Self-pressurizing shaft end seal structure for turbomachinery and turbomachinery

Abstract

The present invention relates to the technical field of seals for turbomachinery, and particularly relates to a self-pressurizing shaft-end seal structure for turbomachinery equipment and turbomachinery equipment. There is a leakage gap between the rotating shaft of the turbomachinery equipment and the outer casing of the impeller. When the impeller of the turbomachinery equipment rotates, the gas working medium leaks from the high-pressure side of the impeller to the main shaft direction through the leakage gap. The above self-pressurizing shaft-end seal structure includes: a channel member that generates a high-pressure gas film to block the leakage of the gas working medium through the leakage gap; an air inlet channel, a pressurizing channel, and a high-pressure gas film channel are arranged on the channel member; when the impeller of the turbomachinery equipment rotates, the gas working medium will enter the pressurizing channel through the air inlet channel for pressure boosting, and generate a high-pressure gas film for sealing the leakage gap in the high-pressure gas film channel. Through the above structure, it is possible to effectively overcome the problem that in the prior art, the turbomachinery equipment is restricted by the processing accuracy and assembly accuracy of the device and it is difficult to effectively reduce leakage.

Description

Technical Field

[0001] The present invention relates to the technical field of seals for turbomachinery, and particularly to a self-boosting shaft-end seal structure for turbomachinery equipment and turbomachinery equipment. Background Art

[0002] Energy storage is an important technology and basic equipment to support the new power system, and is of great significance for promoting the green transformation of energy, coping with extreme events, ensuring energy security, promoting the high-quality development of energy, and achieving the dual-carbon goal. As one of the large-scale physical energy storage technologies, compressed air energy storage technology is not restricted by geographical conditions, has high energy storage efficiency and a long life cycle, has been successfully commercialized, and has broad development prospects. The compression subsystem and the expansion subsystem are the core components of the compressed air energy storage system. The centrifugal compressor is the core component of the compression subsystem, and it realizes the efficient conversion and storage of off-peak electric energy through the high coupling of the compression process and heat storage heat exchange. The radial inflow turbine is the core component of the expansion subsystem, and it realizes the efficient conversion of the internal energy and pressure potential energy of air into electric energy through the high coupling of the expansion process and heat storage heat exchange. The operating efficiency of the centrifugal compressor and the radial inflow turbine directly affects the overall efficiency of the compressed air energy storage system. Therefore, ensuring the efficient operation of the compressor and the expander is crucial for achieving the high efficiency of the compressed air energy storage system.

[0003] The centrifugal compressor and the radial inflow turbine are typical representatives of turbomachinery. As recorded in the prior art Figure 6 As shown, when the turbomachinery is working normally, the impeller 101 and the rotating shaft rotate synchronously at a high speed, and the casing 102 is stationary. Thus, there will be a dynamic-static interface between the rotating shaft and the casing 102. There is a small gap at the above interface, forming an overflow channel. For the impeller of the centrifugal compressor, the high-pressure gas at the impeller outlet will leak in the direction of the main shaft through the above overflow channel; for the radial inflow turbine, the high-pressure gas at the turbine inlet will leak in the main shaft direction through the above overflow channel. Shaft-end leakage will seriously affect the work capacity of the impeller, and thus reduce the impeller efficiency. At present, the main ideas for reducing axial leakage are to reduce the gap size or adopt a labyrinth seal structure. Both of these achieve a reduction in the leakage amount by increasing the flow resistance. However, considering the machining accuracy and assembly constraints, axial leakage always exists and cannot be effectively eliminated. At the same time, the existing methods for reducing the leakage amount also increase the production and processing costs of the centrifugal impeller or the radial inflow turbine. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the turbomachinery equipment is restricted by the machining accuracy and assembly accuracy of the device and it is difficult to effectively reduce leakage. To this end, the present invention provides a self-boosting shaft-end seal structure for turbomachinery equipment, and the turbomachinery equipment includes: a rotating shaft;

[0005] There is a leakage gap between the rotating shaft and the outer casing of the impeller. When the impeller of the impeller mechanical equipment rotates, the gas working medium leaks from the high-pressure side of the impeller to the main shaft direction through the leakage gap. It is characterized in that

[0006] The self-boosting shaft end sealing structure includes:

[0007] A channel member is arranged at the shaft end position of the rotating shaft and is used to generate a high-pressure gas film that blocks the leakage of the gas working medium through the leakage gap; an air inlet channel, a boosting channel and a high-pressure gas film channel are arranged on the channel member;

[0008] The high-pressure gas film channel is an annular groove arranged in the circumferential direction of the channel member, and the high-pressure gas film channel is arranged on the side of the channel member close to the wheel disc; the air inlet channel, the boosting channel and the high-pressure gas film channel are connected in sequence, and the flow area of the boosting channel gradually decreases towards the high-pressure gas film channel;

[0009] When the impeller of the impeller mechanical equipment rotates, the gas working medium will enter the boosting channel through the air inlet channel for boosting pressure, and a high-pressure gas film for blocking the leakage gap will be generated in the high-pressure gas film channel.

[0010] Optionally, the self-boosting shaft end sealing structure for the impeller mechanical equipment further includes:

[0011] An injection pipeline, and the injection pipeline is connected to the air inlet channel through an injection hole on the outer casing of the impeller to form a high-pressure gas film through boosting in the boosting channel.

[0012] Optionally, the high-pressure gas film generated in the high-pressure gas film channel has the same pressure as the leakage flow in the leakage gap 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.

[0013] Optionally, the boosting channel and the channel member are of an integral structure, and the boosting channel and the channel member are produced by an integral machining method.

[0014] Optionally, the boosting channel is detachably fixed on the channel member, the boosting channel and the channel member are processed separately, and are fixed by a connecting piece.

[0015] Optionally, the boosting channel is a channel with a wedge-shaped cross-section; and / or,

[0016] The boosting channel is a channel with an arc-shaped cross-section.

[0017] Optionally, the gas working medium is air, nitrogen, oxygen, fuel gas or carbon dioxide.

[0018] An impeller mechanical device includes: the above self - pressurizing shaft - end sealing structure; and, the impeller mechanical device;

[0019] The impeller mechanical device is a centrifugal impeller or a centripetal turbine.

[0020] The technical solution of the present invention has the following advantages:

[0021] 1. The self - pressurizing shaft - end sealing structure for an impeller mechanical device provided by the present invention includes:

[0022] A channel member is arranged at the shaft end of the rotating shaft and is used to generate a high - pressure gas film that blocks the leakage of the gas working medium through the leakage gap; an air inlet channel, a pressurizing channel, and a high - pressure gas film channel are arranged on the channel member;

[0023] The high - pressure gas film channel is an annular groove arranged in the circumferential direction of the channel member, and the high - pressure gas film channel is arranged on the side of the channel member close to the wheel disc; the air inlet channel, the pressurizing channel, and the high - pressure gas film channel are connected in sequence, and the flow area of the pressurizing channel gradually decreases towards the high - pressure gas film channel;

[0024] When the impeller of the impeller mechanical device rotates, the gas working medium will enter the pressurizing channel through the air inlet channel for pressure boosting, and a high - pressure gas film for blocking the leakage gap will be generated in the high - pressure gas film channel.

[0025] In the present invention, through the above - mentioned channel member, the leakage of the gas working medium from the high - pressure side of the impeller to the main shaft direction through the leakage gap can be effectively inhibited, solving the problem of large flow losses caused by the leakage flow in the gap between the rotating shaft and the outer casing of the impeller during the operation of the impeller mechanical device, meeting the requirements of the efficient operation of the impeller mechanical device, further increasing the aerodynamic efficiency of the impeller mechanical device, promoting the efficient operation of the impeller mechanical device in the energy system, and having the characteristics of convenient processing, low cost, and easy assembly.

[0026] Specifically, at the gap between the rotating shaft and the outer casing of the impeller, and at the shaft - end position of the rotating shaft, a channel member arranged along the circumferential direction of the rotating shaft is provided. The opening direction of the above - mentioned channel member is related to the rotation direction of the impeller mechanical device to realize the work - adding and pressure - boosting of the gas working medium in the air inlet channel by the pressurizing channel.

