Non-boiling heat transfer in horizontal and near horizontal upward inclined gas-liquid two phase flow

摘要

Heat transfer in non-boiling gas-liquid two phase flow finds its practical application in chemical and petroleum industries. So far, majority of the research dedicated to study heat transfer in non-boiling two phase flow is limited to horizontal and vertical pipe orientations with very little attention given to the study of this phenomenon in inclined systems. To contribute and further enhance the general understanding of heat transfer in non-boiling two phase flow, the main focus of this work is to experimentally measure local and average convective heat transfer coefficients for different flow patterns in horizontal and near horizontal upward inclined two phase flow. In total, 368 experiments are carried out in a 12.5 mm I.D. schedule 10S stainless steel pipe at 0, +5, +10 and +20 degrees pipe orientations using air-water as fluid combination. For each pipe orientation, the superficial gas and liquid Reynolds number is varied from 200 to 19,000 and 2000 to 18,000, respectively and the measured values of the averaged heat transfer coefficient were found to be in a range of 1300 W/m2K to 8000 W/m2K. The two phase heat transfer coefficients are compared among the above mentioned orientations. It is found that the two phase heat transfer coefficient increases from 0° to +5° and +10° and then decreases at +20°. Also, correlations in the literature were tested and the best performing correlations have been discussed in the experimental study. Correlation using the concept of Reynolds analogy was developed by modification of the existing correlation in the literature leading towards the better understanding of the relationship of heat transfer phenomenon with the pressure drop.