CN116085300A

CN116085300A - Self-pressurization shaft end sealing structure for impeller mechanical equipment and impeller mechanical equipment

Info

Publication number: CN116085300A
Application number: CN202310254493.0A
Authority: CN
Inventors: 左志涛; 李朋飞; 陈海生; 梁奇; 李文
Original assignee: Institute of Engineering Thermophysics of CAS
Current assignee: Institute of Engineering Thermophysics of CAS
Priority date: 2023-03-07
Filing date: 2023-03-07
Publication date: 2023-05-09

Abstract

The invention relates to the technical field of sealing of impeller machinery, in particular to a self-pressurization shaft end sealing structure for impeller machinery and the impeller machinery. A leakage gap exists between a rotating shaft of the impeller mechanical equipment and a shell at the periphery of the impeller, and when the impeller of the impeller mechanical equipment rotates, gas working medium leaks from the high-pressure side of the impeller to the main shaft direction through the leakage gap. The self-pressurization shaft end sealing structure comprises: the channel component generates a high-pressure air film for blocking the leakage of the gas working medium through the leakage gap; the channel component is provided with an air inlet channel, a pressurizing channel and a high-pressure air film channel; when the impeller of the impeller mechanical equipment rotates, the gas working medium can enter the pressurizing channel through the air inlet channel to boost pressure, and a high-pressure air film for blocking the leakage gap is generated in the high-pressure air film channel. The structure can effectively solve the problems that the impeller mechanical equipment in the prior art is restricted by the machining precision and the assembly precision of the device, and leakage is difficult to effectively reduce.

Description

Self-pressurization shaft end sealing structure for impeller mechanical equipment and impeller mechanical equipment

Technical Field

The invention relates to the technical field of sealing of impeller machinery, in particular to a self-pressurization shaft end sealing structure for impeller machinery and the impeller machinery.

Background

The energy storage is an important technology and basic equipment for supporting a novel power system, and has important significance for promoting energy green transformation, coping with extreme events, guaranteeing energy safety, promoting energy high-quality development and realizing a double-carbon target. The compressed air energy storage technology is used as one of large-scale physical energy storage technologies, the application of the compressed air energy storage technology is not limited by geographical conditions, the energy storage efficiency is high, the life cycle is long, commercial application is successfully realized, and the development prospect is wide. The compression subsystem and the expansion subsystem are the core components of the compressed air energy storage system. Centrifugal compressors are the core component of the compression subsystem, which is highly coupled to the regenerative heat exchange through the compression process to achieve efficient conversion and storage of off-peak electrical energy. The centripetal turbine is a core component of an expansion subsystem, and the centripetal turbine is highly coupled with heat accumulation and heat exchange through an expansion process to realize efficient conversion of air internal energy and pressure potential energy into electric energy. The operating efficiency of the centrifugal compressor and the centripetal turbine directly affects the overall efficiency of the compressed air energy storage system. Therefore, ensuring efficient operation of the compressor and expander is critical to achieving high efficiency of the compressed air energy storage system.

Centrifugal compressors and centripetal turbines are typical representatives of impeller machines. As shown in fig. 6 described in the prior art, when the impeller machine is operating normally, the impeller 101 and the rotary shaft rotate at a high speed in synchronization, and the casing 102 is stationary, so that a dynamic-static joint surface exists between the rotary shaft and the casing 102. And a small gap exists at the joint surface to form a flow passage. For the centrifugal compressor impeller, high-pressure gas at the outlet of the impeller can leak to the main shaft direction through the flow passage; for a centripetal turbine, the high-pressure gas at the inlet of the turbine can leak in the main shaft direction through the above-mentioned flow passage. Shaft end leakage can seriously affect the work capacity of the impeller, thereby reducing the impeller efficiency. Currently, the main idea of reducing axial leakage is to reduce the gap size or to use a labyrinth seal structure. Both of these achieve a reduction in leakage by increasing flow resistance, but axial leakage is always present and cannot be effectively eliminated in view of machining accuracy and assembly constraints. Meanwhile, the existing leakage amount reducing mode also improves the production and processing cost of the centrifugal impeller or the centripetal turbine.

