CN201539437U - High-efficiency axial-flow pump impeller - Google Patents

Abstract

The utility model relates to an axial-flow impeller used in high-specific speed working conditions, namely large-flow low-lift working conditions. The axial-flow impeller is characterized in that molded lines of working face streamlines of blades are calculated by geometrical relationship between streamline inlet-outlet installation angles on different stream surfaces and circular arc molded lines, and then different streamlines of the blade working faces are thickened according to a change formula of airfoil thickness. By practical application, not only geometrical parameters of the axial-flow impeller meet lift and flow requirements of pump design working conditions, but also the axial-flow impeller has high efficiency, fine cavitation corrosion resistance and simple design process, and has certain popularization value.

Description

A kind of efficient axial-flow pump impeller

Technical field

The present invention relates to a kind of major part of non-varactor pump, the front side of vane molded lines of this aial flow impeller is determined by the streamline characteristic, and is thickeied molded lines according to the profile thickness Changing Pattern.This impeller can use for big flow low lift occasion.

Background technique

Axial-flow pump impeller mainly designs with the lift method at present.The supposition of lift method design blade is: the impeller blade number seldom, the fluid winding flow in the impeller blade grid approaches around the streaming of single wing, thereby the influence of aerofoil profile interaction opposing connection properties of flow is little in the impeller blade grid.According to this supposition, each aerofoil profile in the aial flow impeller blade grid is regarded as isolated, and be applied in the test result of carrying out single aerofoil profile in the wind-tunnel and design blade.Because above-mentioned supposition has certain approximation, need convection cell to stream leaf grating for this reason and revise with the difference of independent wing, therefore cause the performance of impeller to have uncertainty.And the most of references of aerofoil profile of axial-flow pump impeller is existing aviation power aerofoil profile at present, and import position plumpness, incompatibility come flow path direction to change the blade of little axial flow pump.

Patent of invention technology 96119277 patent No. aial flow impellers that have have earlier proposed a kind of aial flow impeller that is used to stir of compact structure, this impeller provides bigger discharge amount with less moment of torsion, but this impeller be only applicable to liquid container low in drop in the concentration liquid or the dispersion of particle.Utility model patent ZL02204291.1 has proposed a kind of aial flow impeller of blade tip bending, by the original crooked suitable angle of the rectilinear form perpendicular to the impeller axle center being formed curved surface at the blade tip place, the width of blade tip is along the reverse increasing of impeller rotation, make fluid before leaving blade tip, blade can utilize contained energy, and reaches the purpose that improves energy conversion efficiency.Number of patent application 200580024657.0 strengthens in the aial flow impeller that flows, and the section of outline in its blade is determined by aerodynamics.Above patented technology has proposed the structure and the resemblance of different occasion axial-flow pump impellers, but does not all propose the aerofoil profile feature of the different circumferential sections of axial-flow blower and definite method of vane type line.The performance requirement of the axial-flow pump impeller of these existing patented technologies in can not satisfying engineerings such as China's engineering irrigation, chemical-process.

Summary of the invention

In order to overcome the existing deficiency of using for reference the axial-flow pump impeller of aviation Airfoil Design, the blade of the aial flow impeller among the present invention is to import and export the molded lines that laying angle calculates its working surface according to the streamline on the different stream interfaces, and thickeies according to aerofoil profile thickening rule.

Technological scheme of the present invention is:

A kind of efficient axial-flow pump impeller, the radius R of circular arc molded lines on its blade is to be determined by following formula:

$R=\frac{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="DEST\_PATH\_HSB00000022367300021.png,DEST\_PATH\_HSB00000022367300042.png"\; state="\{\{state\}\}">l</figure-callout>}}{2\sin \frac{\mathrm{\&theta;}}{2}}=\frac{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="DEST\_PATH\_HSB00000022367300021.png,DEST\_PATH\_HSB00000022367300042.png"\; state="\{\{state\}\}">l</figure-callout>}}{2\sin \left(\frac{{\mathrm{\&beta;}}_2-{\mathrm{\&beta;}}_1}{2}\right)}$

R-working surface molded lines radius in the formula; β ₁-streamline import laying angle; β ₂-streamline outlet laying angle; θ-molded lines central angle; L-string of a musical instrument length.

