Entropy generation assessment of shell and tube latent heat storage unit

Thermodynamic optimisation for latent heat thermal energy storage unit (LHSU) is carried out using the theory of minimisation of entropy generation number. The influence of key parameters like heat transfer fluid (HTF) inlet temperature, initial temperature of phase change material (PCM) and mass flow rates of HTF on entropy generation number is analysed. Analysis is carried out for two PCMs, i.e., paraffin wax and stearic acid, with different melting temperature to establish the influence of melting temperature of PCM on entropy generation number. The results show that minimum HTF inlet temperature provides minimum entropy generation number. The results also demonstrate that higher initial temperature of PCM provides minimum entropy generation number during solidification process. The mass flow rate of HTF has negligible influence on the entropy generation number compared with the influence of fluid inlet temperature and initial temperature of PCM.