A centrifugal fan volute having a centrifugal fan and an air conditioning system

Abstract

The present invention provides a centrifugal fan volute, a centrifugal fan having the same, and an air-conditioning system, relating to the technical field of centrifugal fans. The profile line of the volute is surrounded by a spiral part, a volute tongue part, a straight-line diffuser part on the inner side of the volute, and a straight-line diffuser part on the outer side of the volute. Among them, the spiral part is an equiangular spiral, the tangent angle thereof is equal everywhere, and the polar coordinate equation of any point M(ρ, t) on the spiral part is: ρ(t) = 0.5De<supgt;0.001765t< / supgt;, where ρ is the spiral radius, D is the outer diameter of the impeller, e is the base of the natural logarithm, t is the spiral angle, and 60° ≤ t ≤ 400°. It can better collect air flow, guide air flow to expand, reduce pressure loss, improve the static pressure of the fan, improve the flow efficiency of the impeller, increase the air volume by 16.8% compared with the traditional volute, increase the static pressure by 22.3%, and increase the fan efficiency by 3%. Therefore, the energy efficiency ratio of the bus air conditioner and the comfort requirements of the whole vehicle can be improved, and the endurance capacity of the whole vehicle can be enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal fans, and in particular to a centrifugal fan volute having the same and an air conditioning system. Background Art

[0002] With the development of economy and the improvement of people's living standards, passengers have higher and higher requirements for the riding environment, especially the comfort of the interior environment, including the noise level in the car, temperature rise and temperature drop and other key parameters, which put forward higher requirements for bus air conditioners. The new national standard has increased the noise level of the interior of the bus air conditioner from the original 70dB (A) to 65dB (A), and the noise requirements are getting higher and higher. The evaporator fan is the air supply component on the interior of the bus air conditioner, and it is also the main noise source on the interior of the bus air conditioner. Only by improving the noise level of the evaporator fan can the increasingly stringent noise requirements be met. The evaporator fan is generally a centrifugal fan, and its main air duct components include volute and fan blades. The line design of the volute directly determines the performance of the fan. The volute line with excellent performance helps to improve the efficiency of the fan and reduce the noise of the fan. The traditional volute is mostly designed by the equilateral basis method and the unequal basis method. This method is an approximate design, with high noise and low static pressure, which cannot meet the noise requirements.

[0003] Therefore, a new technical solution is urgently needed to solve the problem that the volute design has high noise and low static pressure and cannot meet the noise requirements. Summary of the invention

[0004] In view of this, the present invention provides a centrifugal fan volute, which solves the problems in the prior art that the bus air-conditioning fan has low static pressure, insufficient ability to overcome air duct resistance, and cannot meet the wind speed distribution requirements of the whole vehicle through the design of the volute profile.

[0005] In order to achieve the above-mentioned object, the technical scheme adopted by the present invention is: a centrifugal fan volute, wherein a fan blade is arranged in the volute, and the profile of the volute is surrounded by a spiral line part, a volute tongue part, a linear diffuser part inside the volute, and a linear diffuser part outside the volute, wherein the spiral line part is an equiangular spiral line, and its tangent angle is equal everywhere, and the polar coordinate equation of any point M(ρ,t) on the spiral line part is: ρ(t)=0.5De 0.001765t , where ρ is the spiral radius, D is the outer diameter of the fan blade, e is the base of a natural number, and t is the spiral angle, and 60°≤t≤400°.

[0006] Further optionally, the tongue deflection angle of the tongue portion is 0°≤α≤30°. The tongue deflection angle is determined according to the starting angle of the spiral portion and the tongue radius. The limitation of the tongue deflection angle can ensure the optimal tongue clearance and outlet width; ensure the ratio of the volute outlet opening to the width, so as to achieve the highest diffusion efficiency.

[0007] Further optionally, the angle between the linear diffuser portion inside the volute and the linear diffuser portion S4 outside the volute is a diffuser angle θ, 0°≤θ≤20°.

[0008] Further optionally, the outlet opening of the volute is A, 0.2D≤A≤0.6D, wherein D is the outer diameter of the fan blade.

[0009] Further optionally, the maximum distance between the linear pressure diffuser portion inside the volute and the linear pressure diffuser portion outside the volute is the volute outlet width C, and the pressure diffuser ratio range is 1≤C / A≤3.

[0010] Further optionally, the linear diffusion portion on the outer side of the volute is provided with a wire passing buckle, and the wire passing buckle includes a base and a side plate connected to the volute, the base is connected to the volute, and forms an upward opening with the side plate, wherein the width of the base is L1, d≤L1≤2d, and the width of the opening is L2, 0.3d≤L2≤0.9d, wherein d is the diameter of the cable passed by the wire passing buckle.

