CN209313032U - A vertical grounding structure in power transmission and transformation lines - Google Patents

Abstract

The utility model relates to a vertical grounding structure in power transmission and transformation circuit, including vertical hole, steel pipe, earth connection, wherein the steel pipe is vertically set up in vertical hole, the periphery welding of steel pipe has a plurality of horizontal metal strips, the earth connection passes through set screw contact connection in the periphery of steel pipe to bind with the steel pipe through the strapping, the lower extreme of earth connection is turned back to the steel pipe inside, the lower extreme lateral wall of steel pipe has been seted up a plurality of holes, be provided with conductive cement inside and outside the steel pipe; the construction is convenient, the ground wire with low resistivity can be realized, firm connection between the metal strips and the conductive cement can be guaranteed by welding the metal strips on the periphery of the steel pipe, the conduction between the steel pipe and the conductive cement is facilitated, the contact surface between an electrode and soil can be enlarged by utilizing the conductive cement, the flow range and the flow speed of lightning stroke current are increased, and the safety factor of the power transmission and transformation circuit is improved.

Description

A vertical grounding structure in power transmission and transformation lines

technical field

The utility model relates to a grounding structure, in particular to a vertical grounding structure in power transmission and transformation lines.

Background technique

In power transmission and transformation lines and electrical equipment, in order to prevent damage to insulators caused by lightning strikes and affect the safe and stable operation of power transmission and transformation lines, grounding treatment is required, especially in areas with high resistivity soil, grounding can reduce multi-phase damage caused by lightning strikes For short-circuit and disconnection accidents, in areas where the soil resistivity does not exceed 100Ω·m and the soil resistivity is 100Ω·m<ρ≤300Ω·m, in addition to using the natural grounding of iron towers and reinforced concrete poles, artificial grounding devices should also be added. The buried depth of the ground electrode should not be less than 0.6m; in the area where the soil resistivity is 300Ω·m<ρ≤2000Ω·m, the grounding device laid horizontally can be used, and the buried depth of the electrode should not be less than 0.5m; in the area where the soil resistivity ρ>2000Ω·m In other regions, 6 to 8 radial ground electrodes or continuous elongated ground electrodes with a total length of no more than 500m can be used.

The conventional grounding treatment is to dig a trench with a depth of less than one meter and a length of several meters to more than ten meters on the ground, and backfill the conductive cement in the grounding trench. There is also a tunnel-type grounding method, but these grounding methods need to be grounded A long ditch is dug on the ground, and ground wires are laid in the ditch to ensure the safety of power transmission and transformation lines.

The above-mentioned method is a construction method carried out under a spacious site. However, in the actual construction process, the construction space is often narrow, especially when excavating grounding trenches in cities. There are cable trenches and sewers underground. Once a long trench is excavated, it will cause extremely serious damage to surrounding buildings and underground facilities.

Contents of the invention

Aiming at the situation that underground facilities and buildings on the ground will be affected or damaged when the grounding wire construction of power transmission and transformation lines is carried out in areas with dense urban buildings and underground facilities, the utility model provides a vertical grounding structure in power transmission and transformation lines. When laying underground ground wires, it will not affect the surrounding buildings.

The technical solution of the utility model is: a vertical grounding structure in a power transmission line, including a vertical hole, a steel pipe, and a grounding wire, wherein the steel pipe is vertically arranged in the vertical hole, and a plurality of horizontal metal strips are welded around the steel pipe. The grounding wire is connected to the outer circumference of the steel pipe through fixing screws, and is bound to the steel pipe through a binding band. The lower end of the grounding wire is folded back to the inside of the steel pipe. A plurality of holes are opened on the side wall of the lower end of the steel pipe, and conductive cement is arranged inside and outside the steel pipe.

Preferably, the diameter of the vertical hole is 1.5 to 5 times the diameter of the steel pipe;

Preferably, the diameter of the steel pipe is 100mm~300mm;

Preferably, the depth of the ground wire inside the steel pipe is at least 20mm;

Preferably, the steel pipe height is 1m~3m;

Preferably, the grounding wire is a bare wire, and the cross-sectional area of the grounding wire is 3-9 mm ² .

