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 are arranged on an inner ring of the steam seal body in the radial direction, and a gas seal groove channel is formed in the side, facing the low-pressure end, of each high tooth; 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 invention, 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] The invention relates to the technical field of steam turbine steam seals, and in particular to a steam turbine reverse-impact steam seal device and a steam turbine. Background Art

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

[0003] In order to overcome the deficiencies of the prior art, the present invention provides a steam turbine reverse-impact steam seal device and a steam turbine, which can effectively improve the tightness of the steam seal and, on this basis, can effectively reduce the problem of rotor shaft stringing.

[0004] The first aspect of the present invention provides a steam turbine reverse-impact steam seal device, comprising a steam seal body; the steam seal body has an outer ring and an inner ring, the outer ring is used to cooperate with the steam turbine cylinder body, and the inner ring is used to cooperate 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 steam 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 in the air seal groove, an energy-consuming chamber is formed on the side of the main chamber close to the high-pressure end, a counter-chamber is formed on the 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 mainstream steam passes through the high teeth to produce a throttling expansion effect, it is converted into a radial mainstream steam through the rotor shaft boss, and the radial mainstream steam enters the main chamber from the chamber inlet and then branches into a first steam branch and a second steam branch, the first steam branch enters the energy-consuming chamber toward the high-pressure end, and the second steam branch enters the counter-chamber toward the low-pressure end.

[0007] In the first aspect of the present invention, as a preferred embodiment, an energy-consuming structure is formed on the inner wall of the energy-consuming chamber, and the energy-consuming structure is used to consume the energy of the first steam branch. The energy-consuming chamber has an energy-consuming channel, and the energy-consuming channel connects the first steam branch with the steam mainstream; the counter-attack chamber has a smooth arc-shaped inner cavity, and the counter-attack chamber has a counter-attack channel, and the counter-attack channel is arranged in an opposite direction. The second steam branch forms a steam flow counter-attack effect with the steam mainstream through the counter-attack channel.

[0008] In the first aspect of the present invention, as a preferred embodiment, the energy-consuming chamber is a square inner cavity; the energy-consuming structure is a first disturbance tooth, the root of the first disturbance tooth is fixed to the inner wall of the energy-consuming chamber, and a plurality of the first disturbance teeth are linearly arrayed on the inner wall of the energy-consuming chamber; the first disturbance teeth are straight teeth and / or oblique side teeth.

[0009] In the first aspect of the present invention, as a preferred embodiment, it further includes a first flow guide and a second flow guide, wherein the first flow guide and the second flow guide are arranged in the gas sealing channel; the first flow guide and the second flow guide are fixed to the gas sealing body through a connecting bridge;

[0010] The bottom wall of the energy-consuming chamber is formed outside the first flow guide; the energy-consuming channel is formed between the steam seal body and the first flow guide; the chamber entrance is formed between the first flow guide and the second flow guide;

[0011] The counter-flow channel is formed between the second flow guide and the steam seal body, and the bottom wall of the counter-flow chamber is formed outside the second flow guide.

[0012] In the first aspect of the present invention, as a preferred embodiment, an energy dissipation inlet guide tooth is provided at the inlet of the energy dissipation channel, the root of the energy dissipation inlet guide tooth is fixed to the first guide member, the energy dissipation inlet guide tooth and the bottom wall of the energy dissipation chamber form a first guide angle α1, the first guide angle α1 is: 30°≤α1≤90°, and the length l1 of the energy dissipation inlet guide tooth is: 0mm<l1≤1.6mm;

[0013] An energy-consuming outlet guide tooth is arranged 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.

[0014] In the first aspect of the present invention, as a preferred embodiment, a counter-entry guide tooth is provided at the entrance of the counter-entry channel, the root of the counter-entry guide tooth is fixed to the second guide member, the counter-entry guide tooth and the bottom wall of the counter-entry chamber form a second guide angle β1, the second guide angle β1 is: 90°≤β1≤120°, and the length l2 of the counter-entry guide tooth is: 0mm<l2≤1.6mm;

[0015] An asymptotic surface is formed in the counter-entry chamber, which gradually approaches the counter-entry inlet guide tooth, so that the distance between the inner wall of the counter-entry chamber and the counter-entry inlet guide tooth gradually decreases, thereby forming a tapered jet structure at the inlet of the counter-entry channel.

