The comparative analysis on using the NEPCM materials and nanofluids for microchannel cooling solutions

This paper presents numerical analysis on microchannel laminar heat transfer and fluid flow of nanoencapsulated phase change materials (NEPCM) - water slurry as coolant, with two different melting ranges, 5 °C and 20 °C. In this study n-Octadecane for NEPCM and water is used as base fluid. With the purpose of evaluating best thermal performance, NEPCM-water slurry was compared to Cu-water nanofluid. The diameter ratio of the micro-tube was Di/Do = 0.3/0.5 mm with a tube length L = 100 mm with fixed heat transfer rate Q = 2 W. NEPCM-water slurry and Cu-water nanofluid were considered with various volume concentrations ϕ = 1,3 and 5% and diameter of the particles dp = 36 nm. Two different approaches were used concerning fixed Re and pumping power Π, in terms of average heat transfer coefficient and maximum temperature of the substrate. The results revealed that NEPCM-water slurry, with melting range of 5 °C, presents better thermal performances than base fluid and NEPCM with melting range of 20 °C. Besides, Cu-water nanofluid has much higher heat transfer coefficient (have) and lower maximum temperature of substrate (tmax) for all values of volume concentrations, in cases of both comparison criteria (Re or Π).