三元复合相变蓄冷材料的制备及传热性能优化

Preparation and heat transfer performance optimization of ternary composite phase change cold storage materials

为寻找高潜热的复合相变蓄冷材料,以正癸酸(DA)、十二醇(LA)、十四烷(TD)3种有机物为原料,通过低共熔法得到高潜热的TD-LA二元混合物(质量比为0.68∶0.32),利用此二元混合物为主储能剂,以DA为温度调配剂,制备得到新型三元有机复合相变蓄冷材料。通过DSC测试进行筛选,得到TP(TD∶LA∶DA质量比为0.598∶0.282∶0.12)。针对其热导率低的缺陷,利用膨胀石墨(EG)独特的多孔结构和高吸附性,制备得到高导热复合相变材料TP/EG,并对TP/EG进行100次高低温循环实验。结果表明,TP的相变温度为1.1℃,相变潜热为258.3 J/g,热导率为0.201 W/(m·K),加入EG后得到TP/EG(最优质量比为15∶1),热导率为1.528 W/(m·K),热导率提高7.6倍。在循环过程中热性能均未发生太大变化,具有良好的热稳定性,在冷链物流中具有较大的应用价值。

In order to find appropriate composite phase change materials for cold storage with high latent heat,n-decanoic acid(DA),Lauryl alcohol(LA)and n-Tetradecane(TD)were employed as raw materials,TD-LA binary mixture with high latent heat(mass ratio is 0.68∶0.32)was obtained by the low eutectic method.This binary mixture was used as the main energy storage agent,and DA was used as the temperature blending agent.A new ternary organic composite phase change material for cold storage was prepared.TP(TD∶LA∶DA=0.598∶0.282∶0.12)was obtained by the DSC test.In view of its low thermal conductivity,TP/EG composite phase change material with high thermal conductivity was prepared by using the unique porous structure and high absorbability of Expanded graphite(EG),and the thermal cycling measurements were conducted 100 times for TP/EG at high and low temperature.The results showed that the phase transition temperature of TP was 1.1℃,the latent heat of TP was 258.3 J/g,thermal conductivity was 0.201 W/(m·K).The results also indicated that the thermal conductivity increased to 1.528 W/(m·K)with the optimal ratio of 15∶1 for TP/EG,which was 7.6 times higher than that of TP.TP/EG composite phase change material has excellent thermal stability and great application potential in the cold chain logistics.