冷热气体介质对空气幕阻隔作用的影响  

Influence of normal and high temperatures on the obstruction efficiency of air curtains

作　　者：张晓涛[1] 吕奎[1] 陆愈实[1] 

机构地区：[1]中国地质大学工程学院,湖北武汉430074

出　　处：《哈尔滨工程大学学报》2016年第12期1677-1684,共8页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(61202197)

摘　　要：为了研究高温与常温空气介质对空气幕阻隔作用的影响,利用火灾动力学模拟器软件构建了空气幕局部模型,并设置火灾热压与常温风压情况两种场景,在进行模型合理性验证后,采用大涡模拟的方法对两种场景分别进行了数值模拟。探讨了在空气幕不同出口风速下,两种场景对空气幕射流失效位置、气体渗入临界压差及渗入速率的影响,同时还分析了热压与风压共同作用对空气幕阻隔性能的影响。研究表明:在火灾场景下,热压导致空气幕射流失效的位置高度为常温风压的166.67%~200.00%,造成空气幕失效的临界压差是风压的159.27%~202.33%,渗入速率则是风压的280.41%~315.46%。当空气幕出口风速为10 m/s时,在风压与热压共同作用下,风压每提高1 Pa,空气幕保护区域内温度提高约10~20°C,一氧化碳浓度约提高5×10^(-6)~15×10^(-6)。且随着风压的增加,一氧化碳在空气幕近前方产生明显的累积效应,对火灾扑救与人员疏散不利。To analyze the influence of normal and high temperatures gas medium on the obstruction efficiency of an air curtain, a local air curtain model was numerically constructed by fire dynamic simulator （FDS）. Two cases of pres-sure caused by fire effect and wind effect were simultaneously simulated using the large eddy simulation technique af-ter rationality validation. The disable position at air curtain jet, the critical pressure difference, and the speed of gas seepage at different air curtain jet supply velocity were discussed in this study. The mutual action of the thermal pres-sure and wind pressure on the obstruction efficiency of air curtain was also analyzed. Research results show that the disable positions at air curtain jet caused by thermal pressure in the fire environment are 166.67% ～ 200% of that caused by wind pressure. The critical pressure differences caused by fire effect are 159.27%～202.33% of that caused by wind pressure while infiltration rates are 280.41%～315.46% of that caused by wind pressure. When the air curtain jet supply velocity is 10 m/ s under the influence of thermal pressure and wind pressure, the temperature and carbon monoxide concentration will respectively increase by approximately 10～20°C and 5 ×10^-6～15 × 10^-6when the wind pressure increases by 1 Pa. Meanwhile, the obvious CO accumulating effect will appear at the front of air curtain zone with the increase of the wind pressure,which is adverse to fire suppression and evacuation.

关 键 词：空气幕 空气介质 热压 风压 临界压差 FDS 数值模拟 

分 类 号：X928.7[环境科学与工程—安全科学]