CN111043049A

CN111043049A - Pressure guiding hole structure for multi-stage pump static pressure test and multi-stage pump thereof

Info

Publication number: CN111043049A
Application number: CN201911283272.6A
Authority: CN
Inventors: 孙帅辉; 闫思娜; 陈森林; 张乐福
Original assignee: Xian University of Technology
Current assignee: Xian University of Technology
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2020-04-21
Anticipated expiration: 2039-12-13
Also published as: CN111043049B

Abstract

The invention discloses a pressure guide hole structure for testing the static pressure of a multistage pump, which comprises a first pressure guide hole formed in a pump shell of the multistage pump and a second pressure guide hole formed in the wall surface of a diffuser, wherein the second pressure guide holes are provided with a plurality of annular grooves which are positioned in the same circumferential direction, and the outer side of the wall surface of the diffuser is provided with annular grooves corresponding to the first pressure guide hole along the circumferential direction of a connecting line of the plurality of second pressure guide holes; the invention also discloses a multistage pump adopting the pressure guide hole structure for the multistage pump static pressure test. The pressure guide hole structure for the static pressure test of the multistage pump avoids the situation that a pump shell hole and a diffuser hole are in alignment during installation, and simplifies the diffuser structure and the installation process; the mode that the annular groove is internally provided with a plurality of holes averages the pressure, and is favorable for accurately measuring the back pressure of each stage of impeller.

Description

Pressure guiding hole structure for multi-stage pump static pressure test and multi-stage pump thereof

Technical Field

The invention belongs to the technical field of fluid machinery and engineering equipment, and particularly relates to a pressure guide hole structure for static pressure testing of a multistage pump.

Background

The multistage pump is widely applied to important industries such as thermal power, nuclear power, fire fighting, petrochemical industry, mines, seawater desalination and the like, and plays an irreplaceable important role. The multi-stage pump has a higher head than that of the single-stage pump, but has a complicated structure and a reduced performance due to the presence of unsteady flow interference and unsteady flow between stages. Many scholars have carried out experimental research on the multistage pump, because pressure is one of the important parameters of evaluating pump performance, consequently often need measure its each level pressure in the experimentation to know the loss condition of pump each level energy. The multistage pump is characterized in that a plurality of pump stages are connected in series, an outlet of a front stage is communicated with an inlet of a rear stage, and finally a pump shell is adopted to connect the tail of a pump head and protect an impeller and a diffuser. The basic idea of pressure test is to provide a pressure guide hole, lead out water flow with measuring point pressure from the pressure guide hole, contact with a pressure sensor probe fixed at the other end of the pressure guide hole, and finally transmit pressure parameters through the pressure sensor. The technology related to pressure testing of one pressure guide hole is quite mature, and in the pressure testing of the multi-stage pump, different from the prior technology, pressure guide through holes are required to be formed in a pump shell and a diffuser, water flow is led out from the hole in the diffuser and enters the hole in the pump shell through a gap between the diffuser and the pump shell to be in contact with a sensor probe fixed on the pump shell, and finally the pressure at a testing point is obtained. For a multistage pump, two main schemes are provided for opening the pressure hole: scheme 1, the hole has been opened on pump case and diffuser wall before the pump assembly, then assembles each part of pump, because pass through bayonet coupling between the multistage pump diffuser, does not consider its circumference centering problem, and when the multistage pump assembly, can make the installation become very complicated if considering circumference centering, therefore the circumference centering problem of diffuser hole and pump case hole exists in this kind of scheme. Scheme 2, trompil on the multistage pump that has assembled, the centering problem of scheme 1 does not exist to this kind of scheme, but in the trompil in-process can hardly have the residue and enter into the runner, and the structure of multistage pump is more complicated, and this kind of residue is difficult clean up, can cause the jam to the runner, and simultaneously, in the experimentation, in order to look over the inside condition of pump, often need carry out the dismouting to the pump, and the circumference centering problem that mentions in scheme 1 will appear again when the pump of taking apart carries out the secondary assembly. Therefore, a solution to this problem is needed in multi-stage pump static pressure testing.

