热线法测量建筑保温材料热导率和热扩散率的研究
发布时间：2018-08-28 06:49
【摘要】：摘要：随着节能技术的进步和建筑节能的需要,新型建筑保温材料不断涌现,为及时准确获得建筑保温材料的热导率和热扩散率,促进建筑保温材料的开发、生产与推广,本文设计了一套基于交叉-平行热线法的热导率和热扩散率的测试装置。主要研究内容和结论有： (1)采用交叉-平行热线法对建筑保温材料进行测试,推导了热导率和热扩散率的计算公式。 (2)设计的热线法实验装置主要包括加热系统、测试系统、数据采集系统三部分。确定的热丝长度为300mm,半径小于0.2mmm,试样长度为300mm,厚度大于等于80mm,宽度大于等于160mm,并设计了热丝的可调节可拆卸结构、专用夹具及保温罩。 (3)利用了Matlab和Fluent软件分析了热丝半径、测温点位置等因素对测量误差的影响,理论计算结果表明：热丝半径为0.1mm～0.6mm,热丝半径对测量热导率精度的影响较小；交叉-平行热线法测量热导率及热扩散率的精度较高,且当试样厚度大于等于80mm,0.1R/W0.5时,平行热线法测温点相对位置和自然对流对热扩散率的测量精度影响较小。选取R／W为0.1-0.2,测温热电偶与热丝的相对距离均为15mm。 (4)对于有机泡沫保温材料,交叉-平行热线法重复测量热导率和热扩散率的结果较为稳定,泡沫玻璃板重复性测试结果波动相对较大；实验中采用半径0.095mm的镍铬合金丝作为加热丝,其对应的最小有效测试时间τmin为140s,最大有效测试时间τmax为试样上表面中心处温度上升0.1°C的时刻；有机泡沫保温材料、加气混凝土砖硬质保温材料和泡沫玻璃板的合适线热流密度范围分别为0.7～3.7W·m-1、5～11W·m-1和2-9W·m-’。另基于Visual Studio.NET平台开发的热线法可视化数据采集处理软件,计算快速准确。 (5)采用交叉-平行热线法测试装置对有机泡沫保温材料、加气混凝土砖硬质保温材料及泡沫玻璃板的热导率和热扩散率进行了测量,提出了一种新的热导率简易测算方法,分析结果表明：交叉热线法测量热导率精度较高,其中EPS板热导率的测量值与厂家提供值之间的相对误差仅为3.4%；交叉热线法测量热扩散率误差较大,分析认为主要是由于测温点位置误差造成,交叉-平行热线法测试热扩散率与文献值基本一致；所提出的热导率简易测算方法,测量精度略低于交叉-平行热线法,可用于建筑保温材料热导率的快速估测。
[Abstract]:Abstract: with the progress of energy saving technology and the need of building energy conservation, new building insulation materials are emerging constantly. In order to obtain the thermal conductivity and thermal diffusivity of building insulation materials in time and accurately, to promote the development, production and promotion of building insulation materials. In this paper, a set of apparatus for measuring thermal conductivity and thermal diffusivity based on cross-parallel hot wire method is designed. The main research contents and conclusions are as follows: (1) the cross-parallel hot-wire method is used to test the thermal insulation materials of buildings. The formulas for calculating thermal conductivity and thermal diffusivity are derived. (2) the hot-wire experimental device is mainly composed of three parts: heating system, testing system and data acquisition system. The determined hot filament length is 300 mm, radius is less than 0.2 mm, specimen length is 300 mm, thickness is greater than 80 mm, width is greater than 160 mm, and adjustable detachable structure of hot wire is designed. (3) Matlab and Fluent software are used to analyze the influence of the hot wire radius and the position of the temperature measuring point on the measurement error. The theoretical calculation results show that the radius of hot wire is 0.1mm / 0.6mm, the radius of hot filament has little effect on the accuracy of measuring thermal conductivity, the accuracy of measuring thermal conductivity and thermal diffusivity by cross-parallel hot-wire method is higher, and when the thickness of the sample is greater than 80mm / 0.1RW _ (0.5), The relative position of temperature points and natural convection have little effect on the measurement accuracy of thermal diffusivity. The relative distance between thermocouple and hot filament is 15mm. (4) for organic foam insulation material, the results of repeated measurement of thermal conductivity and thermal diffusivity by cross-parallel hot wire method are stable. The repeatability test results of foamed glass plate fluctuated relatively, and the Ni-Cr alloy wire with radius 0.095mm was used as heating wire in the experiment. The corresponding minimum effective test time 蟿 min is 140 s, and the maximum effective test time 蟿 max is the time when the temperature rises 0. 1 掳C at the center of the upper surface of the sample. The suitable linear heat flux ranges of rigid insulating material and foamed glass plate for aerated concrete brick are 0.737 W m -1 and 2 9 W m -1, respectively. In addition, the visual data acquisition and processing software of hot-wire method based on Visual Studio.NET platform is developed, and the calculation is fast and accurate. (5) the organic foam thermal insulation material is tested by cross-parallel hot-wire method. The thermal conductivity and thermal diffusivity of rigid thermal insulation material and foamed glass plate of aerated concrete brick are measured. A new simple method for measuring thermal conductivity is proposed. The analysis results show that the accuracy of measuring thermal conductivity by cross hot wire method is high. The relative error between the measurement value of thermal conductivity of EPS plate and the value provided by manufacturer is only 3.4, and the error of measuring thermal diffusivity by cross hot wire method is large, which is mainly caused by the position error of temperature measuring point. The measurement accuracy of the proposed method is slightly lower than that of the cross-parallel hot wire method, which can be used to estimate the thermal conductivity of thermal insulation materials.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU551
