Air seal structure of steam turbine for thermoelectricity

Abstract

The utility model discloses an air seal structure of a thermoelectric steam turbine, and relates to the technical field of steam turbines. The air seal device comprises an air seal body, a rotor is rotatably connected to the interior of the air seal body, a plurality of air seal grooves are formed in the air seal body, air seal rings are slidably arranged in the air seal grooves, air seal teeth are slidably arranged at the bottoms of the air seal rings, and a plurality of racks are evenly and fixedly connected to the bottoms of the air seal teeth. The receding assembly and the adjusting assembly are arranged, when the turbine has the critical rotating speed in the start-stop process, the receding assembly can be driven to move through the collision force, the distance between the air seal teeth and the rotor and the distance between the rack and the rotor can be adjusted according to the amplitude of the rotor, and long-time collision and abrasion between the air seal teeth and the rotor and between the rack and the rotor are reduced; the air seal teeth and the rack are prevented from being damaged, secondary buffering protection can be effectively conducted on force borne by the air seal teeth and the rack through operation of the adjusting assembly, and therefore normal operation of equipment is kept.

Description

Technical Field

[0001] This application relates to the technical field of steam turbines, and particularly to a gland seal structure for a steam turbine used for combined heat and power generation. Background Art

[0002] The gland seal of a steam turbine is an important device installed between the moving and static parts of the steam turbine. Its main function is to reduce or prevent steam leakage and air leakage from the vacuum side, ensuring the normal and safe operation of the steam turbine. These gland seals effectively improve the sealing performance and economy of the steam turbine through their respective working principles and characteristics. During the operation of the steam turbine, the gland seal plays a crucial role.

[0003] A dust-proof gland seal structure mentioned in the existing Chinese patent (authorized publication number: CN220167994U) relates to the field of gland seals. It includes a gland seal ring. A shoulder is fixedly installed on the outer side of the gland seal ring. Gland seal teeth are fixedly installed on the inner side of the gland seal ring. A positioning mechanism is fixedly installed on one side of the gland seal ring. The positioning mechanism includes a first inlet and outlet hole, a docking base, a docking through hole, a positioning ring seat, and a positioning groove. The docking base is fixedly installed on the gland seal ring. A positioning ring seat is fixedly installed on the docking base. The first inlet and outlet hole is opened at the upper end of the positioning ring seat. The positioning groove is opened inside the positioning ring seat. The docking through hole is opened on the docking base. A sealing mechanism is arranged in the positioning groove. After tightening the screws on the docking base, the entire device can be fixed on one side of the gland seal ring. When the steam turbine stops, gas can be filled into the sealing airbag through a gas pipeline. After filling the sealing airbag with gas, it will expand, thus blocking the gap between the gland seal and the rotor and preventing dust from entering the device.

[0004] In the above patent, the gap between the gland seal and the rotor can be blocked by the sealing airbag to prevent dust from entering the device. However, in daily use, the size and position of the gland seal teeth in the above patent are fixed. Therefore, when the steam turbine passes through the critical speed during startup and shutdown, the amplitude of the rotor is relatively large. Since the distance between the gland seal teeth cannot be adjusted, the radial installation gap of the gland seal is relatively small at this time, making it easy for the gland seal teeth to collide with and wear the rotor. After the impact and wear, not only will the gland seal teeth be damaged, but also the length and temperature of the heating section of the steam on the shaft will increase, resulting in a larger expansion difference and a reduced sealing effect. For this reason, this application provides a gland seal structure for a steam turbine used for combined heat and power generation. Summary of the Utility Model

[0005] The purpose of this application is to provide a gland seal structure for a steam turbine used for combined heat and power generation to solve the problem that the distance between the gland seal teeth cannot be adjusted, making it easy for the gland seal teeth to collide with and wear the rotor.

