PEG/HDPE/CNT定形相变材料在沥青混凝土中的传热特性分析

Research on the Thermal Performance of the PEG/HDPE/CNT Form-stable Phase Change Material In Asphalt Concrete

通过熔融共混法,制备以聚乙二醇(PEG)为相变工作物质、高密度聚乙烯(HDPE)为定形载体及碳纳米管(CNT)为导热填料的新型定形相变材料-PEG/HDPE/CNT (fs-PCMs),并采取渗漏试验、差示扫描量热法(DSC)、热重分析法(TG)和扫描电子显微镜(SEM)对其定形效果、储热特性、热稳定性及微观形貌进行测试与表征;再将其作为调温材料掺加至AC-13沥青混合料中,制备出具有储热调温作用的相变储热沥青混合料,并采用ANSYS软件对其在经受热源辐射时的传热行为进行数值模拟。结果表明,HDPE具有大量的网络结构,能够起到熔融过程中定形液态PEG的作用;PEG/HDPE/CNT fs-PCMs的相变储热特性良好、热稳定性较高,能够作为相变储热材料掺入至沥青混凝土中;PEG/HDPE/CNT fs-PCMs的掺量越多,则沥青混凝土的储热性能越优,混凝土内部的传热形式也主要以自然对流为主,这更加有利于改善沥青混凝土在夏季高温气候下的温度场。

Taking polyethylene glycol(PEG)as solid-liquid phase change materials,high density polyethylene(HDPE)as the supporting material and carbon nanotube(CNT)as the thermal conductive filler,form-stable phase change materials(fs-PCMs)were prepared successfully by the melt blending method.The setting effect,thermal storage property,thermal stability and microstructure of the PEG/HDPE/CNT fs-PCMs were characterized by the leakage test,differential scanning calorimetry(DSC),thermogravimetric analysis(TG)and scanning electron microscope(SEM).Then,the fs-PCMs were added into AC-13 asphalt mixture as temperature-regulating materials to prepare phase-change asphalt mixture with heat storage and temperature-regulating effect,and its heat transfer behavior under heat source radiation was simulated by ANSYS software.The test results show that HDPE has a large number of network structures,which can form the liquid PEG in the melting process.PEG/HDPE/CNT fs-PCMs has good phase change heat storage characteristics and high thermal stability,and can be mixed into asphalt concrete as phase change heat storage materials.The more PEG/HDPE/CNT fs-PCMs,the better the heat storage performance of asphalt concrete could be obtained.And the heat transfer form inside the concrete is mainly natural convection,which is more conducive to improving the temperature field of asphalt concrete in the high temperature climate in summer.