Ventilation wall and using method thereof

Abstract

The invention relates to the field of ventilation walls, and discloses a ventilation wall and a using method.The ventilation wall comprises a pore plate assembly and only one axial flow fan facing the pore plate assembly, the pore plate assembly comprises a fixed pore plate and a sliding pore plate, the fixed pore plate is provided with a plurality of first holes, the sliding pore plate is provided with a plurality of second holes, the second holes and the first holes are the same in size, the sliding orifice plate is arranged to move at least partially in the direction parallel to the fixed orifice plate so as to change the area of the aligned part of at least part of the first hole and the second hole, and therefore the actual through-flow area of the orifice plate assembly is adjusted. And the axial flow fan is arranged to adjust the air pressure of the upstream side of the pore plate assembly by adjusting the rotating speed of the axial flow fan. A single axial flow fan is adopted as a core wind source, uniform and continuous airflow supply is provided for a wind wall through stable power output, the airflow fluctuation problem caused by individual rotating speed difference of a traditional distributed small fan is avoided, the flow field quality and the flow field intensity are both considered, the mixing area is reduced, and a stable airflow foundation is laid for accurate wind control.

Description

Technical Field

[0001] This invention relates to the field of wind walls, specifically to a wind wall and a method of using a wind wall. Background Technology

[0002] As an innovative dynamic airflow simulation core device in fields such as low-altitude economy, aerospace, new energy, bioengineering, and civil engineering, the wind wall's core function lies in achieving customized adjustment of airflow characteristics such as wind speed gradient, turbulence intensity, and temporal variations through independent and precise control of a distributed wind turbine array. This provides high-fidelity experimental data for verifying the stability of UAVs against gusts, testing non-uniform wind loads on wind turbine blades, studying the airflow adaptation mechanism of biomimetic aircraft, and analyzing tangential wind loads on building complexes. Among these, complex dynamic wind field simulation is one of the core scenarios for wind wall testing. It is mainly used to simulate the dynamic effects of diverse airflow changes in nature, such as low-altitude turbulence, gradient tangential winds, and sudden gusts, on target objects. This is of crucial significance for testing the adaptability of low-altitude aircraft to complex environments, analyzing the fatigue performance of new energy equipment throughout its entire life cycle, optimizing biomimetic flight design, and verifying civil engineering structures resistant to extreme wind disasters.

[0003] Traditional wind walls are controlled by an array of small fans to simulate gusts and shear winds. On one hand, the simulated flow field is constrained by the size of the fans; larger fans result in higher airflow velocity but lower flow field mass, while smaller fans result in lower airflow velocity but higher flow field mass, making it impossible to achieve both simultaneously. Furthermore, due to the special circular structure of the fans, non-airflow structures inevitably exist between the fan array, creating a large mixing region between the wind wall air and the fans. This excessively long mixing region leads to increased flow losses, an unstable flow field, and difficulty in effectively simulating experimental environments. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems in the prior art, such as the inability to simultaneously achieve both the flow field quality and flow field intensity of the wind wall, and the large mixing region between the fan and the wind wall air.

[0005] To achieve the above objectives, the present invention provides an air wall comprising an orifice plate assembly and a single axial flow fan facing the orifice plate assembly. The orifice plate assembly includes a fixed orifice plate and a sliding orifice plate stacked together. The fixed orifice plate has a plurality of first holes, and the sliding orifice plate has a plurality of second holes corresponding one-to-one with the plurality of first holes. The second holes have the same size as the first holes. The sliding orifice plate is configured to move at least partially along a direction parallel to the fixed orifice plate to change the area of ​​the aligned portion of at least a portion of the first holes and the second holes, thereby adjusting the actual flow area of ​​the orifice plate assembly. The axial flow fan is configured to adjust the air pressure on the upstream side of the orifice plate assembly by adjusting its rotational speed.

[0006] In some embodiments, the sliding perforated plate includes a plurality of sub-plates arranged along a first direction parallel to the fixed perforated plate, each sub-plate being provided with a plurality of second holes arranged along a second direction perpendicular to the first direction, and the sliding perforated plate is configured to move each sub-plate independently along the second direction.

