Prediction of the Transition Criterion to Annular Flow in Two-Phase Flow Pattern of Refrigerants

• Published in: JSME International Journal Series B Fluids and Thermal Engineering Vol. 46; no. 4; pp. 618 - 624
• Main Authors: LIM, Tae Woo, PARK, Jong Un
• Format: Journal Article
• Language: English
• Published: Tokyo The Japan Society of Mechanical Engineers 2003; Japan Society of Mechanical Engineers; Japan Science and Technology Agency
• Subjects: Annular Flow; Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Intermittent Flow; Refrigerants; Refrigerating engineering; Refrigerating engineering. Cryogenics. Food conservation; Stratified Flow; Stratified-Wavy Flow; Two-Phase Flow Pattern Map; Wavy flow; Two phase flow; Flow regime; Flow(fluid); Annular flow; Refrigerant fluid; Stratified flow
• ISSN: 1340-8054; 1347-5371
• DOI: 10.1299/jsmeb.46.618

Two-phase flow pattern data during horizontal in-tube flow boiling are presented for pure and mixed refrigerants of R134a and R123. The flow pattern is observed through tubular sight glasses located at inlet and outlet of the test section, which is made of a stainless steel tube, 2m long with 10mm I. D., 1.5mm wall thickness. The obtained results are compared to the available various correlations for flow pattern. The flow pattern map of Hashizume was very well agreement with the present data except the region of low mass velocity. Weisman flow pattern map was also known to satisfactorily predict data for refrigerants in the region of annular flow. In order to establish the transition quality to annular flow in this study, flow pattern are simply classified into two groups; stratified (including intermittent, stratified and stratified-wavy) flow and unstratified (annular) flow. The transition quality from stratified to unstratified flow was obtained by modifying the liquid Froude number.