Study of nitrogen two-phase flow pressure drop in horizontal and vertical orientation

Cryogenic Engineering Conference 2017

材料科学;物理学

Koettig, T.^1 ; Kirsch, H.^1 ; Santandrea, D.^1 ; Bremer, J.^1

CERN, Geneva 23

1211, Switzerland^1

关键词: Adiabatic conditions;    Ambient pressures;    Cooling circuits;    Neutrino oscillations;    Operation temperature;    Saturation pressure;    Short base lines;    Two-phase region;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012128/pdf
DOI  :  10.1088/1757-899X/278/1/012128

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The large-scale liquid argon Short Baseline Neutrino Far-detector located at Fermilab is designed to detect neutrinos allowing research in the field of neutrino oscillations. It will be filled with liquid argon and operate at almost ambient pressure. Consequently, its operation temperature is determined at about 87 K. The detector will be surrounded by a thermal shield, which is actively cooled with boiling nitrogen at a pressure of about 2.8 bar absolute, the respective saturation pressure of nitrogen. Due to strict temperature gradient constraints, it is important to study the two-phase flow pressure drop of nitrogen along the cooling circuit of the thermal shield in different orientations of the flow with respect to gravity. An experimental setup has been built in order to determine the two-phase flow pressure drop in nitrogen in horizontal, vertical upward and vertical downward direction. The measurements have been conducted under quasi-adiabatic conditions and at a saturation pressure of 2.8 bar absolute. The mass velocity has been varied in the range of 20 kg•m-2•s-1to 70 kg•m-2•s-1and the pressure drop data has been recorded scanning the two-phase region from vapor qualities close to zero up to 0.7. The experimental data will be compared with several established predictions of pressure drop e.g. Mueller-Steinhagen and Heck by using the void fraction correlation of Rouhani.