CN102359454A - Design method for cutting performance of inclined flow pump impeller - Google Patents

Abstract

The invention discloses a design method for the cutting performance of an inclined flow pump impeller. A blade adopts a mode of aslant cutting or cutting in parallel to an outlet edge. Meanwhile, a relation of the external diameter of an impeller outlet, water pump specific revolving speed and water pump performance is built. With the design method, the same inclined flow pump impeller can be cut for several times with multiple methods to obtain a plurality of performance parameters, the standardization and the serialization level of an inclined flow pump are improved, and development cost is saved so as to satisfy the requirements of multiple parameter working conditions of the inclined flow pump by the water conservancy and municipal engineering.

Description

A kind of diagonal pumps impeller cutting performance design method

Technical field

The present invention relates to a kind of water pump vane cutting performance design method, is a kind of diagonal pumps impeller cutting performance design method specifically.

Background technique

Specific speed is less than 300 the centrifugal pump that is referred to as, specific speed 300～500 be referred to as diagonal pumps.The centrifugal pump impeller outlet becomes 90 ° with the water pump rotating shaft, and the diagonal pumps impeller outlet becomes 30～60 ° with the water pump rotating shaft.At present, known centrifugal pump impeller cutting performance design method is a similarity law, and the formula of pump performance is following after the cutting that this method is confirmed:

${\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">Q</figure-callout>}}_2=Q_1\left(\frac{D_2}{D_1}\right)$

$H_2=H_1{\left(\frac{D_2}{D_1}\right)}^2$

D2 in the formula---cutting back impeller outer diameter, rice;

D1---impeller outer diameter before the cutting, rice;

Q2---cutting back pump capacity, rice ³/ second;

Q1---pump capacity before the cutting, rice ³/ second;

H2---cutting back pump head, rice;

H1---pump head before the cutting, rice.

But because centrifugal pump and diagonal pumps are different with angle between the water pump rotating shaft, above-mentioned formula is used for the design of diagonal pumps cutting performance, is not inconsistent with actual conditions, and error is very big.

Summary of the invention

It is little that technical problem to be solved by this invention provides a kind of error, can obtain a plurality of diagonal pumps performance parameters, improves the diagonal pumps impeller cutting performance design method of diagonal pumps standardization, seriation level.

In order to solve the problems of the technologies described above; The technological scheme that the present invention adopts is: the diagonal pumps impeller adopt cut sth. askew or with the mode of the outlet parallel cutting in limit (abbreviation truncation); Calculate the equivalent diameter of cutting front and back earlier, again pump performance parameters (flow and lift) and equivalent diameter and specific speed of pump set up following relation:

${\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">Q</figure-callout>}}_2=Q_1{\left(\frac{D_2}{D_1}\right)}^{1.102+0.0018N}$

$H_2=H_1{\left(\frac{D_2}{D_1}\right)}^{1.558+0.0063N}$

${\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">D</figure-callout>}}_2=\sqrt{\frac{D_{21}^2+D_{22}^2}{2}}$

${\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">D</figure-callout>}}_1=\sqrt{\frac{D_{11}^2+D_{12}^2}{2}}$

$N=\frac{3.65n\sqrt{Q_1}}{{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">H</figure-callout>}}_1^{3/4}}$

D2 in the formula---cutting back impeller outlet equivalent diameter, rice;

D21---cutting back impeller outlet external profile diameter, rice;

D22---cutting back impeller outlet inner edge diameter, rice;

D1---impeller outlet equivalent diameter before the cutting, rice;

D11---impeller outlet external profile diameter before the cutting, rice;

D12---impeller outlet inner edge diameter before the cutting, rice;

Q2---cutting back pump capacity, rice ³/ second;

Q1---pump capacity before the cutting, rice ³/ second;

H2---cutting back pump head, rice;

H1---pump head before the cutting, rice;

N---specific speed of pump;

N---pump rotary speed, rev/min.

The invention has the beneficial effects as follows: set up pump performance parameters and impeller outlet external diameter, particularly with the relation of specific speed of pump.Can carry out repeatedly multi-method cutting to same diagonal pumps impeller, obtain a plurality of performance parameters, error is little, has improved diagonal pumps standardization, seriation level, has practiced thrift development cost, thereby satisfies water conservancy and the municipal engineering demand to the multi-parameter operating mode of diagonal pumps.

