Reverse hedging type steam seal device of steam turbine and steam turbine

Abstract

The reverse hedging type steam seal device of the steam turbine comprises a steam seal body, high teeth and low teeth are arranged on an inner ring of the steam seal body in the radial direction, and an air seal groove channel is formed in the side, facing the low-pressure end, of the high teeth. A main cavity is formed in the air seal channel, an energy consumption cavity is formed in the left side of the main cavity, a hedging cavity is formed in the right side, and a cavity inlet is formed in the bottom. After entering the main chamber, the steam main flow leftwards forms a first steam branch flow to enter the energy consumption chamber, and rightwards forms a second steam branch flow to enter the hedging chamber; an energy consumption structure is arranged on the inner wall of the energy consumption chamber, and the energy consumption chamber is provided with an energy consumption channel for communicating the first steam branch flow with the steam main flow; the inner wall of the hedging chamber is smooth, the hedging chamber is provided with a reversely inclined hedging channel, and the second steam branch flow and the steam main flow form a reverse steam flow hedging effect through the hedging channel. According to the utility model, the leakproofness of the steam seal can be effectively improved, and the problem of movement of the rotor shaft is reduced on the basis.

Description

Technical Field

[0001] This utility model relates to the field of steam turbine sealing technology, and in particular to a reverse counter-impact steam sealing device for a steam turbine and a steam turbine. Background Technology

[0002] With the acceleration of industrialization, steam turbines, as core equipment in modern power and industrial production, have a direct impact on energy utilization and production costs due to their efficiency and reliability. Steam seals, as a key component of steam turbines, primarily function to reduce steam leakage between moving and stationary parts, thereby improving the unit's thermal efficiency and safety. Although steam seal technology has made some progress, it still faces many challenges in practical applications. Traditional steam seal structures, such as curved diameter seals, carbon seals, and water seals, can reduce steam leakage to some extent, but with changes in operating conditions and long-term operation, the performance of these traditional seals gradually fails to meet the high efficiency and high reliability requirements of modern steam turbines. In particular, in high-temperature, high-pressure, and high-power steam turbines, traditional seal structures exhibit significant limitations in sealing performance. Furthermore, during turbine operation, the flow of high-pressure steam along the rotor surface towards the low-pressure side causes cross-rotation of the main shaft, affecting not only the tightness of the steam seals but also seriously jeopardizing the turbine's operational safety. Utility Model Content

[0003] In order to overcome the shortcomings of the prior art, this utility model provides a steam turbine reverse counter-impact steam seal device and a steam turbine, which can effectively improve the tightness of the steam seal and, on this basis, effectively reduce the problem of rotor shaft cross-movement.

[0004] The first aspect of this utility model provides a reverse-flush steam seal device for a steam turbine, comprising a steam seal body; the steam seal body has an outer ring and an inner ring, the outer ring being used to connect with the steam turbine cylinder block, and the inner ring being used to connect with the rotor shaft; the two ends of the steam seal body respectively form a high-pressure end and a low-pressure end;

[0005] The inner ring of the gas seal body is radially provided with high teeth, and a gas seal groove is formed on the side of the high teeth facing the low pressure end;

[0006] A main chamber is formed within the gas seal channel. An energy-consuming chamber is formed on the side of the main chamber near the high-pressure end, and a counter-current chamber is formed on the side of the main chamber near the low-pressure end. A chamber inlet is formed at the bottom of the main chamber. After the main steam stream undergoes a throttling expansion effect through the high-tooth structure, it is converted into a radial main steam stream after passing through the rotor shaft boss. The radial main steam stream enters the main chamber through the chamber inlet and then splits into a first steam branch and a second steam branch. The first steam branch enters the energy-consuming chamber in the direction of the high-pressure end, and the second steam branch enters the counter-current chamber in the direction of the low-pressure end.

[0007] In the first aspect of the utility model, as a kind of preferred embodiment, the energy dissipation chamber inner wall is formed with energy dissipation structure, the energy dissipation structure is used to consume the kinetic energy of first steam branch stream, the energy dissipation chamber has energy dissipation passage, and the energy dissipation passage is communicated with first steam branch stream and steam mainstream.

