CN105909537A - Normal-temperature modeling test method for high-temperature molten salt pump - Google Patents

Abstract

The invention provides a normal-temperature modeling test method for a high-temperature molten salt pump. The method is mainly used for conducting research on external characteristics and internal flow of molten salt pumps by replacing high-temperature molten salt with normal-temperature media. Dimensionless numbers such as the specific head, the specific discharge, the Reynolds number and the specific power are obtained through dimensional analysis. On the premise of geometric similarity, it is guaranteed that the Reynolds number, the specific discharge and the specific lift of a prototype pump are equal to those of a model pump, so that the two pumps are similar, and the relational expression of the rotating speeds, the diameters, the flow rates and the lifts of the two pumps is obtained. A modeling test scheme is established and optimized according to the obtained relational expression. The model pump designed according to the modeling test scheme is similar to the prototype pump, and the two pumps have the same dimensionless performance curve. According to the curve, performance conversion between the prototype pump and the model pump can be realized. The internal speeds and pressure distribution rules of the two similar pumps are identical, and the size of the prototype pump is proportional to the size of the model pump.

Description

A kind of room temperature modelling method of testing of high-temperature melting salt pump

Technical field

The present invention relates to the modelling method of testing of a kind of pump for liquid salts, be specially the medium (such as water) using room temperature as test Medium, replaces the high-temperature molten salt in pump for liquid salts to test, or it is super-huge or small to use the model pump after scaled size to replace The pump of type is tested, and obtains actual pump performance by modelling test, and the method is mainly used in the external characteristics of pump for liquid salts and interior Portion's flowing research.

Background technology

Pump for liquid salts is the one of centrifugal pump, for carrying the salt of high-temperature fusion, it is adaptable to tripolycyanamide project, aluminium oxide item Energy-accumulating medium conveying in the Fine Chemicals, and solar light-heat power-generation such as mesh, sheet alkali project.Research and development at pump for liquid salts Cheng Zhong, determines that the performance under different operating mode is very important.But, only by theoretical research come correctly predicted pump external characteristics and Its internal flow has suitable difficulty.

The external characteristics (specifically including that lift, flow, shaft power and efficiency etc.) of pump for liquid salts is the Main Basis of pump type selecting, Directly affect the duty parameter in production process；The internal flow of pump for liquid salts (specifically includes that suction chamber, impeller channel and setting-out Indoor flowing) directly affect the external characteristics of pump for liquid salts, can be effectively improved outside pump by the internal flow state improving pump Characteristic.

It is a more ripe technology that the external characteristics of pump measures technology.Flow can use standard orifice plate, calibrating nozzle, whirlpool Flowmeters etc. measure.Use pressure instrumentation to measure pump inlet and outlet pressure, according to pump inlet and outlet pressure, import and export difference in height Flow velocity with importing and exporting, is calculated pump lift.The available digital instrument directly displayed of measuring of rotating speed measures the measurement time Interior revolution.Moment of torsion can use balance-type type ergometer or torsion type ergometer to measure, and measures rotating speed while measuring moment of torsion, Use twisting resistance moments method can calculate shaft power.According to the definition of the efficiency of pump, above-mentioned measured value can calculate the efficiency of pump.

Technology is measured in centrifugal pump internal flow mainly non-optical measurement technology and Flow Visualization Technologies.Non-optical measurement skill Art mainly includes probe and hot line hotting mask technology, such as porous probe, rotating probe, hot line hot film anemometer and vorticity probe etc., Its shortcoming be probe and hot line/hotting mask intervention all can the true flow field of disturbance, and need to configure complexity telemetry, by collections letter Number it is delivered to stationary reference frame from rotor.Common Flow Visualization Technologies mainly has Particle Image Velocimetry (PIV), laser many General Le velocity measuring technique (LDV) and High-speed Photography Technology (HSP).PIV and LDV can obtain the velocity field of reflection mobility status, but Its experimentation cost and difficulty are far above HSP.HSP is possible not only to obtain VELOCITY DISTRIBUTION situation, and can obtain fluid motion Trace, reproduces the evolution condition of fluid motion intuitively.High speed imaging technology is peeped, by endoscope in there have been developed one in recent years Stretch in pump, the flow at high speed within pump can be continuously shot, it is thus achieved that the prompting message of flowing in pump.

