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平面熱源法對(duì)建筑保溫材料熱導(dǎo)率和熱擴(kuò)散率的測(cè)試研究

發(fā)布時(shí)間:2018-08-13 12:30
【摘要】:目前新型建筑保溫材料不斷涌現(xiàn),但測(cè)試手段有限,測(cè)試數(shù)據(jù)缺乏,使保溫材料的推廣應(yīng)用受到限制。本文基于平面熱源法,設(shè)計(jì)了一套適用于保溫材料熱導(dǎo)率和熱擴(kuò)散率等參數(shù)測(cè)試的實(shí)驗(yàn)裝置,開(kāi)發(fā)了可視化數(shù)據(jù)采集與處理軟件,完成了對(duì)部分建筑保溫材料的熱導(dǎo)率和熱擴(kuò)散率等參數(shù)的測(cè)試,并對(duì)測(cè)試結(jié)果進(jìn)行了優(yōu)化,主要研究?jī)?nèi)容如下: (1)基于平面熱源法設(shè)計(jì)并搭建了保溫材料的熱導(dǎo)率和熱擴(kuò)散率等參數(shù)實(shí)驗(yàn)平臺(tái)。利用FLUENT軟件,分析了試樣長(zhǎng)寬、測(cè)試間距及熱流密度等參數(shù)對(duì)測(cè)試結(jié)果的影響,確定了實(shí)驗(yàn)參數(shù):試樣長(zhǎng)、寬L均為300mm,測(cè)試間距h為10-20mm,熱流密度qw為30~150W·m-2。 (2)基于Visual Studio.NET2008可視化編程平臺(tái),開(kāi)發(fā)了一套可同時(shí)采用常功率平面熱源法和階躍平面熱源法測(cè)試材料熱導(dǎo)率、熱擴(kuò)散率和比熱容的可視化數(shù)據(jù)采集與處理軟件。 (3)通過(guò)理論分析確定了該裝置的有效測(cè)試時(shí)間τmin=100s,τmax為監(jiān)控面溫度上升0.1℃時(shí)刻。并利用實(shí)驗(yàn)研究了保溫罩和熱流密度等因素對(duì)熱導(dǎo)率測(cè)試精度的影響。結(jié)果表明:常功率法和階躍法重復(fù)測(cè)量的復(fù)現(xiàn)性較好,偏差均在3%內(nèi)。加保溫罩時(shí),EPS板的測(cè)試精度可提高0.85%。熱流密度對(duì)水泥泡沫板和泡沫玻璃熱導(dǎo)率的影響較大,在測(cè)試溫度為20-43.5℃時(shí),水泥泡沫板的熱導(dǎo)率隨溫度變化增大而增大,而在測(cè)試溫度為20~66℃時(shí),泡沫玻璃板的熱導(dǎo)率隨溫度變化增大而增大;熱流密度對(duì)EPS (20~43℃)板和砂加氣混凝土磚(20-32℃)的熱導(dǎo)率影響較小,基本可忽略不計(jì)。 (4)采用常功率法和階躍法對(duì)有機(jī)泡沫保溫材料、加氣磚硬質(zhì)保溫材料、水泥泡沫板和泡沫玻璃板的熱導(dǎo)率和熱擴(kuò)散率等參數(shù)進(jìn)行了測(cè)試,兩種方法的測(cè)試結(jié)果有一定的偏差,熱導(dǎo)率測(cè)試結(jié)果的相對(duì)偏差均在5%以?xún)?nèi),熱擴(kuò)散率測(cè)試結(jié)果的相對(duì)偏差波動(dòng)較大,偏差范圍為1.7-22.2%,但無(wú)規(guī)律顯示哪種方法更適合測(cè)試。其中,常功率法和階躍法測(cè)試得到的EPS板熱導(dǎo)率與廠家提供值的相對(duì)誤差分別為-1.95%和2.68%,測(cè)試精度均較高。兩種方法對(duì)熱擴(kuò)散率的測(cè)試與文獻(xiàn)基本一致,實(shí)驗(yàn)測(cè)試完善了真金板、砂加氣混凝土磚、水泥泡沫板和泡沫玻璃板等幾種保溫材料的熱擴(kuò)散率數(shù)據(jù)。此外,基于新的數(shù)據(jù)處理方法,測(cè)量了有機(jī)泡沫保溫材料、加氣磚硬質(zhì)保溫材料、水泥泡沫板和泡沫玻璃板等保溫材料的蓄熱系數(shù),完善了相關(guān)材料蓄熱系數(shù)的數(shù)據(jù)。 (5)基于FLUENT軟件,采用實(shí)驗(yàn)與仿真相結(jié)合的方法修正了熱導(dǎo)率,進(jìn)一步提高了實(shí)驗(yàn)測(cè)試精度。經(jīng)過(guò)修正,EPS板熱導(dǎo)率的相對(duì)誤差從-1.95%減小到-1.22%,誤差精度提高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,

本文編號(hào):2180999

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