Poisson effect based turbine end face middle split face extrusion seal assembly

Abstract

This invention belongs to the technical field of steam turbine design and discloses a steam turbine end split-face compression sealing assembly based on the Poisson effect. The assembly includes an upper metal pressure plate, a lower metal pressure plate, multiple layers of high-temperature rubber sheets, a side metal pressure plate, and side high-temperature rubber sheets. The multiple layers of high-temperature rubber sheets are disposed between the upper and lower metal pressure plates and are fixed by high-strength bolts that penetrate the multiple layers of high-temperature rubber sheets, the upper metal pressure plate, and the lower metal pressure plate. The sealing ends of the multiple layers of high-temperature rubber sheets protrude from the upper and lower metal pressure plates. The thickness of the middle layer of high-temperature rubber sheets is less than that of the top and bottom layers. Bolts are provided at the ends of the upper and lower metal pressure plates, and through bolt holes are provided in the side metal pressure plates and the side high-temperature rubber sheets. The bolt holes in the side metal pressure plates are vertically elongated elliptical holes, and the bolts are matched and fixed with the vertically elongated elliptical holes. This application can achieve sealing of split-face leakage problems existing in narrow spaces.

Description

Technical Field

[0001] This invention belongs to the technical field of steam turbine design, and more specifically, relates to a steam turbine end split-face extrusion sealing assembly based on the Poisson effect. Background Technology

[0002] Steam leakage at the split surface of a steam turbine cylinder is a common problem encountered in power plants. Common solutions include welding and grinding. However, for leaks at the split surface caused by non-surface defects, structural modifications are necessary, but these modifications are subject to various limitations. Adding sealing measures to the outside of the leak point is a flexible, convenient, and efficient approach. This method does not require modification of the cylinder body, carries minimal safety risks, and is easy to implement.

[0003] Chinese patent CN115653697A discloses a leak-proof sealing assembly for the split end of a steam turbine cylinder, which uses a sealing glue injection method. The sealing glue is in a fluid state during injection, requiring a high degree of sealing of the leakage environment. If the sealing is insufficient and the gap is too large, the sealing glue will overflow, causing the sealing pressure to be insufficient and resulting in sealing failure. Furthermore, the sealing glue is often thermosetting, hardening during operation, making secondary leaks difficult to repair. Finally, the glue injection process requires a glue gun and a pressure pump, necessitating a large operating space and complex operation. This patent uses an elastic solid material for sealing, which is completely different in principle from the aforementioned patent, and their performance also differs.

[0004] Patent CN215334429 U provides a rubber sealing device with protective function, which focuses on temperature protection to prevent the rubber from hardening at low temperatures. Its sealing is achieved by two working parts squeezing the middle rubber layer during operation. In this application, the rubber is squeezed by an auxiliary part, which is quite different from that patent.

[0005] Patent CN209262250U provides a rubber sealing gasket assembly structure for an engine, in which a rubber structure is embedded in a metal plate. The upper and lower sealing surfaces compress the protruding structure of the rubber ring, causing it to deform and generate contact pressure to achieve a seal. The deformation and contact pressure of the rubber ring are caused by the protruding structure being squeezed by the mounting plane. This does not allow for flexible adjustment of the contact pressure, i.e., the sealing performance, during operation. In this application, the amount of deformation and the magnitude of the sealing contact pressure can be adjusted with bolts during operation, which is quite different from the patent.

[0006] Patent CN202022008421.2 provides a sealing top cover door for a bag filter, which uses a combination of rubber extrusion sealing and liquid sealing to achieve the sealing of the low-pressure dust removal chamber. Its sealing surface is a regular plane, and corresponding modifications need to be made to the top cover structure of the sealing chamber. It is difficult to adapt to complex sealing surfaces and situations where it is not allowed to modify the original structure. Summary of the Invention

[0007] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a turbine end split surface extrusion sealing component based on the Poisson effect, which can achieve the effect of sealing high-temperature steam or other flowing substances with split surface leakage, without changing the original design structure, and the sealing pressure can be flexibly adjusted.

