Multi-adaptive river-crossing tunnel GIL power transmission tide section layout method

Abstract

The invention relates to the technical field of river-crossing tunnel GIL arrangement, in particular to a multi-adaptability river-crossing tunnel GIL power transmission tide section arrangement method. In order to solve the problems that in the prior art, a 500kV medium-and-long-distance GIL river-crossing tunnel layout scheme is insufficient, especially a feeding port is limited, and structural transformation is difficult, the invention provides a solution of cavity-divided arrangement. The interior of the tunnel is divided into an upper cavity and a lower cavity, four loops of 500kV GIL are symmetrically arranged in the upper cavity, a double-track rail type transportation system is adopted, the design of binding force balance expansion joints is adopted, and the structural stability of the tunnel is ensured. According to the scheme, a flexible transformation space is reserved, and the requirement that a two-loop 1000kV GIL or a two-loop 500kV GIL plus a one-loop direct-current GIL is reconstructed in the future can be met. By optimizing the space between the GIL and the layout of the transportation channel and the stand columns, the problems of installation, operation and maintenance and safety of equipment in the middle and long distance tunnel are solved, and the capacity and adaptability of river-crossing power transmission are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of GIL layout in river-crossing tunnels, and in particular to a multi-adaptability method for arranging power transmission flow sections of GIL in river-crossing tunnels. Background Art

[0002] GIL, short for Gas-Insulated Metal Enclosed Transmission Line, is a high-voltage, high-current electrical device that utilizes gas insulation with a coaxial casing and conductors. It typically consists of an aluminum alloy casing, aluminum alloy conductors, insulating gas, and epoxy supports. Currently, there are no 500kV medium- to long-distance GIL cross-river tunnels. Unlike onshore open-cut tunnels, cross-river shield tunnels have feed openings only in the working shafts at either end of the tunnel; there are no feed openings in the middle of the tunnel. Furthermore, once a tunnel is built, its structure becomes fixed, making modification difficult.

[0003] Power transmission lines primarily include overhead lines, high-voltage cables, and gas-insulated metal-enclosed transmission lines (GILs). Cross-river power transmission traditionally relies on large spans, which require the installation of towers mid-river, impacting the ecological, navigational, and electromagnetic environments. High-voltage cables have limited transmission capacity and are unable to meet the demand for large-scale cross-river power transmission. GILs, with their high transmission capacity and reliability, are the preferred solution for large-capacity power transmission corridors.

[0004] Existing 500kV GIL channels are primarily used in urban onshore open-cut tunnels and power plant connections, particularly those for large nuclear and hydropower plants. These projects typically involve short distances or numerous feed openings, resulting in simple installation and transportation. Their layouts do not consider medium- and long-distance GIL transportation, making them unsuitable for medium- and long-distance river crossing tunnels with limited feed openings.

[0005] However, how to transport and install the internal GIL in a cross-section layout suitable for medium and long distances and when only the working shafts at both ends of the tunnel have feeding ports is a technical problem that needs to be solved. Summary of the Invention

[0006] The problem to be solved by the present invention is to provide a cross-section arrangement scheme suitable for the transportation and installation of inner GIL over medium and long distances, where only the working shafts at both ends of the tunnel have feeding ports.

[0007] In view of the shortcomings of the prior art, the present invention solves the technical problems thereof by adopting a technical solution: a multi-adaptable GIL power transmission flow section layout method for a cross-river tunnel, comprising the following structures and steps:

[0008] The cross-river tunnel adopts a split-chamber structure, with the interior divided into an upper chamber and a lower chamber. The upper chamber has a net height of 6,670 mm and is used to lay a four-circuit 500 kV GIL transmission line. The lower chamber is divided into multiple chambers to accommodate low-voltage power distribution, SF6 exhaust, and drainage facilities.

[0009] Four 500kV GIL circuits are symmetrically arranged on both sides of the upper cavity. Each circuit consists of three vertically arranged GIL cylinders. The 500kV GIL circuits on both sides are symmetrically arranged with the lowest phase center at a height of 800mm from the cavity layer. The lowest phase center of the two middle 500kV GIL circuits is 1300mm-1500mm from the cavity layer.