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

[0017] The root of the flow guide tooth in front of the counter-flow outlet is fixed to the second flow guide member, and the flow guide tooth in front of the counter-flow outlet forms a first counter-flow angle α2 with the axial direction;

[0018] The root of the guide tooth after the counter-attack outlet is fixed to the steam seal body, and the guide tooth after the counter-attack outlet forms a second counter-attack angle β2 with the axial direction;

[0019] The distance between the guide teeth in front of the counter-offset outlet and the guide teeth in the rear of the counter-offset outlet is the tooth spacing l3, and the tooth spacing l3 has a size of: 0.2mm<l3≤0.8mm.

[0020] In the first aspect of the present invention, as a preferred embodiment, the high tooth has a tooth body and a tooth tip, the tooth tip is inclined toward the high-pressure end, the acute angle formed by the tooth tip and the tooth body is the tooth tip bevel angle Ω, and the size of the tooth tip bevel angle Ω is: 0°≤Ω≤90°; the tooth body is provided with a second disturbance tooth on the side facing the high-pressure end.

[0021] In the first aspect of the present invention, as a preferred embodiment, a plurality of high teeth are axially arranged on the inner ring of the steam seal body, low teeth are arranged on the side of the high teeth facing the low-pressure end, and air seal grooves are formed on the side of the high teeth facing the low-pressure end; a plurality of the air seal grooves form a primary steam seal structure.

[0022] A second aspect of the present invention provides a steam turbine, comprising a steam turbine cylinder, a rotor shaft and a steam turbine reverse-impedance steam seal device as described in any one of the first aspects of the present invention;

[0023] The steam turbine cylinder is cooperatively connected with the outer ring of the steam seal body of the steam turbine reverse-impact steam seal device; the rotor shaft is penetrated through the inner ring of the steam seal body of the steam turbine reverse-impact steam seal device.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The steam turbine reverse counter-shock steam seal device of the present invention is provided with a steam seal body, the inner ring of the steam seal body is provided with high teeth, and two reverse expansion chambers are formed axially above the side of the high teeth facing the low-pressure end, wherein the left expansion chamber is an energy-consuming chamber, and the right expansion chamber is a counter-shock chamber, the inner wall of the left energy-consuming chamber is fixedly installed with an energy-consuming structure, and the inner wall of the right counter-shock chamber is smooth. By designing the labyrinth path of the steam turbine countercurrent and counter-shock steam seal as a circular path, the high-pressure steam mainstream passes through the gap between the high teeth and the rotor shaft, and the high teeth throttle the steam mainstream. After the steam passes through the high teeth, the space increases rapidly, causing the steam to reduce pressure and expand; the steam mainstream passes through the rotor shaft boss and turns into a radial steam mainstream. After the radial steam mainstream enters the main chamber from the chamber inlet, it forms a first steam branch and a second steam branch respectively on the opposite sides; wherein the first steam branch enters the energy-consuming chamber in the direction of the high-pressure end, and due to the energy-consuming structure provided in the left energy-consuming chamber, the first steam branch forms a large number of vortices and refluxes therein, and the first steam branch that consumes part of the energy flows. The steam flows out through the energy-consuming channel and rejoins the mainstream steam to the left side of the rotor shaft boss, repeating the above flow state, which greatly improves the kinetic energy dissipation of the steam; the second steam branch flows into the counter-flow chamber in the direction of the low-pressure end, a part of which forms a larger vortex in the counter-flow chamber, and the other part rushes to the top of the rotor shaft boss through the reversely inclined counter-flow channel, which can form a reverse counter-flow with the mainstream, greatly consuming the kinetic energy of the mainstream and improving the sealing efficiency of the steam seal; the steam passing through the counter-flow channel reduces the kinetic energy of the mainstream, thereby reducing the shear force of the mainstream on the main shaft, reducing the string movement of the main shaft, ensuring the stable operation of the rotor shaft, extending the service life of the equipment, and ensuring the safe operation of the steam turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of a reverse-impact steam seal device for a steam turbine according to the present invention;

[0027] Figure 2 It is a partial enlarged view of the A part of the reverse-impact steam seal device of the steam turbine of the present invention;

[0028] Figure 3 It is a partial enlarged view of the B part of the reverse-impact steam seal device of the steam turbine of the present invention;

[0029] Figure 4 It is a structural schematic diagram of the reverse-impedance steam seal device of the steam turbine of the present invention from another angle;

[0030] Figure 5 It is a structural schematic diagram of another embodiment of the steam turbine reverse counter-impact steam seal device of the present invention;

[0031] Figure 6 A vector diagram of the steam seal fluid domain of the steam turbine reverse counter-shock steam seal device of the present invention;

[0032] Figure 7 A vector diagram of the fluid domain in the steam seal groove of the steam turbine reverse counter-shock steam seal device of the present invention;

[0033] Figure 8 A vector diagram of the fluid domain in the energy-consuming chamber of the reverse-impedance steam seal device of the steam turbine of the present invention;

[0034] Fig. 9 It is a vector diagram of the fluid domain in the counter-impact chamber of the steam turbine reverse counter-impact steam seal device of the present invention.

