CN102691671A - Designing method of impeller core main pump wheel - Google Patents

Abstract

The invention relates to a designing method of an impeller core main pump wheel, and provides a designing formula of a main geometrical parameter inlet diameter of an impeller, an outer circle diameter of the impeller, and an outlet width of blades of the impeller. The thickness of a front cover plate side of each blade of the impeller is 30% less than that of a back cover plate side; the thickness of each blade is uniformly thickened from the front cover plate side to the back cover plate side according to the linearity; and the thickness of the impeller from an inlet edge to the outlet along a flowing line direction is gradually increased, wherein the thickness of the inlet edge is 45% of the that of an outlet edge. A flowing line wrap angle of the part, which is close to the front cover plate side, of the impeller is 10 degrees greater than a flowing line wrap angle which is close to the back cover plate side. The impeller comprises 6-8 blades.

Description

A kind of nuclear main pump impeller design method

Technical field

The present invention relates to a kind of design method of examining the major part of main pump, particularly a kind of nuclear main pump impeller design method.

Background technique

In reactor coolant loop, the nuclear main pump is unique rotating equipment, also is a circuit pressure edge device.In nuclear power station one loop; The nuclear main pump is used to drive freezing mixture and in RCP (reactor cooling system) system, circulates; Continuously heat transferred steam generator secondary side (secondary circuit) circulating water that produces in the reactor core, to confirm the reactor stable operation.

Circulating water in a circuit cycle is through contacting with nuclear reactor; Absorb and the transmission great amount of heat, the temperature of circulating water, pressure are very high, also have radioactivity; Therefore the nuclear main pump that drives circulating water has the requirement of HTHP; And the nuclear main pump is unique equipment that runs up in the nuclear island, no matter is to Security or to performance, and its requirement is all high a lot of than common water pump.

The nuclear main pump mainly is made up of parts such as pump case, impeller, stator, motors; And impeller is the most crucial hydraulic part of nuclear main pump; Also be unique moving element, the geometric parameter of impeller is very big to nuclear main pump performance impact, so impeller has material impact to Security and the hydraulic performance of examining main pump.

Summary of the invention

For addressing the above problem, the invention provides a kind of nuclear main pump impeller design method.Through improving the design method of the several important design parameter of impeller, improve mobility status, improve the hydraulic performance and the reliability of nuclear main pump.

Realize that the technological scheme that above-mentioned purpose adopted is:

The main structure parameters of nuclear main pump impeller is obtained by following computational methods:

(1) impeller inlet diameter D _j

$D_j=(4+\frac{n_s-200}{100})\&CenterDot;\sqrt[3]{\frac{Q}{\mathrm{<figure-callout\; id="3"\; label="n"\; filenames="DEST\_PATH\_HSB00000842254800011.png"\; state="\{\{state\}\}">n</figure-callout>}}}$

In the formula: D _j-impeller inlet diameter, rice;

The flow of Q-design conditions, cube meter per second;

The n-wheel speed, rev/min;

n _s-specific speed.

(2) impeller outlet diameter D ₂

Getting the impeller outlet diameter is the arithmetic mean value of impeller front and rear cover plate diameter.

$D_2=\frac{D_{20}+D_{2h}}{2}=(1.083+\frac{n_s-650}{3571})\&CenterDot;(1+\frac{n_s-110}{{10}^5})\&CenterDot;\sqrt[3]{\frac{Q}{\mathrm{<figure-callout\; id="3"\; label="n"\; filenames="DEST\_PATH\_HSB00000842254800011.png"\; state="\{\{state\}\}">n</figure-callout>}}}$

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

D ₂₀The maximum outlet diameter of-impeller, rice;

D _2hThe minimum outlet diameter of-impeller, rice;

The flow of Q-design conditions, cube meter per second;

The n-wheel speed, rev/min;

n _s-specific speed.

(3) exit width b ₂

$b_2=(1.05-\frac{n_s-200}{1263})\&CenterDot;(1-2\&CenterDot;\frac{n_s-135}{10000})\&CenterDot;\sqrt[3]{\frac{\mathrm{<figure-callout\; id="3"\; label="Q\; n"\; filenames="DEST\_PATH\_HSB00000842254800011.png"\; state="\{\{state\}\}">Q</figure-callout>}}{n}}$

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

The flow of Q-design conditions, cube meter per second;

The n-wheel speed, rev/min;

n _s-specific speed.

A kind of nuclear main pump impeller, its structure comprises: impeller cover, blade, wheel hub etc.The inlet diameter of impeller, outlet diameter, blade exit width adopt above-mentioned design method to confirm.The blade front shroud side thickness of impeller is littler by 30% than back shroud side thickness, and vane thickness from front shroud side direction back shroud side according to linear uniform thickened; Blade increases from inlet side along grain direction to the thickness of outlet gradually, and wherein inlet side thickness is 45% of outlet limit thickness.Blade is big 10 ° near back shroud place streamline cornerite near front shroud place streamline cornerite ratio.The number of blade of impeller is 6～8.

