CN108958304A - A kind of First air leveling system and leveling method - Google Patents

Abstract

A kind of First air leveling system disclosed by the invention, including pipeline, pressure difference measuring device and shrinkage cavity self-checking device, the pressure difference measuring device includes the first driving mechanism of Pitot tube, pressure gauge and driving Pitot tube lifting, Pitot tube upper end is connect with pressure gauge, and Pitot tube lower end is deep into pipeline；The shrinkage cavity self-checking device includes the second driving mechanism of adjustable contraction plate and driving adjustable contraction plate rotation, and adjustable contraction plate is located in pipeline, and adjustable contraction plate and inner wall of the pipe cooperate；The leveling of intelligent primary wind is realized by measuring point automatic positioning, Measurement and Data Processing, shrinkage cavity adjust automatically, mitigates tester's labor intensity, operating method is simple and practical.

Description

A primary air leveling system and leveling method

technical field

The invention relates to the technical field of power station boilers, in particular to a primary air leveling system and a leveling method.

Background technique

The primary wind leveling test carried out before the thermal start-up of the boiler in the coal-fired power plant is mainly to measure the wind speed of the pipeline, and adjust it according to the results before measuring until the primary wind leveling. The measurement results are very important for unit operation and parameter adjustment. At present, there are many methods used in the field: according to the equal section method, the testers hold standard pitot tubes and bellows meters, and measure the wind speed in each primary air duct at the outlet of the coal mill in sequence.

In the actual measurement process, there are the following problems:

1. Positioning is prone to deviation during measurement. The on-site working conditions are poor, and the pitot tube needs to be moved several times for each pipeline measurement. Since the center of gravity of the pitot tube is unstable, and the position of the full pressure hole of the pitot tube in the pipeline is completely dependent on the tester's naked eye observation and manual adjustment, position deviation is prone to occur . When the position of the full pressure hole of the pitot tube is not in the direction of the wind speed or the vertical position is incorrect, the deviation of the measurement result is large.

2. Manual work is intensive, takes a long time, and works at heights

Power plant boilers are equipped with multiple coal mills, and the workload of primary wind testing is large. Manual adjustment of pitot tubes requires testers to work on-site with increased labor intensity. The workload and the harsh working environment on site will reduce the safety of personnel and equipment.

3. Manually adjust the shrinkage cavity, the deviation is large

The adjustment process after duct wind speed measurement relies on manual work to easily cause deviations and increase the measurement workload.

Contents of the invention

The purpose of the present invention is to solve the above problems, provide a primary air leveling system and leveling method, realize intelligent primary air leveling through automatic positioning of measuring points, measurement data processing, and automatic adjustment of shrinkage cavity, and reduce the labor intensity of testers. The operation method is simple and practical.

The technical scheme that the present invention solves its technical problem to take is:

A primary air leveling system, including a pipeline, a differential pressure measuring device and an automatic shrinkage cavity adjustment device, the differential pressure measuring device includes a pitot tube, a pressure gauge and a first drive mechanism for driving the pitot tube up and down, the upper end of the pitot tube is in contact with the pressure The lower end of the pitot tube goes deep into the pipeline; the shrinkage hole automatic adjustment device includes an adjustable shrinkage hole plate and a second drive mechanism that drives the adjustable shrinkage hole plate to rotate, the adjustable shrinkage hole plate is located in the pipeline, and the adjustable shrinkage hole plate The orifice fits with the inner wall of the pipe.

Further, a first installation frame is provided between the Pitot tube and the pipeline, the first installation frame is installed on the pipeline, and the Pitot tube and the first installation frame are slidably connected.

Further, a locking sleeve is provided on the Pitot tube, and the locking sleeve is composed of two semicircular rings, one end of the semicircular ring of the locking sleeve is hinged, the other end of the semicircular ring of the locking sleeve is detachably connected, and the locking sleeve is hinged A plane is provided at one end, and a rack is provided on the plane;

The first drive mechanism includes a first servo motor, the first servo motor is installed in the first installation frame through a support frame, a gear is provided at the output end of the first servo motor, and the gear meshes with the rack.

Further, the upper end of the pipeline is provided with an opening, the lower end of the Pitot tube passes through the opening, a first sealing ring is provided between the Pitot tube and the opening, a step is provided on the inner wall of the opening, the first sealing ring is located on the step, and the first sealing ring The upper end is provided with a cover plate for pressing the first sealing ring;

The cover plate is composed of two semicircular rings, and the end face of the cover plate is arc-shaped.