[0007] In some embodiments, the perforated plate assembly includes a plurality of driving mechanisms corresponding one-to-one with the plurality of sub-plates. Each driving mechanism includes a motor, a lead screw connected to the motor, and a lead screw nut screwed to the lead screw. The lead screw nut is fixed to the sub-plate, and the driving mechanism is configured to drive the sub-plate to move along the second direction.

[0008] In some embodiments, the drive mechanism includes a fixed base and a guide rod fixed to the fixed base, the guide rod extending parallel to the lead screw and slidably passing through the lead nut.

[0009] In some embodiments, the fixing plate is formed into a square, and the fixing plate is provided with N rows of first holes arranged along the first direction, and each row is provided with M first holes arranged along the second direction. The sliding plate is provided with N sub-plates, and each sub-plate is provided with M second holes.

[0010] In some embodiments, a transition pipe is further included, wherein the inlet end of the transition pipe is circular, the axial flow fan is housed at the inlet end of the transition pipe, the outlet end of the transition pipe is square, and the fixed orifice plate and the sliding orifice plate are disposed at the outlet end of the transition pipe.

[0011] In some embodiments, the axial flow fan includes an impeller, a variable frequency motor driven to the impeller, a front shroud disposed on the front side of the impeller, and a rear shroud disposed on the rear side of the impeller.

[0012] On the other hand, the present invention also provides a method for using a wind wall, wherein the wind wall is the wind wall of the above-described scheme, comprising: S1, an anemometer is installed on the central axis at the outlet of the wind wall, and an air pressure meter is installed on the front side of the orifice plate assembly; S2, move the sliding perforated plate so that the second hole is completely aligned with the first hole; S3, adjust the rotation speed of the axial flow fan to adjust the air pressure on the front side of the orifice plate assembly, and move the wind speed measuring device along the central axis away from the outlet of the wind wall to detect the distance between the wind speed uniform area and the outlet of the wind wall and the corresponding wind speed. S4. Measure the distance between the wind speed uniform area under different wind pressures and the outlet of the wind wall, and the corresponding wind speed, in order to fit and form a curve relationship between wind pressure and wind speed.

[0013] In some embodiments, it also includes: S5, move the sliding orifice plate in a direction parallel to the fixed orifice plate, and adjust the rotational speed of the axial flow fan to measure the wind speed in the uniform wind speed area when the displacement of the sliding orifice plate is 0.1 times, 0.2 times, 0.3 times, 0.4 times, 0.5 times, and 0.6 times the diameter of the first hole under different wind pressures; S6, calculate the actual flow area of ​​the orifice plate assembly for different displacements, and calculate the area ratio of the flow area to the area of ​​the first orifice, and fit the curve relationship between the area ratio and the wind speed under different wind pressures.

[0014] In some embodiments, it also includes: S7, confirm whether the target wind field type is a steady-state wind field or a complex wind field; S8. For a steady-state wind field, analyze the target wind field data, start the axial flow fan and align the second hole with the first hole. Based on the relationship between wind pressure and wind speed, adjust the rotational speed of the axial flow fan to form the target wind field. For a complex wind field, analyze the target wind field data, start the axial flow fan and align the second hole with the first hole. Based on the relationship between wind pressure and wind speed and the relationship between area ratio and wind speed and wind pressure under different wind pressures, adjust the rotational speed of the axial flow fan and the displacement of the sliding orifice plate to form the target wind field.

[0015] The above technical solution uses a single axial flow fan as the core air source, providing a uniform and continuous airflow supply to the wind wall through stable power output. This avoids the airflow fluctuation problem caused by individual speed differences in traditional distributed small fans, laying a stable airflow foundation for precise wind control, taking into account both flow field quality and flow field intensity, and reducing the mixing area. Attached Figure Description

[0016] Figure 1 This is a sectional view of the wind wall described in this embodiment of the solution; Figure 2 yes Figure 1 Left view of the perforated plate assembly; Figure 3 yes Figure 1 Right view of the orifice plate assembly.