[0006] To achieve the above purpose, this application specifically adopts the following technical solutions:

[0007] A gas seal structure for a thermal power steam turbine comprises a gas seal body, a rotor is rotatably connected to the inside of the gas seal body, a plurality of gas seal grooves are provided in the gas seal body, gas seal rings are slidably provided inside the plurality of gas seal grooves, gas seal teeth are slidably provided at the bottom of the gas seal rings, a plurality of racks are evenly and fixedly connected to the bottom of the gas seal teeth, the heights of the plurality of racks are uneven, a retreat component is installed on the top of the gas seal teeth, an adjustment component is installed inside the gas seal groove, and a wear-resistant layer is provided on the plurality of racks.

[0008] By adopting the above technical solution, when the critical speed of the steam turbine exceeds the critical speed during the start-up and shutdown process, the resistance force will drive the retreat component to move, so that the air seal teeth and the rack will adjust the distance between them and the rotor according to the amplitude of the rotor, thereby reducing long-term collision and wear between them and the rotor, so as to avoid damage to the air seal teeth and the rack. The operation of the adjustment component can effectively provide secondary buffering protection for the force exerted on the air seal teeth and the rack, so as to maintain the normal operation of the equipment. In addition, the wear-resistant layer can further improve the wear-resistant effect when the rack contacts the rotor.

[0009] Furthermore, the retreat component includes a guide column symmetrically and slidably connected to the bottom of the air sealing ring, the bottom end of the guide column is fixedly connected to the top of the air sealing tooth, the outer wall of the guide column is sleeved with a spring 1, one end of the spring 1 is fixedly connected to the bottom of the air sealing ring, the other end of the spring 1 is fixedly connected to the top of the air sealing tooth, and the top of the guide column is fixedly connected to a limiting block.

[0010] By adopting the above technical solution, when the rack is subjected to the force, it will drive the air seal teeth to push the guide column to slide at the bottom of the air seal ring. The contraction and rebound of spring 1 can effectively buffer the impact force, and the position of the air seal teeth and the rack can change with the movement of the rotor.

[0011] Furthermore, the adjustment assembly includes a fixed plate fixedly connected to the top surface of the air sealing groove, a connecting shaft is slidably arranged at the bottom of the fixed plate, the air sealing ring is slidably connected to the connecting shaft, a sliding plate is slidably connected to the connecting shaft, a spring 2 is fixedly connected to the top of the sliding plate, and the connecting shaft is located inside the spring 2.

[0012] By adopting the above technical solution, the force exerted on the gas seal teeth and the rack can be effectively protected by secondary buffering through the rebound and contraction of the second spring.

[0013] Furthermore, a stopper is threadedly connected to the bottom end of the connecting shaft.

[0014] By adopting the above technical solution, the position of the air sealing ring can be limited and intercepted by the stopper.

[0015] Furthermore, a slider is fixedly connected to the top of the connecting shaft, a slide groove is provided inside the fixed plate, the slider is slidably connected in the slide groove, and one end of the spring 2 away from the slide plate is fixedly connected to the bottom of the slider.

[0016] By adopting the above technical solution, the slider is driven to slide inside the slide groove through the guidance of the connecting shaft, which can effectively prevent the gas sealing ring from being damaged when the force is too large.

[0017] Furthermore, buffer pads are fixedly connected to both sides of the interior of the air sealing groove, and both sides of the air sealing ring are in contact with the buffer pads.

[0018] By adopting the above technical solution, the air sealing ring can be effectively prevented from being damaged when the force is too large through the buffer protection of the buffer pad.

[0019] Furthermore, an expansion chamber is provided between the plurality of racks.

[0020] By adopting the above technical solution, through the expansion chamber set inside the rack, the steam can form a strong vortex in the expansion chamber, converting most of the kinetic energy into heat energy, thereby improving the overall sealing effect of the device.

[0021] Furthermore, the wear-resistant layer is polytetrafluoroethylene.

[0022] By adopting the above technical solution, the wear-resistant layer provided by polytetrafluoroethylene can further improve the wear-resistant effect when the rack contacts the rotor.

[0023] In summary, the present application includes at least one of the following beneficial effects:

[0024] 1. The present application is provided with a yield component and an adjustment component. When the critical speed of the steam turbine exceeds the critical speed during the start-up and shutdown process, the resistance force will drive the yield component to move, so that the air seal teeth and the rack will adjust the distance between them and the rotor according to the amplitude of the rotor, thereby reducing long-term collision and wear between them and the rotor, so as to avoid damage to the air seal teeth and the rack. The operation of the adjustment component can effectively provide secondary buffering protection for the force exerted on the air seal teeth and the rack, so as to maintain normal operation of the equipment.

