Condensation heat transfer in presence of non-condensable gases on a vertical tube bundle

초록

In this study, steam condensation with air in a bundle geometry under free convection condition was investigated. The condensation heat transfer in a tube bundle was analyzed numerically using computational fluid dynamics simulations and through experimental testing. In both analyses, the heat transfer of the tube located at the center was smaller than that in tubes at the periphery. The difference in heat transfer according to tube location occurs because each tube competes with nearby tubes for a limited amount of steam (screening effect); the steam accelerates toward the tube bundle which enhances the heat transfer of peripheral tubes (suction effect). An empirical correlation was proposed using the representative mass fraction which assumes the mass fraction at the region between the tubes that takes a single value. The correlation calculated the heat transfer coefficient of the present study within 20% range, and those of open available datasets with various tube bundle geometry within 30% range. The heat transfer in various pitch-to-diameter was analyzed using the proposed correlation; the optimum pitch-to-diameter value that maximize the heat transfer in the seven-tube arrangement of the staggered grid was 2.00. © 2024 Elsevier Ltd

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