A dual-function nitrogen oxide measuring device and measuring method

Abstract

The present invention discloses a dual-function nitrogen oxide measurement device and measurement method, the device includes: a collection mechanism, which is vertically arranged in the flue, and the collection mechanism is used to collect the flue gas in the flue; a temperature detection pool, which is connected to the collection mechanism, and the temperature detection pool is used to detect the flue gas temperature; a data detection pool, which is connected to the temperature detection pool, and the data detection pool is used to detect the flue gas data; a control cabinet, which is electrically connected to the temperature detection pool and the data detection pool, and the control cabinet is used to control the opening of the ammonia injection valve according to the flue gas temperature and the flue gas data. The present application obtains the first initial ammonia injection valve opening through the deviation value, determines the valve opening adjustment amount according to the ammonia escape amount, adjusts the first initial ammonia injection valve opening according to the valve opening adjustment amount, and corrects the second initial ammonia injection valve opening according to the flue gas temperature to obtain the ammonia injection valve opening. The accuracy of ammonia injection valve control is improved, and energy resources are saved.

Description

Technical Field

[0001] The present application relates to the technical field of boiler control, and more specifically, to a dual-function nitrogen oxide measuring device and a measuring method. Background Art

[0002] In the boiler flue gas denitrification project, in order to more effectively improve the denitrification efficiency and reduce a series of negative problems caused by excessive ammonia injection, the NO discharged into the environment X Under the requirements of national environmental protection standards, it is required to reduce the total amount of ammonia injection to the minimum value, and control the total amount of ammonia injection to make denitrification more effective. The most important basis for adjusting the total amount of ammonia injection during denitrification operation is the NO at the denitrification outlet. X Data, get accurate NO X Data is particularly important, and the main factor in improving accuracy is that the flue gas sampled in the flue must be representative.

[0003] In the existing technology, the flue gas sampling schemes for denitrification projects in various power plants are varied and uneven, mainly including single probe sampling, multi-probe sampling, grid sampling, and the sampled flue gas enters the analyzer for analysis to obtain NO X However, the above method only controls the amount of ammonia injection according to the nitrogen oxide content, and the nitrogen oxide content alone cannot accurately reflect the factors affecting the amount of ammonia injection, resulting in inaccurate control and low precision.

[0004] Therefore, how to improve the accuracy of ammonia injection control is a technical problem that needs to be solved. Summary of the invention

[0005] The present invention provides a dual-function nitrogen oxide measuring device to solve the technical problem of low accuracy of ammonia injection control in the prior art. The device is applied to the flue of a coal-fired boiler denitrification system, and the device comprises:

[0006] A collection mechanism is vertically arranged in the flue, and is used to collect the flue gas in the flue;

[0007] A temperature detection pool, connected to the collection mechanism, and used to detect the flue gas temperature;

[0008] A data detection pool, connected to the temperature detection pool, and used to detect smoke data;

[0009] A control cabinet is electrically connected to the temperature detection pool and the data detection pool, and the control cabinet is used to control the opening of the ammonia injection valve according to the flue gas temperature and the flue gas data.

[0010] In some embodiments of the present application, the collection mechanism includes:

[0011] A main pipe connected to the temperature detection pool;

[0012] Branch pipes, wherein the branch pipes are multiple pipes of different lengths;

[0013] A sampling hole is provided at the bottom end of each branch pipe;

[0014] A pneumatic valve is connected to the branch pipes, and the pneumatic valve is used to control the opening and closing of each branch pipe.

[0015] In some embodiments of the present application, the data detection pool includes:

[0016] A first analysis cabinet, electrically connected to the control cabinet, and used to obtain the amount of ammonia escape in the flue gas;

[0017] A second analysis cabinet, electrically connected to the control cabinet, the second analysis cabinet being used to obtain the nitrogen oxide content in the flue gas;

[0018] The third analysis cabinet is electrically connected to the control cabinet, and the third analysis cabinet is used to obtain the temperature of the flue gas.

[0019] In some embodiments of the present application, the control cabinet includes:

[0020] A compressed air control cabinet connected to the flue;

[0021] The PLC control cabinet is electrically connected to the compressed air control cabinet.

