22kV overhead line conductor non-tension deployment construction method

Abstract

The application discloses a 22kV overhead line wire non-tension laying construction method and belongs to the technical field of building construction. In view of the fact that large-scale machines cannot enter the site or the site is a restricted line terrain with small span and continuous corners, the application proposes the following: firstly, path survey and wire distribution are carried out; then, a wire laying pulley is hung on a tower cross arm, and a wire reel is erected at a traction starting point; when laying, no braking tension is applied to the wire reel, the wire is dragged along the ground through traction equipment, the wire is lifted and passed through the pulley by manpower every time a base tower is passed, and the wire is laid base by base; after laying, wire crimping and tight wire pulling in the anchoring direction are sequentially completed; finally, according to the number of poles, poles are distributed and observed, a parallelogram method is used for observation and adjustment of sag, and the wire is fixed on insulators. The application reduces the dependence on large-scale equipment, the required machine is simple, multiple points can be simultaneously constructed, the construction period of a line in a complex terrain such as a mountainous area is effectively shortened, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a non-tension laying method for 22kV overhead line conductors. Background Technology

[0002] With the continuous development of large-scale new energy projects such as photovoltaics, the total area occupied by the power station is often very large, and the distance between the power generation array and the substation is relatively far. In order to transmit the power generated by the power generation array to the substation, and then output it to the grid after being stepped up by the substation, it is usually necessary to design and erect corresponding transmission lines. In conventional overhead transmission line conductor laying construction, tension laying is typically used. However, in actual engineering applications, these specially designed internal overhead lines often have short spans (e.g., an average span of about 50m) and numerous tension sections, with some areas even having continuous bends. In such complex line designs and geographical environments, if the construction area is restricted by roads or located in mountainous areas inaccessible to medium and large machinery, large traction machines, tensioning machines, and other mechanical equipment often cannot be brought into position, making it difficult to use traditional tension laying methods for conductor laying. Forcing the adoption of traditional conductor laying methods is not only difficult to implement, but also leads to a significant increase in construction coordination costs, serious delays in the construction period, and a high risk of quality defects in complex corners and short-span laying. Therefore, the industry urgently needs a non-tension conductor laying construction process that is less dependent on large machinery and equipment and is easy to operate. This process can adapt to confined spaces, short spans, and terrain with continuous corners, while also providing effective prevention and control measures for quality problems that are prone to occur during conductor laying, thereby ensuring that overhead line projects are completed on schedule and with high quality. Summary of the Invention

[0003] The purpose of this invention is to provide a non-tensioned installation method for 22kV overhead line conductors, so as to solve the technical problems in the background art that make conductor installation difficult due to complex terrain restrictions and the inability of large tensioning equipment to enter the site.

[0004] To achieve the above objectives, the present invention provides the following technical solution: Includes the following steps: Construction preparation: Conduct a route survey for the tension section to be erected, and arrange conductor reels according to the survey results; Arrange the wire-laying pulleys and support the wire-laying reel: Hang the wire-laying pulleys on the crossarms of each base tower of the line to be erected, and support the wire reel containing the conductor at the starting point of the traction. Non-tension conductor traction: No braking tension is applied to the conductor at the reel. The traction equipment pulls the traction rope connected to the end of the conductor, causing the conductor to be dragged forward along the line direction. After passing each tower, the traction stops, the deployed conductor is lifted and passed through the laying pulley, and then the conductor continues to be pulled to the next tower until the deployment of a tension section is completed. Wire crimping and tightening: The wire is cut and crimped, and then tightened in the anchoring direction by pulling the wire with a tightening device; Adjusting the sag and fixing the conductor: Observe the sag of the conductor and adjust it to the preset qualified range. Then, remove the conductor from the laying pulley and fix it to the tower insulator.

[0005] Furthermore, in the construction preparation steps: the conductors are matched according to the length of the tension section to be erected, so that the number of joints of the same conductor in the same span does not exceed one, and the distance between the conductor joint and the conductor fixing point is greater than 15m.

