CN105673555A - Single-suction double-channel impeller and design method thereof - Google Patents

Abstract

The invention relates to a single-suction double-channel impeller and a design method thereof, in particular to a hydraulic design method of a centrifugal single-suction double-channel impeller. According to the single-suction double-channel impeller and the design method thereof, the important design parameters, such as the internal impeller inlet diameter Dj1, the external impeller inlet diameter Dj2, the internal impeller blade length L1, the external impeller blade length L2, the internal impeller inlet blade deflection angle theta11, the external impeller inlet blade deflection angle theta21, the internal impeller outlet blade deflection angle theta12, the external impeller outlet blade deflection angle theta22, the impeller inlet edge curvature rho1, the impeller outlet edge curvature rho2, of the impeller are determined through formulas. It is tested through the production practice that by the adoption of the design method, the design efficiency and design standard of the single-suction double-channel impeller are greatly improved, and the design cost and risk are reduced; and a single-suction double-channel impeller pump which is designed and produced through the method has good usability and high economic benefits.

Description

A kind of single-suction double flow path impeller and method of design thereof

Technical field

The present invention relates to a kind of single-suction double flow path impeller and method of design thereof, in particular to the centrifugal single-suction double flow path impeller Hydraulic Design Method of one.

Background technology

The energy has important meaning for the raising of mankind's daily life level and the development of national economy. The development that he is country provides important basic substance. Along with the fast development of China's economy and the minimizing day by day of global energy, how save energy has become the problem that people more and more pay close attention to. Impeller pump is pump series products important in fluid machinery, has that pressure and stability of flow, weight are light, compact construction, convenient and reliable operation and a low advantage of maintenance cost. Low specific speed centrifugal pump due to the advantage of its uniqueness, now by extensive industry-by-industry and field.

Single-suction double flow path wing pump belongs to the scope of impeller pump, because of the feature that it has lift height, flow is big, is widely used in actual production and engineering. Many performance perameters of pump, as the core component of water pump, are played a decisive role by impeller. There is vibration relatively greatly in existing single double-impeller centrifugal pump of inhaling, guide performance is poor, the phenomenon that mobility is not good, can not realize the object of delivery medium very well. For the deficiency of above-mentioned existence, the present inventor has invented " a kind of single-suction double flow path impeller and method of design ", do not only give single-suction double flow path wing pump impeller parameters system, accurate method of design, also solve single-suction double flow path wing pump and vibrate problem big, mobility difference, enhance the reliability of the dynamic wing pump of single-suction double flow, improve the hydraulic efficiency of single-suction double flow path wing pump, extend the work-ing life of pump.

Summary of the invention

In order to solve the problem, the present invention provides a kind of single-suction double flow path impeller Hydraulic Design Method. By improving the method for design of several important parameters of impeller, it is to increase the efficiency of single suction double-impeller pump and reliability. The impeller vibration of the impeller pump of design is diminished, and guide performance is better, and the ability of delivery medium is better. Realizing the technical scheme that above-mentioned purpose adopts is:

1. single-suction double flow path impeller is made up of an outer impeller and an interior impeller, and wherein outer impeller is trash-type impeller, and interior impeller is unshrouded impeller, is connected by cover plate between outer impeller and interior impeller;

2. specific speed n_s, its calculation formula is as follows:

$n_s=\frac{3.65n\sqrt{Q}}{H^{3/4}};$

In formula:

n_sSpecific speed,

The lift of H design conditions, rice;

The flow of Q design conditions, rice³/ the second;

N rotating speed, rev/min;

3. impeller inlet diameter D in_j1, its calculation formula is as follows:

$D_{j1}=\sqrt{{K_1}^2{\left(\sqrt[3]{-0.18765Q+3.158n+0.009425Qn}\right)}^2+{\left(\sqrt[3]{5Mn/\[\mathrm{\τ}\]}\right)}^2}$

In formula:

D_j1Interior impeller inlet diameter, rice;

Mn axle moment of torsion, newton's rice;

The flow of Q design conditions, rice³/ the second;

The allowable shear strss of [τ] material, handkerchief;

