Collectors, centrifugal fans and air conditioning systems

Abstract

The present invention discloses a collector, a centrifugal fan and an air conditioning system. The inner edge of the inlet of the collector is provided with a non-circular flow-guiding structure, and the non-circular flow-guiding structure is obtained by sweeping the side wall profile along the end face profile; the end face profile is formed by at least four arc segments connected in a closed loop, and the end face profile includes two groups of profile combinations, each group of profile combinations is composed of two symmetrically arranged fixed arcs, and the symmetry axes of the two groups of profile combinations are perpendicular to each other. The present invention designs a non-circular flow-guiding structure at the inlet of the collector, and effectively reduces the restriction on the inlet air volume through the non-circular flow-guiding structure, reduces the low-speed area of ​​the volute air outlet, optimizes the uniformity of the volute outlet wind speed distribution, and increases the air volume of the centrifugal fan.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal fans, and in particular to a collector, a centrifugal fan and an air conditioning system. Background Technology

[0002] The collector is usually used in centrifugal fans. Its function is to guide the gas to the impeller of the centrifugal fan, so that the airflow can establish a uniform velocity field and pressure field at the front section of the fan inlet to improve the fan efficiency. The structure, form and size of the collector all affect the air intake condition of the multi-blade centrifugal fan. For example Figure 1 As shown in the figure, the traditional collectors are in the form of cylinder A, cone B, arc C and cone D, among which the performance of arc C and cone D is superior to that of cylinder A and cone B.

[0003] The above four types of collectors are all circular straight tube collectors, which are obtained by sweeping the corresponding side wall profile along the circular end profile. The circular collector has a better impeller envelope, which is conducive to the stable entry of the inlet airflow into the impeller area. However, this design method is based on the ideal state of uniform flow velocity distribution on each cross section of the collector at the volute inlet.

[0004] However, in the actual operation of the fan, the gas flow in the volute is a three-dimensional flow. Since the work capacity of the impeller changes with the blade height, and the air intake conditions of the impeller also change with the blade height, the flow distribution on the collector cross section at the volute inlet is not uniform, which leads to a certain restriction of the inlet air volume by the traditional circular collector. The limited inlet air volume will aggravate the uneven distribution of the air flow velocity in the height direction of the volute outlet. In addition, due to the inconsistent direction of the air flow at the impeller outlet, the air flow velocity distribution along the width direction of the volute outlet is also uneven, resulting in an obvious low-speed area at the volute outlet and low air volume of the centrifugal fan.

[0005] Therefore, how to design a collector that can effectively increase the air volume is a technical problem that needs to be solved urgently in the industry. SUMMARY OF THE INVENTION

[0006] In order to solve the above defects in the prior art, the present invention proposes a collector, a centrifugal fan and an air conditioning system. The non-circular flow guide structure of the collector can effectively reduce the restriction on the inlet air volume, reduce the low-speed area of ​​the volute air outlet, optimize the uniformity of the volute outlet wind speed distribution, and increase the air volume of the centrifugal fan.

[0007] The technical solution adopted by the present invention is that a non-circular flow-guiding structure is provided at the inner edge of the inlet of the collector, and the non-circular flow-guiding structure is obtained by sweeping the side wall profile along the end face profile; the end face profile is formed by at least 2n arc segments connected in a closed loop, and the end face profile includes n groups of profile combinations, each group of profile combinations is composed of two symmetrically arranged fixed arcs, and n is a positive integer.

[0008] In one embodiment, the end face profile includes two sets of profile combinations. Each set of profile combinations is composed of two shaped arcs arranged symmetrically, and the symmetry axes of the two sets of profile combinations are perpendicular to each other.

[0009] Furthermore, the two sets of profile combinations are the first profile combination and the second profile combination respectively. The shaped arc of the first profile combination is the first shaped arc, and the shaped arc of the second profile combination is the second shaped arc.

[0010] Taking the intersection point O of the symmetry axes of the two sets of profile combinations as the coordinate origin, the formula of the end face profile is:

[0011]

[0012] Wherein, the value range of c is: b < c < a. a is the radius of the first shaped arc, c is the radius of the second shaped arc, b is the radius of the inner circle with the intersection point O of the symmetry axes as the center and tangent to the end face profile, and β is the angle between the end point of the second shaped arc and the midpoint of the first shaped arc on the same side.

