DEVELOPMENT OF A MODEL COMPATIBLE WITH SOLAR-ASSISTED CYLINDRICAL ENERGY-STORAGE TANK AND VARIATION OF STORED ENERGY WITH TIME FOR DIFFERENT PHASE-CHANGE MATERIALS

In this work, the performance of a solar assisted cylindrical energy s torage tank is investigated theoretically. A model describing the tran sient behavior of a phase change energy storage unit is used. The mode l of the tank holds the numerical description of a short term (by day) heat-storage tank. Tn the tank, the energy is stored as the latent he at of the phase change material (PCM). In the tank, the PCM is packed in cylinders, and the heat transfer fluid (HTF) flows parallel to it. The basis of the model is the enthalpy method. The resulting set of eq uations is solved by means of the Gauss-Seidel iteration process. Sele cted computer simulations are drawn versus some parameters of the mode l, and the heat storage capacities of different PCMs, which can be use d as heat storage materials for domestic heating by heat pumps, were d etermined and compared. Results show that the PCM, cylinder radius, th e mass how rate, and the inlet temperature of the HTF must be chosen c arefully in order to optimize the performance of the tank. Copyright ( C) 1996 Elsevier Science Ltd