[0010] Tracks are installed on both sides of the upper cavity. The tracks are laid out along the longitudinal direction of the tunnel. The center distance between adjacent loop GILs on both sides is 3500mm-3550mm.

[0011] A force-balancing expansion joint is set to offset the influence of the blind plate force on the tunnel structure. The diameter of the force-balancing expansion joint is 835mm-960mm.

[0012] There are double-sided columns in the middle of the upper cavity to support the two middle circuit GILs. The two middle circuit GILs are symmetrically arranged with a center distance of 1000mm-1100mm.

[0013] Preferably, the diameter of the GIL cylinder is 508mm-600mm, and the collinear GIL cylinders are connected by flanges with a diameter of 625mm-750mm.

[0014] Preferably, the distance between the lowest phase center of the two middle loop GILs and the sub-cavity layer is 1300 mm.

[0015] Preferably, the distance between the side force-balancing expansion joint and the tunnel side wall is greater than 400 mm to meet the bolt tightening space of the force-balancing expansion joint and the hydraulic wrench operation space.

[0016] Preferably, the double-sided columns include a left column and a right column, which are mirror-symmetrically distributed on both sides of the center line of the upper cavity and respectively support the vertical arrangement structures of the two middle circuit GILs.

[0017] Preferably, the rails are fixed to the bottom of the upper cavity, the rail spacing matches the width of the transport vehicle, and a safety distance is reserved on both sides of the rails to prevent equipment collision.

[0018] Preferably, a manhole is provided at the cavity layer.

[0019] Preferably, the inner diameter of the tunnel is 10.5 m, the outer diameter is 11.6 m, the cavity layer adopts a reinforced concrete structure, and the thickness of the cavity layer is determined according to the stress analysis of the tunnel.

[0020] The beneficial effects of the present invention are as follows:

[0021] The cross-sectional layout of this invention takes into account the transportation and installation of internal GIL over medium and long distances, when only the working shafts at the two ends of the tunnel have feed ports. The tunnel adopts a split-chamber design (the upper chamber houses the GIL and the lower chamber accommodates auxiliary facilities), which optimizes the spatial layout, avoids equipment interference, and reduces operation and maintenance risks.

[0022] Up and down connecting manholes are set up every 500m to facilitate rapid passage of personnel and emergency maintenance, shortening the operation and maintenance response time.

[0023] The layout scheme of the present invention is a symmetrical arrangement of two 4-circuit 500kV GILs, combined with a single-circuit vertical arrangement structure, which significantly improves the transmission capacity and meets the power transmission needs of large-span cross-river. In addition, considering that after the construction of the tunnel body, civil engineering transformation is difficult but the power transmission needs are likely to change, the cross-section layout scheme has the adaptability to be converted into 2 1000kV GILs or 2 500kV GILs plus 1 DC GIL without affecting the main structure of the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the 4-circuit 500kV GIL cross-section arrangement scheme of the present invention;

[0025] Figure 2 This is the 2-circuit 1000kV GIL cross-section arrangement scheme of the present invention;

[0026] Figure 3 This is the cross-sectional arrangement scheme of the present invention of 2 500kV GILs + 1 DC GIL;

[0027] Explanation of the accompanying drawings: 1. Tunnel; 2. Upper cavity; 3. Lower cavity; 31. Cavity one; 32. Cavity two; 33. Cavity three; 4. Chamber layer; 5. Track; 6. First column; 7. Second column; 8. Double-sided columns; 81. Left column; 82. Right column; 9. GIL cylinder; 10. Flange; 11. Force balancing expansion joint; 12. DC column. DETAILED DESCRIPTION

[0028] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for purposes of illustration and description and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments are chosen and described to better illustrate the principles of the invention and its practical application, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for specific applications.