[0011] The present invention also provides a centrifugal fan having the centrifugal fan volute described in any one of the above items.

[0012] The present invention provides an air conditioning system, which comprises the centrifugal fan mentioned above.

[0013] Further optionally, the air conditioning system is used in a vehicle.

[0014] Further optionally, the means of transportation is a bus.

[0015] The centrifugal fan volute provided by the present invention can better collect airflow and guide airflow expansion, reduce pressure loss, increase the static pressure of the fan, and improve the flow efficiency of the fan blades through the design of the profile of the centrifugal fan volute. Compared with the traditional volute, the air volume is increased by 16.8%, the static pressure is increased by 22.3%, and the fan efficiency is increased by 3%, thereby improving the energy efficiency ratio of the bus air conditioner and the comfort requirements of the whole vehicle, and improving the endurance of the whole vehicle. The bus using the volute solves the problems of low air volume and low wind speed of the bus air conditioner in the prior art, as well as low static pressure of the bus air conditioner fan, insufficient ability to overcome the air duct resistance, and inability to meet the wind speed distribution requirements of the whole vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will become more apparent by describing in detail its exemplary embodiments with reference to the accompanying drawings. The accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0017] Figure 1 is a line drawing of a volute of a centrifugal fan in an embodiment of the present invention;

[0018] Figure 2 is a cross-sectional view of a volute of a centrifugal fan in an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of a centrifugal fan volute in an embodiment of the present invention;

[0020] Figure 4 It is an enlarged view of the wire buckle on the volute of the centrifugal fan in the embodiment of the present invention.

[0021] In the figure:

[0022] S1-helix part; S2-tongue part; S3-linear diffuser part inside the volute; S4-linear diffuser part outside the volute; 1-wire buckle DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "a", "an" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two, but does not exclude the situation of including at least one.

[0025] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0026] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0027] In order to better understand the technical solution of the present invention, the following embodiments are given.

[0028] Example

[0029] like Figure 1-4 As shown, the present invention provides a centrifugal fan volute used in a centrifugal fan of a bus air conditioning system, specifically as Figure 1 As shown, the centrifugal fan volute is provided with a fan blade, and its profile is surrounded by a spiral line portion S1, a volute tongue portion S2, a linear diffuser portion S3 inside the volute, and a linear diffuser portion S4 outside the volute. The connection point of the spiral line portion S1 and the volute tongue portion S2 is located above the center of the volute, the connection point of the volute tongue portion S2 and the linear diffuser portion S3 inside the volute is located on the left side of the center of the volute, and the connection point of the linear diffuser portion S3 inside the volute and the linear diffuser portion S4 outside the volute is located below the center of the volute. The spiral line portion S1 is an equiangular spiral line, and its tangent angle is equal everywhere, and the polar coordinate equation of any point M(ρ, t) on the spiral line portion S1 is: ρ(t) = 0.5De 0.001765t , where ρ is the spiral radius, D is the outer diameter of the fan blade, e is the base of a natural number, and t is the spiral angle, and 60°≤t≤400°.

[0030] The general volute is composed of four arcs drawn by the equilateral basis method or the unequal basis method to form the part of the volute spiral line. The centers of the circles are respectively located in the four quadrants of the volute center as the coordinate system. The tangent angles a1 = 83.03°, a2 = 86.71°, a3 = 85.84°, and a4 = 80.23°. a1, a2, a3, and a4 are not equal and there is no rule. The non-proportional expansion of the volute will cause airflow reflux and collision with the volute wall, resulting in pressure loss. The volute spiral line S1 of the present invention is an equiangular spiral line, and its tangent angle is equal everywhere and is always equal to β. Different from the equiangular spiral volute with different tangent angles that the direct fan blades should match, the selection of the tangent angle is determined according to the volute tongue gap and the outlet opening, while taking into account the structural space limitations, improving the static pressure recovery efficiency of the volute, and reducing the loss due to excessive speed and collision with the volute wall. In addition, the limiting helix angle in the equation of this embodiment is to illustrate the position of a given volute tongue, which is connected to the outlet and ultimately limits the width of the outlet. Other equations include the Archimedean spiral equation, but it is only the first term of the Taylor expansion of the equiangular helix, which will cause the volute size to be too large.

