CN210317403U

CN210317403U - Steam seal structure convenient to measure and adjust turbine radial clearance

Info

Publication number: CN210317403U
Application number: CN201921459831.XU
Authority: CN
Inventors: 周涛
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-09-04
Filing date: 2019-09-04
Publication date: 2020-04-14
Anticipated expiration: 2029-09-04

Abstract

The utility model provides a steam seal structure convenient to measure and adjust steam turbine radial clearance, including steam seal cover, pivot, spring leaf and polylith steam seal piece, the medial surface of steam seal cover is seted up the annular cavity that the cross section is the T type along the circumferencial direction, and the outer end endotheca of steam seal piece is in the annular cavity, and the endotheca of steam seal piece is located the pivot, and polylith steam seal piece encloses the axial center of revolving the shaft and forms the shaft seal circle, and the internal surface of spring leaf supports and presses in the outer terminal surface of steam seal piece, and the surface of spring leaf supports and presses in the inner diapire of annular cavity; the middle part of the steam seal block is provided with a first thread through hole, and the first thread through hole is screwed with a fixing bolt. The utility model provides a when the vapor seal structure measures radial clearance, support fixing bolt to pressing at the inner diapire of annular cavity from the downthehole screw-out of first screw thread to fixing bolt, the vapor seal cover is fixed with the relative position of vapor seal piece this moment, and this vapor seal structure measures radial clearance's mode is simple, safe and reliable, and the work load is little, and measurement accuracy is high.

Description

Steam seal structure convenient to measure and adjust turbine radial clearance

Technical Field

The utility model relates to a steam turbine vapor seal structure field, concretely relates to vapor seal structure convenient to measure and adjust steam turbine radial clearance.

Background

Along with the continuous development of thermal power generation technology, the energy-saving emission reduction standard is continuously improved, the requirement on the heat consumption of a steam turbine is higher and higher, the reasonable adjustment of the radial clearance d is an important guarantee means for the heat consumption of the steam turbine, and before the radial clearance d is reasonably adjusted, the radial clearance d needs to be measured firstly.

In the prior art, a method of pressing an adhesive tape (or a lead wire) is usually adopted to measure a radial clearance d, when measuring, as shown in figure 1, a bamboo wedge 5 is usually used to plug the back arc position of a steam seal block 2 along the axial direction, but the actual operation process has great difficulty, especially the steam seal of the shaft end is very tight in axial arrangement, the upper half and the lower half are respectively composed of three steam seal blocks 2, at least 4 bamboo wedges 5 are symmetrically plugged at the two axial sides of each steam seal block 2, the bamboo wedges 5 at other positions are difficult to plug except the bamboo wedges of a horizontal combination surface are easy to plug, and the error of the measured radial clearance d is large because the plugging workload is very large, and the individual bamboo wedges 5 often have the phenomenon of not tight plugging. If the shaft end is adjusted to seal a certain steam seal block 2, the steam seal blocks 2 on the two sides are also completely removed, otherwise, the bamboo wedges 5 of the steam seal blocks 2 cannot be plugged in; a batch of waste bamboo wedges 5 are required after each measurement, and the waste bamboo wedges 5 are easy to scatter to positions such as steam extraction holes of the steam seal, so that certain risks exist.

In addition, after the radial clearance d is measured, the radial clearance d usually needs to be adjusted. When the radial clearance d is smaller, the first adjustment mode is to machine the steam seal teeth, so that the machining difficulty and the workload are large, and the steam seal teeth are not practical; as shown in fig. 2, the second adjustment method is to spot-weld the vapor seal back arc and then measure and process the vapor seal back arc into a block 6, which not only has the technical difficulty of spot welding, but also has errors in measurement and processing, and generally needs to be adjusted for many times to meet the requirements, and thus the workload is large; as shown in fig. 3, the third adjustment method is to extrude the protruding points 7 at the back arc portion of the steam seal by using a sample punch, which is unreasonable in practice because the strength of the protruding points 7 is often insufficient, after a major repair cycle, most of the protruding points 7 will be ground flat, and the steam seal block 2 and the rotating shaft 3 will have friction and damage in different degrees, which is harmful; as shown in fig. 4, a fourth adjustment manner is to adjust the radial gap d by adjusting the thickness of the shim 8, and the applicant has performed such adjustment of the radial gap d on the spot, which is not good in practical application effect, large in workload, low in adjustment accuracy, and has a certain potential risk, because the shim 8 is composed of a plurality of shims, the gap adjustment is performed by adding or subtracting the number of the shims 8, the shims have certain unevenness and a large number of layers, the fastening difficulty of the fastening screw 11 is large, different gap values can be generated by different forces, and simultaneously, the adjustment value variation amounts on two sides of the fastening pressure plate 12 are different, and the fixing screw 11 is often not fixed firmly, and the fixing screw 11 is subjected to impact tension during operation, which easily causes the fastening screw 11 to loosen or break and fall off, and has a certain potential safety hazard. The method for measuring and adjusting the radial clearance of the steam seal has low accuracy, often needs to repeatedly measure and adjust for many times, and the partition plate and the cylinder need to be repeatedly disassembled and assembled in the period, so that the workload is extremely high.