[0029] In order to solve the problems raised in the background technology, the present invention proposes a multi-adaptable method for laying out GIL power transmission flow sections in a river-crossing tunnel, comprising the following structures and steps:

[0030] Tunnel 1 has an inner diameter of 10.5m and an outer diameter of 11.6m. The sub-cavity layer 4 is constructed of reinforced concrete and is located between the upper and lower cavities 2 and 3. A manhole is located at this sub-cavity layer 4. Its thickness is determined based on tunnel stress analysis. Cross-river tunnel 1 utilizes a sub-cavity structure, divided into an upper cavity 2 and a lower cavity 3. The upper cavity 2 has a clear height of 6,670mm and is used to accommodate a four-circuit 500kV GIL transmission line. The lower cavity 3 is divided into multiple cavities, including cavity 1 31, cavity 2 32, and cavity 3 33, which house low-voltage power distribution, SF6 exhaust, and drainage facilities.

[0031] Four 500kV GIL circuits are symmetrically arranged on both sides of the upper chamber 2. Each circuit consists of three vertically arranged GIL cylinders 9. The two side circuits are 500kV The GIL is supported by the first column 6 and the second column 7 respectively. The two circuits on the first column 6 and the second column 7 are arranged in a mirror-symmetrical manner. The center height of the lowest phase on the first column 6 and the second column 7 from the sub-cavity layer 4 is H1, and the value of H1 is 800mm. The two middle circuits are supported by bilateral columns 8. The two middle circuits are arranged symmetrically and the center height of the lowest phase from the sub-cavity layer 4 is H4, and the range of H4 can be 1300mm-1500mm; the middle part of the upper cavity 2 is provided with bilateral columns 8, and the bilateral columns 8 include a left column 81 and a right column 82, which are mirror-symmetrically distributed on both sides of the center line of the upper cavity 2. The left column 81 and the right column 82 respectively support the vertical arrangement structure of the two middle circuit GILs. The center distance of the two middle circuit GILs is L3, and the range of L3 can be 1000mm-1100mm; the distance between the lowest phase of the two middle circuit GILs and the sub-cavity layer 4 is preferably 1300mm. The distance between the side force-balancing expansion joint 11 and the tunnel side wall is greater than 400 mm to meet the bolt tightening space of the force-balancing expansion joint 11 and the hydraulic wrench operation space.

[0032] Tracks 5 are provided on both sides of the upper cavity 2 and are arranged longitudinally along the tunnel 1. The center distance between two adjacent loop GILs is 3500mm. The width of the transport channel is adapted to the mechanical transport vehicle. The width of the transport vehicle is 2200mm, and a construction deviation margin of ±170mm is reserved. Tracks 5 are fixed to the bottom of the upper cavity 2. The spacing between tracks 5 matches the width of the transport vehicle, and a safety distance is reserved on both sides of track 5 to prevent equipment collision.

[0033] The GIL cylinder 9 is connected by a force-balancing expansion joint 11 with a diameter of 835mm-960mm. The force-balancing expansion joint 11 is installed between the GIL cylinder 9 and the flange 10 to offset the impact of the blind plate force on the tunnel structure. The collinear GIL cylinders 9 are connected by flanges 10. The diameter of the GIL cylinder 9 is 508mm-600mm, the diameter of the flange 10 is 625mm-750mm, and the diameter of the force-balancing expansion joint 11 is 825mm-960mm.

[0034] The cross-river tunnel GIL power transmission flow section solution of the present invention is as follows: Figure 1 As shown, tunnel 1 has an inner diameter d of 10.5m and an outer diameter D of 11.6m. Tunnel 1 is divided into upper and lower chambers. Upper chamber 2 houses the GIL equipment, while lower chamber 3 houses auxiliary facilities (including low-voltage power distribution, SF6 exhaust, and drainage). Four 500kV GIL circuits are symmetrically arranged on either side of upper chamber 2, with transport tracks symmetrically installed on both sides. Three GILs are arranged vertically on each circuit, and the two middle GILs are elevated. Manholes connecting the upper and lower chambers are located approximately every 500m. The clear height of upper chamber 2 is H, which is 6670mm.

[0035] The main structural parameters influencing the GIL cross-sectional layout are the diameter of the GIL cylinder 9, the diameter of the flange 10, and the diameter of the force-balancing expansion joint 11. A survey of products from leading domestic manufacturers shows that the diameter of the GIL cylinder 9 ranges from 508mm to 600mm, and the diameter of the flange 10 ranges from 625mm to 750mm. To prevent blind plate forces from affecting the cross-river tunnel structure and thus affecting tunnel safety and stability, force-balancing expansion joints 11, unlike those used in conventional open-cut tunnels, are used to eliminate GIL blind plate forces. The diameter of the force-balancing expansion joint 11 ranges from 835mm to 960mm.

