EXERGY ANALYSIS ON SECOND GENERATION MICRO HEAT SINKS

Abstract

A parametric study of thermodynamic efficiency associated with exergy analysis over four micro pin fin heat sinks of different spacing and shapes was conducted. Exergetic efficiency was used to evaluate the thermodynamic performance. The effect of working fluid on exergetic efficiency was also investigated using R-123 and water as working fluids. Exergetic efficiencies were obtained to evaluate and compare the exergetic performances of the micro pin fin heat sinks at fixed mass flow rate, fixed pressure drop, and fixed pumping power. The results of exergy analysis were compared to the results of thermalhydraulic performance study of a past study. Micro pin fin heat sinks having better heat transfer performance rather than thermalhydraulic performance produced better exergetic efficiencies, so that denser configuration and flow separation promoting geometries resulted in higher exergetic efficiencies. Using R-123 instead of water enhanced the exergetic performance with a penalty of having lower heat transfer performance.