This paper briefly introduces the preparation of nanocopper-erythritol. According to the internal mechanism of the change of thermal property in phase change material (PCM)

the causes of material changes in the circulation process are explored. Using test data from differential scanning calorimetry and a thermal conductivity tester (Hotdisk)

the heat conductivity coefficient

supercooling degree

and latent heat during 0

20

40

60

80

and 100 thermal cycles are analyzed. The change process of PCMs is summarized based on the point of growth of material entropy which is introduced through the thermodynamic principle of thermodynamic entropy. Experimental results show that after 100 cycles

the performance parameters of the phase change material have been decreased differently. The declining degree of the thermal conductivity coefficient is lower when the amount of nanocopper increases. The overall cooling degree of erythritol with nanocopper added is less than that of erythritol without nanocopper. In the latter stages

the declining degree of the latent heat value increases as the number of cycles increases.