Self-adaptive bag type damping sealing structure

Abstract

The utility model discloses a self-adaptive bag type damping sealing structure, which is characterized in that a stator shell, flexible self-adaptive deformation sealing teeth which are axially arranged and rigid sealing teeth which are radially arranged form a fluid dissipation chamber, and a leakage chamber with a variable gap is formed between the flexible self-adaptive deformation sealing teeth which are axially arranged and the surface of a rotor; the lower surface of the flexible self-adaptive deformation sealing tooth is provided with an annular groove, and the annular groove and baffles arranged in the circumferential direction form an equal-radian bag type cavity. One part of the working medium flows into the fluid dissipation cavity to generate a thermodynamic effect to form a high-pressure area, and energy is dissipated in this form; and the other part of the working medium flows through the leakage cavity to generate a flow beam contraction effect to form a low-pressure area, so that pressure difference is generated on the upper and lower surfaces of the flexible self-adaptive deformation sealing teeth, the flexible self-adaptive deformation sealing teeth deform to reduce the sealing gap, and the sealing leakage is reduced. In the bag type cavity, the baffles arranged in the circumferential direction of the flexible self-adaptive deformation sealing teeth restrain circumferential flowing of the working medium, and the overall stability of the sealing system is improved.

Description

Technical Field

[0001] This utility model relates to the field of sealing structure technology, specifically to an adaptive bag-type damping sealing structure. Background Technology

[0002] Dynamic sealing structures are crucial components in turbine machinery such as steam turbines, gas turbines, aero engines, pumps, and compressors, responsible for suppressing working fluid leakage. Improving and optimizing sealing structures is one of the main methods for controlling fluid leakage and increasing unit efficiency. From labyrinth seals that increase flow resistance along the leakage path to damping seals that increase the relative roughness of dynamic and static surfaces, such as honeycomb seals, perforated labyrinths, and bag seals, sealing performance has been improved to some extent. However, these are essentially fixed-gap seals, unable to adapt to changes in external loads and operating conditions, thus limiting their ability to suppress working fluid leakage.

[0003] To enable the seal to adapt to the dynamic and static rubbing and clearance adjustment issues caused by actual load and rotor vibration, the following two structures are commonly used in the existing technology:

[0004] ①Brighten seal structure: This seal structure adds multiple helical springs to the end face of each sealing arc segment. In the free state, the sealing arc block is in an open state and away from the rotor under the action of spring stress. When the unit starts up, as the steam flow increases, the steam pressure acting on the back of each sealing arc block gradually increases. When this pressure is sufficient to overcome the spring stress and frictional resistance, the sealing arc block begins to gradually close to the working state. However, this seal also has problems such as spring aging, breakage, and jamming, which cause it to fail in practical applications.

[0005] ② Flexible adaptive dynamic sealing structure. This sealing structure has a flexible tooth structure arranged axially at the tip of the labyrinth seal tooth. It utilizes the different energy conversions of the leaking working fluid in the fluid dissipation chamber and the leakage chamber to form a natural pressure difference on the upper and lower surfaces of the flexible tooth. It adaptively controls the deformation of the flexible tooth and the sealing gap, so that the sealing gap changes with the system operating conditions. For example, the "flexible adaptive dynamic sealing structure" disclosed in patent publication number CN212584255U, in which the stator shell, the axially arranged flexible adaptive deformation sealing tooth and the radially arranged rigid sealing tooth constitute the fluid dissipation chamber, and the axially arranged flexible adaptive deformation sealing tooth and the rotor surface form a leakage chamber with a variable gap.

[0006] However, due to the large circumferential velocity of the leaking working fluid, the circumferential pressure distribution in the sealing flow field is uneven, which is not conducive to the overall stability of the sealing system. Utility Model Content

[0007] The purpose of this invention is to provide an adaptive bag-type damping sealing structure to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] An adaptive bag-type damping sealing structure includes a stator housing for fixing sealing teeth, axially arranged flexible adaptive deformation sealing teeth and radially arranged rigid sealing teeth. The stator housing, the axially arranged flexible adaptive deformation sealing teeth and the radially arranged rigid sealing teeth constitute a fluid dissipation chamber. The axially arranged flexible adaptive deformation sealing teeth and the rotor surface form a leakage chamber with a variable gap.

