ISSN Online: 2377-424X
ISBN Print: 0-89116-559-2
International Heat Transfer Conference 8
BOILING TRANSITION AND THE POSSIBILITY OF SPONTANEOUS NUCLEATION UNDER HIGH SUBCOOLING AND HIGH MASS FLUX DENSITY FLOW IN A TUBE
Abstract
Boiling transition and inverted annular heat transfer for R-113 have been investigated experimentally in a horizontal tube of 1.2 ×10−3 meter inner diameter with heating length over inner diameter ratio of 50. Experiments cover a high mass flux density range, a high local subcooling range and a wide local pressure range. Heat transfer characteristics were obtained by using heat flux control steady-state apparatus.
Film boiling treated here is limited to the case of inverted annular heat transfer with very thin vapor film, on the order of 10−6 meter. Moreover, film boiling region is always limited to a certain downstream part, since the system has a pressure gradient along the flow direction.
Discussions are presented on the parametric trends of boiling heat transfer characteristic curves and characteristic points. The possible existence is suggested of a spontaneous nucleation control surface boiling phenomena. And boiling transition heat flux and inverted annular heat transfer were correlated.
Film boiling treated here is limited to the case of inverted annular heat transfer with very thin vapor film, on the order of 10−6 meter. Moreover, film boiling region is always limited to a certain downstream part, since the system has a pressure gradient along the flow direction.
Discussions are presented on the parametric trends of boiling heat transfer characteristic curves and characteristic points. The possible existence is suggested of a spontaneous nucleation control surface boiling phenomena. And boiling transition heat flux and inverted annular heat transfer were correlated.