Computational Simulation of Thermal Storage Improvement using Water Pipes and PCM in the Thermal Storage Tank of Solar Collector

This study focuses on improving the thermal storage efficiency of evacuate tube solar collectors by integrating phase change materials PCM and water tubes inside a thermal storage tank. The simulation using the software ANSYS-fluent R-22. The simulation is carried out using three values of flow rates 4, 6, 8 L/m and solar radiation rates ranging from 437-630 W/m2 for days in January 17,18,21,31 and days in February 7,12,13,17,18,19,21,22. Although solar energy is abundant, it is not continuous year-round, requiring efficient thermal storage systems to maintain a constant supply of energy. Through the simulation, the use of tubing containing PCM has been shown to enhance heat transfer between the tank and the PCM tubing, as the PCM absorbs heat, stores it as latent heat and releases large amounts of energy during phase transitions. The PCMs, despite undergoing phase transitions for heat storage and release, have an isothermal heat storage characteristic which enhances energy storage. The design also seeks to establish the effects of varying numbers of aluminium tubes in overall heat storage capacity and efficiency of the said system. Despite these shortcomings, the findings reveal that the integration of water tubes improves the system’s heat transfer capability and that higher number of tubes yields better thermal characteristics. While wax based systems have exhibited stability in both liquid and solid phases, there has been a problem of slow heat transfer rates because of low thermal conductivity of wax. This progress in PCM and water tubes makes their functioning in solar collectors of thermal energy storage more efficient, reliable and increases overall energy efficiency and application of renewable energy.