[0013] Furthermore, the value of β changes with the change of the size of c, and the value range of β is 0° to 90°.

[0014] In some embodiments, when c = 0.5×(a + b), β is 65.4°.

[0015] In some embodiments, the value of a is equal to the outlet radius of the centrifugal fan blade of the centrifugal fan where the air collector is located, and the value of b is equal to the inlet radius of the centrifugal fan blade of the centrifugal fan where the air collector is located.

[0016] Furthermore, to make the transition at the connection of the two sets of profile combinations smoother, the two sets of profile combinations are connected by at least one transition arc, and the transition arcs on both sides of each set of profile combinations are symmetrically arranged.

[0017] Furthermore, an installation flange is provided at the outer edge of the inlet of the air collector. The installation flange is provided with circular arc through holes arranged at intervals around the central axis of the air collector. Bolts pass through the circular arc through holes and are fixed on the volute. In actual use, according to different volute forms and different air volumes, etc., the air collector can be rotated to adjust the installation angle between it and the volute to adapt to the required working conditions.

[0018] The present invention also provides a centrifugal fan, including: a volute, a centrifugal fan blade installed in the volute, a motor for driving the centrifugal fan blade to rotate, and the above-mentioned air collector installed at the air inlet of the volute. Air flows through the non-circular flow guiding structure to the centrifugal fan blade.

[0019] In some embodiments, the angle between the plane where the air outlet of the volute is located and the symmetry axis of the second profile combination is α, and the angle is 90°.

[0020] Furthermore, the outlet of the air collector is close to the inlet of the centrifugal fan blade.

[0021] The present invention also provides an air conditioning system, including: the above-mentioned centrifugal fan.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The inner edge of the inlet of the air collector is provided with a non-circular flow guiding structure, which can effectively reduce the restriction of the air collector on the inlet air volume, increase the air intake volume, reduce the area of the low-speed zone at the outlet of the volute, and improve the air outlet uniformity and air outlet volume;

[0024] 2. The outer edge of the inlet of the air collector is provided with an installation border, and a number of circular arc through holes are arranged on the installation border, which can adjust the installation angle of the air collector according to different volute forms and different air volumes, and enhance the adaptability of the centrifugal fan under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be described in detail below with reference to the embodiments and the drawings, wherein:

[0026] Figure 1 is a side view schematic diagram of various forms of the air collector;

[0027] Figure 2 is an assembly schematic diagram of the centrifugal fan in the present invention;

[0028] Figure 3 is an end view schematic diagram of the air collector in the present invention;

[0029] Figure 4 is a schematic diagram of the end face profile in the present invention;

[0030] Figure 5 is a schematic diagram of the installation angle of the air collector in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the drawings and the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] The principle of the present invention will be described in detail below with reference to the drawings and the embodiments.

[0033] As Figure 2As shown in the figure, the collector of the present invention is applicable to centrifugal fans, not limited to centrifugal fans with single inlet or double inlets. Taking the centrifugal fan with single inlet as an example, the centrifugal fan 100 includes: a volute 1, a collector 2, centrifugal impellers 3, and a motor 4. The motor 4 is fixed to the volute 1. The centrifugal impellers 3 are located inside the volute 1 and are connected to the rotating shaft of the motor 4. After the motor 4 is started, it drives the centrifugal impellers 3 to rotate. The collector 2 is fixed to the inlet of the volute 1 by bolts 5. The collector 2 extends from the inlet into the volute 1. One end of the collector 2 is the inlet and the other end is the outlet. The outlet of the collector 2 is close to the inlet of the centrifugal impellers 3 to guide the air flow to the centrifugal impellers 3 and prevent the air flow in the volute 1 from being disordered.

