WO2024066426A1 - Oil and gas dual-effect seal structure for gas turbine - Google Patents

Abstract

An oil and gas dual-effect seal structure for a gas turbine, comprising: a turbine rotor, a fixed sleeve, a supporting ring, a seal ring, a sleeve, an adjusting ring, a bearing, a locking gasket and a nut. The turbine rotor is sleeved with the fixed sleeve, the outer side of the fixed sleeve being sequentially sleeved from left to right with the sleeve, the adjusting ring, the bearing and the nut. The nut is pressed against and fixed to the turbine rotor by means of the locking gasket. A seal groove is formed in the fixed sleeve on the left side of the sleeve, the seal ring being arranged in the seal groove. The outer sides of the fixed sleeve, the seal ring and the sleeve are sleeved with the supporting ring. The oil and gas dual-effect seal structure can prevent gas from leaking out, and also prevent lubricating oil from entering the inner cavity of a turbine and reduce friction, thereby achieving the effects of improving turbine safety and increasing turbine efficiency.

Description

An oil-gas double seal structure for gas turbine Technical Field

The invention relates to an oil-gas double sealing structure for a gas turbine, belonging to the technical field of gas turbines.

Background technique

Gas turbines are required to be small in size and as light as possible, so many thin-walled parts are designed for the rotor and stator. The centrifugal load, extremely uneven temperature changes, instantaneous loads, etc. will cause warping and displacement of components. These need to be solved by sealing structures to achieve the purpose of tight clearance. However, if the clearance of the sealing parts is too small, it will cause friction and wear.

At the same time, as a high-temperature, high-speed rotating machine, gas turbines have always been extremely important to leakage issues. Gas leakage will cause the loss of high-temperature and high-pressure working fluids, reduce unit efficiency, and gas leakage to the bearing part will cause lubricating oil emulsification, while oil leakage from the sealing oil system into the body will seriously affect the safety of the unit.

Therefore, it is urgent to propose a new oil-gas dual seal structure for gas turbines to solve the above technical problems.

technical problem

The purpose of the research and development of the present invention is to solve the problem of an oil-gas double seal structure for a gas turbine, to prevent gas leakage, to prevent lubricating oil from entering the inner cavity of the turbine and to reduce friction, which can increase the safety of the turbine and improve the efficiency of the turbine. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to determine the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

Technical Solutions

The technical solution of the present invention:

An oil and gas double seal structure for a gas turbine comprises a turbine rotor, a fixed sleeve, a support ring, a sealing ring, a sleeve, an adjusting ring, a bearing, a locking washer and a nut. The turbine rotor is sleeved with a fixed sleeve, and the outer side of the fixed sleeve is sleeved with a sleeve, an adjusting ring, a bearing and a nut in sequence from left to right, wherein the nut is pressed and fixed to the turbine rotor by a locking washer, a sealing groove is machined on the fixed sleeve on the left side of the sleeve, a sealing ring is arranged in the sealing groove, and the fixed sleeve, the sealing ring and the outer side of the sleeve are sleeved with a support ring.

Preferably: an axial gap H1 is provided between the left side wall of the sealing ring and the left inner wall of the sealing groove, and the axial gap H1 is 0.2 mm; the right side wall of the sealing ring is tightly fitted with the left end face of the sleeve; a radial gap H2 is provided between the outer side wall of the sealing ring and the supporting ring, and the radial gap H2 is 0.1 mm.

Preferably, a plurality of spiral grooves are evenly arranged on the circumference of the left end surface of the sleeve.

Preferably, the number of the spiral grooves is 40.

Preferably, the plurality of spiral grooves together form a surface texture, and the direction of the surface texture is consistent with the rotation direction of the turbine rotor.

Preferably, the groove width angle _α1 of the spiral groove in the circumferential direction is 4.5°, the width angle _α2 between two adjacent spiral grooves in the circumferential direction is 9°, the groove width ratio γ= _α1 / _α2 , and the groove width ratio γ is 0.5.

Preferably, the groove diameter ratio λ of the spiral groove is (Rs-Rx)/(Ro-Ri), wherein Rs is the outer diameter of the spiral groove, Rx is the inner diameter of the spiral groove, Ro is the outer diameter of the sleeve 5, Ri is the inner diameter of the sleeve 5, and the groove diameter ratio λ ranges from 0.3 to 0.7.

Preferably, the groove depth H3 of the spiral groove is 0.01 mm-0.02 mm.

Preferably, the left end face of the sleeve is a mating end face, the flatness processing requirement of which is 0.001, and the surface is electroplated.

Preferably, the spiral groove is a T-shaped spiral groove, an arc-shaped spiral groove, a C-shaped spiral groove or a V-shaped spiral groove.