[0017] Explanation of reference numerals in the attached figures 1-Axial flow fan, 2-Front rectifier, 3-Impeller, 4-Rear rectifier, 5-Variable frequency motor, 6-Transition fitting, 7-Orifice plate assembly, 8-Fixed orifice plate, 9-First orifice, 10-Sliding orifice plate, 11-Second orifice, 12-Sub-plate, 13-Motor, 14-Lead screw, 15-Lead nut, 16-Fixed seat, 17-Guide rod. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] This invention provides a windbreak wall, comprising an orifice plate assembly 7 and a single axial flow fan 1 facing the orifice plate assembly 7. The orifice plate assembly 7 includes a fixed orifice plate 8 and a sliding orifice plate 10 stacked together. The fixed orifice plate 8 is provided with a plurality of first holes 9, and the sliding orifice plate 10 is provided with a plurality of second holes 11 corresponding one-to-one with the plurality of first holes 9. The second holes 11 have the same size as the first holes 9. The sliding orifice plate 10 is configured to move in a direction parallel to the fixed orifice plate 8 to change the area of ​​the aligned portion of the first holes 9 and the second holes 11, thereby adjusting the actual flow area of ​​the orifice plate assembly 7. The axial flow fan 1 is configured to adjust the wind pressure on the upstream side of the orifice plate assembly 7 by adjusting its rotational speed.

[0020] The rotational speed of the axial flow fan 1 can be adjusted, thereby adjusting the air pressure on the front side (the side facing the axial flow fan 1) of the orifice plate assembly 7.

[0021] The orifice plate assembly 7 includes a fixed orifice plate 8 and a sliding orifice plate 10, which are stacked on top of each other. The fixed orifice plate 8 has a first orifice 9, and the sliding orifice plate 10 has a second orifice 11 that corresponds one-to-one with the first orifice 9. The first orifice 9 and the second orifice 11 are holes of the same size and can be perfectly aligned. The sliding orifice plate 10 can move in a direction parallel to the fixed orifice plate 8, so that the alignment state between the second orifice 11 and the first orifice 9 changes, for example, between a fully aligned state and a fully offset state. In the fully aligned state, the actual flow area of ​​the through hole formed by the second orifice 11 and the corresponding first orifice 9 is the largest. In the fully offset state, the actual flow area of ​​the second orifice 11 and the corresponding first orifice 9 is 0, that is, airflow is no longer allowed.

[0022] By adjusting the wind pressure on the front side of the orifice plate assembly 7 and the actual flow area of ​​the orifice plate assembly 7, the properties of the formed wind field can be changed, such as the distance between the location where the wind speed begins to become uniform (the uniform wind speed area) and the outlet of the wind wall, the wind speed in the uniform wind speed area, and the type of wind field.

[0023] Among them, the axial flow fan 1 includes only one impeller fan, that is, the wind wall of this scheme uses only one impeller fan as the air source.

[0024] In this scheme, a single axial flow fan is used as the core air source. Through stable power output, it provides a uniform and continuous airflow supply to the wind wall, avoiding the airflow fluctuation problem caused by individual speed differences of traditional distributed small fans. This lays a stable airflow foundation for precise wind control, takes into account both flow field quality and flow field intensity, and reduces the mixing area.

[0025] In some embodiments, the sliding orifice plate 10 includes a plurality of sub-plates 12 arranged along a first direction parallel to the fixed orifice plate 8. Each sub-plate 12 is provided with a plurality of second holes 11 arranged along a second direction perpendicular to the first direction. The sliding orifice plate 10 is configured to move each sub-plate 12 independently along the second direction. The sliding orifice plate 10 may include multiple parts, each of which can move independently of the other parts to independently change the alignment state of a portion of the second holes 11 with the corresponding first holes 9. For example, the sliding orifice plate 10 includes a plurality of strip-shaped sub-plates 12 arranged along the first direction. Each sub-plate 12 is provided with a plurality of second holes 11 arranged along the second direction. Each sub-plate 12 can move independently along the second direction, thereby changing the alignment state of the second holes 11 on that sub-plate 12 with the corresponding first holes 9. The relative positions of different sub-plates 12 with the corresponding portions of the fixed orifice plate 8 can be set to be different, thereby forming various wind field shapes.

