Reverse-impingement counteracting steam seal device for steam turbine, and steam turbine

Abstract

A reverse-impingement counteracting steam seal device for a steam turbine, and a steam turbine. The reverse-impingement counteracting steam seal device for the steam turbine comprises a steam seal body. High teeth (13) are provided on an inner ring of the steam seal body in a radial direction, and a steam-seal channel is formed on the side of each high tooth (13) facing a low-pressure end (12); a main chamber is formed inside the steam-seal channel; an energy-dissipating chamber (15) is formed on the left side of the main chamber, an impingement counteracting chamber (16) is formed on the right side of the main chamber, and a chamber inlet (17) is formed at the bottom of the main chamber. A main steam flow enters the main chamber and then partially turns left to form a first steam branch flow to enter the energy-dissipating chamber (15), and partially turns right to form a second steam branch flow to enter the impingement counteracting chamber (16); the inner wall of the energy-dissipating chamber (15) is provided with an energy-dissipating structure, and the energy-dissipating chamber (15) comprises an energy-dissipating passage (151) enabling the first steam branch flow to be communicated with the main steam flow; and the inner wall of the impingement counteracting chamber (16) is smooth, the impingement counteracting chamber (16) comprises a reversely inclined impingement counteracting passage (161), and the second steam branch flow and the main steam flow form a reverse-direction steam flow impingement counteracting effect by means of the impingement counteracting passage (161). Such a reverse-impingement counteracting steam seal device for the steam turbine can effectively improve the sealing tightness of the steam seal, and on this basis, mitigate the problem of rotor shaft axial displacement.

Description

A turbine reverse butt type steam seal device and a turbine TECHNICAL FIELD

[0001] The present application relates to the technical field of turbine steam seal, and particularly relates to a turbine reverse butt type steam seal device and a turbine. BACKGROUND

[0002] With the acceleration of industrialization, as the core equipment in modern power and industrial production, the efficiency and reliability of the turbine have a direct impact on energy utilization and production cost. As a key component in the turbine, the steam seal mainly functions to reduce steam leakage between the moving and static parts, so as to improve the thermal efficiency and safety of the unit. Although the turbine steam seal technology has made certain progress, it still faces many challenges in practical application. Although the traditional steam seal structure, such as labyrinth seal, carbon seal and water seal, can reduce steam leakage to a certain extent, with the change of operating conditions and long-term operation of the equipment, the performance of these traditional steam seals gradually cannot meet the requirements of modern turbines for high efficiency and high reliability. Especially in high-temperature, high-pressure and high-power turbines, the traditional steam seal structure shows obvious limitations in sealing performance. In addition, during the operation of the turbine, when the high-pressure steam flows along the rotor surface to the low-pressure side, it will cause the shaft to move in series, which not only affects the tightness of the steam seal, but also seriously endangers the safety of the turbine operation. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, the present application provides a turbine reverse butt type steam seal device and a turbine, which can effectively improve the tightness of the steam seal and effectively reduce the problem of rotor shaft movement in series.

[0004] The first aspect of the present application provides a turbine reverse butt type steam seal device, which comprises a steam seal body; the steam seal body has an outer ring and an inner ring, the outer ring is used for connecting with the cylinder body of the turbine, and the inner ring is used for connecting with the rotor shaft; the steam seal body is formed with a high-pressure end and a low-pressure end at two ends respectively;

[0005] The inner ring of the steam seal body is provided with high teeth in the radial direction, and the high teeth are formed with a steam seal groove on one side facing the low-pressure end;

[0006] The steam seal groove is formed with a main chamber, an energy consumption chamber is formed on one side of the main chamber close to the high-pressure end, a butt chamber is formed on one side of the main chamber close to the low-pressure end, and a chamber inlet is formed at the bottom of the main chamber; after the steam main flow passes through the high teeth to generate a throttling expansion effect, the steam main flow is converted into a radial steam main flow through the rotor shaft boss, the radial steam main flow enters the main chamber through the chamber inlet and is divided into a first steam branch flow and a second steam branch flow, the first steam branch flow enters the energy consumption chamber in the direction of the high-pressure end, and the second steam branch flow enters the butt chamber in the direction of the low-pressure end.

[0007] In the first aspect of the present application, as a preferred embodiment, the inner wall of the energy dissipation chamber is formed with an energy dissipation structure for dissipating the energy of the first steam branch, and the energy dissipation chamber has an energy dissipation passage for communicating the first steam branch with the steam main stream; the counter-attack chamber has a smooth circular arc inner cavity, and the counter-attack chamber has a counter-attack passage which is reversely inclined, and the second steam branch passes through the counter-attack passage to form a counter-attack effect of steam flow in the opposite direction with the steam main stream.

[0008] In the first aspect of the present application, as a preferred embodiment, the energy dissipation chamber is a square inner cavity; the energy dissipation structure is a first perturbation small tooth, the root of the first perturbation small tooth is fixed with the inner wall of the energy dissipation chamber, and a plurality of first perturbation small teeth are linearly arrayed on the inner wall of the energy dissipation chamber; the first perturbation small tooth is a straight tooth, and / or an inclined side tooth.

