Floating vessel and method of operating a floating vessel

Patent metadata

Field	Value
Publication number	US-2018201352-A1
Application number	US-201815872431-A
Country	US
Kind code	A1
Filing date	Jan 16, 2018
Priority date	Jan 16, 2017
Publication date	Jul 19, 2018
Grant date	—

Abstract

According to one aspect of the present disclosure, a floating vessel, particularly an LNG carrier, is described. The floating vessel comprises: a gas turbine engine-generator assembly configured to generate a first electrical power and to supply the first electrical power to an electrical distribution system; a steam turbine engine-generator assembly configured to generate a second electrical power and to supply the second electrical power to the electrical distribution system; a propulsion system configured to propel the floating vessel using a propulsion power supplied from the electrical distribution system, wherein the gas turbine engine-generator assembly is configured to generate a maximum first electrical power between 10 MW and 18 MW, particularly between 14 MW and 15 MW at 25° C. According to a further aspect, a method of operating a floating vessel is described.

First claim

What is claimed is:

1 . A floating vessel comprising:
a gas turbine engine-generator assembly configured to generate a first electrical power and to supply the first electrical power to an electrical distribution system; a steam turbine engine-generator assembly configured to generate a second electrical power and to supply the second electrical power to the electrical distribution system; and a propulsion system configured to propel the floating vessel using a propulsion power supplied from the electrical distribution system,
wherein the gas turbine engine-generator assembly is configured to generate a maximum first electrical power between 10 MW and 18 MW, particularly between 14 MW and 15 MW at 25° C.

2 . The floating vessel of claim 1 , wherein the steam turbine engine-generator assembly is configured to generate a maximum second electrical power between 3 MW and 10 MW, particularly between 5 MW and 6 MW.

3 . The floating vessel of claim 2 , wherein the propulsion system is configured to propel the floating vessel at a maximum speed of 18 knots or less, when the propulsion power corresponds to a sum of the maximum first electrical power and the maximum second electrical power.

4 . The floating vessel of claim 1 , further comprising one or more diesel engine-generator assemblies configured to provide a black start capability of the gas turbine engine-generator assembly and/or configured to supply a third electrical power to the electrical distribution system, particularly wherein the third electrical power is between 2 MW and 5 MW.

5 . The floating vessel of claim 4 , wherein the propulsion system is configured to propel the floating vessel at a maximum speed of 19 knots more, when the gas turbine engine-generator assembly generates the maximum first electrical power, the steam turbine engine-generator assembly generates the maximum second electrical power and the one or more diesel engine-generator assemblies generate the third electrical power.

6 . The floating vessel of claim 1 , wherein the gas turbine engine-generator assembly comprises a dual fuel gas turbine engine capable of being operated on boil-off gas from an LNG reservoir and on marine gas oil.

7 . The floating vessel of claim 1 , wherein the gas turbine engine-generator assembly comprises a two-shaft engine comprising a high-pressure turbine arranged on a gas compression shaft and configured for driving a gas compressor and a low-pressure turbine arranged on a power generation shaft and configured for power generation.

8 . The floating vessel of claim 7 , wherein the gas turbine engine-generator assembly is configured and arranged in the floating vessel so as to maximize a ship cargo capacity for liquefied natural gas.

9 . The floating vessel of claim 7 , wherein the gas turbine engine-generator assembly comprises variable area turbine nozzles arranged between the high-pressure turbine and the low-pressure turbine and configured to regulate a ratio of the rotational speeds of the high-pressure turbine and the low-pressure turbine.

10 . The floating vessel of claim 7 , wherein the gas turbine engine-generator assembly comprises a multi-stage axial flow compressor, particularly comprising variable inlet guide vanes for providing an inlet gas flow control.

11 . The floating vessel of claim 1 , wherein the gas turbine engine-generator assembly is configured to withstand a load rejection of 3 MW or more, particularly of 6 MW or more, more particularly a full load rejection, without a loss of flame of the gas turbine engine-generator assembly.

12 . The floating vessel of claim 1 , further comprising a steam generator configured to use a hot exhaust gas from the gas turbine engine-generator assembly ( 10 ) and/or a hot gas from an oxidizing unit to generate steam, wherein the steam is configured to drive a steam turbine of the steam turbine engine-generator assembly.

13 . A method of operating a floating vessel, the method comprising:
operating a gas turbine engine-generator assembly configured for generating a maximum first electrical power between 10 MW and 18 MW to generate a first electrical power and supply the first electrical power to an electrical distribution system; operating a steam turbine engine-generator assembly to generate a second electrical power and supply the second electrical power to the electrical distribution system; and propelling the floating vessel with a propulsion system using a propulsion power supplied from the electrical distribution system.

14 . The method of claim 13 , further comprising propelling the floating vessel at a speed of 18 knots or less with a propulsion power corresponding to a sum of the maximum first electrical power and a maximum second electrical power of the steam turbine engine-generator assembly.

15 . The method of claim 13 , further comprising operating one or more diesel engine-generator assemblies to generate a third electrical power and supply the third electrical power to the electrical distribution system, particularly wherein the third electrical power is from 2 MW to 5 MW.

16 . The method of claim 15 , further comprising propelling the floating vessel at a speed of 19 knots or more with a propulsion power corresponding to a sum of the maximum first electrical power, a maximum second electrical power of the steam turbine engine-generator assembly and the third electrical power.

17 . The method of claim 15 , wherein when the floating vessel is operated in a first operation mode requiring the propulsion power below a reference level, no third electrical power is supplied to the electrical distribution system, and/or when the floating vessel is operated in a second operation mode requiring the propulsion power above the reference level, the third electrical power is supplied to the electrical distribution system.

18 . The method of claim 13 , wherein the gas turbine engine-generator assembly is partially or entirely operated on boil-off gas from an LNG reservoir and/or the steam turbine engine-generator assembly is partially or entirely driven by steam generated with a hot exhaust gas from the gas turbine engine-generator assembly.

19 . The method of claim 13 , wherein operating the gas turbine engine-generator assembly comprises adjusting variable area turbine nozzles arranged downstream from a high-pressure turbine and upstream from a low-pressure turbine of the gas turbine engine-generator assembly for regulating a ratio of the rotational speeds of the high-pressure turbine and the low-pressure turbine.

20 . The method of claim 19 , wherein the variable area turbine nozzles are adjusted in dependence of a first electrical power demand and/or in the case of a load rejection at the gas turbine engine-generator assembly.

Assignees

• Nuovo Pignone Tecnologie Srl

Inventors

• Trincia Francesco

Classifications

• B63H21/06

  relating to steam turbines · CPC title

• F01D15/10

  Adaptations for driving, or combinations with, electric generators · CPC title

• F05D2220/76

  an electrical generator · CPC title

• F01K23/10

  with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence) · CPC title

• B63H21/16 Primary

  relating to gas turbines · CPC title