Honeycomb type steam seal structure of steam turbine

Abstract

The utility model relates to the field of steam seal mechanisms, in particular to a honeycomb type steam seal structure of a steam turbine, which comprises a steam seal body, a mounting seat and a rotor shaft, the steam seal body comprises a steam seal base body, steam seal teeth and a circular bead, the steam seal teeth and the circular bead are correspondingly arranged at two ends of the steam seal base body, the circular bead is mounted in the mounting seat, and the steam seal teeth are mounted on the outer side of the rotor shaft. The vertical teeth and the oblique teeth are arranged at one end of the steam seal base body, so that the vertical teeth and the oblique teeth integrally form a structure similar to a honeycomb type, and the honeycomb type grids can cause vortex when steam flows and increase frictional resistance when the steam flows, so that kinetic energy of the steam is reduced; and meanwhile, a first throttling chamber and a second throttling chamber which are different in internal space size are formed between the steam seal teeth and the rotor shaft and between the steam seal teeth and the steam seal base body respectively, so that steam flows from a low-pressure area to a high-pressure area when flowing from the first throttling chamber to the second throttling chamber, the advancing resistance is increased, the outward flowing speed of the steam is slowed down, and the steam leakage speed is reduced.

Description

Technical Field

[0001] The utility model relates to the field of gland mechanisms, in particular to a honeycomb gland structure of a steam turbine. Background Technique

[0002] The gland structure (or gland device) of a steam turbine is an important component in a steam turbine, mainly used to reduce the leakage of the working medium (usually steam) between the high-pressure area and the low-pressure area, thereby improving the efficiency of the steam turbine. The gland structure uses a narrow gap and a complex flow path design to reduce the velocity and pressure of the fluid, minimizing the leakage.

[0003] At present, the Chinese utility model patent with the publication number of CN205578042U and the publication date of September 14, 2016 discloses a brush seal assembly. A brush bundle is fixedly installed at the bottom of the gland, and the brush bundle is made by stacking bristles.

[0004] During use, the bristles replace the rigid gland teeth, enabling the brush bundle to yield freely when colliding with the rotor, reducing the gap between the brush bundle and the rotor, and causing turbulence when the steam passes through the bristles, thereby reducing the steam velocity and the steam leakage amount.

[0005] Aiming at the above technical solution, when the rotor of the steam engine rotates, it will have severe friction with the bristles of the brush bundle, resulting in significant wear of the bristles after a period of use. The worn bristles will generate a large gap with the rotor again, leading to an increase in the steam leakage amount. Content of the Utility Model

[0006] In order to reduce the steam leakage speed of the steam turbine and improve the working efficiency of the steam turbine, the utility model provides a honeycomb gland structure of a steam turbine.

[0007] The utility model provides a honeycomb gland structure of a steam turbine, adopting the following technical solution:

[0008] A honeycomb gland structure of a steam turbine includes a gland body, a mounting seat, and a rotor shaft. The gland body includes a gland base, gland teeth, and a shoulder. The gland teeth are fixedly arranged at one end of the gland base, and the shoulder is fixedly arranged at the end of the gland base far from the gland teeth. The gland teeth include a first vertical tooth, a second vertical tooth, and an inclined tooth. One end of the first vertical tooth and the second vertical tooth is fixedly installed on the gland base. The first vertical tooth and the second vertical tooth are arranged at intervals, and the inclined tooth is fixedly arranged at the ends of the first vertical tooth and the second vertical tooth. An installation groove is formed on the mounting seat, and the shoulder is fitted and installed in the installation groove. The rotor shaft is arranged in cooperation with the gland teeth.

[0009] By adopting such a technical solution, vertical teeth and inclined teeth are arranged at one end of the gland base, so that the vertical teeth and the inclined teeth as a whole form a structure similar to a honeycomb structure. When steam passes through the honeycomb lattice between the first vertical tooth and the second vertical tooth, it can effectively prevent the steam from moving forward. At the same time, the honeycomb lattice also causes the eddy current of the steam and the increase of frictional resistance, further reducing the kinetic energy of the steam and reducing the steam leakage speed.

