Investigation of finned heat sinks with PEG-6000/EG and PEG-6000/MWCNT composite phase change material for thermal management application

Abstract

Present study reports the thermal performance of various cross finned heat sinks involving PEG-6000/EG and PEG-6000/MWCNT composites for thermal management applications. The performance of various heat sink configurations namely, heat sink with one cavity (HSOC), heat sink with four cavities (HSFC), heat sink with nine cavities (HSNC), and heat sink with sixteen cavities (HSSC) are analyzed for different heat flux values (q” = 1.7 kW/m2 to 2.4 kW/m2). Polyethylene glycol-6000 (PEG-6000) is considered as phase change material (PCM); while expanded graphite (EG) and multi-walled carbon nanotubes (MWCNT) with varied weight concentrations (0.5, 1.0 and 2.0 %) are used to prepare composite PCM (CPCM). The characterization has been made to access various thermophysical properties and thermal stability of CPCMs. The thermal performance of heat sinks involving CPCM is estimated by analyzing the enhancement ratio and the modified Stefan Number. A maximum enhancement of 55.80 % in thermal conductivity is achieved for CPCM involving PEG-6000 and 2.0 % MWCNT compared to only PEG-6000. The maximum value of enhancement ratio is found to be 1.37 and 1.18 for HSFC with with PEG-6000 and 2.0 wt% EG at q” = 1.7 kW/m2 and q” = 2.4 kW/m2, respectively. The minimum value of modified Stefan number (St) is found to be 8.25 and 11.65 at q” = 1.7 kW/m2 and q” = 2.4 kW/m2, respectively for PEG-6000 and 2.0 wt% EG. The findings suggest that the HSFC with PEG-6000 and 2.0 wt% EG CPCM has the potential to enhance the thermal performance of heat sinks and can be incorporated for efficient thermal management of electronic components.