[0034] As Figure 3 shown in the figure, a non-circular guiding structure 21 is provided at the inner edge of the inlet of the collector 2. When the centrifugal fan 100 is operating, air enters the centrifugal impellers 3 through the non-circular guiding structure 21. The non-circular guiding structure 21 is obtained by sweeping the sidewall profile along the end face profile. The sidewall profile is the profile reflecting the shape of the sidewall of the non-circular guiding structure 21, and the end face profile is the profile reflecting the shape of the end face of the non-circular guiding structure 21. The end face profile is formed by closing at least 2n arcs in a loop. The end face profile includes n sets of profile combinations. Each set of profile combinations is composed of two fixed arcs symmetrically arranged, and n is a positive integer.

[0035] In one embodiment, the end face profile is formed by closing at least four arcs in a loop, that is, n = 2. The end face profile includes two sets of profile combinations. Each set of profile combinations is composed of two fixed arcs symmetrically arranged. The symmetry axes of the two sets of profile combinations are perpendicular to each other. Through these two sets of profile combinations, the basic shape of the non-circular guiding structure is in the shape of a quasi-ellipse. The non-circular guiding structure 21 obtained in this way can effectively reduce the limitation of the collector on the inlet air volume.

[0036] It should be understood that the present invention does not limit the number of arcs of the end face profile. Transition arcs can be designed between the two sets of profile combinations. That is, there are two types of arcs constituting the end face profile, namely fixed arcs and transition arcs. Through the transition arcs, the connection between the two sets of profile combinations is smoother. The more the number of transition arcs, the smoother the transition between the two sets of profile combinations. The specific number of transition arcs can be designed according to the actual situation. To improve the air inlet uniformity, the transition arcs on both sides of each set of profile combinations are also symmetrically arranged with respect to the symmetry axis of the profile combination.

[0037] As Figure 4 shown in the figure, for the convenience of description, the two sets of profile combinations are distinguished as the first profile combination and the second profile combination. The first profile combination is composed of two first fixed arcs 212 and 213 arranged symmetrically, and the second profile combination is composed of two second fixed arcs 211 and 214 arranged symmetrically.

[0038] Taking the intersection point O of the symmetry axes of the two sets of profile curves as the coordinate origin, the formula for the end face profile curve is:

[0039]

[0040] Among them, the value range of c is: b < c < a, where a is the radius of the first shaped arc, c is the radius of the second shaped arc, b is the radius of the inner circle with the intersection point O of the symmetry axes as the center and tangent to the end face profile curve, β is the angle between the end point of the second shaped arc and the midpoint of the first shaped arc on the same side. When there is no designed transition arc between the first shaped arc and the second shaped arc, β is the angle between the intersection point of the first shaped arc and the second shaped arc and the midpoint of the first shaped arc on the same side. The value of β changes with the size of c, and the value range of β is 0° to 90°. The arc centers of the second shaped arcs 211 and 214 are located at the intersection point O of the symmetry axes, P is the arc center of the first shaped arc 213, and Q is the arc center of the first shaped arc 212.

[0041] As Figures 2 to 4 shown, in the feasible embodiment of the present invention, the value of a is equal to the outlet radius of the centrifugal fan 3, the value of b is equal to the inlet radius of the centrifugal fan 3. The multiple blades of the centrifugal fan 3 enclose a ring shape. The outer ring radius of this ring is the outlet radius of the centrifugal fan 3, and the inner ring radius of this ring is the inlet radius of the centrifugal fan 3. The lengths of the line segments PO and QO are both (a - b), c = 0.5×(a + b), and β is 65.4°. By performing a sweep according to the end face profile curve defined by the formula, the non-circular guide structure 21 of the air collector 2 can be obtained. The maximum opening of the non-circular guide structure 21 at the outlet is 2c, and the minimum opening is 2b. Adjust the installation angle of the air collector 2 at the air inlet of the volute 1, and use the non-circular guide structure 21 to balance the flow state at the air inlet, increase the air intake volume, thereby reducing the area of the low-speed zone at the air outlet 11 of the volute, making the air outlet velocity distribution of the volute more uniform and the air output volume larger.