Further, the adjustable shrinkage plate includes a circular part and a connecting rod, a groove is provided at the flange connection of the pipe, the circular part is located in the pipe, and the connecting rod passes through the groove.

Further, a second sealing ring is provided between the connecting rod and the groove, and baffles are provided on the connecting rod at both ends of the groove.

Further, the second drive mechanism includes a second servo motor, a second mounting frame is provided between the second servo motor and the pipe, the second mounting frame is mounted on the pipe, and the output end of the second servo motor is connected to the connecting rod.

A primary wind leveling method, using the primary wind leveling system, is characterized in that the steps include:

1) Use a single-chip microcomputer to layer the pipeline, and use pitot tubes and pressure gauges to measure the pressure difference of each layer;

2) The pressure gauge transmits the measured dynamic pressure to the single-chip microcomputer, and the single-chip microcomputer performs data processing to obtain ΔP, and the unit of ΔP is Pa;

3) According to the adjustment plan given by the calculation result, the single-chip microcomputer adjusts the wind speed of the pipeline by the shrinkage cavity automatic adjustment device;

4) Repeat the above steps to measure until the deviation of the same layer of pipeline wind speed meets the requirements.

Further, in step 1), the specific steps of pipeline differential pressure measurement are:

A Install the device on the pipeline;

System B is initialized so that the full pressure hole of the pitot tube is located at the bottom of the pipe;

C single-chip microcomputer controls the first servo motor to start, the first servo motor drives the pitot tube to move upwards and records the moving distance until the pitot tube moves to the top of the pipeline, record the moving distance as h, and the unit of h is mm;

D transmits the moving distance to the single-chip microcomputer, and then records the pipe diameter of the pitot tube as d, and the unit of d is mm, and the single-chip computer calculates the pipeline diameter as D=h+2d, and the unit of D is mm;

The single-chip microcomputer determines the measuring points according to the division principle of the grid method and other sections according to the diameter of the pipeline, and obtains the distance of each measuring point;

F The first servo motor of the single-chip microcomputer is started, and the pitot tube is driven to move down to each measuring point, and the pressure gauge is used for dynamic pressure measurement and transmission. Every time the pressure gauge measures one, it is transmitted to the single-chip microcomputer for recording, until the data of each measuring point of all pipelines is recorded Finish;

G measures the atmospheric temperature, inputs the measurement result into the single-chip microcomputer, and obtains the air density ρ according to the atmospheric temperature, and the unit of ρ is Kg/m ³ .

Further, in step 2) single-chip microcomputer utilizes formula For calculation, the unit of v is m/s, and the duct wind speed is obtained after averaging.

Classify the pipes according to the layers of the burner, compare the wind speed of the same layer pipes together, get the average wind speed of the same layer pipes, and get the deviation value of the wind speed of each pipe, when the deviation of each pipe from the average value of the same layer When the values are less than 5%, no adjustment is required; when the deviation exceeds ±5%, adjustment must be made.

Further, in step 3), the single-chip microcomputer controls the start of the second servo motor, and the second servo motor drives the adjustable shrinkage plate to rotate to adjust the wind speed.

The beneficial effects of the present invention are:

1. The present invention is equipped with a differential pressure measuring device and an automatic adjustment device for shrinkage cavity. The differential pressure measuring device measures the differential pressure of the pipeline, and transmits the signal to the single-chip microcomputer, and calculates the wind speed of the air duct through the single-chip microcomputer, and calculates the deviation of the wind speed of each pipeline Afterwards, according to the calculation results, the single-chip microcomputer controls the shrinkage cavity automatic adjustment device to adjust the wind speed, and realizes the primary air leveling of the boiler cold test. The measurement only needs to be installed by the test personnel, and does not require any participation of personnel during the process. It is simple and convenient. The labor intensity is reduced; there is no need to rely on testers to observe with the naked eye and manually adjust the position of the pitot tube, and the servo motor is controlled by a single-chip microcomputer, so that the positioning is accurate and the shrinkage cavity adjustment device is adjusted accurately.

