CN105864103A

CN105864103A - Diffusion pipe structure

Info

Publication number: CN105864103A
Application number: CN201610194292.6A
Authority: CN
Inventors: 李志松; 徐涛
Original assignee: Shanghai Institute of Satellite Engineering
Current assignee: Shanghai Institute of Satellite Engineering
Priority date: 2016-03-30
Filing date: 2016-03-30
Publication date: 2016-08-17
Anticipated expiration: 2036-03-30
Also published as: CN105864103B

Abstract

The invention provides a diffusion pipe structure which comprises a diffusion pipe and a throat straight pipe connected with the diffusion pipe. The central axis of the diffusion pipe and the throat straight pipe coincides with the outer circle tangent line of a volute annular channel, and the pipe section of the diffusion pipe in the outward direction of the axis is increased in one direction. The diffusion pipe structure has the beneficial effects that 1, the speed of fluid can be reduced to a certain extent before entering the throat straight pipe, so that flow loss of the fluid when the fluid enters the throat straight pipe is reduced; 2, the horn-shaped design of the diffusion pipe is close to the contour of a parabola, and linear increase of the axis cross section of the diffusion pipe can be achieved, or the effect that increase of the cross section of the upstream part is slow and increase of the cross section of the downstream part is fast can be achieved; 3, by controlling the speed reducing degree, in-pipe flow separation caused by non-uniform distribution of the flowing speed in a throat can be restrained to a certain extent, or flow separation can be delayed to the downstream part where the in-pipe flowing speed is low, and therefore flow loss in the diffusion pipe is reduced.

Description

Anemostat structure

Technical field

The present invention relates to the design of a kind of anemostat, a kind of anemostat for tangent pump.

Background technology

Anemostat is the vitals on tangent pump.Tangent pump is used mostly annular volute.Fluid, after impeller does work, first makees preliminary deceleration in the annular channel of spiral case, makees to slow down further subsequently into anemostat, and fluid kinetic energy in moderating process is constantly converted into pressure energy, makes static pressure improve.

But, existing tangent pump anemostat is nearly all that the straight line Taper Pipe using single cone angle designs.Owing to the caliber of pump drainage outlet is the most fixing, in the case of pump overall dimension is limited, anemostat has to use relatively large cone angle, thus causes the interior serious flow separation of pipe and pitot loss.Even if size allows, diffuser pipe have employed the smaller cone angles value that experience is recommended, owing to fluid flowing velocity distribution when annular volute enters venturi is uneven, so flow separation and the pitot loss of local in most cases still can be produced in anemostat, and flow separation point is close at the venturi of upstream, speed is the highest in being pipe herein, therefore loses the most very important.

As it is shown in figure 1, in regular section stream pump, spiral case 1 is tangentially stretched out by a venturi straight tube 3, connects with straight line taper anemostat 3.Wherein venturi straight tube 4 cross section is circular, tangent with the annular channel cylindrical of spiral case 1.From the point of view of One Dimension Analysis, the sectional area of straight line taper anemostat 3 is axially varying is nonlinear.According to the conservation of mass, fluid linearly taper anemostat 3 axially flows the retarded motion maximum by first carrying out acceleration, and then acceleration constantly reduces, and leaves straight line taper anemostat 3 brief acceleration minimum.It is the highest state owing to being exactly in bulk velocity when that fluid being made in straight line taper anemostat 3 and the most acutely slowed down, serious flow separation therefore can be caused to lose.

Summary of the invention

For defect of the prior art, it is an object of the invention to provide a kind of service behaviour more preferably anemostat structure.

For solving above-mentioned technical problem, a kind of anemostat structure that the present invention provides, including interconnective anemostat and venturi straight tube, the central axis of described anemostat and described venturi straight tube overlaps with the cylindrical tangent line of spiral case annular channel, and described anemostat is dull increase along axis tube section the most upwards.

Preferably, transition conduit, the inwall of the described transition conduit described spiral case annular channel of laminating are connected in one end of described venturi straight tube.

