CN106870462A - A kind of method for designing of the elbow inlet passage of pumping plant - Google Patents

Abstract

The invention belongs to the application field of pumping plant, and in particular to a kind of method for designing of the elbow inlet passage of pumping plant.Using a kind of design formula of the main geometric parameters of the elbow inlet passage of pumping plant of the invention, including：Impeller central to water inlet flow channel base plate height L, the inlet height M of water inlet flow channel, Proportional coefficient K, water inlet flow channel import to pump shaft line length X, the width B of water inlet flow channel inducer, the outer curvature radius R of water inlet flow channel bending section, the incurvature radius r of water inlet flow channel bending section, the top taper angle α of water inlet flow channel inducer, the lower sideline angle of inclination beta of water inlet flow channel inducer, the inlet height h of water inlet flow channel bending section, height l of water inlet flow channel outlet section etc., the stability and high efficiency of pumping station operation can not only be improved, extend the service life of pump and the time between overhauls(TBO) of pumping plant simultaneously.Moreover, it also has good economic benefit, be more beneficial for computer R. concomitans, make it possible Parametric designing.

Description

A kind of method for designing of the elbow inlet passage of pumping plant

Technical field

The invention belongs to the application field of pumping plant, more particularly to a kind of method for designing of elbow inlet passage.

Background technology

Under normal circumstances, large pumping station typically unites two into one intake pool with suction hose to reduce construction volume, be into Water flow passage, while also making the motor have the good working environment of comparing.General large pumping station uses vertical pump, but due to vertical The axial dimension of pump is than larger, so reducing the height of pump house and the depth of pump house base plate as far as possible.However, too low pump house Height and bottom plate depth influence whether Inlet flow pattern again, in some instances it may even be possible to cause cavitation and its vibration of water pump, and can reduce pump The operational efficiency stood and the economic benefit for reducing pumping plant, so, there is comparing design high for the water inlet flow channel of large pumping station It is required that.

Additionally, the change of Inlet flow pattern necessarily causes the change of water pump in pump station working condition, Inlet flow pattern is bad not only The operating efficiency of water pump is reduced, and the anti-cavitation performance of water pump can be reduced.Because water inlet flow channel directly affects water pump vane The flow velocity and pressure distribution of admission section, therefore performance to water pump has a significant impact.Moreover, if water inlet flow channel Geomery selection is improper, just very possible in water inlet flow channel to produce vortex, or even can form vortex rope, once vortex rope enters water Pump, water pump will occur strong vibration with unit.As can be seen here, water inlet flow channel is an important component of pump works, Being intended to must be very rigorous to the design of water inlet flow channel.

Water inlet flow channel has various patterns, is all Forebay of Pumping Station and water pump vane although various water inlet flow channel shapes differ Changeover portion between room, its effect is provided to make current preferably turn to and add during entering water pump vane room from forebay Speed, to meet water pump vane as far as possible to the condition required by blade wheel chamber's import flow-shape.Water inlet flow channel can by water inlet direction It is divided into unidirectional water inflow runner and two-way water inflow passage, and elbow inlet passage is just belonging to unidirectional, and elbow inlet passage Suitable for vertical-type axial-flow pump and guide vane mixed flow pump, its shape is similar with the draft tube of the hydraulic turbine.

A kind of elbow inlet passage is disclosed in the patent that Patent No. 201220011514.3, it provides one kind The excellent elbow inlet passage of hydraulic performance, it makes hydraulic loss in runner relatively smaller, this for pumping station operation stability, Security and high efficiency all have very important significance.However, the main design parameters of elbow inlet passage are according to water conservancy The empirical estimating of the staff of aspect, is not provided with improving accurate design, and its method for designing ratio for being given Broad generally no specific aim, many special occasions are likely difficult to realize.The China that Patent No. 201410369192.3 A kind of elbow inlet passage is disclosed in patent of invention, it also gives a kind of method for designing of elbow inlet passage, from very big The hydraulic loss of elbow inlet passage is reduced in degree.However, it does not provide the top of elbow inlet passage inducer The design formula of taper angle, therefore, its design and imperfection, to a certain extent the Inlet flow pattern to water inlet flow channel have very Big influence.

