Thermal performance enhancement of a new dual-PCM heat sink using two-objective optimization. (1st August 2022)

• Record Type: Journal Article
• Authors: Mozafari, M; Lee, Ann
• Is Part Of: Thermal science and engineering progress. Volume 33(2022)
• Publication Date: 2022-08-01
• Subjects: Phase change material (PCM) -- Heat sink -- Optimization -- Dual-PCM -- Electronics cooling -- Numerical; Heat engineering -- Periodicals; Heat engineering; Thermodynamics; Periodicals; 621.402
• DOI: 10.1016/j.tsep.2022.101383
• Languages: English
• ISSNs: 2451-9049

Abstract

Highlights: Numerical study on a new dual-PCM heat sink with realistic heat loss considerations. Two-objective optimizations improved the charging by 7%, and discharging by 4.2%. RSM with desirability function approach achieved slow heating and fast cooling. The effects of geometrical parameters on thermal performance are examined. The new designs render better performances while offering compact volumes up to 23%. Abstract: Phase change materials (PCMs) can effectively improve the performance of electronic heat sinks especially when subjected to intermittent heat loads. PCMs however brings some shortcomings such as increased size of component, and slowed heat rejection during the discharging, which urged the inevitability in development of optimized design. This study presents the results of the two-objective shape optimization of a new dual-PCM heat sink. The cooling phenomenon is analysed with thorough and realistic consideration of heat loss through the fin tips to the ambient, as well as heat transfer between the PCM and the air above it. Natural convection of liquid PCM and its volume variation during phase change transition are taken into account. Two-objective optimizations are performed to maximize the heat sink operational time in the charging process and minimize the discharging time, for three critical temperatures of 50 °C, 65°C, and 80 °C. Response Surface Methodology (RSM) is utilized to attain this goal. The fin thickness, the fin height, the width of ducts and the base thickness are selected as design parameters. The optimum volumetric percentages of PCM are found to be 80.50%, 76.94% and 74.81% for set point temperatures (SPTs) of 50 °C, 65 °C, and 80 °C, respectively. The optimized designs for three SPTs deliver charging periods up to 7% longer and discharging periods up to 4.2% shorter than the reference geometry. Furthermore, total volume of the heat sink is decreased up to 23% due to current optimizations, signifying a favourable compact design.