High-voltage Cable Extension Device and Extension Method in Large-diameter Shield Tunnels

Abstract

The present invention discloses a high-voltage cable extension device and an extension method in a large-diameter shield tunnel, aiming to solve the technical problem that the cable laying in the existing shield tunnel is time-consuming and laborious. The present invention includes a cable spool frame and a guiding frame; the cable spool frame is used for storing the qualified high-voltage cables, and the guiding frame includes a bracket and more than two rollers vertically arranged on the bracket. The guiding frame is arranged on one side close to the tunnel inner wall when the cable spool frame moves, so as to realize the guiding when the high-voltage cable is released. The beneficial effects of the present invention are as follows: the device is simple and convenient, saving manpower and material resources, can greatly shorten the cable replacement time, and reduce the pressure maintenance risk of the shield machine.

Description

Technical Field

[0001] The present invention relates to the technical field of cable laying in shield tunnels, and in particular to a method for laying cables in a large-diameter shield tunnel.

[0002] High voltage cable extension device and extension method. Background Art

[0003] At present, shield technology is constantly developing, and large-diameter shields are increasingly being used. When a shield machine is in operation, it needs electricity to provide driving power. The electricity is provided by a power distribution center located on the ground. The shield machine is always moving forward, and the shield tunnel can be several kilometers long. This requires that the high-voltage cable that transmits electricity continues to extend forward with the shield machine until the tunnel is through.

[0004] Cable laying in a shield tunnel is different from ordinary cable laying. The cables in a shield tunnel are used to power the shield machine, and the cables are required to be energized during the laying process. In addition, the connection between the two sections of cable needs to be safe and fast and must not affect the excavation progress of the shield machine.

[0005] The existing cable laying in shield tunnels relies on the high-voltage cable extension system configured on the large-diameter shield machine trailer. First, the high-voltage cable needs to be stored in a cable drum or a cable storage box, and is continuously released as the shield machine advances. However, due to its heavy weight, the high-voltage cable sags and is not easy to be placed on the cable hook manually. Sometimes, forklifts and other machinery are required to enter the site to cooperate, occupying the working space in the tunnel. Second, when the stored high-voltage cable is used up, the new high-voltage cable needs to be stored in a cable drum or a storage box, which consumes a lot of manpower and material resources. Third, it is also necessary to carry out processes such as high-voltage cable joint production and cable pressure resistance testing, which takes a lot of time. In addition, when the high-voltage cable is extended, the shield machine needs to be powered off. If the power is off for a long time, the pressure maintenance safety risk of the shield machine is extremely high. Summary of the invention

[0006] The purpose of the present invention is to provide a high-voltage cable extension device and extension method in a large-diameter shield tunnel, so as to solve the technical problem that the existing shield tunnel cable laying is time-consuming and labor-intensive.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A high-voltage cable extension device in a large-diameter shield tunnel is designed, comprising a trailer, a wire coiling frame, and a guide frame; the wire coiling frame is installed on the trailer; the guide frame is arranged on a side of the wire coiling frame close to the inner wall of the tunnel when the wire coiling frame is working and walking, so as to guide the high-voltage cable when it is released.

[0009] Furthermore, the bottom of the trailer is provided with walking wheels, and the front and rear ends of the trailer are respectively provided with traction rods.

[0010] Further, the guiding frame includes a bracket and two or more rollers vertically arranged on the bracket.

[0011] Design a method for extending high-voltage cables using the high-voltage cable extension device in the large-diameter shield tunnel described above, including the following steps:

[0012] (1) Connect the head of the high-voltage cable carried in the cable coiling frame to the high-voltage cable joint box on the tail platform of the corresponding shield machine trailer, and connect the tail to the corresponding substation.

[0013] (2) Before the initial high-voltage cable is used up, coil the high-voltage cable into the spare cable coiling frame outside the tunnel, and perform insulation, withstand voltage detection on the high-voltage cable in the box and make terminal joints at both ends.

[0014] (3) After the high-voltage cable in the tunnel is used up, replace the cable coiling frame.

[0015] (4) Connect the head of the high-voltage cable in the spare cable coiling frame to the high-voltage cable joint box on the tail platform of the shield machine trailer, and connect the tail to the high-voltage cable junction box on the inner wall of the shield tunnel.

[0016] Further, when the high-voltage cable carried in the cable coiling frame in step (1) is laid, the high-voltage cable in the cable coiling frame falls into the cable hanger on the inner wall of the tunnel under the guiding action of the roller and the action of gravity.

[0017] Further, after the high-voltage cable in the tunnel in step (3) is used up, the head of the high-voltage cable needs to be disconnected from the high-voltage cable joint box at the tail of the shield machine and connected to the high-voltage cable junction box on the inner wall of the corresponding shield tunnel.

