A novel numerical investigation of a solar PCM heat exchanger for indoor temperature stabilization

Minimization of temperature variations in indoor buildings is a challenge in tropical climates having a disparity with outdoor weather conditions. This paper presents a novel method to numerically analyze thermal stabilization characteristics for an indoor test volume (TV) using a phase change material heat exchanger (PCM-HX). In this approach, the computational time and power costs of numerical simulations is three times reduced by replacing an actual 3D HX with three 2D orthographic projections. The numerical results are experimentally validated with a maximum deviation of 4.5 % and 6.5 % for the PCM and TV temperatures, respectively. The effects of the size of the TV, position of the HX and different PCM phase change temperatures are explored in a parametric study. The final temperature achieved at the end of the melting process are 49 °C, 46 °C and 37 °C for TV1 (0.1125 m³), TV2 (0.76455 m³), TV3 (2.43965 m³), respectively, demonstrating the effectiveness of the PCM-HX even in larger volumes. The PCM-HX performs the best while positioned in the middle of the TV with a highest TV temperature of 47.72 °C at the end of charging. The PCM having the lowest melting range (30 °C - 35 °C) achieves complete melting in the fastest time of 0.161 h.