纳米氧化铜/辛酸-肉豆蔻酸相变储能材料的制备及热物性

辛酸(OA)-肉豆蔻酸(MA)是一种极有发展潜力的相变材料,但是因过低的导热系数限制了其进一步大规模推广。通过添加纳米氧化铜(CuONP)改善其导热性,制备了一种融化温度在7~9℃的可用于空调蓄冷系统的新型相变储能材料。利用理论模型预测OA-MA二元共熔体系的融化温度与相变潜热,发现计算结果与实验不符。对比不同分散剂对CuONP的分散效果,发现白猫洗洁精分散效果最好。通过步冷试验、差示扫描量热法(DSC)、瞬态平面热源法(Hotdisk)及加速热循环实验,对比不同质量比CuONP对OA-MA在宏观热表现、融化温度、相变潜热、导热系数与热扩散率等方面的影响来研究纳米流体的传热传质机理,并提出了热扩散率与相变潜热的拟合曲线;根据材料300次与600次循环后的融化温度与相变潜热,发现该材料循环热稳定性较好。

Preparation and Thermophysical Properties of Nanometer Copper Oxide/Octylic-myristic Acid as PCMs for Thermal Energy Storage

Octylic acid (OA)/myristic acid (MA)is one of phase change materials (PCMs)with great poten-tial,but it is limited due to its low thermal conductivity.Nanometer copper oxide (CuONP)was added into to OA-MA,and a novel PCMs with melting temperature of 7-9 ℃ for air-conditioning energy storage system is prepared. Theoretical forecast model was used to predict the melting temperature and latent heat of eutectic mixture (OA-MA), and prediction is in bad agreement with the experimental results.White-cat detergent was found to have best disper-sion effect by comparing with other three dispersants.The influences of different mass fractions of nanometer copper oxide on composite′s macroscale thermal performance,melting temperature,latent heat,thermal conductivity and thermal diffusivity were obtained by means of thermal performance test,differential scanning calorimeter (DSC), transient plane source method(Hotdisk)and accelerated thermal cycling test.The results were compared in order to explore heat and mass transfer mechanism of nanofluid,and the fitting formulas of thermal diffusivity and latent heat were proposed.The resultant composite was found to perform well in thermal reliability according to its melting tem-perature and latent heat after 300 and 600 cycles.