[0018] Compared with the prior art, the main beneficial technical effects of the present invention are as follows:

[0019] 1. The cable extension device designed by the present invention is replaceable and easy to replace; the cable laying method allows construction personnel to pre-fabricate the required high-voltage cable on the ground and coil it in the cable coiling frame. Compared with the currently common laying method, the present invention can greatly shorten the cable replacement time and reduce the risk of shield machine pressure maintenance during cable replacement.

[0020] 2. The guiding device designed by the present invention enables the cable to be placed on the cable hanger on the inner wall of the tunnel by relying on its own gravity, greatly saving manpower and material resources.

[0021] 3. The cable laying device designed by the present invention is easy to use, low in cost, does not require an additional power mechanism, and can realize the laying of high-voltage cables only by following the shield machine forward. Brief Description of the Drawings

[0022] Figure 1 It is a cross-sectional schematic diagram of the device of the present invention in Embodiment 1.

[0023] Figure 2 It is a longitudinal sectional schematic diagram of the device of the present invention in Embodiment 1.

[0024] Figure 3 It is a schematic diagram of the guide frame of the device of the present invention in Embodiment 1.

[0025] Figure 4 It is a schematic diagram of the working surface cross-section of the device of the present invention in the working state in Embodiment 2.

[0026] Figure 5 It is a schematic diagram of the device of the present invention in the working state in Embodiment 2.

[0027] In the above figures, 10 is a wire coiling frame, 11 is a towing rod, 2 is a traveling wheel, 3 is a guide frame, 30 is a bracket, 31 is a roller, 4 is a high-voltage cable, 5 is a high-voltage cable junction box, and 6 is a cable hook. Detailed implementation manners

[0028] The following combines the drawings and embodiments to illustrate the detailed implementation manners of the present invention. However, the following embodiments are only used to illustrate the present invention in detail and do not limit the scope of the present invention in any way.

[0029] In the description of the technical solution of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In this application, terms such as "first" and "second" are used to distinguish similar objects, rather than to define a specific order or sequence.

[0030] For the unit modules, components, structures, mechanisms and other devices involved in the following embodiments, if not otherwise specified, they are all conventional commercially available products.

[0031] Embodiment 1: A high-voltage cable extension device in a large-diameter shield tunnel, see Figures 1 to 5 , including a towing frame, a wire coiling frame 10, a lock, and a guide frame; the bottom of the towing frame is provided with traveling wheels, the front and rear ends of the towing frame are respectively provided with towing rods, the front towing rod of the towing frame is movably connected to the platform at the tail of the shield machine trailer, and locks for fixing the wire coiling frame are respectively arranged at the four corners of the towing frame. The guide frame includes a bracket and a certain number of rollers vertically arranged on the bracket. The guide frame is arranged on one side close to the tunnel inner wall when the wire coiling frame is working and walking, so as to realize the guiding when the high-voltage cable is released.

[0032] The method for extending cables by using the above-mentioned high-voltage cable extension device in a large-diameter shield tunnel is as follows (see Figure 4 , 5 ):

[0033] Lay the cables carried by the initial cable reel frame. Connect the head of the cable to the high-voltage cable junction box on the tail platform of the corresponding shield machine trailer, and connect the tail to the corresponding substation. Before the initial cable is used up, fabricate a cable reel frame on the ground that is the same as the extension system, wind the new cable on the reel frame, perform insulation and withstand voltage tests, make terminal joints at both ends, and wait for use.

[0034] After the initial cable in the tunnel is used up, the shield machine performs shutdown and pressure maintenance work. Disconnect the head of the cable and connect it to the junction box on the inner wall of the shield tunnel. Open the latches around the trailer, replace the cable reel frame with a truck-mounted crane. After the new cable reel frame is fixed to the trailer with latches, connect the head of the cable in the new cable reel frame to the high-voltage cable junction box on the tail platform of the corresponding shield machine trailer, and connect the tail to the corresponding high-voltage cable junction box on the inner wall of the shield tunnel. After passing the test, energize the power to complete the cable extension work.

[0035] Embodiment 2: A single-tunnel double-track tunnel with a total length of 4,700 m. A super-large shield slurry shield machine with an excavation diameter of φ14.04 m is used for the construction of the interval tunnel. The cutter head excavation diameter of the shield machine is 14.04 m, the total length of the main machine is about 14.48 m, the total length of the whole machine is 110 m, the total weight of the whole machine is about 3,400 T, the trailing gantry is composed of No. 1 to No. 4 gantries, and the total installed power is about 7,000 Kw. High-voltage power supply uses 2 3×120 + 2×70 mm 2 armored rubber-sheathed high-voltage cables. Construction power is divided into two 10KV high-voltage lines from the ground central power distribution room and enters 2 high-voltage switch cabinets of the shield machine. A 450kW diesel generator is configured on the shield machine as an emergency power source.

