GIL pipe joint fixing device fault inspection and repair method

Abstract

The present invention relates to a fault inspection and repair method for a GIL pipe joint fixing device. Firstly, whether the thermal expansion limit deformation of the GIL equipment exceeds the adjustment range of the axial expansion joint and the radial expansion joint is considered, and then whether the straight pipe section formed by the GIL pipe joint and the axial expansion joint is deflected is considered. Then, whether the inner diameter of the GIL pipe joint fixing device is smaller than the radial expansion limit outer diameter of the GIL pipe joint is considered. Finally, whether the slider and the guide rail of the GIL pipe joint fixing device are eccentrically worn is considered. Thus, the lining strip falling out fault and the GIL pipe joint clamp cracking fault can be solved, and the essential causes of the lining strip falling out and the GIL pipe joint clamp cracking can be solved, thereby reducing the probability of the fault occurring again, and indirectly reducing the maintenance cost of the GIL pipe joint fixing device and the maintenance cost of the expansion joint.

Description

Technical Field

[0001] The invention relates to the technical field of fault repair of a GIL pipe joint fixing device, and in particular to a fault inspection and repair method for a GIL pipe joint fixing device. Background Art

[0002] Gas-insulated transmission line (GIL) is a metal-enclosed transmission equipment insulated by SF6 gas or SF6 and N2 mixed gas. It has the characteristics of large transmission capacity, flexible spatial distribution, high reliability and low environmental impact. It is generally used in long-distance and complex environmental projects. It can be arranged horizontally, inclined and vertically. It has been gradually widely used in the world. When the GIL is running, the shell will cause thermal expansion and contraction displacement changes due to eddy current induction heating in the direction of current conduction. This characteristic may cause the fixture to fail, and in severe cases, damage the fixture.

[0003] The Yuyang I line of the UHV Nanyang Station uses GIL pipelines and adopts a single-phase busbar structure. Figure 1 As shown, the GIL pipeline is arranged along the inner wall of the station and leads out from behind the east wall. It is 1,340 meters long and contains 98 GIL units (including 52 straight units, 25 corner units, 6 force balance units, and 15 zipper units), 24 GIS units, and is divided into 36 gas chambers using embedded basin insulators, which are filled with a total of 35.7 tons of SF6 gas. The GIL installation starting and ending sections are arranged horizontally, and the middle section is arranged vertically. During use, the operation and maintenance personnel inspected and reported that the gaskets of some GIL pipe joint fixing devices had fallen out of the slots (see Figure 2 ), the lower clamp of some GIL pipe joint fixing devices was cracked (see Figure 3-4 ), axial expansion joint guide rod deformation (see Figure 5 ) and other phenomena. Summary of the invention

[0004] The object of the present invention is to provide a GIL pipe joint fixing device fault inspection and repair method, so as to reduce the probability of the fault recurring while repairing the GIL pipe joint fixing device fault.

[0005] The technical solution of the present invention is:

[0006] A method for troubleshooting a GIL pipe joint fixing device, wherein the GIL pipe joint fixing device comprises a GIL pipe joint clamp, a slider and a guide rail, wherein the slider and the guide rail are movably connected, and the GIL pipe joint clamp is used to fix the GIL pipe joint, comprising the following steps:

[0007] Step S1, the GIL device includes a GIL pipe joint, an axial expansion joint, a radial expansion joint and a conductor, a finite element model of the GIL device is established based on the GIL device data, and a temperature factor and an internal air pressure factor of the GIL device are applied to obtain the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL device of the finite element model of the GIL device;

[0008] Step S2, calculating the adjustment range of the axial expansion joint and the radial expansion joint, and comparing the thermal expansion limit deformation of the GIL device with the adjustment range of the axial expansion joint and the radial expansion joint;

[0009] If the thermal expansion limit deformation of the GIL device is greater than or equal to the adjustment range of the axial expansion joint and the radial expansion joint, replace the axial expansion joint and / or the radial expansion joint to make the thermal expansion limit deformation of the GIL device less than the adjustment range of the axial expansion joint and the radial expansion joint, re-arrange the GIL pipe joint fixing device, and proceed to step S3;

[0010] If the thermal expansion limit deformation of the GIL device is less than the adjustment range of the axial expansion joint and the radial expansion joint, proceed to step S3;

[0011] Step S3, measuring the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint;

[0012] If the axes of the straight pipe segments are on a straight line, proceed to step S4;

[0013] If the axes of the straight pipe sections are not on a straight line, the GIL pipe joint fixing device is adjusted so that the axes of the straight pipe sections are arranged on a straight line, and step S4 is performed;

[0014] Step S4, measuring the inner diameter of the GIL pipe joint fixing device, and comparing the inner diameter of the GIL pipe joint fixing device with the radial expansion limit outer diameter of the GIL pipe joint;

[0015] If the inner diameter of the GIL pipe joint fixing device is less than the radial expansion limit outer diameter of the GIL pipe joint, the GIL pipe joint clamp is maintained to make the inner diameter of the GIL pipe joint fixing device greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint, and step S5 is performed;

[0016] If the inner diameter of the GIL pipe joint fixing device is greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint, proceed to step S5;

[0017] Step S5, observing the eccentric wear condition of the slider and the guide rail of the GIL pipe joint fixing device;

[0018] If the slider and guide rail of the GIL pipe joint fixing device are worn on one side, the GIL pipe joint fixing device should be maintained so that the center of gravity of the GIL pipe joint is set at the connection center of the slider and the guide rail.

[0019] Preferably, in step S1, the temperature factors include the highest temperature of the GIL shell formed by superimposing the temperature rise of sunlight and the temperature rise of conductor heating on the basis of the highest temperature of the climate, and the lowest temperature of the GIL shell formed by the lowest temperature of the climate.

