Primary air volume leveling device and leveling method for pulverized coal boilers in power plants

Abstract

This invention provides a primary air volume leveling device and method for a pulverized coal boiler in a power plant. The leveling method includes determining the positions of all measuring probes on each measuring rod; inserting a target measuring rod into a corresponding measuring hole, with the adsorption module at the top of the target measuring rod adsorbing onto the inner wall of the primary air duct to be measured, thus fixing the target measuring rod; sealing the measuring hole where the target measuring rod is installed; adjusting the air speed to a first air speed; determining a first primary air duct to be adjusted based on the real-time air speed of all primary air ducts to be measured and a preset air speed deviation; and adjusting an adjustable constriction orifice on the first primary air duct to be adjusted based on its air speed deviation and its real-time air speed until the air speed deviation of the first primary air duct to be adjusted conforms to the preset air speed deviation. The primary air volume leveling method provided by this invention can improve the accuracy of air speed leveling.

Description

Technical Field

[0001] This invention relates to the field of boiler air velocity leveling technology, and in particular to a primary air volume leveling device and leveling method for a pulverized coal boiler in a power plant. Background Technology

[0002] A pulverized coal boiler is an industrial or utility boiler that generates heat by burning pulverized coal blown into the combustion chamber. The basic idea behind combustion systems using pulverized fuel is to use the entire furnace to burn solid fuel. The coal is ground into fine particles, mixed with air, and burned in the flue gas stream. This type of boiler dominates in coal-fired power plants.

[0003] Primary air plays a crucial role in the combustion process of pulverized coal boilers. It transports the produced pulverized coal to the boiler and provides some oxygen for combustion. The primary air volume directly affects the normal operation of the boiler. Specifically, whether the primary air volume in the pulverized coal boiler is leveled affects the pulverized coal carrying capacity of each duct. If the air velocity in some ducts is too low, pulverized coal will accumulate, causing flame backfire, damaging the nozzles, and leading to boiler safety accidents. If the air velocity in some ducts is too high, it will also scour the water-cooled walls, causing uneven heating, resulting in a large temperature difference between the steam sides of the furnace, coking and tube rupture in the furnace, and even furnace shutdown.

[0004] Furthermore, deviations in the primary air velocity of each duct exceeding standard requirements will affect the distribution of pulverized coal in each pulverized coal duct. The distribution of pulverized coal directly impacts the tangential shape and size of the furnace, significantly affecting the safety and economy of the pulverized coal boiler. Standards require that the velocity deviation of each primary air duct in the same layer or mill should not exceed 5%. For intermediate storage pulverizing systems, this requirement applies to ducts in the same layer; for direct-fired pulverizing systems, it applies to ducts in the same mill. After a major overhaul or when replacing the reduced-orifice section, a cold-state primary air volume leveling test is conducted. For pulverized coal boilers, performing a proper primary air volume leveling test is crucial.

[0005] Currently, most airflow leveling tests are performed on the primary air ducts in a cold state, when the unit is shut down. The test instruments and methods used are roughly the same, using an air velocity measuring instrument in conjunction with a Pitot tube or back-to-back tube. Traditional measurement methods have the following drawbacks:

[0006] First, manual measurement suffers from significant errors and low accuracy. The air velocity distribution within the primary air duct is uneven, with different values ​​at different locations. When measuring manually by hand or against the duct, the pitot tube may wobble or move slightly, easily causing the actual measured air velocity to differ from the intended value. This requires a high level of skill from the testing personnel. The handheld pitot tube measurement inevitably introduces wobbling, and human error cannot be eliminated, making it impossible to guarantee instrument stability and accurate angles, thus significantly impacting test accuracy. According to industry standards for on-site performance testing of fans, the deviation between the air volume and the average air volume in each primary air duct of the same pulverized coal boiler or on the same floor should be within 5%. This requires a substantial workload and results in poor test accuracy.

[0007] Secondly, the labor intensity is high. Generally speaking, a single air volume leveling test requires three working conditions. If the test data is ideal, three working conditions are needed. If it is not ideal, more working conditions need to be added. The test location usually requires the erection of scaffolding. Multiple climbing tests place high demands on the physical strength of the test personnel. Therefore, the labor intensity of the test is high, testing the physical strength and patience of the test personnel.

[0008] Third, the measurement process is time-consuming. There are many primary air ducts; a typical 600MW power plant boiler has 36 primary air ducts. Each primary air duct needs to be measured individually, which is time-consuming, increases the power consumption of the fans, and increases the testing cost.