[0008] In the first aspect of the utility model, as a kind of preferred embodiment, the energy dissipation chamber inner wall is formed with energy dissipation structure, the energy dissipation structure is used to consume the kinetic energy of first steam branch stream, the energy dissipation chamber has energy dissipation passage, and the energy dissipation passage is communicated with first steam branch stream and steam mainstream.

[0009] In the first aspect of the utility model, as a kind of preferred embodiment, the energy dissipation chamber inner wall is formed with energy dissipation structure, the energy dissipation structure is used to consume the kinetic energy of first steam branch stream, the energy dissipation chamber has energy dissipation passage, and the energy dissipation passage is communicated with first steam branch stream and steam mainstream.

[0010] In the first aspect of the utility model, as a kind of preferred embodiment, the energy dissipation chamber inner wall is formed with energy dissipation structure, the energy dissipation structure is used to consume the kinetic energy of first steam branch stream, the energy dissipation chamber has energy dissipation passage, and the energy dissipation passage is communicated with first steam branch stream and steam mainstream.

[0011] In the first aspect of the utility model, as a kind of preferred embodiment, the energy dissipation chamber inner wall is formed with energy dissipation structure, the energy dissipation structure is used to consume the kinetic energy of first steam branch stream, the energy dissipation chamber has energy dissipation passage, and the energy dissipation passage is communicated with first steam branch stream and steam mainstream.

[0012] The energy dissipation passage outlet is provided with energy dissipation outlet flow guide tooth, and the root of the energy dissipation outlet flow guide tooth is fixed with the first flow guide piece.

[0013] In the first aspect of the utility model, as a kind of preferred embodiment, the energy dissipation chamber inner wall is formed with energy dissipation structure, the energy dissipation structure is used to consume the kinetic energy of first steam branch stream, the energy dissipation chamber has energy dissipation passage, and the energy dissipation passage is communicated with first steam branch stream and steam mainstream.

[0014] The energy dissipation passage outlet is provided with energy dissipation outlet flow guide tooth, and the root of the energy dissipation outlet flow guide tooth is fixed with the first flow guide piece.

[0015] The distance between the front flow guide tooth of the opposite chamber outlet and the rear flow guide tooth of the opposite chamber outlet is tooth spacing l3, and the size of the tooth spacing l3 is 0.2mm < l3 ≤0.8mm.

[0016] In the first aspect of the utility model, as a kind of preferred embodiment, the high tooth has tooth body and tooth tip, the tooth body root is fixed with steam seal body, the other end is connected with tooth tip, the tooth tip is inclined to high pressure end direction;Second perturbation small tooth is equipped with in the tooth body side towards high pressure end.

[0017] In the first aspect of the utility model, as a kind of preferred embodiment, the steam seal body inner ring is axially provided with several high teeth, the side of high tooth towards low pressure end is provided with low tooth, and the high tooth and low tooth are formed with gas seal channel.

[0018] The second aspect of the utility model provides a steam turbine, including steam turbine cylinder, rotor shaft and the steam turbine reverse hedge type steam seal device as any one of the first aspect of the utility model;

[0019] The steam turbine cylinder is connected with the steam seal body outer ring of the steam turbine reverse hedge type steam seal device;The rotor shaft is arranged in the steam seal body inner ring of the steam turbine reverse hedge type steam seal device.