The invention has the beneficial effects as follows: the impeller of the design's method design has outstanding hydraulic performance, and anti-cavitation performance is good, and has improved the reliability of nuclear main pump.

Description of drawings

Fig. 1 is the impeller axis projection of one embodiment of the invention

Fig. 2 is same embodiment's impeller blade figure

Among the figure: 1. impeller cover, 2. impeller inlet diameter, 3. impeller outer circular diameter, the 4. maximum outside diameter of impeller, 5. minimum outside diameter, 6. impeller blade exit width, 7. blade, 8. wheel hub of impeller.

Embodiment

Fig. 1 and Fig. 2 have confirmed this embodiment's impeller shape jointly.It has impeller cover (1), and front shroud and back shroud are arranged respectively, is a kind of double shrouded wheel, and the number of blade 6≤z≤8, can improve mobility status, improves the hydraulic performance and the reliability of nuclear main pump.The present invention confirms impeller inlet diameter (2) D through following relation _j, impeller outlet diameter (3) D ₂, impeller blade exit width (6) b ₂

$D_j=(4+\frac{n_s-200}{100})\&CenterDot;\sqrt[3]{\frac{Q}{\mathrm{<figure-callout\; id="3"\; label="n"\; filenames="DEST\_PATH\_HSB00000842254800011.png"\; state="\{\{state\}\}">n</figure-callout>}}};$

$D_2=\frac{D_{20}+D_{2h}}{2}=(1.083+\frac{n_s-650}{3571})\&CenterDot;(1+\frac{n_s-110}{{10}^5})\&CenterDot;\sqrt[3]{\frac{Q}{\mathrm{<figure-callout\; id="3"\; label="n"\; filenames="DEST\_PATH\_HSB00000842254800011.png"\; state="\{\{state\}\}">n</figure-callout>}}};$

$b_2=(1.05-\frac{n_s-200}{1263})\&CenterDot;(1-2\&CenterDot;\frac{n_s-135}{10000})\&CenterDot;\sqrt[3]{\frac{\mathrm{<figure-callout\; id="3"\; label="Q\; n"\; filenames="DEST\_PATH\_HSB00000842254800011.png"\; state="\{\{state\}\}">Q</figure-callout>}}{n}}.$

The blade front shroud side thickness of impeller is littler by 30% than back shroud side thickness, and vane thickness from front shroud side direction back shroud side according to linear uniform thickened; Blade increases from inlet side along grain direction to the thickness of outlet gradually, and wherein inlet side thickness is 45% of outlet limit thickness.Blade is big 10 ° near back shroud place streamline cornerite near front shroud place streamline cornerite ratio.The number of blade of impeller is 6～8.

Claims (2)

1. examine the main pump impeller design method for one kind, comprise the design formula of the exit width of impeller main geometric parameters inlet diameter, impeller outer circular diameter, impeller blade.It is characterized in that: relation below being fit between impeller geometric parameter and the pump design conditions point performance parameter:

$D_j=(4+\frac{n_s-200}{100})\&CenterDot;\sqrt[3]{\frac{Q}{n}};$

$D_2=\frac{D_{20}+D_{2h}}{2}=(1.083+\frac{n_s-650}{3571})\&CenterDot;(1+\frac{n_s-110}{{10}^5})\&CenterDot;\sqrt[3]{\frac{Q}{n}};$

$b_2=(1.05-\frac{n_s-200}{1263})\&CenterDot;(1-2\&CenterDot;\frac{n_s-135}{10000})\&CenterDot;\sqrt[3]{\frac{Q}{n}}.$

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

D ₂-impeller outlet diameter, rice;

b ₂-impeller blade exit width, rice

D ₂₀The maximum outlet diameter of-impeller, degree;

D _2hThe minimum outlet diameter of-impeller, degree;

The n-wheel speed, rev/min;

n _s-specific speed, rev/min.

2. a kind of nuclear main pump impeller design method according to claim 1 is characterized in that: nuclear main pump impeller structure comprises: impeller cover (2), blade (7), wheel hub (8).The inlet diameter of impeller, outlet diameter, blade exit width adopt above-mentioned design method to confirm.The blade front shroud side thickness of impeller is littler by 30% than back shroud side thickness, and vane thickness from front shroud side direction back shroud side according to linear uniform thickened; Blade increases from inlet side along grain direction to the thickness of outlet gradually, and wherein inlet side thickness is 45% of outlet limit thickness.Blade is big 10 ° near back shroud place streamline cornerite near front shroud place streamline cornerite ratio.The number of blade of impeller is 6～8.

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