冻融循环对渠道保温材料导热性能的影响  

Influence of Freeze-thaw Cycle on the Thermal Conductivity of Insulation Materials

作　　者：朱顺元 明锋 ZHU Shun-yuan;MING Feng(Qinghai Huangyuan Highway Engineering Construction Co.,Ltd.,Xining 81000,Qinghai Province,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu Province,China)

机构地区：[1]青海省湟源公路工程建设有限公司,青海西宁810000 [2]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000

出　　处：《中国农村水利水电》2023年第8期185-190,197,共7页China Rural Water and Hydropower

基　　金：国家自然科学基金(41701060)。

摘　　要：为明确冻融过程对渠道保温材料导热性能的影响程度,以聚苯乙烯(XPS)保温材料为对象,采用快速冻融实验方法,获取了冻融作用下XPS板吸水率及导热系数的变化规律。结合保温材料多孔结构特征,构建了材料三相导热系数模型,并引入参数对体积分数进行修正,从而提高了模型预测精度。最后利用实验结果和既有模型,验证了该模型的可靠性。结果表明:冻融循环200次后,XPS的导热系数约增大43%。通过调整两个拟合参数,导热系数预测值与实测值的最大相对误差可小于5%。建议充分预留保温性能安全系数,以应对保温材料导热系数增大带来的问题。研究成果可为保温层设计及保温材料性能优化提供参考。To clarify the influence of freeze-thaw process on the thermal conductivity of insulation materials,the changes of water absorption and thermal conductivity of polystyrene(XPS)are obtained by rapid freeze-thaw experiment.Combined with the porous structure characteristics of insulation materials,the thermal conductivity model of three-phase materials is constructed,and the volume fraction correction parameter is introduced to improve the prediction accuracy of the proposed model.Finally,the reliability of the proposed model is verified.The results show that after 200 freeze-thaw cycles,the water content of the XPS increases about 4.55%and the thermal conductivity of the XPS increases by about 43%.By adjusting the two fitting parameters,the maximum relative error between the predicted thermal conductivity and the measured value is less than 5%.The long-term thermal insulation properties of XPS board are influenced by freeze-thaw cycles,so it is of great significance to improve its freeze-thaw resistance.Besides,it is recommended to raise the safety factor of thermal insulation performance to cope with the problems caused by the increase in thermal conductivity of materials.

关 键 词：渠道工程 XPS板 冻融循环 导热系数 吸水率 

分 类 号：TV49[水利工程—水工结构工程]