Enhanced Performance of a Single Basin Double Slope Solar Still with Thin Film of Water Flowing over the Cover Plate

Abstract

This paper presents the experimental investigation of single basin double slope solar still. The experiments were conducted in India using a double slope solar still with cover tilt angles ranging from 11? to 70?. The optimum tilt angle was found to be 20? during the month of February. The still productivity was also compared with conventional single slope solar still of the same size and the effect of orientations like east-west and north-south on productivity. After fixing the orientation, effect of water depth was studied. The results show that distillate output decreased linearly with increasing water depth in the still. The effects of cooling water flow over the cover plate were studied. Flow rates in the range of 100ml/min to 1800 ml/min were considered and an optimum flow rate for production was found to be 250ml/min. The maximum distillate output of 3.98 L/Day/m² was obtained with minimum depth of 10mm of water in the basin and at an optimum flow of water flowing over the cover plate. The percentage increase in water production with cooling arrangement was 30.5%in comparison with double slope solar still without cooling. The economic analysis depicted a payback period of 288 days.

Keywords: Cover plate angle, solar still, orientation, water depth, water flow, desalination, productivity