Device for preventing lubricating oil in intermediate bearing box of steam turbine from coking

Abstract

The invention relates to a device for preventing lubricating oil in an intermediate bearing box of a steam turbine from coking. The oil retainer abuts against the inner side wall of the middle bearing box; the oil baffle teeth are arranged on the oil baffle ring and are far away from the middle bearing box; the rotor is arranged at the position close to the oil blocking teeth, and a gap exists between the rotor and the oil blocking teeth; the gap ranges from 0.2 mm to 0.3 mm; one end of the compressed air pipeline is connected with an external air source, the other end of the compressed air pipeline is communicated with the middle bearing box, and compressed air is introduced into the compressed air pipeline to cool the oil retainer. The oil retainer is arranged on the intermediate bearing box, and the compressed air pipeline is synchronously connected to the intermediate bearing box to blow compressed air to the oil retainer, so that the temperature of the oil retainer is reduced, the oil retainer is utilized to block the influence of external steam on lubricating oil in the intermediate bearing box, the coking phenomenon of the lubricating oil is avoided, and the production safety is improved; and stable operation of the device is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbines, and in particular to a device for preventing lubricating oil from coking in an intermediate bearing box of a steam turbine. Background Art

[0002] The 60MW ultra-high temperature subcritical steam turbine unit is the world's first 60MW subcritical unit produced by Dongfang Steam Turbine Co., Ltd. It adopts a dual-cylinder, single-exhaust design structure. The medium and low pressure rotors are transitionally connected through a rigid coupling in the intermediate bearing box. There is no oil baffle on the low pressure cylinder side of the middle box, only a steam baffle ring is set on the outside of the box body, with a large gap and very close to the low pressure front steam seal. At the same time, the high temperature steam leaking from the low pressure cylinder front steam seal easily enters the intermediate bearing box. The high temperature radiation of the cylinder body puts the lubricating oil in the intermediate bearing box in a high temperature environment. The coking of the lubricating oil leads to the deterioration of the oil quality, and the indicators are seriously exceeded, which causes the turbine bearing vibration to fluctuate greatly and alarm. The unit cannot run at full load due to vibration restriction, which restricts the power generation of the unit. Summary of the invention

[0003] The purpose of the present invention is to provide a device for preventing lubricating oil from coking in the intermediate bearing box of a steam turbine, thereby solving the problem of lubricating oil coking in the intermediate bearing box of a steam turbine in the prior art.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: The present invention provides a device for preventing lubricating oil from coking in an intermediate bearing box of a steam turbine, comprising: Intermediate bearing box; An oil retainer ring abutting against an inner side wall of the intermediate bearing box; An oil-blocking tooth, the oil-blocking tooth being arranged on the oil-blocking ring and away from the intermediate bearing box; A rotor, wherein the rotor is arranged near the oil deflector teeth, and there is a gap between the rotor and the oil deflector teeth; the gap between the rotor and the oil deflector teeth is 0.2 mm to 0.3 mm; A compressed air pipeline; one end of the compressed air pipeline is connected to an external air source; the other end of the compressed air pipeline is communicated with the intermediate bearing box; and the oil retaining ring is cooled by introducing compressed air into the compressed air pipeline.

[0005] Furthermore, a compressed air sealing interface is provided on the intermediate bearing box, and the compressed air pipeline is threadedly connected to the compressed air sealing interface.

[0006] Furthermore, the intermediate bearing box and the oil retaining ring are assembled and fixed by fastening screws.

[0007] Furthermore, a pneumatic triplet is provided on the compressed air pipeline, and the pneumatic triplet includes an air filter, a pressure reducing valve and an oil mist collector which are sequentially arranged along the flow direction of the compressed air; The air filter is used to filter the compressed air introduced into the compressed air pipeline; the pressure reducing valve is used to control the introduction pressure of the compressed air; the oil mist collector uses the compressed air as power and cooperates with the compressed air to work.

[0008] Furthermore, a pressure gauge is provided between the pressure reducing valve and the oil mist collector for monitoring the delivery pressure of the compressed air.

[0009] Furthermore, a manual ball valve I is provided at the front end of the air filter for controlling the on-off of the air source on the compressed air pipeline.

[0010] Furthermore, a nitrogen gas source pipeline is connected in front of the manual ball valve I, and a manual ball valve II is provided on the nitrogen gas source pipeline for controlling the on-off of the nitrogen gas source.

