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Indexed by:期刊论文

Date of Publication:2017-01-25

Journal:Joint Conference of the 5th UK-China and 13th UK Particle Technology Forum

Included Journals:SCIE、EI、CPCI-S

Volume:111

Page Number:1548-1556

ISSN No.:1359-4311

Key Words:Falling film evaporation; Horizontal tube; Superhydrophilic surface; Heat transfer enhancement; Low spray density

Abstract:This paper presents a series of experiments concerning heat transfer in a vertical row of horizontal-tube falling film evaporator. By visualization and heat transfer experiments, the effects of hydrophilic modification on the inter-tube flow patterns and evaporation heat transfer performance on different tubes, the superhydrophilic, hydrophilic and plain tubes, were investigated. The visualization results indicated that four flow patterns, droplet, droplet/jet, jet and jet/sheet mode was achieved in this study and the hydrophilic modification has 'little effect on flow mode transition. Experiments have been indicated that the superhydrophilic and hydrophilic tubes were completely wetted while the plain tubes were partially wetted at low spray density. The heat transfer results demonstrated that superhydrophilic tubes could maintain a high heat transfer coefficient at a wide range of flow rates (Re, from 60 to 700). While, high enhancement was achieved at low spray density, at which the plain tube was not be wetted. When Re, reached 350, three surfaces had the similar heat transfer performance. Simultaneously, the heating water inlet temperature had little effect on heat transfer coefficient for superhydrophilic tubes and had a negative influence on plain tubes and hydrophilic tubes at low spray density. (C) 2016 Elsevier Ltd. All rights reserved.