[0020] Preferably, in step S3, a total station or a laser straightness meter is used to measure the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint.

[0021] Preferably, the GIL pipe joint fixing device failure is a GIL pipe joint clamp cracking failure. In step S2, the GIL equipment thermal expansion limit deformation is less than the adjustment range of the axial expansion joint and the radial expansion joint. In step S3, the axes of the straight pipe segments are on a straight line, and in step 4, the inner diameter of the GIL pipe joint fixing device is greater than or equal to the GIL pipe joint radial expansion limit outer diameter. In step S5, the contents of maintaining the GIL pipe joint fixing device include:

[0022] Replace the GIL pipe clamp or repair the cracks in the GIL pipe clamp;

[0023] The relative position of the GIL pipe joint fixing device and the GIL pipe joint is adjusted so that the center of gravity of the GIL pipe joint is set at the connection center of the slider and the guide rail.

[0024] Further preferably, the slider includes an upper slider and a lining strip, the bottom surface of the upper slider is provided with two goose-tail grooves, and the lining strip is installed in the goose-tail grooves. Then, in step S5, the relative position of the GIL pipe joint fixing device and the GIL pipe joint is adjusted so that the two goose-tail grooves are axially symmetrically arranged on both sides of the center of gravity plane of the GIL pipe joint.

[0025] Preferably, the slider includes an upper slide and a lining strip, the bottom surface of the upper slide is provided with two goose-tail grooves, the lining strip is installed in the goose-tail grooves, the failure of the GIL pipe joint fixing device is a single-side lining strip detachment failure, in the step S2, the thermal expansion limit deformation of the GIL equipment is less than the adjustment range of the axial expansion joint and the radial expansion joint, in the step S3, the axes of the straight pipe sections are on a straight line, and in the step 4, the inner diameter of the GIL pipe joint fixing device is greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint, then in the step S5, the contents of maintaining the GIL pipe joint fixing device include:

[0026] Installing a lining strip on the upper slide plate;

[0027] The relative position of the GIL pipe section fixing device and the GIL pipe section is adjusted so that the two goose-tail grooves are axially symmetrically arranged on both sides of the center of gravity surface of the GIL pipe section.

[0028] The inventors analyzed that the deformation of the axial telescopic joint guide rod (see Figure 5 ) are as follows: ① After the GIL tube section in the A direction is deformed by thermal expansion and contraction, the end of the GIL tube section in the B direction is pushed or stretched and deviated. If it exceeds the adjustment range of the radial expansion joint, the axial expansion joint guide rod in the GIL tube section in the B direction will be deformed, and the lower clamp of the GIL tube section fixing device will be cracked, and the slider and guide rail will be worn eccentrically; ② The GIL tube section is deflected due to the installation process. The thermal expansion and contraction of the GIL tube section aggravates the deflection of the GIL tube section, causing the axial expansion joint guide rod in the GIL tube section to be deformed, and the lower clamp of the GIL tube section fixing device will be cracked, and the slider and guide rail will be worn eccentrically. This causes cracks in the lower clamp (see Figure 3-4 ) are as follows: ① The inner diameter of the GIL pipe joint clamp is less than the outer diameter of the GIL pipe joint radial expansion limit, which causes the GIL pipe joint to crack the lower clamp; ② The slider and the guide rail are worn eccentrically, causing the GIL pipe joint clamp to be subjected to concentrated force on one side, leading to the cracking of the lower clamp; causing the gasket of the GIL pipe joint fixing device to fall out of the slot (see Figure 2 ) The reasons are: the two goose-tail grooves are not axially symmetrically arranged on both sides of the center of gravity of the GIL pipe joint, causing eccentric wear of the slider and the guide rail.

[0029] According to the above analysis, the reason for the gasket falling out of the slot in the GIL pipe joint fixing device may be that the thermal expansion and contraction deformation of the GIL pipe joint exceeds the adjustment range of the radial expansion joint, or it may be caused by the deflection of the GIL pipe joint during installation and the superposition of the thermal expansion and contraction deformation of the GIL pipe joint, or it may be caused by the two goose-tail grooves not being axially symmetrically arranged on both sides of the center of gravity of the GIL pipe joint. The reason for the cracking of the lower clamp in the GIL pipe joint fixing device may be that the thermal expansion and contraction deformation of the GIL pipe joint exceeds the adjustment range of the radial expansion joint, or it may be caused by the deflection of the GIL pipe joint during installation and the superposition of the thermal expansion and contraction deformation of the GIL pipe joint, or it may be caused by the cracking of the lower clamp of the GIL pipe joint, or it may be caused by the two goose-tail grooves not being axially symmetrically arranged on both sides of the center of gravity of the GIL pipe joint.

[0030] Based on the above considerations, after discovering the expansion joint failure, for the lining strip disengagement failure of the GIL pipe joint fixing device and the GIL pipe joint clamp cracking failure, the inventor first considered whether the thermal expansion limit deformation of the GIL equipment exceeded the adjustment range of the axial expansion joint and the radial expansion joint, and then considered whether the straight pipe section formed by the GIL pipe joint and the axial expansion joint was skewed, and then considered whether the inner diameter of the GIL pipe joint fixing device was smaller than the radial expansion limit outer diameter of the GIL pipe joint, and finally considered whether the slider and the guide rail of the GIL pipe joint fixing device were eccentrically worn, thereby solving the lining strip disengagement failure and the GIL pipe joint clamp cracking failure, and solving the fundamental causes of the lining strip disengagement and the GIL pipe joint clamp cracking, thereby reducing the maintenance cost of the GIL pipe joint fixing device and the maintenance cost of the expansion joint.

