Sealing type partition plate capable of reducing steam leakage

Abstract

The invention relates to the technical field of steam turbine partition plates, in particular to a sealing type partition plate capable of reducing steam leakage, which comprises an upper partition plate and a lower partition plate, a placement groove is formed in the inner wall of an inner ring, a sealing strip is placed in the placement groove, a plurality of extrusion parts are arranged on the outer side of the sealing strip at equal intervals, and a groove is formed in the side surface of the inner ring. A groove is formed in the inner ring, an extrusion ring is placed in the groove, when the extrusion ring is impacted by steam, the extrusion ring shrinks towards the interior of the groove, the multiple extrusion parts in the containing groove can be pushed to move, the multiple extrusion parts extrude the sealing strip from multiple directions at the same time, and therefore the sealing strip can make close contact with the rotor shaft of the inner ring. When the wedge-shaped block extrudes the porous silicon nitride-graphene composite ceramic, oil liquid in the porous silicon nitride-graphene composite ceramic can be extruded out, the extruded oil liquid can permeate into the felt strips, lubricating oil liquid can well lubricate the rotor main shaft, abrasion of the rotor main shaft is reduced, and the sealing efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbine diaphragms, and in particular to a sealing diaphragm for reducing steam leakage. Background Art

[0002] The turbine diaphragm is a component of the turbine cylinder. It is installed in the turbine cylinder and divides the cylinder into several chambers with different pressures. Its main function is to install nozzles or stationary blades and prevent inter-stage steam leakage. When the steam working medium flows through the nozzle installed on the diaphragm, the potential energy is converted into kinetic energy. It is generally divided into two halves, upper and lower, straddling the rotating shaft, and the rotating shaft passes through its center.

[0003] For example, the Chinese patent announcement number CN212508446U discloses a turbine partition sealing device, which has a sealing strip between the annular groove and the partition rim, a sealing ring between the coupling and the center shaft, an upper partition and a lower partition meshingly connected and a sealant in the middle, so that the sealing performance of the entire partition sealing mechanism is better, and the sealing strip and the sealing ring have a certain ductility, which can play a role in reducing damage caused by machine vibration, and is worthy of vigorous promotion.

[0004] However, the sealing ring is prone to wear and tear after being used for a period of time, and the sealing ring cannot form an oil film seal during the sealing process, which makes it easy for the sealing ring and the rotating shaft to wear during the sealing process, resulting in a gap between the partition and the rotor, affecting the working efficiency of the turbine. Summary of the invention

[0005] In view of this, the purpose of the present invention is to propose a sealed partition that reduces steam leakage, so as to solve the problem that the existing partition and the rotor are mostly sealed by a sealing ring, and the sealing ring will wear after a period of use, resulting in a gap between the partition and the rotor, causing steam leakage.

[0006] Based on the above purpose, the present invention provides a sealed baffle for reducing steam leakage, comprising an upper baffle and a lower baffle, wherein the upper baffle and the lower baffle both comprise an outer ring and an inner ring, and an outer peripheral band is fixedly connected to the inner side of the outer ring, an inner peripheral band is fixedly connected to the outer side of the inner ring, and a nozzle blade is fixedly connected between the outer peripheral band and the inner peripheral band; a placement groove is provided on the inner wall of the inner ring, a sealing strip is placed in the placement groove, and a plurality of extrusion parts are arranged at equal intervals on the outer side of the sealing strip, a groove is provided on the side of the inner ring, and an extrusion ring is placed in the groove; When the extrusion ring is impacted by steam, the extrusion ring shrinks into the groove, pushing the multiple extrusion parts in the placement groove to move, and the multiple extrusion parts simultaneously squeeze the sealing strip from multiple directions, so that the sealing strip can be in close contact with the rotor shaft of the inner ring; A linking portion is provided at the contacting position of the ends of the upper partition plate and the lower partition plate, and the connecting portion is used to fix the upper partition plate and the lower partition plate.

[0007] Preferably, the sealing strip is a felt strip with oil absorption function.

[0008] Preferably, the extrusion portion includes an arc-shaped ceramic block bonded to the outside of the felt strip, and a wedge-shaped groove is opened inside the arc-shaped ceramic block, and a wedge-shaped block matching the wedge-shaped groove is slidably arranged in the wedge-shaped groove, and a transmission rod is fixedly connected to the top of the wedge block, and the top end of the transmission rod passes through the inner ring and is connected to the extrusion ring.

