A new experimental strategy to enhance thermal stratification of solar hot water storage tank using different PCM layouts

The study examines the effect of different positions and layouts of phase change material (PCM) inside the solar hot water storage tank experimentally. Three similar circular horizontal perforated plates similar to baffles are designed for placing some PCM cylindrical capsules. The thermal stratification performance and collector's efficiency are sought. The circular plates are considered at the height of 100, 200, 300, and 400 mm from the top of tank. Various conditions including without PCM and with one, two, and three plates of PCM are investigated. The results indicate that the temperature difference improves 37.3% for the single-row of PCM at a height of 30 cm as compared to the without PCM. In addition, during the PCM discharging period, the tank shows better thermal stratification for a single row of PCM at a height of 300 mm. In discharging process, in one or two- row which are from middle or above middle of the tank, the arithmetic mean temperature at different heights is 3.6 degrees C and 2.6 degrees C higher than the water tank without PCM. However, this study shows that during charging and discharging one row and two rows perform better for charging and discharging process. Results show that the perforated plates act as stabilizers.