[0009] In the first aspect of the present application, as a preferred embodiment, it further comprises a first flow guide and a second flow guide, and the first flow guide and the second flow guide are arranged in the gas seal groove; the first flow guide and the second flow guide are fixed with the gas seal body through a connecting bridge;

[0010] The outer side of the first flow guide forms the bottom wall of the energy dissipation chamber; the energy dissipation passage is formed between the gas seal body and the first flow guide; the chamber inlet is formed between the first flow guide and the second flow guide;

[0011] The counter-attack passage is formed between the second flow guide and the gas seal body, and the outer side of the second flow guide forms the bottom wall of the counter-attack chamber.

[0012] In the first aspect of the present application, as a preferred embodiment, an energy dissipation inlet flow guide tooth is arranged at the inlet of the energy dissipation passage, the root of the energy dissipation inlet flow guide tooth is fixed with the first flow guide, the energy dissipation inlet flow guide tooth forms a first flow guide angle a1 with the bottom wall of the energy dissipation chamber, the size of the first flow guide angle a1 is 30°≤a1≤90°, and the length l1 of the energy dissipation inlet flow guide tooth is 0mm

[0013] An energy dissipation outlet flow guide tooth is arranged at the outlet of the energy dissipation passage, and the root of the energy dissipation outlet flow guide tooth is fixed with the first flow guide.

[0014] In the first aspect of the present application, as a preferred embodiment, a counter-attack inlet flow guide tooth is arranged at the inlet of the counter-attack passage, the root of the counter-attack inlet flow guide tooth is fixed with the second flow guide, the counter-attack inlet flow guide tooth forms a second flow guide angle b1 with the bottom wall of the counter-attack chamber, the size of the second flow guide angle b1 is 90°≤b1≤120°, and the length l2 of the counter-attack inlet flow guide tooth is 0mm

[0015] The counter-punching chamber is formed with a tapering surface gradually approaching the counter-punching entrance guide tooth, so that the distance between the counter-punching chamber inner wall and the counter-punching entrance guide tooth gradually decreases, thereby forming a convergent jet structure at the counter-punching passage entrance.

[0016] In the first aspect of the present application, as a preferred embodiment, the counter-punching passage outlet is provided with a counter-punching outlet front guide tooth and a counter-punching outlet rear guide tooth;

[0017] The counter-punching outlet front guide tooth root is fixed with the second guide member, and the counter-punching outlet front guide tooth forms a first counter-punching included angle a2 with the axial direction;

[0018] The counter-punching outlet rear guide tooth root is fixed with the gas seal body, and the counter-punching outlet rear guide tooth forms a second counter-punching included angle b2 with the axial direction;

[0019] The distance between the counter-punching outlet front guide tooth and the counter-punching outlet rear guide tooth is a tooth spacing l3, and the tooth spacing l3 is 0.2mm < l3 < 0.8mm.

[0020] In the first aspect of the present application, as a preferred embodiment, the high tooth has a tooth body and a tooth tip, the tooth tip is inclined to the high pressure end direction, the acute angle formed by the tooth tip and the tooth body is a tooth tip oblique angle Omega, and the tooth tip oblique angle Omega is 0° < Omega < 90°; the tooth body is provided with a second disturbance small tooth on the side of the high pressure end.

[0021] In the first aspect of the present application, as a preferred embodiment, the gas seal body inner ring is axially provided with a plurality of high teeth, the side of the high tooth facing the low pressure end is provided with a low tooth, and the side of the high tooth facing the low pressure end is formed with a gas seal groove; a plurality of the gas seal grooves form a primary gas seal structure.

[0022] The second aspect of the present application provides a steam turbine, which comprises a steam turbine cylinder, a rotor shaft and a steam turbine reverse counter-punching gas seal device as claimed in any one of the first aspect of the present application;

[0023] The steam turbine cylinder is connected with the gas seal body outer ring of the steam turbine reverse counter-punching gas seal device in a matching manner; and the rotor shaft is arranged in the gas seal body inner ring of the steam turbine reverse counter-punching gas seal device.

[0024] Compared with the prior art, the present application has the following advantages:

[0025] The steam turbine reverse butt-charge gland device of the application is characterized in that a gland body is arranged, the inner ring of the gland body is provided with high teeth, two reverse expansion chambers are formed on the upper side of the side of the high teeth facing the low-pressure end along the axial direction, the left expansion chamber is an energy consumption chamber, the right expansion chamber is a butt-charge chamber, the inner wall of the left energy consumption chamber is fixedly provided with an energy consumption structure, and the inner wall of the right butt-charge chamber is smooth. The labyrinth path of the steam turbine reverse butt-charge gland device is designed as a surrounding path, the high-pressure steam main stream passes through the gap between the high teeth and the rotor shaft, the high teeth throttle the steam main stream, the space rapidly increases after the steam passes through the high teeth, so that the steam is depressurized and expanded; the steam main stream is converted into a radial steam main stream after passing through the rotor shaft boss, the radial steam main stream enters the main chamber through the chamber inlet, and the first steam branch stream and the second steam branch stream are formed on the opposite sides, respectively; the first steam branch stream enters the energy consumption chamber in the direction of the high-pressure end, a large number of vortexes and backflows are formed in the energy consumption structure arranged in the left energy consumption chamber, the first steam branch stream that consumes part of the energy flows out through the energy consumption channel and re-joins the steam main stream to reach the left side of the rotor shaft boss, the above flow state is repeated, and the kinetic energy dissipation of the steam flow is greatly improved; the second steam branch stream enters the butt-charge chamber in the direction of the low-pressure end, a large vortex is formed in the butt-charge chamber, another part of the second steam branch stream is butted to the top of the rotor shaft boss through the reverse inclined butt-charge channel, and the reverse butt-charge with the main stream is formed, so that the kinetic energy of the main stream is greatly consumed, and the sealing efficiency of the gland is improved; the steam passing through the butt-charge channel reduces the kinetic energy of the main stream, thereby reducing the shear force of the main stream on the large shaft, reducing the string movement of the large shaft, ensuring the stable operation of the rotor shaft and prolonging the service life of the equipment, and ensuring the safe operation of the steam turbine. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 is a structural schematic view of the steam turbine reverse butt-charge gland device of the application;

[0027] Fig. 2 is a local enlarged view of the A part of the steam turbine reverse butt-charge gland device of the application;

[0028] Fig. 3 is a local enlarged view of the B part of the steam turbine reverse butt-charge gland device of the application;

[0029] Fig. 4 is a structural schematic view of the steam turbine reverse butt-charge gland device of the application from another angle;

[0030] Fig. 5 is a structural schematic view of another embodiment of the steam turbine reverse butt-charge gland device of the application;

[0031] Fig. 6 is a vector diagram of the steam gland fluid domain of the steam turbine reverse butt-charge gland device of the application;

[0032] Fig. 7 is a vector diagram of the fluid domain in the steam gland channel of the steam turbine reverse butt-charge gland device of the application;

[0033] Fig. 8 is a vector diagram of the fluid domain in the energy dissipation chamber of the turbine reverse flush steam seal device of the present application;

[0034] Fig. 9 is a vector diagram of the fluid domain in the flush chamber of the turbine reverse flush steam seal device of the present application.

[0035] In the drawings: 10, steam seal main body; 11, high pressure end; 12, low pressure end; 13, high tooth; 131, tooth body; 132, tooth tip; 133, second perturbation pinion; 14, low tooth; 15, energy dissipation chamber; 151, energy dissipation passage; 152, first perturbation pinion; 16, flush chamber; 161, flush passage; 162, asymptotic surface; 17, chamber inlet; 20, first flow guide; 21, first connecting bridge; 22, energy dissipation chamber bottom wall; 23, energy dissipation inlet flow guide tooth; 24, energy dissipation outlet flow guide tooth; 30, second flow guide; 31, second connecting bridge; 32, flush chamber bottom wall; 33, flush inlet flow guide tooth; 34, flush outlet front flow guide tooth; 35, flush outlet rear flow guide tooth; 41, third connecting bridge; 90, rotor shaft; 91, rotor shaft boss. DETAILED DESCRIPTION

[0036] Hereinafter, the application will be further described with reference to the drawings and specific embodiments, it should be noted that the following described embodiments or technical features can be combined in any manner to form new embodiments, unless there is a conflict. Unless otherwise specified, the materials and equipment used in the embodiments can be purchased from the market. Examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application.

[0037] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0038] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "communication", "connection" should be understood in a broad sense, for example, it can be fixed connection, or connection through intermediate medium, or internal connection of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] The terms "first", "second", and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices. Embodiment 1

[0040] Please refer to figures 1-9, the present embodiment provides a steam turbine reverse hedge type steam seal device, including steam seal body 10;The steam seal body 10 has an outer ring and an inner ring, the outer ring is used for matching connection with the steam turbine cylinder, the inner ring is used for sleeving the rotor shaft 90 circumferentially, so as to fix the steam turbine reverse hedge type steam seal device between the steam turbine cylinder and the rotor shaft 90.

[0041] Steam seal body 10 two ends respectively form high pressure end 11 and low pressure end 12;The high pressure end 11 is the end close to the high pressure steam, and the low pressure end 12 is the end away from the high pressure steam;Steam seal body 10 has an axis, the outer side of the present embodiment is the side away from the axis of steam seal body 10, and the inner side is the side close to the axis of steam seal body 10.

[0042] Specifically, the inner ring of steam seal body 10 is provided with high tooth 13 radially, the high tooth 13 is formed with steam seal groove on the side of the low pressure end, the steam seal groove is formed with main chamber inside, the main chamber is formed with energy consumption chamber 15 close to the high pressure end 11 side, the main chamber is formed with hedge chamber 16 close to the low pressure end 12 side, and the main chamber is formed with chamber entrance 17 at the bottom.

