Experimental Study on Heat Transfer Characteristics of a Rectangular Thermosyphon Loop with Micro Phase Change Fluids

• Main Authors: Jing-Feng Lin, 林敬峰
• Other Authors: Ching-Jenq Ho
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/72603545611035504004

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 91 === The primary objective of present study is to experimentally heat transfer characteristics of a rectangular thermosyphon loop of phase change material（PCM）suspension. A rectangular loop of 34.5 cm in height and 34.5 cm in width was constructed with a stainless steel（AISI）tube of outer and inner diameters of 9.5 mm and 8.3 mm. Steady state heat transfer experiments of loop were performed for the relevant parameters in the following ranges: the heat input in the heated section q=4~20, the average out surface temperature in the cooled section T=10~25, and the mass fraction of the PCM particles(c=0~0.15). Experimental results obtained show the effectiveness of heat dissipation in the heated section of the circulation loop incorporating the PCM suspension appears inferior to that of pure water(c=0), which may be attributed to occurrence of supercooling of the PCM particles. Corresponding to the experiments, numerical simulations taking the supercooling phenomenon into account were undertaken. Fairly good agreement between the numerical predictions and the experimental data was found for the outer wall temperature distribution along the loop, lending clear evidences of occurrence of supercooling phenomenon in the PCM suspension. The supercooling of PCM particles can thus be detrimental to effectiveness of the suspension as a heat transfer enhancement medium.