EXPERIMENTAL STUDY ON THERMAL ENERGY STORAGE PRODUCED BY SOLAR ENERGY FOR DRIVING DOMESTIC FREEZER

Abstract

A prototype of photovoltaic based domestic chest type freezer was constructed, the prototype incorporates Phase Change Materials (PCM), as a thermal storage medium. Thereby, the units can work without the aid of the conventional batteries. A eutectic potassium chloride (KCl) aqueous solution was prepared to serve as phase change material. The PCM was stored in an integrated tank within the freezer box. Using PCM enables the freezer to preserve its cool storage at a temperature level below (-8 °C) for a holdover period not less than 30 hours without the need for power supply. The effect of PCM mass and PCM integrated storage tank thickness on the thermal performance of the freezer were studied experimentally. The experimental results showed that for 7 mm integrated storage thickness; the freezer box reaches steady state condition in two days with net compressor period operating time of 16 hours in which, the PCM changes from liquid to solid phase. The minimum temperature obtained was (-10 °C). In 18 mm integrated storage tank thickness three days of net compressor period operating time of 24 hours was required to reach steady state condition. In which, the minimum PCM temperature was (-8 °C). The study was extended to find the effect of frequently freezer door opening on the thermal performance of freezer.

Keywords

• Battery-free refrigerator
• Domestic refrigerator
• PCM
• Solar refrigeration