[0036] The distance between the two GILs on one side is limited by the transport width. Long-distance cross-river tunnels are not suitable for the use of manual trolleys with extremely low transport efficiency. Mechanically driven transport vehicles include three types: trackless tire type, single-track tire type, and double-track rail type. The double-track rail type system has a simple structure and can effectively avoid collisions with equipment and personnel during transportation. The GIL transport equipment in the layout structure of the present invention adopts a double-track rail type. According to special research, the transport width of the transport vehicle is 2200m. Considering the shaking during transportation and the line deviation of tunnel construction (±170mm), the center distance between the GILs on both sides of the upper cavity 2 is L1, and L1 is set at 3500mm-3550mm.

[0037] The distance from the center of the bottom phase of the two side phases to the ground is H1. H1 is set to 800mm to accommodate the positioning of the lowest GIL cylinder 9. A low-voltage cable trough is installed on the side wall of Tunnel 1. To facilitate access to the side of Upper Chamber 2 for maintenance personnel, and to meet GIL positioning and installation restrictions, H2 and H3 are set to 1000mm-1050mm. The distance from the top GIL cylinder 9 to the side wall of Tunnel 1 is L2. The installation bolts of the force-balancing expansion joint 11 on L2 must be tightened with a hydraulic wrench. L2 is designed to be greater than 400mm.

[0038] The double-sided columns 8 are located in the middle of the upper chamber 2, and two GILs are installed above them. The two middle GILs on the double-sided columns 8 are appropriately raised to open the manhole cover, which facilitates personnel to communicate between the upper and lower chambers. Excessive height will affect the stability of the transport vehicle, and the transport channel needs to be increased. Taking into account the stability of the transport vehicle and the need for personnel connection, the distance between the lowest center of the two middle GILs and the ground is H4, which is set at 1300mm to 1500mm. The center distance between the two GILs on the double-sided columns 8 is L3. L3 is related to the width of the double-sided columns 8. The double-sided columns 8 support a total of 6 GILs in two cycles. The width of the double-sided columns 8 is 400mm to ensure that the cylinder does not collide and is easy to install. The center distance L3 between the two middle GILs is set at 1000mm-1100mm. The distance between the center of the lower phase of the two middle GILs and the bottom of the upper chamber 2 is H4, which ranges from 1300mm to 1500mm. The center distance between the lower and middle phases is H5, and the distance between the middle and upper phases is H6, with H5 and H6 ranging from 1000mm to 1050mm. The height of the chamber layer 4 is H7, the height of the lower chamber 3 is H8, and the heights of chambers 1, 31, 32, and 33 are H9. H7, H8, and H9 are 580mm, 2200mm, and 1050mm, respectively.

[0039] The GIL section designed with 4 500kV GILs can be designed based on the future power system requirements and equipment development, such as Figure 2 Change to 2 1000kV GILs as shown, or Figure 3 The configuration shown is one DC GIL plus two 500kV GILs. Figure 2 When the tunnel is converted to a 2-circuit 1000kV GIL, the center distance and column layout of the original 4-circuit 500kV GIL are adapted to the 1000kV GIL cylinder diameter and installation requirements, and there is no need to adjust the main structure of the tunnel. Figure 3 When the 2-circuit 500kV GIL is added to the 1-circuit DC GIL, a DC column 12 is set at the position of the original double-side columns 8. The DC GIL is laid on the DC column 12, and the DC GIL is installed using the space reserved by the double-side columns 8. The center of the DC GIL below is at a distance of H from the compartment layer 4. 10 , H 10The range of available options is 1200mm to 1400mm. The center distance between the two DC GILs on the DC column 12 is H. 11 ,H 11 The selectable range is 1500mm to 1650mm.

