Heat Exchanger Exergetic Lifecycle Cost Optimization using Evolutionary Algorithms

Considering lifecycle cost analysis during the design phase of thermal systems gives the design effort more worth. Furthermore thermodynamic exergetic optimization is a proven useful method for determining the most lifecycle cost optimal design of thermal systems for given thermodynamic constraints. The most thermodynamic efficient heat exchanger design basing on first law analysis may not be the better method for economic lifecycle cost estimation of a heat exchanger. Nevertheless, including the second law (exergetic) analysis in the lifecycle cost optimization technique will definitely result in a thermodynamic efficient and heat exchanger design. In this study lifecycle cost optimization procedure for shell and tube heat exchanger has developed. The total cost includes capital and operating costs, which are the components of objective function. The study searches for the optimum cost if they exist, by doing the optimum first the parametric study based on both sizing and rating problems. The study also searches for the optimum (minimum cost) using the evolutionary method of optimization, and results are confirmed using genetic optimization method, direct search method and simplex method. Evolutionary Optimization has recently experienced a remarkable growth. New concepts, methods and applications are being continually proposed and exploited to provide efficient tools for solving a variety of optimization problems. These techniques include Genetic Algorithms, Genetic Programming, Evolutionary Programming and Evolution Strategies among others, all of which have inspired by restricted models of natural evolution. Cost of the heat exchanger has been optimized basing on different constraints, like length, shell diameter, tube pitch etc. Key-Words: heat exchanger, operating cost, optimization, entropy generation, exergy destruction, thermodynamics, evolutionary method,