[0009] Fourth, there are certain safety risks. Most primary wind speed measurement locations require the construction of scaffolding. Coupled with the high labor intensity and long time consumption, the test personnel have to climb and measure repeatedly, which inevitably leads to physical exhaustion or a relaxation of safety awareness, creating safety hazards and risks.

[0010] Fifth, during the current primary wind speed leveling process, ducts with lower wind speeds need to have their orifices enlarged to increase wind speed, while ducts with higher wind speeds need to have their orifices closed to decrease wind speed. The number of turns required to close the orifice and the number required to enlarge it largely depends on experience and intuition. For example, the average wind speed of the four ducts in this mill is 28 meters per second, with one duct having a wind speed of 30 meters per second, a difference of 2 meters per second. The testers first try closing the orifice 3 or 5 turns to see how much it reduces the wind speed. If it only reduces it by 0.5 meters, it needs to be closed another 3 or 5 turns. The orifice conditions for each duct are not necessarily the same. At the same opening degree, some orifices reduce the wind speed by 2 meters after 5 turns, while others reduce it by only 1 meter. This is the most time-consuming part of the primary wind speed leveling test for pulverized coal boilers.

[0011] However, current primary air duct leveling tests are mainly conducted in a cold state. When the unit is shut down, manual testing using an air velocity measuring instrument in conjunction with a Pitot tube or back-mounted duct is required, resulting in low accuracy and a lengthy testing time. Reducing the primary air duct leveling time and improving testing accuracy has become a pressing technical problem that needs to be solved. Summary of the Invention

[0012] This invention provides a primary air volume leveling device and method for a pulverized coal boiler in a power plant, to solve the problems of low accuracy and long time consumption caused by current manual testing.

[0013] In a first aspect, embodiments of the present invention provide a method for adjusting the primary air volume of a pulverized coal boiler in a power plant, comprising:

[0014] Determine the position of all measuring probes on each measuring rod; wherein, each measuring rod is installed in a measuring hole in a primary air duct to be measured, and the primary air duct to be measured consists of at least 4 primary air ducts on the same pulverized coal boiler or on the same floor, and each primary air duct to be measured has at least one measuring hole.

[0015] The target measuring rod is inserted into the measuring hole corresponding to the target measuring rod, and the adsorption module at the top of the target measuring rod is adsorbed onto the inner wall of the primary air duct to be measured, so as to fix the target measuring rod.

[0016] After sealing the measuring hole where the target measuring rod is installed, adjust the wind speed to the first wind speed. Based on the real-time wind speed of all the primary air ducts to be measured and the preset wind speed deviation, determine the first primary air duct to be adjusted.

[0017] Based on the wind speed deviation value of the first primary air duct to be adjusted and its real-time wind speed, adjust the adjustable constriction orifice on it until the wind speed deviation of the first primary air duct to be adjusted meets the preset wind speed deviation.

[0018] In one possible implementation, determining the positions of all measuring probes on each measuring rod includes:

[0019] Based on the inner diameter of the primary duct to be measured to be installed on each measuring rod, and the Chebyshev method or the area method, determine the position of the point to be measured in the measuring hole; based on the position of the point to be measured in the measuring hole, determine the position of each measuring probe of the measuring rod installed in the measuring hole.

[0020] In one possible implementation, after adjusting the adjustable constriction orifice on the primary air duct to be adjusted based on the wind speed deviation value and its real-time wind speed, until the wind speed deviation of the first primary air duct to be adjusted meets the preset wind speed deviation, the method further includes:

[0021] The wind speed of the pulverized coal boiler in the power plant is adjusted to the second wind speed. Based on the real-time wind speed of all primary air ducts to be measured and the preset wind speed deviation, it is determined whether there is a second primary air duct to be adjusted.

[0022] When there is a second primary air duct to be adjusted, the adjustable constriction orifice on it is adjusted based on the wind speed deviation value of the second primary air duct to be adjusted and its real-time wind speed until the wind speed deviation of the second primary air duct to be adjusted meets the preset wind speed deviation.

[0023] The wind speed of the pulverized coal boiler in the power plant is adjusted to the third wind speed. Based on the real-time wind speed of all primary air ducts to be measured and the preset wind speed deviation, it is determined whether there is a third primary air duct to be adjusted.

[0024] When there is a third primary air duct to be adjusted, the adjustable orifice on it is adjusted based on the wind speed deviation value of the second primary air duct to be adjusted and its real-time wind speed until the wind speed deviation of all the third primary air ducts to be adjusted meets the preset wind speed deviation.

[0025] When there is no third primary air duct to be adjusted, the adjustment of the primary air volume is stopped; where the first air speed, the second air speed and the third air speed are different air speeds.

