Performance Evaluation of Latent Heat Thermal Storage Unit by integrating it with Flat Plate type Solar Air Heater

Abstract

Renewable energies are sustainable and expected to play the significant role for pollution-free energy supply soon. Most traditional renewable energies are solar energy, wind energy, bioenergy, geothermal energy, tidal energy, and hydro-energy. Moreover, solar energy is characterized by their intermittent nature, as it is not available all the time. Another characteristic of these types of energy source is strong fluctuations (on the day), i.e., strong variations of available energy. This intermittent and fluctuation problem can be resolved by energy storage. This paper presents the performance studies on a forced convection solar air heater integrated with the latent-heat type thermal energy storage. The thermal energy storage is designed to maintain 50°C to 55°C temperature during sunshine hours and off sunshine hours especially for food processing. The experimental studies were carried out in the month of summer 2018. The average percentage of the energy recovered is found to be 44 % during the trials. There is a 6°C to 9°C temperature difference between thermal energy storage outlet and ambient air was invariably observed for 6 hours after adequate sunshine hours which is noticeable. Further, the maximum temperature of flat plate type air heater was not increased beyond 70 °C while the maximum outlet temperature from thermal energy storage system was observed 56°C during the entire day during the experiments. It shows no overheating of the system and assures outlet air in the required temperature range for food processing. This system is most useful with the solar dryer which can be used to dry fruits, vegetables, and fishes. This system can also be customized for any particular food item too.