Preferably, described transition conduit be arranged on the impeller in described spiral case annular channel the center of circle place central angle as the center of circle less than 90 degree.

Preferably, described anemostat be shaped as tubaeform.

Compared with prior art, beneficial effects of the present invention is as follows:

1, make fluid can necessarily be slowed down before entering trunnion straight way, reduce flow losses when entering trunnion straight way.

2, the flare design of anemostat, close to parabolical profile, can realize the linear increase along anemostat axis cross section, or the cross section of upstream increases relatively slow, and the cross section in downstream increases very fast.

3, by the control to degree of deceleration, can to a certain degree suppress the Bottomhole pressure that venturi flowing velocity distribution causes time uneven to separate, or postpone flow separation to the relatively low downstream of Bottomhole pressure speed, thus flow losses in reducing anemostat.

Accompanying drawing explanation

The detailed description made non-limiting example with reference to the following drawings by reading, the further feature purpose of the present invention and advantage will become more apparent upon.

Fig. 1 is prior art anemostat structure sectional view；

Fig. 2 is anemostat structure sectional view of the present invention.

In figure:

1-spiral case 2-impeller 3-anemostat

4-venturi straight tube 5-transition conduit

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention is described in detail.Following example will assist in those skilled in the art and are further appreciated by the present invention, but limit the present invention the most in any form.It should be pointed out that, to those skilled in the art, without departing from the inventive concept of the premise, it is also possible to make some changes and improvements.These broadly fall into protection scope of the present invention.

As in figure 2 it is shown, the central axis of venturi straight tube 4 and anemostat 3 overlaps with the cylindrical tangent line of spiral case 1 annular channel in the present invention.The shape flare of anemostat 3, but diffuse up pipe 3 cross section along axis outward and keep dullness to increase.Owing to venturi straight tube 4 has partial cross section outside the annular channel of annular volute 1, so arranging a venturi inlet transforms pipe 5.The size of transition conduit 5, the corner centered by impeller 2 rotating shaft calculates, less than 90 degree.

In the present invention designs, venturi inlet transforms pipe 5 therein expands the space of spiral case 1 annular channel, and local adds the radius of annular channel, compared with the conventional design in Fig. 1, fluid can necessarily be slowed down before entering venturi, reduce flow losses when entering venturi straight tube 4.And the flare design of anemostat 3, close to parabolical profile, the linear increase along anemostat 3 axis cross section can be realized, or the cross section of upstream increases relatively slow, the cross section in downstream increases very fast.Result makes fluid even retardation in anemostat 3 exactly, or fluid slows down gentler when upstream, slows down when downstream more violent.So by the control to degree of deceleration, can to a certain degree suppress the Bottomhole pressure that venturi flowing velocity distribution causes time uneven to separate, or postpone flow separation to the relatively low downstream of Bottomhole pressure speed, thus reduce flow losses in anemostat 3.

Above the specific embodiment of the present invention is described.It is to be appreciated that the invention is not limited in above-mentioned particular implementation, those skilled in the art can make a variety of changes within the scope of the claims or revise, and this has no effect on the flesh and blood of the present invention.In the case of not conflicting, the feature in embodiments herein and embodiment can arbitrarily be mutually combined.

Claims

1. an anemostat structure, including interconnective anemostat and venturi straight tube, described anemostat and described venturi The central axis of straight tube overlaps with the cylindrical tangent line of spiral case annular channel, it is characterised in that described anemostat is along axis court Foreign side's tube section upwards is dull increase.

Anemostat structure the most according to claim 1, it is characterised in that in one end of described venturi straight tube even Connect transition conduit, the inwall of the described transition conduit described spiral case annular channel of laminating.

Anemostat structure the most according to claim 2, it is characterised in that described transition conduit is to be arranged on described snail The center of circle of the impeller in shell annular channel is that the place central angle in the center of circle is less than 90 degree.

Anemostat structure the most according to claim 1, it is characterised in that described anemostat be shaped as loudspeaker Shape.