[0026] In one possible implementation, the first primary air duct to be adjusted is determined based on the real-time wind speed of all primary air ducts to be measured and a preset wind speed deviation, including:

[0027] The average wind speed is determined based on the real-time wind speed of all primary air ducts to be measured.

[0028] When the deviation between the real-time wind speed and the average wind speed of the target primary air duct to be measured is greater than the preset wind speed deviation, the target primary air duct to be measured is determined as the first primary air duct to be adjusted; wherein, the target primary air duct to be measured is any primary air duct to be measured.

[0029] In one possible implementation, the real-time wind speed of each primary duct to be measured is the average of the wind speeds measured by all the measuring probes on the measuring rod installed in the primary duct to be measured.

[0030] The wind speed deviation value of the first primary air duct to be adjusted is the difference between the real-time wind speed and the average wind speed of the first primary air duct to be adjusted, divided by the average wind speed.

[0031] In one possible implementation, the target measuring rod is aligned with the diameter of the cross-section where the measuring hole is located.

[0032] In a second aspect, embodiments of the present invention provide a primary air volume leveling device for a pulverized coal boiler in a power plant, which uses the primary air volume leveling method of the first aspect of the pulverized coal boiler in a power plant to level the primary air duct. The leveling device includes: multiple data measurement modules, a data acquisition module and a data processing module.

[0033] Each data measurement module includes a measuring rod and multiple measuring probes. The measuring rod is inserted into the top of the primary air duct to be measured and is equipped with an adsorption module to fix the measuring rod to the inner wall of the primary air duct. The measuring probes are fixed on the measuring rod, and the position of each measuring probe on the measuring rod is determined based on the inner diameter of the primary air duct to be measured and Chebyshev or area method.

[0034] The data acquisition module includes multiple signal input channels and at least one signal output channel. Each measurement probe is electrically connected to one signal input channel, and the signal output channel is electrically connected to the input terminal of the data processing module.

[0035] The data processing module is used to process the received wind speed data and display the wind speed information of all the primary ducts to be measured.

[0036] In one possible implementation, the measuring rod is a hollow metal tube, and the measuring probe is a hot-wire anemometer probe.

[0037] In one possible implementation, the measuring probe is fixed to the measuring rod by a clip, plastic hook, or tape; the adsorption module is a magnetic adsorption module.

[0038] In one possible implementation, the wind speed information includes the real-time wind speed of each duct to be measured, the wind speed of each measuring probe of each duct to be measured, and the deviation of each duct from the average wind speed.

[0039] This invention provides a method, apparatus, equipment, and storage medium for adjusting the primary air volume of a pulverized coal boiler in a power plant. First, the positions of all measuring probes on each measuring rod are determined. Then, the target measuring rod is inserted into the corresponding measuring hole, and the adsorption module at the top of the target measuring rod is adsorbed onto the inner wall of the primary air duct to be measured, thus fixing the target measuring rod. Next, after sealing the measuring hole where the target measuring rod is installed, the air speed is adjusted to a first air speed. Based on the real-time air speed of all primary air ducts to be measured and a preset air speed deviation, a first primary air duct to be adjusted is determined. Finally, based on the air speed deviation value of the first primary air duct to be adjusted and its real-time air speed, the adjustable constriction orifice on it is adjusted until the air speed deviation of the first primary air duct to be adjusted conforms to the preset air speed deviation. By installing a measuring rod in each primary air duct to be measured, the wind speed of all primary air ducts can be measured simultaneously. After determining the primary air duct to be adjusted, the wind speed change can be observed in real time while adjusting the adjustable orifice of the duct, thus making the adjustment more accurate and allowing the wind speed of all primary air ducts to be measured to be within the preset wind speed deviation range without spending a long time. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the primary air volume leveling device for a pulverized coal boiler in a power plant provided in an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the measuring rod provided in an embodiment of the present invention;

[0043] Figure 3 This is a flowchart illustrating the implementation of the primary air volume leveling method for a pulverized coal boiler in a power plant, as provided in this embodiment of the invention.

[0044] Figure 4 This is a schematic diagram of the leveling test of the four primary air ducts of each mill in a boiler with a tangential combustion method provided in an embodiment of the present invention. Detailed Implementation

[0045] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0047] To address the problems of existing technologies, embodiments of the present invention provide a primary air volume leveling device and method for a pulverized coal boiler in a power plant. The primary air volume leveling device for a pulverized coal boiler provided in this embodiment will be described below.

