Molded wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable and preparation method thereof

Abstract

The invention relates to the technical field of power cables, in particular to a molded line stranded aluminum alloy conductor optical fiber composite low-voltage power cable and a preparation method thereof.The molded line stranded aluminum alloy conductor optical fiber composite low-voltage power cable comprises a plurality of power line cores which are tangent in pairs and stranded mutually, and heat dissipation channels are formed in the inner sides of the N power line cores; the heat conduction layer is filled in the heat dissipation channel and forms a preset shape; and the foaming filling layer is filled at the outer sides of the two adjacent power wire cores and is wrapped and fixed by a wrapping layer to form a cable core with a circular cross section. The distribution positions of the wire cores and the optical fibers and the heat dissipation channels of the optical fibers are improved, and heat generated by the power wire cores can be transmitted to the outside of the cable by avoiding the positions of the optical fibers through the first heat conduction channels of the inner sheath, the shielding layer and the outer sheath; and the heat dissipation channel on the inner side of the conductor can be used as a second heat conduction channel to transmit along the axis of the cable, so that the temperature of the environment where the optical fiber unit is located can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power cables, and particularly to a type-stranded aluminum alloy conductor optical fiber composite low-voltage power cable and a preparation method thereof. Background Art

[0002] The optical and electrical composite cable simultaneously transmits optical signals and electrical signals to achieve the integration of power and electrical signal transmission. In the conduction structure of the optical and electrical composite cable, the optical fiber and the cable are combined into one, saving the laying space and cost. Inside the optical and electrical composite cable, there are optical fibers for transmitting optical signals and metal / alloy cores for conducting electrical energy.

[0003] When the power transmission line with a rated voltage of 0.6 / 1 kV operates normally, the power core transmits electrical energy and generates heat, resulting in the temperature rise of the cable. Under normal circumstances, the temperature of the metal or alloy conductor (copper alloy, aluminum alloy, etc.) remains around 50 °C for a long time, but the instantaneous temperature rise caused by overload or short circuit can reach 80 °C or even higher. The maximum long-term operating temperature of the conventional optical fiber in the optical unit needs to be kept at no more than 70 °C. The temperature rise of the power unit will have an adverse effect on the optical transmission of the optical fiber.

[0004] On the one hand, the high temperature rise of the optical and electrical composite cable will cause the attenuation characteristics of the optical fiber to change, increasing the loss of optical signals during transmission, reducing the transmission quality and stability of optical signals, and affecting the reliability and accuracy of communication. Especially when the cable operating temperature exceeds 60 °C, the change rate of the core refractive index can reach 0.8% / °C, causing the optical signal attenuation rate to rise above 3 dB / km. On the other hand, temperature changes may also cause thermal expansion of the optical fiber, resulting in small changes in the geometric shape of the optical fiber, affecting the optical signal transmission mode and coupling efficiency, and further deteriorating the transmission performance of optical signals. In addition, being in a high-temperature environment for a long time will accelerate the aging of the optical fiber material, shorten the service life of the optical fiber, increase the maintenance cost and potential safety hazards.

[0005] In the existing technology, for example, an optical and electrical composite cable control cable proposed in the publication number CN116403764A, the optical fiber unit is either stranded together with the power core or arranged outside the cable core, but neither can effectively suppress the temperature influence of the power unit on the optical fiber unit. Therefore, how to effectively solve the influence of the temperature rise of the power unit on the optical fiber in the optical and electrical composite cable has become an urgent technical problem to be solved. Summary of the Invention

[0006] In view of the technical problems existing in the power cable in the prior art, the first aspect of the present invention provides a type-stranded aluminum alloy conductor optical fiber composite low-voltage power cable, including:

[0007] N power cores that are pairwise tangent and mutually stranded, and a heat dissipation channel is formed inside the N power cores;

[0008] A heat-conducting layer filled in the heat dissipation channel and forming a predetermined shape;

