A fan bell, a wind guiding device and a wind guiding device control method

Abstract

The application discloses a fan flow guide ring, a wind guide device and a wind guide device control method, and belongs to the field of air flow guide. The fan flow guide ring comprises at least one telescopic unit. Each telescopic unit comprises a first section, a second section and an adjusting device. The first section and the second section are sleeved, and the adjusting device is connected with the first section and the second section respectively. The adjusting device adjusts the sleeving length of the sleeving part of the first section and the second section, and changes the length of the flow guide ring. Therefore, the length of the flow guide ring can be adjusted according to the wind speed of the fan, so that the noise generated by the fan can be reduced while the efficiency of the fan is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air guiding, in particular, to a fan guide ring, a wind guiding device and a wind guiding device control method. BACKGROUND

[0002] In the technical field of wind guiding devices, the efficiency of the outdoor unit axial flow fan blade directly affects the overall performance of the wind guiding device. The traditional design of the fan guide ring of the outdoor unit of the wind guiding device is often relatively simple, and the influence of the fan guide ring on the inlet air speed and angle of the axial flow fan blade is not fully considered, thereby affecting the efficiency of the fan and possibly increasing the noise of the outdoor unit. The existing design of the fan guide ring focuses more on structural stability and cost considerations, while ignoring its potential in improving fan efficiency and reducing noise.

[0003] Even if there is a fan guide ring that reduces noise, it is achieved by changing the shape and internal structure of the fan guide ring to eliminate or reduce noise, rather than changing the length of the fan guide ring. Therefore, the length of the traditional fan guide ring is fixed and cannot be adjusted according to different wind speeds, which to some extent limits the efficiency and noise control of the fan. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the present application provides a fan guide ring, a wind guiding device and a wind guiding device control method to solve the problem that the length of the traditional fan guide ring is fixed and cannot be adjusted according to different wind speeds, which to some extent limits the efficiency and noise control of the fan.

[0005] The technical solution adopted by the present application to solve its technical problems is:

[0006] In a first aspect, a fan guide ring is provided, comprising: at least one telescopic unit; the telescopic unit can change the length of the guide ring;

[0007] The telescopic unit comprises a first segment, a second segment and an adjusting device;

[0008] The first segment and the second segment are sleeved;

[0009] The adjusting device is connected to the first segment and the second segment, respectively, and is used to adjust the sleeving length of the sleeving part of the first segment and the second segment, the sleeving length being the length of the overlap of the first segment and the second segment.

[0010] Further, the adjusting device is a ball screw;

[0011] The ball screw comprises a screw rod, a nut, balls and a circulator;

[0012] The screw is connected to the first segment, and the nut is connected to the second segment; the circulator drives the nut through the ball bearings, so that the nut drives the second segment to move.

[0013] Furthermore, the screw is equipped with a limit switch, which is used to cut off the power supply to the circulator when the sleeve length is less than a threshold.

[0014] Furthermore, it also includes a locking unit, used to fix the sleeve length of the first segment and the second segment unchanged when the adjusting device does not adjust the sleeve length.

[0015] Secondly, an air guiding device is provided, including the aforementioned fan guide ring.

[0016] Thirdly, a method for controlling an air guiding device is provided, the method comprising:

[0017] If a preset condition is triggered, the target length of the guide ring is determined. The target length is the length of the guide ring when the noise is minimized while the fan speed remains constant at the current fan speed.

[0018] The length of the guide ring is controlled to the target length, wherein the length of the guide ring is adjustable.

[0019] Furthermore, the triggering preset condition includes any one of the following:

[0020] The noise changed and the fan speed changed;

[0021] Alternatively, the fan speed may change.

[0022] Further, determining the target length of the guide coil includes:

[0023] Obtain the current fan speed;

[0024] The target length is determined based on the current wind turbine speed.

[0025] Further, determining the target length based on the current wind turbine rotation speed includes:

[0026] The minimum and maximum preset lengths of the guide ring are determined based on the current fan speed.

[0027] The guide ring is controlled to extend from the minimum preset length to the maximum preset length, and the noise change is recorded;

[0028] The length corresponding to the minimum noise level is taken as the target length.

