Optical fiber remote-detection type multifunctional gas leakage listening instrument and method

Abstract

The invention discloses an optical fiber remote-detection type multifunctional gas leakage listening instrument and method and belongs to the technical field of optical fiber sensing and gas detection. The instrument comprises a laser light source, an optical cable, an optical fiber leakage listening probe, a broadband light source, an optical fiber coupler, a serrated signal generator, an adder,a sinusoidal signal generator, a phase-locked loop, a spectrometer and an industrial control computer. The optical fiber leakage listening probe is of a double-cantilever-beam structure, is used for directly detecting acoustic wave signals generated by leakage of gas, can reduce the influence of environmental noise and vibration on measurement of photoacoustic signals with combination of an activenoise reduction technology, and meanwhile achieves high-sensitivity and high-reliability measurement of the concentration of the gas, namely, the optical fiber leakage listening probe has an opticalear function and an optical nose function. By designing two optical fiber extrinsic Fabry-Perot interferometers with the different cavity lengths, simultaneous non-interference demodulation can be conducted on two cantilever beam acoustic sensors through one spectrometer, so that the system structure is simplified. The optical fiber remote-detection type multifunctional gas leakage listening instrument provided by the invention has the advantages of remote detection and intrinsic safety.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing and gas detection, and relates to an optical fiber telemetry multifunctional gas leakage instrument and method. Background technique [0002] Gas leakage monitoring plays an important role in ensuring the safe and reliable operation of gas stations, gas pipelines and chemical plants, because the leakage of flammable, explosive or toxic gases may lead to major safety accidents. [0003] Currently, gas leak detection can be done by looking, hearing and smelling. Leaks can be “seen” with thermal imaging cameras, but this passive imaging method is susceptible to changes in ambient temperature. The "listening" method can also be used, such as the literature WangX, Zhen S, Li X, et al. Non-contact gas leakage detection of tank based on low-coherence optical fiber interferometer[C] / / International Conference on Optical and Photonics Engineering( icOPEN 2016). International Society for Opti...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to propose an optical fiber telemetry multifunctional gas leakage instrument and method, aiming at solving the problem of poor resistance to environmental noise and vibration interference in the all-optical gas leakage detector based on laser photoacoustic spectroscopy, and Realize the simultaneous measurement of gas leakage sound and leakage gas concentration, that is, it has two functions of "light ear" and "light nose", which expands the application of optical fiber sensing technology and laser photoacoustic spectroscopy technology in the field of gas leakage monitoring Space

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