Method for manufacturing longitudinal and radial water-blocking medium-voltage power cable and cable

Abstract

The invention provides a method for manufacturing a longitudinal and radial water-blocking medium-voltage power cable. The method comprises the steps of (1) manufacturing wire cores, and (2) manufacturing a cable core, and (3) manufacturing a protective layer. The step (1) comprises the steps of preparing conductors, and sequentially coating the conductors with first layer water-blocking expandedstrips, semi-conductive conductor shielding layers, water-resistant tree-type cross-linked polyethylene insulating layers and semi-conductive insulating shielding layers, the step (2) comprises the steps of sequentially coating cables prepared in step (1) with second layer water-blocking expanded strips and metal shielding layers, and the step (3) comprises the steps of coating a cable prepared instep (2) with a first wrapping tape layer, a radial waterproof layer and a first sheath layer. The first layer water-blocking expanded strips are formed by wrapping semi-conductive water-blocking belt, the semi-conductive conductor shielding layers, the water-resistant tree-type cross-linked polyethylene insulating layers and the semi-conductive insulating shielding layer are formed by extrusion,the second layer water-blocking expanded strips are formed by wrapping semi-conductive water-blocking belts, the first wrapping tape layer is formed by wrapping a wrapping tape, and the radial waterproof layer is formed by vertically wrapping the first wrapping tape layer with an aluminum-plastic composite belt in the axial direction of the cable core.

Description

technical field [0001] The invention relates to the field of cable technology, and in particular relates to a manufacturing method of a multi-core longitudinal and radial water-blocking high-voltage power cable and the cable. Background technique [0002] Cables are distributed in every corner, and the installation, laying and use environments vary widely. After the cable arrives at the construction site, it is generally placed in the open air. Once the seal is not good after removing the head cap, it is inevitable that water vapor will seep into the cable; when the cable is laid, it needs to cross roads, bridges and culverts frequently, due to other reasons such as weather or geography, A lot of water often accumulates around the cable. During the production process of the cable head, if it is exposed for a long time or the construction personnel are negligent, it is inevitable that the cable head will be immersed in water; when pulling and passing through the pipe, sometim...

AI Technical Summary

Problems solved by technology

After the cable arrives at the construction site, it is generally placed in the open air. Once the seal is not good after removing the head cap, it is inevitable that water vapor will seep into the cable; when the cable is laid, it needs to cross roads, bridges and culverts frequently, due to other reasons such as weather or geography, A lot of water often accumulates around the cable. During the production process of the cable head, if it is exposed for a long time or the construction personnel are negligent, it is inevitable that the cable head will be immersed in water; when pulling and passing through the pipe, sometimes the sheath will be scratched. This phenomenon is especially prominent when mechanical traction is used; when the cable is in normal operation, if the cable has serious faults such as breakdown or breakage due to some external reason, the cable will also enter the water

If water soaks into the cable, it is easy to produce water trees, which will seriously reduce the electrical performance of the cable, and eventually lead to cable breakdown, affecting the safe and stable operation of the power grid; the direct water ingress of the cable will cause corrosion of metal layers such as steel strips and copper strips, and the insulation performance will decline , a single-phase or three-phase fault will occur, and even an explosion will hurt people.

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