[0010] Optionally, a spring groove is further arranged on the shoulder, and an annular spring is installed inside the spring groove.

[0011] By adopting such a technical solution, installing an annular spring inside the spring groove can cause the gland base to retreat in the radial direction when the rotor shaft deflects, avoiding severe friction between the gland teeth and the rotor shaft, and automatically resetting the gland base after the rotor shaft returns to its original position, effectively extending the service life of the gland structure.

[0012] Optionally, the gland base is composed of two identical semi-circular half-gland bodies. An I-shaped groove is arranged on the cross-section of the end of the half-gland body, and an I-shaped protrusion is arranged on the cross-section of the other end of the half-gland body.

[0013] By adopting such a technical solution, an I-shaped groove and an I-shaped protrusion are arranged on the cross-sections at both ends of the semi-circular gland base. After the gland base is installed inside the mounting seat, the two half-gland bodies can be engaged, effectively reducing steam leakage from the connection surface of the half-gland bodies.

[0014] Optionally, the I-shaped groove and the I-shaped protrusion are arranged in a matching manner. The width of the I-shaped groove is smaller than the width of the I-shaped protrusion, and a chamfer is further arranged on the edge of the I-shaped protrusion.

[0015] By adopting such a technical solution, since the width of the I-shaped groove is smaller than the width of the I-shaped protrusion, the chamfer of the I-shaped protrusion will be stuck in the I-shaped groove when the I-shaped protrusion and the I-shaped groove are engaged, and the chamfer of the I-shaped protrusion and the I-shaped groove will be more tightly engaged together by the extrusion of the steam turbine casing, so that the two half-gland bodies are sealed to prevent steam from leaking from the connection surface of the half-gland bodies.

[0016] Optionally, the inclined tooth is of a V-shaped structure. The middle part of the inclined tooth is fixedly connected to the ends of the first vertical tooth and the second vertical tooth, and the opening of the inclined tooth faces away from the gland base.

[0017] By adopting such a technical solution, the inclined tooth can guide the steam in the steam inflow direction, guide the steam to flow upward, promote the generation of eddy current of the steam in the honeycomb lattice, and offset the kinetic energy of the steam by itself, effectively reducing the steam leakage speed.

[0018] Optionally, a first throttling chamber is formed between the first vertical teeth, the second vertical teeth, the helical teeth, the rotor shaft and the gland base body, a second throttling chamber is formed between the helical teeth and the rotor shaft, and the internal space of the first throttling chamber is larger than that of the second throttling chamber.

[0019] By adopting this technical solution, when steam flows in the first throttling chamber and the second throttling chamber, since the space becomes larger when the steam enters the first throttling chamber from the second throttling chamber, according to the ideal gas equation and the gas expansion principle, the pressure in the second throttling chamber is higher than that in the first throttling chamber, resulting in the steam flowing from the first throttling chamber to the next second throttling chamber being from a low-pressure area to a high-pressure area, and the gas being subjected to a large resistance, slowing down the speed of steam leakage to the outside.

[0020] Optionally, a diagonal brace is further provided at one end of the gland base body away from the shoulder. The diagonal brace is of a triangular structure. One surface of the diagonal brace is fixedly arranged on the gland base body, and the first vertical teeth and the second vertical teeth are fixed on the diagonal brace. The first vertical teeth and the second vertical teeth are fixedly arranged on the edge of the diagonal brace away from the gland base body.

[0021] By adopting this technical solution, the diagonal braces are respectively arranged between the first vertical teeth, the second vertical teeth and the gland base body, which can play a supporting role in the transverse direction for the first vertical teeth and the second vertical teeth, reduce the deformation generated when the gland teeth are squeezed by the high pressure of steam, and reduce the gap generated between the gland teeth and the rotor shaft when the gland teeth are deformed, thereby reducing the steam leakage amount.

[0022] Optionally, the height of the first vertical teeth is greater than that of the second vertical teeth.