[0031] The beneficial effects of the present invention are:

[0032] 1. In the GIL pipe joint fixing device fault inspection and repair method of the present invention, in step S1, a GIL device finite element model is established based on the GIL device data, and the temperature factor and the internal air pressure factor of the GIL device are applied at the same time to obtain the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL device of the finite element model of the GIL device, which is helpful to obtain the theoretical radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL device; in step S2, the adjustment range of the axial expansion joint and the radial expansion joint is calculated, and the thermal expansion limit deformation of the GIL device is compared with the adjustment range of the axial expansion joint and the radial expansion joint, so as to confirm or eliminate the lining strip disengagement failure and the GIL pipe joint clamp cracking caused by the thermal expansion limit deformation of the GIL device exceeding the adjustment range of the axial expansion joint and the radial expansion joint. Fault; in step S3, measure the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint; this can confirm or exclude the liner stripping fault and the GIL pipe joint clamping hoop cracking fault caused by the deflection of the straight pipe section formed by the GIL pipe joint and the axial expansion joint and the GIL pipe joint thermal expansion amplification effect; in step S4, measure the inner diameter of the GIL pipe joint fixture and compare the inner diameter of the GIL pipe joint fixture with the radial expansion limit outer diameter of the GIL pipe joint, so as to confirm or exclude the GIL pipe joint clamping hoop cracking fault caused by the inner diameter of the GIL pipe joint fixture < the radial expansion limit outer diameter of the GIL pipe joint; in step S5, observe the eccentric wear of the slider and the guide rail of the GIL pipe joint fixture, so as to confirm or exclude the liner stripping fault caused by the uneven force of the GIL fixture. After confirming the cause of the fault, design a targeted maintenance method. In this way, the GIL pipe joint fixing device fault inspection and repair method of the present invention can not only solve the lining strip falling off fault and the GIL pipe joint clamp cracking fault, but also solve the essential causes of the lining strip falling off and the GIL pipe joint clamp cracking, thereby reducing the probability of the fault occurring again, and indirectly reducing the maintenance cost of the GIL pipe joint fixing device and the maintenance cost of the expansion joint.

[0033] 2. In the GIL pipe joint fixing device fault inspection method of the present invention, in the step S1, the temperature factors include the highest temperature of the GIL shell formed by adding the temperature rise of sunlight and the temperature rise of conductor heating on the basis of the highest temperature of the climate, and the lowest temperature of the GIL shell formed by the lowest temperature of the climate. In this way, the temperature factors are considered comprehensively, which helps to make the obtained GIL pipe joint radial expansion limit outer diameter and the GIL equipment thermal expansion limit deformation closer to the actual value.

[0034] 3. In the GIL pipe joint fixing device fault inspection method of the present invention, in step S3, a total station or a laser straightness meter is used to measure the straightness of the straight pipe segment formed by the GIL pipe joint and the axial expansion joint. Using an instrument to measure the straightness of the straight pipe segment is helpful to find small deviations and solve the repeated occurrence of faults caused by the corresponding problems.

[0035] 4. In the GIL pipe joint fixing device fault inspection and repair method of the present invention, the GIL pipe joint fixing device fault is a GIL pipe joint clamp cracking fault. After confirming that the GIL pipe joint clamp cracking fault is caused by the two goose tail grooves not being axially symmetrically arranged on both sides of the center of gravity plane of the GIL pipe joint, in the step S5, the content of maintaining the GIL pipe joint fixing device includes: replacing the GIL pipe joint clamp, or repairing the crack of the GIL pipe joint clamp; adjusting the relative position of the GIL pipe joint fixing device and the GIL pipe joint so that the two goose tail grooves are axially symmetrically arranged on both sides of the center of gravity plane of the GIL pipe joint.

[0036] 5. In the GIL pipe joint fixing device fault inspection and repair method of the present invention, the sliding block includes an upper sliding block and a lining strip, the bottom surface of the upper sliding block is provided with two goose tail grooves, the lining strip is installed in the goose tail grooves, and the GIL pipe joint fixing device fault is a single-sided lining strip detachment fault. After confirming that the single-sided lining strip detachment fault is caused by the two goose tail grooves not being axially symmetrically arranged on both sides of the center of gravity plane of the GIL pipe joint, in the step S5, the content of maintaining the GIL pipe joint fixing device includes: installing the lining strip on the upper sliding block; adjusting the relative position of the GIL pipe joint fixing device and the GIL pipe joint so that the two goose tail grooves are axially symmetrically arranged on both sides of the center of gravity plane of the GIL pipe joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the layout diagram of the GIL equipment for Yuyang I Line of the UHV Nanyang Station.

[0038] Figure 2 This is a diagram of the lining strip detachment failure of the GIL pipe joint fixing device.

[0039] Figure 3 This is the crack failure diagram of the lower half clamp of the GIL pipe joint fixing device;

[0040] Figure 4 for Figure 3 A local magnified image of a medium crack failure.

[0041] Figure 5 This is the deformation failure diagram of the axial telescopic joint guide rod.

[0042] Figure 6 It is a structural schematic diagram of a GIL pipe joint fixing device;

[0043] Figure 7This is one of the partial enlarged views of a GIL pipe joint fixing device;

[0044] Figure 8 This is the second partial enlarged view of a GIL pipe joint fixing device.

[0045] Fig. 9 A schematic diagram of the compensation amount of a radial expansion joint.

[0046] Fig.10 This is a schematic diagram of the GIL equipment and GIL pipe joint fixing device of Yuyang I line of UHV Nanyang Station.

