Investigating Heat Transfer Enhancement Using Metal Foam in Double Tube Heat Exchangers-Experimental Approach

Abstract

This study addresses the imperative requirement for efficient utilization of solar energy by examining the incorporation of metal foam heat exchangers into solar flat plate collectors, with a focus on enhancing their thermal performance. The primary objective of this study is to experimentally evaluate single-phase double-tube heat exchangers with and without the incorporation of metal foam in the annular space. By conducting experiments with hot and cold water at various flow rates, the research aims to assess the impact of metal foam on key parameters such as heat transfer coefficient, Nusselt number, Reynolds number, effectiveness, and pressure drop. Furthermore, the study compares the experimental results with established correlations from existing literature. The experiments are performed with hot and cold water at different flow rates of 25 liters per hour and (25-50) liters per hour at 650C and room temperature, respectively. Nickel metal foam with 10 Pores Per Inch and 0.9 porosity is fitted in the annular space. The results of the study indicate that the incorporation of metal foam leads to a significant improvement in heat transfer performance, up to 2.2 times compared to a traditional heat exchanger. However, this enhancement in heat transfer comes at the cost of increased pressure drop across the metal foam heat exchanger. The investigation is significant as it offers insights into the potential of metal foam to improve heat exchanger performance. Therefore, the research highlights the existence of a trade-off between heat transfer efficiency and pressure drop when designing double-tube heat exchangers with metal foam. This work provides valuable insights into