基于光纤光声传感的油中溶解气体分析系统

Analysis system of dissolved gas in oil based on optical fiber photoacoustic sensing

针对目前变压器油中溶解气体分析装置体积庞大、抗电磁干扰能力弱、油路复杂等问题,将光纤传感和光声光谱技术结合,设计了一种基于光纤光声传感的变压器油中溶解气体分析系统,用于检测油中溶解的微量乙炔气体。通过谱线分析优化激光波长,并设计了恒温激光驱动模块。采用两根单模光纤分别将泵浦激光和探测光传输到光声探头中,气体吸收光能产生的光声信号由法布里-珀罗干涉型悬臂梁探测,并利用设计的光谱测量和信号处理模块进行解调。实验结果表明,设计的光纤光声传感系统可有效探测出变压器油中溶解的乙炔气体的光声信号,检出限达到0.5μL/L。

In view of the problems existed in the traditional analysis devices of dissolved gas in transformer oil,such as large size,complicated oil circuit and susceptibility to electromagnetic interference,an analysis system based on optical fiber photoacoustic sensing is designed to detect trace acetylene gas dissolved in transformer oil.In the system,the laser wavelength is optimized through spectral line analysis,and a thermostatically controlled laser driving module is designed.The pump laser and probe light are transmitted into the photoacoustic sensor probe by two single-mode fibers.The photoacoustic signal generated by gas molecules absorbing the pump laser energy is detected by a Fabry-Perot interference cantilever,and then demodulated by a self-designed spectral measurement and signal processing module.Experimental results show that the designed optical fiber photoacoustic sensor system can effectively detect photoacoustic signal of acetylene gas dissolved in transformer oil,with a detection limit of 0.5μL/L.