Boiler flue flow field flow velocity measurement method and system

Abstract

The invention relates to the technical field of boiler flue flow velocity, in particular to a boiler flue flow field flow velocity measurement method and system, and the method comprises the steps: arranging a plurality of flue gas flow velocity measurement points in an area from an economizer to an inlet of an air preheater, and arranging a matrix type flue gas flow velocity measurement device at each flue gas flow velocity measurement point, the matrix type flue gas flow velocity measuring device is used for monitoring the flue gas flow velocity of the flue in real time; acquiring the flue gas flow velocity of each flue gas flow velocity measuring point, and calculating to obtain a flue gas flow velocity average value H; and obtaining boiler operation data, determining a correction coefficient according to the operation data, and adjusting the flue gas flow velocity average value H according to the correction coefficient to obtain a flue gas flow velocity final value. According to the method, the boiler operation data are acquired, the correction coefficient is determined according to the operation data, and the flue gas flow velocity average value is adjusted according to the correction coefficient, so that the representativeness and accuracy of the overall flue gas flow velocity measurement data of the boiler flue are improved.

Description

Technical Field

[0001] The invention relates to the technical field of boiler flue flow velocity, and in particular to a boiler flue flow field velocity measurement method and system. Background Art

[0002] SCR denitrification is the most widely used and most mature flue gas denitrification technology in the world. The basic principle of the SCR ammonia injection closed-loop automatic adjustment system is to calculate the theoretical value of ammonia injection based on operating parameters such as flue gas temperature, flue gas flow, inlet and outlet NOX concentration of the SCR reactor and outlet ammonia escape, control the opening of the ammonia injection valve, and adjust the amount of ammonia injection.

[0003] In the SCR denitrification ammonia injection closed-loop automatic control system, the calculation of the theoretical ammonia injection amount requires the use of the flue gas flow signal, which plays a great role in the quality of the ammonia injection closed-loop automatic adjustment. However, the large smoke and air ducts of power station boilers are affected by the layout, and the straight sections are generally short. It is difficult to accurately measure the flow rate in the smoke and air ducts, and the overall flue gas flow rate data of the boiler flue is poorly representative.

[0004] Therefore, how to accurately measure the overall flue gas velocity of the power plant boiler flue has become a new development trend. Summary of the invention

[0005] In view of this, the present invention proposes a boiler flue flow field velocity measurement method and system, mainly to solve the problem of how to accurately measure the overall flue gas velocity of a power station boiler flue.

[0006] In one aspect, the present invention provides a method for measuring flow velocity of a boiler flue flow field, the method comprising:

[0007] By setting a plurality of flue gas flow velocity measuring points in the area from the economizer to the air preheater inlet, a matrix flue gas flow velocity measuring device is set at each of the flue gas flow velocity measuring points, and the matrix flue gas flow velocity measuring device is used to monitor the flue gas flow velocity of the flue in real time;

[0008] Obtain the flue gas flow rate of each of the flue gas flow rate measurement points and calculate to obtain the average flue gas flow rate H;

[0009] Obtain boiler operation data, determine a correction coefficient according to the operation data, and adjust the average value H of the flue gas flow rate according to the correction coefficient to obtain a final value of the flue gas flow rate;

[0010] The operating data include: flue gas oxygen content, exhaust gas temperature, and furnace negative pressure.

[0011] In some embodiments of the present application, when determining the correction coefficient according to the operating data, it includes:

[0012] The preset correction coefficient is set to A, and A=1;

[0013] Obtaining the flue gas oxygen content at each of the flue gas flow rate measurement points, and calculating the average value B of the flue gas oxygen content;

[0014] A first preset flue gas oxygen content value B1, a second preset flue gas oxygen content value B2, a third preset flue gas oxygen content value B3, and a fourth preset flue gas oxygen content value B4 are preset, and B1>B2>B3>B4; a first preset adjustment coefficient b1, a second preset adjustment coefficient b2, a third preset adjustment coefficient b3, and a fourth preset adjustment coefficient b4 are preset, and 1.1>b1>b2>1>b3>b4>0.9;

[0015] When B≥B1, the first preset adjustment coefficient b1 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b1;

[0016] When B1>B≥B2, the second preset adjustment coefficient b2 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b2;

[0017] When B2>B≥B3, the third preset adjustment coefficient b3 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b3;

[0018] When B3>B≥B4, the fourth preset adjustment coefficient b3 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b3.

