Sealing device for high and medium pressure cylinder of steam turbine

Abstract

The sealing device comprises a high-pressure cylinder, the high-pressure cylinder is connected with an intermediate-pressure cylinder through a bearing box, the high-pressure cylinder and the intermediate-pressure cylinder are in sealing connection with the two ends of the bearing box through a set of flange plates and sealing assemblies arranged outside the flange plates in a sleeving mode respectively, and a heat-resisting sealing ring is clamped between each set of flange plates; each sealing assembly comprises an outer sealing cylinder and an inner sealing cylinder connected with the outer sealing cylinder in a sliding mode. One end of the outer sealing barrel sleeves a cylinder body, close to the flange plate, of the high-pressure cylinder or the medium-pressure cylinder, one end of the inner sealing barrel sleeves a box body, close to one end of the flange plate, of the bearing box, a closed cavity is formed among the outer sealing barrel, the inner sealing barrel, the high-pressure cylinder or the medium-pressure cylinder and the bearing box, and the closed cavity is filled with lubricating oil. The sealing performance of connection between the high-pressure cylinder and the bearing box and between the medium-pressure cylinder and the bearing box is improved, and normal operation and operation efficiency of the high-pressure cylinder and the medium-pressure cylinder are ensured.

Description

Technical Field

[0001] The present application relates to sealing technology, and in particular to a sealing device for high and medium pressure cylinders of a steam turbine. Background Art

[0002] A steam turbine, also known as a steam turbine engine, is a rotary steam power device. A steam turbine is generally equipped with a high-pressure cylinder, a medium-pressure cylinder and a low-pressure cylinder for steam to pass through. Since the high-pressure cylinder needs to be made of austenite alloy steel, while medium and low-pressure steels do not, in order to save the expensive austenite alloy steel, the high, medium and low-pressure cylinders generally adopt a separate cylinder structure. At this time, corresponding sealing components need to be used to seal between the high-pressure cylinder and the medium-pressure cylinder to reduce steam leakage.

[0003] The common high-pressure cylinder and medium-pressure cylinder are generally connected by a bearing box. The high-pressure cylinder, medium-pressure cylinder and bearing box are generally fixed with flanges, and sealing rings are used between the flanges for sealing. However, if sealing rings are used directly for sealing, cracks will appear on the sealing rings due to long-term use and subsequent aging of the sealing rings exposed to the outside. The cracks will affect the sealing effect of the sealing rings and the sealing performance. In addition, since the equipment is large, it is also troublesome to replace the sealing rings. Utility Model Content

[0004] The present application provides a sealing device for a high and medium pressure cylinder of a steam turbine, which is used to solve the technical problems described in the above-mentioned background technology.

[0005] In order to solve the above technical problems, this application adopts the following technical problems to achieve:

[0006] The present application provides a sealing device for a high and medium pressure cylinder of a steam turbine, comprising:

[0007] A high-pressure cylinder, wherein the high-pressure cylinder is connected to a medium-pressure cylinder through a bearing box, and the high-pressure cylinder and the medium-pressure cylinder are respectively sealed and connected to both ends of the bearing box through a set of flanges and a sealing assembly sleeved outside the flanges, and a heat-resistant sealing ring is sandwiched in the middle of each set of flanges;

[0008] Each of the sealing assemblies comprises an outer sealing cylinder and an inner sealing cylinder slidably connected to the outer sealing cylinder; one end of the outer sealing cylinder is sleeved on the cylinder body of the high-pressure cylinder or the medium-pressure cylinder close to the flange, and one end of the inner sealing cylinder is sleeved on the box body of the bearing box close to one end of the flange; a closed chamber is formed between the outer sealing cylinder, the inner sealing cylinder, the high-pressure cylinder or the medium-pressure cylinder and the bearing box, and the closed chamber is filled with lubricating oil.

[0009] Optionally, the heat-resistant sealing ring is provided with an elastic metal ring inside the sleeve, and the elastic metal ring is provided with a hollow sealing ring inside the sleeve.

[0010] Optionally, the elastic metal ring is made of memory metal.

[0011] Optionally, a fixing groove is provided on each of the flanges, and the fixing groove is used to fix the heat-resistant sealing ring between the two flanges to seal the two flanges.

[0012] Optionally, each of the sealing assemblies further comprises an oil filling pipe;

[0013] One end of the oil filling pipe passes through the outer sealing cylinder and the inner sealing cylinder in sequence and extends into the sealed chamber, and the other end of the oil filling pipe is located outside the sealed chamber and is provided with a sealing cover thereon.