[0008] To achieve the above objectives, according to one aspect of the present invention, an irregularly shaped elastic external sealing assembly for the split surface of a steam turbine end is provided. The assembly includes an upper metal pressure plate, a lower metal pressure plate, multiple layers of high-temperature rubber sheets, a side metal pressure plate, and a side high-temperature rubber sheet. The multiple layers of high-temperature rubber sheets are disposed between the upper and lower metal pressure plates and are fixed by high-strength bolts passing through the multiple layers of high-temperature rubber sheets, the upper metal pressure plate, and the lower metal pressure plate. The sealing ends of the multiple layers of high-temperature rubber sheets protrude beyond the upper and lower metal pressure plates. The thickness of the middle layer of high-temperature rubber sheets is less than that of the top and bottom layers of high-temperature rubber sheets. Bolts are provided at the ends of the upper and lower metal pressure plates, and through bolt holes are provided in the side metal pressure plates and the side high-temperature rubber sheets. The bolt holes in the side metal pressure plates are vertically elongated elliptical holes, and the bolts are matched and fixed to the vertically elongated elliptical holes.

[0009] Preferably, the thickness of the multilayer high-temperature rubber sheet gradually decreases from the top and bottom to the middle layer, and the thickness of the middle layer is 1.5 to 2.5 mm.

[0010] Preferably, the bolt holes through which the high-strength bolts pass on the upper metal plate and the lower metal plate have different diameters.

[0011] Preferably, the bolt hole on the lower metal plate that accommodates the high-strength bolt is a threaded hole with an inlet guide tapered section, and the bolt hole on the upper metal plate that accommodates the high-strength bolt is larger than the bolt hole on the lower metal plate that accommodates the high-strength bolt.

[0012] Preferably, the component further includes a thin metal pressure plate disposed between the upper metal pressure plate and the multilayer high-temperature rubber sheet, and between the lower metal pressure plate and the multilayer high-temperature rubber sheet.

[0013] Preferably, the cross-section of the thin metal pressure plate is larger than that of the upper metal pressure plate and the lower metal pressure plate, but smaller than that of the multilayer high-temperature rubber sheet, and also slightly smaller than the cross-section of the space in which it is located.

[0014] Preferably, the longitudinal ends of the side metal pressure plate protrude inward to limit the longitudinal displacement of the side high-temperature rubber sheet.

[0015] Preferably, the surface of the side metal pressure plate that contacts the side high-temperature rubber sheet is provided with anti-slip small protrusions.

[0016] Another aspect of this application provides an application of the aforementioned irregularly shaped elastic external sealing assembly for the split surface of a steam turbine end, wherein the outer contour of the rubber of the assembly matches and is slightly smaller than the opening to be sealed on the steam turbine, so that the assembly can withstand pressure during sealing.

[0017] In summary, compared with the prior art, the turbine end split-face extrusion sealing technology and components based on the Poisson effect provided by this invention have the following advantages:

[0018] 1. The sealing assembly of this application has expansion and contraction margins in multiple directions. Based on the Poisson effect, the assembly achieves expansion and compression in the other two directions through controllable and uniform compression in one direction. Due to the elasticity of rubber, it is suitable for uneven curved surfaces and can achieve external sealing of the split surface in narrow through-spaces to prevent air leakage.

[0019] 2. The sealing process of this application does not affect the normal operation of the steam turbine. It can be replaced in time after the high-temperature rubber fails. When the sealing pressure is insufficient, it can increase the pressure without injecting glue. It is simple to operate and economical.

[0020] 3. High-temperature rubber materials have strong deformation capabilities, enabling them to adapt to uneven cylinder end walls, fill small defects in the walls to achieve a sealing effect, and adapt to gaps larger than those of flowing sealant.