[0019] In some embodiments of the present application, after selecting the i-th adjustment coefficient bi to adjust the preset correction coefficient A, i=1, 2, 3, 4, and obtaining the adjusted preset correction coefficient A*bi, the following further includes:

[0020] Get the exhaust gas temperature value D;

[0021] A first preset exhaust temperature value D1, a second preset exhaust temperature value D2, a third preset exhaust temperature value D3, and a fourth preset exhaust temperature value D4 are preset, and D1>D2>D3>D4; a first preset adjustment coefficient d1, a second preset adjustment coefficient d2, a third preset adjustment coefficient d3, and a fourth preset adjustment coefficient d4 are preset, and 1.1>d1>d2>1>d3>d4>0.9;

[0022] When D≥D1, the first preset adjustment coefficient d1 is selected to perform secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after secondary adjustment is A*bi*d1;

[0023] When D1>D≥D2, the second preset adjustment coefficient d2 is selected to perform a secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after the secondary adjustment is A*bi*d2;

[0024] When D2>D≥D3, the third preset adjustment coefficient d3 is selected to perform secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after secondary adjustment is A*bi*d3;

[0025] When D3>D≥D4, the fourth preset adjustment coefficient d4 is selected to perform a second adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after the second adjustment is A*bi*d4.

[0026] In some embodiments of the present application, after selecting the i-th adjustment coefficient di to perform a secondary adjustment on the adjusted preset correction coefficient A*bi, i=1, 2, 3, 4, and obtaining the preset correction coefficient after the secondary adjustment as A*bi*di, the following further includes:

[0027] Obtain the furnace negative pressure value E, and pre-set the furnace negative pressure standard value E0;

[0028] When E≤E0, there is no risk of furnace air leakage in the boiler, and the adjusted preset correction coefficient A*bi*di is not adjusted three times;

[0029] When E>E0, there is a risk of furnace air leakage in the boiler, and the adjusted preset correction coefficient A*bi*di is adjusted three times.

[0030] In some embodiments of the present application, when determining whether there is a risk of furnace air leakage in the boiler, the method further includes:

[0031] A first preset furnace negative pressure value E1, a second preset furnace negative pressure value E2, a third preset furnace negative pressure value E3, and a fourth preset furnace negative pressure value E4 are preset, and E1>E2>E3>E4, and E4=E0; a first preset adjustment coefficient e1, a second preset adjustment coefficient e2, a third preset adjustment coefficient e3, and a fourth preset adjustment coefficient e4 are preset, and 0.9<e1<e2<1<e3<e4<1.1;

[0032] When E≥E1, the first preset adjustment coefficient e1 is selected to adjust the adjusted preset correction coefficient A*bi*di three times, and the preset correction coefficient after the three adjustments is A*bi*di*e1;

[0033] When E1>E≥E2, the second preset adjustment coefficient e2 is selected to adjust the adjusted preset correction coefficient A*bi*di three times, and the preset correction coefficient after three adjustments is A*bi*di*e2;

[0034] When E2>E≥E3, the third preset adjustment coefficient e3 is selected to adjust the adjusted preset correction coefficient A*bi*di three times, and the preset correction coefficient after the three adjustments is A*bi*di*e3;

[0035] When E3>E≥E4, the fourth preset adjustment coefficient e4 is selected to adjust the adjusted preset correction coefficient A*bi*di three times, and the preset correction coefficient after the three adjustments is A*bi*di*e4.

[0036] In some embodiments of the present application, after selecting the i-th adjustment coefficient ei to adjust the preset correction coefficient A*bi after the second adjustment three times, i=1, 2, 3, 4, and obtaining the preset correction coefficient A*bi*di*ei after the three adjustments, the following is also included:

[0037] The preset correction coefficient after three adjustments is A*bi*di*ei as the final correction coefficient A0;

[0038] The final correction coefficient A0 is obtained to correct the average flue gas flow rate H. The corrected average flue gas flow rate is H*A0. The corrected average flue gas flow rate H*A0 is used as the final flue gas flow rate H0.

[0039] In another aspect, the present invention provides a boiler flue flow field velocity measurement system, the system comprising:

[0040] A data acquisition unit, used to acquire the flue gas flow rate of each flue gas flow rate measurement point and boiler operation data;

[0041] The data processing unit is used to calculate the average flue gas flow rate H according to the flue gas flow rate of each flue gas flow rate measuring point, determine the correction coefficient according to the operation data, and adjust the average flue gas flow rate H according to the correction coefficient to obtain the final flue gas flow rate value.