[0022] A dual-function nitrogen oxide measurement method is applied to the dual-function nitrogen oxide measurement device mentioned above, and the method comprises:

[0023] Open the pneumatic valves of all branch pipes to obtain the average value of nitrogen oxides, ammonia escape and flue gas temperature;

[0024] Close all pneumatic valves, and open the pneumatic valves one by one in the preset opening sequence to obtain the nitrogen oxide rotation value;

[0025] A first initial ammonia injection valve opening is obtained according to the nitrogen oxide mean value and the nitrogen oxide rotation value, a second initial ammonia injection valve opening is obtained based on the first initial ammonia injection valve opening and the ammonia slip amount, and the second initial ammonia injection valve opening is corrected according to the flue gas temperature to obtain the ammonia injection valve opening.

[0026] In some embodiments of the present application, the first initial ammonia injection valve opening is obtained according to the nitrogen oxide mean value and the nitrogen oxide rotation value, specifically:

[0027] The deviation value is obtained according to the nitrogen oxide mean value and the nitrogen oxide rotation value;

[0028] Obtain a first initial ammonia injection valve opening according to the deviation value, set the deviation value to A, and preset the deviation value array A0 (A1, A2, A3, A4), wherein the first preset deviation value is A1, the second preset deviation value is A2, the third preset deviation value is A3, the fourth preset deviation value is A4, and A1<A2<A3<A4;

[0029] The first initial ammonia injection valve opening is set to B, and a first initial ammonia injection valve opening array B0 (B1, B2, B3, B4) is preset, wherein the first preset first initial ammonia injection valve opening is B1, the second preset first initial ammonia injection valve opening is B2, the third preset first initial ammonia injection valve opening is B3, the fourth preset first initial ammonia injection valve opening is B4, and B1<B2<B3<B4;

[0030] Determine the first initial ammonia injection valve opening according to the relationship between the deviation value and each preset deviation value;

[0031] If A<A1, determine the first preset first initial ammonia injection valve opening B1 as the first initial ammonia injection valve opening;

[0032] If A1≤A<A2, determine the second preset first initial ammonia injection valve opening B2 as the first initial ammonia injection valve opening;

[0033] If A2≤A<A3, determine the third preset first initial ammonia injection valve opening B3 as the first initial ammonia injection valve opening;

[0034] If A3≤A<A4, the fourth preset first initial ammonia injection valve opening B4 is determined as the first initial ammonia injection valve opening.

[0035] In some embodiments of the present application, the second initial ammonia injection valve opening is obtained based on the first initial ammonia injection valve opening and the ammonia slip amount, specifically:

[0036] A valve opening adjustment amount is obtained according to the ammonia slip amount, and a second initial ammonia injection valve opening is obtained according to the first initial ammonia injection valve opening and the valve opening adjustment amount;

[0037] The ammonia slip amount is set to C, and an ammonia slip amount array C0 (C1, C2, C3, C4) is preset, wherein the first preset ammonia slip amount is C1, the second preset ammonia slip amount is C2, the third preset ammonia slip amount is C3, the fourth preset ammonia slip amount is C4, and C1<C2<C3<C4;

[0038] A preset valve opening adjustment amount array △Q0 (△Q1, △Q2, △Q3, △Q4), wherein the first preset valve opening adjustment amount is △Q1, the second preset valve opening adjustment amount is △Q2, the third preset valve opening adjustment amount is △Q3, the fourth preset valve opening adjustment amount is △Q4, and △Q1<△Q2<△Q3<△Q4;

[0039] Determine the valve opening adjustment amount according to the relationship between the ammonia slip amount and each preset ammonia slip amount, and obtain the second initial ammonia injection valve opening according to the valve opening adjustment amount;

[0040] If C<C1, the first preset valve opening adjustment amount △Q1 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q1;

[0041] If C1≤C<C2, the second preset valve opening adjustment amount △Q2 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q2;

[0042] If C2≤C<C3, the third preset valve opening adjustment amount △Q3 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q3;

[0043] If C3≤C<C4, the fourth preset valve opening adjustment amount △Q4 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q4.