[0020] Compared with prior art, the utility model has the beneficial effects that:

[0021] The steam turbine reverse opposite-punching type gland sealing device has the advantages that the labyrinth path of the steam turbine reverse flow and opposite-punching type gland sealing device is designed as a surrounding type path, the high-pressure steam main flow passes through the gap between the high tooth and the rotor shaft, the high tooth throttles the steam main flow, and the space rapidly increases after the steam passes through the high tooth, so that the steam is depressurized and expanded; the steam main flow is converted into a radial steam main flow after passing through the rotor shaft boss, and the radial steam main flow forms first steam branch flow and second steam branch flow after entering the main chamber through the chamber inlet and moving to the opposite sides; the first steam branch flow 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 chamber due to the energy consumption structure arranged in the left energy consumption chamber, the first steam branch flow that consumes part of energy flows out through the energy consumption channel and re-joins the steam main flow to reach the left side of the rotor shaft boss, the above flow state is repeated, the kinetic energy dissipation of the steam flow is greatly improved; the second steam branch flow enters the opposite-punching chamber in the direction of the low-pressure end, a large vortex is formed in the opposite-punching chamber, another part of the second steam branch flow is punched to the top of the rotor shaft boss through the opposite-punching channel, the opposite-punching channel is opposite to the main flow, the kinetic energy of the main flow is greatly consumed, and the sealing efficiency of the gland is improved; the steam passing through the opposite-punching channel reduces the kinetic energy of the main flow, thereby reducing the shearing force of the main flow 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

[0022] Figure 1 It is a structure schematic view of the steam turbine reverse opposite-punching type gland sealing device of the utility model;

[0023] Figure 2 It is a partial enlarged view of A part of the steam turbine reverse opposite-punching type gland sealing device of the utility model;

[0024] Figure 3 It is a partial enlarged view of B part of the steam turbine reverse opposite-punching type gland sealing device of the utility model;

[0025] Figure 4 It is a structure schematic view of another angle of the steam turbine reverse opposite-punching type gland sealing device of the utility model;

[0026] Figure 5 It is a structure schematic view of another embodiment of the steam turbine reverse opposite-punching type gland sealing device of the utility model;

[0027] Figure 6 It is a vector diagram of the steam sealing fluid domain of the steam turbine reverse opposite-punching type gland sealing device of the utility model;

[0028] Figure 7 Vector diagram of fluid domain in the steam seal groove of the reverse opposed steam seal device of the steam turbine of the utility model;

[0029] Figure 8 Vector diagram of fluid domain in the energy consumption chamber of the reverse opposed steam seal device of the steam turbine of the utility model;

[0030] Figure 9 Vector diagram of fluid domain in the opposed chamber of the reverse opposed steam seal device of the steam turbine of the utility model.

[0031] In the figure: 10, steam seal main body; 11, high pressure end; 12, low pressure end; 13, high tooth; 131, tooth body; 132, tooth tip; 133, second disturbance pinion; 14, low tooth; 15, energy consumption chamber; 151, energy consumption passage; 152, first disturbance pinion; 16, opposed chamber; 161, opposed passage; 162, asymptotic surface; 17, chamber inlet; 20, first flow guide; 21, first connecting bridge; 22, energy consumption chamber bottom wall; 23, energy consumption inlet flow guide tooth; 24, energy consumption outlet flow guide tooth; 30, second flow guide; 31, second connecting bridge; 32, opposed chamber bottom wall; 33, opposed inlet flow guide tooth; 34, opposed outlet front flow guide tooth; 35, opposed outlet rear flow guide tooth; 41, third connecting bridge; 90, rotor shaft; 91, rotor shaft boss. DETAILED DESCRIPTION

[0032] In the following, the utility model is further described in combination with the drawings and the specific implementation, and it should be noted that the following described embodiments or the technical features between the embodiments can be combined to form new embodiments without conflict. Except for the special description, the materials and equipment used in the embodiments can be purchased from the market. The examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the application, and cannot be understood as a limitation on the application.

[0033] In the description of the 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 for the convenience of describing the application and simplifying 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 a limitation on the application. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0034] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "communicated", "connected" should be understood in a broad sense, for example, it can be fixedly connected, or connected through an intermediate medium, or the internal connection of two elements or the 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.

[0035] 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 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 necessarily limit to those clearly listed steps or units, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0036] Embodiment 1:

[0037] Please refer to Figures 1-9 The present embodiment provides a reverse hedge type steam seal device of steam turbine, including steam seal body 10; the steam seal body 10 has outer ring and inner ring, the outer ring is used for matching connection with steam turbine cylinder, the inner ring is used for setting in the circumferential direction of rotor shaft 90, so as to fix the reverse hedge type steam seal device of steam turbine between steam turbine cylinder and rotor shaft 90.

