CN113803120A - Enhanced pressure-reducing steam seal - Google Patents

Abstract

The invention discloses an enhanced pressure-reducing steam seal which comprises a steam seal body which is arranged on the outer ring of a rotor at intervals, wherein a plurality of annular grooves which are arranged at intervals along the axial direction of the rotor are formed in the surface, close to the rotor, of the steam seal body, a flow deflector is arranged at the notch of each annular groove and used for guiding high-speed airflow rotating along with the rotor into the annular grooves, and a hollowed-out opening communicated with the annular grooves is formed in one side of each flow deflector, so that a flow disturbing cavity allowing the airflow to enter from the flow deflector and to exit from the hollowed-out opening is formed in each annular groove. Above-mentioned enhancement mode decompression vapor seal has set up the vortex chamber based on current gland casing structure to consume the kinetic energy of air current, reduced air pressure, and guide high-speed air current through the water conservancy diversion piece, greatly increased the air current and got into vortex chamber probability, steam gets into the kinetic energy that the vortex chamber just can reduce steam better more, thereby effectively prevents the air current leakage, reaches better sealed effect, and the optimization effect is showing.

Description

Enhanced pressure-reducing steam seal

Technical Field

The invention relates to the technical field of steam turbine accessories, in particular to an enhanced pressure reduction steam seal.

Background

The steam turbine is a large-scale and precise thermal power conversion power machine rotating at a high speed. Certain axial and radial gaps must be reserved between the static bodies such as the cylinder and the partition plate and the rotating bodies such as the main shaft and the blades so as to prevent the dynamic and static parts of the unit from being rubbed during working. In order to reduce the steam leakage of the steam seal gap, a steam seal device must be arranged, and on the premise of ensuring no dynamic and static friction, the steam seal gap is in a standard range and tends to the minimum value, so that the steam leakage loss between each stage and each cylinder of the multi-stage steam turbine can be reduced, and the heat efficiency of the unit is improved.

However, when the steam turbine is running, a low-pressure area is formed in the axis, high-pressure steam quickly rushes into a gland seal gap, so that steam exciting force causes shafting vibration, the sealing performance of the gland seal is damaged, and a gland seal body is seriously failed to cause direct friction collision between moving and static parts of the steam turbine, thereby damaging a large shaft of the steam turbine.

The working principle of the existing comb-tooth steam seal is that airflow is blocked by high teeth and low teeth to weaken the pressure of the airflow to achieve the sealing effect, but in practical use, most of the airflow still flows along the surface of a rotor towards the axis direction, the kinetic energy of steam is not well reduced, and the sealing effect of the steam seal is greatly reduced.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an enhanced pressure relief steam seal to more effectively reduce the kinetic energy of steam and increase the sealing performance of the steam seal.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides an enhancement mode decompression gland, its gland body that includes the space and lie in the rotor outer lane, set up the hoop recess that a plurality of arranged along rotor axial interval on the face that the gland body is close to the rotor, the notch of hoop recess is provided with the water conservancy diversion piece, the water conservancy diversion piece is used for the leading-in hoop recess of high-speed air current rotatory along with the rotor, the fretwork mouth that link up with the hoop recess is seted up to one side of water conservancy diversion piece to form in the hoop recess and allow the air current to advance from the water conservancy diversion piece, from the turbulent flow chamber that the fretwork mouth goes out.

Particularly, a plurality of guide teeth are arranged on the guide plate, the guide teeth are obliquely arranged facing the rotation direction of the rotor, and a flow channel for guiding airflow is formed between every two adjacent guide teeth.

Particularly, the cross section of the flow guide tooth is any one of parallelogram, trapezoid or streamline water drop shape.

Particularly, the guide vane is inserted into the annular groove, and the side surface of the guide vane and/or the groove wall of the annular groove are/is provided with a slot.

Particularly, the inner wall of the turbulent flow cavity is provided with turbulent flow teeth which are arranged against the direction of the airflow.

