Centrifugal fan, ducted fan and air conditioning system
By setting concave and convex guide surfaces in the air outlet duct of the centrifugal fan, the airflow path is optimized, which solves the problem of high noise in ducted air conditioners and achieves the effect of noise reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- QINGDAO HAIER AIR CONDITIONER GENERAL CORP LTD
- Filing Date
- 2025-05-29
- Publication Date
- 2026-06-16
Smart Images
Figure CN224364097U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of duct air conditioning technology, specifically providing a centrifugal fan, a duct air conditioning unit, and an air conditioning system. Background Technology
[0002] In modern air conditioning systems, ducted air conditioners are a common type of air conditioning equipment, generally employing centrifugal fans to drive airflow through the evaporator. The principle behind this operating mode is that the centrifugal fan uses the centrifugal force generated by its rotating impeller to draw in and accelerate air, then guides the high-speed airflow towards the evaporator. At the evaporator, the air comes into full contact with the low-temperature evaporator surface, achieving heat exchange, and is then blown out from the exhaust vent of the ducted air conditioner, thus achieving the purpose of air conditioning.
[0003] However, due to the inherent wind resistance of the evaporator and its location at the outlet of the centrifugal fan, the airflow discharged by the centrifugal fan is obstructed, resulting in poor airflow. When the volute outlet uses a straight volute tongue structure, the vortex phenomenon is even more severe. These vortices not only interfere with the normal airflow but also generate discrete noise. This noise problem not only reduces the user experience but can also cause noise pollution to the surrounding environment, and the problem is particularly prominent in places with high requirements for quietness, such as bedrooms, offices, and conference rooms.
[0004] Therefore, a new technical solution is needed in this field to solve the above problems. Utility Model Content
[0005] This application aims to solve the above-mentioned technical problem, namely, to solve the problem of excessive noise when the centrifugal fan in the existing duct air conditioner blows air.
[0006] In a first aspect, this application provides a centrifugal fan, comprising:
[0007] The volute has an air inlet and an air outlet;
[0008] An impeller is disposed inside the volute, and the impeller divides the volute into an air inlet channel and an air outlet channel;
[0009] A flow guide is disposed within the air outlet channel and close to the air outlet, and the flow guide has a concave-convex flow guide surface.
[0010] Optionally, the guide surface extends in a wave shape along a first direction, which is the axial direction of the impeller.
[0011] Optionally, the length of the impeller in the first direction is a, the guide surface has crests and troughs in the first direction, and the distance between the crests and the troughs in the first direction is c, where 0.3a≤c≤0.5a.
[0012] Optionally, multiple peaks and troughs are provided, and the peaks and troughs are alternately distributed along the first direction.
[0013] Optionally, the air outlet channel includes a first sidewall and a second sidewall disposed opposite to each other. The guide member is disposed on the first sidewall. The distance between the wave crest and the second sidewall gradually increases along a second direction, and the distance between the wave trough and the second sidewall gradually increases along the second direction, where the second direction is the airflow direction. Optionally, the air outlet channel further includes a third sidewall and a fourth sidewall disposed opposite to each other. The distance between the third sidewall and the fourth sidewall is b, where 1.1a ≤ b ≤ 1.3a.
[0014] Optionally, the flow guide is detachably connected to the volute.
[0015] Optionally, the guide element is integrally formed with the volute.
[0016] In a second aspect, this application provides a duct air conditioner, including a centrifugal fan as described in any one of the first aspects.
[0017] In a third aspect, this application provides an air conditioning system, including a ducted air conditioner as described in the second aspect.
[0018] When the above technical solution is adopted, the centrifugal fan provided in this application has a concave-convex guide surface at its air outlet. When the fan is running, the guide surface can effectively improve the airflow and reduce airflow turbulence, thereby significantly reducing noise.
[0019] This application provides a duct air conditioner including the aforementioned centrifugal fan. When the centrifugal fan is applied in the duct air conditioner of this application, the duct air conditioner can also effectively reduce noise during operation by utilizing the noise reduction characteristics of the centrifugal fan. The specific principles and related content of centrifugal fan noise reduction have been explained in detail above and will not be repeated here.