[0009] Preferably, the surface of the arc-shaped ceramic block is coated with an oleophilic coating, and the interior has a network structure of interconnected pores.

[0010] Preferably, the arc-shaped ceramic block is a porous silicon nitride-graphene composite ceramic with oil storage performance.

[0011] Preferably, the connecting part includes two arc-shaped connecting rods, and the ends of the upper partition and the lower partition are both provided with arc-shaped grooves adapted to the arc-shaped connecting rods, and one of the arc-shaped connecting rods is slidably set in the arc-shaped groove of the upper partition, and the other arc-shaped connecting rod is slidably set in the arc-shaped groove of the lower partition.

[0012] Preferably, a locking bolt is fixedly connected to the arc-shaped connecting rod, and arc-shaped through grooves for the locking bolt to move are provided on the upper partition and the lower partition, and a locking nut is threadedly connected to the locking bolt and abuts against the upper partition or the lower partition.

[0013] Beneficial effects of the present invention: The present invention provides a sealed partition for reducing steam leakage. During the installation of the partition, one side with an extrusion ring is installed near the steam inlet. When the extrusion ring is impacted by steam, the extrusion ring shrinks into the groove to squeeze the wedge block. Since the wedge block is matched with the wedge groove inside the arc-shaped ceramic block, the arc-shaped ceramic block is pushed to extrude the felt strip, so that the felt strip can always be in close contact with the rotor shaft. In addition, the porous silicon nitride-graphene composite ceramics also have oil storage properties, so that when the wedge block extrude the porous silicon nitride-graphene composite ceramics, the oil in the porous silicon nitride-graphene composite ceramics can be squeezed out, and the squeezed oil can penetrate into the felt strips. The lubricating oil can better lubricate the rotor main shaft, reduce the wear of the rotor main shaft, improve the sealing efficiency, and avoid the wear of the felt strips after long-term use, resulting in a gap between the partition and the rotor, causing steam leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 For the embodiment of the present invention Figure 1 A schematic diagram of the rear perspective structure; Figure 3 This is a schematic diagram of the structure after the upper partition and the lower partition are separated according to an embodiment of the present invention; Figure 4 This is a schematic structural diagram of an upper baffle, an extrusion portion and a sealing strip according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the arc-shaped ceramic block, the wedge-shaped block and the sealing strip according to an embodiment of the present invention; Figure 6 Schematic diagram of the structure of the arc-shaped ceramic block and the wedge-shaped block according to an embodiment of the present invention.

[0016] In the figure: 1. upper baffle; 2. lower baffle; 3. outer ring; 4. inner ring; 5. outer band; 6. inner band; 7. nozzle blade; 8. sealing strip; 9. extrusion ring; 10. extrusion part; 101. arc-shaped ceramic block; 102. wedge-shaped block; 103. transmission rod; 11. connecting part; 111. arc-shaped connecting rod; 112. locking bolt; 113. arc-shaped through groove. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0018] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0019] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, a sealed baffle for reducing steam leakage comprises an upper baffle 1 and a lower baffle 2, both of which comprise an outer ring 3 and an inner ring 4, and an outer band 5 is fixedly connected to the inner side of the outer ring 3, an inner band 6 is fixedly connected to the outer side of the inner ring 4, and a nozzle blade 7 is fixedly connected between the outer band 5 and the inner band 6; a placement groove is provided on the inner wall of the inner ring 4, a sealing strip 8 is placed in the placement groove, and a plurality of extrusion portions 10 are arranged at equal intervals on the outer side of the sealing strip 8, a groove is provided on the side of the inner ring 4, and an extrusion ring 9 is placed in the groove; When the extrusion ring 9 is impacted by steam, the extrusion ring 9 shrinks into the groove, pushing the multiple extrusion parts 10 placed in the groove to move, and the multiple extrusion parts 10 squeeze the sealing strip 8 from multiple directions at the same time, so that the sealing strip 8 can be in close contact with the rotor shaft of the inner ring 4. The extrusion ring 9 is located on the side where steam enters. When the steam continuously passes through the nozzle blades 7, it will continuously impact the extrusion ring 9. The impact force of the extrusion will squeeze the sealing strip 8 from the circumferential direction with the cooperation of the multiple extrusion parts 10, so that the sealing strip 8 can always be in contact with the rotor shaft, avoiding the wear of the sealing strip 8 due to long-term use, resulting in a gap; A connecting portion 11 is provided at the contact point between the ends of the upper partition 1 and the lower partition 2, and the connecting portion 11 is used to fix the upper partition 1 and the lower partition 2. Through the setting of the connecting portion 11, when the upper partition 1 and the lower partition 2 are aligned and installed, the upper partition 1 and the lower partition can be quickly and firmly fixed, and the fixing effect is good.

