In order to solve the problems of high supercooling degree

low thermal conductivity and poor cycle stability of single hydrated salt phase change material

ammonium aluminum sulfate dodecahydrate was used as phase change material

Al_2O_3 and xanthan gum were used as additives to modify ammonium aluminum sulfate dodecahydrate by melt blending

and a new composite phase change material was prepared by using porous adsorption method to composite modified expanded graphite and modified ammonium aluminum sulfate dodecahydrate. The thermophysical properties

supercooling degree

cycle stability and material compatibility were analyzed. The results show that

the melting point

latent heat and thermal conductivity of the composite phase change material were 93.23 ℃

235.40 k J/kg and 4.086 W/(m·K)

respectively. After 50 cycles

the supercooling degree was stable at 24 ℃

and after 300 cycles

the latent heat only decreased by 5.9%

with good stability. The 316 L stainless steel and composite phase change materials have good compatibility

and can be used as packaging container materials. The composite phase change material has good performance and great application potential in building heating.