[0021] 4. The thickness of the multi-layer high-temperature rubber sheet gradually decreases from the top and bottom to the inner layer, which can achieve the sealing of tiny gaps.

[0022] 5. The combination of thick and thin metal pressure plates in this application facilitates installation and controls the gap between the external sealing component and the cylinder wall. Furthermore, the thin metal pressure plate can be further processed according to the site conditions and installation process to make its shape fit the cylinder wall more closely. This application can also seal wall leakage problems in other narrow or semi-open spaces. Attached Figure Description

[0023] Figure 1 This is an overall schematic diagram of the steam turbine cylinder;

[0024] Figure 2 This is a magnified view of a portion of the gap at the end of a steam turbine cylinder;

[0025] Figure 3 This is a schematic diagram of leakage at the cylinder end;

[0026] Figure 4This is a schematic diagram of the sealing principle;

[0027] Figure 5 This is a schematic diagram of the structure of a turbine end split-face extrusion sealing technology and component based on the Poisson effect according to an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of the metal pressure plate structure in an embodiment of this application;

[0029] Figure 7 This is a schematic diagram of the metal pressure plate structure in an embodiment of this application;

[0030] Figure 8 This is a schematic diagram of the thin metal pressure plate structure according to an embodiment of this application;

[0031] Figure 9 This is a schematic diagram of the high-temperature rubber sheet structure according to an embodiment of this application;

[0032] Figure 10 This is a schematic diagram of the side metal pressure plate structure in an embodiment of this application.

[0033] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0034] 1-Upper metal pressure plate; 2-Lower metal pressure plate; 3-Thin metal pressure plate; 4-Multi-layer high-temperature rubber sheet; 5-Side metal pressure plate; 6-Side high-temperature rubber sheet; 7-High-strength bolt; 8-High-strength washer. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0036] This invention provides a turbine end split-face extrusion sealing assembly based on the Poisson effect, such as... Figure 5 As shown, the component includes an upper metal pressure plate 1, a lower metal pressure plate 2, a multi-layer high-temperature rubber sheet 4, a side metal pressure plate 5, and a side high-temperature rubber sheet 6.

[0037] Figure 1 The location of the leak is marked by a circle in the turbine cylinder where the steam leak occurred. Figure 2 This is a magnified view of the leak location.

[0038] A simplified diagram of the leak location is shown below. Figure 3 As shown, the upper and lower halves of the container are in contact through a mating surface. During actual operation of the cylinder, a leak was found at the end of the mating surface (the position marked in bold in the figure).

[0039] Figure 4 This is a schematic diagram of the sealing principle of the present invention. High-strength bolts 7 apply force to both sides of the upper metal pressure plate 1 and the lower metal pressure plate 2, thereby squeezing the upper and lower surfaces of the high-temperature rubber sheet 4. According to the Poisson effect, the high-temperature rubber sheet 4 will expand to both sides, thereby squeezing the cylinder side wall and increasing the contact pressure with the cylinder wall to achieve sealing.

[0040] A multi-layer high-temperature rubber sheet 4 is disposed between the upper metal pressure plate 1 and the lower metal pressure plate 2, and is fixed by a high-strength bolt 7 that passes through the multi-layer high-temperature rubber sheet 4, the upper metal pressure plate 1 and the lower metal pressure plate 2.

[0041] In a further preferred embodiment, the upper metal pressure plate 1 (e.g.) Figure 6 The diameter of the bolt hole (shown) and the bolt hole through which the high-strength bolt 7 passes on the lower metal pressure plate 2 are different.

[0042] In a further preferred embodiment, the bolt hole on the lower metal pressure plate 2 that accommodates the high-strength bolt 7 is a threaded hole with an inlet guide tapered section, such as... Figure 7 As shown, this facilitates the assembly and positioning of the high-strength bolts. The bolt holes on the upper metal plate 1 that are adapted to the high-strength bolts 7 are larger than the bolt holes on the lower metal plate 2 that are adapted to the high-strength bolts 7, ensuring that the upper metal plate 1 and the lower metal plate 2 can be misaligned within a certain limit to accommodate the misalignment of the upper and lower cylinders.