[0042] As Figure 5 shown, the angle between the plane where the air outlet 11 of the volute is located and the symmetry axis of the second set of profile curves is α, and this angle is the installation angle of the air collector 2. Generally, the default installation angle α is 90°, and the specific angle can be adjusted according to needs. As Figure 1 、 2 shown, in order to facilitate the adjustment of the installation angle of the air collector 2, an installation flange 22 is provided at the outer edge of the inlet of the air collector 2. The installation flange 22 is provided with a plurality of circular arc through holes 221, 222, 223 arranged at intervals around the central axis of the air collector 2. The bolts 5 pass through the circular arc through holes 221, 222, 223 and are fixed on the volute 1. During actual use, according to different volute forms and different air volumes, etc., the air collector 2 can be rotated to adjust its installation angle α with the volute 1 to adapt to the required working conditions.

[0043] In the above feasible embodiments, the installation angle of the air collector 2 is 90°. At the same rotational speed, through calculation and comparison, it is obtained that the air volume of the centrifugal fan with the non-circular air collector of the present invention is increased by 7% compared with that of the traditional circular air collector. The non-circular air collector has a relatively obvious effect on improving the air volume of the centrifugal fan.

[0044] The centrifugal fan 100 proposed by the present invention can be applied in an air conditioning system. The outlet air speed of the centrifugal fan 100 is evenly distributed and the air output is large, greatly optimizing the use experience of the air conditioning system. Of course, the centrifugal fan 100 can also be applied to other devices, and the present invention does not make special restrictions on this.

[0045] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A current collector, characterized in that: The inner edge of the inlet of the current collector is provided with a non-circular flow guiding structure, which is obtained by sweeping the side wall profile along the end face profile. The end face profile is formed by connecting at least four arcs in a closed loop. The end face profile includes two sets of profile combinations, and each set of profile combinations is composed of two fixed arcs arranged symmetrically. The symmetry axes of the two sets of profile combinations are perpendicular to each other; The two sets of profile combinations are the first profile combination and the second profile combination respectively. The fixed arc of the first profile combination is the first fixed arc, and the fixed arc of the second profile combination is the second fixed arc; Taking the intersection point O of the symmetry axes of the two sets of profile combinations as the coordinate origin, the formula of the end face profile is: wherein, the value range of c is: b < c < a. a is the radius of the first fixed arc, c is the radius of the second fixed arc, b is the radius of the inner circle with the intersection point O of the symmetry axes as the center and tangent to the end face profile, and β is the angle between the end point of the second fixed arc and the midpoint of the first fixed arc on the same side of it.

2. The current collector according to claim 1, characterized in that: The value of β changes with the change of the size of c, and the value range of β is 0° to 90°.

3. The current collector according to claim 1, characterized in that: When c = 0.5×(a + b), β is 65.4°.

4. The current collector according to claim 1, characterized in that: The value of a is equal to the outlet radius of the centrifugal fan blade of the centrifugal fan where the current collector is located, and the value of b is equal to the inlet radius of the centrifugal fan blade of the centrifugal fan where the current collector is located.

5. The current collector according to claim 1, characterized in that: The two sets of profile combinations are connected by at least one transition arc.

6. The current collector according to claim 5, characterized in that: The transition arcs on both sides of each set of profile combinations are symmetrically arranged.

7. The current collector according to claim 1, characterized in that: The outer edge of the inlet of the current collector is provided with an installation border, and the installation border is provided with circular arc through holes arranged at intervals around the central axis of the current collector.

8. Centrifugal fan, including: A volute, a centrifugal fan blade installed in the volute, a motor for driving the centrifugal fan blade to rotate, and a current collector installed at the air inlet of the volute, characterized in that the current collector adopts the current collector according to any one of claims 1 to 7, and air flows to the centrifugal fan blade through the non-circular flow guiding structure.

9. The centrifugal fan according to claim 8, characterized in that: The included angle between the plane where the air outlet of the volute is located and the symmetry axis of the second profile combination is α, and the included angle is 90°.

10. The centrifugal fan according to claim 8, characterized in that: The outlet of the current collector is close to the inlet of the centrifugal fan blade.

11. Air conditioning system, including: A centrifugal fan, characterized in that the centrifugal fan adopts the centrifugal fan according to any one of claims 8 to 10.

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