Performance Evaluation of Low Inertia Multi Stage Solar Still

In an attempt to increase distillation yield per unit evaporation area by decreasing the thermal inertia of the water mass, a new type of multi-stage solar still of low inertia was designed, fabricated and tested. The energy balance equations for various parts of the still were solved by Gaussseidel iteration method. Computer model was made to predict the performance of the still and experimentally validated. The computer model was used to estimate the annual performance and pay back period of the still for Indian city of Ludhiana. At optimum combination of absorption area of solar water heater and evaporation area, the annual distillate yield and annual average performance ratio for the still were 2223.0 litres/m2 aperture area and 0.73 respectively assuming 300 clear days. Annual average performance ratio of distillation unit alone is 2.73. The pay back period of the still was estimated to be three years.