Through tests of thermal and resistance performance for air-cooled heat transfer elements with steel-made oval tubes and rectangular fins of different tube diameter and different fin intervals,the corresponding heat-transfer corelated equation and resistance equation have been obtained,providing with reference for engineering design.

Applying the 3D physics- mathematics models, the numerical analysis is performed for the air-side flow and heat transfer characteristics of rectangular-fin elliptic-tube, which are the fundamental element used in direct air-cooled power plant.

The numerical analysis were performed for the air-side flow and heat transfercharacteristics of rectangular-fin elliptic-tube and tube bundle, which are thefundamental element used in direct air-cooled power plant by applying the 3D physics-mathematics models.

With the help of a steady state constant wall temperature method a study was conducted of the heat transfer and resistance characteristics of two air cooled heat exchangers made respectively of three elliptical finned tubes and one circular finned tube.