Low-noise evaporative condenser fan ring

Abstract

The utility model discloses a low -noise's evaporation formula condenser fan air ring belongs to refrigeration equipment accessory technical field. In view of the existing fan air ring because of airflow turbulence, aerodynamic disturbance is big etc. and leads to the problem of high noise, it includes annular flow guide air ring, noise reduction fan blade subassembly, cylindrical rotary support frame and streamline noise reduction shell, annular flow guide air ring is located in the front end of air intake and is fixed with shell air intake end, cylindrical rotary support frame is coaxially installed in the shell and is welded with shell inner wall in both ends, and noise reduction fan blade subassembly is located in the air ring air exhaust side behind, is rotatably connected with support frame center drive assembly through the pivot, and the shell wraps up support frame and fan blade subassembly and forms continuous airflow channel. Each structure passes through the grating flow guide, S shape fan blade rib, oval support rod, streamline shell etc. design, and the cooperation reduces airflow turbulence and vibration, realizes low -noise operation, is applicable to industrial refrigeration, air conditioning refrigeration etc. scene.

Description

Technical Field

[0001] This utility model relates to the technical field of refrigeration equipment accessories, specifically to a low-noise fan ring for use in evaporative condensers. Background Technology

[0002] Evaporative condensers are key equipment in refrigeration systems. They use a fan to drive airflow to exchange heat with sprayed water and refrigerant, thereby achieving refrigerant condensation and heat dissipation. The fan shroud, as the core component of the fan, mainly plays the role of guiding airflow, supporting fan components, and protecting the internal structure, directly affecting the airflow and operating noise level of the fan.

[0003] In existing technologies, the fan casing of an evaporative condenser typically consists of a simple annular fan casing, flat or simple curved fan blades, a metal frame support structure, and a straight-walled outer casing. The annular fan casing is often a single annular or sparsely spaced grid structure with poor airflow guidance. When airflow enters the fan, it easily forms impacts and eddies at the inlet, causing turbulent noise. The fan blades often adopt a planar or single-curvature arc design without special noise reduction structures on the blade surface. During rotation, airflow easily separates on the blade surface, generating significant aerodynamic noise. Furthermore, the connection stability between the fan blades and the hub is insufficient, easily exacerbating vibration. The support structure is often a square or cylindrical frame welded with straight rods. The circular cross-section of the support rods strongly obstructs airflow, easily generating turbulent noise. Simultaneously, the connection strength between the support frame and the outer casing is insufficient, easily generating mechanical vibration noise during fan operation. The outer casing is often a straight-walled structure without a smooth transition design on the inner wall. Airflow resistance is high when flowing within the casing, and the outlet lacks a flared or rounded corner structure, allowing airflow to easily collide with the outer casing edge during discharge, further increasing noise. The defects of the existing structure mentioned above result in high overall noise during the operation of the evaporative condenser fan ring, making it difficult to meet the requirements for low-noise equipment in industrial production and civil scenarios. Utility Model Content

[0004] To address the problem of high noise levels caused by poor airflow guidance, large aerodynamic disturbances, significant mechanical vibration, and high airflow resistance in existing evaporative condenser fan rings, this invention provides a low-noise evaporative condenser fan ring. By optimizing the shape, connection method, and layout of each core structure, it achieves smooth airflow, reduced aerodynamic noise, and reduced mechanical vibration, ultimately solving the noise problem of existing technologies.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] This utility model discloses a low-noise evaporative condenser fan ring, comprising an annular guide ring, a noise-reducing fan blade assembly, a cylindrical rotating support frame, and a streamlined noise-reducing outer shell. These components work together to form the overall structure of the low-noise fan ring. The specific connection and structural design are as follows:

[0007] The annular guide vane is located at the air inlet front of the entire air ring. Its outer periphery is fixedly connected to the inner side of the air inlet end of the streamlined noise reduction shell by bolts. The central axis of the annular guide vane coincides with the central axis of the streamlined noise reduction shell, ensuring that the airflow enters smoothly along the axial direction. The annular guide vane is a concentric circle grid structure, composed of 3-5 concentric annular lines and 12-16 radial lines welded together. The diameter of the annular lines increases from the inside to the outside. The radial lines are evenly distributed along the circumference of the annular guide vane. The included angle between adjacent radial lines is 22.5°-30°. The resulting grid mesh is an isosceles trapezoid, and the mesh area gradually increases from the inner circle to the outer circle to adapt to the airflow requirements from the inlet to the fan blades and reduce airflow impact.

