A method for improving the combustion state of a counter-fired coal-fired boiler

Abstract

This invention relates to a method for improving the combustion state of a counter-firing coal-fired boiler, comprising: installing flow guiding devices and uniformly distributed grids at multiple first bends on one side of the secondary main air duct outlet; installing online air volume measuring devices at the burner and burnout air inlets; installing multiple oxygen meters and a CO concentration monitoring device at the economizer outlet section; and adjusting the burner air volume and burnout air volume based on the burner air volume and burnout air volume measured by the online air volume measuring devices, the oxygen content at the economizer outlet section measured by the multiple oxygen meters, and the CO emission at the furnace outlet monitored by the CO concentration monitoring device. This method improves the combustion state of the counter-firing coal-fired boiler.

Description

Technical Field

[0001] This invention relates to the field of boiler combustion technology, and more specifically to a method for improving the combustion state of a counter-fired coal-fired boiler. Background Technology

[0002] In opposed-flow coal-fired boilers, burners are typically arranged in an opposed or staggered configuration on the front and rear walls. In an opposed-flow arrangement, the two opposing jets meet and mix in the center of the furnace, promoting heat and mass exchange and forming a strong combustion center. In a staggered arrangement, the diffusion fronts of the two opposing jets intertwine, increasing the filling degree and providing an ignition heat source for the adjacent root jets, reducing the upper diffused zone and strengthening the lower circulating agitation. This arrangement helps to uniform the heat load on the front and rear walls and expands the adaptability to different coal types. However, the flue gas temperature deviation in this configuration is closely related to the initial combustion deviation in the furnace and operational controls, exhibiting significant randomness and making prevention and control difficult.

[0003] Meanwhile, due to the special structure and layout of the secondary air duct of the counter-coal-fired boiler, which is arranged symmetrically on both sides, a single side was selected, as shown in the attached diagram. Figure 2 As shown, this airflow arrangement first flows through the burners and burnout air on both sides at a high velocity, then converges with the burner and burnout air in the middle at a low velocity. This results in high static pressure in the middle burner and burnout air box, and low static pressure in the burners and burnout air on both sides. Furthermore, the secondary airflow enters the secondary main air duct after several bends, and then enters the layer air duct after another bend, making the airflow field highly turbulent. In addition, there is a significant slope from the layer air duct into the burner air box, causing vortices and backflow in the airflow near the burners on both sides. The combination of these two factors leads to an oxygen-deficient state in the sidewall burners. Under hot operation, the operating oxygen content exhibits a distribution pattern of high in the middle and low on both sides, as shown in the attached diagram. Figure 3 As shown.

[0004] Due to the inherent structural differences in the secondary air ducts, even with the same opening degree of the inner and outer secondary air dampers on the burners and burnout air, significant differences will inevitably exist between the burners and burnout air. Therefore, in actual operation, the dampers for the burners on both sides are opened wider, while the dampers for the middle burner and burnout air are closed narrower to alleviate combustion conditions within the furnace. However, the specific opening and closing range is mainly determined by experience and cannot be precisely controlled. Simultaneously, operators can refer to the distribution of online oxygen meters at the economizer outlet section to understand the combustion conditions within the furnace, or the CO concentration parameters in the CMES of the desulfurization tower, and then make optimization adjustments. However, this is limited by the number of online meters on site (oxygen meters are generally 2-3, as shown in the attached diagram). Figure 4 As shown, there is only one CO concentration meter, and due to factors such as air leakage in the furnace and air preheater, operators can only refer to limited data on the dial. Summary of the Invention

[0005] This application provides a method for improving the combustion state of a counter-rotating coal-fired boiler, in order to at least address the shortcomings of current methods for mitigating combustion deterioration in counter-rotating coal-fired boilers.

[0006] The first aspect of this application provides a method for improving the combustion state of a counter-fired coal-fired boiler, comprising:

[0007] A flow guide device and a uniformly distributed grille are installed at multiple first bends on one side of the secondary main air duct outlet.

[0008] Online air volume measurement devices are installed at the burner and the burnout air inlet;

[0009] Multiple oxygen meters and CO concentration monitoring devices were installed at the economizer outlet section.

[0010] The burner air intake and burnout air intake are adjusted based on the burner air intake and burnout air intake measured by the online air volume measurement device, the oxygen content at the economizer outlet section measured by multiple oxygen meters, and the CO emission at the furnace outlet monitored by the CO concentration monitoring device.

