Experimental Investigation on Productivity Enhancement of a Solar Still Modified with the Evacuated Tube Heat Pipe using Paraffin Wax

Abstract

The current work involves experimental investigation on a conventional solar still to improve the productivity of fresh water by introducing the evacuated tube thermosyphon heat pipe. The evacuated tube thermosyphon acts as additional heat source to the solar still. The paraffin wax was utilized as latent heat storing medium, filled between the evacuated glass tube and thermosyphon heat pipe to escalate the fresh water productivity during off-sunshine hours. Two identical solar stills, one with three evacuated tube thermosyphon and another without it, were constructed and tested simultaneously. The solar radiation intensity, volume of fresh water produced, and temperature at various points such as basin water, glass cover, ambient and evaporator and condenser section of the heat pipe were measured. The utilization of evacuated tube heat pipe as an additional heat source increases heat input by 84.5%. The increase in heat input upsurges the gathering of fresh water by more than three times when compared to the conventional solar still. Accumulative fresh water productivity from the modified solar still was 215.7% higher than fresh water productivity from the conventional solar still. The modified solar still was capable to yield fresh water during no sunshine hours of evening as an effect of utilization of phase change material. The study suggests that direct coupling of the evacuated heat pipe to the solar still performs well in terms of fresh water yield and the same can be employed for household purpose.