Second Law Efficiency and Costing Analysis of a Combined Power and Desalination Plant

Abstract

Flow diagrams for exergy have been made for Unit 2 at the Umm Al Nar West power plant in Abu Dhabi. This unit is one of six in a combined power and desalination facility, each delivering 60 MW of electricity and 18000 metric tons per day of freshwater at design conditions. The diagrams show the rates of exergy flow between all of the components in the facility as well as the consumption in each. For the desalination facility, diagrams were developed for both summer and winter operation, at design conditions. The steam generation and power plant diagrams were made for full and three-quarter electrical loads, and full-load delivery of steam to the desalination plant. Furthermore, detailed exergy costing diagrams have been constructed for the steam/power facility, at both full and three-quarter electrical load conditions. Conclusions are drawn regarding means for improving the existing plant and future designs.