熱線法測量建筑保溫材料熱導率和熱擴散率的研究
發(fā)布時間：2018-08-28 06:49
【摘要】：摘要：隨著節(jié)能技術的進步和建筑節(jié)能的需要,新型建筑保溫材料不斷涌現(xiàn),為及時準確獲得建筑保溫材料的熱導率和熱擴散率,促進建筑保溫材料的開發(fā)、生產與推廣,本文設計了一套基于交叉-平行熱線法的熱導率和熱擴散率的測試裝置。主要研究內容和結論有： (1)采用交叉-平行熱線法對建筑保溫材料進行測試,推導了熱導率和熱擴散率的計算公式。 (2)設計的熱線法實驗裝置主要包括加熱系統(tǒng)、測試系統(tǒng)、數(shù)據(jù)采集系統(tǒng)三部分。確定的熱絲長度為300mm,半徑小于0.2mmm,試樣長度為300mm,厚度大于等于80mm,寬度大于等于160mm,并設計了熱絲的可調節(jié)可拆卸結構、專用夾具及保溫罩。 (3)利用了Matlab和Fluent軟件分析了熱絲半徑、測溫點位置等因素對測量誤差的影響,理論計算結果表明：熱絲半徑為0.1mm～0.6mm,熱絲半徑對測量熱導率精度的影響較��；交叉-平行熱線法測量熱導率及熱擴散率的精度較高,且當試樣厚度大于等于80mm,0.1R/W0.5時,平行熱線法測溫點相對位置和自然對流對熱擴散率的測量精度影響較小。選取R／W為0.1-0.2,測溫熱電偶與熱絲的相對距離均為15mm。 (4)對于有機泡沫保溫材料,交叉-平行熱線法重復測量熱導率和熱擴散率的結果較為穩(wěn)定,泡沫玻璃板重復性測試結果波動相對較大；實驗中采用半徑0.095mm的鎳鉻合金絲作為加熱絲,其對應的最小有效測試時間τmin為140s,最大有效測試時間τmax為試樣上表面中心處溫度上升0.1°C的時刻；有機泡沫保溫材料、加氣混凝土磚硬質保溫材料和泡沫玻璃板的合適線熱流密度范圍分別為0.7～3.7W·m-1、5～11W·m-1和2-9W·m-’。另基于Visual Studio.NET平臺開發(fā)的熱線法可視化數(shù)據(jù)采集處理軟件,計算快速準確。 (5)采用交叉-平行熱線法測試裝置對有機泡沫保溫材料、加氣混凝土磚硬質保溫材料及泡沫玻璃板的熱導率和熱擴散率進行了測量,提出了一種新的熱導率簡易測算方法,分析結果表明：交叉熱線法測量熱導率精度較高,其中EPS板熱導率的測量值與廠家提供值之間的相對誤差僅為3.4%；交叉熱線法測量熱擴散率誤差較大,分析認為主要是由于測溫點位置誤差造成,交叉-平行熱線法測試熱擴散率與文獻值基本一致；所提出的熱導率簡易測算方法,測量精度略低于交叉-平行熱線法,可用于建筑保溫材料熱導率的快速估測。
[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 擄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.
【學位授予單位】：中南大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：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 擄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.
【學位授予單位】：中南大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TU551
【參考文獻】
相關期刊論文 前10條
1 劉世英;于亞鑫;邱竹賢;;耐火保溫材料導熱系數(shù)的測定[J];東北大學學報;2006年02期
2 吳Y，
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