Beneficial Effects

The present invention has the following beneficial effects:

1. The present invention provides an oil-gas double seal structure for high-temperature, high-speed, large-size rotating gas turbines, which can not only prevent gas leakage, but also prevent lubricating oil from entering the turbine cavity. At the same time, it plays a role in increasing turbine safety and improving turbine efficiency;

2. The invention has a simple structure, can operate smoothly under high temperature, high pressure and high speed, can maintain long-term stable operation and is not easy to wear and damage, has low design and processing difficulty, is simple to install, has high safety, and has strong applicability;

3. The spiral groove structure provided by the present invention can balance the opening force for separating the dynamic and static rings and the amount of leakage, reduce the occurrence of wear, and enhance the sealing performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of an oil-gas dual seal structure for a gas turbine according to the present invention;

FIG2 is a diagram of the matching and installation of a seal ring and a sleeve of an oil-gas dual seal structure for a gas turbine according to the present invention;

FIG3 is a B-direction view of the sleeve in FIG2;

Fig. 4 is a cross-sectional view taken along line E-E of Fig. 3;

In the figure, 1-turbine rotor, 2-fixing sleeve, 3-support ring, 4-sealing ring, 5-sleeve, 6-adjusting ring, 7-bearing, 8-locking washer, 9-nut, 21-sealing groove, 51-spiral groove.

Embodiments of the present invention

In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but not limited to conventional detachable methods such as threaded connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can always be found in the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs. For example: a fixed connection is a welding connection, and a detachable connection is a hinge connection.

Specific implementation method one: Combined with Figures 1 to 4, this implementation method is described. An oil and gas double seal structure for a gas turbine in this implementation method includes a turbine rotor 1, a fixed sleeve 2, a support ring 3, a sealing ring 4, a sleeve 5, an adjusting ring 6, a bearing 7, a locking washer 8 and a nut 9. The support ring 3 and the sealing ring 4 are stator components, and the rest are rotor components. The turbine rotor 1 is sleeved with a fixed sleeve 2, and the outer side of the fixed sleeve 2 is sleeved with a sleeve 5, an adjusting ring 6, a bearing 7 and a nut 9 in sequence from left to right, wherein the nut 9 is pressed and fixed to the turbine rotor 1 by a locking washer 8 to ensure that the nut 9 does not loosen. The fixed sleeve 2, the sealing ring 4 and the outer side of the sleeve 5 are sleeved with a support ring 3, and a sealing groove 21 is processed on the fixed sleeve 2 on the left side of the sleeve 5, and a sealing ring 4 is arranged in the sealing groove 21; the fixed sleeve 2, the support ring 3, the sleeve 5, the adjusting ring 6, the bearing 7, the locking washer 8 and the nut 9 are all annular metal parts, which have a simple structure, low design and processing difficulty, simple installation, high safety, and strong applicability. Due to its simple structure, this embodiment can operate smoothly under high temperature, high pressure and high speed, and has the advantages of being able to operate stably for a long time and not being easily damaged.

An axial gap H1 is set between the left side wall of the sealing ring 4 and the left inner wall of the sealing groove 21, and the axial gap H1 is 0.2mm. The right side wall of the sealing ring 4 is tightly fitted with the left end face of the sleeve 5. A radial gap H2 is set between the outer side wall of the sealing ring 4 and the supporting ring 3, and the radial gap H2 is 0.1mm, which serves as the matching sealing surface between the rotor part and the stator part.

The left end surface of the sleeve 5 is evenly arranged with 40 spiral grooves 51, which are T-shaped spiral grooves. The T-shaped spiral grooves together form an annular surface texture, and the direction of the surface texture is consistent with the rotation direction of the turbine rotor 1. The spiral grooves 51 achieve a sealing effect under pressure through the shear flow generated by themselves and the pressure difference between the sealed gas and the outside.

The surface texture is a spiral groove 51 opened in the middle of the sealing end face. Compared with the traditional groove method, it has a higher fluid dynamic and static pressure effect and reduces the occurrence of wear. In the non-lubricated state, the surface texture will have a lower friction coefficient and a more stable friction state. The groove can collect and contain wear particles, thereby slowing down the loss of the friction pair here.

Since the high-temperature gas will leak outward through the top gap from the gas side P1, affecting the unit efficiency, the bearing lubricating oil that must be used by the bearing 7 will leak through the oil side P2, and then enter the turbine cavity through the top gap of the sleeve 5. Therefore, it is designed that the high-temperature gas leaks into the bottom of the sealing ring 4 through the axial gap H1 between the sealing ring 4 and the fixed sleeve 2, and a part of the high-temperature gas passes through the middle hole to form a slightly higher pressure air cavity at the top of the sealing ring 4, which can not only prevent the bearing lubricating oil from leaking into the main shaft and damaging the unit safety, but also reduce the leakage of high-temperature gas; another part of the high-temperature gas enters the surface texture formed by the spiral groove 51 of the sleeve 5, forming an air film during high-speed rotation to reduce friction.

When in a stationary state, the sealing ring 4 and the end face of the sleeve 5 are tightly fitted together due to the tightening force of the nut 9, and are in a "tightly sealed" state. When the turbine rotates at high speed, fluid dynamic pressure is generated in the surface texture of the sleeve 5, generating a certain air film. The air film separates the rotor part and the stator part of the sealing gap, turning it into a non-contact mechanical seal, which can reduce the friction loss of the sealing end face.