[0009] A foamed filling layer is filled on the outer sides of two adjacent power line cores and is formed into a cable core with a circular cross-section by being wrapped with a wrapping layer;

[0010] An inner sheath layer is extruded on the outer wall of the cable core, and grooves are provided on the surface of the inner sheath layer;

[0011] An optical fiber unit is arranged in the groove;

[0012] A shielding layer is coated on the outer wall of the inner sheath layer;

[0013] An outer sheath layer is extruded on the outer wall of the shielding layer;

[0014] Wherein, the inner sheath layer is divided into several regions in the cross-sectional direction of the cable, including N first regions and N second regions. Along the axial direction of the cable, the first region or the second region is set to be strip-shaped and is distributed in a spiral around the axis of the cable;

[0015] In the cross-sectional direction of the cable, the first region corresponds to the position of the power line core, the second region corresponds to the gap between two adjacent power line cores, the heat conduction performance of the inner sheath layer in the first region is greater than that in the second region, and the groove is arranged in the second region of the inner sheath layer.

[0016] Preferably, in the cross-sectional direction of the cable, the arc length corresponding to the first region is L1, and the arc length corresponding to the second region is L2, wherein, L1 / L2 = 4 / 6 - 5 / 5.

[0017] Preferably, a heat-conducting filler is provided in the first region of the inner sheath layer, and the first region and the second region of the inner sheath layer are extruded by a co-extrusion method.

[0018] Preferably, the content of the heat-conducting filler in the first region is set to be higher in the central part of the first region than in the two side parts of the first region.

[0019] Preferably, at least one groove is provided in each second region, and the length of the groove is greater than the length of the second region.

[0020] Preferably, the groove is arranged in the second region along a trajectory that periodically approaches the first side and the second side edges of the second region.

[0021] Preferably, the width of the second region is defined as W, and the maximum span of the groove in the width direction of the second region does not exceed 0.6W.

[0022] Preferably, the power line core includes a circular stranded conductor, a sector stranded conductor, and an insulating layer. A semiconductive water blocking tape is provided between the circular stranded conductor and the sector stranded conductor, and between the sector stranded conductor and the insulating layer. A double-sided water blocking tape is filled between each sector strand block in the sector stranded conductor.

[0023] Preferably, the shielding layer includes a longitudinally wrapped metal tape shielding layer, a braided shielding layer, and a non-woven fabric wrapping layer distributed from the inside out. The longitudinally wrapped metal tape shielding layer includes a longitudinally wrapped copper-plastic composite tape. The braided shielding layer includes a fine copper wire braided shielding layer with a braiding density greater than 85%.

[0024] In a second aspect of the present invention, a technical solution is proposed. A method for manufacturing the above-mentioned type wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable includes the following steps:

[0025] Step 1: Prepare the power line core:

[0026] Step 11: Use circular aluminum alloy wires to form a circular stranded conductor by left-handed stranding of 1 + 6;

[0027] Step 12: Wrap a semiconductive water blocking tape on the surface of the circular stranded conductor to form an inner conductor;

[0028] Step 13: Use sector aluminum alloy wires and a double-sided water blocking tape to strand outside the inner conductor to form an outer conductor;

[0029] Step 14: Wrap a semiconductive water blocking tape outside the outer conductor;

[0030] Step 15: Extrude an insulating layer on the outer layer of the semiconductive water blocking tape to form a power line core;

[0031] Step 2: Cable stranding:

[0032] Step 21: Arrange multiple foam strips outside the power line core and strand them with multiple power line cores. At the same time, fill a heat-conducting medium in the heat dissipation channels formed inside after the multiple power line cores are stranded;

[0033] Step 22: Use a wrapping tape to wrap the stranded foam strips and power line cores together to form a cable;

[0034] Step: Extrude an inner sheath layer:

[0035] Step 31: Use a double-channel co-extrusion die to extrude the first area and the second area of the inner sheath layer at the die head. While extruding, control the rotation of the die head so that the extruded first area corresponds to the position of the power line core. At the same time, through the periodic swing of the plug on the die head, form grooves on the surface of the second area;

