New algorithm simplifies heat-exchanger calculations

The original algorithm by Urbicain and Paloshi for the simulated operation of air-cooled heat exchangers has been modified. The new method reduces the running time of the programs by assuming that a row of tubes cannot belong to several passes. Simulated programs of air-cooled heat exchangers are useful tools for the design and operation of this type of equipment. Because of the wide variety of ambient temperatures occurring over the course of a year, or even a day, at refining and petrochemical facilities, a complete description of the behavior of air-cooled heat exchangers is necessary to adapt the appropriate control. The algorithm presented in this article is similar to Urbicain and Paloshi's, which is based on dividing the heat-transfer area of each tube into a finite number of elements. When the resulting equation system is solved, the algorithm provides an accurate profile of the equipment.