[0025] 2. The present application is provided with an expansion chamber and a wear-resistant layer. By setting the expansion chamber inside the rack, the steam can form a strong vortex in the expansion chamber, converting most of the kinetic energy into heat energy, thereby improving the overall sealing effect of the device. The wear-resistant layer set by polytetrafluoroethylene can further improve the wear-resistant effect when the rack contacts the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the device body in this application.

[0027] Figure 2 It is the front view of the device main body in this application.

[0028] Figure 3 is Figure 2 the enlarged view at position A in

[0029] Figure 4 It is the schematic diagram of the connection structure between the connecting shaft and the fixing plate in this application.

[0030] Explanation of reference numerals:

[0031] 1. Gas seal body; 2. Rotor; 3. Gas seal groove; 4. Gas seal ring; 5. Gas seal tooth; 6. Rack; 7. Guide post; 8. Spring I; 9. Limit block; 10. Fixing plate; 11. Connecting shaft; 12. Stop block; 13. Sliding plate; 14. Spring II; 15. Slide block; 16. Slide groove; 17. Buffer pad; 18. Expansion chamber. Specific embodiments

[0032] The following will further elaborate on this application in conjunction with the attached Figures 1-4 drawings.

[0033] The embodiment of this application discloses a gas seal structure for a thermoelectric steam turbine.

[0034] Referring to Figure 1 , Figure 2 and Figure 3 , a gas seal structure for a thermoelectric steam turbine includes a gas seal body 1, a rotor 2 is rotatably connected inside the gas seal body 1, a plurality of gas seal grooves 3 are opened inside the gas seal body 1, a gas seal ring 4 is slidably arranged inside each of the plurality of gas seal grooves 3, a gas seal tooth 5 is slidably arranged at the bottom of the gas seal ring 4, a plurality of racks 6 are uniformly fixedly connected to the bottom of the gas seal tooth 5, the heights of the plurality of racks 6 are uneven, a yielding component is installed at the top of the gas seal tooth 5, an adjusting component is installed inside the gas seal groove 3, wear-resistant layers are arranged on each of the plurality of racks 6, buffer pads 17 are fixedly connected to both sides inside the gas seal groove 3, both sides of the gas seal ring 4 are in contact with the buffer pads 17, and the wear-resistant layer is polytetrafluoroethylene.

[0035] In use, when the steam turbine passes through the critical speed during the start-up and shutdown processes, the amplitude of the rotor 2 will be relatively large. At this time, the rotor 2 will gradually come into contact with the rack 6 at the bottom of the labyrinth tooth 5. At this time, the abutting force will drive the yielding component to move, so that the labyrinth tooth 5 and the rack 6 will adjust the distance from the rotor 2 according to the amplitude of the rotor 2, reducing the long-term collision and wear with the rotor 2, so as to avoid damaging the labyrinth tooth 5 and the rack 6. In this way, it effectively reduces the length and temperature of the heating section of the steam on the shaft, resulting in a larger expansion difference, greatly improves the sealing effect, increases the service life of the labyrinth tooth 5 and the rack 6, and when the collision force is greater than the yielding distance of the yielding component, it will push the labyrinth ring 4 to contract inside the labyrinth groove 3. At this time, through the operation of the adjusting component, the force received by the labyrinth tooth 5 and the rack 6 can be effectively buffered and protected, so as to keep the equipment running normally. Secondly, during the use of the steam turbine, the adjusting component can also make the labyrinth ring 4 slightly adjust in the left and right directions inside the labyrinth groove 3. Then, through the buffering protection of the buffer pad 17, it can effectively prevent the labyrinth ring 4 from being damaged when the force is too large. And through the wear-resistant layer set by polytetrafluoroethylene, the wear-resistant effect when the rack 6 contacts the rotor 2 can be further improved.

[0036] Refer to Figure 1 、 Figure 2 and Figure 3 As shown in FIGS.

