Local Flow and Heat Transfer of a 2-row Offset Strip Fin-tube Heat Exchanger

摘要

A numerical study has been performed of the local flow and heat transfer characteristics of a 2-row offset strip fin-tube heat exchagner of 7 mm in tube diameter, with a view to investigating the mechanism of heat transfer in the heat exchanger. The increases in dimensionless local heat flux at the leading edge of he slit and the bottom surface of the fin has been examined quantitatively in the present study. It has been found that the air temeprature downstream the 2nd row of the offset strip fin-tube heat exchawger is more uniform than that of a plain plate fin-tube heat exchanger because of the augmented energy mixing effect caused by the slit. It has also found that, as the inlet air velocity is raised, the regional contribution to heat transfer decreases in the lst row and increases in the 2nd row.