吴冰, 朱鸿鹄, 曹鼎峰, 王家琛, 魏广庆, 施斌. 2019: 基于主动加热光纤法的冻土相变温度场特征分析. 工程地质学报, 27(5): 1093-1100. DOI: 10.13544/j.cnki.jeg.2019135
    引用本文: 吴冰, 朱鸿鹄, 曹鼎峰, 王家琛, 魏广庆, 施斌. 2019: 基于主动加热光纤法的冻土相变温度场特征分析. 工程地质学报, 27(5): 1093-1100. DOI: 10.13544/j.cnki.jeg.2019135
    WU Bing, ZHU Honghu, CAO Dingfeng, WANG Jiachen, WEI Guangqing, SHI Bin. 2019: INVESTIGATION OF PHASE CHANGE TEMPERATURE FIELD IN FROZEN SOIL BASED ON ACTIVELY HEATED FIBER OPTICS METHOD. JOURNAL OF ENGINEERING GEOLOGY, 27(5): 1093-1100. DOI: 10.13544/j.cnki.jeg.2019135
    Citation: WU Bing, ZHU Honghu, CAO Dingfeng, WANG Jiachen, WEI Guangqing, SHI Bin. 2019: INVESTIGATION OF PHASE CHANGE TEMPERATURE FIELD IN FROZEN SOIL BASED ON ACTIVELY HEATED FIBER OPTICS METHOD. JOURNAL OF ENGINEERING GEOLOGY, 27(5): 1093-1100. DOI: 10.13544/j.cnki.jeg.2019135

    基于主动加热光纤法的冻土相变温度场特征分析

    INVESTIGATION OF PHASE CHANGE TEMPERATURE FIELD IN FROZEN SOIL BASED ON ACTIVELY HEATED FIBER OPTICS METHOD

    • 摘要: 冻土温度场分析对于冻土特性研究及冻土地区工程建设具有重要的作用,而冰水相变所产生的相变潜热大大增加了冻土温度场分析的复杂性。针对该问题,基于线热源模型和冻土传热基本理论,在考虑未冻水和相变潜热的情况下计算了冻土导热系数、体积热容和相变热容,分析其与测量初始温度的关系;在分析结果的基础上,对冻土含冰量的光纤测量技术进行了理论修正。基于主动加热光纤(AHFO)法,开展了一系列室内验证试验:在恒定的加热功率和时间下,采用自主研发的光纤光栅(FBG)刚玉管传感器,对同一初始含水量的冻土试样进行温度监测。结果表明:在本文试验条件下,FBG刚玉管传感器的影响半径小于5 cm,可以忽略边界效应;传感器所测温度增量与时间对数线性关系良好,主动加热对于冻土导热系数影响较小,线源模型适用于冻土导热系数测量;冻土导热系数与试验初始温度呈线性增长关系;在初始温度低于-6 ℃时,相变热容趋于稳定;在-6~0 ℃时,相变热容随温度升高逐渐增大,且变化趋势愈渐强烈;当初始温度高于-5 ℃时,相变热容甚至大于冻土自身的体积热容。相关结论为进一步提高冻土含冰量测试技术的精度提供了参考。

       

      Abstract: The analysis of frozen soil temperature field plays an important role in the research on frozen soil and engineering construction in permafrost regions. The latent heat caused by the phase change between ice and water increases the complexity of the analysis. In order to solve this problem, the volumetric heat capacity due to phase change and thermal conductivity is obtained through back calculation based on the linear heat source model and the basic theory of heat transfer in frozen soil. In this paper, a series of laboratory tests on frozen soil are conducted for the same initial moisture content. Based on the method of Actively Heated Fiber Optics(AHFO), the FBG corundum tube sensor is used as a heat source and temperature sensor to detect thermal response characteristics of frozen soil under different initial temperature. The results show that under the experimental conditions, the influence radius of the FBG corundum tube sensor is less than 5 cm. The temperature increment measured by the FBG corundum tube sensor has a linear relationship with the logarithm of time. With the increase of initial temperature, the measured thermal conductivity of frozen soil has a linear relationship with temperature. The phase change heat capacity tends to be stable when the initial temperature is lower than -6℃, and increases gradually with the increase of temperature from -6℃ to 0℃. When the initial temperature is higher than -5℃, the phase change heat capacity is even greater than the volume heat capacity of the frozen soil itself. These results provide references for the modification of the AHFO-based monitoring method of ice content in frozen soil.

       

    /

    返回文章
    返回