Disclosure of Invention

The invention aims to provide a pressure guide hole structure for a multistage pump static pressure test, which can accurately measure the back pressure of an impeller of each stage.

Another object of the present invention is to provide a multistage pump employing the above pressure leading hole structure for static pressure test of a multistage pump.

The first technical scheme adopted by the invention is as follows: the utility model provides a draw pressure hole structure for multistage pump static pressure test, draws the pressure hole including seting up the first second that draws pressure hole and diffuser wall on the multistage pump case, the second draws the pressure hole and has seted up a plurality ofly and be located same circumference, and the diffuser wall outside draws the circumference of pressure hole line along a plurality of seconds and sets up the ring channel that corresponds with the first pressure hole that draws.

The first technical solution of the present invention is also characterized in that,

the second pressure leading holes are uniformly distributed on the circumference of the annular groove at intervals.

The second pressure guide holes are provided with at least four.

The second technical scheme adopted by the invention is as follows: a multi-stage pump with pressure-inducing hole structure for the static pressure test of multi-stage pump is composed of cylindrical pump casing with inlet and outlet pump covers fixed to both ends, outlet pipe and outlet bearing seat, inlet and bearing boxes, inlet bearing seat for connecting pump casing to inlet pipe, bearing box with bearing box axle, pump shaft, and several static diffusers between pump cover and outlet pump cover, one end of the diffuser close to the inlet pump cover is provided with a closed impeller fixedly sleeved with the pump shaft in a matching way;

the pump case is provided with a first pressure leading hole corresponding to each stage of diffuser, the first pressure leading hole is internally provided with a pressure sensor, the wall surface of each stage of diffuser is provided with a second pressure leading hole, the second pressure leading hole on the wall surface of each stage of diffuser is provided with a plurality of pressure leading holes and is positioned in the same circumferential direction, and the outer side of the wall surface of each stage of diffuser is provided with an annular groove corresponding to the first pressure leading hole in the same stage along the circumferential direction of a plurality of second pressure leading hole connecting lines.

The second technical solution of the present invention is also characterized in that,

an inlet fluid director is arranged between the inlet bearing seat and the wheel cover of the first-stage impeller, the other end of the wheel cover of the first-stage impeller is connected to the first-stage diffuser, an outlet fluid director is arranged between the last-stage diffuser and the outlet bearing seat, and the wheel discs of the plurality of stages of impellers are fixedly sleeved with the pump shaft.

A support bushing is arranged at the position, extending out of the bearing box, of the bearing box shaft, an inlet bearing bushing is arranged at the position, penetrating through the inlet bearing seat, of the pump shaft, and an outlet bearing bushing is arranged at the position, penetrating through the outlet bearing seat, of the pump shaft.

First O-shaped sealing rings are arranged between the inlet pump cover and the inlet connecting pipe and between the outlet pump cover and the outlet connecting pipe; second O-shaped sealing rings are arranged between the plurality of stages of diffusers and the pump shell.

Spring retainer rings are arranged at one end of the pump shaft, which is positioned in the outlet bearing seat, and at one end of the pump shaft, which is positioned in the inlet bearing seat.

And antiwear rings are arranged at one end of the wheel cover of the impeller, which is close to the diffuser matched with the impeller.

The bearing box shaft is sleeved with a pump inlet mechanical seal and a water throwing ring in parallel, and the pump inlet mechanical seal is close to the inlet connecting pipe.

The invention has the beneficial effects that:

(1) the pump shell hole and the diffuser hole are prevented from being in alignment during installation, and the diffuser structure and the installation process are simplified;

(2) the mode that the annular groove is internally provided with a plurality of holes averages the pressure, and is favorable for accurately measuring the back pressure of each stage of impeller.

Drawings

FIG. 1 is a schematic structural diagram of a pressure-leading hole structure for a multi-stage pump static pressure test according to the present invention;

FIG. 2 is a cross-sectional view A-A of the pressure pilot hole configuration of FIG. 1 for static pressure testing of a multi-stage pump according to the present invention;

FIG. 3 is a radial view of a pressure orifice configuration of the present invention for static pressure testing of a multi-stage pump;

fig. 4 is a schematic diagram of a multi-stage pump structure using a pressure-inducing hole structure for a multi-stage pump static pressure test according to the present invention.

