Pore-scale numerical analysis of randomly packed core-shell particles containing high-temperature carbonate phase change material

Authors:
  • WLWenwei Liu
    Wenwei Liu
  • XSXinlin Shi
    Xinlin Shi
  • PPPeng Peng
    Peng Peng
  • JWJiangyan Wang
    Jiangyan Wang
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Abstract
The melting performance of spherical particles with core-shell structure containing sodium carbonate as high temperature phase change material is systematically investigated through a fully resolved lattice Boltzmann simulation. Three types of highly conductive shell materials are considered to facilitate the melting of PCM. The numerical simulation shows that the complete melting time of a single particle decreases linearly with the increase of shell thickness. It is suggested that the thermal conductivity of the shell material is at least 10 times of that of PCM to realize significant improvement of melting performance. For randomly packed particle bed, the melting time decreases exponentially with the increase of packing density due to the contact network with high thermal conductivity. Therefore, the optimized packing density is expected to be ϕ=0.5~0.6, which is close to the densest state of a random packing of particles.