[0036] Step 32: Cool the extruded inner sheath layer;

[0037] Step 4: Press the optical fiber unit into the groove;

[0038] Step 5: longitudinally wrap a longitudinally wrapped metal tape shielding layer on the outer layer of the inner sheath layer, then braid fine copper wires outside the longitudinally wrapped metal tape shielding layer to form a braided shielding layer, and wrap a double-layer non-woven fabric tape around the outer wall of the braided shielding layer to form a non-woven fabric wrapping layer;

[0039] Step 6: Extrude a thermoplastic polyurethane elastic sheath on the outer wall of the non-woven fabric wrapping layer to form an outer sheath layer.

[0040] Due to the implementation of the above technical solutions, the significant advantages of the shaped wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable of the present invention are as follows:

[0041] In the design of the shaped wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable of the present invention, the distribution positions of the power core and the optical fiber and the heat dissipation channels of the optical fiber are improved. The heat generated by the power core can be transferred to the outside of the cable by avoiding the position where the optical fiber is located through the first heat conduction channels of the inner sheath, the shielding layer and the outer sheath, or can be transferred along the axis of the cable through the heat dissipation channels inside the conductor as the second heat conduction channels. In this way, the temperature of the environment where the optical fiber unit is located can be effectively reduced, the influence of temperature on the optical performance of the optical fiber can be reduced, the stable transmission of the optical signal can be ensured, and at the same time, the aging speed of the optical fiber material can be slowed down, thereby prolonging the service life of the optical fiber, reducing the maintenance cost and the replacement frequency. Brief Description of the Drawings

[0042] The drawings are not intended to be drawn to scale. In the drawings, each identical or approximately identical component shown in each figure may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the drawings.

[0043] Figure 1 is a schematic structural diagram of the shaped wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable shown in the present invention.

[0044] Figure 2 is a schematic cross-sectional structural diagram of the shaped wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable shown in the present invention.

[0045] Figure 3 is a schematic structural diagram of the power core shown in the present invention.

[0046] Figure 4 is a schematic diagram of heat transfer in the cross-sectional direction of the cable shown in the present invention.

[0047] Figure 5 is a schematic diagram of the distribution of the grooves on the surface of the second region shown in the present invention. Detailed Embodiments

[0048] In order to better understand the technical content of the present invention, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows.

[0049]

Profile-stranded Aluminum Alloy Conductor Optical Fiber Composite Low-voltage Power Cable

[0050] Combined with Figure 1 and Figure 2 As shown, the profile-stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to the first aspect embodiment of the present invention includes a cable core, an inner sheath layer 4, an optical fiber unit 5, a shielding layer, and an outer sheath layer 9.

[0051] In the embodiment of the present invention, the optical fiber unit 5 and the power unit are separated by the inner sheath layer 4. The power unit is inside the cable core, and the optical fiber unit 5 is outside the cable core, so that the distance between the power unit and the optical fiber unit 5 is farther, to avoid the influence of the heat generated by the power unit on the optical fiber unit 5.

[0052] Combined with Figure 1 and Figure 2 As shown, N power line cores 2 that are pairwise tangent and mutually stranded. A heat dissipation channel is formed inside the N power line cores 2, and a heat-conducting medium is filled in the heat dissipation channel to form a heat-conducting layer 1 with a predetermined shape. Wherein N is a positive integer greater than or equal to 4. In the example of the present invention, 4 power line cores are taken as an example for illustration.

[0053] In an optional embodiment, combined with Figure 3 as shown, the power line core 2 includes a circular stranded conductor 21, a sector stranded conductor 22, and an insulating layer 25. A semiconductive water-blocking tape 24 is provided between the circular stranded conductor 21 and the sector stranded conductor 22, and between the sector stranded conductor 22 and the insulating layer 25. A double-sided water-blocking tape 23 is filled between each sector strand block in the sector stranded conductor 22.

