CN112555200A

CN112555200A - Multistage gas-liquid mixed transportation pump suitable for high gas content

Info

Publication number: CN112555200A
Application number: CN202011308868.XA
Authority: CN
Inventors: 罗兴锜; 李晨昊; 冯建军; 朱国俊; 张乐福; 马天勇
Original assignee: Xian University of Technology
Current assignee: Xian University of Technology
Priority date: 2020-11-20
Filing date: 2020-11-20
Publication date: 2021-03-26

Abstract

The invention discloses a multistage gas-liquid mixed transportation pump suitable for high gas content, which comprises a pump shaft arranged along the vertical direction, wherein a pump shell is coaxially sleeved outside the pump shaft, a plurality of stages of diversion shells are sequentially arranged along the length direction of the pump shaft at intervals, an impeller is coaxially arranged in each diversion shell, an inlet threaded pump cover is arranged at the inlet of the pump shell, and the inlet threaded pump cover is connected with a water inlet connecting pipe through a three-way pipe; an outlet threaded pump cover is arranged at the outlet of the pump shell and connected with an outlet connecting pipe; one end of the pump shaft is connected with the central shaft of the bearing box through a spline coupling B. The invention can safely and efficiently operate under the working condition of high gas content, is easy to process and install, and solves the problem of low operation pressurization capacity of the mixing transportation pump under the working condition of high gas content.

Description

Multistage gas-liquid mixed transportation pump suitable for high gas content

Technical Field

The invention belongs to the technical field of fluid machinery and engineering equipment, and relates to a multistage gas-liquid mixed delivery pump suitable for high gas content.

Background

The pump is the most widely applied equipment in national economic construction, and is widely applied in the fields of petrochemical engineering, hydraulic engineering, urban construction, metallurgy, transportation, ocean engineering, aerospace, nuclear power and the like. Gas-liquid two-phase flow is frequently seen in various industries, so that a gas-liquid two-phase mixed delivery pump is produced, along with the continuous and deep industrialization process of the country, the demand on mineral resources such as oil, gas and the like is increased day by day, and liquid phase and natural gas delivered in a chemical process are typical practical projects in the aspect of pumping gas-liquid two-phase flow.

The research on the gas-liquid two-phase mixed transportation technology is a technology for ensuring the efficient and stable operation of a mixed transportation pump while conveying gas-liquid mixed media to a specified site or position. Most typically, deep sea oil and gas resources are collected and conveyed, and a gas-liquid mixed conveying pump is one of core equipment of a gas-liquid mixed conveying technology. Due to the two-phase or even three-phase mixed medium conveyed by the composite material, higher requirements are put on the performance and the service life of the composite material.

In order to convey the mixed medium farther, the gas-liquid mixed conveying pump is generally multistage, which can increase the lift and improve the overall hydraulic efficiency. The mixing and conveying pump is divided into a turbine type multiphase mixing and conveying pump and a volumetric type multiphase mixing and conveying pump according to the working principle. Among the multiphase pumps, the most studied and practically used gas-liquid two-phase pump is currently used. Although the multistage centrifugal gas-liquid mixed transportation pump has higher lift than a single-stage pump, has larger flow than a piston pump, a diaphragm pump, a screw pump and the like, has the advantages of safe and stable operation, low noise, long service life, convenient installation and maintenance and the like, and is widely applied to a plurality of fields of petrochemical industry, electric power, urban water supply and the like, the efficiency and the pressurization capacity of the multistage centrifugal gas-liquid mixed transportation pump under high gas content are greatly weakened.

Disclosure of Invention

The invention aims to provide a multistage gas-liquid mixed delivery pump suitable for high gas content, which can safely and efficiently operate under the working condition of high gas content and is easy to process and install, and the problem of low operation pressurization capacity of the mixed delivery pump under the working condition of high gas content is solved.