[0011] The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0012] This invention provides a method for improving the combustion state of a counter-coiled coal-fired boiler, comprising: installing flow guiding devices and uniformly distributed grids at multiple first bends on one side of the secondary main air duct outlet; installing online air volume measuring devices at the burner and burnout air inlets; installing multiple oxygen meters and a CO concentration monitoring device at the economizer outlet section; and adjusting the burner air volume and burnout air volume based on the burner air volume and burnout air volume measured by the online air volume measuring devices, the oxygen content at the economizer outlet section measured by the multiple oxygen meters, and the CO emission at the furnace outlet monitored by the CO concentration monitoring device. This invention addresses the shortcomings of current methods for mitigating combustion deterioration in counter-coiled coal-fired boilers, thereby improving the combustion state of the boiler.

[0013] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0014] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0015] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0016] Figure 1 This is a flowchart of a method for improving the combustion state of a counterbalanced coal-fired boiler according to an embodiment of this application;

[0017] Figure 2 This is a schematic diagram of the secondary air duct arrangement in the background technology;

[0018] Figure 3 This is a measured distribution map of oxygen content at the economizer outlet;

[0019] Figure 4 This is a cross-sectional distribution diagram of the economizer outlet test measuring points and online measuring points;

[0020] Figure 5 This is an optimized secondary air duct layout diagram provided in an embodiment of this application for a method to improve the combustion state of a counter-fired coal-fired boiler;

[0021] Figure 6 This is a schematic diagram of the test of each air stream on the burner in a method for improving the combustion state of a counterbalanced coal-fired boiler according to an embodiment of this application;

[0022] Figure 7 This is a schematic diagram of the test of each air stream above the burnout air in a method for improving the combustion state of a counterbalanced coal-fired boiler according to an embodiment of this application;

[0023] Figure 8 This is a schematic diagram of the structure of an online air volume measurement device in a method for improving the combustion state of a counter-fired coal-fired boiler according to an embodiment of this application.

[0024] Explanation of reference numerals in the attached figures:

[0025] Secondary main air duct-1, first elbow-2; air guide device-3, air guide plate-301, uniformly distributed grid-4, layered air duct-5, second elbow-6, burner-7, burnout air-8, online air volume measurement device-9, tertiary air measurement device-10, inner and outer secondary air damper-11, secondary air duct-12, secondary air cyclone separator-13, primary air measurement device-14, primary air duct-15; secondary air annular air duct inlet-901; secondary air annular air duct outlet-902; first electrostatic sensor-903; second electrostatic sensor-904; sensor mounting base-905; annular air duct-906. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0027] This application proposes a method for improving the combustion state of a counter-coal-fired boiler, comprising: installing flow guiding devices and uniformly distributed grids at multiple first bends on one side of the secondary main air duct outlet; installing online air volume measuring devices at the burner and burnout air inlets; installing multiple oxygen meters and a CO concentration monitoring device at the economizer outlet section; and adjusting the burner air volume and burnout air volume based on the burner air volume and burnout air volume measured by the online air volume measuring devices, the oxygen content at the economizer outlet section measured by the multiple oxygen meters, and the CO emission at the furnace outlet monitored by the CO concentration monitoring device. This invention addresses the shortcomings of current methods for mitigating combustion deterioration in counter-coal-fired boilers, thereby improving the combustion state of the boiler.

[0028] The following describes a method for preventing corrosion of water-cooled walls based on online precision measurement, according to an embodiment of this application, with reference to the accompanying drawings.

[0029] Example 1

[0030] Figure 1 This is a flowchart illustrating a method for improving the combustion state of a counterbalanced coal-fired boiler according to an embodiment of this application. Figure 5 This is an optimized secondary air duct layout diagram provided according to an embodiment of this application for a method to improve the combustion state of a counter-fired coal-fired boiler, such as... Figure 1 and Figure 5 The method includes:

[0031] Step 1: Install a flow guide device 3 and a uniformly distributed grille 4 at multiple first bends 2 on one side of the air outlet of the secondary main air duct 1.

[0032] It is important to note that Figure 5 This is merely a schematic diagram of this embodiment. The diagram only shows the three flow guiding devices 3 corresponding to the three first bends 2 and the three uniformly distributed grids 4 corresponding to the other three first bends 2. Figure 5 Each of the other first bends 2 is also equipped with a flow guide device 3 or a uniformly distributed grid 4, and in Figure 5 The text is not shown in the original. Figure 5 This does not imply any limitation on the invention.