[0035] In the figure: 10, steam seal body; 11, high pressure end; 12, low pressure end; 13, high tooth; 131, tooth body; 132, tooth tip; 133, second disturbance toothlet; 14, low tooth; 15, energy consumption chamber; 151, energy consumption channel; 152, first disturbance toothlet; 16, counter-attack chamber; 161, counter-attack channel; 162, asymptotic surface; 17, chamber inlet; 20, first guide member; 21, first connecting bridge; 22, bottom wall of energy consumption chamber; 23, energy consumption inlet guide tooth; 24, energy consumption outlet guide tooth; 30, second guide member; 31, second connecting bridge; 32, bottom wall of counter-attack chamber; 33, counter-attack inlet guide tooth; 34, counter-attack outlet front guide tooth; 35, counter-attack outlet rear guide tooth; 41, third connecting bridge; 90, rotor shaft; 91, rotor shaft boss. DETAILED DESCRIPTION

[0036] Below, in conjunction with the accompanying drawings and specific embodiments, the invention is further described. It should be noted that, under the premise of no conflict, the various embodiments described below or the various technical features can be arbitrarily combined to form a new embodiment. Except as otherwise specified, the materials and equipment used in this embodiment can be purchased from the market. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying 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", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0038] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through an intermediary medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0040] Embodiment 1:

[0041] Please refer to Figure 1-9 As shown, this embodiment provides a steam turbine reverse counter-type steam seal device, including a steam seal body 10; the steam seal body 10 has an outer ring and an inner ring, the outer ring is used to cooperate with the turbine cylinder body, and the inner ring is used to be sleeved on the circumference of the rotor shaft 90, so as to fix the steam turbine reverse counter-type steam seal device between the turbine cylinder body and the rotor shaft 90.

[0042] A high-pressure end 11 and a low-pressure end 12 are formed at both ends of the steam seal body 10; 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; the steam seal body 10 has an axis, and the outer side involved in this embodiment is the side away from the axis of the steam seal body 10, and the inner side involved is the side close to the axis of the steam seal body 10.

[0043] Specifically, the inner ring of the steam seal body 10 is radially provided with high teeth 13, and a gas seal groove is formed on the side of the high teeth 13 facing the low-pressure end, and a main chamber is formed inside the gas seal groove. The main chamber forms an energy consumption chamber 15 on the side close to the high-pressure end 11, and forms a counter chamber 16 on the side close to the low-pressure end 12. A chamber inlet 17 is formed at the bottom of the main chamber;

[0044] After the main stream of steam passes through the high teeth 13 to generate a throttling expansion effect, it passes through the rotor shaft boss 91 and turns into a radial main stream of steam. A part of the main stream of radial steam leaks and flows along the axial direction of the boss, and this part of the leakage flow will meet the fluid in the counter chamber head-on on the boss; a part of it enters the main chamber through the chamber inlet 17 to form a first steam branch and a second steam branch. The first steam branch enters the energy consumption chamber 15 toward the direction of the high-pressure end 11, and the second steam branch enters the counter chamber 16 toward the direction of the low-pressure end 12; In this embodiment, after the radial steam mainstream collides with the inner wall of the main chamber, it can be formed into two reverse tributaries along the axial direction. Based on this, a diversion structure can also be set on the inner wall of the main chamber. The diversion structure can be a diversion tooth. The two opposite sides of the diversion tooth can be provided with guide surfaces inclined toward the energy consumption chamber 15 and the counter-chamber 16 respectively; the tip of the diversion tooth can be located inside the main chamber, or it can extend out of the chamber inlet 17 to pre-divert and guide the steam mainstream, so as to achieve precise control of the division ratio, division position and flow direction of the two tributaries. Those skilled in the art who set the diversion structure during the implementation of this scheme belong to the protection scope of the present invention.

[0045] An energy-consuming structure is formed on the inner wall of the energy-consuming chamber 15, and the energy-consuming structure is used to consume the kinetic energy of the first steam branch. The energy-consuming chamber 15 has an energy-consuming channel 151, and the energy-consuming channel 151 connects the first steam branch with the steam mainstream. The counter-current chamber 16 has a smooth inner wall, and the counter-current chamber 16 has a counter-current channel 161. The counter-current channel 161 is inclined toward the high-pressure end to form a reverse counter-current with the mainstream. The second steam branch forms a reverse steam flow counter-current effect with the steam mainstream through the counter-current channel 161.