In view of this, the present invention is especially provided.

Disclosure of Invention

To the problem that radial clearance size measurement and adjustment exist among the prior art, the utility model provides a vapor seal structure convenient to measure and adjust steam turbine radial clearance through optimizing vapor seal block structure, can improve radial clearance's measurement accuracy.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a steam seal structure convenient for measuring and adjusting the radial clearance of a steam turbine comprises a steam seal sleeve, a rotating shaft, a spring piece and a plurality of steam seal blocks with I-shaped cross sections, wherein an annular cavity with a T-shaped cross section is formed in the inner side surface of the steam seal sleeve along the circumferential direction, the outer ends of the steam seal blocks are sleeved in the annular cavity, the inner ends of the steam seal blocks are sleeved on the rotating shaft, a plurality of steam seal blocks form a shaft seal ring around the axial center of the rotating shaft, the inner surface of the spring piece is pressed against the outer end surface of the steam seal block, and the outer surface of the spring piece is pressed against the inner bottom wall of the annular cavity; every first screw thread through-hole has all been seted up at the middle part of vapour seal piece, first screw thread through-hole spiro union has fixing bolt.

The utility model provides a pair of vapor seal structure convenient to measure and adjust steam turbine radial clearance, when measuring radial clearance, only need follow the interior diapire that screws out to fixing bolt and support to press at annular cavity from first screw through-hole, the vapor seal cover is fixed with the relative position of vapor seal piece this moment, can measure radial clearance.

The utility model provides a when the vapor seal structure measures radial clearance, fixed vapor seal cover is simple, safe and reliable with vapor seal piece relative position fixed mode, and the work load is little, and the accurate nature of measuring radial clearance is high moreover.

Additionally, the utility model discloses a vapor seal structure convenient to measure and adjust steam turbine radial clearance can also have following additional technical characterstic:

according to an example of the present invention, the first threaded through hole is a M5-M8 fine thread hole.

According to the utility model discloses an example, at least one second screw through-hole has radially been seted up along the pivot at the both ends of every vapor seal piece, second screw through-hole spiro union has adjusting bolt.

According to the utility model discloses an example, two second screw through-holes have been seted up to the bilateral symmetry of every one end of gland sealing piece.

According to an example of the present invention, the second threaded through hole is a M1.6-M2.5 fine thread hole.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

FIG. 1 is a schematic view of a steam seal structure in the prior art when a radial gap is measured by a method of pressing an adhesive tape (or a lead wire);

FIG. 2 is a schematic view of spot welding of a vapor seal back arc when a radial gap is small in the prior art;

FIG. 3 is a schematic diagram of a vapor seal back arc extrusion forming salient point when a radial gap is small in the prior art;

FIG. 4 is a schematic view of a prior art radial gap adjustment using a shim when the radial gap is small;

FIG. 5 is a schematic view of a steam seal configuration for facilitating measurement and adjustment of a radial clearance of a steam turbine as provided in example 1;

FIG. 6 is a partial cross-sectional view of a steam seal configuration that facilitates measuring and adjusting a radial clearance of a steam turbine as provided in example 1;

FIG. 7 is a partial cross-sectional view of a steam seal configuration that facilitates measuring and adjusting a turbine radial clearance as provided in example 2.

In the reference symbols:

1. a steam envelope; 1a, an annular cavity; 2. a steam seal block; 20. a shaft seal ring; 21. a first threaded through hole; 22. a second threaded through hole; 3. a rotating shaft; 4. a spring plate; 5. bamboo wedge; 6. a block body; 7. salient points; 8. a gasket; 9. adjusting the bolt; 10. fixing the bolt; 11. fastening screws; 12. fastening a pressure plate; d. a radial gap; e. the gap is adjusted.

Detailed Description

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

Example 1:

as shown in fig. 5 to 6, the present embodiment provides a steam seal structure convenient for measuring and adjusting a radial clearance of a steam turbine, which includes a steam seal cover 1, a rotating shaft 3, a spring plate 4, and a plurality of steam seal blocks 2 with i-shaped cross sections, wherein an annular cavity 1a with a T-shaped cross section is formed on an inner side surface of the steam seal cover 1 along a circumferential direction, an outer end of each steam seal block 2 is sleeved in the annular cavity 1a, an inner end of each steam seal block 2 is sleeved on the rotating shaft 3, a plurality of steam seal blocks 2 form a shaft seal ring 20 around an axial center of the rotating shaft 3, an inner surface of each spring plate 4 abuts against an outer end surface of each steam seal block 2, an outer surface of each spring plate 4 abuts against an inner bottom wall of the annular cavity 1a, a first threaded through hole 21 is formed in a middle portion of each steam seal block 2, and a fixing bolt 10 is screwed in the first.

