甲酸钠/氧化铜复合相变材料的制备与热力学性能测试

摘要

Nano-copper oxide/sodium formate composites as phase change material were prepared. Sodium formate (HCOONa · 2H2O)was selected as a phase change material by comparing its cooling curve with sodium acetate (CH3COONa),sodium propionate(C2H5COONa)and ammonium chloride(NH4Cl)solutions. Experimental results showed that sodium formate solutions with mass fraction of 29.4 wt% performed best. Nano-copper oxide(nano-CuO)was chosen to improve the thermal conductivity of the composites among different kinds of nano-metals and nano-metal oxides. An ultrasonic oscillation device was used to make the nanoparticle solution. The results also showed that the sodium formate with 0.5 wt%nano-copper oxide was optimal. Thermal performances of the compos⁃ites were investigated by a differential scanning calorimetry and a thermal constant analyzer. The results showed that the latent heat of phase change of the composites was 250.4 J/g and phase change temperature was-16 ℃. Thermal conductivity of the composite with 0.5 wt%nano-copper oxide was 1.078 W/(m · K),increased by 9.66%compared with 0.983 W/(m · K)of pure sodium formate solution. Chemical degradation of the nano-copper oxide/sodium formate composites didn’t occur.%配制了甲酸钠/氧化铜复合相变材料。通过恒温槽实验对比了甲酸钠，乙酸钠，丙酸钠以及氯化铵的性能，选择了性能最优的甲酸钠。通过配制不同浓度的甲酸钠溶液，对比其性能，发现29.4 wt%甲酸钠溶液的效果最好。为了优化溶液的导热性能，通过对比不同纯金属纳米材料和金属氧化物纳米材料的种类以及对比添加同种纳米材料不同的质量分数，发现添加0.5 wt%的氧化铜效果最优。通过Hot Disk和DSC实验对配方进行了导热值以及潜热值的测量，结果显示添加了纳米材料的配方其潜热为250.4 J/g，相变温度为-16℃，导热系数为1.078 W/（m·K），比未添加的导热能力提高了9.66%。实验过程中未发生化学沉降等现象。