THERMAL AND ECONOMIC VIABILITIES OF A CASE-TYPE SOLAR OVEN MANUFACTURED FROM DISUSED RECYCLABLE ELEMENTS
Solar energy; Box Type Solar Oven; Food Baking; Low Cost, Material Reuse.
Studies on the thermal and economic feasibility of a solar box-type oven made from recycled elements in disuse are presented. The solar furnace manufacturing, assembly and operational processes are described. The device was tested in two configurations, empty and loaded. Five tests were carried out: stagnation, sensitive heat, baking six cakes (4,500 g); two lasagna (1,600 g) and with a load of varied foods (3,200 g). A mathematical model was also developed, based on the fundamental heat transfer equations, to estimate the temperatures reached by the main elements of the oven. In addition, a comparative-qualitative study was carried out between the studied device, the conventional gas stove and the solar ovens developed by national and international researchers. The results showed that the absorbing surface and the air reached temperatures of 144.2 ° C and 124.5 ° C respectively, obtained in the vacuum test. The cakes were baked in 80 min; lasagna in 34 minutes and the simultaneous loading of a pizza, six breads, two cakes, and ten breads, in 65 minutes. Still, the tests of stagnation and sensitive heat presented the following figures of merit, F1 = 0.0728 and F2 = 0.534 respectively. The mathematical model showed good agreement between the theoretical and experimental results. The comparative study showed the superiority between the proposed solar oven and the others analyzed. It was also demonstrated the viability of the solar oven to produce several foods simultaneously. Therefore, it can be used as a food manufacturer, which could be sold by people with low purchasing power, to generate jobs and income.