Thermal and hydrodynamic performance of flow boiling through a heat exchanger filled with various metallic foam samples

Abstract

The present paper deals with the study of heat transfer and pressure drop behaviors in a small heat exchanger filled with various metallic foam samples, during flow boiling. The tested metallic foam samples are made with copper, NiFeAlCr and Inconel. With 20 PPI (Pore per Inch) and 93% of porosity and the working fluid is the n-pentane. The independent variables are the inlet velocity, which is calculated by dividing the volume flow rate by the cross section. It is varied in the range of 0.02–0.06 m/s and the boiling heat flux density varied between 30 and 70 kW/m2. The heat transfer coefficient versus boiling heat flux and vapor quality is presented. The metallic foam made from copper enhanced the heat transfer by a factor varying between 130 and 300%, while its increase the pressure drop with average factor equal to 42%. The two other samples have a negative influence on the heat transfer coefficient and pressure drop compared to the copper one.