Long-distance high-capacity pipeline bus liquid cooling microgravity supporting structure and method

Abstract

The invention discloses a long-distance large-capacity SF6 gas pipeline bus total immersion liquid cooling microgravity supporting structure and method, and the structure comprises a total immersion environment system which comprises a total immersion environment system housing, an SF6 pipeline bus, a water body, and a plurality of radial limiting supporting structures. The SF6 pipeline bus and the radial limiting support structure are arranged in a closed cavity formed by the shell of the total immersion environment system, the radial limiting support structure is sleeved outside the SF6 pipeline bus, and the radial limiting support structure can move back and forth in the total immersion environment system; the space between the outer wall of the SF6 pipeline bus and the inner wall of the full-immersion environment system shell is filled with water, and the full-immersion water charging and discharging device is mounted on the full-immersion environment system shell; the shell of the pipeline bus is liquid-cooled, so that the cooling capacity of the pipeline bus is greatly improved; the radial limiting and supporting structure can freely slide in a full-immersion environment system, accumulative stretching and deformation of a long-distance and long vertical pipeline bus are achieved, and the problems of high-fall supporting and stretching of the pipeline bus are solved.

Description

Technical Field

[0001] The present invention belongs to the field of electromechanical engineering and power transmission and transformation technology, and particularly relates to a liquid-cooled microgravity support structure and method for a long-distance, large-capacity pipeline busbar. Background Art

[0002] Gas-insulated Metal Enclosed Transmission Lines (GILs) transmit electricity using metal conductive rods enclosed in a grounded metal casing and insulated by pressurized gas. SF6 busbars are busbars that use sulfur hexafluoride (SF6) gas as the insulating medium. High-voltage SF6 busbars (GILs) are power transmission equipment with a fully welded metal casing. The internal conductors are supported on the casing by supports or gas-insulated pot insulators. The interior is filled with SF6 insulating gas at a pressure of 0.2 to 0.8 MPa (typically 0.5 MPa for 500 kV).

[0003] The GIL busbar housing is typically suspended from a support using hangers or slings, or the housing is directly fixed to a wall or the ground via a support. The housing is connected to the support via a sliding mechanism, allowing for horizontal and vertical movement within a certain range to accommodate expansion and contraction of the GIL line due to temperature and load fluctuations.

[0004] For horizontal GILs, the continuous sliding structure with multi-point support over long distances is also difficult to adapt to due to the support force in the GIL load direction. That is, when the outer shell support structure bears the large load of the GIL long-distance unit, sliding in the telescopic direction can easily lead to damage and dangerous deformation of the GIL body.

[0005] Thermal expansion and contraction are a particular concern for the casing supports of long vertical GIL sections. Bellows expansion joints or expansion joints are typically installed in the GIL casing to absorb and compensate for this deformation. However, for long vertical GIL sections, both bellows expansion joints and expansion joints increase the number of connection interfaces and reduce operational reliability. Summary of the Invention

[0006] The purpose of the present invention is to provide a long-distance, large-capacity pipeline busbar liquid-cooled microgravity support structure and method to solve the problems of heat dissipation, high-drop support and expansion of long vertical SF6Q gas pipeline busbars.

[0007] To achieve the above objectives, the technical solution of the present invention is: A long-distance, large-capacity SF6 gas pipeline busbar fully immersed liquid-cooled microgravity support structure includes a fully immersed environment system, which includes a fully immersed environment system shell, an SF6 pipeline busbar, a water body and multiple radial limiting support structures; the SF6 pipeline busbar and the multiple radial limiting support structures are arranged in a closed cavity formed by the fully immersed environment system shell, and the radial limiting support structure is sleeved on the outside of the SF6 pipeline busbar, and the radial limiting support structure can move back and forth inside the fully immersed environment system; the space between the outer wall of the SF6 pipeline busbar and the inner wall of the fully immersed environment system shell is filled with water, and the fully immersed water filling and discharging device is installed on the fully immersed environment system shell.

[0008] Furthermore, the housing of the full immersion environment system is a fully enclosed concrete water pipe, steel pipe or prestressed reinforced concrete pipe.