[0047] Explanation of the reference numerals: 1-GIL pipe joint, 10-GIL pipe shell, 101-flange, 11-spacing maintaining insulator, 12-conductor, 2-GIL pipe joint clamp, 211-upper GIL pipe shell protection pad, 212-lower GIL pipe shell protection pad, 221-upper clamp, 222-lower clamp, 223-bolt connector, 3-slider, 30-upper slide, 31-lining strip, 32-connecting plate, 4-guide rail, 410-lower slide, 411-first connecting bolt, 412-adjusting nut, 421-heightening pad, 422-anti-dropping block, 423-second connecting bolt, 5-bracket, 50-crossbeam, 51-thickening pad. DETAILED DESCRIPTION

[0048] The present invention is described in the form of embodiments in conjunction with the accompanying drawings to assist those skilled in the art in understanding and implementing the present invention. Unless otherwise specified, the following embodiments and the technical terms therein should not be understood without departing from the technical knowledge background of the technical field.

[0049] Figure 1 The diagram shows the layout of the GIL equipment of Yuyang I line of UHV Nanyang Station. The GIL pipeline is arranged along the inner wall of the station and leads to the east wall. It is 1,340 meters long and contains 98 GIL units (including 52 straight units, 25 corner units, 6 force balance units, and 15 zipper units), 24 GIS units, and is divided into 36 gas chambers using embedded basin insulators, filled with a total of 35.7 tons of SF6 gas. The GIL installation starting section and the end section are arranged horizontally, and the middle section is arranged vertically.

[0050] Figure 6-8A GIL pipe joint fixing device used in the GIL equipment of Yuyang I line of UHV Nanyang Station is shown. The GIL pipe joint clamp 2 is fixedly connected to the GIL pipe joint 1, and an upper GIL pipe shell protection pad 211 and a lower GIL pipe shell protection pad 212 are also provided between the GIL pipe joint clamp 2 and the GIL pipe joint 1. The GIL pipe joint clamp 2 is fixedly connected to the slider 3, the guide rail 4 is fixedly connected to the bracket 5, and the slider 3 is installed on the guide rail 4. When the GIL pipe joint 1 is thermally expanded or contracted, the slider 3 can slide on the axis of the GIP pipe joint 1 relative to the guide rail 4.

[0051] See also Figure 6-7 In the GIL pipe segment 1, flanges 101 are provided at both ends of the GIL pipe shell 10, a conductor 10 is provided in the GIL pipe shell 10, and the conductor 10 is coaxially arranged with the GIL pipe shell 10 through a spacing maintaining insulator 11. The spacing maintaining insulator 11 is fixedly connected to the conductor 12, part of the spacing maintaining insulator 11 is fixedly connected to the GIL pipe shell 10, and part of the spacing maintaining insulator 11 is slidably connected to the GIL pipe shell 10.

[0052] See also Figure 6-7 , the GIL pipe joint clamp 2, the upper clamp 221 and the lower clamp 222 are connected by a bolt connector 223 to form a detachable clamp. When in use, an upper GIL pipe shell protection pad 211 is provided between the upper clamp 221 and the GIL pipe shell 10, and a lower GIL pipe shell protection pad 212 is provided between the lower clamp 222 and the GIL pipe shell 10. The upper GIL pipe shell protection pad 211 and the lower GIL pipe shell protection pad 212 act as force transmission parts, so that the GIL pipe joint clamp 2 can not only hold the GIL pipe shell 10 well, but also avoid material fatigue caused by holding too tightly.

[0053] The GIL shell 10 is made of 5754-H111 aluminum alloy tube, the upper clamp 221 and the lower clamp 222 are both made of 5083 aluminum alloy rolled plate, and the upper GIL shell protection pad 211 and the lower GIL shell protection pad 212 are both chloroprene rubber plates.

[0054] See also Figure 6-7 In the slider 3, the upper slide plate 30 is fixedly connected to the lower half hoop 222 through the connecting plate 32, and the bottom surface of the upper slide plate 30 is provided with a goose tail groove, and the lining strip 31 is installed in the goose tail groove. The lining strip 31 is a rubber pad.

[0055] See also Figure 6 , 8 In the bracket 5 , a thickened pad 51 is welded on the cross beam 50 .

[0056] See also Figure 6 , 8In the guide rail 4, the lower slide plate 410, the heightening pad 421, and the anti-slipping block 422 form a guide groove of the slider 3, and the second connecting bolt 423 passes through the fixing hole A on the anti-slipping block 422 and the fixing hole B on the heightening pad 421 and is threadedly connected with the threaded hole of the lower slide plate 410, so as to fix the anti-slipping block 422 and the heightening pad 421 on the lower slide plate 410. The first connecting bolt 411 is screwed with an adjusting nut 412, and the first connecting bolt 411 passes through the fixing hole C on the lower slide plate 410 and is threadedly connected with the threaded hole on the thickening pad 51. By setting the position of the adjusting nut 412 on the first connecting bolt 411, the adjusting nut 411 presses the lower slide plate 410 onto the bracket 5.

[0057] On a certain day in May 2021, the operation and maintenance personnel of Nanyang Station reported during their inspection that the lining strips of some GIL pipe joint fixing devices had fallen out of the goosetail groove of the upper slide (see Figure 2 ), cracks appeared on the ears of the lower clamps of some GIL pipe joint fixing devices (see Figure 3 , 4 ), axial expansion joint guide rod deformation (see Figure 5 On a certain day in March 2022, Nanyang Station once again checked the GIL pipe joint fixture and found that there were 50 new cracks in the ears of the lower half of the GIL pipe joint fixture and 25 new suspected ear cracks.

