SU1247616A1 - Device for damping pressure pulsations - Google Patents

Description

The invention relates to mechanical engineering, in particular, to means of damping pressure pulsations and controlling the boundary layer in pipeline systems.

The goal of the acquisition is to expand the range of damped frequencies, quenching both acoustic and turbulent pressure pulsations and controlling the boundary layer of the liquid.

FIG. 1 shows a longitudinal section of the device; in fig. 2 is a section A-A in FIG. one; in fig. 3 - elliptical tube, cross section.

A device for damping pressure pulsations and controlling the boundary layer of fluid in pipeline systems includes a housing 1, a central pipeline 2 with perforations 3 placed in the housing, elliptical damping tubes 4, a pressure connection 5.

The device works as follows.

The working fluid through the perforations 3 of the central pipeline 2 fills the cavities of the housing 1. Thus, the elliptical tubes 4 will be under the pressure of a pulsating fluid, and from the inside - under the pressure of compressed air. Since the conductivity of the perforation 3 of the central conduit 2 and the ellipticity of the damping tubes 4 vary in length, the degree of damping will be different, while it creates a negative pressure gradient along the length of the device. With a negative pressure gradient along the length of the working fluid flow, a stable boundary layer is obtained.

The damping of the wave energy in the device is based on the following.

Wave energy is expended on friction in the perforations 3, on the compression of fluid in the housing and on the elastic deformations of the elliptical tubes 4

(ABOUT

W .F +

EU “+

equals

(2)

C is the speed of sound;

S is the cross-sectional area

central pipeline; t - time (some number of full

periods);

DR — pressure pulsations (amplitude values); P is the density of the liquid at normal pressure. Energy 5 dissipation on perforations is equal to

CFondSJ

F

4 rr V

(3)

de P - the number of perforation holes;

d is the diameter of q perforations; So is the cross-sectional area

perforations; 4 - fluid oscillation speed

in perforations; V is the volume of the device. The energy of fluid compression is equal

V

KC

23C

D P2

)

(four)

Where

ee - volume compression ratio

fluid.

The potential energy of the elastic deformation of elliptical tubes is equal to

E 0,5 DR-Y.dr ,.

(five)

where uQ is the increment of the volume of the elliptical tube; N is the number of tubes.

thirty

4Q iS H,

(6)

35

40

whereAS is the increment of the area and cross section of the elliptical tube;

E is the length of the tube.

Instead of an elliptic section, if we consider an oval section with the same semi-axes, then approximately the extension of the cross-sectional area can be determined by a known method

& S AR Q

(7)

45

50

where Q is a coefficient depending on the elastic properties of the material of the elliptic tube and on its geometric dimensions.

Consequently

E 0,5-QlN jr2.

substitute for dR

(8) (3), (4) and (8) in (1), UPUP / s,

(9)

31247616. four

As can be seen from (9), AP depends on i d, on the geometrical parameters and the conductivity of the central perforations of the elliptical damping pipeline, i.e. from pi. tube.

fig.Z

(pi / 3. 2

Editor A, Dolinich

Compiled by D. Kiselev

Tehred I.Popovich Proofreader I, Muska

 Order 4106/36 Circulation 880 Subscription

VNIIPI USSR State Committee

on affairs of inventions and discoveries 113035 ,, Moscow, Zh-35, Raushsk nab. 4/5

Production and printing company, Uzhgorod, st. Design. four

Claims (1)

DEVICE FOR EXTINGUISHING PRESSURE PULSATIONS and controlling the boundary layer of the working fluid in pipe-line systems, comprising a central pipe with perforation and damping pipes filled with compressed gas and installed parallel to the central pipe, located in the housing, characterized in that, in order to expand the range of the quenched frequencies, the tubes have a cross-sectional shape of an ellipse with a decreasing ratio of its major and minor axes, and the total perforation area is increased in the direction of movement of the liquid STI Yu Od Od 1-247616