A nonlinear optimization algorithm is applied to the design of air-cooled h
ear exchangers. In such equipment. the cold fluid (air) is impelled across
hanks of finned tubes by means of fans in forced or induced draft. The hot
stream flows inside the tubes in one or more passes, and the process that r
akes place may be cooling of either a gas or a liquid. or condensation of e
ither a pure vapor or a mixture.
The objective function is the minimum cost of the unit (investment and oper
ation), subject to certain geometric and thermohydraulic constraints.
The optimization algorithm used is that developed by Biegler and Cuthrell [
1], and programmed by them in the OPT package. The problem posed in this ca
se is made of 10 optimization variables, subject to five constraints relate
d to geometric and operational parameters of the hear exchanger