Experiences and optimisation of a TIM covered massive solar cooker

During the past four years two massive solar cookers with a TIM cover were built and monitored on the outdoor test facility of the Fraunhofer-Institute for Solar Energy Systems in Freiburg. The monitoring results showed that even under the climatic conditions of Freiburg (Germany) temperatures of 110 degree C could be reached. Therefore, the concept proved to be promising since the cooker is designed for use in developing countries where climatic conditions are more favourable than in central Europe. A number of questions arose after the results of these two prototypes were analysed. To answer these questions, a two-dimensional finite difference model of the current cooker design was written. It allows a variation of insulation thickness, material properties and the geometry. The model was validated with the data taken at the Freiburg test facility. The comparison of simulated and measured temperatures in the cooker showed good agreement. The program proved to be very helpful in optimi zing the cooker design.