A wind volume measurement correction system for a non-uniform wind field wind tunnel

Abstract

This invention provides an airflow measurement and correction system for non-uniform wind field ducts, comprising an airflow measurement system based on big data analysis and an airflow measurement system based on the average wind speed value of the data points, with airflow meters set at these locations. By setting up the airflow measurement system based on big data analysis and the airflow measurement system based on the average wind speed value of the data points in different cross-sections of the non-uniform wind field duct, the airflow velocity values ​​Fdps and Fpps are measured simultaneously. If the difference between Fdps and Fpps is large, the airflow measurement value is taken as Fdps, or the location of the airflow meter at the average wind speed value point is manually or automatically readjusted. The two systems complement each other and verify each other, accurately and reliably solving the problem of inaccurate and unreliable measurement of duct airflow by the geometric mean wind speed value in existing airflow measurement devices.

Description

Technical Field

[0001] This invention belongs to the field of air volume measurement technology, and relates to an air volume measurement correction system. In particular, it relates to an air volume measurement correction system that combines a big data analysis-based air volume measurement system for non-uniform wind field ducts with an air volume measurement system that sets up air volume flow meters based on the average wind speed value of the data. Background Technology

[0002] In the design of coal-fired power generating units, for the sake of overall project cost economy, the length of the straight pipe section without equipment or bends in the boiler air inlet duct is often less than one duct diameter or cross-sectional side length. This falls far short of the requirements of Clause 6.2 of the national standard GB / T2624.4—2006 / ISO5167-4:2003, "Measurement of Full-Pipe Fluid Flow Rate by Differential Pressure Device Installed in Circular Cross-Section Pipes—Part 4: Venturi Tubes," which stipulates the minimum upstream and downstream straight pipe sections required for installation between various fittings and Venturi tubes. Furthermore, the boiler air inlet duct in coal-fired power generating units contains regulating dampers, support structures, elbows, baffles, and even diameter-changing sections. These factors result in a non-uniform airflow field at no cross-section within the boiler air inlet duct, failing to meet the requirements of the airflow measurement device for the upstream and downstream straight pipe sections.

[0003] The existing airflow measurement devices for the aforementioned non-uniform wind field ducts include the following:

[0004] (1) Averaging velocity tube air volume measurement device:

[0005] The averaging pitot tube airflow measurement device is mainly composed of an airflow meter based on the Pitot tube speed measurement principle. Multiple pairs of sampling holes (two or more pairs) are evenly arranged along the length of the straight pipe section of the airflow meter. The full positive pressure and full negative pressure of the fluid are measured separately. Then, the average differential pressure is measured within the straight pipe section to calculate the fluid flow rate. Examples of averaging pitot tube airflow meters include V-Bar, Annubar, Deltabar, Welbar, and Superbar. Averaging pitot tube airflow meters are simple in structure, easy to install and disassemble, and have low pressure loss. They are relatively accurate for airflow measurement in uniform airflow ducts. However, when used in non-uniform airflow ducts, due to the linear arrangement of its multiple sampling holes (one-dimensional), the differential pressure after pressure averaging within the straight pipe section cannot accurately represent the actual wind speed value of the cross-section of the non-uniform airflow duct. That is, the geometric mean wind speed value of the cross-section is not equal to the actual wind speed value of the cross-section, thus making it impossible to accurately measure the airflow value of the duct.

[0006] (2) Air volume measurement device based on Venturi tube type air volume flow meter

[0007] The Venturi tube-type air volume flow meter is an air volume measurement device that utilizes the principle that when gas flows through the air volume flow meter, it first narrows to increase the gas flow rate, and then a "vacuum" zone is formed at the rear of the throat where the gas narrows to widen. A negative pressure sampling port is provided in the vacuum zone, and the differential pressure formed between the sampling port and the inlet sampling port is used to measure the air volume. The advantages of Venturi tube flow meters are large differential pressure, high accuracy, and low resistance loss. When a Venturi tube flow meter is installed in a uniform airflow duct, airflow measurement is relatively accurate. However, when a single point is placed in a non-uniform airflow duct, the accuracy of airflow measurement cannot be guaranteed. Similarly, when multiple points are geometrically uniformly placed in a non-uniform airflow duct, the average differential pressure cannot accurately measure the average airflow value of the cross-section of the duct in real time. This is determined by the nature of the non-uniform airflow field. To some extent, the large differential pressure of single-point or multi-point Venturi flow meters may become a disadvantage in non-uniform airflow fields, amplifying the error. Venturi tube flow meters include single-throat, double-throat, and multi-throat types.

[0008] (3) Wing airflow measurement device

[0009] The airfoil airflow measurement device mainly consists of one or more airfoil-shaped throttling devices with a flow cross-sectional area smaller than the duct cross-sectional area, which are fixedly placed in the air duct of the wind farm. The airflow is measured by the pressure difference generated before and after the fluid flows through the airfoil-shaped throttling device. The airfoil airflow measurement system was widely used in early small-power coal-fired generator sets. Its advantages are that the throttling device is prefabricated in the duct, which has both rectification and measurement functions, and the airflow measurement is relatively accurate. However, its disadvantages are that it is bulky, has large throttling losses, complex structure, difficult installation, and is prone to clogging.

[0010] (4) Multi-point insertion air volume measurement device

[0011] The air volume measurement device based on the multi-point insertion air volume flow meter mainly uses an upper and lower inclined back pipe (with steel wire inserted to prevent blockage) to make multiple geometric average points on the cross-section of the air duct. Differential pressure is established in each branch pipe, and then the branch pipes are connected to equalize the pressure, and finally led to the main pipe. It obtains the geometric average wind speed value, that is, the actual wind speed value, after multiple geometric pressure equalizations. However, this geometric average wind speed value is not an approximate actual wind speed value, and the error is particularly large. Furthermore, during continuous multi-point pressure equalization airflow measurement, micro-flow phenomena of the measured gas occur in the equalization branch pipes, sub-branch pipes, and back-pipes of the main pipe. Simultaneously, particles from the airflow field are carried into these branch pipes, sub-branch pipes, and the main pipe. This micro-flow phenomenon exists constantly with changes in load and airflow eddies, causing the main pipe to quickly become clogged with dust, resulting in a decreasing differential pressure. To solve this dust clogging problem, existing technologies use steel wires that vibrate with the wind speed in the upper and lower inclined back-pipes. However, in reality, these steel wires only vibrate at a specific load wind speed; they do not vibrate at other load wind speeds. Moreover, under normal load, alternating wind speeds in the duct cannot cause the steel wires to vibrate. Therefore, inserting steel wires into the upper and lower inclined back-pipes cannot clear the dust clogging problem inside the multi-point insertion airflow meter. Thus, it is difficult to achieve accurate airflow measurement in non-uniform airflow ducts using a matrix multi-point insertion airflow meter based on geometrically distributed sampling points.

[0012] In summary, existing air volume measurement technologies cannot accurately measure the air volume in non-uniform airflow ducts, especially in the air intake ducts of coal-fired boilers, in real time. Summary of the Invention

[0013] To address the problem of inaccurate airflow measurement in non-uniform wind field ducts in the prior art, this invention provides an airflow measurement and correction system that combines an airflow measurement system based on average wind speed values ​​and a big data analysis-based airflow measurement system for non-uniform wind field ducts. The system includes both an airflow measurement system based on big data analysis and an airflow measurement system based on average wind speed values ​​and a big data analysis-based airflow measurement system.

[0014] Preferred, the air volume measurement system based on big data analysis mainly consists of a big data air volume dynamic sensing device set in the cross-section of the air duct, an air volume transmitter connected to it, and a control monitoring and analysis unit A for controlling and monitoring them; the air volume measurement system based on the average wind speed value point for setting an air volume flow meter mainly consists of an air volume flow meter B set at at least one average wind speed value point offset from the big data air volume dynamic sensing device in the cross-section of the air duct, an air volume transmitter B connected to it, and a monitoring and analysis unit B for monitoring them.

