CN105971929A - Structure design method for V-shaped cutting structure of edge folding blades at inlet end of impeller of double suction pump - Google Patents

Abstract

The invention discloses a structure design method for a V-shaped cutting structure of edge folding blades at the inlet end of an impeller of a double suction pump. The cavitation prevention performance of the double suction pump is reduced due to the fact that the blades are cut at an outlet, and therefore the cavitation prevention performance of the pump is improved in manners that the cutting shape and degree are reasonably controlled, the edge folding inlet blades are adopted to be staggered at an inlet of the impeller, the blades at the outlet are cut to be of a V-shaped structure, the staggered blades are designed to have different inlet setting angles and wrap angles, and different blade widths exist at the inlet of the impeller, according to the actual requirement of the edge folding blades, the impeller inlet equivalent diameter, the impeller inlet diameter, the impeller outlet diameter, the impeller outlet width, the blade outlet setting angles, the blade wrap angles, the actual outer diameter obtained after cutting and the thickness of each blade at the outlet of the impeller are reasonably designed, and the area of the inlet of the impeller and the flowing state in a runner are changed in the running process of the double suction pump.

Description

A kind of double-suction pump impeller entrance point edge folding blades V-type cutting construction design method

Technical field

The present invention relates to a kind of double-suction pump impeller blade construction method for designing, particularly to a kind of double-suction pump impeller import End edge folding blades V-type cutting construction design method.

Background technology

Pump is a kind of application universal machine the most widely, of a great variety, has inseparable pass with the life of the mankind System, every place having liquid to flow, nearly all there is the operation work of pump.Along with scientific and technological level constantly improves, pump is transported Field the most constantly expand.Double entry pump is the most common a kind of pump, due to it have that flow is big, lift is high, simple in construction, The features such as maintenance is convenient, are widely used in various hydraulic engineering field, are the one being most widely used in various pump, extensively It is applied in each department of the social lifes such as city water, petrochemical industry, shipping industry agricultural irrigation and national economy.Therefore Double suction pump performance is proposed the highest requirement, the requirement that runs such as inclined stable conditions, the requirement of low-noise vibrating and High reliability etc..But in engineering reality, it is frequently present of pump head far above the situation of lift needed for output system.This is usually The requirement of different user is met so that it is can work, simultaneously under specific lift and flow point by the way of cutting impeller Reach the purpose of energy saving in pumping station.Owing to cut-off blade causes internal flow in double entry pump running to change and anti-cavitation Can decline, easily make double entry pump generation cavitation, the generation of cavitation often affects the proper flow of fluid in pump, produce vibration, Degradation series of problems under noise, flow passage components corrosion failure and pump performance, even affect when cavitation is serious whole system without Method is properly functioning.

Summary of the invention

For problem produced in double entry pump running, the invention provides a kind of double-suction pump impeller entrance point flanging Blade V-type cutting construction design method.Due to exit cut-off blade, cause double entry pump anti-cavitation hydraulic performance decline, the most permissible By reasonably controlling cutting profile and degree, flanging inlet side blade is used to make blade stagger at impeller inlet, exit Blade cuts is V-structure, and the blade that design is staggered has different import laying angles and cornerite and has difference at impeller inlet Width of blade, go out the import equivalent diameter of impeller, impeller inlet diameter, leaf according to the actual requirement appropriate design of edge folding blades Take turns leaf at the actual outside diameter after outlet diameter, impeller outlet width, blade exit laying angle, subtended angle of blade, cutting, impeller outlet Sheet thickness, the flow regime in the area of change double entry pump impeller import department in running and runner, so that pump is anti- Cavitation performance improves.

1, impeller inlet equivalent diameter D₀Determined by following formula:

$D_0=\left\{\begin{array}{c}(4.5n^{-0.333}{Q}^{0.333}+\frac{H}{150}{n}^{-0.333}{Q}^{0.333})(H\≤100)\\ (5.1n^{-0.333}{Q}^{0.333}+\frac{H}{150}{n}^{-0.333}{Q}^{0.333})(H>100)\end{array}\right.$

In formula:

D₀Impeller inlet equivalent diameter, m；

Q flow, m³/s；

H lift, m；

N rotating speed, rev/min；

2, impeller blade entrance width b₁Determined by below equation:

(a) impeller flanging blade entrance width b₁₁Determined by below equation:

$b_{11}=\left\{\begin{array}{c}0.06D_0+0.001n^{-1}{\left(2gH\right)}^{0.5}(H\≤100)\\ 0.07D_0+0.0021n^{-1}{\left(2gH\right)}^{0.5}(H>100)\end{array}\right.$

(b) impeller flanging lower blade entrance width b₁₂Determined by below equation:

$b_{12}=\left\{\begin{array}{c}0.04D_0+0.0004n^{-1}{\left(2gH\right)}^{0.5}(H\≤100)\\ 0.03D_0+0.0012n^{-1}{\left(2gH\right)}^{0.5}(H>100)\end{array}\right.$

In formula:

b₁₁Blade entrance width, m；

b₁₂Lower blade entrance width, m；

N rotating speed, rev/min；

D₀Impeller inlet equivalent diameter, m

Q flow, m³/s；

H lift, m；

G acceleration of gravity, m²/s；

3, impeller outlet diameter D₂Determined by following formula:

$D_2=\left\{\begin{array}{c}(1.37Z^{0.01}-0.2)(8.7n^{-0.833}{Q}^{0.083}{H}^{0.375}{\left(2g\right)}^{0.5}+0.01)(H\≤100)\\ 8.6(1.37Z^{0.01}-0.2)n^{-0.833}{Q}^{0.083}{H}^{0.375}{\left(2g\right)}^{0.5}(H>100)\end{array}\right.$

In formula:

D₂Impeller outlet diameter, m；

The Z number of blade, piece；

N rotating speed, rev/min；

Q flow, m³/s；

H lift, m；

G acceleration of gravity, m²/s；

4, vane inlet lays angle beta₁Size is determined by following formula:

A angle beta is laid in the flanging blade import of () impeller₁₁Determined by below equation:

${\mathrm{\β}}_{11}=\left\{\begin{array}{c}arctan\left(\right(0.07Z+0.7\left)\frac{80Q}{{\mathrm{nD}}_0^2{b}_{11}}\right)(H\≤100)\\ \arctan \left(\right(1.21Z^{0.02}+0.02\left)\frac{70Q}{{\mathrm{nD}}_0^2{b}_{11}}\right)(Q>3600)\end{array}\right.$

B angle beta is laid in the flanging lower blade import of () impeller₁₂Determined by below equation:

${\mathrm{\β}}_{12}=\left\{\begin{array}{c}arctan\left(\right(0.07Z+0.7\left)\frac{80Q}{{\mathrm{nD}}_0^2{b}_{12}}\right)(H\≤100)\\ \arctan \left(\right(1.21Z^{0.02}+0.02\left)\frac{70Q}{{\mathrm{nD}}_0^2{b}_{12}}\right)(H>100)\end{array}\right.$

In formula:

β₁₁Blade import laying angle, °；

β₁₂Lower blade import laying angle, °；

D₀Impeller inlet equivalent diameter, m；

b₁₁Upper impeller inlet width, m；

b₁₂Lower impeller entrance width, m；

Q flow, m³/s；

The Z number of blade, piece；

5, blade exit width b₂Size is determined by following formula:

$b_2=(1.1~1.2)\frac{D_0(b_{11}+b_{12})}{D_2}$

In formula:

b₂Impeller outlet width, m；

D₀Impeller inlet equivalent diameter, m；

D₂Impeller outlet diameter, m；

b₁₁Upper impeller inlet width, m；

b₁₂Lower impeller entrance width, m；

6, subtended angle of bladeSize is determined by following formula:

(a) impeller flanging blade corneriteDetermined by below equation:

(b) impeller flanging lower blade corneriteDetermined by below equation:

In formula:

Blade cornerite, °；

Lower blade cornerite, °；

D₀Impeller inlet equivalent diameter, m；

D₂Impeller outlet diameter, m；

7, the import department thickness S of impeller blade₁Determined by below equation

(a) impeller flanging blade import department thickness S₁₁Determined by below equation:

S₁₁=0.8 (1+Z^-0.02)(b₁₁+b₁₂)

(b) impeller flanging lower blade import department thickness S₁₂Determined by below equation:

S₁₂=0.3 (1+Z^-0.07)(b₁₁+b₁₂)

In formula:

