AN OPTIMAL INVESTIGATION OF HEAT TRANSFER IN A CRYOGENIC TANK

摘要

Sources of natural gas are scattered relatively evenly around the globe, with the results that a trade has developed in transferring the gas to areas of large demand. Thus there are major pipelines around the world. However much gas is liquefied for both transport and storage to take advantage of the large decrease in specific volume, which is achieved without the necessity for pressurization.).rnThe estimation of heat transfer in cryogenics tanks under both laminar and turbulent regimes is an important subject, as it enables to predict the evaporation of the stored cryogenic fluids, which involves simultaneously heat and mass transfer operations. Few studies have looked in detail at this problem using, for example, the approximate method. In this paper, experimental results obtained for liquid nitrogen cryostats, concerning heat transfer through conductive, convective and radiation modes under natural and turbulent regimes between the vapor and the necks, as well as velocity, stream and thermal profiles along the cryostat necks are presented. These results, which may be important in this field, are compared firstly with a numerical simulation, which has been developed and solved through the Fluent industrial code, and secondly with a theoretical model which uses basic principles of heat transfer. rnThe study enables to determine the main parameters affecting the heat losses in this tank and validate the industrial package code, Fluent, for the estimation of these parameters, and therefore can be considered as an important contribution to the improvement of the design of cryogenic tanks.