[0015] Preferably, air volume flow meters B are installed at the two different average wind speed points. The number of air volume transmitters B is the same as the number of air volume flow meters B, and each of them is connected to a sampling tube. Alternatively, the air volume flow meters B are connected to an air volume transmitter B through positive and negative pressure equalization tubes.

[0016] Preferably, the big data air volume dynamic sensing device includes an active sensing unit and a driven air volume sensing unit, and an active sensing unit drive unit. The active sensing unit drive unit includes a transmission unit that drives the active sensing unit and a drive unit. The driven air volume sensing unit includes a dynamic air volume sensing element and a rotating part that moves the dynamic air volume sensing element back and forth on the active sensing unit. Alternatively, the driven air volume sensing unit includes a plurality of air volume flow meters evenly distributed on the active sensing unit.

[0017] Preferably, the big data air volume dynamic sensing device is a big data air volume dynamic latitude and longitude sensing device or a big data air volume dynamic axial and radial sensing device.

[0018] Preferably, the big data air volume dynamic latitude and longitude sensing device includes a latitude sensing active unit and its latitudinal driven air volume sensing unit, and a latitude sensing active unit drive unit. The latitude sensing active unit drive unit includes a vertical transmission unit that drives the latitude sensing active unit in the latitude direction and its vertical drive unit.

[0019] Preferably, the latitudinal driven air volume sensing unit includes a latitudinal dynamic air volume sensor and a lateral rotating part that moves the latitudinal dynamic air volume sensor laterally back and forth on the air duct of the longitudinal sensing active unit.

[0020] Preferably, the latitudinal dynamic air volume sensor includes a slider and an air volume flow meter fixed thereon.

[0021] Preferably, the latitudinal driven air volume sensing unit includes a plurality of air volume flow meters evenly distributed on the longitudinal active sensing unit.

[0022] Preferably, the number of air volume transmitters is the same as the number of air volume flow meters, and each is connected to a sampling tube, or the air volume flow meter is connected to an air volume transmitter through positive and negative pressure equalization tubes.

[0023] Preferably, the air volume flow meter is at least one of a Pitot tube air volume flow meter and a Venturi air volume flow meter.

[0024] Preferably, the Venturi-type airflow meter is at least one of a single-throat pipe airflow meter, a double-throat pipe airflow meter, and a multi-throat pipe airflow meter.

[0025] Preferably, the longitudinal sensing active part includes a transverse part and a vertical part. The transverse part has an inverted C-shaped cross-section, and the vertical part is a long, closed shell. The transverse and vertical parts are welded together to form an inverted T-shaped structure. The transverse rotating part includes left and right transverse fixed pulleys located at both ends of the transverse part and partially exposed on the top surface of the transverse part. Left and right angular fixed pulleys are located on the inner sides of the lower end of the vertical part and an upper fixed pulley is located on the inner side of the upper end. A transverse rotating steel wire is wound around the left and right transverse fixed pulleys, the left and right angular fixed pulleys, and the upper fixed pulley. A transverse stepper motor drives the upper fixed pulley. The latitudinal dynamic air volume sensor is fixed at the lower end of the transverse part and is located on the transverse rotating steel wire.

[0026] Preferably, the vertical transmission part includes a vertical transmission part body and upper and lower fixed seats with bearings respectively provided at its upper and lower ends, and a vertical screw fixed in the bearings of the upper and lower fixed seats; the upper end of the horizontal part body is also provided with a nut that is threadedly connected to the vertical screw; the driving part is a vertical stepper motor, which is fixed on the upper end surface of the vertical transmission part body and drives the vertical screw axially.

[0027] Preferably, the longitudinal sensing active part includes a horizontal part and a vertical part. The cross-section of the horizontal part is an inverted C-shaped structure, and the vertical part is a long strip-shaped closed shell. The horizontal part and the vertical part are welded together to form an inverted T-shaped structure. The air volume flow meter is fixed at the lower end of the horizontal part.

[0028] Preferably, the vertical transmission part includes a vertical transmission part body and upper and lower fixed seats with bearings respectively at its upper and lower ends, and a vertical screw fixed in the bearings of the upper and lower fixed seats; the upper end of the horizontal part body is also provided with a nut that is threadedly connected to the vertical screw; the driving part is a vertical stepper motor, which fixes the upper end surface of the vertical transmission part body and drives the vertical screw axially.

[0029] This invention utilizes two airflow measurement systems: one based on big data analysis and the other based on average wind speed values, installed in different cross-sections of a non-uniform wind duct. These systems simultaneously measure wind speeds (Fdps and Fpps). If the difference between Fdps and Fpps is significant, Fdps is used for airflow measurement, or the positions of the average wind speed values ​​and flow meters are manually or automatically adjusted. The two systems complement and verify each other, reliably solving the problem of inaccurate measurement of airflow using geometric mean wind speed in existing airflow measurement devices. In particular, applying this invention to coal-fired boilers in power generation units allows for more accurate achievement or proximity to the optimal air-coal ratio, significantly improving boiler safety, combustion efficiency, energy conservation, and environmental protection. It also enhances the flexibility of power generation in coal-fired power units, resulting in substantial economic benefits and improved overall power grid stability. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the front structure of a big data air volume measurement dynamic latitude and longitude sensor device provided in Embodiment 1, which is installed in a rectangular air duct.

[0031] Figure 2 yes Figure 1 A schematic diagram of the side cross-section of the large data air volume measurement dynamic latitude and longitude sensor device installed in the rectangular air duct in the AA direction.

[0032] Figure 3 This is a schematic diagram of the plan layout of the primary hot air duct inlet section of a simulated 300MW coal-fired power generating unit entering the ball mill, based on a big data analysis-based air volume measurement system provided in Embodiment 1.

[0033] Figure 4 yes Figure 3 Schematic diagram of the elevation layout of the primary hot air duct entering the ball mill in the BB direction;

[0034] Figure 5a yes Figure 3 3D wind speed measurement curve of the air volume measurement system in the simulated air duct section at a load value of 33%;

[0035] Figure 5b yes Figure 3 3D wind speed measurement curve of the air volume measurement system in the simulated air duct section at a load value of 41.7%;

[0036] Figure 5c yes Figure 3 3D wind speed measurement curve of the air volume measurement system in the simulated air duct section at a load value of 58.3%;

[0037] Figure 5d yes Figure 33D wind speed measurement curve of the air volume measurement system in the simulated air duct section at a load value of 70%;

[0038] Figure 5e yes Figure 3 3D wind speed measurement curve of the air volume measurement system in the simulated air duct section at a load value of 87.6%;

[0039] Figure 5f yes Figure 3 3D wind speed measurement curve of the air volume measurement system in the simulated air duct section when the load value is 100%;

[0040] Figure 6 yes Figure 3 3D curve of the average wind speed point selected when the error of the average wind speed value of the set data of the air volume measurement system based on big data analysis in the simulated air duct section is 6 / 4500.

[0041] Figure 7 This invention provides a schematic flowchart of an air volume measurement method based on big data analysis.

[0042] Figure 8 This invention provides a flowchart illustrating a method for determining the location of average wind speed values ​​using a wind volume measurement system based on big data analysis.

[0043] Figure 9 This invention provides a schematic diagram of a calibration method that combines an air volume measurement system based on big data analysis with an air volume flow meter set at the location of the average wind speed value.

[0044] Figure 10 This is a schematic diagram of the front structure of a dynamic axial radial sensing device for measuring air volume in a circular air duct, as provided in Embodiment 2.

[0045] Figure 11 yes Figure 10 A schematic diagram of the side cross-section structure of the dynamic axial radial sensing device for measuring air volume in the circular air duct in the CC direction.

