The Research Of Modified Carbon Foam And Its Phase Change Material

Graphite, as a phase change material container (PCM), could improve the thermal conductivity of PCMs. Besides, the compression strength, the corrosion resistance and the stability to environment could also be improved. However, there is still space optimizing the conductivity and compression strength. The application of graphite foam with PCMs has attracted great concentration.In this paper, the pitch foam was prepared via blowing method, after carbonization and graphitization, the PCMs was filled into the graphite foam by infiltration.The research content are followed:(1)During the progress of pitch blowing, choosing appropriate temperature (330?),and controlling blowing pressure from 2MPa to lOMPa.The micro-properties were investigated by XRD?SEM and the bulk density, compression strength characterization by flash diffusivity instrument or universal tester.(2)Adding nano carbon powder/graphite particles/carbon nanotube/boron carbide to modify carbon foam, investigating the porosity, pore size distribution, ligament width and graphitization degree and crystallinity performance which were affected by fillers. The results showed that:20wt% graphite particles was the most appropriate addition on compressive strength, reaching 8.07MPa. Adding 1wt% CNTs under the condition of 1600? carbonization made the carbon foam's thermal conductivity reach 7.1W/(m·K), which was the best choice. After graphitization the thermal conductivity could reach 14.51 W/(m-K).(3)Using melting impregnation method to make pure bubble and modified foam carbon composite respectively, comparing their different of impregnation ratio, phase change latent heat after impregnation and modification. The results indicated that taking both the thermal conductivity and the compressive strength into consideration, 1wt% CNTs was the most suitable choice, and the maximal value of impregnation rate and phase change latent heat reached maximal value 164.4%,142.5kJ/kg.