[0037] In use, when the rotor 2 gradually comes into contact with the rack 6 at the bottom of the labyrinth tooth 5, it will abut and collide with the rack 6. At this time, after the rack 6 receives the acting force, it will drive the labyrinth tooth 5 to push the guide post 7 to slide at the bottom of the labyrinth ring 4 and compress the first spring 8. Through the contraction and rebound of the first spring 8, the impact force can be effectively buffered, and the labyrinth tooth 5 and the rack 6 can change their positions as the rotor 2 moves, adjusting the distance from the rotor 2, reducing the long-term collision and wear with the rotor 2, so as to avoid damaging the labyrinth tooth 5 and the rack 6. In this way, it effectively reduces the length and temperature of the heating section of the steam on the shaft, resulting in a larger expansion difference, greatly improves the sealing effect, and increases the service life of the labyrinth tooth 5 and the rack 6.

[0038] Refer to Figure 2 、 Figure 3 and Figure 4The adjusting component includes a fixed plate 10 fixedly connected to the top surface of the inner part of the gas sealing groove 3, a connecting shaft 11 is slidably arranged at the bottom of the fixed plate 10, the gas sealing ring 4 is slidably connected to the connecting shaft 11, a sliding plate 13 is slidably connected to the connecting shaft 11, a spring 2 14 is fixedly connected to the top of the sliding plate 13, the connecting shaft 11 is located in the spring 2 14, a stopper 12 is threadedly connected to the bottom end of the connecting shaft 11, a slider 15 is fixedly connected to the top of the connecting shaft 11, a sliding groove 16 is opened inside the fixed plate 10, the slider 15 is slidably connected in the sliding groove 16, and one end of the spring 2 14 away from the sliding plate 13 is fixedly connected to the bottom of the slider 15.

[0039] During use, when the collision force is greater than the retreat distance of the guide column 7, the air sealing ring 4 will be pushed to shrink inside the air sealing groove 3. At this time, the sliding plate 13 will be pushed to slide on the connecting shaft 11 through the bottom of the air sealing ring 4, and the spring 2 14 will be squeezed to shrink. Through the rebound and shrinkage of the spring 2 14, the force exerted on the air sealing teeth 5 and the rack 6 can be effectively buffered for a second time, so as to keep the equipment running normally. Secondly, during the use of the steam turbine, the amplitude of the rotor 2 will also make the air sealing ring 4 vibrate left and right in the air sealing groove 3. At this time, the slider 15 will be driven to slide in the slide groove 16 through the guidance of the connecting shaft 11, and then the buffering protection of the buffer pad 17 can effectively prevent the air sealing ring 4 from being damaged when the force is too large, thereby improving the service life of the device.

[0040] Reference Figure 1 , Figure 2 and Figure 3 An expansion chamber 18 is provided between the plurality of racks 6 .

[0041] When in use, through the expansion chamber 18 set inside the rack 6, the steam can form a strong vortex in the expansion chamber 18, converting most of the kinetic energy into heat energy, thereby improving the sealing effect.

[0042] The implementation principle of the gas seal structure of a thermal power steam turbine in this embodiment is as follows: in use, when the steam turbine exceeds the critical speed during the start-up and shutdown process, the amplitude of the rotor 2 will be relatively large. At this time, the rotor 2 will gradually contact the rack 6 at the bottom of the gas seal tooth 5. At this time, the rack 6 will collide with the rack 6 through the resistance force. At this time, after the rack 6 is subjected to the force, it will drive the gas seal tooth 5 to push the guide column 7 to slide at the bottom of the gas seal ring 4, and squeeze the spring 18 to contract. The contraction and rebound of the spring 18 can effectively buffer the impact force, and the gas seal tooth 5 and the rack 6 can change their positions with the movement of the rotor 2, adjust the distance between them and the rotor 2, reduce long-term collision and wear between them and the rotor 2, so as to avoid damage to the gas seal tooth 5 and the rack 6, thereby effectively reducing the length of the heating section of the steam on the shaft and the temperature causing the expansion difference to become larger, greatly improving the sealing effect, and increasing the service life of the gas seal tooth 5 and the rack 6;