[0029] Further, determining the target length of the guide coil includes:

[0030] The flow guide ring is controlled to extend from its minimum length to its maximum length, and the noise change is recorded.

[0031] The length corresponding to the minimum noise level is taken as the target length.

[0032] Beneficial effects:

[0033] This application provides a fan guide ring, a guide device, and a control method for the guide device. The fan guide ring includes at least one telescopic unit. Each telescopic unit includes a first segment, a second segment, and an adjusting device. The first segment and the second segment are sleeved together, and the adjusting device is connected to both the first segment and the second segment. The adjusting device changes the length of the guide ring by adjusting the sleeve length of the sleeved portion of the first segment and the second segment. Therefore, by adjusting the length of the guide ring according to the different wind speeds of the fan, the fan efficiency can be increased while the noise generated by the fan can be reduced. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a structural schematic diagram of the relative positions of a fan and a guide ring provided in an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the structure of a guide ring provided in an embodiment of this application;

[0037] Figure 3 This is a schematic diagram of a guide ring installation provided in an embodiment of this application;

[0038] Figure 4 This is a flowchart of a method for controlling an air guide device provided in an embodiment of this application;

[0039] Figure 5 This is a flowchart of a specific air guide device control method provided in an embodiment of this application;

[0040] Figure 6 This is a schematic diagram of the structure of a wind-guiding equipment control device provided in an embodiment of this application;

[0041] Figure 7 This is a schematic diagram of a wind-guiding device control system provided in an embodiment of this application. Attached image description:

[0043] 100-Fan, 200-Guide ring, 210-First section, 220-Second section, 230-Adjusting device, 231-Screw, 232-Nut, 300-Panel. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] The relative positions of the guide ring 200 and the fan 100 are as follows: Figure 1 As shown, the rotational speed of the fan 100 determines the velocity of the airflow and the mode of kinetic energy conversion within the fan 100. As the rotational speed of the fan 100 increases, it means that the fan 100 needs stronger airflow guiding capabilities to effectively guide the high-speed airflow to the outlet, while reducing eddies and fluid separation phenomena. This reduces air oscillations and disturbances caused by these irregular airflow movements, thereby reducing noise generation. Therefore, high-speed fans 100 typically require longer fan guide rings to ensure stable airflow dynamics during high-speed operation and maximize the conversion of airflow kinetic energy into effective output power. Secondly, the situation of low-speed fans 100 also needs to be considered. Although low-speed fans typically do not need to handle atmospheric flow energy like high-speed fans 100, an appropriately long fan guide ring is still required to avoid unnecessary energy loss and hydrodynamic failures. Short fan guide rings may lead to airflow dispersion and fluid separation, reducing the efficiency and performance of the fan 100, especially in situations requiring long-term operation or stable operation.

[0046] To solve this problem, refer to Figure 2 This application provides a fan guide ring, including: at least one telescopic unit; the telescopic unit is capable of changing the length of the guide ring 200; for ease of explanation, Figure 2 There is only one telescopic unit in the middle. In practice, multiple telescopic units can be added to increase the adjustable range of the 200mm guide ring length.

[0047] The telescopic unit includes a first segment 210, a second segment 220, and an adjustment device 230;

[0048] The first segment 210 and the second segment 220 are connected together;

[0049] The adjusting device 230 is connected to the first segment 210 and the second segment 220 respectively. The adjusting device 230 is used to adjust the sleeve length of the sleeved portion of the first segment 210 and the second segment 220, and the sleeve length is the overlapping length of the first segment 210 and the second segment 220. The adjusting device 230 of the telescopic unit can change the length of the guide ring 200 by changing the sleeve length of the sleeved portion of the first segment 210 and the second segment 220.

[0050] like Figure 2 As shown, the adjusting device 230 is a ball screw;

[0051] The ball screw includes a screw 231, a nut 232, balls, and a circulator;

[0052] The screw 231 is connected to the first segment 210, and the nut 232 is connected to the second segment 220; the circulator drives the nut 232 through the ball bearings, so that the nut 232 drives the second segment 220 to move.