Disclosure of Invention

Therefore, the invention aims to solve the technical problems that the impeller mechanical equipment in the prior art is limited by the machining precision and the assembly precision of the device, and leakage is difficult to effectively reduce. To this end, the present invention provides a self-pressurizing shaft end seal structure for an impeller mechanical apparatus, the impeller mechanical apparatus comprising: a rotation shaft;

a leakage gap exists between the rotating shaft and the shell around the impeller, when the impeller of the impeller mechanical equipment rotates, gas working medium leaks from the high-pressure side of the impeller to the main shaft direction through the leakage gap,

the self-pressurization shaft end sealing structure comprises:

the channel component is arranged at the shaft end of the rotating shaft and is used for generating a high-pressure air film for blocking leakage of the gas working medium through the leakage gap; an air inlet channel, a pressurizing channel and a high-pressure air film channel are arranged on the channel component;

the high-pressure air film channel is an annular groove arranged in the circumferential direction of the channel member, and is arranged on one side of the channel member, which is close to the wheel disc; the air inlet channel, the pressurizing channel and the high-pressure air film channel are sequentially communicated, and the flow area of the pressurizing channel gradually decreases towards the high-pressure air film channel;

when the impeller of the impeller mechanical equipment rotates, the gas working medium can enter the pressurizing channel through the air inlet channel to be pressurized, and a high-pressure air film for blocking the leakage gap is generated in the high-pressure air film channel.

Optionally, the self-pressurization shaft end sealing structure for the impeller mechanical equipment further comprises:

and the air injection pipeline is communicated with the air inlet channel through an air injection hole on the shell at the periphery of the impeller so as to boost the pressure through the pressurizing channel to form a high-pressure air film.

Optionally, the pressure of the leakage flow in the leakage gap is the same as the pressure of the high-pressure air film generated in the high-pressure air film channel, so as to inhibit the leakage of the gas working medium from the high-pressure side of the impeller to the main shaft direction through the leakage gap.

The pressurizing channel and the channel member are optionally in an integrated structure, and are produced in an integrated processing mode.

Optionally, the pressurizing channel is detachably fixed on the channel member, and the pressurizing channel and the channel member are processed respectively and fixed by a connecting piece.

Optionally, the pressurizing channel is a channel with a wedge-shaped cross section; and/or the number of the groups of groups,

the pressurizing channel is a channel with a circular arc-shaped cross section.

Optionally, the gas working medium is air, nitrogen, oxygen, fuel gas or carbon dioxide.

An impeller machine apparatus comprising: the self-pressurization shaft end sealing structure is characterized in that the self-pressurization shaft end sealing structure comprises a self-pressurization shaft end sealing structure; and, an impeller mechanical device;

the impeller mechanical equipment is a centrifugal impeller or a centripetal turbine.

The technical scheme of the invention has the following advantages:

1. the invention provides a self-pressurizing shaft end sealing structure for impeller mechanical equipment, which comprises the following components:

According to the invention, the channel member can effectively inhibit the leakage of the gas working medium from the high-pressure side of the impeller to the main shaft direction through the leakage gap, so that the problem of large flow loss caused by gap leakage flow between the rotating shaft and the peripheral shell of the impeller in the operation process of the impeller mechanical equipment is solved, the requirement of efficient operation of the impeller mechanical equipment is met, the pneumatic efficiency of the impeller mechanical equipment is further increased, the efficient operation of the impeller mechanical equipment on an energy system is promoted, and the device has the characteristics of convenience in processing, low manufacturing cost, convenience in assembly and the like.

