A ship includes: a boil-off gas heat exchanger which heat-exchanges a compressed boil-off gas (a first fluid) by means of a boil-off gas discharged from the storage tank as a refrigerant; a compressor installed on the downstream of the boil-off gas heat exchanger and compressing a part of the boil-off gas discharged from the storage tank; first and second extra compressors provided in parallel with the compressor on the downstream of the boil-off gas heat exchanger and compressing the other part of the boil-off gas discharged from the storage tank; a refrigerant heat exchanger which additionally cools the first fluid cooled by means of the boil-off gas heat exchanger; a refrigerant decompressing device which expands a second fluid, which has been sent to the refrigerant heat exchanger and cooled by means of the refrigerant heat exchanger, and then sending the expanded second fluid back to the refrigerant heat exchanger.

A hydrogen supply method includes a two-side heat exchange mode in which both introducing a second fluid into a hydrogen storage part after the second fluid exchanges heat with a first fluid in a second heat exchanger in a state in which a compressor is driven to compress the first fluid and introducing the second fluid into the hydrogen storage part after the second fluid is heated or cooled in the thermal device are performed. The method also includes a one-side heat exchange mode in which one of introducing the second fluid into the hydrogen storage part after the second fluid exchanges heat with the first fluid in the second heat exchanger in a state in which the compressor is driven to compress the first fluid and introducing the second fluid into the hydrogen storage part after the second fluid is heated or cooled in the thermal device is performed.

A hydrogen supply method includes a two-side heat exchange mode in which both introducing a second fluid into a hydrogen storage part after the second fluid exchanges heat with a first fluid in a second heat exchanger in a state in which a compressor is driven to compress the first fluid and introducing the second fluid into the hydrogen storage part after the second fluid is heated or cooled in a thermal device are performed. The method also includes a one-side heat exchange mode in which one of introducing the second fluid into the hydrogen storage part after the second fluid exchanges heat with the first fluid in the second heat exchanger in a state in which the compressor is driven to compress the first fluid and introducing the second fluid into the hydrogen storage part after the second fluid is heated or cooled in the thermal device is performed.

A compressed air production facility that reduces an extension cost without stopping an operating air compressor in a case of increasing the number of air compressors to cope with an increase in demands for compressed air is provided. A compressed air system supplies compressed air to compressed air consuming devices connected to a compressed air distributions line, the compressed air system including a plurality of air compressor units connected to the compressed air distributions line via respective air tanks. Each of the air compressor units includes: an air compressor main body; an adjustor of pressure setpoint that adjusts a pressure setpoint of an air tank to which the air compressor unit including the adjustor of pressure setpoint is connected; and a controller of air compressor that operates a rotational frequency of the air compressor main body on the basis of the pressure setpoint adjusted by the adjustor of pressure setpoint and a pressure of the air tank. The adjustor of pressure setpoint adjusts the pressure setpoint on the basis of a control variable indicating the rotational frequency of the air compressor main body or the pressure of the air tank.

An apparatus for reliquefaction of boil-off gas for a vessel, comprises: a compression unit for compressing the boil-off gas discharged from the storage tank; and a heat exchanger for heat-exchanging the compressed boil-off gas compressed by the compression unit with the boil-off gas discharged from the storage tank; a first expansion means for dividing the boil-off gas passing through the heat exchanger into at least two flows including a first flow and a second flow, and expanding the divided first flow; a first intercooler for cooling the second flow remaining after the division of the first flow by using the first flow expanded by the expansion means as a refrigerant; and a receiver for receiving a second flow having passed through the first intercooler, in which a downstream pressure of the compression unit is controlled by a flow discharged from the receiver.

A ship including a storage tank for storing a liquefied gas includes: a boil-off gas (BOG) heat exchanger installed on a downstream of a storage tank and heat-exchanges a compressed BOG (a first fluid) by a BOG discharged from the storage tank as a refrigerant, to cool the BOG; a compressor installed on a downstream of the BOG heat exchanger and compresses a part of the BOG discharged from the storage tank; an extra compressor installed on a downstream of the BOG heat exchanger and in parallel with the compressor and compresses the other part of the BOG discharged from the storage tank; a refrigerant heat exchanger which additionally cools the first fluid cooled by the BOG heat exchanger; and a refrigerant decompressing device which expands a second fluid sent to the refrigerant heat exchanger, and then sends the second fluid back to the refrigerant heat exchanger.

An expansion turbine/compressor type high-pressure hydrogen gas filling system is simple in configuration, low in site work cost, small in the burden of maintenance work, and capable of reducing the operating cost including cost of power consumption, and it is not necessary to separately provide a way to take out the energy produced in the expansion equipment and effectively use outside such as generator, and that can be applied for temperature lowering system technology such as pre-cooler function in the final filling portion of the hydrogen station, the expansion turbine portion has with a process to incorporate the expansion turbine/compressor in the expansion turbine portion in the filling system to do the enthalpy lowering of the hydrogen gas using the expansion turbine, when the hydrogen gas accumulated at high pressure is pressurized and filled into the tank.

A filling station for supplying vehicles with gas containing hydrogen comprises: a storage unit comprising high pressure gas containers; a compression unit comprising compressors for increasing the pressure of gas for the storage unit; and a supply unit comprising a supply device for supplying a vehicle; a storage circuit for circulating gas from the compression unit to the storage unit; and a filling circuit for circulating gas from the storage unit to the compression unit. The storage circuit comprises a storage pipe network connecting each compressor to each container and at least one storage distributor for selectively associating the compressors and the containers. The filling circuit includes a filling pipe network connecting each container with each compressor and a filling distributor for selectively associating the containers and the compressors. The station further includes control means for controlling the storage and filling distributors.

A ship comprises: a liquefied gas storage tank; a multi-stage compressor for compressing a boil-off gas discharged from a storage tank and comprising a plurality of compression cylinders; a second heat exchanger for heat exchanging a fluid, which has been compressed by the multi-stage compressor, and thus cooling same; a first decompressing device for expanding a flow (flow a1) partially branched from the flow (flow a) that has been cooled by the second heat exchanger; a third heat exchanger for heat exchanging, by flow a1 which has been expanded by the first decompressing device as a refrigerant, the remaining flow (flow a2) of flow a after excluding flow a1 that has been branched and thus cooling same; and a second decompressing device for expanding flow a2 which has been cooled by the third heat exchanger.

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.