Particularly, the surface of the rotor is provided with city wall teeth corresponding to each circumferential groove, one side groove edge of each circumferential groove is provided with a steam seal low tooth in clearance fit with the convex part of the city wall tooth, and the other side groove edge of each circumferential groove is provided with a steam seal high tooth in clearance fit with the concave part of the city wall tooth.

In conclusion, the enhanced pressure-reducing steam seal has the advantages that the turbulence cavity is arranged on the basis of the existing steam seal body structure to consume the kinetic energy of airflow, the airflow pressure is reduced, high-speed airflow is guided through the flow guide sheet, the probability that the airflow enters the turbulence cavity is greatly increased, the kinetic energy of the steam can be better reduced as more steam enters the turbulence cavity, the airflow leakage is effectively prevented, a better sealing effect is achieved, and the optimization effect is obvious.

Drawings

FIG. 1 is a schematic diagram of an enhanced pressure relief gland provided by an embodiment of the present invention;

FIG. 2 is an enlarged view at A in FIG. 1;

fig. 3 is a schematic cross-sectional view of a first flow deflector in an enhanced pressure relief gland provided in accordance with an embodiment of the present invention;

fig. 4 is a schematic cross-sectional view of a second flow deflector in an enhanced pressure relief gland provided in accordance with an embodiment of the present invention;

fig. 5 is a schematic cross-sectional view of a third cross-sectional shape of a flow deflector in an enhanced pressure relief gland provided in accordance with an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar parts throughout or parts having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning a fixed connection, a removable connection, a mechanical connection, an electrical connection, an indirect connection via an intermediary, a communication between two elements, or an interaction between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, unless otherwise expressly specified or limited, the first feature "on" or "under" the second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature being in contact not directly but with another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Referring to fig. 1 and 2, the preferred embodiment provides an enhanced pressure reducing steam seal, which includes a steam seal body 2 located at the outer ring of a rotor 1 with a gap, and a plurality of circumferential grooves 3 arranged at intervals along the axial direction of the rotor 1 are formed on the surface of the steam seal body 2 close to the rotor 1. The surface of the rotor 1 is provided with city wall teeth 4 corresponding to each annular groove 3, one side groove edge of each annular groove 3 is provided with a steam seal low tooth 5 in clearance fit with the convex part of the city wall teeth 4, and the other side groove edge is provided with a steam seal high tooth 6 in clearance fit with the concave part of the city wall teeth 4 so as to perform one-stage pressure reduction and speed reduction on high-pressure high-speed steam.

Particularly, the notch of the circumferential groove 3 is provided with a flow deflector 7, the flow deflector 7 is used for guiding high-speed airflow rotating along with the rotor 1 into the circumferential groove 3, and the flow deflector 7 can be designed into different groups according to the gland casings 2 with different widths. One side of the flow deflector 7 is provided with a hollowed-out opening 8 communicated with the annular groove 3, so that a turbulent flow cavity 12 allowing air flow to enter from the flow deflector 7 and exit from the hollowed-out opening 8 is formed in the annular groove 3, and the air flow is subjected to secondary pressure reduction and speed reduction in the turbulent flow cavity 12.

The guide vane 7 is provided with a plurality of guide teeth 9, the guide teeth 9 are obliquely arranged facing the rotation direction of the rotor 1, and a flow channel 10 for guiding airflow is formed between the adjacent guide teeth 9. As shown in fig. 3 to 5, the cross section of the guide teeth 9 is preferably in the shape of parallelogram, trapezoid, streamline drop, etc. to ensure smooth entry of air flow, so as to increase the probability of entering the turbulent flow chamber.

The flow deflector 7 is preferably inserted into the annular groove 3, and slots are correspondingly formed in the side face of the flow deflector 7 and the wall of the annular groove 3, so that the flow deflector is convenient to install and fix.

