A model of an improved low cost-indoor-solar-cooker in Tanta

Abstract

A simple flat-plate solar cooker with focusing plane mirrors and energy storage capabilities has been designed and constructed by the locally available materials in Tanta University. The temperature distributions during the test periods through the absorbing plate, the glass covers, the cooking pot, the cooking fluid, the storage medium and the ambient were determined. The diurnal variations of incident global solar insolation were presented. The utilization of sensible heat storage medium such as sand was investigated thoroughly. A jacket of sand ( 1 2 - cm thick) around the cooking pot has improved the cooker performance tremendously. The temperature differences between the heat source and the heat sink during the test time were determined and the results were discussed. Six hour per day of cooking time has been recorded. Approximately three hours per day of indoor cooking has been achieved. An overall energy conversion efficiency up to 28.4% has been obtained which is considered the best among other solar cookers in the literature. The possibility of using a phase change material as a storage medium to obtain longer cooking periods was studied. A thin layer of the salt hydrate Ba(OH) 2 ·8H 2 O as a jacket around the cooking pot was suggested. The cost of the whole cooker is not more than $15 including the pot and the labour expenses. A step for commercial production of two-pots-solar-cooker has been taken. Extensive efforts are required to diffuse this technology into the villages of the people who could benefit from it.