[0014] Optionally, a sliding groove is provided on the inner circumferential wall of the outer sealing cylinder along its length direction, and a sliding key is provided on the outer circumferential wall of the inner sealing cylinder along its length direction, and the sliding key matches the sliding groove.

[0015] Optionally, a first sealing plate is provided at one end of the outer sealing cylinder, a first through hole is formed on the first sealing plate, and the first sealing plate is sealed and connected to the cylinder body of the high-pressure cylinder or the medium-pressure cylinder close to the flange through the first through hole;

[0016] A second sealing plate is disposed at one end of the inner sealing cylinder, a second through hole is disposed on the second sealing plate, and the second sealing plate is sealed and connected to the housing of the bearing box at one end close to the flange through the second through hole.

[0017] Optionally, a first sealing sleeve is provided at a connection between the outer sealing sleeve and the high-pressure cylinder or the medium-pressure cylinder, and a second sealing sleeve is provided at a connection between the inner sealing sleeve and the bearing box.

[0018] The sealing device for high and medium pressure cylinders of steam turbines provided by the present application is provided with a heat-resistant sealing ring in the middle of each set of flanges, and the heat-resistant sealing ring is used to seal the two flanges in each set of flanges, and the heat-resistant sealing ring can resist the high temperature of the high-pressure cylinder and the medium-pressure cylinder, thereby extending the service life of the heat-resistant sealing ring and making the sealing between the flanges better. In addition, the connection between the two flanges in each set of flanges is sealed by the closed chamber formed between the outer sealing cylinder and the inner sealing cylinder slidably connected thereto, and lubricating oil is filled in the closed chamber, so that the sealing effect between the two flanges in each set of flanges is better, avoiding the cracking of the heat-resistant sealing ring due to exposure to the outside and the frequent replacement of the heat-resistant sealing ring, thereby improving the sealing of the connection between the high-pressure cylinder and the bearing box and the medium-pressure cylinder and the bearing box, ensuring the normal operation and efficiency of the high-pressure cylinder and the medium-pressure cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic structural diagram of a sealing device for a high and medium pressure cylinder of a steam turbine provided in one embodiment of the present application;

[0021] Figure 2 A schematic diagram of a structure in which a fixing groove is provided on a flange provided in an embodiment of the present application;

[0022] Figure 3 A cross-sectional view of a heat-resistant sealing ring provided in one embodiment of the present application;

[0023] Figure 4 A schematic diagram of a structure in which a sliding groove is provided on an outer sealing cylinder and a first sealing plate is provided at one end thereof, provided in an embodiment of the present application;

[0024] Figure 5 A schematic diagram of a structure in which a sliding key is provided on the inner sealing cylinder and a second sealing plate is provided at one end thereof, provided in an embodiment of the present application;

[0025] Figure 6 A schematic diagram of the structure of a first sealing cylinder and a second sealing cylinder provided in one embodiment of the present application.

[0026] In the figure: 100, high-pressure cylinder; 200, bearing box; 300, medium-pressure cylinder; 400, flange; 500, sealing assembly; 501, outer sealing cylinder; 5011, sliding groove; 5012, first sealing plate; 5013, first through hole; 502, inner sealing cylinder; 5021, sliding key; 5022, second sealing plate; 5023, second through hole; 503, oil filling pipe; 5031, sealing cover; 600, heat-resistant sealing ring; 601, elastic metal ring; 6011, sealing ring; 700, closed chamber; 800, first sealing sleeve; 900, second sealing sleeve. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present application.

[0028] refer to Figures 1 to 5The present application provides a sealing device for a high and medium pressure cylinder of a steam turbine, comprising:

[0029] The high-pressure cylinder 100 is connected to the medium-pressure cylinder 300 through the bearing box 200. The high-pressure cylinder 100 and the medium-pressure cylinder 300 are respectively sealed and connected to the two ends of the bearing box 200 through a group of flanges 400 and a sealing assembly 500 sleeved on the outside of the flanges 400. A heat-resistant sealing ring 600 is sandwiched in the middle of each group of flanges 400; wherein, the heat-resistant sealing ring 600 can be made of rubber material, specifically NBR nitrile rubber, HNBR hydrogenated nitrile rubber, SIL silicone rubber, VITON fluororubber, FLS fluorosilicone rubber, EPDM ethylene propylene rubber, etc. The function of the heat-resistant sealing ring 600 is to seal the two interconnected flanges 400 under the premise of high temperature resistance. Therefore, the specific material of the heat-resistant sealing ring 600 can be set according to the actual temperature, etc., and the present application does not make specific limitations on it.