[0053] Optionally, the adjusting device 230 may also be a motor and transmission device, or a cylinder, as long as the adjusting device 230 can change the length of the guide ring 200 when it drives the first segment 210 and the second segment 220 to move. This application does not make specific limitations in this regard.

[0054] In a preferred implementation of this application, a limit switch is provided on the screw 231. The limit switch is used to cut off the power supply to the circulator when the sleeve length is less than a threshold. This prevents the nut 232 from directly detaching from the screw 231, ensuring the safety of the device.

[0055] In practical use, a locking unit is also included to maintain the connection length of the first segment 210 and the second segment 220 unchanged when the adjusting device 230 is not adjusting the connection length. Because the connection between the first segment 210 and the second segment may become unstable after some adjusting devices 230 are adjusted, a locking unit is provided to lock them in place. This ensures that the length of the guide ring 200 remains unchanged when the adjusting device 230 is not involved in the adjustment.

[0056] The fan guide ring provided in this embodiment includes at least one telescopic unit. Each telescopic unit includes a first segment 210, a second segment 220, and an adjusting device 230. The first segment 210 and the second segment 220 are sleeved together, and the adjusting device 230 is connected to both the first segment 210 and the second segment 220. The adjusting device 230 changes the length of the guide ring 200 by adjusting the sleeve length of the sleeved portion of the first segment 210 and the second segment 220. Therefore, by adjusting the length of the guide ring 200 according to the different wind speeds of the fan 100, the efficiency of the fan 100 can be increased while the noise generated by the fan 100 is reduced.

[0057] Based on the same inventive concept, this application provides an air guiding device, including a fan guide ring as provided in the above embodiments. The air guiding device includes a fan 100. The air guiding device includes, but is not limited to, air conditioners, fans, atomizers, etc. Taking an air conditioner as an example, the guide ring 200 is disposed on the outdoor unit of the air conditioner, such as... Figure 3 As shown, the guide ring 200 is fixed on the panel 300.

[0058] The guide ring structure consists of at least two retractable segments connected by a ball screw mechanism. The guide ring is designed to be retractable, typically divided into a first segment and a second segment. The first segment is fixed to the panel, while the second segment is a movable part that moves with the ball screw, thus changing the overall length of the guide ring to form a single retractable guide ring. The nut of the ball screw is fixed to the second segment, which is furthest from the outdoor unit panel. A circulator in the groove between the screw and nut guides the balls in the groove to circulate between the screw and nut, providing a linear force to the nut, causing the nut to drive the sliding second segment, furthest from the outdoor unit panel, in a linear motion. To ensure safe operation, a limit switch is installed at the screw's ultimate safety position. When the screw reaches its ultimate safety position, the limit switch cuts off the power to the circulator, preventing excessive extension or retraction. To ensure the stability of the structure, three ball screws are installed between the first and second sections to synchronously control the extension and retraction of the guide ring. Each pair of devices is spaced 120 degrees apart, forming a stable triangular support effect. Of course, in actual control, only two ball screws can be used, or four or more ball screws can be installed.

[0059] Based on the same inventive concept, such as Figure 4 As shown, this application provides a method for controlling an air guiding device, the method comprising:

[0060] S11: If a preset condition is triggered, the target length of the guide ring is determined. The target length is the length of the guide ring when the noise is minimized when the fan speed remains constant at the current fan speed.

[0061] In one embodiment, the preset trigger condition is that the noise changes and the fan speed changes; that is, after the sound sensor detects that the noise has changed, it then determines whether the fan speed has changed.

[0062] In another embodiment, the preset trigger condition is a change in noise. In this case, if the fan speed does not change, the target length is the current length; if the fan speed changes, the target length needs to be redefined.

[0063] However, in actual operation, changes in both the environment and the fan speed can lead to a change in noise levels. In such cases, the length of the guide ring is not adjusted. However, the noise of the air-guiding device could actually be lower. Therefore, in another embodiment, the trigger condition is a change in the fan speed. That is, noise is no longer considered; the fan speed is used directly for judgment.

[0064] As a preferred implementation of this application embodiment, determining the target length of the guide ring includes:

[0065] The current fan speed can be obtained; the actual fan speed can be detected based on the gear position or by setting up an additional sensor.

