Novel composite sensing optical cable

Abstract

The invention discloses a novel composite sensing optical cable comprising a carbon fiber filament, temperature-sensitive fibers, power supply wires, a sheath, and an insulating wrapping layer. The carbon fiber filament, the temperature-sensitive fibers, the power supply wires, and the sheath are wrapped in the insulating wrapping layer. The carbon fiber filament is wrapped in the sheath. More than one temperature-sensitive fiber and a pair of the power supply wires are provided. The carbon fiber filament and the surrounding power supply wires are in crossed connection so as to form a parallel circuit. Power is supplied simultaneously such that the optical cable is uniformly heated at long distance by means of a fact that the carbon fiber filament generates heat after being supplied with power. The temperature-sensitive fibers are wrapped in the carbon fiber filament or arranged in parallel with the carbon fiber filament. The carbon fiber filament is heated after being supplied with power so as to uniformly heat the optical cable. Temperature measurement at various points along the cable is achieved by means of distributed fiber temperature measurement technology. The optical cable can be uniformly heated for long distance (more than 2km) and long-distance leakage can be detected.

Description

technical field [0001] The invention relates to a new type of sensing medium, in particular to a new type of sensing optical cable which can be used for monitoring dam leakage, oil and gas leakage, water pipe leakage, underground water flow and water content of rock and soil. technical background [0002] Distributed optical fiber temperature measurement technology (DTS) uses optical cable as the detection device, which has the advantages of distributed measurement, long test distance, simple construction and high long-term stability. It has been widely used in fire fighting, cable temperature measurement, concrete temperature measurement and In fields such as leakage monitoring, in order to obtain better monitoring results, various functional optical cables with specific sensing characteristics are constantly inventing and creating. [0003] The use of distributed temperature measurement technology for leakage monitoring has been applied in some engineering projects, but th...

AI Technical Summary

Problems solved by technology

The existing technology used in this type of product is to lay metal electric heating wires in parallel with optical fibers, and then energize and heat the electric heating wires to achieve the purpose of heating the optical fibers in the optical cable. However, there are many problems in practice: (1) Heating uneven

The electric heating wire is in point contact with the optical fiber, the temperature at the contact point is very high, and even the optical fiber burns and the sheath breaks, and the temperature of the optical fiber at the non-contact point is low, the temperature distribution is uneven, and the detection effect is not good; smaller

To achieve a uniform heating effect, the resistance wire needs to be made very thin, and the thin resistance wire is easily broken during construction and cannot be heated; (3) The heating distance of the optical cable is short

Due to the use of mains heating, the voltage is limited, and the heating distance is often only a few hundred meters, which cannot meet the actual monitoring needs of large-scale projects

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