[0031] like Figure 2-3As shown, according to the above spiral equation, the spiral part of the volute is drawn according to different diameters. Preferably, the volute tongue deflection angle α of the volute tongue part S2 is selected according to the starting angle of the spiral part and the volute tongue radius, 0°≤α≤30°, so that the volute tongue gap and the outlet width are optimized; the ratio of the volute outlet opening to the width is determined to achieve the highest diffusion efficiency;

[0032] Draw the volute tongue, preferably, select the volute outlet diffusion angle θ, 0°≤θ≤20°, draw the volute inner outlet straight line part, and then draw the volute outer outlet straight line part, the length is to be determined.

[0033] In order to determine the length of the straight line inside and outside the volute, the outlet opening A is selected and determined. The outlet opening A directly determines the overall size of the volute, and its size needs to match the diameter of the fan blade. The effect is that the appropriate opening can be selected according to the actual structural space limitations. If it is too large or too small, the performance of the volute will be affected, but it can be compensated by optimizing parameters such as the outlet expansion ratio. In this implementation, the outlet opening A of the volute is preferably 0.2D≤A≤0.6D, where D is the outer diameter of the fan blade. In this embodiment, a large outlet opening is used. This opening is the core parameter that determines the equiangular spiral. A larger opening helps to recover the pressure in the volute, improve the static pressure recovery efficiency of the volute, and reduce the loss due to excessive speed and collision with the volute wall.

[0034] Considering the comprehensive factors of the pressure diffusion efficiency and the structural size limitation of the actual volute, it is preferred in this implementation that the maximum distance between the linear pressure diffusion part S3 on the inner side of the volute and the linear pressure diffusion part S4 on the outer side of the volute is the volute outlet width C, and the pressure diffusion ratio range is 1≤C / A≤3. Then the volute outlet pressure diffusion ratio is selected, and then the volute outlet width C is determined according to the outlet opening A and the outlet pressure diffusion ratio. Finally, the length of the inner and outer straight parts of the volute outlet can be determined according to the size of C. At this point, a complete volute profile is drawn, and then the profile is stretched and molded in the three-dimensional modeling software according to this profile to complete the final volute product design.

[0035] In the optimal implementation scheme, according to design experience, the cutting angle β of the spiral part S1 is 84.38°, and the volute tongue adopts a shallow volute tongue design to ensure that the outlet width C of the volute is as large as possible in a limited space, while taking into account low noise, and the volute tongue angle α is selected as α=17.7°; the volute adopts a large outlet opening design to guide the airflow to fully expand, while reducing expansion losses and improving fan efficiency. The volute outlet opening A is preferably A=0.3D; the volute adopts a small outlet expansion angle and a large expansion ratio design. A small expansion angle can improve the expansion efficiency, and a large expansion ratio can reduce the outlet speed and reduce the expansion loss. Preferably, the expansion angle θ=8° and the expansion ratio C / A=1.76 are selected to design the volute profile. The final designed volute product has a 16.8% increase in air volume, a 22.3% increase in static pressure, and a 3% increase in fan efficiency compared to the general volute, thereby improving the energy efficiency ratio of the bus air conditioner and the comfort requirements of the whole vehicle, and improving the endurance of the whole vehicle.

[0036] In addition to the preferred embodiment of the invention, the spiral part S1 cutting angle β=83.68°, the volute tongue angle α is selected as α=27.52°, and the volute outlet opening A is selected as A=0.4D=58.13; the diffusion angle is selected as θ=13°, and the diffusion ratio C / A=1.5 is selected for the volute profile design. The designed volute can also obtain a higher static pressure. The specific parameters can be selected according to actual requirements, such as large air volume, high static pressure, high efficiency, low noise, etc.

[0037] In order to fully verify the technical effect of the technical solution of the present invention, this embodiment also provides a comparison of the static pressure efficiency experimental data of the volute design scheme in this embodiment and the volute of the prior art, as shown in Table 1 and Table 2.

[0038] Table 1 Comparison of structural parameters of the volute in this embodiment and the volute in the prior art

[0039]

[0040] Table 2 Comparison of experimental data of air volume and static pressure efficiency of the volute in this embodiment and the volute in the prior art

[0041] Prior art volute This embodiment of the spiral shell 1 This embodiment of the spiral shell 2 <![CDATA[Flow rate m 3 / h]]> 1238.5 1446 1386.5 Static pressure pa 102.63 125.49 120.3 Fan efficiency 17.0％ 20.0％ 21％

[0042] Compared with the volute in the prior art, the volute product in this embodiment has an air volume increased by 16.8%, a static pressure increased by 22.3%, and a fan efficiency increased by 3%, thereby improving the energy efficiency ratio of the bus air conditioning and the comfort requirements of the entire vehicle, and improving the endurance of the entire vehicle.