[0066] The target length is determined based on the current wind turbine speed.

[0067] In one embodiment, determining the target length based on the current wind turbine rotation speed includes: directly determining the target length corresponding to the current wind turbine rotation speed based on a preset correspondence or a preset table. The preset correspondence or preset table sets a corresponding target length for each wind turbine rotation speed. The preset correspondence and preset table are obtained through testing.

[0068] However, in actual use, the actual environmental conditions and working conditions may differ from those during testing, so the target length obtained in this way may not be the optimal value.

[0069] Based on this, in another embodiment, determining the target length based on the current wind turbine rotation speed includes:

[0070] The minimum and maximum preset lengths of the guide ring are determined based on the current fan speed. These preset lengths are pre-set values ​​within a range that maximizes fan efficiency for each fan speed, with the lower limit being the minimum preset length and the upper limit being the maximum preset length. In other words, this embodiment of the application reduces noise while ensuring high fan efficiency.

[0071] The guide ring is controlled to extend from the minimum preset length to the maximum preset length, and the noise change is recorded.

[0072] The length corresponding to the minimum noise level is taken as the target length.

[0073] As another optional implementation of this application embodiment, determining the target length of the guide ring includes:

[0074] The flow guide ring is controlled to extend from its minimum length to its maximum length, and the noise change is recorded.

[0075] The length corresponding to the minimum noise level is taken as the target length.

[0076] In other words, this embodiment does not guarantee high fan efficiency, but only guarantees minimal noise.

[0077] The two methods can be selected according to actual needs. For example, if the noise is greater than the threshold, only the minimum noise level is guaranteed. If the noise is less than or equal to the threshold, the noise level is reduced while ensuring high fan efficiency.

[0078] S12: Control the length of the guide ring to the target length, wherein the length of the guide ring can be adjusted.

[0079] The air guide device control method provided in this application determines the target length of the guide ring when a preset condition is triggered. Since the target length is the length of the guide ring when the noise is minimized while maintaining the current fan speed, controlling the guide ring length to the target length results in the lowest noise level for the air guide device. This effectively reduces noise and improves the user experience.

[0080] Taking air conditioning as an example, the air guide ring is used on the outdoor unit of the air conditioner. When the outdoor unit's speed increases, the noise can be reduced by adjusting the length of the air guide ring. This is mainly based on the principles of fluid mechanics and aerodynamics. The air guide ring plays a role in guiding and rectifying the airflow. Adjusting its length can change the airflow's entry angle and flow path, thereby affecting the noise level generated when the fan speed increases.

[0081] The specific principle is as follows:

[0082] 1. Airflow Rectification: The extended guide ring can make fast, turbulent airflow orderly and stable, reducing airflow turbulence. When the airflow passes through the guide ring, the flow direction is guided more evenly, reducing turbulent collisions between the airflow and the heat exchanger, and reducing noise generation.

[0083] 2. Reduce eddies: Optimized design of the guide ring can reduce eddies formed around the heat exchanger, a significant source of noise. By adjusting the length of the guide ring, airflow distribution can be effectively controlled, reducing eddy formation and thus lowering noise caused by friction and vibration.

[0084] 3. Wind resistance adjustment: The length of the air guide ring also affects the wind resistance entering the outdoor unit. An appropriate length can reduce the wind resistance effect brought by high-speed airflow, allowing the airflow to pass through more smoothly, reducing airflow separation and turbulence caused by wind resistance, thereby reducing noise.

[0085] 4. Mechanical Vibration Suppression: High-speed rotating fans, without proper airflow guidance, are prone to resonance due to uneven airflow resistance, increasing the vibration and noise of mechanical components. Adjusting the length of the airflow guide ring can help disperse or absorb these vibrations, reducing noise propagation.

