An experimental investigation of convection heat transfer to supercritical carbon dioxide in miniature tubes

摘要

Expeimental results of convection heat transfer to supercritical carbon dioxide in heated horizontal and vertical miniature tubes are reported in this paper. stainless steel circular tubes having diameters of 0.70, 1.40, and 2.16 mm were investigated for pressures ranging from 74 to 120 bar, temperatures from 20 to 110 deg.C, and mass flow rates from 0.2 to 0.2 kg/min. The corresponding Reynolds numbers and Prandtl numbers ranged from 10~4 to 2x10~5 and from 0.9 to 10, respectively. It is found that the buoyancy effects were significant for all the flow orientations, although Reynolds numbers were as high as 10~5/