[0058] After asking the design institute, we learned that the designers determined the thermal expansion limit of the GIL equipment based on Q / GDW 11716-2017 "Technical Specifications for Expansion Joints for Gas Insulated and Metal-Enclosed Switchgear". Taking a 45m long GIL pipe section arranged in a straight line as an example, its thermal expansion limit is:

[0059] Thermal expansion limit elongation of GIL pipe joint

[0060] ΔL1=L×α1×(T g +T e +T s -T a )

[0061] Where L is the length of the GIL tube segment, α1 is the linear expansion coefficient of the shell of the GIL tube segment, T g is the maximum ambient temperature, T e The temperature of the casing rises due to the operation of the GIL equipment, T s is the temperature rise of the shell caused by sunlight, T a The temperature when the GIL pipe joint is installed;

[0062] Thermal expansion limit shrinkage of GIL pipe joint

[0063] ΔL2=L×α1×(T d -T a )

[0064] Where L is the length of the GIL tube segment, α1 is the linear expansion coefficient of the shell of the GIL tube segment, T d is the minimum ambient temperature, T a The temperature when the GIL pipe joint is installed;

[0065] For the UHV Nanyang Station, T g =41.4℃, T d =-25℃, T a =20℃, T s =32.2℃, T e =62℃,α1=23.9×10 -6 K -1 , L = 45m;

[0066] The thermal expansion limit elongation of the GIL pipe joint ΔL1 = 52.9 mm;

[0067] The thermal expansion limit shrinkage of the GIL pipe joint ΔL2 = -48.4mm;

[0068] The thermal expansion limit expansion amount of the GIL pipe joint ΔL=ΔL1-ΔL2=52.9mm-(-48.4mm)=101.3mm.

[0069] Taking into account the manufacturing and installation errors of the equipment, the adjustment range of the axial expansion joint configured for every 45m pipe section of the UHV Nanyang Station is ±55mm. In this way, the axial expansion joint configured for every 45m long GIL pipe section can absorb the manufacturing and installation errors of 8.7mm.

[0070] Considering that the GIL pipe segment includes the GIL straight pipe segment and the GIL corner pipe segment, the thermal expansion and contraction of one GIL straight pipe segment will affect the end point offset of another GIL straight pipe segment with an angle. The designers used the above method to determine the end point offset of the GIL straight pipe segment and configured the radial expansion joint in the GIL device accordingly (see Fig. 9 ). The radial expansion joint is composed of two hinged expansion joints, and the standard displacement value of each hinged expansion joint is ±2.5°. The compensation amount of the radial expansion joint is ΔL3 = ±L×tan2.5°.

[0071] Therefore, the designers designed the GIL equipment and its matching GIL pipe segment fixing device, and arranged no less than two brackets for every 18m GIL pipe segment. Fig.10 .

[0072] After studying the lining strip fallout failure of the GIL pipe joint fixing device in the UHV Nanyang Station, the inventors found that all lining strip fallout failures were single-sided lining strip fallouts, which were actually caused by one-side wear between the slider and the guide rail of the GIL pipe joint fixing device, and the side where the lining strip fell out was the side with the wear.

[0073] The inventors analyzed that the deformation of the axial telescopic joint guide rod (see Figure 5 ) are as follows: ① After the GIL tube section in the A direction is deformed by thermal expansion and contraction, the end of the GIL tube section in the B direction is pushed or stretched and deviated. If it exceeds the adjustment range of the radial expansion joint, the axial expansion joint guide rod in the GIL tube section in the B direction will be deformed, and the lower clamp of the GIL tube section fixing device will be cracked, and the slider and guide rail will be worn eccentrically; ② The GIL tube section is deflected due to the installation process. The thermal expansion and contraction of the GIL tube section aggravates the deflection of the GIL tube section, causing the axial expansion joint guide rod in the GIL tube section to be deformed, and the lower clamp of the GIL tube section fixing device will be cracked, and the slider and guide rail will be worn eccentrically. This causes cracks in the lower clamp (see Figure 3-4 ) are as follows: ① The inner diameter of the GIL pipe joint clamp is less than the outer diameter of the GIL pipe joint radial expansion limit, which causes the GIL pipe joint to crack the lower clamp; ② The slider and the guide rail are worn eccentrically, causing the GIL pipe joint clamp to be subjected to concentrated force on one side, leading to the cracking of the lower clamp; causing the gasket of the GIL pipe joint fixing device to fall out of the slot (see Figure 2 ) The reasons are: the two goose-tail grooves are not axially symmetrically arranged on both sides of the center of gravity of the GIL pipe joint, causing eccentric wear of the slider and the guide rail.

[0074] See also Figure 3 In a GIL pipe joint fixing device, there are two lower half hoops 222 and two upper half hoops 221, which are connected to form a GIL pipe joint hoop through four bolt connectors 223. During installation, it is not possible to ensure that the axes of the GIL pipe joint hoop are collinear and the inner diameters are consistent. Therefore, it is possible that the hoop cracks due to reason ①.

[0075] According to the above analysis, the reason for the gasket falling out of the slot in the GIL pipe joint fixing device may be that the thermal expansion and contraction deformation of the GIL pipe joint exceeds the adjustment range of the radial expansion joint, or it may be caused by the deflection of the GIL pipe joint during installation and the superposition of the thermal expansion and contraction deformation of the GIL pipe joint, or it may be caused by the two goose-tail grooves not being axially symmetrically arranged on both sides of the center of gravity of the GIL pipe joint. The reason for the cracking of the lower clamp in the GIL pipe joint fixing device may be that the thermal expansion and contraction deformation of the GIL pipe joint exceeds the adjustment range of the radial expansion joint, or it may be caused by the deflection of the GIL pipe joint during installation and the superposition of the thermal expansion and contraction deformation of the GIL pipe joint, or it may be caused by the cracking of the lower clamp of the GIL pipe joint, or it may be caused by the two goose-tail grooves not being axially symmetrically arranged on both sides of the center of gravity of the GIL pipe joint.