[0027] When the impeller of the impeller machinery rotates, the gas working medium will enter the pressurizing channel through the intake channel for pressure increase, and a high-pressure gas film for sealing the leakage gap will be generated in the high-pressure gas film channel. The above-mentioned high-pressure gas film can effectively inhibit the leakage of the gas working medium from the gap between the rotating shaft and the outer casing of the impeller towards the main shaft direction. In addition, when the impeller machinery in the present invention is working normally, the high-pressure gas film generated at the gap position between the rotating shaft and the outer casing of the impeller belongs to non-contact sealing, which not only has a simple and reliable manufacturing process, but also has the advantage of a long service life.

[0028] 2. The self-pressurizing shaft end sealing structure for the impeller machinery provided by the present invention further includes: an injection pipeline, and the injection pipeline is connected to the intake channel through an injection hole on the outer casing of the impeller to form a high-pressure gas film through pressure increase in the pressurizing channel.

[0029] In the present invention, the gas medium can be effectively introduced into the intake channel through the above-mentioned injection pipeline, so as to perform work on and pressurize the gas working medium through the pressurizing channel, and then form a high-pressure gas film in the above-mentioned high-pressure gas film channel.

[0030] 3. The self-pressurizing shaft end sealing structure for the impeller machinery provided by the present invention, the high-pressure gas film generated in the high-pressure gas film channel has the same pressure as the leakage flow in the leakage gap to inhibit the leakage of the gas working medium from the high-pressure side of the impeller towards the main shaft direction through the leakage gap.

[0031] In the present invention, by adjusting the specific dimensions of the channel component, it can be ensured that the high-pressure gas film generated in the high-pressure gas film channel has the same pressure as the leakage flow in the leakage gap, so as to completely inhibit the leakage of the gas working medium through the above-mentioned leakage gap.

[0032] 4. The self-pressurizing shaft end sealing structure for the impeller machinery provided by the present invention, the pressurizing channel and the channel component are of an integral structure, and the pressurizing channel and the channel component are produced by an integral processing method. And / or, the pressurizing channel is detachably fixed on the channel component, and the pressurizing channel and the channel component are processed separately and fixed through a connecting piece.

[0033] In the present invention, when the pressurizing channel is designed to be detachably fixed on the channel component, the staff can replace the pressurizing channel for the channel component according to needs, which is convenient for replacement after the pressurizing channel is worn. In addition, the integral structure of the pressurizing channel and the channel component has the advantages of firm and reliable structure.

[0034] 5. The impeller machinery provided by the present invention includes: a self-pressurizing shaft end sealing structure; and, an impeller machinery; the impeller machinery is a centrifugal impeller or a centripetal turbine.

[0035] The impeller machinery in the present invention includes a self-boosting shaft end seal structure, so it has all the advantages of the self-boosting shaft end seal structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 Schematic diagram of the self-boosting shaft end seal structure for the impeller machinery provided by the present invention;

[0038] Figure 2 Schematic diagram of the centripetal turbine structure with the self-boosting shaft end seal structure provided by the present invention;

[0039] Figure 3 Provided by the present invention Figure 2 Partial enlarged schematic diagram of the self-boosting shaft end seal structure of the centripetal turbine impeller structure shown;

[0040] Figure 4 Schematic diagram of the centrifugal impeller structure with the self-boosting shaft end seal structure provided by the present invention;

[0041] Figure 5 Schematic diagram of the structure for installing the channel member on the rotating shaft of the centrifugal impeller through the connecting member provided by the present invention;

[0042] Figure 6 Schematic diagram of the leakage flow direction of the working medium leaking between the impeller and the casing of the impeller machinery in the prior art.

[0043] Description of the reference numerals:

[0044] 1 - impeller shroud; 2 - disc; 3 - blade; 4 - rotating shaft; 5 - leakage gap; 6 - channel member; 7 - impeller outer casing; 8 - intake channel; 9 - boosting channel; 10 - high-pressure gas film channel; 11 - injection pipeline; 12 - connecting member; 101 - impeller; 102 - casing. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0047] Embodiment 1

[0048] In this embodiment, a self - pressurizing shaft - end sealing structure for an impeller mechanical device is provided. As Figure 2 and Figure 4 shown, the impeller mechanical device has a rotating shaft 4; there is a leakage gap 5 between the rotating shaft 4 and the impeller peripheral housing 7. When the impeller of the impeller mechanical device rotates, the gas working medium leaks from the high - pressure side of the impeller to the main - shaft direction through the leakage gap 5.