[0043] The sealing end of the multilayer high-temperature rubber sheet 4 protrudes from the upper metal pressure plate 1 and the lower metal pressure plate 2. The multilayer high-temperature rubber sheet 4 (e.g.) Figure 9 The thickness of the middle layer high-temperature rubber sheet (as shown) is less than that of the top layer high-temperature rubber sheet and the bottom layer high-temperature rubber sheet. For example, the thickness of the top and bottom high-temperature rubber sheets can be set to 10mm, and the middle layer can be set to 4 layers with a thickness of 5mm, which can better compensate for the gaps in the cylinder split surface.

[0044] In a further preferred embodiment, the thickness of the multilayer high-temperature rubber sheet 4 gradually decreases from the top and bottom to the inner layer.

[0045] Bolts are provided at the ends of the upper metal pressure plate 1 and the lower metal pressure plate 2. Bolt holes are provided in the side metal pressure plate 5 and the side high-temperature rubber sheet 6. The bolt holes in the side metal pressure plate 5 are vertically elongated elliptical holes. The bolts are matched and fixed with the vertically elongated elliptical holes. After the multi-layer high-temperature rubber sheet 4 is compressed, the upper metal pressure plate 1 and the lower metal pressure plate 2 can move up and down within a certain limit.

[0046] In a further preferred embodiment, the ends of the upper metal pressure plate 1 and the lower metal pressure plate 2 are provided with bolt holes, and the bolts fix the side high-temperature rubber sheet 6 and the side metal pressure plate 5 to the ends of the upper and lower metal pressure plates 1 and 2.

[0047] In a further preferred embodiment, the component also includes a thin metal pressure plate 3 (such as...). Figure 8 As shown, the thin metal pressure plate 3 is disposed between the upper metal pressure plate 1 and the multi-layer high-temperature rubber sheet 4, and between the lower metal pressure plate 2 and the multi-layer high-temperature rubber sheet 4. The area of ​​the thin metal pressure plate 3 is larger than that of the upper metal pressure plate 1 and the lower metal pressure plate 2, but slightly smaller than that of the multi-layer high-temperature rubber sheet 4. The outer contour dimension of the thin metal pressure plate 3 is slightly smaller than that of the cylinder end contour (preferably 0.2-0.4 mm). Because the thin metal pressure plate 3 is relatively thin, it can be easily inserted even if its outer contour is slightly smaller than that of the cylinder end contour. The thin metal pressure plate 3, placed between the upper metal pressure plate 1, the lower metal pressure plate 2 and the multi-layer high-temperature rubber sheet 4, can evenly transmit the pressure of the upper and lower metal pressure plates 1 and 2 to the multi-layer high-temperature rubber sheet 4, avoiding excessive local deformation and damage to the edges of the multi-layer high-temperature rubber sheet 4 due to the squeezing of the upper metal pressure plate 1 and the lower metal pressure plate 2.

[0048] In further optimized solutions, such as Figure 10 As shown, the side metal pressure plate 5 protrudes inward at both ends to restrict the longitudinal displacement of the side high-temperature rubber sheet 6. The surface of the side metal pressure plate 5 that contacts the side high-temperature rubber sheet 6 is provided with anti-slip protrusions to increase the friction between it and the side high-temperature rubber sheet 6, ensuring that the side high-temperature rubber sheet 6 will not deform excessively or slide out.

[0049] The multi-layer high-temperature rubber sheet and the side high-temperature rubber sheet can be made of silicone rubber (methyl vinyl silicone rubber). Experimental testing has shown that the elasticity and sealing effect of silicone rubber meet the sealing requirements. The high-strength bolts can be pointed high-strength bolts, which, when used with threaded holes featuring inlet guide tapered sections, facilitate assembly and positioning. Preferably, two high-strength bolts are used, and a high-strength washer 8 is provided at the point where the high-strength bolt mates with the nut.

