Composite anticorrosion and double-extrusion process photovoltaic inhaul cable and preparation method thereof

Abstract

The photovoltaic inhaul cable comprises a composite anti-corrosion type cable body, the two ends of the composite anti-corrosion type cable body are wrapped in variable cross-section extrusion sleeves of an inner cavity structure, one end of each variable cross-section extrusion sleeve is provided with an opening, and the opening is sealed through 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. According to the design of a brand-new anchoring mode and 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, convenient to install, convenient to replace and construct and the like.

Description

[Technical field]

[0001] The present invention relates to the field of flexible photovoltaic brackets, and in particular to a flexible photovoltaic cable and a preparation method thereof. [Background technology]

[0002] At present, the domestic photovoltaic industry is developing rapidly, from the previous centralized photovoltaic industry to the decentralized photovoltaic structure, especially in the large-span structure, the flexible photovoltaic cable is favored. The flexible photovoltaic cable structure has great advantages: for example, it can improve the utilization rate of environmental space, and compared with the traditional steel frame structure, the flexible photovoltaic bracket uses less steel, has a small load-bearing capacity, is relatively low in cost, has low site foundation requirements, a short construction period, and has strong environmental adaptability. It can select different cable structures and build photovoltaic power stations under complex terrain conditions such as mountains, barren slopes, pools, and fish ponds. This is particularly important in the context of the country's vigorous promotion of fishery-photovoltaic complementarity and agricultural-photovoltaic complementarity projects.

[0003] However, flexible photovoltaic cables are currently in their infancy, and their application and performance also have the following shortcomings: in harsh environments, the durability of flexible cables may be affected, resulting in a shortened service life; long-term exposure to moisture, acid rain and other environments will accelerate the corrosion of steel strands, reduce the cable cross-section, reduce the load-bearing capacity, and cause breakage due to fatigue factors. Further improving the performance of flexible photovoltaic cables is an important technical link in distributed photovoltaic power generation. [Summary of the invention]

[0004] The purpose of the present invention is to provide a composite anti-corrosion and double-extrusion photovoltaic cable that is stronger and has a better stress state, aiming to solve the problem that the performance of flexible photovoltaic cables is not ideal.

[0005] The technical solution adopted by the present invention is: a composite anti-corrosion and double-extrusion process 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-section extrusion sleeve of an inner cavity structure with an opening at one end, and the opening is sealed with an arc-shaped pressure cover. The variable-section extrusion sleeve is arranged in sequence from the opening to the back and is divided into a guide arc-shaped cone surface, a first extrusion surface, an excessive pressure relief section, a second extrusion surface and a non-extrusion surface. The composite anti-corrosion cable body includes zinc-aluminum alloy steel strands or epoxy-coated steel strands, and the surface of the steel strands is wrapped with an extruded gripping polyurea layer.

[0006] A further technical solution of the present invention is that the inner cavity of the variable-section extrusion sleeve is provided with inner cavity threads.

[0007] A further technical solution of the present invention is that a cross-cutting line groove vertically extending in longitudinal and transverse directions is provided in the cross section of the opening of the guide arc-shaped cone surface.

[0008] A further technical solution of the present invention is that 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 its extension length is determined by the cable length adjustment range.

[0009] A further technical solution of the present invention is: the composite anti-corrosion cable body also includes boss points arranged in a bidirectional spiral line on the outer surface.

[0010] A further technical solution of the present invention is that the outer diameter of the non-extrusion surface is less than the outer diameter of the first extrusion surface and less than the outer diameter of the second extrusion surface.