[0044] In some embodiments of the present application, the second initial ammonia injection valve opening is corrected according to the flue gas temperature to obtain the ammonia injection valve opening, specifically:

[0045] Set the smoke temperature to T, and preset the smoke temperature array T0 (T1, T2, T3, T4), wherein the first preset smoke temperature is T1, the second preset smoke temperature is T2, the third preset smoke temperature is T3, the fourth preset smoke temperature is T4, and T1<T2<T3<T4;

[0046] The second initial ammonia injection valve opening is set to D, and a second initial ammonia injection valve opening correction coefficient array k0 (k1, k2, k3, k4) is preset, wherein the first preset second initial ammonia injection valve opening correction coefficient is k1, the second preset second initial ammonia injection valve opening correction coefficient is k2, the third preset second initial ammonia injection valve opening correction coefficient is k3, and the fourth preset second initial ammonia injection valve opening correction coefficient is k4, and 1<k1<k2<k3<k4<1.8;

[0047] Determine the second initial ammonia injection valve opening correction coefficient according to the relationship between the flue gas temperature and each preset flue gas temperature, thereby obtaining the ammonia injection valve opening;

[0048] If T<T1, the first preset second initial ammonia injection valve opening correction coefficient k1 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k1;

[0049] If T1≤T<T2, the second preset second initial ammonia injection valve opening correction coefficient k2 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k2;

[0050] If T2≤T<T3, the third preset second initial ammonia injection valve opening correction coefficient k3 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k3;

[0051] If T3≤T<T4, the fourth preset second initial ammonia injection valve opening correction coefficient k4 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k4.

[0052] By applying the above technical solution, a collection mechanism is vertically arranged in the flue, and the collection mechanism is used to collect the flue gas in the flue; a temperature detection pool is connected to the collection mechanism, and the temperature detection pool is used to detect the flue gas temperature; a data detection pool is connected to the temperature detection pool, and the data detection pool is used to detect the flue gas data; a control cabinet is electrically connected to the temperature detection pool and the data detection pool, and the control cabinet is used to control the opening of the ammonia injection valve according to the flue gas temperature and the flue gas data. The present application obtains the first initial ammonia injection valve opening through the deviation value, determines the valve opening adjustment amount according to the ammonia escape amount, adjusts the first initial ammonia injection valve opening according to the valve opening adjustment amount, and corrects the second initial ammonia injection valve opening according to the flue gas temperature to obtain the ammonia injection valve opening. The accuracy of ammonia injection valve control is improved, and energy resources are saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0054] Figure 1 A schematic structural diagram of a dual-function nitrogen oxide measuring device proposed in an embodiment of the present invention is shown;

[0055] Figure 2 A schematic diagram of the structure of the sampling hole partition in an embodiment of the present invention is shown;

[0056] Figure 3 A schematic flow chart of a dual-function nitrogen oxide measurement method in an embodiment of the present invention is shown.

[0057] Among them, 1. Main pipe; 2. Branch pipe; 3. Sampling hole; 4. Temperature detection pool; 5. Data detection pool; 51. First analysis cabinet; 52. Second analysis cabinet; 53. Third analysis cabinet; 6. Compressed air control cabinet; 7. PLC control cabinet. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] The present application provides a dual-function nitrogen oxide measuring device, which is applied to the flue of a coal-fired boiler denitrification system. Figure 1 As shown, the device comprises:

[0060] A collection mechanism is vertically arranged in the flue, and is used to collect the flue gas in the flue;

[0061] A temperature detection pool 4 is connected to the collection mechanism, and the temperature detection pool 4 is used to detect the flue gas temperature;

[0062] A data detection pool 5 is connected to the temperature detection pool 4, and is used to detect flue gas data, including nitrogen oxide mean value, ammonia escape amount, and nitrogen oxide rotation value;

[0063] The control cabinet is electrically connected to the temperature detection pool 4 and the data detection pool 5, and the control cabinet is used to control the opening of the ammonia injection valve according to the flue gas temperature and flue gas data.

[0064] In some embodiments of the present application, the collection mechanism includes:

[0065] The main pipe 1 is connected to the temperature detection pool 4;

[0066] Branch pipe 2, wherein the branch pipe 2 is a plurality of pipes of different lengths;

[0067] A sampling hole 3 is provided at the bottom end of each branch pipe 2;

[0068] A pneumatic valve is connected to the branch pipe 2 , and the pneumatic valve is used to control the opening and closing of each branch pipe 2 .

[0069] In this embodiment, the arrangement of each sampling hole 3 and branch pipe 2 is based on the distribution of the ammonia injection grid, and each sampling hole 3 corresponds to an ammonia injection grid. Figure 2 As shown, it can be understood that each sampling hole 3 is a different area, dividing the vertical cross section of the flue into ①②③④⑤⑥⑦⑧⑨⑩ There are three small areas: ①, ④, ⑦, and ⑩ are all at the same level, ②, ⑤, ⑧, All are at the same level, ③, ⑥, ⑨, All are at the same level. ①, ②, ③ gradually decrease in height, ④⑤⑥ gradually decrease in height, ⑦⑧⑨ gradually decrease in height, ⑩ The height gradually decreases.

