AERODYNAMIC AND HEAT TRANSFER PERFORMANCE OF AN INDUSTRIAL AIR-COOLED HEAT EXCHANGER
Aerodynamic and heat transfer performance measurements have been made on an industrial sized air-cooled heat exchanger operated as a 3 pass unit in the forced draught mode and used to cool water and a 25% ethylene glycol-water mixture in different test series. Results are presented for airflow and air temperature distribution above the finned tube bundle and for static pressure distribution beneath the bundle. Mean airside heat transfer coefficients and pressure drop across the bundle were best predicted by the finned tube manufacturers equations. The fan static heads were found to be about 10% lower than predicted from the fan manufacturers curves based on ideal wind tunnel tests and the fan powers were from 5 to 15% higher than predicted from manufacturers curves. Process side measurements of the number of velocity heads lost through the exchanger with the two fluids were in good agreement.