[0046] In this embodiment, a steam seal body is provided, and a high tooth 13 is provided in the inner ring of the steam seal body, and two opposite expansion chambers are formed axially above the high tooth 13 on the side facing the low-pressure end, wherein the left expansion chamber is an energy-consuming chamber 15, and the right expansion chamber is a counter-chamber 16, an energy-consuming structure is fixedly installed on the inner wall of the energy-consuming chamber on the left, and the inner wall of the counter-chamber 16 on the right is smooth. In this embodiment, the labyrinth path of the countercurrent and counter-hedge steam seal of the steam turbine is designed as a circular path. The main flow of high-pressure steam passes through the gap between the high teeth 13 and the rotor shaft 90. The high teeth 13 throttle the main flow of steam. After the steam passes through the high teeth 13, the space increases rapidly, causing the steam to reduce pressure and expand. The main flow of steam is converted into a radial main flow of steam through the rotor shaft boss 91. After the radial main flow of steam enters the main chamber from the chamber inlet 17, it forms a first steam branch and a second steam branch on the opposite sides respectively. Among them, the first steam branch enters the energy-consuming chamber 15 in the direction of the high-pressure end 11. Due to the energy-consuming structure arranged in the left energy-consuming chamber 15, the first steam branch forms a large number of vortices and refluxes therein, which consume part of the kinetic energy of the first steam branch. The steam flows out through the energy-consuming channel 151 and rejoins the mainstream steam to the left side of the rotor shaft boss 91, repeating the above-mentioned flow state, which greatly improves the kinetic energy dissipation of the steam flow; the second steam branch flows into the counter-flow chamber 16 in the direction of the low-pressure end 12, a part of which forms a larger vortex in the counter-flow chamber 16, and the other part rushes to the top of the rotor shaft boss 91 through the reversely inclined counter-flow channel 161, which can form a reverse counter-flow with the mainstream, greatly consuming the kinetic energy of the mainstream and improving the sealing efficiency of the steam seal; the steam passing through the counter-flow channel reduces the kinetic energy of the mainstream, thereby reducing the shear force of the mainstream on the main shaft, reducing the string movement of the main shaft, ensuring the stable operation of the rotor shaft 90, extending the service life of the equipment, and ensuring the safe operation of the steam turbine.

[0047] Specifically, the energy dissipation chamber 15 is a square inner cavity; the inner cavity with a square structure can accelerate the dissipation of the kinetic energy of the steam. The energy dissipation structure is a first disturbance tooth 152, the root of the first disturbance tooth 152 is fixed to the inner wall of the energy dissipation chamber 15, and a plurality of the first disturbance teeth 152 are linearly arrayed on the inner wall of the energy dissipation chamber 15; the first disturbance tooth 152 can be a straight tooth, or an oblique side tooth, or a combination of straight teeth and oblique side teeth. The first disturbance tooth 152 is used to form a local vortex in the first steam branch flow, thereby accelerating the dissipation of the kinetic energy of the steam. The root of the tooth involved in this embodiment refers to the end of the tooth used for fixing, that is, the end opposite to the free end of the tooth.

[0048] The energy dissipation chamber 15 of this embodiment and the energy dissipation structure arranged in the energy dissipation chamber 15 are mainly used to consume the kinetic energy of the first steam branch; as for the shape of the inner cavity of the energy dissipation chamber 15, in addition to the square inner cavity, it can also be other irregular shaped inner cavities, which can achieve the purpose of consuming the kinetic energy of the first steam branch. As for the energy dissipation structure, this embodiment preferably sets it in the form of a first disturbance tooth 152 for kinetic energy consumption. In addition, as a deformation of the first disturbance tooth 152, it can also be set by setting teeth, grooves, chambers or even labyrinth channels of other structures, which can also achieve the purpose of consuming the kinetic energy of the first steam branch, and belong to the protection scope of the present invention.

[0049] The counter-entry chamber 16 is an arc-shaped inner cavity. The smooth arc-shaped inner cavity can make the second steam branch flow lose less energy when changing direction. When the second steam branch flow rushes out through the counter-entry channel 161, it can maintain a large kinetic energy and collide with the steam mainstream, thereby achieving more energy loss.

[0050] In the steam seal channel of the present embodiment, a first flow guide 20 and a second flow guide 30 are disposed. The first flow guide 20 and the second flow guide 30 are fixed to the gas seal body via a connecting bridge.