The invention adopts the technical scheme that the multistage gas-liquid mixed transportation pump suitable for high gas content comprises a pump shaft arranged along the vertical direction, a pump shell is coaxially sleeved outside the pump shaft, a plurality of stages of diversion shells are sequentially arranged along the length direction of the pump shaft at intervals, an impeller is coaxially arranged in each diversion shell, an inlet threaded pump cover is arranged at an inlet of the pump shell, and the inlet threaded pump cover is connected with a water inlet connecting pipe through a three-way pipe; an outlet threaded pump cover is arranged at the outlet of the pump shell and connected with an outlet connecting pipe; one end of the pump shaft is connected with the central shaft of the bearing box through a spline coupling B.

The invention is also characterized in that;

and a pump inlet transition section is arranged between the inlet end of the pump shell and the inlet threaded pump cover.

The joint of the guide shell and the pump shaft is respectively provided with an upper sliding bearing and a lower sliding bearing.

The spline coupler B is arranged in the three-way pipe, and a first port of the three-way pipe is connected with the inlet threaded pump cover through a hexagonal connecting bolt component B; the second port of the three-way pipe is connected with the bearing box fixing component through a hexagonal connecting bolt component C; and a third port of the three-way pipe is connected with a water inlet connecting pipe.

The guide shell of a plurality of stages is clamped on the inner wall of the pump shell, a clamping groove is formed in the outer wall of the guide shell, and an O-shaped sealing ring is installed in the clamping groove.

The impeller and the pump shaft are fixedly connected by a key.

The impeller is provided with four blades, and three axial force balancing holes with different apertures are arranged on the rear wheel cover of the impeller near the head of each blade.

The outer wall of the diversion shell is also provided with an annular pressure measuring hole A, and a pressure measuring hole B is arranged on the pump shell at a position corresponding to the diversion shell.

The invention has the advantages that the invention improves the gas phase distribution in a gas-liquid two-phase flow field to a certain extent by the action of the impeller and the guide shell which are suitable for the multistage mixed delivery pump with high gas content, reduces the risk of blocking the flow channel by meteorology when the multistage mixed delivery pump is operated with high gas content due to less impeller blades and large flow area of the flow channel, simultaneously can break up large gas clusters by the rotation of the impeller, prevents the gas clusters from being aggregated, improves the anti-cavitation capability of the impeller blades, also improves the gas phase volume distribution of gas-liquid two-phase media entering the subsequent centrifugal mixed delivery pump, and effectively improves the supercharging capability of the mixed delivery pump. In addition, with the structural design that the bearing box and the pump body are separately arranged, the flow state in the mixed transportation pump is greatly improved, the operation stability is improved, the installation and maintenance processes are simplified, the maintenance period is shortened, and the hydraulic efficiency of the mixed transportation pump is also improved.

Drawings

FIG. 1 is a schematic structural diagram of a multi-stage gas-liquid mixed transportation pump suitable for high gas content;

FIG. 2 is a schematic structural diagram of an impeller in a multistage gas-liquid mixed transportation pump suitable for high gas content according to the present invention;

FIG. 3 is a perspective view of an impeller of the multistage gas-liquid mixture pump suitable for high gas content;

FIG. 4 is a schematic structural diagram of a guide shell in a multistage gas-liquid mixed transportation pump suitable for high gas content according to the present invention;

fig. 5 is a perspective view of a guide shell in the multistage gas-liquid mixed transportation pump suitable for high gas content.

In the drawing, 1, an impeller, 2, a guide shell, 3, an upper sliding bearing, 4, a lower sliding bearing, 5, a key, 6, a pump shaft, 7, a thrust sleeve, 8, an inlet threaded pump cover, 9, a pump shell, 10, a final guide shell, 11, an outlet section sleeve, 12, a spring retainer, 13, an outlet threaded pump cover, 14, a hexagonal connecting bolt assembly A, 17, an outlet connecting pipe, 18, a spline coupling A, 19, a hexagonal connecting bolt assembly B, 22, a spline coupling B, 23, a three-way pipe, 24, a water inlet connecting pipe, 25, a hexagonal connecting bolt assembly C, 28, a bearing box fixing assembly, 40, a pump inlet transition section, 41, a mechanical seal, 42, a water slinger, 43, a central shaft, 44, a bearing box, 45, a balance hole, 46, 47, a side pressure hole A, 48 and a guide vane.

