the historical data storage module, and the SNCR reaction model establishment module are electrically connected. The first correspondence is determined as follows: The first correspondence is the correspondence between the air volume of the reaction zone and the oxygen content. Based on the historical data, a reaction zone air volume interval matrix A is preset, and A (A1, A2, A3, A4) is set, where A1 is the first preset air volume interval, A2 is the second preset air volume interval, A3 is the third preset air volume interval, A4 is the fourth preset air volume interval, and A1 < A2 < A3 < A4. A preset oxygen content matrix B (B1, B2, B3, B4) is provided, where B1 is the first preset oxygen content, B2 is the second preset oxygen content, B3 is the third preset oxygen content, and B4 is the fourth preset oxygen content, and B1 < B2 < B3 < B4. When the air volume in the reaction zone is adjusted to c, the oxygen content in the reaction zone is selected according to the relationship between the air volume in the reaction zone c and the preset air volume interval matrix A. When c < A1, select the first preset oxygen quantity B1 as the current oxygen quantity in the reaction zone; When A1≤c<A2, select the second preset oxygen quantity B2 as the current oxygen quantity in the reaction zone; When A2≤c<A3, select the third preset oxygen quantity B3 as the current oxygen quantity in the reaction zone; When A3≤c<A4, select the fourth preset oxygen quantity B4 as the current oxygen quantity in the reaction zone; The second correspondence is determined as follows: The second correspondence is the correspondence between the oxygen content and the ammonia usage. Based on the historical data, a matrix E of ammonia usage values ​​is preset, and E (E1, E2, E3, E4) is set, where E1 is the first preset ammonia usage value, E2 is the second preset ammonia usage value, E3 is the third preset ammonia usage value, and E4 is the fourth preset ammonia usage value, and E1 < E2 < E3 < E4. When the current oxygen content in the reaction zone is detected to be the first preset oxygen content B1, the ammonia water usage in the reaction zone is determined to be the first preset ammonia water usage value E1. When the current oxygen content in the reaction zone is detected to be the second preset oxygen content B2, the ammonia water usage in the reaction zone is determined to be the second preset ammonia water usage value E2. When the current oxygen content in the reaction zone is detected to be the third preset oxygen content B3, the ammonia water usage in the reaction zone is determined to be the third preset ammonia water usage value E3. When the current oxygen content in the reaction zone is detected to be the fourth preset oxygen content B4, the ammonia water usage in the reaction zone is determined to be the fourth preset ammonia water usage value E4. Also includes: The boiler bed temperature is monitored in real time, and the ammonia dosage is corrected according to the boiler bed temperature. A preset ammonia dosage correction coefficient matrix α is set, α (α1, α2, α3, α4), where α1 is the first preset ammonia dosage correction coefficient, α2 is the second preset ammonia dosage correction coefficient, α3 is the third preset ammonia dosage correction coefficient, and α4 is the fourth preset ammonia dosage correction coefficient, and α1 < α2 < α3 < α4 < 1; A preset boiler bed temperature matrix T is defined as T(T1, T2, T3, T4), where T1 is the first preset boiler bed temperature, T2 is the second preset boiler bed temperature, T3 is the third preset boiler bed temperature, and T4 is the fourth preset boiler bed temperature, and T1 < T2 < T3 < T4. When the preset ammonia dosage is the i-th preset ammonia dosage value, i=1, 2, 3, 4, the boiler bed temperature d is detected in real time, and the ammonia dosage value is corrected according to the relationship between the bed temperature d and the preset boiler bed temperature matrix. When d < T1, the first preset ammonia dosage correction coefficient α1 is selected to correct the i-th preset ammonia dosage value, and the corrected ammonia dosage value is α1. Ei; When T1≤d<T2, the second preset ammonia dosage correction coefficient α2 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α2. Ei; When T2≤d<T3, the third preset ammonia dosage correction coefficient α3 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α3. Ei; When T3≤d<T4, the fourth preset ammonia dosage correction coefficient α4 is selected to correct the i-th preset ammonia dosage value. The corrected ammonia dosage value is α4. Ei; In step three, the third correspondence is determined, specifically as follows: The third correspondence is the correspondence between the air volume of the reaction zone and the nitrogen oxide emissions. A nitrogen oxide emission matrix K is preset based on historical data, and K (K1, K2, K3, K4) is set, where K1 is the first preset nitrogen oxide emission, K2 is the second preset nitrogen oxide emission, K3 is the third preset nitrogen oxide emission, K4 is the fourth preset nitrogen oxide emission, and K4 < K3 < K2 < K1; The nitrogen oxide emissions are determined based on the relationship between the air volume c in the reaction zone and the preset air volume interval matrix A. When c < A1, the first preset nitrogen oxide emission K1 is determined to be the current nitrogen oxide emission of the reaction zone; When A1≤c<A2, the second preset nitrogen oxide emission K2 is determined to be the current nitrogen oxide emission of the reaction zone; When A2≤c<A3, the fourth preset nitrogen oxide emission K4 is determined to be the current nitrogen oxide emission of the reaction zone; When A3≤c<A4, the third preset nitrogen oxide emission K3 is determined as the current nitrogen oxide emission of the reaction zone.

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