Performance Evaluation of Coupled Thermal Enhancement through Novel Wire-Wound Fins Design and Graphene Nano-Platelets in Shell-and-Tube Latent Heat Storage System.

Abstract

Technological development in latent heat storage (LHS) system is essential for energy security and energy management for both renewable and non-renewable sources. In this article, the numerical analyses on shell-and-tube based LHS system with coupled thermal enhancement through ex-tended fins and nano-additives are conducted to propose optimal combinations for guaranteed higher discharging rate, enthalpy capacity and thermal distribution. Transient numerical simu-lations of fourteen scenarios with varied combinations are investigated in three-dimensional computational models. Shell-and-tube includes paraffin as phase change material (PCM), longi-tudinal, radial and wire-wound fins and graphene nano-platelets (GNP) as extended fins and nano-additives, respectively. The extended fins have demonstrated better effectiveness than nano-additives. For instance, the discharging durations for paraffin with longitudinal, radial and wire-wound fins are shortened by 88.76%, 95.13% and 96.44% as compared to 39.33% for paraffin with 2.5% GNP. The combined strengths of extended fins and nano-additives have indicated further enhancement in neutralising the insulative resistance and stratification of paraffin. However, the increase in volume fraction from 1% to 3% and 5% is rather detrimental to total enthalpy capacity. Hence, the novel designed wire-wound fins with both base paraffin and paraffin with 1% GNP are proposed as optimal candidates owing to their significantly higher heat transfer potentials. The proposed novel designed configuration can retrieve 11.15 MJ of thermal enthalpy in 1.08 h as compared to 44.5 h for paraffin in conventional shell-and-tube without fins. In addition, the proposed novel designed LHS systems have prolonged service life with zero maintenance and flexible scalability to meet both medium and large-scale energy storage demands.