CN103711727A - Hydraulic design method of high-cavitation-resistance nuclear main pump impeller and high-cavitation-resistance nuclear main pump impeller - Google Patents

Abstract

The invention provides a hydraulic design method of a high-cavitation-resistance nuclear main pump impeller and the high-cavitation-resistance nuclear main pump impeller. According to the design method, an inlet diameter Dj, an outlet diameter D2 and a blade outlet width b2 are determined by selecting proper rotation speed and proper specific speed so as to improve the flow state and improve cavitation resistance and hydraulic performance of the nuclear main pump impeller. The high-cavitation-resistance nuclear main pump impeller designed through the method can provide high flow in a short time to bring away heat of a reactor core, so that the probability of nuclear accidents is reduced. The high-cavitation-resistance nuclear main pump impeller has excellent hydraulic performance, has high cavitation resistance under coolant loss accidents, and therefore improves operation safety and stability of a nuclear main pump under the coolant loss accidents.

Description

The Hydraulic Design Method of high anti-cavitation core main pump impeller and high anti-cavitation core main pump impeller

Technical field

The invention belongs to fluid machinery design field, especially a kind of Hydraulic Design Method under loss of-coolant accident (LOCA) with the core main pump impeller of high anti-cavitation.

Background technique

Reactor coolant circulation main pump is called for short core main pump, it is the reactor cooling system important component part of (being called for short " RCP "), be unique rotating equipment in nuclear island reactor, be also the important component part on a circuit pressure border simultaneously, belongs to nuclear safety I level equipment.When there is earthquake or high vibration, the loine pressure of reactor cooling system changes, and may cause breaking of pipeline, thereby loss of-coolant accident (LOCA) occurs.In loss of-coolant accident (LOCA), the fluid in core main pump becomes heterogeneously from single-phase, compares with single fluid-phase, and under gas-liquid two-phase, the service behaviour of core main pump can significantly decline, and then core main pump can not be worked normally, causes the generation of nuclear accident.

Therefore design a kind of can under gas-liquid two-phase, have high-cavitation-resistance can reactor coolant circulation main pump impeller most important to the stable operation of whole nuclear power station.

Summary of the invention

For Shortcomings in prior art, the invention provides a kind of Hydraulic Design Method under loss of-coolant accident (LOCA) with the core main pump impeller of high-cavitation-resistance energy, and high anti-cavitation core main pump impeller.

Technological scheme of the present invention is:

The Hydraulic Design Method of high anti-cavitation core main pump impeller, is characterized in that: the inlet diameter D that determines impeller by formula (1), (2), (3) _j, outlet diameter D ₂, blade exit width b ₂:

$D_j=(3.65+\frac{n_s-150}{300})\sqrt[3]{\frac{Q}{n}}---\left(1\right)$

$D_2=(1.178+\frac{n_s-850}{3571})(0.908+\frac{n_s}{{10}^5})\sqrt[3]{\frac{Q}{n}}---\left(2\right)$

${\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000444847940000011.png,HDA0000444847940000012.png"\; state="\{\{state\}\}">b</figure-callout>}}_2=(1.052-\frac{n_s-200}{1263})[1-2.23\frac{(n_s-135)}{10000}]\sqrt[3]{\frac{Q}{n}}---\left(3\right)$

In formula:

D _j-inlet diameter, m;

D ₂-inlet diameter, m;

B ₂-blade exit width, m;

Flow under Q-design conditions, 17000～24000m ³/ h;

N-rotating speed, r/min, span is 1450～1800r/min;

N _s-specific speed, span 340～420.

The high anti-cavitation core main pump impeller of design method design of the present invention, comprises front shroud of impeller, blade, back shroud of impeller and wheel hub, the inlet diameter D of impeller _j, outlet diameter D ₂, blade exit width b ₂adopt formula (1), (2), (3) to determine.

Preferably, the thickness of the Thickness Ratio back shroud of impeller side of described front shroud of impeller side is little by 20%, and vane thickness evenly increases according to linearity from inlet side to Exit-edge; Inlet side thickness is 35%～45% of Exit-edge thickness, large 20 ° than the streamline cornerite in outlet port of the streamline cornerites of inlet, and the number of blade is 5～7.

The Hydraulic Design Method of high anti-cavitation core main pump impeller of the present invention, by changing the inlet diameter D of core main pump impeller _j, outlet diameter D ₂, blade exit width b ₂, improve flowing state, improve anti-cavitation performance and the hydraulic performance of core main pump impeller.In the high anti-cavitation core main pump impeller process of design, adopt the method for the rotating speed that improves core main pump to improve the lift that under loss of-coolant accident (LOCA), core main pump sharply declines; Choosing core main pump rotating speed is 1800r/min, to increase core main pump at the pressure of loss of-coolant accident (LOCA) lower inlet.Specific speed is selected according to following theoretical: when specific speed is too low, flow reduces and lift is too high.But under loss of-coolant accident (LOCA), the main heat that need to provide at short notice larger flow to take away reactor core of core main pump, thus reduce the possibility that nuclear accident occurs.Therefore, with reference to the high hydraulic model of anti-cavitation performance, by specific speed n _sspan elect 340～420 as.

Design method of the present invention, by selecting high rotating speed, suitable specific speed to design the main structure parameters of described impeller.Make described impeller can provide at short notice larger flow to take away the heat of reactor core, thereby reduce the possibility that nuclear accident occurs, not only there is outstanding hydraulic performance, and under loss of-coolant accident (LOCA), there is high-cavitation-resistance energy, thereby improved the safety and stability that core main pump moves under loss of-coolant accident (LOCA).