N rotating speed, rev/min;

K₁Interior impeller speed coefficient;

4. impeller speed COEFFICIENT K in₁, design formula is as follows:

(1) efficiency is mainly considered

$K_1=3.509e^{0.0004427n_s}$

(2) efficiency and cavitation is taken into account

K₁=60.96sin (0.006227n_s+0.4195)+56.73sin(0.006486n_s+3.518)

(3) cavitation is mainly considered

$K_1=962.3e^{-{\left(\frac{n_s-0.0001657}{7145}\right)}^2}$

In formula:

n_sSpecific speed;

K₁Interior impeller speed coefficient;

5. outer impeller inlet diameter D_j2, its calculation formula is as follows:

$D_{j2}=\sqrt{{K_2}^2{\left(\sqrt[3]{-0.18802Q+3.3n+0.009Qn}\right)}^2+{\left(\sqrt[3]{5Mn/\[\mathrm{\τ}\]}\right)}^2}$

In formula:

D_j2Outer impeller inlet diameter, rice;

Mn axle moment of torsion, newton's rice;

The flow of Q design conditions, rice³/ the second;

The allowable shear strss of [τ] material, handkerchief;

N rotating speed, rev/min;

K₂Outer impeller speed coefficient;

6. outer impeller speed COEFFICIENT K₂, design formula is as follows:

(1) efficiency is mainly considered

$K_2=4.632e^{0.0004427n_s}$

(2) efficiency and cavitation is taken into account

K₂=80.47sin (0.006227n_s+0.4195)+74.88sin(0.006486n_s+3.518)

(3) cavitation is mainly considered

$K_2=1270e^{-{\left(\frac{n_s-0.0001657}{7145}\right)}^2}$

In formula:

n_sSpecific speed;

K₂Outer impeller speed coefficient;

7. impeller vane length L in₁, design formula is as follows:

$L_1=\frac{300}{400}{e}^{-{\left(\frac{n_s-41.69}{340.5}\right)}^2}(K_{D2}\sqrt[3]{\frac{Q}{n}}-K_{Dj}{D}_{j1})$

In formula:

L₁Interior impeller vane length, rice;

K_D2Impeller outlet diameter correction factor, K_D2=1.022～1.175;

K_DjImpeller inlet diameter correction factor, K_Dj=0.7～1.0;

n_sSpecific speed;

D_j1Interior impeller inlet diameter, rice;

The flow of Q design conditions, rice³/ the second;

N rotating speed, rev/min;

8. siphonal lobe wheel blade length L₂, design formula is as follows:

$L_2=1.004{n_s}^{-0.0008053}(K_{D2}\sqrt[3]{\frac{Q}{n}}-K_{Dj}{D}_{j2})$

In formula:

L₂Siphonal lobe wheel blade length, rice;

K_D2Impeller outlet diameter correction factor, K_D2=1.022～1.175;

K_DjImpeller inlet diameter correction factor, K_Dj=0.7～1.0;

n_sSpecific speed;

D_j2Outer impeller inlet diameter, rice;

The flow of Q design conditions, rice³/ the second;

N rotating speed, rev/min;

9. impeller inlet blade bias angle theta in₁₁, design formula is as follows:

(1) as 10 < n_s< when 80, such as Fig. 4 a,

θ₁₁=90 °

(2) as 80 < n_s< when 150, such as Fig. 4 b,

${\mathrm{\&theta;}}_{11}=\frac{425.52}{\mathrm{\&pi;}}{e}^{-{\left(\frac{n_s-428.3}{545}\right)}^2}$

(3) as 150 < n_s< when 300, such as Fig. 4 c,

${\mathrm{\&theta;}}_{11}=\frac{271.08}{\mathrm{\&pi;}}{e}^{0.0009636n_s}$

In formula:

θ₁₁Interior impeller inlet blade drift angle, degree;

n_sSpecific speed;

10. outer impeller inlet vane bias angle theta₂₁, design formula is as follows:

(4) as 10 < n_s< when 80, such as Fig. 5 a,

θ₂₁=90 °

(5) as 80 < n_s< when 150, such as Fig. 5 b,

${\mathrm{\&theta;}}_{21}=\frac{103.23}{\mathrm{\&pi;}}{n_s}^{0.2304}$

(6) as 150 < n_s< when 300, such as Fig. 5 c,

${\mathrm{\&theta;}}_{21}=\frac{0.3413n_s+274.327}{\mathrm{\&pi;}}$

In formula:

θ₂₁Outer impeller inlet vane drift angle, degree;

n_sSpecific speed;

Impeller outlet blade bias angle theta in 11.₁₂, design formula is as follows:

(1) as 10 < n_s< when 80, such as Fig. 4 a,

θ₁₂=90 °

(2) as 80 < n_s< when 150, such as Fig. 4 b,

${\mathrm{\&theta;}}_{12}=\frac{352.44}{\mathrm{\&pi;}}{e}^{-{\left(\frac{n_s+255.4}{701.4}\right)}^2}$

(3) as 150 < n_s< when 300, such as Fig. 4 c,

${\mathrm{\&theta;}}_{12}=\frac{1}{\mathrm{\&pi;}}(7.05e^{0.004536n_s}+327.78e^{-0.001389n_s})$

In formula:

θ₁₂Interior impeller outlet blade drift angle, degree;

n_sSpecific speed, $n_s=\frac{3.65n\sqrt{Q}}{H^{3/4}};$

The lift of H design conditions, rice;

12. outer impeller outlet blade bias angle theta₂₂, design formula is as follows:

(1) as 10 < n_s< when 80, such as Fig. 5 a,

θ₂₂=90 °

(2) as 80 < n_s< when 150, such as Fig. 5 b,

${\mathrm{\&theta;}}_{22}=\frac{339.48}{\mathrm{\&pi;}}{e}^{-0.001978n_s}$

(3) as 150 < n_s< when 300, such as Fig. 5 c,

${\mathrm{\&theta;}}_{22}=\frac{1}{\mathrm{\&pi;}}(-0.4221n_s+315)$

In formula:

θ₂₂Outer impeller outlet blade drift angle, degree;

n_sSpecific speed;

13. impeller inlet limit curvature ρ₁, design formula is as follows:

(1) as 10 < n_s< when 80, such as Fig. 4 a,

ρ₁=0

(2) as 80 < n_s< when 150, such as Fig. 4 b,

${\mathrm{\&rho;}}_1=0.003633e^{-0.002748n_s}$

(3) as 150 < n_s< when 300, such as Fig. 4 c,

ρ₁=0.01809n_s ^-0.4126

In formula:

ρ₁Impeller inlet limit curvature, rice^-1;

n_sSpecific speed;

14. impeller outlet limit curvature ρ₂, design formula is as follows:

(1) as 10 < n_s< when 80, such as Fig. 5 a,

ρ₂=0

(2) as 80 < n_s< when 150, such as Fig. 5 b,

ρ₂=0.002021-0.0006062cos (0.02055n_s)+0.0002749sin(0.02055n_s)

(3) as 150 < n_s< when 300, such as Fig. 5 c,

${\mathrm{\&rho;}}_2=\frac{0.3989}{n_s+30.18}$

In formula:

ρ₂Impeller outlet limit curvature, rice^-1;

n_sSpecific speed;

Arc radius R between impeller and rear cover plate in 15., design formula is as follows:

$R=0.03323e^{0.0004127n_s}\sqrt[3]{\frac{66Q}{5n}}$

In formula:

Arc radius between impeller and rear cover plate in R, rice;

The flow of Q design conditions, rice³/ the second;

N rotating speed, rev/min;

n_sSpecific speed;

The invention has the beneficial effects as follows:

Provide a kind of single-suction double flow path impeller Hydraulic Design Method, improve the flow state of single-suction double flow path wing pump inside, decrease vibration, it is to increase guide performance, substantially increase the efficiency of pump.

Accompanying drawing explanation

Fig. 1 is the three-dimensional modeling front view of embodiment of the present invention impeller.

Fig. 2 is the three-dimensional modeling vertical view of embodiment of the present invention impeller.