[0046] Explanation of the numbers in the diagram: 1. Rectangular air duct; 2. Meridional sensor active unit drive unit, 2-1. Vertical transmission unit, 2-1-1. Vertical transmission unit body, 2-1-2. Upper fixed base, 2-1-3. Lower fixed base, 2-1-4. Vertical screw, 2-1-5. Vertical track, 2-2. Vertical drive unit; 3. Meridional sensor active unit, 3-1. Horizontal part, 3-1-1. Horizontal part body, 3-1-2. Horizontal track, 3-2. Vertical part, 3-2-1. Vertical drive unit. 3-2-2 Nut; 4 Zonal driven air volume sensor, 4-1 Zonal dynamic air volume sensor, 4-1-1 slider, 4-1-2 air volume flow meter, 4-2 lateral rotating part, 4-2-1 left lateral fixed pulley, 4-2-2 right lateral fixed pulley, 4-2-3 left corner fixed pulley, 4-2-4 right corner fixed pulley, 4-2-5 upper fixed pulley, 4-2-6 lateral rotating steel wire, 4-2-7 lateral stepper motor;

[0047] 1. Circular air duct; 5. Axial sensing active part, 5-1 Axial sensing active part body, 5-1-1 Transverse track A, 5-1-2 Sleeve; 6. Radial driven air volume sensing part, 6-1 Radial dynamic air volume sensing element, 6-1-1 Slider A, 6-1-2 Air volume flow meter A, 6-2 Radial rotating part, 6-2-1 Central fixed pulley, 6-2-2 Peripheral fixed pulley, 6-2-3 Dynamic radial transmission steel wire, 6-2-4 Static transmission part, 6-2-6 Central outer fixed pulley; 7.1 Axial transmission part, 7-1-1 Axial transmission part body, 7-1-2 Central inner fixed pulley, 7-1-3 Right end inner fixed pulley, 7-1-4 Static axial transmission steel wire;

[0048] 10 Ball mill, 11 Expansion joint A, 12 Expansion joint B, 13 Cold air duct, 14 Cold air outlet, 15 Shut-off valve, 16 Regulating valve, 17 Expansion joint C, 0.00 elevation 0.00 m, 2.235 elevation 2.235 m, 6.10 elevation 6.10 m, 8.30 elevation 8.30 m. Detailed Implementation

[0049] The concept of a big data dynamic airflow sensing device is as follows: In a non-uniform wind field duct, it can individually measure the wind speed at several points uniformly or substantially uniformly distributed within a cross-section perpendicular to the gas flow direction, thereby comprehensively measuring the duct wind speed and determining the average wind speed value or / and the points representing the average wind speed value through big data analysis. Examples include big data dynamic latitude and longitude sensing devices and big data dynamic axial and radial sensing devices.

[0050] The big data air volume dynamic sensing device includes an active sensing unit and its driven air volume sensing unit, and an active sensing unit drive unit. The active sensing unit drive unit includes a transmission unit that drives the active sensing unit and its drive unit (sampling in the longitudinal or axial direction). The driven air volume sensing unit includes a dynamic air volume sensor and a rotating part that moves the dynamic air volume sensor back and forth on the active sensing unit (sampling in the latitudinal or radial direction); or the driven air volume sensing unit includes a plurality of air volume flow meters (sampling in the latitudinal or radial direction) evenly distributed on the active sensing unit.

[0051] The big data air volume dynamic sensing device is installed in the cross-section of the non-uniform wind field duct, connected to the air volume transmitter, and together with the control monitoring and analysis unit A that controls and monitors them, constitutes an air volume measurement system based on big data analysis.

[0052] Under a specific load value of a certain air duct, the control monitoring and analysis unit A controls the big data air volume dynamic sensing device to measure the wind speed of several points that are evenly or substantially evenly distributed in the cross-section of the vertical gas flow direction, thereby measuring the air duct wind speed from all directions and obtaining the average wind speed value or determining the corresponding points.

[0053] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments; it should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0054] Example 1

[0055] like Figure 1 and 2 The diagram shows a schematic of a large-scale dynamic airflow sensing device provided by the present invention, installed within a rectangular air duct. The large-scale dynamic airflow sensing device is a large-scale dynamic airflow sensing device. The large-scale dynamic airflow sensing device is installed within a cross-section of the rectangular air duct 1, and includes a longitudinal sensing active part 3 and a latitudinal driven airflow sensing part 4, and a longitudinal sensing active part drive part 2. The longitudinal sensing active part drive part 2 includes a vertical transmission part 2-1 for longitudinally driving the longitudinal sensing active part and a vertical drive part 2-2. The latitudinal driven airflow sensing part 4 includes a latitudinal dynamic airflow sensing element 4-1 and a lateral rotation part 4-2 that moves the latitudinal dynamic airflow sensing element 4-1 (in the X-axis direction, i.e., the latitudinal direction) back and forth in the air duct on the longitudinal sensing active part.

[0056] The meridional sensing active unit 3 includes a horizontal part 3-1 and a vertical part 3-2. The body of the meridional sensing active unit 3 has an inverted T-shaped structure in the horizontal direction. The cross-section of the horizontal part body 3-1-1 is an inverted C-shaped structure. A horizontal track 3-1-2 is provided on the inner top surface of the C-shaped structure. The vertical part body 3-2-1 is a long strip-shaped closed shell. The horizontal part body 3-1-1 and the vertical part body 3-2-1 are welded together to form an inverted T-shaped structure. A nut 3-2-2 is provided at the upper rear side of the vertical part body.

[0057] The transverse rotating part 4-2 includes left and right transverse fixed pulleys 4-2-1 and 4-2-2 respectively at both ends of the transverse part body 3-1-1, which are partially exposed on the top surface of the transverse part body 3-1-1; left and right corner fixed pulleys 4-2-3 and 4-2-4 respectively on the two inner sides of the lower end of the vertical part body 3-2-1; an upper fixed pulley 4-2-5 on the upper end of the vertical part body 3-2-1; a transverse rotating steel wire 4-2-6 wound on the above-mentioned left and right transverse fixed pulleys, left and right corner fixed pulleys and upper fixed pulley; and a transverse stepper motor 4-2-7 driving the upper fixed pulley.

[0058] The latitudinal dynamic air volume sensor 4-1 is fixed to the lower end of the transverse part body and is mounted on the transverse rotating steel wire 4-2-6; the latitudinal dynamic air volume sensor 4-1 includes a slider 4-1-1 that slides along the transverse track and an air volume flow meter 4-1-2 that is fixed thereon and located below the C-shaped structure of the transverse part body.

[0059] The vertical transmission unit 2-1 includes a vertical transmission unit body 2-1-1 and upper and lower fixed seats 2-1-2 and 2-1-3, each with bearings, respectively, and a vertical screw 2-1-4 fixed in the bearings of the upper and lower fixed seats. The vertical drive unit 2-2 is a vertical stepper motor, which is fixed on the upper surface of the transmission unit body 2-1-1 and drives the vertical screw 2-1-4 axially. The cross-section of the vertical transmission unit body 2-1-1 is a groove-shaped structure, with a vertical track 2-1-5 at the bottom of the groove (to allow the nut 3-2-2 to slide smoothly up and down in the groove). The entire body is vertically fixed on the outer wall above the rectangular air duct 1. In this way, the meridional sensing active unit 3 is driven by the nut 3-2-2 to move up and down on the vertical screw 2-1-4 (in the Y-axis direction, i.e., the meridional direction).

[0060] The rectangular duct air volume measurement system composed of the above-mentioned big data air volume dynamic latitude and longitude sensing device also includes an air volume transmitter connected to the air volume flow meter in the big data air volume dynamic latitude and longitude sensing device, and a control monitoring and analysis unit A for controlling and monitoring the big data air volume dynamic latitude and longitude sensing device.

[0061] like Figure 7As shown in the diagram, this embodiment provides a flowchart of a big data analysis-based airflow measurement method for non-uniform wind field ducts based on the aforementioned rectangular duct airflow measurement system. The steps are as follows:

[0062] 1) In the control monitoring and analysis unit A, set the angular displacement of the air volume flow meter in both the latitudinal and longitudinal directions (i.e., set the magnitude of each movement displacement of the air volume flow meter in both the horizontal (X-axis direction, i.e., latitudinal) and vertical (Y-axis direction, i.e., longitudinal) directions in the control monitoring and analysis unit A, i.e., set the preset angular displacement of the horizontal stepper motor and the vertical stepper motor respectively; the angular displacement of each movement in the two directions can be the same or different).

