The invention discloses a miniature skid type
nitrogen expansion
natural gas liquefaction system and method thereof.
Natural gas is supercharged by a
natural gas supercharging prying block and cooled, and enters into a
natural gas depickling and dehydrating prying block for removing
impurity, and is cooled by a first stage
heat exchanger and then enters into a heavy
hydrocarbon separator, thereby obtaining a heavy
hydrocarbon from the bottom; after the heavy
hydrocarbon is removed, the natural gas is cooled by a second stage
heat exchanger for
liquefaction; after pressure of a
throttle valve is reduced to the storage pressure of the
liquefied natural gas, the natural gas enters into a natural gas
liquefaction separator for obtaining a
liquefied natural gas, and a
flash evaporation gas returns to the
heat exchanger for providing
cooling capacity. A
nitrogen is supercharged and cooled by a
nitrogen compression prying block, and is supercharged and cooled by a two-stage
supercharger, and then enters into the first stage heat exchanger for precooling; after precooling, the nitrogen is expanded and refrigerated by the two-grade expander and providing a
cooling capacity for liquefaction of natural gas. The miniature skid-mounted type nitrogen expansion natural gas liquefaction has the advantages of simple flow, fast starting and convenient maintenance, and is convenient for prying equipment with low
energy consumption, and simultaneously has better adaptability for different gas sources.