[0054] Specifically, the circular stranded conductor 21 is formed by stranding 8000-series circular aluminum alloy conductors, and the sector stranded conductor 22 is formed by stranding 8000-series sector aluminum alloy conductors. By using the sector stranded conductor 22, the filling rate of the cable is increased, and it is also beneficial to the heat dissipation of the conductor.

[0055] In an optional embodiment, the insulating layer 25 adopts a cross-linked polyethylene insulating layer.

[0056] In an optional embodiment, the heat-conducting medium can be selected as heat-conducting paste or heat-conducting silicone grease, which can play a role in water-blocking and transferring heat along the axis of the cable, can avoid local high temperature, and make the heat more evenly distributed in the axial direction of the cable.

[0057] Furthermore, the foamed filling layer 3 is filled outside two adjacent power line cores 2 and is wrapped by the wrapping layer 4 to form a cable core with a circular cross-section.

[0058] In an alternative embodiment, the wrapping layer 4 is formed by double wrapping with a polyester tape. The polyester tape wrapping structure has good tensile properties and flexibility, making the cable easy to bend and adapt to a smaller bending laying environment.

[0059] Furthermore, the inner sheath layer 4 is extruded on the outer wall of the cable core. Among them, a groove 41 is provided on the surface of the inner sheath layer 4. The optical fiber unit 5 is arranged in the groove 41.

[0060] In an alternative embodiment, the foamed filling layer 3 uses a silicone rubber foam strip, which has both elasticity and water resistance, and also has a certain compressive strength to support the cable.

[0061] In this way, the optical fiber unit 5 and the power line core 2 are separated by the inner sheath layer 4 and are in different enclosed spaces. The foamed filling layer can form a heat transfer barrier between the optical fiber unit 5 and the power line core 2.

[0062] In an alternative embodiment, as shown in combination with Figure 4 and Figure 5 , the inner sheath layer 4 is divided into several regions in the cross-sectional direction of the cable, including N first regions 401 and N second regions 402. Along the axial direction of the cable, the first region 401 or the second region 402 is set as a strip shape and is distributed in a spiral around the axis of the cable.

[0063] Furthermore, in the cross-sectional direction of the cable, the position of the first region 401 corresponds to the power line core 2, and the position of the second region 402 corresponds to the gap between two adjacent power line cores 2. The thermal conductivity of the inner sheath layer 4 in the first region 401 is greater than that in the second region 402. The groove 41 is provided in the second region 402 of the inner sheath layer 4.

[0064] In this way, the inner sheath layer 4 is designed such that the thermal conductivity of a part is better than that of another part, that is, the thermal conductivity of the first region 401 corresponding to the distribution of the power line core 2 is higher than that of the second region corresponding to the gap of the power line core 2. Therefore, the heat generated by the power line core 2 can be conducted to the outside through the first region 401, and the temperature of the position of the second region 402 where the optical fiber unit 5 is arranged is relatively low. Therefore, the influence of the heat of the power line core 2 on the optical fiber unit 5 can be reduced.

[0065] In the above embodiment, a thermal conductive filler is provided in the first region 401 of the inner sheath layer 4, and the first region 401 and the second region 402 of the inner sheath layer 4 are extruded by co-extrusion.

[0066] Thus, by setting heat-conducting fillers in the local area, the first region 401 and the second region 402 of the inner sheath layer 4 have different heat-conducting characteristics.

[0067] In a preferred embodiment, the content of the heat-conducting fillers in the first region 401 is set to be higher in the central part of the first region 401 than in the two side parts of the first region 401.

[0068] Thus, by controlling the distribution gradient of the heat-conducting fillers in the material, the filler concentration in the middle region is high, that is, the thermal conductivity is high, and it gradually decreases towards both sides, that is, the thermal conductivity decreases, forming a smoothly transitional interface layer, reducing the thermal stress difference and mechanical stress concentration between materials, and at the same time also inhibiting the heat transfer from the first region 401 to the second region 402.

