Abstract:
This study discusses the behaviour of convective heat transfer at low temperature storage tank containing non boiling liquid nitrogen. The aim of this experimental and theoretical study is to have a better understanding of the instability phenomena occurring in cryogenic liquids under storage conditions. The thermodynamic model we developed in this study, describing both the Interfacial thermal boundary layer and the wall boundary layer, is based on the experimental data at the laboratory scale. Experimental study gives a better indication on the evaporation mechanism of the stored liquid near the evaporative surface region. The temperature difference between the surface and the bulk liquid for various absorptive heat flows resulting in different rate of evaporation was measured for a cryogenic liquid stored. Theoretical study devoted to the free convection theory by using the integral approach including the coupling of dynamic and thermal phenomena gives the temperature and velocity profiles in laminar and turbulent wall boundary layers at various wall heat flux as well as the evolution of the thickness of the interfacial boundary layer as a function of the evaporated mass flow.