Boil-off gas treatment apparatus for electric-propelled lng carrier having re-liquefaction function and method thereof

Abstract

The present invention relates to a boil-off gas treatment device and method of an electric propulsion LNG carrier with reliquefaction function, wherein, comprising: a boil-off gas cooler (10), which receives natural boil-off gas (Natural Boil-Off Gas) generated in an LNG cargo hold , N-BOG), thereby exchanging heat with the refrigerant and cooling; the gas compressor (20), which receives the natural evaporated gas cooled in the evaporated gas cooler (10), and compresses it to be usable Air pressure in a DFDE (Dual Fuel Diesel Electric) propulsion engine (3); the engine feeds a gas cooler (30) which cools the naturally evaporated gas warmed up by said gas compressor (20) to The temperature used in the DFDE propulsion engine (3) is supplied to the DFDE propulsion engine (3) side; and the reliquefaction heat exchanger (50) is supplied from the engine to the gas cooler (30) Downstream receives the remaining natural evaporated gas not used in the DFDE propulsion engine (3), exchanges heat with the refrigerant, and supplies it to the side of the LNG cargo tank after being cooled and reliquefied, so that the gas produced in the LNG cargo tank While the natural evaporated gas is used as the power source required for the ship's navigation, the remaining gas that is not used in the propulsion process can be reliquefied to minimize the waste of the naturally evaporated gas.

Description

technical field [0001] The present invention relates to a device and method for treating boil-off gas of an electric propulsion LNG carrier with a reliquefaction function, and in more detail, relates to a method for effectively applying natural boil-off gas generated in an LNG cargo tank as energy to propulsion of a ship, and at the same time A device and method for treating boil-off gas of an LNG carrier capable of reducing waste of remaining gas not used during propulsion as much as possible. Background technique [0002] Generally, a liquefied natural gas carrier (LNG carrier) is a ship that transports liquefied natural gas (LNG) from a production base to a receiving base, and is usually referred to as an LNG carrier or LNGC (LNG Carrier). LNG (Liquefied Natural Gas) liquefies natural gas with methane (CH4) as the main component at minus 162°C under atmospheric pressure. The volume ratio of liquid and gas in LNG is about 1 / 600, and the specific gravity of LNG in the lique...

AI Technical Summary

Problems solved by technology

Therefore, there is a limitation that an additional compressor needs to be provided for the DFDE propulsion engine alone, or the existing reliquefaction plant can only be operated with low reliquefaction efficiency

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