Low-pressure cylinder last-stage blade anti-erosion structure of steam turbine
By designing ratchet and ratchet mechanisms on the last-stage blades of a steam turbine to achieve self-rotation cleaning, and combining this with the brushing function of a brush plate, the problem of oxidation and corrosion of the last-stage blades during shutdown is solved, improving the protection effect and service life of the blades.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- INNER MONGOLIA UNIV OF TECH
- Filing Date
- 2025-08-21
- Publication Date
- 2026-07-31
AI Technical Summary
The last stage blades of a steam turbine are easily oxidized and corroded by water droplets when the turbine is shut down, and existing technologies lack effective protective measures.
An anti-corrosion structure including a blade unit and a cleaning unit was designed. The blade unit achieves self-rotation cleaning of the blade through a ratchet and ratchet mechanism. The cleaning unit uses a brush plate to brush the outer surface of the blade when the blade rotates and uses centrifugal force to remove water droplets.
It effectively prevents the blades from being corroded by liquid when the machine is stopped, extends the service life of the blades, improves cleaning efficiency, and reduces oxidation and corrosion.
Smart Images
Figure CN224579374U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of steam turbine technology, and in particular to an anti-corrosion structure for the last stage blades of a low-pressure cylinder of a steam turbine. Background Technology
[0002] A steam turbine, also known as a steam engine, is a rotary steam power unit. High-temperature, high-pressure steam passes through a fixed nozzle, becomes an accelerated airflow, and is then injected onto the blades, causing the rotor, which is equipped with rows of blades, to rotate and perform work. Steam turbines are the main equipment in modern thermal power plants and are also used in the metallurgical industry, chemical industry, and ship propulsion systems. The last stage blades in a steam turbine are most susceptible to corrosion and decay.
[0003] When existing steam turbines are shut down, water droplets easily remain on the last-stage blades. Since the last-stage blades are most susceptible to contact with the outside air, they are prone to oxidation and corrosion. Therefore, an anti-corrosion structure for the last-stage blades is needed. Utility Model Content
[0004] This utility model discloses an anti-corrosion structure for the last stage blades of a low-pressure cylinder of a steam turbine, which aims to solve the technical problems in the background art.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A corrosion-resistant structure for the last stage blades of a steam turbine low-pressure cylinder includes blade units and a cleaning unit.
[0007] The blade unit includes a turbine casing and a main drive rod. A connecting collar is fixedly installed on one side of the main drive rod. A connecting plate is fixedly installed on one end of the connecting collar. A ratchet is fixedly installed on one end of the connecting plate. A first motor is fixedly installed inside the connecting collar. An impeller ring is fixedly installed at the output end of the first motor. A blade body is fixedly installed on the outer wall of the impeller ring. A ratchet tooth is spring-hinged to one end of the impeller ring.
[0008] The cleaning unit includes a telescopic housing, which is fixedly installed on the outer wall of the turbine housing. A brush plate is slidably installed on the inner wall of the telescopic housing. A threaded rod is threaded inside the brush plate, and a second motor output shaft is fixedly installed at one end of the threaded rod.
[0009] In a preferred embodiment, there are multiple ratchet teeth, each of which is torsion spring hinged to one side of the impeller ring.
[0010] In a preferred embodiment, the ratchet is rotatably mounted on one side of the impeller ring, and the outer walls of the plurality of ratchet teeth are fitted and engaged with the ratchet.
[0011] In a preferred embodiment, an mounting ring is fixedly installed on the outer wall of the first motor, and the mounting ring of the first motor is welded to the connecting sleeve for fixed installation.
[0012] In a preferred embodiment, a through groove is provided inside the turbine casing, and the brush plate is slidably inserted into the turbine casing through the through groove.
[0013] In a preferred embodiment, the second motor is fixedly mounted on one side of the telescopic housing, and the output shaft of the second motor is rotatably through the telescopic housing.
[0014] As can be seen from the above, the anti-corrosion structure for the last stage blade of the low-pressure cylinder of a steam turbine provided by this utility model has the following technical effects.
[0015] Firstly, when the steam turbine is not in use and there is liquid residue on the outer wall of the blade body, the blade body is easily corroded by the liquid. At this time, the first motor drives the impeller ring to rotate counterclockwise. At this time, the ratchet will not block the ratchet, and the impeller ring will not drive the main drive rod to rotate. Therefore, the blade body can rotate at high speed to throw the liquid outward from the surface of the blade body.