[0038] Steam seal body 10 two ends form high pressure end 11 and low pressure end 12 respectively; high pressure end 11 is the end close to high pressure steam, and low pressure end 12 is the end away from 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.

[0039] Specifically, the inner ring of steam seal body 10 is provided with high tooth 13 in the radial direction, the high tooth 13 is formed with gas seal groove towards the side of the low pressure end, the gas seal groove is formed with main chamber inside, the main chamber is formed with energy consumption chamber 15 close to the side of high pressure end 11, the main chamber is formed with hedge chamber 16 close to the side of low pressure end 12, and the main chamber is formed with chamber inlet 17 at the bottom;

[0040] The steam main flow passes through the high tooth 13 to generate throttling expansion effect, and is converted into a radial steam main flow through the rotor shaft boss 91. A part of the radial steam main flow flows axially along the boss, and the part of the leakage flow meets the fluid in the counter-attack chamber on the boss; a part of the first steam branch flow and the second steam branch flow are formed after entering the main chamber through the chamber inlet 17. 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-attack 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, and then two reverse branch flows are formed along the axial direction. Based on this, a flow dividing structure can also 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-attack 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. The person skilled in the art can set the flow dividing structure based on the scheme during implementation, which belongs to the protection scope of the utility model.

[0041] 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 for connecting the first steam branch flow and the steam main flow. The counter-attack chamber 16 has a smooth inner wall. The counter-attack chamber 16 has a counter-attack channel 161 inclined to the high pressure end, which forms a reverse counter-attack with the main flow. The second steam branch flow passes through the counter-attack channel 161 to form a reverse steam flow counter-attack effect with the steam main flow.

[0042] 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 facing 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. In the embodiment, the labyrinth path of the counterflow and hedging steam seal of the steam turbine is designed as a surrounding path, the high-pressure steam main stream passes through the gap between the high teeth 13 and the rotor shaft 90, the high teeth 13 throttle the steam main stream, 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 stream is converted into a radial steam main stream after passing through the rotor shaft boss 91, and the radial steam main stream forms a first steam branch stream and a second steam branch stream on the opposite sides after entering the main chamber through the chamber inlet 17; the first steam branch stream 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 energy consumption chamber 15 due to the energy consumption structure arranged in the left energy consumption chamber 15, the first steam branch stream that consumes part of the kinetic energy flows out through the energy consumption channel 151 and reenters the steam main stream to reach the left side of the rotor shaft boss 91, and the above flow state is repeated, so that the kinetic energy dissipation of the steam flow is greatly improved; the second steam branch stream enters the hedging chamber 16 in the direction of the low-pressure end 12, a part of the second steam branch stream forms a large vortex in the hedging chamber 16, and the other part of the second steam branch stream hits the top of the rotor shaft boss 91 through the reversely inclined hedging channel 161, so that the main stream is formed in the reverse hedging, the kinetic energy of the main stream 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 stream, thereby reducing the shear force of the main stream 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.

[0043] 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, so that the first steam branch stream forms a local vortex through the first disturbance small tooth 152, and the kinetic energy dissipation of the steam is accelerated. In the embodiment, the root of the tooth refers to the end of the tooth for fixation, that is, the end opposite to the free end of the tooth.

[0044] 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 the 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 utility model.

[0045] The butt chamber 16 is a circular arc-shaped inner cavity, and the smooth circular arc-shaped inner cavity 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.

[0046] The first flow guide 20 and the second flow guide 30 are arranged in the steam seal groove in the embodiment.

[0047] Please refer to Figure 4 In one of the embodiments of the connecting bridge, the connecting bridge includes a first connecting bridge 21 and a second connecting bridge 31; the first flow guide 20 is fixed to 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 to the second flow guide 30 through a plurality of second connecting bridges 31 on the other side; the first flow guide 20 forms an energy consumption chamber bottom wall 22 on the outside; 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, and 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 utility model.