[0069] As described above, by optimizing the thermal matching of the material bonding interface, the interface delamination or cracks caused by the sudden change of the thermal conductivity are avoided, and at the same time, the elasticity and durability of the overall structure are improved.

[0070] In an alternative embodiment, the inner sheath layer 4 can be selected as a ceramicized silicone rubber or a nitrile rubber inner sheath. High heat-conducting fillers such as aluminum nitride and silicon carbide can be added to the ceramicized silicone rubber, which can improve the heat-conducting performance without affecting the elasticity and ceramicization characteristics. The nitrile rubber can use thermally conductive carbon black or graphite as the heat-conducting filler.

[0071] Specifically, in combination with Figure 4 As shown, taking four power line cores 2 as an example, the four power line cores 2 are twisted together, and a cross-shaped heat dissipation channel is formed in the connection direction of the four power line cores 2 in the cross-sectional direction. The first region 401 is arranged in the extension direction of the connection line between the power line core 2 and the cable axis, that is, the heat is transferred from the power line core 2 - the first region 401 - the shielding layer - the outer sheath layer 9 to the outside of the cable.

[0072] In an alternative embodiment, along the cross-sectional direction of the cable, the arc length corresponding to the first region 401 is L1, and the arc length corresponding to the second region 402 is L2, where L1 / L2 = 4 / 6 - 5 / 5.

[0073] Thus, by controlling the lengths of the first region 401 and the second region 402, the heat can be controlled to be transferred mainly through the first region 401, and the region where the optical fiber unit 5 is located has a lower temperature compared to the first region 401.

[0074] In combination with Figure 4 As shown, three grooves 41 are provided in the second region 402, and the optical fiber unit 5 is preferably arranged in the middle groove 41. Thus, the grooves on both sides can act as heat transfer barriers and stress transfer barriers, providing a better use environment for the optical fiber unit 5.

[0075] Further, at least one groove 41 is provided in each second region 402, and the length of the groove 41 is greater than the length of the second region 402. In this way, when the cable is bent or stretched, the optical fiber unit 5 can reduce the tensile stress and bending stress due to its longer length, avoiding mechanical damage.

[0076] Combined with Figure 5 As shown, the groove 41 is arranged in the second region 402 along a trajectory that periodically approaches the first and second side edges of the second region 402. In this way, the optical fiber unit 5 can be distributed in a wavy shape in the second region 402. When the cable is twisted, bent, and under pressure, the optical fiber unit 5 can avoid being damaged by excessive bending or tensile stress. At the same time, through the thermal insulation structure, the optical fiber unit 5 can maintain a high-performance signal transmission function for a long time and delay the aging and performance degradation of the optical fiber.

[0077] Among them, the width of the second region 402 is defined as W, and the maximum span of the groove 41 in the width direction of the second region 402 does not exceed 0.6W.

[0078] In this way, by increasing the distance between the optical fiber unit 5 and the first region 401, the optical fiber unit 5 is further prevented from being affected by the heat in the first region 401.

[0079] Further, the shielding layer is coated on the outer wall of the inner sheath layer 4.

[0080] In an optional embodiment, the shielding layer includes a longitudinally wrapped metal tape shielding layer 6, a braided shielding layer 7, and a non-woven wrapping layer 8 distributed from the inside out. The longitudinally wrapped metal tape shielding layer 6 includes a longitudinally wrapped copper-plastic composite tape, and the braided shielding layer 7 includes a fine copper wire braided shielding layer with a braiding density greater than 85%.

[0081] In this way, through the cooperation of the longitudinally wrapped metal tape and the fine copper wire braided shielding layer, a continuous shielding layer can be provided, effectively blocking external electromagnetic interference. The braided structure further enhances the shielding effect, effectively suppressing electromagnetic interference inside and outside the cable, ensuring the transmission quality of the signal. At the same time, the non-woven wrapping layer is arranged on the outer layer of the braided shielding, which can improve the tensile performance of the cable and the water blocking ability of the shielding layer, and also prevent the braided fine copper wire from directly contacting the sheath.

