PERFORMANCE ANALYSIS OF A COMPACT SOLAR WATER HEATER WITH PARAFFIN WAX STORAGE UNIT

Abstract

The present work experimentally studies the thermal performance of a solar collector integrated with a thermal storage unit to form a compact solar water heater. The storage capacity is further enhanced by attaching a phase-change storage unit containing phase change material (PCM) which is paraffin wax. The two units (tanks) take the form of two shallow rectangular boxes (compartments) tilted at 45o to the horizon and are firmly attached to ensure complete mutual heat transfer between them. Water and PCM fill the top and bottom tanks respectively. Measurements were carried out from 8 a.m. to 4 p.m. where the temperatures at various locations in the system were measured along with ambient temperature and solar radiation intensity. Results show that the temperature of both compartments increases continuously during the simulated period with the upper tank having the higher temperatures. The PCM average temperature did not reach melting range (55oC – 60oC) which requires either decreasing the amount of PCM or using a PCM with a lower melting point. The maximum temperatures reached are 82oC for water and 47oC for PCM which are measured at 4 p.m. and the maximum overall system efficiency of the system was 74% at 11:30 a.m.