EFFECTS OF STRATIFICATION ON BOIL-OFF RATES IN LNG TANKS
摘要
Roll-over is a term that has been used to describe a phenomenon in which a bottom portion of the liquid in a cryogenic storage tank is superheated, as a result of heat leak, and then migrates suddenly to the surface accompanied by the evolution of a large quantity of vapor. Studies have shown that roll-over cannot occur in large cryogenic storage tanks containing nearly pure liquids. Roll-over has not been observed in cryogenic tanks that have been used for storing LNG of essentially uniform composition and density, ammonia, liquid oxygen, or liquid nitrogen. The addition of LNG of different densities to partially filled LNG tanks can lead to the temporary formation of stratified layers. Mathematical model of roll-over is developed and safety in LNG tanks is discussed.