Performance Criteria for Cooling Systems on Agricultural and Industrial Machines.

摘要

The report summarizes a study of performance evaluation criteria for heat exchangers,particularly the compact heat exchangers used in cooling systems for agricultural and industrial machines. The comprehensive review of published work indicates that existing performance ratios must be modified to account for variable temperature difference between hot and cold fluids and/or the thermal resistance external to the air side. Nine of these extended performance evaluation criteria are presented. Computer programs are presented for convenient application of four criteria,those which are probably of greatest interest to the designer of compact heat exchangers used for engine cooling. Sample calculations compare six cores for which detailed geometrical and thermal-hydraulic data are available. There are wide variations in performance among these cores. A variation of the basic program is presented to handle the computation of ratios when only overall heat duty and pressure drop data are available.