[0008] The cylindrical rotating support frame is coaxially disposed inside the streamlined noise-reducing shell. The annular frames at both ends of its axial direction are fixed to the inner wall of the streamlined noise-reducing shell by welding, forming a stable support structure spanning the interior of the shell. The cylindrical rotating support frame is composed of 8-10 axial support rods and 4-6 annular support rods cross-welded together. The axial support rods are evenly distributed circumferentially, and the annular support rods are spaced apart axially. The cross-sections of both the axial support rods and the annular support rods are elliptical, with the major axis aligned with the airflow direction to reduce obstruction to the airflow. A central drive assembly is provided in the axial center of the cylindrical rotating support frame. The central drive assembly is fixedly connected to the annular support rods by 4 radial connecting rods. A bearing mounting groove is provided inside the central drive assembly for mounting bearings to cooperate with the rotation of the noise-reducing fan blade assembly.

[0009] The noise-reducing fan blade assembly is located behind the air outlet side of the annular guide vane. A rotating shaft is located at its center, with both ends of the shaft rotatably connected to the bearing mounting slots of the central drive assembly via bearings, allowing the noise-reducing fan blade assembly to rotate stably around the central axis of the vane. The noise-reducing fan blade assembly also includes a cylindrical hub and fan blades distributed circumferentially along the hub. A keyway is provided at the center of the hub to mate with the rotating shaft, ensuring synchronous rotation between the shaft and the hub. The fan blades are a one-piece molded three-dimensional curved surface structure, with each blade exhibiting an S-shaped curvature transition and a radius of curvature of 80mm. -120mm, the root of the fan blade is welded and fixed to the outer peripheral wall of the hub, the top extends away from the hub, and the fan blade is inclined relative to the radial plane of the hub at an angle of 15°-25°; the surface of the fan blade has several axial ribs evenly distributed along its length, the cross-section of the ribs is semi-circular, which is used to guide the airflow to flow smoothly along the blade surface; the number of fan blades is 9-11, the circumferential spacing between adjacent fan blades is equal, and the thickness of the fan blades gradually decreases from the root to the top, further optimizing aerodynamic performance.

[0010] The streamlined noise-reducing shell is wrapped around the cylindrical rotating support frame and the noise-reducing fan blade assembly. Its inner wall has a smooth transition curve from the air inlet end to the air outlet end to avoid the formation of vortices in the airflow within the shell. The diameter of the air inlet end of the streamlined noise-reducing shell is equal to the maximum outer diameter of the annular guide air ring to ensure that the airflow enters without gaps. The diameter of the middle part of the shell is equal to the outer diameter of the cylindrical rotating support frame to ensure stable installation of the support frame. The diameter of the air outlet end of the shell is 1.2-1.5 times the diameter of the middle part, and the edge of the air outlet end has a rounded transition structure to reduce the resistance and collision noise when the airflow is discharged. Finally, a continuous and stable airflow channel is formed from the air inlet of the annular guide air ring, the airflow guided by the noise-reducing fan blade assembly, through the cylindrical rotating support frame, to the air outlet end of the shell.

[0011] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages compared with the prior art:

[0012] A. Excellent airflow guidance effect: The concentric circular grille structure and isosceles trapezoidal mesh design of the annular guide fan ring guide the airflow evenly and smoothly into the fan along the axial direction, avoiding airflow impact and turbulence at the inlet, reducing airflow at the source.

