IR measurements of heat transfer coefficients and nucleation parameters during saturated nucleate boiling of water–glycerin mixtures

Case Studies in Thermal Engineering

Matic Može¹  Iztok Golobič²  Viktor Vajc²  Matevž Zupančič³  Radek Šulc³ 

[1] Corresponding author.;Czech Technical University in Prague, Faculty of Mechanical Engineering, Department of Process Engineering, Technická 4, 160 00, Prague, Czech Republic;University of Ljubljana, Faculty of Mechanical Engineering, Laboratory for Thermal Technology, Aškerčeva 6, 1000, Ljubljana, Slovenia;

关键词: Nucleate boiling;    Pool boiling;    Heat transfer coefficient;    Water–glycerin mixtures;    Bubble departure diameter;    Nucleation frequency;   

DOI  :  

来源: DOAJ

【 摘 要 】

Heat transfer coefficients and nucleation parameters were experimentally measured during saturated nucleate boiling of water–glycerin mixtures on a thin smooth titanium foil. Infrared thermometry was employed to study boiling of water–glycerin mixtures at atmospheric pressure in water mass fraction range from 100 % down to 60 % and heat flux range from 0 to 200 kW m−2. Heat transfer coefficients were found to deteriorate with an increase of concentration of glycerin in the boiling mixture. The deterioration was more pronounced for mixtures with lower water mass fraction and for higher heat fluxes. Bubble departure diameters were observed to be weakly dependent on heat flux and independent of composition of the boiling mixture. Nucleation frequencies were found to increase with heat flux and to be inversely proportional to water mass fraction of the boiling mixture. Thermal energy transferred during nucleation of individual bubbles was independent of both heat flux and mixture composition. Values and trends of evaluated parameters suggest that for investigated mixtures and boiling conditions, heat transfer into the liquid phase is more important relative to the transport of latent heat by nucleating bubbles.

【 授权许可】

Unknown