[0043] The steam main flow passes through the high tooth 13 to generate throttling expansion effect, and is converted into radial steam main flow through the rotor shaft boss 91. Part of the radial steam main flow flows along the boss in the axial direction, and the part of the leakage flow meets the fluid in the counter chamber head-on on the boss. Part of the fluid enters the main chamber through the chamber inlet 17 to form a first steam branch flow and a second steam branch flow. The first steam branch flow enters the energy consumption chamber 15 in the direction of the high pressure end 11, and the second steam branch flow enters the counter chamber 16 in the direction of the low pressure end 12. In this embodiment, the radial steam main flow collides with the inner wall of the main chamber to form two reverse branch flows in the axial direction. Based on this, a flow dividing structure can be arranged on the inner wall of the main chamber. The flow dividing structure can be a flow dividing tooth. The opposite sides of the flow dividing tooth can be provided with guide surfaces inclined to the energy consumption chamber 15 and the counter chamber 16, respectively. The tip of the flow dividing tooth can be located inside the main chamber or can extend out of the chamber inlet 17 to pre-divide and guide the steam main flow. In this way, the precise control of the division ratio, division position and flow direction of the two branch flows is realized. Those skilled in the art can set the flow dividing structure based on this scheme during implementation, which belongs to the protection scope of the present application.

[0044] The inner wall of the energy consumption chamber 15 is formed with an energy consumption structure for consuming the kinetic energy of the first steam branch flow. The energy consumption chamber 15 has an energy consumption channel 151 that communicates the first steam branch flow with the steam main flow. The counter chamber 16 has a smooth inner wall. The counter chamber 16 has a counter channel 161 that is inclined to the high pressure end and forms a reverse counter flow with the main flow. The second steam branch flow passes through the counter channel 161 to form a reverse steam flow counter flow effect with the steam main flow.

[0045] The embodiment is characterized in that the steam seal body is provided, the inner ring of the steam seal body is provided with high teeth 13, two reverse expansion chambers are formed on the upper side of the side of the high teeth 13 towards the low pressure end along the axial direction, the left expansion chamber is an energy consumption chamber 15, the right expansion chamber is a hedging chamber 16, the inner wall of the left energy consumption chamber is fixedly installed with an energy consumption structure, and the inner wall of the right hedging chamber 16 is smooth. The labyrinth path of the steam turbine counterflow hedging steam seal is designed as a surrounding type path, the high pressure steam main flow passes through the gap between the high teeth 13 and the rotor shaft 90, the high teeth 13 throttle the steam main flow, and the space rapidly increases after the steam passes through the high teeth 13, so that the steam is depressurized and expanded; the steam main flow is converted into a radial steam main flow by the rotor shaft boss 91, and the radial steam main flow forms a first steam branch flow and a second steam branch flow on the opposite sides after entering the main chamber from the chamber inlet 17; the first steam branch flow enters the energy consumption chamber 15 in the direction of the high pressure end 11, a large number of vortexes and backflows are formed in the first steam branch flow in the energy consumption chamber 15 due to the energy consumption structure arranged in the left energy consumption chamber 15, the first steam branch flow with part of the kinetic energy consumed flows out through the energy consumption channel 151 and reflows into the steam main flow to the left side of the rotor shaft boss 91, the above flow state is repeated, and the kinetic energy dissipation of the steam flow is greatly improved; the second steam branch flow enters the hedging chamber 16 in the direction of the low pressure end 12, a part of the second steam branch flow forms a large vortex in the hedging chamber 16, and the other part of the second steam branch flow hits the top of the rotor shaft boss 91 through the reverse inclined hedging channel 161, so that the reverse hedging with the main flow is formed, the kinetic energy of the main flow is greatly consumed, and the sealing efficiency of the steam seal is improved; the steam passing through the hedging channel reduces the kinetic energy of the main flow, thereby reducing the shear force of the main flow on the large shaft, reducing the string motion of the large shaft, ensuring the stable operation of the rotor shaft 90 and prolonging the service life of the equipment, and ensuring the safe operation of the steam turbine.

[0046] Specifically, the energy consumption chamber 15 is a square inner cavity; the square inner cavity can accelerate the kinetic energy dissipation of the steam. The energy consumption structure is a first disturbance small tooth 152, the root of the first disturbance small tooth 152 is fixed to the inner wall of the energy consumption chamber 15, and a plurality of first disturbance small teeth 152 are linearly arranged on the inner wall of the energy consumption chamber 15; the first disturbance small tooth 152 can be a straight tooth, an inclined tooth or a combination of the straight tooth and the inclined tooth, the first disturbance small tooth 152 forms a local vortex in the first steam branch flow, and the kinetic energy dissipation of the steam is accelerated. The root of the tooth in the embodiment refers to the end of the tooth for fixation, that is, the end opposite to the free end of the tooth.

