Maryam haghighi - CAPE center, Chem.Eng.Dept., Iran University of Sci. & Tech., Tehran, Iran
Mohsen sadeghi - CAPE center, Chem.Eng.Dept., Iran University of Sci. & Tech., Tehran, Iran
Norollah kasiri - CAPE center, Chem.Eng.Dept., Iran University of Sci. & Tech., Tehran, Iran

With growing the air coolers different models were developed in order to design or rating them and subsequently many related software created, but in order to their complexity they cannot used as a usual and comprehensive model. Beside this reason some of the proposed models don’t cover or are not suitable for different phase states, various heat transfer coefficient models or process conditions. This work offers and presents a flexible mathematical model for rating and predicting outlet conditions of tube side stream (temperature and pressure and fluid flow) by combining halving and Newton-Raphson methods. This model covers all phase conditions and increases the precision in comparison with other software for rating the air cooler (same as Aspen-Aerotran and Acol) with good running time and this is the main objective of this work. It shall be pointed that in recently years many companies pursue this goal with exorbitant cost. A computer program was written and tested base on above mentioned model and results have been compared by two sets of air-cooler data, located on MARUN plant in Iran that shows very good compatibility by experimental IRASCO-AHWAZ/ data with less than 5 percent error.

Air cooler, Rating, Flexible mathematical model, Newton-Raphson, Halving method