The content of the invention

For the weak point that the above is present, the present inventor has invented a kind of setting for elbow inlet passage of pumping plant Meter method, does not only give the accurate design of main design parameters system, and can by itself and computer R. concomitans, Make it possible Parametric designing.

Raising pumping station operation is reached by controlling the relevant parameter such as inducer, bending section and outlet section of water inlet flow channel Reliability and high efficiency, while making pump work more stablize, and the time between overhauls(TBO) of pumping plant can be extended.

In order to solve the above problems, The present invention gives a kind of method for designing of the elbow inlet passage of pumping plant.Pass through Improve the several important geometric parameter of elbow inlet passage, including Proportional coefficient K, impeller central to water inlet flow channel base plate Height L, the length X of water inlet flow channel import to pump shaft line, the length P of water inlet flow channel inducer, the width of water inlet flow channel inducer Degree B, water inlet flow channel inlet height M, the profile height h of water inlet flow channel inducer_i, water inlet flow channel inducer cross-sectional area F_i, enter The transitional radius r of water flow passage inducer_i, the outer curvature radius R of water inlet flow channel bending section, the incurvature of water inlet flow channel bending section Radius r, the top taper angle α of water inlet flow channel inducer, the lower sideline angle of inclination beta of water inlet flow channel inducer, water inlet flow channel outlet section Height l, the height N of water inlet flow channel bending section, the inlet height h of water inlet flow channel bending section, reach raising pump to improve flowing The stability and security stood, additionally, patent of the present invention takes water inlet flow channel outlet diameter for impeller diameter.

Realizing the technical scheme that above-mentioned purpose is used is：

(1) Proportional coefficient K, impeller central are to the height L of water inlet flow channel base plate, the length of water inlet flow channel import to pump shaft line X, the length P of water inlet flow channel inducer, the width B of water inlet flow channel inducer computing formula it is as follows：

Patent of the present invention takes water inlet flow channel outlet diameter for impeller diameter

In formula：

K-proportionality coefficient；

L-impeller central to water inlet flow channel base plate height, rice；

X-water inlet flow channel import to pump shaft line length, rice；

The length of P-water inlet flow channel inducer, rice；

The width of B-water inlet flow channel inducer, rice；

The rotating speed of n-pumping plant pump, rev/min；

The impeller diameter of D-pumping plant pump, rice；

The flow of Q-pumping plant pump, rice³/ the second；

n_sThe specific speed of-pumping plant pump；

The lift of H-pumping plant pump, rice.

(2) computing formula of the inlet height M of water inlet flow channel is：

M=-154.3-1.721Q+289.3B-0.002161Q²+0.8455QB-76.69B² (6)

In formula：

The inlet height of M-water inlet flow channel, rice；

The flow of Q-pumping plant pump, rice³/ the second；

The width of B-water inlet flow channel inducer, rice.

(3) the profile height h of water inlet flow channel inducer_iComputing formula be：

h_i=202.9sin (0.000354M-0.00155)+1.024sin (0.1215M-3.477) (7)

In formula：

h_iThe profile height of-water inlet flow channel inducer, rice；

The inlet height of M-water inlet flow channel, rice.

(4) the cross-sectional area F of water inlet flow channel inducer_iComputing formula be：

F_i=-237.5B^-0.8613+93.29 (8)

In formula：

F_iThe cross-sectional area of-water inlet flow channel inducer, rice²；

The width of B-water inlet flow channel inducer, rice.

(5) the transitional radius r of water inlet flow channel inducer_iComputing formula be：

In formula：

r_iThe transitional radius of-water inlet flow channel inducer, rice；

The flow of Q-pumping plant pump, rice³/ the second.

(6) the outer curvature radius R of water inlet flow channel bending section, the computing formula of incurvature radius r are：

In formula：

The outer curvature radius of R-water inlet flow channel bending section, rice；

The incurvature radius of r-water inlet flow channel bending section, rice；

The impeller diameter of D-pumping plant pump, rice.