[0042] In some embodiments of the present application, the operating data include: flue gas oxygen content, exhaust gas temperature, and furnace negative pressure.

[0043] Compared with the prior art, the present invention has the following beneficial effects: firstly, the present invention sets a plurality of flue gas flow velocity measurement points, monitors the flue gas flow velocity of the flue in real time based on a matrix flue gas flow velocity measurement device, calculates the average value of the flue gas flow velocity of each flue gas flow velocity measurement point, and obtains the average value of the flue gas flow velocity of the boiler flue. Meanwhile, the boiler operation data is obtained, a correction coefficient is determined according to the operation data, and the average value of the flue gas flow velocity is adjusted according to the correction coefficient to obtain the final value of the flue gas flow velocity. The final value of the flue gas flow velocity is used as the final measurement data, and the flue gas flow velocity mean is adjusted and corrected accordingly according to the boiler operation data, so as to improve the representativeness and accuracy of the overall flue gas flow velocity measurement data of the boiler flue. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings:

[0045] Figure 1 A flow chart of a method for measuring flow velocity in a boiler flue flow field provided by an embodiment of the present invention;

[0046] Figure 2 A functional block diagram of a boiler flue flow field velocity measurement system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0048] See also Figure 1 As shown, this embodiment provides a method for measuring the flow velocity of a boiler flue flow field, the method comprising:

[0049] S101: multiple flue gas velocity measurement points are set in the area from the economizer to the air preheater inlet;

[0050] S102: real-time monitoring of the flue gas flow velocity of the flue through a matrix flue gas flow velocity measuring device;

[0051] S103: Obtain the flue gas flow rate of each flue gas flow rate measurement point and calculate the average flue gas flow rate H;

[0052] S104: Acquire boiler operation data, and determine a correction coefficient according to the operation data;

[0053] S105: Adjust the average value H of the flue gas flow rate according to the correction coefficient to obtain a final value of the flue gas flow rate.

[0054] Specifically, in this embodiment, a matrix flue gas flow velocity measurement device is provided at each flue gas flow velocity measurement point to monitor the flue gas flow velocity at each flue gas flow velocity measurement point in real time.

[0055] Specifically, the operating data include: flue gas oxygen content, exhaust gas temperature, and furnace negative pressure.

[0056] It can be understood that in this embodiment, a plurality of flue gas flow rate measuring points are set in the SCR denitrification area from the economizer to the air preheater inlet. The position of each flue gas flow rate measuring point can be specifically set according to the actual situation, and again no specific limitation is made. After the average flue gas flow rate of each flue gas flow rate measuring point is obtained by calculation, the correction coefficient is determined by obtaining the operating data of the boiler, and the average flue gas flow rate is corrected according to the correction coefficient to obtain the final flue gas flow rate value, thereby improving the accuracy and representativeness of the overall flue gas flow rate measurement of the boiler.

[0057] In a specific embodiment of the present application, when determining the correction coefficient according to the operating data, it includes:

[0058] The preset correction coefficient is set to A, and A=1;

[0059] Obtain the flue gas oxygen content at each flue gas flow rate measurement point, and calculate the average flue gas oxygen content B;

[0060] A first preset flue gas oxygen content value B1, a second preset flue gas oxygen content value B2, a third preset flue gas oxygen content value B3, and a fourth preset flue gas oxygen content value B4 are preset, and B1>B2>B3>B4; a first preset adjustment coefficient b1, a second preset adjustment coefficient b2, a third preset adjustment coefficient b3, and a fourth preset adjustment coefficient b4 are preset, and 1.1>b1>b2>1>b3>b4>0.9;

[0061] When B≥B1, the first preset adjustment coefficient b1 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b1;

[0062] When B1>B≥B2, the second preset adjustment coefficient b2 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b2;

[0063] When B2>B≥B3, the third preset adjustment coefficient b3 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b3;

[0064] When B3>B≥B4, the fourth preset adjustment coefficient b3 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b3.

[0065] It can be understood that in this embodiment, the flue gas oxygen content at each flue gas flow rate measuring point during the operation of the boiler is obtained, the average flue gas oxygen content at each measuring point is calculated, and the corresponding adjustment coefficient is selected according to the average flue gas oxygen content to adjust the preset correction coefficient, so as to avoid the influence of the flue gas oxygen content on the flue gas flow rate, thereby improving the accuracy of adjusting the average flue gas flow rate.