In the present embodiment, the first threaded through hole 21 is an M5-M8 fine threaded hole, and preferably, the first threaded through hole 21 is an M6 fine threaded hole.

Before measuring the radial clearance d of the steam seal structure provided by the embodiment, the spring piece 4 is firstly removed, then the fixing bolt 10 is rotated outwards, the outer end face of the fixing bolt 10 is tightly pressed on the inner bottom wall of the annular cavity 1a, at the moment, the steam seal block 2 cannot generate relative displacement with the steam seal sleeve 1, then, when the steam seal clearance d is measured, the steam seal block 2 cannot generate deformation and yielding, the running state is consistent, and the accurate coefficient of the measured steam seal clearance d is high.

Compared with the prior art, the steam seal structure that this embodiment provided, steam seal cover 1 can be realized through rotatory fixing bolt 10 with the fixed relative position of steam seal piece 2, and its regulative mode is simple, quick, convenient, and more importantly has avoided using the bamboo wedge, can stop the bamboo wedge and scatter positions such as steam seal extraction hole, has improved the security performance of steam seal machine.

Example 2:

as shown in fig. 7, the present embodiment is further optimized based on embodiment 1, and the optimization is as follows:

two ends of each steam seal block 2 are radially provided with at least one second threaded through hole 22 along the rotating shaft 3, and the second threaded through holes 22 are in threaded connection with the adjusting bolts 9.

In this embodiment, two second threaded through holes 22 are symmetrically formed at two sides of each end of the steam seal block 2.

In the present embodiment, the second threaded through hole 22 is a M1.6-M2.5 fine threaded hole, preferably, the second threaded through hole 22 is a M2 fine threaded hole, the fine threaded hole of M2 is matched with the corresponding adjusting bolt 9, the adjustment value of the gland radial clearance d is one thread pitch of 0.25mm per rotation, the half-rotation is one half thread pitch of 0.125mm per rotation, and so on, so that the adjustment precision and the strength are high.

When the steam seal gap d at a certain position of the steam seal structure provided by the embodiment 1 is larger, the steam seal block 2 can be directly subjected to back arc processing, and the steam seal gap d becomes smaller after the processing; when the steam seal gap d at a certain position is smaller, the adjusting bolt 9 can be rotated inwards, so that the length of the adjusting bolt 9 extending out of the second threaded through hole 22 is gradually increased (the length is the same as the adjusting gap e in fig. 7), and finally, a reasonable radial gap d is achieved. The steam seal structure is suitable for radial clearance adjustment of the partition plate steam seal and the shaft end steam seal of high, middle and low cylinders of the steam turbine, and the adjustment precision can reach 0.01mm-0.02 mm.

The steam seal structure convenient to measure and adjust the radial clearance of the steam turbine that this embodiment provided both can carry out the precision measurement to radial clearance d, can make radial clearance d change again through adjusting bolt 9 and the relative length of second screw through-hole 22, finally reaches reasonable steam seal clearance d.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims

1. A steam seal structure convenient for measuring and adjusting the radial clearance of a steam turbine comprises a steam seal sleeve (1), a rotating shaft (3), a spring piece (4) and a plurality of steam seal blocks (2) with I-shaped cross sections, wherein annular cavities (1a) with T-shaped cross sections are formed in the inner side surface of the steam seal sleeve (1) along the circumferential direction, the outer ends of the steam seal blocks (2) are sleeved in the annular cavities (1a), the inner ends of the steam seal blocks (2) are sleeved on the rotating shaft (3), a plurality of steam seal blocks (2) form a shaft seal ring (20) around the axial center of the rotating shaft (3), the inner surface of the spring piece (4) is pressed against the outer end surface of the steam seal block (2), and the outer surface of the spring piece (4) is pressed against the inner bottom wall of the annular cavity (1 a); the method is characterized in that:

every first screw thread through-hole (21) has all been seted up in the middle part of vapour seal piece (2), first screw thread through-hole (21) spiro union has fixing bolt (10).

2. The gland seal structure for facilitating measurement and adjustment of radial clearance of a steam turbine according to claim 1, wherein: the first threaded through hole (21) is an M5-M8 fine thread threaded hole.

3. The gland seal structure for facilitating measurement and adjustment of radial clearance of a steam turbine according to claim 1, wherein: at least one second threaded through hole (22) is radially arranged at two ends of each steam seal block (2) along the rotating shaft (3), and the second threaded through holes (22) are connected with adjusting bolts (9) in a threaded mode.

4. A gland seal arrangement to facilitate measurement and adjustment of turbine radial clearance according to claim 3, wherein: two second threaded through holes (22) are symmetrically formed in two sides of each end of the steam seal block (2).

5. The gland seal structure for facilitating measurement and adjustment of radial clearance of a steam turbine according to claim 4, wherein: the second threaded through hole (22) is a threaded hole with M1.6-M2.5 fine teeth.