[0009] Furthermore, the housing of the full immersion environment system is a sealed cylinder.

[0010] Furthermore, the radial limiting support structure is a disc concentric with the SF6 pipe busbar casing, a circular hole is provided in the middle of the disc, the circular hole is sleeved on the periphery of the SF6 pipe busbar, the disc and the SF6 pipe busbar casing are clearance-matched, four protrusions are evenly spaced on the outer circumference of the disc, the line connecting two oppositely arranged protrusions passes through the center of the disc, and four long strip grooves are provided on the inner wall of the cylindrical full immersion environment system casing along the axial direction, the grooves move along the axial direction of the cylinder, each of the protrusions is stuck in a long strip groove, and the protrusions are clearance-matched with the grooves.

[0011] Furthermore, the sum of the deadweight of the GIL pipeline busbar of the unit and the deadweight of the position-limiting support structure is equal to the buoyancy of the unit length.

[0012] A method for achieving microgravity support of a pipeline busbar by using the long-distance, large-capacity SF6 gas pipeline busbar fully immersed in liquid cooling microgravity support structure comprises: Make the sum of the self-weight of the GIL pipeline busbar of the unit and the self-weight of the limit support structure equal to the buoyancy of the GIL pipeline busbar of the unit length; Fill the space on the outer wall of the SF6 pipeline busbar and the inner wall of the fully immersed environment system shell with water.

[0013] The beneficial effects of the present invention are as follows: 1. The traditional fixed support method for GIL pipeline busbars is support in the air, that is, full gravity support. Under the method of the present invention, the GIL pipeline busbar can be floated or suspended in the full immersion system by counterweights, so that only the position limit in the container needs to be considered, without considering the load. The present invention utilizes the full immersion and counterweight method of the SF6 pipeline busbar (GIL) to evenly transfer the load of the GIL pipeline busbar to the inner wall of the fully immersed pipeline. The GIL achieves equal matching of buoyancy and weight under the full immersion method through counterweights, thereby changing the support in the fully immersed pipeline from the existing GIL full-load support method to a floating load-free support method (only position is required), which can greatly simplify the internal support structure and realize the telescopic deformation of the long-distance GIL. At the same time, in full immersion mode, the GIL casing is in a static liquid-cooled state, greatly improving the cooling capacity and flow capacity of the GIL pipeline busbar. As a result, under the same casing / conductor structure dimensions, the GIL can adopt a high-current transmission mode, increasing the rated current range of conventional air-cooled GIL by more than 30% (6000A-10000A) compared to 4000A-8000A. This significantly increases the transmission capacity of long-distance GIL.

[0014] 2. The method of the present invention can achieve long-distance, large-capacity GIL in a fully enclosed metal casing that is highly adaptable to expansion and contraction deformation under long-distance conditions. In particular, the fully immersed gravity-free support method provides a new support method for long vertical sections of GIL in deep underground power pipeline corridors, solving the problems of high-drop support and expansion and contraction of long vertical GIL. The fully immersed liquid cooling method of the GIL casing provides the possibility of ultra-large capacity power transmission under the same conditions, which greatly improves the economy and the reliability of the GIL equipment. The present invention provides a new solution for the use of large-capacity, high-pressure SF6 pipeline busbars, especially for deep underground (burial depth greater than 100m) and ultra-long distances (greater than 10km). BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an example diagram of the single-phase vertical section structure of a fully immersed microgravity supported SF6 insulated pipeline busbar GIL.

[0016] Figure 2 This is an example diagram of the structure of a fully immersed microgravity supported SF6 insulated pipeline busbar (GIL single-phase horizontal section).

[0017] Figure 3 Example diagram of the cross-sectional structure of a fully immersed microgravity-supported SF6 insulated pipeline busbar.

