摘要

A novel cross-flow heat exchanger with a rotated aligned tube bank is designed and utilized in a cement plant. The heat exchanger is numerically modeled with various tube pitches in order to obtain correlations of the shell-side average Nusselt number and friction factor. Then, a multi-objective optimization approach is performed based on the genetic algorithm. The goal of this study is to maximize the heat transfer rate and minimize the pressure drop. Pareto optimal solutions are obtained, which indicate that the increase in the heat transfer rate leads to an increase in pressure drop, and vice versa. In addition, heat exchanger effectiveness, total cost, and the ratio of the heat transfer rate to the fan/pumping power demonstrate different variations with the two objective functions. Several selection criteria are discussed to determine the optimal design and to help designers select an appropriate solution based on actual requirements. Two multi-objective optimization design schemes are compared to the original design under the same heat transfer rate. Results show that pressure drop decreases by 67.9% and 69.7%, respectively, and total annual cost decreases by 2.4% and 16.3%, respectively.