Liquefied natural gas(LNG) is a liquid hydrocarbon mixture dominated by methane. Natural gas liquefaction is a low-temperature cooling process. After purification treatment, the raw natural gas enters the heat exchanger for low-temperature cooling and condensation. When cooled to a certain temperature (related to pressure), it becomes liquid, which is liquefied natural gas (LNG). The volume of liquefied natural gas(LNG) is about 1/600 of its gas volume, which is conducive to transportation and storage.