A method for calculating the remaining usage time of a gas cylinder equipped with a pressure reducer, the method comprising the following steps: (a) measuring the pressure of the gas in the cylin-der; (b) calculating the variation of pressure of the gas in the cylinder over time while gas is out-putted; (c) calculating a remaining usage time Tr based on the measured pressure in the cylinder and the calculated variation of pressure. Step (c) takes into account characteristics of the pressure reducer relative to variations of its nominal flow rate along the decrease of its inlet pressure while emptying the cylinder.

A method of recondensing boil off gas includes receiving liquefied natural gas from a storage tank and increasing the pressure of the received liquefied natural gas to produce increased pressure liquefied natural gas. The method further includes receiving boil off gas from the storage tank at a gas inlet of an ejector, and receiving the increased pressure liquefied natural gas at a liquefied gas inlet of the ejector. The pressure of the increased pressure liquefied gas is used as a motive force to eject combined liquefied natural gas and boil off gas at a pressure greater than that of the boil off gas received at the gas inlet of the ejector. The method additionally includes increasing the pressure of the fluid ejected from the ejector to produce increased pressure ejected fluid.

The present invention relates to a method and an apparatus for storing liquefied gas in at least one insulated container (1) while withdrawing evaporated gas from one or more of the at least one container (1), wherein at least a part of the evaporated gas is supplied to a recondenser (11) and wherein liquefied gas is withdrawn from one or more of the at least one container (1) and at least in part supplied to the recondenser (11) for recondensing the evaporated gas supplied to the recondenser (11) such that recondensed gas is obtained at a recondenser outlet, wherein before supplying the liquefied gas to the recondenser (11), the liquefied gas is subcooled by passing it through a refrigeration unit (8, 9), at least a part of the subcooled liquefied gas being supplied to the recondenser (11), and wherein at least a part of the recondensed gas obtained at the outlet of the recondenser (11) is reintroduced into one or more of the at least one container (1).

Disclosed is a method of discharging lubricant oil from a BOG reliquefaction system configured to reliquefy BOG by compressing the BOG by a compressor, cooling the compressed BOG through heat exchange with non-compressed BOG by a heat exchanger, and reducing a pressure of fluid cooled through heat exchange by a pressure reducer. In the lubricant oil discharge method, the compressor comprises at least one oil-lubrication type cylinder and it is determined that it is time to discharge condensed or solidified lubricant oil, if at least one of preset conditions is satisfied.

The invention relates to a gas treatment method and system of a gas storage facility (2), in particular on board a ship, the method comprising the following stages: an extraction of a first gas (4a, 4b, 5a, 5b,) in the liquid state from a first tank (4) or first vessel (5; 500), a first subcooling of the first gas in the liquid state, and storage of the subcooled first gas in the liquid state in the lower part of the first tank (4) or of the first vessel (5; 500) or of a second tank or of a second vessel, so as to constitute a reserve layer of cold (4c, 5c, 500c) of the subcooled first gas in the liquid state at the bottom of the first or second tank (4) or of the first or second vessel (5; 500).

Disclosed is a BOG reliquefaction system. The BOG reliquefaction system includes: a compressor compressing BOG; a heat exchanger cooling the BOG compressed by the compressor through heat exchange using BOG discharged from a storage tank as a refrigerant; a bypass line through which the BOG is supplied to the compressor after bypassing the heat exchanger; a second valve disposed on a second supply line through which the BOG used as the refrigerant in the heat exchanger is supplied to the compressor, the second valve regulating a flow rate of fluid and opening/closing of the second supply line; and a pressure reducer disposed downstream of the heat exchanger and reducing a pressure of fluid cooled by the heat exchanger, wherein the compressor includes at least one oil-lubrication type cylinder and the bypass line is joined to the second supply line downstream of the second valve.

The process comprises the following steps: mixing a gaseous stream of flash gas and a gaseous stream of boil-off gas to form a mixed gaseous flow; compressing the mixed gaseous flow in at least one compression apparatus to form a flow of compressed combustible gas; withdrawing a bypass flow in the flow of compressed combustible gas; compressing the bypass flow in at least one downstream compressor; cooling and expanding the compressed bypass flow; reheating at least a first stream derived from the expanded bypass flow in at least one downstream heat exchanger, reintroducing the first reheated stream in the mixed gaseous flow upstream from the compression apparatus.

Disclosed is a re-liquefying device using a boil-off gas as a cooling fluid so as to reliquefy the boil-off gas generated from a liquefied gas storage tank provided in a ship. A boil-off gas re-liquefying device for a ship comprises: a multi-stage compression unit for compressing boil-off gas generated from a liquefied gas storage tank; a heat exchanger in which the boil-off gas generated from the storage tank and the boil-off gas compressed exchange heat; a vaporizer for heat exchanging the boil-off gas cooled by the heat exchanger and a separate liquefied gas supplied to a fuel demand source of a ship, and thus cooling the boil-off gas; an intermediate cooler for cooling the boil-off gas that has been cooled by the heat exchanger; and an expansion means for branching a part of the boil-off gas, which is supplied to the intermediate cooler, and expanding the same.

Disclosed herein are a diagnostic method using laser induced breakdown spectrum analysis and a diagnostic device for performing the same. The diagnostic device may include a laser projection module projecting a pulsed laser to a specimen, a light receiving module receiving a light generated by a plasma ablation induced at the specimen by the pulsed laser, a spectral member receiving and dividing the light generated by the plasma ablation; a sensor array including a plurality of sensors arranged to receive the divided light for each wavelength, and a controller obtaining spectrum data of the light generated by the plasma ablation from a specific exposure period, and determining whether or not the specimen is diseased based on the spectrum data of the light generated by the plasma ablation.

Disclosed herein are a method for diagnosing a disease of a body tissue by using LIBS (Laser-Induced Breakdown Spectroscopy) comprising: preparing a laser device including: a laser projection module, outputting the laser to a suspicious region of the body tissue, a light receiving module, receiving a plurality of light, a spectrum measurement module, and a guide unit; and projecting the laser to generate plasma by inducing tissue ablation in the suspicious region; wherein the laser projected to the suspicious region has a target area, and wherein the target area has smaller size than the suspicious region such that the target area is located inside the suspicious region.