[0023] By adopting this technical solution, the first vertical teeth and the second vertical teeth are arranged at intervals, and the first vertical teeth and the second vertical teeth are arranged as high and low teeth, ensuring that even if the high teeth are worn, there are still low teeth to fill the gaps and maintain the sealing effect. At the same time, since the high teeth and the low teeth are arranged at intervals, the contact area between the gland teeth and the rotor shaft can be effectively controlled, preventing the contact area between the gland teeth and the rotor shaft from being too large and causing serious wear.

[0024] In summary, the present utility model includes at least one of the following beneficial technical effects:

[0025] By arranging vertical teeth and helical teeth at one end of the gland base body, the vertical teeth and the helical teeth form a structure similar to a honeycomb as a whole. The honeycomb-like cells can cause the eddy current of steam and increase the frictional resistance when the steam flows, further reducing the kinetic energy of the steam and reducing the speed of steam leakage.

[0026] The labyrinth teeth form a first throttle chamber and a second throttle chamber between the rotor shaft and the labyrinth base respectively. Since the space becomes larger when the steam enters the first throttle chamber from the second throttle chamber, the pressure in the second throttle chamber is higher than that in the first throttle chamber, resulting in the steam flowing from the first throttle chamber to the next second throttle chamber from the low-pressure area to the high-pressure area, and the gas is subject to a large resistance, slowing down the outflow speed of the steam.

[0027] I-shaped protrusions and I-shaped grooves are respectively arranged on the cross-sections at both ends of the labyrinth base. When the two semi-circular labyrinth bases are connected together, the I-shaped protrusions and I-shaped grooves can be engaged to reduce the leakage of steam from the connection surface of the semi-circular labyrinth base.

[0028] By respectively arranging diagonal braces between the first vertical teeth, the second vertical teeth and the labyrinth base, the diagonal braces can support the first vertical teeth and the second vertical teeth in the transverse direction, reduce the deformation generated when the labyrinth teeth are squeezed by the high pressure of the steam, and reduce the gap generated between the labyrinth teeth and the rotor shaft when the labyrinth teeth are deformed, thereby reducing the leakage of steam. Brief Description of the Drawings

[0029] Figure 1 is a schematic structural diagram of the installation position of the labyrinth body in the embodiment of the present invention;

[0030] Figure 2 is an enlarged schematic structural diagram of the installation position of the labyrinth body in the embodiment of the present invention;

[0031] Figure 3 is a schematic cross-sectional diagram of the labyrinth body in the embodiment of the present invention;

[0032] Figure 4 is a schematic structural diagram of the semi-labyrinth body in the embodiment of the present invention;

[0033] Figure 5 is a schematic installation diagram of the semi-labyrinth body in the embodiment of the present invention.

[0034] Description of the reference numerals: 1. Labyrinth body; 11. Semi-labyrinth body; 101. Labyrinth base; 102. Labyrinth teeth; 1021. First vertical teeth; 1022. Second vertical teeth; 103. Shoulder; 1031. Spring groove; 104. I-shaped groove; 1041. I-shaped protrusion; 105. Diagonal brace; 106. Helical teeth; 2. Mounting seat; 3. Rotor shaft; 4. Annular spring; 5. First throttle chamber; 6. Second throttle chamber. Detailed Description of the Embodiment

[0035] The following is a further detailed description of the present invention in conjunction with Figures 1 to 5 to further illustrate the present invention in detail.

[0036] The embodiment of the present invention discloses a honeycomb labyrinth structure of a steam turbine. Refer to Figures 1 to 2, an embodiment of the utility model discloses a honeycomb steam seal structure of a steam turbine, which includes a steam seal body 1, a mounting seat 2 and a rotor shaft 3. The steam seal body 1 includes a steam seal base body 101, steam seal teeth 102 and shoulders 103. The steam seal teeth 102 and shoulders 103 are correspondingly arranged at both ends of the steam seal base body 101. The shoulders 103 are installed in the mounting seat 2, and the steam seal teeth 102 are installed outside the rotor shaft 3.