Specifically, a channel member is provided at a gap between the rotary shaft and the impeller peripheral casing at a shaft end position of the rotary shaft, and is provided along a circumferential direction of the rotary shaft. The opening direction of the channel component is related to the rotation direction of the impeller mechanical equipment, so that the pressurizing channel can realize the work and the pressurizing of the gas working medium in the air inlet channel.

When the impeller of the impeller mechanical equipment rotates, the gas working medium can enter the pressurizing channel through the air inlet channel to be pressurized, and a high-pressure air film for blocking the leakage gap is generated in the high-pressure air film channel, so that the leakage of the gas working medium from the gap between the rotating shaft and the peripheral shell of the impeller to the main shaft direction can be effectively inhibited by the high-pressure air film. In addition, when the impeller mechanical equipment of the invention works normally, the high-pressure air film generated at the clearance position between the rotating shaft and the peripheral shell of the impeller belongs to non-contact sealing, so that the manufacturing process is simple and reliable, and the impeller mechanical equipment has the advantage of long service life.

2. The invention provides a self-pressurizing shaft end sealing structure for impeller machinery equipment, which further comprises: and the air injection pipeline is communicated with the air inlet channel through an air injection hole on the shell at the periphery of the impeller so as to boost the pressure through the pressurizing channel to form a high-pressure air film.

In the invention, the gas medium can be effectively introduced into the gas inlet channel through the gas injection pipeline, so that the gas working medium is subjected to work and pressure increasing through the pressure increasing channel, and a high-pressure gas film is formed in the high-pressure gas film channel.

3. According to the self-pressurization shaft end sealing structure for the impeller mechanical equipment, the high-pressure air film generated in the high-pressure air film channel is the same as the leakage flow pressure in the leakage gap, so that the leakage of the gas working medium from the high-pressure side of the impeller to the main shaft direction through the leakage gap is restrained.

In the invention, the specific size of the channel member is adjusted, so that the high-pressure air film generated in the high-pressure air film channel is ensured to be the same as the pressure of the leakage flow in the leakage gap, and the leakage of the gas working medium through the leakage gap is completely inhibited.

4. The self-pressurizing shaft end sealing structure for the impeller mechanical equipment provided by the invention has the advantages that the pressurizing channel and the channel component are of an integrated structure, and the pressurizing channel and the channel component are produced in an integrated processing mode. And/or the pressurizing channel is detachably fixed on the channel member, and the pressurizing channel and the channel member are respectively processed and fixed through a connecting piece.

In the invention, when the pressurizing channel is designed to be detachably fixed on the channel member, a worker can replace the pressurizing channel for the channel member according to the requirement, so that the pressurizing channel can be replaced conveniently after being worn. In addition, the pressurizing channel and the channel member of the integrated structure have the advantage of firm and reliable structure.

5. The present invention provides an impeller mechanical apparatus comprising: a self-pressurizing shaft end sealing structure; and, an impeller mechanical device; the impeller mechanical equipment is a centrifugal impeller or a centripetal turbine.

The impeller machinery in the present invention includes the self-pressurizing shaft end sealing structure, so that all the advantages of the self-pressurizing shaft end sealing structure are provided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a self-pressurizing shaft end seal configuration for an impeller machine according to the present invention;

FIG. 2 is a schematic view of a centripetal turbine with a self-pressurizing shaft end sealing structure provided by the invention;

FIG. 3 is an enlarged schematic view of a portion of a self-pressurizing shaft end seal structure of the radial inflow turbine wheel structure of FIG. 2 provided by the present invention;

FIG. 4 is a schematic diagram of a centrifugal impeller with a self-pressurizing shaft end sealing structure provided by the invention;

FIG. 5 is a schematic view of the structure of the present invention in which the channel member is mounted on the rotational shaft of the centrifugal impeller by means of a connector;

fig. 6 is a schematic diagram of the leakage flow of working fluid from between the impeller and the casing of an impeller machine of the prior art.