(7) the lower sideline angle of inclination beta of water inlet flow channel, the computing formula of the top taper angle α of water inlet flow channel inducer are：

In formula：

The lower sideline inclination angle of β-water inlet flow channel, degree；

The top taper angle of α-water inlet flow channel inducer, degree；

n_sThe specific speed of-pumping plant pump；

The lift of H-pumping plant pump, rice；

The rotating speed of n-pumping plant pump, rev/min；

K-proportionality coefficient；

The impeller diameter of D-pumping plant pump, rice.

(8) the height l of water inlet flow channel outlet section, the computing formula of the height N of water inlet flow channel bending section are：

N=-83.18D^-6.283+4.633 (15)

In formula：

The height of l-water inlet flow channel outlet section, rice；

The height of N-water inlet flow channel bending section, rice；

The flow of Q-pumping plant pump, rice³/ the second；

K-proportionality coefficient；

The impeller diameter of D-pumping plant pump, rice.

(9) computing formula of the inlet height h of water inlet flow channel bending section is：

In formula：

The inlet height of h-water inlet flow channel bending section, rice；

The impeller diameter of D-pumping plant pump, rice.

The main geometric parameters of the elbow inlet passage of the accurate pumping plant of comparatively perfect can be obtained by above step Method for designing.

Beneficial effects of the present invention are：

The method for designing is different from Conventional wisdom method, and the present invention is to the width of inducer, height, top taper angle and following The parameters such as line inclination angle carry out a certain proportion of adjustment, reduce inducer to the collision hydraulic loss between bending section, substantially improve The stability of Inlet flow pattern.In addition, optimizing design by the outer curvature radius to bending section and incurvature radius to drop Low bending section is to the vortex between outlet section and along journey hydraulic loss, while also cause that the flow-shape of water exit end is more steady, So as to improve stability, high efficiency and the economy of pumping station operation to a certain extent.

Brief description of the drawings

Fig. 1 is a kind of profile of the elbow inlet passage of pumping plant.

Fig. 2 is a kind of plan of the elbow inlet passage of pumping plant.

Fig. 3 is a kind of sectional drawing of the elbow inlet passage inducer of pumping plant.

Specific implementation method

The present invention is further described with reference to the accompanying drawings and detailed description.

The present invention determines a kind of main geometric parameters of the elbow inlet passage of pumping plant by following formula, Including：Impeller central is to the height L of water inlet flow channel base plate, length X, Proportional coefficient K, the water inlet of water inlet flow channel import to pump shaft line The length P of tunnel inlets section, the width B of water inlet flow channel inducer, water inlet flow channel inlet height M, water inlet flow channel bending section it is outer Radius of curvature R, the incurvature radius r of water inlet flow channel bending section, the lower sideline angle of inclination beta of water inlet flow channel inducer, water inlet flow channel enter The top taper angle α of mouthful section, the profile height h of water inlet flow channel inducer_i, the height l of water inlet flow channel outlet section, water inlet flow channel it is curved The height N of tune, the cross-sectional area F of water inlet flow channel inducer_i, water inlet flow channel inducer transitional radius r_i, water inlet flow channel it is curved Inlet height h of tune etc..

This embodiment is in given design conditions flow Q, design conditions lift H, design conditions rotating speed n, pumping plant pump Impeller diameter D calculates a kind of main geometric parameters of the elbow inlet passage of pumping plant：

M=-154.3-1.721Q+289.3B-0.002161Q²+0.8455QB-76.69B² (6)

h_i=202.9sin (0.000354M-0.00155)+1.024sin (0.1215M-3.477) (7)

F_i=-237.5B^-0.8613+93.29 (8)

N=-83.18D^-6.283+4.633 (15)

By taking inducer of the present invention as an example：

Work as Q=5m³When/s, B=3.41m, M=2.44m,

ByCan obtain, v=0.6m/s,

By Darcy formula：Can obtain,

Table look-up：ε=0.1, i.e. H_f=0.0018m, this parthydraulic loss is far smaller than the water that Conventional wisdom method is given Power is lost,

In formula：H_f- partially along journey hydraulic loss, m；

ε-coefficient of partial resistance；

Mean flow rate in v-pipeline on effective cross-section, m/s；

G-acceleration of gravity, m/s²。

Therefore, the inducer parthydraulic loss that the present invention is given more may be used than the hydraulic loss that Conventional wisdom method draws Lean on, other each several part hydraulic loss algorithms are similarly.

