CN-122014663-A - Inflatable sealing type stationary blade bearing for axial flow turbine unit and sealing method

Abstract

The invention relates to the technical field of large-scale turbomachinery, and provides an inflatable sealed stationary blade bearing for an axial flow turbine unit, which comprises a bearing body, wherein the bearing body is of a cylindrical structure, a cavity which is penetrated along the axial direction is formed in the bearing body and is used for installing and supporting a rotating shaft of a stationary blade, one end of the bearing body is provided with a flange sealing surface connected with the bearing body of the unit, an air inlet threaded duct is formed in the flange sealing surface and is used for introducing sealing air into an internal air passage arranged in the bearing body, the internal air passage comprises an axial duct communicated with the air inlet threaded duct, a radial duct communicated with the axial duct far away from an air inlet end, an annular pressure equalizing groove which is arranged on the outer wall of the bearing body and is communicated with the radial duct, and a plurality of air guide duct which is communicated with the annular pressure equalizing groove and the cavity, and the top bearing and the bottom bearing are respectively arranged at two ends of the cavity. The problem that in the prior art, a machine set is easy to cause static blade blocking due to operation environment damage, so that a system is forced to stop is solved.

Inventors

• JI TINGTING
• SUN BIAO
• LIU JIE
• REN WEI
• Ju Xinshe
• LIU QIN
• LIU ZHUANG
• CHEN LIANG
• JIA PENGFEI
• DENG CHONG
• LI QI
• LIU HAO
• REN JIANMING
• SHANG YONGBO
• FU PENGFEI
• LIU YUANHAO

Assignees

• 西安陕鼓动力股份有限公司

Dates

Publication Date

20260512

Application Date

20260224

Claims (10)

1. 1. An inflatable sealed stationary blade bearing for an axial flow turbine unit comprises a bearing body (1), wherein the bearing body (1) is arranged on a unit bearing cylinder body (8) of the axial flow turbine unit, The bearing body (1) is of a cylindrical structure, a cavity which is penetrated along the axial direction is formed in the bearing body, a rotating shaft for installing and supporting stationary blades is arranged in the bearing body, a flange sealing surface connected with the unit bearing body (8) is arranged at one end of the bearing body (1), and an air inlet threaded hole channel (15) is formed in the flange sealing surface and used for introducing sealing air into an internal air channel arranged in the bearing body (1); the internal gas circuit comprises an axial pore canal (14) communicated with a gas inlet threaded pore canal (15), a radial pore canal (16) communicated with the axial pore canal (14) far away from a gas inlet end, an annular pressure equalizing groove (19) arranged on the outer wall of the bearing body (1) and communicated with the radial pore canal (16), and a plurality of gas guide pore canals (17) communicated with the annular pressure equalizing groove (19) and the cavity, wherein the gas guide pore canals (17) are uniformly arranged along the circumferential direction; the two ends of the cavity are respectively provided with a top bearing (2) and a bottom bearing (3).
2. 2. The gas-filled sealed stator bearing for an axial turbine set of claim 1, wherein the top bearing (2) is disposed at an end proximate to an axial duct (14), the top bearing (2) further comprising a positioning flange (211), the positioning flange (211) being secured to an end of the top bearing (2) and closing a port of the axial duct (14) proximate to an end of a flange sealing face; the working surfaces of the top bearing (2) and the bottom bearing (3) are provided with self-lubricating structures.
3. 3. The gas-filled sealed stationary blade bearing for an axial flow turbine set of claim 1, wherein the cavity comprises, in axial sequence, a first cavity section (12), a second cavity section and a third cavity section (13) coaxially arranged, the second cavity section having a smaller diameter than the first cavity section (12) and the third cavity section (13); The top bearing (2) is mounted to the first chamber section (12), and the bottom bearing (3) is mounted to the third chamber section (13).
4. 4. The gas-filled sealed stator bearing for an axial turbine set of claim 3, wherein the first and third cavity sections (12, 13) are each provided with a1 ° chamfer inwardly.
5. 5. A gas-filled sealed stator bearing for an axial turbine set according to claim 3, characterized in that a polytetrafluoroethylene sealing ring (5) is arranged between the bottom bearing (3) and the cavity wall of the third cavity section (13).
6. 6. The gas-filled sealed vane bearing for an axial turbine set of claim 1, wherein the gas duct (17) is provided with four.
7. 7. The inflatable sealed stationary blade bearing for an axial flow turbine unit according to claim 1, characterized in that the bearing body (1) is provided with a ring groove (18) on the outer wall of one end provided with a bottom bearing (3), the ring groove (18) being used for mounting a sealing ring (4).
8. 8. The gas-filled sealed vane bearing for an axial flow turbine set of claim 1 wherein two connecting bolt holes are provided on the flange sealing face.
9. 9. Sealing method for an inflatable sealed stator blade bearing of an axial turbine unit, characterized in that it is used for the stator blade bearing according to any one of claims 1-8, comprising the steps of, S1, mounting and fixing the stator blade bearing in a unit bearing cylinder body (8), and enabling a stator blade rotating shaft to penetrate through a cavity of the bearing body (1); S2, introducing sealing gas into the air inlet threaded hole channel (15); s3, the sealing gas sequentially flows through the axial pore canal (14) and the radial pore canal (16) to enter the annular pressure equalizing groove (19); S4, after the sealing gas is subjected to pressure equalization in the annular pressure equalizing groove (19), the sealing gas uniformly flows into a gap between the stationary blade rotating shaft and the inner wall of the bearing body (1) through the plurality of air guide pore canals (17) to form an annular air curtain; And S5, maintaining the pressure of the sealing gas to be continuously higher than the medium pressure of the environment where the static blade bearing is positioned.
10. 10. The sealing method for an axial flow turbine set gas-filled sealed vane bearing of claim 9, wherein maintaining the sealing gas pressure in S5 is, S51, providing a high-pressure inflation branch from the front of the pneumatic regulating valve and a low-pressure inflation branch from the rear of the pneumatic regulating valve; s52, selecting a high-pressure inflating branch or a low-pressure inflating branch as an air source according to the real-time value of the medium pressure; And S53, adjusting the pressure of the air source to be stably higher than the medium pressure by 20 kPa to 30 kPa.