[0066] In a specific embodiment of the present application, after selecting the i-th adjustment coefficient bi to adjust the preset correction coefficient A, i=1, 2, 3, 4, and obtaining the adjusted preset correction coefficient A*bi, it also includes:

[0067] Get the exhaust gas temperature value D;

[0068] A first preset exhaust temperature value D1, a second preset exhaust temperature value D2, a third preset exhaust temperature value D3, and a fourth preset exhaust temperature value D4 are preset, and D1>D2>D3>D4; a first preset adjustment coefficient d1, a second preset adjustment coefficient d2, a third preset adjustment coefficient d3, and a fourth preset adjustment coefficient d4 are preset, and 1.1>d1>d2>1>d3>d4>0.9;

[0069] When D≥D1, the first preset adjustment coefficient d1 is selected to perform secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after secondary adjustment is A*bi*d1;

[0070] When D1>D≥D2, the second preset adjustment coefficient d2 is selected to perform a secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after the secondary adjustment is A*bi*d2;

[0071] When D2>D≥D3, the third preset adjustment coefficient d3 is selected to perform secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after secondary adjustment is A*bi*d3;

[0072] When D3>D≥D4, the fourth preset adjustment coefficient d4 is selected to perform a second adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after the second adjustment is A*bi*d4.

[0073] It can be understood that in this embodiment, the adjusted preset correction coefficient is adjusted twice by selecting the corresponding adjustment coefficient according to the exhaust temperature value. Since the increase in flue gas flow rate will cause the exhaust temperature to increase, the preset correction coefficient is adjusted twice according to the exhaust temperature value to improve the representativeness of the average flue gas flow rate.

[0074] In a specific embodiment of the present application, after selecting the i-th adjustment coefficient di to perform secondary adjustment on the adjusted preset correction coefficient A*bi, i=1, 2, 3, 4, and obtaining the secondary adjusted preset correction coefficient A*bi*di, it also includes:

[0075] Obtain the furnace negative pressure value E, and pre-set the furnace negative pressure standard value E0;

[0076] When E≤E0, there is no risk of furnace air leakage in the boiler, and the preset correction coefficient A*bi*di after the secondary adjustment is not adjusted for the third time;

[0077] When E>E0, there is a risk of furnace air leakage in the boiler, and the preset correction coefficient A*bi*di after the second adjustment is adjusted three times.

[0078] In a specific embodiment of the present application, when determining whether there is a risk of furnace air leakage in the boiler, it also includes:

[0079] A first preset furnace negative pressure value E1, a second preset furnace negative pressure value E2, a third preset furnace negative pressure value E3, and a fourth preset furnace negative pressure value E4 are preset, and E1>E2>E3>E4, and E4=E0; a first preset adjustment coefficient e1, a second preset adjustment coefficient e2, a third preset adjustment coefficient e3, and a fourth preset adjustment coefficient e4 are preset, and 0.9<e1<e2<1<e3<e4<1.1;

[0080] When E≥E1, the first preset adjustment coefficient e1 is selected to adjust the preset correction coefficient A*bi*di after the secondary adjustment three times, and the preset correction coefficient after the three adjustments is A*bi*di*e1;

[0081] When E1>E≥E2, the second preset adjustment coefficient e2 is selected to adjust the preset correction coefficient A*bi*di after the second adjustment three times, and the preset correction coefficient after the third adjustment is A*bi*di*e2;

[0082] When E2>E≥E3, the third preset adjustment coefficient e3 is selected to adjust the preset correction coefficient A*bi*di after the second adjustment three times, and the preset correction coefficient after the third adjustment is A*bi*di*e3;

[0083] When E3>E≥E4, the fourth preset adjustment coefficient e4 is selected to perform a third adjustment on the preset correction coefficient A*bi*di after the second adjustment, and the preset correction coefficient after the third adjustment is A*bi*di*e4.

[0084] It can be understood that this embodiment also determines whether there is a risk of air leakage in the boiler furnace by obtaining the furnace negative pressure. When there is a risk of air leakage in the boiler furnace, it can promptly warn the staff to arrange maintenance to ensure the normal operation of the boiler. At the same time, the preset correction coefficient is adjusted three times according to the corresponding adjustment coefficient selected according to the furnace negative pressure to avoid an increase in the flue gas flow rate caused by furnace leakage, thereby reducing the representativeness of the average flue gas flow rate.