[0048] The second flow guide 30 is fixed to 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 second flow guide 30 forms a butt chamber bottom wall 32 on the outside.

[0049] 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 equipment. In this way, the connection stability of 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.

[0050] Please refer to Figure 5 As another embodiment of the connecting bridge, the connecting bridge of the embodiment only includes the third connecting bridge 41. One end of the third connecting bridge 41 is fixed to the first flow guide 20, the other end of the third connecting bridge 41 is fixed to the second flow guide 30, and 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 of the first flow guide 20, the second flow guide 30 and the steam seal body 10 is realized, and the continuity of the counter-attack channel 161 and the energy consumption channel 151 is maintained at the same time.

[0051] 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

[0052] 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 β1 with the bottom wall 32 of the counter-attack chamber. The size of the second flow guide angle β1 is 90°≤β1≤120°. The length l2 of the counter-attack inlet flow guide tooth is 0mm

[0053] As the deformation of the energy-consuming inlet guide vane 23, the energy-consuming outlet guide vane 24 and the butt-inlet guide vane 33, the skilled in the art can adaptively adjust the specific length, angle and number according to the actual situation, and the above adjustments all belong to the protection range recorded in the embodiment.

[0054] The butt-inlet guide vane 33 is gradually close to the butt-inlet guide vane 33, so that the distance between the inner wall of the butt-inlet guide vane 33 and the butt-inlet guide vane 33 is gradually reduced, thereby forming a convergent jet structure at the entrance of the butt-inlet guide vane 33. The second steam branch flow is accelerated to flow into the butt-inlet guide vane 33 under the action of the convergent jet structure, thereby improving the reverse butt-inlet ability.

[0055] Further, the butt-inlet guide vane 33 is gradually close to the butt-inlet guide vane 33, so that the distance between the inner wall of the butt-inlet guide vane 33 and the butt-inlet guide vane 33 is gradually reduced, thereby forming a convergent jet structure at the entrance of the butt-inlet guide vane 33. The second steam branch flow is accelerated to flow into the butt-inlet guide vane 33 under the action of the convergent jet structure, thereby improving the reverse butt-inlet ability.

[0056] The butt-inlet guide vane 33 is gradually close to the butt-inlet guide vane 33, so that the distance between the inner wall of the butt-inlet guide vane 33 and the butt-inlet guide vane 33 is gradually reduced, thereby forming a convergent jet structure at the entrance of the butt-inlet guide vane 33. The second steam branch flow is accelerated to flow into the butt-inlet guide vane 33 under the action of the convergent jet structure, thereby improving the reverse butt-inlet ability.

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

[0058] The distance between the butt-inlet guide vane 33 and the butt-inlet guide vane 33 is the tooth spacing l3, and the tooth spacing l3 is 0.2mm<l3≤0.8mm.

[0059] Since the angles of the front and rear guide vanes of the butt-inlet are 50° to 70°, the narrow gap formed between them makes the second steam branch flow entering the butt-inlet guide vane 33 form an axial airflow opposite to the direction of the steam main flow, thereby playing a butt-inlet role and greatly reducing the kinetic energy of the leaked steam, thereby achieving a better sealing effect.

[0060] 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 high tooth 13, 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, and 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 facing 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, accelerating the kinetic energy dissipation of the steam, effectively improving the steam sealing effect.

[0061] 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 main steam flow passes through, thereby playing 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 sealing groove is arranged between the high tooth 13 and the low tooth 14.

[0062] The inner circle of the steam sealing 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 sealing 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 sealing groove therebetween; a plurality of gas sealing grooves form a one-stage steam sealing structure. Through the plurality of gas sealing grooves, each gas sealing 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 the plurality of gas sealing grooves, the large shaft stringing is reduced, the shear force of the main flow on the large shaft is reduced, and the stringing phenomenon is greatly reduced.

