Experimental process investigation of a latent heat energy storage system with a staggered heat exchanger with different phase change materials for solar thermal energy storage applications

¹ Technological Educational Institute of Sterea Ellada, Mechanical Engineering Department, Energy and Environmental Research Laboratory, 344 00 Psachna, Evia, Greece
² Z&X Mechanical Installations Ltd, 12 Agapinoros Street, 8049 Paphos Cyprus
³ Technological Educational Institute of Sterea Ellada, Department of Electrical Engineering, Laboratory of Chemistry and Materials Technology, 344 00 Psachna, Evia, Greece

^* Corresponding author: mkoukou@mail.teiste.gr, m_koukou@otenet.gr

Abstract

This work investigates melting and solidification processes of four different Phase Change Materials (PCM) used as latent heat thermal storage system. The experimental rig was consisted of an insulated tank, filled with the under investigation PCM, a staggered heat exchanger to supply or extract heat from the PCM cavity and a water pump to circulate Heat Transfer Fluid (HTF). Both charging (melting) and discharging (solidification) processes were conducted for two different HTF flow rates. The main scope of this work was to develop a first approach and to investigate the behaviour of PCM under various load conditions (different HTF flow rates). Results show that different HTF flow rates affect melting and solidification time periods; in both processes time was reduced while HTF flow rate was increased but in differentways due to the transition from conduction to convection heat transfer mechanisms.