Design and Optimization of Air-Cooled Heat Exchangers

Abstract

A computer code has been developed for analysis of air-cooled heat exchangers and was coupled with a numerical optimization program to produce an automated air-cooled, heat-exchanger design and optimization procedure. A general iteration free approximation method was used for the analysis which calculates the mean overall heat-transfer coefficient and the overall pressure drop for many flow arrangements. The analysis takes into account the variation of the heat-transfer coefficients and the pressure drop with temperature and/or length of flow path. The code is not limited to surfaces found in the literature, but will accommodate any triangular pitch bank of finned tubes in multiple-pass configurations. The numerical optimization code is a general purpose program based on the Method of Feasible Directions and the Augmented Lagrange Multiplier Method. The capability is demonstrated by the design of an air-to-water finned-tube heat exchanger and is shown to be a useful tool for heat exchanger design.