[0018] Among them: a fully immersed environment system shell 1; an SF6 pipeline busbar 2; a metal conductive rod 21; a water body and multiple radial limiting support structures 3; and a bump 31. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific examples described herein are some embodiments of the present invention, rather than all embodiments, and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] A long-distance, large-capacity SF6 gas pipeline busbar fully immersed liquid-cooled microgravity support structure includes a fully immersed environment system, which includes a fully immersed environment system shell 1, an SF6 pipeline busbar 2, a water body and multiple radial limiting support structures 3; the SF6 pipeline busbar 2 and the multiple radial limiting support structures 3 are arranged in a closed cavity formed by the fully immersed environment system shell 1, and the radial limiting support structure 3 is sleeved on the outside of the SF6 pipeline busbar 2, and the radial limiting support structure 3 can move back and forth inside the fully immersed environment system 1; the space between the outer wall of the SF6 pipeline busbar 2 and the inner wall of the fully immersed environment system shell 1 is filled with water.

[0021] The systems and functions that constitute and implement the fully immersed liquid-cooled microgravity support structure for long-distance, large-capacity SF6 gas pipeline busbars are described as follows: The fully enclosed, pressurized GIL single-phase or three-phase shared enclosure system is designed for underwater immersion. The enclosure 1 can be a large-diameter, long-distance sealed pipe water container, designed for use in a fully submerged GIL single-phase or three-phase shared enclosure. The enclosure 1 is a pressurized, fully enclosed metal or metal-composite concrete structure, enabling long-distance interconnection. The pipeline possesses sufficient rigidity to meet the strength requirements for evenly distributing the suspended load of the fully submerged GIL within it through the water medium on the inner wall of the pipeline. In one specific embodiment, the enclosure 1 is a metal cylinder or a metal-composite concrete cylinder.

[0022] The SF6 pipeline busbar 2 is a 110kV to 1000kV high-voltage SF6 pipeline busbar (GIL). It is a high-voltage power transmission device with a fully welded metal casing. The SF6 pipeline busbar uses one or three metal conductive rods 21 for power transmission. The internal metal conductive rods 21 are supported on the casing by supports or basin-type insulators with gas isolation. The interior is filled with SF6 insulating gas at a pressure of 0.2 MPa to 0.8 MPa (typically 0.5 MPa for 550 kV). For example, a 500 kV GIL, with an aluminum alloy casing outer diameter of approximately 500 mm and a thickness of 20 mm, weighs approximately 160 kg per meter (busbar casing and conductors).

[0023] The radial limiting support structure of the SF6 pipeline busbar housing in the fully immersed pipeline is a concentric disk or ring. The SF6 pipeline busbar is located in the GIL single-phase or three-phase common box fully immersed environment system. The radial limiting support structure 3 is used for radial limiting of the SF6 pipeline busbar in the GIL single-phase or three-phase common box fully immersed environment system. In a specific embodiment, the GIL single-phase or three-phase common box fully immersed environment system housing 1 is cylindrical, specifically a cylinder made of metal, or a cylinder made of metal composite concrete. The SF6 pipeline busbar housing is also cylindrical. The radial limiting support structure 3 can adopt a disc structure concentric with the GIL housing. In a specific embodiment, the radial limiting support structure is a disc with a circular hole in the middle of the disc. The size of the circular hole is adapted to the SF6 pipeline busbar. The circular hole is sleeved on the periphery of the SF6 pipeline busbar. The disc is clearance-matched with the SF6 pipeline busbar housing. Four protrusions 31 are evenly spaced on the outer circumference of the disc. The line connecting the two oppositely positioned protrusions 31 passes through the center of the disk. The housing 1 of the GIL single-phase or three-phase fully immersed environment system, i.e., a cylinder made of metal or metal-composite concrete, has four elongated grooves arranged along the axial direction. The grooves move along the axial direction of the cylinder, and each protrusion 31 is retained within a groove. The protrusion 31 and the groove are loosely fitted. When thermal expansion and contraction occur, the protrusion 31 slides along the groove, allowing the radial limiting support structure to slide freely along the GIL axis (line direction) under microgravity conditions within the GIL single-phase or three-phase fully immersed environment system, thereby achieving cumulative expansion and contraction of the GIL over long distances and vertical lengths. In specific applications, multiple radial limiting support structures 3 are evenly spaced along the axial direction around the periphery of the SF6 pipeline busbar.