[0033] In the embodiments of this disclosure, the provision of a flow guiding device 3 and a uniformly distributed grid 4 at multiple first bends 2 of the secondary main air duct 1 includes:

[0034] Determine whether the smoothness of the secondary airflow at each first bend 2 is greater than the set smoothness threshold.

[0035] The first bend 2, which corresponds to a smoothness level greater than the smoothness threshold, is designated as the first type of bend.

[0036] The first type of bend 2, whose smoothness is less than or equal to the smoothness threshold, is designated as the second type of bend, wherein the smoothness of the first type of bend is less than that of the second type of bend.

[0037] A flow guide device 3 is installed at the first type of bend, and a uniformly distributed grid 4 is installed at the second type of bend. By installing the flow guide device 3 at the first type of bend and the uniformly distributed grid 4 at the second type of bend, the velocity field distribution is balanced, the flow field of the secondary total air duct is optimized, and the problem of airflow deflection caused by the secondary air volume is improved.

[0038] It is important to note that Figure 5 Only the three guide devices 3 corresponding to the three first bends 2 are shown above. Figure 5 This is merely a schematic diagram of this embodiment and does not represent a limitation of the present invention.

[0039] In the embodiments of this disclosure, the flow guiding device 3 includes multiple arc-shaped flow guiding plates 301. In this embodiment, one flow guiding device 3 includes 3 to 4 flow guiding plates 301. In other embodiments of the present invention, the number of flow guiding plates 301 included in one flow guiding device 3 is not limited. Multiple sets of test installation positions and installation angles of the flow guiding plates 301 are used to simulate the combustion state of a coal-fired boiler. The installation position and installation angle of the flow guiding plates 301 are adjusted and determined from the multiple sets of test installation positions and installation angles. That is, the position and angle of the flow guiding plates 301 need to be designed and calculated in detail using numerical simulation software.

[0040] Specifically, by collecting on-site drawings, a model was created, meshed, and simulated at a 1:1 scale with the on-site duct dimensions. By installing multiple guide vanes 301 on the corresponding first bend 2 and determining the position and angle of the guide vanes 301, after implementing the above-mentioned guide device 3, the relative standard deviation of the velocity at the secondary wind test section was reduced to 6.0%, and the uniformity and smoothness of the flow field were greatly improved.

[0041] In the embodiments of this disclosure, the method further includes: simulating the combustion state of a coal-fired boiler using multiple sets of preset test installation angles of the uniformly distributed grid 4, and selecting the actual installation angle of the uniformly distributed grid 4 from the multiple sets of test installation angles.

[0042] It is important to note that Figure 5 Only the three evenly distributed grids 4 corresponding to the three first bends 2 are shown above. Figure 5 This is merely a schematic diagram of this embodiment and does not represent a limitation of the present invention.

[0043] Furthermore, the uniformly distributed grid 4 divides the corresponding layer air duct 5 of the second type of bend where the uniformly distributed grid 4 is installed in the height direction. In this embodiment, the uniformly distributed grid 4 divides the corresponding layer air duct 5 into 3 segments in the height direction and 4 segments in the width direction. In other embodiments of the present invention, there is no limitation on the number of segments into which the uniformly distributed grid 4 divides the layer air duct in the height and width directions. By setting the uniformly distributed grid 4 at the second type of bend, the maximum relative standard deviation of the secondary test section of the layer is reduced to 38.8%, and the flow field uniformity is significantly improved.

[0044] In embodiments of this disclosure, such as Figure 5 As shown, a flow guiding device 3 is installed on multiple second bends 6 on the side of the air inlet of the secondary main air duct 1 to improve the smoothness of the secondary air entering the air inlet of the secondary main air duct 1.

[0045] It should be noted that the flow guiding device 3 installed on the second bend 6 has the same structure as the flow guiding device 3 installed on the first bend 2, and will not be described in detail here.

[0046] Step 2: Install an online air volume measurement device 9 at the air inlet of burner 7 and burnout air 8;

[0047] Figure 6 This is a schematic diagram of the airflow test on the burner in a method for improving the combustion state of a counterbalanced coal-fired boiler according to an embodiment of this application. Figure 7 This is a schematic diagram of the test of each air stream above the burnout air in a method for improving the combustion state of a counter-fired coal-fired boiler according to an embodiment of this application, as shown in the diagram. Figure 6 and Figure 7 As shown, multiple online air volume measuring devices 9 are provided, and these devices are installed at the inlets of the burner 7 and the burnout air 8. Specifically, the online air volume measuring devices 9 are respectively installed at the secondary air inlet of the burner 7 and the secondary air duct 12 inlet of the burnout air 8 to measure the secondary air at the inlets of the burner 7 and the burnout air 8.