In the drawing, 1, a pump shell, 2, an inlet pump cover, 3, an outlet pump cover, 4, an outlet connecting pipe, 5, an outlet bearing seat, 6, an inlet connecting pipe, 7, a bearing box, 8, an inlet bearing seat, 9, a bearing box shaft, 10, a pump shaft, 11, a coupling, 12, a diffuser, 13, an impeller, 14, an inlet fluid director, 15, an outlet fluid director, 16, a bracket bushing, 17, an inlet bearing bushing, 18, an outlet bearing bushing, 19, a first O-shaped sealing ring, 20, a second O-shaped sealing ring, 21, a spring retainer ring, 22, an anti-wear ring, 23, a pump inlet mechanical seal, 24, a water slinging ring, 25, a first pressure guide hole, 26, an annular groove and 27, a second pressure guide hole are arranged.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention provides a pressure guide hole structure for a multistage pump static pressure test, which comprises a first pressure guide hole 25 arranged on a multistage pump casing 1 and a second pressure guide hole 27 arranged on the wall surface of a diffuser 12, wherein the second pressure guide holes 27 are provided with a plurality of annular grooves 26 which are positioned in the same circumferential direction, and the outer side of the wall surface of the diffuser 12 is provided with an annular groove 26 corresponding to the first pressure guide hole 25 along the circumferential direction of the connecting line of the plurality of second pressure guide holes 27, as shown in figures 1 to 3.

The second pressure guiding holes 27 are uniformly distributed around the annular groove 26 at intervals, and at least four second pressure guiding holes 27 are arranged.

The invention also provides a multistage pump adopting a pressure guide hole structure for a multistage pump static pressure test, which comprises a cylindrical pump shell 1, wherein an inlet pump cover 2 and an outlet pump cover 3 are respectively and fixedly arranged at two ends of the pump shell 1, the other end of the outlet pump cover 3 is fixedly connected with an outlet connecting pipe 4, an outlet bearing seat 5 for communicating the pump shell 1 with the outlet connecting pipe 4 is coaxially arranged on the outlet pump cover 3, an inlet connecting pipe 6 and a bearing box 7 are sequentially and fixedly connected with the other end of the inlet pump cover 2, an inlet bearing seat 8 for communicating the pump shell 1 with the inlet connecting pipe 6 is coaxially arranged on the inlet pump cover 2, a bearing box shaft 9 with one end extending into the inlet connecting pipe 6 is arranged in the bearing box 7, a pump inlet mechanical seal 23 and a water slinger ring 24 are sleeved on the bearing box shaft 9 in parallel, the pump inlet mechanical seal 23 is close to the inlet connecting pipe 6, a pump shaft 10 is, one end of a pump shaft 10 penetrates through an inlet bearing seat 8 and extends into an inlet connecting pipe 6 and is connected with a bearing box shaft 9 through a coupling 11, the other end of the pump shaft 10 is positioned in an outlet bearing seat 5, a plurality of stages of static diffusers 12 are sequentially and uniformly sleeved on the pump shaft 10 between an inlet pump cover 2 and an outlet pump cover 3 along the axial direction, one end, close to the inlet pump cover 2, of each diffuser 12 is provided with a closed impeller 13 fixedly sleeved with the pump shaft 10 in a matched mode, one end, close to the diffuser 12 matched with the closed impeller 13, of a wheel cover of each impeller 13 is provided with an anti-wear ring 22, an inlet fluid director 14 is arranged between the inlet bearing seat 8 and the wheel cover of the first-stage impeller 13, the other end of the wheel cover of the first-stage impeller 13 is connected to the first-stage diffuser 12, an outlet 15 is arranged between the; a support bush 16 is arranged at the position where the bearing box shaft 9 extends out of the bearing box 7, an inlet bearing bush 17 is arranged at the position where the pump shaft 10 passes through the inlet bearing seat 8, and an outlet bearing bush 18 is arranged at the position where the pump shaft 10 passes through the outlet bearing seat 5; first O-shaped sealing rings 19 are arranged between the inlet pump cover 2 and the inlet connecting pipe 6 and between the outlet pump cover 3 and the outlet connecting pipe 4; second O-shaped sealing rings 20 are arranged between the plurality of stages of diffusers 12 and the pump shell 1; one end of the pump shaft 10 located in the outlet bearing seat 5 and one end of the pump shaft 10 located in the inlet bearing seat 8 are both provided with spring retainer rings 21.

