青藏高原多年冻土区热棒路基设计计算

结合青藏铁路试验工程,在分析热棒路基热周转特性的基础上,建立热棒路基热工计算模型,阐述热棒路基的设计计算过程,讨论设计计算中基本参数的选取,热棒产冷量的计算,产冷量与间距、蒸发段长度、散热面积的关系,安全系数的选取。青藏铁路多年冻土区清水河试验段热棒路基的设计计算结果表明:采用直径76 mm、散热面积3.27 m2、蒸发段长度5 m的热棒,能够很好地起到保护多年冻土的作用,其产冷量达1 900 MJ。热棒的合理纵向间距应在3.5~4.0 m;安全系数在1.1~1.2。相比之下,散热面积、蒸发段长度对产冷量的影响较明显,热棒直径的影响较弱。

Design Calculation of Heat Pipe Subgrade in Permafrost Regions of Qinghai-Tibet Plateau

The heat turnover characteristics of heat pipe subgrade are analyzed. Based on this and in combination with practical engineering of Qinghai-Tibet railway, model for thermotechnical calculation of heat pipe subgrade is built and the process of the design calculation of heat pipe subgrade is explained. Such subjects are discussed in this paper as the choice of basic calculation of heat pipe; the relationship between cooling parameters in design calculation; cooling capacity capacity and interval, evaporator length and radiation area; and the choice of safety factor. It can be concluded, from the design calculation results of the heat pipe sunbgrade of Qingshuihe test section in the permafrost regions of Qinghai-Tibet railway, that using the heat pipe with the diameter of 76 mm, radiation area of 3. 27 m^2 and evaporator length of 5 m can well protect permafrost soil. Its cooling capacity can reach 1 900 MJ. The reasonable longitudinal spacing should be 3.5-4.0 m and the safety factor 1.1-1.2. In contrast, radiation area and evaporator length affect the cooling capacity more obviously than the diameter of heat pipe.