Marcinkowski, M.; Taler, D.; Taler, J.; Węglarz, K. Air-Side Nusselt Numbers and Friction Factor’s Individual Correlations of Finned Heat Exchangers. Energies2022, 15, 5630.
Marcinkowski, M.; Taler, D.; Taler, J.; Węglarz, K. Air-Side Nusselt Numbers and Friction Factor’s Individual Correlations of Finned Heat Exchangers. Energies 2022, 15, 5630.
Marcinkowski, M.; Taler, D.; Taler, J.; Węglarz, K. Air-Side Nusselt Numbers and Friction Factor’s Individual Correlations of Finned Heat Exchangers. Energies2022, 15, 5630.
Marcinkowski, M.; Taler, D.; Taler, J.; Węglarz, K. Air-Side Nusselt Numbers and Friction Factor’s Individual Correlations of Finned Heat Exchangers. Energies 2022, 15, 5630.
Abstract
The object of this work is to determine the correlation on the Nusselt number on the individual rows of a four-row tubular finned heat exchanger with continuous fins with a staggered tube arrangement using CFD modelling. Correlations for calculating Darcy-Weisbach friction factors on individual tube rows were also determined. Relationships for the Nusselt number and friction factor derived for the entire exchanger based on CFD modelling were compared with those available in the literature determined using experimental data. The maximum relative differences between the Nusselt number for a four-row exchanger determined experimentally and by CFD modelling are in the range from 22% for a Reynolds number based on a tube's outside diameter of 1,000 to 30% for a Reynolds number of 13,000. The maximum relative differences between the friction factor for a four-row exchanger determined experimentally and by CFD modelling are in the range of 50% for a Reynolds number based on a tube outer diameter of 1,000 to 10% for a Reynolds number of 13,000. The CFD modeling performed shows that in the range of Reynolds numbers based on hydraulic diameters from 150 to 1,400, the Nusselt number for the first row in a four-row finned heat exchanger is about 22% to 15% higher than the average Nusselt number for the entire exchanger. In the range of Reynolds number changes based on hydraulic diameter from 2,800 to 6,000, the Nusselt numbers on the first and second rows of tubes are close to each other. Correlations on Nusselt numbers and friction factors derived for individual tube rows can be used in the design of plate-fin and tube heat exchangers used in equipment such as air-source heat pumps, automotive radiators, air-conditioning systems and in air hot-liquid coolers. In particular, the correlations can be used to select the optimum number of tube rows in the exchanger.
Keywords
plate-fin and tube heat exchanger; air-side Nusselt number; different heat transfer coefficient in particular tube row; numerical simulation; CFD simulation; air heat pump
Subject
Engineering, Energy and Fuel Technology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