[0085] In a specific embodiment of the present application, after selecting the i-th adjustment coefficient ei to adjust the preset correction coefficient A*bi after the second adjustment three times, i=1, 2, 3, 4, and obtaining the preset correction coefficient A*bi*di*ei after the three adjustments, it also includes:

[0086] The preset correction coefficient after three adjustments is A*bi*di*ei as the final correction coefficient A0;

[0087] The final correction coefficient A0 is obtained to correct the average flue gas flow rate H. The corrected average flue gas flow rate is H*A0. The corrected average flue gas flow rate H*A0 is used as the final flue gas flow rate H0.

[0088] In another aspect, the present invention provides a boiler flue flow field velocity measurement system, the system comprising:

[0089] A data acquisition unit, used to acquire the flue gas flow rate of each flue gas flow rate measurement point and boiler operation data;

[0090] The data processing unit is used to calculate the average flue gas flow rate H according to the flue gas flow rate of each flue gas flow rate measuring point, determine the correction coefficient according to the operation data, and adjust the average flue gas flow rate H according to the correction coefficient to obtain the final flue gas flow rate value.

[0091] In a specific embodiment of the present application, the operating data include: flue gas oxygen content, exhaust gas temperature, and furnace negative pressure.

[0092] This embodiment first sets up multiple flue gas flow rate measurement points, monitors the flue gas flow rate of the flue in real time based on a matrix flue gas flow rate measurement device, and calculates the average value of the flue gas flow rate of each flue gas flow rate measurement point to obtain the average value of the flue gas flow rate of the boiler flue. At the same time, the boiler operation data is obtained, and a correction coefficient is determined according to the operation data. The average value of the flue gas flow rate is adjusted according to the correction coefficient to obtain a final value of the flue gas flow rate. The final value of the flue gas flow rate is used as the final measurement data, and the flue gas flow rate average is correspondingly adjusted and corrected according to the boiler operation data to improve the representativeness and accuracy of the overall flue gas flow rate measurement data of the boiler flue.

[0093] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0094] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0095] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0096] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for measuring the flow velocity of a boiler flue flow field, characterized in that: include: By setting a plurality of flue gas flow velocity measuring points in the area from the economizer to the air preheater inlet, a matrix flue gas flow velocity measuring device is set at each of the flue gas flow velocity measuring points, and the matrix flue gas flow velocity measuring device is used to monitor the flue gas flow velocity of the flue in real time; Obtain the flue gas flow rate of each of the flue gas flow rate measurement points and calculate to obtain the average flue gas flow rate H; Obtain boiler operation data, determine a correction coefficient according to the operation data, and adjust the average value H of the flue gas flow rate according to the correction coefficient to obtain a final value of the flue gas flow rate; The operating data include: flue gas oxygen content, exhaust gas temperature, and furnace negative pressure.

2. The method for measuring the flow velocity of a boiler flue flow field according to claim 1, characterized in that: When determining the correction coefficient according to the operating data, it includes: The preset correction coefficient is set to A, and A=1; Obtaining the flue gas oxygen content at each of the flue gas flow rate measurement points, and calculating the average value B of the flue gas oxygen content; A first preset flue gas oxygen content value B1, a second preset flue gas oxygen content value B2, a third preset flue gas oxygen content value B3, and a fourth preset flue gas oxygen content value B4 are preset, and B1>B2>B3>B4; a first preset adjustment coefficient b1, a second preset adjustment coefficient b2, a third preset adjustment coefficient b3, and a fourth preset adjustment coefficient b4 are preset, and 1.1>b1>b2>1>b3>b4>0.9; When B≥B1, the first preset adjustment coefficient b1 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b1; When B1>B≥B2, the second preset adjustment coefficient b2 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b2; When B2>B≥B3, the third preset adjustment coefficient b3 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b3; When B3>B≥B4, the fourth preset adjustment coefficient b3 is selected to adjust the preset correction coefficient A, and the adjusted preset correction coefficient is A*b3.