[0082] Further, the outer sheath layer 9 is extruded on the outer wall of the shielding layer.

[0083] In an optional embodiment, the outer sheath layer 9 uses a thermoplastic polyurethane elastomer sheath. The TPU sheath can maintain good stability under the influence of environmental factors such as ultraviolet rays, oxidation, and high temperature, and is not prone to aging phenomena, so it has a long service life.

[0084]

Preparation Method of Shaped Wire Stranded Aluminum Alloy Conductor Optical Fiber Composite Low-Voltage Power Cable

[0085] In a second aspect of the present invention, a technical solution is proposed. A method for manufacturing a shaped-strand aluminum alloy conductor optical fiber composite low-voltage power cable as described above includes the following steps:

[0086] Step 1: Prepare the power line core 2:

[0087] Step 11: Use round aluminum alloy wires to form a round stranded conductor 21 by left-handed stranding in the pattern of 1 + 6;

[0088] Step 12: Wrap a semiconductive water-resistant tape around the surface of the round stranded conductor 21 to form an inner conductor;

[0089] Step 13: Use sector-shaped aluminum alloy wires and a double-sided water-resistant tape to strand outside the inner conductor to form an outer conductor;

[0090] Step 14: Wrap a semiconductive water-resistant tape around the outside of the outer conductor;

[0091] Step 15: Extrude an insulating layer 25 on the outside of the semiconductive water-resistant tape to form the power line core 2;

[0092] Step 2: Cable stranding:

[0093] Step 21: Arrange a plurality of foam strips outside the power line core 2 and strand them together with multiple power line cores 2. At the same time, fill a heat-conducting medium in the heat dissipation channels formed inside after the multiple power line cores 2 are stranded;

[0094] Step 22: Use a wrapping tape to wrap the stranded foam strips and the power line core 2 together to form a cable;

[0095] Step 3: Extrude the inner sheath layer 4:

[0096] Step 31: Use a dual-channel co-extrusion die to extrude the first region 401 and the second region 402 of the inner sheath layer 4 at the die head. While extruding, control the rotation of the die head so that the extruded first region 401 corresponds to the position of the power line core 2. At the same time, through the periodic swing of the plug on the die head, form a groove 41 on the surface of the second region 402;

[0097] Step 32: Cool the extruded inner sheath layer 4;

[0098] Step 4: Press the optical fiber unit 5 into the groove 41;

[0099] Step 5: Longitudinally wrap a longitudinally wrapped metal tape shield layer 6 on the outside of the inner sheath layer 4, then braid fine copper wires outside the longitudinally wrapped metal tape shield layer 6 to form a braided shield layer 7, and wrap a double-layer non-woven fabric tape around the outer wall of the braided shield layer 7 to form a non-woven fabric wrapping layer 8;

[0100] Step 6: Extrude a thermoplastic polyurethane elastic sheath on the outer wall of the non-woven wrapping layer 8 to form an outer sheath layer 9.

[0101] In the above embodiment, for the co-extrusion process of the inner sheath layer 4, the die head of the double-channel co-extrusion die used has eight extrusion cavities, which respectively correspond to four first regions 401 and four second regions 402. The extrusion cavities corresponding to the four first regions 401 are connected to the first flow channel of the extruder, and the extrusion cavities corresponding to the four second regions 402 are connected to the second flow channel of the extruder.

[0102] Taking ceramicized silicone rubber as an example, the ceramicized silicone rubber matrix is heated to a molten state by a screw extruder. No heat-conducting filler is added to the second flow channel. An intermediate filling flow channel and two side filling flow channels are arranged in the first flow channel. A high-concentration heat-conducting filler is injected into the intermediate filling flow channel, and a low-concentration heat-conducting filler is injected into the side filling flow channels. A gradient distribution is formed by flowing in the first flow channel, and finally an inner sheath structure spliced by the first region 401 and the second region 402 is extruded at the die head.