[0006] Furthermore, in the steps of arranging the wire-laying pulleys and supporting the wire-laying reel: Set the suspension height of the wire-laying pulley to be higher than that of the pin insulator on the tower; Adjust the wire feeding frame so that the wire reel is at least 50mm off the ground and keep the reel level, ensuring that it does not tilt in the direction of wire pulling.

[0007] Furthermore, in the non-tension traction step of the conductor: Protective isolation facilities are laid on the ground before the conductor is laid to the ground to prevent the conductor from directly contacting the ground; When the deployed conductor is lifted and passed through the laying pulley, the hemp rope that has been passed through the laying pulley is pulled to lift the conductor, and then the lifted conductor is poured into the laying pulley.

[0008] Furthermore, in the wire crimping and tightening steps, the wire crimping process includes: Remove the outer aluminum stranded wire from the crimped part of the conductor to expose the steel core, and clean the conductor and crimping tube. The cleaning length should be no less than twice the length of the crimping tube. Remove the oxide film from the aluminum contact surface of the wire connection, apply a layer of electrical composite grease, and then perform hydraulic crimping; After crimping, remove any burrs and flash from the surface of the crimped pipe and apply anti-corrosion treatment to the steel crimped pipe.

[0009] Furthermore, the parameters for hydraulic crimping are as follows: When using aluminum alloy crimping tubes for crimping, the rated working pressure of the hydraulic system shall not be less than 63MPa, and the overlap crimping length between two adjacent dies shall not be less than 10mm. When using steel crimping pipes for crimping, the rated working pressure of the hydraulic system shall not be less than 80MPa, and the overlap crimping length between adjacent molds shall not be less than 5mm.

[0010] Furthermore, the tensioning process is as follows: initially, a pulley block is used to pull and tighten the conductor; once the conductor tension reaches a certain level, a lever hoist is used to continue tightening, and the conductor is shaken appropriately to ensure that the tension of the conductor remains consistent in each span.

[0011] Furthermore, in the process of adjusting the sag and fixing the conductor, the parallelogram method is used for sag observation, and the sag observation points are selected according to the number of spans of the tight line segment: When the tight line segment is at or below level 5, select a level close to the middle as the observation level; When the tight line segment is in range 6 to 12, select one range near each end as the observation range; When the tight segment is above 12 levels, select one level near each end and the middle as the observation level.

[0012] Furthermore, when fixing the conductor to the tower insulator, aluminum tape is wrapped around the contact area between the conductor and the insulator, and the wrapping length of the aluminum tape exceeds the contact area by 30mm, and the wrapping direction is consistent with the stranding direction of the outer layer of the conductor. After the conductor is fixed, two parallel groove clamps are used to connect the drain line at the tension pole. The distance between the two clamps is controlled to be moderate, and the drain line is in a natural catenary shape.

[0013] The effects described in the invention are merely those of the embodiments, and not all the effects of the invention. The above technical solutions have the following advantages or beneficial effects: 1. This invention specifically solves the problem of cable laying in mountainous areas where road conditions restrict access and medium and large machinery cannot enter, as well as in special working conditions such as short track spans, many tension sections, and continuous turns. In these scenarios where traditional tension cable laying equipment is difficult to deploy, this invention demonstrates extremely high application value. 2. The machinery and equipment used in this invention are simple, requiring only small implements such as tractors, lever hoists, and pulleys, without relying on expensive large tension machines and traction units, which greatly reduces equipment rental, maintenance, and transportation costs; 3. This invention is easy to operate and has few site restrictions. It can enable construction to be carried out simultaneously at multiple points along the entire line, breaking through the limitations of traditional line setting which must rely on large machine sites and proceed segment by segment, thus significantly shortening the overall project progress. 4. By laying isolation facilities before the conductor is laid to the ground and cooperating with a dedicated person to monitor it, this invention effectively solves the problem of easy wear of conductors in non-tension laying, ensuring that the appearance and electrical performance of the conductor are not affected; 5. This invention provides detailed specifications for the wire crimping process, ensuring that the mechanical strength and conductivity of the connection parts meet high standards by clarifying key parameters such as the rated pressure of the hydraulic system, the cleaning length, and the amount of overlapping crimping. 6. This invention adopts a strategy of flexibly selecting observation points according to the number of spans in the tight section, and combines it with the parallelogram observation method to control the difference in sag of each phase conductor within the same span within 50mm, and the sag error does not exceed 5%, thus ensuring the safety of line operation. 7. Due to the use of lightweight equipment, the range of movement of personnel and machinery during construction is small. Furthermore, by standardizing the traction path and taking measures to clean up waste, this invention minimizes damage to surface vegetation and turf, thus meeting the requirements for environmentally friendly construction. 8. By combining a reasonable installation sequence of accessories and simplifying tool requirements, this invention effectively reduces the safety risks associated with complex cross-operations and large machinery. Attached Figure Description