[0040] Aiming at the difficulty of laying out GIL in medium and long-distance cross-river tunnels, the present invention proposes a multi-adaptable power transmission flow section solution. By optimizing the spatial layout through cavity design and combining the double-track transportation system with the force-balancing expansion joint technology, the equipment installation and structural safety issues under the condition of restricted feeding port are solved. Based on the initial layout of 4-circuit 500kV GIL, this solution reserves flexible transformation space and can be seamlessly upgraded to a high voltage level or a hybrid transmission mode to meet future changes in electricity demand. Key parameters (such as GIL spacing, transportation channel width and column layout) have been scientifically calculated, taking into account construction efficiency, operation and maintenance convenience and tunnel stability, significantly improving the reliability and economy of cross-river power transmission, and are suitable for large-capacity, long-distance transmission scenarios.

Claims

1. A multi-adaptable GIL power transmission flow section layout method for a river-crossing tunnel, characterized by: It includes the following structures and steps: The river-crossing tunnel (1) adopts a split-cavity structure, and is internally divided into an upper cavity (2) and a lower cavity (3) by a cavity layer (4). The upper cavity (2) has a net height of 6670mm and is used to lay a 4-circuit 500kV GIL transmission line; the lower cavity (3) is divided into multiple cavities to accommodate low-voltage power distribution, SF6 exhaust and drainage facilities. Four 500kV GIL circuits are symmetrically arranged on both sides of the upper chamber (2), and each circuit is composed of three vertically arranged GIL cylinders (9). The 500kV GIL circuits on both sides are symmetrically arranged and the height of the lowest phase center from the chamber layer (4) is 800mm. The height of the lowest phase center from the chamber layer (4) of the two middle 500kV GIL circuits is 1300mm-1500mm. Tracks (5) are provided on both sides of the upper cavity (2), and the tracks (5) are arranged longitudinally along the tunnel (1), and the center distance between adjacent loop GILs on both sides is 3500mm-3550mm; A force balancing expansion joint (11) is provided to offset the influence of the blind plate force on the tunnel (1) structure, and the diameter of the force balancing expansion joint (11) is 835 mm to 960 mm; The middle of the upper chamber (2) is provided with double-side upright columns (8) for supporting the two middle circuit GILs. The two middle circuit GILs are symmetrically arranged with a center distance of 1000mm-1100mm.

2. The multi-adaptable GIL power transmission flow section layout method for a river-crossing tunnel according to claim 1 is characterized by: The diameter of the GIL cylinder (9) is 508mm-600mm, and the collinear GIL cylinders (9) are connected by flanges (10), and the diameter of the flanges (10) is 625mm-750mm.

3. The multi-adaptable GIL power transmission flow section layout method for a river-crossing tunnel according to claim 1 is characterized by: The distance between the lowest phase center of the two middle loop GILs and the cavity layer (4) is 1300 mm.

4. The multi-adaptable GIL power transmission flow section layout method for a river-crossing tunnel according to claim 1 is characterized in that: The distance between the side force-balancing expansion joint (11) and the side wall of the tunnel (1) is greater than 400 mm, so as to meet the bolt tightening space of the force-balancing expansion joint (11) and the hydraulic wrench operation space.

5. The multi-adaptable GIL power transmission flow section layout method for a river-crossing tunnel according to claim 1 is characterized in that: The double-sided columns (8) include a left column (81) and a right column (82). The left column (81) and the right column (82) are distributed on both sides of the center line of the upper cavity (2) in a mirror-symmetrical manner and respectively support the vertical arrangement structure of the two middle loop GILs.

6. The multi-adaptable GIL power transmission flow section layout method for a river-crossing tunnel according to claim 1 is characterized by: The track (5) is fixed to the bottom of the upper cavity (2), the spacing between the tracks (5) matches the width of the transport vehicle, and a safety distance is reserved on both sides of the track (5) to prevent equipment collision.

7. The multi-adaptable GIL power transmission flow section layout method for a river-crossing tunnel according to claim 1 is characterized by: A manhole is provided at the cavity layer (4).

8. The multi-adaptable GIL power transmission flow section layout method for a river-crossing tunnel according to claim 1 is characterized in that: The inner diameter of the tunnel (1) is 10.5 m, and the outer diameter is 11.6 m. The cavity layer (4) adopts a reinforced concrete structure, and the thickness of the cavity layer (4) is determined according to the stress analysis of the tunnel.

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