Pump performance when these measurement technology above-mentioned are often applicable under room temperature operating mode carry water is measured.For conveying high temperature melting The pump of salt, due to the impact of high temperature, test difficulty is greatly increased, and is limited by measurement equipment, is difficult to obtain its performance accurately. Currently for pump for liquid salts, typically directly approximate as performance during conveying high-temperature molten salt using water as performance during test(ing) medium； For some super-huge or hypomegetic pump, the restriction of the measurement device scope that is put to the test, it tends to be difficult to carry out correlation test.

Summary of the invention

In order to solve current high-temperature melting salt pump, super-huge or microminiature pump performance be difficult to the problem accurately measured, the present invention There is provided the room temperature modelling method of testing of a kind of high-temperature melting salt pump, when using the method can not only measure pump for liquid salts conveying high-temperature medium Performance, and super-huge or microminiature pump performance can be accurately measured.

The technical solution adopted for the present invention to solve the technical problems is:

A kind of room temperature modelling method of testing of high-temperature melting salt pump, the method comprises the following steps:

1) with high-temperature melting salt pump to be tested as archetypal pump, model pump, model are designed by archetypal pump size equal proportion scaling Pump uses room temperature medium to carry out modelling test；

2) model pump is with archetypal pump on the premise of geometry is similar, meets Reynolds number, specific discharge simultaneously and compares lift Equal, then two pumps performance is similar, and according to following corresponding relation, designs modelling testing scheme:

$n_m=n_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{1-2x},D_m=D_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^x;$

Wherein, the density of archetypal pump pumped (conveying) medium is ρ_p, viscosity is μ_p, rotating speed is n_p, impeller diameter is D_p；Model pump is defeated The density sending medium is ρ_m, viscosity is μ_m, rotating speed is n_m, impeller diameter is D_m；X is similarity coefficient, span be-1≤x≤ 1；

3) each performance parameter of model pump is obtained by the method for simulation or test, including model pump lift H_m, flow Q_m, shaft power P_m, efficiency eta_m；

4) according to each performance parameter of the model pump obtained, and according to following corresponding relation, archetypal pump after conversion, is obtained Can parameter；

$Q_m=Q_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{1+x},H_m=H_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{2-2x},$ η_m=η_p；

Wherein, the flow of archetypal pump is Q_p, lift is H_p, shaft power is P_p, efficiency is η_p；The flow of model pump is Q_m, raise Journey is H_m, shaft power is P_m, efficiency is η_m。

The design further of the present invention is:

The method also includes similarity coefficient x is taken in span multiple value, obtains organizing modelling scheme more, therefrom screens Meet the reasonable modelling scheme of following condition: the rotating speed of model pump controls between 100～6000r/min；The flow of model pump Should be greater than 1m³/ h, lift should be greater than 0.1m；The impeller diameter of model pump controls between 0.1～0.6m, according to rational modelling Scheme and then determine similarity coefficient x value.

Described room temperature medium be 0～35 ° under the conditions of water or oil.

When directly using archetypal pump as model pump, D_p=D_m；When archetypal pump impeller diameter is in 0.1～0.6m scope, Directly can carry out Modelling Test using archetypal pump as model pump.In this case the pump size that designs a model avoids the need for scaling.

The design principle of the present invention is as follows:

The present invention provides the room temperature modelling method of testing of a kind of high-temperature melting salt pump, is mainly used in room temperature medium and replaces high temperature melting Salt carries out external characteristics and the internal flow research of pump for liquid salts.The dimensionless number of pump is obtained: than lift, ratio stream by dimensional analysis Amount, Reynolds number, specific power.Under geometric similarity premise, it is ensured that archetypal pump and the Reynolds number of model pump, specific discharge and ratio lift phase Deng so that two pumps is similar, obtains the relational expression between the rotating speed of two pumps, diameter, flow, lift.According to gained relational expression Set up and preferred modelling testing scheme.Similar to archetypal pump according to the model pump of modelling testing scheme design, they have identical Dimensionless performance curve, according to this curve can realize between archetypal pump and model pump performance conversion.Similar two pumps its Internal speed is identical with pressure law, is in proportion.