[0026] In some embodiments, the perforated plate assembly 7 includes multiple driving mechanisms corresponding one-to-one with the multiple sub-plates 12. Each driving mechanism includes a motor 13, a lead screw 14 driven to the motor 13, and a nut 15 screwed to the lead screw 14. The nut 15 is fixed to the sub-plate 12. The driving mechanism is configured to drive the sub-plate 12 to move along the second direction. The motor 13 can drive the lead screw 14 to rotate, thereby driving the nut 15 to move along the length of the lead screw 14, thus moving the corresponding sub-plate 12 along the second direction. The extension direction of the lead screw 14 is the second direction. Of course, in other embodiments, hydraulic cylinders or pneumatic cylinders can also be used to drive the sub-plate 12 to move along the second direction.

[0027] In some embodiments, the drive mechanism includes a fixed base 16 and a guide rod 17 fixed to the fixed base 16. The guide rod 17 extends parallel to the lead screw 14 and slidably passes through the lead screw nut 15. The guide rod 17 also extends in a second direction, through which the lead screw nut 15 receives the guide rod 17, and the guide rod 17 supports and guides the lead screw nut 15 to slide in the second direction.

[0028] In some embodiments, the fixed perforated plate 8 is square, and has N rows of first holes 9 arranged along the first direction, with M first holes 9 arranged along the second direction in each row. The sliding perforated plate 10 has N sub-plates 12, and each sub-plate 12 has M second holes 11. M and N can be equal, and the first holes 9 are spaced the same along both the first and second directions, forming a square array of first holes 9 on the fixed perforated plate 8. Correspondingly, the sliding perforated plate 10 includes N sub-plates 12, and each sub-plate 12 includes M second holes 11.

[0029] In some embodiments, the air wall also includes a transition pipe 6, the inlet end of which is circular, and the axial flow fan 1 is housed at the inlet end of the transition pipe 6. The outlet end of the transition pipe 6 is square, and the fixed perforated plate 8 and the sliding perforated plate 10 are disposed at the outlet end of the transition pipe 6. The circular inlet end of the transition pipe 6 can accommodate the axial flow fan 1, and its square outlet end corresponds to the square perforated plate assembly 7. The cross-sectional shape of the transition pipe 6 gradually changes from a circle at the inlet end to a square at the outlet end, so as to form a channel between the axial flow fans 1 and the perforated plate assembly 7. This solution can cover the entire area, achieving airflow distribution without dead angles. The air outlet range of the axial flow fan is precisely matched with the overall size of the air wall, ensuring that the airflow evenly covers all areas of the air wall, without any local airflow weakness or blind spots. This solves the problem of traditional air walls being prone to "local no-wind zones" due to the limited fan size and dispersed layout, and meets the airflow requirements of the entire test area.

[0030] In some embodiments, the axial flow fan 1 includes an impeller 3, a variable frequency motor 5 driven to the impeller 3, a front shroud 2 located on the front side of the impeller 3, and a rear shroud 4 located on the rear side of the impeller 3. The impeller 3, i.e., the fan, includes multiple blades that can form an airflow flowing axially toward the orifice plate assembly 7. The output speed of the variable frequency motor 5 can be adjusted to regulate the speed of the impeller 3, thereby changing the air pressure. The front shroud 2 is approximately hemispherical, which can reduce airflow resistance, while the rear shroud 4 has a tapered outer diameter, which can guide the airflow to be more evenly distributed throughout the entire cross-sectional area of ​​the transition pipe 6.

[0031] On the other hand, this solution also provides a method for using a wind wall, wherein the wind wall is the wind wall described in the above solution, including: S1, an anemometer is installed on the central axis at the outlet of the wind wall, and an air pressure meter is installed on the front side of the orifice plate assembly 7; S2, move the sliding perforated plate 10 so that the second hole 11 is completely aligned with the first hole 9; S3, adjust the rotation speed of the axial flow fan 1 to adjust the air pressure on the front side of the orifice plate assembly 7, and move the wind speed measuring device along the central axis away from the outlet of the wind wall to detect the distance between the wind speed uniform area and the outlet of the wind wall and the corresponding wind speed. S4. Measure the distance between the wind speed uniform area under different wind pressures and the outlet of the wind wall, and the corresponding wind speed, in order to fit and form a curve relationship between wind pressure and wind speed.