[0076] Based on the above considerations, after discovering the expansion joint failure, for the lining strip disengagement failure of the GIL pipe joint fixing device and the GIL pipe joint clamp cracking failure, the inventor first considered whether the thermal expansion limit deformation of the GIL equipment exceeded the adjustment range of the axial expansion joint and the radial expansion joint, and then considered whether the straight pipe section formed by the GIL pipe joint and the axial expansion joint was skewed, and then considered whether the inner diameter of the GIL pipe joint fixing device was smaller than the radial expansion limit outer diameter of the GIL pipe joint, and finally considered whether the slider and the guide rail of the GIL pipe joint fixing device were eccentrically worn, thereby solving the lining strip disengagement failure and the GIL pipe joint clamp cracking failure, and solving the fundamental causes of the lining strip disengagement and the GIL pipe joint clamp cracking, thereby reducing the maintenance cost of the GIL pipe joint fixing device and the maintenance cost of the expansion joint.

[0077] Based on this, the inventor designed a GIL pipe joint fixing device fault inspection and repair method.

[0078] Embodiment 1: A method for troubleshooting a GIL pipe joint fixing device, wherein the GIL pipe joint fixing device comprises a GIL pipe joint clamp, a slider and a guide rail, wherein the slider and the guide rail are movably connected, and the GIL pipe joint clamp is used to fix the GIL pipe joint, comprising the following steps:

[0079] Step S1, the GIL device includes a GIL pipe joint, an axial expansion joint, a radial expansion joint and a conductor, a finite element model of the GIL device is established based on the GIL device data, and a temperature factor and an internal air pressure factor of the GIL device are applied to obtain the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL device of the finite element model of the GIL device;

[0080] In this embodiment, the GIL pipe joint includes a GIL straight pipe joint and a GIL corner pipe joint. In this embodiment, in step S1, the temperature factor includes the highest temperature of the GIL shell formed by adding the temperature rise of sunlight and the temperature rise of conductor heating on the basis of the highest temperature of the climate, and the lowest temperature of the GIL shell formed by the lowest temperature of the climate, which affects the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL equipment. The internal air pressure factor of the GIL equipment is that the GIL equipment is filled with SF6 gas, which itself forms compressive stress on the GIL shell. After the temperature rises, the compressive stress on the GIL shell will also change, and affect the radial expansion limit outer diameter of the GIL pipe joint.

[0081] Step S2, calculating the adjustment range of the axial expansion joint and the radial expansion joint, and comparing the thermal expansion limit deformation of the GIL device with the adjustment range of the axial expansion joint and the radial expansion joint;

[0082] If the thermal expansion limit deformation of the GIL device is greater than or equal to the adjustment range of the axial expansion joint and the radial expansion joint, proceed to step S31;

[0083] If the thermal expansion limit deformation of the GIL device is less than the adjustment range of the axial expansion joint and the radial expansion joint, proceed to step S32;

[0084] Step S31, replace the axial expansion joint and / or the radial expansion joint, so that the thermal expansion limit deformation of the GIL device is less than the adjustment range of the axial expansion joint and the radial expansion joint, re-arrange the GIL pipe joint fixing device, and proceed to step S32;

[0085] Step S32, measuring the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint;

[0086] If the axes of the straight pipe segments are not on a straight line, proceed to step S41;

[0087] If the axes of the straight pipe segments are on a straight line, proceed to step S42;

[0088] Step S41, adjusting the GIL pipe joint fixing device so that the axis of the straight pipe section is set on a straight line, and proceeding to step S42;

[0089] Step S42, measuring the inner diameter of the GIL pipe joint fixing device, and comparing the inner diameter of the GIL pipe joint fixing device with the radial expansion limit outer diameter of the GIL pipe joint;

[0090] If the inner diameter of the GIL pipe joint fixing device is less than the radial expansion limit outer diameter of the GIL pipe joint, proceed to step S51;

[0091] If the inner diameter of the GIL pipe joint fixing device is greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint, proceed to step S52;

[0092] Step S51, maintaining the GIL pipe joint clamp, making the inner diameter of the GIL pipe joint fixing device ≥ the radial expansion limit outer diameter of the GIL pipe joint, and proceeding to step S52;

[0093] Step S52, observing the eccentric wear condition of the slider and the guide rail of the GIL pipe joint fixing device;

[0094] If the slider and guide rail of the GIL pipe joint fixing device are worn on one side, the GIL pipe joint fixing device should be maintained so that the center of gravity of the GIL pipe joint is set at the connection center of the slider and the guide rail.

[0095] Preferably, in the step S1, preferably, in the step S3, a total station or a laser straightener is used to measure the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint.

[0096] Embodiment 2: A method for troubleshooting a GIL pipe joint fixing device, wherein the GIL pipe joint fixing device comprises a GIL pipe joint clamp, a slider and a guide rail, wherein the slider and the guide rail are movably connected, and the GIL pipe joint clamp is used to fix the GIL pipe joint. In this embodiment, the fault of the GIL pipe joint fixing device is a cracking fault of the GIL pipe joint clamp, and the method comprises the following steps:

[0097] Step S1, the GIL device includes a GIL pipe joint, an axial expansion joint, a radial expansion joint and a conductor, a finite element model of the GIL device is established based on the GIL device data, and a temperature factor and an internal air pressure factor of the GIL device are applied to obtain the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL device of the finite element model of the GIL device;

[0098] In this embodiment, the GIL pipe joint includes a GIL straight pipe joint and a GIL corner pipe joint. In this embodiment, in step S1, the temperature factor includes the highest temperature of the GIL shell formed by adding the temperature rise of sunlight and the temperature rise of conductor heating on the basis of the highest temperature of the climate, and the lowest temperature of the GIL shell formed by the lowest temperature of the climate, which affects the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL equipment. The internal air pressure factor of the GIL equipment is that the GIL equipment is filled with SF6 gas, which itself forms compressive stress on the GIL shell. After the temperature rises, the compressive stress on the GIL shell will also change, and affect the radial expansion limit outer diameter of the GIL pipe joint.

