Thermoeconomic Analysis and Multiobjective Optimization of a Solar Desalination Plant

Abstract

A solar desalination plant consisting of solar parabolic collectors, steam generators, and MED unit was simulated technoeconomically and optimized using multiobjective genetic algorithm. A simulation code was developed using MATLAB language programming. Indirect steam generation using different thermal oils including THERMINOL VP1, THERMINOL66, and THERMINOL59 was also investigated. Objective function consisted of 17 essential parameters such as diameter of heat collector element, collector width, steam generator pinch, approach temperatures, and MED number of effects. Simulation results showed that THERMINOL VP1 had superior properties and produced more desalinated water than other heat transfer fluids. Performance of the plant was analyzed on four characteristic days of the year to show that multiobjective optimization technique can be used to obtain an optimized solution, in which the product flow rate increased, while total investment and O&M costs decreased compared to the base case.

Comparative 4E analysis for solar desalinated water production by utilizing organic fluid and water

“…All are considered in the mean temperature of tube surface and ambient, T ave . For outer surface forced convection, Nusselt number is gained by Zhukauskas correlation towards a direction perpendicular to the isothermal cylinder surface [41,52].…”

“…Radiation amount between tube surface and the ambient is assessed by: q ¼ q Solar − q conv þ q cond;bracket À Á ðA À 15Þ where σ, Ɛ, θ and T sky are respectively the Stefan Boltzmann constant, emissivity, collector angle with the sky and the sky temperature that is achieved in [41]. In these equations, ΔT in is the temperature difference between input and output water flows for cooling the condenser.…”

“…The solar farm has been designed in [41], and some of the important equations are depicted in Appendix A.…”

“…These tubes are installed in different rows and heat the VP1 (Therminol VP1) oil by increasing the oil temperature to 400°C. According to Mokhtari et al research [41], this type of oil produces more steam compared to other oils. Then, the oil enters into an organic fluid producer exchanger in saturated phase.…”

Multiobjective optimization design of the solar field and reverse osmosis system with preheating feed water using Genetic algorithm

“…The energy absorbed by the absorber pipes which can cause the VP1 oil to be warm and its temperature increase up to 400. According to the reference this oil produces higher steam in comparison with other thermal oils. Subsequently, the oil is transferred into a steam generator that includes three components.…”