Utilization of Cryogenic Exergy of LNG by MGT (Mirror Gas Turbine)

In the course of the worldwide efforts to suppress the global warming, the saving energy becomes more important. Recently, the LNG (liquefied natural gas) terminals in our country have received more than 50 million tons of LNG per year. Therefore, the utilization of the cryogenic exergy in connection with the regasification of LNG gains more and more importance. The aim of this paper is the recovery of the energy consumed in liquefaction using the MGT (Mirror Gas Turbine), which is a kind of new combined cycle of a conventional gas turbine worked as a topping cycle and TG (inverted Brayton cycle) as a bottoming cycle. The optimum characteristics have been calculated and it is shown that this cycle is superior to the current-use gasification systems in employing seawater heats in terms of thermal efficiency and specific output. In the present cycle, the cold of LNG is used to cool the exhaust gas from a turbine of TG, and then the exergy of the liquefied natural gas is transformed to electric energy with a very high efficiency. The main feature of this new concept is the removal of an evaporation system using seawater.Copyright © 2000 by ASME