Zmywaczyk, J.; Zbińkowski, P.; Koniorczyk, P. Thermophysical Properties of POLWAX LTP ST Paraffin Doped with or without Carbon Nanotubes or Silver Nanowires and Passive Cooling of a High-Power LED Panel. Energies2023, 16, 6068.
Zmywaczyk, J.; Zbińkowski, P.; Koniorczyk, P. Thermophysical Properties of POLWAX LTP ST Paraffin Doped with or without Carbon Nanotubes or Silver Nanowires and Passive Cooling of a High-Power LED Panel. Energies 2023, 16, 6068.
Zmywaczyk, J.; Zbińkowski, P.; Koniorczyk, P. Thermophysical Properties of POLWAX LTP ST Paraffin Doped with or without Carbon Nanotubes or Silver Nanowires and Passive Cooling of a High-Power LED Panel. Energies2023, 16, 6068.
Zmywaczyk, J.; Zbińkowski, P.; Koniorczyk, P. Thermophysical Properties of POLWAX LTP ST Paraffin Doped with or without Carbon Nanotubes or Silver Nanowires and Passive Cooling of a High-Power LED Panel. Energies 2023, 16, 6068.
Abstract
Commercially available paraffin wax LTP ST, manufactured in Poland by POLWAX, was used as a phase change material (PCM) for passive cooling of a LED panel containing 28 high power light emitting diodes (LEDs). Paraffin wax LTP ST of density = 930 kgm-3 at room temperature (RT) was chosen over other POLWAX waxes (LUXOLINA, LUXOLINA-ST, LTP 56-20) because of its melting point range (44.5 – 55.4)℃, relatively high latent heat of fusion H = 218.8 Jg-1, high specific heat Cp = 2.11 Jg-1K-1 and thermal conductivity k=0.233 Wm-1K-1 at 0 ℃ [1]. The thermophysical properties were studied in samples of pure LTP ST paraffin and doped with multi-walled carbon nanotubes (1.99, 3.49, 5.35, 10.49 wt%, MWCNT) or silver nanowires (0.26, 0.32, 1.06, 2.10, 7.35 wt%, SNW). Analysis of the thermal effects of doped samples showed a relative increase in the degree of subcooling, averaging 100% for MWCNT and 46% for SNW , a relative 15÷25% decrease in enthalpy of melting for MWCNT and 14÷16% for SNW. A 44% increase in thermal conductivity was found for the sample containing 5.35 wt% MWCNTs and a 91% increase for 1.06 wt% SNW. The results of cooling efficiency tests for 3 types of developed heat sinks made of AW-2017A aluminum alloy are presented, i.e.: (a) - full system without PCM filling, (b) - system with PCM chamber without intracellular ribs, (c) system with PCM chamber with intracellular fins.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
