Influence of fin arrangement on fluid flow and heat transfer in the inlet of a plate-fin heat exchanger

Abstract

Fin arrangement, which can cause temperature to be distributed non-uniformly and decrease heat exchange efficiency, can also affect fluid flow and distribution in different channels of a plate-fin heat exchanger. To reduce fluid maldistribution, the fluid flow and distribution should be investigated systematically. However, there is as yet no research reported on the fin arrangement effect. We investigated fluid flow and heat transfer at the inlet of a plate-fin heat exchanger by numerical calculation combined with simulation analysis. We simulated the fluid flow under seven kinds of fin arrangement, and analyzed the effects. The distribution of fluid parameters in four monitor positions among three sections was examined when the inlet flow velocity was 1 m/s with an inlet structure arranged with different numbers of fins. Denser fin arrangements among inlet, diversion, and heat exchange sections all intensify the turbulence at the outlet. With increase of arrangement density, the fluid flow direction will be changed and the fluid distribution inside the exchanger will be intensified to equalize the fluid temperature in different channels of the same layer. Furthermore, the effects of 18 combinations of fins in different sections on fluid flow were studied. Fin arrangements in different sections have more significant effect on turbulence than flow velocity and pressure; in comparison with the inlet and heat exchange sections, the diversion section has a significant effect on turbulence at the outlet of the heat exchanger.