[0032] In other words, with all the second holes 11 and the first hole 9 perfectly aligned, the wind speed in the uniform wind speed region and the distance to the wind wall outlet in the wind field formed under different wind pressures are measured by adjusting the rotation speed of the axial flow fan 1.

[0033] The outlet of the wind wall is located on the rear side of the orifice plate assembly 7 (the side facing away from the axial flow fan 1).

[0034] Regarding the uniform wind speed region, on the central axis of the wind wall outlet, the anemometer is moved in a direction away from the wind wall outlet and the wind speed is measured. For example, the anemometer can be moved a predetermined distance (e.g., 10 mm or other values) and the wind speed is measured each time. When the wind speed value no longer changes, the area with that wind speed is the uniform wind speed region.

[0035] Based on the measured data, a coordinate system can be established with wind pressure on the horizontal axis and wind speed on the vertical axis, and a curve relationship between wind pressure and wind speed can be formed by fitting the data (the measured data are points with wind pressure on the horizontal axis and wind speed on the vertical axis, and the points are connected to form a fitted curve).

[0036] In addition, in some embodiments, the method of using the wind wall includes: S5, move the sliding orifice plate 10 in a direction parallel to the fixed orifice plate 8, and adjust the rotational speed of the axial flow fan 1 so as to measure the wind speed in the wind speed uniform region when the displacement of the sliding orifice plate 10 is 0.1 times, 0.2 times, 0.3 times, 0.4 times, 0.5 times, and 0.6 times the diameter of the first hole 9 under different wind pressures; S6, calculate the actual flow area of ​​the orifice plate assembly 7 under different displacements, and calculate the area ratio of the flow area to the area of ​​the first hole 9, and fit the curve relationship between the area ratio and the wind speed under different wind pressures.

[0037] Under different wind pressures, the sliding orifice plate 10 was moved as a whole, and the wind speed in the uniform wind speed area was measured when the displacement was 0.1 times, 0.2 times, 0.3 times, 0.4 times, 0.5 times, and 0.6 times the diameter of the first orifice 9.

[0038] Calculate the area ratio of the actual flow area to the maximum flow area under different displacements.

[0039] A coordinate system is established with the area ratio as the horizontal axis and the displacement as the vertical axis, thus forming curves of area ratio versus wind speed under different wind pressures.

[0040] In addition, the use of wind walls also includes: S7, confirm whether the target wind field type is a steady-state wind field or a complex wind field; S8. For a steady-state wind field, analyze the target wind field data, start the axial flow fan 1 and make the second hole 11 completely aligned with the first hole 9. Based on the curve relationship between wind pressure and wind speed, adjust the rotation speed of the axial flow fan 1 to form the target wind field. For a complex wind field, analyze the target wind field data, start the axial flow fan 1 and make the second hole 11 aligned with the first hole 9. Based on the curve relationship between wind pressure and wind speed and the curve relationship between area ratio and wind speed under different wind pressures, adjust the rotation speed of the axial flow fan 1 and the displacement of the sliding orifice plate 10 to form the target wind field.

[0041] For a steady-state wind field, the second hole 11 on the sliding orifice plate 10 can be made to be completely aligned with the first hole 9. By adjusting the rotational speed of the axial flow fan 1, a target wind field can be formed, for example, the wind speed in the uniform wind speed region of the formed wind field reaches the target value.

[0042] For complex wind fields, such as gusts, shear winds, and pulsating winds, it is necessary to adjust the rotational speed of the axial fan 1 and the displacement of the sliding orifice plate 10 to form the target wind field. As mentioned above, the sliding orifice plate 10 includes multiple strip-shaped sub-plates 12, and each sub-plate 12 needs to be adjusted independently according to the different wind field types.

[0043] This solution overcomes the limitations of traditional wind walls, which are restricted by fan size and cannot effectively improve the flow field. It allows for sufficiently small individual pixels within the wind wall, thus enhancing the flow field quality. By replacing fans with vents, the effective flow area is increased, reducing the impact of high-speed fan rotation on airflow. This significantly shortens the mixing zone, reduces airflow loss, and improves efficiency. Furthermore, the single-fan speed control method reduces the number of fans required for control. A limited number of motors are sufficient to adjust the complex flow field of the wind wall, saving on control circuitry, significantly reducing labor costs and installation / commissioning time. It also reduces system complexity, improves system reliability, and greatly lowers the failure rate.