[0020] This application provides an air conditioning system that uses the ducted air conditioner mentioned above. The ducted air conditioner described in detail above, equipped with a centrifugal fan featuring a guide surface at the air outlet, effectively reduces noise during operation. When such a high-performance ducted air conditioner is applied to the air conditioning system of this application, the entire air conditioning system also benefits from the noise reduction advantage of the ducted air conditioner, significantly reducing noise generation during operation. Attached Figure Description
[0021] The preferred embodiments of this application are described below with reference to the accompanying drawings, in which:
[0022] Figure 1 This is a schematic diagram of the internal structure of a ductwork unit according to an embodiment of this application;
[0023] Figure 2 yes Figure 1 A side view of the structure of a central duct air conditioning unit;
[0024] Figure 3 This is a schematic diagram of a volute using a straight volute tongue structure in the prior art;
[0025] Figure 4 This is a schematic diagram of the structure of a volute according to an embodiment of this application;
[0026] Figure 5 yes Figure 4 A front view schematic diagram of the volute structure in the image;
[0027] Figure 6 This is a schematic diagram of the structure of a volute cut along its central plane according to an embodiment of this application;
[0028] Figure 7 This is a schematic diagram of the volute casing cut along section 1 according to an embodiment of this application;
[0029] Figure 8 This is a schematic diagram of the volute casing cut along section 2 according to an embodiment of this application;
[0030] Figure 9 This is a schematic diagram of the volute casing cut along section 3 according to an embodiment of this application;
[0031] Figure 10 This is a schematic diagram of the volute casing cut along section 4 according to an embodiment of this application;
[0032] Figure 11 This is a schematic diagram of the structure of the volute along section 5 according to an embodiment of this application;
[0033] Figure 12 This is a schematic diagram comparing the noise levels of the centrifugal fan provided in this embodiment with those of a centrifugal fan using a straight volute tongue structure, based on simulation analysis.
[0034] List of reference numerals in the attached diagram:
[0035] 100 - Ductless air conditioner; 101 - Evaporator;
[0036] 102-Centrifugal fan, 11-Volume, 1101-Air inlet, 1102-Air outlet, 111-First sidewall, 112-Second sidewall, 113-Third sidewall, 114-Fourth sidewall, 12-Impeller, 131-Guide surface, 1301-Crest, 1302-Trough, 20-Straight volute tongue. Detailed Implementation
[0037] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.
[0038] It should be noted that in the description of this application, terms such as "upper," "lower," "left," "right," "inner," and "outer," which indicate direction or positional relationship, are based on the direction or positional relationship shown in the accompanying drawings. These terms are used merely for ease of description and do not indicate or imply that the relevant device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, ordinal numbers such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0039] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0040] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the centrifugal fan 102 installed in the duct unit 100 according to the present application. Figure 2 yes Figure 1 A simplified schematic diagram of the left-side structure of the 100-type central duct unit. Figure 1 and Figure 2 The arrows in the diagram indicate the direction of airflow.
[0041] Specifically, the centrifugal fan 102 provided in this embodiment includes a volute 11 and an impeller 12 disposed within the volute 11. The volute 11 adopts a spirally expanding cavity design, with an axial air inlet 1101 at its front end for drawing in ambient air, and a rectangular cross-section air outlet 1102 extending laterally to achieve directional air delivery. The impeller 12, as a power source, is installed inside the volute 11. The centrifugal force generated when it rotates converts the air from axial intake to radial discharge, thereby naturally separating the air inlet channel and the air outlet channel within the volute 11.
[0042] As the airflow accelerates from the inlet channel through the impeller 12 and flows to the outlet channel, and is finally delivered from the outlet 1102, a volute tongue is needed to guide the airflow direction to prevent some high-speed airflow from forming a recirculation inside the volute 11, ensuring that the airflow is efficiently output along the designed path. The volute tongue refers to the flow guiding structure on the inner side of the outlet 1102 of the volute 11 adjacent to the outer edge of the impeller 12. Its geometric characteristics directly affect the airflow separation state, and thus affect the fan efficiency and noise level.
[0043] refer to Figure 3 , Figure 3 A schematic diagram of a volute using a straight volute tongue 20 is shown, where the straight volute tongue 20 has a rectangular cross-section and is essentially flush with the outlet wall. As described in the background section, because the edge of the straight volute tongue 20 near the impeller is relatively straight, when the impeller rotates at high speed, the airflow is instantly forced to change direction at the volute tongue. During this process, the airflow collides and rubs violently with the edge of the straight volute tongue 20, breaking the originally relatively stable airflow state and forming a large number of turbulence and vortices. These turbulence and vortices continuously rotate and interact inside the volute, making the pressure and velocity distribution of the airflow extremely uneven. This uneven airflow state can cause rotational noise.
