Hou Pumin, Mao Jinfeng, Chen Fei, Li Yong, Dong Xian
College of Defense Engineering, Army Engineering University of PLA, Nanjing 210007, China.
Materials (Basel). 2018 Nov 9;11(11):2230. doi: 10.3390/ma11112230.
In this paper, a series of Na₂SO₄·10H₂O⁻KCl eutectic mixtures were prepared by adding different mass fractions of KCl (1 wt.%, 3 wt.%, 5 wt.%, or 7 wt.%) to Na₂SO₄·10H₂O. Polyacrylamide (PAM) was proposed as the thickener, sodium tetraborate decahydrate (STD) was proposed as the nucleating agent, and expanded graphite (EG) was proposed as the high thermal conductivity medium for Na₂SO₄·10H₂O⁻5 wt.% KCl eutectics. The results showed that in Na₂SO₄·10H₂O⁻5 wt.% KCl eutectics with 5 wt.% PAM and 5 wt.% STD, almost no phase separation occurred, and the degree of supercooling was reduced to 0.4 °C. The thermal performance of Na₂SO₄·10H₂O⁻5 wt.% KCl composite phase change materials (CPCMs) with varying contents of EG was explored. The results showed that EG could improve the thermal conductivity effectively and that the mass fraction of EG should be no more than 3%, otherwise the crystallization value and supercooling would deteriorate. The thermal reliability of the Na₂SO₄·10H₂O⁻5 wt.% KCl eutectic CPCMs containing 5 wt.% PAM, 5 wt.% STD, and 3 wt.% EG was investigated, mainly through the ambient temperature, thermal cycling test, and TGA analysis. The results demonstrated that these CPCMs showed perfect thermal reliability.
在本文中，通过向十水合硫酸钠（Na₂SO₄·10H₂O）中添加不同质量分数（1 wt.%、3 wt.%、5 wt.%或7 wt.%）的氯化钾（KCl），制备了一系列Na₂SO₄·10H₂O⁻KCl共晶混合物。提出将聚丙烯酰胺（PAM）用作增稠剂，十水合四硼酸钠（STD）用作成核剂，膨胀石墨（EG）用作Na₂SO₄·10H₂O⁻5 wt.% KCl共晶体系的高导热介质。结果表明，在含有5 wt.% PAM和5 wt.% STD的Na₂SO₄·10H₂O⁻5 wt.% KCl共晶体系中，几乎不发生相分离，过冷度降低至0.4℃。探索了不同EG含量的Na₂SO₄·10H₂O⁻5 wt.% KCl复合相变材料（CPCM）的热性能。结果表明，EG能有效提高热导率，且EG的质量分数不应超过3%，否则结晶值和过冷度会变差。主要通过环境温度、热循环试验和热重分析（TGA）研究了含有5 wt.% PAM、5 wt.% STD和3 wt.% EG的Na₂SO₄·?10H₂O⁻5 wt.% KCl共晶CPCM的热可靠性。结果表明，这些CPCM表现出良好的热可靠性。
