EXPERIMENTAL STUDY ON COOLING HEAT TRANSFER OF SUPERCRITICAL CARBON DIOXIDE FLOWING IN HORIZONTAL GROOVED TUBES
In this study, experimental study on cooling heat transfer of pure CO2 flowing in horizontal grooved tubes was carried out under supercritical pressure conditions. The heat transfer coefficients were measured for four different shapes of grooves in test tubes at 8 and 10 MPa in pressure and 360～690kg/(m2 s) in mass velocity. The ranges of the geometrical parameters in the grooved tubes are 4.76 to 5.11 mm in average inner diameter, 0.15 to 0.24 mm in depth of groove, 5 to 25 degrees in helix angle, 46 to 52 in number of grooves and 1.4 to 2.3 in area expansion ratio. While the available correlation equation of the heat transfer coefficient for the grooved tubes, which were developed for single-phase turbulent fluid flow, showed similar trends in comparison to those of the data on the variation of Reynolds number and fin shapes, its predicted results greatly deviated from the almost all of measured values. In order to improve the prediction method for the cooling heat transfer coefficient of supercritical carbon dioxide, the new correlation was developed empirically based on measured data and this correlation predicted almost all of the measured heat transfer coefficients within ±20％.
Shigeru KOYAMA Shinya HIGAHIIUE Ken KUWAHARA Daisuke ITO
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University 6-1 Kasuga-koen, Kasuga-shi Fukuoka, 816-8580, Japan
国际会议
The 22nd International Congress of Refrigeration(第22届国际制冷大会)
北京
英文
2007-08-21（万方平台首次上网日期，不代表论文的发表时间）