IRREVERSIBLE LOSS ANALYSIS OF WAVY FINNED TUBE HEAT EXCHANGER
This paper deals with a wavy finned tube heat exchanger working as an air cooling condenser The effects of the exchanger geometric dimensions on the irreversible loss in the exchanger are discussed based on the second law of thermodynamics The irreversible loss is characterized by the sum of the entropy generation caused by the temperature difference between the airflow and exchanger surface and that caused by the air friction pressure drop The calculation results show that the entropy generation per unit heat transfer rate (Δ S/Q ) increases gently with increasing corrugation angle of the fin but is nearly independent of the fin pitch When the number of tube rows ( N ) is increased, the Δ S/Q initially decreases, but turns to increase after reaching a minimum at a certain N .The Δ S/Q increases monotonously as the air velocity increases