[0016] Secondly, when using centrifugal force to clean water droplets on the outside of the blade body, the threaded rod is driven to rotate by the second motor, thereby driving the brush plate to insert into the turbine casing. At the same time, the brush plate comes to the outer surface of the blade body and brushes the outermost edge of the blade body while the blade body rotates. Since the outermost edge of the blade body is most susceptible to corrosion, cleaning the outermost edge of the blade body with the brush plate and residual water stains can extend the service life of the blade body. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the main structure proposed in this utility model.
[0018] Figure 2 This is a schematic diagram of the side cross-sectional structure proposed in this utility model.
[0019] Figure 3 This is a partial structural schematic diagram of the present invention.
[0020] Figure 4 The present utility model proposes Figure 3 Enlarged structural diagram at point A in the middle.
[0021] Figure 5 This is a schematic diagram of the partially disassembled structure proposed in this utility model.
[0022] In the attached diagram: 100, blade unit; 200, cleaning unit; 101, turbine casing; 102, blade body; 103, main drive rod; 104, connecting collar; 105, connecting plate; 106, ratchet; 107, first motor; 108, impeller ring; 109, ratchet tooth; 201, telescopic casing; 202, brush plate; 203, second motor; 204, threaded rod. Detailed Implementation
[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0024] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0025] Reference Figures 1-5 A corrosion-resistant structure for the last stage blades of a low-pressure cylinder of a steam turbine, comprising a blade unit 100 and a cleaning unit 200:
[0026] The blade unit 100 includes a turbine housing 101 and a main drive rod 103. The main drive rod 103 is connected to the main body of the turbine. A connecting collar 104 is fixedly installed on one side of the main drive rod 103. A connecting plate 105 is fixedly installed on one end of the connecting collar 104. A ratchet 106 is fixedly installed on one end of the connecting plate 105. A first motor 107 is fixedly installed inside the connecting collar 104. An impeller ring 108 is fixedly installed at the output end of the first motor 107. A blade body 102 is fixedly installed on the outer wall of the impeller ring 108. A ratchet 109 is hinged to one end of the impeller ring 108 by a torsion spring. The impeller ring 108 is driven to rotate independently by the first motor 107, without driving the entire turbine to rotate, thereby cleaning the blade body 102 with minimal power.
[0027] The cleaning unit 200 includes a telescopic housing 201, which is fixedly installed on the outer wall of the turbine housing 101. A brush is provided on the inner side of the telescopic housing 201, and the brush is attached to the outer wall of the blade body 102. The blade body 102 is cleaned by rotating inside the brush. A brush plate 202 is slidably installed on the inner wall of the telescopic housing 201. A threaded rod 204 is threaded inside the brush plate 202. The output shaft of a second motor 203 is fixedly installed at one end of the threaded rod 204. The second motor 203 drives the threaded rod 204 to rotate, thereby driving the brush plate 202 to extend and retract. It extends when cleaning is needed and retracts when the turbine is working normally, without affecting the normal operation of the turbine.
[0028] In this embodiment, when the steam turbine is not in use and liquid remains on the outer wall of the blade body 102, the blade body 102 is easily corroded by the liquid. At this time, the first motor 107 drives the impeller ring 108 to rotate counterclockwise. At this time, the ratchet 109 will not block the ratchet 106, and the impeller ring 108 will not drive the main drive rod 103 to rotate. Therefore, the blade body 102 can rotate at high speed to throw the liquid outward from the surface of the blade body 102.
[0029] In a preferred embodiment, there are multiple ratchet teeth 109, and each ratchet tooth 109 is torsion spring hinged to one side of the impeller ring 108.
[0030] In this embodiment, multiple ratchet teeth 109 make the engagement between the ratchet teeth 109 and the ratchet wheel 106 more compact.
[0031] In a preferred embodiment, the ratchet 106 is rotatably mounted on one side of the impeller ring 108, and the outer walls of the plurality of ratchet teeth 109 are fitted and engaged with the ratchet 106.
[0032] In this embodiment, the forward and reverse rotation of the ratchet 109 can control whether the impeller ring 108 drives the ratchet 106 to rotate.
[0033] In a preferred embodiment, an mounting ring is fixedly installed on the outer wall of the first motor 107, and the mounting ring of the first motor 107 is welded and fixedly installed with the connecting sleeve 104.
