导　　师： 张正国

学科专业： 081701

授予学位： 硕士

作　　者： ;

机构地区： 华南理工大学

摘　　要： 目前，储热技术的出现，正逐渐改善全球能源利用的现状，尤其在建筑节能方面的应用引起了全世界各界的广泛关注。对于如何制备出新型相变储热材料，如何了解其相变动力学特征，如何提高相变材料与建筑材料之间的相容性和稳定性等问题的深入研究，将对储热技术的发展及其应用于建筑节能具有很大的实际意义。 本文选取了相变石蜡（RT28）、十八烷（OC）和正十二醇（AL）为相变材料，膨胀珍珠岩为载体，以毛细吸附法制备三种膨胀珍珠岩基复合相变储热材料。采用吸附饱和度分析、扫描电镜/(SEM/)分析、X射线衍射/(XRD/)分析、差示扫描量热分析/(DSC/)等表征了复合相变储热材料的结构和热性能。膨胀珍珠岩对三种有机相变材料的最大吸附饱和度均为40wt/%，且均具有较好的封装效果，复合相变储热材料的相变温度与纯相变材料相差不大，其相变潜热值与基于相变材料质量百分含量的计算值相当。 在相变动力学研究中，以40wt/%RT28//EG-PCM、40wt/%OC//EP-PCM及40wt/%LA//EP-PCM为研究对象，通过Kissinger方程和Ozawa方程估算活化能E和指前因子A，通过Coats-Redfern积分方程和Ozawa方程外推处理后，得出结论：三种材料的机理函数分别符合Mampel Power法则/(幂函数法则/)、Mample单行法则/(一级/)和Avrami-Erofeev方程，其机理函数的积分方程分别为G/(α/)=α3//2、G /(α/)=-ln/(1-α/)和G/(α/)=/[-ln/(1-α/)/]2//3。 在复合相变储热材料在建筑材料的应用研究中，将已制备好的RT28//EP-PCMs与水泥和水按一定体积比掺混制备复合相变储热砂浆，再通过标准试模/(70.7×70.7×70.7mm~3/)和自制试模/(10×100×100mm~3/)制备出复合相变储热水泥块和水泥板。当RT28含量达到40wt/%时，制得的复合水泥板的表观密度、7天抗压强度及导热系数与普通膨胀珍珠岩水泥板相比约分别升高37.2/%、40/%和35.2/%，均可达到建筑应用的标准。 将制备好的复合相变储热水泥板组合成封闭立方体空间，尺寸为100×100×100mm~3，壁厚10mm，在氙灯模拟太阳光辐射的实验条件下，测试立方体各测试点温度的变化情况，来研究复合水泥板的节能效果，分别进行了A组和B组测试。在相同的外界辐射条件下，随着RT28含量的增加，立方体上板外壁与立方体内部的最大温差逐渐增大，当RT28含量为40wt/%，A组和B组对应的最大温差分别为25.231℃和18.717℃。因此，在普通建筑材料中加入一定量的相变材料可对室温发挥一定的调节作用，减小室内温度的波动，并且相变材料的含量越高，温度调节的效果越明显，节能效果越好。 At present, the current situation of making use of energy globally is gradually improvedas the emergence of thermal energy storage technology, particularly its application in buildingenergy-saving has aroused widespread concern in the whole world. For these issues, such ashow to prepare a new phase change heat storage materials, how to analyse their phase changedynamics features, how to improve the compatibility and stability between phase changematerials and constructive materials, etc, the in-depth study will make great practicalsignificance for the development of thermal storage technology and its application in buildingenergy-saving. In this paper, firstly, three kinds of expanded perlite/(EP/) based composite phase changematerials/(PCMs/) were prepared, in which expanded perlite acted as the supporting material,RT28, octadecane/(OC/) and lauryl alcohol/(LA/) were served as latent heat storage materialsrespectively. The structure and thermal properties of PCMs were then characterized by meansof adsorption saturation analysis, SEM, XRD, DSC, etc. It is shown that, expanded perlite hasa same maximum absorptive capacity as40/%for all the three organic phase change materials,all of which still are form-stable with no liquid leakage performance after being heated. Inaddition, there was little difference of the phase change temperature between EP-basedcomposite PCMs and the pure organic PCM, were similar to that of the pure organic PCM,and their latent heat values were equivalent to the calculated values based on the mass fractionof the pure organic PCM in the PCMs. Took40wt/%RT28//EG-PCM,40wt/%OC//EP-PCM and40wt/%LA//EP-PCM as theresearch objects to study the phase transformation kinetics, firstly the activation energy E andthe former factor A could be estimated by the Kissinger equation and Ozawa equation,through extrapolation processing with Coats-Redfern integral equation and Ozawa equation,then it could be concluded that, the mechanism functions for three kinds of materialsseparately in accordance with Mampel Power Rule, Mample single-line Rule /(first class/),Avrami-Erofeev Equation. The integral equations of mechanism function are G/(α/)=α3//2, G/(α/)=-ln/(1-α/) and G/(α/)=/[-ln/(1-α/)/]2//3respectively. In the research of the application of PCMs in construction materials, at first, according to a certain volume ratio, mixed RT28//EP-PCMs, which have been prepared well before, withcement and water to make the PCMs heat storage mortar, then PCMs cement boards andPCMs cement plates were prepared through the standard mold /(70.7×70.7×70.7mm~3/) andself-made mold /(10×100×100mm~3/) respectively. Compared with the normal swellingperlite cement boards, when the content of RT28reached40wt/%, the values of apparentdensity,7-days compressive strength and thermal conductivity of PCMs cement boards orplates almost increased by37.2/%,40/%and35.2/%, respectively, all of which were within thestandard values. A closed cube was made with six PCMs cement plates to measure the energy-savingefficiency by using the Xenon lampe simulating the solar radiation, of which the size was100×100×100mm~3and the thickness was10mm. Then the temperature variation of four testingpoint of the cube was measured respectively, which was divided into group A and group B test.Under the same conditions, the maximum temperature difference between the outside topplate and the internal room of the cube increased with the increasing amount of RT28inPCMs gradually. In addition, when the mass ratio of RT28increased to40wt/%, the maximumtemperature difference of group A and B jumped to25℃and25.231℃, respectively. It canbe concluded that, the ordinary building materials, after being added with a certain amount ofPCMs, could play a role in adjusting and reducing the fluctuation of indoor temperature.Moreover, the higher content of RT28was, the energy-saving performance would be thebetter.

关 键 词： 相变材料 膨胀珍珠岩 相变动力学 建筑材料

分 类 号： [TU50]

领　　域： [建筑科学]