正二十烷/十二水磷酸氢二钠/膨胀石墨复合相变蓄热储能材料的制备与性能分析

The study on the preparation and performance of the N-E/DHPD/EG composite phase change materials

为解决十二水磷酸氢二钠的过冷、相分离、循环稳定性等问题,研发制备N-E/DHPD/EG复合相变材料,并对其各项性能进行表征分析。N-E/DHPD/EG复合相变材料过冷度降低到1℃以内,同时保持了229 J/g以上的相变焓,在保证相变焓不产生过大降低的情况下,复合相变材料过冷度问题得到很好的改善。同时,膨胀石墨的加入,极大的提升了复合相变材料的导热系数达1.086 W/(m·K)以上,且循环稳定性较好。

To solve the problems of supercooling,phase separation and cycle stability of disodium hydrogen phosphate dodecahydrate,the N-E/DHPD/EG composite phase change materials are developed and prepared,and their properties are characterized,and the law and mechanism of performance change are explored.N-E/DHPD/EG composite phase change materials were prepared by vacuum impregnation.The supercooling degree of the composite phase change material is reduced to less than 1℃,and the enthalpy of phase change above 229 J/g is maintained.Under the condition that the enthalpy of phase change does not decrease too much,the supercooling degree of the composite phase change material has been solved.The mechanism of supercooling problem is revealed from thermodynamic point of view.By adding expanded graphite,the thermal conductivity of the composite phase change material is more than 1.086 W/(m·K),and the cycle stability is better.