Browsing by Author "Morosuk, Tatiana"
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Item Process optimization and revamping of combined-cycle heat and power plants integrated with thermal desalination processes.(2021-06-06)Optimal revamping, sizing, and operation of an existing gas-turbine combined-cycle dual-purpose power/desalination plant – simultaneous electricity and freshwater generation – which operates with a heat recovery steam generation with one-pressure level (1P-HRSG) and a multi-stage flash desalination process, is addressed. The sizes and configurations of the gas turbine and desalination unit are kept the same as in the existing plant through the study. However, the 1P-HRSG is conveniently extended to twoor three-pressure levels with different exchanger arrangements, including steam reheating. To this end, a superstructure-based representation of the HRSG simultaneously embedding several candidate structures was proposed and a mixed-integer nonlinear programming model was derived from it. One revamping case consisted in maximizing the ratio between the freshwater production rate and the heat transfer area of HRSG, keeping unchanged the electricity generation rate (around 73 MW). It was found that the inclusion of a 3P-HRSG resulted in an increase of 13.782 kg⋅s−1 in the freshwater production, requiring 22753 m2 of heat transfer area less in the HRSG. Another revamping case consisted in maximizing the profit, contemplating the possibility to sell extra amounts of electricity and freshwater. Sale prices, for which producing extra electricity and freshwater is beneficial, were determined.Item Renewable energy-water nexus: optimal design of an integrated system including a single flash geothermal plant, kalina cycle and reverse Osmosis desalination unit(2023-12)Resumen de artículo presentado en la Conferencia. This paper addresses the optimization of a dual-purpose desalination system based on a geothermal flash cycle, Kalina cycle, and a reverse osmosis seawater desalination plant. A nonlinear mathematical programming (NLP) optimization is developed and implemented in GAMS – general algebraic modeling system – 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-link libraries (DLLs) are developed and implemented in the programming code C with the aim of rigorously calculating the thermodynamic properties of all process streams. The DLLs are systematically called from the GAMS environment. In addition, a solution strategy has been developed to facilitate model convergence. In this approach, several models are sequentially solved, starting with the simplest model progressing to solving a more complex model. As a result, the optimal sizing and operating conditions of all 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 proposed mathematical model is a powerful decision-making tool for the design and synthesis of integrated geothermal 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.