The Effect of Angular Orientation and Eccentricity on the Melting Characteristics of a Latent Heat Thermal Energy Storage System: A Numerical Investigation

Abstract

Abstract Phase change materials (PCMs) are employed for storing latent heat energy contents in small regions owing to their high energy storage capacity at nearly constant temperature. The structural adjustment is proposed to study the effect on the melting rate of PCM to tackle the low thermal conductivity issue. A two-dimensional numerical model was developed to study the overall performance related to charging behaviour by way of firstly, performance analysis of the concentric position of Latent heat storage in a twin tube thermal energy system (TTTES) and secondly eccentricity of the inside tube in the heat exchanger. Analysis has been conducted for cases involving inclination in the heat exchanger, including scenarios with both concentric and eccentric configurations. In total 35 modes for the angular positions of 0°, 15°, 30°, 45°, 60°, 75°, and 90° having an inner tube eccentricity of 10, 20, 30, and 40 mm were identified and simulated. The findings revealed that the 90° angle of inclination (vertical) outperformed in terms of melting in comparison to other configurations of concentric TTTES. The result could be documented in terms of melting time reduction by 75% for a 90° angle of inclination in contrast to its 0° counterpart. Alongside that, the inner tube with a 20 mm eccentricity value recorded the best melting performance in comparison to all other eccentricity values. The TTTES demonstrates its maximum energy storage capacity of 307.72 kJ/kg at an inclination angle of 75° and an eccentricity of 10 mm.