[0049] As Figure 1 shown, the self - pressurizing shaft - end sealing structure includes:

[0050] A channel member 6 is arranged at the shaft - end position of the rotating shaft 4 and is used to generate a high - pressure gas film that blocks the leakage of the gas working medium through the leakage gap 5; an air inlet channel 8, a pressurizing channel 9, and a high - pressure gas - film channel 10 are arranged on the channel member 6. And, the above - mentioned pressurizing channel 9 is a channel with a wedge - shaped cross - section. In addition, the above - mentioned pressurizing channel 9 and the channel member 6 are of an integral structure, and the pressurizing channel 9 and the channel member 6 are produced by an integral machining method;

[0051] An injection gas pipeline 11, and the injection gas pipeline 11 is connected to the air inlet channel 8 through an injection hole on the impeller peripheral housing 7 to form a high - pressure gas film through pressurization by the pressurizing channel 9;

[0052] The high - pressure gas - film channel 10 is an annular groove arranged in the circumferential direction of the channel member 6, and the high - pressure gas - film channel 10 is arranged on the 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 gas - film channel 10 are connected in sequence, and the flow area of the pressurizing channel 9 gradually decreases towards the high - pressure gas - film channel 10;

[0053] When the impeller of the impeller machinery rotates, the gas working medium will enter the pressurizing channel 9 through the intake channel 8 for pressure boosting, and a high-pressure gas film for blocking the leakage gap 5 will be generated in the high-pressure gas 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 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.

[0054] Of course, this embodiment does not specifically limit the specific type of the gas working medium. In other embodiments, the gas working medium is air, nitrogen, oxygen, fuel gas or carbon dioxide.

[0055] Of course, this embodiment does not specifically limit the pressure value of the high-pressure gas film generated in the high-pressure gas film channel 10. In other embodiments, the pressure of the high-pressure gas film generated in the high-pressure gas film channel 10 can also be less than or greater than the pressure of the leakage flow in the leakage gap 5.

[0056] Of course, this embodiment does not specifically limit the connection method between the channel member 6 and the pressurizing channel 9. In other embodiments, as Figure 5 shown, the pressurizing channel 9 is detachably fixed on the channel member 6. The pressurizing channel 9 and the channel member 6 are processed separately and fixed by a connecting member 12.

[0057] Of course, this embodiment does not specifically limit the cross-sectional shape of the pressurizing channel 9. In other embodiments, the pressurizing channel 9 is a channel with an arc-shaped cross-section.

[0058] Embodiment 2

[0059] A centrifugal impeller includes: a self-pressurizing shaft end sealing structure; and, as Figure 4 shown, an impeller shroud 1, a disk 2 provided on the impeller shroud 1, and blades 3 provided between the impeller shroud 1 and the disk 2.

[0060] As Figure 4 and Figure 5 shown, the self-pressurizing shaft end sealing structure includes:

[0061] A channel member 6 is provided at the shaft end position of the rotating shaft 4 for generating a high-pressure gas film to block the leakage of the gas working medium through the leakage gap 5; an intake channel 8, a pressurizing channel 9, and a high-pressure gas film channel 10 are provided on the channel member 6;

[0062] An injection pipeline 11, the injection pipeline 11 is connected to the intake channel 8 through an injection hole on the outer casing 7 of the impeller to form a high-pressure gas film through pressure boosting by the pressurizing channel 9;

[0063] The high-pressure gas film channel 10 is an annular groove provided in the circumferential direction of the channel member 6, and the high-pressure gas film channel 10 is provided on the side of the channel member 6 close to the disk 2; the intake channel 8, the pressurizing channel 9, and the high-pressure gas film channel 10 are connected in sequence, and the flow area of the pressurizing channel 9 gradually decreases towards the high-pressure gas film channel 10;

[0064] When the impeller of the impeller mechanical equipment rotates, the gas working medium will enter the pressurizing channel 9 through the intake channel 8 for pressurization, and generate a high-pressure gas film for blocking the leakage gap 5 in the high-pressure gas film channel 10.

[0065] Embodiment 3

[0066] A centripetal turbine includes: a self-pressurizing shaft end seal structure.