[0047] The main function of the energy consumption chamber 15 and the energy consumption structure arranged in the energy consumption chamber 15 in the embodiment is to consume the kinetic energy of the first steam branch flow; as for the shape of the inner cavity in the energy consumption chamber 15, in addition to the square inner cavity, other irregularly shaped inner cavities can also achieve the purpose of consuming the kinetic energy of the first steam branch flow. As for the energy consumption structure, the first perturbation small tooth 152 is preferred in the embodiment to consume kinetic energy, in addition, as a deformation of the first perturbation small tooth 152, other structures such as teeth, grooves, chambers and even labyrinth channels can also achieve the purpose of consuming the kinetic energy of the first steam branch flow, which belongs to the protection scope of the application.

[0048] The butt chamber 16 is a circular arc-shaped inner cavity, a smooth circular arc-shaped inner cavity, which can make the second steam branch flow lose less energy when changing direction, and can keep a large kinetic energy when the second steam branch flow collides with the steam main flow through the butt passage 161, so as to achieve more energy loss.

[0049] The first flow guide 20 and the second flow guide 30 are arranged in the steam seal groove in the embodiment, and the first flow guide 20 and the second flow guide 30 are fixed with the steam seal body through the connecting bridge.

[0050] Please refer to FIG. 4, in one of the embodiments of the connecting bridge, the connecting bridge includes the first connecting bridge 21 and the second connecting bridge 31; the first flow guide 20 is fixed with the steam seal body 10 through a plurality of first connecting bridges 21 on one side close to the high-pressure end 11, and is fixed with the second flow guide 30 through a plurality of second connecting bridges 31 on the other side; the outer side of the first flow guide 20 forms the energy consumption chamber bottom wall 22; the energy consumption passage 151 is formed in the area surrounded by the steam seal body 10, the first flow guide 20 and the adjacent two first connecting bridges 21; the chamber inlet 17 is formed in the area surrounded by the first flow guide 20, the second flow guide 30 and the adjacent two second connecting bridges 31; the chamber inlet 17 in the embodiment is a straight inlet, in other embodiments, the chamber inlet 17 can also be arranged as a curved path inlet or other special-shaped inlet, as long as the steam main flow can pass through, which belongs to the protection scope of the application.

[0051] The second flow guide 30 is fixed with the first flow guide 20 on one side close to the high-pressure end 11, and is arranged close to the steam seal body 10 on the other side; the butt passage 161 is formed between the second flow guide 30 and the steam seal body 10, and the outer side of the second flow guide 30 forms the butt chamber bottom wall 32.

[0052] The first connecting bridge 21 and the second connecting bridge 31 are fixed to the inner ring of the steam seal body in a ring array mode to ensure that the rotor shaft 90 is subjected to uniform radial force during operation of the device. In this way, the stability of the connection between the first flow guide 20 and the second flow guide 30 is ensured, the continuity and integrity of the counter-attack channel 161 are maintained, and a complete steam seal barrier is formed.

[0053] As another embodiment of the connecting bridge, the connecting bridge of the present embodiment only includes a third connecting bridge 41. One end of the third connecting bridge 41 is fixed to the first flow guide 20, and the other end of the third connecting bridge 41 is fixed to the second flow guide 30. The outer side of the third connecting bridge 41 is fixed to the steam seal body 10. A plurality of third connecting bridges 41 are fixed to the inside of the steam seal body 10 in a ring array mode. In this way, the connection between the first flow guide 20, the second flow guide 30 and the steam seal body 10 is achieved, and the continuity of the counter-attack channel 161 and the energy consumption channel 151 is maintained at the same time.

[0054] Further, the energy consumption inlet flow guide tooth 23 is arranged at the inlet of the energy consumption channel 151. The root of the energy consumption inlet flow guide tooth 23 is fixed to the first flow guide 20. The energy consumption inlet flow guide tooth 23 forms a first flow guide angle a1 with the bottom wall 22 of the energy consumption chamber. The size of the first flow guide angle a1 is preferably 30°≤a1≤90°. The length l1 of the energy consumption inlet flow guide tooth 23 is preferably 0mm

[0055] The counter-attack inlet flow guide tooth 33 is arranged at the inlet of the counter-attack channel 161. The root of the counter-attack inlet flow guide tooth 33 is fixed to the second flow guide 30. The counter-attack inlet flow guide tooth 33 forms a second flow guide angle b1 with the bottom wall 32 of the counter-attack chamber. The size of the second flow guide angle b1 is 90°≤b1≤120°. The length l2 of the counter-attack inlet flow guide tooth is 0mm

[0056] As the deformation of the energy-consuming inlet guide vane 23, the energy-consuming outlet guide vane 24 and the opposite-inlet guide vane 33, the skilled in the art can make adaptive adjustment to the specific length, angle and number according to the actual situation, and the above adjustment is within the protection scope of the embodiment.

[0057] The opposite-inlet guide vane 33 is gradually close to the opposite-inlet guide vane 33, so that the distance between the opposite-inlet guide vane 33 and the inner wall of the opposite-inlet guide vane 33 gradually reduces, thereby forming a convergent jet structure at the inlet of the opposite-inlet guide vane 33, and the second steam branch flow accelerates to flow to the opposite-inlet guide vane 33 under the action of the convergent jet structure, thereby improving the reverse opposite-inlet ability.

