Heat Transfer Experiment on a Natural Circulation Loop of Water-based Suspensions of Phase Change Nanocapsules with Minichannel Heatsink and Heatsource
| Autor: | Yan-ZhongChen, 陳彥仲 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 In this study, experiments were conducted to obtain a better understanding of heat transfer characteristics of water-based suspensions of phase change material nanocapsules in a natural circulation loop with minichannel heat sink and heat source. With the core material of n-Eicosane and the shell of urea-formaldehyde resin, the phase change material nanocapsules of a mean particle size of 150nm were fabricated successfully and then dispersed in pure water as the based fluid to form the water-based nanofluids having the mass fractions of the nanocapsules in the ranges of 0.1-1 wt.%. Of the natural circulation loop, the heat sink and heat source sections were fabricated from copper consist of 26 and 34 rectangular minichannels, respectively, each of which has a width of 0.8 mm, a depth of 1.2 mm, a length of 50 mm with a hydraulic diameter of 0.96 mm. While the adiabatic sections of the circulation loop were constructed using PMMA circular tubes of 4 mm and 6 mm in inner and outer diameters.The experiments were performed with the modified Rayleigh numbers ranged from 3.99×〖10〗^7 to 3.21×〖10〗^8. The experimental results clearly indicate that water-based suspensions of phase change nanocapsules can markedly enhance the heat transfer performance of the natural circulation loop. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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