Double-Pass Solar air Heater (DP-SAH) utilizing Latent Thermal Energy Storage (LTES)

The solar air heater is a device rises air flowing temperature in numerous engineering applications as; heating of buildings, and agricultural crops drying. An indoor investigation was experimentally established using the solar simulator to test the flat plate double-pass solar air heater performance with and without paraffin wax-based on phase change material PCM. Although the temperature inside this collector is higher than the required temperature. Therefore, being a paraffin wax may be used as a heat storing material will enable the collector to work during the night. The tests were applied to evaluate the charge and discharge process of the new system and was performed under various air MFRs of (0.6, 0.9, 1.2, 1.5, and 1.8) kg/min and constant solar irradiation of 625 W/m². The results showed that the maximum thermal efficiencies obtained for the double-pass with and without PCM were 63.53% and 68.23%, respectively, for airflow rate of 1.8 kg/min and also the efficiencies is a strongly dependence on the air MFR. Also, the maximum air temperature rise was about 10.9°C, and 12.25 °C with and without PCM, respectively, above the inlet temperature at air MAF of 0.6 kg/min and solar irradiation of 625 W/m² during charging period and this leads to energy saving. The experimental tests showing reasonable agreement with the previous study with a maximum error of thermal efficiency was about (4.5%) at the same indoor conditions.