三水合醋酸钠纳米成核剂的性能研究

三水合醋酸钠是一种具有较高的储能密度和热导率的储热相变材料,但是在凝固过程中的过冷和相分离现象限制了它的应用,需要寻求有效的成核剂和增稠剂来克服过冷和相分离的问题。本文实验分析了几种纳米材料（AIN、Si₃N₄、ZrB₂、SiO₂、BC₄、SiB₆）的成核效果,结果表明质量分数5%或4%的Si₃N₄、10%ZrB₂、5%AlN在自然分散下就能够消除三水合醋酸钠过冷度,质量分数2%的SiO₂在熔化的三水合醋酸钠中经磁力搅拌和超声分散后能够消除其过冷度。结合纳米材料的粒度分析结果,表明粒度分布在几十纳米到300纳米左右的纳米材料有较好的成核效果。

Study on the Performance of Nanoparticles as Nucleating Agents for Sodium Acetate Trihydrate

Sodium acetate trihydrate（SAT）,which has high energy storage density and high thermal conductivity,is an important phase change material（PCM） for thermal storage.However,the problems of supercooling and phase segregation during the freezing process limit its application,which need the effective nucleating and thickening agents.In this study,the effect of several nano-materials （AlN,Si₃N₄,ZrB₂,SiO₂,BC₄,SiB₆） as nucleating agents for SAT are experimental investigated.The results show that the additions of 5%or 4%Si₃N₄,10%ZrB₂,5%AlN naturally dispersed in SAT are able to eliminate the supercooling of SAT.2%ultrasonic dispersed nano-SiO₂,which is premixed by magnetic stirring in the melting SAT,can be to eliminate the supercooling.The measured size distributions show that the nanoparticles with the size range from several tens of nanometers to about 300 nm are the effective nucleating agents for SAT.