[0063] 2) Control monitoring and analysis unit A first controls the air volume flow meter to move a preset angular displacement from its initial position in the meridional direction, and then controls the air volume flow meter to measure the wind speed (i.e., differential pressure) at all preset points in the latitudinal direction one by one. At the same time, the air volume measured at the corresponding preset point is sent to the air volume transmitter, and then the air volume transmitter stores its air volume electrical signal in control monitoring and analysis unit A (i.e., control monitoring and analysis unit A first controls the vertical stepper motor to move a preset angular displacement, and then controls the horizontal stepper motor to drive the upper fixed pulley to drive the horizontal rotating steel wire 4-2-6 to rotate a preset angular displacement, thereby driving the air volume flow meter to measure the wind speed (i.e., differential pressure) at all preset points in the lateral direction one by one. At the same time, the air volume transmitter stores its air volume electrical signal in control monitoring and analysis unit A).

[0064] 3) Then, control the vertical stepper motor of the control monitoring and analysis unit A to move by a preset angular displacement, and repeat step 2 until the air volume flow meter measures the wind speed value of all preset points in the rectangular air duct from all directions.

[0065] 4) The control monitoring and analysis unit sums up the wind speed measurements at all the preset points and divides them by the number of preset points in the rectangular duct to obtain the average wind speed value of the duct data within the sampling period T. This value is the duct air volume measurement value.

[0066] The wind speed measurement of all preset points in the entire rectangular duct requires a sampling period T. However, the size of this sampling period T is determined by factors such as the speed of the horizontal and vertical stepper motors, the size of the rectangular duct, the number of preset points in the rectangular duct, and the wind speed in the rectangular duct. The shorter the sampling period T, the more accurate the average wind speed value of the duct data. However, when the duct load is constant, the average wind speed value of the duct data is independent of the size of the sampling period T.

[0067] The preset point interval is determined by requirements such as the size of the duct, the complexity of the wind field, and the accuracy of its air volume measurement.

[0068] like Figure 8As shown, this embodiment also provides a method for determining the location of the average wind speed value using the above-mentioned rectangular duct airflow measurement system, based on the above-mentioned non-uniform wind field duct airflow measurement system. The steps are as follows:

[0069] 1) In the control monitoring and analysis unit A, set the angular displacement of the air volume flow meter in both the latitudinal and longitudinal directions (i.e., set the magnitude of each movement displacement of the air volume flow meter in both the horizontal (X-axis direction, i.e., latitudinal) and vertical (Y-axis direction, i.e., longitudinal) directions in the control monitoring and analysis unit A, i.e., set the angular displacement of the horizontal stepper motor and the vertical stepper motor respectively; the angular displacement of each movement in the two directions can be the same or different).

[0070] 2) Control monitoring and analysis unit A collects specific load values ​​for the air duct;

[0071] 3) Control monitoring and analysis unit A first controls the air volume flow meter to move a preset angular displacement from its initial position in the meridional direction, and then controls the air volume flow meter to measure the wind speed (i.e., differential pressure) at all preset points in the latitudinal direction one by one. At the same time, the air volume measured at the corresponding preset point is sent to the air volume transmitter. The air volume transmitter then stores the air volume electrical signal, its position signal, and the specific load value in the control monitoring and analysis unit A in a one-to-one correspondence. (That is, control monitoring and analysis unit A first controls the vertical stepper motor to move a preset angular displacement, and then controls the horizontal stepper motor to drive the upper fixed pulley to drive the horizontal rotating steel wire 4-2-6 to rotate a preset angular displacement, thereby driving the air volume flow meter to measure the wind speed (i.e., differential pressure) at all preset points in the lateral direction one by one. At the same time, the air volume measured at the corresponding preset point is sent to the air volume transmitter. The air volume transmitter then stores the air volume electrical signal, its position signal, and the specific load value in the control monitoring and analysis unit in a one-to-one correspondence.)

[0072] 4) Then, control the air volume flow meter to move in the meridional direction by a preset angular displacement, and repeat step 3 until the air volume flow meter measures the wind speed value at all preset points in the rectangular air duct from all directions.

[0073] 5) Adjust the duct load values ​​in step 2 one by one (e.g., 35%, 40%, 50%, 60%, 70%, 80%, 90%, 100%); repeat steps 2, 3, and 4 until all preset points of the duct load value under the monitored duct load value (select load values ​​evenly within the allowable range of duct load value, such as 35%, 40%, 50%, 60%, 70%, 80%, 90%, 100% load) are measured;

[0074] 6) The control monitoring and analysis unit A sums up the wind speed values ​​at all preset points under different load values ​​of the monitored duct, and then divides each sum by the number of preset points to calculate the average wind speed value for each load value. The average wind speed error of the duct data is then gradually increased from zero until at least one common preset point is determined, which is the point for the average wind speed value of this duct data. The wind speed measurement value at this common preset point is within the range of the sum of the average wind speed value for each load value and the increased average wind speed error of the duct data.

[0075] In addition, this embodiment also provides an airflow measurement system based on the location of average wind speed points: airflow meters are installed at each average wind speed point determined by the method described above. Since the wind speed values ​​measured at each average wind speed point are basically the same, there is almost no airflow between the airflow meters at each average wind speed point. The wind speed values ​​measured by the airflow meters at each average wind speed point are equalized by a pressure equalization tube before being connected to an airflow transmitter. This, along with the control, monitoring, and analysis unit A, constitutes an airflow measurement system based on the location of average wind speed points. Of course, the airflow meters at each average wind speed point can also be connected to an airflow transmitter without using a pressure equalization tube, thus making the airflow measurement system more accurate.

[0076] Since the wind field of the duct is non-uniform under different load values, the above method can accurately find the specific common points where the average wind speed value of the data is located in the cross section of the duct, and set up air volume flow meters at these points to measure the air volume of the duct in real time and accurately.

[0077] Secondly, based on the aforementioned airflow measurement system based on big data analysis and the airflow measurement system with airflow meters set at points corresponding to average wind speed values, this embodiment provides a calibration system combining these two systems. The calibration system includes a big data dynamic latitude and longitude sensor installed in the cross-section of the duct, at least one airflow meter with average wind speed values ​​set at a point on the duct cross-section offset from the sensor, and airflow transmitters and control monitoring and analysis units A and B connected to each sensor respectively. Of course, to ensure the reliability of the duct airflow measurement results, this calibration system can also allow the big data analysis-based airflow measurement system and the airflow measurement system with airflow meters set at points corresponding to average wind speed values ​​to operate simultaneously, with one system in standby mode to ensure the reliability and accuracy of the duct airflow measurement.

[0078] Finally, based on the above correction system, this embodiment provides a correction method that combines an airflow measurement system based on big data analysis and an airflow measurement system based on the average wind speed value of the data to set up the airflow meter. Figure 9The diagram illustrates a calibration method combining a big data analysis-based airflow measurement system and an airflow measurement system based on average wind speed values ​​set at specific locations. The method utilizes at least one big data dynamic latitude and longitude sensor installed in the cross-section of the duct to perform omnidirectional dynamic point-by-point wind speed measurements at preset intervals within each sampling period. The wind speed measurements at all preset points are then summed and divided by the number of preset points to obtain the average wind speed value Fdps for the duct data. (For detailed explanations of the airflow measurement method, please refer to...) Figure 7 The diagram illustrates a method for measuring airflow in a non-uniform wind field duct based on big data analysis, along with its explanatory section. Simultaneously, airflow is measured in real-time using at least one average wind speed point airflow meter set within the duct cross-section. The measured average wind speed values ​​at each point are then summed and divided by the number of average wind speed points or the geometric equalization pressure of the average wind speed point airflow meter to obtain the average wind speed value Fpps. Next, the difference between the average wind speed value Fdps and the average wind speed value Fpps is calculated. If the difference exceeds a predetermined measurement error value, an early warning signal is output, and the average wind speed value Fdps is used. If the difference is less than the predetermined measurement error value, a normal signal is output, and either the average wind speed value Fdps or the average wind speed value Fpps is used. When the above difference exceeds the predetermined measurement error value, an early warning signal can be output, and the setting position of the airflow meter at the data average wind speed value point can be manually or automatically adjusted. The predetermined measurement error value is no greater than 2% (i.e., the secondary accuracy requirement for industrial airflow measurement).

