NUMERICAL-SIMULATION OF A MULTILAYER LATENT-HEAT THERMAL-ENERGY STORAGE-SYSTEM

A computational model for the prediction of the thermal behaviour of a compact multi-layer latent heat storage unit is presented. The model is based on the conservation equations of energy for the phase change material (PCM) and the heat transfer fluid (HTF). Electrical heat sour ces embedded inside the PCM are used for heat storage (melting) while the flow of an HTF is employed for heat recovery (solidification). Par ametric studies are performed to assess the effect of various design p arameters and operating conditions on the thermal behaviour of the uni t. Results indicate that the average output heat load during the recov ery period is strongly dependent on the minimum operating temperature, on the thermal diffusivity of the liquid phase, on the thickness of t he PCM layer and on the. HTF inlet mass flowrate and temperature. It i s, on the other hand, nearly independent of the wall thermal diffusivi ty and thickness and of the maximum operating temperature. Correlation s are proposed for the total energy stored and the output heat load as a function of the design parameters and the operating conditions. (C) 1998 John Wiley & Sons, Ltd.