[0011] The present invention also provides a method for preparing a composite anti-corrosion and double extrusion process photovoltaic cable, the steps of which include: A. Preparation of a composite anti-corrosion cable body, first cleaning the steel strand substrate with a cleaning agent and drying it, then twisting the steel strand substrate into a steel strand, and then spraying the oily wax on the surface of the steel strand under high pressure through a special oily wax injection device and an injection mold to form a dense inner anti-corrosion layer to wrap it up, and then wrapping the outer surface with a layer of protective film to form a sealing wrapping layer for the oily wax, and then passing the steel strand through a traction tooling to pass it through a polyurea injection mold, hot-melt-extrude the polyurea on the steel strand at high temperature to form an integral outer anti-corrosion layer, and then step-cooling the integrally extruded polyurea through a temperature-controlled cooling trough to finally form a multi-layer composite anti-corrosion cable body; B. Preparation of a variable-section anchor sleeve, including a variable-section extrusion sleeve and an arc-shaped pressure cover seal, wherein one end of the variable-section extrusion sleeve is open and extends inward to form an inner cavity, and the variable-section extrusion sleeve is arranged in sequence from the opening to the rear It is divided into a guiding arc-shaped cone surface, a first extrusion surface, an excessive pressure relief section, a second extrusion surface and a non-extrusion surface. The arc-shaped pressure cover adopts an inner cone surface design to be screwed and matched with the guiding arc-shaped cone surface; C. Preparation of the mold, the mold includes a mold base for supporting and fixing, and also includes a first extrusion die and a second extrusion die corresponding to the first extrusion surface and the second extrusion surface respectively, and also includes a limiting screw around the non-extrusion surface and a top pressure head at the end face of the non-extrusion surface; D. Preparation of the photovoltaic cable, firstly, one end of the composite anti-corrosion cable body is introduced into the mold base and assembled with the variable-section anchor sleeve, and then introduced into the extrusion die through the top pressure head to the first extrusion surface and the second extrusion surface respectively corresponding to the first extrusion die and the second extrusion die, preparing to enter the double-die extrusion stage. In the double-die extrusion stage, the top pressure head applies axial top pressure while the first extrusion die and the second extrusion die apply radial force to cause radial gripping deformation at the first extrusion surface and the second extrusion surface, and repeat the operation to extrude the other end of the composite anti-corrosion cable body to complete the anchor head production to form a photovoltaic cable.

[0012] A further technical solution of the present invention is that a nozzle hole is designed on the side of the first extrusion die.

[0013] The beneficial effects of the present invention are: due to the adoption of the above-mentioned technical scheme, the design of the new anchoring form and the improvement of the anti-corrosion measures of the present invention solve the corrosion resistance of the cable, have high stress fatigue resistance, good seismic resistance, reliable anchoring performance, and have the advantages of compact anchor structure, easy production, installation and cable replacement construction.

Brief Description of the Drawings

[0014] Figure 1 It is a structural schematic diagram of a composite anti-corrosion and double extrusion process photovoltaic cable according to the present invention;

[0015] Figure 2 It is a schematic diagram of the structure of the variable cross-section extrusion sleeve of the present invention;

[0016] Figure 3 It is a schematic diagram of the structure of the composite anti-corrosion cable body of the present invention;

[0017] Figure 4 It is a structural schematic diagram of a method for preparing a composite anti-corrosion and double extrusion process photovoltaic cable according to the present invention;

[0018] Figure 5 It is a structural schematic diagram of the arc-shaped gland of the present invention. [Specific implementation method]

[0019] The steel strand described in the present invention may also be other cables. The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0020] like Figure 1 The composite anti-corrosion and double extrusion process photovoltaic cable shown in the figure mainly comprises a semi-open variable-section extrusion sleeve 1, an arc-shaped pressure cover 2 and a composite anti-corrosion cable body 3 to form a photovoltaic cable structure system.

[0021] like Figure 2 The variable cross-section extrusion sleeve structure shown in the figure has an overall structure consisting of six aspects of structural innovation design, namely, a guiding arc-shaped cone surface 11, a threaded structure of an inner cavity 12, a second extrusion surface 13, a non-extrusion surface 14, an excessive pressure relief section 15, and a first extrusion surface 16.

