Convective heat transfer by micro-encapsulated PCM in a mini-duct

Abstract

The phase change materials (PCMs) have almost constant temperature during phase change. This property makes them favorable materials in the heat transfer process. This paper examines the heat transfer characteristics of these particles in a mini-channel using the two-phase model in the Eulerian-Lagrangian view. In this method, fluid is studied using a control volume method (SIMPLE for velocity and pressure domains), and particles are studied using the Lagrangian view. The study is performed for water-based fluid and Paraffin wax micro-particles with 30 μm diameter which have been covered by a thin layer of Fe3O4, with different volumetric concentrations from 0 to 10% and Subcooling number in the range of Sb = 0 to 0.8 and in a wide range of the Reynolds number from 250 to 1000. The results show that the most increase in the heat transfer rate occurs at Sb = 0. In this case and for Re = 1000 and the volumetric concentration of 10%, Nusselt number increases by 13%. This increase is small due to the absence of particles near the wall.