Impact Of Pre-Heated Feed Water Via Nozzle On The Performance Of A Solar Still

Abstract

Introduction: Water is a vital resource for human health, and its purification is essential for safe consumption. Solar stills offer an eco-friendly solution for desalinating brackish and saline water using renewable solar energy. The efficiency of a solar still depends on various factors, including meteorological conditions, geometric configurations, and operational parameters.

Methods: In this study, a double slope solar still (DSSS) was evaluated under different configurations: with and without an external energy unit (EEU) incorporating nozzles for feed water pre-heating. Specifically, the setups included a 1 mm nozzle in parallel mode and a 2 mm nozzle in series mode. A water depth of 4mm is maintained throughout the experiment for the absorber basin tray by using a solenoid valve controlled by a level control circuit. The metrological parameters including solar radiation intensity, wind velocity were continuously monitored recorded at 30 minutes interval. By using a measuring jar the distillate output was recorded once in a hour besides overnight production.

Results: Among the tested configurations, the DSSS with EEU using a 1 mm nozzle in parallel mode demonstrated the highest performance in terms of water yield.A water depth of 4mm is maintained throughout the study. From the observations, it is inferred that DSSS with EEU (1mm nozzle-parallel mode) yield higher distillate production of 3700ml with a maximum efficiency of 34.96% when compared to the other three parameters chose for the study.

Conclusions: The input energy required per litre of distillate production is estimated to be 1515W/m2 for DSSS with EEU (1mm nozzle-parallel mode) and also overall daily thermal efficiency is estimated to be 43.24% .Hence, the performance and distillate production of DSSS with EEU (1mm nozzle-parallel mode) is better when compared to the other parameters such as DSSS with EEU (2mm nozzle-parallel mode and series mode) and DSSS without EEU.