A Generalized Dependence for Convective Heat Transfer in Horizontal Bundles of Finned Tubes with Free Air Convection

Abstract

Results of a study of free convective heat transfer in two-, three-, and four-row horizontal in-line bundles of bimetallic finned tubes with coefficient of finning 16.8 are presented. The steps in the breakdown in the tubular sheets correspond to the applicable standardized steps in air-cooled heat exchangers with cross step S₁ = 58–76 mm, and values of the longitudinal step S₂ in the range 58–100 mm correspond to each value of S₁. A generalizing equation for calculating the average convective heat-transfer coefficient, taking into account geometric parameters studied in the range of Reynolds numbers from 20000 to 70000, is obtained. Through the use of the dependence, it has become possible to design a wide range of gas–liquidtype heat exchangers for different purposes that function in free convection regimes.