[0030] Each sealing assembly 500 includes an outer sealing cylinder 501 and an inner sealing cylinder 502 slidably connected to the outer sealing cylinder 501; one end of the outer sealing cylinder 501 is sleeved on the cylinder body of the high-pressure cylinder 100 or the medium-pressure cylinder 300 close to the flange 400, and one end of the inner sealing cylinder 502 is sleeved on the box body of the bearing box 200 close to the flange 400. A closed chamber 700 is formed between the outer sealing cylinder 501, the inner sealing cylinder 502 and the high-pressure cylinder 100 or the medium-pressure cylinder 300 and the bearing box 200, and the closed chamber 700 is filled with lubricating oil. Among them, the arrangement of the outer sealing cylinder 501 and the inner sealing cylinder 502 forms a closed chamber 700, and the closed chamber 700 allows the two flanges 400 connected to each other and the heat-resistant sealing ring 600 arranged between the two flanges 400 to be located in the closed chamber 700, thereby avoiding the phenomenon of cracks due to their exposure to the outside, thereby improving the service life of the heat-resistant sealing ring 600 and the sealing of the connections between the high-pressure cylinder 100 and the bearing box 200 and the medium-pressure cylinder 300 and the bearing box 200, thereby ensuring the operating efficiency of the turbine.

[0031] The sealing device for high and medium pressure cylinders of a steam turbine provided in the present application is configured such that a heat-resistant sealing ring 600 is arranged in the middle of each group of flanges 400, and the heat-resistant sealing ring 600 is used to seal between two flanges 400 in each group of flanges 400. The heat-resistant sealing ring 600 can withstand the high temperature of the high-pressure cylinder 100 and the medium-pressure cylinder 300, thereby extending the service life of the heat-resistant sealing ring 600 and improving the sealing performance between the flanges 400. In addition, the connection between the two flanges 400 in each set of flanges 400 is sealed by forming a closed chamber 700 between an outer sealing cylinder 501 and an inner sealing cylinder 502 slidably connected thereto, and lubricating oil is filled in the closed chamber 700, so that the sealing effect between the two flanges 400 in each set of flanges 400 is better, avoiding cracks in the heat-resistant sealing ring 600 due to exposure to the outside and frequent replacement of the heat-resistant sealing ring 600, thereby improving the sealing of the connection between the high-pressure cylinder 100 and the bearing box 200 and between the medium-pressure cylinder 300 and the bearing box 200, ensuring the normal operation and efficiency of the high-pressure cylinder 100 and the medium-pressure cylinder 300.

[0032] In some embodiments, reference Figure 3 In the present application, the heat-resistant sealing ring 600 is provided with an elastic metal ring 601, and the elastic metal ring 601 is provided with a hollow sealing ring 6011. The elastic metal ring 601 has a certain degree of deformation ability and will deform under high temperature. During its deformation, it contacts the hollow sealing ring 6011. The sealing ring 6011 under high temperature will generate an extrusion force on the elastic metal ring 601 after being heated and expanded, so as to restore the elastic metal ring 601 to its original state as much as possible. During the restoration process, the elastic metal ring 601 will apply a reset force to the heat-resistant sealing ring 600, so that the contact between the heat-resistant sealing ring 600 and the two flanges 400 is closer, thereby improving the sealing performance of the heat-resistant sealing ring 600 to the two flanges 400. The sealing ring 6011 can be made of rubber.

[0033] In some embodiments, the elastic metal ring 601 in the present application is made of memory metal, which refers to a special metal material that can recover its original macroscopic shape in another temperature range after undergoing plastic deformation in a certain temperature range, in order to ensure the deformability of the elastic metal ring 601 .

[0034] In some embodiments, reference Figure 2 In the present application, each flange 400 is provided with a fixing groove 401, and the fixing groove 401 is used to fix the heat-resistant sealing ring 600 between the two flanges 400 so as to seal the two flanges 400. The depth of the fixing groove 401 depends on the thickness of the heat-resistant sealing ring 600, and mainly plays the role of fixing the heat-resistant sealing ring 600, so the present application does not specifically limit it.