[Abstract]:Abstract: with the progress of energy saving technology and the need of building energy conservation, new building insulation materials are emerging constantly. In order to obtain the thermal conductivity and thermal diffusivity of building insulation materials in time and accurately, to promote the development, production and promotion of building insulation materials. In this paper, a set of apparatus for measuring thermal conductivity and thermal diffusivity based on cross-parallel hot wire method is designed. The main research contents and conclusions are as follows: (1) the cross-parallel hot-wire method is used to test the thermal insulation materials of buildings. The formulas for calculating thermal conductivity and thermal diffusivity are derived. (2) the hot-wire experimental device is mainly composed of three parts: heating system, testing system and data acquisition system. The determined hot filament length is 300 mm, radius is less than 0.2 mm, specimen length is 300 mm, thickness is greater than 80 mm, width is greater than 160 mm, and adjustable detachable structure of hot wire is designed. (3) Matlab and Fluent software are used to analyze the influence of the hot wire radius and the position of the temperature measuring point on the measurement error. The theoretical calculation results show that the radius of hot wire is 0.1mm / 0.6mm, the radius of hot filament has little effect on the accuracy of measuring thermal conductivity, the accuracy of measuring thermal conductivity and thermal diffusivity by cross-parallel hot-wire method is higher, and when the thickness of the sample is greater than 80mm / 0.1RW _ (0.5), The relative position of temperature points and natural convection have little effect on the measurement accuracy of thermal diffusivity. The relative distance between thermocouple and hot filament is 15mm. (4) for organic foam insulation material, the results of repeated measurement of thermal conductivity and thermal diffusivity by cross-parallel hot wire method are stable. The repeatability test results of foamed glass plate fluctuated relatively, and the Ni-Cr alloy wire with radius 0.095mm was used as heating wire in the experiment. The corresponding minimum effective test time 蟿 min is 140 s, and the maximum effective test time 蟿 max is the time when the temperature rises 0. 1 掳C at the center of the upper surface of the sample. The suitable linear heat flux ranges of rigid insulating material and foamed glass plate for aerated concrete brick are 0.737 W m -1 and 2 9 W m -1, respectively. In addition, the visual data acquisition and processing software of hot-wire method based on Visual Studio.NET platform is developed, and the calculation is fast and accurate. (5) the organic foam thermal insulation material is tested by cross-parallel hot-wire method. The thermal conductivity and thermal diffusivity of rigid thermal insulation material and foamed glass plate of aerated concrete brick are measured. A new simple method for measuring thermal conductivity is proposed. The analysis results show that the accuracy of measuring thermal conductivity by cross hot wire method is high. The relative error between the measurement value of thermal conductivity of EPS plate and the value provided by manufacturer is only 3.4, and the error of measuring thermal diffusivity by cross hot wire method is large, which is mainly caused by the position error of temperature measuring point. The measurement accuracy of the proposed method is slightly lower than that of the cross-parallel hot wire method, which can be used to estimate the thermal conductivity of thermal insulation materials.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU551
【参考文献】
相关期刊论文 前10条
1 刘世英;于亚鑫;邱竹贤;;耐火保温材料导热系数的测定[J];东北大学学报;2006年02期
2 吴Y，
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