CN110671335A

CN110671335A - Multi-stage high-temperature pump with disrotatory structure

Info

Publication number: CN110671335A
Application number: CN201910900514.5A
Authority: CN
Inventors: 龙云; 陈一鸣; 朱荣生; 安策; 付强; 王秀礼
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2019-09-23
Filing date: 2019-09-23
Publication date: 2020-01-10
Anticipated expiration: 2039-09-23
Also published as: CN110671335B

Abstract

The invention provides a counter-rotating structure multistage high-temperature pump, which comprises a shell, a secondary impeller and a primary impeller, wherein the shell is provided with a plurality of grooves; the shell is sequentially provided with a suction chamber, a first-stage guide vane, a second-stage guide vane and a pump body according to the flow direction of sucked fluid; the rotatable first-stage impeller of coaxial arrangement between suction chamber and the first-stage stator, the rotatable secondary impeller of coaxial arrangement between first-stage stator and the secondary stator, the rotational speed of first-stage impeller and secondary impeller is inequality, just turning to of first-stage impeller and secondary impeller is inequality. A hollow shaft is supported in the first stage guide vane and the second stage guide vane and is in transmission connection with a secondary impeller; the solid shaft is supported in the hollow shaft, and the solid shaft penetrates through the hollow shaft to be in transmission connection with the primary impeller. The invention solves the problems of narrow high-efficiency area, low efficiency in low-flow operation, poor unit vibration and cavitation resistance and the like, and greatly reduces the influence of prerotation of the first-stage guide vane outlet, thereby effectively improving the lift of the pump.

Description

Multi-stage high-temperature pump with disrotatory structure

Technical Field

The invention relates to the field of high-temperature pumps, in particular to a multistage high-temperature pump with a disrotatory structure.

Background

At present, with the continuous adjustment of energy structures, the proportion of pump products in actual production is higher and higher. The multistage pump mainly takes a centrifugal impeller as a main part, adopts a multistage series structure so as to meet the requirement of high lift, and is widely applied to the important fields of national defense and national economy such as nuclear industry energy, chemical industry, electric power and the like. The general traditional centrifugal pump has the difficulties of large volume, narrow high-efficiency area, low efficiency during small-flow operation and the like during design, and has the problems of vibration, noise, cavitation and the like, thereby seriously influencing the safety and reliability of system operation. In the multistage pump, because first order stator export can prerevolve, lead to the reduction of secondary lift, adopt to revolve the influence that the structure can reduce last one-level stator export prerevolved to effectively improve the lift of pump. The Chinese invention patent discloses a dual-drive counter-rotating axial flow pump, which widens the range of the axial flow pump and can partially replace a mixed flow pump. However, the structure adopts a double-end double-drive design, so that the installation and the use are not convenient enough, and the inlet is easy to cause larger hydraulic loss.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the counter-rotating structure multi-stage high-temperature pump, solves the problems of narrow high-efficiency area, low efficiency in low-flow operation, poor unit vibration and cavitation resistance and the like, and greatly reduces the influence of prerotation of the first-stage guide vane outlet, thereby effectively improving the pump lift.

The present invention achieves the above-described object by the following technical means.

A pair of multistage high-temperature pumps of rotary structure, including the body, the said body has suction chambers, first stage guide vane, secondary guide vane and pump body sequentially according to the flow direction which sucks the fluid, also include secondary impeller and first stage impeller; the rotatable first-stage impeller of coaxial arrangement between suction chamber and the first-stage stator, the rotatable secondary impeller of coaxial arrangement between first-stage stator and the secondary stator, the rotational speed of first-stage impeller and secondary impeller is inequality, just turning to of first-stage impeller and secondary impeller is inequality.

The hollow shaft is supported in the first stage guide vane and the second stage guide vane and is in transmission connection with the secondary impeller; the solid shaft is supported in the hollow shaft, and the solid shaft penetrates through the hollow shaft to be in transmission connection with the primary impeller.

Furthermore, one end of the hollow shaft penetrates through the shell to be connected with the first transmission device; the first-stage guide vane is provided with a first shaft sleeve, the second-stage guide vane is provided with a second shaft sleeve, and the other end of the hollow shaft is supported by the first shaft sleeve and the second shaft sleeve.

Further, one end of the solid shaft penetrates through the first transmission device and is connected with the second transmission device; and a shaft shoulder is arranged at the other end of the solid shaft penetrating through the hollow shaft, and a plane bearing is arranged between the shaft shoulder and the end face of the other end of the hollow shaft.

Furthermore, a shaft sleeve chamber is fixed in the suction chamber through a flow guide rib plate, a third shaft sleeve is installed in the shaft sleeve chamber, and the other end of the solid shaft penetrates through the first-stage impeller and then is supported in the third shaft sleeve.

Further, the surface of the solid shaft is plated with copper for preventing the shaft from expanding and deforming under heat.

Further, the rotating speed of the primary impeller is less than that of the secondary impeller.

