Utilization of cryogenic exergy of LNG by MGT (mirror gas turbine)

摘要

Recently, the LNG (liquefied natural gas) terminals in our country have received more than 50 million tons of LNC 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 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 conventional combined cycle and cogeneration systems 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, 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 that the removal of an evaporation system using seawater.