[0044] In view of this, refer to Figure 4 In this embodiment, the volute 11 is provided with a novel flow guide in the air outlet channel near the air outlet 1102. The flow guide has a concave-convex flow guide surface 131, which can effectively rectify turbulent airflow: when the airflow passes through the flow guide, the concave-convex surface of the flow guide can guide the airflow to change direction, so that the unstable airflow flows along a specific path, transforming turbulence and eddies into relatively stable laminar flow, thereby improving the pressure and velocity distribution of the airflow, making it more uniform, and thus reducing the pressure and velocity differences in the entire airflow channel. The orderly airflow can reduce the intense friction noise between the airflow and the volute 11, and also avoid the noise generated by the airflow colliding with each other, thereby reducing the noise during the operation of the fan.
[0045] In one embodiment, the flow guide and the volute 11 are integrally formed. The integral design avoids problems such as gas leakage and turbulence caused by the connection parts, allowing the fluid to pass through the flow guide more smoothly, thereby achieving the purpose of noise reduction.
[0046] In another embodiment, the flow guide is detachably connected to the volute 11. This method facilitates the easy replacement of the flow guide to meet different usage needs when the product is updated or its performance is upgraded, thus improving the product's flexibility and adaptability.
[0047] In a preferred embodiment, refer to Figure 5The guide surface 131 is a wave-shaped surface extending along a first direction, and the wave-shaped guide surface 131 has multiple crests 1301 and troughs 1302. The crests 1301 and troughs 1302 are alternately distributed along the first direction to form a continuous curved surface, where the first direction refers to the axial direction of the impeller 12. Since the wave-shaped guide surface 131 is a continuous curved structure, the impact of the airflow when it comes into contact with it is small. When flowing along the wave-shaped surface, it can achieve continuous and smooth turning, thereby reducing the noise generated by the airflow impact.
[0048] Furthermore, the noise reduction performance of the wave-shaped guide surface 131 can be optimized by adjusting its shape in the first direction (impeller 12 axis direction) and its shape in the second direction (airflow direction).
[0049] In one embodiment, the shape of the wave-shaped guide surface 131 in the second direction is first optimized: in conjunction with reference Figure 4 and Figure 5 The air outlet duct includes a first sidewall 111 and a second sidewall 112 arranged opposite to each other. The air guide is disposed on the first sidewall 111. The distance between the wave crest 1301 and the second sidewall 112 gradually increases along the second direction, and the distance between the wave trough 1302 and the second sidewall 112 gradually increases along the second direction. That is, the air duct in the area of the air guide surface 131 gradually expands. When air flows over this air guide surface 131, the airflow speed decreases because the air duct gradually expands. The noise energy of different frequencies will decrease step by step, thereby reducing noise.
[0050] In one embodiment, reference Figure 6 The geometric angle α formed by the extension line of the lateral wall of the volute tongue and the tangent of the curved lateral wall at the connection point is determined through experimental simulation. When the range of the angle α is 175°... 0 ~180 0 When the connection between the volute tongue sidewall and the curved sidewall is nearly tangential, the noise generated by the fan is relatively low. Furthermore, the included angle α also affects demolding quality. Specifically, after the product is formed, it needs to be ejected from the mold. If the connection between the volute tongue sidewall and the curved sidewall is unreasonable, it may lead to difficulties in demolding, or even damage to the product or the mold during the demolding process. A near-tangential connection design makes the product's shape within the mold more regular, allowing it to eject from the mold along a smoother path during demolding, reducing resistance and friction.
[0051] In this embodiment, the included angle α is selected as 179°. 0 This is the preferred option.
[0052] In one embodiment, reference Figure 5The air outlet duct includes a third sidewall 113 and a fourth sidewall 114 arranged opposite to each other. The distance between these two sidewalls is represented by the letter b, and the length of the impeller 12 in the first direction is represented by the letter a. Wherein, 1.1a≤b≤1.3a, that is, the width of the air outlet duct is slightly larger than the axial distance of the impeller 12. This can avoid the problem of the air outlet duct being too narrow, which would obstruct the smooth flow of air and cause noise and vibration problems; it can also avoid the problem of the air outlet duct being too wide, which may cause waste of space and increase the size and cost of the equipment.
[0053] In one specific embodiment, the distance between the crests 1301 and troughs 1302 of the guide surface 131 in the first direction is c, that is, the spacing between each wave undulation is c. Aeroacoustic simulation experiments revealed that to achieve better noise reduction, the distance c between the crests 1301 and troughs 1302 in the first direction must be controlled within a certain range. Experimental data show that when this range is 0.3a ≤ c ≤ 0.5a, the guide plate can reduce the sound pressure level in the main noise frequency band while maintaining airflow efficiency.
