A heated subsea pipeline includes a direct electrical heating (DEH) system that heats a central major portion of the pipeline. Supplementary heating systems extend along respective end portions of the pipeline, longitudinally outboard of the central portion heated by the DEH system. A flow of heating fluid is circulated along the end portions and may be circulated through an underwater vehicle that pumps and heats the flow.

Hydrate remediation systems, apparatuses, and methods of making and using same including at least one pair of electrodes detachably or fixedly attached to a pipeline or flowline in a spaced relationship so that a current may be imposed across a section of the pipeline or flowline between each pair of electrodes resulting in electrical heating of the section for a time sufficient to raise a temperature of a fluid in the section of the pipeline or flowline to a temperature above a dissociation temperature of hydrates formed in the fluid.

Hydrate remediation systems, apparatuses, and methods of making and using same including at least one pair of electrodes detachably or fixedly attached to a pipeline or flowline in a spaced relationship so that a current may be imposed across a section of the pipeline or flowline between each pair of electrodes resulting in electrical heating of the section for a time sufficient to raise a temperature of a fluid in the section of the pipeline or flowline to a temperature above a dissociation temperature of hydrates formed in the fluid.

A subsea cable system (10) for transfer of electric power to a subsea device is disclosed where the subsea cable system comprises a subsea cable (11) with a first end portion (26) and a second end portion (27). The first end portion (26) is adapted for connection to a supply of electrical energy. The subsea cable (11) comprises at least a first supply cable (21), a second supply cable (22) and at least one return cable (24, 25) where the first supply cable (21), the second supply cable (22) and the at least one return cable (24, 25) each comprises a conductor element (101, 102, 103, 104) for conduction of an electric current. The subsea cable system (10) further comprises a conductor transition element (66) comprising a conductor element (67) that is provided with at least a first conductor leg (73), a second conductor leg (74) and a third conductor leg (75). The first conductor leg (73) is connected to the conductor element (101) of the first supply cable (21), the second conductor leg (74) is connected to the conductor element (102) of the second supply cable (22) and the third conductor leg (75) is connected to conductor element (56) of an end supply cable (53) that is connectable to a consumer device (46). A method for supplying electrical power to a subsea consumer device of electricity is also disclosed.

A subsea cable system (10) for transfer of electric power to a subsea device is disclosed where the subsea cable system comprises a subsea cable (11) with a first end portion (26) and a second end portion (27). The first end portion (26) is adapted for connection to a supply of electrical energy. The subsea cable (11) comprises at least a first supply cable (21), a second supply cable (22) and at least one return cable (24, 25) where the first supply cable (21), the second supply cable (22) and the at least one return cable (24, 25) each comprises a conductor element (101, 102, 103, 104) for conduction of an electric current. The subsea cable system (10) further comprises a conductor transition element (66) comprising a conductor element (67) that is provided with at least a first conductor leg (73), a second conductor leg (74) and a third conductor leg (75). The first conductor leg (73) is connected to the conductor element (101) of the first supply cable (21), the second conductor leg (74) is connected to the conductor element (102) of the second supply cable (22) and the third conductor leg (75) is connected to conductor element (56) of an end supply cable (53) that is connectable to a consumer device (46). A method for supplying electrical power to a subsea consumer device of electricity is also disclosed.

A subsea direct electrical heating power supply system includes at least one input device adapted to couple the direct electrical heating power supply system to a power supply and a subsea variable speed drive, for receiving electrical power from the at least one input device and for providing an AC output, including a plurality of series-connected power cells. Each power cell includes an inverter and a bypass device to selectively bypass the power cell. The system further includes an adjustable subsea capacitor connected to the AC output of the subsea variable speed drive; an output device adapted to couple the direct electrical heating power supply system to a subsea pipeline section; and a controller, adapted to adjust the capacitance of the adjustable subsea capacitor such that upon the system output voltage being reduced, the current output by the direct electrical heating power supply system is increased.

Disclosed is an air duct and an air system and methods and uses of said air ducts and air system. The air duct has electrically conductive elements integrated with the walls of said air ducts for insulation of walls of said air ducts, and/or heating of the air flowing through the air ducts. The air duct can be used in an air system, for instance an air system for purposes of air cleaning, heating, refrigeration, ventilation or air conditioning in a building or means of transport.

Proposed is a device (110) comprising at least one pipeline (112) for receiving at least one feedstock. The device (110) has at least one current-conducting medium (129). The device (110) has at least one current or voltage source (126) which is configured to generate an electrical current in the current-conducting medium (129), which heats the pipeline (112) by means of Joule heating which is produced when the electrical current passes through the current-conducting medium (129).

Proposed is a device (110) comprising at least one pipeline (112) for receiving at least one feedstock. The device (110) has at least one current-conducting medium (129). The device (110) has at least one current or voltage source (126) which is configured to generate an electrical current in the current-conducting medium (129), which heats the pipeline (112) by means of Joule heating which is produced when the electrical current passes through the current-conducting medium (129).

A system and method for heating steam sample and chemical sample and feed tubes/lines in a natural gas fired heat recovery steam generator (HRSG) power plant including a tube impedance heater (IH) control system and at least one impedance heated tube having an outer insulation and an electrically conducting inner tube member, the impedance heated tube having an input IH feed power electrical connector and electrically connected at a first connection to the inner tube member, and a return IH power electrical connector electrically connected at a second connection by a first end of a return electrical cable and a first connector and second connector each mechanically and fluidly coupling the first and second connections respectively to the inner tube member to the steam sample or chemical sample or feed tube/line and electrically isolating the first end and second ends.