Experimental and numerical investigation of thermal performance of a new design solar parabolic dish desalination system

Abstract

• A new design of Solar Parabolic Dish Desalination System (SPDDS) was proposed. • Τhermal performance of SPDDS was investigated experimentally and numerically. • Optical simulation for SPDDS was performed using COMSOL model. • The model showed that thermal performance of absorber within glass enclosure was promising. • The maximum daily thermal efficiency of SPDDS was calculated to be 36.04%. The objective of the present study is to construct a cheap, new design of small-scale solar parabolic dish desalination system made from reused local recyclable materials without complex parts and power source with advantageous approach due to its unique configuration. The desalting system including a new design of cleanable vessel acts as a boiler that accommodate inside a glass box to minimize the heat losses by the wind. The proposed system was investigated by experiments and numerical model. Moreover, the optical efficiency of the system was simulated using COMSOL model. The experimental data using different levels of salt concentrations and brine masses was compared to those of numerical to validate the model. The model validation revealed that the mean bias error and mean percentage error for brine were −1.05 °C and 0.86%, respectively, while the maximum predicted concentration ratio reached ∼16,000 and ∼9000 for ideal and real reflectors, respectively. The experimental results of were compared to those numerical to validate the model using different levels of salt concentrations and brine masses. The obtained daily average values of radiative heat transfer coefficient proved the effective role of the glass box and vessel in reducing the heat losses to surroundings. At brine mass of 0.75 kg and salt concentration of 15 g/kg, the increase of the salt concentration from 0 to 200 g/kg decreases numerically the daily productivity and daily efficiency from 500 to 320 ml/m 2 .day and from 88.60 to 19%, respectively. Experimentally, the maximum instantaneous and daily thermal efficiency were found to be 53.40% and 36.04%,respectively, while the cost of freshwater production from the proposed system was 0.64 $/l.