[0022] The guiding arc-shaped cone surface 11 is mainly designed with two points: one is to realize the purpose of centering and guiding when the front end of the variable-section extrusion sleeve enters the extrusion die, which makes it easier for the extrusion die and the extrusion sleeve to be extruded smoothly and not easy to get stuck; the second is that the front end adopts an arc-shaped surface, and a cross-cut wire groove 17 is designed vertically in the longitudinal and transverse directions, so that the arc-shaped pressure cover 2 can apply a certain arc-shaped compressive stress to the front end of the variable-section extrusion sleeve in the later stage, and the inward extrusion deformation of the arc surface of the front end of the extrusion sleeve is realized under the effect of deformation, which is transmitted to the steel strand to generate deformation, so as to achieve better sealing and waterproof effect of the front port.

[0023] After the inner cavity 12 is countersunk by drilling, the hole is tapped to produce a serrated surface on the inner hole to facilitate the engagement of the steel strand after extrusion, avoiding the cumbersome process of radial pressurization such as inserting an extrusion spring into the end of the steel strand, saving the corresponding manufacturing process and achieving cost control.

[0024] The extrusion surface of the outer surface of the variable cross-section extrusion sleeve 1 includes two surfaces with different extrusion amounts, namely the first extrusion surface 16 and the second extrusion surface 13. The first extrusion surface is the first section extrusion structure of the steel strand. Since its outer diameter extrusion amount is relatively small, it is mainly used to solve the problem that the extrusion amount of the entire anchor body of the conventional extrusion sleeve is consistent, which is easy to produce a large extrusion friction force at the front end, and the extrusion force on the extrusion surface is too large to produce surface metal accumulation and metal wire drawing, which can easily cause the extrusion sleeve to bend or get stuck. The present invention adopts a segmented extrusion process with different extrusion amounts, and adopts a dual-mold extrusion process to realize the simultaneous segmented extrusion process, completing two extrusion processes with different extrusion amounts at one time. The advantage of the two extrusion amounts is that a smaller excessive gripping force is achieved at the front end of the extrusion sleeve to avoid the above phenomenon caused by excessive extrusion force, while ensuring the release of extrusion force and the ductility of the extruded metal. In addition, an excessive pressure relief section 15 is provided in the middle of the variable-section extrusion sleeve 1. Through the design of excessive chamfering, the release of the front end extrusion ductility force is greatly released, and it is also beneficial to the centering and stress re-concentration of the large extrusion amount at the rear end, which can improve the fatigue performance of the steel strand inside the extrusion sleeve and avoid the phenomenon of extrusion fracture of the steel strand caused by excessive stress in the extrusion sleeve.

[0025] The comparison of the effects of the two extrusion processes is shown in the following table:

[0026]

[0027] The rear end of the variable cross-section extrusion sleeve 1 is designed with a non-extrusion surface 14, and a closed end design is adopted, so that the sealing of the entire extrusion sleeve can be improved and the end of the extrusion sleeve can be prevented from being corroded by water vapor intrusion. The outer diameter of the extrusion surface is smaller than that of the first extrusion surface, which is conducive to threading the anchor body first in the semi-finished product processing stage, and the entire anchor body only uses the non-extrusion surface for cable length adjustment.

[0028] The opening is cut into two cross-vertical wire grooves, which facilitates the composite anti-corrosion layer on the outer surface of the steel strand to be squeezed into the cut wire groove during extrusion and cable making. An interference fit is formed after metal extrusion, which makes the installation more secure. At the same time, a certain arc-shaped compressive stress is applied to the front end of the extrusion sleeve during the spiral screwing process. Under the action of the deformation of the front end of the extrusion sleeve, the inward extrusion deformation of the arc-shaped metal surface of the front end of the extrusion sleeve is generated, and the deformation is transmitted to the composite coating protective surface of the steel strand to achieve better sealing and waterproofing effect of the front port.

