The investigation of using phase change material for solar pond insulation

Abstract

Solar ponds are systems that store solar energy in salt water as heat energy. In order to store heat energy for a long time in solar pond, the heat insulation should be done well. In this study, the effect of phase change materials (PCMs) was investigated to improve the insulation of the pond and to store the heat energy for a longer time. The melting temperature is a key parameter in the selection of PCMs. The temperature distribution of the solar pond was examined and PCMs with melting temperatures in the range of the pond average temperature ? 10?C were selected.Three different phase change materials were used in the walls of the solar pond for insulation. The temperature and enthalpy changes of the system were calculated numerically for a year. The heat storage ratio of the solar pond was determined by using the obtained enthalpy and solar radiation data. Consequently, the heat storage ratio of the pond with glass-wool is maximum 20.95% in July and minimum 7.92% in January. The heat storage ratio of the solar pond which Paraffin C18, Capric acid and Paraffin 44 are used as PCMs is maximum 32.22%, 34.85% and 47.81% in December, respectively. It is observed that the appropriate selection of PCMs is provided a longer storage time for solar ponds.