Composite photovoltaic inhaul cable

Abstract

The utility model relates to a composite photovoltaic inhaul cable, which comprises a composite anti-corrosion cable body, two ends of the composite anti-corrosion cable body are respectively wrapped in a variable cross-section extrusion sleeve of an inner cavity structure, one end of the variable cross-section extrusion sleeve is open, and the opening is sealed by an arc-shaped gland. The variable cross-section extrusion sleeve is divided into a guide arc-shaped conical surface, a first extrusion surface, an excessive pressure relief section, a second extrusion surface and a non-extrusion surface which are sequentially arranged backwards from an opening, the composite anti-corrosion cable body comprises a zinc-aluminum alloy steel strand or an epoxy coating steel strand, and the surface of the steel strand is wrapped with an extrusion bond-wrapping type polyurea layer. Due to the design of a brand-new anchoring mode and the improvement of anti-corrosion measures, the corrosion resistance of the inhaul cable is achieved, and the inhaul cable has the advantages of being high in stress fatigue resistance, good in shock resistance, reliable in anchoring performance, compact in anchorage device structure, convenient to manufacture, install and replace and the like.

Description

[Technical Field]

[0001] This utility model relates to the field of flexible photovoltaic support, and in particular to a composite photovoltaic cable. [Background Technology]

[0002] The photovoltaic industry in China is developing rapidly, evolving from centralized photovoltaic systems to distributed photovoltaic structures, with flexible photovoltaic cables, especially in large-span structures, gaining popularity. Flexible photovoltaic cable structures offer significant advantages: for example, they improve environmental space utilization; compared to traditional steel frame structures, flexible photovoltaic supports use less steel, have lower load-bearing capacity, relatively lower costs, lower site and foundation requirements, shorter construction periods, and strong environmental adaptability. They can be used to construct photovoltaic power stations in complex terrains such as mountains, barren slopes, ponds, and fishponds, allowing for the selection of different cable structure options. This is particularly important given the national promotion of projects such as fishery-solar integration and agriculture-solar integration.

[0003] However, flexible photovoltaic cables are still in their early stages of application, and their application and performance have some shortcomings: In harsh environments, the durability of flexible cables may be affected, leading to a shortened service life. Long-term exposure to humid and acid rain environments will accelerate the corrosion of steel strands, reduce the cable cross-section, reduce load-bearing capacity, and cause fracture due to fatigue factors. Further improving the performance of flexible photovoltaic cables is an important technical aspect of distributed photovoltaic power generation. [Utility Model Content]

[0004] The purpose of this invention is to provide a more robust composite photovoltaic cable with better stress conditions, aiming to solve the problem of the less-than-ideal performance of flexible photovoltaic cables.

[0005] The technical solution adopted by this utility model is: a composite photovoltaic cable, including a composite anti-corrosion cable body. The two ends of the composite anti-corrosion cable body are respectively wrapped in a variable cross-section extrusion sleeve with an open inner cavity structure. The opening is sealed with an arc-shaped cap. The variable cross-section extrusion sleeve is arranged sequentially from the opening to the rear as a guide arc-shaped conical surface, a first extrusion surface, an over-pressure relief section, a second extrusion surface, and a non-extrusion surface. The composite anti-corrosion cable body includes zinc-aluminum alloy steel strand or epoxy-coated steel strand. The surface of the steel strand is wrapped with an extrusion-bonded polyurea layer. The inner cavity of the variable cross-section extrusion sleeve has an inner cavity thread. The cross-section of the opening of the guide arc-shaped conical surface has vertically and horizontally perpendicular cross-cut grooves.

[0006] A further technical solution of this utility model is: the non-extrusion surface is a sealing end extending from the second extrusion surface, and the inner cavity also extends into the non-extrusion surface and its extension length is determined by the cable length adjustment range.

[0007] A further technical solution of this utility model is: the composite anti-corrosion cable body also includes protrusions arranged in a bidirectional spiral pattern on the outer surface.

[0008] A further technical solution of this utility model is: the outer diameter of the non-extrusion surface is less than the outer diameter of the first extrusion surface and the outer diameter of the second extrusion surface.

[0009] The beneficial effects of this utility model are as follows: Due to the adoption of the above technical solution, the design of the new anchoring form and the improvement of the anti-corrosion measures of this utility model solve the problems of corrosion resistance of the cable, high stress fatigue resistance, good seismic resistance, reliable anchoring performance, and has the advantages of compact anchor structure, convenient manufacturing, convenient installation and cable replacement construction. [Attached Image Description]

[0010] Figure 1 This is a schematic diagram of the structure of a composite photovoltaic cable described in this utility model;

[0011] Figure 2 This is a schematic diagram of the structure of the variable cross-section extrusion sleeve described in this utility model;

[0012] Figure 3 This is a schematic diagram of the structure of the composite corrosion-resistant cable body described in this utility model;

[0013] Figure 4 This is a schematic diagram of the structure during the preparation of the composite photovoltaic cable described in this utility model;

[0014] Figure 5 This is a schematic diagram of the arc-shaped pressure cap described in this utility model.