[0086] Therefore, by adjusting the appropriate length of the air guide ring, the noise of the outdoor unit of the air conditioner during high-speed operation can be effectively controlled and reduced, while maintaining or even improving heat exchange efficiency, achieving quiet and efficient operation. Typically, the speed of a household air conditioner's outdoor unit is below 1000 rpm. Generally, the function of the air guide ring is to improve the airflow structure and reduce turbulence, thereby reducing noise. Table 1 below is a simplified model based on industry experience and experimental data, used to illustrate the impact of the air guide ring extension length on noise at different speeds, and the recommended corresponding data:

[0087] 1. When the fan speed is less than or equal to 600 rpm, in order to reduce noise while ensuring air volume, it is recommended that the guide ring extension length be a1-a2 mm. At this time, the noise level can be controlled at 32-41 dB, which is about 1 dB(A) lower than the existing outdoor unit noise level.

[0088] 2. When the fan speed is 600-800rpm, the extension length of the guide ring can be adjusted to a2-a3mm, which helps to further optimize airflow and reduce noise to 41-48dB, which is about 1dB(A) lower than the noise level of the existing outdoor unit.

[0089] 3. When the fan speed is 800-1000 rpm, due to the increase in speed and airflow velocity, the extension length of the guide ring should be appropriately increased to a3-a4 mm to effectively suppress noise, thereby keeping the noise in the range of 48-54 dB, which is about 2 dB(A) lower than the existing outdoor unit noise level.

[0090] Table 1

[0091] Fan speed rpm Length of baffle mm Noise level dB Noise reduction dB ≤600 a1-a2 32-41 1 600-800 a2-a3 41-48 1 800-1000 a3-a4 48-54 2

[0092] In practical applications, factors such as fan characteristics (e.g., blade design, motor performance), duct design, and installation environment all affect noise levels. Therefore, the above data only serves as a mapping relationship between initial fan speed, guide ring length, and noise. The actual guide ring extension length needs to be dynamically adjusted by real-time noise monitoring during outdoor unit operation and feedback to the system to ensure optimal noise control.

[0093] To more clearly illustrate the solution proposed in this application, a specific implementation method is provided below, such as... Figure 5 As shown, the control method includes a sensor system installed in the outdoor unit's air duct system to detect noise within the outdoor unit's air duct.

[0094] Specifically, the sensor used to detect outdoor unit noise monitors the outdoor unit noise every ΔT interval and records the noise data.

[0095] When the monitored noise data changes, a signal is sent to the outdoor unit controller, which will analyze and determine whether the outdoor unit speed has changed at the two times.

[0096] If the outdoor unit speed does not change, the guide ring remains in its current state and does not change; if the outdoor unit speed changes, the state of the guide ring is adjusted, and the length of the guide ring is adjusted according to the outdoor unit speed, noise, and guide ring length data table.

[0097] First, determine the outdoor unit speed and the preset length variation range of the guide ring at the current speed.

[0098] According to the preset data table, adjust the guide ring length to the shortest length corresponding to the current rotational speed, and begin to extend the guide ring at a constant speed of 1mm / s until the maximum distance within the current range is reached. During this process, every [time period]... Δ Noise data is recorded every 1 second (t=1s). This data corresponds to the noise level at each millimeter of guide ring extension. Based on this noise data within the guide ring adjustment range, the guide ring length is adjusted to the position with the minimum noise level, thus completing one guide ring length adjustment process. During actual outdoor unit operation, the guide ring length can be adjusted in real-time according to the outdoor unit's rotational speed using the above control method, thereby controlling the outdoor unit's noise.

[0099] The specific air guide device control method provided in this application embodiment can control the length of the guide ring according to the real-time fan speed of the air guide device, thereby realizing the expansion and contraction adjustment of the guide ring to adapt to the adjustment of the air guide device under different working conditions. This automated adjustment not only improves the overall performance of the fan, but also effectively reduces the noise generated during the operation of the air guide device.

[0100] Based on the same inventive concept, such as Figure 6 As shown, this application also provides a wind deflector control device 60, the wind deflector control device 60 comprising:

[0101] The target length determination module 61 is used to determine the target length of the guide ring if a preset condition is triggered. The target length is the length of the guide ring when the noise is minimized when the fan speed is kept constant at the current fan speed.

[0102] The triggering preset condition includes any one of the following:

[0103] The noise changed and the fan speed changed;

[0104] Alternatively, the fan speed may change.