[0043] And when the collision force is greater than the retreat distance of the guide column 7, the air seal ring 4 will be pushed to shrink inside the air seal groove 3. At this time, the bottom of the air seal ring 4 will push the sliding plate 13 to slide on the connecting shaft 11 and squeeze the spring 2 14 to shrink. Through the rebound and shrinkage of the spring 2 14, the force exerted on the air seal teeth 5 and the rack 6 can be effectively buffered for a second time to keep the equipment running normally. Secondly, during the use of the steam turbine, the amplitude of the rotor 2 will also make the air seal ring 4 vibrate left and right inside the air seal groove 3. At this time, the slider 15 is driven to slide inside the slide groove 16 through the guidance of the connecting shaft 11, and then the buffer protection of the buffer pad 17 can effectively prevent the air seal ring 4 from being damaged when the force is too large, thereby improving the service life of the device. By setting the expansion chamber 18 inside the rack 6, the steam can form a strong vortex in the expansion chamber 18, converting most of the kinetic energy into heat energy, thereby improving the sealing effect. In addition, the wear-resistant layer set by polytetrafluoroethylene can further improve the wear-resistant effect of the rack 6 when it contacts the rotor 2.

Claims

1. A gas seal structure for a thermal power steam turbine, comprising a gas seal body (1), characterized in that: The air seal body (1) is rotatably connected to a rotor (2), the air seal body (1) is provided with a plurality of air seal grooves (3), air seal rings (4) are slidably arranged inside the plurality of air seal grooves (3), air seal teeth (5) are slidably arranged at the bottom of the air seal ring (4), a plurality of racks (6) are evenly and fixedly connected to the bottom of the air seal teeth (5), the heights of the plurality of racks (6) are uneven, a retreat component is installed at the top of the air seal teeth (5), an adjustment component is installed inside the air seal groove (3), and a wear-resistant layer is provided on the plurality of racks (6).

2. The gas seal structure of a thermal power steam turbine according to claim 1, characterized in that: The retreat component comprises a guide column (7) symmetrically slidably connected to the bottom of the air seal ring (4), the bottom end of the guide column (7) being fixedly connected to the top of the air seal tooth (5), the outer wall of the guide column (7) being sleeved with a spring 1 (8), one end of the spring 1 (8) being fixedly connected to the bottom of the air seal ring (4), the other end of the spring 1 (8) being fixedly connected to the top of the air seal tooth (5), and the top of the guide column (7) being fixedly connected to a limiting block (9).

3. The gas seal structure of a thermal power steam turbine according to claim 1, characterized in that: The adjustment assembly comprises a fixed plate (10) fixedly connected to the inner top surface of the gas sealing groove (3), a connecting shaft (11) being slidably provided at the bottom of the fixed plate (10), the gas sealing ring (4) being slidably connected to the connecting shaft (11), a sliding plate (13) being slidably connected to the connecting shaft (11), a spring 2 (14) being fixedly connected to the top of the sliding plate (13), and the connecting shaft (11) being located inside the spring 2 (14).

4. The gas seal structure of a thermal power steam turbine according to claim 3, characterized in that: The bottom end of the connecting shaft (11) is threadedly connected with a stopper (12).

5. The gas seal structure of a thermal power steam turbine according to claim 3, characterized in that: A slider (15) is fixedly connected to the top of the connecting shaft (11), a slide groove (16) is provided inside the fixed plate (10), the slider (15) is slidably connected in the slide groove (16), and one end of the spring (14) away from the slide plate (13) is fixedly connected to the bottom of the slider (15).

6. The gas seal structure of a thermal power steam turbine according to claim 1, characterized in that: Buffer pads (17) are fixedly connected to both sides of the interior of the air sealing groove (3), and both sides of the air sealing ring (4) are in contact with the buffer pads (17).

7. The gas seal structure of a thermal power steam turbine according to claim 1, characterized in that: An expansion chamber (18) is provided between each of the plurality of racks (6).

8. The gas seal structure of a thermal power steam turbine according to claim 1, characterized in that: The wear-resistant layer is polytetrafluoroethylene.

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