Abstract: An LNG fuel tank system for at least one gas engine used for ship propulsion is comprising at least one LNG fuel tank (4) and a gas vessel (8), the LNG fuel tank to be-bunkered from an onshore LNG pressure tank filling facility by means of an LNG filling line (1). According to the present invention the LNG fuel tank (4) is a ship low pressure controlled atmospheric pressure LNG tank, and the gas vessel (8) is a single shell non-insulated pressure vessel arranged to accumulate flashed and boil-off gas during LNG bunkering and pressure relieving the LNG fuel tank, respectively, and the gas engines are fuelled from either the gas vessel (8) or the LNG fuel tank (4), dependent on a predefined gas vessel pressure.

Abstract: A gas supply system for dual-fuel or gas engines is adapted for integration with a boil-off gas reliquefaction plant. The system includes a cryogenic heat exchanger, a boil-off gas compressor having a boil-off gas preheater, and a nitrogen loop with a compander. The gas is in the form of liquefied natural gas from cargo tanks or condensate from the reliquefaction plant. The gas supply system also includes an evaporator (optimizer) that extracts cold duty from the gas, and/or an evaporator that is arranged in a closed loop, which includes at least one pump and a heating source for an intermediate medium used to optimize extraction of the cold duty.

Abstract: A method and apparatus of pre-heating LNG boil-off gas stream flowing from a reservoir in a reliquefaction system, before compression. The method comprises heat exchanging the BOG stream in a first heat exchanger, against a second coolant stream having a higher temperature than the BOG stream, where the second coolant stream is obtained by selectively splitting a first coolant stream into second and third coolant streams, third coolant stream being flowed into a first coolant passage in a reliquefaction system cold box, whereby the BOG has reached near-ambient temperatures prior to compression and the low temperature duty from the BOG is substantially preserved within the reliquefaction system, and thermal stresses in the cold box are reduced. Before the compression step, the BOG is pre-heated to substantially ambient temperatures, by heat exchanging the BOG with said coolant, said coolant prior to the heat exchange having a higher temperature than the BOG.

Abstract: An apparatus and method for controlling temperature in a boil-off gas in a liquefaction plant prior to compression, wherein boil-off gas originating from an LNG storage tank is compressed and at least partially condensed, and wherein the condensed boil-off gas (LNG) is being returned to the storage tank. A heat exchanger (20) is connected to the boil-off gas feed line upstream of the compressor (10), and a first conduit (22) fluidly connects the line for returning LNG to the storage tank and the heat exchanger (20). A second conduit (26) fluidly connects the heat exchanger (20) to the boil-off gas feed line at a point upstream of the heat exchanger (20). Boil-off gas is heat exchanged against the cooler (24) prior to being fed into the compressor (10). Thus, the boil-off gas temperature is lowered downstream of the heat exchange.