[0070] Nitrogen oxide average value: relying on flue differential pressure drainage, ensure that the air intake of each sampling hole 3 is consistent, and the air is mixed into the main pipe 1 outside the flue to form a mixed flow, and then enters the analysis cabinet to measure the full-section NO X value, the data obtained is NO X Mean (obtained according to the principle of the analyzer, equivalent to the average value, that is, NO in a certain space X Average content). Nitrogen oxide rotation: relying on flue differential pressure drainage, ensure that the intake volume of each sampling hole 3 is consistent, and the air is taken in in sequence, and then enters the analyzer (second analysis cabinet 52) ​​to measure the small area NO X The data obtained is the NOX value of one small area. Similarly, the NOX value of all sampling holes 3 is measured. X The deviation value is the difference between the NOx wheel value and the NOx mean value.

[0071] It is understandable that the above-mentioned multiple small areas can be adapted to the conditions according to the number of sampling holes 3 and the number of branch pipes 2, and the number of sampling holes 3 and the number of branch pipes 2 can be adjusted according to actual conditions, which all fall within the protection scope of this application.

[0072] In some embodiments of the present application, the data detection pool 5 includes:

[0073] A first analysis cabinet 51, electrically connected to the control cabinet, and used to obtain the amount of ammonia escape in the flue gas;

[0074] A second analysis cabinet 52, electrically connected to the control cabinet, and the second analysis cabinet 52 is used to obtain the nitrogen oxide content in the flue gas;

[0075] The third analysis cabinet 53 is electrically connected to the control cabinet, and the third analysis cabinet 53 is used to obtain the temperature of the flue gas.

[0076] In this embodiment, different analysis cabinets are equipped with different analyzers and other equipment for acquiring required data.

[0077] In some embodiments of the present application, the control cabinet includes:

[0078] A compressed air control cabinet 6, connected to the flue;

[0079] The PLC control cabinet 7 is electrically connected to the compressed air control cabinet 6 .

[0080] By applying the above technical solution, the collection mechanism is vertically arranged in the flue, and the collection mechanism is used to collect the flue gas in the flue; the temperature detection pool 4 is connected to the collection mechanism, and the temperature detection pool 4 is used to detect the flue gas temperature; the data detection pool 5 is connected to the temperature detection pool 4, and the data detection pool 5 is used to detect the flue gas data; the control cabinet is electrically connected to the temperature detection pool 4 and the data detection pool 5, and the control cabinet is used to control the opening of the ammonia injection valve according to the flue gas temperature and the flue gas data. The present application obtains the first initial ammonia injection valve opening through the deviation value, determines the valve opening adjustment amount according to the ammonia escape amount, adjusts the first initial ammonia injection valve opening according to the valve opening adjustment amount, and corrects the second initial ammonia injection valve opening according to the flue gas temperature to obtain the ammonia injection valve opening. The accuracy of ammonia injection valve control is improved, and energy resources are saved.

[0081] A dual-function nitrogen oxide measurement method is applied to the dual-function nitrogen oxide measurement device mentioned above, such as Figure 3 As shown, the method includes:

[0082] Step S101, open the pneumatic valves of all branch pipes 2 to obtain the average value of nitrogen oxides, ammonia escape amount and flue gas temperature.

[0083] In this embodiment, when obtaining the average value of nitrogen oxides, it is necessary to open the pneumatic valves of all branch pipes 2 and perform sampling at all sampling holes 3. Ammonia escape, the so-called ammonia escape is literally understood as: ammonia escapes. In fact, it is when too much ammonia is sprayed, and the excess part that reacts with nitrogen oxides flows along the flue gas to the desulfurization tower, the dust collector, and finally is discharged from the chimney. This series of processes is called ammonia escape, and the detected amount is the ammonia escape.

[0084] Step S102, close all pneumatic valves, open the pneumatic valves one by one according to a preset opening sequence, and obtain the nitrogen oxide rotation value.

[0085] In this embodiment, when obtaining the nitrogen oxide rotation value, the pneumatic valves need to be opened one by one. When a certain pneumatic valve is opened, the other pneumatic valves are closed. Only in this way can the nitrogen oxide content in a single small area be measured.

