Effect of nanoparticle dispersion and inclination angle on melting of PCM in a shell and tube heat exchanger

This paper presents an experimental numerical study on melting behavior of a phase change material in a shell and tube heat exchanger. Thus the effects of parameters including adding Nano-Enhanced Phase Change Material (NEPCM) and inclination angle are considered and investigated. Experimental studies are designed to characterize PCM/NEPCM properties. The details of the process progression are presented via temperature contours, streamlines and phase front displacement. Enthalpy porosity method is used for modeling of the phase change process in which pure conduction and natural convection are considered in the simulation. Results reveal that thermal conduction mechanism is dominated at initial and final steps of melting that slows down the process. As the process advances, the buoyancy effect becomes dominant in the melting process. By increasing mass fractions of nanoparticle, thermal conductivity coefficient increases that leads to faster melting rate at the bottom of the heat exchanger. Also results indicate that increasing inclination angle leads to faster pace of melting at higher attitudes that results in shorter total melting time. Contemporaneous adding nanoparticle and increasing inclination angle reveals that both natural convection and thermal conductivity improves that leads to better melting of NEPCM. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.