微乳相变材料的流变及储热性能试验  

Experimental studies on rheological and thermal storage behaviors of micro emulsion phase change materials

作　　者：王娜峰 王炜 姚华[1] 李悦悦 黄云[1] WANG Wei;WANG Na-feng;YAO Hua;LI Yue-yue;HUANG Yun(State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;State Grid Shenyang Power Supply Company,Shenyang 110035,China)

机构地区：[1]中国科学院过程工程研究所多相复杂系统国家重要实验室,北京100190 [2]国网公司沈阳供电公司,沈阳110035

出　　处：《安全与环境学报》2021年第6期2737-2742,共6页Journal of Safety and Environment

基　　金：国家自然科学基金项目(21975262,21808225);国家重点研发计划项目(2017YFB0903601);国网公司沈阳供电公司研究计划项目(SGLNSY00FZJS1801423)。

摘　　要：为提高微乳相变材料的储热性能,制备了石蜡-饱和盐溶液的油包水型微乳相变材料。探究乳化剂种类对液滴直径分布、流变特性及黏温曲线的影响,并重点关注KNO_(3)、NaNO_(3)、NaSO_(4)饱和盐溶液对微乳相变材料热容的影响规律。同时,借助导热仪测定微乳相变材料的热扩散速率,并进一步得到材料的导热系数。此外,为提高微乳相变材料导热性能,对比了添加导热油后的导热性能。结果表明:Span-80作为表面活性剂时,黏度下降较为明显;而Triton(曲拉通)作为表面活性剂时,温度超过75℃黏度才出现下降趋势。值得注意的是,黏度随剪切速率的变化规律归因于材料自身的剪切变稀行为。在40~90℃温度区间内,相变材料的最大热容为182 kJ/kg,是相同条件下水介质的4.3倍。添加导热油可显著提高材料的导热性能,50℃时导热系数由0.233 W/(m·K)提高至0.456 W/(m·K),当温度升至60℃时,这种趋势更加明显。In this paper,the micro emulsion phase change materials of paraffin and salt-saturated solution with water-in-oil structure were prepared in order to improve the thermal storage performances of micro emulsion phase change materials.The influences of emulsifier types on droplet size distribution,rheological properties and viscosity-temperature curves were explored,and the effects of one or more saturated salt solutions on the heat capacity of micro emulsion phase change materials were investigated.At the same time,the thermal diffusion coefficient of the micro emulsion phase change material was measured with a thermal conductivity meter,and then the thermal conductivity of the materials was further obtained.Besides,the heat-transfer oil was added to further elevate the thermal conductivity performances.For the emulsion phase change materials with span-80,the viscosity sharply decreases.On the contrary,the viscosity of Triton first keeps constant and then tends to decrease when the temperature exceeds 80 ℃.It is noteworthy that the decreasing in the viscosity with the shear rate is attributed to the shear thinning behavior.Moreover,it is found that the emulsion phase change materials can be considered as an attractive alternative to water since their highest heat capacity(182 kJ/kg) is 4.3 times as high as that of water when the temperature ranges from 40 ℃ to 90 ℃.Adding thermal conductivity oil leads to the increase of thermal conductivity from 0.233 W/(m·K) to 0.456 W/(m·K),and the trend becomes more obvious when the temperature rises to 60 ℃.The above experimental results show that the prepared micro emulsion phase change materials exhibit higher heat capacity and thermal conductivity,and their broad application prospects in industrial waste heat recovery and heat transfer fields are expected in the future.

关 键 词：环境工程学 相变储热材料 微乳 流变特性 储热性能 

分 类 号：X5[环境科学与工程—环境工程]