Fig. 3 is the axial plane sectional view of impeller of the present invention.

Fig. 4 is impeller inlet blade drift angle of the present invention view.

Fig. 5 is impeller outlet blade drift angle of the present invention view.

Description of reference numerals:

In Fig. 3: 1 outer impeller vane; 2 middle wallboards; Impeller vane in 3; Impeller inlet diameter in 4; 5 outer impeller inlet diameters; 6 outer impeller outlet widths; Impeller outlet width in 7; 8 impeller outlet diameters.

In Fig. 4: n_sSpecific speed; θ₁₁Interior impeller inlet blade drift angle; θ₁₂Interior impeller outlet blade drift angle; ρ₁Impeller inlet limit curvature.

In Fig. 5: n_sSpecific speed; θ₂₁Outer impeller inlet vane drift angle; θ₂₂Outer impeller outlet blade drift angle; ρ₂Impeller outlet limit curvature.

Embodiment

Fig. 1 and Fig. 2 is the two impeller geometrical shape of list suction and the size that the three-dimensional modeling figure of embodiment of the present invention impeller, Fig. 3 determine this embodiment. The present invention determines single interior impeller inlet diameter D inhaling two impeller by following relational expression_j1, outer impeller inlet diameter D_j2, interior impeller vane length L₁, siphonal lobe wheel blade length L₂, interior impeller inlet blade bias angle theta₁₁, outer impeller inlet vane bias angle theta₂₁, interior impeller outlet blade bias angle theta₁₂, outer impeller outlet blade bias angle theta₂₂, impeller inlet limit curvature ρ₁, impeller outlet limit curvature ρ₂, wait the important design parameter of impeller.

$D_{j1}=\sqrt{{K_1}^2{\left(\sqrt[3]{-0.18765Q+3.158n+0.009425Qn}\right)}^2+{\left(\sqrt[3]{5Mn/\&lsqb;\mathrm{\&tau;}\&rsqb;}\right)}^2}$

$n_s=\frac{3.65n\sqrt{Q}}{H^{3/4}}$

K₁=60.96sin (0.006227n_s+0.4195)+56.73sin(0.006486n_s+3.518)

$D_{j2}=\sqrt{{K_2}^2{\left(\sqrt[3]{-0.18802Q+3.3n+0.009Qn}\right)}^2+{\left(\sqrt[3]{5Mn/\&lsqb;\mathrm{\&tau;}\&rsqb;}\right)}^2}$

K₂=80.47sin (0.006227n_s+0.4195)+74.88sin(0.006486n_s+3.518)

$L_1=\frac{300}{400}{e}^{-{\left(\frac{n_s-41.69}{340.5}\right)}^2}(K_{D2}\sqrt[3]{\frac{Q}{n}}-K_{Dj}{D}_{j1})$

$L_2=1.004{n_s}^{-0.0008053}(K_{D2}\sqrt[3]{\frac{Q}{n}}-K_{Dj}{D}_{j2})$

${\mathrm{\&theta;}}_{11}=\frac{425.52}{\mathrm{\&pi;}}{e}^{-{\left(\frac{n_s-428.3}{545}\right)}^2}$

${\mathrm{\&theta;}}_{21}=\frac{103.23}{\mathrm{\&pi;}}{n_s}^{0.2304}$

${\mathrm{\&theta;}}_{12}=\frac{352.44}{\mathrm{\&pi;}}{e}^{-{\left(\frac{n_s+255.4}{701.4}\right)}^2}$

${\mathrm{\&theta;}}_{22}=\frac{339.48}{\mathrm{\&pi;}}{e}^{-0.001978n_s}$

${\mathrm{\&rho;}}_1=0.003633e^{-0.002748n_s}$

ρ₂=0.002021-0.0006062cos (0.02055n_s)+0.0002749sin(0.02055n_s)

The present invention is generally applicable to a kind of single-suction double flow path impeller Hydraulic Design Method, and design formula is comprehensive, the flow characteristics substantially envisaged in impeller pump, proposes to original creation a kind of single-suction double flow path impeller Hydraulic Design Method.

