Open AccessR245fa Flow Boiling inside a 4.2 mm ID Microfin Tube
Author(s) -
Giovanni Antonio Longo,
Simone Mancin,
Giulia Righetti,
Claudio Zilio
Publication year - 2017
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/923/1/012016
Subject(s) - pressure drop , materials science , refrigerant , vapor quality , thermodynamics , heat transfer coefficient , thermocouple , boiling , tube (container) , mechanics , heat transfer , flow boiling , composite material , nucleate boiling , heat exchanger , physics
This paper presents the R245fa flow boiling heat transfer and pressure drop\udmeasurements inside a mini microfin tube with internal diameter at the fin tip of 4.2 mm, having\ud40 fins, 0.15 mm high with a helix angle of 18°. The tube was brazed inside a copper plate and\udelectrically heated from the bottom. Sixteen T-type thermocouples are located in the copper plate\udto monitor the wall temperature. The experimental measurements were carried out at constant\udmean saturation temperature of 30 °C, by varying the refrigerant mass velocity between 100\udkg m-2 s-1 and 300 kg m-2 s-1, the vapour quality from 0.15 to 0.95, at two different heat fluxes:\ud30 and 60 kW m-2. The experimental results are presented in terms of two-phase heat transfer\udcoefficient, onset dryout vapour quality, and frictional pressure drop. Moreover, the\udexperimental measurements are compared against the most updated models for boiling heat\udtransfer coefficient and frictional pressure drop estimations available in the open literature for\udmicrofin tubes