ENGINEERING JOURNAL OF RESEARCH AND DEVELOPMENTVolume 31, No. 04, Month OCTOBER, Year 2020, Pages 129 - 144
Performancr evaluation an air-cooled of an air-cooled heat exchanger based on entropy generation
Wanchai Asvapoositkul, Kanthaporn Tatong
Abstract Download PDFIn this study, the performance of an air-cooled heat exchanger wasevaluated based on entropy generation under variations in operating conditions. The entropy generation wastakeninto account the irreversibility associated with heat transfer only. The predictions were validated and showedgood agreement with analytical results and experimental measurements. The results revealthat the difference temperature between the inlet hot water and the ambient air or the initial temperature difference (ITD)canbe used as the parameter to determine the effect of operating conditions.The heat transfer and entropy generation number increase with increasing ITD.The entropy generation numberslightly increases with mass flow ratio of water to air(GL) and the effecte is less as the ITD is reduced.Themoderate ITD is required for the operation of the air-cooled heat exchanger. Its limiting temperature (minITD) is obtained when the outlet air temperature is minimize. Working below this value results in over-sensitivity to small change.
air-cooled heat exchanger; entropy generation;exergy analysis;thermal capacity; operating parameters; ITD