[0048] Please see also Figures 1 to 2 A primary air volume leveling device for a pulverized coal boiler in a power plant includes multiple data measurement modules 10, a data acquisition module 20, and a data processing module 30.

[0049] Each data measurement module 10 includes a measuring rod 11 and multiple measuring probes 12. The measuring rod 11 extends into the primary air duct to be measured, and its top end is equipped with an adsorption module 13 for fixing the measuring rod 11 to the inner wall of the primary air duct. The measuring probes 12 are fixed on the measuring rod 11, and the position of each measuring probe 12 on the measuring rod 11 is determined based on the inner diameter of the primary air duct to be measured and the Chebyshev method or the area method.

[0050] The data acquisition module 20 includes multiple signal input channels 21 and at least one signal output channel 22. Each measurement probe 12 is electrically connected to a signal input channel 21, and the signal output channel 22 is electrically connected to the input terminal of the data processing module 30.

[0051] The data processing module 30 is used to process the received wind speed data and display the wind speed information of all the primary ducts to be measured.

[0052] In some embodiments, the measuring rod 11 is a lightweight metal rod, each metal rod being about 1 meter long. The inner diameter of the duct to be measured is approximately 460mm-630mm, and the diameter of the metal rod is about 1 cm.

[0053] In this embodiment, the metal rod can be made into a hollow structure for easy carrying and installation, so as to reduce the weight of the measuring rod 11.

[0054] For example, the measuring rod 11 can be a hollow rod of aluminum alloy.

[0055] In some embodiments, the adsorption module 13 fixed to the top of the measuring rod 11 can be a magnet with a certain magnetic force. When the measuring rod 11 is inserted into the primary air duct to be measured, it can be fixed to the inner wall of the primary air duct by the magnet at its top, thus maintaining the stability of the measuring rod 11 in the primary air duct to be measured.

[0056] Specifically, during measurement, the measuring rod 11 needs to be inserted into the measuring hole from the measuring hole along the diameter direction of the primary air duct section to be measured until the measuring rod contacts the inner wall on the other side of the air duct. The function of the magnet at the top of the measuring rod 11 is to tightly connect the rod-shaped measuring rod 11 with the inner wall of the primary air duct to be measured, so that it will not be blown away or shaken by the air in the primary air duct.

[0057] In some embodiments, to accurately measure the wind speed in the primary air duct, six wind speed measuring probes 12 can be installed on the measuring rod 11. The measuring principle of these probes 12 is the same as that of a hot-wire anemometer, which can be either a constant current principle or a constant resistance principle.

[0058] In this embodiment, the size of the measuring probe 12 can be the same as that of the hot-wire anemometer probe. The installation positions of each measuring probe 12 can be determined based on the size of the primary air duct to be measured, typically six points. The positions of these six points are calculated based on the size of the primary air duct and using the Chebyshev method or a linear method. The measuring probe 12 is then fixed at each point. The fixing method can use clips, plastic snaps, or adhesive tape to ensure that the measuring probe 12 is firmly fixed to the measuring rod 11 without shaking or vibrating, thus ensuring that the measuring probe 12 can accurately measure the wind speed.

[0059] For example, the measuring probe 12 can be a hot-wire anemometer probe. Regardless of whether the measurement is performed using the current method or the resistance method, each measuring probe 12 needs to be connected to the data acquisition module 20, such as by using a wire connection.

[0060] For example, for a measuring rod 11 using a hollow metal tube, the connecting wires of all measuring probes 12 can be passed through the inside of the measuring rod 11. Alternatively, the wires of each measuring probe 12 can be placed on the leeward side of the measuring rod 11 and secured to the leeward side of the measuring rod 11 with plastic knots.

[0061] In some embodiments, the data acquisition module 20 acquires the wind speed data measured by the measuring probe 12 and transmits the acquired wind speed data to the data processing module 30. The data acquisition module 20 has multiple signal input channels, the number of which corresponds to the number of measuring probes 12. Each signal input channel can be connected to the measuring probe 12 via a data cable or wireless transmission. This allows the data acquisition module 20 to acquire the wind speed of all the ducts to be measured at once. The signal output channel of the data acquisition module 20 can be connected to the data processing module 30 via a wired connection, a USB interface, or wireless transmission.

[0062] In some embodiments, the data processing module 30 can be a computer with software installed on it that is interconnected with the data acquisition module 20. Through this software, the wind speed of each duct to be measured, the wind speed of each measuring probe, and the deviation of each duct to be measured from the average wind speed can be displayed.

