CN202732479U - 300MW reactor coolant pump hydraulic part - Google Patents

Abstract

The utility model relates to a 300MW reactor coolant pump hydraulic part which comprises a pump body, an impeller, a guide blade and an impeller cover. The pump body comprises an annular pumping chamber, an inlet pipe orifice is designed at the bottom of the pump body, and coolant is pressurized after sucked axially along the impeller from an inlet pipe and then discharged from a radial horizontal outlet pipe. The impeller is positioned in the impeller cover which is positioned at a conical suction inlet of the pump body, and the gap between the outer edge of the impeller and the impeller cover is about 1mm. The guide blade is closely connected with an impeller outlet and connected with the end of the impeller cover to serve as transition for water flow between the impeller and the annular pumping chamber and has the functions of recovering coolant at the impeller outlet and converting kinetic energy into pressure energy. Tests show that the prototype efficiency of the hydraulic part is up to 84% at a design point, the head curve is smooth and steep, and the hydraulic part is stable in operation within the designed flow range and meets the operation requirements of 300MW nuclear power plants.

Description

300MW reactor coolant pump hydraulic part

Technical field: the utility model relates to a kind of 300MW reactor coolant pump hydraulic part.

Background technique: nuclear power station can be divided into two-part substantially, and the part that produces steam is called nuclear island; The part that steam is converted to electric energy is called conventional island.In the Class PWR Plants, the major loop of nuclear island system is comprised of the pressurized container (in-built reactor core) of reactor, steam generator, reactor coolant pump etc., is called a circuit system.In nuclear island one circuit system, reactor coolant pump is unique rotating equipment, is used for driving freezing mixture and circulates in reactor coolant loop, continuously the heat transferred steam generator secondary side feedwater that produces in the reactor core.The coolant flow that reactor coolant pump must be guaranteed suitable flow is arranged is through reactor core, to keep departure from nucleate boiling ratio greater than permitted value.

Reactor coolant pump (abbreviation main pump) and general industry are its special technical requirement with the maximum differential of pump.These special technical requirements far surpass the technical requirements that general industry is used pump, and it highlights the integrity of pressure-bearing and the running ability of pump.Main pump requires to have absolute reliability, be in the present nuclear reactor unique domestic manufacturing not equipment, complete dependence on import, its autonomous Design and to make be the Focal point and difficult point that China advances the nuclear power autonomy-oriented.Hydraulic part in the main pump is one of core component, because flow is large, lift hangs down factors such as reaching the specific speed height, impeller generally is designed to axial flow or mixed-flow.For ease of manufacturing, pumping chamber adopts annular or spherical.Pass through the stator transition between impeller and pump case.For 300MW reactor coolant pump hydraulic part, still belong at home blank.

Summary of the invention: the purpose of this utility model provides a kind of circulation of freezing mixture in a circuit system that realize, in order to the heat of reactor is brought to the 300MW reactor coolant pump hydraulic part of steam generator heating secondary circuit hot working fluid.The technical solution of the utility model is: a kind of 300MW reactor coolant pump hydraulic part, consisted of by the pump housing (1), impeller (2), diffuser (3) and impeller chimney (4), the described pump housing (1) is the annular pumping chamber structure, be provided with entrance and exit on the annular pumping chamber, impeller chimney (4) is positioned at the pump housing (1) annular pumping chamber entrance, and is solidly set on outside the diffuser (3) with bolt.Impeller (2) is arranged on impeller chimney (4) inside and is positioned at the annular pumping chamber entrance, and diffuser (3) tightly holds impeller (2) outlet and is connected with impeller chimney (4) end, and is positioned at the pump housing (1) annular pumping chamber.

The effect of invention:

The Main Function of reactor coolant pump is for reactor coolant provides drive ram, guarantees enough circular flows by reactor core, and the heat of reactor generation is delivered to steam generator, produces the steam of pushing turbine acting.The fundamental function of its hydraulic part is that the mechanical energy with pump shaft passes to freezing mixture and changes into the static energy of freezing mixture.

Reactor coolant enters along the impeller axis from the pump case bottom, upwards enters impeller, obtains energy by the rotation of impeller.Diffuser plays the freezing mixture that reclaims impeller outlet as the transition of current between impeller and annular pumping chamber, kinetic transformation is become the effect of pressure energy.

The design parameter of 300MW reactor coolant pump is seen Fig. 4.The model pump test result obtains flow, lift, efficient and cavitation curve such as Fig. 2 of prototype after converting.Can find out, in 80%-120% range of flow doubly, head curve is smooth and precipitous, without the hump district, meets designing requirement.Optimum point efficient is about 84%, meets design requirement.In whole design discharge scope, net positive suction head has satisfied designing requirement preferably less than 60m.