Further, the inner wall of the spoiler cavity 12 is provided with spoiler teeth 11 arranged against the direction of the air flow, so as to better reduce the kinetic energy of the air flow in the spoiler chamber.

The specific pressure reduction and speed reduction process is as follows:

high-pressure steam enters the steam seal gap and is blocked by the city wall teeth 4, so that the kinetic energy of the steam is initially reduced; meanwhile, the rotor 1 rotates at a high speed, and the airflow is influenced by the rotation of the high-speed rotor 1 and can rotate in the gland casing 2 along with the rotor 1; due to the arrangement of the flow deflector 7 (the flow deflector 7 inclines at a certain angle towards the direction of the rotor 1 by taking the rotor 1 as a circle center), at the moment, airflow rotating at a high speed is forced to be guided into the flow disturbing cavity 12 after encountering the flow deflector 7, and then kinetic energy of the airflow is consumed through the flow disturbing teeth 11 in the flow disturbing cavity 12; finally, the steam with reduced kinetic energy is discharged through the hollow opening 8.

Experiments can predict that the enhanced pressure-reducing steam seal structure can improve the tightness by 50% compared with the original steam seal, if the steam seal structure is used in the national power industry, the standard coal is saved for the country by 1.2 million tons every year, about 3 million tons of carbon dioxide are reduced for the country every year, and the enhanced pressure-reducing steam seal structure has high popularization value.

In conclusion, the enhancement mode decompression vapor seal has set up the vortex chamber based on current vapor seal body structure to consume the kinetic energy of air current, reduced air pressure, and guide high-speed air current through the water conservancy diversion piece, greatly increased the air current and got into vortex chamber probability, steam gets into the vortex chamber more and just can reduce the kinetic energy of steam better, thereby effectively prevent the air current leakage, reach better sealed effect, the optimization effect is showing.

The foregoing embodiments are merely illustrative of the principles and features of this invention, which is not limited to the above-described embodiments, but is capable of various modifications and changes without departing from the spirit and scope of the invention, which are intended to be within the scope of the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (6)

1. The utility model provides an enhancement mode decompression gland, its characterized in that, lies in the gland casing of rotor outer lane including the space, set up the hoop recess that a plurality of was arranged along rotor axial interval on the face of gland casing is close to the rotor, the notch of hoop recess is provided with the water conservancy diversion piece, the water conservancy diversion piece is used for leading-in hoop recess with the rotatory high-speed air current of rotor, the fretwork mouth that link up with the hoop recess is seted up to one side of water conservancy diversion piece to form in the hoop recess and allow the air current from the water conservancy diversion piece in, from the turbulent flow chamber of fretwork mouth play.

2. The enhanced pressure relief gland seal according to claim 1, wherein: the air guide plate is provided with a plurality of air guide teeth, the air guide teeth are obliquely arranged towards the rotation direction of the rotor, and a flow channel for guiding air flow is formed between every two adjacent air guide teeth.

3. The enhanced pressure relief gland seal according to claim 2, wherein: the cross section of the flow guide tooth is any one of a parallelogram, a trapezoid or a streamline water drop shape.

4. The enhanced pressure relief gland seal according to claim 1, wherein: the flow deflector is inserted into the annular groove, and a slot is formed in the side surface of the flow deflector and/or the wall of the annular groove.

5. The enhanced pressure relief gland seal according to claim 1, wherein: and turbulence teeth which are arranged against the direction of the airflow are arranged on the inner wall of the turbulence cavity.

6. The enhanced pressure relief gland seal according to claim 1, wherein: the surface of the rotor is provided with city wall teeth corresponding to the circumferential grooves, one side groove edge of each circumferential groove is provided with a steam seal low tooth in clearance fit with the convex part of the city wall tooth, and the other side groove edge of each circumferential groove is provided with a steam seal high tooth in clearance fit with the concave part of the city wall tooth.

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