[0063] The data processing module 30 can calculate and organize the wind speed collected by the data acquisition module 20, draw it into a table, or directly process the data into a more intuitive image, so that the test personnel can directly determine which primary air ducts to be measured need to be adjusted and how much deviation needs to be adjusted based on the organized data.

[0064] When adjusting the adjustable orifice of a primary air duct whose wind speed deviation exceeds the preset deviation, the real-time wind speed after adjustment can be viewed through the data processing module 30. This allows for more accurate adjustment of the wind speed in the primary air duct. Furthermore, the adjustment also reflects the performance of the adjustable orifice. For example, some adjustable orifices show significant wind speed changes after a few adjustments, while others show little change even after 10 adjustments. Generally, adjustable orifices with poor performance are those with severe wear and long operating times, which can provide valuable information for the maintenance of adjustable orifices.

[0065] The primary air volume leveling device for a pulverized coal boiler provided by this invention can simultaneously level all primary air ducts to be measured. During the leveling process, the adjustable orifices on the primary air ducts to be measured can be adjusted based on the wind speed data displayed on the data processing module. The adjusted wind speed can be displayed in real time during the adjustment process, thus accurately adjusting the wind speed of all primary air ducts to be measured, ensuring that the wind speed of all primary air ducts is within a preset deviation range. The primary air volume leveling device provided by this invention can achieve automatic wind speed measurement. Since the adjustment of the adjustable orifice and the measurement of wind speed are synchronized in this application, the adjusted wind speed can be displayed in real time on the data processing module during adjustment. This allows the wind speed of all first-layer air ducts on the same pulverized coal boiler or on the same floor to be adjusted to within 2% of the average air volume deviation, or even within 1%, greatly improving the accuracy of the test.

[0066] Furthermore, the measuring rod in this application is equipped with multiple measuring probes, which greatly improves measurement accuracy. When the measuring rod is inserted into the measuring hole on the duct to be measured, the adsorption module at its top secures the measuring rod to the inside of the duct, preventing it from being affected by the wind inside the duct. Moreover, the leveling device provided in this application allows for multiple adjustments to the wind speed without repeatedly opening the measuring hole, thus reducing the harm of dust to test personnel.

[0067] Secondly, such as Figure 3 As shown, the present invention also provides a method for adjusting the primary air volume of a pulverized coal boiler in a power plant, comprising the following steps:

[0068] S310. Determine the position of all measuring probes on each measuring rod.

[0069] Each measuring rod is installed in a measuring hole in a primary air duct to be measured. The primary air ducts to be measured are at least four primary air ducts from the same pulverized coal boiler or on the same floor, and each primary air duct to be measured has at least one measuring hole.

[0070] In some embodiments, the position of each measuring probe can first be determined based on the inner diameter of the primary duct to be measured, and the Chebyshev method or the area method, to determine the position of the point to be measured within the measuring hole. Then, based on the position of the point to be measured within the measuring hole, the position of each measuring probe of the measuring rod installed within the measuring hole is determined.

[0071] In this embodiment, the installation position of each measuring probe can be marked on the measuring rod with a marker, and the measuring probe can be fixed to the measuring rod with plastic clips. After the measuring probes are fixed, the wires connected to each measuring probe are fixed to the measuring rod.

[0072] In some embodiments, before the test begins, a 220V power bank or a 220V power supply tray and several blocking cloths are required. If it is a power supply tray, it needs to be powered on and placed on a convenient platform nearby. The data acquisition module and data processing module are then started, and the power supply is checked to ensure it is sufficient.

[0073] S320. Insert the target measuring rod into the measuring hole corresponding to the target measuring rod, and the adsorption module at the top of the target measuring rod adsorbs onto the inner wall of the primary air duct to be measured.

[0074] After fixing the measuring probes to all the measuring rods according to step S310, the target measuring rod can be inserted into the measuring hole corresponding to that target measuring rod. Since the position of the measuring probe on each measuring rod is set according to the size of each primary duct to be measured, the specific target measuring rod to be used in each measuring hole must also be determined. The target measuring rod can be any measuring rod.

[0075] When the measuring rod is inserted into the measuring hole, it must be ensured that the measuring rod is aligned with the diameter of the cross-section of the measuring hole until the adsorption module at the top of the measuring rod is attracted to the inner wall of the primary air duct. It must not be tilted, otherwise significant errors will occur. One end of the measuring rod is fixed in place by an adsorption module, such as a magnet.

[0076] S330. After sealing the measuring hole where the target measuring rod is installed, adjust the wind speed to the first wind speed. Based on the real-time wind speed of all primary air ducts to be measured and the preset wind speed deviation, determine the first primary air duct to be adjusted.

