基于泡沫铜骨架高导热复合相变储热材料的热性能研究

Research on Thermal Performance of High Thermal Conductivity Composite Phase Change Material Based on Foamed Copper Framework Material

八水氢氧化钡(Ba(OH)_(2)·8H_(2)O)是低温相变材料(0~200℃)中相变潜热最高的相变材料,但因为其稳定性差、导热系数低,限制了它在相变储热领域进一步发展。在八水氢氧化钡中添加纳米氧化铜与羟乙基纤维素制得了改性八水氢氧化钡,并在此基础上将改性八水氢氧化钡填充进泡沫铜中制得泡沫铜/改性八水氢氧化钡定型复合相变材料。实验研究发现,加入0.2%(质量分数)纳米氧化铜、0.5%(质量分数)羟乙基纤维素时,改性八水氢氧化钡热性能最好,过冷度为0.5℃,无相分离现象,对比纯八水氢氧化钡相变潜热仅下降3.6%。改性八水氢氧化钡/泡沫铜复合相变材料导热系数为12.4 W/(m·K),是纯八水氢氧化钡导热系数的10.3倍,此定型复合相变材料兼具良好的稳定性与高导热性能。

Barium hydroxide octahydrate(Ba(OH)_(2)·8H_(2)O)is the phase change material with the highest latent heat of phase change among low temperature phase change materials(0—200℃).However,it is limited to developed further in the field of phase change heat storage due to the poor stability and low thermal conductivity.Nano⁃copper oxide and hydroxyethyl cellulose were added to barium hydroxide octahydrate to prepare modified barium hydroxide octahydrate,and on this basis,the modified barium hydroxide octahydrate was filled into the foamed copper to prepare the foamed copper/modified barium hydroxide octahydrate composite phase change material.It is found that,when 0.2wt%nano⁃copper oxide and 0.5wt%hydroxyethyl cellulose are added,the thermal performance of modified barium hydroxide octahydrate is the best,with the subcooling degree of 0.5℃and no phase separation phenomenon,and compared with pure barium hydroxide octahydrate,the latent heat of phase change only decreases by 3.6%.The thermal conductivity of the modified barium hydroxide octahydrate/copper foam composite phase change material is 12.4 W/(m·K),which is 10.3 times as high as the thermal conductivity of pure barium hydroxide octahydrate.The shaped composite phase change material has both great stability and high thermal conductivity.