[0034] In this embodiment, the mounting ring increases the contact area between the first motor 107 and the connecting collar 104, making the welding more stable.
[0035] In a preferred embodiment, a through groove is provided inside the turbine housing 101, and the brush plate 202 is slidably inserted into the turbine housing 101 through the through groove.
[0036] In this embodiment, the turbine housing 101 and the brush plate 202 are slidably connected and installed, so that the brush plate 202 can extend and retract within the turbine housing 101.
[0037] In a preferred embodiment, the second motor 203 is fixedly installed on one side of the telescopic housing 201, and the output shaft of the second motor 203 is rotatably installed through the telescopic housing 201.
[0038] In this embodiment, the second motor 203 is prevented from rotating during driving by fixing its position.
[0039] Working principle: When in use, the blade body 102 is first affected by the airflow and rotates clockwise. The ratchet 109 and ratchet 106 will directly drive the connecting plate 105 to rotate, thereby driving the main drive rod 103 to rotate, which meets the daily use of the steam turbine.
[0040] When the steam turbine is not in use and liquid remains on the outer wall of the blade body 102, the blade body 102 is easily corroded by the liquid. At this time, the first motor 107 drives the impeller ring 108 to rotate counterclockwise. At this time, the ratchet 109 will not block the ratchet 106, and the impeller ring 108 will not drive the main drive rod 103 to rotate. Therefore, the blade body 102 can rotate at high speed to throw the liquid outward from the surface of the blade body 102.
[0041] When using centrifugal force to clean water droplets on the outside of the blade body 102, the second motor 203 drives the threaded rod 204 to rotate, thereby driving the brush plate 202 to insert into the turbine casing 101. At the same time, the brush plate 202 comes to the outer surface of the blade body 102 and brushes the outermost edge of the blade body 102 while the blade body 102 rotates. Since the outermost edge of the blade body 102 is most easily corroded, cleaning the outermost edge of the blade body 102 with the brush plate 202 and residual water stains can extend the service life of the blade body 102.
[0042] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Substitutions may include replacements for some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made based on the technical solution and inventive concept of this utility model should all be covered within the scope of protection of this utility model.
Claims
1. A corrosion-resistant structure for the last stage blades of a low-pressure cylinder of a steam turbine, comprising a blade unit (100) and a cleaning unit (200), characterized in that: The blade unit (100) includes a turbine housing (101) and a main drive rod (103). A connecting collar (104) is fixedly installed on one side of the main drive rod (103). A connecting plate (105) is fixedly installed on one end of the connecting collar (104). A ratchet (106) is fixedly installed on one end of the connecting plate (105). A first motor (107) is fixedly installed inside the connecting collar (104). An impeller ring (108) is fixedly installed at the output end of the first motor (107). A blade body (102) is fixedly installed on the outer wall of the impeller ring (108). A ratchet (109) is spring-hinged to one end of the impeller ring (108). The cleaning unit (200) includes a telescopic housing (201), which is fixedly installed on the outer wall of the turbine housing (101). A brush plate (202) is slidably installed on the inner wall of the telescopic housing (201). A threaded rod (204) is threaded inside the brush plate (202), and the output shaft of a second motor (203) is fixedly installed at one end of the threaded rod (204).
2. The anti-corrosion structure for the last stage blades of a low-pressure cylinder of a steam turbine according to claim 1, characterized in that, There are multiple ratchet teeth (109), and each ratchet tooth (109) is torsion spring hinged to one side of the impeller ring (108).
3. A low pressure turbine bucket tip erosion protection structure according to claim 2, wherein, The ratchet (106) is rotatably mounted on one side of the impeller ring (108), and the outer walls of the multiple ratchet teeth (109) are fitted and engaged with the ratchet (106).
4. The erosion protection structure for the last stage blade of a low-pressure cylinder of a steam turbine according to claim 1, characterized by An mounting ring is fixedly installed on the outer wall of the first motor (107), and the mounting ring of the first motor (107) is welded and fixedly installed with the connecting sleeve (104).
5. A low pressure turbine bucket tip erosion protection structure according to claim 1, wherein The turbine housing (101) has a through groove inside, and the brush plate (202) is slidably inserted into the turbine housing (101) through the through groove.
6. A low pressure turbine bucket tip erosion protection structure according to claim 1, wherein The second motor (203) is fixedly installed on one side of the telescopic housing (201), and the output shaft of the second motor (203) is rotatably installed through the telescopic housing (201).