[0077] After inserting the target measuring rod into the measuring hole, the gap between the measuring rod and the measuring hole needs to be sealed tightly with a plug or sealing material. At this point, the plug also serves to secure the rod. One end of the measuring rod is fixed to the inner wall of the duct via its top adsorption module, while the other end is sealed tightly with a plug or sealing material to ensure the measuring rod is fixed and not affected by the airflow inside the duct, which could cause the measuring rod to move and affect the accuracy of the measuring probe.

[0078] After connecting and turning on the primary air volume leveling device, the test can be conducted by adjusting the operating conditions. First, adjust the air speed to the highest possible speed, such as approximately 27 m / s for each duct. Begin the test, measuring each floor sequentially. The data processing module calculates and organizes the obtained air speeds, plotting them in a table or directly processing them into a more intuitive graph. It can display the air speed of each primary air duct to be measured, as well as the air speed at each measuring point within each duct.

[0079] First, the average wind speed can be determined based on the real-time wind speed of all primary air ducts to be measured. Then, when the wind speed deviation between the real-time wind speed and the average wind speed of the target primary air duct is greater than a preset wind speed deviation, the target primary air duct to be measured is designated as the first primary air duct to be adjusted. The target primary air duct to be measured can be any one of the primary air ducts to be measured.

[0080] Specifically, the real-time wind speed of each primary air duct to be measured is the average wind speed measured by all measuring probes on the measuring rod installed inside the primary air duct. The wind speed deviation value of the first primary air duct to be adjusted is the difference between the real-time wind speed and the average wind speed of the first primary air duct to be adjusted, divided by the average wind speed.

[0081] For example, in a boiler with tangential combustion, each mill consists of four primary air ducts, such as... Figure 4 As shown, each primary air duct has a measuring hole, and each measuring hole contains three measuring probes. Each measuring probe is connected to a signal input channel within the data acquisition module 20, and the signal output channel of the data acquisition module 20 is connected to the data processing module 30. The data processing module 30 displays the wind speed of the four primary air ducts, the average wind speed of the four primary air ducts, and the deviation between the primary wind speed and the average wind speed of each duct, all of which can be shown on a computer in the form of tables or graphs. For example, the air velocity in primary air duct No. 1 of a coal mill is 26 m / s, the air velocity in primary air duct No. 2 is 26 m / s, the air velocity in primary air duct No. 3 is 27 m / s, and the air velocity in primary air duct No. 4 is 29 m / s. The average air velocity of the four ducts is 27 m / s. The deviation of primary air duct No. 1 from the average air velocity is 3.70%, the deviation of primary air duct No. 2 from the average air velocity is 3.70%, the deviation of primary air duct No. 3 from the average air velocity is 0%, and the deviation of primary air duct No. 4 from the average air velocity is 7.40%. The preset deviation is set to 5%. Based on the preset deviation, the air velocity of the ducts exceeding the preset deviation needs to be adjusted. From the data above, it can be seen that the air velocity deviation value of primary air duct No. 4, 7.40%, is greater than 5%, and adjustment is required. Therefore, primary air duct No. 4 is determined as the first primary air duct to be adjusted.

[0082] S340. Based on the wind speed deviation value of the first primary air duct to be adjusted and its real-time wind speed, adjust the adjustable constriction orifice on it until the wind speed deviation of the first primary air duct to be adjusted meets the preset wind speed deviation.

[0083] Based on the wind speed deviation value of the first primary air duct to be adjusted and its real-time wind speed, determine the adjustment amount required. Using the example above: the wind speed of primary air duct No. 4 is 29 m / s, the average wind speed is 27 m / s, and the deviation between the wind speed of primary air duct No. 4 and the average wind speed is 7.40%.

[0084] During the adjustment process, you can judge by experience or by continuous trial and error. First, try closing the adjustable orifice by 3 turns. Then, through the data processing module in the primary air volume leveling device, you can see that the air velocity of the No. 4 primary air duct after adjustment has decreased from 29 m / s to 28.7 m / s. You still need to continue to reduce the opening of the adjustable orifice by closing it a few more turns. Finally, through the data processing module in the primary air volume leveling device, you can see that the air velocity of the No. 4 primary air duct after adjustment has become 28 m / s. The deviation between the air velocity and the average air velocity is within 5%, so no further adjustment is needed.

[0085] To ensure the accuracy of all measured duct air velocity leveling, it is necessary to test again under different operating conditions after the first leveling.