[0029] like Figure 3 The composite anti-corrosion cable body 3 shown is mainly composed of boss points 31, composite protective layer 32, and steel strands 33, wherein the boss points 31 are in the form of a bidirectional spiral line combination, which is beneficial to enhancing the friction force on the surface of the cable body, facilitating the photovoltaic buckle plate overlap to improve the fastening effect of the buckle, and increasing the anti-slip effect. At the same time, its boss points can also cut the wind direction under hurricane conditions, reducing the effect of wind force on the wind vibration of the cable. The outer surface of the cable body is further increased by a thermoplastic extrusion process to increase the boss points on the surface of the cable body, thereby enhancing the buckling force between the photovoltaic panel and the cable body, so that the buckle on the photovoltaic panel can completely increase the friction with the cable body, improve the buckling effect, and avoid the effect of loosening or slipping of the buckling force under wind vibration for a long time.

[0030] The composite protective layer of the cable body is composed of an extruded polyurea layer wrapped around a zinc-aluminum alloy or epoxy-coated steel strand. Its characteristic is that the polyurea is directly wrapped on 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 body is improved. Compared with the spray-type polyurea method, it has good adhesion effect and is not easy to fall off. In addition, its preparation process has low pollution and loss.

[0031] like Figure 4 The preparation method of a composite anti-corrosion and double extrusion process photovoltaic cable shown requires mold installation, and the mold 4 includes a mold base 41 for supporting and fixing, and also includes a first extrusion die 42 and a second extrusion die 43 corresponding to the first extrusion surface 16 and the second extrusion surface 13 respectively, and also includes 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 introduced into the mold base and assembled with the variable-section anchor sleeve to form a set, and then introduced into the extrusion die through the top pressure head to the first extrusion surface and the second extrusion surface respectively corresponding to the first extrusion die and the second extrusion die, preparing to enter the double-die extrusion stage. During the double-die extrusion stage, the top pressure head applies axial top pressure while the first extrusion die and the second extrusion die apply radial force to cause radial gripping deformation at the first extrusion surface and the second extrusion surface, and the operation is repeated to extrude the other end of the composite anti-corrosion cable body to complete the anchor head production to form a photovoltaic cable. The first extrusion die and the second extrusion die are in linkage mode. The side of the first extrusion die is designed with a nozzle hole 46, through which a certain amount of hydraulic oil is injected to perform the double extrusion stage, and then the hydraulic pressure in the first extrusion die is released through the nozzle hole, so that the two-half extrusion die releases the internal pressure, making it convenient for the extrusion sleeve to be pulled out of the inner hole of the first extrusion die as a whole.

[0032] like Figure 5 As shown, the innovative design of the arc-shaped pressure cover 2 adopts the design concept of the inner conical surface 21 and the arc-shaped surface 22, which are screwed together with the outer conical surface of the extrusion sleeve to produce extrusion deformation of the arc-shaped surface, so that the guide arc-shaped conical surface with a cutting line processed at the front end of the extrusion sleeve produces annular deformation, forming an extrusion sealing effect on the cable body, achieving a double extrusion sealing effect of the inner arc-shaped surface and the conical surface, and forming two waterproof and water-isolating barriers.

[0033]

[0034] The manufacturing process of composite anti-corrosion cable body (taking steel strand as an example): first, the steel strand base material is broken up, cleaned, and cleaned with a special cleaning agent, and then twisted back into the original steel strand structure. Through special oily wax injection equipment, the oily wax is sprayed on the surface of the steel strand under high pressure through an injection mold to wrap it up, forming a dense anti-corrosion layer. The outer surface of a single steel strand coated with oily wax is wrapped with a layer of protective film to form a sealing wrapping layer for the oily wax. The steel strand is then passed through a polyurea injection mold through a traction tooling, and polyurea is hot-melt extruded onto the steel strand at a certain high temperature to form an integral anti-corrosion layer, replacing the conventional spray polyurea process. The integral extruded polyurea is then cooled in a step-by-step manner through a temperature-controlled cooling trough, and finally a multi-layer composite anti-corrosion cable body protective layer is formed.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite anti-corrosion and double extrusion photovoltaic cable, characterized by: It comprises a composite anti-corrosion cable body, the two ends of which are respectively wrapped in a variable-section extrusion sleeve of an inner cavity structure with an opening at one end, the opening is sealed with an arc-shaped pressure cover, and the variable-section extrusion sleeve is arranged in sequence from the opening to the rear to form a guide arc-shaped cone surface, a first extrusion surface, an excessive pressure relief section, a second extrusion surface and a non-extrusion surface. The composite anti-corrosion cable body comprises a zinc-aluminum alloy steel strand or an epoxy-coated steel strand, and the surface of the steel strand is wrapped with an extruded gripping polyurea layer.