[0010] The lower surface of the flexible adaptive deformation sealing tooth has one or more annular grooves along the axial direction. A baffle arranged circumferentially is provided in the annular groove, and the annular groove and the circumferentially arranged baffle form a bag-shaped chamber with equal arc.

[0011] Preferably, the flexible adaptive deformation sealing tooth includes a flexible adaptive deformation body and a sealing tooth body disposed on the inner side of the free end of the flexible adaptive deformation body.

[0012] Preferably, the thickness of the flexible adaptive deformable body gradually decreases from the rigid sealing tooth toward its free end.

[0013] Preferably, the thickness of the flexible adaptive deformable body is 0.4 mm-0.8 mm; the radius of the sealing tooth is 0.2 mm; the annular groove is arranged 1 mm away from the tip of the sealing tooth, and there are two grooves with a spacing of 0.5 mm. The depth of the annular groove is 0.3 mm and the width is 1 mm.

[0014] Preferably, there are eight sets of baffles arranged in the annular groove, and the thickness of the baffles is 0.5mm.

[0015] Preferably, the flexible adaptive deformable body is made of Hyster nickel-based superalloy, and the sealing tooth body is made of composite material.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] This invention replaces the smooth, flexible, adaptive deformation sealing teeth with flexible, adaptive bag-type sealing teeth with bag-type chambers to form a bag-type damping structure. When the unit is running, the bag-type chambers arranged circumferentially by the flexible, adaptive deformation sealing teeth suppress the circumferential flow of the working fluid, improve the overall stability of the sealing system, and at the same time enhance energy dissipation of the working fluid in the bag-type chambers, reducing sealing leakage.

[0018] Numerical simulations show that, under the same conditions, the leakage of the flexible adaptive deformable sealing teeth with bag-shaped chambers is reduced by 16.8% compared with the smooth flexible adaptive dynamic sealing structure, and the effective damping coefficient is increased by a maximum of 23.4%, effectively improving the unit performance. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0021] Figure 2 This is a cross-sectional view of the sealing meridian of this utility model;

[0022] Figure 3 This is a schematic diagram of a single flexible adaptive deformation sealing tooth model of this utility model;

[0023] Figure 4 This is a cross-sectional view of the flexible adaptive deformation sealing tooth of this utility model;

[0024] Figure 5 This is a schematic diagram of the sealing tooth structure at the end of the flexible adaptive deformation sealing tooth of this utility model.

[0025] The reference numerals in the figure are as follows:

[0026] 1. Airflow inlet; 2. Stator housing; 3. Rotor; 4. Flexible adaptive deformation sealing teeth; 5. Rigid sealing teeth; 6. Bag chamber; 7. Airflow outlet; 8. Baffle; 9. Flexible adaptive deformation sealing teeth deformed under pressure; 10. Sealing tooth body.

[0027] C r 1. The gap between the flexible adaptive deformation sealing teeth and the rotor surface; P in Chamber inlet pressure; P out Chamber outlet pressure; P s Pressure within the fluid dissipation chamber; P c Pressure in the variable gap leakage chamber; F The stress on the flexible adaptive deformation sealing teeth under the action of pressure difference between the upper and lower parts. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0029] Example:

[0030] like Figure 1 , Figure 2 As shown, an adaptive bag-type damping sealing structure includes: a stator housing 2 for fixing the sealing teeth, multiple sets of axially arranged flexible adaptive deformation sealing teeth 4, and multiple sets of radially arranged rigid sealing teeth 5. The flexible adaptive deformation sealing teeth 4 are relatively fixed to the end of the rigid sealing teeth 5 near the rotor 3 and located on the side near the airflow inlet 1.