In pump, the physical parameter involved by flowing includes: specific energy gH, efficiency of pump η, volume flow Q, rotating speed n, fluid Density p, fluid viscosity μ, impeller diameter D.According to Buckingham theorem, this problem can be described with following mathematical formulae,

f₁(gH, Q, D, n, ρ, μ)=0 (1)

Because relating to 3 basic dimensions in above formula: mass M, length L, time T, therefore can obtain

f₂(π₁,π₂,π₃)=0 (2)

Choose D, n, ρ as basic physical parameters, then have

${\mathrm{\π}}_1={\mathrm{gHD}}^{a_1}{n}^{b_1}{\mathrm{\ρ}}^{c_1}---\left(3\right)$

${\mathrm{\π}}_2={\mathrm{QD}}^{a_2}{n}^{b_2}{\mathrm{\ρ}}^{c_2}---\left(4\right)$

${\mathrm{\π}}_3={\mathrm{\μD}}^{a_3}{n}^{b_3}{\mathrm{\ρ}}^{c_3}---\left(5\right)$

According to dimension harmony principle, then

${\mathrm{\π}}_1={\mathrm{gHD}}^{-2}{n}^{-2}=\frac{gH}{n^2{D}^2}=\mathrm{\ψ}---\left(6\right)$

Above formula is the ratio lift of pump, represents with symbol ψ.

${\mathrm{\π}}_2={\mathrm{QD}}^3{n}^{-1}=\frac{Q}{{\mathrm{nD}}^3}=\mathrm{\φ}---\left(7\right)$

Above formula is the specific discharge of pump, represents with symbol φ.

${\mathrm{\π}}_3={\mathrm{\μD}}^{-2}{n}^{-1}{\mathrm{\ρ}}^{-1}=\frac{\mathrm{\μ}}{{\mathrm{\ρnD}}^2}---\left(8\right)$

Above formula is the inverse of the Reynolds number of pump.Above formula is carried out conversion and can obtain the Reynolds number of pump.

${\mathrm{Re}}_c=\frac{1}{{\mathrm{\π}}_3}=\frac{{\mathrm{\ρnD}}^2}{\mathrm{\μ}}---\left(9\right)$

By the operation to above-mentioned dimensionless variable, it is also possible to obtain following useful dimensionless number.

$Ne={\mathrm{\π}}_1\·{\mathrm{\π}}_2\·{\mathrm{\η}}^{-1}=\frac{gH}{n^2{D}^2}\·\frac{Q}{{\mathrm{nD}}^3}\·\frac{\mathrm{\ρ}}{\mathrm{\ρ}}\·{\mathrm{\η}}^{-1}=\frac{P}{{\mathrm{\ρn}}^3{D}^5}---\left(10\right)$

Above formula is the specific power of pump, and P is the shaft power of pump.

The medium of pump for liquid salts conveying is high-temperature molten salt, owing to temperature is the highest, directly uses high-temperature molten salt to carry out as medium Test difficulty is very big, is considered as normal-temperature water (or oily, such as diesel oil) for this and replaces high-temperature molten salt to test as medium.Fused salt Density all differ compared with water with viscosity, want result of the test can be converted into conveying fused salt time pump performance, it is necessary to enter Row modelling test design so that model pump meets similar with archetypal pump.