[0079] Of course, to ensure the reliability of the duct airflow measurement results, this calibration method can also be used to simultaneously run an airflow measurement system based on big data analysis and an airflow measurement system based on the average wind speed value of the data points to verify each other and ensure the reliability and accuracy of the duct airflow measurement.

[0080] Simulation Experiment

[0081] Based on the aforementioned big data dynamic latitude and longitude sensor device for air volume measurement, this simulation experiment uses a rectangular air duct to simulate a 300MW coal-fired power unit's rectangular air duct, and the following simulated air volume measurement experiment is conducted:

[0082] (I) Introduction to the simulation experiment system:

[0083] like Figure 3 and 4This is a schematic diagram of the simulated air duct structure for an air volume measurement system based on big data analysis. The simulated air duct section is a rectangular air duct section for primary hot air entering the ball mill 10 from a 300MW coal-fired generator unit. The simulation ratio of the actual air duct to the simulated air duct is 2:1. Expansion joints A 11, B 12, cold air duct 13, cold air outlet 14, shut-off valve 15, regulating valve 16, and expansion joint C 17 in the actual air duct are omitted, resulting in a simplified simulated air duct structure. Simultaneously, a fan is installed at the primary hot air inlet, and a big data air volume dynamic latitude and longitude sensor (i.e., a large data air volume dynamic latitude and longitude sensor) is installed on the cross-section of the simulated air duct near the ball mill 10. Figure 1 and 2 The data shows a dynamic latitude and longitude sensing device for air volume. In the figure, 0.00, 2.235, 6.10, and 8.30 represent elevations of 0.00 meters, 2.235 meters, 6.10 meters, and 8.30 meters, respectively.

[0084] Based on the simulated duct velocity requirements, the following fan was selected: Shanghai Halong Fan & Electric Co., Ltd., fan model 4-72, air volume 10562-3712 m³ / h. 3 / h, total pressure 1673 / 2554Pa, and equipped with its frequency conversion speed control device: ABB frequency converter product model ACSS10, meeting the 25-100% wind speed adjustment range; at the same time, according to the size of the simulated air duct cross-section, the above-mentioned large data air volume dynamic latitude and longitude sensing device is designed with appropriate size and installed on the cross-section of the simulated air duct. Among them, the air volume flow meter model of the large data air volume dynamic latitude and longitude sensing device is: AFM-110 type insertion multi-throat flow measurement device (i.e., air volume flow meter), and the Rosemount 3051 connected to it is selected. The CD0A02A1A1H2B3M5 series intelligent differential pressure transmitter (i.e., air volume transmitter) has a range of 0-5171 kPa, a power supply of 10.5-55 VDC, serial number 27315068110, calibration range of 0-747 Pa, and an output of 4-20 mA. The control, monitoring, and analysis unit A includes: 1) one Jingwei mobile control data storage box (specification: Coolmax CM6024), 2) one Lenovo laptop and a set of software for visual analysis and optimization of the air volume measurement cross-section flow field. Horizontal and vertical stepper motors are optionally equipped with Leadshine Intelligent 57CME26 stepper motors. The differential pressure transmitter transmits the air volume measurement data corresponding to each preset point under the monitored duct load value to the Jingwei Mobile Control Data Storage Box via a data cable. The load value, preset point and its corresponding air volume measurement value in the Jingwei Mobile Control Data Storage Box are transmitted one by one to the Lenovo laptop and big data analysis and processing are performed using the air volume measurement section flow field visualization analysis and optimization point selection software.

[0085] (II) Simulation Experiment Measurement Process and Results:

[0086] 1) First, set the number of preset points on the cross-section measured on the control monitoring and analysis unit A: the intersection of the x and y axes on the cross-section measured on the simulated air duct is the preset point: the x-axis is divided into 20 lines and the y-axis is divided into 6 lines, for a total of 120 preset points;

[0087] 2) Wind speed samples were taken at the preset points on the measured cross-section under load values ​​of 33%, 41.7%, 58.3%, 70%, 87.6%, and 100%. The wind speed electrical signals at each preset point were transmitted to the control, monitoring, and analysis unit A via an air volume transmitter to form a database. After all the pre-selected load samples were completed, the database was imported into the "Air Volume Measurement Cross-Section Flow Field Visualization Analysis and Optimization Point Selection Software" for analysis and processing to generate a three-dimensional cross-section-wind speed peak diagram. This allows for a direct visualization of the wind speed at different locations on the measured cross-section under the same load value. Figures 5a to 5f The images show 3D airflow measurement curves of the airflow measurement system when the load values ​​are 33%, 41.7%, 58.3%, 70%, 87.6%, and 100%, respectively.

[0088] 3) Simultaneously, the control monitoring and analysis unit uses image observation and big data calculation to select the average wind speed points for the data: the sum of the wind speeds measured at all 120 preset points under a certain load value, divided by 120, yields the average wind speed value for that load value; the average wind speed error of the set duct data is gradually increased to 0, 1 / 4500, 2 / 4500, 3 / 4500, 4 / 4500… (where 4500 is the maximum wind speed value measured in the simulated duct), confirming several common preset points corresponding to the wind speed values ​​of the preset points that fall within the set average wind speed error of the duct data under the measured load value, i.e., the pre-selected points for the average wind speed value (at least one), such as… Figure 6 The figure shows a 3D curve of the average wind speed points selected when the average wind speed error of the set data of the wind volume measurement system based on big data analysis in the simulated wind duct section is 6 / 4500. The five black dots in the figure are the pre-selected points for the average wind speed values ​​of the five data points when the average wind speed error of the set wind duct data is 6 / 4500.

[0089] (III) Analysis of Simulation Experiment Data:

[0090] Of course, the location of the average wind speed value of the cross-section data measured by the above simulated wind duct experiment is affected by the limitations of the simulation ratio and the actual equipment, support, and online sampling in load adjustment within the actual wind duct. Therefore, it is necessary to set up an air volume measuring instrument at the corresponding location of the actual measured wind duct cross-section to measure the wind speed and compare it with the air volume measurement results of the simulated wind duct experiment. Then, the air volume measurement system composed of dynamic latitude and longitude sensors based on big data air volume measurement is installed on the actual wind duct cross-section to correct or verify it, so as to meet the accuracy requirements of wind duct air volume measurement.

[0091] Although the above experiment was conducted on simulated duct airflow measurement, it is entirely feasible to apply the above device and method to actual non-uniform wind field ducts. This is because the duct simulation experiment is simply a scaled-down version of the actual duct. Even if the actual duct is complex, the wind speed measurement surface diagrams of all non-uniform wind field ducts are irregular 3D surfaces. As long as we can accurately find a few points in the non-uniform wind field duct where the average wind speed value is located (i.e., a set of such points can be found within a reasonable range of airflow measurement error) to represent the points where the average wind speed value is located within the duct cross-section, it is sufficient.

[0092] The technical solution of this invention finds the data average wind speed value points within the cross-section of the duct by simulating experiments or actually measuring the air volume of the duct. Then, an air volume flow meter is set at the data average wind speed value points. Compared with existing air volume measurement technologies, this method sets points in a targeted manner, overturning the existing concept that the geometric average wind speed value represents the actual wind speed value, and greatly improving the accuracy of the air volume measurement system.

[0093] Example 2

[0094] This embodiment provides a large-scale dynamic latitude and longitude sensing device for air volume in a rectangular air duct, which is an optimization based on Embodiment 1. The difference is that the latitudinal dynamic air volume sensing unit in Embodiment 1 includes several air volume flow meters evenly distributed on the transverse main body. This eliminates the transverse rotating part in Embodiment 1, namely the transverse stepper motor, upper fixed pulley, left and right corner fixed pulleys, left and right transverse fixed pulleys and the transverse transmission steel wire between them. This can greatly shorten the time required for monitoring the air volume of the entire air duct under a specific load value, reduce the sampling period T, and ensure the real-time measurement of air volume; the rest refers to the corresponding content of Embodiment 1.