[0086] Step S103, obtaining a first initial ammonia injection valve opening according to the nitrogen oxide mean value and the nitrogen oxide rotation value, obtaining a second initial ammonia injection valve opening based on the first initial ammonia injection valve opening and the ammonia slip amount, and correcting the second initial ammonia injection valve opening according to the flue gas temperature to obtain the ammonia injection valve opening.

[0087] In order to improve the accuracy of ammonia injection control, in some embodiments of the present application, the first initial ammonia injection valve opening is obtained according to the nitrogen oxide mean value and the nitrogen oxide rotation value, specifically:

[0088] The deviation value is obtained according to the nitrogen oxide mean value and the nitrogen oxide rotation value;

[0089] Obtain a first initial ammonia injection valve opening according to the deviation value, set the deviation value to A, and preset the deviation value array A0 (A1, A2, A3, A4), wherein the first preset deviation value is A1, the second preset deviation value is A2, the third preset deviation value is A3, the fourth preset deviation value is A4, and A1<A2<A3<A4;

[0090] The first initial ammonia injection valve opening is set to B, and a first initial ammonia injection valve opening array B0 (B1, B2, B3, B4) is preset, wherein the first preset first initial ammonia injection valve opening is B1, the second preset first initial ammonia injection valve opening is B2, the third preset first initial ammonia injection valve opening is B3, the fourth preset first initial ammonia injection valve opening is B4, and B1<B2<B3<B4;

[0091] Determine the first initial ammonia injection valve opening according to the relationship between the deviation value and each preset deviation value;

[0092] If A<A1, determine the first preset first initial ammonia injection valve opening B1 as the first initial ammonia injection valve opening;

[0093] If A1≤A<A2, determine the second preset first initial ammonia injection valve opening B2 as the first initial ammonia injection valve opening;

[0094] If A2≤A<A3, determine the third preset first initial ammonia injection valve opening B3 as the first initial ammonia injection valve opening;

[0095] If A3≤A<A4, the fourth preset first initial ammonia injection valve opening B4 is determined as the first initial ammonia injection valve opening.

[0096] In this embodiment, the larger the deviation value (the difference between the nitrogen oxide rotation value and the nitrogen oxide mean value), the greater the amount of ammonia required, and the opening of the ammonia injection valve is controlled accordingly. The larger the opening of the ammonia injection valve, the greater the amount of ammonia injected.

[0097] In order to further improve the accuracy of ammonia injection control, in some embodiments of the present application, the second initial ammonia injection valve opening is obtained based on the first initial ammonia injection valve opening and the ammonia slip amount, specifically:

[0098] A valve opening adjustment amount is obtained according to the ammonia slip amount, and a second initial ammonia injection valve opening is obtained according to the first initial ammonia injection valve opening and the valve opening adjustment amount;

[0099] The ammonia slip amount is set to C, and an ammonia slip amount array C0 (C1, C2, C3, C4) is preset, wherein the first preset ammonia slip amount is C1, the second preset ammonia slip amount is C2, the third preset ammonia slip amount is C3, the fourth preset ammonia slip amount is C4, and C1<C2<C3<C4;

[0100] A preset valve opening adjustment amount array △Q0 (△Q1, △Q2, △Q3, △Q4), wherein the first preset valve opening adjustment amount is △Q1, the second preset valve opening adjustment amount is △Q2, the third preset valve opening adjustment amount is △Q3, the fourth preset valve opening adjustment amount is △Q4, and △Q1<△Q2<△Q3<△Q4;

[0101] Determine the valve opening adjustment amount according to the relationship between the ammonia slip amount and each preset ammonia slip amount, and obtain the second initial ammonia injection valve opening according to the valve opening adjustment amount;

[0102] If C<C1, the first preset valve opening adjustment amount △Q1 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q1;

[0103] If C1≤C<C2, the second preset valve opening adjustment amount △Q2 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q2;

[0104] If C2≤C<C3, the third preset valve opening adjustment amount △Q3 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q3;

[0105] If C3≤C<C4, the fourth preset valve opening adjustment amount △Q4 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q4.

[0106] In this embodiment, the ammonia slip amount is relatively large, indicating that too much ammonia is injected and the ammonia injection amount needs to be reduced, and the opening of the first initial ammonia injection valve is adjusted accordingly.