According to the dimensionless performance of above-mentioned centrifugal pump, under geometric similarity premise, if simultaneously ensure model pump and The Reynolds number of archetypal pumpSpecific dischargeWith than liftEqual, then two pumps is similar, two All dimensionless numbers of pump are the most equal, i.e. Re_cm=Re_cp, φ_m=φ_p, ψ_m=ψ_p, Ne_m=Ne_p, η_m=η_p.Assume: archetypal pump The density of pumped (conveying) medium is ρ_p, viscosity is μ_p, the density of model pump pumped (conveying) medium is ρ_m, viscosity is μ_m.The thunder of archetypal pump to be ensured Promise number Re_cpReynolds number Re equal to model pump_cm, then archetypal pump and the rotating speed of model pump and diameter must are fulfilled for following relation:

$n_m=n_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{1-2x}---\left(11\right)$

$D_m=D_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^x---\left(12\right)$

The specific discharge φ of archetypal pump to be ensured_pSpecific discharge φ equal to model pump_m, then the flow of archetypal pump and model pump must Must meet following relation:

$Q_m=Q_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{1+x}---\left(13\right)$

The ratio lift ψ of archetypal pump to be ensured_pRatio lift ψ equal to model pump_m, then archetypal pump and model pump lift are necessary Meet following relation:

$H_m=H_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{2-2x}---\left(14\right)$

Specific power Ne of archetypal pump to be ensured_pSpecific power Ne equal to model pump_m, then the power of archetypal pump and model pump must Must meet following relation:

$P_m=P_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{3-x}\left(\frac{{\mathrm{\ρ}}_m}{{\mathrm{\ρ}}_p}\right)---\left(15\right)$

In formula:

X similarity coefficient, takes different values and can obtain different modelling schemes.

Only rotating speed, diameter, flow, lift and shaft power meets above-mentioned 5 formula, archetypal pump and model pump just phase simultaneously Seemingly.For the two pumps of geometric similarity, by regulation rotating speed and flow, formula (11)～(13) can be met simultaneously, but problem It is crucial that under such operating mode, whether lift meets formula (14).If it is satisfied, then show that archetypal pump is similar with model pump, logical Cross the performance that model pump records and can be converted into prototype pump performance.

Archetypal pump conveying fused salt physical property as listed in table 1, rotating speed n=1450r/min, impeller diameter D=250mm, flow Q =25m³/h.Using water to replace fused salt to test, according to formula (11)～(14), the modelling scheme of establishment as listed in table 2, is limited to Length, water replaces modelling scheme during other fused salts to omit.

Table 1 pumped medium physical property

Table 2 water replaces modelling scheme during fused salt #1

By the modelling scheme in table it appeared that: different modelling schemes can be obtained when x takes different value, say, that When replacing fused salt as test(ing) medium with water, modelling test can be carried out by changing the rotating speed of pump, flow and physical dimension, deposit In multiple modelling scheme.When x takes-1, model pump is identical with the flow of archetypal pump；When x takes 0, model pump and the chi of archetypal pump Very little identical；When x takes 1/2, model pump is identical with the rotating speed of archetypal pump；When x takes 1, model pump is identical with prototype pump lift.

When replacing the medium that viscosity is the highest to carry out modelling test with water when, rotating speed, physical dimension, flow and lift etc. Parameter is difficult to reach reasonably to be worth (reasonable value here refers to be more or less the same compared with the relevant parameter of archetypal pump) simultaneously.Have Numerical value in a little schemes only has theory significance, and is difficulty with in engineering, such as: replace fused salt #5 to carry out modelling survey with water Examination, when x takes-1, model pump is identical with the flow of archetypal pump, but model pump lift be only archetypal pump lift 6.1207 × 10^-10Times, this almost cannot record in engineering.

When rotating speed is chosen for reasonable value, physical dimension, flow and lift are the least；When physical dimension chooses reasonable value Time, rotating speed, flow and lift are the least；When flow chooses reasonable value, rotating speed and lift are the least, and physical dimension is the biggest；When raising When journey chooses reasonable value, rotating speed is very big, and physical dimension and flow are the least.Above-mentioned 4 kinds of situations are as listed in table 3.