[0099] Step S2, calculating the adjustment range of the axial expansion joint and the radial expansion joint, and comparing the thermal expansion limit deformation of the GIL device with the adjustment range of the axial expansion joint and the radial expansion joint;

[0100] If the thermal expansion limit deformation of the GIL device is less than the adjustment range of the axial expansion joint and the radial expansion joint, step S32 is performed;

[0101] Step S32, measuring the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint;

[0102] If the axes of the straight pipe segments are on a straight line, proceed to step S42;

[0103] Step S42, measuring the inner diameter of the GIL pipe joint fixing device, and comparing the inner diameter of the GIL pipe joint fixing device with the radial expansion limit outer diameter of the GIL pipe joint;

[0104] If the inner diameter of the GIL pipe joint fixing device is greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint, proceed to step S52;

[0105] Step S52, observing the eccentric wear condition of the slider and the guide rail of the GIL pipe joint fixing device;

[0106] If the slider and guide rail of the GIL pipe joint fixing device are worn on one side, replace the GIL pipe joint clamp or repair the crack of the GIL pipe joint clamp; adjust the relative position of the GIL pipe joint fixing device and the GIL pipe joint so that the center of gravity of the GIL pipe joint is set at the connection center of the slider and the guide rail. Figure 6-8 The GIL pipe segment fixing device shown is such that the two goose-tail grooves are axially symmetrically arranged on both sides of the center of gravity plane of the GIL pipe segment.

[0107] Whether to replace the GIL pipe joint clamp or repair the cracks in the GIL pipe joint clamp depends on the cracking condition of the clamp.

[0108] Embodiment 3: A method for troubleshooting a GIL pipe joint fixing device, wherein the GIL pipe joint fixing device comprises a GIL pipe joint clamp, a slider and a guide rail, wherein the slider and the guide rail are movably connected, the slider comprises an upper slide plate and a lining strip, the bottom surface of the upper slide plate is provided with two goose-tail grooves, the lining strip is installed in the goose-tail grooves, and the GIL pipe joint clamp is used to fix the GIL pipe joint. In this embodiment, the fault of the GIL pipe joint fixing device is a single-side lining strip detachment fault, comprising the following steps:

[0109] Step S1, the GIL device includes a GIL pipe joint, an axial expansion joint, a radial expansion joint and a conductor, a finite element model of the GIL device is established based on the GIL device data, and a temperature factor and an internal air pressure factor of the GIL device are applied to obtain the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL device of the finite element model of the GIL device;

[0110] In this embodiment, the GIL pipe joint includes a GIL straight pipe joint and a GIL corner pipe joint. In this embodiment, in step S1, the temperature factor includes the highest temperature of the GIL shell formed by adding the temperature rise of sunlight and the temperature rise of conductor heating on the basis of the highest temperature of the climate, and the lowest temperature of the GIL shell formed by the lowest temperature of the climate, which affects the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL equipment. The internal air pressure factor of the GIL equipment is that the GIL equipment is filled with SF6 gas, which itself forms compressive stress on the GIL shell. After the temperature rises, the compressive stress on the GIL shell will also change, and affect the radial expansion limit outer diameter of the GIL pipe joint.

[0111] Step S2, calculating the adjustment range of the axial expansion joint and the radial expansion joint, and comparing the thermal expansion limit deformation of the GIL device with the adjustment range of the axial expansion joint and the radial expansion joint;

[0112] If the thermal expansion limit deformation of the GIL device is less than the adjustment range of the axial expansion joint and the radial expansion joint, step S32 is performed;

[0113] Step S32, measuring the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint;

[0114] If the axes of the straight pipe segments are on a straight line, proceed to step S42;

[0115] Step S42, measuring the inner diameter of the GIL pipe joint fixing device, and comparing the inner diameter of the GIL pipe joint fixing device with the radial expansion limit outer diameter of the GIL pipe joint;

[0116] If the inner diameter of the GIL pipe joint fixing device is greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint, proceed to step S52;

[0117] Step S52, observing the eccentric wear condition of the slider and the guide rail of the GIL pipe joint fixing device;

[0118] If the slider and guide rail of the GIL pipe joint fixing device are worn on one side, a lining strip is installed on the upper slide plate; the relative position of the GIL pipe joint fixing device and the GIL pipe joint is adjusted so that the two goosetail grooves are axially symmetrically arranged on both sides of the center of gravity surface of the GIL pipe joint.

[0119] The lining strip installed on the upper sliding plate can be a new lining strip or a reusable lining strip.

[0120] The present invention is described in detail above with reference to the accompanying drawings and embodiments. It should be understood that it is impossible to describe all possible implementation methods in practice, and the inventive concept of the present invention is described as much as possible by way of example. Without departing from the inventive concept of the present invention and without creative work, the technical personnel in this technical field make selections and combinations of the technical features in the above embodiments, make experimental changes to the specific parameters, or use the prior art in this technical field to conventionally replace the disclosed technical means of the present invention to form specific embodiments, which should all belong to the implicit disclosure of the present invention.

