CN102003407A - Design method for high-efficiency overload-free vortex pump impeller - Google Patents

Abstract

The invention relates to a design method for a high-efficiency overload-free vortex pump impeller. By designing blades of the impeller to be cambered blades with double curvature or single curvature and designing installation performance parameters of the outlet diameter of the blades, the outlet diameter of the blades changes according to a certain rule. The vortex loss of the impeller at the outlet can be reduced, and overload is not produced for the operation in a full-head range while the vortex pump runs at a high-efficiency region.

Description

A kind of efficient nothing overload torque flow pump impeller design method

Technical field

The present invention relates to a kind of design method of non-varactor pump major part, particularly a kind of efficient nothing overload torque flow pump impeller design method.

Background technique

At present, what existing torque flow pump adopted is the radioactivity impeller, and this impeller can only guarantee that torque flow pump moves in very narrow range of flow, if but operating conditions exceeds the range of operation of pump, and may cause motor to burn.But the operating conditions of torque flow pump varies, bigger variation can appear in the pump-unit lift, causes torque flow pump actual conditions point to move in big range of flow.According to statistics, in the engineering submersible pump of reprocessing, its fault has 70% to be caused by overload approximately.Motor caused the reliability of this class pump lower because of overload loses efficacy, and had limited the using scope of torque flow pump greatly.The impeller that this just requires us to design can move in big range of flow and not transship.

The main path of head it off was to strengthen the power backup coefficient in the past, on the air horsepower of torque flow pump design point, multiply by a foundation that is not less than 1.4 coefficient as the apolegamy motor, this coefficient causes investment to increase and energy waste obviously greater than the respective value 1.1-1.2 of centrifugal pump.

Summary of the invention

For solving the deficiency of existing torque flow pump impeller performance, the invention provides a kind of efficient nothing overload torque flow pump impeller design method.By the Blade Design with impeller is the arc shaped blade of double curvature or single-curvature, and the outlet diameter installation capability parameter of blade designs, and makes the outlet diameter of blade change according to certain rules.Can reduce impeller in the loss of the whirlpool in outlet port, not only satisfy the requirement of suitable for casting, also satisfy torque flow pump and in no overload level, move the requirement that can not occur transshipping with the impeller geometric parameter of the present invention's design.Therefore, the capacity of apolegamy motor be can reduce, investment, energy saving reduced.

Realize that above-mentioned purpose adopted technological scheme:

1, the external diameter of impeller

The formula of impeller outer diameter $D_2=16\frac{\sqrt{2\mathrm{gH}}}{n{\left(\sin {\mathrm{\β}}_2\right)}^{0.25}};$

In the formula: D ₂-impeller outer diameter, rice;

The lift of H-design conditions, rice;

The n-wheel speed, rev/min;

β ₂-impeller blade outlet laying angle, degree;

α-blade exit tilt angle, degree.

2, blade exit width

Blade exit width formula: $\frac{b_2}{D_2}=0.00055{n_s}^{1.25};$

In the formula: b ₂-impeller blade exit width, rice;

D ₂-impeller outer diameter, rice;

n _s-specific speed, rev/min;

3, blade exit laying angle

Blade exit laying angle β ₂=15 °～25 °, specific speed gets the small value greatly;

4, subtended angle of blade

Subtended angle of blade

5, blade exit tilt angle

Blade exit inclined angle alpha=5 °～25 °.

The invention has the beneficial effects as follows: the impeller geometric parameter not only satisfies the requirement of suitable for casting, and can also move in no overload level and can not occur transshipping guaranteeing to satisfy torque flow pump in the operation of efficient district.

Description of drawings

Fig. 1 is the impeller blade figure of one embodiment of the invention;

Fig. 2 is same embodiment's an impeller axial plane sectional view;

Among the figure: 1. back shroud of impeller, 2. impeller blade outside diameter, 3. blade, 4. impeller blade exit width, 5. blade exit tilt angle, 6. impeller blade outlet laying angle, 7. impeller cornerite

Embodiment

Fig. 1 and Fig. 2 have determined this embodiment's impeller shape jointly.It is the same with most of centrifugal pump impellers, has back shroud of impeller (1), is a kind of unshrouded impeller.The present invention determines the exit width b of impeller blade by following relation ₂, impeller blade outside diameter D ₂, impeller blade outlet laying angle β ₂, the impeller blade cornerite With the blade exit inclined angle alpha, make the satisfied nothing overload of torque flow pump performance requirement among this embodiment.

$D_2=16\frac{\sqrt{2\mathrm{gH}}}{n{\left(\sin {\mathrm{\β}}_2\right)}^{0.25}};$

$\frac{b_2}{D_2}=0.00055{n_s}^{1.25};$

β ₂＝15°～25°；

α＝5°～25°。

In the drawings, blade exit laying angle (6) chooses and specific speed n _sSize relevant, specific speed is big, the outlet laying angle (6) get the small value.Subtended angle of blade is chosen between 150 °～220 ° according to the difficulty or ease situation of casting and sand removal.

Claims (1)

1. one kind is not efficiently had overload torque flow pump impeller design method, the design formula of blade main geometric parameters external diameter, exit width, outlet laying angle and subtended angle of blade.It is characterized in that: the port radius that goes out to blade designs according to certain rule, when impeller is concerned below satisfying:

$D_2=16\frac{\sqrt{2\mathrm{gH}}}{n{\left(\sin {\mathrm{\β}}_2\right)}^{0.25}};$

$\frac{b_2}{D_2}=0.00055{n_s}^{1.25};$

β ₂＝15°～25°；

Satisfy blade exit inclined angle alpha=5 °～25 °.

In the formula: the lift of H-design conditions, rice;

D ₂-impeller outer diameter, rice;

b ₂-impeller blade exit width, rice;

β ₂-impeller blade outlet laying angle, degree.

The n-wheel speed, rev/min

n _s-specific speed, rev/min;

-impeller blade cornerite, degree;

α-blade exit tilt angle, degree.

Images