Scaling effect analysis on FLNG laboratory and pilot liquefaction tests

The liquefaction process of floating liquefied natural gas (FLNG) is greatly sensitive to liquefaction capacity, components of feed gas and environmental conditions. To realize large-scale industrial application, it is necessary to carry out scale up experiment on liquefaction laboratory test and pilot test units. In this paper, the FLNG laboratory test and pilot test units for propane pre-cooling dual nitrogen expander liquefaction process were built, and the FLNG scale up performance in the tests was analyzed. It is shown that the propane pre-cooling dual nitrogen expander liquefaction process becomes less sensitive to the feed gas parameters and the effect of pre-cooling section becomes more visible, as the liquefaction capacity of feed gas increases, so that the energy consumption, nitrogen liquefaction and super-cooling load are cut down, and the amount of nitrogen circulation is reduced. Thus, the liquefaction capacity of the process is improved. In the tilting and sloshing conditions, the temperature of the feed gas in the cold box changes little and the whole liquefaction unit is highly adaptable to sloshing. Besides, the efficiency and capacity of the whole liquefaction system are greatly controlled by the selection of liquefaction process and equipment and the recovery amount. With the increasing of liquefaction capacity, efficient units and reasonable energy recovery modes can effectively reduce the energy consumption of the whole system while keeping the liquefaction system in normal operation, ultimately bringing about considerable economic benefits.