[0095] The rectangular duct airflow measurement system, comprised of the aforementioned big data dynamic latitude and longitude sensing device, also includes the same number of airflow transmitters or one airflow transmitter connected to several airflow meters in the big data dynamic latitude and longitude sensing device, as well as a control, monitoring, and analysis unit A for controlling and monitoring the big data dynamic latitude and longitude sensing device. To accurately measure airflow or precisely locate the average wind speed point, the number of airflow transmitters is the same as the number of airflow meters, and each is connected to the others. However, for more accurate airflow measurement within the duct, the positive and negative pressure sampling holes of the airflow meters can be connected to a positive pressure equalization pipe and a negative pressure equalization pipe, respectively, and then connected to an airflow transmitter through the positive and negative pressure equalization pipes.

[0096] Similarly, based on the big data dynamic latitude and longitude sensing device for air volume in a rectangular air duct, this embodiment also provides a big data analysis-based air volume measurement method for non-uniform wind field air ducts, a method for determining the location of the average wind speed value using the above-mentioned big data analysis-based air volume measurement method for non-uniform wind field air ducts, an air volume measurement system for setting up an air volume flow meter based on the location of the average wind speed value, and a calibration system and method combining the big data analysis-based air volume measurement system for non-uniform wind field air ducts and the air volume measurement system for setting up an air volume flow meter based on the location of the average wind speed value. The corresponding contents are the same as the corresponding parts of Embodiment 1.

[0097] Example 3

[0098] This embodiment provides a dynamic axial-radial sensing device for large air volume within a circular air duct, such as... Figure 10 and 11 This invention provides a schematic diagram of a large-scale dynamic airflow axial-radial sensing device installed within a circular air duct. The large-scale dynamic airflow sensing device is an axial-radial sensing device installed within a cross-section of the circular air duct 1'. It includes an axial sensing active unit 5, a radially driven airflow sensing unit 6, and an axial sensing active unit drive unit. The axial sensing active unit drive unit includes an axial transmission unit 7-1 and an axial drive unit for axially driving the axial sensing active unit. The radially driven airflow sensing unit 6 includes a radial dynamic airflow sensing element 6-1 and a radial rotation unit 6-2 that moves the radial dynamic airflow sensing element back and forth radially within the air duct on the axial sensing active unit.

[0099] The axial sensing active unit 5 includes an axial sensing active unit body 5-1, the cross-section of which is C-shaped, with its opening located on its right side and a transverse track A 5-1-1 on its inner bottom surface; the radial rotating part 6-2 includes a central fixed pulley 6-2-1 and a peripheral fixed pulley 6-2-2 respectively disposed at both ends of the axial sensing active unit body 5-1, a dynamic radial transmission steel wire 6-2-3 between them, a static transmission part 6-2-4 that axially drives the central fixed pulley to rotate, and a radial stepper motor that drives it; the radial dynamic air volume sensor 6-1 is fixed on the side of the opening of the axial sensing active unit body 5-1 and is provided with the dynamic radial transmission steel wire 6-2-3.

[0100] The axial transmission unit 7-1 includes an axial transmission unit body 7-1-1 with an I-shaped cross-section, and a central inner fixed pulley 7-1-2 and a right-end inner fixed pulley 7-1-3 located at the center of the circular air duct and at its right end, respectively, and a static axial transmission steel wire 7-1-4 between them; the axial transmission unit body 7-1-1 passes through the center of the circular air duct and its two ends are fixed to the left and right walls of the circular air duct 1' respectively, with the right end extending out of the outer wall of the air duct; the axial drive unit is an axial stepper motor, which is fixed on the axial transmission unit body 7-1-1 and drives the right-end inner fixed pulley 7-1-3 through a shaft connection.

[0101] The axial sensing active part body 5-1 is also provided with a sleeve 5-1-2 at the center point of its air duct. One end of the sleeve is fixed to the axial sensing active part body at the center point of the circular air duct, and the other end is fixed between the inner and outer bearings in the I-shaped vertical rib of the axial transmission part body 7-1-1. The inner wall of the central inner fixed pulley 7-1-2 is embedded in the outer wall of the sleeve.

[0102] The static transmission part 6-2-4 includes a central outer fixed pulley 6-2-6 and a right-end outer fixed pulley located at the center of the circular air duct on the rear side of the axial transmission part body 7-1-1, and a static radial transmission steel wire between them; the radial stepper motor is fixed on the axial transmission part body 7-1-1 and drives the right-end outer fixed pulley through a shaft connection; the central outer fixed pulley 6-2-6 drives the central fixed pulley 6-2-1 to rotate through a connecting shaft, and the connecting shaft between the central outer fixed pulley and the central fixed pulley is embedded in an inner bearing.

[0103] The radial dynamic air volume sensor 6-1 includes a slider A 6-1-1 that slides along the transverse track A 5-1-1 and an air volume flow meter A 6-1-2 that is fixed thereon and located above the C-shaped structure of the axial sensing active part body.

[0104] The circular duct airflow measurement system composed of the above-mentioned big data airflow dynamic axial radial sensing device also includes an airflow transmitter connected to the airflow meter A in the big data airflow dynamic axial radial sensing device, and a control monitoring and analysis unit A for controlling and monitoring the big data airflow dynamic axial radial sensing device.

[0105] like Figure 7 This embodiment provides a schematic flowchart of a method for measuring air volume in a non-uniform wind field duct based on the above-mentioned circular duct air volume measurement system. The steps are as follows:

[0106] 1) In the control monitoring and analysis unit A, set the angular displacement of the air volume flow meter A in both the axial and radial directions for each step (i.e., set the angular displacement and linear displacement of the air volume flow meter A in both the radial and axial directions in the control monitoring and analysis unit A, i.e., set the angular displacement of the radial stepper motor and the axial stepper motor for each step; the angular displacement in both directions can be the same or different).

[0107] 2) Control monitoring and analysis unit A first controls the air volume flow meter A to move axially from its initial position by a preset angular displacement, and then controls the air volume flow meter A to measure the wind speed (i.e., differential pressure) at all preset points in the radial direction one by one. At the same time, the air volume measured at the corresponding preset point is sent to the air volume transmitter, and then the air volume transmitter stores its air volume electrical signal in control monitoring and analysis unit A (i.e., control monitoring and analysis unit A first controls the axial stepper motor to move by a preset angular displacement, and then controls the radial stepper motor to drive the air volume flow meter A in the radial rotating part 6-2 to measure the wind speed (i.e., differential pressure) at all preset points in the radial direction one by one. At the same time, the wind speed (i.e., differential pressure) measured at the corresponding preset point is sent to the air volume transmitter, and then the air volume transmitter stores its air volume electrical signal in control monitoring and analysis unit A).

[0108] 3) Then, control the air volume flow meter A to move axially by a preset angular displacement, and repeat step 2 until the air volume flow meter A has measured the wind speed values ​​at all preset points in the entire circular air duct.

[0109] 4) Control monitoring and analysis unit A sums up the wind speed measurement values ​​of all the preset points and divides them by the number of preset points to obtain the average wind speed value of the duct data within the sampling period T. This value is the duct air volume measurement value.

[0110] The wind speed measurement of all preset points in the entire circular duct requires a sampling period T. However, the size of this sampling period T is determined by factors such as the speed of the axial stepper motor and the radial stepper motor, the size of the circular duct, the number of preset points in the circular duct, and the wind speed in the circular duct. The shorter the sampling period T, the more accurate the average wind speed value of the duct data. However, when the duct load is constant, the average wind speed value of the duct data is independent of the size of the sampling period T.

[0111] The preset point interval is determined by requirements such as the size of the duct, the complexity of the wind field, and the accuracy of its air volume measurement.

[0112] like Figure 8 This embodiment, based on the aforementioned circular duct airflow measurement system, also provides a flowchart illustrating a method for determining the location of average wind speed values ​​using the aforementioned non-uniform wind field duct airflow measurement method. The steps are as follows:

[0113] 1) In the control monitoring and analysis unit A, set the angular displacement of the air volume flow meter A in both the axial and radial directions for each step (i.e., set the linear displacement and angular displacement of the air volume flow meter A in both the radial and axial directions for each step, i.e., set the angular displacement of the radial stepper motor and the axial stepper motor for each step; the angular displacement in both directions can be the same or different).

