Experimental analysis of heat transfers in a cryogenic tank without lateral insulation

The estimation of heat transfer in cryogenic storage tanks is an important subject, as it enables us to predict the evaporation of the stored cryogenic fluids. Many published research works have tried to understand and explain these heat transfers and proposed some methods to estimate these heat fluxes, but frequently without considering the radiation mode and assuming lateral insulation. The purpose of this paper is to present an experimental investigation of heat transfer in a cryostat without lateral insulation. The analysis enabled us to locate the main heat transfer phenomena observed in this case. It appears that the dominant heat transfer modes are radiation in the isolating cavity, conduction in the neck towards the liquid phase and convection between the inner wall of the neck and the cold vapour coming from the liquid bath. This study also enables to show that the approximation methods generally adopted for the determination of the radiation heat transfer between the external envelop and neck walls are not always valid.