[0058] Further, the opposite-inlet guide vane 33 is gradually close to the opposite-inlet guide vane 33, so that the distance between the opposite-inlet guide vane 33 and the inner wall of the opposite-inlet guide vane 33 gradually reduces, thereby forming a convergent jet structure at the inlet of the opposite-inlet guide vane 33, and the second steam branch flow accelerates to flow to the opposite-inlet guide vane 33 under the action of the convergent jet structure, thereby improving the reverse opposite-inlet ability.

[0059] The opposite-inlet guide vane 33 is gradually close to the opposite-inlet guide vane 33, so that the distance between the opposite-inlet guide vane 33 and the inner wall of the opposite-inlet guide vane 33 gradually reduces, thereby forming a convergent jet structure at the inlet of the opposite-inlet guide vane 33, and the second steam branch flow accelerates to flow to the opposite-inlet guide vane 33 under the action of the convergent jet structure, thereby improving the reverse opposite-inlet ability.

[0060] The opposite-inlet guide vane 33 is gradually close to the opposite-inlet guide vane 33, so that the distance between the opposite-inlet guide vane 33 and the inner wall of the opposite-inlet guide vane 33 gradually reduces, thereby forming a convergent jet structure at the inlet of the opposite-inlet guide vane 33, and the second steam branch flow accelerates to flow to the opposite-inlet guide vane 33 under the action of the convergent jet structure, thereby improving the reverse opposite-inlet ability.

[0061] The distance between the opposite-inlet guide vane 33 and the opposite-inlet guide vane 33 is the tooth spacing l3, and the tooth spacing l3 is 0.2mm

[0062] Since the angles of the front and rear guide vanes of the opposite-inlet guide vane 33 are 50° to 70°, the narrow gap formed between the two can form an airflow opposite to the direction of the steam main flow in the axial direction, thereby playing a role of opposite-inlet, greatly reducing the kinetic energy of the leaked steam, and achieving a good sealing effect.

[0063] Further, the high tooth 13 has a tooth body 131 and a tooth tip 132, the tooth body 131 is fixed at the root of the steam seal body 10, the tooth tip 132 is formed at the end of the tooth body 131, the tooth tip 132 is inclined to the high pressure end 11, the acute angle formed by the tooth tip 132 and the tooth body 131 is the oblique angle Ω of the tooth tip 132, the size of the oblique angle Ω of the tooth tip 132 is: 0°≤Ω≤90°, preferably, 20°≤Ω≤35°; The tooth body 131 is provided with a second disturbance small tooth 133 on the side of the high pressure end 11. The obliquely folded tooth tip 132 at the end of the high tooth 13 helps to further hinder the flow of steam, and the second disturbance small tooth 133 arranged on the side of the high tooth 13 can form a local vortex flow, accelerate the kinetic energy dissipation of the steam, and effectively improve the steam sealing effect.

[0064] The high tooth 13 is provided with a low tooth 14 on one side, the low tooth 14 is preferably an inclined tooth inclined to the high pressure end, and the inclined low tooth 14 helps to form a swirling vortex flow in front of the rotor shaft boss and the low tooth 14 when the steam main flow passes, and plays a better interception and energy dissipation role; The low tooth 14 is arranged on the side of the high tooth 13 facing the low pressure end 12; Further, the gas seal groove is arranged between the high tooth 13 and the low tooth 14.

[0065] The inner circle of the steam seal body 10 of the embodiment is provided with a plurality of high teeth 13, and the plurality of high teeth 13 are arranged in sequence along the axial direction of the steam seal body 10; The side of the high tooth 13 facing the low pressure end 12 is provided with the low tooth 14, and the high tooth 13 and the low tooth 14 form the gas seal groove; A plurality of gas seal grooves form a one-stage steam seal structure. Through a plurality of gas seal grooves, each gas seal groove can further reduce steam leakage; Each energy dissipation chamber 15 can consume the energy of the steam, and each collision chamber 16 can increase the flow resistance of the steam, thereby reducing the possibility of leakage, and through the joint action of a plurality of gas seal grooves, the shaft stringing is reduced, the shear force of the main flow on the large shaft is reduced, and the stringing phenomenon is greatly reduced.

