Improving energy efficiency of a heat exchanger using recovered metal chips during forced convection

The aim of this study is to conduct a comparative experimental investigation on forced convection between two scenarios: an empty channel and a channel filled with unconsolidated porous media (metal chips) recovered from turning machine. The investigation is divided into two main parts: a thermal analysis focusing on the enhancement of the heat transfer and improving energy efficiency, and a hydrodynamic analysis addressing the pressure losses in both cases. Experiments were conducted using an in-situ test section. During experimentation, the water mass flux varied from 1.4 l/min to 4.2 l/min, with a heating power of 140 W. The used metal chips are made from hard steel. The results indicate that the insertion of metal chips made from hard steel in the channel increased the mean Nusselt number by an average factor of 3.97. However, the pressure drop in the channel filled with metal chips was four times greater compared to the empty channel.