METHOD OF TRANSPORTING LIQUEFIED GASES, IN PARTICULAR LNG, AT A TEMPERATURE BELOW SATURATION TEMPERATURE

摘要

In proposed method of liquefied gases (primarily LNG) transportation the liquefied gas is cooled prior to its loading into tanks of carrying vessel (e.g. a ship, an automobile, a railcar) to temperature which is lower, than saturation temperature at design pressure in tanks during the transportation. During the transportation heat inflow from the environment is absorbed by free increasing of liquefied gas temperature from subcooled liquid to saturated liquid state. Liquefied gas is not boiled off (as it would otherwise be the case for absorption of heat inflow) so it is not necessary to use reliquefaction plant on board of the carrying vessel or to dispose of boil-off gas. Seagoing ships transport large mass of liquefied gas so difference between liquefied gas temperature at the beginning of the transportation and saturation temperature will be relatively small. For example for LNG tanker having volume of tanks 150,000 m3 its value is 4.5 °C.