Detailed Implementation Methods

[0015] The steel strand described in this utility model can also be other cables. The utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0016] like Figure 1 The composite photovoltaic cable shown is mainly composed of a semi-open variable cross-section extrusion sleeve 1, an arc-shaped pressure cap 2, and a composite anti-corrosion cable body 3, forming a photovoltaic cable structure system.

[0017] like Figure 2 The variable cross-section extrusion sleeve structure shown is composed of six innovative structural designs: a guide arc-shaped conical surface 11, a threaded structure in the inner cavity 12, a second extrusion surface 13, a non-extrusion surface 14, an overpressure relief section 15, and a first extrusion surface 16.

[0018] The guide arc-shaped conical surface 11 has two main design purposes: First, it serves to center and guide the front end of the variable cross-section extrusion sleeve when it enters the extrusion die, making the extrusion die and extrusion sleeve move more smoothly during the extrusion process and less prone to jamming. Second, the front end adopts an arc-shaped surface and is designed with vertical cross-cut grooves 17, which facilitates the application of a certain arc-shaped compressive stress to the front end of the variable cross-section extrusion sleeve by the arc-shaped pressure cap 2. Under the action of deformation, the arc-shaped surface of the front end of the extrusion sleeve is deformed inward, which is transmitted to the steel strand to generate deformation, achieving a better sealing and waterproof effect at the front end.

[0019] After drilling a countersunk hole, the inner cavity 12 is tapped to create a serrated tooth surface on the inner hole surface. This facilitates the engagement of the steel strand after extrusion, avoiding the cumbersome process of inserting extrusion springs and other radial pressure into the ends of the steel strand. It also saves on the corresponding manufacturing steps and achieves cost control.

[0020] The outer surface of the variable cross-section extrusion sleeve 1 comprises two extrusion surfaces with different extrusion amounts: a first extrusion surface 16 and a second extrusion surface 13. The first extrusion surface is the first segment of the steel strand extrusion structure. Due to its relatively small outer diameter extrusion amount, it primarily addresses the issue of uniform extrusion amount across the entire anchor body in conventional extrusion sleeves. This can easily lead to significant extrusion friction at the front end, and excessive extrusion pressure on the extrusion surface can cause metal accumulation and metal wire drawing, potentially resulting in extrusion sleeve bending or die jamming. This invention employs a segmented extrusion process with different extrusion amounts and a dual-die extrusion process, achieving simultaneous segmented extrusion and completing the extrusion process with two different extrusion amounts in one step. The advantage of two extrusion amounts is that the front end of the extrusion sleeve experiences a smaller gripping force, avoiding the aforementioned problems caused by excessive extrusion pressure, while ensuring the release of extrusion pressure and the ductility of the extruded metal. In addition, the variable cross-section extrusion sleeve 1 is provided with an over-pressure relief section 15 in the middle. Through the design of the over-bevel, the extrusion and stretching force at the front end is greatly released. At the same time, it is also conducive to the centering and stress re-concentration of the large extrusion volume at the rear end. This can improve the fatigue performance of the steel strand inside the extrusion sleeve and avoid the phenomenon of excessive stress in the steel strand inside the extrusion sleeve leading to extrusion fracture.

[0021]

[0022] The variable cross-section extrusion sleeve 1 has a non-extrusion surface 14 at its rear end, and adopts a closed end design, which can compensate for the sealing of the entire extrusion sleeve and prevent water vapor from entering and corroding the end of the extrusion sleeve. The outer diameter of the extrusion surface is smaller than that of the first extrusion surface, which is beneficial to perform thread processing on the anchor body in the semi-finished product processing stage first, and the entire anchor body can be adjusted for cable length only using the non-extrusion surface.

[0023] The opening is cut into two intersecting perpendicular grooves to facilitate the extrusion of the composite anti-corrosion layer on the outer surface of the steel strand into the cut grooves during the extrusion process. After metal extrusion, an interference fit is formed, making the installation more secure. At the same time, during the spiral screwing process, a certain arc-shaped compressive stress is applied to the front end of the extrusion sleeve. Under the deformation of the front end of the extrusion sleeve, an inward extrusion deformation is generated on the arc-shaped metal surface of the front end of the extrusion sleeve, which is then transferred to the composite coating protective surface of the steel strand to cause deformation, achieving a better sealing and waterproof effect at the front end.

[0024] like Figure 3 The composite anti-corrosion cable body 3 shown mainly consists of raised points 31, a composite protective layer 32, and steel strands 33. The raised points 31 are arranged in a bidirectional spiral pattern, which enhances the friction on the cable body surface, improves the fastening effect of the fasteners at the photovoltaic panel overlap, and increases the anti-slip effect. Simultaneously, the raised points also cut through the wind direction under hurricane conditions, reducing the wind's impact on the cable's vibration. The outer surface of the cable body is further enhanced with raised points through a thermoplastic extrusion process, strengthening the fastening force between the photovoltaic panel and the cable body. This ensures that the fasteners on the photovoltaic panel can fully engage with the cable body, increasing friction and improving the fastening effect, preventing loosening or slippage of the fasteners under wind vibration over a long period.