[0048] A secondary air cyclone separator 13 is also provided in the secondary air duct 12 of the burnout air 8. The secondary air cyclone separator 13 is used to generate rotation of the secondary air entering the burnout air 8. The secondary air cyclone separator 13 is existing technology and will not be described in detail here.

[0049] Figure 8 This is a schematic diagram of the structure of an online air volume measurement device in a method for improving the combustion state of a counter-fired coal-fired boiler according to an embodiment of this application. The online measurement device 9 includes: an annular air duct 906, a secondary air annular air duct inlet 901, a secondary air annular air duct outlet 902, a first electrostatic sensor 903, a second electrostatic sensor 904, and a sensor mounting base 905.

[0050] The secondary air annular duct inlet 901 is the inlet of the annular duct 906, and the secondary air annular duct outlet 902 is the outlet of the annular duct 906.

[0051] The first electrostatic sensor 903 and the second electrostatic sensor 904 are disposed inside the inlet 901 of the secondary air annular duct along the direction from the inlet to the outlet of the annular duct 906. They are used to measure the dust carried in the secondary air passing through the annular duct. By measuring the time difference between the dust carried in the secondary air passing through the first electrostatic sensor 903 and the second electrostatic sensor 904, the secondary air velocity is calculated, that is, the burner air intake and the burnout air intake are calculated.

[0052] The secondary air annular duct inlet 901 and the secondary air annular duct outlet 902 correspond to each other to form an annular pipeline, namely the annular duct 906.

[0053] It should be noted that the first electrostatic sensor 903 and the second electrostatic sensor 904 are ring structures used to measure the secondary wind carrying dust through the entire annular air duct. Specifically, since the secondary wind is an annular air duct, a single straight sensor cannot accurately measure the wind speed of the entire cross section. Therefore, an annular structure sensor with a radius of less than 360 degrees was designed so that the sensor almost covers the annular air duct, greatly increasing the accuracy of the measurement.

[0054] The first electrostatic sensor 903 and the second electrostatic sensor 904 are respectively installed inside the annular air duct through their corresponding sensor mounting bases 905.

[0055] In the embodiments disclosed herein, the method for improving the combustion state of a counter-fired coal-fired boiler further includes:

[0056] The air intake volume of burner 7 and the air intake volume of burnout air 8 are measured using the online air volume measurement device 9.

[0057] The measurement of the inlet air volume of burner 7 and the inlet air volume of burnout air 8 using the online air volume measurement device 9 includes the following steps:

[0058] Dust carried in the inlet and outlet of the secondary air annular duct was collected;

[0059] The time K1 for the secondary wind carrying dust to pass through the first electrostatic sensor is measured, and the time K2 for the secondary wind carrying dust to pass through the second electrostatic sensor is measured.

[0060] The time difference K2 of the secondary wind carrying dust passing through the second electrostatic sensor and the time K1 of the secondary wind carrying dust passing through the first electrostatic sensor are processed to obtain the time difference K3 of the secondary wind carrying dust passing through the first electrostatic sensor and the second electrostatic sensor.

[0061] The air intake volume of burner 7 and the air intake volume of burnout air 8 are obtained through the time difference K3. Specifically, an annular electrostatic airflow measurement device is used at the burner and burnout air inlet. When secondary air passes through the inlet through different channels, the electrostatic bar collects the dust carried in the air. Through charge-voltage conversion and signal amplification, the relationship between wind speed and dust concentration is obtained after data processing. The wind speed can be measured in a cold state using a calibrated anemometer, and the online airflow coefficient can be corrected to achieve accurate measurement.

[0062] It is important to note that Figure 6 The burner in this invention is a swirl burner, but in other embodiments of the invention, the type of burner is not limited.

[0063] In addition, a tertiary air measuring device 10 is installed at the tertiary air inlet of the swirl burner for measuring the tertiary air; a primary air measuring device 14 is installed at the primary air inlet of the burnout air duct 15. The tertiary air measuring device 10 and the primary air measuring device 14 have the same structure as the online air volume measuring device 9, and will not be described in detail here.

[0064] Step 3: Install multiple oxygen meters and CO concentration monitoring devices at the economizer outlet section.