Detailed Description

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

The invention relates to a multistage gas-liquid mixed delivery pump suitable for high gas content, which comprises a pump shaft 6 arranged along the vertical direction, wherein a pump shell 9 is coaxially sleeved outside the pump shaft 6, a plurality of stages of diversion shells 2 are sequentially arranged along the length direction of the pump shaft 6 at intervals, an impeller 1 is coaxially arranged in each diversion shell 2, an inlet threaded pump cover 8 is arranged at the inlet of the pump shell 9, and an outlet threaded pump cover 13 is arranged at the outlet of the pump shell 9, as shown in figure 1. The guide shell 2 is coaxially sleeved on the pump shaft 6.

A pump inlet transition section 40 is arranged between the inlet end of the pump shell 9 and the inlet threaded pump cover 8;

the impeller 1 and the pump shaft 6 are fixedly connected by a key 5;

the connection part of the guide shell 2 and the pump shaft 6 is respectively provided with an upper sliding bearing 3 and a lower sliding bearing 4, and the guide shell 2 is connected with the rotating part and the static part of the pump shaft 6 through the upper sliding guide bearing 3 and the lower sliding guide bearing 4.

The inlet pump cover 8 and the outlet pump cover 13 are connected with the pump shell 9 by threads, and the guide shells 2 at all levels are tightly pressed by the threads to achieve the fixing effect;

one end of the pump shaft 6 is connected with a central shaft 43 of the bearing box 44 through a spline coupler B22, and the bearing box 44 is connected with the three-way pipe 23 through the bearing box fixing assembly 28.

The other end of the pump shaft 6 is connected with a spline coupling A18.

The spline coupler B22 is arranged in the three-way pipe 23, and a first port of the three-way pipe 23 is connected with the inlet threaded pump cover 8 through a hexagonal connecting bolt assembly B19; the second port of the three-way pipe 23 is connected with the bearing box fixing component 28 through a hexagonal connecting bolt component C25; and a third port of the three-way pipe 23 is connected with a water inlet connecting pipe 24.

The connection of the pump shaft 6 and the central shaft 43 of the bearing box 44 is provided with a thrust sleeve 7.

The outlet end of the pump shaft 6 is provided with an outlet section sleeve 11.

The outlet screw pump cover 13 is connected to the outlet connection pipe 17 by a hexagonal connection bolt assembly a 14.

The central shaft 43 of the bearing box 44 is fixedly connected with the output shaft of the motor, and the mechanical seal 41 and the water slinging ring 42 are sequentially and coaxially sleeved on the central shaft 43. A mechanical seal 41 is provided adjacent to the water inlet connection 24.

The guide shell 2 of a plurality of stages is clamped on the inner wall of the pump shell 9, a clamping groove is formed in the outer wall of the guide shell 2, an O-shaped sealing ring is installed in the clamping groove, an upper sliding bearing 3 and a lower sliding bearing 4 are arranged on the pump shaft 6, sliding connection is guaranteed, the pump shell 9 cannot rotate in the operation of the pump, and the O-shaped sealing ring also blocks flow between the upper pump and the lower pump. Two adjacent blower inlet casings 2 are mutually clamped, and each stage of blower inlet casing is pressed tightly through the action of the inlet thread pump cover 8 and the outlet thread pump cover 13 on the blower inlet casing 2.

Lie in on the pump shaft 6 import screw pump cover 8 and export pump cover 13 between evenly cup jointed 15 static blower inlet casing 2 of level along the axial in proper order, 15 level blower inlet casing 2 all block in 9 inner walls of pump case and with between the pump shaft 6, and equal sliding connection, the blower inlet casing 2 that lies in 9 both ends of pump case supports respectively on import screw pump cover 8 and export screw pump cover 13, mutual joint between the adjacent blower inlet casing 2, every blower inlet casing 2 is close to the one end of import screw pump cover 8 and all cooperates and is provided with the impeller 1 who cup joints with 6 fixed pump shafts, be the key-type connection between impeller 1's rim plate and the pump shaft 6, the advancing of pump shaft 6, offer flutedly along circumference on the export end, the recess fit has thrust collar and circlip 12.