[0036] It includes 2 trailers, 2 reel frames, each reel frame stores 1 1,000-meter high-voltage cable, and 2 guide frames. The reel frame is fixedly connected to the corresponding trailer. Traction rods are respectively arranged at the head and tail ends of the trailer. The two trailers are movably connected back and forth through the traction rods. The front trailer is movably connected to the platform at the tail of the shield machine trailer through the traction rod and follows the shield machine forward. High-voltage cable junction boxes are arranged at the tail of the trailer and on the inner wall of the shield tunnel to facilitate cable extension. 4 nylon roller cylinders are arranged on the guide frame, and the distance between the rollers can allow the high-voltage cable to pass smoothly.

[0037] See Figure 3As shown, the initial cable head is connected to the corresponding high-voltage cable junction box at the trailer tail. The tail bypasses the roller on the bracket and is connected to the corresponding ground power supply station. As the shield machine advances, the cable is placed on the cable hooks on the inner wall of the tunnel through the action of the roller. Before the in-tunnel cable is used up, 2 trailers and cable spool frames identical to the extension system are newly made on the ground. The trailer is fixedly connected to the cable spool frame. The high-voltage cable to be newly added is spooled in the cable spool frame. After insulation and withstand voltage tests are done, 10KV high-voltage cable terminal joints are made at both ends. This work does not occupy the normal tunneling construction time of the shield machine.

[0038] After the in-tunnel high-voltage cable is used up, the shield machine does the shutdown pressure maintenance work, and starts the generator on the shield machine to maintain the normal operation of the pressure maintenance system and the lighting system. Then, the 10KV terminal joint of the high-voltage cable in the high-voltage cable junction box at the trailer tail is removed and connected to the high-voltage cable junction box set on the inner wall of the shield tunnel. The connection between the trailer and the platform at the trailer tail of the shield machine is disconnected, and the two trailers with cable spool frames are towed out of the tunnel through traction. Then, another two trailers with cable spool frames are transported to the trailer tail of the shield machine and connected to the platform at the trailer tail of the shield machine. The newly added high-voltage cable has been spooled in this cable spool frame in the above steps. Then, the front-end terminal joint of the newly added high-voltage cable is connected to the corresponding high-voltage cable junction box on the platform at the trailer tail of the shield machine, and the rear-end terminal joint is connected to the corresponding high-voltage cable junction box set on the inner wall of the shield tunnel. After passing the test, power is supplied to complete the high-voltage cable extension work.

[0039] The present invention has been described in detail above in conjunction with the accompanying drawings and embodiments. However, those skilled in the art can understand that without departing from the concept of the present invention, various specific parameters in the above embodiments can be changed, or equivalent substitutions can be made for related components, structures and materials, thereby forming multiple specific embodiments, which are all within the common change range of the present invention and will not be elaborated one by one here.

Claims

1. A high-voltage cable extension device inside a large-diameter shield tunnel, characterized in that, it includes a towing frame, a cable coiling frame, and a guiding frame; the cable coiling frame is installed on the towing frame; the guiding frame is arranged on one side close to the tunnel inner wall when the cable coiling frame is working and moving, for guiding when the high-voltage cable is released; the guiding frame includes a bracket and more than two rollers vertically arranged on the bracket, and the distance between the rollers enables the high-voltage cable to pass through smoothly; the end face of the bracket for installing the rollers is arranged in an inclined shape; when the high-voltage cable carried in the cable coiling frame is laid, the high-voltage cable in the cable coiling frame falls into the cable hanger on the tunnel inner wall under the guiding action of the rollers and the action of gravity.

2. The high-voltage cable extension device inside a large-diameter shield tunnel according to claim 1, characterized in that, walking wheels are arranged at the bottom of the towing frame, and towing rods are respectively arranged at the head and tail ends of the towing frame.

3. A method for extending a high-voltage cable by using the high-voltage cable extension device inside a large-diameter shield tunnel according to claim 1, comprising the following steps: (1) Connect the head of the high-voltage cable carried in the cable coiling frame to the high-voltage cable joint box on the tail platform of the corresponding shield machine trailer, and the tail to the corresponding substation; when the high-voltage cable carried in the cable coiling frame is laid, the high-voltage cable in the cable coiling frame falls into the cable hanger on the tunnel inner wall under the guiding action of the rollers and the action of gravity; (2) Before the initial high-voltage cable is used up, wind the high-voltage cable into the spare cable coiling frame outside the tunnel, and perform insulation, withstand voltage detection on the high-voltage cable in the box and make terminal joints at both ends; (3) After the high-voltage cable inside the tunnel is used up, replace the cable coiling frame; (4) Connect the head of the high-voltage cable in the spare cable coiling frame to the high-voltage cable joint box on the tail platform of the shield machine trailer, and the tail to the high-voltage cable connection box on the inner wall of the shield tunnel.

4. The method for extending a high-voltage cable by using the high-voltage cable extension device inside a large-diameter shield tunnel according to claim 3, characterized in that, in the step (3), after the high-voltage cable inside the tunnel is used up, the head of the high-voltage cable needs to be disconnected from the cable joint box at the tail of the shield machine and connected to the high-voltage cable connection box on the inner wall of the corresponding shield tunnel.

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