[0051] Please refer to Figure 4 As shown, in one embodiment 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 on one side close to the high-pressure end 11 by a plurality of first connecting bridges 21, and is fixed to the second flow guide 30 on the other side by a plurality of second connecting bridges 31; an energy-consuming chamber bottom wall 22 is formed on the outer side of the first flow guide 20; the energy-consuming channel 151 is formed in the area surrounded by the steam seal body 10, the first flow guide 20 and the two adjacent 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 two adjacent second connecting bridges 31; the chamber inlet 17 of this embodiment is a straight inlet, and in some other embodiments, the chamber inlet 17 can also be set as a tortuous inlet, or other special-shaped inlets, as long as the passage of the mainstream steam can be achieved, it belongs to the protection scope of the present invention.

[0052] 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 counter-entry channel 161 is formed between the second flow guide 30 and the steam seal body 10, and a counter-entry chamber bottom wall 32 is formed on the outer side of the second flow guide 30.

[0053] The first connecting bridge 21 and the second connecting bridge 31 are fixed to the inner ring of the steam seal body in a circular array to ensure that the radial force of the rotor shaft 90 is uniform during the operation of the equipment. In this way, the connection stability of the first guide member 20 and the second guide member 30 is ensured, the continuity and integrity of the counter-channel 161 are maintained, and a complete steam seal barrier is formed.

[0054] Please refer to Figure 5 As shown, as another embodiment of the connecting bridge, the connecting bridge of this embodiment only includes a third connecting bridge 41; one end of the third connecting bridge 41 is fixed to the first guide member 20, the other end of the third connecting bridge 41 is fixed to the second guide member 30, the outer side of the third connecting bridge 41 is fixed to the steam seal body 10, and a plurality of third connecting bridges 41 are fixed to the inside of the steam seal body 10 in a circular array, thereby realizing the connection between the first guide member 20, the second guide member 30 and the steam seal body 10, and maintaining the continuity of the offset channel 161 and the energy consumption channel 151 at the same time.

[0055] Further, an energy-consuming inlet guide tooth 23 is provided at the entrance of the energy-consuming channel 151, and the root of the energy-consuming inlet guide tooth 23 is fixed to the first guide member 20, and the energy-consuming inlet guide tooth 23 forms a first guide angle α1 with the bottom wall 22 of the energy-consuming chamber, and the size of the first guide angle α1 is preferably 30°≤α1≤90°, and the length l1 of the energy-consuming inlet guide tooth 23 is preferably 0mm<l1≤1.6mm; an energy-consuming outlet guide tooth 24 is provided at the outlet of the energy-consuming channel 151, and the root of the energy-consuming outlet guide tooth 24 is fixed to the first guide member 20, and the energy-consuming outlet guide tooth 24 can be a straight tooth arranged in parallel with the high tooth 13, or it can be a helical tooth; when the energy-consuming outlet guide tooth 24 is a straight tooth, its tooth tip can be a right-angle tooth tip, or it can be an obliquely folded tooth tip; the energy-consuming outlet guide tooth 24 can be a long tooth or a short tooth, and those skilled in the art can implement it according to actual needs, which belongs to the protection scope of the present invention. By setting the energy-consuming inlet guide teeth 23, the first steam branch is helped to form a large vortex in the energy-consuming chamber 15; by setting the energy-consuming outlet guide teeth 24, the first steam branch flows out of the left energy-consuming chamber 15 under the guiding effect of the energy-consuming outlet guide teeth 24, re-joins the mainstream and reaches the left side of the rotor shaft boss 91 to form a radial steam flow to repeat the above flow state.

[0056] The counter-entry guide tooth 33 is provided at the entrance of the counter-entry channel 161, the root of the counter-entry guide tooth 33 is fixed to the second guide member 30, and the counter-entry guide tooth 33 forms a second guide angle β1 with the bottom wall 32 of the counter-entry chamber, and the second guide angle β1 is 90°≤β1≤120°, and the length l2 of the counter-entry guide tooth is 0mm<l2≤1.6mm;

[0057] As variations of the energy-consuming inlet guide teeth 23, the energy-consuming outlet guide teeth 24, and the counter-impact inlet guide teeth 33, those skilled in the art may adaptively adjust their specific lengths, angles, and quantities according to actual conditions, and the above adjustments all fall within the protection scope described in this embodiment.

[0058] An asymptotic surface 162 is formed in the counter-impact chamber 16, which gradually approaches the counter-impact inlet guide tooth 33, so that the distance between the inner wall of the counter-impact chamber 16 and the counter-impact inlet guide tooth 33 is gradually reduced, thereby forming a tapered jet structure at the entrance of the counter-impact channel 161. Under the action of the tapered jet structure, the second steam branch is accelerated to flow toward the counter-impact channel 161, thereby improving the reverse counter-impact capability.