2. The upper end of the pipeline of the present invention is provided with an opening, the lower end of the Pitot tube passes through the opening, and a first sealing ring is provided between the Pitot tube and the opening, and the first sealing ring plays the role of sealing the pipeline and the Pitot tube to prevent the wind in the pipeline from leaking , affecting primary wind leveling.

3. There is a step on the inner wall of the opening of the present invention, the first sealing ring is located on the step, and the upper end of the first sealing ring is provided with a cover plate for pressing the first sealing ring. The cover plate and the steps can prevent the first sealing ring from following the pitot tube. It moves up and down with good reliability; the cover plate is composed of two semi-circular rings, and the cover plate is fixed on the pipe through screws, which will not interfere with the pitot tube and is convenient for installation.

4. A second sealing ring is provided between the connecting rod and the groove of the present invention, and baffles are provided on the connecting rod at both ends of the groove, the connecting rod rotates in the groove, and the connecting rod drives the circular part to rotate, In order to adjust the wind speed in the pipe, the baffle can prevent the connecting rod from moving axially, and the circular part will not wear with the inner wall of the pipe, which increases the service life and adjustment accuracy; the second sealing ring can prevent debris from entering the pipe, ensuring safety Environmental friendly.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, In other words, other drawings can also be obtained from these drawings on the premise of not paying creative work.

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a sectional view of the differential pressure measuring device of the present invention;

Fig. 3 is a partial enlarged view of H in Fig. 2;

Fig. 4 is a schematic structural diagram of a locking sleeve of the present invention;

Fig. 5 is a schematic diagram of the structure of the cover plate of the present invention;

Fig. 6 is the front view of the cover plate of the present invention;

Fig. 7 is a cross-sectional view of the shrinkage cavity automatic adjustment device of the present invention;

Fig. 8 is a partial enlarged view of I place in Fig. 7;

Fig. 9 is a schematic diagram of the structure of the adjustable shrinkage hole plate of the present invention.

In the figure: pipe 1, pitot tube 2, pressure gauge 3, first mounting frame 4, locking sleeve 5, plane 6, rack 7, first servo motor 8, support frame 9, gear 10, opening 11, first Seal ring 12, cover plate 13, semi-circular ring 14, adjustable shrinkage hole plate 15, circular part 16, connecting rod 17, groove 18, second seal ring 19, baffle plate 20, second servo motor 21, first Two mounting brackets 22.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described The embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

As shown in Figures 1 and 7, a primary air leveling system includes a pipeline 1, a differential pressure measuring device and an automatic shrinkage cavity adjustment device, and the differential pressure measuring device includes a pitot tube 2, a pressure gauge 3 and a driving pitot tube 2. The first driving mechanism for lifting, the full pressure interface and the static pressure interface on the upper end of the pitot tube 2 are respectively connected to the pressure gauge 3, and the pressure gauge 3 is connected to the single-chip microcomputer through a wire, and the pressure gauge 3 transmits the dynamics measured by different measuring points to the single-chip microcomputer , the lower end of the pitot tube 2 goes deep into the pipeline 1; the shrinkage hole automatic adjustment device includes an adjustable shrinkage hole plate 15 and a second drive mechanism that drives the adjustable shrinkage hole plate 15 to rotate, and the adjustable shrinkage hole plate 15 is located in the pipeline 1 , the adjustable shrinkage hole plate 15 cooperates with the inner wall of the pipeline 1 .

As shown in Figure 2, a first mounting frame 4 is provided between the pitot tube 2 and the pipeline 1, the first mounting frame 4 is installed on the pipeline 1 through a hoop, and the pitot tube 2 and the first mounting frame 4 are slidably connected, The upper and lower ends of the first mounting frame 4 are provided with openings, the pitot tube 2 passes through the openings on the upper and lower ends of the first mounting frame 4, and a sealing ring is arranged between the upper and lower ends of the pitot tube 2 and the upper and lower ends of the first mounting frame 4. .

