An Experimental Study on a Combined Sensible-Latent Heat Thermal Energy Storage System for Different Positions of PCM

Global energy demand has proliferated in the past few decades and it is likely to escalate in the future. This alarming situation has called for an alternative source of energy that is renewable and environment-friendly. Solar energy is abundantly available and renewable in nature and can cater to the balance of energy demand and supply. Due to the intermittent nature and of solar energy, there is a need to integrate efficient solar energy storage systems. In TES systems, sensible and latent heat storage technologies were later innovated into a novel combined sensible-latent heat thermal energy storage system. The experimental investigation has been performed using concrete balls and paraffin wax encapsulated with stainless steel as phase change material (PCM) capsules of the same size as sensible and latent heat storage media respectively. Under this present experimental study, emphasis has been given to the effect of the placement of PCM spheres inside the storage container. The experimental trials were performed on combined TES with a 20% volume fraction of PCM for two different positions of PCM. It was observed that keeping the flow rate constant at 0.025 kg/s and 0.032 kg/s while shifting the PCM from the middle to top of the tank resulted in an increment of total energy storage by 6% and 4% respectively simultaneously reducing the charging time by 8% and 7.5% respectively.