[0043] Considering that in actual processes, the cables of the fan are often fixed to the side of the metal plate with wire ties. During the actual operation of the product, due to road vibration, the cables are easily cut, causing the fan to leak or fail. In order to solve this problem, Figure 4As shown, preferably, the linear expansion portion S4 on the outer side of the volute is provided with a wire-passing buckle 1, and the wire-passing buckle 1 includes a base and a side plate connected to the volute, the base is connected to the volute, and forms an upward opening with the side plate, wherein the width of the base is L1, d≤L1≤2d, and the width of the opening is L2, 0.3d≤L2≤0.9d, wherein d is the diameter of the cable passed by the wire-passing buckle 1. The wire-passing buckle 1 fixes the cable in the volute wire-passing buckle 1, effectively protecting the cable and preventing it from being cut. At the same time, in order to prevent the cable from being loosened and cut, these parameters are reasonably designed. Further preferably, in this embodiment, the width of the base is L1=1.5d, and the opening width is 0.3d≤L2≤0.9d. Further preferably, the opening width is L2=0.5d. Finally, in the product vibration test, the cable is firmly and reliably fixed without damage, and passes the test smoothly.

[0044] In summary, the present invention provides a centrifugal fan volute, the profile of the volute is surrounded by a spiral part, a volute tongue part, a linear diffuser part inside the volute, and a linear diffuser part outside the volute, wherein the spiral part is an equiangular spiral line, the tangent angles of which are equal everywhere, and the polar coordinate equation of any point M(ρ, t) on the spiral part is: ρ(t) = 0.5De 0.001765t , where ρ is the spiral radius, D is the blade diameter, e is the natural number base, t is the spiral angle, and 60°≤t≤400°. It can better collect airflow and guide airflow expansion, reduce pressure loss, increase the static pressure of the fan, and improve the flow efficiency of the fan blades. Compared with the traditional volute, the air volume is increased by 16.8%, the static pressure is increased by 22.3%, and the fan efficiency is increased by 3%, thereby improving the energy efficiency ratio of the bus air conditioner and the comfort requirements of the whole vehicle, and improving the endurance of the whole vehicle.

[0045] The exemplary embodiments of the present disclosure are specifically shown and described above. It should be understood that the present disclosure is not limited to the detailed structures, configurations or implementations described herein; on the contrary, the present disclosure is intended to cover various modifications and equivalent configurations included in the spirit and scope of the appended claims.

Claims

1. A centrifugal fan volute, wherein a fan blade is arranged inside the volute, characterized in that: The profile of the volute is formed by a spiral portion (S1), a volute tongue portion (S2), a linear diffuser portion (S3) on the inner side of the volute, and a linear diffuser portion (S4) on the outer side of the volute, wherein the spiral portion (S1) is an equiangular spiral, the tangent angles of which are equal everywhere, and the polar coordinate equation M (ρ, t) of any point on the spiral portion (S1) is: ρ (t) = 0.5De 0.001765t , Where ρ is the spiral radius, D is the outer diameter of the fan blade, e is the base of a natural number, and t is the spiral angle, and 60°≤t≤400°; The snail tongue deflection angle of the snail tongue portion (S2) is 0°≤α≤30°; The angle between the linear diffuser portion (S3) on the inner side of the volute and the linear diffuser portion (S4) on the outer side of the volute is a diffuser angle θ, 0°≤θ≤20°.

2. A centrifugal fan volute as claimed in claim 1, characterized in that: The outlet opening A of the volute satisfies: 0.2D≤A≤0.6D, where D is the outer diameter of the fan blade.

3. A centrifugal fan volute as claimed in claim 2, characterized in that: The maximum distance between the linear pressure diffuser portion (S3) on the inner side of the volute and the linear pressure diffuser portion (S4) on the outer side of the volute is the volute outlet width C, and the pressure diffuser ratio range is 1≤C / A≤3.

4. A centrifugal fan volute as claimed in claim 3, characterized in that: The linear expansion part (S4) outside the volute is provided with a wire buckle (1), and the wire buckle (1) comprises a base and a side plate connected to the volute, and the base is connected to the volute and forms an upward opening with the side plate.

5. A centrifugal fan volute as claimed in claim 4, characterized in that: The width of the base is L1, d≤L1≤2d, and the width of the opening is L2, 0.3d≤L2≤0.9d, wherein d is the diameter of the cable passed by the cable buckle (1).

6. A centrifugal fan, characterized in that: A centrifugal fan volute according to any one of claims 1 to 5.

7. An air conditioning system, characterized in that: A centrifugal fan as claimed in claim 6.

8. The air conditioning system according to claim 7, characterized in that: The air conditioning system is used in a vehicle.

9. The air conditioning system according to claim 8, characterized in that: The means of transportation is a bus.

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