[0103] Among them, a periodically swinging plug is arranged on the die head, so that grooves 41 with a wavy distribution are formed on the surface of the second region 402.

[0104] Further, the rotation speed of the entire die head matches the stranding pitch of the core. The calculation formula is: N = V 绞合 / P 节距 .

[0105] Among them, N is the die rotation speed (r / min), V 绞合 is the stranding traction speed (m / min), and P 节距 is the stranding pitch (m / r).

[0106] Specifically, a servo motor is used to drive the die to rotate. The traction speed and pitch of the core stranding equipment are monitored in real time through an encoder and fed back to the die rotation control system to achieve dynamic matching.

[0107] Combined with the above embodiments, in the present application, the distribution positions of the core and the optical fiber and the heat dissipation channels of the optical fiber are improved. The heat generated by the power core can be transferred to the outside of the cable by avoiding the position where the optical fiber is located through the first heat conduction channels of the inner sheath, the shielding layer, and the outer sheath, or can be transferred along the axis of the cable through the heat dissipation channels inside the conductor as the second heat conduction channels. In this way, the temperature of the environment where the optical fiber unit is located can be effectively reduced, the influence of temperature on the optical performance of the optical fiber can be reduced, the stable transmission of the optical signal can be ensured, and at the same time, the aging speed of the optical fiber material can be slowed down, thereby extending the service life of the optical fiber and reducing the maintenance cost and replacement frequency.

[0108] In addition, through the synergistic effect of the first channel and the second channel, the heat generated by the power line core can be more effectively dissipated, reducing the temperature inside the cable. The lower temperature can reduce the heat loss of the cable, improve the efficiency of power transmission, and reduce energy consumption. At the same time, it also reduces the risks such as the decline of insulation performance, ensuring the reliability of the cable during long-term operation.

[0109] Although the present invention has been disclosed above in its preferred embodiments, it is not intended to limit the present invention. Those of ordinary skill in the technical field to which the present invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to that defined by the claims.

Claims

1. A profiled-strand stranded aluminum alloy conductor optical fiber composite low-voltage power cable, characterized in that, Including: N pairwise tangent and intertwined power line cores (2), a heat dissipation channel is formed inside the N power line cores (2); N is a positive integer greater than or equal to 4; A heat-conducting layer (1) filled in the heat dissipation channel and forming a predetermined shape; A foam filling layer (3), filled on the outer sides of two adjacent power line cores (2), and the cable core with a circular cross-section is fixed by a wrapping layer (4); An inner sheath layer (4), extruded on the outer wall of the cable core, and grooves (41) are provided on the surface of the inner sheath layer (4); An optical fiber unit (5), arranged in the grooves (41); A shielding layer, covering the outer wall of the inner sheath layer (4); An outer sheath layer (9), extruded on the outer wall of the shielding layer; Wherein, the inner sheath layer (4) is divided into several regions along the cross-section direction of the cable, including N first regions (401) and N second regions (402). Along the axial direction of the cable, the first region (401) or the second region (402) is arranged in a strip shape and spirally distributed around the axis of the cable; In the cross-section direction of the cable, the first region (401) corresponds to the position of the power line core (2), the second region (402) corresponds to the gap between two adjacent power line cores (2), the heat conductivity of the inner sheath layer (4) in the first region (401) is greater than that in the second region (402), and the grooves (41) are provided in the second region (402) of the inner sheath layer (4).

2. The shaped wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to claim 1, characterized in that, In the cross-section direction of the cable, the arc length corresponding to the first region (401) is L1, and the arc length corresponding to the second region (402) is L2, wherein, L1 / L2 = 4 / 6 - 5 / 5.

