CN209324437U - A kind of steam turbine shaft end combination sealing gland - Google Patents

Abstract

A combined steam seal device for a shaft end of a steam turbine, comprising a seal body and a rotor, the inner ring of the seal is provided with an upper seal tooth slot and a T-shaped slot, and the upper seal tooth slot is provided with an upper seal tooth, The T-shaped groove is provided with a leaf spring, a T-like carrier, a follow-up suspension seal tooth, and a plug, and the T-shaped groove, a leaf spring, a T-like carrier, a follow-up suspension seal tooth, and a plug form a follow-up Dynamic suspension gear seal, the rotor is provided with a lower seal gear slot, the lower seal gear slot is provided with a lower seal gear, and the adjacent upper seal teeth and lower seal teeth are arranged crosswise Constitute a labyrinth seal, using a combination of a labyrinth seal and a follow-up suspension tooth seal, which overcomes the inherent defects of a single seal type, and uses the characteristics of the two seals to consume the energy of the seal leakage. Reduce the temperature and pressure of the gas, thereby blocking and reducing steam leakage, so that the overall sealing effect of the shaft end of the steam turbine is remarkable, and at the same time, the cost of use is taken into account.

Description

A steam turbine shaft end combined steam seal device

technical field

The utility model relates to the field of steam turbines, in particular to a steam turbine shaft end combined steam seal device.

Background technique

In the design and use of the steam turbine unit, the steam leakage of the shaft end seal has always been the key research object of engineers and technicians. In order to improve the reliability, a steam seal device will be installed at the shaft end of the steam turbine, and the traditional steam seal seal types mainly include comb labyrinth seal, honeycomb seal and brush soft tooth seal.

The basic sealing principle of the comb-tooth labyrinth seal is multi-stage throttling expansion, which consumes the energy of the steam flow to produce a damping effect, thereby reducing the axial leakage of steam. Direct flow will reduce the sealing effect to a certain extent, especially in the high temperature and high pressure steam working environment, the leakage is relatively large. The honeycomb air seal is a regular hexahedral grid honeycomb belt formed by special equipment installed in the air seal body. The steam in the seal cavity is blocked from flowing in the circumferential direction to play a sealing role, which can effectively reduce the probability of rotor self-excited vibration, but Due to the limitation of the structure, the processing is relatively difficult, it is inconvenient to measure the gap during installation, and it is easy to fall off and damage the shaft after static and dynamic interference, and the service life is short. The brush-type soft-tooth seal belongs to the contact seal. It uses the transverse flow generated by the uneven structure of the gap between the brush filaments to destroy the co-directional flow, thereby producing a self-sealing effect. It is easy to curl, fall and break when the high-speed and high-pressure steam flow scours. Aiming at the defects of the above-mentioned traditional shaft end seal types, a follower suspension tooth seal that is in contact with the rotor and can be freely retreated has appeared in recent years. It is not easy to install on the surface, the interchangeability is poor, and the price is higher than that of the comb-teeth seal.

Utility model content

The purpose of this utility model is to solve the above-mentioned problems by designing a steam turbine shaft-end combined steam seal device which is mixed with a labyrinth type steam seal and a follow-up suspension gear steam seal. The device has strong sealing performance, simple structure, and convenient installation. Good versatility, can effectively improve the economy and safety of unit operation.

In order to achieve the above purpose, a steam turbine shaft end combined steam seal device of the present invention includes a steam seal body and a rotor. The inner ring of the steam seal is provided with an upper seal gear slot and a T-shaped groove. The upper seal gear There are upper steam seal teeth in the card slot, and the T-shaped slots are equipped with leaf springs, T-like carriers, follow-up suspension seal teeth, and plugs, and the T-shaped slots, leaf springs, T-like carriers, follow-up Suspension seal gears and plug strips form follow-up suspension gear seals. The rotor is provided with a lower seal gear slot, and the lower seal gear slot is provided with lower seal teeth. The adjacent SAIC The seal teeth and the lower seal teeth are intersected to form a labyrinth seal.

