Multi-arc comb tooth type steam seal

Abstract

The utility model discloses a multi-arc comb tooth type steam seal which comprises a steam seal body, the steam seal body is formed by combining a plurality of groups of steam seal blocks which are arranged in an arc structure, steam seal block inner arcs are arranged on two sides of each steam seal block, and a spring mounting round hole is formed in the center of the back of each steam seal block. A spring mounting round hole is formed in the bottom of the steam sealing block, a pressure spring used for providing centripetal moment for the steam sealing block is mounted in the spring mounting round hole, multiple groups of steam sealing block low teeth and multiple groups of steam sealing block high teeth are arranged at the bottom of the steam sealing block, and the multiple groups of steam sealing block low teeth and steam sealing block high teeth are arranged at intervals to form a comb tooth structure. And the steam seal main body is formed by combining not less than 10 groups of steam seal blocks with arc-shaped structures. The utility model relates to a tooth sealing structure of a steam seal, in particular to a multi-arc comb tooth type steam seal which shortens the arc length of a steam seal block and can provide centripetal moment of the steam seal block.

Description

Technical Field

[0001] The utility model relates to a tooth seal structure for steam seal, in particular to a multi-arc segment labyrinth seal. Background Art

[0002] There are various types of steam seals, mainly divided into two types: contact type steam seals and non-contact type steam seals. Among them, the labyrinth seal is one of the steam seals with the largest usage amount and the most reliable performance in China at present. The labyrinth seal pieces are embedded on the seal blocks. Each ring of the steam seal is composed of 6 - 8 seal blocks, and the arc length of each seal block is about 200mm - 400mm. When installed, the steam seal clearance is adjusted by adjusting the front and rear thicknesses of the seal blocks. The steam seal of the steam turbine cannot be adjusted after the unit is put into operation. The overhaul period of the steam turbine is 5 - 7 years. For the unit that is put into operation for the first time after the steam seal is installed, the performance test is relatively close to the expected result. However, after the unit runs for a long time, the performance indicators deteriorate year by year. There are mainly three reasons. One is the wear of the labyrinth seal pieces, the second is the failure and damage of the back spring pieces, and the third is the deformation of the seal blocks. No matter what situation occurs, it needs to be dealt with during the overhaul of the steam turbine. Moreover, due to the large arc length of the original labyrinth seal, the centripetal moment is provided by two spring pieces at both ends of the back. When one spring piece breaks, the function of the whole seal block will be lost by more than 3 / 4, resulting in a serious decline in the steam seal efficiency of the steam seal part. Therefore, improvements are needed for the existing problems. Content of the Utility Model

[0003] In view of the above situation, to make up for the above-mentioned existing defects, the utility model provides a multi-arc segment labyrinth seal with a shortened arc length of the seal block and capable of providing the centripetal moment of the seal block.

[0004] The utility model provides the following technical solution: A multi-arc segment labyrinth seal proposed in this solution includes a steam seal main body, which is composed of a plurality of seal blocks arranged in an arc structure. Seal block inner arcs are provided on both sides of the seal block, and a spring installation round hole is provided at the center of the back of the seal block. A compression spring for providing the centripetal moment for the seal block is installed in the spring installation round hole.

[0005] Further, seal block low teeth and seal block high teeth are respectively provided at the bottom of the seal block. There are multiple groups of the seal block low teeth and the seal block high teeth, and the multiple groups of the seal block low teeth and the seal block high teeth are arranged at intervals to form a comb-like structure.

[0006] Further, the steam seal main body is composed of no less than 10 seal blocks arranged in an arc structure.

[0007] Further, the seal block low teeth, the seal block high teeth and the seal block are respectively processed from metal materials with different properties.

[0008] The beneficial effects achieved by the present utility model with the above structure are as follows: A multi-arc comb-type steam seal proposed by the present utility model has the following advantages:

[0009] 1. By setting a steam seal body composed of no less than 10 groups of steam seal blocks with arc-shaped structures, the arc length of the steam seal blocks in the prior art is shortened. As a result, the deformation amount of the steam seal body after long-term operation of the unit is correspondingly reduced, and the change amount of the gap after steam seal adjustment during installation is also relatively reduced, making the fixation of the steam seal teeth more firm.

[0010] 2. Since the metal materials of the low teeth and high teeth of the steam seal block are different from the metal material of the steam seal block, their expansion and contraction amounts are also different. Therefore, the mutual influence during the thermal expansion and contraction process is reduced after the size of the steam seal body is reduced, and further the deformation amounts of the low teeth and high teeth of the steam seal block are reduced.

[0011] 3. Different from the design of the spring piece on the traditional steam seal block, in this application, by setting a compression spring at the center of the back of the steam seal block, it can prevent breakage. Even if the compression spring breaks, the backward retreat clearance of the steam seal block is much smaller than that of the spring piece type steam seal block.

[0012] 4. Since the steam seal body is composed of dozens of steam seal blocks, when one of the compression springs of the steam seal block is damaged, it will not have an obvious impact on the steam leakage amount of the entire steam seal body.