The impeller 1 is structurally shown in fig. 2 and 3, the impeller 1 is provided with four blades 46, three axial force balance holes 45 with different hole diameters are arranged near the head of each blade 46 on the rear wheel cover of the impeller 1, so that on one hand, the axial force in the operation of the multistage mixing and conveying pump is reduced, the service life of a bearing box is prolonged, and on the other hand, the gas accumulation in a flow channel can be improved in the working condition operation of gas-liquid two-phase flow.

The structure of the guide shell 2 is shown in fig. 4 and 5, 7 guide vanes 48 are arranged in the guide shell 2, an annular pressure measuring hole A47 is further arranged at the outer wall of the guide shell 2, and a pressure measuring hole B is arranged at a corresponding position on the pump shell 9, so that the pressure boost capability of each stage of pump can be monitored in real time.

Impeller 1 and kuppe 2 all are provided with 15 grades, and impeller 1 has reduced blade quantity, has increased the blade cornerite, reduces runner length, has increased the flow area, and the export of impeller 1 is pressed close to with 2 imports of kuppe simultaneously more. The number of the axial force balance holes is increased near the blade head of the impeller 1, and the hole diameters are different, so that the axial force of the multistage mixing and transporting pump is weakened to the greatest extent, and the gas phase aggregation degree in the flow channel is also improved.

The guide shell 2 shortens the length of the guide blades and reduces the number of the guide blades, meanwhile, the diameter ratio of an inlet to an outlet is reduced, pressure measuring holes are formed in the inlet of the guide shell 2, and the pressure of the transition section of a rotating part and a static part is detected.

A bracket bushing is arranged at the position where the central shaft 43 extends out of the bearing box 44, an inlet bearing bushing is arranged at the position where the pump shaft 6 penetrates through the water inlet connecting pipe 24, and an outlet bearing bushing is arranged at the position where the pump shaft 6 penetrates through the outlet connecting pipe 17. O-shaped sealing rings are arranged between the inlet thread pump cover 8 and the water inlet connecting pipe 24, between the outlet thread pump cover 13 and the outlet connecting pipe 17 and between each stage of guide shell 2 and the pump shell 9.

The invention relates to a working principle of a multistage gas-liquid mixed delivery pump suitable for high gas content, which is characterized in that when the gas-liquid mixed delivery pump works, a mixed medium enters a pump shell 9 through a three-way pipe 23 and a water inlet connecting pipe 24 through an inlet thread pump cover 8, then flows through a pump inlet transition section 40 and enters a wheel cover of a first-stage impeller 1, under the rotating action of the impeller 1, the mixed medium obliquely flows into a guide shell 2 along the wheel cover of the impeller 1, the kinetic energy of liquid is converted into static pressure energy in the guide shell 2, and the static pressure energy sequentially passes through 15 stages of impellers 1 (the invention takes a 15-stage impeller as an example, the stage number of the impeller is designed according to specific conditions in practical application) and the guide shell 2 and then is led out into an outlet connecting pipe 17 through an outlet thread pump cover 13 by a final-stage guide shell 10 (the final-stage guide shell 10 refers to.

The vanes of the impeller 1 and the guide vanes of the guide shell 2 are reduced in number, wrap angles are increased, and meanwhile, the arc vanes are adopted, so that the mixed transportation pump can still achieve high operation efficiency under the working condition of high gas content, and meanwhile, the vanes of the impeller 1 rotate to break large air masses under the working condition of high gas content, so that gas phase aggregation and blockage do not occur in a flow passage, and the operation efficiency of the mixed transportation pump is improved.

In addition, the impeller 1 and the guide shell 2 designed by the invention enable flowing media to pass through the whole runner more smoothly without large change of flow direction and large cavity and boss, and simultaneously realize the change of the flow direction of fluid in the runner by one guide shell 2 and ensure that the fluid has smaller turbulent flow state when entering the next-stage runner;

the invention adopts the 15-stage impeller 1 and the guide shell 2 to break up larger air mass under high air-containing rate as much as possible under the condition of ensuring stable flow state, and provides certain pressurization, thereby improving the flow state of fluid entering the inlet of the subsequent conventional mixing and conveying pump and reducing the relative air-containing rate.

