Please use this identifier to cite or link to this item: http://buratest.brunel.ac.uk/handle/2438/9444
Title: Measurement and Modeling of Void Fraction in High Pressure Condensing Flows through Microchannels
Authors: Keinath, B
Garimella, S
4th Micro and Nano Flows Conference (MNF2014)
Keywords: Microchannel;Condensation;Void fraction;Visualization;Refrigerants
Issue Date: 2014
Publisher: Brunel University London
Citation: 4th Micro and Nano Flows Conference, University College London, UK, 7-10 September 2014, Editors CS König, TG Karayiannis and S. Balabani
Series/Report no.: ID 201
Abstract: Void fraction measurements are obtained using high speed video for the condensation of R404A in tubes of diameter 0.508, 1.00, and 3.00 mm. Experiments were conducted on refrigerant R404A throughout the entire condensation quality range (0.05 < x < 0.95) at varying mass fluxes (200 ≤ G ≤ 800 kg m-2 s-1) and saturation temperatures from 30 to 60°C (0.38 ≤ pr ≤ 0.77). These high pressures are representative of actual operation of air-conditioning and refrigeration equipment. The influence of saturation temperature on void fraction is most pronounced in the quality range 0.25 < x < 0.75. In addition, it was found that the influence of mass flux on void fraction was negligible for all saturation temperatures and tube diameters investigated. A new drift flux void fraction model is developed to predict void fraction for condensing flows in microchannels and compared with the R404A data and R134a void fraction data from Winkler et al. (2012a). Overall the model is able to predict 92.3% of the R404A data and 81.6% of all refrigerant data within 25%.
Description: This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.
URI: http://bura.brunel.ac.uk/handle/2438/9444
ISBN: 978-1-908549-16-7
Appears in Collections:Brunel Institute for Bioengineering (BIB)
The Brunel Collection

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