Solar stills coupled with solar collectors and storage tank––analytical simulation and experimental validation of energy behavior

The behavior of a conventional greenhouse-type solar still coupled with hot water storage tank heated by a solar collector field is investigated by a series of extensive testing, on the base of which a simple and efficient mathematical model is theoretically and experimentally evaluated. The ‘‘input–output’’ model relates main climatic data and operating conditions of the solar distillation system with distilled water output in daily and night base with linear equations using characteristic coefficients. Evaluation of the method is performed in three steps, the first being experimental determination of the coefficients followed by prediction of output, the second being calculation of coefficient values through analytical relations and the third being the use of the model in a continuous way. The agreement between the predicted and experimental water production and also between experimental and theoretical values of the characteristic parameters reveals the validity and suitability of the developed method. Furthermore, the validity of the method is also proved for the case of the theoretical and experimental variation of the depth of still basin water. The results of the investigation show that this method can be a valuable tool used during the design of similar solar distillation systems for their optimization and also for evaluation of test results of such existing installations in order to further improve it. 2003 Elsevier Ltd. All rights reserved