The invention relates to the technical field of
natural gas low temperature equipment, in particular to an LNG
energy recovery process. By an LNG hydraulic
turbine device (or expanding machinery in other forms),
high pressure and low temperature LNG converts pressure energy to
mechanical energy which is output by a supercharging end of the LNG hydraulic
turbine device. Depressurized LNG is further cooled, a
gas phase and a
liquid phase generated in a depressurizing process are separated by a gas-liquid separation tank, the liquid LNG is charged to an
LNG storage tank, and the
gas phase BOG and
BOG of the
LNG storage tank are supercharged together by the supercharging end, namely, a
BOG supercharger, of the LNG hydraulic
turbine device. The LNG hydraulic turbine device replaces a J-T valve of the LNG product for expanding throttling, as the LNG is lower in temperature, output of the BOG is reduced, LNG yield is improved, and
mechanical energy can be recovered by BOG supercharging of the BOG supercharging end.