2. The composite anti-corrosion and double extrusion photovoltaic cable according to claim 1 is characterized in that: The inner cavity of the variable-section extrusion sleeve is provided with inner cavity threads.

3. The composite anti-corrosion and double extrusion photovoltaic cable according to claim 1 is characterized in that: The cross section of the opening of the guide arc-shaped cone surface is provided with a vertical and horizontal cross-cutting line groove.

4. The composite anti-corrosion and double extrusion photovoltaic cable according to claim 1 is characterized in that: 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.

5. The composite anti-corrosion and double extrusion photovoltaic cable according to claim 1 is characterized in that: The composite anti-corrosion cable body also includes boss points arranged in a bidirectional spiral line on the outer surface.

6. The composite anti-corrosion and double extrusion photovoltaic cable according to claim 4 is characterized in that: The outer diameter of the non-extrusion surface is smaller than the outer diameter of the first extrusion surface and smaller than the outer diameter of the second extrusion surface.

7. A method for preparing a composite anti-corrosion and double extrusion photovoltaic cable, characterized in that: The steps include: A. Preparation of composite anti-corrosion cable body: First, clean the steel strand base material with a cleaning agent and dry it, then twist and pull the steel strand base material into steel strand, and then use special oil wax injection equipment and injection mold to spray the oil wax on the surface of the steel strand under high pressure to form a dense inner anti-corrosion layer to wrap it up, and then add a layer of protective film to wrap the outer surface to form a sealing wrapping layer for the oil wax, and then let the steel strand pass through the polyurea injection mold through the traction tooling, and hot-melt polyurea is extruded on the steel strand at high temperature to form an integral outer anti-corrosion layer, and then the integral extruded polyurea is cooled stepwise through the temperature-controlled cooling tank to finally form a multi-layer composite anti-corrosion cable body; B. Preparation of variable-section anchor sleeve, including variable-section extrusion sleeve and arc-shaped gland seal, wherein one end of the variable-section extrusion sleeve is open and extends inward to form an inner cavity, and the variable-section extrusion sleeve is arranged in sequence from the opening to the back to be divided into a guide arc-shaped cone surface, a first extrusion surface, an excessive pressure relief section, a second extrusion surface and a non-extrusion surface, and the arc-shaped gland adopts an inner cone surface design to be screwed and matched with the guide arc-shaped cone surface; C. Preparation of the mold, the mold includes a mold base for supporting and fixing, a first extrusion die and a second extrusion die corresponding to the first extrusion surface and the second extrusion surface respectively, and also includes a limiting screw around the non-extrusion surface and a top pressure head at the end surface of the non-extrusion surface; D. Preparation of photovoltaic cables. First, one end of the composite anti-corrosion cable body is passed into the die seat and assembled with the variable-section anchor sleeve. Then, it is passed into the extrusion die through the top pressure head to the first extrusion surface and the second extrusion surface respectively corresponding to the first extrusion die and the second extrusion die, preparing to enter the double-die extrusion stage. During the double-die extrusion stage, the top pressure head applies axial top pressure while the first extrusion die and the second extrusion die apply radial force to cause radial gripping deformation at the first extrusion surface and the second extrusion surface. Repeat the operation to extrude the other end of the composite anti-corrosion cable body to complete the anchor head production to form a photovoltaic cable.

8. The method for preparing a composite anti-corrosion and double extrusion photovoltaic cable according to claim 7, characterized in that: The side surface of the first extrusion die is designed with an oil nozzle hole.

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