International Journal

Flow patterns and heat transfer characteristics of R-1234ze(E) for downward condensation in a plate heat exchanger
Year of publication 2021
Title of paper Flow patterns and heat transfer characteristics of R-1234ze(E) for downward condensation in a plate heat exchanger
Author DongChan Lee, Sungho Yun, JunYoung Choi, Yongchan Kim
Publication in journal International Journal of Heat and Mass Transfer
Publication date August 2021
Volume & other data Volume 175, 121373
Abstract This study investigates the condensation flow patterns and heat transfer characteristics of a low global warming potential refrigerant R-1234ze(E) for downward flow in a plate heat exchanger through flow visualization. An asymmetric flow aspect for downward condensation is characterized by vapor- and liquid-preferred paths owing to the effect of gravity. Flow patterns for downward condensation are classified into two regimes: steady film flow without intermittent flooding and pulsating film flow involving intermittent flooding. Additionally, the condensation heat transfer coefficient and frictional pressure drop were analyzed considering flow patterns. Intermittent flooding is hardly related to the heat transfer performance. A frequency analysis of the pressure drop exhibited a considerable difference in periodic characteristics between the flow regimes with and without intermittent flooding. Finally, the visualization data coincided with the flow pattern map proposed by the existing study, and an empirical correlation for predicting the flow transition between pulsating and steady film flow was developed in terms of the Weber number.
Keywords Flow pattern, Condensation, Plate heat exchanger, R-1234ze(E), Low GWP
issn Number 00179310
Status of publication
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