[0105] In one embodiment, determining the target length of the guide coil includes:

[0106] Obtain the current fan speed;

[0107] The target length is determined based on the current wind turbine speed.

[0108] Further, determining the target length based on the current wind turbine rotation speed includes:

[0109] The minimum and maximum preset lengths of the guide ring are determined based on the current fan speed.

[0110] The guide ring is controlled to extend from the minimum preset length to the maximum preset length, and the noise change is recorded;

[0111] The length corresponding to the minimum noise level is taken as the target length.

[0112] In another embodiment, determining the target length of the guide coil includes:

[0113] The flow guide ring is controlled to extend from its minimum length to its maximum length, and the noise change is recorded.

[0114] The length corresponding to the minimum noise level is taken as the target length.

[0115] The guide ring control module 62 is used to control the length of the guide ring to the target length, wherein the length of the guide ring is adjustable.

[0116] The air guide device control device provided in this application embodiment determines the target length of the guide ring when a preset condition is triggered. Since the target length is the length of the guide ring when the noise is minimized while maintaining the current fan speed, controlling the guide ring length to the target length results in the minimum noise of the air guide device. This effectively reduces noise and improves the user experience.

[0117] Based on the same inventive concept, such as Figure 7 As shown, this application also provides a wind deflector control system 70, comprising:

[0118] At least one processor 71 and at least one memory 72;

[0119] The memory stores the executable instructions of the processor;

[0120] The processor is configured to perform the wind turbine guide coil method provided in the above embodiments.

[0121] The air guiding device control system provided in this application stores executable instructions of the processor in a memory. When the executable instructions are executed, the processor can determine the target length of the air guide ring when a preset condition is triggered. Since the target length is the length of the air guide ring when the fan speed is kept constant and the noise is minimized, the noise of the air guiding device is minimized when the length of the air guide ring is controlled to the target length. This effectively reduces noise and improves the user experience.

[0122] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0123] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

Claims

1. A method for controlling an air guiding device, characterized in that, The method includes: If a preset condition is triggered, the target length of the guide ring is determined. The target length is the length of the guide ring when the noise is minimized while the fan speed remains constant at the current fan speed. The length of the guide ring is controlled to the target length, wherein the length of the guide ring is adjustable; Determining the target length of the guide coil includes: Obtain the current fan speed; The minimum and maximum preset lengths of the guide ring are determined based on the current fan speed; the minimum and maximum preset lengths are the lower and upper limits of the range of highest fan efficiency corresponding to the current fan speed, respectively. The guide ring is controlled to extend from the minimum preset length to the maximum preset length, and the noise change is recorded; The length corresponding to the minimum noise level is taken as the target length. The triggering preset condition includes any one of the following: The noise changed and the fan speed changed; Alternatively, the fan speed may change.

2. The method according to claim 1, characterized in that, Determining the target length of the guide coil includes: The flow guide ring is controlled to extend from its minimum preset length to its maximum preset length, and the noise change is recorded. The length corresponding to the minimum noise level is taken as the target length.

3. A wind guiding device, characterized in that, The air guiding device, which is described by any one of claims 1-2, includes a guide ring; The guide ring includes at least one telescopic unit; the telescopic unit is capable of changing the length of the guide ring. The telescopic unit includes a first segment, a second segment, and an adjustment device; The first segment and the second segment are nested together; The adjusting device is connected to the first segment and the second segment respectively. The adjusting device is used to adjust the sleeve length of the sleeve portion of the first segment and the second segment. The sleeve length is the overlapping length of the first segment and the second segment.

4. The air guiding device according to claim 3, characterized in that: The adjusting device is a ball screw; The ball screw includes a screw, a nut, balls, and a circulator; The screw is connected to the first segment, and the nut is connected to the second segment; the circulator drives the nut through the ball bearings, so that the nut drives the second segment to move.

5. The air guiding device according to claim 4, characterized in that: The screw is equipped with a limit switch, which is used to cut off the power supply to the circulator when the sleeve length is less than a threshold.

6. The air guiding device according to claim 3, characterized in that, Also includes: A locking unit is used to fix the sleeve length of the first segment and the second segment unchanged when the adjusting device does not adjust the sleeve length.

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