فهرست نشریات علمی دسترسی آزاد ایران

This study experimentally investigates a latent heat thermal energy storage system integrated into an indirect solar cooker, using Magnesium Nitrate Hexahydrate as the phase change material (PCM). A comprehensive energy and exergy analysis was conducted to evaluate the system’s performance during both charging (noon) and discharging (afternoon) operations with two different water loads (0.5 and 1 L). Results demonstrate that while the PCM system effectively enables afternoon cooking by storing solar thermal energy, it involves a trade-off: the charging process increased the noon boiling time for 1 L of water by 50 min (111%) compared to a conventional system without storage. The energy and exergy efficiencies of the storage-integrated cooking unit decreased by 16.28 and 5.72 percentage points, respectively. System-level analysis showed overall energy and exergy efficiencies of 5.05 and 0.56% for the PCM-based system. However, the storage system demonstrated robust performance during discharge, maintaining water temperatures above 80°C for over 3 h. This research is particularly innovative as it provides a first-of-its-kind comparative exergetic evaluation of a solar cooker with and without latent heat storage, quantifying the thermodynamic price of energy shift and offering crucial design insights for optimizing such systems. This work provides valuable insights into the thermodynamic trade-offs in PCM-based thermal energy storage systems for solar cooking applications.