平面热源法对建筑保温材料热导率和热扩散率的测试研究
发布时间：2018-08-13 12:30
【摘要】：目前新型建筑保温材料不断涌现,但测试手段有限,测试数据缺乏,使保温材料的推广应用受到限制。本文基于平面热源法,设计了一套适用于保温材料热导率和热扩散率等参数测试的实验装置,开发了可视化数据采集与处理软件,完成了对部分建筑保温材料的热导率和热扩散率等参数的测试,并对测试结果进行了优化,主要研究内容如下： (1)基于平面热源法设计并搭建了保温材料的热导率和热扩散率等参数实验平台。利用FLUENT软件,分析了试样长宽、测试间距及热流密度等参数对测试结果的影响,确定了实验参数：试样长、宽L均为300mm,测试间距h为10-20mm,热流密度qw为30～150W·m-2。 (2)基于Visual Studio.NET2008可视化编程平台,开发了一套可同时采用常功率平面热源法和阶跃平面热源法测试材料热导率、热扩散率和比热容的可视化数据采集与处理软件。 (3)通过理论分析确定了该装置的有效测试时间τmin=100s,τmax为监控面温度上升0.1℃时刻。并利用实验研究了保温罩和热流密度等因素对热导率测试精度的影响。结果表明：常功率法和阶跃法重复测量的复现性较好,偏差均在3%内。加保温罩时,EPS板的测试精度可提高0.85%。热流密度对水泥泡沫板和泡沫玻璃热导率的影响较大,在测试温度为20-43.5℃时,水泥泡沫板的热导率随温度变化增大而增大,而在测试温度为20～66℃时,泡沫玻璃板的热导率随温度变化增大而增大；热流密度对EPS (20～43℃)板和砂加气混凝土砖(20-32℃)的热导率影响较小,基本可忽略不计。 (4)采用常功率法和阶跃法对有机泡沫保温材料、加气砖硬质保温材料、水泥泡沫板和泡沫玻璃板的热导率和热扩散率等参数进行了测试,两种方法的测试结果有一定的偏差,热导率测试结果的相对偏差均在5%以内,热扩散率测试结果的相对偏差波动较大,偏差范围为1.7-22.2%,但无规律显示哪种方法更适合测试。其中,常功率法和阶跃法测试得到的EPS板热导率与厂家提供值的相对误差分别为-1.95%和2.68%,测试精度均较高。两种方法对热扩散率的测试与文献基本一致,实验测试完善了真金板、砂加气混凝土砖、水泥泡沫板和泡沫玻璃板等几种保温材料的热扩散率数据。此外,基于新的数据处理方法,测量了有机泡沫保温材料、加气砖硬质保温材料、水泥泡沫板和泡沫玻璃板等保温材料的蓄热系数,完善了相关材料蓄热系数的数据。 (5)基于FLUENT软件,采用实验与仿真相结合的方法修正了热导率,进一步提高了实验测试精度。经过修正,EPS板热导率的相对误差从-1.95%减小到-1.22%,误差精度提高0.73%。
[Abstract]:At present, new building insulation materials are emerging constantly, but the limited testing means and the lack of test data limit the popularization and application of thermal insulation materials. Based on the plane heat source method, a set of experimental equipment is designed for the measurement of thermal conductivity and thermal diffusivity of thermal insulation materials, and a visual data acquisition and processing software is developed. The thermal conductivity and thermal diffusivity of some building insulation materials are tested, and the test results are optimized. The main research contents are as follows: (1) based on the planar heat source method, the thermal conductivity and thermal diffusivity of the thermal insulation materials are designed and built. By using FLUENT software, the influence of the parameters such as sample length and width, test distance and heat flux on the test results is analyzed. The experimental parameters are determined as follows: sample length, The width L is 300mm, the test distance h is 10-20mm, the heat flux QW is 3010W m ~ (-2). (2) based on the Visual Studio.NET2008 visual programming platform, a set of constant power plane heat source method and step plane heat source method are developed to measure the thermal conductivity of the material. Visual data acquisition and processing software for thermal diffusivity and specific heat capacity. (3) through theoretical analysis, the effective test time 蟿 max is determined to be 0. 1 鈩，
本文编号：2180999
[Abstract]:At present, new building insulation materials are emerging constantly, but the limited testing means and the lack of test data limit the popularization and application of thermal insulation materials. Based on the plane heat source method, a set of experimental equipment is designed for the measurement of thermal conductivity and thermal diffusivity of thermal insulation materials, and a visual data acquisition and processing software is developed. The thermal conductivity and thermal diffusivity of some building insulation materials are tested, and the test results are optimized. The main research contents are as follows: (1) based on the planar heat source method, the thermal conductivity and thermal diffusivity of the thermal insulation materials are designed and built. By using FLUENT software, the influence of the parameters such as sample length and width, test distance and heat flux on the test results is analyzed. The experimental parameters are determined as follows: sample length, The width L is 300mm, the test distance h is 10-20mm, the heat flux QW is 3010W m ~ (-2). (2) based on the Visual Studio.NET2008 visual programming platform, a set of constant power plane heat source method and step plane heat source method are developed to measure the thermal conductivity of the material. Visual data acquisition and processing software for thermal diffusivity and specific heat capacity. (3) through theoretical analysis, the effective test time 蟿 max is determined to be 0. 1 鈩，
本文编号：2180999
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