[0014] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0015] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0016] Example 1 See Figure 1 A non-tension laying method for 22kV overhead line conductors is proposed. This embodiment is applicable to lines with a large land area, short spans, many tension sections, and multiple continuous turns, where large traction machines and tensioning machines cannot be brought into the site.

[0017] The specific implementation steps of the non-tension laying method for conductors according to the present invention are as follows: Step 1: Construction Preparation and Precise Reel Placement: First, a route survey is conducted for the tension section to be erected, verifying the terrain, elevation, and objects being crossed. Conductor joints are mechanically weak points and points of resistance heating in overhead lines. To maximize the safety of line operation, this embodiment uses precise reel placement based on the actual conductor length of the tension section calculated in the preliminary survey. The principle of reel placement is to ensure that the number of joints on the same conductor within the same span does not exceed one, and to control the position of the conductor joints to be more than 15m away from the conductor fixing point to avoid stress concentration damage to the joints caused by slight wind vibrations.

[0018] Step Two: Setting up the Wire Laying Pulleys and Wire Laying Reel: Workers climb the poles and suspend the wire laying pulleys from the crossarms of each base tower using iron wire. To facilitate the subsequent movement of the conductor into the pin insulator, the suspension height of the wire laying pulleys is set slightly higher than the top slot of the pin insulator on the tower, and the hemp rope used for subsequent conductor lifting is pre-passed through the pulleys and lowered to the ground. At the traction starting point, the wire laying reel is positioned, and the wire laying frame is adjusted to raise the reel 50mm off the ground, ensuring the reel remains level. A 50mm distance from the ground ensures free rotation of the reel without being affected by ground resistance and allows for rapid braking in case of accidental jamming; a level reel, not tilted in the pulling direction, effectively prevents the conductor from becoming tangled or falling off the slot during rapid pulling.

[0019] Step 3: Tension-Free Traction and Wear Protection for Conductors: The core of this method lies in tension-free deployment, meaning no tensioning machine is installed at the conductor reel, and no braking tension is applied to the conductor. After connecting the conductor end to the traction rope, a small traction device such as a tractor is used to pull the traction rope, causing the conductor to be dragged forward along the line direction on the ground. Since the biggest drawback of tension-free deployment is that direct dragging of the conductor on the ground easily causes wear on the aluminum strands, tarpaulins or straw mats are laid along the entire ground before the conductor hits the ground for protection and isolation, and dedicated personnel are assigned to patrol and protect it. Traction is carried out in a tower-by-tower deployment mode. After passing each tower, the traction equipment stops, and ground personnel pull the hemp rope pre-threaded on the pulley to lift the deployed conductor end. Personnel on the pole cooperate to pour the conductor into the laying pulley. After confirming that it is in the groove, the traction equipment continues to pull the conductor to the next tower until the entire tension section is completed.

[0020] Step 4: Refined Wire Crimping and Graded Tightening: Temporarily anchor and cut both ends of the wire using wire clamps. Strip the outer layer of aluminum stranded wire from the crimped area to expose the inner steel core. Use a wire brush to remove the oxide film from the aluminum contact surface, and clean the wire and crimping tube with a special cleaning agent. The cleaning length should be strictly controlled to be no less than twice the length of the crimping tube. Then apply a layer of electrical composite grease to isolate air, prevent oxidation, and reduce contact resistance. When performing hydraulic crimping, strictly control the hydraulic parameters: for aluminum alloy crimping tubes, the rated working pressure of the hydraulic system should not be less than 63MPa, and the overlap crimping length between adjacent molds should not be less than 10mm; for steel crimping tubes, the rated working pressure should not be less than 80MPa, and the overlap crimping length should not be less than 5mm. After crimping, grind off any burrs and apply anti-corrosion treatment to the steel crimping tube.

