Temperature-Pressure-Time Relationships in a Closed Cryogenic Container

Abstract

One of the problems in the storage of cryogenic liquids is the increase in pressure in the closed container, A considerable quantity of heat may be transferred into the container because of the large temperature difference between the ambient temperature outside the container and the temperature of the cryogenic liquid. The increase in pressure in a closed container due to this heat leak may be calculated from the increase in liquid temperature, obtained from the heat-leak rate, and the vapor pressure-temperature equilibrium relation. Experience has shown, however, that the container pressure may be considerably greater than the calculated pressure based on an average liquid temperature. The difference between the actual pressure and that calculated from an average liquid temperature has been attributed to the development of temperature gradients in the liquid, O. A, Hansen,¹ Linde Air Products, Inc., and M. D. Andonian,² Cambridge Corporation, referred to the presence of liquid-temperature strata in their papers presented at the 1956 Cryogenic Engineering Conference.