[0114] 2) Control monitoring and analysis unit A collects specific load values ​​for the air duct;

[0115] 3) Control monitoring and analysis unit A first controls the air volume flow meter A to move axially from its initial position by a preset angular displacement, and then controls the air volume flow meter A to measure the wind speed (i.e., differential pressure) at each preset point in the radial direction one by one. At the same time, the air volume measured at the corresponding preset point is sent to the air volume transmitter. The air volume transmitter then stores the air volume electrical signal, its position signal, and the specific load value in the control monitoring and analysis unit A in a one-to-one correspondence. (That is, control monitoring and analysis unit A first controls the axial stepper motor to move by a preset angular displacement, and then controls the radial stepper motor to drive the air volume flow meter A in the radial rotating part 6-2 to measure the wind speed (i.e., differential pressure) at each preset point in the radial direction one by one. At the same time, the air volume measured at the corresponding preset point is sent to the air volume transmitter. The air volume transmitter then stores the air volume electrical signal, its position signal, and the specific load value in the control monitoring and analysis unit A in a one-to-one correspondence.)

[0116] 4) Then, control the air volume flow meter A to move axially by a preset angular displacement, and repeat step 3 until the air volume flow meter A has measured the wind speed values ​​at all preset points in the circular air duct.

[0117] 5) Adjust the duct load values ​​in step 2 one by one (e.g., 35%, 40%, 50%, 60%, 70%, 80%, 90%, 100%); repeat steps 2, 3, and 4 until all preset points of the duct load value under the monitored duct load value (i.e., uniformly select load values ​​within the allowable range of duct load value, such as 35%, 40%, 50%, 60%, 70%, 80%, 90%, 100% load) are measured;

[0118] 6) Control monitoring and analysis unit A sums up the wind speed values ​​at all preset points under different load values ​​of the monitored duct, and then divides each sum by the number of preset points to calculate the average wind speed value for each load value. It then gradually increases the set average wind speed error of the duct data from zero until at least one common preset point is determined. The wind speed measurement value at this common preset point is within the range of the sum of the average wind speed value for each load value and the increased average wind speed error of the set duct data.

[0119] In addition, this embodiment provides an airflow measurement system based on the location of average wind speed points, where airflow meters are installed. Airflow meters are installed at each average wind speed point determined by the method described above. Since the wind speed values ​​measured at each average wind speed point are essentially the same, there is almost no airflow between the airflow meters at each point. After equalizing the wind speed values ​​measured by the airflow meters at each point, the system is connected to an airflow transmitter, and then combined with a control, monitoring, and analysis unit A to form an airflow measurement system based on the location of average wind speed points. Of course, each average wind speed point airflow meter can also be connected to a separate airflow transmitter, making the airflow measurement system more accurate.

[0120] Since the wind field of the duct is non-uniform under different load values, the above method can accurately find the specific common points where the average wind speed value of the data is located in the cross section of the duct, and set up air volume flow meters at these points to measure the air volume of the duct in real time and accurately.

[0121] Secondly, based on the aforementioned airflow measurement system based on big data analysis and the airflow measurement system based on average wind speed points, this embodiment also provides a calibration system combining the two systems. The calibration system includes a big data dynamic axial-radial sensing device installed in the cross-section of the duct, at least one average wind speed point-based airflow meter on a misaligned cross-section of the duct, and airflow transmitters and control, monitoring, and analysis units connected to each device. Of course, to ensure the reliability of the duct airflow measurement results, this calibration system can also allow the big data analysis-based airflow measurement system and the average wind speed point-based airflow meter system to operate simultaneously, with one system in standby mode to ensure reliable and accurate duct airflow measurement.

[0122] Finally, based on the above correction system, this embodiment also provides a correction method that combines an airflow measurement system based on big data analysis and an airflow measurement system based on the average wind speed value of the data to set up the airflow meter, such as... Figure 9The diagram illustrates a calibration method combining a big data analysis-based airflow measurement system and an airflow measurement system based on average wind speed values ​​at designated points. The method involves using an airflow meter A, part of a big data dynamic axial-radial sensing device installed in the cross-section of the duct, to perform omnidirectional dynamic point-to-point wind speed measurements at preset point intervals within each sampling period. The sum of all wind speed measurements at these preset points, divided by the number of preset points, yields the average wind speed value Fdps for the duct data. (For detailed explanations of the airflow measurement method, please refer to...) Figure 7 The diagram illustrates a flow chart and explanatory section of a big data analysis-based airflow measurement method for a non-uniform wind field duct. Simultaneously, an airflow meter is installed at least one average wind speed point within the duct cross-section to measure airflow in real time. The measured average wind speed values ​​at each point are then summed and divided by the number of average wind speed points or geometric pressure equalization to obtain the average wind speed value Fpps at each point. Next, the difference between the average wind speed value Fdps and the average wind speed value Fpps is calculated. If this difference exceeds a predetermined measurement error value, an early warning signal is output, and the average wind speed value Fdps is used. If the difference is less than the predetermined measurement error value, a normal signal is output, and either the average wind speed value Fdps or the average wind speed value Fpps is used. If the difference exceeds the predetermined measurement error value, an early warning signal can also be output, and the position of the airflow meter A at the average wind speed point can be manually or automatically adjusted. The predetermined measurement error value is no greater than 2% (i.e., the second-level requirement for industrial measurement accuracy).

[0123] Of course, to ensure the reliability of the duct airflow measurement results, this calibration method can also be used to simultaneously run an airflow measurement system based on big data analysis and an airflow measurement system based on the average wind speed value of the data points to verify each other and ensure the reliability and accuracy of the duct airflow measurement.

[0124] Example 4

[0125] This embodiment provides a dynamic axial-radial sensing device for large data volume within a circular duct, which is an optimization based on Embodiment 3. The difference is that the radial driven air volume sensing unit in Embodiment 3 includes several air volume flow meters A evenly distributed radially on the axial sensing active unit body. This eliminates the need for the radial rotating part 6-2 in Embodiment 3, significantly shortening the time required for monitoring the air volume of the entire duct under a certain load value, reducing the sampling period T, and ensuring the real-time performance of the measured air volume; the remaining parts refer to the corresponding content in Embodiment 3.

[0126] The circular duct airflow measurement system, comprised of the aforementioned large-scale dynamic airflow sensing axial-radial device, also includes an airflow transmitter connected to several airflow meters A within the large-scale dynamic airflow sensing axial-radial device, and a control, monitoring, and analysis unit A for controlling and monitoring the large-scale dynamic airflow sensing axial-radial device. To accurately measure airflow or pinpoint the location of the average wind speed value, the number of airflow transmitters is the same as the number of airflow meters A, and each is connected to the others. However, for more accurate airflow measurement, the positive and negative pressure sampling holes of the airflow meters A can be connected to a positive pressure equalizing pipe and a negative pressure equalizing pipe, respectively, and then connected to the airflow transmitter through the positive and negative pressure equalizing pipes.

[0127] Similarly, based on the large data air volume dynamic axial-radial sensing device in the circular air duct, this embodiment also provides an air volume measurement method for a non-uniform air field duct, a method for determining the data average wind speed value point through the above-mentioned air volume measurement method for a non-uniform air field duct, an air volume measurement system based on the data average wind speed value point air volume flow meter, and a calibration system and method based on the large data air volume measurement system and the data average wind speed value point air volume flow meter air volume measurement system. The corresponding contents are the same as the corresponding parts of Embodiment 3.

[0128] In the big data air volume dynamic sensing device described in this invention, the air volume flow meter is an AFM-110 type insertion multi-throat flow measurement device. Other Venturi-type air volume flow meters, such as single-throat pipe, double-throat pipe, multi-throat pipe, etc., can also be selected. Pitot tube air volume flow meters can also be selected.