Further, the ratio of the rotating speed of the primary impeller to the rotating speed of the secondary impeller is 0.5-0.7.

Further, the device also comprises a constant-pressure air supply device, and a gap between the solid shaft and the hollow shaft is an air chamber; the constant-pressure gas supply device is used for conveying constant-pressure inert gas into the gas chamber.

The invention has the beneficial effects that:

compared with a single-stage pump, the counter-rotating structure multi-stage high-temperature pump can reduce pre-rotation of the outlet of the first-stage guide vane, improve the operation stability of the pump and improve the lift of the pump; compared with the traditional multistage pump, the invention has small volume and relatively simple structure, and can improve the anti-cavitation performance; the invention can also prevent the air chamber from being blocked by the crystallization of the conveying medium under the cold working condition, and avoid the shaft clamping and the abrasion of the moving and static parts caused by the crystallization of the conveying medium.

Drawings

Fig. 1 is a sectional view of a casing of a counter-rotating multistage high-temperature pump according to the present invention.

Fig. 2 is a schematic structural diagram of a counter-rotating multistage high-temperature pump according to the present invention.

Fig. 3 is a partially enlarged view of fig. 1.

In the figure:

1-a suction chamber; 2-a shaft sleeve chamber; 3-a thrust washer; 4-a flow guide rib plate; 5-first stage impeller; 6-first stage guide vanes; 7-a first sleeve; 8-a secondary impeller; 9-secondary vanes; 10-a second shaft sleeve; 11-solid shaft motor; 12-a hollow shaft motor; 13-a pump body; 14-a third sleeve; 15-a solid shaft; 16-a hollow shaft; 17-a snap ring; 18-constant pressure air supply device; 19-copper plating; 20-air chamber; 21-plane bearing.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.

As shown in fig. 1 and 2, the counter-rotating multistage high-temperature pump of the present invention includes a housing, a secondary impeller 8, and a primary impeller 5, wherein the housing is sequentially provided with a suction chamber 1, a primary guide vane 6, a secondary guide vane 9, and a pump body 13 according to a flow direction of a suction fluid; the suction chamber 1, the first stage guide vane 6 and the second stage guide vane 9 are coaxially arranged. Rotatable primary impeller 5 of coaxial arrangement between suction chamber 1 and the primary stator 6, rotatable secondary impeller 8 of coaxial arrangement between primary stator 6 and the secondary stator 9, primary impeller 5 passes through snap ring 17 to be fixed on solid shaft 15, secondary impeller 8 passes through snap ring 17 to be fixed on hollow shaft 16. The rotating speeds of the primary impeller 5 and the secondary impeller 8 are different, and the rotating directions of the primary impeller 5 and the secondary impeller 8 are different.

A hollow shaft 16 is supported in the first stage guide vane 6 and the second stage guide vane 9, and the hollow shaft 16 is in transmission connection with a secondary impeller 8; the solid shaft 15 is supported in the hollow shaft 16, and the solid shaft 15 is in transmission connection with the primary impeller 5 through the hollow shaft 16. One end of the hollow shaft 16 penetrates through the shell to be connected with the hollow shaft motor 12 or the reduction box; the first-stage guide vane 6 is provided with a first shaft sleeve 7, the second-stage guide vane 9 is provided with a second shaft sleeve 10, and the other end of the hollow shaft 16 is supported by the first shaft sleeve 7 and the second shaft sleeve 10. One end of the solid shaft 15 penetrates through an output shaft of the hollow shaft motor 12 and is connected with the solid shaft motor 11; one end of the solid shaft 15 can also penetrate through the reduction gearbox to be connected with the other reduction gearbox; the other end of the solid shaft 15 penetrating through the hollow shaft 16 is provided with a shaft shoulder, and a plane bearing 21 is arranged between the shaft shoulder and the end face of the other end of the hollow shaft 16.

The shaft sleeve chamber 2 is fixed in the suction chamber 1 through a flow guide rib plate 4, a third shaft sleeve 14 is installed in the shaft sleeve chamber 2 and positioned through a thrust washer 3, and the other end of the solid shaft 15 penetrates through the first-stage impeller 5 and then is supported in the third shaft sleeve 14.

As shown in fig. 3, the gap between the solid shaft 15 and the hollow shaft 16 is an air chamber 20; the constant pressure air supply device 18 is used for conveying constant pressure inert gas into the air chamber 20, and prevents the high temperature medium from crystallizing and blocking the air chamber under the cold working condition, and avoids conveying medium crystals to clamp the shaft and cause abrasion of moving and static parts.

