寒区高速铁路隧道空气幕保温机理及评价方法研究

Laying insulation layer has a certain range of adaptation and is not suitable for all the cold region tunnels, it is especially difficult to apply to high speed railway tunnels in cold region. Therefore, the research on the thermal insulation mechanism and evaluation method of the air curtain for the high speed railway tunnel in cold region is put forward in this project. By means of mutual validation of theoretical research, model test and numerical simulation, a calculation model for the temperature field of air mixture inside and outside the high speed railway tunnel with air curtain in cold region is established, and the calculation methods of air curtain barrier efficiency and the mixing temperature associated with air curtain air flow and air inside tunnel are proposed as well. Furthermore, the experimental device for air curtain thermal insulation model of high speed railway tunnel in cold region is developed, and its test method is presented. Finally, a scientific and reasonable thermal insulation model for the air curtain of high speed railway tunnel in cold region is put forward, and the evaluation model of which is also established. On the basis of the above research, the thermal insulation mechanism of the air curtain for the high speed railway tunnel in cold region is clarified, and the heat preservation law of the air curtain for the high speed railway tunnel in the cold region is revealed. The research results of this project will help solve the problem of frost damage, and contribute to the promotion of new energy-saving active insulation measures, so as to provide new methods for cold proof design of railway tunnels in cold region.

铺设保温层具有一定的适应范围，并不适用于所有的寒区隧道，尤其难以适用于寒区高速铁路隧道。为此本项目提出开展寒区高速铁路隧道空气幕保温机理及评价方法的研究。采用理论研究、模型试验和数值模拟相互验证的方法，建立寒区高速铁路隧道空气幕洞内外混合气体温度场的计算模型，提出寒区高速铁路隧道空气幕阻隔效率及空气幕气流与隧道洞内空气的混合温度的计算方法，研发寒区高速铁路隧道空气幕保温模型试验装置并提出试验方法，提出科学合理的寒区高速铁路隧道空气幕保温模型，建立寒区高速铁路隧道空气幕保温模型评价模型，在上述研究基础上，阐明寒区高速铁路隧道空气幕保温机理，揭示寒区高速铁路隧道空气幕的保温规律。本项目的研究成果将有助于冻害问题的解决，为推进新型节能的主动保温措施做出贡献，为寒区铁路隧道防寒保温设计提供新方法。

冻害问题不利于隧道的通行安全，制约了寒区隧道工程的发展。传统保温层法在隧道内铺设保温层，利用其导热系数低的特点，阻止寒冷气温入侵围岩内部。但是该方法温度适应范围窄、建设和维护费用高，无法完全解决隧道冻害问题。.为预防隧道冻害的发生，课题组提出了一种高效的空气幕保温系统，该系统利用空气幕的竖向强风，阻隔寒冷气流入侵隧道内部，确保隧道衬砌结构与围岩接触面的温度达到0℃以上，预防隧道冻害的发生。构建了寒区隧道空气幕阻隔效率的控制方程，研究了该系统的主要设计参数与空气幕阻隔效率之间的变化规律，优化了该系统主要的设计参数。提出了空气幕作用下隧道围岩径向温度场分布的计算方法，为寒区隧道防寒保温工作提供理论基础。设计并研制了空气幕作用下寒区隧道温度场试验系统，探究了隧道内空气流场和围岩径向温度场的变化规律，验证了空气幕保温系统的可靠性，同时也为寒区隧道防寒保温工作提供试验数据支撑。.课题针对隧道冻害这个行业痛点问题开展研究工作，创新性地将空气幕保温方法应用到寒区隧道保温领域，为寒区隧道防寒保温工作提供新方法，对促进寒区隧道工程的发展起到了积极的推动作用。