Experimental investigation of single-bubble growth during the saturated pool boiling of water and self-rewetting aqueous n-butanol mixtures

Zupančič, Matevž (avtor), Zakšek, Peter (avtor), Golobič, Iztok (avtor)

Self-rewetting fluids are commonly used in heat pipes, but their performance is not well understood in pool boiling. Here, we performed boiling of n-butanol-water mixtures on thin titanium foil and utilized synchronous high-speed IR and video cameras to capture transient temperature fields and bubble dynamics. At the onset of nucleate boiling, self-rewetting fluids offered higher nucleation site density and smaller bubble diameters compared to water. However, with increasing heat flux, a significant depletion of n-butanol was created in the vicinity of nucleation sites, which caused periodic temporal fluctuations in nucleation temperature and bubble evaporation energy. Average surface temperature and bubble departure diameter for self-rewetting fluids even exceeded the values of pure water. This shows that Marangoni effects cannot overcome limited mass diffusion of more volatile component towards nucleation sites in pool boiling on flat horizontal heaters. Based on our observations, the use of a self-rewetting fluid will not increase the heat transfer coefficient when compared to pure water, which is also known for conventional mixtures with negative temperature-dependent surface tension. Our experiments offer a step towards better understanding nucleate boiling of complex mixtures and a possibility for indirect evaluation of concentration variations based on synchronous high-speed video and IR thermography.

• Jezik: Angleški jezik
• Ključne besede: pool boiling, water, n-butanol, self-rewetting fluids, IR thermography, high-speed imaging
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2021
• Št. strani: 11 str.
• Številčenje: Vol. 28, art. 101513
• PID: 20.500.12556/RUL-131956
• UDK: 536.24
• ISSN pri članku: 2214-157X
• DOI: 10.1016/j.csite.2021.101513
• COBISS.SI-ID: 79463683
• Datum objave v RUL: 07.10.2021

Gradivo je del revije

• Naslov: Case studies in thermal engineering
• Založnik: Elsevier
• ISSN: 2214-157X
• COBISS.SI-ID: 519660057

Licence

• Licenca: CC BY-NC-ND 4.0, Creative Commons Priznanje avtorstva-Nekomercialno-Brez predelav 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc-nd/4.0/deed.sl
• Opis: Najbolj omejujoča licenca Creative Commons. Uporabniki lahko prenesejo in delijo delo v nekomercialne namene in ga ne smejo uporabiti za nobene druge namene.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: vrenje v bazenu, voda, n-butanol, samoomočljivi fluidi, IR termografija, hitrotekoča vizualizacija

Projekti

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: P2-0223
• Naslov: Prenos toplote in snovi

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: J2-2486
• Naslov: Izboljšan prenos toplote pri vrenju z uporabo hierarhičnih funkcionaliziranih površin (eHEATs)