[0013] 5. Since the increase in the number of steam seal blocks reduces its arc length, and a compression spring is installed on the back of each steam seal block, the follow-up performance of the low teeth and high teeth of the entire circle of steam seal blocks on the rotor will also increase. Compared with the original comb-type steam seal, the steam seal efficiency can be greatly improved. Description of the Drawings

[0014] The drawings are used to provide a further understanding of the present utility model and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model and do not constitute a limitation to the present utility model. In the drawings:

[0015] Figure 1 is a schematic diagram of the overall structure of the multi-arc comb-type steam seal of this solution;

[0016] Figure 2 is Figure 1 the cross-sectional structure schematic diagram of part A - A of

[0017] Among them, 1. Steam seal body, 2. Steam seal block, 3. Inner arc of the steam seal block, 4. Spring installation round hole, 5. Compression spring, 6. Low teeth of the steam seal block, 7. High teeth of the steam seal block. Detailed Embodiment

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0019] It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the accompanying drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0020] As Figure 1 and Figure 2 shown, the technical solution adopted by the present invention is as follows: The present invention provides the following technical solution: A multi-arc segment comb-type steam seal proposed in this solution includes a steam seal main body 1, which is composed of a plurality of steam seal blocks 2 arranged in an arc structure. Steam seal blocks 3 are provided on both sides of the steam seal block 2, and a spring installation round hole 4 is provided at the center of the back of the steam seal block 2. A compression spring 5 for providing a centripetal moment for the steam seal block 2 is installed in the spring installation round hole 4. Steam seal block low teeth 6 and steam seal block high teeth 7 are respectively provided at the bottom of the steam seal block 2. There are multiple groups of steam seal block low teeth 6 and steam seal block high teeth 7, and multiple groups of steam seal block low teeth 6 and steam seal block high teeth 7 are arranged at intervals to form a comb structure.

[0021] Among them, the steam seal main body 1 is composed of no less than 10 groups of steam seal blocks 2 with an arc structure.

[0022] Among them, the steam seal block low teeth 6, the steam seal block high teeth 7 and the steam seal block 2 are respectively processed from metal materials with different properties.

[0023] During specific use, the gland seal body 1 is composed of no less than 10 groups of gland seal blocks 2 with arc-shaped structures, which shortens the arc length of the gland seal blocks in the prior art. As a result, the deformation amount of the gland seal body 1 after the long-term operation of the unit is correspondingly reduced, and the change amount of the clearance after the gland seal adjustment during installation is also relatively reduced, making the fixation of the low teeth 6 and high teeth 7 of the gland seal block more firm. Since the metal materials of the low teeth 6 and high teeth 7 of the gland seal block are different from the metal material of the gland seal block 2, their expansion amounts and shrinkage amounts are also different. Therefore, after the size of the gland seal body 1 is reduced, the mutual influence during the thermal expansion and contraction process is reduced accordingly, and then the deformation amounts of the low teeth 6 and high teeth 7 of the gland seal block are also correspondingly reduced. Due to the increase in the number of gland seal blocks 2, the arc length is reduced, and a compression spring 5 is installed on the back of each gland seal block 2, which can also increase the follow-up performance of the low teeth 6 and high teeth 7 of the gland seal block on the rotor. The compression spring 5 arranged at the center of the back of the gland seal block 2 can prevent breakage. Even if the compression spring 5 breaks, the backward retreat clearance of the gland seal block 2 is within a controllable range; since the gland seal body 1 is composed of dozens of gland seal blocks 2, when the compression spring 5 on one of the gland seal blocks 2 is damaged, it will not have an obvious impact on the steam leakage amount of the entire gland seal body 1, and the gland seal efficiency can be greatly improved compared with the original comb-type gland seal.

[0024] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, material or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, material or device.

[0025] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-arc comb-tooth steam seal, characterized in that: It includes a steam seal body, which is composed of a plurality of steam seal blocks with arc-shaped structures. Steam seal block inner arcs are arranged on both sides of the steam seal block. A spring mounting circular hole is arranged at the center of the back of the steam seal block. A compression spring for providing centripetal torque for the steam seal block is installed in the spring mounting circular hole.

2. A multi-arc comb-tooth steam seal according to claim 1, characterized in that: The bottom of the steam seal block is respectively provided with a steam seal block low tooth and a steam seal block high tooth, and the steam seal block low tooth and the steam seal block high tooth are each provided with multiple groups, and the multiple groups of the steam seal block low teeth and the steam seal block high teeth are arranged at intervals to form a comb tooth structure.

3. A multi-arc comb-tooth steam seal according to claim 2, characterized in that: The steam seal body is composed of no less than 10 groups of arc-shaped steam seal blocks.

4. A multi-arc comb-tooth steam seal according to claim 3, characterized in that: The steam seal block low teeth, the steam seal block high teeth and the steam seal block are respectively made of metal materials with different properties.

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