[0031] The stator housing 2, the axially arranged flexible adaptive deformation sealing teeth 4, and the radially arranged rigid sealing teeth 5 constitute a fluid dissipation chamber. The axially arranged flexible adaptive deformation sealing teeth 4 and the surface of the rotor 3 form a leakage chamber with a variable gap. The annular groove on the lower surface of the flexible adaptive deformation sealing teeth 4 and the circumferentially arranged baffle 8 form multiple bag-shaped chambers 6 with equal arc.

[0032] The flexible adaptive deformation sealing tooth 4 extends from the front sidewall of the rigid sealing tooth 5 towards the airflow inlet 1. The axially arranged flexible adaptive deformation sealing tooth 4 includes a flexible adaptive deformation body made of Hyster nickel-based high-temperature alloy and a sealing tooth body 10 made of composite material. The composite material can be composed of polyimide + solid lubricant (PTFE / graphite), possessing temperature resistance up to 400°C (up to 500°C for short periods), a softer texture, greater flexibility and wear resistance than PEEK, suitable for high-temperature wear-resistant conditions, and exhibiting good self-lubricating properties even in dry friction environments. Figure 5 As shown, the sealing tooth 10 is disposed on the inner side of the front end (free end) of the flexible adaptive deformable body; the thickness of the Hyster nickel-based superalloy decreases from the front sidewall of the rigid sealing tooth 5, and the thickness of the Hyster nickel-based superalloy is 0.4 mm-0.8 mm; the radius of the sealing tooth is 0.2 mm; the flexible adaptive deformable sealing tooth 4 composed of Hyster nickel-based superalloy and composite materials has the characteristics of high temperature resistance, soft texture, wear resistance, and self-lubrication;

[0033] like Figure 3 As shown, two annular grooves with a depth of 0.3 mm and a width of 1 mm are arranged 1 mm away from the tip of the sealing tooth of the flexible adaptive deformation sealing tooth 4. The distance between the two annular grooves is 0.5 mm, and eight baffles 8 with a thickness of 0.5 mm are evenly distributed in the annular grooves along the circumference.

[0034] The gap between the axially arranged flexible adaptive deformation sealing teeth 4 and the rotor 3 surface varies with the random load adjustment, which can avoid problems such as rubbing, spring jamming, seal failure, and rotor damage. The circumferentially arranged baffles 8 form a bag-like chamber 6, which inhibits the circumferential flow of the working fluid and improves the stability of the sealing structure.

[0035] like Figures 1-3 As shown, the working fluid enters from inlet 1 (pressure is...) P in ) flows to the outlet 7 (pressure is P out ,and P out <P in When the working fluid flows through the axially arranged flexible adaptive deformation sealing teeth 4, a portion of the working fluid flows into the fluid dissipation chamber formed by the stator shell 2 containing the sealing teeth, the axially arranged flexible adaptive deformation sealing teeth 4, and the radially arranged rigid sealing teeth 5, generating a thermodynamic effect that converts kinetic energy into pressure energy. P s (pressure P out <P s <P in The working fluid and heat energy form a high-pressure zone, and dissipate energy in this way; another part of the working fluid flows at a higher velocity through the leakage chamber between the axially arranged flexible adaptive deformation sealing teeth 4 and the surface of the rotor 3, producing a flow stream contraction effect, increasing the fluid velocity and pressure. P c ( P out <P c <P s The pressure decreases, creating a low-pressure zone, which in turn causes a pressure difference between the upper and lower surfaces of the flexible adaptive deformation sealing tooth 4. F Under the action of this pressure difference F, the flexible adaptive deformation sealing tooth 4 deforms as follows: Figure 3 The flexible, adaptive deformation sealing tooth 9, marked with a dashed line, is subject to pressure deformation. Figure 3 As shown, this further reduces the sealing gap. C r Reduce and decrease seal leakage.