[0059] Furthermore, the outlet of the counter-impact channel 161 is provided with a counter-impact outlet front guide tooth 34 and a counter-impact outlet rear guide tooth 35;

[0060] The root of the front guide tooth 34 of the counter-offset outlet is fixed to the second guide member 30, and the front guide tooth 34 of the counter-offset outlet forms a first counter-offset angle α2 with the axial direction, and the magnitude of the first counter-offset angle α2 is: 50°≤α2≤70°;

[0061] The root of the counter-exit outlet rear guide tooth 35 is fixed to the steam seal body 10, and the counter-exit outlet rear guide tooth 35 forms a second counter-exit angle β2 with the axial direction, and the second counter-exit angle β2 is 50°≤β2≤70°;

[0062] The distance between the front guide teeth 34 of the counter-outlet and the rear guide teeth 35 of the counter-outlet is the tooth spacing l3, and the tooth spacing l3 has a size of: 0.2mm<l3≤0.8mm.

[0063] Since the angles of the front and rear guide teeth of the counter-flow outlet are both 50° to 70°, the narrow gap formed between the two causes the second steam branch entering the counter-flow channel 161 to form an airflow in the axial direction opposite to the main steam flow, which plays a counter-flow role, greatly reduces the kinetic energy of the leaked steam, and achieves a better sealing effect.

[0064] Furthermore, the high tooth 13 has a tooth body 131 and a tooth tip 132, the root of the tooth body 131 is fixed to 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 toward the high pressure end 11, the acute angle formed by the tooth tip 132 and the tooth body 131 is the tooth tip 132 oblique angle Ω, the size of the tooth tip 132 oblique angle Ω is: 0°≤Ω≤90°, preferably, 20°≤Ω≤35°; the tooth body 131 is provided with a second disturbance toothlet 133 on the side facing the high pressure end 11. The oblique tooth tip 132 at the end of the high tooth 13 helps to further hinder the flow of steam, and the second disturbance toothlet 133 arranged on the side of the high tooth 13 can form a local vortex, accelerate the dissipation of the kinetic energy of the steam, and effectively improve the steam seal effect.

[0065] A low tooth 14 is arranged on one side of the high tooth 13, and the low tooth 14 is preferably a helical tooth inclined toward the high-pressure end. The inclined low tooth 14 helps to form a swirling vortex between the rotor shaft boss and the low tooth 14 when the mainstream steam passes through, thereby playing a better role in intercepting energy consumption; the low tooth 14 is arranged on the side of the high tooth 13 facing the low-pressure end 12; further, the air seal groove is arranged between the high tooth 13 and the low tooth 14.

[0066] The steam seal body 10 of this embodiment is provided with a plurality of high teeth 13 in the inner ring, and the plurality of high teeth 13 are arranged in sequence along the axial direction of the steam seal body 10; the high teeth 13 are provided with the said low teeth 14 on the side facing the low-pressure end 12, and the said high teeth 13 and the said low teeth 14 are formed with air-sealing grooves; the said air-sealing grooves form a primary steam seal structure. Through the plurality of air-sealing grooves, each air-sealing groove can further reduce the steam leakage; each energy-consuming chamber 15 can consume the energy of the steam, and each counter-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 air-sealing grooves, the large shaft stringing is reduced, and the shear force of the mainstream on the large shaft is reduced, thereby greatly reducing the stringing phenomenon.

[0067] Based on the above structure, please refer to Figure 6-7 The vector diagram of the steam seal fluid domain is shown in the figure; the high-pressure steam flows axially from the tooth tip 132 of the high tooth 13 along the rotor shaft 90. After reaching the left side of the rotor shoulder, the direction of the main stream of steam changes by 90 degrees and turns into radial flow. Part of the steam flows axially from the gap between the steam seal 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 along the axial direction. Please refer to Figure 8The vector diagram of the fluid domain in the energy dissipation chamber 15 is shown; the steam flowing to the left forms the first steam branch, which first forms a large vortex on the right side under the action of the energy dissipation inlet guide tooth 23 of the energy dissipation chamber 15. A part of the first steam branch forms a small-scale local vortex under the action of the first disturbance tooth 152 inside the energy dissipation chamber 15. These vortices play a role in dissipating kinetic energy. The first steam branch that consumes part of the energy flows out under the guidance of the energy dissipation outlet guide tooth 24 at the bottom of the energy dissipation chamber 15, rejoins the steam mainstream and reaches the left side of the rotor shaft boss 91, repeating the above flow state. Please refer to Fig. 9 The vector diagram of the fluid domain in the counter-attack chamber 16 is shown; the steam flowing to the right side forms a second steam branch, and a part of the second steam branch will form a larger vortex on the left side of the counter-attack inlet guide tooth 33 at the upper part of the counter-attack chamber 16, and the other part of the second steam branch will enter the counter-attack chamber 16, and then rush to the top of the rotor shaft boss 91 from the narrow counter-attack channel 161 formed between the counter-attack outlet front guide tooth 34 and the counter-attack outlet rear 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 main flow direction of the leaking steam in the axial direction, which plays a counter-attack role. On the one hand, it reduces the kinetic energy of the leaking steam, and on the other hand, it plays a sealing role, thereby greatly enhancing the tightness of the steam seal.