[0013] Flow noise;

[0014] B. Significantly Reduced Aerodynamic Noise: The S-shaped curved blades, tilt angle, and semi-circular axial rib design of the noise-reducing fan blade assembly reduce airflow separation and vortices on the blade surface. Furthermore, the gradual change in the number and thickness of the blades further optimizes...

[0015] Improved aerodynamic performance and significantly reduced aerodynamic noise;

[0016] C. Reduction of Mechanical Vibration and Turbulent Noise: The elliptical support rods and stable welded structure of the cylindrical rotating support frame provide reliable support for the noise-reducing fan blade assembly, reducing mechanical vibration, and also minimize obstruction to airflow, thus avoiding turbulence.

[0017] noise;

[0018] D. Low airflow resistance: The smooth inner wall of the streamlined noise-reducing shell, the suitable diameter design, and the rounded corner structure at the air outlet can reduce the flow resistance of airflow in the shell, reduce airflow reflection and collision noise, and the various structures work together to achieve overall noise reduction and meet the requirements for low-noise use.

[0019] Other advantages, objectives and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be taught from the practice of this invention. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the assembly of a low-noise evaporative condenser fan ring according to the present invention.

[0021] Figure 2 This is a cross-sectional view of the fan coil unit of a low-noise evaporative condenser according to the present invention.

[0022] Figure 3 This is an exploded view of the fan coil unit of a low-noise evaporative condenser according to this utility model.

[0023] Figure 4 This is a cross-sectional view of the hub portion of the fan ring of a low-noise evaporative condenser according to this utility model.

[0024] Figure 5 This is a partial enlarged view of the fan blades of a low-noise evaporative condenser fan according to this utility model.

[0025] As shown in the figure:

[0026] 1. Annular air guide ring; 2. Noise-reducing fan blade assembly; 3. Cylindrical rotating support frame; 4. Streamlined noise-reducing housing; 21. Shaft; 22. Hub; 23. Fan blade; 24. Axial ribs; 31. Central drive assembly; 32. Bearing mounting slot. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] like Figure 1-5 As shown in the figure, this embodiment provides a low-noise evaporative condenser fan fan ring, the specific structure of which is as follows:

[0031] Annular airflow guide ring 1: A concentric circular grid structure is formed by intersecting and welding 4 concentric annular lines and 14 radial lines. The included angle between adjacent radial lines is 25.7°, resulting in an isosceles trapezoidal mesh with an inner area of ​​25 cm². 2 The outer ring area is 45cm. 2 The outer periphery is fixed to the inner side of the streamlined noise reduction housing 4 air inlet by M8 bolts, and the central axis coincides with the housing axis;

[0032] Noise-reducing fan blade assembly 2: includes a cylindrical hub 22, 10 fan blades 23 and a rotating shaft 21. The hub 22 has a keyway in the center that mates with the rotating shaft 21. The fan blades 23 have an S-shaped curvature radius of 100mm and are inclined at 20° relative to the radial plane of the hub 22. The surface has 7 semi-circular axial ribs 24 (rib height 2mm, spacing 12mm) along the length direction. The fan blades 23 have a root width of 40mm and a thickness of 6mm, a top width of 20mm and a thickness of 3mm, and are welded and fixed to the outer peripheral wall of the hub 22.

[0033] Cylindrical rotating support frame 3: It is composed of 9 axial support rods and 5 ring support rods welded together. The cross-section of the axial support rods and the ring support rods is elliptical (major axis 10mm, minor axis 5mm). The central drive assembly 31 is fixed to the middle of the frame by 4 radial connecting rods. The inner diameter of the bearing mounting groove 32 is adapted to the rotating shaft 21. The ring frame at both ends of the frame is welded and fixed to the inner wall of the streamlined noise reduction shell 4.

[0034] Streamlined noise reduction housing 4: The diameter of the air inlet and the maximum outer diameter of the annular air guide ring 1 are both 500mm, the diameter of the middle part and the outer diameter of the cylindrical rotating support frame 3 are both 480mm, the diameter of the air outlet is 624mm (1.3 times the diameter of the middle part), the radius of the rounded corner of the air outlet is 15mm, and the inner wall is a smooth transition curved surface.

