Abstract
This paper presents a comparison between experimental results from recent liquid hydrogen (LH2) transfer line chilldown experiments at high Reynolds (Re) numbers versus liquid nitrogen (LN2) experiments conducted at low Re numbers. Parasitic heat leak, inner wall temperatures, inner wall heat fluxes, and heat transfer coefficients are computed to compare between the two systems. Analysis of temperature traces and flow visualization indicates that the chilldown process evolves much more rapidly at higher Re numbers due to a quick transition from vapor flow to annular liquid flow and near immediate liquid contact along the pipe walls. The lower kinematic viscosity and surface tension of LH2, along with reduced parasitic heat leak and higher Re numbers relative to the LN2 experiments, causes chilldown to proceed almost immediately into the nucleate boiling regime, in comparison to low Re flows where >75% of the chilldown is spent in vapor film boiling.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
