Utilization of Brayton and Reversed Brayton Cycles in Liquefied Natural Gas regasification process

Liquefied Natural Gas (LNG) is transported by the sea-ships with relatively low pressure (0.13-0.14 MPa) and very low temperature (about 100 K) in cryo-containers. Before further utilization it is compressed and then regasified. After that it can be directed to high pressure gas pipelines. Mentioned operations usually take place on the on-shore LNG terminals or on the local distribution stations. The LNG is transported to the local stations by means of tank trucks. Of course, the amounts the regasified gas in the on-shore terminal and in the local stations can not be compared - they are of different scale. Liquid phase, as far as low temperature of the medium is connected with its high exergy. LNG receives this exergy during the liquefaction and is related with energy consumption in this process. When the LNG is evaporated in atmospheric regasifiers (what takes place in many on-shore terminals as well as in local regasifier stations) the cryogenic exergy is totally lost. What's more, in many cases, atmospheric regasifiers are thermally supported by gas combustion which additional increases the cost of evaporation. But there are also a lot of installations dedicated for exergy recovery during LNG regasification. They are mainly used for the production of electricity, but there are also rare examples of utilization of the LNG cryogenic exergy for other tasks, for example it is utilized in the fruit lyophilization process. In the paper instalations based on the Brayton and Reversed Brayton Cycles gas turbines are proposed. The thermodynamic analyses of LNG regasifiers supplementing gas turbine cycle in various configurations are shown. Several schemes are discussed. The multiparameter analysis of each proposed solution is provided. The influence of basic work parameters on the energetic efficiency of the schemes is discussed.