[0024] The fully immersed GIL zero-load counterweight device is configured according to the GIL dimensions and loads of different voltage levels and different transmission capacity levels, that is, the buoyancy generated by the GIL closed pipeline under full immersion conditions (limit unit length) = GIL deadweight (limit unit length); when the GIL is at a high voltage level, the increase in the outer diameter causes the buoyancy per unit length to be greater than the deadweight of the GIL of the same length. The radial limit support structure and the counterweight device can be integrated into one, which becomes the following integrated counterweight limit support structure.

[0025] The integrated counterweight limit support structure is to configure the limit unit length and the weight of the limit support structure when the buoyancy of the GIL unit length is greater than the deadweight of the same length, so that the deadweight of the GIL pipeline busbar of the unit + the radial limit support structure = the buoyancy of the unit length, that is, to achieve the overall underwater microgravity support of the SF6 pipeline busbar and its limit structure.

[0026] In the present invention, a fully immersed system water charging and discharging device can be provided on the fully immersed environment system housing 1. The fully immersed system water charging and discharging device includes pipes and valves provided on the fully immersed environment system housing 1. The fully immersed system water charging and discharging device provides a clean water source and pipes and valves for the GIL single-phase or three-phase common box fully immersed environment system, and reaches the fully immersed SF6 pipeline bus, forming a fully immersed pressure (heavy) system running through the entire GIL path.

[0027] This invention leverages the characteristics of the fully enclosed SF6 pipeline busbar (GIL) pressure vessel. By utilizing appropriate counterweights, the GIL can achieve a suspended state in a fully immersed environment. Specifically, the GIL's deadweight + counterweight = buoyancy. In this configuration, the GIL's outer casing supports the pipeline only in the radial direction (no force applied). The SF6 pipeline, including at the butt welds, is free of load from its own equipment, significantly improving the stress conditions at the welds. Both horizontal and vertical sections of the SF6 pipeline busbar experience near-zero resistance (free sliding) when suspended in zero gravity, effectively accommodating the expansion and contraction of the GIL over long distances. Furthermore, when fully immersed in water for cooling, the GIL's high specific heat capacity allows the GIL's outer casing to operate in a fully immersed environment with minimal temperature fluctuations for extended periods, significantly improving heat dissipation and enabling ultra-high-capacity power transmission within comparable structural dimensions.

[0028] Taking the transmission of GIL (three single-phases) with a rated voltage of 550 kV and a rated current of 1000 A in an underground power pipeline corridor of a large underground hydropower station as an example, the system of the present invention is as follows.

[0029] like Figure 1 、 Figure 2 As shown, the single-phase casing of a 550kV GIL is an aluminum tube with an outer diameter of 512mm and a thickness of 10mm. The conductor is a pure aluminum tube with an outer diameter of 180mm and a thickness of 20mm. The internal SF6 pressure is 0.5MPa. The GIL has a length of 10km to 50km, all located within deep underground power pipeline corridors. The GIL is a three-phase split-phase system. The total weight of a 1m long 550kV GIL is approximately 69.93kg per phase. This example uses one phase to illustrate the method and system configuration of the present invention.

[0030] A PCCP (prestressed concrete liner) with an inner diameter of approximately 850mm is used as the fully immersed pipe for the single-phase 500kV GIL (outer diameter 512mm). Water is injected into the PCCP pipe of the above-mentioned fully immersed SF6 gas pipeline busbar (GIL) system through a water filling and discharging device, so that the vertical or horizontal section of the GIL (including fixed and non-fixed counterweights) is fully immersed.

[0031] In this example, the buoyancy of the GIL, a cylindrical structure with an outer diameter of 512 mm and a length of 1000 mm, in water is approximately 1926.36 Newtons, or 196 kg (force). The condition for achieving zero load (microgravity) is (assuming a 10-meter unit), resulting in a counterweight of (196 - 69.93) * 10 = 1260.76 kg. This integrated counterweight and limit support structure can be constructed with a concrete-steel lining. The outer edge mates with the concrete pipe structure, while the inner edge utilizes steel clamps that mate with the outer circular clamps of the SF6 pipeline busbar, creating a structure with radial restraint on the outer side and free axial sliding on the inner side. The length of this annular structure (concrete wall outer diameter 820 mm, wall thickness 150 mm, inner steel lining outer diameter 520 mm, wall thickness 10 mm) along the GIL axis is approximately 1.43 m, based on the counterweight.

