Proceedings of Symposium on Energy Engineering in the 21st Century (SEE2000) Volume I-IV

ISBN Print: 1-56700-132-7

BOILING HEAT TRANSFER IN NORMAL AND QUANTUM LIQUID HELIUM

DOI: 10.1615/SEE2000.100
pages 127-137

Abstract

The use of superfluid helium as the cooling mechanism for superconducting cavity or superconducting magnet is a key point for many years and recently for the Large Hadron Collider (LHC) which will be built at CERN (Switzerland), stimulating complementary studies on its heat transfer properties. Topics are now likely such as two phase flow of a quantum liquid helium II and its vapour, heat transfer in the very narrow geometry filled by helium II of the electrical insulation of superconductor cable, or peak heat flux and boiling configurations for surfaces wetted by either the normal liquid helium I or the quantum liquid helium II. On the other hand, these applied researches provide new information on complex and fundamental phenomena encountered with liquid helium II, as two-phase flow, heat and mass flow in porous media and boiling heat transfer. It is thus interesting to look at them on a basic point of view and compare the behaviour of a normal and a quantum fluid subjected to a boiling process. In this short review of the few experimental and theoretical works on the subject, widely using our experimental results on boiling configurations by means of photographs and high speed camera, the attention is focused on the quite complex phenomena of boiling heat transfer from a heated surface or more specially a thin cylindrical wire immersed in helium II. We then try to get the special feature of a boiling quantum fluid in configurations often referred as silent and noisy boiling regimes. A special attention is given to the silent boiling states as shown in the movie presented at the conference.