[0063] Based on the above structure, please refer to the vector diagram of the steam sealing fluid domain shown in Figures 6-7 The high pressure steam flows along the rotor shaft 90 in the axial direction from the tooth tip 132 of the high tooth 13, and after reaching the left side of the rotor shoulder, the direction of the main steam flow changes by 90° and converts into radial flow, part of the steam flows in the axial direction from the gap between the steam sealing body 10 and the rotor shaft 90, and part of the steam continues to flow upward after reaching the chamber inlet 17. When the steam enters the main chamber, it flows in two directions, left and right, in the axial direction. Please refer to Figure 8The vector diagram of the fluid domain in the energy consumption chamber 15 is shown; the steam flowing to the left forms a first steam branch, which first forms a large vortex on the right side of the energy consumption chamber 15 under the action of the energy consumption inlet guide vane 23, and a part of the first steam branch forms a small-range local vortex under the action of the first disturbance small tooth 152 inside the energy consumption chamber 15, which plays a role of kinetic energy dissipation, and the first steam branch with part of the energy consumed flows out under the guide action of the energy consumption outlet guide vane 24 at the bottom of the energy consumption chamber 15, re-joins the steam main stream to reach the left side of the rotor shaft boss 91, and repeats the above flow state. Please refer to Figure 9 The vector diagram of the fluid domain in the energy consumption chamber 15 is shown; the steam flowing to the left forms a first steam branch, which first forms a large vortex on the right side of the energy consumption chamber 15 under the action of the energy consumption inlet guide vane 23, and a part of the first steam branch forms a small-range local vortex under the action of the first disturbance small tooth 152 inside the energy consumption chamber 15, which plays a role of kinetic energy dissipation, and the first steam branch with part of the energy consumed flows out under the guide action of the energy consumption outlet guide vane 24 at the bottom of the energy consumption chamber 15, re-joins the steam main stream to reach the left side of the rotor shaft boss 91, and repeats the above flow state. Please refer to

[0064] Embodiment 2:

[0065] The embodiment provides a steam turbine based on the steam turbine of embodiment 1.

[0066] The steam turbine comprises a steam turbine cylinder, a rotor shaft 90 and the steam turbine reverse opposing type gland seal device as described in embodiment 1.

[0067] The steam turbine cylinder is connected with the outer ring of the steam gland seal body 10 of the steam turbine reverse opposing type gland seal device, and the rotor shaft 90 is arranged in the inner ring of the steam gland seal body 10 of the steam turbine reverse opposing type gland seal device.

[0068] 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, so as to circulate, which greatly dissipates the kinetic energy of part of the steam. Another part of the steam enters the opposite chamber 16 to the right and accelerates downward flow under the action of the converging jet structure. Since the first opposite angle α2 and the second opposite angle β2 are both 50°-70°, the steam at the outlet of the opposite channel 161 and the leakage steam are oppositely opposite 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 opposite chamber 16 oppositely collides with the leakage flow, which reduces the shear force of the leakage flow, thereby reducing the stringing of the large shaft; secondly, the two oppositely arranged energy dissipation chambers 15 and opposite chambers 16 split the steam mainstream, and the steam mainstream enters two opposite directions to form two opposite steam branch flows, one of which is directed to the high-pressure end 11 and is subjected to a large amount of kinetic energy dissipation under the action of the square chamber and the disturbance pinion, and the other one in the opposite direction accumulates kinetic energy to form opposite 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 on 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.

[0069] 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 all belong to the scope of protection required by the present application.

Claims

1. A reverse-flush steam seal device for a steam turbine, characterized in that, Includes a steam seal body; the steam seal body has an outer ring and an inner ring, the outer ring is used to connect with the turbine cylinder block, and the inner ring is used to connect with the rotor shaft; the two ends of the steam seal body respectively form a high-pressure end and a low-pressure end; The inner ring of the gas seal body is radially provided with high teeth, and a gas seal groove is formed on the side of the high teeth facing the low pressure end; A main chamber is formed within the gas seal channel. An energy-consuming chamber is formed on the side of the main chamber near the high-pressure end, and a counter-current chamber is formed on the side of the main chamber near the low-pressure end. A chamber inlet is formed at the bottom of the main chamber. After the main steam stream undergoes a throttling expansion effect through the high-tooth structure, it is converted into a radial main steam stream after passing through the rotor shaft boss. The radial main steam stream enters the main chamber through the chamber inlet and then splits into a first steam branch and a second steam branch. The first steam branch enters the energy-consuming chamber in the direction of the high-pressure end, and the second steam branch enters the counter-current chamber in the direction of the low-pressure end.