[0086] The air velocity of the pulverized coal boiler in the power plant is adjusted to a second air velocity. Based on the real-time air velocity of all primary air ducts to be measured and the preset air velocity deviation, it is determined whether there is a second primary air duct to be adjusted. The second air velocity is different from the first air velocity.

[0087] When a second primary air duct to be adjusted exists, its adjustable orifice is adjusted based on the airflow deviation value and real-time airflow of the second primary air duct until the airflow deviation of the second primary air duct meets the preset airflow deviation. The adjustment method is the same as that for the first primary air duct to be adjusted, and will not be repeated here. When there is no second primary air duct to be adjusted, it is not necessary to adjust the adjustable orifices of all air ducts.

[0088] To further ensure the accuracy of all measured duct air velocity leveling, three leveling operations are usually required. After the second leveling, a third operating condition is required for testing again.

[0089] The air velocity of the pulverized coal boiler in the power plant is adjusted to the third air velocity. Based on the real-time air velocity of all primary air ducts to be measured and the preset air velocity deviation, it is determined whether a third primary air duct to be adjusted exists. If a third primary air duct to be adjusted exists, the adjustable orifice on it is adjusted based on the air velocity deviation value of the second primary air duct to be adjusted and its real-time air velocity until the air velocity deviation of all third primary air ducts to be adjusted meets the preset air velocity deviation. If no third primary air duct to be adjusted exists, the adjustment of the primary air volume is stopped.

[0090] Normally, leveling primary air ducts requires adjusting using three different operating conditions. However, depending on the actual application scenario, more operating conditions can be selected to level all primary air ducts.

[0091] The leveling method provided by this invention can simultaneously display the real-time air velocity of all ducts to be measured, and the change in airflow during the adjustment of the duct can also be directly observed on the leveling device. It allows for simultaneous adjustment of the adjustable orifice opening and measurement of the duct air velocity, thereby improving adjustment accuracy, reducing air velocity errors, and saving time. Furthermore, the adjustment of the adjustable orifice can also serve as an evaluation criterion for orifice wear.

[0092] The single-pass air volume leveling method provided by this invention can achieve the measurement and collection of more data in a short time, avoiding the need for multiple large-scale measurements by test personnel. Furthermore, multiple tests can be conducted by opening the measuring hole only once, eliminating the need to open the measuring hole for each test, thus reducing the leakage of residual coal dust from the measuring hole.

[0093] This invention provides a method for leveling the primary air volume of a pulverized coal boiler in a power plant. First, the positions of all measuring probes on each measuring rod are determined. Then, the target measuring rod is inserted into the corresponding measuring hole, and the adsorption module at the top of the target measuring rod is adsorbed onto the inner wall of the primary air duct to be measured, thus fixing the target measuring rod. Next, after sealing the measuring hole where the target measuring rod is installed, the air speed is adjusted to a first air speed. Based on the real-time air speed of all primary air ducts to be measured and a preset air speed deviation, the first primary air duct to be adjusted is determined. Finally, based on the air speed deviation value of the first primary air duct to be adjusted and its real-time air speed, the adjustable constriction orifice on it is adjusted until the air speed deviation of the first primary air duct to be adjusted conforms to the preset air speed deviation. By installing a measuring rod in each primary air duct to be measured, the wind speed of all primary air ducts can be measured simultaneously. After determining the primary air duct to be adjusted, the wind speed change can be observed in real time while adjusting the adjustable orifice of the duct, thus making the adjustment more accurate and allowing the wind speed of all primary air ducts to be measured to be within the preset wind speed deviation range without spending a long time.