Claims

1. A method for troubleshooting a GIL pipe joint fixing device, wherein the GIL pipe joint fixing device comprises a GIL pipe joint clamp, a slider and a guide rail, wherein the GIL pipe joint clamp is fixedly connected to the slider, the slider and the guide rail are movably connected, and the GIL pipe joint clamp is used to fix the GIL pipe joint. It is characterized in that The following steps are involved: Step S1, the GIL device includes a GIL pipe joint, an axial expansion joint, a radial expansion joint and a conductor, a finite element model of the GIL device is established based on the GIL device data, and a temperature factor and an internal air pressure factor of the GIL device are applied to obtain the radial expansion limit outer diameter of the GIL pipe joint and the thermal expansion limit deformation of the GIL device of the finite element model of the GIL device; Step S2, calculating the adjustment range of the axial expansion joint and the radial expansion joint, and comparing the thermal expansion limit deformation of the GIL device with the adjustment range of the axial expansion joint and the radial expansion joint; If the thermal expansion limit deformation of the GIL device is greater than or equal to the adjustment range of the axial expansion joint and the radial expansion joint, replace the axial expansion joint and / or the radial expansion joint to make the thermal expansion limit deformation of the GIL device less than the adjustment range of the axial expansion joint and the radial expansion joint, re-arrange the GIL pipe joint fixing device, and proceed to step S3; If the thermal expansion limit deformation of the GIL device is less than the adjustment range of the axial expansion joint and the radial expansion joint, proceed to step S3; Step S3, measuring the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint; If the axes of the straight pipe segments are on a straight line, proceed to step S4; If the axes of the straight pipe sections are not on a straight line, the GIL pipe joint fixing device is adjusted so that the axes of the straight pipe sections are arranged on a straight line, and step S4 is performed; Step S4, measuring the inner diameter of the GIL pipe joint fixing device, and comparing the inner diameter of the GIL pipe joint fixing device with the radial expansion limit outer diameter of the GIL pipe joint; If the inner diameter of the GIL pipe joint fixing device is less than the radial expansion limit outer diameter of the GIL pipe joint, the GIL pipe joint clamp is maintained to make the inner diameter of the GIL pipe joint fixing device greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint, and step S5 is performed; If the inner diameter of the GIL pipe joint fixing device is greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint, proceed to step S5; Step S5, observing the eccentric wear condition of the slider and the guide rail of the GIL pipe joint fixing device; If the slider and guide rail of the GIL pipe joint fixing device are worn on one side, the GIL pipe joint fixing device should be maintained so that the center of gravity of the GIL pipe joint is set at the connection center of the slider and the guide rail.

2. The GIL pipe joint fixing device fault inspection and repair method according to claim 1, It is characterized in that In step S1, the temperature factors include the highest temperature of the GIL shell formed by adding the temperature rise of sunlight and the temperature rise of conductor heating on the basis of the highest temperature of the climate, and the lowest temperature of the GIL shell formed by the lowest temperature of the climate.

3. The GIL pipe joint fixing device fault inspection and repair method according to claim 1, It is characterized in that In step S3, a total station or a laser straightness meter is used to measure the straightness of the straight pipe section formed by the GIL pipe joint and the axial expansion joint.

4. The GIL pipe joint fixing device fault inspection and repair method according to claim 1, It is characterized in that The GIL pipe joint fixing device failure is a GIL pipe joint clamp cracking failure. In step S2, the GIL equipment thermal expansion limit deformation is less than the adjustment range of the axial expansion joint and the radial expansion joint. In step S3, the axes of the straight pipe segments are on a straight line, and in step 4, the inner diameter of the GIL pipe joint fixing device is greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint. In step S5, the contents of maintaining the GIL pipe joint fixing device include: Replace the GIL pipe clamp or repair the cracks in the GIL pipe clamp; The relative position of the GIL pipe joint fixing device and the GIL pipe joint is adjusted so that the center of gravity of the GIL pipe joint is set at the connection center of the slider and the guide rail.

5. The GIL pipe joint fixing device fault inspection and repair method according to claim 4, It is characterized in that The GIL pipe joint clamp includes an upper clamp and a lower clamp, and the upper clamp and the lower clamp are connected by bolt connectors to form a detachable clamp; the slider includes an upper slide plate and a lining strip, and the upper slide plate is fixedly connected to the lower clamp via a connecting plate, and the bottom surface of the upper slide plate is provided with two goose tail grooves, and the lining strip is installed in the goose tail grooves. Then, in step S5, the relative position of the GIL pipe joint fixing device and the GIL pipe joint is adjusted so that the two goose tail grooves are axially symmetrically arranged on both sides of the center of gravity surface of the GIL pipe joint.

6. The GIL pipe joint fixing device fault inspection and repair method according to claim 1, It is characterized in that The GIL pipe joint clamp comprises an upper clamp and a lower clamp, and the upper clamp and the lower clamp are connected by bolt connectors to form a detachable clamp; the slider comprises an upper slide plate and a lining strip, and the upper slide plate is fixedly connected to the lower clamp via a connecting plate, and the bottom surface of the upper slide plate is provided with two goose-tail grooves, and the lining strip is installed in the goose-tail grooves. The failure of the GIL pipe joint fixing device is a single-side lining strip detachment failure. In the step S2, the thermal expansion limit deformation of the GIL equipment is less than the adjustment range of the axial expansion joint and the radial expansion joint. In the step S3, the axes of the straight pipe sections are on a straight line, and in the step 4, the inner diameter of the GIL pipe joint fixing device is greater than or equal to the radial expansion limit outer diameter of the GIL pipe joint. In the step S5, the contents of maintaining the GIL pipe joint fixing device include: Installing a lining strip on the upper slide plate; The relative position of the GIL pipe section fixing device and the GIL pipe section is adjusted so that the two goose-tail grooves are axially symmetrically arranged on both sides of the center of gravity surface of the GIL pipe section.

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