[0068] Embodiment 2:

[0069] This embodiment provides a steam turbine based on the first embodiment.

[0070] A steam turbine of this embodiment includes a steam turbine cylinder, a rotor shaft 90 and a steam turbine reverse-impedance steam seal device as described in Embodiment 1;

[0071] The steam turbine cylinder is cooperatively connected with the outer ring of the steam seal body 10 of the steam turbine reverse counter-impact steam seal device; the rotor shaft 90 is penetrated through the inner ring of the steam seal body 10 of the steam turbine reverse counter-impact steam seal device.

[0072] This embodiment forms a local vortex by providing a disturbance tooth on the left side of the high tooth 13 and inside the left chamber, thereby accelerating the dissipation of the kinetic energy of the steam; in addition, the square structure of the energy dissipation chamber 15 further accelerates the dissipation of the kinetic energy of the steam. After the high-pressure steam enters the chamber inlet 17 from the high tooth 13, a part of it enters the energy dissipation chamber 15 to the left for energy dissipation under the guidance of the energy dissipation inlet guide tooth 23, and then moves downward, and re-enters the chamber inlet 17 driven by the main flow of steam, so as to circulate. This method greatly dissipates the kinetic energy of part of the steam. Another part of the steam enters the counter-chamber 16 to the right, and accelerates the downward flow under the action of the gradually contracting jet structure. Since the angles of the first counter-chamber angle α2 and the second counter-chamber angle β2 are both 50°-70°, the steam at the outlet of the counter-chamber channel 161 and the leaked steam are reversely counter-challenged to a certain extent, which greatly reduces the kinetic energy of the leaked steam and achieves a better sealing effect. More importantly, the steam outflow from the counter-flow chamber 16 counter-flows against the leakage flow, reducing the shear force of the leakage flow, thereby reducing the vibration of the main shaft; secondly, the main steam flow is diverted by two oppositely arranged energy-consuming chambers 15 and counter-flow chambers 16. After the main steam flow enters, it forms two reverse steam branches in two opposite directions, one of which dissipates kinetic energy to a large extent toward the high-pressure end 11 under the action of the square chamber and the disturbance teeth, and the other in the opposite direction accumulates kinetic energy to form a counter-flow steam flow under the action of the smooth arc-shaped inner cavity and the tapered jet structure. The separate treatment and adjustment can, to a certain extent, make the axial stresses generated by the two on the rotor shaft 90 offset each other, balance the axial force on the rotor shaft 90, reduce the vibration of the main shaft, ensure the stable operation of the rotor shaft 90, extend the service life of the equipment, and ensure the safe operation of the steam turbine.

[0073] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A steam turbine reverse counter-impact steam seal device, characterized in that: It comprises a steam seal body; the steam seal body has an outer ring and an inner ring, the outer ring is used to cooperate with the turbine cylinder body, and the inner ring is used to cooperate with the rotor shaft; the two ends of the steam seal body form a high-pressure end and a low-pressure end respectively; The inner ring of the steam 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 in the air seal groove, an energy-consuming chamber is formed on the side of the main chamber close to the high-pressure end, a counter-chamber is formed on the 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 mainstream steam passes through the high teeth to produce a throttling expansion effect, it is converted into a radial mainstream steam through the rotor shaft boss, and the radial mainstream steam enters the main chamber from the chamber inlet and then branches into a first steam branch and a second steam branch, the first steam branch enters the energy-consuming chamber toward the high-pressure end, and the second steam branch enters the counter-chamber toward the low-pressure end.

