THERMAL PERFORMANCE OF SELECTED OILS IN UGANDA FOR INDIRECT SOLAR DOMESTIC COOKING APPLICATIONS

Abstract

Abstract and figures
This study experimentally evaluated the thermal performance of selected oils in Uganda for indirect solar domestic cooking applications. The oil samples used were refined sun- flower oil, refined palm oil and thermia B; these oils are locally available in Uganda. Their heat retention capacities were investigated to determine their suitability for TES. Ther- mal stratification, energy and energy analysis were performed for each oil and a hybrid TES system consisting of rock pebbles and oil. A thermosiphon principle was used to charge the storage for 6 hours. The results showed that both refined sunflower oil and refined palm oil reached a maximum temperature of 236 deg. C in 30 minutes while thermia B took longer to attain a maximum temperature of 220.8 deg. C in 45 minutes. Furthermore, during charging an oil-only-TES system, refined sunflower oil attained maximum energy of 0.13 MJ in 1 hour and 42 minutes while refined palm oil attained maximum energy of 0.12 MJ in 2 hours and 18 minutes and lastly thermia B attained maximum energy of 0.10 deg. C in 2 hours and 54 minutes. Generally the thermal performance of refined sun- flower oil was comparative to refined palm oil which was better than that of thermia B. However, refined sunflower oil retained more heat as compared to refined palm oil which makes it most preferred for TES medium for indirect solar cooking applications. More investigation needs to be done on a hybrid TES and TES system sizing with insulation.