Análise térmica de uma planta de dessalinização de múltiplo efeito (MED) com alimentação paralela

Abstract

In this work we present a study on a desalination unit for sea water, it has evaporators with horizontal tubular floating pipes working with thin film water spray. Energy for the unit is provided by hot water at 85°C, the heat is obtained by flat solar collectors. With mass and energy conservation equations for the system of multiple evaporators, and functions which can provide the boiling point elevation of the saline solutions, the latent heat of saturated steam, the specific heat of the solutions and the heat transfer coefficients for the evaporators; a system of linear equations was obtained, na iterative solution must be used. The system also hás a pré heating unit and recirculation of the concentrated saline solution, all to decrease energy and chemicals (anti scalants, pH correctors, bactericide) consumption, added to the feeding stream of sea water. Calculation was made by a FORTRAN 90 program. Tables and graphics are presented, describing how the system works for distilled water production of 100000 Litres?day to 200000 Litres/Day. On the solar energy side, the solarimetric data were obtained by the RADIASOL program and the yields of the solar collector by the CODEPRO program. The needed collector area was calculated using a FORTRAN 90 program, with data from the two previously mentioned applications.