Accompanying drawing explanation

Fig. 1 is the axial plane sectional view of high anti-cavitation core main pump impeller of the present invention.

Fig. 2 is the structural drawing of the wheel end face of high anti-cavitation core main pump impeller of the present invention.

Description of reference numerals is as follows:

1-front shroud of impeller, 2-back shroud of impeller, 3-blade, 4-wheel hub.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment, the present invention is further illustrated, but protection scope of the present invention is not limited to this.

The Hydraulic Design Method of high anti-cavitation core main pump impeller of the present invention, adopts the method for the rotating speed that improves core main pump to improve the lift that under loss of-coolant accident (LOCA), core main pump sharply declines; Choosing core main pump rotating speed is 1800r/min, to increase core main pump at the pressure of loss of-coolant accident (LOCA) lower inlet.Specific speed is selected according to following theoretical: when specific speed is too low, flow reduces and lift is too high.But under loss of-coolant accident (LOCA), the main heat that need to provide at short notice larger flow to take away reactor core of core main pump, thus reduce the possibility that nuclear accident occurs.Therefore, with reference to the high hydraulic model of anti-cavitation performance, by specific speed n _sspan elect 340～420 as.By formula (1), (2), (3), determine the inlet diameter D of impeller _j, outlet diameter D ₂, blade exit width b ₂:

$D_j=(3.65+\frac{n_s-150}{300})\sqrt[3]{\frac{Q}{n}}---\left(1\right)$

$D_2=(1.178+\frac{n_s-850}{3571})(0.908+\frac{n_s}{{10}^5})\sqrt[3]{\frac{Q}{n}}---\left(2\right)$

${\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000444847940000011.png,HDA0000444847940000012.png"\; state="\{\{state\}\}">b</figure-callout>}}_2=(1.052-\frac{n_s-200}{1263})[1-2.23\frac{(n_s-135)}{10000}]\sqrt[3]{\frac{Q}{n}}---\left(3\right)$

In formula:

D _j-inlet diameter, m;

D ₂-inlet diameter, m;

B ₂-blade exit width, m;

Flow under Q-design conditions, 17000～24000m ³/ h;

N-rotating speed, r/min, value is 1450～1800r/min;

N _s-specific speed, span 340～420.

The Hydraulic Design Method of high anti-cavitation core main pump impeller of the present invention, by changing the inlet diameter D of core main pump impeller _j, outlet diameter D ₂, blade exit width b ₂, improve flowing state, improve anti-cavitation performance and the hydraulic performance of core main pump impeller.

As shown in Figure 1 and Figure 2, the high anti-cavitation core main pump impeller of design method design of the present invention, comprises front shroud of impeller, blade, back shroud of impeller and wheel hub, the inlet diameter D of impeller _j, outlet diameter D ₂, blade exit width b ₂adopt formula (1), (2), (3) to determine.The thickness of the Thickness Ratio back shroud of impeller side of front shroud of impeller side is little by 20%, and vane thickness evenly increases according to linearity from inlet side to Exit-edge; Wherein inlet side thickness is the streamline cornerite of 35%～45% inlet of Exit-edge thickness than the streamline cornerite in outlet port large 20 °, and the number of blade is 5～7.

Described high anti-cavitation core main pump impeller, can improve mobility status, improves the cavitation performance of core main pump under loss of-coolant accident (LOCA), thereby has improved the safety and stability that core main pump moves under loss of-coolant accident (LOCA).

Described embodiment is preferred embodiment of the present invention; but invention is not limited to above-mentioned mode of execution; in the situation that not deviating from flesh and blood of the present invention, any apparent improvement, replacement or modification that those skilled in the art can make all belong to protection scope of the present invention.

Claims (3)

1. the Hydraulic Design Method of high anti-cavitation core main pump impeller, is characterized in that: the inlet diameter D that determines impeller by formula (1), (2), (3) _j, outlet diameter D ₂, blade exit width b ₂:

$D_j=(3.65+\frac{n_s-150}{300})\sqrt[3]{\frac{Q}{n}}---\left(1\right)$

$D_2=(1.178+\frac{n_s-850}{3571})(0.908+\frac{n_s}{{10}^5})\sqrt[3]{\frac{Q}{n}}---\left(2\right)$

$b_2=(1.052-\frac{n_s-200}{1263})[1-2.23\frac{(n_s-135)}{10000}]\sqrt[3]{\frac{Q}{n}}---\left(3\right)$

In formula:

D _j-inlet diameter, m;

D ₂-inlet diameter, m;

B ₂-blade exit width, m;

Flow under Q-design conditions, 17000～24000m ³/ h;

N-rotating speed, r/min, span is 1450～1800r/min;

N _s-specific speed, span 340～420.

2. the high anti-cavitation core main pump impeller of design method design according to claim 1, is characterized in that, comprises front shroud of impeller, blade, back shroud of impeller and wheel hub, the inlet diameter D of impeller _j, outlet diameter D ₂, blade exit width b ₂adopt formula (1), (2), (3) to determine.

3. high anti-cavitation core main pump impeller according to claim 2, is characterized in that, the thickness of the Thickness Ratio back shroud of impeller side of described front shroud of impeller side is little by 20%, and vane thickness evenly increases according to linearity from inlet side to Exit-edge; Inlet side thickness is 35%～45% of Exit-edge thickness, large 20 ° than the streamline cornerite in outlet port of the streamline cornerites of inlet, and the number of blade is 5～7.

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