[0032] According to the present invention, the vertical section of the fully submersible GIL's counterweight is fixedly connected to the GIL's pipeline busbar housing (meeting the requirements for initial installation and dry maintenance). The vertical section GIL and counterweight slide together along the GIL's axial direction on the inner wall of the fully submersible pipe. The horizontal section of the fully submersible GIL's counterweight is non-fixedly connected to the GIL's pipeline busbar housing (providing only radial restraint). The GIL and counterweight stopper can each slide freely along the GIL's axial direction (the direction of the line path).

[0033] The above embodiments are merely examples for clarity of explanation and are not intended to limit the embodiments. Those skilled in the art will appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all embodiments here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A fully immersed liquid-cooled microgravity support structure for a long-distance, high-capacity SF6 gas pipeline busbar, including a fully immersed environment system, characterized by: The fully immersed environment system comprises a fully immersed environment system shell (1), an SF6 pipeline busbar (2), a water body, and a plurality of radial limiting support structures (3); the SF6 pipeline busbar (2) and the plurality of radial limiting support structures (3) are arranged in a closed cavity formed by the fully immersed environment system shell (1), and the radial limiting support structure (3) is sleeved outside the SF6 pipeline busbar (2), and the radial limiting support structure (3) can move back and forth inside the fully immersed environment system (1); the space between the outer wall of the SF6 pipeline busbar (2) and the inner wall of the fully immersed environment system shell (1) is filled with water, and the fully immersed water filling and discharging device (4) is installed on the fully immersed environment system shell (1).

2. The microgravity support structure for a long-distance, large-capacity SF6 gas pipeline busbar fully immersed in liquid cooling according to claim 1 is characterized in that: The fully immersed environment system housing (1) is a fully enclosed concrete water pipe, steel pipe or prestressed reinforced concrete pipe.

3. The microgravity support structure for a long-distance, large-capacity SF6 gas pipeline busbar fully immersed in liquid cooling according to claim 1 is characterized in that: The fully immersed environment system housing (1) is a cylindrical body in a sealed state.

4. The microgravity support structure for a long-distance, large-capacity SF6 gas pipeline busbar fully immersed in liquid cooling according to claim 1 is characterized in that: The radial limiting support structure (3) is a disc concentric with the SF6 pipeline busbar housing, a circular hole is provided in the middle of the disc, the circular hole is sleeved on the periphery of the SF6 pipeline busbar, the disc and the SF6 pipeline busbar housing are in clearance fit, four protrusions (31) are evenly spaced on the outer circumference of the disc, the line connecting two oppositely arranged protrusions (31) passes through the center of the disc, the inner wall of the cylindrical full immersion environment system housing (1) is provided with four long strip grooves along the axial direction, the grooves move along the axial direction of the cylinder, each of the protrusions (31) is stuck in a long strip groove, and the protrusion (31) is in clearance fit with the groove.

5. The microgravity support structure for a long-distance, large-capacity SF6 gas pipeline busbar fully immersed in liquid cooling according to claim 1 is characterized in that: The sum of the deadweight of the GIL pipeline busbar and the deadweight of the position-limiting support structure of the unit is equal to the buoyancy of the unit length.

6. A method for achieving microgravity support for a long-distance, large-capacity SF6 gas pipeline busbar using the fully immersed liquid-cooled microgravity support structure for the long-distance, large-capacity SF6 gas pipeline busbar according to claim 1, the method comprising: Make the sum of the self-weight of the GIL pipeline busbar of the unit and the self-weight of the limit support structure equal to the buoyancy of the GIL pipeline busbar of the unit length; The space between the outer wall of the SF6 pipeline busbar (2) and the inner wall of the fully immersed environment system housing (1) is filled with water.

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