The rotating speed of the primary impeller 5 is less than that of the secondary impeller 8. The ratio of the rotating speed of the primary impeller 5 to the rotating speed of the secondary impeller 8 is in the range of 0.5-0.7, so that the pressure at the inlet of the secondary impeller 8 is conveniently increased; the primary impeller 5 and the secondary impeller 8 rotate in different directions, and if the primary impeller 5 rotates clockwise when viewed from the inlet direction of the pump, the secondary impeller 8 rotates counterclockwise; the hollow shaft 16 and the solid shaft 15 are made of stainless steel, the outer surface of the solid shaft 15 adopts a copper plating technology, and a copper plating layer 19 is arranged to prevent the shaft from expanding and deforming under heat; the solid shaft 15 is mounted with the hollow shaft 16 with care being taken to ensure concentricity.

In the actual operation process of the counter-rotating structure multistage high-temperature pump, the hollow shaft 16 and the solid shaft 15 which are arranged on the hollow shaft motor 12 and the solid shaft motor 11 respectively drive the secondary impeller 8 and the primary impeller 5, the rotation directions of the primary impeller 5 and the secondary impeller 8 are different, and if the primary impeller 5 rotates clockwise when viewed from the inlet direction of the pump, the secondary impeller 8 rotates anticlockwise. Meanwhile, the rotating direction and the rotating speed of the primary impeller 5 and the secondary impeller 8 in the counter-rotating mechanism are controlled by performing variable frequency adjustment on the hollow shaft motor 12 and the solid shaft motor 11, so that the working condition adaptability of the unit is improved.

Along with the operation of the unit, the primary impeller 5 rotates along with the solid shaft 15 to drive the working medium to enter the primary guide vane 6 and then enter the secondary impeller 8 through the guide of the primary guide vane 6. The residual energy flowing out of the primary impeller 5 is fully utilized by the secondary impeller 8, and meanwhile, prerotation does not exist, so that the lift is improved. The secondary impeller 8 rotates along with the hollow shaft 16 and the solid shaft 15 in the opposite direction, drives the working medium to enter the secondary guide vane 9, and finally flows out of the pump body 13 through the secondary guide vane 9.

The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A counter-rotating structure multi-stage high-temperature pump comprises a shell, wherein the shell is sequentially provided with a suction chamber (1), a first stage guide vane (6), a second stage guide vane (9) and a pump body (13) according to the flow direction of sucked fluid, and is characterized by further comprising a second stage impeller (8) and a first stage impeller (5); rotatable first-stage impeller (5) of coaxial arrangement between suction chamber (1) and first-stage stator (6), rotatable secondary impeller (8) of coaxial arrangement between first-stage stator (6) and secondary stator (9), the rotational speed of first-stage impeller (5) and secondary impeller (8) is inequality, just turning to of first-stage impeller (5) and secondary impeller (8) is inequality.

2. A counter-rotating multi-stage high temperature pump according to claim 1, further comprising a solid shaft (15) and a hollow shaft (16), wherein the hollow shaft (16) is supported in the first stage guide vanes (6) and the second stage guide vanes (9), and the hollow shaft (16) is in transmission connection with the secondary impeller (8); the solid shaft (15) is supported in the hollow shaft (16), and the solid shaft (15) penetrates through the hollow shaft (16) to be in transmission connection with the primary impeller (5).

3. A counter-rotating multistage high temperature pump according to claim 2, wherein one end of the hollow shaft (16) is connected to a first transmission through the housing; install first axle sleeve (7) on first grade stator (6), install second axle sleeve (10) on secondary stator (9), the hollow shaft (16) other end is supported through first axle sleeve (7) and second axle sleeve (10).

4. A counter-rotating multistage high-temperature pump according to claim 2, wherein one end of the solid shaft (15) is connected with a second transmission device through a first transmission device; the other end of the solid shaft (15) penetrating through the hollow shaft (16) is provided with a shaft shoulder, and a plane bearing (21) is arranged between the shaft shoulder and the end face of the other end of the hollow shaft (16).

5. A pair-rotation structure multistage high-temperature pump according to claim 4, wherein the shaft sleeve chamber (2) is fixed in the suction chamber (1) through the guide rib plates (4), a third shaft sleeve (14) is installed in the shaft sleeve chamber (2), and the other end of the solid shaft (15) penetrates through the first-stage impeller (5) and then is supported in the third shaft sleeve (14).

6. A counter-rotating multi-stage high-temperature pump according to claim 2, wherein the solid shaft (15) is plated with copper on the surface for preventing the shaft from thermal expansion deformation.

7. A counter-rotating multistage high temperature pump according to any one of claims 1 to 6, wherein the rotation speed of the primary impeller (5) is less than the rotation speed of the secondary impeller (8).

8. A counter-rotating multi-stage high-temperature pump according to claim 7, wherein the ratio of the rotation speed of the primary impeller (5) to the rotation speed of the secondary impeller (8) is in the range of 0.5-0.7.

9. A counter-rotating multistage high-temperature pump according to claim 2, further comprising a constant-pressure gas supply device (18), wherein the gap between the solid shaft (15) and the hollow shaft (16) is a gas chamber (20); the constant-pressure gas supply device (18) is used for conveying constant-pressure inert gas into the gas chamber (20).