[0054] In a preferred embodiment, continue to refer to Figure 5 The figure shows the structure of the wave-shaped guide surface 131, which has two peaks 1301 and one trough 1302, and the guide surface 131 is symmetrical about the central surface of the air outlet 1102 along the first direction.
[0055] The following describes in detail the construction of the parametric model based on the guide surface 131. This model is constructed by abstracting the geometric features of the guide surface 131, defining the cross-sectional parameter association, and embedding constraint conditions.
[0056] Specifically, taking the half-side guide surface 131 near the third sidewall 113 as the research object, a mathematical representation of its geometric parameters is established. Based on the center plane as the reference plane, the guide surface 131 is longitudinally cut along a direction perpendicular to the first direction, and cut surfaces 1 to 5 are selected. Figure 5 As shown by the dashed line, these five sections are section 1, section 2, section 3, section 4, and section 5, which are directed along the central plane toward the third sidewall 113. The distances of the five sections to the central plane are represented by L1, L2, L3, L4, and L5, respectively. After simulation testing, the values of L1 = 0.11b, L2 = 0.22b, L3 = 0.33b, L4 = 0.39b, and L5 = 0.5b were obtained. Here, b represents the distance between the third sidewall 113 and the fourth sidewall 114 mentioned above. It can be seen that section 5 coincides with the third sidewall 113.
[0057] Further, refer to Figure 6-11 , Figure 6-11The diagrams show the volute structure cut along the central plane and sections 1 to 5, respectively. First, the impeller diameter is defined as Φ, and the planes containing the impeller's central axis are the X plane and the Y plane (the two planes are perpendicular to each other and their intersection is the axis). Based on this coordinate system, the geometric features of the guide surface 131 are further quantified: the normal distance from the vertex of the wavy guide surface 131 at each section to the second sidewall 112 is D, and the normal distance to the Y plane is d. At the same time, the spatial angle between the local contour line of the guide surface 131 and the X plane is defined as θ.
[0058] Specifically Figure 6 A schematic diagram of the volute structure cut along the central plane is shown. D0 represents the normal distance from the vertex of the wavy guide surface 131 at the central plane to the second sidewall 112, d0 represents the normal distance from the vertex of the wavy guide surface 131 at the central plane to the Y-plane, and θ0 represents the spatial angle between the outline of the wavy guide surface 131 at the central plane and the X-plane. Where D0 = 0.6Φ, d0 = 0.61Φ, and θ0 = 16... 0 .
[0059] Figure 7 A schematic diagram of the volute structure cut along section 1 is shown. D1 represents the normal distance from the vertex of the wavy guide surface 131 at section 1 to the second sidewall 112, d1 represents the normal distance from the vertex of the wavy guide surface 131 at section 1 to the Y-plane, and θ1 represents the spatial angle between the outline of the wavy guide surface 131 at section 1 and the X-plane. Where D1 = 0.6Φ, d1 = 0.61Φ, and θ1 = 16... 0 .
[0060] Figure 8 A schematic diagram of the volute structure cut along section 2 is shown. D2 represents the normal distance from the vertex of the wavy guide surface 131 at section 2 to the second sidewall 112, d2 represents the normal distance from the vertex of the wavy guide surface 131 at section 2 to the Y-plane, and θ2 represents the spatial angle between the outline of the wavy guide surface 131 at section 2 and the X-plane. Where D2 = 0.54Φ, d2 = 0.61Φ, and θ2 = 13... 0 .
[0061] Figure 9 A schematic diagram of the volute structure cut along section 3 is shown. D3 represents the normal distance from the vertex of the wavy guide surface 131 at section 3 to the second sidewall 112, d3 represents the normal distance from the vertex of the wavy guide surface 131 at section 3 to the Y-plane, and θ3 represents the spatial angle between the outline of the wavy guide surface 131 at section 3 and the X-plane. Where D3 = 0.46Φ, d3 = 0.61Φ, and θ3 = 12... 0 .
[0062] Figure 10A schematic diagram of the volute structure cut along section 4 is shown. D4 represents the normal distance from the vertex of the wavy guide surface 131 at section 4 to the second sidewall 112, d4 represents the normal distance from the vertex of the wavy guide surface 131 at section 4 to the Y-plane, and θ4 represents the spatial angle between the outline of the wavy guide surface 131 at section 4 and the X-plane. Where D4 = 0.45Φ, d4 = 0.59Φ, and θ4 = 17°. 0 .
[0063] Figure 11 A schematic diagram of the volute structure cut along section 5 is shown. D5 represents the normal distance from the vertex of the wavy guide surface 131 at section 5 to the second sidewall 112, d5 represents the normal distance from the vertex of the wavy guide surface 131 at section 5 to the Y-plane, and θ5 represents the spatial angle between the outline of the wavy guide surface 131 at section 5 and the X-plane. Where D5 = 0.47Φ, d5 = 0.59Φ, and θ5 = 30°. 0 .