Table 3 modelling project plan comparison

Modelling scheme	Rotating speed	Physical dimension	Flow	Lift
					1	Rationally	Less	Less	Less
2	Less	Rationally	Less	Less
					3	The least	The biggest	Rationally	The least
4	The biggest	The least	The least	Rationally

When many modelling schemes are chosen the best alternatives, be considered as rotating speed, physical dimension, flow and lift etc. comprehensively because of Element, in order to experiment can be carried out smoothly.The size of rotating speed should determine according to the ability of motor, and general rotating speed controls 100 ～6000r/min；Flow and lift should not be the least, if the least precision that may affect measurement, general flow is more than 1m³/ h is Preferably, lift is advisable more than 0.1m；The size of model should not be the least, if the impact of the least in test model surface roughness can Can be very big, size also should not be too big, and too conference brings difficulty to the processing of model pump, also can improve the requirement of test-bed, The impeller diameter of universal model pump is advisable in the range of 0.1～0.6m.When formulating modelling scheme, rotating speed, geometry should be controlled as far as possible The parameters such as size, flow and lift are within the scope of recommending, and then determine x value.When there is the modelling scheme of many reasonable set, Can be the most optional one group.

The invention has the beneficial effects as follows:

(1) do not affected by operating temperature.Use method provided by the present invention, high temperature can be avoided, use room temperature to be situated between Matter is tested, and the model pump performance recorded is converted into prototype pump performance.

(2) do not affected by medium physical property.Archetypal pump conveying is high viscosity, highdensity medium, no matter which kind of carries The medium of physical property, when using the method for the present invention to carry out modelling test, all can use the cheap water being readily available or oil generation Test for this medium.

(3) do not affected by physical dimension.For some oversized pump, to test, large-scale electricity need to be configured Machine, the measuring instruments of wide range；And for some hypomegetic pump, owing to its performance value is less, need to use that range is little, precision High instrument measures.Generally, test battery device is difficult to the measurement of Multiple Type pump performance.Simultaneously for Super-huge and hypomegetic pump, the measurement difficulty of its internal flow is the biggest.The method using the present invention, then can avoid pump knot The impact of structure size, by geometric similarity, zooms to the size easily tested by pump.

Accompanying drawing explanation

The present invention is further described with embodiment below in conjunction with the accompanying drawings.

Fig. 1 is pump for liquid salts geometric model.

Fig. 2 is lift-flow performance curve.

Fig. 3 is shaft power-flow performance curve.

Fig. 4 is efficiency-flow performance curve.

Fig. 5 is than lift-specific discharge performance curve.

Fig. 6 is specific power-specific discharge performance curve.

Fig. 7 is efficiency-specific discharge performance curve.

Fig. 8-1 to Fig. 8-7 is that various modelling scheme drag pump internal speed is distributed (m/s).

Fig. 9-1 to Fig. 9-6 is that various modelling scheme drag pump internal pressure is distributed (Pa).

Detailed description of the invention

The invention will be further described below in conjunction with the accompanying drawings:

Embodiment one:

For convenience, numerical simulation is used to replace the modelling method of testing that the description of test present invention is put forward.Use Pro-e Software carries out Geometric Modeling, and uses Gambit software to carry out stress and strain model, and geometric model is as shown in Figure 1.Archetypal pump is mainly tied Structure parameter and performance parameter are as listed by table 4.Model pump medium uses the water of normal temperature condition (20 DEG C)；Use Fluent software to pump Flowing during conveying fused salt #1 carries out numerical simulation.

The main structure parameters of table 4 pump for liquid salts and design conditions parameter

All modelling schemes are chosen several schemes the most feasible in engineering (take x=-1/6 respectively, 0,1/6,1/3, 1/2,2/3) numerical simulation is carried out, to verify the correctness of put forward modelling method of testing.Analog result is shown in Table 5.

Table 5 water replaces modelling result during fused salt #1

Note: in table, the first row data are archetypal pump numerical simulation result, other data use water as medium difference mould for adopting Numerical simulation result under change scheme.

From data in table, the simulation lift of numerical computations gained is raised than with according to the theory of modelling method of testing gained Journey ratio is the most completely the same, and the efficiency of the model pump under various similar operating conditions is nearly identical with the efficiency of archetypal pump, shows Carried modelling method of testing is correct.Completely can use water as test(ing) medium replace full-bodied fused salt to carry out by adopting Modelling is tested.

