The transient behavior of a small-scale cryogenic transfer line was investigated during chilldown to cryogenic temperatures. The vacuum-jacketed apparatus consisted of a verticle tube followed by a near-horizontal tube. The tube diameter was 1 cm and the overall length was 4.4 m. The apparatus was equipped with view-ports in the near-horizontal section to allow visual observation of the flow patterns. Wall temperatures were measured at various locations along the length of the transfer line. Each test was conducted at a constant liquid volumetric flowrate at the transfer line inlet until saturation temperatures were obtained throughout minutes to several hours. An optimum flowrate exists that minimizes liquid consumption during the chilldown process. At higher flowrates, there is insufficient time for heat transfer from the liquid to the wall and inefficiencies result from the greater amount of incompletely vaporized liquid passing throuhg the system. At lower flowrates, chilldown time and total ambient heat leak into the system increse, which raises liquid consumption. The experimental values of liquid consumption are compared to analytical estimates. At low flowrates, the data compares favorable to a minimum consumption model while at high flowrates, the maximum comsumption model overpredicts hydrogen consumption and underpredicts nitrogen consumption.
Cryogenic Engineering Conference | | Advances in Cryogenic Engineering Vol. 49A: Transactions of the Cryogenic Engineering Conference - CEC | AIP
September 22-26, 2003
AIP Conference Proceedings
chilldown, cryogenic, liquid hydrogen, liquid nitrogen, transfer line
Van Dresar, N.
and Siegwarth, J.
Cryogenic Transfer Line Chilldown, Cryogenic Engineering Conference | | Advances in Cryogenic Engineering Vol. 49A: Transactions of the Cryogenic Engineering Conference - CEC | AIP, Undefined
(Accessed December 3, 2023)