An experimental device for simulating the leakage of steam through the split face of a steam turbine cylinder

Abstract

This invention belongs to the technical field of steam turbines and discloses a simulation experimental device for steam leakage at the split surface of a steam turbine cylinder. The device includes an upper cylinder simulator and a lower cylinder simulator, wherein the contour dimensions of the upper and lower cylinder simulators are consistent with the contour dimensions of the steam leakage location at the split surface of the simulated cylinder. The two are connected by a set of split-surface simulated steel plates. The influence of the surface quality of the cylinder split surface on sealing performance is simulated by adjusting the roughness of the opposite surfaces of these steel plates. Bolt holes and pin holes are provided at corresponding positions on the set of split-surface simulated steel plates. Different bolt hole tightening and different tightening forces are used to simulate the influence of the distribution and magnitude of bolt tightening force on the sealing performance at the cylinder split surface. Through this invention, the sealing performance of the steam turbine cylinder split surface under the influence of factors such as misalignment of the upper and lower cylinders, surface quality, bolt tightening force distribution, tightening force magnitude, and temperature is simulated, and the effectiveness of different sealing measures is verified.

Description

Technical Field

[0001] This invention belongs to the technical field of steam turbines, and more specifically, relates to a simulation experimental device for steam leakage at the split surface of a steam turbine cylinder. Background Technology

[0002] Steam leakage at the split surface of the turbine cylinder is a common phenomenon in the daily operation of traditional thermal power and nuclear power units. This leakage not only reduces the unit's efficiency but also affects its safe operation. Common measures to address this leakage include: scraping the split surface, localized welding and plating, increasing the local bolt tension, and applying cylinder sealing grease.

[0003] Cylinder sealing modifications require consideration of sealing effectiveness and sealing time. Sealing measures are difficult to evaluate through analysis or numerical simulation, and cylinder overhaul periods are generally long; if a sealing modification fails, it must wait until the next overhaul period before it can be repeated. Due to the enormous size of the cylinder, conducting experiments on specific sections is difficult and resource-intensive. Therefore, there is an urgent need to design a simulation experimental device for surface leakage in turbine cylinders. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a simulation experimental device for steam leakage at the split surface of a steam turbine cylinder. This device simulates the sealing performance of the split surface of a steam turbine cylinder under the influence of factors such as misalignment of the upper and lower cylinders, surface quality, bolt tightening force distribution, tightening force magnitude, and temperature, and verifies the effectiveness of different sealing measures.

[0005] To achieve the above objectives, according to the present invention, a simulation experimental device for steam leakage at a split surface in a steam turbine cylinder is provided. This device includes an upper cylinder simulation component and a lower cylinder simulation component, wherein...

[0006] The outline dimensions of the upper cylinder simulation component and the lower cylinder simulation component are consistent with the outline dimensions of the leakage position on the split surface of the simulated cylinder. The two are connected by a set of split surface simulation steel plates. The influence of the surface quality of the split surface of the cylinder on the sealing performance is simulated by adjusting the roughness of the opposite surfaces of the set of split surface simulation steel plates.

[0007] Multiple bolt holes and pin holes are provided on the bottom surface of the upper cylinder simulation component and the top surface of the lower cylinder simulation component. Bolt holes and pin holes are also provided at corresponding positions on the set of split-face simulation steel plates. The distribution and magnitude of bolt tension on the cylinder split-face are simulated by using different bolt hole tightening and different tightening forces.

[0008] More preferably, heating plates are provided on the sides and bottom surfaces of both the upper cylinder simulation component and the lower cylinder simulation component, so as to simulate the influence of different temperature distributions on the sealing performance of the cylinder split surface by heating at different locations.

[0009] More preferably, the pin holes are divided into multiple groups, and the pin holes on the upper cylinder simulation component and the lower cylinder simulation component are staggered to different degrees. By using different pin holes for positioning, the influence of different degrees of misalignment of the cylinder split surface during installation on the sealing performance is simulated.

[0010] More preferably, the lower bottom surface of the upper cylinder simulator is provided with a pressure injection port for injecting pressurized fluid between the upper cylinder simulator and the lower cylinder simulator after they are connected.

[0011] More preferably, a U-shaped sealing groove is provided on the upper surface of the lower cylinder simulation component, and a sealing strip is provided in the sealing groove. When pressure is injected from the injection port, the sealing strip divides the middle surface into a leakage test area and a non-test area.

[0012] More preferably, the upper cylinder simulation component and the lower cylinder simulation component are welded plate shell components, which are convenient for processing.

[0013] In summary, the technical solutions conceived by this invention have the following beneficial effects compared with the prior art:

[0014] 1. This invention simulates steam leakage at the end of a steam turbine cylinder by using an upper cylinder simulation component and a lower cylinder simulation component on the split surface. It simulates the leakage phenomenon on the split surface of the cylinder caused by steam pressure by injecting pressure into the injection port. The influence of bolt force, cylinder sealing grease material, steam temperature and injection pressure on steam leakage is simulated by changing them.