S₁₁Impeller flanging blade import department thickness, m；

S₁₂Impeller flanging lower blade import department thickness, m；

The Z number of blade, piece；

b₁₁Upper impeller inlet width, m；

b₁₂Lower impeller entrance width, m；

8, actual outside diameter D' after the cutting of impeller blade exit₂Determined by below equation:

D'₂=D₂-b₂tanθ

In formula:

D'₂Actual outside diameter after the cutting of impeller blade exit, m；

D₂Impeller outlet diameter, m；

b₂Impeller outlet width, m；

θ impeller blade exit cutting angle, 0 °～15 °；

The invention has the beneficial effects as follows:

By the optimum structure parameter of the blade appropriate design double entry pump at flanging impeller outlet, can effectively alleviate double entry pump Impact loss at impeller inlet, improves anti-cavitation performance and the feasibility of operation of centrifugal pump, the effective water improving impeller Force efficiency and the noise and the vibration problem that alleviate centrifugal pump；Improve the stability in double suction pump performance and running.

Accompanying drawing explanation

Fig. 1 is the plane figure of the embodiment of the present invention.

Fig. 2 is the axial plane figure of the embodiment of the present invention.

Fig. 3 is that the present invention implements impeller blade schematic diagram.

Fig. 1: β₁₁Blade stagger angle, β₁₂Lower blade stagger angle,Blade cornerite,Inferior lobe Sheet cornerite.

Fig. 2: D₀Impeller inlet equivalent diameter, D₂Impeller outlet diameter, b₁₁Blade entrance width, b₁₂Inferior lobe Sheet entrance width, S₁₁Impeller flanging blade import department thickness, S₁₂Impeller flanging lower blade import department thickness.

Fig. 3: 1 impeller blade, 2 impeller lower blades.

Detailed description of the invention

Design requires: design conditions flow is 0.096764 cube of meter per second, and design conditions lift is 60 meters, and rotating speed is 2900 revolutions per seconds, g takes 10 meters/square metre, and the number of blade takes 4 pieces.

The numerical value of impeller structure parameter: D can be obtained according to data above₀=170mm；D₂=390mm；D’₂=300mm；β₁₁ =20 °；β₁₂=22 °；b₁₁=11mm；b₁₂=8mm；S₁₁=6mm；S₁₂=5mm.

In the design process, the selection of other coefficient needs to carry out coefficient according to concrete practical situation and choose, such as impeller Spiral case parameter needs to select according to the actual motion of pump.

Above, by the present invention with reference to illustrating that embodiment is made, but the present invention is not limited to above-described embodiment, Also the other embodiments in the range of present inventive concept or variation are comprised.

Claims (8)

1. a double-suction pump impeller entrance point edge folding blades V-type cutting construction design method, it is characterised in that: at design double entry pump During impeller blade, impeller blade entrance point uses layering folded edges；Wherein impeller inlet equivalent diameter D₀Determined by following formula:

$D_0=\left\{\begin{array}{c}(4.5n^{-0.333}{Q}^{0.333}+\frac{H}{150}{n}^{-0.333}{Q}^{0.333})(H\≤100)\\ (5.1n^{-0.333}{Q}^{0.333}+\frac{H}{150}{n}^{-0.333}{Q}^{0.333})(H>100)\end{array}\right.$

In formula:

D₀Impeller inlet equivalent diameter, m；

Q flow, m³/s；

H lift, m；

N rotating speed, rev/min.

2. a kind of double-suction pump impeller entrance point edge folding blades V-type cutting construction design method, its feature exists In: impeller blade entrance width b₁Determined by below equation:

(a) impeller flanging blade entrance width b₁₁Determined by below equation:

$b_{11}=\left\{\begin{array}{c}0.06D_0+0.001n^{-1}{\left(2gH\right)}^{0.5}(H\≤100)\\ 0.07D_0+0.0021n^{-1}{\left(2gH\right)}^{0.5}(H>100)\end{array}\right.$

(b) impeller flanging lower blade entrance width b₁₂Determined by below equation:

$b_{12}=\left\{\begin{array}{c}0.04D_0+0.0004n^{-1}{\left(2gH\right)}^{0.5}(H\≤100)\\ 0.03D_0+0.0012n^{-1}{\left(2gH\right)}^{0.5}(H>100)\end{array}\right.$

