基于气体浓度和烟颗粒消光系数的复合火灾预警系统

Compound fire alarm system based on gas concentration and extinction coefficient of smoke particles

为解决火灾烟雾颗粒的消光效应对光声火灾检测带来的影响,以近红外激光为光源,结合波长调制技术和谐波检测技术对光声信号和颗粒消光系数进行了测量,并建立了火灾复合探测模型。利用棉绳阴燃、木材热解2组阴燃火实验以及正庚烷明火、木材明火2组明火实验进行了火灾模拟探测,并结合特定算法对结果进行了判定。结果表明系统能较好地对实验产生的CO浓度和烟颗粒消光系数进行探测,且运行稳定,能够满足火灾预警需求。

In order to solve the influence by the extinction effect of fire smoke particles on photoacoustic fire detection,the photoacoustic signals and extinction coefficient of the smoke particles were measured by using the near-infrared laser as the light source,combined with the wavelength modulation technology and the harmonic detection technology,and a compound fire detection model was established. The simulated fire detection was carried out by means of two smoldering fire tests,i. e.cotton rope smoldering fire and wood pyrolysis,as well as 2 open fire tests,i. e. n-heptane fire and wood fire,and the results were determined with the specific algorithm. It showed that the system can successfully detect the concentration of carbon monoxide and the extinction coefficient of smoke particles generated in the four tests mentioned above,and runs stably,which can meet the requirements of fire alarm.