[0065] In this embodiment of the disclosure, multiple oxygen meters and CO concentration monitoring devices are installed at the economizer outlet section, including:

[0066] Multiple oxygen meters were installed on both sides of the economizer outlet section;

[0067] Multiple oxygen meters were used to monitor the set oxygen points on both sides of the economizer outlet section. The set oxygen points were the measurement points for oxygen concentration.

[0068] Multiple CO concentration monitoring devices were installed on both sides of the economizer outlet section;

[0069] Multiple CO concentration monitoring devices are used to monitor CO emissions at the furnace outlet, and the CO concentration test results on both sides are displayed on the monitoring screen on the monitoring equipment used by the operators through a rotating test method.

[0070] For details, please refer to Figure 3 and Figure 4 ,according to Figure 3 The oxygen distribution data shown are Figure 4 As can be seen from the distribution of online oxygen meters, they cannot detect low oxygen levels near the economizer outlet section. Therefore, 1-2 additional online oxygen meters need to be installed near the economizer outlet section. In this embodiment, the addition of oxygen meters at the economizer outlet section ensures at least 5 online meters. Simultaneously, 3 CO concentration measuring points are installed at the economizer outlet section, and 2 sets of medium-temperature CO online monitoring devices are installed on both sides of the economizer outlet section to monitor CO emissions at the furnace outlet. The CO concentration test results on both sides are displayed on the operator's monitoring screen through alternating measurements, helping operators to understand the combustion status inside the furnace in a timely manner.

[0071] Step 4: Adjust the burner air intake and burnout air intake based on the burner air intake and burnout air intake measured by the online air volume measuring device 9, the oxygen content at the economizer outlet section measured by multiple oxygen meters, and the CO emission at the furnace outlet monitored by the CO concentration monitoring device.

[0072] In this embodiment of the disclosure, the adjustment of the burner air intake and burnout air intake based on the burner air intake and burnout air intake measured by the online air volume measuring device 9, the economizer outlet section oxygen content measured by multiple oxygen meters, and the furnace outlet CO emission monitored by the CO concentration monitoring device includes:

[0073] The burner air intake and burnout air intake are measured by the online air volume measuring device 9. The inner and outer secondary air dampers 11 of the burner 7 and burnout air 8 are adjusted once.

[0074] The oxygen content at the economizer outlet and the CO emission at the furnace outlet, as monitored at the economizer outlet section, are used to make secondary adjustments to the internal and external secondary air dampers 11 of the burner and burnout air.

[0075] Specifically, based on online monitoring data such as the online measuring device 9, the oxygen content at the economizer outlet, and the CO emission at the furnace outlet, the online air volume is precisely adjusted manually or automatically to achieve dynamic adjustment of combustion within the furnace and alleviate combustion deterioration. That is, through the air volume measuring device 9, precise control can be achieved on the internal and external secondary air dampers 11, ensuring a balance between the air intake and burnout air intake of each burner, and achieving coarse adjustment of the internal and external secondary air dampers 11 of burner 7 and burnout air 8; further, with the addition of an oxygen meter at the economizer outlet section and a CO concentration monitoring device, fine adjustment of the internal and external secondary air dampers 11 of burner 7 and burnout air 8 is achieved, improving the unit's combustion state, thus improving the combustion state of the counter-coal-fired boiler.