In formula:

b₁₁Upper impeller inlet width, m；

b₁₂Lower impeller entrance width, m；

D₀Impeller inlet equivalent diameter, m；

N rotating speed, rev/min；

H lift, m；

G acceleration of gravity, m²/s。

3. a kind of double-suction pump impeller entrance point edge folding blades V-type cutting construction design method, its feature exists In: impeller outlet diameter D₂Determined by following formula formula:

In formula:

D₂Impeller outlet diameter, m；

The Z number of blade, piece；

N rotating speed, rev/min；

Q flow, m³/s；

H lift, m；

G acceleration of gravity, m²/s。

4. a kind of double-suction pump impeller entrance point edge folding blades V-type cutting construction design method, its feature exists In: angle beta is laid in impeller blade import₁Determined by below equation:

A angle beta is laid in the flanging blade import of () impeller₁₁Determined by below equation:

${\mathrm{\β}}_{11}=\left\{\begin{array}{c}arctan\left(\right(0.07Z+0.7\left)\frac{80Q}{{\mathrm{nD}}_0^2{b}_{11}}\right)(H\≤100)\\ \arctan \left(\right(1.21Z^{0.02}+0.02\left)\frac{70Q}{{\mathrm{nD}}_0^2{b}_{11}}\right)(Q>3600)\end{array}\right.$

B angle beta is laid in the flanging lower blade import of () impeller₁₂Determined by below equation:

${\mathrm{\β}}_{12}=\left\{\begin{array}{c}arctan\left(\right(0.07Z+0.7\left)\frac{80Q}{{\mathrm{nD}}_0^2{b}_{12}}\right)(H\≤100)\\ \arctan \left(\right(1.21Z^{0.02}+0.02\left)\frac{70Q}{{\mathrm{nD}}_0^2{b}_{12}}\right)(H>100)\end{array}\right.$

In formula:

β₁₁Blade import laying angle, °；

β₁₂Lower blade import laying angle, °；

D₀Impeller inlet equivalent diameter, m；

b₁₁Upper impeller inlet width, m；

b₁₂Lower impeller entrance width, m；

Q flow, m³/s；

The Z number of blade, piece.

5. a kind of double-suction pump impeller entrance point edge folding blades V-type cutting method construction design method, it is special Levy and be: impeller blade exit width b₂Determined by below equation:

$b_2=(1.1~1.2)\frac{D_0(b_{11}+1.1b_{12})}{D_2}$

In formula:

b₂Impeller outlet width, m；

D₀Impeller inlet equivalent diameter, m；

D₂Impeller outlet diameter, m；

b₁₁Upper impeller inlet width, m；

b₁₂Lower impeller entrance width, m.

6. a kind of double-suction pump impeller entrance point edge folding blades V-type cutting construction design method, its feature exists In: impeller blade corneriteDetermined by below equation:

(a) impeller flanging blade corneriteDetermined by below equation:

(b) impeller flanging lower blade corneriteDetermined by below equation:

In formula:

Blade cornerite, °；

Lower blade cornerite, °；

D₀Impeller inlet equivalent diameter, m；

D₂Impeller outlet diameter, m.

7. a kind of double-suction pump impeller entrance point edge folding blades V-type cutting construction design method, its feature exists In: the import department thickness S of impeller blade₁Determined by below equation:

(a) impeller flanging blade import department thickness S₁₁Determined by below equation:

S₁₁=0.8 (1+Z^-0.02)(b₁₁+b₁₂)

(b) impeller flanging lower blade import department thickness S₁₂Determined by below equation:

S₁₂=0.3 (1+Z^-0.07)(b₁₁+b₁₂)

In formula:

S₁₁Impeller flanging blade import department thickness, m；

S₁₂Impeller flanging lower blade import department thickness, m；

The Z number of blade, piece；

b₁₁Upper impeller inlet width, m；

b₁₂Lower impeller entrance width, m.

8. a kind of double-suction pump impeller entrance point edge folding blades V-type cutting construction design method, its feature exists In: actual outside diameter D' after the cutting of impeller blade exit₂Determined by below equation:

D'₂=D₂-b₂tanθ

In formula:

D'₂Actual outside diameter after the cutting of impeller blade exit, m；

D₂Impeller outlet diameter, m；

b₂Impeller outlet width, m；

θ impeller blade exit cutting angle, 0 °～15 °.