[0035] In this embodiment, when the low-noise evaporative condenser fan ring is running, the airflow smoothly enters through the grid mesh of the annular guide ring 1, is guided by the S-shaped fan blades 23 and axial ribs 24 of the noise-reducing fan blade assembly 2, flows along the gap of the elliptical support rod of the cylindrical rotating support frame 3, and is finally smoothly discharged through the air outlet of the streamlined noise-reducing shell 4. The airflow is not significantly disturbed, separated or collided throughout the process, and the mechanical vibration is small, thus achieving low-noise operation.

[0036] Based on the above implementation scheme, this utility model needs to be adjusted according to specific implementation requirements during use, as follows:

[0037] I. Industrial Refrigeration System Scenarios (Used with Large Evaporative Condensers)

[0038] Connection and installation details with existing technologies / devices

[0039] In existing industrial refrigeration systems, evaporative condensers are typically equipped with high-power drive motors, condenser coil assemblies, and spray systems. The fan coil unit must be linked with the air inlet of the condenser housing and the drive motor. The installation and connection method for this device is as follows:

[0040] The outer periphery of the streamlined noise reduction housing 4 is fixed to the air inlet flange of the existing evaporative condenser housing by M10 high-strength bolts. A sealing gasket is added at the connection to ensure that the gap is less than 1mm to avoid airflow leakage and vibration transmission.

[0041] The rotating shaft 21 of the noise reduction fan blade assembly 2 is coaxially connected to the output shaft of the existing drive motor through an elastic coupling. The elastic buffer structure of the coupling adapts to the fluctuation of motor speed and reduces the transmission of mechanical vibration.

[0042] The ends of the axial support rods of the cylindrical rotating support frame 3 are welded and reinforced to the fixed brackets inside the condenser housing, forming a rigid linkage structure of "shell-housing-support frame" to improve the overall vibration resistance;

[0043] The air inlet side of the annular guide fan ring 1 is aligned with the existing condenser air inlet grille, and the distance between the grille and the fan ring is controlled at 50-80mm to ensure that the airflow enters the guide channel of this device without obstruction.

[0044] Usage status of each structure

[0045] 1. Annular air guide ring: Located at the first airflow guiding position at the front end of the condenser air inlet, 3-5 concentric grilles in the water mist environment of the spray device, through isosceles trapezoidal gradient mesh to sort the mist-containing airflow, avoid water mist impact with the air ring to form water droplet noise, and at the same time guide the airflow to flow precisely to the fan blade area;

[0046] Noise-reducing fan blade assembly 2: Driven by the drive motor, it rotates at a speed of 1200-1500r / min. The 15°-25° tilt angle of the S-shaped curved fan blade 23 is adapted to the high flow rate requirements of industrial refrigeration. The semi-circular axial ribs 24 divide the airflow to prevent water mist from condensing on the blade surface and forming turbulence. The 9-11 equidistantly distributed fan blades balance the rotational inertia and reduce vibration.

[0047] Cylindrical rotating support frame 3: Under the impact of high-speed airflow, the long axis of the support rod along the airflow direction reduces wind resistance. The deep groove ball bearing in the bearing mounting groove 32 of the central drive component 31 bears the combined load of the motor and the fan blade, ensuring rotational accuracy and avoiding eccentric vibration.

[0048] Streamlined noise-reducing housing 4: The smooth curved surface of the inner wall guides the airflow through the area above the condenser coil assembly. The 1.2-1.5 times wider structure at the air outlet connects with the existing air outlet duct of the condenser. The rounded corner transition reduces the collision between the airflow and the duct wall. At the same time, the housing isolates the superimposed transmission of fan blade rotation noise and spray water noise.