[0021] Tightening Operation: Pull the wire towards the anchoring direction to tighten it. The tightening process is divided into two stages: In the initial stage, the conductor sags significantly due to its own weight, and the tension is relatively low, so a pulley block is used for rapid and large-amplitude traction and tightening; as the conductor gradually rises into the air and the tension reaches a certain level where traction becomes noticeably difficult, a hand lever hoist is used for slow, fine-tuning tightening. Simultaneously, the operator gently shakes the conductor on the ground to overcome the friction at each pulley, ensuring that the tension of the conductor is quickly transmitted and maintained consistently within each span.

[0022] Step 5: Adjust the sag and fix the conductor: Sag refers to the vertical distance between the line connecting the suspension points of a conductor and the lowest point of the conductor. Excessive sag can cause the conductor to expand and droop in the high temperatures of summer, potentially leading to ground faults and short circuits; insufficient sag can cause the conductor to contract and experience increased tension in the cold winter, potentially resulting in conductor breakage and pole collapse. Therefore, sag must be controlled within the design tolerance range.

[0023] When tensioning a long section of track, the tension is difficult to achieve perfect balance instantaneously due to pulley friction. Therefore, this embodiment employs segmented fixed-point observation based on the number of tensioning sections: when the tensioning section has 5 or fewer tensions, only one tension near the middle is selected as the observation tension; when the tensioning section has 6 to 12 tensions, one tension near each end of the track is selected as the observation tension; when the tensioning section has more than 12 tensions, one tension near each end and the middle of the track is selected for simultaneous observation. Parallelogram Observation Method: After selecting the observation section, the standard sag value is first determined by referring to a table based on the ambient temperature. Workers climb to the poles at both ends of the observation section, measure the vertical distance downwards from the conductor suspension point, and horizontally tie two marker poles at each position. At this point, the line connecting the conductor suspension points of the two poles and the line connecting the two marker poles are parallel, forming a parallelogram in space. The observer, on one of the poles, looks at the two marker poles at eye level, forming a horizontal horizon line. Simultaneously, the tensioner operates a lever hoist to fine-tune the conductor tension. As the conductor slowly rises with increasing tension, and its lowest point of sag is exactly tangent to the horizontal horizon line in front of the observer, a signal is immediately given to stop tensioning. This indicates that the actual sag has precisely reached the design value.

[0024] After the sag adjustment is satisfactory, the conductor is lifted using a hemp rope, removed from the pulley, and lowered into the top groove of the pin insulator. Aluminum tape is tightly wrapped around the contact area between the conductor and the insulator. This tape not only prevents hard friction between the conductor and the insulator but also absorbs vibration energy from light winds. The wrapping length must extend 30mm beyond each side of the insulator contact area, and the wrapping direction must be consistent with the stranding direction of the outermost strands of the conductor to prevent loosening. Finally, at the tension pole, two parallel-grooved clamps are used to overlap the drain line, adjusting its length to create a natural catenary shape. This ensures an aesthetically pleasing appearance while avoiding safety hazards caused by point discharge and wind deflection, completing the conductor deployment.

[0025] Although the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Based on the technical solutions of the present invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the present invention.

Claims

1. A method for tension-free installation of conductors for 22kV overhead lines, characterized in that, Includes the following steps: Construction preparation: Conduct route surveys for the tension section to be erected, and arrange conductor reels according to the survey results; Arrange the wire-laying pulleys and support the wire-laying reel: Hang the wire-laying pulleys on the crossarms of each base tower of the line to be erected, and support the wire reel containing the conductor at the starting point of the traction. Non-tension conductor traction: No braking tension is applied to the conductor at the reel. The traction equipment pulls the traction rope connected to the end of the conductor, causing the conductor to be dragged forward along the line direction. After passing each tower, the traction stops, the deployed conductor is lifted and passed through the laying pulley, and then the conductor continues to be pulled to the next tower until the deployment of a tension section is completed. Wire crimping and tightening: The wire is cut and crimped, and then tightened in the anchoring direction by pulling the wire with a tightening device; Adjusting the sag and fixing the conductor: Observe the sag of the conductor and adjust it to the preset qualified range. Then, remove the conductor from the laying pulley and fix it to the tower insulator.