Correspond every grade of diffuser 12 on the pump case 1 and all seted up first pressure hole 25 that draws, all be provided with pressure sensor in the first pressure hole 25 that draws, all seted up the second on every grade of diffuser 12 wall and drawn pressure hole 27, the second on every grade of diffuser 12 wall is drawn pressure hole 27 and has all seted up a plurality ofly and be located same circumference, the ring channel 26 that corresponds with the first pressure hole 25 that draws of the same grade is all seted up along the circumference of a plurality of seconds pressure hole 27 lines in every grade of diffuser 12 wall outside.

When the pump works, a liquid medium passes through the inlet bearing seat 8 on the inlet pump cover 2 through the inlet connecting pipe 6 to enter the pump shell 1, then flows through the inlet fluid director 14 to enter the wheel cover of the first-stage impeller 13, and under the rotating action of the wheel disc of the impeller 13, the liquid flows into the diffuser 12 along the wheel cover radial direction of the impeller 13, the kinetic energy of the liquid is converted into static pressure energy in the diffuser 12, and the static pressure energy is guided out to the outlet connecting pipe 4 through the outlet bearing seat 5 by the outlet fluid director 15 after sequentially passing through the multi-stage impeller 13 and the diffuser 12; in the process, the water in the diffuser 12 is led out from the 4 second pressure leading holes 27 and enters the annular groove 26, so that the circumferential centering problem caused by the through holes formed in the wall surfaces of the pump shell 1 and the diffuser 12 is solved, uniform water pressure is formed in the annular groove 26, and the water pressure enters the first pressure leading holes 25 in the wall surface of the pump shell 1 through the gap between the diffuser 12 and the pump shell 1 and is in contact with the pressure sensor so as to measure the pressure at the position. In addition, the arrangement of the inlet fluid director 14 and the outlet fluid director 15 ensures that the flow channels are smooth without large cavities or bulges, thereby reducing the flow loss and realizing the effect of stable backflow; the arrangement of the antiwear ring 22 ensures that when the wheel disc of the impeller 13 works, the wheel disc moves towards the pump outlet side under the action of centrifugal force, so as to prevent the wheel disc from directly contacting and rubbing with the diffuser 12, reduce friction loss and prolong the service life of the wheel disc; the water slinger ring 24 is arranged to prevent working medium seeped out from the pump inlet mechanical seal 23 from entering the bearing box 7, and plays a role in protection when being matched with the pump inlet mechanical seal 23.

Through the mode, the pressure guide hole structure for the static pressure test of the multistage pump avoids the alignment of the first pressure guide hole 25 on the pump shell 1 and the second pressure guide hole 27 on the diffuser during installation, and simplifies the structure and the installation process of the diffuser; while the pressure is averaged by the second pilot holes 27 to facilitate accurate measurement of the back pressure of the impeller 13 at each stage.

Claims

1. The utility model provides a draw pressure hole structure for multistage pump static pressure test, its characterized in that draws pressure hole (27) including the first pressure hole (25) of drawing and the second on diffuser (12) wall of seting up on multistage pump case (1), and the second is drawn pressure hole (27) and has been seted up a plurality ofly and be located same circumference, and diffuser (12) wall outside draws pressure hole (27) line's circumference along a plurality of seconds and has seted up ring channel (26) that correspond with first pressure hole (25) of drawing.

2. The pressure-leading hole structure for the static pressure test of the multi-stage pump as claimed in claim 1, wherein the second pressure-leading holes (27) are uniformly distributed at intervals around the annular groove (26).

3. Pressure tapping hole structure for multi-stage pump static pressure testing according to claim 1 or 2, characterized in that said second pressure tapping hole (27) is provided with at least four.

