开放表面透壁通风管路堤碎石的降温机理分析  

Analysis for Cooling Mechanism of Embankment Crushed Rock by Perforated Ventilation Pipe on Open Surface

作　　者：孙斌祥[1] 刘琦[1] 杨丽君[1] 杨秋伟[1] 徐学祖[1] 

机构地区：[1]绍兴文理学院土木工程系,浙江绍兴312000

出　　处：《中国公路学报》2011年第6期16-23,30,共9页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(40772194;40972203)

摘　　要：为揭示青藏高原冻土区采用的透壁通风管增强开放边界路堤碎石的降温机理,对埋设水平透壁通风管的100cm×60cm×100cm碎石试样进行了室内试验。结果表明:透壁通风管开放路堤碎石存在4种传热过程,即通风管的管壁与管内流动空气的对流换热,外界大气通过路堤碎石开放边界与其内部孔隙空气循环引起的强迫对流换热,管内流动空气通过管壁的透气小孔与附近碎石层内的孔隙空气循环引起的强迫对流换热及路堤表面的热传导换热;当通风期间进入透壁通风管内的空气温度低于通风管周围碎石区域的温度时,路堤碎石通过开放边界及管壁透气小孔使外界冷空气与路堤碎石层内孔隙空气形成的循环运动能增强路堤碎石冬季冷空气引起的降温效果。In order to study cooling mechanism of the crushed rock embankment enhanced by a perforated ventilation pipe on open surface in permafrost regions of Qinghai-Tibet Plateau,laboratory test of 100 cm × 60 cm × 100 cm crushed rock sample embedded horizontal perforated ventilation pipe was carried out.The results show that the heat transfer processes in the crushed rock embankment with a perforated ventilation pipe include the following four modes： convective heat transport between the in-duct air and the pipe wall surface,forced convective heat transport due to ambient air imposed on the crushed rock open surface and its internal pore air circulation,forced convective heat transport due to in-duct air imposed on pore of pipe wall and pore air circulation near crushed rock layer,and convective heat transport of embankment surface.When air temperatures in perforated ventilation pipe during the ventilating period is lower than the pore air temperatures near crushed rock region of ventilation pipe,circulation motion induced by cold ambient air and pore air in embankment crushed rock layer through action of open surface and pore of pipe wall,can enhance the cooling effect of crushed rock embankment induced by cold air in winter.

关 键 词：道路工程 路堤碎石 室内模拟试验 透壁通风管 开放表面 降温机理 

分 类 号：U416.168[交通运输工程—道路与铁道工程]