Experimental Investigation on a Solar Thermal Energy Packed Bed Sensible Heat Storage Combined with Latent Heat Storage

The thermal energy storage is required to store the solar energy, which can be stored by using sensible, latent and thermo-chemical heat storage energy systems. The sensible heat storage is more reliable and full-fledged technology, but it is low efficient due to low heat storage density. In the present study, experimental setup is developed by combining the sensible heat storage with a latent heat storage unit in order to store the solar energy. The developed thermal energy storage unit contains an insulated cylindrical tank having hollow spherical capsules of HDPE (filled with fatty acid which has phase-change property). The water and oil liquid transport medium is used as a heat-carrying substance which works as a transporting heat energy from high-temperature container to TES tank and act as SHS materials. The temperature of the transport medium is maintained constant at inlet of the tank during charging and discharging processes. The effect of flow rate and inlet temperature of HTF is analyzed on charging time with the help of charging experiments. The performance parameters viz. cumulative heat stored and efficiency are analyzed during charging and discharging processes. The result shows that efficiency of the system with water as HTF is more than that of oil.