Abstract:

A group of four undergraduate students were given a project to find an alternative way of using the solar radiation to obtain a solar kitchen. A constant supervision was given during one semester. This type of project is highly motivated for using all the skills they have learned during the undergraduate training to obtain a working prototype.

This project aims to make a comparative study of the thermal properties of two solar ovens: box type and parabolic concentrator, by determining maximum temperatures reached, power and efficiency, as well as the advantages and disadvantages of each one of them. The use of this type of solar kitchens in rural and suburban areas is an alternative solution to the problem of deforestation and air pollution caused using wood as one of the main sources of fuel and energy in those communities of our country. The solar oven can partially contribute to solve this problem and reduce the emission of greenhouse gases in the atmosphere. Thanks to the solar radiation, that is a source of clean, abundant, and free energy. Mexico is a country with a high incidence of it in the vast majority of its territory, equivalent to 2000 Kwh/m2 per annum. The experimental design included the following stages: enabling a solar box oven and the adaptation of a SKY reception antenna into a solar parabolic concentrator oven; the thermic characterization of both ovens, through the determination of their power, the merit factors, the maximum temperatures of operation and the time in which these temperatures are reached, the heat capacity and the total caloric efficiency (use of the radiant energy). The results show that the evaluated equipment complies with the specifications to make efficient use of the radiant energy captured in the area of solar absorption and that its operation is satisfactory.

The use of constructive learning is highly motivated, and the students tend to go very deep in the acquisition of knowledge in order to solve the problem. Having a real model motivate the students to give the most of them.

Keywords:

Solar radiation, Solar ovens, Thermal evaluation, Cooking power, Merit factors, Total heat capacity, Thermal efficiency Greenhouse effect.