Renewable Energy-Water Nexus: Optimal Design of an Integrated System including a Single Flash Geothermal Plant, Kalina Cycle and Reverse Osmosis Desalination Unit

MANASSALDI, JUAN I.; MUSSATI, MIGUEL C.; INCER-VALVERDE, JIMENA; MOROSUK, TATIANA; MUSSATI, SERGIO F.

Warsaw

Conferencia; The 16th Conference on Research and Development in Power Engineering; 2023

INSTITUTE OF HEAT ENGINEERING, FACULTY OF POWER AND AERONAUTICAL ENGINEERING WARSAW UNIVERSITY OF TECHNOLOGY

This paper addresses the optimization of a dual-purpose desalination system based on a geothermalflash cycle, Kalina cycle, and a reverse osmosis seawater desalination plant. A nonlinear mathematicalprogramming (NLP) optimization is developed and implemented in GAMS – general algebraic modelingsystem – which is a high-level modeling environment widely used in Process System Engineering PSE.CONOPT, which is a derivate-based optimization algorithm, is used as an NLP solver. Also, dynamic-linklibraries (DLLs) are developed and implemented in the programming code C with the aim of rigorouslycalculating the thermodynamic properties of all process streams. The DLLs are systematically calledfrom the GAMS environment. In addition, a solution strategy has been developed to facilitate modelconvergence. In this approach, several models are sequentially solved, starting with the simplest modelprogressing to solving a more complex model. As a result, the optimal sizing and operating conditions ofall process units are simultaneously obtained. Finally, a sensitivity analysis of the key model parameters,electrical power, and freshwater demands on the optimization criterion is discussed. The proposedmathematical model is a powerful decision-making tool for the design and synthesis of integratedgeothermal power and desalination processes, which can be used as either a simulator or an optimizer,depending on the number of freedom degrees specified by the user.