Description of drawings:

Fig. 1 the utility model overall structure figure

Fig. 2 is the utility model hydraulic part performance curve

Fig. 3 is model pump design parameter table

Fig. 4 is the prototype design parameter

Embodiment:

As shown in Figure 1, a kind of 300MW reactor coolant pump hydraulic part, consisted of by the pump housing 1, impeller 2, diffuser 3 and impeller chimney 4, the described pump housing 1 is the annular pumping chamber structure, be provided with entrance and exit on the annular pumping chamber, impeller chimney 4 is positioned at the pump housing 1 annular pumping chamber entrance, and be fixed on outside diffuser 3 with the bolt suit, impeller 2 is arranged on impeller chimney 4 inside and is positioned at the annular pumping chamber entrance, diffuser 3 tightly holds impeller 2 outlets and is connected with impeller chimney 4 ends, and diffuser 3 is positioned at the pump housing 1 annular pumping chamber.

According to 300MW reactor coolant pump power station Operational Limits, design discharge

Rated lift 60m.

Specific speed calculates: $n_S=\left(\frac{3.65\&CenterDot;n\&CenterDot;\sqrt{\mathrm{<figure-callout\; id="3"\; label="Q\; H"\; filenames="HDA00002058431500032.png"\; state="\{\{state\}\}">Q</figure-callout>}}}{H^{}}\right)$

In the formula: n _s---specific speed

N---rotating speed r/min

Q--flow m ³/ s

H--lift m

$n_S=\left(\frac{3.65\&times;1490\&times;\sqrt{16800/3600}}{{60}^{3/4}}\right)=545$

This specific speed n _SIn 500～1030 scopes, the blade wheel structure form is axial flow.The number of blade is elected 5 as.The major function of stator is to be pressure energy with the liquid kinetic transformation that impeller produces, and its design is very large on the impact of efficient, adopts axial diffuser, and the number of blade is elected 11 as.

Model pump design parameter such as Fig. 4, parameter is after dwindling 2.4637 times by prototype impeller physical dimension, to obtain according to similarity law in the table.

The hydraulic model that design is processed carries out model test, model pump design parameter table such as Fig. 3, obtain the performance curve of hydraulic model, and convert by following hydraulic similarity formula and finally to obtain prototype performance curve such as Fig. 2, can find out, in 80%-120% range of flow doubly, head curve is smooth and precipitous, without the hump district, meet designing requirement.Optimum point efficient is about 84%, meets design requirement.In whole design discharge scope, net positive suction head has satisfied designing requirement preferably less than 60m.

The geometric proportion of prototype and model is

The hydraulic similarity formula is as follows:

(1) flow rate conversion

$Q=Q_M\&CenterDot;\frac{n}{n_M}\&CenterDot;{\mathrm{\&lambda;}}^3$

(2) lift converts

$H=H_M\&CenterDot;{\left(\frac{n}{n_M}\right)}^2\&CenterDot;{\mathrm{\&lambda;}}^2$

(3) efficient converts

1) optimum point: known models engine efficiency value, utilize the Hutton formula to calculate prototype optimum point efficient.

The Hutton formula:

$(1-\mathrm{\&eta;})=(1-{\mathrm{\&eta;}}_M)[0.3+0.7{\left(\frac{{\mathrm{Re}}_m}{\mathrm{Re}}\right)}^{1/5}]$

In the formula:

$\mathrm{Re}=\frac{\mathrm{Du}}{\mathrm{\&upsi;}}$

In the formula:

The nominal diameter of D--impeller (m);

The peripheral velocity (m/s) at u---impeller nominal diameter place;

The kinematical viscosity of υ---liquid (m2/s).

2) other operating point: obtain the poor of optimum point prototype efficient and prototype efficient, it is added to respectively on the efficiency value of other operating point prototype, can obtain the efficiency value of each operating point of prototype.

Claims (1)

1. 300MW reactor coolant pump hydraulic part, by the pump housing (1), impeller (2), diffuser (3) and impeller chimney (4) consist of, it is characterized in that: the described pump housing (1) is the annular pumping chamber structure, be provided with entrance and exit on the annular pumping chamber, impeller chimney (4) is positioned at the pump housing (1) annular pumping chamber entrance, and be fixed on outside the diffuser (3) with the bolt suit, impeller (2) is arranged on impeller chimney (4) inside and is positioned at the annular pumping chamber entrance, diffuser (3) tightly holds impeller (2) outlet and is connected with impeller chimney (4) end, and diffuser (3) is positioned at the pump housing (1) annular pumping chamber.

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