Transient Modeling of a New Solar Distillation Unit for Remote Areas

Abstract

The concept of lack of fresh water in our daily life is hard to imagine in recent times with its increasing demand. Lack of fresh water supplies has become one of the major current societal concerns, especially for people living in remote areas, where there is limited or no resources of fresh water. Large amount of fresh water is produced using the conventional desalination technologies like thermal and membrane process. The conventional desalination technologies for large water production are Multi Stage Flash (MSF), Multi Effect Desalination (MED), Vapor Compression (VC) and Reverse Osmosis (RO). Big shares of Thermo and/or electrical energies are utilized using these processes. These technologies require high quality operation and maintenance. They require the usage of fossil fuels, which causes negative environmental effects. In order to minimize these effects and especially for remote areas, where the demand of fresh water is less, renewable energy integrated with desalination is the optimum solution. This thesis presents the transient modeling of a novel solar desalination system for remote areas. The new system consists of Solar Still (SS) integrated with multi effect Humidification-Dehumidification (HDH) with built in solar absorber. As the conventional solar still distillation has drawbacks of low specific productivity due to the loss of condensation energy as well as the adverse effect in environment due to brine discharge, the aim is to model and design a solar driven integrated SS-HDH-Absorber desalination unit that can produce the fresh water capacity of 50 Liter with zero brine discharge (ZBD) for a single family use. The main objective is to enhance the unit's water production by utilizing the waste latent heat of condensation of the still and solar absorber thermal energy for additional water production in addition to recovering brine salts as by product. This will lead to produced water cost reduction while maintaining the simplicity of the system operation and maintenance. A numerical code is developed in MATLAB to simulate the integrated system and study the effect of various environmental, design and operational parameters on the unit's productivity.