4. A multi-stage pump adopting the pressure guide hole structure for the multi-stage pump static pressure test according to claim 1, which is characterized by comprising a cylindrical pump shell (1), wherein an inlet pump cover (2) and an outlet pump cover (3) are respectively and fixedly arranged at two ends of the pump shell (1), an outlet connecting pipe (4) is fixedly connected at the other end of the outlet pump cover (3), an outlet bearing seat (5) for communicating the pump shell (1) with the outlet connecting pipe (4) is coaxially arranged on the outlet pump cover (3), an inlet connecting pipe (6) and a bearing box (7) are sequentially and fixedly connected at the other end of the inlet pump cover (2), an inlet bearing seat (8) for communicating the pump shell (1) with the inlet connecting pipe (6) is coaxially arranged on the inlet pump cover (2), and a bearing box shaft (9) with one end extending into the inlet connecting pipe (6) is arranged in the bearing box (7), a pump shaft (10) is coaxially arranged in a pump shell (1), one end of the pump shaft (10) penetrates through an inlet bearing seat (8) and extends into an inlet connecting pipe (6) and is connected with a bearing box shaft (9) through a coupler (11), the other end of the pump shaft (10) is positioned in an outlet bearing seat (5), a plurality of stages of static diffusers (12) are sequentially and uniformly sleeved between an inlet pump cover (2) and an outlet pump cover (3) on the pump shaft (10) along the axial direction, and one end, close to the inlet pump cover (2), of each diffuser (12) is provided with a closed impeller (13) fixedly sleeved with the pump shaft (10) in a matched mode;

correspond every grade of diffuser (12) on pump case (1) and all seted up first pressure hole (25) that draws, all be provided with pressure sensor in first pressure hole (25) that draws, all seted up the second on every grade of diffuser (12) wall and drawn pressure hole (27), second on every grade of diffuser (12) wall draws pressure hole (27) and has all seted up a plurality ofly and be located same circumference, the circumference of every grade of diffuser (12) wall outside along a plurality of seconds draw pressure hole (27) line all sets up ring channel (26) that correspond with the first pressure hole (25) that draws of the same grade.

5. The multistage pump adopting the pressure leading hole structure for the multistage pump static pressure test is characterized in that an inlet flow guider (14) is arranged between the inlet bearing seat (8) and the wheel cover of the first-stage impeller (13), the other end of the wheel cover of the first-stage impeller (13) is connected to the first-stage diffuser (12), an outlet flow guider (15) is arranged between the last-stage diffuser (12) and the outlet bearing seat (5), and wheel discs of a plurality of stages of impellers (13) are fixedly sleeved with the pump shaft (10).

6. A multi-stage pump with a pressure tapping hole structure for multi-stage pump static pressure test according to claim 4, characterized in that the position where the bearing box shaft (9) protrudes from the bearing box (7) is provided with a bracket bushing (16), the position where the pump shaft (10) passes through the inlet bearing block (8) is provided with an inlet bearing bushing (17), and the position where the pump shaft (10) passes through the outlet bearing block (5) is provided with an outlet bearing bushing (18).

7. The multistage pump adopting the pressure guide hole structure for the multistage pump static pressure test is characterized in that first O-shaped sealing rings (19) are arranged between the inlet pump cover (2) and the inlet connecting pipe (6) and between the outlet pump cover (3) and the outlet connecting pipe (4); second O-shaped sealing rings (20) are arranged between the plurality of stages of diffusers (12) and the pump shell (1).

8. A multi-stage pump with a pressure leading hole structure for multi-stage pump static pressure test according to claim 4, characterized in that the end of the pump shaft (10) located in the outlet bearing seat (5) and the end of the pump shaft (10) located in the inlet bearing seat (8) are provided with spring retaining rings (21).

9. The multistage pump adopting the pressure leading hole structure for the multistage pump static pressure test is characterized in that an antiwear ring (22) is arranged at one end of a wheel cover of the impeller (13) close to a diffuser (12) matched with the impeller.

10. The multistage pump adopting the pressure leading hole structure for the multistage pump static pressure test is characterized in that a pump inlet mechanical seal (23) and a water slinging ring (24) are sleeved on the bearing box shaft (9) in parallel, and the pump inlet mechanical seal (23) is close to the inlet connecting pipe (6).