Two-phase flow heat transfer of CO2 vaporization in smooth horizontal minichannels

Flow boiling heat transfer in minichannels at high saturation temperatures: Part II – Assessment of predictive methods and impact of flow regimes

“…On Fig. 6(a), the models of [8,9] provide the same trend as the experimental one. At 120°C, the trends provided by these models are more similar to the experimental trends than those provided by the asymptotic models developed for other fluids than the carbon dioxide and presented in Section 4.2.1 (see Fig.…”

“…Table 9 summarizes the results of the statistical analysis of these comparisons. These models work relatively well to predict the whole database, especially the model of [9] with 88.8% of the data falling within AE30% error band. For intermittent flow regime, these models overpredict the flow boiling heat transfer coefficient.…”

“…Using the model of [61], they modified the factors S and F. They changed the Lockhart-Martinelli parameter to take into account the important effect of quality, density ratio and viscosity ratio. [9] modified the coefficients F and S for carbon dioxide flow boiling. [42] modified the model of [5] to predict the flow boiling heat transfer coefficient of R-134a over a wide range of tube diameters.…”

“…The experimental heat transfer coefficients are compared to those predicted by the asymptotic models of [8,9,19,21,58]. These models were developed from database obtained for carbon dioxide with or without other fluids.…”

A Critical Review of Recent Investigations on Flow Pattern and Heat Transfer During Flow Boiling in Micro-Channels

“…Nucleate boiling and convective boiling mechanisms were observed in the experiments. Choi et al (2007a) reported the heat transfer characteristics of CO 2 through circular channels having diameters of 1.5 a nd 3 m m. They indicated that nucleate boiling was predominant in the low vapour quality region and a convective boiling heat transfer contribution appeared in moderate and high vapour quality regions. The variation of l ocal heat transfer coefficient with heat flux, mass flux, vapour quality and saturation temperature was discussed.…”