[0076] In summary, the present invention provides a method for improving the combustion state of a counter-firing coal-fired boiler, comprising: installing a flow guiding device and a uniformly distributed grid at multiple first bends on one side of the secondary main air duct outlet; installing an online air volume measuring device at the burner and the burnout air inlet; installing multiple oxygen meters and a CO concentration monitoring device at the economizer outlet section; and adjusting the burner air volume and burnout air volume based on the burner air volume and burnout air volume measured by the online air volume measuring device, the oxygen content at the economizer outlet section measured by the multiple oxygen meters, and the CO emission at the furnace outlet monitored by the CO concentration monitoring device. This application optimizes the flow field of the secondary main air duct and monitors the air intake of burner 7 and burnout air 8, achieving precise control of the internal and external secondary air dampers 11. This ensures the balance of air intake for each burner and burnout air, enabling coarse adjustment of the internal and external secondary air dampers 11 of burner 7 and burnout air 8. In addition, the application uses an added economizer outlet section oxygen meter and CO concentration monitoring device to finely adjust the internal and external secondary air dampers 11 of burner 7 and burnout air 8, thereby improving the combustion state of the counter-coal-fired boiler.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0078] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0079] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for improving the combustion state of a counter-fired coal-fired boiler, characterized in that, The method includes: Determine whether the smoothness of the secondary airflow at each first bend is greater than the set smoothness threshold; The first bend with a smoothness level greater than the smoothness threshold is designated as the first type of bend. The first type of bend with a smoothness level less than or equal to the smoothness threshold is designated as the second type of bend, wherein the smoothness level of the first type of bend is less than that of the second type of bend. A flow guiding device is installed at multiple first-type bends on one side of the air outlet of the secondary main air duct, and a uniformly distributed grid is installed at multiple second-type bends on one side of the air outlet of the secondary main air duct. The uniformly distributed grid divides the corresponding layer air duct into 3 segments in the height direction and 4 segments in the width direction. Online air volume measurement devices are installed at the burner and the burnout air inlet; Multiple oxygen meters and CO concentration monitoring devices are installed at the economizer outlet section. Specifically, this includes: installing multiple oxygen meters on both sides of the economizer outlet section; using multiple oxygen meters to monitor the set oxygen points on both sides of the economizer outlet section; installing multiple CO concentration monitoring devices on both sides of the economizer outlet section; using multiple CO concentration monitoring devices to monitor the CO emissions at the furnace outlet, and displaying the CO concentration test results on both sides on the monitoring screen displayed on the monitoring equipment used by the operators through a rotating measurement method. The burner air intake and burnout air intake are adjusted based on the burner air intake and burnout air intake measured by the online air volume measurement device, the oxygen content at the economizer outlet section measured by multiple oxygen meters, and the CO emission at the furnace outlet monitored by the CO concentration monitoring device. Specifically, this includes: adjusting the inner and outer secondary air dampers of the burner and burnout air based on the burner air intake and burnout air intake measured by the online air volume measurement device; and adjusting the inner and outer secondary air dampers of the burner and burnout air based on the economizer outlet oxygen content monitored at the economizer outlet section and the CO emission at the furnace outlet. The online air volume measurement device includes: an annular air duct, a secondary air annular air duct inlet, a secondary air annular air duct outlet, a first electrostatic sensor, and a second electrostatic sensor. The secondary air annular duct inlet is the inlet of the annular duct, and the secondary air annular duct outlet is the outlet of the annular duct; The first electrostatic sensor and the second electrostatic sensor are installed inside the inlet of the secondary air annular duct along the direction from the inlet to the outlet of the annular duct. They are used to measure the dust carried in the secondary air passing through the annular duct. The time difference between the dust carried in the secondary air passing through the first electrostatic sensor and the second electrostatic sensor is measured by the first electrostatic sensor and the second electrostatic sensor, and then the secondary air velocity is calculated, that is, the burner air intake and the burnout air intake are calculated. Among them, the first electrostatic sensor and the second electrostatic sensor are ring structure sensors with a diameter of less than 360 degrees. The method further includes: By using multiple sets of preset test installation angles for the uniformly distributed grid, the combustion state of the coal-fired boiler is simulated, and the actual installation angle of the uniformly distributed grid is selected from the multiple sets of test installation angles.

2. The method according to claim 1, characterized in that, The flow guiding device includes an arc-shaped flow guiding plate. By using multiple sets of test installation positions and installation angles of the flow guiding plate, the combustion state of the coal-fired boiler is simulated. The installation position and installation angle of the flow guiding plate are determined by adjusting from multiple sets of test installation positions and installation angles.

3. The method according to claim 2, characterized in that, Each flow guiding device includes multiple flow guiding plates.

4. The method according to claim 1, characterized in that, A flow guiding device is installed on several second bends on the side of the air inlet of the secondary main air duct.

5. The method according to claim 1, characterized in that, The method further includes: The burner air intake and burnout air intake are measured using an online air volume measurement device. The steps involved in measuring the burner inlet air volume and the burnout air inlet air volume using an online air volume measurement device are as follows: Dust carried in the inlet and outlet of the secondary air annular duct was collected; The time K1 for the secondary wind carrying dust to pass through the first electrostatic sensor is measured, and the time K2 for the secondary wind carrying dust to pass through the second electrostatic sensor is measured. The time difference K2 of the secondary wind carrying dust passing through the second electrostatic sensor and the time K1 of the secondary wind carrying dust passing through the first electrostatic sensor are processed to obtain the time difference K3 of the secondary wind carrying dust passing through the first electrostatic sensor and the second electrostatic sensor. The burner air intake and burnout air intake are obtained through the time difference K3.

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