NEW GENERATION OF LNG PLANTS BASED ON INNOVATIVE LIQUEFACTION TRAIN CONFIGURATIONS NOUVELLE GENERATION DE GNL USINES BASEE SUR DES INNOVAIT CONFIGURATIONS DE TRAINS DE LIQUEFACTION

摘要

The International LNG trade keeps expanding rapidly and, as LNG complexes get larger, owners keep looking for ways to lower costs by benefiting from economies of scale. The trend toward even larger plants is marked in the industry and we see LNG plant designs in the coming decade falling broadly into three groups, with nominal capacities in the ranges of 3.5-4 mtpy, 5.0-5.5 mtpy, and new "mega-trains" of 7.5-8 mtpy. These train capacities are likely to co-exist in the coming years, as different owners find it advantageous to choose one vs. another. The rising capacity requires a major focus on train configuration and compressor selection. The goal of the detailed study was to provide insight on both aspects. The study is based on the Phillips Optimized Cascade LNG Process with three refrigerants (propane, ethylene, and open-loop methane) and explores four different compressor configurations based on single shaft GE Frame 7 and GE Frame 9 large gas turbine and variable frequency driven (VFD) controlled motor drivers, and includes the utilization of heat recovery systems and steam turbine drivers. Plant capacities considered range between 5.5 mtpy and 7.5 mtpy plus. We have concluded that large trains can be feasible and cost-effective. Although the compressors utilized in our studies represent some of the world's largest. They all meet guidelines for design parameters such as: aerodynamic flow coefficients, peripheral and eye Mach numbers, rotor dynamics and operating range flexibility. In addition, we still maintain the unique "parallel" reliability configuration which results in a high availability typical of the Phillips Optimized Cascade process.