Research On Double Wavelength Optical Fiber Methane Sensing System

In the background of scale in coal industry in China, coal mine safety production deeply relates to the stability and sustainable development of the national economy. Coal mine safety issues embodied in the methane gas accident, it has become an important restricted factor of safety production in coal mine. The frequently happen of the coal mine safety accident, especially the important methane explosion accident, is great threat to the life and safety of underground miners, at the same time also cause significant economic losses. The availability supervision to the coal mine safety production can largely prevent methane gas accidents.This paper analyzes the coal mine methane gas monitoring technique home, abroad and system of traditional, then build an optical fiber methane sensing system based on double wavelength technique, it monitor the methane gas in coal mine by using the method of combining the double wavelength technique and laser absorption spectrum technique, at the same time it greatly improve the detection sensitivity, safety and anti-interference intensity by using the features of optical fiber.This paper firstly study and analyze the method of double wavelength choice, and compare the several methods of double wavelength choice. Finally K coefficient is chose. And then introduce the measurement theory of double wavelength optical gas sensing system. Adopting double wavelength measurement technique based on laser absorption spectrum measurement theory to eliminate interference caused by light source and gas chamber, and greatly improve sensitivity of system. Finally through experiments on the system performance test, comparative test and stability test to verify the feasibility of the system.The result of experiment shows that double wavelength optical fiber methane sensing system can realize the online, real time, fast monitor on coal mine methane concentration. The data from experiment can record the methane concentration, detection signal intensity and related coefficient at real time. All the data can be callout and save forever. Moreover, when the detection value is higher than alarm limit, system will alarm. The research of optical fiber methane sensing system based on double wavelength has very important meaning, its popularization in coal mine methane gas monitoring has broad application prospects.Figure [56] table [5] reference [60]...