Combined heat and mass transfer analyses in solar distillation systems – The restrictive conditions and a validity range investigation

The present work aims at the investigation of the validity range and accuracy of earlier developed theories which have been proposed for the modeling of heat and mass transfer within confined spaces in solar distillation systems. The investigation which is based on the evaluation of agreement between theoretical results and an extensive body of earlier field and laboratory measurements covers a very wide range of operating conditions and allows a comparable validation of the earlier proposed theories. It also clearly defines the restrictions, limitations and the validity range in relationship to yield as well as to the operating temperature level, beyond which significant deviations between predictions from both the earlier Dunkle’s as well as more recent analogy models and measurements occur for practical solar stills.

► Modeling of combined heat and mass transfer in solar distillation systems. ► Definition of validity range restrictions of earlier developed analyses. ► Model assessment through a massive database of experimental measurements. ► Basic Dunkle’s model can be valid up to about m˙=0.3gr/m2s and t¯=60°C. ► Chilton–Colburn model is accurate at broad operating range up to about m˙=0.3gr/m2s.