[0064] Furthermore, combined Figure 6 The geometric sectional relationship between the center plane and the tangent planes 1 to 5 is defined. The radius of curvature of the continuous arc segment at the connection between the bottom surface of the guide surface 131 and the volute curve is defined as R. Its value range is determined by simulation test to be 0.05Φ≤R≤0.1Φ.
[0065] The data regarding the structure of the guide surface 131 mentioned above were obtained through rigorous simulation experiments. Therefore, refer to... Figure 12 In the experiment, we compared the proposed guide surface 131 structure with the traditional straight volute tongue 20 structure. By recording and analyzing relevant data, we plotted a noise reduction value comparison curve. The curve clearly shows that the guide surface 131 structure determined using this data has a significant noise reduction effect. This result fully demonstrates that the wave-shaped guide surface 131 design has outstanding advantages in noise reduction, providing an important reference for the optimization and improvement of related products.
[0066] This application provides a duct air conditioner 100, including the centrifugal fan 102 as described above. (Reference) Figure 1 , Figure 1The diagram shows two centrifugal fans 102 arranged side-by-side inside the duct unit 100. As mentioned earlier, each centrifugal fan 102 has a concave-convex guide surface 131 at its outlet 1102. During operation, this guide surface 131 effectively improves airflow and reduces airflow turbulence, thereby significantly reducing noise. Therefore, when this centrifugal fan 102 is applied to the duct unit 100 in this embodiment, the duct unit 100 can also effectively reduce noise during operation by utilizing the noise reduction characteristics of the centrifugal fan 102. The specific principles and related content regarding the noise reduction of the centrifugal fan 102 have been explained in detail above and will not be repeated here.
[0067] This application provides an air conditioning system that uses the ducted air conditioner 100 mentioned above. The ducted air conditioner 100, described in detail above, is equipped with a centrifugal fan 102 with a guide surface 131 at the air outlet 1102, which effectively reduces noise during operation. When this high-performance ducted air conditioner 100 is applied to the air conditioning system of this embodiment, the entire air conditioning system also benefits from the noise reduction advantage of the ducted air conditioner 100, significantly reducing noise generation during operation.
[0068] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.
Claims
1. A centrifugal fan (102), characterized in that, include: The volute (11) has an air inlet (1101) and an air outlet (1102); An impeller (12) is disposed inside the volute (11), and the impeller (12) divides the volute (11) into an air inlet channel and an air outlet channel; A flow guide is disposed within the air outlet channel and near the air outlet (1102), and the flow guide has a concave-convex flow guide surface (131).
2. The centrifugal fan (102) according to claim 1, characterized in that, The guide surface (131) extends in a wave shape along a first direction, which is the axial direction of the impeller (12).
3. The centrifugal fan (102) according to claim 2, characterized in that, The length of the impeller (12) in the first direction is a, the guide surface (131) has a crest (1301) and a trough (1302) in the first direction, and the distance between the crest (1301) and the trough (1302) in the first direction is c, where 0.3a≤c≤0.5a.
4. The centrifugal fan (102) according to claim 3, characterized in that, Multiple peaks (1301) and valleys (1302) are provided, and the peaks (1301) and valleys (1302) are alternately distributed along the first direction.
5. The centrifugal fan (102) according to claim 3, characterized in that, The air outlet channel includes a first sidewall (111) and a second sidewall (112) arranged opposite to each other. The guide is disposed on the first sidewall (111). The distance between the wave crest (1301) and the second sidewall (112) gradually increases along a second direction. The distance between the wave trough (1302) and the second sidewall (112) gradually increases along the second direction. The second direction is the flow direction of the airflow.
6. The centrifugal fan (102) according to claim 3, characterized in that, The air outlet channel also includes a third side wall (113) and a fourth side wall (114) arranged opposite to each other, the distance between the third side wall (113) and the fourth side wall (114) is b, where 1.1a≤b≤1.3a.
7. The centrifugal fan (102) according to any one of claims 1 to 6, characterized in that, The flow guide is detachably connected to the volute (11).
8. The centrifugal fan (102) according to any one of claims 1 to 6, characterized in that, The guide component is integrally formed with the volute (11).
9. A ducted air conditioner (100), characterized in that, Includes the centrifugal fan (102) as described in any one of claims 1 to 8.
10. An air conditioning system, characterized in that, Includes the duct unit (100) as described in claim 9.