The present invention carries out a kind of main geometric parameters of the elbow inlet passage of pumping plant using accurate formula design method Design, it can improve the reliability of pumping station operation, while extending the service life of pump and the maintenance cycle of pumping plant.Due to this The method for designing of invention is different from traditional empirical method, therefore can effectively improve the security performance of pumping plant, while making pump work more Stabilization.Moreover, its also have good economic benefits, be more beneficial for computer R. concomitans, make Parametric designing into It is possible.

In sum, be patent of the present invention with reference to illustrating that embodiment is made, but the invention is not limited in upper Embodiment is stated, also comprising the other embodiment and variation in the range of present inventive concept.

Claims (9)

1. a kind of method for designing of the elbow inlet passage of pumping plant, it is characterised in that the elbow inlet passage it is main several What parameter includes Proportional coefficient K, the height L of impeller central to water inlet flow channel base plate, the length of water inlet flow channel import to pump shaft line X, the length P of water inlet flow channel inducer, the width B of water inlet flow channel inducer, patent of the present invention take water inlet flow channel outlet diameter and are Impeller diameter, computing formula is as follows：

$K=(-25.67n^{0.5911}+2023)\·{\left(\frac{D}{10.5}\right)}^2---\left(1\right)$

$L=-75.15+737.52\sqrt{\frac{Q}{K}}+0.0161{\ln }_s-1664.775\frac{Q}{K}-0.0861\sqrt{\frac{Q}{K}}{n}_s-4.214e^{-7}{n_s}^2---\left(2\right)$

$X=-716.9+628.1D+\frac{1.472045n\sqrt{Q}}{H^{\frac{3}{4}}}-131.4D^2-\frac{0.709195Dn\sqrt{Q}}{H^{\frac{3}{4}}}-\frac{47.294875e^{-5}{n}^{2}Q}{H^{\frac{3}{2}}}---\left(3\right)$

$P=0.1815e^{-0.181Q^2}+0.9065sin\left(0.7761\mathrm{\π}DQ\right)+0.3688---\left(4\right)$

$B=4.149+0.8059sin\left(0.8941\mathrm{\π}DQ\right)+0.9304e^{-{\left(0.5112Q\right)}^2}---\left(5\right)$

In formula：

K-proportionality coefficient；

L-impeller central to water inlet flow channel base plate height, rice；

X-water inlet flow channel import to pump shaft line length, rice；

The length of P-water inlet flow channel inducer, rice；

The width of B-water inlet flow channel inducer, rice；

The rotating speed of n-pumping plant pump, rev/min；

The impeller diameter of D-pumping plant pump, rice；

The flow of Q-pumping plant pump, rice³/ the second；

n_sThe specific speed of-pumping plant pump；

The lift of H-pumping plant pump, rice.

2. a kind of method for designing of the elbow inlet passage of pumping plant according to claim 1, it is characterised in that the elbow The geometric parameter of shape water inlet flow channel also includes the inlet height M of water inlet flow channel, and design formula is：

M=-154.3-1.721Q+289.3B-0.002161Q²+0.8455QB-76.69B² (6)

In formula：

The inlet height of M-water inlet flow channel, rice；

The flow of Q-pumping plant pump, rice³/ the second；

The width of B-water inlet flow channel inducer, rice.

3. a kind of method for designing of the elbow inlet passage of pumping plant according to claim 2, it is characterised in that the elbow The geometric parameter of the shape water inlet flow channel also profile height h including water inlet flow channel inducer_i, design formula is：

h_i=202.9sin (0.000354M-0.00155)+1.024sin (0.1215M-3.477) (7)

In formula：

h_iThe profile height of-water inlet flow channel inducer, rice；

The inlet height of M-water inlet flow channel, rice.