The construction method of the vertical grounding structure in the power transmission and transformation line is carried out according to the following steps:

1) Use a drilling rig to open a vertical hole in the ground;

2) Insert a steel pipe with a grounding wire fixed on the outside into the vertical hole, and make the distance between the outside of the steel pipe and the periphery of the vertical hole consistent;

3) Connect the outlet of the mud pump to the upper end of the steel pipe inserted into the ground through the joint, and connect the inlet of the mud pump to the outlet of the mixer through a conductive cement delivery pipe. There is a valve between the mud pump and the steel pipe, which can be used according to the conductive cement. The pressure of the delivery pipe adjusts the flow rate, and the mixer is equipped with a stirring rod, which is driven by a motor;

4) Use a mud pump to pour conductive cement into the steel pipe and compress it, so that the conductive cement flows out from the hole opened on the lower side wall of the steel pipe, and pours it into the space of the vertical hole outside the steel pipe until the conductive cement rises to the position of the vertical hole , so that the conductive cement is consistent with the ground level;

5) Continue the above steps 1) to 5) as needed to set up multiple vertical grounding structures;

6) The grounding wires of multiple vertical grounding structures are connected in series to form a grounding electrode.

The target resistance of the ground electrode is below 10Ω, the number of buried ground wires is selected according to the needs, and the distance between the steel pipes is between 1-5m.

The vertical grounding structure of the utility model is convenient for construction when the underground or surrounding environment does not allow a large area to be opened, and can realize a low-resistivity grounding wire, and will not affect the surrounding environment due to construction, resulting in poor traffic, water and electricity. It can prevent damage to electrical facilities caused by lightning. By using low-resistance conductive cement, the soil around the grounding electrode can be kept moist and prevent the soil from corroding the grounding wire, which will increase the resistance of the grounding wire. Multiple metal strips are welded around to ensure a firm connection between the metal strip and the conductive cement, and to facilitate the conduction between the steel pipe and the conductive cement. The use of conductive cement can expand the contact surface between the electrode and the soil and increase the lightning current. The flow range and flow speed improve the safety factor of power transmission and transformation lines.

Description of drawings

Fig. 1 is the structural representation of the utility model;

As shown in the figure: 1. Mixer, 1a, motor, 2. Conductive cement delivery pipe, 3. Mud pump, 4. Valve, 5. Connection part, 6. Vertical hole, 7. Steel pipe, 7a, hole, 7b, metal Strip, 8, ground wire, 8a, binding strap, 8b, fixing screw, 9, ground, 10, conductive cement.

Detailed ways

In order to better understand and realize the technical solution of the utility model, some embodiments of the utility model are provided here, and these embodiments are to better explain the technical solution of the utility model, and do not constitute any form of limitation to the utility model .

The specific technical solutions of the present utility model are further described in detail below with reference to the accompanying drawings.

As shown in Figure 1, the technical solution of the utility model is: a vertical grounding structure in a power transmission line, including a vertical hole 6, a steel pipe 7, and a grounding wire 8, wherein the steel pipe 7 is vertically arranged in the vertical hole 6, The periphery of the steel pipe 7 is welded with a plurality of transverse metal strips 7b. The grounding wire 8 is connected to the outer periphery of the steel pipe 7 through a fixing screw 8b, and is bound to the steel pipe 7 by a binding band 8a. The lower end of the grounding wire 8 is returned to the inside of the steel pipe 7. The lower side wall of the steel pipe 7 is provided with a plurality of holes 7a, and the inside and outside of the steel pipe 7 are provided with conductive cement 10 .

Preferably, the diameter of the vertical hole 6 is 1.5 to 5 times the diameter of the steel pipe 7;

Preferably, the diameter of the steel pipe 7 is between 100mm and 300mm;

Preferably, the depth of the ground wire 8 inside the steel pipe 7 is at least 20mm;

Preferably, the steel pipe 7 has a height of 1m~3m;

Preferably, the ground wire 8 is a bare wire, and the cross-sectional area of the ground wire 8 is 3-9 mm ² .

