摘要
碎石层的传热机理研究对寒区路基改善技术的应用以及自然界中的“异常”冻土分布的解释有着重要的意义。很多研究者曾对碎石层进行了试验研究,但试验中的温度设置并无统一标准。相较于细颗粒土,粗颗粒材料中水分的影响较小,因此在试验中的温度设置对试验的结果起到了关键作用。为了对比不同的温度设置情况对碎石传热过程的影响,以不同的顶板温度、底板温度以及环境温度进行复合,并对不同组合情况应用COMSOL软件,在考虑碎石层多孔介质传热的情况下进行模拟。结果表明:即使在保温层包裹的情况下,环境温度依然能对温度剖面以及垂直方向上的热通量产生明显的影响。当环境温度与碎石层平均温度一致时,垂直方向上的热通量达到最小值,此时换热效率最低。因此,在此后的室内碎石层试验设计中,若需减少水平方向上的热量交换带来的影响,应尽量将环境温度设置在碎石层平均温度附近。工程中可通过降低碎石层侧边界温度来增强碎石层内外的热量交换,从而增强碎石层的换热效率。
The study of heat transfer mechanism of gravel layer is of great significance to the application of sub⁃grade improvement technology in cold regions and the interpretation of“abnormal”frozen soil distribution in na⁃ture.Many researchers have carried out experimental research on the gravel layer,but there is no unified stan⁃dard for the temperature setting in the test.Compared with fine-grained soil,the influence of moisture in coarsegrained material is smaller,so the temperature setting in the test plays a key role in the test results.In order to compare the influence of different temperature settings on the three-dimensional heat transfer process of gravel,different roof temperatures,floor temperatures and ambient temperatures are combined,and COMSOL software is used to simulate different combinations under the condition of considering the heat transfer of porous media in gravel layer.The results show that even when the insulation is wrapped,the ambient temperature can still have a significant impact on the temperature profile and the heat flux in the vertical direction.When the ambient temper⁃ature is consistent with the average temperature of the gravel layer,the heat flux in the vertical direction reaches the minimum,and the heat transfer efficiency is the lowest.Therefore,in the subsequent indoor gravel layer test design,if it is necessary to reduce the impact of heat exchange in the horizontal direction,the ambient tempera⁃ture should be set near the average temperature of the gravel layer as far as possible.In the project,the heat ex⁃change inside and outside the gravel layer can be enhanced by reducing the side boundary temperature of the gravel layer,so as to enhance the heat exchange efficiency of the gravel layer.
作者
梁铭轩
葛建锐
牛永红
LIANG Mingxuan;GE Jianrui;NIU Yonghong(State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《冰川冻土》
CSCD
北大核心
2023年第3期1006-1015,共10页
Journal of Glaciology and Geocryology
基金
国家重点研发计划项目(2017YFC0405103)
甘肃省高等学校青年博士基金项目(2022QB-051)资助。