4. a kind of method for designing of the elbow inlet passage of pumping plant according to claim 1, it is characterised in that the elbow The geometric parameter of the shape water inlet flow channel also cross-sectional area F including water inlet flow channel inducer_i, design formula is：

F_i=-237.5B^-0.8613+93.29 (8)

In formula：

F_iThe cross-sectional area of-water inlet flow channel inducer, rice²；

The width of B-water inlet flow channel inducer, rice.

5. a kind of method for designing of the elbow inlet passage of pumping plant according to claim 1, it is characterised in that the elbow The geometric parameter of the shape water inlet flow channel also transitional radius r including water inlet flow channel inducer_i, design formula is：

$r_i=\frac{0.0006084Q^2+1.049Q+43.79}{Q+91.53}---\left(9\right)$

In formula：

r_iThe transitional radius of-water inlet flow channel inducer, rice；

The flow of Q-pumping plant pump, rice³/ the second.

6. a kind of method for designing of the elbow inlet passage of pumping plant according to claim 1, it is characterised in that the elbow The geometric parameter of shape water inlet flow channel also includes outer curvature radius R, the incurvature radius r of water inlet flow channel bending section, and design formula is：

$R=2.822e^{-{\left(\frac{D-2.75}{1.325}\right)}^2}---\left(10\right)$

$r=1.922e^{-{\left(\frac{D-2.925}{0.9717}\right)}^2}---\left(11\right)$

In formula：

The outer curvature radius of R-water inlet flow channel bending section, rice；

The incurvature radius of r-water inlet flow channel bending section, rice；

The impeller diameter of D-pumping plant pump, rice.

7. a kind of method for designing of the elbow inlet passage of pumping plant according to claim 1, it is characterised in that the elbow The geometric parameter of shape water inlet flow channel also lower sideline angle of inclination beta, the top taper angle α of water inlet flow channel inducer including water inlet flow channel, Design formula is：

$\mathrm{\β}=\frac{{n_s}^2{H}^{\frac{3}{2}}}{1178.9823n^2}-1.356---\left(12\right)$

$\mathrm{\α}=\frac{e^{-5}{K}^2{D}^4}{4480.30317}-\frac{{\mathrm{KD}}^2}{8190.93611}+6.952---\left(13\right)$

In formula：

The lower sideline inclination angle of β-water inlet flow channel, degree；

The top taper angle of α-water inlet flow channel inducer, degree；

n_sThe specific speed of-pumping plant pump；

The lift of H-pumping plant pump, rice；

The rotating speed of n-pumping plant pump, rev/min；

K-proportionality coefficient；

The impeller diameter of D-pumping plant pump, rice.

8. a kind of method for designing of the elbow inlet passage of pumping plant according to claim 1, it is characterised in that the elbow The geometric parameter of shape water inlet flow channel also height l, the height N of water inlet flow channel bending section including water inlet flow channel outlet section, design are public Formula is：

$l=-0.2289+4.49505\sqrt{\frac{Q}{K}}+8.239e^{-5}Q---\left(14\right)$

N=-83.18D^-6.283+4.633 (15)

In formula：

The height of l-water inlet flow channel outlet section, rice；

The height of N-water inlet flow channel bending section, rice；

The flow of Q-pumping plant pump, rice³/ the second；

K-proportionality coefficient；

The impeller diameter of D-pumping plant pump, rice.

9. a kind of method for designing of the elbow inlet passage of pumping plant according to claim 1, it is characterised in that the elbow The geometric parameter of shape water inlet flow channel also includes the inlet height h of water inlet flow channel bending section, and design formula is：

$h={1.329}^{-{\left(\frac{D-2.2}{0.3097}\right)}^2}e+{1.302}^{-{\left(\frac{D-1.743}{0.6033}\right)}^2}---\left(16\right)$

In formula：

The inlet height of h-water inlet flow channel bending section, rice；

The impeller diameter of D-pumping plant pump, rice.