[0035] In some embodiments, reference Figure 1 , each sealing assembly 500 in the present application further includes an oil filling pipe 503; specifically, one end of the oil filling pipe 503 sequentially penetrates the outer sealing cylinder 501 and the inner sealing cylinder 502 and extends into the sealed chamber 700, and the other end of the oil filling pipe 503 is located outside the sealed chamber 700 and is provided with a sealing cover 5031. The sealing cover 5031 is opened, and the lubricating oil is injected into the sealed chamber 700 through the other end of the oil filling pipe 503 through the oil filling pipe 503. After the oil filling is completed, the sealing cover 5031 is covered on the oil filling pipe 503 to ensure that the sealed chamber 700 is in a sealed state. Specifically, the body of the oil filling pipe 503 is sealedly connected with the outer sealing cylinder 501 and the inner sealing cylinder 502.

[0036] In some embodiments, reference Figure 4 and Figure 5 In the present application, a sliding groove 5011 is arranged on the inner peripheral wall of the outer sealing cylinder 501 along its length direction, and a sliding key 5021 is arranged on the outer peripheral wall of the inner sealing cylinder 502 along its length direction, and the sliding key 5021 matches the sliding groove 5011. There can be multiple sliding grooves 5011, and there can also be multiple sliding keys 5021. The multiple sliding keys 5021 correspond to the multiple sliding grooves 5011 one by one, so as to improve the stability of the connection between the outer sealing cylinder 501 and the inner sealing cylinder 502. In addition, the sliding key 5021 is sealed and connected to the sliding groove 5011, so that the sealing performance of the closed chamber 700 can be further ensured.

[0037] In some embodiments, reference Figure 4 and Figure 5 A first sealing plate 5012 is provided at one end of the outer sealing cylinder 501 in the present application, and a first through hole 5013 is opened on the first sealing plate 5012. The first sealing plate 5012 is sealed and connected to the cylinder body of the high-pressure cylinder 100 or the medium-pressure cylinder 300 near the flange 400 through the first through hole 5013; wherein the aperture of the first through hole matches the outer diameter of the cylinder body of the high-pressure cylinder 100 or the medium-pressure cylinder 300 near the flange 400.

[0038] A second sealing plate 5022 is provided at one end of the inner sealing cylinder 502, and a second through hole 5023 is provided on the second sealing plate 5022. The second sealing plate 5022 is sealed and connected to the housing of the bearing housing 200 at one end close to the flange 400 through the second through hole 5023. The aperture of the second through hole 5023 matches the outer diameter of the housing of the bearing housing 200 at one end close to the flange 400.

[0039] In the above embodiment, the first sealing plate 5012 and the first through hole 5013 thereon, the second sealing plate 5022 and the second through hole 5023 thereon improve the sealing performance of the closed chamber 700 and avoid the phenomenon that the heat-resistant sealing ring 600 is exposed to the outside and cracks.

[0040] In some embodiments, reference Figure 6 In the present application, a first sealing sleeve 800 is provided at the connection between the outer sealing sleeve 501 and the high-pressure cylinder 100 or the medium-pressure cylinder 300, and a second sealing sleeve 900 is provided at the connection between the inner sealing sleeve 502 and the bearing box 200. The first sealing sleeve 800 and the second sealing sleeve 900 are both made of materials with high temperature resistance, corrosion resistance and other characteristics. The first sealing sleeve 800 is used to further seal the connection between the outer sealing sleeve 501 and the high-pressure cylinder 100 or the medium-pressure cylinder 300, and the second sealing sleeve 900 is used to seal the connection between the inner sealing sleeve 502 and the bearing box 200, thereby improving the sealing performance of the closed chamber 700.

[0041] The use principle of the sealing device for high and medium pressure cylinders of steam turbines provided in this application is as follows:

