Remote power-generating assembly

A remote power-generation assembly for a subsea system, comprising

• an expansion turbine for generating power to supply to subsea equipment;
• a condenser positioned below sea level, the condenser being in fluid communication with the expansion turbine to receive vapor exiting the expansion turbine and to condense the vapor to liquid;
• a downcomer and boiler assembly comprising tubular inner and outer conduits thereby defining an outer annulus, the outer annulus being in fluid communication with the condenser to receive the liquid from the condenser, the inner conduit terminating above a closed lower end of the outer conduit so that the interior of the inner conduit is in fluid communication with the outer annulus, the interior of the inner conduit being in fluid communication with an inlet of the expansion turbine;
• a tubular boiler assembly extending concentrically through the inner conduit to thereby define an inner annulus within the inner conduit, the boiler assembly carrying air and fuel through the inner conduit;
• and
• an igniter positioned toward a lower end portion of the boiler assembly to ignite the fuel and air and to cause the liquid received by the inner annulus from the outer annulus to boil into vapor for communication to the expansion turbine.

A method for providing power to offshore equipment positioned remote distances from shore and from a production facility, comprising

• (a) conveying a liquid down an outer annulus located between an outer conduit and an inner conduit to an inner annulus formed inside of the inner conduit;
• (b) boiling the liquid in the inner annulus with a boiler assembly positioned within the inner conduit;
• (c) conveying vapor from the boiling liquid from the inner conduit to an inlet of a expansion turbine above sea level in order to produce power;
• (d) conveying vapor from an outlet of the expansion turbine to a cooling section positioned substantially below sea level;
• and
• (e) cooling the vapor within the cooling section to form the liquid which is fed into the outer annulus.