It is more than the concrete explanation that patent of the present invention is made with reference to embodiment, but the present invention is not limited to above-described embodiment, also comprises other embodiments within the scope of present inventive concept or variation.

Claims (10)

1. a single-suction double flow path impeller, it is characterised in that, described single-suction double flow path impeller is made up of an outer impeller and an interior impeller, and wherein outer impeller is trash-type impeller, and interior impeller is unshrouded impeller, is connected by cover plate between outer impeller and interior impeller.

2. the method for design of a kind of single-suction double flow path impeller according to claim 1, it is characterised in that, the interior impeller inlet diameter D of described single-suction double flow path impeller_j1, outer impeller inlet diameter D_j2, obtain by following formula:

$D_{j1}=\sqrt{{K_1}^2{\left(\sqrt[3]{-0.18765Q+3.158n+0.009425Qn}\right)}^2+{\left(\sqrt[3]{5Mn/\&lsqb;\mathrm{\&tau;}\&rsqb;}\right)}^2}$

$D_{j2}=\sqrt{{K_2}^2{\left(\sqrt[3]{-0.18802Q+3.3n+0.009Qn}\right)}^2+{\left(\sqrt[3]{5Mn/\&lsqb;\mathrm{\&tau;}\&rsqb;}\right)}^2}$

In formula:

D_j1Interior impeller inlet diameter, rice;

D_j2Outer impeller inlet diameter, rice;

Mn axle moment of torsion, newton's rice;

The flow of Q design conditions, rice³/ the second;

The allowable shear strss of [τ] material, handkerchief;

N rotating speed, rev/min;

K₁Interior impeller speed coefficient;

K₂Outer impeller speed coefficient.

3. the method for design of a kind of single-suction double flow path impeller according to claim 1, it is characterised in that, the interior impeller vane length L of described single-suction double flow path impeller₁, siphonal lobe wheel blade length L₂, design formula is as follows:

$L_1=\frac{300}{400}{e}^{-{\left(\frac{n_s-41.69}{340.5}\right)}^2}(K_{D2}\sqrt[3]{\frac{Q}{n}}-K_{Dj}{D}_{j1})$

$L_2=1.004{n_s}^{-0.0008053}(K_{D2}\sqrt[3]{\frac{Q}{n}}-K_{Dj}{D}_{j2})$

In formula:

L₁Interior impeller vane length, rice;

L₂Siphonal lobe wheel blade length, rice;

The flow of Q design conditions, rice³/ the second;

N rotating speed, rev/min;

n_SSpecific speed of hydraulic turbine;

K_D2Impeller outlet diameter correction factor, K_D2=1.022～1.175;

K_DjImpeller inlet diameter correction factor, K_Dj=0.7～1.0.

4. the method for design of a kind of single-suction double flow path impeller according to claim 1, it is characterised in that, the interior impeller inlet blade bias angle theta of described single-suction double flow path impeller₁₁, outer impeller inlet vane bias angle theta₂₁, design formula is as follows:

(1) as 10 < n_s< when 80,

θ₁₁=90 °; θ₂₁=90 °;

(2) as 80 < n_s< when 150,

${\mathrm{\&theta;}}_{11}=\frac{425.52}{\mathrm{\&pi;}}{e}^{-{\left(\frac{n_s-428.3}{545}\right)}^2};$

${\mathrm{\&theta;}}_{21}=\frac{103.23}{\mathrm{\&pi;}}{n_s}^{0.2304};$

(3) as 150 < n_s< when 300,

${\mathrm{\&theta;}}_{11}=\frac{271.08}{\mathrm{\&pi;}}{e}^{0.0009636n_s};$

${\mathrm{\&theta;}}_{21}=\frac{0.3413n_s+274.327}{\mathrm{\&pi;}};$

In formula:

θ₁₁Interior impeller inlet blade drift angle, degree;

θ₂₁Outer impeller inlet vane drift angle, degree;

n_sSpecific speed.