The arrangement of the pump inlet transition section 40 and the final-stage guide shell 10 ensures that the whole flow passage is smooth without a large cavity or a boss, reduces the flow loss and realizes the effect of stable overflowing; the water slinger 42 is arranged to prevent the working medium seeped out from the pump inlet mechanical seal 41 from entering the bearing box 44, and is used with the pump inlet mechanical seal 41 to play a role in protection.

The multistage gas-liquid mixed transportation pump suitable for high gas content can meet the requirement of efficient and stable operation under the working condition of high gas content, and the impeller and the guide shell reduce the number of blades and increase the flow area on one hand and break larger air masses in a flow channel by the rotation of the impeller on the other hand. The multi-stage design is adopted, on one hand, certain pressurization is provided for a gas-liquid mixed medium, on the other hand, long-distance conveying can be met, the high efficiency can be achieved under the condition that the gas content is guaranteed to be 40%, the efficiency is over 60%, each stage of guide shell 2 is provided with a radial guide bearing, an O-shaped sealing ring and an annular pressure measuring hole are arranged on the outer side of the guide shell, and the guide shell is prevented from rotating and axially moving in a pump shell.

The invention improves the problems that the traditional leaving type mixed transportation pump has low efficiency and the flow channel is easy to generate gas phase blockage, reduces the relative volume occupation ratio of the gas phase, improves the production efficiency, structurally improves the connection form between a rotating part and a static part, ensures that the flow channel is smoother, meets the actual engineering requirement and runs stably. The number and the aperture of the circumferential force balance holes are increased on the impeller 1, the design is suitable for the operation of a more multistage gas-liquid mixed delivery pump, and the gas-liquid mixed delivery at a longer distance can be realized.

Claims

1. The utility model provides a multistage gas-liquid multiphase pump suitable for high gas content, its characterized in that: the pump comprises a pump shaft arranged along the vertical direction, a pump shell is coaxially sleeved outside the pump shaft, a plurality of stages of guide shells are sequentially arranged along the length direction of the pump shaft at intervals, an impeller is coaxially arranged in each guide shell, an inlet threaded pump cover is arranged at the inlet of the pump shell, and the inlet threaded pump cover is connected with a water inlet connecting pipe through a three-way pipe; an outlet threaded pump cover is arranged at the outlet of the pump shell and connected with an outlet connecting pipe; one end of the pump shaft is connected with the central shaft of the bearing box through a spline coupling B.

2. The multistage gas-liquid mixture pump suitable for the high gas content according to claim 1, characterized in that: and a pump inlet transition section is arranged between the inlet end of the pump shell and the inlet threaded pump cover.

3. The multistage gas-liquid mixture pump suitable for the high gas content according to claim 1, characterized in that: and an upper sliding bearing and a lower sliding bearing are respectively arranged at the joint of the guide shell and the pump shaft.

4. The multistage gas-liquid mixture pump suitable for the high gas content according to claim 1, characterized in that: the spline coupler B is arranged in the three-way pipe, and a first port of the three-way pipe is connected with the inlet threaded pump cover through a hexagonal connecting bolt component B; the second port of the three-way pipe is connected with the bearing box fixing component through a hexagonal connecting bolt component C; and a third port of the three-way pipe is connected with a water inlet connecting pipe.

5. The multistage gas-liquid mixture pump suitable for the high gas content according to claim 1, characterized in that: the guide shell of a plurality of stages is clamped on the inner wall of the pump shell, a clamping groove is formed in the outer wall of the guide shell, and an O-shaped sealing ring is installed in the clamping groove.

6. The multistage gas-liquid mixture pump suitable for the high gas content according to claim 1, characterized in that: the impeller and the pump shaft are fixedly connected by a key.

7. The multistage gas-liquid mixture pump suitable for the high gas content according to claim 1, characterized in that: the impeller is provided with four blades, and three axial force balancing holes with different apertures are arranged on the rear wheel cover of the impeller near the head of each blade.

8. The multistage gas-liquid mixture pump suitable for the high gas content according to claim 1, characterized in that: and the outer wall of the diversion shell is also provided with an annular pressure measuring hole A, and a pressure measuring hole B is formed in the position, corresponding to the diversion shell, on the pump shell.