As shown in Figure 2 and Figure 4, the pitot tube 2 is provided with a locking sleeve 5, the locking sleeve 5 is composed of two semi-circular rings, one end of the semi-circular ring of the locking sleeve 5 is hinged, and the semi-circular ring of the locking sleeve 5 The other end of the ring is detachably connected, and the hinged end of the locking sleeve 5 is provided with a plane 6, and a rack 7 is provided on the plane 6;

As shown in Figures 1 and 2, the first drive mechanism includes a first servo motor 8, the first servo motor 8 is installed in the first installation frame 4 through a support frame 9, and the output end of the first servo motor 8 is provided with a gear 10, the gear 10 meshes with the rack 7. When in use, the Pitot tube 2 is installed in the first mounting frame 4, and the locking sleeve 5 is firstly hugged onto the Pitot tube 2, and the detachable end of the locking sleeve 5 is locked by a bolt, and the rack 7 and the gear 10 are meshed , put the lower end of Pitot tube 2 deep into the pipeline 1, and fix the first mounting bracket 4 on the pipeline 1 through the hoop. When installing, make the full pressure hole of Pitot tube 2 be in the vertical initial state, that is, the full pressure hole is at the pipeline wind speed Incoming direction.

As shown in Figure 3 and Figure 5, the upper end of the pipe 1 is provided with an opening 11, the lower end of the Pitot tube 2 passes through the opening 11, and a first sealing ring 12 is provided between the Pitot tube 2 and the opening 11, and the first sealing ring 12 is made of heat-resistant Filling material, the inner wall of the opening 11 is provided with a step, the first sealing ring 12 is located on the step, and the upper end of the first sealing ring 12 is provided with a cover plate 13 for compressing the first sealing ring 12; the cover plate 13 and the step can prevent The first sealing ring 12 moves up and down along with the pitot tube 2 to better seal the pipeline and has good reliability.

As shown in Figure 6, the cover plate 13 is composed of two semi-circular rings 14. The cover plate 13 is fixed on the pipeline by screws, which is convenient for installation and will not interfere with the Pitot tube 2. The end surface of the cover plate 13 is arc-shaped, which can Better fit with the outer cylindrical surface of the pipe 1.

As shown in Figures 8 and 9, the adjustable shrinkage plate 15 includes a circular portion 16 and a connecting rod 17, the adjustable shrinkage plate 15 is located at the flange connection of the pipeline 1, and the flange connection of the pipeline 1 is provided with a concave The groove 18, the circular part 16 is located in the pipe 1, and the connecting rod 17 passes through the groove 18.

As shown in FIG. 8 and FIG. 9 , a second sealing ring 19 is provided between the connecting rod 17 and the groove 18 , and baffles 20 are provided on the connecting rod 17 at both ends of the groove 18 . The connecting rod 17 rotates in the groove 18, and the connecting rod 17 drives the circular part 16 to rotate, thereby adjusting the air flow rate and the wind speed in the pipeline. The baffle plate 20 can prevent the connecting rod 17 from moving axially, and the circular part 16 does not There will be wear between the inner wall of the pipeline 1, and the second sealing ring 19 can prevent sundries from entering the pipeline, which is safe and environmentally friendly.

As shown in Figure 7, the second drive mechanism includes a second servo motor 21, a second mounting bracket 22 is arranged between the second servo motor 21 and the pipeline 1, the second mounting bracket 22 is installed on the pipeline 1, and the second The output end of the servo motor 21 is connected with the connecting rod 17 through a coupling.

The first servo motor 8, the second servo motor 21 and the pressure gauge 3 are all connected with the single-chip microcomputer by wires, and the opening and closing of the first servo motor 8 and the second servo motor 21 are controlled by the single-chip microcomputer, and the pressure gauge 3 will measure different measurement points. The dynamic pressure difference is transmitted to the single-chip microcomputer to calculate the wind speed of different measuring points, and after averaging, the average value of the pipeline wind speed is calculated.

A primary air leveling method, using the primary air leveling system, the steps include:

1) Use a single-chip microcomputer to layer the pipeline, and use pitot tubes and pressure gauges to measure the pressure difference of each layer;

2) The pressure gauge transmits the measured dynamic pressure to the single-chip microcomputer, and the single-chip microcomputer performs data processing to obtain ΔP, and the unit of ΔP is Pa;

3) According to the adjustment plan given by the calculation result, the single-chip microcomputer adjusts the wind speed of the pipeline by the shrinkage cavity automatic adjustment device;

4) Repeat the above steps to measure until the deviation of the same layer of pipeline wind speed meets the requirements, that is, the deviation of the average value of the same layer is less than 5%.

In step 1), the specific steps of pipeline differential pressure measurement are:

A Install the device on each pipe, mark the pipes in sequence, and make the pitot tube in the vertical initial position, that is, the full pressure hole of the pitot tube is roughly in the direction of the wind speed of the pipe.