[0107] In some embodiments of the present application, the second initial ammonia injection valve opening is corrected according to the flue gas temperature to obtain the ammonia injection valve opening, specifically:

[0108] Set the smoke temperature to T, and preset the smoke temperature array T0 (T1, T2, T3, T4), wherein the first preset smoke temperature is T1, the second preset smoke temperature is T2, the third preset smoke temperature is T3, the fourth preset smoke temperature is T4, and T1<T2<T3<T4;

[0109] The second initial ammonia injection valve opening is set to D, and a second initial ammonia injection valve opening correction coefficient array k0 (k1, k2, k3, k4) is preset, wherein the first preset second initial ammonia injection valve opening correction coefficient is k1, the second preset second initial ammonia injection valve opening correction coefficient is k2, the third preset second initial ammonia injection valve opening correction coefficient is k3, and the fourth preset second initial ammonia injection valve opening correction coefficient is k4, and 1<k1<k2<k3<k4<1.8;

[0110] Determine the second initial ammonia injection valve opening correction coefficient according to the relationship between the flue gas temperature and each preset flue gas temperature, thereby obtaining the ammonia injection valve opening;

[0111] If T<T1, the first preset second initial ammonia injection valve opening correction coefficient k1 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k1;

[0112] If T1≤T<T2, the second preset second initial ammonia injection valve opening correction coefficient k2 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k2;

[0113] If T2≤T<T3, the third preset second initial ammonia injection valve opening correction coefficient k3 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k3;

[0114] If T3≤T<T4, the fourth preset second initial ammonia injection valve opening correction coefficient k4 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k4.

[0115] In this embodiment, the amount of ammonia injection will affect the flue gas temperature to a certain extent. Therefore, the second initial ammonia injection valve opening needs to be corrected according to the flue gas temperature to obtain an accurate ammonia injection valve opening (ammonia injection amount).

[0116] It is understandable that the first initial ammonia injection valve opening and the second initial ammonia injection valve opening are both preset or assumed initial ammonia injection valve openings and are not implemented.

[0117] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present invention can be implemented by hardware, or by means of software plus a necessary general hardware platform. Based on such an 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 (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each implementation scenario of the present invention.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements 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 the present application.

