Investigation of transient chill down phenomena in tubes using liquid nitrogen

Cryogenic Engineering Conference 2017

材料科学;物理学

Shukla, A.K.^1,2 ; Sridharan, Arunkumar^2 ; Atrey, M.D.^2

ISRO Propulsion Complex, Tamilnadu, Mahendragiri

627133, India^1

Indian Institute of Technology Bombay, Maharashtra, Mumbai

400076, India^2

关键词: Boiling curve;    Cryogenic transfer line;    Energy conservation equations;    Film boiling;    Indian institute of technologies;    Measured temperatures;    Single phase liquid flow;    Temperature variation;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012035/pdf
DOI  :  10.1088/1757-899X/278/1/012035

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Chill down of cryogenic transfer lines is a crucial part of cryogenic propulsion as chill down ensures transfer of single phase fluid to the storage tanks of cryogenic engines. It also ensures single phase liquid flow at the start of the engine. Chill down time depends on several parameters such as length of the pipe, pipe diameter, orientation, mass flux etc. To understand the effect of these parameters, experiments are carried out in a set up designed and fabricated at Indian Institute of Technology Bombay using tubes of two different diameters. Experiments are conducted at different inlet pressures and mass flow rate values to understand their effect. Two different pipe sizes are taken to study the effect of variation in diameter on chill down time and quantity of cryogen required. Different orientations are taken to understand their effect on the chill down time, heat transfer coefficient and critical heat flux for the same inlet pressure and mass flux. Pipe inner wall temperature, heat transfer coefficient for different boiling regimes and critical heat flux are calculated based on measured outer surface temperature history for each case. A one dimensional energy conservation equation is solved for transient chill down process considering constant mass flux and inlet pressure to predict the chill down time. Temperature variation during chill down obtained from the numerical simulations are compared with the measured temperature history.