System B is initialized so that the full pressure hole of the pitot tube is located at the bottom of the pipe;

C single-chip microcomputer controls the first servo motor to start, the first servo motor drives the pitot tube to move upwards and records the moving distance until the pitot tube moves to the top of the pipeline, record the moving distance as h, and the unit of h is mm;

D transmits the moving distance to the single-chip microcomputer, and then records the pipe diameter of the pitot tube as d, and the unit of d is mm, and the single-chip computer calculates the pipeline diameter as D=h+2d, and the unit of D is mm;

The single-chip microcomputer determines the measuring points according to the division principle of the grid method and other sections according to the diameter of the pipeline, and obtains the distance of each measuring point. According to the pipe diameter of the coal mill of the power plant boiler, eight measuring points can generally be set;

F The first servo motor of the single-chip microcomputer is started, and the pitot tube is driven to move down to each measuring point, and the pressure gauge is used for dynamic pressure measurement and transmission. Every time the pressure gauge measures one, it is transmitted to the single-chip microcomputer for recording, until the data of each measuring point of all pipelines is recorded Finish;

G measures the atmospheric temperature, inputs the measurement result into the single-chip microcomputer, and obtains the air density ρ according to the atmospheric temperature, and the unit of ρ is Kg/m ³ .

In step 2), the single-chip microcomputer utilizes the formula For calculation, the unit of v is m/s, and the duct wind speed is obtained after averaging.

Classify the ducts according to the layers of the burner, and compare the wind speeds of the same-layer ducts together to obtain the average wind speed of the same-layer ducts and the deviation value of the wind speed of each duct. When the deviation of each pipeline from its average value of the same layer is less than 5%, no adjustment is required; when the deviation exceeds ±5%, adjustment must be made. As shown in the table below.

In step 3), the single-chip microcomputer controls the start of the second servo motor 21, and the second servo motor 21 drives the adjustable shrinkage plate 15 to rotate, and the rotation angle varies according to different adjustment schemes. When the wind speed deviation of the same layer is large, the shrinkage cavity should be adjusted in the direction of wind speed decrease; when the deviation is small, the shrinkage cavity should be adjusted in the direction of wind speed increase. confirm. After the shrinkage cavity adjustment is completed, re-measure the wind speed of the pipeline and record the data, then check the wind speed deviation, and adjust and measure again when the result does not meet the requirements.

The leveling of the primary air mentioned in this application refers to adjusting the wind speed of the pipeline on the same layer as the burner to a deviation of less than 5%.

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "left", "right", "upper" and "lower" are based on the orientations or positional relationships shown in the drawings, and are only for It is convenient to describe the present invention and simplify the description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it may be mechanically connected, or electrically connected, directly connected, or indirectly connected through an intermediary, or internally connected between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

Claims (10)