[0042] The outer sealing cylinder 501 is sleeved on the cylinder body of the high-pressure cylinder 100 or the medium-pressure cylinder 300 close to the bearing box 200, and the inner sealing cylinder 502 is sleeved on the box bodies at both ends of the bearing box 200. A flange 400 is respectively provided at both ends of the bearing box 200, and a flange 400 is respectively provided at one end of the high-pressure cylinder 100 or the medium-pressure cylinder 300 close to the bearing box 200 (the flange 400 can be provided by welding), wherein a heat-resistant sealing ring 600 is embedded in a fixing groove 401 on a flange 400 in each set of flanges 400, and the inner sealing cylinder 502 on one end of the bearing box 200 is inserted toward the outer sealing cylinder 502 on the high-pressure cylinder 100. The cylinder 501 is moved so that the two slide and are sealed, and then the outer sealing cylinder 501 on the medium-pressure cylinder 300 is moved toward the inner sealing cylinder 502 on the other end of the bearing box 200 so that the two slide and are sealed, and a first sealing sleeve 800 is respectively set between the high-pressure cylinder 100 and the outer sealing cylinder 501 and between the medium-pressure cylinder 300 and the outer sealing cylinder 501, and a second sealing sleeve 900 is set between the bearing box 200 and the inner sealing cylinder 502, and lubricating oil is injected into the closed chamber 700 formed between the outer sealing cylinder 501 and the inner sealing cylinder 502 through the oil filling pipe 503, and the sealing cover 5031 is covered on the oil filling pipe 503, thereby realizing the sealing of the high and medium pressure cylinders of the turbine.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A sealing device for a high and medium pressure cylinder of a steam turbine, characterized in that: include: A high-pressure cylinder (100), wherein the high-pressure cylinder (100) is connected to a medium-pressure cylinder (300) via a bearing box (200), the high-pressure cylinder (100) and the medium-pressure cylinder (300) are respectively sealedly connected to both ends of the bearing box (200) via a set of flanges (400) and a sealing assembly (500) sleeved outside the flanges (400), and a heat-resistant sealing ring (600) is sandwiched between each set of flanges (400); Each of the sealing assemblies (500) comprises an outer sealing cylinder (501) and an inner sealing cylinder (502) slidably connected to the outer sealing cylinder (501); one end of the outer sealing cylinder (501) is sleeved on the cylinder body of the high-pressure cylinder (100) or the medium-pressure cylinder (300) close to the flange (400), and one end of the inner sealing cylinder (502) is sleeved on the box body of the bearing box (200) close to one end of the flange (400); a closed chamber (700) is formed between the outer sealing cylinder (501), the inner sealing cylinder (502), the high-pressure cylinder (100) or the medium-pressure cylinder (300) and the bearing box (200), and the closed chamber (700) is filled with lubricating oil; A sliding groove (5011) is provided on the inner peripheral wall of the outer sealing cylinder (501) along its length direction, and a sliding key (5021) is provided on the outer peripheral wall of the inner sealing cylinder (502) along its length direction, and the sliding key (5021) matches the sliding groove (5011).

2. The sealing device for high and medium pressure cylinders of a steam turbine according to claim 1, characterized in that: An elastic metal ring (601) is sleeved inside the heat-resistant sealing ring (600), and a hollow sealing ring (6011) is sleeved inside the elastic metal ring (601).

3. The sealing device for high and medium pressure cylinders of a steam turbine according to claim 2, characterized in that: The elastic metal ring (601) is made of memory metal.

4. The sealing device for high and medium pressure cylinders of a steam turbine according to claim 1, characterized in that: A fixing groove (401) is provided on each flange (400), and the fixing groove (401) is used to fix the heat-resistant sealing ring (600) between the two flanges (400) so as to seal the two flanges (400).

5. The sealing device for high and medium pressure cylinders of a steam turbine according to claim 1, characterized in that: Each of the sealing assemblies (500) further comprises an oil injection pipe (503); One end of the oil filling pipe (503) passes through the outer sealing cylinder (501) and the inner sealing cylinder (502) in sequence and extends into the sealed chamber (700); the other end of the oil filling pipe (503) is located outside the sealed chamber (700) and is provided with a sealing cover (5031).

6. The sealing device for high and medium pressure cylinders of a steam turbine according to claim 1, characterized in that: A first sealing plate (5012) is provided at one end of the outer sealing cylinder (501), a first through hole (5013) is provided on the first sealing plate (5012), and the first sealing plate (5012) is sealingly connected to the cylinder body of the high-pressure cylinder (100) or the medium-pressure cylinder (300) close to the flange (400) through the first through hole (5013); A second sealing plate (5022) is provided at one end of the inner sealing cylinder (502), a second through hole (5023) is provided on the second sealing plate (5022), and the second sealing plate (5022) is sealingly connected to the housing of the bearing box (200) at one end close to the flange (400) via the second through hole (5023).

7. The sealing device for high and medium pressure cylinders of a steam turbine according to any one of claims 1 to 6, characterized in that: A first sealing sleeve (800) is provided at the connection between the outer sealing sleeve (501) and the high-pressure cylinder (100) or the medium-pressure cylinder (300), and a second sealing sleeve (900) is provided at the connection between the inner sealing sleeve (502) and the bearing box (200).

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