Two-Phase Flow Pressure Drop of Liquid Nitrogen Boiling in the Straight Section Downstream of U-Bend

doi:10.1007/s12204-014-1530-6

Abstract

Abstract: The gas-liquid (two-phase) flow pressure drop of liquid nitrogen boiling in the straight section downstream of U-bend is investigated experimentally. The mass flux ranges from 32 to 280 kg/(m2· s). The inlet pressure of U-tube is from 140 to 272 kPa. And the curvature ratio is from 6.67 to 15. The tube wall including the U-bend is heated uniformly and the heat flux ranges from 0 to 22 kW/m2. The tube with higher inlet pressure has higher pressure drop in the downstream section of the bend. The bended degree of the U-bend influences the pressure drop in the downstream straight section of U-bend. A new correlation taking the effect of the secondary flow into account is proposed for the two-phase slip speed ratio. The pressure drop in the straight section downstream of U-bend calculated by the new correlation agrees well with experimental measurements.

Key words: pressure drop| downstream of U-bend| secondary flow| liquid nitrogen

摘要： The gas-liquid (two-phase) flow pressure drop of liquid nitrogen boiling in the straight section downstream of U-bend is investigated experimentally. The mass flux ranges from 32 to 280 kg/(m2· s). The inlet pressure of U-tube is from 140 to 272 kPa. And the curvature ratio is from 6.67 to 15. The tube wall including the U-bend is heated uniformly and the heat flux ranges from 0 to 22 kW/m2. The tube with higher inlet pressure has higher pressure drop in the downstream section of the bend. The bended degree of the U-bend influences the pressure drop in the downstream straight section of U-bend. A new correlation taking the effect of the secondary flow into account is proposed for the two-phase slip speed ratio. The pressure drop in the straight section downstream of U-bend calculated by the new correlation agrees well with experimental measurements.

关键词: pressure drop| downstream of U-bend| secondary flow| liquid nitrogen

CLC Number:

TB 75

DENG Dong (邓冬), XIE Si-wei (谢斯卫), WANG Rong-shun*(汪荣顺). Two-Phase Flow Pressure Drop of Liquid Nitrogen Boiling in the Straight Section Downstream of U-Bend[J]. Journal of shanghai Jiaotong University (Science), 2014, 19(4): 495-501.

References

[1] Wang C C, Chen I Y, Lin Y T, et al. A visual observation of the air-water two-phase flow in small diameter tubes subject to the influence of vertical return bends [J]. Chemical Engineering Research and Design,2008, 86(11): 1223-1235.
[2] Patil P A, Sapali S N. Condensation pressure drop of HFC-134a and R-404A in a smooth and micro-fin U-tube [J]. Experimental Thermal and Fluid Science,2011, 35(1): 234-242.
[3] Abdulkadir M, Zhao D, Azzi A, et al. Two-phase air–water flow through a large diameter vertical 180? return bend [J]. Chemical Engineering Science, 2012,79(10): 138-152.
[4] Da Silva Lima R J, Thome J R. Two-phase flow patterns in U-bends and their contiguous straight tubes for different orientations, tube and bend diameters[J]. International Journal of Refrigeration, 2012, 35(5):1439-1454.
[5] Da Silva Lima R J, Thome J R. Two-phase frictional pressure drops in U-bends and contiguous straight tubes for different refrigerants, orientations, tube, and bend diameters. Part 2. New models (RP-1444) [J].HVAC & Rresearch, 2012, 18(6): 1072-1097.
[6] Chen I Y, Wang C C, Lin Y T. Measurements and correlations of frictional single-phase and two-phase pressure drops of R-410A flow in small U-type return bends [J]. International Journal of Heat and Mass Transfer, 2004, 47(10-11): 2241-2249.
[7] Domanski P A, Hermes C J L. An improved correlation for two-phase pressure drop of R-22 and R-410A in 180? return bends [J]. Applied Thermal Engineering,2008, 28(7): 793-800.
[8] Padilla M, Revellin R, Bonjour J. Two-phase flow visualization and pressure drop measurements of HFO-1234yf and R-134a refrigerants in horizontal return bends [J]. Experimental Thermal and Fluid Science,2012, 39: 98-111.
[9] Traviss D P, Rohsenow W M. The influence of return bends on the downstream pressure drop and condensation heat transfer in tubes [R]. Cambridge, USA:MIT Heat Transfer Laboratory, 1971.
[10] De Kerpel K, Ameel B, Huisseune H, et al. Twophase flow behaviour and pressure drop of R134a in a smooth hairpin [J]. International Journal of Heat and Mass Transfer, 2012, 55(4): 1179-1188.
[11] Xu Ji-yun. Boiling heat transfer and gas-liquid twophase flow [M]. Beijing, China: Atomic Energy Press, 2001 (in Chinese).

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