Reference numerals illustrate:

1-impeller wheel cover; 2-a wheel disc; 3-leaf blades; 4-rotating shaft; 5-leak gap; 6-channel members; 7-impeller peripheral shell; 8-an air inlet channel; 9-a pressurization channel; 10-high-pressure air film channels; 11-an air injection pipeline; 12-connecting piece; 101-an impeller; 102-a casing.

Detailed Description

The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Example 1

In the present embodiment, a self-pressurizing shaft end sealing structure for an impeller mechanical apparatus is provided, and the impeller mechanical apparatus has a rotation shaft 4 as shown in fig. 2 and 4; a leakage gap 5 exists between the rotating shaft 4 and the impeller peripheral casing 7, and when the impeller of the impeller mechanical equipment rotates, gas working medium leaks from the high-pressure side of the impeller to the main shaft direction through the leakage gap 5.

As shown in fig. 1, the self-pressurizing shaft-end sealing structure includes:

the channel member 6 is arranged at the shaft end position of the rotating shaft 4 and is used for generating a high-pressure air film for blocking leakage of the gas working medium through the leakage gap 5; the channel member 6 is provided with an air inlet channel 8, a pressurizing channel 9 and a high-pressure air film channel 10. The pressurizing channel 9 has a wedge-shaped cross section. In addition, the pressurizing channel 9 and the channel member 6 are of an integrated structure, and the pressurizing channel 9 and the channel member 6 are produced by adopting an integrated processing mode;

the gas injection pipeline 11 is communicated with the gas inlet channel 8 through gas injection holes on the impeller peripheral shell 7 so as to form a high-pressure gas film through the pressure boosting channel 9;

the high-pressure air film channel 10 is an annular groove arranged in the circumferential direction of the channel member 6, and the high-pressure air film channel 10 is arranged at one side of the channel member 6 close to the wheel disc 2; the air inlet channel 8, the pressurizing channel 9 and the high-pressure air film channel 10 are sequentially communicated, and the flow area of the pressurizing channel 9 gradually decreases towards the high-pressure air film channel 10;

when the impeller of the impeller mechanical equipment rotates, the gas working medium can enter the pressurizing channel 9 through the air inlet channel 8 to be pressurized, and a high-pressure air film for blocking the leakage gap 5 is generated in the high-pressure air film channel 10. In this embodiment, the high-pressure gas film generated in the high-pressure gas film channel 10 has the same pressure as the leakage flow in the leakage gap 5, so as to inhibit the leakage of the gas working medium from the high-pressure side of the impeller to the main shaft direction through the leakage gap 5.

Of course, the specific working medium type of the gas working medium in this embodiment is not specifically limited, and in other embodiments, the gas working medium is air, nitrogen, oxygen, fuel gas or carbon dioxide.

Of course, the high-pressure air film pressure value generated in the high-pressure air film channel 10 is not particularly limited in this embodiment, and in other embodiments, the high-pressure air film pressure generated in the high-pressure air film channel 10 may be smaller or larger than the leakage flow pressure in the leakage gap 5.

Of course, the connection manner of the channel member 6 and the pressurizing channel 9 is not specifically limited in this embodiment, and in other embodiments, as shown in fig. 5, the pressurizing channel 9 is detachably fixed on the channel member 6, and the pressurizing channel 9 and the channel member 6 are respectively processed and fixed by the connecting piece 12.

Of course, the cross-sectional shape of the pressurizing channel 9 is not particularly limited in this embodiment, and in other embodiments, the pressurizing channel 9 is a channel with a circular arc cross-section.

Example 2

A centrifugal impeller, comprising: a self-pressurizing shaft end sealing structure; and an impeller shroud 1 as shown in fig. 4, a wheel disc 2 provided on the impeller shroud 1, and blades 3 provided between the impeller shroud 1 and the wheel disc 2.