Aerofoil profile a from the wheel rim to the wheel hub, b, c, d, e maximum ga(u)ge are respectively 5.2mm, 6.9mm, 8.6mm, 10.3mm, 12mm.According to the varied in thickness rule of following formula aerofoil profile, respectively five molded lines of working surface are thickeied to the back side from working surface.

δ/δ _max＝2.1437(x/l) ³-6.9947(x/l) ²+4.8445(x/l)+0.052

L-string of a musical instrument length in the formula; δ-profile thickness; δ _Max-maximum profile thickness, X-aerofoil profile suction surface is to the distance of inlet side.

Determine and the blade thickening rule of vane type line are the unique design part of impeller of the present invention, and be simple and practical.By facts have proved, this impeller not only can satisfy the requirement of design parameter, and the efficient height, and combination property is good.

Description of drawings

The present invention is further described below in conjunction with drawings and Examples.

Fig. 1 is an axial-flow pump impeller of the present invention.

Fig. 2 is the aerofoil profile figure of axial-flow pump impeller a of the present invention, b, c, d and e stream interface.

Fig. 3 is axial-flow pump impeller a of the present invention, b, c, d and e stream interface key plan.

Fig. 4 is an aerofoil profile working surface circular arc type line geometry parameters relationship schematic representation.

Fig. 5 is the schematic representation of aerofoil profile working surface molded lines thickening rule.

Fig. 6 is a blade plane projection drawing among the embodiment.

Fig. 7 is a sharf face projection drawing among the embodiment.

Fig. 8 be among the embodiment blade A to view.

Fig. 9 is blade a stream interface aerofoil profile figure among the embodiment.

Figure 10 is blade b stream interface aerofoil profile figure among the embodiment.

Figure 11 is blade c stream interface aerofoil profile figure among the embodiment.

Figure 12 is blade d stream interface aerofoil profile figure among the embodiment.

Figure 13 is blade e stream interface aerofoil profile figure among the embodiment.

β ₁, β ₂-molded lines is into and out of bicker; γ-molded lines the angle of curvature; θ-molded lines central angle;

H-aerofoil profile camber; L-string of a musical instrument length; δ-profile thickness; δ _Max-maximum profile thickness; T-pitch, R-circular arc molded lines radius, β _L-aerofoil profile laying angle, x-aerofoil profile suction surface arrive the distance of inlet side.

