Numerical simulation study on heat transfer enhancement of a heat exchanger wrapped with metal foam

Abstract

Tube bank wrapped with metal foam is a new compact heat exchanger with high specific surface area. The thermo-hydraulic properties of metal foam is key parameters to determine the structure of the tube bank covered on metal foam. Previous studies focused on the thermal performance of metal foam fully filled in channel, and analyzed the effects of tube bank structure qualitatively. However, the thermo-hydraulic mechanisms of porous and fluid in tube bank need further research. So a 3D numerical simulation was presented to reveal the flow and heat transfer properties of a new tube bank design covered on metal foam. The influences of foam structure parameters on heat transfer are examined. It can be observed that the exterior heat transfer performance is improved with the increasing of Reynolds number. The results indicate that the overall heat transfer rate is more sensitive to the porosity ɛ, whereas the pore density PPI made a complex effects on the thermal performance. The tube bank covering metal-foam with a low porosity and a low pore density offers strong benefits compared to the bare tube bank.