Design and Taguchi-based optimization of the latent heat thermal storage in the form of structured porous-coated pipe

In this paper, the solidification and melting processes of phase change material within a Structured Porous-Coated Pipe (SPCP) are investigated, numerically. It is the first time that the applicability of Structured Porous in heat transfer enhancement in PCM is studied. In an SPCP, a pipe is surrounded by a coarse structured porous media and filled with PCM. Since the pore geometry is structured, its behavior is not statistically randomized. Different geometries for SPCP with different materials are designed and simulated. Substantial improvement in heat transfer enhancement, by as much as an order of magnitude, is observed. For example for stainless steel with a relatively low thermal conductivity, the average heat transfer rate increases to 0.61 W from 0.12 W. So, the melting time is reduced to 20% of the required time for simple annuls. For more conductive materials like aluminum and copper, the average heat transfer is 13.5 and 15.25 times a simple annulus, respectively. Finally, Taguchi–based sensitivity analysis and ANOVA are performed. It is shown that the type of material is more important than the thickness of the porous structure. The material contributions percentage for charging and discharging are 51.1% and 40.5%. Also, these values for ΔT are 40.4% and 45.3%, respectively.