[0049] Link Advantage

[0050] Compared to existing simple frame-type fan rings, this device achieves three major optimizations in its linkage with industrial refrigeration systems: First, it is linked with the flexible coupling of the drive motor, reducing the transmission of motor vibration to the fan blades and lowering resonance noise; second, it is sealed and fixed to the condenser housing, avoiding pressure loss and eddy noise caused by airflow leakage; and third, it is linked with the airflow guidance of the spray device, reducing the interference of water mist on airflow through the structural design of the fan ring and fan blades, thus solving the problem of increased noise in traditional fan rings in foggy environments.

[0051] II. Commercial Air Conditioning Refrigeration System Scenarios (Used with Small and Medium-Sized Evaporative Condensers)

[0052] Connection and installation details with existing technologies / devices

[0053] Existing commercial air conditioners typically feature compact evaporative condensers integrated into the outdoor unit, requiring the fan coil unit to be compatible with its miniaturized structure and low-power motor. The connection and installation method for this device is as follows:

[0054] The streamlined noise-reducing housing 4 is fixed to the air intake panel of the existing air conditioning outdoor unit through a snap-on structure, and reinforced with bolts. It is compatible with the lightweight design of the unit and facilitates later maintenance and disassembly.

[0055] The hub 22 of the noise reduction fan blade assembly 2 is directly mounted on the output shaft of the existing low-power motor via a key connection. The bearings at both ends of the shaft 21 are embedded in the bearing mounting groove 32 of the central drive assembly 31, forming a compact linkage structure of "motor-fan blade-support frame".

[0056] After the outer periphery of the annular air guide ring 1 is welded and fixed to the inner side of the air inlet end of the outer shell 4, the whole is aligned with the air inlet filter of the air conditioning unit. The distance between the filter and the air ring is controlled at 30-50mm to achieve a continuous airflow path of "filter dust removal - air ring air guidance".

[0057] The two ends of the cylindrical rotating support frame 3 are bolted to the internal bracket of the air conditioning unit through angle brackets. The frame and the unit shell form a secondary support, which improves the stability of the small unit during operation.

[0058] Usage status of each structure

[0059] 1. Annular air guide ring: A dense grille formed by 12-16 radial lines, which, in the low wind speed environment (8-10m / s) of the air conditioning unit, organizes the airflow filtered by the filter into a uniform axial flow, avoiding backflow noise in the compact space of the small unit.

[0060] Noise-reducing fan blade assembly 2: The S-shaped curvature radius of the fan blade 23 is designed with a small size of 80-100mm to match the speed of low-power motors (800-1200r / min). The semi-circular axial ribs 24 on the blade surface reduce the probability of separation of low-speed airflow. The gradual structure of the fan blade thickness from the root to the top reduces rotational inertia and reduces motor load.

[0061] Cylindrical rotating support frame 3: 8-10 axial support rods with an elliptical cross section (major axis 8-10mm), which balances support strength and air permeability in a compact space. The radial connecting rod of the central drive assembly 31 shortens the lever arm and reduces the impact of vibration on rotational accuracy of small units.

[0062] Streamlined noise-reducing housing 4: The 10-15mm rounded corner transition structure at the air outlet adapts to the air outlet direction of the air conditioning unit (usually upward or sideways), avoiding direct airflow impact on building walls or other equipment. The thin-walled streamlined design of the housing also reduces its own vibration noise, meeting the low noise requirements of commercial scenarios.

[0063] Link Advantage

[0064] Compared to the simple arc-shaped fan ring of existing commercial air conditioners, the core advantages of this device are: first, its compact connection with a low-power motor, which reduces motor energy consumption through optimized fan blade structure and solves the problem of motor overheating caused by high fan blade resistance in traditional fan rings; second, its coordinated fixation with the unit's filter and internal support reduces noise amplified by vibration in small units; and third, its design adapted to the air outlet direction avoids secondary collision noise from airflow, meeting the stringent noise requirements of commercial buildings for outdoor equipment.

