Moslem Namjoo

In special case of spirulina drying, the energy and exergy investigations were performed for a pure solar dryer and a hybrid solar/infrared (IR) drying system. For three drying temperatures 40, 50 and 60 ◦C, the specific energy consumption (SEC) and energy utility ratio (EUR) were evaluated and it was found that the maximum contribution of IR to the drying process was at 40 ◦C, in which SEC was reduced by 12.18 % and EUR was increases by 14.4 %. But at higher temperatures, negligible contribution of auxiliary heat source was found and less fraction of supplied power was used for removing the water content of the samples. The variation of exergy efficiency was also evaluated at different temperatures, and it was noted that the hybrid dryer had the best performance at 40 ◦C, while the conventional solar dryer showed better exergy efficiencies at 50 ◦C and 60 ◦C. As a result, a convenient criterion was established for optimum use of IR source in a hybrid system. Uncertainty analysis was performed.