Field synergy analysis of different flow patterns in falling-film dehumidification system with horizontal pipes

Abstract

Effects of the flow pattern of intertubular liquid film on mass and heat transfer synergies in a falling-film dehumidification system with horizontal pipes are studied. A flow model of the dehumidifying solution between horizontal pipes is established using Fluent software, the rule of transitions of the flow pattern between pipes is studied, critical Reynolds numbers of flow pattern transitions are obtained, and the accuracy of the model is verified by experiments. The mass transfer synergy angle and heat transfer synergy angle are respectively used as evaluation criteria for the mass transfer synergy and heat transfer synergy, and distribution laws of the synergy angles for droplet, droplet columnar and curtain flow patterns are obtained. Simulation results show that the mass transfer synergy angles corresponding to droplet, droplet columnar and curtain flow patterns all rise to a plateau with time. The mean mass-transfer synergy angle is 98° for the droplet flow pattern, higher than 96.5° for the droplet columnar flow pattern and 95° for the curtain flow pattern. The results show that the mass transfer synergy of the droplet flow pattern is better than that of the droplet columnar flow pattern and that of the curtain flow pattern.

Keywords

film falling between horizontal pipes / fluent software / flow pattern of liquid film / synergy angle / mass and heat transfer

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