[0011] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: The present invention discloses a device for preventing lubricating oil from being coked in an intermediate bearing box of a steam turbine. The device comprises the following steps: an oil retaining ring is installed on the intermediate bearing box, and a compressed air pipeline is synchronously connected to the intermediate bearing box to blow compressed air to the oil retaining ring. The temperature at the oil retaining ring is reduced, and the oil retaining ring is used to block the influence of external steam on the lubricating oil in the intermediate bearing box, thereby avoiding the coking of the lubricating oil, improving the production safety, and ensuring the stable operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings: Figure 1 A plan view of a device for preventing lubricating oil from coking in an intermediate bearing box of a steam turbine provided by the present invention; Figure 2 A planar device diagram of the intermediate bearing box, the oil retaining ring and the rotor provided in the present invention; Figure 3 It is a cross-sectional schematic diagram in the direction of A provided in the present invention; Figure 4 This is an enlarged view of point B in a device for preventing lubricating oil from coking in an intermediate bearing box of a steam turbine provided by the present invention; Figure 5 It is a schematic diagram of the structure of the oil deflector ring provided in the present invention; The reference numerals are as follows: 1. Intermediate bearing box; 101. Compressed air sealing interface; 2. Oil deflector ring; 3. Oil deflector gear; 4. Rotor; 5. Compressed air pipeline; 50. Pneumatic triplex; 501. Air filter; 502. Pressure reducing valve; 503. Oil mist collector; 504. Pressure gauge; 505. Manual ball valve I; 6. Nitrogen gas source pipeline; 601. Manual ball valve II. DETAILED DESCRIPTION

[0013] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] See also Figures 1 to 5 The device for preventing lubricating oil from coking in an intermediate bearing box of a steam turbine disclosed in the present invention comprises an intermediate bearing box 1, an oil retaining ring 2, an oil retaining tooth 3, a rotor 4 and a compressed air pipeline 5.

[0015] Specifically, see Figure 2 and Figure 5 The oil retaining ring 2 is in contact with the inner wall of the intermediate bearing box 1. More specifically, the oil retaining ring 2 is an annular structure, which is actually located on the inner side of the intermediate bearing box 1, surrounding the axis of the intermediate bearing box 1 to form a sealed ring to prevent lubricating oil from leaking from the bearing.

[0016] Regarding how to connect the oil retaining ring 2 to the intermediate bearing box 1, in the embodiment of the present invention, refer to Figure 3 , assemble and fix the oil retaining ring 2 and the intermediate bearing box 1 by fastening screws. Of course, it is not limited to the above method for assembly, and the oil retaining ring 2 and the intermediate bearing box 1 can also be fixedly connected by a snap ring or a direct embedded design, as long as the effect of stable assembly can be achieved.

[0017] In addition, the material of the oil retaining ring 2 used in the embodiment of the present invention is selected from wear-resistant and oil-resistant materials, such as metal alloys, etc., to improve the sealing effect and durability between the oil retaining ring 2 and the intermediate bearing box 1.

[0018] For the aforementioned oil deflector 3, see Figure 2 In the embodiment of the present invention, it is arranged on the oil deflector ring 2 and away from the aforementioned intermediate bearing box 1. The number of oil deflector teeth 3 is set to be several, and the specific number is arranged according to actual needs.

[0019] The rotor 4 is arranged near the oil deflector 3, and there is a certain gap between the rotor 4 and the oil deflector 3 to avoid friction between the rotor 4 and the oil deflector 3. In the embodiment of the present invention, the size of the gap is controlled between 0.2 mm and 0.3 mm.

[0020] In addition, in the embodiment of the present invention, refer to Figure 1 A compressed air pipeline 5 is also connected to the intermediate bearing box 1, which is intended to provide a compressed air source for the interior of the intermediate bearing box 1, and use the compressed air source to cool and blow the interior of the intermediate bearing box 1, and then cool and blow the aforementioned oil retaining ring 2 to prevent the lubricating oil in the intermediate bearing box 1 from high-temperature coking.

[0021] Regarding how to connect the intermediate bearing box 1 and the compressed air pipeline 5, in the embodiment of the present invention, refer to Figure 4 A compressed air sealing interface 101 is provided on the intermediate bearing box 1, and is threadedly connected to the compressed air pipeline 5 through the compressed air sealing interface 101. The threaded connection is convenient for later disassembly and maintenance to ensure the sealing between the compressed air pipeline 5 and the compressed air sealing interface 101. Of course, it is not limited to the above connection method, and the compressed air pipeline 5 can also be connected to the compressed air sealing interface 101 by welding, flange connection or clamp connection, as long as the air tightness of the connection is ensured.

[0022] In addition, in the embodiment of the present invention, refer to Figure 1 A pneumatic triplex 50 is arranged on the aforementioned compressed air pipeline 5. Specifically, the pneumatic triplex 50 includes an air filter 501, a pressure reducing valve 502 and an oil mist collector 503 which are sequentially arranged along the flow direction of the compressed air.

[0023] The air filter 501 is used to filter and remove impurities from the compressed air source entering the compressed air pipeline 5, in order to provide a clean air source for downstream equipment and prevent impurities in the air source from blocking equipment components and affecting production. At the same time, the air filter 501 can also filter the moisture in the compressed air to prevent the moisture from entering the downstream equipment along with the gas.

[0024] The pressure reducing valve 502 is used to control the compressed air supply pressure on the compressed air pipeline 5, stabilize the compressed air source, and keep the air source in a constant state, thereby reducing hardware damage to valves or other devices caused by sudden changes in the air source pressure.

[0025] The oil mist device 503 uses compressed air as a power source to lubricate components that are inconvenient to add lubricating oil. In this embodiment, the oil mist device 503 is not added with lubricating oil, thereby avoiding the impact of high temperature fire.

