Pareto optimization of a combined cycle power system as a decision support tool for trading off investment vs. operating costs

The monetary optimization of thermodynamic processes may be approached by inherently thermodynamic frameworks like exergo-economic analysis, or a rigid direct cost evaluation is applied. This paper, treating the optimization of a combined cycle power plant, follows the second path. Operation and investment costs are usually treated as a combined value by means of an annualization factor. Due to the rather far-stretching time horizon of turbine energy conversion systems, differing behaviour of those contributions with time, and varying subjective weighting and assumptions of future developments, this conventional subsumption is not necessarily a sensible one to identify the best solution for a given decision situation. It is therefore favorable to address both costing goals independently and identify the pareto set of the problem prior to a final decision on which parametrization of the system should be chosen. A numerical pareto optimization technique based on an evolutionary base strategy is discussed that addresses this type of problem in an efficient and easy to adapt manner. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.