Heat transfer to boiling liquids in a single vertical tube thermosiphon reboiler

Novel application of support vector machines to model the two phase boiling heat transfer coefficient in a vertical tube thermosiphon reboiler

“…Page 12 of 52 A c c e p t e d M a n u s c r i p t 10 It has been reported that the heat transfer in the boiling section of the thermosiphon tubes is mainly due to the microconvection resulting from the nucleation, growth and detachment of vapor bubbles from the heating surface and to a certain extent by the macroconvection caused by the bulk flow of liquid with changing phase from single to two-phase (Kamil et al, 1995).…”

“…The generalization performance of this model has been evaluated comprehensively by applying it to a hitherto unutilized test dataset. Finally, the developed SVR model has been compared with the conventional models developed by Agarwal (1980), Ali (1989), Kamil et al (1995), Nihaluddin (1993) and Zaidi et al (2006).…”

“…Later on, efforts were made to develop empirical correlations for predicting boiling heat transfer coefficient of pure components by Agarwal (1980), Ali (1989), Nihaluddin (1993), Kamil et al (1995), and Zaidi (2006). All of these correlations predict the boiling heat transfer coefficient as Nusselt number in terms of four dimensionless numbers.…”

“…All of these correlations predict the boiling heat transfer coefficient as Nusselt number in terms of four dimensionless numbers. While three Page 7 of 52 A c c e p t e d M a n u s c r i p t 5 dimensionless numbers namely, the Peclet number for boiling (P eB ), the Lockhart-Martinelli parameter (X tt ), the Prandtl number (Pr B ) are common in all the models, the fourth parameter has been taken differently as the ratio of kinematic viscosity of water to that of the liquid at their saturation temperatures (ν water /ν L ) (Agarwal, 1980); the ratio of surface tension of water to that of liquid at their saturation temperatures (σ water /σ L ) ( Ali, 1989;Kamil et al, 1995 andZaidi, 2006) ; and the ratio of kinematic viscosity of liquid to that of its vapor at its saturation temperatures (ν L /ν V ) (Nihaluddin, 1993). It was observed that although all these correlations aid in the understanding and prediction of boiling heat transfer coefficient in thermosiphon reboilers, but the statistical information about most of these models is scant; only the constants, coefficients, and the maximum deviation are provided.…”

Experimental Study of Thermo-siphon Generator for Solar Energy LiBr Absorption Refrigerator

“…Their results indicated the bubble pump operates at slug flow regime with a churn flow regime at the entrance of the bubble pump tube. The effects of heat flux, submergence and physical properties on the heat transfer and circulation rate of bubble pump have been studied experimentally by many workers [11][12][13][14]. Besides, effects of service conditions of generator were studied by researchers [15] [16].…”