The construction method of the vertical grounding structure in the power transmission and transformation line is carried out according to the following steps:

1) Use a drilling rig to open a vertical hole 6 on the ground;

2) Insert the steel pipe 7 with the ground wire 8 fixed on the outside into the vertical hole 6, and make the distance between the outside of the steel pipe 7 and the periphery of the vertical hole 6 consistent;

3) Connect the outlet of the mud pump 3 to the upper end of the steel pipe 7 inserted into the ground through the connection part 5, and connect the inlet of the mud pump 3 to the outlet of the mixer 1 through the conductive cement delivery pipe 2. Between the mud pump 3 and the steel pipe 7 A valve 4 is provided to adjust the flow rate according to the pressure of the conductive cement delivery pipe 2. The mixer 1 is provided with a stirring rod, and the stirring rod is driven by the motor 1a;

4) Use the mud pump 3 to pour conductive cement into the steel pipe 7 and compress it, so that the conductive cement flows out from the hole opened on the lower side wall of the steel pipe, and pours into the space of the vertical hole outside the steel pipe until the conductive cement 10 rises to the vertical hole 6. The position of the orifice makes the conductive cement 10 consistent with the height of the ground 9;

5) Continue the above steps 1) to 5) as needed to set up multiple vertical grounding structures;

6) Connecting multiple grounding wires 8 of the vertical grounding structure in series to form a grounding electrode.

The target resistance of the ground electrode is below 10Ω, the number of buried ground wires is selected according to the needs, and the distance between the steel pipes is between 1-5m.

The vertical grounding structure of the utility model is convenient for construction when the underground or surrounding environment does not allow a large area to be opened, and can realize a low-resistivity grounding wire, and will not affect the surrounding environment due to construction, resulting in poor traffic, water and electricity. It can prevent damage to electrical facilities caused by lightning. By using low-resistance conductive cement, the soil around the grounding electrode can be kept moist and prevent the soil from corroding the grounding wire, which will increase the resistance of the grounding wire. Multiple metal strips are welded around to ensure a firm connection between the metal strip and the conductive cement, and to facilitate the conduction between the steel pipe and the conductive cement. The use of conductive cement can expand the contact surface between the electrode and the soil and increase the lightning current. The flow range and flow speed improve the safety factor of power transmission and transformation lines.

After the various specific embodiments of the present utility model have been described in detail above, those of ordinary skill in the art should be able to clearly understand that various equivalent changes, Equivalent replacement or simple modification shall all belong to the scope of the technical solution of the present utility model.

Claims (6)

1. the vertical ground structure in a kind of power transmission and transformation line, including vertical hole, steel pipe, ground line, it is characterised in that: steel pipe is perpendicular Straight to be arranged in vertical hole, the periphery of steel pipe is welded with multiple transverse metal items, and ground line is connected by fixing screws The periphery of steel pipe, and being bound by strapping and steel pipe, the lower end of ground line are turned back to steel duct, and the bottom side of the wall of steel pipe is opened Equipped with multiple holes, steel pipe has been arranged inside and outside electroconductive cement.

2. the vertical ground structure in a kind of power transmission and transformation line according to claim 1, it is characterised in that: the vertical hole Diameter be 1.5 ~ 5 times of diameter of steel tube.

3. the vertical ground structure in a kind of power transmission and transformation line according to claim 1, it is characterised in that: the diameter of steel pipe In 100mm ~ 300mm.

4. the vertical ground structure in a kind of power transmission and transformation line according to claim 1, it is characterised in that: ground line is in steel Depth inside pipe is at least in 20mm.

5. the vertical ground structure in a kind of power transmission and transformation line according to claim 1, it is characterised in that: steel pipe height exists 1m~3m。

6. the vertical ground structure in a kind of power transmission and transformation line according to claim 1, it is characterised in that: the ground line For bare wire, the cross-sectional area of ground line is 3 ~ 9mm²。