3. The shaped wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to claim 1, wherein Thermal conductive fillers are provided in the first region (401) of the inner sheath layer (4), and the first region (401) and the second region (402) of the inner sheath layer (4) are extruded by co-extrusion.

4. The profiled-strand stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to claim 3, characterized in that, The thermal conductive fillers in the first region (401) are arranged such that the content near the central part of the first region (401) is higher than the content on both sides of the first region (401).

5. The shaped-strand stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to claim 1, characterized in that, At least one groove (41) is provided in each second region (402), and the length of the groove (41) is greater than the length of the second region (402).

6. The profiled-strand stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to claim 5, characterized in that, The groove (41) is arranged in the second region (402) along a trajectory that periodically approaches the first side and the second side edges of the second region (402).

7. The shaped-strand stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to claim 6, wherein Defining the width of the second region (402) as W, the maximum span of the groove (41) in the width direction of the second region (402) does not exceed 0.6W.

8. The shaped-strand stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to claim 1, wherein The power line core (2) includes a circular stranded conductor (21), a sector stranded conductor (22), and an insulating layer (25). A semiconductive water-blocking tape (24) is provided between the circular stranded conductor (21) and the sector stranded conductor (22), and between the sector stranded conductor (22) and the insulating layer (25). A double-sided water-blocking tape (23) is filled between each sector strand block in the sector stranded conductor (22).

9. The profile-stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to claim 1, characterized in that, The shielding layer includes a longitudinally wrapped metal tape shielding layer (6), a braided shielding layer (7), and a non-woven fabric wrapping layer (8) distributed from the inside out. The longitudinally wrapped metal tape shielding layer (6) includes a longitudinally wrapped copper-plastic composite tape, and the braided shielding layer (7) includes a fine copper wire braided shielding layer with a braiding density greater than 85%.

10. The preparation method of the profiled wire stranded aluminum alloy conductor optical fiber composite low-voltage power cable according to any one of claims 1-9, characterized in that, It includes the following steps: Step 1, prepare the power line core (2): Step 11, use round aluminum alloy wires to form a round stranded conductor (21) by left-handed stranding of 1+6; Step 12, wrap a semi-conductive water-blocking tape on the surface of the round stranded conductor (21) to form an inner conductor; Step 13, use sector-shaped aluminum alloy wires and a double-sided water-blocking tape to strand outside the inner conductor to form an outer conductor; Step 14, wrap a semi-conductive water-blocking tape outside the outer conductor; Step 15, extrude an insulating layer (25) on the outer layer of the semi-conductive water-blocking tape to form the power line core (2); Step 2, cable stranding: Step 21, arrange a plurality of foamed strips outside the power line core (2) and strand them with multiple power line cores (2). At the same time, fill a heat-conducting medium in the heat dissipation channel formed inside after the multiple power line cores (2) are stranded; Step 22, use a wrapping tape to wrap the stranded foamed strips and the power line core (2) together to form a cable; Step 3, extrude the inner sheath layer (4): Step 31, use a double-channel co-extrusion die to extrude the first area (401) and the second area (402) of the inner sheath layer (4) at the die head. While extruding, control the rotation of the die head so that the extruded first area (401) corresponds to the position of the power line core (2). At the same time, through the periodic swing of the plug on the die head, form a groove (41) on the surface of the second area (402); Step 32, cool the extruded inner sheath layer (4); Step 4, press the optical fiber unit (5) into the groove (41); Step 5, longitudinally wrap a longitudinally wrapped metal tape shielding layer (6) on the outer layer of the inner sheath layer (4), then braid fine copper wires outside the longitudinally wrapped metal tape shielding layer (6) to form a braided shielding layer (7), and wrap a double-layer non-woven fabric tape on the outer wall of the braided shielding layer (7) to form a non-woven fabric wrapping layer (8); Step 6, extrude a thermoplastic polyurethane elastic sheath on the outer wall of the non-woven fabric wrapping layer (8) to form an outer sheath layer (9).

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