[0026] In addition, it is not limited to using a pneumatic triplet to perform joint operation on the compressed air pipeline 5, and it is also possible to only use the air filter 501 and the pressure reducing valve 502 together to form a pneumatic doublet to perform the operation. The specific joint operation situation is reasonably adjusted according to actual production needs.

[0027] In the embodiment of the present invention, a pressure gauge 504 is provided between the aforementioned pressure reducing valve 502 and the oil mist collector 503 for monitoring the delivery pressure of the compressed air, so as to avoid damage to components of other components due to excessive delivery pressure of the compressed air, and also to avoid failure to meet production requirements due to excessive delivery pressure of the compressed air.

[0028] In the embodiment of the present invention, a manual ball valve I 505 is also provided at the front end of the air filter 501 to control the on-off of the compressed air source on the compressed air pipeline 5. In addition, in the embodiment of the present invention, a nitrogen gas source pipeline 6 is also connected in front of the manual ball valve I 505. The nitrogen gas source pipeline 6 is provided so that when the compressed air supply is interrupted, it can be switched to the nitrogen gas source pipeline 6, and nitrogen is used for sealed cooling to ensure that the cooling operation of the entire system is not affected. The nitrogen gas source pipeline 6 is synchronously provided with a manual ball valve II 601 to control the on-off of the nitrogen gas source.

[0029] It is worth noting that, no matter whether the compressed air pipeline 5 or the nitrogen gas source pipeline 6 is used, care should be taken to control the ventilation volume of the gas introduced during operation to avoid affecting the negative pressure of the turbine oil supply system and ensure smooth oil return in the system.

[0030] In summary, the device for preventing lubricating oil from coking in the intermediate bearing box of a steam turbine disclosed in the present invention installs an oil retaining ring on the intermediate bearing box, and simultaneously connects a compressed air pipeline to the intermediate bearing box to blow compressed air to the oil retaining ring, thereby reducing the temperature at the oil retaining ring and using the oil retaining ring to block the influence of external steam on the lubricating oil in the intermediate bearing box, thereby avoiding the coking of the lubricating oil, improving production safety, and ensuring stable operation of the device. An additional bypass nitrogen gas source pipeline is added to prevent interruption of the compressed air pipeline supply and ensure the continuity of the cooling operation.

[0031] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for preventing lubricating oil from coking in the intermediate bearing box of a steam turbine, characterized in that: include: Intermediate bearing housing (1); An oil deflector ring (2), the oil deflector ring (2) abutting against an inner side wall of the intermediate bearing box (1); An oil deflector tooth (3), the oil deflector tooth (3) being arranged on the oil deflector ring (2) and away from the intermediate bearing box (1); A rotor (4), the rotor (4) being arranged close to the oil deflector tooth (3), and a gap being present between the rotor (4) and the oil deflector tooth (3); the gap between the rotor (4) and the oil deflector tooth (3) being 0.2 mm to 0.3 mm; A compressed air pipeline (5); one end of the compressed air pipeline (5) is connected to an external air source; the other end of the compressed air pipeline (5) is in communication with the intermediate bearing box (1); and the oil retaining ring (2) is cooled by introducing compressed air into the compressed air pipeline (5).

2. A device for preventing lubricating oil from coking in the intermediate bearing box of a steam turbine according to claim 1, characterized in that: The intermediate bearing box (1) is provided with a compressed air sealing interface (101), and the compressed air pipeline (5) is threadedly connected to the compressed air sealing interface (101).

3. A device for preventing lubricating oil from coking in an intermediate bearing box of a steam turbine according to claim 1, characterized in that: The intermediate bearing box (1) and the oil retaining ring (2) are assembled and fixed by means of fastening screws.

4. A device for preventing lubricating oil from coking in an intermediate bearing box of a steam turbine according to claim 1, characterized in that: The compressed air pipeline (5) is provided with a pneumatic triplet (50), and the pneumatic triplet (50) comprises an air filter (501), a pressure reducing valve (502) and an oil mist collector (503) which are sequentially arranged along the flow direction of the compressed air; The air filter (501) is used to filter the compressed air introduced into the compressed air pipeline (5); the pressure reducing valve (502) is used to control the introduction pressure of the compressed air; the oil mist collector (503) uses the compressed air as power and cooperates with the compressed air to operate.

5. A device for preventing lubricating oil from coking in the intermediate bearing box of a steam turbine according to claim 4, characterized in that: A pressure gauge (504) is provided between the pressure reducing valve (502) and the oil mist collector (503) for monitoring the delivery pressure of the compressed air.

6. A device for preventing lubricating oil from coking in the intermediate bearing box of a steam turbine according to claim 4, characterized in that: A manual ball valve I (505) is provided at the front end of the air filter (501) for controlling the on / off of the air source on the compressed air pipeline (5).

7. A device for preventing lubricating oil from coking in the intermediate bearing box of a steam turbine according to claim 6, characterized in that: A nitrogen gas source pipeline (6) is connected in front of the manual ball valve I (505), and a manual ball valve II (601) is provided on the nitrogen gas source pipeline (6) for controlling the on and off of the nitrogen gas source.

Images