复杂气流条件下竖井型隧道火灾烟气流动特性及优化控制

In recent years, natural ventilation shaft has been gradually applied in tunnels at home and abroad. Due to the effect of terrain, weather, traffic and other factors, complex airflows may exist inside and outside the tunnel, which will influence the smoke exhausting efficiency of shafts, however, there are relatively scarce studies. In this project, theoretical analysis, experiment and numerical simulation method will be used to: (1) clarify the impact mechanism of environmental wind above the shaft on the smoke exhausting process, reveal the smoke movement characteristics under the couple effect of inertial force of environmental wind and vertical thermal buoyancy of smoke itself, and establish the critical criterion on the failure of natural ventilation system under a strong environmental wind; (2) reveal the change regularity of longitudinal smoke temperature decay, smoke stratification stability and smoke layer thickness, and smoke diffusion speed and distance in the tunnel, under the combined effect of environmental wind above the shaft and longitudinal wind inside the tunnel; (3) confirm the feasibility of combining mechanical smoke exhausting system to conduct auxiliary smoke exhausting when natural ventilation mode loses effectiveness, and determine how to coordinate the two systems to obtain a better smoke control effect..This study can enrich the understanding of characteristics of natural ventilation shaft in tunnel fires, and provide theoretical support for optimizing tunnel fire safety design and enhancing smoke exhausting capacity.

近年来，竖井自然排烟系统已在国内外隧道中逐步得到应用。而由于地形、天气、交通等因素的影响，隧道内外往往存在着复杂的气流，这很有可能影响竖井的排烟效果，但对此的研究还比较缺乏。本项目拟通过理论分析、实验和数值模拟相结合的方法：(1)明晰竖井上部环境风对自然排烟过程的影响机制，揭示环境风的水平惯性力与烟气本身竖向热浮力耦合作用下的烟气运动特征，建立强环境风条件下竖井自然排烟系统失效的临界判据；(2)揭示竖井上部环境风、隧道内纵向风共同作用下隧道内烟气温度的纵向衰减规律、烟气分层稳定性和厚度变化机制、烟气扩散速度和蔓延距离演化规律；(3)确认竖井自然排烟系统失效时结合射流风机纵向送风进行辅助排烟的可行性，确定协调竖井自然排烟和纵向机械排烟两种模式以获得较好烟气控制效果的优化策略。.本研究可丰富对隧道火灾中竖井自然排烟系统特征行为的认识，为优化隧道消防安全设计和提高排烟能力，提供理论支撑。

近年来，竖井自然排烟系统已在国内外隧道中逐步得到应用。而由于地形、天气、交通等因素的影响，隧道内外往往存在着复杂的气流，这很有可能影响竖井的排烟效果，但相关研究还比较缺乏。本项目针对隧道内外复杂气流边界，系统开展了竖井型隧道火灾烟气流动特性及优化控制研究，提出了适用于不同吸穿程度条件下的排热效率模型，明晰了竖井上部环境风水平惯性力与竖井内烟囱效应耦合作用下的烟气运动特征，建立了强环境风条件下竖井自然排烟流量的预测模型；揭示了竖井上部环境风、隧道内纵向风作用下的温度衰减规律、烟气分层稳定性变化机制和烟气扩散特征；确认了竖井自然排烟系统失效时结合射流风机纵向送风进行辅助排烟的可行性，确定了协调竖井自然排烟和纵向机械排烟两种模式以获得较好烟气控制效果的优化策略。研究成果可为优化隧道消防安全设计和提高排烟能力提供理论支撑。项目负责人以第一作者或通讯作者在本领域国际期刊发表SCI论文14篇（其中JCR1区论文8篇），包括国际隧道协会官方期刊Tunnelling and Underground Space Technology 3篇、国际火灾领域知名期刊Fire and Materials 3篇、国际燃烧领域知名期刊Combustion Science and Technology 1篇，1篇论文入选ESI高被引论文；受邀在本领域权威系列学术会议作口头报告3次；授权发明专利2项，申请发明专利4项；获得2019中国消防协会科学技术创新奖一等奖、2017全国建筑防灾技术交流会优秀论文一等奖、2019 International Conference on Urban Public Safety and Emergency Rescue Outstanding Paper；被6个国际SCI期刊授予Outstanding Reviewer；培养研究生4名。