[0015] 2. In this invention, the diameter of the bolt hole on the split-up cylinder simulation part is larger than the diameter of the bolt hole on the split-up lower cylinder simulation part, and the pin hole on the split-up cylinder simulation part is not completely aligned with the pin hole on the split-up lower cylinder simulation part, which can simulate the situation of incomplete alignment when the turbine cylinder is installed in the field.

[0016] 3. In this invention, the split cylinder simulation part has a rectangular cross-sectional groove on the split surface. By adding a sealing strip in the rectangular cross-sectional groove, the steam leakage location can be limited to a specific area to simulate cylinder steam leakage under actual conditions.

[0017] 4. In this invention, the split-face cylinder simulation component and the split-face lower cylinder simulation component are welded from steel plates of a certain thickness. The experimental device is simple and lightweight, and realizes the local simulation of the cylinder end. Attached Figure Description

[0018] Figure 1 This is an overall schematic diagram of a steam turbine cylinder constructed according to a preferred embodiment of the present invention;

[0019] Figure 2This is a partially enlarged view of the end of a steam turbine cylinder constructed according to a preferred embodiment of the present invention;

[0020] Figure 3 It is constructed according to a preferred embodiment of the present invention. Figure 2 A magnified view of the central gap at the end of a steam turbine cylinder;

[0021] Figure 4 This is an assembly diagram of the experimental apparatus constructed according to a preferred embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the lower cylinder simulation component structure constructed according to a preferred embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the upper cylinder simulation component structure constructed according to a preferred embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the bolt holes, pin holes, and sealing strip of the experimental apparatus constructed according to a preferred embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of the welding injection interface of the upper cylinder simulation component constructed according to a preferred embodiment of the present invention.

[0026] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0027] 1-Upper cylinder simulation component, 2-Lower cylinder simulation component, 3-Injection port, 4-Heating plate, 5-Bolt hole, 6-Pin hole No. 1, 7-Pin hole No. 2, 8-Pin hole No. 3, 9-Injection port, 10-Rectangular section groove, 11-Sealing strip, 12-Mid-face simulation steel plate. Detailed Implementation

[0028] 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.

[0029] Steam turbine cylinder, such as Figure 1 As shown, it is formed by the interlocking of upper and lower cylinders, and the gap at its ends is as follows. Figure 2 and Figure 3 As shown, steam leakage simulation is therefore required.

[0030] This invention provides a simulation experimental device for testing steam leakage at the end of a steam turbine cylinder, such as... Figure 4As shown, the experimental setup includes an upper cylinder simulator 1, a lower cylinder simulator 2, a pressure injection port 3, a heating plate 4, a sealing strip 11, and a split-face simulated steel plate 12.

[0031] Both the upper cylinder simulation component 1 and the lower cylinder simulation component 2 are shells welded from steel plates of a certain thickness. The outline structure dimensions of the experimental section of both are consistent with the outline structure dimensions of the steam leakage position on the split surface of the cylinder, and the overall weight of the experimental device is relatively light.

[0032] like Figure 4 As shown, the heating plate 4 is attached to the inner wall of the chamber of the upper and lower cylinder simulation parts 2; the split-face simulation steel plate 12 is sandwiched between the upper cylinder simulation part 1 and the lower cylinder simulation part 2, and bolt holes 5 and pin holes 6, 7, and 8 are arranged at the corresponding positions of the upper cylinder simulation part 1 and the lower cylinder simulation part 2.

[0033] like Figure 5 As shown, the upper part of the steel plate of the lower cylinder simulation component 2 is provided with several bolt holes 5 and three sets of pin holes 6, 7, 8, and a rectangular cross-section groove 10 is arranged inside the bolt holes 5, in which a sealing strip 11 is placed. The two ends of the rectangular cross-section groove 10 extend to the opening on one side of the lower cylinder simulation component 2, thereby forming a steam leakage simulation area.

[0034] like Figure 6 As shown, several bolt holes 5 and three sets of pin holes 6, 7, 8 are also arranged on the corresponding position of the lower steel plate of the upper cylinder simulation part 1. The diameter of the bolt holes 5 of the upper cylinder simulation part 1 is slightly larger than the diameter of the bolt holes 5 of the lower cylinder simulation part 2. The diameter of the pin holes 6, 7, 8 of the upper cylinder simulation part 2 is the same as the diameter of the pin holes 6, 7, 8 of the lower cylinder simulation part 2.

