Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7051696 | Experimental Thermal and Fluid Science | 2018 | 50 Pages |
Abstract
Flow patterns and local heat transfer coefficients were investigated experimentally during flow boiling of R-290 in a tube with inner diameter equal to 1.0â¯mm. The tests were conducted at heat fluxes ranging from 5 to 60â¯kW/m2, mass flux from 240 to 480â¯kg/(m2s) at 25â¯Â°C saturation temperature. Both mass flux and heat flux have a significant influence on the heat transfer coefficient. A new flow pattern identification method is proposed, using non-dimensional parameters based on phase velocities and heat flux. The main flow patterns identified were bubbly, plug, slug, churn, wavy- and smooth-annular flow. Convective boiling was found to be predominant for most flow patterns. Moreover, the resulting heat transfer coefficients were compared with predicting correlations available in the literature.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Jeferson Diehl de Oliveira, Júlio Cesar Passos, Jacqueline Biancon Copetti, Cees W.M. van der Geld,