The application of a network programming algorithm, the Out of Kilter algorithm, to the analysis and design of heat exchanger networks with multiple external utilities, is presented. From the various methods existing in the literature for the solution of this problem, heuristic and thermodynamic procedures have received in the past most of the attention. Nevertheless, the presence of schemes with multiple external utilities impose serious restrictions in the use of traditional methods. According to the results attained, the Out of Kilter algorithm performs very satisfactorily in spite of the complexity introduced by more than one external heating source.
