柞木燃烧蔓延规律及释烟特性研究  

A Study on Spreading Laws and Smoke Emission Characteristics of Xylosma racemosum Combustion

作　　者：魏建珩 高仲亮 马泽南 王京鲁 王何晨阳 李智 龙腾腾 王秋华 舒立福[2] WEI Jianheng;GAO Zhongliang;MA Zenan;WANG Jinglu;WANG Hechenyang;LI Zhi;LONG Tengteng;WANG Qiuhua;SHU Lifu(Civil Engineering College,Southwest Forestry University,Kunming 650224,China;Institute of Forest Ecological Environment and Protection,CAF,Beijing 100091,China)

机构地区：[1]西南林业大学土木工程学院,云南昆明650224 [2]中国林科院森林生态环境与保护研究所,北京100091

出　　处：《江西农业大学学报》2021年第6期1371-1380,共10页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家自然科学基金项目(31860214,301660210,31960318);云南省教育厅科学研究基金项目(2021Y227);国家重点研发计划项目(2017YFD0600106);西南林业大学科研启动基金项目(111437)。

摘　　要：【目的】灌木林内植被生长连续、多藤蔓附生,在垂直、水平方向分布紧密,可燃物负荷量大,燃烧蔓延速率快、火强度高。柞木是云南省典型灌木林植物代表,开展燃烧蔓延及释烟特征研究可为灌木林火防治提供科学依据,减少灌木林火发生频率,保护森林资源。【方法】以云南省局部山地地形、柞木植被数据为基础,利用Fire Dynamics Simulator(FDS)建立微观山体柞木林模型,设置5种坡度(0°、15°、25°、35°、45°)、2个火源位置(火源1、2分别位于坡度15°、0°),分别模拟4种风速(0 m/s、1.5 m/s、2.5 m/s、3.5 m/s)条件下柞木林火燃烧,研究柞木林火燃烧蔓延规律、温度变化趋势、CO浓度、CO_(2)浓度、烟气流速、烟气热辐射。【结果】微观柞木林模型燃烧约100 s趋于稳定,风速≤2.5 m/s的初始燃烧阶段,坡度15°与25°、35°与45°区域燃烧温度几乎同时达到反应温度300℃,柞木林火在以上连续坡度范围内蔓延速度更快;火源1为起火点时,25 s内,3.5 m/s风速时坡度15°区域为主要蔓延位置;平地内燃烧温度可达2000℃、烟气热辐射量为1500~1700 kW/m^(2)、烟气流速约15 m/s,均高于其它坡度;下山火受逆风影响蔓延较为困难,风速3.5 m/s时下山火发生概率较小;在柞木林火模拟过程中,烟气流速与坡度呈负相关,坡度增加风速降低,烟气流速越小;烟气热辐射的初始上升速率较为缓慢,150 s左右数值变化趋于稳定。【结论】FDS软件模拟微观柞木林模型燃烧与实际火灾发生蔓延状况大致相同,可作为森林火灾燃烧蔓延规律及烟气释放特征研究的有力工具。模拟结果可为柞木林火预防、扑救提供科学指导,有效提高森林防火的工作效率。[Objective]The vegetation in the shrubby grows continuously and is epiphytic with many vines,the combustibles in shrubbery are closely distributed in space,with a large load,fast burning spread rate,and high fire intensity.Xylosma racemosum is a typical shrub in Yunnan Province.The study of its spreading laws and smoke emission characteristics can provide a scientific basis for prevention and control of shrub forest fire and reduce the frequency of shrub forest fire and preserve forest resources.[Method]The micro-mountain model of Xylosma racemosum was established by FDS software,the data were based on the local mountain topog⁃raphy and Xylosma racemosum vegetation in Yunnan Province.Two fire origins(Fire origins 1,fire origins 2 were located at slope 15°and slope 0°),four wind speeds(0,1.5,2.5,3.5 m/s),and five slopes(0°,15°,25°,35°,45°)were set in this model to study the law of fire spread,temperature change,CO concentration value,CO_(2) concentration value,velocity of flue gas,and radiative heat flux gas of Xylosma racemosum.[Result]The micro Xylosma racemosum model combustion was stable within 100 s.At the initial stage of combustion,when the wind speed was≤2.5 m/s,the temperature reached 300°C in the slope area of 15°and 25°,35°and 45°at the same time,and the spread rate of Xylosma racemosum fire in the above continuous slope range was faster.When the wind speed was 3.5 m/s within 25 s,the Xylosma racemosum fire spread was mainly at the slope of 15°under the fire origin 1.In the flat land,the combustion temperature could reach 2000℃and the radiative heat flux gas was 1500-1700 kW/m^(2),and the smoke velocity was about 15 m/s,which were higher than those at other slopes.It was difficult for downslope fire to spread under the influence of headwinds,and downwind fires rarely occurred when the wind speed was 3.5 m/s.The smoke velocity was negatively correlated with the slope in the simulation process of Xylosma racemosum fire,and it was found that the greater the slope was,the smaller the wind

关 键 词：柞木林火 数值模拟 FDS 蔓延规律 释烟特性 

分 类 号：S762.1[农业科学—森林保护学]