Experimental method to study the evolution of the performance of solar cookers as a function of solar altitude

Abstract

The performance of solar cookers, mainly box cookers and panel cookers, depends on the solar altitude. To study the effect of solar altitude, using the ASAE S580.1 standard or another method that uses liquids. Many tests are required, at different times of the year (different solar altitudes). For this reason, a study method was developed that does not use liquids as study fluid. Leaving only the pot full of air. When the pot is without liquid inside, the pot is operating with small inertia because the measure air temperature achieves much higher values, with short delay, than the ones obtained with liquids. Moreover, the registered evolutions can represent also how the stagnation temperature depends on the solar altitude angle. Thus, the plots provide valuable information about what is the most suitable ranges of solar altitude angle for each solar cooker. This method has been validated and has been improved with several experimental tests in different solar cookers.