2. A steam turbine reverse counter-pressure steam seal device according to claim 1, characterized in that: An energy-consuming structure is formed on the inner wall of the energy-consuming chamber, and the energy-consuming structure is used to consume the kinetic energy of the first steam branch. The energy-consuming chamber has an energy-consuming channel, and the energy-consuming channel connects the first steam branch with the steam mainstream. The counter-attack chamber has a smooth arc-shaped inner cavity, and the counter-attack chamber has a counter-attack channel, which is arranged to be tilted in the opposite direction. The second steam branch forms a steam flow counter-attack effect in the opposite direction with the steam mainstream through the counter-attack channel.

3. A steam turbine reverse counter-impact 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 disturbance tooth, the root of the first disturbance tooth is fixed to the inner wall of the energy-consuming chamber, and a plurality of the first disturbance teeth are linearly arrayed on the inner wall of the energy-consuming chamber; the first disturbance teeth are straight teeth and / or oblique side teeth.

4. A steam turbine reverse counter-shock steam seal device according to claim 2, characterized in that: It also includes a first flow guide and a second flow guide, which are arranged in the gas seal channel; the first flow guide and the second flow guide are fixed to the gas seal body through a connecting bridge; The bottom wall of the energy-consuming chamber is formed outside the first flow guide; the energy-consuming channel is formed between the steam seal body and the first flow guide; the chamber entrance is formed between the first flow guide and the second flow guide; The counter-flow channel is formed between the second flow guide and the steam seal body, and the bottom wall of the counter-flow chamber is formed outside the second flow guide.

5. A steam turbine reverse counter-shock steam seal device according to claim 4, characterized in that: An energy consumption inlet guide tooth is provided at the entrance of the energy consumption channel, the root of the energy consumption inlet guide tooth is fixed to the first guide member, the energy consumption inlet guide tooth and the bottom wall of the energy consumption chamber form a first guide angle α1, the first guide angle α1 is 30°≤α1≤90°, and the length l1 of the energy consumption inlet guide tooth is 0mm<l1≤1.6mm; An energy-consuming outlet guide tooth is arranged 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.

6. A steam turbine reverse counter-impact steam seal device according to claim 4, characterized in that: The counter-entry inlet guide tooth is arranged at the inlet of the counter-entry channel, the root of the counter-entry guide tooth is fixed to the second guide member, the counter-entry guide tooth and the bottom wall of the counter-entry chamber form a second guide angle β1, the second guide angle β1 is: 90°≤β1≤120°, and the length l2 of the counter-entry inlet guide tooth is: 0mm<l2≤1.6mm; An asymptotic surface is formed in the counter-entry chamber, which gradually approaches the counter-entry inlet guide tooth, so that the distance between the inner wall of the counter-entry chamber and the counter-entry inlet guide tooth gradually decreases, thereby forming a tapered jet structure at the inlet of the counter-entry channel.

7. A steam turbine reverse counter-shock steam seal device according to claim 4, characterized in that: The outlet of the counter-impact channel is provided with a counter-impact outlet front guide tooth and a counter-impact outlet rear guide tooth; The root of the flow guide tooth in front of the counter-flow outlet is fixed to the second flow guide member, and the flow guide tooth in front of the counter-flow outlet forms a first counter-flow angle α2 with the axial direction; The root of the guide tooth after the counter-attack outlet is fixed to the steam seal body, and the guide tooth after the counter-attack outlet forms a second counter-attack angle β2 with the axial direction; The distance between the guide teeth in front of the counter-offset outlet and the guide teeth in the rear of the counter-offset outlet is the tooth spacing l3, and the tooth spacing l3 has a size of: 0.2mm<l3≤0.8mm.

8. A steam turbine reverse counter-shock 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 toward the high-pressure end. The acute angle formed by the tooth tip and the tooth body is the tooth tip bevel angle Ω, and the size of the tooth tip bevel angle Ω is: 0°≤Ω≤90°; a second disturbance tooth is provided on the side of the tooth body facing the high-pressure end.

9. A steam turbine reverse counter-shock steam seal device according to claim 1, characterized in that: The inner ring of the steam seal body is axially provided with a plurality of high teeth, and the side of the high teeth facing the low-pressure end is provided with low teeth, and the side of the high teeth facing the low-pressure end is formed with a gas seal groove; the plurality of gas seal grooves form a primary steam seal structure.

10. A steam turbine, characterized in that: It comprises a steam turbine cylinder, a rotor shaft and a steam turbine reverse-impedance steam seal device as claimed in any one of claims 1 to 9; The steam turbine cylinder is cooperatively connected with the outer ring of the steam seal body of the steam turbine reverse-impact steam seal device; the rotor shaft is penetrated through the inner ring of the steam seal body of the steam turbine reverse-impact steam seal device.

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