Density Wave Oscillation in a Natural Circulation Loop of Liquid Nitrogen

Abstract

Dynamic behavior and flow instability problems have been widely investigated in these three decades in relation with the development of nuclear power plants [Lahey & Drew 1980]. On the other hand, the dynamic behavior and/or flow instabilities in cryogenic systems have been investigated only in a limited range of experiments so far [Friedly et al. 1979, Hands 1979, Akagawa et al. 1989. Fukuda et al. 1984 and so on]. Recently, increasing attention has been given to the flow instability problems in air separation systems, where thermosyphon reboiler-condensers have significant influence on the system performance. In the thermosyphon reboiler-condenser, heating of the primary fluid in the reboiler side is conducted by the condensation of the secondary fluid. Then the dynamic behavior of circulation velocities in both sides and the thermal interaction between the reboiler and the condenser play important roles in the dynamics of the total system, which makes the dynamics of the system complicated one. For better understanding such dynamics, it is necessary, at the first step, to conduct investigations in a simplified system such as without any thermal coupling.