Enhancement of critical heat flux using nano-fluids for Invessel Retention¨CExternal Vessel Cooling

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• 作者：Q.T. Pham  ; ;   ; ^{phamquynhtrang7984@gmail.com} ; T.I. Kim ;   ; ^{skyimgf@kaist.ac.kr} ; S.S. Lee ;   ; ^{bluesaturn@kaist.ac.kr} ; S.H. Chang ;   ; ^{shchang@kaist.ac.kr}
• 关键词：Pool boiling ; CHF ; Nano-fluids ; IVR ; Contact angle ; Roughness
• 刊名：Applied Thermal Engineering
• 出版年：2012
• 出版时间：March 2012
• 年：2012
• 卷：35
• 期：Complete
• 页码：157-165
• 全文大小：1484 K

文摘

This study investigated the pool boiling critical heat flux (CHF) of water-based nano-fluids under atmospheric pressure for Invessel Retention (IR)¨CExternal Vessel Cooling (EVC). The heated surface was a stainless steel foil inclined at different orientation angle from 0¡ã (horizontal downward facing position) to 90¡ã (vertical position). Three working nano-fluids with high suspension stability were selected by the zeta potential method to investigate the effect of each nano-fluid on CHF at the heated surface, which were 0.05 % Alumine (Al₂O₃), 0.05 % carbon nanotubes (CNT)?+?10 % boric acid and 0.05 % Al₂O₃?+?0.05 % CNT. It was observed that these nano-fluids enhanced CHF significantly (up to 220 % ) compared to deionized (DI) water. Furthermore, for all test fluids, CHF increased when the orientation angle increased. The surface characterization after boiling tests shows that the CHF enhancement with nano-fluids can be related to the increase of both surface roughness and wettability caused by nanoparticle deposition during the boiling processes.