Claims

1. A nitrogen oxide measurement method applied to a dual-function nitrogen oxide measurement device, applied to the flue of a coal-fired boiler denitrification system, characterized in that: The device comprises: A collection mechanism is vertically arranged in the flue, and is used to collect the flue gas in the flue; A temperature detection pool, connected to the collection mechanism, and used to detect the flue gas temperature; A data detection pool, connected to the temperature detection pool, and used to detect smoke data; A control cabinet, electrically connected to the temperature detection pool and the data detection pool, and used to control the opening of the ammonia injection valve according to the flue gas temperature and flue gas data; The method comprises: Open the pneumatic valves of all branch pipes to obtain the average value of nitrogen oxides, ammonia escape and flue gas temperature; Close all pneumatic valves, and open the pneumatic valves one by one in the preset opening sequence to obtain the nitrogen oxide rotation value; Obtain a first initial ammonia injection valve opening according to the nitrogen oxide mean value and the nitrogen oxide rotation value, obtain a second initial ammonia injection valve opening based on the first initial ammonia injection valve opening and the ammonia slip amount, and correct the second initial ammonia injection valve opening according to the flue gas temperature to obtain the ammonia injection valve opening; The first initial ammonia injection valve opening is obtained according to the nitrogen oxide average value and the nitrogen oxide rotation value, specifically: The deviation value is obtained according to the nitrogen oxide mean value and the nitrogen oxide rotation value; According to the deviation value, a first initial ammonia injection valve opening is obtained, the deviation value is set to A, and a deviation value array A0 is preset, wherein A0 is composed of a first preset deviation value A1, a second preset deviation value A2, a third preset deviation value A3, and a fourth preset deviation value A4; and A1<A2<A3<A4; The first initial ammonia injection valve opening is set to B, and a first initial ammonia injection valve opening array B0 is preset, wherein B0 is composed of a first preset first initial ammonia injection valve opening B1, a second preset first initial ammonia injection valve opening B2, a third preset first initial ammonia injection valve opening B3, and a fourth preset first initial ammonia injection valve opening B4, and B1<B2<B3<B4; Determine the first initial ammonia injection valve opening according to the relationship between the deviation value and each preset deviation value; If A<A1, determine the first preset first initial ammonia injection valve opening B1 as the first initial ammonia injection valve opening; If A1≤A<A2, determine the second preset first initial ammonia injection valve opening B2 as the first initial ammonia injection valve opening; If A2≤A<A3, determine the third preset first initial ammonia injection valve opening B3 as the first initial ammonia injection valve opening; If A3≤A<A4, determine the fourth preset first initial ammonia injection valve opening B4 as the first initial ammonia injection valve opening; The second initial ammonia injection valve opening is obtained based on the first initial ammonia injection valve opening and the ammonia slip amount, specifically: A valve opening adjustment amount is obtained according to the ammonia slip amount, and a second initial ammonia injection valve opening is obtained according to the first initial ammonia injection valve opening and the valve opening adjustment amount; The ammonia slip amount is set to C, and an ammonia slip amount array C0 is preset, wherein C0 consists of a first preset ammonia slip amount C1, a second preset ammonia slip amount C2, a third preset ammonia slip amount C3, and a fourth preset ammonia slip amount C4, and C1<C2<C3<C4; A preset valve opening adjustment amount array △Q0, wherein △Q0 is composed of a first preset valve opening adjustment amount △Q1, a second preset valve opening adjustment amount △Q2, a third preset valve opening adjustment amount △Q3, and a fourth preset valve opening adjustment amount △Q4, and △Q1<△Q2<△Q3<△Q4; Determine the valve opening adjustment amount according to the relationship between the ammonia slip amount and each preset ammonia slip amount, and obtain the second initial ammonia injection valve opening according to the valve opening adjustment amount; If C<C1, the first preset valve opening adjustment amount △Q1 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q1; If C1≤C<C2, the second preset valve opening adjustment amount △Q2 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q2; If C2≤C<C3, the third preset valve opening adjustment amount △Q3 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q3; If C3≤C<C4, the fourth preset valve opening adjustment amount △Q4 is determined as the valve opening adjustment amount, and the second initial ammonia injection valve opening is B-△Q4; The second initial ammonia injection valve opening is corrected according to the flue gas temperature to obtain the ammonia injection valve opening, which is specifically: Set the smoke temperature to T, and preset the smoke temperature array T0, wherein T0 consists of a first preset smoke temperature T1, a second preset smoke temperature T2, a third preset smoke temperature T3, and a fourth preset smoke temperature T4, and T1<T2<T3<T4; The second initial ammonia injection valve opening is set to D, and a second initial ammonia injection valve opening correction coefficient array k0 is preset, wherein K0 is composed of a first preset second initial ammonia injection valve opening correction coefficient k1, a second preset second initial ammonia injection valve opening correction coefficient k2, a third preset second initial ammonia injection valve opening correction coefficient k3, and a fourth preset second initial ammonia injection valve opening correction coefficient k4, and 1<k1<k2<k3<k4<1.8; Determine the second initial ammonia injection valve opening correction coefficient according to the relationship between the flue gas temperature and each preset flue gas temperature, thereby obtaining the ammonia injection valve opening; If T<T1, the first preset second initial ammonia injection valve opening correction coefficient k1 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k1; If T1≤T<T2, the second preset second initial ammonia injection valve opening correction coefficient k2 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k2; If T2≤T<T3, the third preset second initial ammonia injection valve opening correction coefficient k3 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k3; If T3≤T<T4, the fourth preset second initial ammonia injection valve opening correction coefficient k4 is determined as the second initial ammonia injection valve opening correction coefficient, and the ammonia injection valve opening is D*k4.

2. The method for measuring nitrogen oxides according to claim 1, characterized in that: The collection mechanism includes: A main pipe connected to the temperature detection pool; Branch pipes, wherein the branch pipes are multiple pipes of different lengths; A sampling hole is provided at the bottom end of each branch pipe; A pneumatic valve is connected to the branch pipes, and the pneumatic valve is used to control the opening and closing of each branch pipe.

3. The method for measuring nitrogen oxides according to claim 2, characterized in that: The data detection pool comprises: A first analysis cabinet, electrically connected to the control cabinet, and used to obtain the amount of ammonia escape in the flue gas; A second analysis cabinet, electrically connected to the control cabinet, the second analysis cabinet being used to obtain the nitrogen oxide content in the flue gas; The third analysis cabinet is electrically connected to the control cabinet, and the third analysis cabinet is used to obtain the temperature of the flue gas.

4. The method for measuring nitrogen oxides according to claim 3, characterized in that: The control cabinet comprises: A compressed air control cabinet connected to the flue; The PLC control cabinet is electrically connected to the compressed air control cabinet.

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