The application discloses a
liquefied natural gas (LNG) heat value regulation and stepwise
recovery device, which comprises a stepwise separation
tower, an LNG feeding port and a tangential feeding port, the LNG feeding port is arranged at the top of the stepwise separation
tower, the tangential feeding port is arranged at one side of the stepwise separation
tower, a three-stage nested tower core is arranged in the stepwise separation tower, the three-stage nested tower core comprises an upper cone which is fixedly installed in the stepwise separation tower, a middle cone which is fixedly installed in the upper cone, a lower cone which is fixedly installed in the middle cone, and a feeding
pipe which is fixedly connected with the tangential feeding port. The upper cone, the middle cone and the lower cone are coaxially nested and sequentially penetrated at the lower ends, three independent temperature zones are formed, LNG flows through the outer walls of the cones under the action of gravity,
methane is discharged from a first gas extraction port after being gasified in the upper cone, ethane is discharged from a second gas extraction port after being gasified in the middle cone, and heavy
hydrocarbon is collected in a bottom liquid collecting groove, so that flexible output of
natural gas with different heat values is realized.