固定式可燃气体和有毒气体检测器布点设计优化

Optimization of layout design for fixed combustible gas andtoxic gas detectors

简述了常用气体扩散模型,分析了气体检测器的工程设计标准、规格参数等。采用PHAST软件,以液化石油气(LPG)和H_(2)S为例计算泄漏扩散,得到可燃气体和有毒气体浓度随时间、空间的变化关系,确定了固定点式可燃气体检测器和固定式H_(2)S检测器设置的有效空间区域。在选取的介质参数、泄漏场景和气象条件下,固定点式可燃气体检测器距释放源的水平距离不应超过8.4 m;固定式H_(2)S检测器距释放源的水平距离不应超过5.4 m;如果要在距H_(2)S释放源4 m范围内检测到一级报警值(体积分数0.005‰),则泄漏气体中H_(2)S初始体积分数达到0.75‰以上时就应设置固定式H_(2)S检测器。

This article briefly describes the commonly used gas diffusion models and analyzes the engineering design standards and specification parameters of gas detectors.Using PHAST software,leakage diffusion is calculated using LPG(liquefied petroleum gas)and H_(2)S as examples,and the relationship between the concentration of combustible and toxic gases over time and space is obtained,and the effective spatial area for setting fixed point combustible gas detectors and H_(2)S detectors is determined.Under the selected medium parameters,leakage scenarios,and meteorological conditions in this article,the horizontal distance between the fixed point combustible gas detector and the release source should not exceed 8.4 m,the horizontal distance between the fixed H_(2)S detector and the release source should not exceed 5.4 m.If the first level alarm value of 0.005‰(volume fraction)is to be detected within a range of 4 meters from the H_(2)S release source,a fixed H_(2)S detector should be installed when the initial concentration of H_(2)S in the leaked gas reaches 0.75‰(volume fraction)or above.