3. The method for measuring the flow velocity of a boiler flue flow field according to claim 2, characterized in that: After selecting the i-th adjustment coefficient bi to adjust the preset correction coefficient A, i=1, 2, 3, 4, and obtaining the adjusted preset correction coefficient A*bi, the method further includes: Get the exhaust gas temperature value D; A first preset exhaust temperature value D1, a second preset exhaust temperature value D2, a third preset exhaust temperature value D3, and a fourth preset exhaust temperature value D4 are preset, and D1>D2>D3>D4; a first preset adjustment coefficient d1, a second preset adjustment coefficient d2, a third preset adjustment coefficient d3, and a fourth preset adjustment coefficient d4 are preset, and 1.1>d1>d2>1>d3>d4>0.9; When D≥D1, the first preset adjustment coefficient d1 is selected to perform secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after secondary adjustment is A*bi*d1; When D1>D≥D2, the second preset adjustment coefficient d2 is selected to perform a secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after the secondary adjustment is A*bi*d2; When D2>D≥D3, the third preset adjustment coefficient d3 is selected to perform secondary adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after secondary adjustment is A*bi*d3; When D3>D≥D4, the fourth preset adjustment coefficient d4 is selected to perform a second adjustment on the adjusted preset correction coefficient A*bi, and the preset correction coefficient after the second adjustment is A*bi*d4.

4. The method for measuring the flow velocity of a boiler flue flow field according to claim 3, characterized in that: After selecting the i-th adjustment coefficient di to perform secondary adjustment on the adjusted preset correction coefficient A*bi, i=1, 2, 3, 4, and obtaining the secondary adjusted preset correction coefficient A*bi*di, the method further includes: Obtain the furnace negative pressure value E, and pre-set the furnace negative pressure standard value E0; When E≤E0, there is no risk of furnace air leakage in the boiler, and the adjusted preset correction coefficient A*bi*di is not adjusted three times; When E>E0, there is a risk of furnace air leakage in the boiler, and the adjusted preset correction coefficient A*bi*di is adjusted three times.

5. The method for measuring the flow velocity of a boiler flue flow field according to claim 4, characterized in that: When judging whether there is a risk of furnace air leakage in a boiler, the following factors should also be considered: A first preset furnace negative pressure value E1, a second preset furnace negative pressure value E2, a third preset furnace negative pressure value E3, and a fourth preset furnace negative pressure value E4 are preset, and E1>E2>E3>E4, and E4=E0; a first preset adjustment coefficient e1, a second preset adjustment coefficient e2, a third preset adjustment coefficient e3, and a fourth preset adjustment coefficient e4 are preset, and 0.9<e1<e2<1<e3<e4<1.1; When E≥E1, the first preset adjustment coefficient e1 is selected to adjust the adjusted preset correction coefficient A*bi*di three times, and the preset correction coefficient after the three adjustments is A*bi*di*e1; When E1>E≥E2, the second preset adjustment coefficient e2 is selected to adjust the adjusted preset correction coefficient A*bi*di three times, and the preset correction coefficient after three adjustments is A*bi*di*e2; When E2>E≥E3, the third preset adjustment coefficient e3 is selected to adjust the adjusted preset correction coefficient A*bi*di three times, and the preset correction coefficient after the three adjustments is A*bi*di*e3; When E3>E≥E4, the fourth preset adjustment coefficient e4 is selected to adjust the adjusted preset correction coefficient A*bi*di three times, and the preset correction coefficient after the three adjustments is A*bi*di*e4.

6. The method for measuring the flow velocity of a boiler flue flow field according to claim 5, characterized in that: After selecting the i-th adjustment coefficient ei to adjust the preset correction coefficient A*bi after the second adjustment three times, i=1, 2, 3, 4, and obtaining the preset correction coefficient A*bi*di*ei after the three adjustments, the method further includes: The preset correction coefficient after three adjustments is A*bi*di*ei as the final correction coefficient A0; The final correction coefficient A0 is obtained to correct the average flue gas flow rate H. The corrected average flue gas flow rate is H*A0. The corrected average flue gas flow rate H*A0 is used as the final flue gas flow rate H0.

7. A boiler flue flow field velocity measurement system, characterized in that: The method for measuring the flow velocity of a boiler flue flow field as claimed in any one of claims 1 to 7 comprises: A data acquisition unit, used to acquire the flue gas flow rate of each flue gas flow rate measurement point and boiler operation data; The data processing unit is used to calculate the average flue gas flow rate H according to the flue gas flow rate of each flue gas flow rate measuring point, determine the correction coefficient according to the operation data, and adjust the average flue gas flow rate H according to the correction coefficient to obtain the final flue gas flow rate value.

8. The boiler flue flow field velocity measurement system according to claim 7, characterized in that: The operating data include: flue gas oxygen content, exhaust gas temperature, and furnace negative pressure.

Images