[0066] Based on the above structure, please refer to the vector diagram of the steam seal fluid domain shown in Figures 6-7; high-pressure steam flows from the high-tooth 13 tooth tip 132 along the rotor shaft 90 in the axial direction, after reaching the left side of the rotor shoulder, the direction of the steam main flow changes by 90° to convert to radial flow, a part of the steam flows in the axial direction from the gap between the steam seal main body 10 and the rotor shaft 90, and a part of the steam continues to flow upwards after reaching the chamber inlet 17. When the steam enters the main chamber, it flows in two directions, left and right, along the axial direction. Please refer to the vector diagram of the fluid domain in the energy-consuming chamber 15 shown in Figure 8; the steam flowing to the left forms a first steam branch, which first forms a large vortex on the right side of the energy-consuming chamber 15 under the action of the energy-consuming inlet flow guide tooth 23, a part of the first steam branch forms a small range of local vortex under the action of the first perturbation tooth 152 inside the energy-consuming chamber 15, which plays a role in kinetic energy dissipation and consumes part of the energy of the first steam branch. The first steam branch flows out under the guidance of the energy-consuming outlet flow guide tooth 24 at the bottom of the energy-consuming chamber 15, re-enters the steam main flow to the left side of the rotor shaft boss 91, and repeats the above flow state. Please refer to the vector diagram of the fluid domain in the counter-attack chamber 16 shown in Figure 9; the steam flowing to the right forms a second steam branch, a part of the second steam branch forms a larger vortex on the left side of the counter-attack inlet flow guide tooth 33 at the upper part of the counter-attack chamber 16, and another part of the second steam branch enters the counter-attack chamber 16, and then flows to the top of the rotor shaft boss 91 from the narrow counter-attack channel 161 formed between the counter-attack outlet front flow guide tooth 34 and the counter-attack outlet rear flow guide tooth. Since the first counter-attack angle α2 and the second counter-attack angle β2 are both 50°-70°, they are opposite to the direction of the leaked steam main flow in the axial direction, which plays a role in counter-attack, on the one hand, it reduces the kinetic energy of the leaked steam, on the other hand, it plays a role in plugging, thereby greatly enhancing the tightness of the steam seal. Example 2

[0067] The present embodiment provides a steam turbine based on example 1.

[0068] The steam turbine of the present embodiment comprises a steam turbine cylinder, a rotor shaft 90, and a steam turbine reverse counter-attack type steam seal device as described in example 1.

[0069] The steam turbine cylinder is connected with the outer ring of the steam seal main body 10 of the steam turbine reverse counter-attack type steam seal device; the rotor shaft 90 is arranged in the inner ring of the steam seal main body 10 of the steam turbine reverse counter-attack type steam sealing device.

[0070] The embodiment forms local vortex and accelerates kinetic energy dissipation of steam by setting disturbance pinion on the left side of the high tooth 13 and inside the left chamber. In addition, the square structure of the energy dissipation chamber 15 further accelerates the kinetic energy dissipation of steam. After the high-pressure steam enters the chamber inlet 17 from the high tooth 13, part of the steam enters the energy dissipation chamber 15 to the left under the flow guiding effect of the energy dissipation inlet flow guide 23, and then moves downward to re-enter the chamber inlet 17 under the driving of the steam mainstream, thereby circulating, which greatly dissipates the kinetic energy of part of the steam. Another part of the steam enters the opposing chamber 16 to the right, accelerates downward flow under the action of the converging jet structure, and due to the angles of the first opposing angle α2 and the second opposing angle β2 being 50°-70°, the steam at the outlet of the opposing channel 161 and the leakage steam are oppositely opposed to a certain extent, which greatly reduces the kinetic energy of the leakage steam, and achieves a good sealing effect. More importantly, the steam flowing out of the opposing chamber 16 opposingly collides with the leakage flow, which reduces the shear force of the leakage flow, thereby reducing the stringing of the large shaft; secondly, the steam mainstream is divided by the oppositely arranged energy dissipation chamber 15 and the opposing chamber 16, and after entering the two opposite directions, two oppositely directed steam branch flows are formed, one of which towards the high-pressure end 11 is greatly dissipated in kinetic energy under the action of the square chamber and the disturbance pinion, and the other oppositely directed steam branch flow is accumulated in kinetic energy to form an opposing steam flow under the action of the smooth arc-shaped inner cavity and the converging jet structure, which respectively processes and adjusts the axial stress generated by the two on the rotor shaft 90 to a certain extent, balances the axial force received by the rotor shaft 90, reduces the stringing of the large shaft, ensures the stable operation of the rotor shaft 90 and prolongs the service life of the equipment, and ensures the safe operation of the steam turbine.

[0071] The above-mentioned embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and replacements made by those skilled in the art on the basis of the present application are within the scope of protection of the present application.

Claims

1. A reverse flush steam seal device for a steam turbine, characterized by, The steam seal body has an outer ring and an inner ring, the outer ring is used for matching connection with a steam turbine cylinder, and the inner ring is used for matching with a rotor shaft; The inner ring of the steam seal body is radially provided with a high tooth, and the high tooth is formed with a gas seal groove on one side facing the low pressure end; The gas seal groove is formed with a main chamber, the main chamber is formed with an energy consumption chamber on one side close to the high pressure end, the main chamber is formed with a counter-attack chamber on one side close to the low pressure end, and the main chamber is formed with a chamber inlet at the bottom; After the steam main flow passes through the high tooth to generate a throttling expansion effect, the steam main flow is converted into a radial steam main flow through the rotor shaft boss, the radial steam main flow enters the main chamber through the chamber inlet, and then the radial steam main flow is divided into a first steam branch flow and a second steam branch flow, the first steam branch flow enters the energy consumption chamber in the direction of the high pressure end, and the second steam branch flow enters the counter-attack chamber in the direction of the low pressure end.