Description of drawings

Fig. 1 is impeller cutting front pinacoid figure.

Fig. 2 is axial plane figure after blade is cut sth. askew.

Fig. 3 is axial plane figure after the blade truncation.

Among the figure: 1. blade, 2. wheel hub, 3. impeller outlet external profile diameter before the cutting, 4. impeller outlet inner edge diameter before the cutting, 5. cutting back impeller outlet external profile diameter, 6. cutting back impeller outlet inner edge diameter.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is described further.

Referring to Fig. 1, Fig. 2 and Fig. 3, wheel hub 2 and blade 1 have been confirmed the shape of diagonal pumps impellers jointly.Adopt cut sth. askew blade 1 or Fig. 3 of Fig. 2 signal to illustrate truncation blade 1 mode, all can confirm cutting performance through following relation:

${\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">Q</figure-callout>}}_2=Q_1{\left(\frac{D_2}{D_1}\right)}^{1.102+0.0018N}$

$H_2=H_1{\left(\frac{D_2}{D_1}\right)}^{1.558+0.0063N}$

${\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">D</figure-callout>}}_2=\sqrt{\frac{D_{21}^2+D_{22}^2}{2}}$

${\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">D</figure-callout>}}_1=\sqrt{\frac{D_{11}^2+D_{12}^2}{2}}$

$N=\frac{3.65n\sqrt{Q_1}}{{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000090224980000011.png,HDA0000090224980000012.png"\; state="\{\{state\}\}">H</figure-callout>}}_1^{3/4}}$

D2 in the formula---cutting back impeller outlet equivalent diameter, rice;

D21---cutting back impeller outlet external profile diameter, rice;

D22---cutting back impeller outlet inner edge diameter, rice;

D1---impeller outlet equivalent diameter before the cutting, rice;

D11---impeller outlet external profile diameter before the cutting, rice;

D12---impeller outlet inner edge diameter before the cutting, rice;

Q2---cutting back pump capacity, m3/s;

Q1---pump capacity before the cutting, m3/s;

H2---cutting back pump head, rice;

H1---pump head before the cutting, rice;

N---specific speed of pump;

N---pump rotary speed, rev/min;

Such cutting performance design method can obtain a plurality of diagonal pumps performance parameters, improves diagonal pumps standardization, seriation level.

Personnel in the present technique field should be realized that the foregoing description is not with the qualification of the present invention of opposing, as long as in connotation scope of the present invention, any the foregoing description technique variation, flexible program are not all exceeded protection scope of the present invention.

Claims (1)

1. diagonal pumps impeller cutting performance design method; It is characterized in that: the diagonal pumps impeller adopt cut sth. askew or with the mode of the outlet parallel cutting in limit; Calculate earlier the equivalent diameter before and after the cutting, again pump performance parameters flow and lift and equivalent diameter and specific speed of pump set up following relation:

$Q_2=Q_1{\left(\frac{D_2}{D_1}\right)}^{1.102+0.0018N}$

$H_2=H_1{\left(\frac{D_2}{D_1}\right)}^{1.558+0.0063N}$

$D_2=\sqrt{\frac{D_{21}^2+D_{22}^2}{2}}$

$D_1=\sqrt{\frac{D_{11}^2+D_{12}^2}{2}}$

$N=\frac{3.65n\sqrt{Q_1}}{H_1^{3/4}}$

D2 in the formula---cutting back impeller outlet equivalent diameter, rice;

D21---cutting back impeller outlet external profile diameter, rice;

D22---cutting back impeller outlet inner edge diameter, rice;

D1---impeller outlet equivalent diameter before the cutting, rice;

D11---impeller outlet external profile diameter before the cutting, rice;

D12---impeller outlet inner edge diameter before the cutting, rice;

Q2---cutting back pump capacity, rice ³/ second;

Q1---pump capacity before the cutting, rice ³/ second;

H2---cutting back pump head, rice;

H1---pump head before the cutting, rice;

N---specific speed of pump;

N---pump rotary speed, rev/min.

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