干扰气溶胶及火灾烟颗粒光散射特性数值模拟研究  

Numerical simulation study on light scattering characteristics of interfering aerosol and fire smoke particles

作　　者：全珈兴 杨泽伟 周勇[1] QUAN Jiaxing;YANG Zewei;ZHOU Yong(State Key Laboratory of Fire Science,University of Science and Technology of China,Hefei Anhui 230026,China)

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,安徽合肥230026

出　　处：《中国安全生产科学技术》2023年第7期11-16,共6页Journal of Safety Science and Technology

基　　金：民航热灾害防控与应急重点实验室开放基金项目(RZH2021-KF-06)。

摘　　要：为解决传统光电感烟探测器易受到干扰气溶胶(水蒸气、粉尘等)影响而导致误报率较高的问题,提出1种火灾烟颗粒和干扰气溶胶区分识别方法。根据不同粒径大小、复折射率及形貌特征,建立明火烟颗粒(分形凝聚体)、阴燃/热解烟颗粒(球形)、水滴(球形)、粉尘(椭球)的散射模型,基于离散偶极子近似方法及Mie散射理论,研究其在405 nm波长和870 nm波长下的光散射特性。研究结果表明:火灾烟颗粒与干扰气溶胶在2种波长下的散射光强具有较大区别,尤其在前向散射角度时S 11比值的区别更为明显。研究结果可对传统光电感烟探测器光路结构设计优化改进,降低误报率。To solve the problem that traditional photoelectric smoke detectors are easily affected by nuisance aerosol(water vapor,dust,etc.)and thus have a high false alarm rate,a method to distinguish the fire smoke particles and nuisance aerosol for identification was proposed.The scattering models of fire smoke particles(fractal aggregate),smoldering/pyrolysis smoke particles(sphere),water droplets(sphere),and dust particles(ellipsoid)were established according to their different particle sizes,complex refractive indices,and morphological features,and the light scattering characteristics of these particles under 405 nm and 870 nm wavelengths were studied based on the discrete dipole approximation(DDA)method and Mie scattering theory.The results show that the scattered light intensities of fire smoke particles and nuisance aerosol under two wavelengths have a large difference,especially in the forward scattering angle,the difference of S11 ratio is more obvious.The results can be used to optimize and improve the optical path structure design of traditional photoelectric smoke detector and reduce the false alarm rate.

关 键 词：光散射 离散偶极子近似方法 MIE散射理论 双波长 误报 

分 类 号：X932[环境科学与工程—安全科学]