Computational analysis for a multi-effect distillation (MED) plant driven by solar energy in Chile

This study presents a numerical model for a multi-effect distillation (MED) plant driven by solar energy. The model is based on mass, energy, and heat transfer equations applicable to the coupled MED and steam generation plants. The MED plant model has been validated with experimental data from the multi-effect distillation plant of the Plataforma Solar de Almería (PSA) in Spain [1]. Additionally, the model of the solar steam generation plant is validated using experimental data acquired from the parabolic trough collector (PTC) at the SANDIA National Laboratory, USA [2]. Both validations show good agreement between model and measurements, with a relative error smaller than 3%. Additionally, the heat transfer processes that occur in evaporators and preheaters are studied herein, and several heat transfer correlations are tested. The heat transfer model used in evaporators appears to be a key factor for performance predictions and may require further studies. Finally, the validated model is used to assess the technical feasibility of the installation of a solar MED plant in Valparaíso, Chile. The main results are analyzed under variable weather conditions. In addition, the MED plant is evaluated in different Chilean cities, and a linear dependence between fresh water production and solar radiation is established. In conclusion, a powerful computational tool is developed that may be useful for the design, optimization, and assessment of the technical feasibility of installation of future solar MED plants.