2. The turbine reverse-flush steam seal device according to claim 1, characterized in that, The inner wall of the energy-consuming chamber is formed with an energy-consuming structure, which is used to consume the kinetic energy of the first steam branch. The energy-consuming chamber has an energy-consuming channel that connects the first steam branch to the main steam flow.

3. A turbine reverse-flush steam seal device according to claim 2, characterized in that, The counter-flow chamber has a smooth, arc-shaped inner cavity and a counter-flow channel. The counter-flow channel is inclined in the opposite direction, and the second steam branch forms a counter-flow effect with the main steam flow through the counter-flow channel.

4. A turbine reverse-flush steam seal device according to claim 2, characterized in that, The energy-consuming chamber is a square inner cavity; the energy-consuming structure is a first perturbation tooth, the root of which is fixed to the inner wall of the energy-consuming chamber; the first perturbation tooth is a straight tooth and / or a slanted tooth.

5. A turbine reverse-flush steam seal device according to claim 3, characterized in that, It also includes a first guide member and a second guide member, which are disposed in the air seal channel; the first guide member and the second guide member are fixed to the air seal body by a connecting bridge; an energy dissipation chamber bottom wall is formed on the outer side of the first guide member; and an anti-flushing chamber bottom wall is formed on the outer side of the second guide member.

6. A turbine reverse-flush steam seal device according to claim 5, characterized in that, An energy-consuming inlet guide tooth is provided at the inlet of the energy-consuming channel, and the root of the energy-consuming inlet guide tooth is fixed to the first guide member; an energy-consuming outlet guide tooth is provided at the outlet of the energy-consuming channel, and the root of the energy-consuming outlet guide tooth is fixed to the first guide member. The anti-flush channel entrance is provided with anti-flush inlet guide teeth, and the root of the anti-flush inlet guide teeth is fixed to the second guide member.

7. A turbine reverse-flush steam seal device according to claim 5, characterized in that, The outlet of the counter-flushing channel is provided with a front guide tooth for the counter-flushing outlet and a rear guide tooth for the counter-flushing outlet. The root of the front guide tooth of the counter-flush outlet is fixed to the second guide member; the root of the rear guide tooth of the counter-flush outlet is fixed to the steam seal body; The distance between the front guide tooth of the counter-flush outlet and the rear guide tooth of the counter-flush outlet is the tooth pitch l3, and the size of the tooth pitch l3 is: 0.2mm < l3 ≤ 0.8mm.

8. A turbine reverse-flush steam seal device according to claim 1, characterized in that, The high tooth has a tooth body and a tooth tip. The root of the tooth body is fixed to the steam seal body, and the other end is connected to the tooth tip. The tooth tip is inclined towards the high-pressure end. A second disturbance tooth is provided on the side of the tooth body facing the high-pressure end.

9. A turbine reverse-flush steam seal device according to claim 1, characterized in that, The inner ring of the gas seal body is provided with a number of high teeth along the axial direction, and low teeth are provided on the side of the high teeth facing the low pressure end. Gas seal channels are formed between the high teeth and the low teeth.

10. A steam turbine, characterized in that, Includes a turbine cylinder block, a rotor shaft, and a turbine reverse-flush steam seal device as described in any one of claims 1-9; The turbine cylinder block is connected to the outer ring of the steam seal body of the turbine reverse counter-impact steam seal device; the rotor shaft passes through the inner ring of the steam seal body of the turbine reverse counter-impact steam seal device.

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