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

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