[0020] In a preferred embodiment of the present invention, the sealing strip 8 is a felt strip with an oil absorption function. After absorbing the oil, the felt strip forms an oil-adhesive pad, which slowly releases the lubricating oil and reduces friction and wear.

[0021] In another preferred embodiment of the present invention, the extrusion portion 10 includes an arc-shaped ceramic block 101 bonded to the outside of the felt strip, and a wedge-shaped groove is opened inside the arc-shaped ceramic block 101, and a wedge-shaped block 102 adapted to the wedge-shaped groove is slidably arranged in the wedge-shaped groove, and a transmission rod 103 is fixedly connected to the top of the wedge block 102, and the top end of the transmission rod 103 passes through the inner ring 4 and is connected to the extrusion ring 9.

[0022] The extrusion ring 9 is located on the side where steam enters. When the steam impacts the extrusion ring 9, the extrusion ring 9 shrinks into the groove. The extrusion ring 9 pushes multiple transmission rods 103 inward to move, and the transmission rods 103 push the wedge block 102 to move. Since the wedge block 102 is adapted to the wedge groove inside the arc-shaped ceramic block 101, when the wedge block 102 moves, it will push the arc-shaped ceramic block 101 to move, and the arc-shaped ceramic block 101 will extrude the sealing strip 8, so that the sealing strip 8 can always be in contact with the rotor shaft, thereby improving the sealing effect of the sealing strip 8.

[0023] In another preferred embodiment of the present invention, the surface of the arc-shaped ceramic block 101 is coated with an oleophilic coating, and the interior has a network structure of interconnected pores.

[0024] Through pore-forming agents (such as polystyrene microspheres) or 3D printing technology, a connected pore network (porosity 30%~40%) is formed, and lubricating oil (such as silicone oil and perfluoropolyether oil) is adsorbed in the pores.

[0025] Surface modification: The ceramic surface is coated with an oleophilic coating (such as silane coupling agent) to enhance oil wettability and storage stability.

[0026] It should be noted that the arc-shaped ceramic block (101) is a porous silicon nitride-graphene composite ceramic having oil storage performance.

[0027] Porous silicon nitride-graphene composite ceramics have the following characteristics: Oil storage capacity, Porous structure: A connected pore network (porosity 30%~40%) is formed through pore-forming agents (such as polystyrene microspheres) or 3D printing technology, and lubricating oil (such as silicone oil and perfluoropolyether oil) is adsorbed in the pores; Surface modification: The ceramic surface is coated with an oleophilic coating (such as silane coupling agent) to enhance oil wettability and storage stability.

[0028] Elastic recovery, Graphene toughening: Graphene sheets are dispersed in the silicon nitride matrix to form a "bridging structure" that absorbs external force energy and inhibits crack propagation, giving the material metal-like elastic deformation capabilities (elastic modulus can reach 250~300 GPa).

[0029] Gradient pore design: the surface is dense (porosity <10%), and the interior is porous (porosity >30%). When under pressure, the internal pores are compressed and the stored oil is released to form a lubricating film. After the external force is removed, the elasticity of graphene helps the pores to partially recover.

[0030] The manufacturing process of porous silicon nitride-graphene composite ceramics is as follows: Powder mixing: Evenly mix silicon nitride powder, graphene nanosheets (1%~5wt%) and pore-forming agent.

[0031] Molding and sintering: After cold isostatic pressing, the pore-forming agent is decomposed to form a porous structure by reaction sintering (1600-1800°C) in a nitrogen atmosphere; Alternatively, 3D printing (photocuring / binder jetting) can be used to construct gradient pores layer by layer, followed by sintering for densification.

[0032] Post-processing Surface coating: growing graphene on the inner wall of the pores by chemical vapor deposition (CVD) or coating with silane coupling agent.

[0033] Impregnation lubrication: Vacuum impregnation of liquid lubricant (such as high-temperature silicone oil) to ensure full adsorption of pores.