[0025] The composite protective layer consists of a zinc-aluminum alloy or epoxy-coated steel strand wrapped with an extruded polyurea layer. Its characteristic is that the polyurea is directly wrapped onto the surface of the steel strand through thermoplastic extrusion to form an integral coating. The overall adhesion of the polyurea layer of the steel strand is improved. Compared with the sprayed polyurea method, it has a better adhesion effect and is not easy to fall off. Moreover, its preparation process has less pollution and less loss.

[0026] like Figure 4The method for preparing a composite photovoltaic cable requires mold installation. Mold 4 includes a mold base 41 for support and fixation, a first extrusion mold 42 and a second extrusion mold 43 corresponding to the first extrusion surface 16 and the second extrusion surface 13 respectively, a limiting screw 44 around the non-extrusion surface 14, and a top pressure head 45 at the end face of the non-extrusion surface 14. First, one end of the composite anti-corrosion cable body is fed into the mold base and assembled with the variable cross-section anchor sleeve. Then, it is fed into the extrusion mold through the top pressure head to the first extrusion surface and the second extrusion surface, which correspond to the first extrusion mold and the second extrusion mold respectively, preparing to enter the double-mold extrusion stage. During the double-mold extrusion stage, the top pressure head applies axial pressure while the first extrusion mold and the second extrusion mold apply radial force, causing radial gripping deformation at the first extrusion surface and the second extrusion surface. The operation is repeated to extrude the other end of the composite anti-corrosion cable body to complete the anchor head production and form a photovoltaic cable. The first extrusion die and the second extrusion die are linked. The side of the first extrusion die is designed with an oil nozzle hole 46. A certain amount of hydraulic oil is injected through the nozzle hole to carry out the double extrusion stage. Then, the hydraulic pressure inside the first extrusion die is released through the oil nozzle hole, so that the internal pressure of the two-part extrusion die is released, making it convenient for the extrusion sleeve to be pulled out of the inner hole of the first extrusion die as a whole.

[0027] like Figure 5 As shown, the innovative design of the arc-shaped pressure cap 2 adopts the design concept of inner conical surface 21 and arc-shaped surface 22, which are screwed and matched with the outer conical surface of the extrusion sleeve to produce extrusion deformation of the arc-shaped surface. This causes the guide arc-shaped conical surface with cutting lines at the front end of the extrusion sleeve to undergo circumferential deformation, forming an extrusion sealing effect on the cable body. This achieves the double extrusion sealing effect of the inner arc-shaped surface and the conical surface, forming two waterproof barriers.

[0028]

[0029] Composite anti-corrosion cable manufacturing process (taking steel strand as an example): First, the steel strand substrate is broken up and cleaned with a special cleaning agent. Then, it is re-twisted into the original steel strand structure. Using a special oil-based wax injection device, oil-based wax is sprayed onto the surface of the steel strand under high pressure through an injection mold to form a dense anti-corrosion layer. A protective film is then applied to the outer surface of each individual steel strand coated with oil-based wax to form a sealed coating layer. Next, the steel strand is passed through a polyurea injection mold using a traction device. Polyurea is then hot-melt extruded onto the steel strand at a certain high temperature to form an integral anti-corrosion layer, replacing the conventional polyurea spraying process. Finally, the extruded polyurea is cooled in stages through a temperature-controlled cooling tank to form a multi-layer composite anti-corrosion cable protective layer.

[0030] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A composite photovoltaic pull cable, characterized by: The composite anticorrosion cable body is wrapped in a variable cross-section extrusion sleeve with an open inner cavity structure at both ends, and the opening is sealed by an arc-shaped gland, the variable cross-section extrusion sleeve is sequentially arranged from the opening to the rear into a guide arc-shaped conical surface, a first extrusion surface, a gradual pressure relief section, a second extrusion surface and a non-extrusion surface, the composite anticorrosion cable body comprises a zinc-aluminum alloy steel strand or an epoxy coated steel strand, the surface of the steel strand is wrapped with an extruded grip type polyurea layer, the inner cavity of the variable cross-section extrusion sleeve is provided with an inner cavity thread, and the opening of the guide arc-shaped conical surface is provided with a longitudinal and transverse vertical cross-cut line groove.

2. The compound photovoltaic pull cord of claim 1, wherein: The non-extrusion surface is a sealing end extending from the second extrusion surface, the inner cavity also extends into the non-extrusion surface and the extension length is determined by the cable length adjustment range.

3. The compound photovoltaic pull cord of claim 2, wherein: The composite anticorrosion cable body further comprises convex boss points arranged in a bidirectional spiral line on the outer surface.

4. The composite photovoltaic pull cable of any one of claims 2 or 3, wherein: The outer diameter of the non-extrusion surface is less than that of the first extrusion surface, and the outer diameter of the first extrusion surface is less than that of the second extrusion surface.

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