2. A reverse-lap type steam seal device for a steam turbine according to claim 1, characterized by The inner wall of the energy consumption chamber is formed with an energy consumption structure, the energy consumption structure is used for consuming the kinetic energy of the first steam branch flow, the energy consumption chamber has an energy consumption channel, and the energy consumption channel communicates the first steam branch flow with the steam main flow; the counter-attack chamber has a smooth circular arc inner cavity, the counter-attack chamber has a counter-attack channel, the counter-attack channel is reversely inclined, and the second steam branch flow passes through the counter-attack channel to form a counter-attack effect of steam flow in the opposite direction with the steam main flow.

3. A reverse labyrinth seal for a steam turbine as claimed in claim 2, wherein The energy consumption chamber is a square inner cavity; the energy consumption structure is a first disturbance small tooth, the root of the first disturbance small tooth is fixed with the inner wall of the energy consumption chamber, and a plurality of first disturbance small teeth are linearly arranged on the inner wall of the energy consumption chamber; the first disturbance small tooth is a straight tooth, and / or an inclined side tooth.

4. A reverse labyrinth seal for a steam turbine as set forth in claim 2 wherein, Further comprising a first flow guide and a second flow guide, the first flow guide and the second flow guide are arranged in the gas seal groove; the first flow guide and the second flow guide are fixed with the steam seal body through a connecting bridge; The outer side of the first flow guide forms the bottom wall of the energy consumption chamber; the energy consumption channel is formed between the steam seal body and the first flow guide; the chamber inlet is formed between the first flow guide and the second flow guide; The counter-attack channel is formed between the second flow guide and the steam seal body, and the outer side of the second flow guide forms the bottom wall of the counter-attack chamber.

5. A reverse labyrinth seal for a steam turbine as claimed in claim 4, wherein The energy consumption inlet flow guide tooth is fixed with the first flow guide at the root, the energy consumption inlet flow guide tooth forms a first flow guide angle a1 with the bottom wall of the energy consumption chamber, the size of the first flow guide angle a1 is 30°≤a1≤90°, and the length l1 of the energy consumption inlet flow guide tooth is 0mm The energy consumption outlet flow guide tooth is fixed with the first flow guide at the root.

6. A reverse labyrinth seal for a steam turbine as set forth in claim 4 wherein, The counter-attack inlet flow guide tooth is fixed with the second flow guide at the root, the counter-attack inlet flow guide tooth forms a second flow guide angle b1 with the bottom wall of the counter-attack chamber, the size of the second flow guide angle b1 is 90°≤b1≤120°, and the length l2 of the counter-attack inlet flow guide tooth is 0mm The counter-punching chamber is formed with a tapering surface gradually approaching the counter-punching entrance guide tooth, so that the distance between the counter-punching chamber inner wall and the counter-punching entrance guide tooth gradually decreases, thereby forming a converging jet structure at the counter-punching passage entrance.

7. A reverse labyrinth seal for a steam turbine as defined in claim 4 wherein, The counter-punching passage outlet is provided with a counter-punching outlet front guide tooth and a counter-punching outlet rear guide tooth; The counter-punching outlet front guide tooth root is fixed with the second guide member, and the counter-punching outlet front guide tooth forms a first counter-punching included angle α2 with the axial direction; The counter-punching outlet rear guide tooth root is fixed with the gas seal body, and the counter-punching outlet rear guide tooth forms a second counter-punching included angle β2 with the axial direction; The distance between the counter-punching outlet front guide tooth and the counter-punching outlet rear guide tooth is a tooth spacing l3, and the tooth spacing l3 is 0.2mm < l3 ≤ 0.8mm.

8. A reverse labyrinth seal for a steam turbine as defined in claim 1 wherein, The high tooth has a tooth body and a tooth tip, the tooth body root is fixed with the gas seal body, the other end is connected with the tooth tip, the tooth tip is inclined to the high pressure end direction, the acute angle formed by the tooth tip and the tooth body is a tooth tip oblique angle Ω, and the tooth tip oblique angle Ω is 0° ≤ Ω ≤ 90°; the tooth body is provided with a second disturbance small tooth on the side of the high pressure end.

9. A reverse labyrinth seal for a steam turbine as defined in claim 1 wherein, The high tooth is provided with a low tooth on the side of the low pressure end, and the high tooth is formed with a gas seal groove on the side of the low pressure end; a plurality of the gas seal grooves form a primary gas seal structure.

10. A steam turbine, characterized by The steam turbine cylinder, the rotor shaft and the steam turbine reverse counter-punching gas seal device according to any one of claims 1-9 are included. The steam turbine cylinder is connected with the outer ring of the gas seal body of the steam turbine reverse counter-punching gas seal device, and the rotor shaft is arranged in the inner ring of the gas seal body of the steam turbine reverse counter-punching gas seal device.

Images