1. A primary air leveling system is characterized in that it comprises a pipeline (1), a differential pressure measuring device and an automatic adjustment device for shrinkage cavities, and the differential pressure measuring device includes a pitot tube (2), a manometer (3) and The first driving mechanism that drives the pitot tube (2) to lift, the upper end of the pitot tube (2) is connected to the pressure gauge (3), and the lower end of the pitot tube (2) goes deep into the pipeline (1); the shrinkage cavity automatic adjustment device includes Adjustable shrinkage orifice plate (15) and the second driving mechanism that drives adjustable shrinkage orifice plate (15) to rotate, adjustable shrinkage orifice plate (15) is located in pipeline (1), adjustable shrinkage orifice plate (15) and pipeline ( 1) Inner wall fit. 2. A primary air leveling system according to claim 1, characterized in that a first mounting frame (4) is provided between the pitot tube (2) and the pipeline (1), and the first mounting frame (4) Installed on the pipeline (1), the Pitot tube (2) is slidably connected to the first installation frame (4). 3. A primary air leveling system according to claim 2, characterized in that, the pitot tube (2) is provided with a locking sleeve (5), and the locking sleeve (5) is composed of two semicircular rings, One end of the semi-circular ring of the locking sleeve (5) is hinged, and the other end of the semi-circular ring of the locking sleeve (5) is detachably connected. The hinged end of the locking sleeve (5) is provided with a plane (6), and a There is a rack (7); The first drive mechanism includes a first servo motor (8), the first servo motor (8) is installed in the first mounting frame (4) through a support frame (9), and the output end of the first servo motor (8) is provided with Gear (10), and gear (10) meshes with rack (7). 4. A primary air leveling system according to claim 3, characterized in that the upper end of the pipe (1) is provided with an opening (11), the lower end of the Pitot tube (2) passes through the opening (11), and the Pitot tube (2) ) and the opening (11) is provided with a first sealing ring (12), the inner wall of the opening (11) is provided with a step, the first sealing ring (12) is located on the step, and the upper end of the first sealing ring (12) is provided There is a cover plate (13) for compressing the first sealing ring (12); The cover plate (13) is made up of two semicircular rings (14), and the end face of the cover plate (13) is arc-shaped. 5. A primary air leveling system according to claim 1, characterized in that, the adjustable shrinkage hole plate (15) includes a circular part (16) and a connecting rod (17), and the pipe (1) method A groove (18) is provided at the flange connection, the circular part (16) is located in the pipe (1), and the connecting rod (17) passes through the groove (18); A second seal ring (19) is provided between the connecting rod (17) and the groove (18), and baffles (20) are provided on the connecting rod (17) at both ends of the groove (18). 6. A primary air leveling system according to claim 5, characterized in that, the second drive mechanism comprises a second servo motor (21), and the gap between the second servo motor (21) and the pipeline (1) is A second installation frame (22) is provided, the second installation frame (22) is installed on the pipeline (1), and the output end of the second servo motor (21) is connected with the connecting rod (17). 7. A primary wind leveling method, utilizing the primary wind leveling system according to any one of claims 1 to 7, characterized in that the steps include: 1) Use a single-chip microcomputer to layer the pipeline, and use pitot tubes and pressure gauges to measure the pressure difference of each layer; 2) The pressure gauge transmits the measured dynamic pressure to the single-chip microcomputer, and the single-chip microcomputer performs data processing to obtain ΔP, and the unit of ΔP is Pa; 3) According to the adjustment plan given by the calculation result, the single-chip microcomputer adjusts the wind speed of the pipeline by the shrinkage cavity automatic adjustment device; 4) Repeat the above steps to measure until the deviation of the same layer of pipeline wind speed meets the requirements. 8. A kind of primary wind leveling method according to claim 7, is characterized in that, in step 1), the specific steps of pipeline differential pressure measurement are: A Install the device on the pipeline; System B is initialized so that the full pressure hole of the pitot tube is located at the bottom of the pipe; C single-chip microcomputer controls the first servo motor to start, the first servo motor drives the pitot tube to move upwards and records the moving distance until the pitot tube moves to the top of the pipeline, record the moving distance as h, and the unit of h is mm; D transmits the moving distance to the single-chip microcomputer, and then records the pipe diameter of the pitot tube as d, and the unit of d is mm, and the single-chip computer calculates the pipeline diameter as D=h+2d, and the unit of D is mm; The single-chip microcomputer determines the measuring points according to the division principle of the grid method and other sections according to the diameter of the pipeline, and obtains the distance of each measuring point; F The first servo motor of the single-chip microcomputer is started, and the pitot tube is driven to move down to each measuring point, and the pressure gauge is used for dynamic pressure measurement and transmission. Every time the pressure gauge measures one, it is transmitted to the single-chip microcomputer for recording, until the data of each measuring point of all pipelines is recorded Finish; G measures the atmospheric temperature, inputs the measurement result into the single-chip microcomputer, and obtains the air density ρ according to the atmospheric temperature, and the unit of ρ is Kg/m ³ . 9. A kind of primary air leveling method according to claim 8, is characterized in that, in step 2), single-chip microcomputer utilizes formula For calculation, the unit of v is m/s, and the duct wind speed is obtained after averaging. Classify the pipes according to the layers of the burner, compare the wind speed of the same layer pipes together, get the average wind speed of the same layer pipes, and get the deviation value of the wind speed of each pipe, when the deviation of each pipe from the average value of the same layer When the values are less than 5%, no adjustment is required; when the deviation exceeds ±5%, adjustment must be made. 10. A primary air leveling method according to claim 7, characterized in that, in step 3), the single-chip microcomputer controls the start of the second servo motor (21), and the second servo motor (21) drives the adjustable shrinkage hole plate (15) Turn to adjust the wind speed.