[0036] Within the annular groove of the flexible adaptive deformable sealing tooth 4, circumferentially arranged baffles 8 suppress the circumferential flow of the working fluid, improving the overall stability of the sealing system. Simultaneously, the working fluid flows into the bag-type chamber 6, generating a thermodynamic effect that dissipates energy and reduces seal leakage.

[0037] Tables 1 and 2 below present the structural and operating parameters of the "flexible adaptive dynamic sealing structure" disclosed in patent publication number CN212584255U and the adaptive bag-type damping sealing structure proposed in this utility model (taking 4 sealing teeth as an example) based on numerical simulation. Table 3 below shows the maximum radial deformation of the flexible adaptive deformable sealing tooth 4. Table 4 below compares the numerical simulation results of the two seals. It can be seen that during unit operation, due to the pressure difference between the upper and lower surfaces, the flexible adaptive deformable sealing tooth 4 generates radial deformation pointing towards the rotor. Among them, the deformation of the last sealing tooth is the largest, followed by the first tooth. The last tooth generates a maximum radial deformation of 0.1545 mm, which reduces the corresponding sealing gap by 50%. Compared with the smooth flexible adaptive dynamic sealing structure, the adaptive bag-type damping sealing structure has a significant inhibitory effect on the circumferential flow of the leaking working fluid, reducing the average circumferential velocity of the working fluid by 21.3%. Under the same conditions, the leakage can be reduced by 30%-50% compared with the traditional sealing structure.

[0038] Table 1 Sealing geometry parameters

[0039]

[0040] Table 2 Numerical Calculation Conditions

[0041]

[0042] Table 3 Maximum radial deformation of flexible adaptive bag seal teeth

[0043]

[0044] Table 4 Numerical simulation results

[0045]

[0046] This invention employs a bag-type damping structure to suppress the circumferential flow of leaking fluid, thereby improving the overall stability of the sealing system. It also combines a flexible tooth structure that can adaptively adjust with changes in operating conditions to reduce gaps and minimize leakage.

[0047] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. An adaptive pocket damping seal structure, comprising a stator casing (2) for fixing a seal tooth, axially arranged flexible adaptive deformed seal tooth (4) and radially arranged rigid seal tooth (5), the stator casing (2) and axially arranged flexible adaptive deformed seal tooth (4) and radially arranged rigid seal tooth (5) constitute a fluid dissipation chamber, the axially arranged flexible adaptive deformed seal tooth (4) and the rotor (3) surface form a variable gap leakage chamber, characterized in that: the lower surface of the flexible adaptive deformed seal tooth (4) is provided with one or more annular grooves along the axial direction, and the annular grooves are provided with circumferentially arranged baffles (8), and the annular grooves and the circumferentially arranged baffles (8) form an equal-arc pocket chamber (6). The flexible adaptive deformed seal tooth (4) comprises a flexible adaptive deformed body and a seal tooth body arranged inside the free end of the flexible adaptive deformed body.

2. The self-adapting pocketed damper seal structure of claim 1, wherein: The thickness of the flexible adaptive deformed body tapers from the rigid seal tooth (5) to the free end thereof.

3. A self-adapting pocketed damper seal structure according to claim 2, wherein: The thickness of the flexible adaptive deformed body is 0.4 mm-0.8 mm; the radius of the seal tooth body is 0.2 mm; the annular groove is arranged at a distance of 1 mm from the tooth tip of the seal tooth body, and two annular grooves with a spacing of 0.5 mm are arranged, the depth of the annular groove is 0.3 mm, and the width is 1 mm.

4. The self-adapting pocketed damper seal structure of claim 3, wherein: The baffles (8) arranged in the annular groove have eight groups, and the thickness of the baffles (8) is 0.5 mm.

5. A self-adapting pocketed damper seal structure according to claim 4, wherein: The flexible adaptive deformed body is made of Hayster nickel-based superalloy, and the seal tooth body is made of composite material.

6. The self-adapting pocketed damper seal structure of claim 2, wherein: ​

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