Enhanced Performance of Solar Diffusion Driven Desalination

Abstract

This study concerns an improvement in the solar diffusion driven desalination process under dynamic operating conditions for decentralized water production. The utilization of a heat exchanger for the solar diffusion driven desalination (DDD) process to recuperate the latent heat of condensation has been examined. It is found that the recuperated latent heat is best used for preheating the air inlet to the evaporator. Improvements in the system performance are achieved by increasing fresh water production by 30% for the solar DDD with a 0.75 effectiveness in the integrated heat exchanger. A theoretical model is implemented for analyzing the integrated desalination system, and a numerical assessment of the system performance for different operating conditions is presented. It is found that the installation of a heat exchanger for heat recovery in the air stream prior to entering the direct contact condenser increases the water production rate and reduces the specific energy consumption. It is concluded that the delayed operating mode for the solar DDD with an integrated heat exchanger is the best operating mode.