The groove width angle _α1 of the spiral groove 51 in the circumferential direction is 4.5°, the width angle _α2 between two adjacent spiral grooves 51 in the circumferential direction is 9°, the groove width ratio γ= _α1 / _α2 , and the groove width ratio γ is 0.5. As the groove width ratio γ increases, the end surface area occupied by the groove area continues to increase, the opening force will continue to increase, and the leakage will decrease; but as the groove width ratio γ continues to increase, the opening force begins to decrease and the leakage begins to increase. When the groove width ratio γ is near 0.5, the opening force reaches the maximum value and the leakage is the minimum value.

The groove diameter ratio λ of the spiral groove 51 is (Rs-Rx)/(Ro-Ri), where Rs is the outer diameter of the spiral groove 51, Rx is the inner diameter of the spiral groove 51, Ro is the outer diameter of the sleeve 5, and Ri is the inner diameter of the sleeve 5. As the groove diameter ratio λ increases, the opening force increases first and then gradually decreases, and the leakage begins to increase after decreasing to a certain value. Therefore, the groove diameter ratio λ cannot be too large or too small, and the groove diameter ratio λ ranges from 0.3 to 0.7.

The groove depth H3 of the spiral groove 51 is 0.018 mm. According to finite element calculation, the opening force that can separate the dynamic and static rings generally increases with the increase of the groove depth, but the leakage will also increase with the increase of the groove depth, so the value of H3 needs to be comprehensively considered, and generally does not exceed 0.02 mm.

The left end face of the sleeve 5 is a mating end face, and its flatness processing requirement is 0.001. The surface is electroplated to enhance the surface hardness and enhance the wear resistance.

The spiral groove 51 may also be an arc-shaped spiral groove, a C-shaped spiral groove or a V-shaped spiral groove. Different groove types still need to ensure that the groove width ratio, groove diameter ratio and groove depth are within the value range.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and/or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and/or combinations thereof.

Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values of the parts and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. An oil-gas dual seal structure for a gas turbine, characterized in that it comprises a turbine rotor (1), a fixed sleeve (2), a support ring (3), a sealing ring (4), a sleeve (5), an adjustment ring (6), a bearing (7), a locking washer (8) and a nut (9); the turbine rotor (1) is sleeved with a fixed sleeve (2); the outer side of the fixed sleeve (2) is sleeved with a sleeve (5), an adjustment ring (6), a bearing (7) and a nut (9) in sequence from left to right; the nut (9) is fixed to the turbine rotor (1) by means of a locking washer (8); a sealing groove (21) is machined on the fixed sleeve (2) on the left side of the sleeve (5); a sealing ring (4) is arranged in the sealing groove (21); and the outer sides of the fixed sleeve (2), the sealing ring (4) and the sleeve (5) are sleeved with a support ring (3).
2. According to claim 1, an oil-gas dual seal structure for a gas turbine is characterized in that an axial gap H1 is provided between the left side wall of the sealing ring (4) and the left inner wall of the sealing groove (21), and the axial gap H1 is 0.2 mm; the right side wall of the sealing ring (4) is tightly fitted with the left end face of the sleeve (5); and a radial gap H2 is provided between the outer side wall of the sealing ring (4) and the supporting ring (3), and the radial gap H2 is 0.1 mm.
3. The oil-gas dual seal structure for a gas turbine according to claim 2 is characterized in that a plurality of spiral grooves (51) are evenly arranged on the circumference of the left end surface of the sleeve (5).
4. The oil-gas dual seal structure for a gas turbine according to claim 3, characterized in that the number of the spiral grooves (51) is 40.
5. An oil-gas dual seal structure for a gas turbine according to claim 3 or 4, characterized in that the plurality of spiral grooves (51) together form a surface texture, and the direction of the surface texture is consistent with the rotation direction of the turbine rotor (1).
6. An oil-gas dual seal structure for a gas turbine according to claim 5, characterized in that: a groove width angle _α1 of the spiral groove (51) in the circumferential direction is 4.5°, a width angle _α2 between two adjacent spiral grooves (51) in the circumferential direction is 9°, a groove width ratio γ= _α1 / _α2 , and the groove width ratio γ is 0.5.
7. According to claim 6, an oil-gas dual seal structure for a gas turbine is characterized in that: the groove diameter ratio λ of the spiral groove (51) is (Rs-Rx)/(Ro-Ri), wherein Rs is the outer diameter of the spiral groove (51), Rx is the inner diameter of the spiral groove (51), Ro is the outer diameter of the sleeve (5), Ri is the inner diameter of the sleeve (5), and the groove diameter ratio λ ranges from 0.3 to 0.7.
8. The oil-gas dual seal structure for a gas turbine according to claim 7, characterized in that the groove depth H3 of the spiral groove (51) is 0.01 mm-0.02 mm.
9. According to claim 8, an oil-gas dual seal structure for a gas turbine is characterized in that the left end face of the sleeve (5) is a mating end face, the flatness processing requirement of which is 0.001, and the surface is electroplated.
10. The oil-gas dual seal structure for a gas turbine according to claim 3, characterized in that the spiral groove (51) is a T-shaped spiral groove, an arc-shaped spiral groove, a C-shaped spiral groove or a V-shaped spiral groove.