[0067] As Figure 2 and Figure 3 shown, the self-pressurizing shaft end seal structure includes:

[0068] A channel member 6 is provided at the shaft end position of the rotating shaft 4 for generating a high-pressure gas film to block the leakage of the gas working medium through the leakage gap 5; an intake channel 8, a pressurizing channel 9, and a high-pressure gas film channel 10 are provided on the channel member 6;

[0069] An injection pipeline 11, the injection pipeline 11 is connected to the intake channel 8 through an injection hole on the outer casing 7 of the impeller to form a high-pressure gas film through pressurization in the pressurizing channel 9;

[0070] The high-pressure gas film channel 10 is an annular groove provided in the circumferential direction of the channel member 6, and the high-pressure gas film channel 10 is provided on the side of the channel member 6 close to the disk 2; the intake channel 8, the pressurizing channel 9, and the high-pressure gas film channel 10 are connected in sequence, and the flow area of the pressurizing channel 9 gradually decreases towards the high-pressure gas film channel 10;

[0071] When the impeller of the impeller mechanical equipment rotates, the gas working medium will enter the pressurizing channel 9 through the intake channel 8 for pressurization, and generate a high-pressure gas film for blocking the leakage gap 5 in the high-pressure gas film channel 10.

[0072] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A self - pressurizing shaft - end sealing structure for a turbomachinery, the turbomachinery comprising: Rotating shaft (4); There is a leakage gap (5) between the rotating shaft (4) and the impeller peripheral housing (7). When the impeller of the impeller mechanical equipment rotates, the gas working medium leaks from the high-pressure side of the impeller to the main shaft direction through the leakage gap (5). It is characterized in that The self-pressurizing shaft end sealing structure includes: A channel member (6) is arranged at the shaft end position of the rotating shaft (4) for generating a high-pressure gas film to block the leakage of the gas working medium through the leakage gap (5); an air inlet channel (8), a pressurizing channel (9) and a high-pressure gas film channel (10) are arranged on the channel member (6); The high-pressure gas film channel (10) is an annular groove arranged in the circumferential direction of the channel member (6), and the high-pressure gas film channel (10) is arranged on the 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 gas film channel (10) are sequentially connected and communicated, and the flow area of the pressurizing channel (9) gradually decreases towards the high-pressure gas film channel (10); When the impeller of the impeller mechanical equipment rotates, the gas working medium will enter the pressurizing channel (9) through the air inlet channel (8) for pressure boosting, and a high-pressure gas film for blocking the leakage gap (5) is generated in the high-pressure gas film channel (10).

2. The self - pressurizing shaft - end sealing structure for a turbomachinery according to claim 1, wherein, It also includes: An injection pipeline (11), and the injection pipeline (11) is connected and communicated with the air inlet channel (8) through an injection hole on the impeller peripheral housing (7) to form a high-pressure gas film through pressure boosting in the pressurizing channel (9).

3. The self - pressurizing shaft - end sealing structure for a turbomachinery according to claim 1 or 2, wherein, 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) 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).

4. The self - pressurizing shaft - end sealing structure for a turbomachinery according to claim 1, wherein, The pressurizing channel (9) and the channel member (6) are of an integral structure, and the pressurizing channel (9) and the channel member (6) are produced by an integral machining method.

5. The self - pressurizing shaft - end sealing structure for a turbomachinery according to claim 1, wherein, The pressurizing channel (9) is detachably fixed on the channel member (6), the pressurizing channel (9) and the channel member (6) are processed separately, and are fixed through a connecting piece (12).

6. The self - pressurizing shaft - end sealing structure for a turbomachinery according to claim 1, wherein, The pressurizing channel (9) is a channel with a wedge-shaped cross-section; and / or The pressurizing channel (9) is a channel with an arc-shaped cross-section.

7. The self - pressurizing shaft - end sealing structure for a turbomachinery according to claim 1, wherein, The gas working medium is air, nitrogen, oxygen, fuel gas or carbon dioxide.

8. A turbomachinery, wherein, It includes: The self-pressurizing shaft end sealing structure according to any one of claims 1 to 7; And an impeller mechanical equipment; The impeller mechanical equipment is a centrifugal impeller or a centripetal turbine.

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