[0037] Referring to Figures 1 to 2 , the steam seal base body 101 is composed of two identical semi-steam seal bodies 11 in a semi-circular ring shape. Tooth-shaped grooves are evenly arranged on the inner ring end face of the semi-steam seal body 11 by cutting. The tooth-shaped grooves are arranged in a ring along the inner ring surface of the steam seal base body 101. The protruding parts between the tooth-shaped grooves form a diagonal brace 105. The tip of the diagonal brace 105 is welded with the steam seal teeth 102. The steam seal teeth 102 include a first vertical tooth 1021, a second vertical tooth 1022 and an inclined tooth 106. The first vertical tooth 1021 and the second vertical tooth 1022 are welded to the diagonal brace 105 at intervals. The length of the first vertical tooth 1021 is greater than that of the second vertical tooth 1022. The inclined tooth 106 is of a V-shaped structure. The middle part of the inclined tooth 106 is fixed to the ends of the first vertical tooth 1021 and the second vertical tooth 1022 by welding. The open end of the inclined tooth 106 is arranged in a direction away from the diagonal brace 105. When steam passes through, it will first pass through the inclined tooth 106 installed at the end of the first vertical tooth 1021 and enter the second throttling chamber 6 formed by the inclined tooth 106 and the rotor shaft 3. Then it passes through the inclined tooth 106 and enters the first throttling chamber 5 formed by the inclined tooth 106, the first vertical tooth 1021, the diagonal brace 105, the second vertical tooth 1022 and the rotor shaft 3. Then it passes through the second throttling chamber 6 and the first throttling chamber 5 in sequence. Because the internal space of the first throttling chamber 5 is larger than that of the second throttling chamber 6, the air pressure will decrease after the steam enters the large space from the small space, making the internal pressure of the first throttling chamber 5 less than the internal pressure of the second throttling chamber 6. As a result, when the steam flows from the first throttling chamber 5 to the next second throttling chamber 6, it flows from the low-pressure area to the high-pressure area, and the steam flow is blocked, thereby slowing down the speed of steam leakage. At the same time, the first vertical tooth 1021, the second vertical tooth 1022, the inclined tooth 106 and the diagonal brace 105 as a whole form a honeycomb structure. Among them, the inclined tooth 106 and the diagonal brace 105 can guide the steam flow direction, causing the steam to form a vortex in the first throttling chamber 5, further blocking the steam flow, reducing the kinetic energy of the steam, and thus reducing the power of leakage.

[0038] Referring to Figures 1 to 4, a shoulder 103 is further provided on the outer ring surface of the semi-sealing body 11. The shoulder 103 can be fitted and installed in the mounting seat 2. A spring groove 1031 is further provided on the shoulder 103. An annular spring 4 is fixedly installed in the spring groove 1031. When the sealing body 101 is displaced, the annular spring 4 can cause the sealing body 101 to retreat in the radial direction and automatically reset the sealing body 101 after the rotor shaft 3 returns to its position, avoiding severe friction between the sealing teeth 102 and the rotor shaft 3 and effectively extending the service life of the sealing structure.

[0039] Referring to Figures 1 to 5 , a T-shaped groove 104 is provided on the semi-circular cross-section at the end of the semi-sealing body 11, and a T-shaped protrusion 1041 is provided on the semi-circular cross-section at the other end of the semi-sealing body 11. A chamfer is provided at the edge of the T-shaped protrusion 1041. During installation, the sealing body 101 is slidably installed in the mounting seat 2. When the upper and lower halves of the sealing body 101 are butted, the T-shaped protrusion 1041 will be stuck in the T-shaped groove 104, and the two semi-circular sealing bodies 101 are extruded by the housing of the steam turbine, and the T-shaped protrusion 1041 is tightly installed in the T-shaped groove 104 to ensure that the T-shaped groove 104 and the T-shaped protrusion 1041 can be tightly combined, reducing the leakage of steam on the contact surface between the two semi-sealing bodies 11.

[0040] The specific working principle of this embodiment is as follows: When steam leaks, it will pass through the sealing body 1. The steam will pass through the gap between the sealing teeth 102 and the rotor shaft 3 and pass through the second throttling chamber 6 and the first throttling chamber 5 in sequence. Since the internal space of the first throttling chamber 5 is larger than that of the second throttling chamber 6, the air pressure of the steam will decrease after entering the large space from the small space, resulting in the steam flowing from the first throttling chamber 5 to the next second throttling chamber 6 from a low-pressure area to a high-pressure area, and the steam flow is blocked. The kinetic energy of the steam flowing outwards is reduced through multiple blockings to prevent the steam from leaking outwards. At the same time, the helical teeth 106 and the diagonal braces 105 can guide the flow direction of the steam, causing the steam to form a vortex, further blocking the steam flow and reducing the kinetic energy of the steam, achieving the sealing effect.