A further solution is that the leaf spring is arranged in the innermost part of the T-shaped slot, the T-like carrier is fixed in the T-shaped slot through the leaf spring, and a slot is opened in the middle of the T-like carrier, and the follow-up One end of the suspension air seal tooth is tightened in the slot through a plug, and the other end of the follow-up suspension air seal tooth protrudes to the rotor. The T-like carrier is divided into 4 equal parts or 6 equal parts along the circumferential direction. . The characteristic of this structure is that the use and installation of the follow-up suspension seal tooth adopts advanced building block technology, that is, the seal body, the T-like carrier and the follow-up suspension tooth are designed separately. In the actual installation Firstly, put one side of the moving suspension seal tooth into the slot of the T-like carrier, tighten it through the plug, and then put it into the T-slot on the corresponding seal body as a whole, and fix it with the leaf spring.

A further solution is that the follow-up suspension gear adopts the form of two superimposed use, and the front and rear of the follow-up suspension gear seal are respectively provided with no less than one level of labyrinth seals. The characteristic of this structure is that the follow-up suspension gear seal can be arranged according to the actual structure of the steam turbine unit with 1 to 3 stages of follow-up suspension gear seals, and at the same time, no less than Level 1 labyrinth seal.

A further solution is that the radial clearance between the upper seal gear and the rotor is 0.25-0.45 mm; the radial clearance between the lower seal gear and the seal body is 0.25-0.45 mm. The feature of this structure is that it can not only avoid radial friction, but also ensure a small enough sealing gap.

A further solution is that the inner ring of the steam seal is provided with a steam seal retaining ring, and the steam seal retaining ring is attached to the back side of the steam-facing side of the follow-up suspension seal tooth, and the steam seal retaining ring is connected to the rotor The gap is 0.3~0.8mm. The characteristic of this structure is that, on the one hand, the seal retaining ring is used to enhance the bending strength of the follow-up suspension seal teeth, and on the other hand, it is used to limit the elastic retreat path of the follow-up suspension seal teeth.

A further solution is that the upper steam seal gear slot, the lower upper steam seal gear slot and the T-shaped groove are all annular grooves.

The beneficial effects of the utility model are:

1. The combined use of the labyrinth seal and the follow-up suspension tooth seal overcomes the inherent defects of a single seal type, and uses the characteristics of the two seals to consume the energy of the seal leakage and reduce the gas pressure. Temperature and pressure, so as to block and reduce steam leakage, so that the overall sealing effect of the shaft end of the steam turbine is remarkable, while taking into account the cost of use;

2. The follow-up suspension gear steam seal is a contact seal, which can freely retreat when the top of the steam seal gear is stressed, and realizes a zero-gap seal to a certain extent, prevents steam seal leakage, and enhances the overall sealing performance;

3. The new type of steam seal device belongs to the category of traditional labyrinth seal as a whole, with high safety and reliability and little damage to the rotor;

4. Using building block technology and T-like carrier to install the follow-up suspension seal teeth, separate design and installation of the seal body and follow-up suspension, so that the overall seal structure can be used flexibly, easy to install, strong interchangeability, reducing the Gas seal design cost and maintenance cost.

Description of drawings

Fig. 1 is a sectional view of the overall structure of the utility model.

Fig. 2 is a sectional view of a T-like carrier of the present invention.

Fig. 3 is a cross-sectional view of the installation structure of the movable suspension tooth of the present invention.

Fig. 4 is a sectional view of the overall structure of the utility model with a steam seal retaining ring.

Among them: seal body 1, plate spring 2, T-like carrier 3, upper seal teeth 4, lower seal teeth 5, labyrinth seal 6, follower suspension seal teeth 7, plug strip 8, rotor 9, steam seal Sealing ring 10.

Detailed ways

The utility model is further described below in conjunction with embodiment:

Example 1:

As shown in Figures 1 to 3, the utility model is a combined steam seal device for the shaft end of a steam turbine, which includes a seal body 1 and a rotor 9, and the inner ring of the seal body 1 is provided with an upper seal tooth slot and a T-shaped Slot, the upper steam seal tooth slot is provided with upper steam seal tooth 4, and the T-shaped groove is provided with leaf spring 2, T-like carrier 3, follow-up suspension steam seal tooth 7, plug strip 8, and T-shaped Groove, plate spring 2, T-like carrier 3, follow-up suspension seal teeth 7, plug strips 8 form follow-up suspension teeth seals, the rotor 9 is provided with a lower seal gear slot, the lower seal The lower seal teeth 5 are arranged in the gear slots, and the adjacent upper seal teeth 4 and lower seal teeth 5 are intersected to form a labyrinth seal 6 . The leaf spring 2 is arranged in the innermost part of the T-shaped slot, the T-like carrier 3 is fixed in the T-shaped slot by the leaf spring 2, and a slot is opened in the middle of the T-like carrier 3, and the follow-up suspension One end of the seal tooth 7 is tightened in the slot through the plug 8, and the other end of the follower suspension seal tooth 7 protrudes to the rotor 9, and the T-like carrier 3 is divided into 4 equal parts along the circumferential direction or 6 equal parts. The follow-up suspension gear seal 7 adopts the form of two superimposed use, and the front and back of the follow-up suspension gear seal are respectively provided with no less than one level of labyrinth seal 6 . The radial clearance between the upper seal gear 4 and the rotor 9 is 0.25-0.45mm; the radial clearance between the lower seal gear 5 and the seal body 1 is 0.25-0.45mm.

As shown in Figure 4, the inner ring of the steam seal body 1 is provided with a steam seal retaining ring 10, and the steam seal retaining ring 10 is attached to the back side of the steam-facing side of the follow-up suspension seal tooth 7, and the steam seal The gap between the sealing ring 10 and the rotor is 0.3-0.8mm.

The upper steam seal gear slot, the lower upper steam seal gear slot and the T-shaped slot are all annular grooves.

The specific implementation manners of the utility model described above further describe the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above descriptions are only specific implementations of the present utility model, and are not intended to limit the protection scope of the present utility model. All modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims (6)

1. A steam turbine shaft-end combined steam seal device, including a steam seal body (1) and a rotor (9), characterized in that: the inner ring of the steam seal body (1) is provided with an upper seal gear slot and a T-shaped slot, the upper steam seal gear slot is provided with upper steam seal teeth (4), and the T-shaped groove is equipped with leaf springs (2), T-like carriers (3), and follow-up suspension steam seal teeth (7) , plug (8), and T-shaped groove, leaf spring (2), similar T-shaped carrier (3), follow-up suspension gear (7), and plug (8) form a follow-up suspension gear seal, so The rotor (9) is provided with a lower seal tooth slot, and the lower seal tooth (5) is arranged in the lower seal tooth slot, and the adjacent upper seal teeth (4) and lower seal teeth (5) The cross setting constitutes a labyrinth seal (6). 2. A steam turbine shaft end combined steam seal device according to claim 1, characterized in that, the leaf spring (2) is arranged in the innermost part of the T-shaped slot, and the T-like carrier (3) passes through the leaf spring (2) Fixed in a T-shaped slot, a slot is opened in the middle of the T-like carrier (3), and one end of the follow-up suspension air seal tooth (7) is tightened by a plug (8). In the groove, the other end of the moving suspension seal tooth (7) protrudes to the rotor (9), and the T-like carrier (3) is equally divided into 4 or 6 equal parts along the circumferential direction. 3. A steam turbine shaft-end combined steam seal device according to claim 1, characterized in that, the follow-up suspension seal teeth (7) are in the form of two superimposed pieces, and the follow-up suspension gear steam There are not less than one level of labyrinth seals (6) before or after the seal respectively. 4. A shaft-end combined steam seal device for a steam turbine according to claim 1, characterized in that the radial clearance between the upper seal gear (4) and the rotor (9) is 0.25-0.45mm; The radial clearance between the lower seal teeth (5) and the seal body (1) is 0.25-0.45 mm. 5. A steam turbine shaft end combined steam seal device according to claim 1, 2, 3 or 4, characterized in that, the inner ring of the steam seal body (1) is provided with a steam seal retaining ring (10) , the seal retaining ring (10) is bonded to the back of the steam-facing side of the moving suspension seal tooth (7), and the gap between the seal retaining ring (10) and the rotor is 0.3-0.8 mm. 6 . The combined steam seal device for the shaft end of a steam turbine according to claim 1 , wherein the upper seal gear slot, the lower and upper steam seal gear slot and the T-shaped groove are all annular grooves. 7 .