[0050] Another aspect of this application provides a turbine end split-face extrusion sealing assembly based on the Poisson effect, wherein the left and right sides of the high-temperature rubber sheet 6 of the assembly have the same shape as the cylinder wall and adhere tightly to the cylinder wall after being compressed.

[0051] The outer contour of the multi-layer high-temperature rubber sheet 4 is slightly smaller than the cylinder end contour. When subjected to pressure, it will be squeezed and deformed and will be tightly attached to the cylinder wall in the circumferential direction. Combined with the auxiliary effects of cylinder sealant, a high contact pressure is formed on the outer periphery of the steam leakage area in the cylinder. When this contact pressure exceeds the steam pressure, it achieves the effect of external sealing and preventing steam leakage.

[0052] This application applies to the sealing problem of leakage at the end of a steam turbine. If the sealing problem is at the end of another pressure vessel, and the leakage surface is a plane without forming a semi-enclosed space, appropriate modifications need to be made based on this patent to add a semi-enclosed shell and weld it to the pressure vessel. The shape of the pressure plate and the shape of the rubber sheet in this patent also need to be modified accordingly.

[0053] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A turbine end split-face extrusion sealing assembly based on the Poisson effect, characterized in that, The component includes an upper metal pressure plate (1), a lower metal pressure plate (2), multiple layers of high-temperature rubber sheets (4), a side metal pressure plate (5), and a side high-temperature rubber sheet (6), wherein: The multi-layer high-temperature rubber sheet (4) is disposed between the upper metal pressure plate (1) and the lower metal pressure plate (2) and is fixed by high-strength bolts (7) that pass through the multi-layer high-temperature rubber sheet (4), the upper metal pressure plate (1) and the lower metal pressure plate (2). The sealing end of the multi-layer high-temperature rubber sheet (4) protrudes from the upper metal pressure plate (1) and the lower metal pressure plate (2). The thickness of the middle layer of the multi-layer high-temperature rubber sheet (4) is less than that of the top layer and the bottom layer. The upper metal pressure plate (1) and the lower metal pressure plate (2) are provided with bolts at their ends, and the side metal pressure plate (5) and the side high-temperature rubber sheet (6) are provided with through bolt holes. The bolt holes of the side metal pressure plate (5) are vertically elongated elliptical holes, and the bolts are matched and fixed with the vertically elongated elliptical holes. The component also includes a thin metal plate (3), which is disposed between the upper metal plate (1) and the multilayer high-temperature rubber sheet (4), and between the lower metal plate (2) and the multilayer high-temperature rubber sheet (4); The cross-section of the thin metal plate (3) is larger than that of the upper metal plate (1) and the lower metal plate (2). The side metal pressure plate (5) protrudes inward at both ends in the longitudinal direction to limit the longitudinal displacement of the side high-temperature rubber sheet (6); The surface of the side metal pressure plate (5) that contacts the side high-temperature rubber sheet (6) is provided with anti-slip small protrusions to restrict the movement of the side high-temperature rubber sheet (6).

2. The component according to claim 1, characterized in that, The thickness of the multi-layer high-temperature rubber sheet (4) gradually decreases from the top and bottom to the middle, and the thickness of the middle layer of rubber sheet is 1.5~2.5mm.

3. The component according to claim 1 or 2, characterized in that, The bolt hole on the lower metal plate (2) that is adapted to the high-strength bolt (7) is a threaded hole with an inlet guide tapered section. The bolt hole on the upper metal plate (1) that is adapted to the high-strength bolt (7) is a smooth hole, and the hole diameter is larger than that of the bolt hole on the lower metal plate (2) that is adapted to the high-strength bolt (7).

Images