[0041] The above are all the preferred embodiments of the present invention, and the protection scope of the present invention is not limited hereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A honeycomb steam seal structure for a steam turbine, characterized in that: It comprises a steam seal body (1), a mounting seat (2) and a rotor shaft (3), The steam seal body (1) comprises a steam seal base (101), a steam seal tooth (102) and a shoulder (103), wherein the steam seal tooth (102) is fixedly arranged at one end of the steam seal base (101), and the shoulder (103) is fixedly arranged at one end of the steam seal base (101) away from the steam seal tooth (102); The steam seal teeth (102) comprise a first vertical tooth (1021), a second vertical tooth (1022) and an oblique tooth (106); one end of the first vertical tooth (1021) and the second vertical tooth (1022) are fixedly mounted on the steam seal base (101); the first vertical tooth (1021) and the second vertical tooth (1022) are arranged at intervals; and the oblique tooth (106) is fixedly arranged at the ends of the first vertical tooth (1021) and the second vertical tooth (1022); The mounting seat (2) is provided with a mounting groove, the shoulder (103) is mounted in the mounting groove, and the rotor shaft (3) is arranged in cooperation with the steam seal tooth (102).

2. The honeycomb steam seal structure of a steam turbine according to claim 1, characterized in that: The shoulder (103) is also provided with a spring groove (1031), and an annular spring (4) is installed inside the spring groove (1031).

3. The honeycomb steam seal structure of a steam turbine according to claim 1, characterized in that: The steam seal base (101) is two completely identical semi-annular semi-steam seal bodies (11), an I-shaped groove (104) is provided on the cross section of the end of the semi-steam seal body (11), and an I-shaped protrusion (1041) is provided on the cross section of the other end of the semi-steam seal body (11).

4. The honeycomb steam seal structure of a steam turbine according to claim 3, characterized in that: The I-shaped groove (104) and the I-shaped protrusion (1041) are arranged in coordination, the width of the I-shaped groove (104) is smaller than the width of the I-shaped protrusion (1041), and the edge of the I-shaped protrusion (1041) is also provided with a chamfer.

5. A honeycomb steam seal structure for a steam turbine according to any one of claims 1 to 4, characterized in that: The oblique teeth (106) are of a V-shaped structure, the middle portion of the oblique teeth (106) is fixedly connected to the ends of the first vertical teeth (1021) and the second vertical teeth (1022), and the opening of the oblique teeth (106) faces in a direction away from the steam seal base (101).

6. A honeycomb steam seal structure for a steam turbine according to any one of claims 1 to 4, characterized in that: A first throttling chamber (5) is formed between the first vertical tooth (1021), the second vertical tooth (1022), the helical tooth (106), the rotor shaft (3) and the steam seal base (101); a second throttling chamber (6) is formed between the helical tooth (106) and the rotor shaft (3); and the internal space of the first throttling chamber (5) is larger than the internal space of the second throttling chamber (6).

7. A honeycomb steam seal structure for a steam turbine according to any one of claims 1 to 4, characterized in that: An oblique support (105) is also provided at one end of the steam seal base (101) away from the shoulder (103); the oblique support (105) is a triangular structure; one surface of the oblique support (105) is fixedly arranged on the steam seal base (101); the first vertical tooth (1021) and the second vertical tooth (1022) are fixedly arranged on the oblique support (105); and the first vertical tooth (1021) and the second vertical tooth (1022) are fixedly arranged on the edge of the oblique support (105) away from the steam seal base (101).

8. A honeycomb steam seal structure for a steam turbine according to any one of claims 1 to 4, characterized in that: The height of the first vertical tooth (1021) is greater than the height of the second vertical tooth (1022).

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