[0065] III. Cold Chain Logistics Condensation Equipment Scenarios (Used in conjunction with mobile / vehicle-mounted evaporative condensers)

[0066] Connection and installation details with existing technologies / devices

[0067] Existing vehicle-mounted evaporative condensers in cold chain logistics need to withstand the bumps and vibrations of vehicles during operation, and are usually equipped with anti-vibration brackets and miniaturized drive systems. The connection and installation of this device requires enhanced anti-vibration linkage.

[0068] The streamlined noise reduction housing 4 is fixed to the existing vehicle condenser anti-vibration bracket bolts through shock-absorbing pads. The elastic modulus of the shock-absorbing pads is adapted to the vertical and horizontal vibrations during vehicle operation, reducing the rigid collision between the housing and the condenser box.

[0069] The rotating shaft 21 of the noise reduction fan blade assembly 2 is connected to the central drive assembly 31 through a seated bearing. The bearing seat is equipped with a buffer rubber ring to form a vibration-resistant linkage structure of "rotating shaft-bearing-buffer ring-support frame" to resist the eccentric impact caused by vehicle bumps.

[0070] The outer periphery of the annular air guide ring 1 is connected to the outer shell 4 by a double connection method of welding and bolt reinforcement to prevent the air guide ring from falling off in a vibration environment. A protective net is installed on the air inlet side of the air guide ring, which is linked with the dustproof structure of the vehicle condenser to prevent foreign objects from entering.

[0071] The annular support rod of the cylindrical rotating support frame 3 is welded to the coil fixing bracket of the vehicle condenser to form an integrated anti-vibration structure of "support frame-coil bracket-condenser housing", which improves the overall rigidity.

[0072] Usage status of each structure

[0073] 1. Annular airflow guide ring: A dense grille with 3-4 concentric ring lines quickly sorts out the turbulent airflow in the turbulent environment of vehicle movement. The gradient structure of the isosceles trapezoidal mesh adapts to the instantaneous changes in airflow speed, avoiding vibration and noise caused by airflow impacting the airflow ring.

[0074] Noise Reduction Fan Blade Assembly 2: The root thickness of the fan blade 23 is thickened by 5-8mm to improve vibration resistance. The high curvature (100-120mm) of the S-shaped surface design can still maintain stable airflow when the fan blade is slightly eccentric due to vehicle bumps. The axial ribs 24 enhance the rigidity of the blade surface and prevent the fan blade from vibrating and deforming.

[0075] Cylindrical rotating support frame 3: The short axis direction (4-6mm) of the elliptical support rod enhances the bending strength. The four radial connecting rods are firmly welded to the central drive assembly 31 to ensure the positional accuracy of the bearing mounting groove 32 and avoid bearing wear and increased noise caused by vibration.

[0076] Streamlined noise reduction housing 4: The smooth curved surface of the inner wall reduces the probability of turbulence in the airflow in the vibration environment. The gradually expanding structure of the air outlet adapts to the side air outlet requirements of the vehicle condenser. The overall streamlined design of the housing reduces wind resistance when the vehicle is driving, while isolating the combined noise of the fan blades and road bumps.

[0077] Link Advantage

[0078] Compared to the simple fan rings of existing vehicle-mounted condensers, the core linkage of this device solves key pain points in mobile scenarios: First, the linkage with the anti-vibration bracket and shock-absorbing pad reduces the transmission of vehicle vibration to the fan ring assembly, solving the problem of increased noise in traditional fan rings during bumpy rides; second, the integrated fixation with the coil rack improves overall vibration resistance and avoids mechanical noise caused by loose components; third, the linkage with the dustproof protection structure enhances the durability of the fan ring while ensuring low noise, making it suitable for the harsh operating environment of cold chain logistics.