[0094] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0095] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for adjusting the primary air volume of a pulverized coal boiler in a power plant, characterized in that, include: Determine the position of all measuring probes on each measuring rod; wherein, each measuring rod is installed in a measuring hole in a primary air duct to be measured, and the primary air duct to be measured consists of at least 4 primary air ducts on the same pulverized coal boiler or on the same floor, and each primary air duct to be measured has at least one measuring hole. The target measuring rod is inserted into the measuring hole corresponding to the target measuring rod, and the adsorption module at the top of the target measuring rod is adsorbed onto the inner wall of the primary air duct to be measured, so as to fix the target measuring rod. After sealing the measuring hole of the target measuring rod, the wind speed is adjusted to the first wind speed. Based on the real-time wind speed of all primary air ducts to be measured and the preset wind speed deviation, the first primary air duct to be adjusted is determined. The average wind speed, primary wind speed and average wind speed deviation of all primary air ducts to be measured are displayed in tables or images. Based on the wind speed deviation value of the first primary air duct to be adjusted and its real-time wind speed, adjust the adjustable constriction orifice on it until the wind speed deviation of the first primary air duct to be adjusted meets the preset wind speed deviation. The wind speed of the pulverized coal boiler in the power plant is adjusted to the second wind speed. Based on the real-time wind speed of all primary air ducts to be measured and the preset wind speed deviation, it is determined whether there is a second primary air duct to be adjusted. When there is a second primary air duct to be adjusted, the adjustable constriction orifice on it is adjusted based on the wind speed deviation value of the second primary air duct to be adjusted and its real-time wind speed until the wind speed deviation of the second primary air duct to be adjusted meets the preset wind speed deviation. The wind speed of the pulverized coal boiler in the power plant is adjusted to the third wind speed. Based on the real-time wind speed of all primary air ducts to be measured and the preset wind speed deviation, it is determined whether there is a third primary air duct to be adjusted. When there is a third primary air duct to be adjusted, the adjustable constriction orifice on it is adjusted based on the wind speed deviation value of the second primary air duct to be adjusted and its real-time wind speed until the wind speed deviation of all the third primary air ducts to be adjusted meets the preset wind speed deviation. When the third primary air duct to be adjusted is not present, the adjustment of the primary air volume is stopped; wherein the first air speed, the second air speed and the third air speed are different air speeds.

2. The method for adjusting the primary air volume of a power plant pulverized coal boiler as described in claim 1, characterized in that, Determining the position of all measuring probes on each measuring rod includes: Based on the inner diameter of the primary duct to be measured to be installed on each measuring rod, and the Chebyshev method or the area method, determine the position of the point to be measured in the measuring hole; based on the position of the point to be measured in the measuring hole, determine the position of each measuring probe of the measuring rod installed in the measuring hole.

3. The method for adjusting the primary air volume of a power plant pulverized coal boiler as described in claim 1, characterized in that, The process of determining the first primary air duct to be adjusted based on the real-time wind speed of all primary air ducts to be measured and the preset wind speed deviation includes: The average wind speed is determined based on the real-time wind speed of all primary air ducts to be measured. When the real-time wind speed deviation between the target primary air duct to be measured and the average wind speed is greater than the preset wind speed deviation, the target primary air duct to be measured is determined as the first primary air duct to be adjusted; wherein, the target primary air duct to be measured is any primary air duct to be measured.

4. The method for adjusting the primary air volume of a power plant pulverized coal boiler as described in claim 3, characterized in that, The real-time wind speed of each primary air duct to be measured is the average value of the wind speeds measured by all the measuring probes on the measuring rod installed in the primary air duct to be measured. The wind speed deviation value of the first primary air duct to be adjusted is the difference between the real-time wind speed and the average wind speed of the first primary air duct to be adjusted, divided by the average wind speed.

5. The method for adjusting the primary air volume of a power plant pulverized coal boiler as described in any one of claims 1-4, characterized in that, The target measuring rod is along the direction of the diameter of the cross section where the measuring hole is located.

6. A primary air volume leveling device for a power plant pulverized coal boiler, characterized in that, The primary air volume leveling method for a pulverized coal boiler in a power plant according to any one of claims 1-5 is used to level the primary air duct. The leveling device includes: multiple data measurement modules, a data acquisition module, and a data processing module. Each of the data measurement modules includes a measuring rod and multiple measuring probes. The measuring rod is provided with an adsorption module at its top end, which extends into the primary air duct to be measured, for fixing the measuring rod to the inner wall of the primary air duct. The measuring probes are fixed on the measuring rod, and the position of each measuring probe on the measuring rod is determined based on the inner diameter of the primary air duct to be measured and Chebyshev's method or the area method. The data acquisition module includes multiple signal input channels and at least one signal output channel. Each measurement probe is electrically connected to one signal input channel, and the signal output channel is electrically connected to the input terminal of the data processing module. The data processing module is used to process the received wind speed data and display the wind speed information of all the primary ducts to be measured.

7. The primary air volume leveling device for a power plant pulverized coal boiler as described in claim 6, characterized in that, The measuring rod is a hollow metal tube, and the measuring probe is a hot-wire anemometer probe.

8. The primary air volume leveling device for a power plant pulverized coal boiler as described in claim 7, characterized in that, The measuring probe is fixed to the measuring rod by a clip, plastic hook, or tape; the adsorption module is a magnetic adsorption module.

9. The primary air volume leveling device for a power plant pulverized coal boiler as described in claim 6, characterized in that, The wind speed information includes the real-time wind speed of each duct to be measured, the wind speed of each measuring probe of each duct to be measured, and the deviation of each duct from the average wind speed.

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