5. the method for design of a kind of single-suction double flow path impeller according to claim 1, it is characterised in that, the interior impeller outlet blade bias angle theta of described single-suction double flow path impeller₁₂, outer impeller outlet blade bias angle theta₂₂, design formula is as follows:

(1) as 10 < n_s< when 80,

θ₁₂=90 °; θ₂₂=90 °;

(2) as 80 < n_s< when 150,

${\mathrm{\&theta;}}_{12}=\frac{352.44}{\mathrm{\&pi;}}{e}^{-{\left(\frac{n_s+255.4}{701.4}\right)}^2};$

${\mathrm{\&theta;}}_{22}=\frac{339.48}{\mathrm{\&pi;}}{e}^{-0.001978n_s};$

(3) as 150 < n_s< when 300,

${\mathrm{\&theta;}}_{12}=\frac{1}{\mathrm{\&pi;}}(7.05e^{0.004536n_s}+327.78e^{-0.001389n_s});$

${\mathrm{\&theta;}}_{22}=\frac{1}{\mathrm{\&pi;}}(-0.4221n_s+315);$

In formula:

n_SSpecific speed of hydraulic turbine;

θ₁₂Interior impeller outlet blade drift angle, degree;

θ₂₂Outer impeller outlet blade drift angle, degree.

6. the method for design of a kind of single-suction double flow path impeller according to claim 1, it is characterised in that, the impeller inlet limit curvature ρ of described single-suction double flow path impeller₁, impeller outlet limit curvature ρ₂, design formula is as follows:

(1) as 10 < n_s< when 80,

ρ₁=0; ρ₂=0;

(2) as 80 < n_s< when 150,

${\mathrm{\&rho;}}_1=0.003633e^{-0.002748n_s};$

ρ₂=0.002021-0.0006062cos (0.02055n_s)+0.0002749sin(0.02055n_s);

(3) as 150 < n_s< when 300,

ρ₁=0.01809n_s ^-0.4126;

${\mathrm{\&rho;}}_2=\frac{0.3989}{n_s+30.18};$

In formula:

n_SSpecific speed of hydraulic turbine;

ρ₁Impeller inlet limit curvature, rice^-1;

ρ₂Impeller outlet limit curvature, rice^-1。

7. the method for design of a kind of single-suction double flow path impeller according to claim 1, it is characterised in that, the arc radius R between the interior impeller of described single-suction double flow path impeller and rear cover plate, design formula is as follows:

$R=0.03323e^{0.0004127n_s}\sqrt[3]{\frac{66Q}{5n}}$

In formula:

n_SSpecific speed of hydraulic turbine;

Arc radius between impeller and rear cover plate in R, rice.

8. the method for design of a kind of single-suction double flow path impeller according to claim 1, it is characterised in that, the interior impeller speed COEFFICIENT K of described single-suction double flow path impeller₁, design formula is as follows:

(1) efficiency is mainly considered

$K_1=3.509e^{0.0004427n_s}$

(2) efficiency and cavitation is taken into account

K₁=60.96sin (0.006227n_s+0.4195)+56.73sin(0.006486n_s+3.518)

(3) cavitation is mainly considered

$K_1=962.3e^{-{\left(\frac{n_s-0.0001657}{7145}\right)}^2}$

In formula:

n_SSpecific speed of hydraulic turbine;

K₁Interior impeller speed coefficient.

9. the method for design of a kind of single-suction double flow path impeller according to claim 1, it is characterised in that, the outer impeller speed COEFFICIENT K of described single-suction double flow path impeller₂, design formula is as follows:

(1) efficiency is mainly considered

$K_2=4.632e^{0.0004427n_s}$

(2) efficiency and cavitation is taken into account

K₂=80.47sin (0.006227n_s+0.4195)+74.88sin(0.006486n_s+3.518)

(3) cavitation is mainly considered

$K_2=1270e^{-{\left(\frac{n_s-0.0001657}{7145}\right)}^2}$

In formula:

n_SSpecific speed of hydraulic turbine;

K₂Outer impeller speed coefficient.

10. the method for design of a kind of single-suction double flow path impeller described in claim any one of claim 3-9, it is characterised in that, specific speed n_sFor:Wherein, H is the lift of design conditions, and Q is the flow of design conditions, and n is rotating speed.