Energy and exergy analysis of a new solar air heater with latent storage energy

In this paper, we propose a new solar air heater with a packed-bed latent storage energy system using PCM spherical capsules. At daytime, the solar heating system stored the thermal solar energy as sensible and latent heat, however, at night it restored. Some parameters, such as the global solar radiation and the mass flow rate are varied to investigate their effect on the absorbed, used, and recovered heat from the system. An optimization study using the first and second laws of thermodynamics is also carried out to obtain the energy and exergy efficiencies. The experimental study was conducted, designed, and realized in the Research and Technology Center of Energy (CRTEn) in Tunisia. The experimentally obtained results are used to analyze the performance of the system, based on temperature distribution in different parts of the collectors, absorbed, instantaneous stored and used thermal energy. The daily energy efficiency varied between 32% and 45%. While the daily exergy efficiency varied between 13% and 25%. The effect of the mass flow rate of air on the outlet temperature of the solar air heater is examined.