Thermal analysis of latent heat storage system in vertical and horizontal configurations under simultaneous charging and discharging processes

Abstract

• Thermal transport with simultaneous changing and discharging analyzed. • Melting behavior of PCM for vertical and horizontal configurations studied. • Examined heat transfer fluids temperature gradient on thermal performance. • Horizontal configuration exhibited better thermal performance. The study aims to evaluate the thermal performance of a phase change material (PCM) based shell and tube heat exchanger in vertical and horizontal configurations under simultaneous charging and discharging (SCD) processes. The PCM considered is lauric acid. The influence of temperature gradient between hot and cold heat transfer fluids (HTFs), mass flow rate, and position (vertical and horizontal) on temperature, melt fraction, energy storage, and thermal transport are investigated. Numerical analysis is performed by the enthalpy porosity model. Two cases are considered to analyze the influence of the temperature gradient of the hot and cold HTFs. In case 1 the hot fluid inlet temperature is varied and the cold fluid inlet temperature is maintained constant Δ T h , and for case 2 the cold HTF inlet temperature is varied and the hot HTF inlet temperature is maintained constant Δ T c . It is found that the melting process can be considerably improved for case 1 by increasing the temperature gradient. However, in case 2 by increasing the temperature gradient the influence on the melting process is not significant for horizontal but exhibited a stronger influence for vertical configuration. With the reduction of Δ T h from 53 °C to 33 °C the energy storage is noted to decrease by 50.83 % and 43.99 % in vertical and horizontal configurations. Additionally, the mass flow rates of hot and cold HTFs are observed to have less effect on thermal transport.