[0044] The method of the present invention will be further described in detail below with reference to specific implementation examples: 1) Construct a single-fan wind wall with the following dimensions: axial fan diameter 800mm, power 3kW, two-stage, impeller with 8 blades, perforated plate assembly with a wind wall outlet size of 800mm*800mm, perforation array of 10*10=100 holes, hole diameter 50mm. The width of the sliding perforated plate sub-plate is 60mm.

[0045] 2) Measurement of the starting point of the uniform zone (distance from the wind wall outlet):

[0046] 3) The derivation formula for calculating the actual flow area S of the orifice plate assembly is as follows, where d is the displacement of the sub-plate and r is the radius of the orifice.

[0047]

[0048] The ratio of the actual flow area to the maximum flow area (the area of ​​the first hole of the fixed orifice plate) under different displacements is as follows.

[0049]

[0050] 4) Measure the effect of different area ratios on wind speed under different wind pressures. The following is the relationship between area ratio and wind speed when the wind pressure is 50 Pa.

[0051]

[0052] The wind wall in this design has the following advantages: 1) A single fan is used as the core air source. Through stable power output, it provides a uniform and continuous airflow supply to the wind wall, avoiding the airflow fluctuation problem caused by individual speed differences of traditional distributed small fans, and laying a stable airflow foundation for subsequent precise wind control. 2) Full-area coverage achieves airflow distribution without dead corners. The air outlet range of the fan is precisely matched with the overall size of the wind wall, which can ensure that the airflow evenly covers all areas of the wind wall. There are no local airflow weak or blind spots. This solves the problem of traditional wind walls being scattered due to fan size limitations and prone to "local no-wind areas". It meets the airflow requirements of the entire test area. 3) "Centralized air supply + adjustable aperture" solves the problem of traditional wind walls having to compromise between "high airflow intensity" and "good flow field". It ensures the overall airflow intensity through a single fan, and at the same time, relying on the independent adjustment function of the aperture array, the aperture can theoretically be infinitely small, achieving the synergy of "strong air supply" and "good flow field", breaking the compatibility limitations of traditional design. 4) The wind wall aperture adjustment system is adapted to wind field simulation in multiple scenarios. With the independent adjustment capability of the row level of the wind wall aperture array, the aperture of different rows of apertures can be controlled differently (such as increasing the aperture of some rows and decreasing the aperture of some rows) to flexibly generate complex wind fields such as gusts and shear winds that meet different test requirements. For example, sudden gusts can be simulated by quickly switching the aperture of a few rows of apertures, or the wind speed gradient of shear wind can be reproduced by setting the aperture gradient of different rows in the vertical direction (such as 0.3d for the bottom row of apertures and 0.6d for the top row of apertures), which greatly expands the scenario adaptation range of the wind wall.

[0053] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A windbreak wall, characterized in that, The assembly includes an orifice plate assembly (7) and a single axial flow fan (1) facing the orifice plate assembly (7). The orifice plate assembly (7) includes a fixed orifice plate (8) and a sliding orifice plate (10) stacked together. The fixed orifice plate (8) is provided with a plurality of first holes (9). The sliding orifice plate (10) is provided with a plurality of second holes (11) corresponding one-to-one with the plurality of first holes (9). The second holes (11) are the same size as the first holes (9). The sliding orifice plate (10) is configured to move at least partially in a direction parallel to the fixed orifice plate (8) to change the area of ​​the aligned portion of at least a portion of the first holes (9) and the second holes (11), thereby adjusting the actual flow area of ​​the orifice plate assembly (7). The axial flow fan (1) is configured to adjust the wind pressure on the upstream side of the orifice plate assembly (7) by adjusting its rotational speed.