[0034] It should be noted that the connecting part 11 includes two arc-shaped connecting rods 111, and the ends of the upper partition 1 and the lower partition 2 are both provided with arc-shaped grooves adapted to the arc-shaped connecting rods 111, and one of the arc-shaped connecting rods 111 is slidably set in the arc-shaped groove of the upper partition 1, and the other arc-shaped connecting rod 111 is slidably set in the arc-shaped groove of the lower partition 2.

[0035] Based on the above embodiment, a locking bolt 112 is fixedly connected to the arc-shaped connecting rod 111, and an arc-shaped through groove 113 for the locking bolt 112 to move is provided on the upper partition 1 and the lower partition 2, and a locking nut is threadedly connected to the locking bolt 112 to abut against the upper partition 1 or the lower partition 2.

[0036] When the upper partition 1 and the lower partition 2 need to be fixed, when the upper partition 1 and the lower partition 1 are aligned, the arc-shaped connecting rod 111 is inserted into the arc-shaped groove, and then the locking nut is tightened so that the locking nut abuts against the upper partition 1 or the lower partition 2, thereby achieving the limited fixation of the locking bolt 112.

[0037] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0038] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sealed baffle for reducing steam leakage, comprising an upper baffle (1) and a lower baffle (2), wherein the upper baffle (1) and the lower baffle (2) each comprise an outer ring (3) and an inner ring (4), wherein an outer peripheral band (5) is fixedly connected to the inner side of the outer ring (3), an inner peripheral band (6) is fixedly connected to the outer side of the inner ring (4), and a nozzle vane (7) is fixedly connected between the outer peripheral band (5) and the inner peripheral band (6); characterized in that: The inner wall of the inner ring (4) is provided with a placement groove, a sealing strip (8) is placed in the placement groove, and a plurality of extrusion parts (10) are arranged at equal intervals on the outer side of the sealing strip (8); the side of the inner ring (4) is provided with a groove, and an extrusion ring (9) is placed in the groove; when the extrusion ring (9) is impacted by steam, the extrusion ring (9) contracts into the groove, pushing the plurality of extrusion parts in the placement groove to move, and the plurality of extrusion parts simultaneously squeeze the sealing strip (8) from multiple directions, so that the sealing strip (8) can be in close contact with the rotor shaft of the inner ring (4); a connecting part (11) is provided at the contact point between the ends of the upper baffle (1) and the lower baffle (2), and the connecting part (11) is used to fix the upper baffle (1) and the lower baffle (2).

2. A sealed partition for reducing steam leakage according to claim 1, characterized in that: The sealing strip (8) is a felt strip with an oil absorption function.

3. A sealed partition for reducing steam leakage according to claim 2, characterized in that: The extrusion portion (10) comprises an arc-shaped ceramic block (101) bonded to the outside of the felt strip, a wedge-shaped groove is provided inside the arc-shaped ceramic block (101), a wedge-shaped block (102) adapted to the wedge-shaped groove is slidably arranged in the wedge-shaped groove, a transmission rod (103) is fixedly connected to the top of the wedge-shaped block (102), and the top end of the transmission rod (103) passes through the inner ring (4) and is connected to the extrusion ring (9).

4. A sealed partition for reducing steam leakage according to claim 3, characterized in that: The surface of the arc-shaped ceramic block (101) is coated with an oleophilic coating, and the interior has a network structure of interconnected pores.

5. A sealed partition for reducing steam leakage according to claim 3, characterized in that: The arc-shaped ceramic block (101) is a porous silicon nitride-graphene composite ceramic with oil storage performance.

6. A sealed partition for reducing steam leakage according to claim 1, characterized in that: The connecting portion (11) comprises two arc-shaped connecting rods (111), and the ends of the upper partition (1) and the lower partition (2) are both provided with arc-shaped grooves adapted to the arc-shaped connecting rods (111), and one of the arc-shaped connecting rods (111) is slidably disposed in the arc-shaped groove of the upper partition (1), and the other arc-shaped connecting rod (111) is slidably disposed in the arc-shaped groove of the lower partition (2).

7. A sealed partition for reducing steam leakage according to claim 6, characterized in that: A locking bolt (112) is fixedly connected to the arc-shaped connecting rod (111), and an arc-shaped through groove (113) for the locking bolt (112) to move is provided on the upper partition (1) and the lower partition (2), and a locking nut abutting against the upper partition (1) or the lower partition (2) is threadedly connected to the locking bolt (112).

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