Embodiment

The specific speed of this aial flow impeller is 1000, impeller diameter D ₂=300, n=1450r/min, as shown in Figure 1.Concrete implementation process can be with reference to table 1.Stream interface is general to divide 5～7, and the number of blade is 3 in this enforcement, and each blade divides 5 stream interface a, b, c, d, e, and the stream interface spacing equates, as Fig. 1 and Fig. 3.Calculate the import flow angle β of streamline on each stream interface ₁', be respectively 15.37 °, 18.28 °, 22.39 °, 28.06 °, 36.86 °, select angle of attack Δ β ₁, Δ β ₁The scope of selecting for use be (0 °～3 °), determine inlet blade angle β ₁=β ₁'+Δ β ₁, be respectively 16.97 °, 19.48 °, 23.19 °, 28.46 °, 36.86 °.Calculate each streamline outlet flow angle β ₂', be respectively 17.18 °, 21.11 °, 27.27 °, 37.51 °, 58.54 °.Consider factor affecting such as the limited number of blade, Δ β ₂The scope of selecting for use be (0 °～3 °), every streamline adds the angle of attack and determines 1 ° in the present embodiment, then blade outlet angle β ₂=β ₂'+Δ β ₂, be respectively 18.18 °, 22.11 °, 28.27 °, 38.51 °, 59.54 °.Select the string of a musical instrument length l of different streamlines, be respectively 188.50mm, 176.24mm, 160.54mm, 139.96mm, 116.87mm.Calculating formula according to working surface molded lines radius R $R=\frac{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="DEST\_PATH\_HSB00000022367300021.png,DEST\_PATH\_HSB00000022367300042.png"\; state="\{\{state\}\}">l</figure-callout>}}{2\sin \frac{\mathrm{\&theta;}}{2}}=\frac{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="DEST\_PATH\_HSB00000022367300021.png,DEST\_PATH\_HSB00000022367300042.png"\; state="\{\{state\}\}">l</figure-callout>}}{2\sin \left(\frac{{\mathrm{\&beta;}}_2-{\mathrm{\&beta;}}_1}{2}\right)}$ Calculate circular arc line radius R, result of calculation is respectively 8943mm, 3831mm, and 1811mm, 799mm, 297mm, as shown in Figure 2.Import laying angle β according to working surface ₁With outlet laying angle β ₂Draw the aerofoil profile unfolded drawing with the molded lines radius, as shown in Figure 4.

The aial flow impeller computational process of table 1 specific speed 1000

The aerofoil profile maximum ga(u)ge of wheel hub by formula ${\mathrm{\&delta;}}_{\max }=(0.012~0.015)D_2\sqrt{H}$ Estimating, is 300 axial-flow pump model usually for diameter, and blade outer edge side maximum ga(u)ge is got 5mm, and the hub side maximum ga(u)ge is got 14mm, and the thickness from the wheel hub to the wheel rim changes according to linear rule.Determine that aerofoil profile 5,4,3,2,1 maximum ga(u)ge of blade from the wheel rim to the wheel hub is respectively 5.2mm, 6.9mm, 8.6mm, 10.3mm, 12mm is according to formula δ/δ _Max=2.1437 (x/l) ³-6.9947 (x/l) ²+ 4.8445 (x/l)+0.052 calculate profile thickness thickening rule such as following table 2:

The varied in thickness rule of table 2 aerofoil profile

According to profile thickness thickening rule, the working surface molded lines is thickeied, and blade is imported and exported cavetto, as shown in Figure 5.Make the plane figure (Fig. 6) of blade at last,, axis projection (Fig. 7) and A be to view (Fig. 8), and makes stream interface a respectively, b, c, the aerofoil profile of d and e is seen Fig. 9, Figure 10, Figure 11, Figure 12 and Figure 13 respectively.

Claims (2)

1. an efficient axial-flow pump impeller is characterized in that, the radius R of circular arc molded lines on the blade of axial-flow pump impeller is to be determined by following formula: $R=\frac{l}{2\sin \frac{\mathrm{\&theta;}}{2}}=\frac{l}{2\sin \left(\frac{{\mathrm{\&beta;}}_2-{\mathrm{\&beta;}}_1}{2}\right)}$

R-working surface molded lines radius in the formula;

β ₁-streamline import laying angle;

β ₂-streamline outlet laying angle;

θ-molded lines central angle;

L-string of a musical instrument length.

2. axial-flow pump impeller as claimed in claim 1 is characterized in that: blade has a, b, c, d, five molded lines of e from the wheel rim to the wheel hub, the maximum ga(u)ge of a, b, c, d, e is respectively 5.2mm, 6.9mm, 8.6mm, 10.3mm, 12mm; Article five, molded lines thickens to the back side from working surface, and thickness meets following formula with the different Changing Pattern of extension position:

δ/δ _max＝2.1437(x/l) ³-6.9947(x/l) ²+4.8445(x/l)+0.052

L-string of a musical instrument length in the formula; δ-profile thickness; δ _Max-maximum profile thickness, x-aerofoil profile suction surface is to the distance of inlet side.

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