Share
IIR document
Optical investigation of R134a two-phase flows in a microchannel.
Author(s) : REVELLIN R., THOME J. R.
Summary
An optical measurement method for two-phase flow characterization in microtubes has been applied to determine the frequency of bubbles exiting a micro-evaporator, the coalescence rates of these bubbles and their lengths as well as their mean two-phase vapour velocity. The tests were run in a 0.5 mm diameter glass channel using R134a at 26, 30 and 35 °C saturation temperatures. Four flow patterns (bubbly flow, slug flow, semi-annular flow and annular flow) with their transitions (bubbly/slug flow and slug/semi-annular flow) were detected. The two-phase flow pattern transitions observed with R134a did not compare well to a leading microscale flow map for refrigerants nor to a microscale map for air-water flows. No significant influence of the inlet subcooling (2, 3, 5 °C) nor the saturation pressure has been observed on the flow pattern transitions. Furthermore, changing the heated length from 70 to 30 mm before the glass tube did not influence the location of the transition lines.
Available documents
Format PDF
Pages: 2005-3
Available
Public price
20 €
Member price*
Free
* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).
Details
- Original title: Optical investigation of R134a two-phase flows in a microchannel.
- Record ID : 2006-0666
- Languages: English
- Source: Commercial Refrigeration. Thermophysical Properties and Transfer Processes of Refrigerants. Proceedings of the IIR International Conferences.
- Publication date: 2005/08/02
Links
See other articles from the proceedings (140)
See the conference proceedings
Indexing
-
Themes:
Heat transfer;
Mass transfer;
Two-phase flow - Keywords: Two-phase flow; R134a; Periodic phenomenon; Optics; Bubble; Microchannel; Measurement; Laser; Refrigerant
-
Phase distribution of R134a in minichannel-bran...
- Author(s) : KOYAMA S., KUWAHARA K., IKUTA S., et al.
- Date : 2005/08/02
- Languages : English
- Source: Commercial Refrigeration. Thermophysical Properties and Transfer Processes of Refrigerants. Proceedings of the IIR International Conferences.
- Formats : PDF
View record
-
Flow distribution and pressure drop in micro-ch...
- Author(s) : TOMPKINS D. M., YOO T., HRNJAK P. S., et al.
- Date : 2002/07/16
- Languages : English
- Source: 2002 Purdue conferences. 2002 compressor engineering & refrigeration and air conditioning conferences at Purdue [CD-ROM].
View record
-
Pressure drop and visualization of R134a two-ph...
- Author(s) : TU X., HRNJAK P. S.
- Date : 2003
- Languages : English
- Source: ASHRAE Transactions. 2003 Winter Meeting, Chicago, Illinois. Volume 109, part 1 + CD-ROM.
View record
-
Experimental investigation of local heat transf...
- Author(s) : BERTSCH S. S., GROLL E. A., GARIMELLA S. V.
- Date : 2007/08/21
- Languages : English
- Source: ICR 2007. Refrigeration Creates the Future. Proceedings of the 22nd IIR International Congress of Refrigeration.
- Formats : PDF
View record
-
Evaporation and two-phase flow in microchannels.
- Author(s) : THOME J. R.
- Date : 2002/03/07
- Languages : English
- Source: Qualità ambientale e soluzioni sostenibili. 43e Convegno Internazionale AICARR [CD-ROM]./ Environmental quality and sustainable technology. 43rd International conference of AICARR [CD-ROM].
View record