As shown in fig. 4 and 5, the self-pressurizing shaft-end seal structure includes:

the channel member 6 is arranged at the shaft end position of the rotating shaft 4 and is used for generating a high-pressure air film for blocking leakage of the gas working medium through the leakage gap 5; an air inlet channel 8, a pressurizing channel 9 and a high-pressure air film channel 10 are arranged on the channel member 6;

when the impeller of the impeller mechanical equipment rotates, the gas working medium can enter the pressurizing channel 9 through the air inlet channel 8 to be pressurized, and a high-pressure air film for blocking the leakage gap 5 is generated in the high-pressure air film channel 10.

Example 3

A centripetal turbine, comprising: self-pressurizing shaft end sealing structure.

As shown in fig. 2 and 3, the self-pressurizing shaft-end seal structure includes:

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.

Claims

1. A self-pressurizing shaft end seal structure for an impeller machine, the impeller machine comprising: a rotation shaft (4);

a leakage gap (5) is arranged between the rotating shaft (4) and the impeller peripheral casing (7), when the impeller of the impeller mechanical equipment rotates, gas working medium leaks from the high-pressure side of the impeller to the main shaft direction through the leakage gap (5), and the device is characterized in that,

the self-pressurization shaft end sealing structure comprises:

the channel member (6) is arranged at the shaft end position of the rotating shaft (4) and is used for generating a high-pressure air film for blocking leakage of the gas working medium through the leakage gap (5); an air inlet channel (8), a pressurizing channel (9) and a high-pressure air film channel (10) are arranged on the channel member (6);

the high-pressure air film channel (10) is an annular groove arranged in the circumferential direction of the channel member (6), and the high-pressure air film channel (10) is arranged on one side, close to the wheel disc (2), of the channel member (6); the air inlet channel (8), the pressurizing channel (9) and the high-pressure air film channel (10) are sequentially communicated, and the flow area of the pressurizing channel (9) is gradually reduced towards the high-pressure air film channel (10);

when the impeller of the impeller mechanical equipment rotates, the gas working medium can enter the pressurizing channel (9) through the air inlet channel (8) to be pressurized, and a high-pressure air film for blocking the leakage gap (5) is generated in the high-pressure air film channel (10).

2. The self-pressurizing shaft end seal structure for an impeller machine according to claim 1, further comprising:

the air injection pipeline (11) is communicated with the air inlet channel (8) through an air injection hole on the impeller peripheral shell (7) so as to boost through the pressurizing channel (9) to form a high-pressure air film.

3. The self-pressurizing shaft end seal structure for an impeller machine according to claim 1 or 2, wherein the high-pressure gas film generated in the high-pressure gas film channel (10) is the same as the leakage flow pressure in the leakage gap (5) to suppress leakage of the gas working medium from the high-pressure side of the impeller through the leakage gap (5) to the main shaft direction.

4. Self-pressurizing shaft end sealing structure for an impeller machine according to claim 1, characterized in that the pressurizing channel (9) and the channel member (6) are of an integrated structure, the pressurizing channel (9) and the channel member (6) being produced in an integrated manner.

5. Self-pressurizing shaft end sealing structure for an impeller machine according to claim 1, characterized in that the pressurizing channel (9) is detachably fixed to the channel member (6), the pressurizing channel (9) and the channel member (6) being machined separately and fixed by means of a connecting piece (12).

6. Self-pressurizing shaft end sealing structure for an impeller machine according to claim 1, characterized in that the pressurizing channel (9) is a channel with a wedge-shaped cross section; and/or the number of the groups of groups,

the pressurizing channel (9) is a channel with a circular arc-shaped cross section.

7. The self-pressurizing shaft end seal structure for an impeller machine according to claim 1, wherein the gas working medium is air, nitrogen, oxygen, gas or carbon dioxide.

8. An impeller machine, comprising: the self-pressurizing shaft end seal structure according to any one of claims 1 to 7; and, an impeller mechanical device;