2. The windbreak wall according to claim 1, characterized in that, The sliding perforated plate (10) includes a plurality of sub-plates (12) arranged in a first direction parallel to the fixed perforated plate (8), each sub-plate (12) having a plurality of second holes (11) arranged in a second direction perpendicular to the first direction, and the sliding perforated plate (10) is configured to move each sub-plate (12) independently in the second direction.

3. The windbreak wall according to claim 2, characterized in that, The perforated plate assembly (7) includes multiple driving mechanisms corresponding to the multiple sub-plates (12). Each driving mechanism includes a motor (13), a lead screw (14) connected to the motor (13), and a lead screw nut (15) screwed to the lead screw (14). The lead screw nut (15) is fixed to the sub-plate (12). The driving mechanism is configured to drive the sub-plate (12) to move along the second direction.

4. The windbreak wall according to claim 3, characterized in that, The drive mechanism includes a fixed base (16) and a guide rod (17) fixed on the fixed base (16), the guide rod (17) extending parallel to the lead screw (14) and slidably passing through the lead screw nut (15).

5. The windbreak wall according to claim 2, characterized in that, The fixed hole plate (8) is square in shape. The fixed hole plate (8) is provided with N rows of first holes (9) arranged along the first direction. Each row is provided with M first holes (9) arranged along the second direction. The sliding hole plate (10) is provided with N sub-plates (12). Each sub-plate (12) is provided with M second holes (11).

6. The windbreak wall according to claim 1, characterized in that, It also includes a transition pipe (6), the inlet end of which is circular, the axial flow fan (1) is housed at the inlet end of the transition pipe (6), the outlet end of which is square, and the fixed orifice plate (8) and the sliding orifice plate (10) are disposed at the outlet end of the transition pipe (6).

7. The windbreak wall according to claim 1, characterized in that, The axial flow fan (1) includes an impeller (3), a variable frequency motor (5) connected to the impeller (3), a front shroud (2) located on the front side of the impeller (3), and a rear shroud (4) located on the rear side of the impeller (3).

8. A method of using a windbreak wall, characterized in that, The wind wall is the wind wall described in any one of claims 1-7, comprising: S1, a wind speed measuring device is installed on the central axis at the outlet of the wind wall, and a wind pressure measuring device is installed on the front side of the orifice plate assembly (7); S2, move the sliding perforated plate (10) so that the second hole (11) is completely aligned with the first hole (9); S3, adjust the rotation speed of the axial flow fan (1) to adjust the air pressure on the front side of the orifice plate assembly (7), and move the wind speed measuring device along the central axis away from the outlet of the wind wall to detect the distance between the wind speed uniform area and the outlet of the wind wall and the corresponding wind speed. S4. Measure the distance between the wind speed uniform area under different wind pressures and the outlet of the wind wall, and the corresponding wind speed, in order to fit and form a curve relationship between wind pressure and wind speed.

9. The method of using the windbreak wall according to claim 8, characterized in that, include: S5, move the sliding orifice plate (10) in a direction parallel to the fixed orifice plate (8), and adjust the rotation speed of the axial flow fan (1) so as to measure the wind speed in the uniform wind speed area when the displacement of the sliding orifice plate (10) is 0.1 times, 0.2 times, 0.3 times, 0.4 times, 0.5 times, and 0.6 times the diameter of the first hole (9) under different wind pressures. S6, calculate the actual flow area of ​​the orifice plate assembly (7) under different displacements, and calculate the area ratio of the flow area to the area of ​​the first hole (9), and fit the curve relationship between the area ratio and the wind speed under different wind pressures.

10. The method of using the windbreak wall according to claim 9, characterized in that, include: S7, confirm whether the target wind field type is a steady-state wind field or a complex wind field; S8. For a steady-state wind field, analyze the target wind field data, start the axial flow fan (1) and align the second hole (11) with the first hole (9). Based on the curve relationship between wind pressure and wind speed, adjust the rotation speed of the axial flow fan (1) to form the target wind field. For a complex wind field, analyze the target wind field data, start the axial flow fan (1) and align the second hole (11) with the first hole (9). Based on the curve relationship between wind pressure and wind speed and the curve relationship between area ratio and wind speed and wind pressure under different wind pressures, adjust the rotation speed of the axial flow fan (1) and the displacement of the sliding orifice plate (10) to form the target wind field.

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