The variation effects of parabolic mirrors surface on energy and exergy efficiencies in a double-exposure solar cooker

The energy and exergy efficiencies for a double exposure solar cooker are determined. In order to observe the variation effects of a parabolic mirrors surface on energy and exergy efficiencies two identical systems were designed, constructed and tested under the same climatic conditions; the parabolic mirrors in one of the systems have been fully exposed to the sun and mirrors of the one were movable to see the variation effects on the energy and exergy efficiencies. The results show that using a double exposure solar cooker is recommended when high temperature is needed for cooking purpose. For other applications, such as food heating and pasteurization it is better that solar box-type cooker is employed. In such case, the system would be simpler, less costly and easier for transportation. This research is designed to develop a suitable double-exposure solar cooker performance and the tests were carried out in the Research Institute of Food Science and Technology, located at 36 latitude and 54 longitudes in Mashhad, Iran.