2. The non-tension laying construction method for 22kV overhead line conductors according to claim 1, characterized in that, In the construction preparation steps: the reels are matched according to the length of the conductor to be erected in the tension section, so that the number of joints of the same conductor in the same span does not exceed one, and the distance between the conductor joint and the conductor fixing point is greater than 15m.

3. The method for tension-free laying of conductors for 22kV overhead lines according to claim 1, characterized in that, In the steps of arranging the wire-laying pulley and supporting the wire-laying reel: Set the suspension height of the wire-laying pulley to be higher than that of the pin insulator on the tower; Adjust the wire feeding frame so that the wire reel is at least 50mm off the ground and keep the reel level, ensuring that it does not tilt in the direction of wire pulling.

4. The non-tension laying construction method for 22kV overhead line conductors according to claim 1, characterized in that, In the non-tension traction step of the conductor: Protective isolation facilities are laid on the ground before the conductor is laid to the ground to prevent the conductor from directly contacting the ground; When the deployed conductor is lifted and passed through the laying pulley, the hemp rope that has been passed through the laying pulley is pulled to lift the conductor, and then the lifted conductor is poured into the laying pulley.

5. The method for tension-free laying of conductors for 22kV overhead lines according to claim 1, characterized in that, In the wire crimping and tightening process, the wire crimping process includes: Remove the outer aluminum stranded wire from the crimped part of the conductor to expose the steel core, and clean the conductor and crimping tube. The cleaning length should be no less than twice the length of the crimping tube. Remove the oxide film from the aluminum contact surface of the wire connection, apply a layer of electrical composite grease, and then perform hydraulic crimping; After crimping, remove any burrs and flash from the surface of the crimped pipe and apply anti-corrosion treatment to the steel crimped pipe.

6. The method for tension-free laying of conductors for 22kV overhead lines according to claim 5, characterized in that, The parameters for hydraulic crimping are: When using aluminum alloy crimping tubes for crimping, the rated working pressure of the hydraulic system shall not be less than 63MPa, and the overlap crimping length between two adjacent dies shall not be less than 10mm. When using steel crimping pipes for crimping, the rated working pressure of the hydraulic system shall not be less than 80MPa, and the overlap crimping length between adjacent molds shall not be less than 5mm.

7. The method for tension-free laying of conductors for 22kV overhead lines according to claim 1, characterized in that, In the wire crimping and tightening process, the tightening process is as follows: initially, a pulley block is used to pull and tighten the wire; when the wire tension reaches a certain level, a lever hoist is used to continue tightening, and the wire is shaken appropriately to keep the tension of the wire consistent in each span.

8. The non-tension laying construction method for 22kV overhead line conductors according to claim 1, characterized in that, In the process of adjusting the sag and fixing the conductor, the parallelogram method is used for sag observation, and the sag observation points are selected according to the number of spans of the tight line segment: When the tight line segment is at or below level 5, select a level close to the middle as the observation level; When the tight line segment is in range 6 to 12, select one range near each end as the observation range; When the tight segment is above 12 levels, select one level near each end and the middle as the observation level.

9. A method for tension-free laying of conductors for 22kV overhead lines according to claim 1, characterized in that, When fixing the conductor to the tower insulator, aluminum tape is wrapped around the contact area between the conductor and the insulator, and the length of the aluminum tape wrapping exceeds the contact area by 30mm. The wrapping direction is consistent with the stranding direction of the outer strands of the conductor. After the conductor is fixed, two parallel groove clamps are used to connect the drain line at the tension pole. The distance between the two clamps is controlled to be moderate, and the drain line is in a natural catenary shape.

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