环境风对高层建筑火灾轰燃影响机理研究

With the increase in the number of high-rise buildings, the problems of high-rise building fire are also increasingly prominent. Due to the impact of environmental wind and stack effect, the development of fires in the high-rise building is significantly different from the development of fires in the common buildings. Flashover is a sudden mutation process of the increase in the intensity and destructive power during the process of the fire development. For the environmental wind and stack effect, related flashover theories of high-rise buildings have important theoretical implications and practical values for fire prevention.. The project takes the high-rise building fire flashover as the research object and the fire heat accumulation and heat loss in the fire room as the main line, and it also regards the critical power and time of occurrence of flashover and the flooding flame characteristics after flashover under the influence of environmental wind and stack effect in the fire room of high-rise building as the goal. Through the means of combining theoretical analysis, experiment research and numerical simulation research, systematic study the occurrence of high-rise building fire flashover and the development process. Under the joint influence of the environmental wind and stack effect, the predicting model of the occurrence of flashover, critical power and overflow flame characteristics of firing rooms in the high-rise buildings can be eventually established. The results will provide theoretical guidance to the fire prevention and evacuation of the high-rise buildings, and provide data and theoretical support for the future development of relevant standards and technical specifications.

随着我国高层建筑数量增加，高层建筑火灾问题也日益突出。由于受环境风和烟囱效应的影响，高层建筑火灾发展过程体现出与普通建筑火灾明显不同的特征。轰燃是火灾发展过程中强度骤增、破坏力巨大的突变过程，研究环境风和烟囱效应作用下，高层建筑火灾轰燃相关理论对于高层建筑火灾防治具有重要的理论意义和实用价值。. 本项目以环境风和烟囱效应作用下，高层建筑火灾轰燃为研究对象，以着火房间中的热增益和热损失为主线，以揭示高层建筑着火房间轰燃临界功率、发生时间以及轰燃发生之后溢流火焰特征规律为目标。通过理论分析、实验研究和数值模拟研究相结合的手段，系统研究高层建筑火灾轰燃发生、发展的过程。最终建立环境风和烟囱效应作用下高层建筑着火房间轰燃发生时间、临界功率以及溢流火焰特性的预测模型。研究结果将为高层建筑火灾防治以及人员疏散提供理论指导，并为今后相关标准和技术规范的制定提供数据和理论支持。

由于受环境风和烟囱效应的影响，高层建筑火灾发展过程体现出与普通建筑火灾明显不同的特征。本项目以高层建筑火灾轰燃为研究对象，以着火房间中的热增益和热损失为主线，通过理论分析并结合实验数据，建立了无风情况下双开口着火房间溢流火焰高度和水平长度与火源功率之间的关系模型，并分析了溢流火焰周期性震荡现象与着火房间内通风状况的关系。通过建立外界风作用下双开口着火房间内中性面位置与环境风速的关系模型，分析了外界风作用下着火房间内的通风状况，并根据中性面理论和临界风速解释外界风对着火房间燃烧速率和温度变化的影响机制。根据理论分析建立了防火挑檐下方溢流火焰形态模型，结合实验数据，建立了防火挑檐宽度、火源功率与挑檐上方温度之间的关系预测模型。研究结果将有助于高层建筑防火设计。