(1) archetypal pump and model pump performance curve's analysis

According to modelling method of testing, adopt and use water as test(ing) medium, to pumped (conveying) medium density p_p=1938kg/m³, viscosity, mu_p =0.00729Pa s, rotating speed n_p=1450r/min, impeller diameter D_pThe archetypal pump of=250mm carries out modelling test.

Consider the parameter areas such as rotating speed, physical dimension, flow and lift, choose x=0, according to equation below:

$n_m=n_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{1-2x},D_m=D_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^x;$

Obtain the rotating speed n of model pump_m=386.2r/min, impeller diameter D_m=250mm.

Under different flow rate working conditions, model pump carries out numerical simulation, and (can also adopt is that traditional test methods obtains mould The each parameter value of type pump), computation model pump lift, shaft power and efficiency.

Lift H can represent calculating by equation below

$H=\frac{{\left\{p_t\right\}}_{out}-{\left\{p_t\right\}}_{in}}{\mathrm{\ρ}g}---\left(16\right)$

In formula: { p_t}_in、{p_t}_outFor the stagnation pressure on pump import and export cross section, result of calculation is carried out post processing can be somebody's turn to do Value.

Shaft power P can calculate by equation below

P=M ω (17)

In formula: M is to act on the moment on impeller, result of calculation carries out post processing can this value；ω is centrifugal pump Rotational angular velocity, is set to boundary condition in numerical procedure.

Efficiency eta can be calculated by lift H and moment M, and its computing formula is

$\mathrm{\η}=\frac{\mathrm{\ρ}gQH}{M\mathrm{\ω}}---\left(18\right)$

In formula: ρ is the density of pumped (conveying) medium；G is acceleration of gravity；Q is the flow of centrifugal pump, sets in numerical procedure It is set to boundary condition.

It is calculated H-Q, P-Q, η-Q curve, the model pump performance curve as shown in Fig. 2～Fig. 4 according to above-mentioned formula. According to following equation (in formula, x is taken as 0 equally):

$Q_m=Q_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{1+x},H_m=H_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{2-2x},$ η_m=η_p

The performance curve of model pump is converted into the performance curve of archetypal pump, the archetypal pump performance as shown in Fig. 2～Fig. 4 Curve.

Flow in Fig. 2～Fig. 4, lift and shaft power are wholly converted into nondimensional specific discharge, than lift with compare merit Rate, repaints the dimensionless performance curve of archetypal pump and model pump, as shown in Fig. 5～Fig. 7.As seen from the figure, model pump and former The dimensionless performance curve of type pump is completely superposed, and shows, according to the dimensionless performance of a series of pumps of modelling method of testing design Curve all can represent with same dimensionless performance curve, and the performance obtained by model pump test can be converted into archetypal pump Performance.

Above-mentioned three kinds of dimensionless performance curves are fitted:

Than lift and the relational expression of specific discharge:

ψ=0.00165+3.00031 × 10^-4φ-4.18269×10^-4φ²+5.95276×10^-5φ³ (19)

Specific power and the relational expression of specific discharge:

Ne=3.47999 × 10^-7+9.83087×10^-8φ+2.41437×10^-7φ²-8.06603×10^-8φ³ (20)

Efficiency and the relational expression of specific discharge:

η=-0.3662+146.34 φ-89.391 φ²+16.592φ³ (21)

The dimensionless performance curve of a series of similar pumps can be expressed with above three formula.