[0035] like Figure 7 As shown, pin hole 6 makes the edges of the upper and lower cylinder simulation parts 1 and 2 completely aligned. Pin holes 7 and 8 are staggered by different distances to create the effect of different misalignment states of the upper and lower cylinders after installation. The sealing strip 11 is placed in the rectangular section groove 10.

[0036] like Figure 8 As shown, the injection port 9 is arranged on the inner surface of the lower steel plate of the cylinder simulation part 1 in the middle of the split surface; the injection port 9 is used with PTFE tape or sealant to ensure the seal at the injection port, or a tapered thread seal is used.

[0037] The shape of heating plate 4 should be the same as the shape of the inner cavity of the experimental device to ensure uniform heating of the experimental device.

[0038] The split surfaces of the upper and lower cylinder simulation parts 1 and 2 on the split surface should have a surface quality of 0.8, so that the cylinder sealing grease simply applied to the split surface can achieve a sealing effect.

[0039] A high-temperature resistant sealing strip is placed inside the rectangular groove 10.

[0040] A pair of steel plates with identical bolt holes 5 and pin holes 6, 7, and 8 can be added between the upper cylinder simulation component 1 and the lower cylinder simulation component 2 of the split surface. The steel plates are fixed between the upper cylinder simulation component 1 and the lower cylinder simulation component 2 of the split surface with bolts and pins. The surface accuracy of the steel plates on one side of 12 is 0.8, and the other side can be processed to different surface qualities to simulate the effect of poor surface quality of the split surface of the actual steam turbine on steam leakage of the split surface.

[0041] The experimental steps are as follows:

[0042] S1. Place the sealing strip 11 into the rectangular section groove 10 of the lower cylinder simulation part 2;

[0043] S2 applies the corresponding cylinder sealing grease to the contact surfaces of the upper and lower cylinder simulation parts 1 and 2 and the middle split simulation steel plate 12.

[0044] S3 inserts a pin into a specific pin hole and uses bolts to fasten the upper and lower cylinder simulation parts 1 and 2 and the middle simulation steel plate 12.

[0045] S4 turns on the heating plate 4 to heat the experimental apparatus to a specific temperature;

[0046] S5 connects the injection port 9 to the pressurizer to inject fluid at a specific pressure into the split surface.

[0047] S6. By changing the bolt preload, the misalignment of the upper and lower cylinder simulation parts 1 and 2 on the split surface, and the temperature and pressure of the experimental setup, the influence of these factors on steam leakage is investigated.

[0048] 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 simulation test device for a split face steam leakage in a steam turbine cylinder, characterized by, The device includes an upper cylinder simulator (1) and a lower cylinder simulator (2), wherein, The outline structure dimensions of the upper cylinder simulation component (1) and the lower cylinder simulation component (2) are consistent with the outline structure dimensions of the leakage position of the cylinder in the simulated cylinder. The two are connected by a set of middle-section simulation steel plates. The influence of the surface quality of the cylinder in the middle section on the sealing performance is simulated by adjusting the roughness of the opposite surfaces of the set of middle-section simulation steel plates (12). Multiple bolt holes (5) and pin holes are provided on the bottom surface of the upper cylinder simulation part (1) and the top surface of the lower cylinder simulation part (2). Bolt holes and pin holes are also provided at corresponding positions on the set of mid-section simulation steel plates. By using different bolt hole locking and different locking forces, the distribution and magnitude of the bolt tightening force on the mid-section of the cylinder are simulated to affect the sealing performance. Heating plates are provided on the sides and bottom surfaces of the upper cylinder simulation component (1) and the lower cylinder simulation component (2). Heating at different locations simulates the effect of different temperature distributions on the sealing performance of the cylinder split surface. The pin holes are divided into multiple groups. The pin holes on the upper cylinder simulation part and the lower cylinder simulation part are staggered to different degrees. By using different pin holes for positioning, the influence of different degrees of misalignment of the cylinder split surface on the sealing performance during the installation of the upper and lower cylinders is simulated.

2. The simulation experimental device for steam leakage at a split surface in a steam turbine cylinder as described in claim 1, characterized in that, The lower bottom surface of the upper cylinder simulation component (1) is provided with a pressure injection port (9) for injecting pressurized fluid between the upper cylinder simulation component and the lower cylinder simulation component after they are connected.

3. The simulation experimental device for steam leakage at a split surface in a steam turbine cylinder as described in claim 2, characterized in that, The upper surface of the lower cylinder simulation component (2) is provided with a U-shaped sealing groove, and a sealing strip is provided in the sealing groove. When pressurized fluid is injected from the injection port, the sealing strip divides the middle surface into a leakage test area and a non-test area.

4. The simulation experimental device for steam leakage at a split surface in a steam turbine cylinder as described in claim 1, characterized in that, The upper cylinder simulation component (1) and the lower cylinder simulation component (2) are welded plate shell components, which are convenient to process.

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