Distributed type optical fiber Raman photon temperature sensing fire disaster detector

Abstract

The invention discloses a distributed optical fiber Raman photon temperature sensing fire detector. The detector is a fire detector produced on the basis of integrated optical fiber wavelength division multiplex technology by utilizing the principle that the strength of the optical fiber anti-Stokes Raman photon is modified by the temperature of the optical fiber and the principle of optical time domain reflection. The fire detector comprises a light pulse laser device, an integrated optical fiber wavelength division multiplexer, intrinsic temperature sensing optical fiber, two avalanche photodiodes, a digital signal processor and a display or an alarm. The intrinsic temperature sensing optical fiber laid in the fireproof site is uncharged, electromagnetic interference resistant, radiation resistant and corrosion resistant, and is both a transmission media and a sensing media. The fire detector has the advantages of low cost, long service life, simple structure, good signal-to-noise ratio and good reliability, thereby being suitable for medium range and short range temperature sensing and fire detection within 100 meters-15 kilometers.

Description

technical field [0001] The invention relates to a fire monitor, in particular to a distributed optical fiber Raman photon temperature-sensitive fire detector. Background technique [0002] For a long time, in the field of fire protection technology and engineering at home and abroad, linear temperature-sensing cables are mainly used as linear temperature-sensing fire detectors. The temperature-sensing cable is a two-core cable designed with the "on / off" principle. When the built-in two-core wire is heated and dissolved at the preset temperature, a short circuit will be formed and an alarm will be issued. Temperature-sensing cables are relatively cheap, but they cannot be located, nor can they predict the temperature change process at the disaster prevention site. [0003] Developed in recent years, the use of distributed optical fiber temperature sensors and quasi-distributed optical fiber temperature sensors (mainly fiber grating type and optical fiber Fab type) is used as...

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Problems solved by technology

[0004] The Raman scattering of optical fiber is very weak. The existing foreign mid-range distributed optical fiber Raman photon temperature sensor adopts discrete wavelength division multiplexer system and 1064nm fiber laser , The discrete wavelength division multiplexer has complex structure, large loss, low isolation, high cost, poor reliability, and the fiber loss in the 1064nm band is large

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