Tunable semiconductor laser spectrum boiler internal gas detection system

CO and $\mathrm{H}_{2} \mathrm{~S}$ are an important part of the atmosphere in coal-fired boiler furnace. Their concentration can not only reflect the combustion condition, but also be used as the basis for judging the degree of high temperature corrosion of water wall. Therefore, it is of great significance to realize the accurate measurement of CO and $\mathrm{H}_{2} \mathrm{~S}$ concentration. This paper presents a high sensitivity real-time detection system of internal gas based on tunable semiconductor laser absorption spectroscopy technology, using optical communication band fiber coupling near infrared distribution feedback (DFB) semiconductor laser as the light source, using the modulation frequency technology to realize the internal signature gas CO, $\mathrm{H}_{2} \mathrm{~S}$, the minimum detection limit of CO is about 1 ppm, which can meet the needs of internal gas detection in the furnace.