Abstract: A method for storage and transport of LPG on LPG carriers, in particular two cargoes of different LPG types on same shipment, having reliquefaction units in which vaporized gases are condensed and then returned into at least one cargo tank for the respective LPG cargo type. The method is further comprising: using the reliquefaction units, at a minimum one running, as to condense vapor from the first cargo type; passing the condensed vapor through a heat exchanger; simultaneously flowing vapor from the second cargo type through the heat exchanger as to condense vapor by means of heat exchanging with the condensed vapor; and returning the condensed vapors leaving the heat exchanger back into the respective cargo types. The present invention is also disclosing a system for storage and transport of LPG on LPG carriers.
Abstract: A method for storage and transport of LPG on LPG carriers, in particular two cargoes of different LPG types on same shipment, having reliquefaction units (300, 400) in which vaporized gases are condensed and then returned into at least one cargo tank (100) for the respective LPG cargo type. The method is further comprising: using the reliquefaction units (300, 400), at a minimum one running, as to condense vapor from the first cargo type; passing the condensed vapor through a heat exchanger (500); simultaneously flowing vapor from the second cargo type through the heat exchanger (500) as to condense vapor by means of heat exchanging with the condensed vapor; and returning the condensed vapors leaving the heat exchanger back into the respective cargo types. The present invention is also disclosing a system for storage and transport of LPG on LPG carriers.
Abstract: A method for storage and transport of LPG on LPG carriers, in particular two cargoes of different LPG types on same shipment, having reliquefaction units in which vaporized gases are condensed and then returned into at least one cargo tank for the respective LPG cargo type. The method is further comprising: using the reliquefaction units, at a minimum one running, as to condense vapour from the first cargo type; passing the condensed vapour through a heat exchanger; simultaneously flowing vapour from the second cargo type through the heat exchanger as to condense vapour by means of heat exchanging with the condensed vapour; and returning the condensed vapours leaving the heat exchanger back into the respective cargo types. The present invention is also disclosing a system for storage and transport of LPG on LPG carriers.
Abstract: A method and system for producing liquefied and sub-cooled natural gas by means of a refrigeration assembly using a single phase gaseous refrigerant comprising: at least two expanders (1-3); a compressor assembly (5-7); a heat exchanger assembly (8) for heat absorption from natural gas; and a heat rejection assembly (10-12). The novel features according to the present invention are arranging the expanders (1-3) in expander loops; using only one and the same refrigerant in all loops; passing an expanded refrigerant flow from the respective expander into the heat exchanger assembly (8), each being at a mass flow and temperature level adapted to de-superheating, condensation or cooling of dense phase and/or sub-cooling of natural gas; and serving the refrigerant to the respective expander in a compressed flow by means of the compressor assembly having compressors or compressor stages enabling adapted inlet and outlet pressures for the respective expander.
Type:
Grant
Filed:
August 27, 2009
Date of Patent:
October 20, 2015
Assignee:
Wärtsilä Oil & Gas Systems AS
Inventors:
Arne Jakobsen, Carl J. Rummelhoff, Bjorn H. Haukedal
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.