ISSN Online: 2377-424X
International Heat Transfer Conference 4
EXPERIMENTAL STUDY OF HEAT TRANSFER IN UPWARD AND DOWNWARD TWO-PHASE FLOW OF AIR AND OIL THROUGH 70-mm TUBES
Résumé
Forced convective heat-transfer coefficients of the non-boiling system gas oil/air have been measured in a 70-mm diameter coil. Liquid and gas velocities have been varied between 0.02 and 4.64 m/s and between 0.01 and 100 m/s, respectively.
Generally the heat-transfer coefficients increase with increasing flow velocities. However, in the range where a transition in flow pattern takes place from slug flow to annular/mist flow there is a sharp decrease, and in the transition zone from bubble to slug flow the heat-transfer coefficient drops below the value for single-phase liquid flow.
Other authors report much higher heat-transfer coefficients. This is ascribed to a strong effect of tube diameter.
Generally the heat-transfer coefficients increase with increasing flow velocities. However, in the range where a transition in flow pattern takes place from slug flow to annular/mist flow there is a sharp decrease, and in the transition zone from bubble to slug flow the heat-transfer coefficient drops below the value for single-phase liquid flow.
Other authors report much higher heat-transfer coefficients. This is ascribed to a strong effect of tube diameter.