[0079] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A low-noise evaporative condenser fan fan ring, characterized in that, It includes an annular airflow guide ring (1), a noise-reducing fan blade assembly (2), a cylindrical rotating support frame (3), and a streamlined noise-reducing shell (4); The annular guide air ring (1) is located at the air inlet front end of the entire air ring. Its outer periphery is fixedly connected to the inner side of the air inlet end of the streamlined noise reduction shell (4) by bolts, and the central axis of the annular guide air ring (1) coincides with the central axis of the streamlined noise reduction shell (4). The cylindrical rotating support frame (3) is coaxially arranged inside the streamlined noise reduction shell (4), and the annular frame at both ends of its axial direction is fixed to the inner wall of the streamlined noise reduction shell (4) by welding, forming a support structure spanning the inside of the shell. The noise reduction fan blade assembly (2) is located behind the air outlet side of the annular guide air ring (1), and is rotatably connected to the central drive assembly (31) of the cylindrical rotating support frame (3) through the rotating shaft (21) at its center. The two ends of the rotating shaft (21) are engaged with the central drive assembly (31) through bearings, so that the noise reduction fan blade assembly (2) can rotate around the central axis. The streamlined noise-reducing shell (4) is wrapped around the cylindrical rotating support frame (3) and the noise-reducing fan blade assembly (2). Its inner wall has a smooth transition from the air inlet end to the air outlet end, forming a continuous airflow channel from the annular guide air ring (1), through the noise-reducing fan blade assembly (2), through the cylindrical rotating support frame (3) to the air outlet end of the shell.

2. The low-noise evaporative condenser fan coil unit according to claim 1, characterized in that, The annular guide wind ring (1) is a concentric circular grid structure, which is composed of 3-5 concentric annular lines and 12-16 radial lines welded together. The diameter of the annular lines increases from the inside to the outside. The radial lines are evenly distributed along the circumference of the annular guide wind ring (1). The included angle between adjacent radial lines is 22.5°-30°. The grid mesh formed is an isosceles trapezoid, and the mesh area gradually increases from the inner circle to the outer circle.

3. The low-noise evaporative condenser fan coil unit according to claim 1, characterized in that, The noise reduction fan blade assembly (2) includes a hub (22) and fan blades (23) distributed circumferentially along the hub (22). The hub (22) is cylindrical and has a keyway in the center that mates with the rotating shaft (21). The fan blade (23) is a three-dimensional curved structure formed in one piece. The blade surface of each fan blade (23) has an S-shaped curvature transition with a curvature radius of 80mm-120mm. The root of the fan blade (23) is welded and fixed to the outer peripheral wall of the hub (22). The top extends away from the hub (22), and the fan blade (23) is inclined relative to the radial plane of the hub (22) with an inclination angle of 15°-25°. The surface of the fan blade (23) has several axial ribs (24) evenly distributed along its length. The cross-section of the ribs is semi-circular, which is used to guide the airflow.

4. The low-noise evaporative condenser fan fan ring according to claim 1, characterized in that, The cylindrical rotating support frame (3) is composed of 8-10 axial support rods and 4-6 ring support rods welded together. The axial support rods are evenly distributed along the circumference, and the ring support rods are spaced apart along the axial direction. The central drive assembly (31) is located in the axial middle of the cylindrical rotating support frame (3) and is fixedly connected to the ring support rods by 4 radial connecting rods. The inner ring of the central drive assembly (31) is provided with a bearing mounting groove (32) corresponding to the rotating shaft (21).

5. The low-noise evaporative condenser fan coil unit according to claim 1, characterized in that, The diameter of the air inlet of the streamlined noise reduction shell (4) is equal to the maximum outer diameter of the annular guide ring (1), the diameter of the middle part of the shell is equal to the outer diameter of the cylindrical rotating support frame (3), the diameter of the air outlet of the shell is 1.2-1.5 times the diameter of the middle part, and the edge of the air outlet is a rounded transition structure.

6. The low-noise evaporative condenser fan fan ring according to claim 3, characterized in that, The number of fan blades (23) is 9-11, the circumferential spacing between adjacent fan blades (23) is equal, and the thickness of the fan blades (23) gradually decreases from the root to the top.

7. The low-noise evaporative condenser fan coil unit according to claim 4, characterized in that, Both the axial support rod and the annular support rod have elliptical cross-sections, with their major axes aligned with the airflow direction.

Images