(2) archetypal pump is analyzed with model pump internal flow

Adopt and use water as test(ing) medium and replace viscosity to be that the fused salt of 0.00729Pa s carries out modelling test, to each in table 5 The rationally pump internal flow under modelling scheme carries out numerical simulation.Fig. 8-1 to Fig. 8-7 shows various reasonable modelling scheme lower mold VELOCITY DISTRIBUTION within type pump, is equal size by model pump size adjusting in figure, and colour code is adjusted to total head territory and shows.Wherein, Fig. 8-1 is the VELOCITY DISTRIBUTION within archetypal pump, corresponding impeller D_p=250.0mm；The corresponding impeller D of Fig. 8-2_m=311.7mm；Fig. 8-3 Corresponding impeller D_m=250.0mm；The corresponding impeller D of Fig. 8-4_m=200.5mm；The corresponding impeller D of Fig. 8-5_m=160.8mm；Fig. 8-6 is right Answer impeller D_m=129.0mm；The corresponding impeller D of Fig. 8-7_m=103.5mm.As seen from the figure, its internal speed regularity of distribution of similar pump Identical, velocity magnitude is proportional, and along with the reduction of model pump size, absolute velocity increases.

Fig. 9-1 to Fig. 9-6 shows the pressure distribution within each reasonable kind of modelling scheme drag pump, by model pump in figure Size shows in proportion, and pressure shows under identical colour code.As seen from the figure, the similar pressure in pump is along with model pump size Reduction and increase, pressure is in proportion.The corresponding impeller D of Fig. 9-1_m=311.7mm；The corresponding impeller D of Fig. 9-2_m=250.0mm； The corresponding impeller D of Fig. 9-3_m=200.5mm；The corresponding impeller D of Fig. 9-4_m=160.8mm；The corresponding impeller D of Fig. 9-5_m=129.0mm；Figure 9-6 correspondence impeller D_m=103.5mm.If the pressure colour code of each model pump is adjusted to total head territory show, and VELOCITY DISTRIBUTION one Sample, its internal pressure regularity of distribution of similar pump is identical.

Claims (4)

1. a room temperature modelling method of testing for high-temperature melting salt pump, is characterized in that: the method comprises the following steps:

1) with high-temperature melting salt pump to be tested as archetypal pump, designing model pump by archetypal pump size equal proportion scaling, model pump is adopted Modelling test is carried out with room temperature medium；

2) model pump is with archetypal pump on the premise of geometry is similar, meets Reynolds number, specific discharge and more equal than lift simultaneously, Then two pumps performance is similar, and according to following corresponding relation, designs modelling testing scheme:

$n_m=n_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^{1-2x},D_m=D_p\×{\left(\frac{{\mathrm{\μ}}_m/{\mathrm{\μ}}_p}{{\mathrm{\ρ}}_m/{\mathrm{\ρ}}_p}\right)}^x;$

Wherein, the density of archetypal pump pumped (conveying) medium is ρ_p, viscosity is μ_p, rotating speed is n_p, impeller diameter is D_p；Model pump pumped (conveying) medium Density be ρ_m, viscosity is μ_m, rotating speed is n_m, impeller diameter is D_m；X is similarity coefficient, and span is-1≤x≤1；

3) each performance parameter of model pump is obtained by the method for simulation or test, including model pump lift H_m, flow Q_m, axle Power P_m, efficiency eta_m；

4) according to each performance parameter of the model pump obtained, and according to following corresponding relation, archetypal pump performance ginseng after conversion, is obtained Number；

η_m=η_p；

Wherein, the flow of archetypal pump is Q_p, lift is H_p, shaft power is P_p, efficiency is η_p；The flow of model pump is Q_m, lift is H_m, shaft power is P_m, efficiency is η_m。

Modelling method of testing the most according to claim 1, is characterized in that: the method also includes similarity coefficient x in value In the range of take multiple value, obtain organizing modelling scheme more, therefrom screening meets the reasonable modelling scheme of following condition: turning of model pump Speed controls between 100～6000r/min；The flow of model pump should be greater than 1m³/ h, lift should be greater than 0.1m；The leaf of model pump Wheel diameter controls between 0.1～0.6m, according to rational modelling scheme and then determine similarity coefficient x value.

Modelling method of testing the most according to claim 1 and 2, is characterized in that: under the conditions of described room temperature medium is 0～35 ° Water or oil.

Modelling method of testing the most according to claim 3, is characterized in that: when directly using archetypal pump as model pump, D_p =D_m；When archetypal pump impeller diameter is in 0.1～0.6m scope, directly Modelling Test can be carried out using archetypal pump as model pump.