Investigation of using of phase change materials to increase energy efficency in solar collectors

Since solar energy is an intermittient energy source, it must be stored peridically. The main energy obtained from solar energy is thermal energy. Solar collectors, which enable us to benefit from solar energy, store thermal energy and meet the need for hot water. Since the solar colloctors work from the sun, there is a situation that is limited by the setting of the sun. Latent heat storage, which is one of the various thermal energy storage methods, is one of the best methods due to small temperature change and high storage density according to its volume. In this thesis, RT31 and RT35, which have high thermal energy storage capability, were used as phase change materials. In the thesis study, the instantaneous efficiencies and the charging and discharging times of the PCM fort he provinces of Gaziantep, Ankara and Trabzon in three different configurations were calculated. İn the applied configurations, the phase change material used in 1 cm, 2 cm and 3 cm thicknesses was placed between the fluid pipe and the insulation material. According to the results of the research, it is seen that the collector efficiency of the phase change materials in solar collectors cganges depending on the thickness, material type and melting temperature. Collector effiencies decrease during the charging time of the phase-change material and increase during the the discharge time. It is seen that the RT31-1 cm configuration performs appropriately in all three provinces and the stored latent heat continues after sunset. The thickness of the PCM used at certain melting temperatures is not suitable for all months and the highest yield values were reached in july in Gaziantep fort the RT31-3 cm configuration.