Description

Inflatable sealing type stationary blade bearing for axial flow turbine unit and sealing method Technical Field The invention relates to the technical field of large-scale turbomachinery, in particular to an inflatable sealing type stationary blade bearing for an axial flow turbine unit and a sealing method. Background The large industrial axial flow turbine set (such as an axial flow compressor, a blower and the like) is key core equipment in the fields of petrochemical industry, coal chemical industry, metallurgy and the like, and the running continuity and stability of the large industrial axial flow turbine set are directly related to the safety and economic benefits of the whole production device. In order to adapt to complex process working condition changes, a static blade adjustable technology is generally adopted in a modern large-scale axial flow unit, namely, the efficiency of the unit is optimized and the gas flow is regulated by changing the installation angle of a static blade (static blade) in real time. In the vane adjustable mechanism, a vane bearing is a core base member that realizes an adjusting function. The stator blade rotating shaft is fixedly arranged on a stator blade bearing body or a casing of the unit, and the stator blade rotating shaft is assembled in an inner hole of the bearing. The stator blade bearing plays roles of supporting and lubricating, rotating a central shaft and sealing an interface, and meanwhile, the stator blade is driven by the driving ring and the stator blade tail crank to rotate, so that the angle of the stator blade is adjusted, and the aim of adjusting the gas flow is fulfilled. At present, two ends of a common static blade bearing are lubricated and sealed by adopting graphite sleeves. The graphite material has certain self-lubricating property and high temperature resistance, and can perform in a short period under clean working conditions. However, in actual industrial operating environments, the compressed process gas often contains corrosive media such as dust, catalyst particles, moisture, condensate, or even hydrogen sulfide. Because the graphite material is relatively soft, abrasion is inevitably generated between the graphite material and the stationary blade in long-term operation, and the fit clearance is gradually increased. The increased gap provides a passageway for impurities and condensate in the gas. These contaminants can invade the small gaps between the bearings and the vanes, mix with the graphite powder produced by wear, gradually harden, scale, and form a tough scale layer. Finally, the rotation resistance of the static blade is increased sharply until the static blade is completely blocked and cannot rotate. Once the static blades are blocked, the problems that the angle of the static blades cannot be adjusted, a crank pin shaft is sheared, a pistol plate is broken and the like are caused, the static blade adjustable function of the machine set is thoroughly invalid, the process operation is affected, the whole system is forced to be stopped and overhauled, and huge economic loss is caused. Disclosure of Invention The invention provides an inflatable sealing type stator blade bearing for an axial flow turbine unit and a sealing method, which are used for solving the problem that in the prior art, the unit is easy to cause the blocking of stator blades due to the damage of an operating environment, so that a system is forced to stop. The invention provides an inflatable sealing type stator blade bearing for an axial flow turbine unit, which comprises a bearing body, wherein the bearing body is arranged on a unit bearing cylinder body of the axial flow turbine unit, the bearing body is of a cylindrical structure, a cavity which is communicated with the bearing body along the axial direction is arranged in the bearing body and is used for installing and supporting a rotating shaft of a stator blade, one end of the bearing body is provided with a flange sealing surface connected with the unit bearing cylinder body, an air inlet threaded duct is arranged on the flange sealing surface and is used for introducing sealing air into an internal air passage arranged in the bearing body, the internal air passage comprises an axial duct communicated with the air inlet threaded duct, a radial duct communicated with the axial duct and a radial duct, an annular pressure equalizing groove arranged on the outer wall of the bearing body and communicated with the radial duct, and a plurality of air guide ducts communicated with the annular pressure equalizing groove and the cavity, and the two ends of the cavity are respectively provided with a top bearing and a bottom bearing. The top bearing is arranged at one end close to the axial duct, the top bearing further comprises a positioning flange, the positioning flange is fixed at the end part of the top bearing and seals a port of the axial duct close to one end of a flange sealing surface, and self-