[0129] If the big data air volume dynamic sensing device described in this invention is installed in a dusty air duct, a back-purge device for measuring gas pipelines, as described in Chinese Patent CN111520611A, can be used to solve the problem of inaccurate air volume measurement in the air duct caused by dust clogging the air volume flow meter in the big data air volume dynamic sensing device.

[0130] Although the above embodiments are examples of large-scale air volume dynamic sensing devices designed for specific shapes of air ducts such as rectangles and circles, it should be understood that the invention point of this invention is: the large-scale air volume dynamic sensing device presets the number of preset points evenly distributed in the air duct and measures the wind speed in all directions within the cross-section of the air duct, and performs massive big data monitoring and analysis to obtain the average wind speed value of the air duct data and its corresponding points (of course, preset points can also be evenly distributed in the air duct, as long as all-round wind speed measurement can be performed to find the average wind speed value and its points), and sets up an air volume measurement system and method composed of air volume flow meters, etc., and a correction system and method; its purpose is: to find the average wind speed value of the data through big data sampling and analysis, and use this average wind speed value to replace the geometric average wind speed value in the prior art to accurately measure the air duct wind speed; its function is: to solve the problem of inaccurate air volume measurement in the prior art, and greatly improve the accuracy of air volume measurement in the air duct; its effect is: to more accurately achieve the optimal air-coal ratio requirement of coal-fired boilers, so that (1) safety aspect: By improving the real-time accuracy of boiler air volume measurement, the safety of operation is greatly improved; (2) Energy saving: No excessive air enters, reducing the continuous loss of flue gas, which improves the boiler combustion efficiency; (3) Environmental protection: Eliminating the oxygen environment in the furnace, preventing the generation of nitrogen oxides at a high temperature of 1200° in the center of the furnace, greatly reducing air pollution; (4) Improving the flexibility of coal-fired power generation: Precise oxygen supply can greatly improve the flexibility of the power generation unit and earn additional electricity price subsidies; Although the above effects only illustrate the effect of the technical solution of the present invention on the air duct of the coal-fired boiler, of course, the technical solution of the present invention is also feasible for other air ducts that require accurate air volume measurement. Those skilled in the art can make changes or improvements to the present invention without departing from the above-mentioned inventive points, spirit and scope, but all such changes should fall within the protection scope of the technical solution of the present invention.

Claims

1. A system for measuring and correcting airflow in a non-uniform wind field duct, characterized in that, The wind volume measurement system includes a big data analysis-based wind volume measurement system and a wind volume measurement system with wind volume flow meters set at data average wind speed value points. The big data analysis-based wind volume measurement system includes a big data wind volume dynamic sensing device arranged in a wind channel cross section, a wind volume transmitter connected to the big data wind volume dynamic sensing device, and a control monitoring analysis unit A for controlling and monitoring the big data wind volume dynamic sensing device and the wind volume transmitter. The big data wind volume dynamic sensing device is a big data wind volume dynamic longitude-latitude sensing device. The big data wind volume dynamic longitude-latitude sensing device includes a longitude sensing main driving part, a latitude sensing driven wind volume sensing part, a longitude sensing main driving part driving part, a vertical transmission part for driving the longitude sensing main driving part, and a vertical driving part. The longitude sensing main driving part includes a horizontal part and a vertical part, the horizontal part has a body cross section in the shape of an inverted C, and the vertical part has a long strip-shaped closed housing, the horizontal part body and the vertical part body are welded together in the shape of an inverted T. The vertical transmission part includes a vertical transmission part body, upper and lower fixed seats with bearings respectively arranged at the upper and lower ends of the vertical transmission part body, and a vertical screw rod fixed in the bearings of the upper and lower fixed seats.

2. The wind measurement correction system of claim 1, wherein, The wind volume measurement system with wind volume flow meters set at data average wind speed value points includes a wind volume flow meter B arranged at at least one data average wind speed value point in the wind channel cross section with the big data wind volume dynamic sensing device, a wind volume transmitter B connected to the wind volume flow meter B, and a monitoring analysis unit B for monitoring the wind volume flow meter B and the wind volume transmitter B.

3. The wind measurement correction system of claim 2, wherein, At the at least one data average wind speed value point, the wind volume flow meter B is arranged, the number of the wind volume transmitters B is the same as the number of the wind volume flow meters B, and each wind volume transmitter B is connected to a corresponding wind volume flow meter B through a sampling pipe, or the wind volume flow meter B is connected to a wind volume transmitter B through positive and negative equalizing pipes.

4. The wind measurement correction system of claim 2 or 3, wherein, The big data wind volume dynamic sensing device includes a sensing main driving part, a driven wind volume sensing part, a sensing main driving part driving part, a transmission part for driving the sensing main driving part, and a driving part.

5. The wind measurement correction system of claim 1, wherein, The big data wind volume dynamic sensing device can also be a big data wind volume dynamic axial radial sensing device.

6. The wind measurement correction system of claim 1 or 2 or 3, wherein, The latitude sensing driven wind volume sensing part includes a latitude dynamic wind volume sensing member and a horizontal rotation part for moving the latitude dynamic wind volume sensing member back and forth in the wind channel in the longitude sensing main driving part.

7. The wind measurement correction system of claim 6, wherein, The latitude dynamic wind volume sensing member includes a slider and a wind volume flow meter fixed on the slider.

8. The wind measurement correction system of claim 1 or 2 or 3, wherein, The latitude sensing driven wind volume sensing part includes a plurality of wind volume flow meters arranged on the longitude sensing main driving part.

9. The wind measurement correction system of claim 8, wherein, The number of the wind volume transmitters is the same as the number of the wind volume flow meters, and each wind volume transmitter is connected to a corresponding wind volume flow meter through a sampling pipe, or the wind volume flow meter is connected to a wind volume transmitter through positive and negative equalizing pipes.

10. The wind measurement correction system of claim 7 or 9, wherein, The wind volume flow meter is at least one of a Pitot tube wind volume flow meter and a Venturi type wind volume flow meter.

11. The wind measurement correction system of claim 10, wherein, The Venturi type air flow meter is at least one of a single-throat diameter tube air flow meter, a double-throat diameter tube air flow meter and a multi-throat diameter tube air flow meter.

12. The wind measurement correction system of claim 6, wherein, The horizontal rotation part comprises left and right horizontal fixed pulleys respectively arranged at two ends of the horizontal part body and partially exposed on the top surface of the horizontal part body, left and right corner fixed pulleys respectively arranged at two inner sides of the lower end of the vertical part body, an upper fixed pulley arranged at the inner side of the upper end of the vertical part body, a horizontal rotation steel wire wound on the left and right horizontal fixed pulleys, the left and right corner fixed pulleys and the upper fixed pulley, and a horizontal stepping motor driving the upper fixed pulley; and the weft dynamic air flow sensing member is fixed on the lower end of the horizontal part body and arranged on the horizontal rotation steel wire.

13. The wind measurement correction system of claim 7, wherein, The horizontal rotation part comprises left and right horizontal fixed pulleys respectively arranged at two ends of the horizontal part body and partially exposed on the top surface of the horizontal part body, left and right corner fixed pulleys respectively arranged at two inner sides of the lower end of the vertical part body, an upper fixed pulley arranged at the inner side of the upper end of the vertical part body, a horizontal rotation steel wire wound on the left and right horizontal fixed pulleys, the left and right corner fixed pulleys and the upper fixed pulley, and a horizontal stepping motor driving the upper fixed pulley; and the weft dynamic air flow sensing member is fixed on the lower end of the horizontal part body and arranged on the horizontal rotation steel wire.

14. The wind measurement correction system of claim 12 or 13, wherein, The vertical driving part is a vertical stepping motor fixed on the upper end surface of the vertical transmission part body and axially driving the vertical screw rod.

15. The wind volume measurement correction system of claim 8, wherein, The air flow meter is fixed on the lower end of the horizontal part body.

16. The wind volume measurement correction system of claim 9, wherein, The air flow meter is fixed on the lower end of the horizontal part body.

17. The wind measurement correction system of claim 15 or 16, wherein, The vertical driving part is a vertical stepping motor fixed on the upper end surface of the vertical transmission part body and axially driving the vertical screw rod.

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