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EP-4414536-B1 - STEAM TURBINE BYPASS FOR INCREASED WATER HEAT ABSORPTION CAPACITY STEAM INJECTED TURBINE ENGINE

EP4414536B1EP 4414536 B1EP4414536 B1EP 4414536B1EP-4414536-B1

Inventors

  • TERWILLIGER, NEIL J.
  • TURNEY, JOSEPH E.

Dates

Publication Date
20260506
Application Date
20231208

Claims (15)

  1. A turbine engine assembly (20) comprising: a core engine (22) generating an exhaust gas flow (38); a condenser (48) where water is extracted from the exhaust gas flow (38); an evaporator (64) where heat is input into the water extracted by the condenser (48) to generate a first steam flow (58); a first steam turbine (68) where the first steam flow (58) is expanded and cooled to generate a first cooled flow (62); characterised by a bypass passage (76) defining a path for the first steam flow (58) around the first steam turbine (68); and a superheater (66) where the first cooled flow (62) is reheated to generate a second steam flow (60).
  2. The turbine engine assembly (20) as recited in claim 1, including a valve (78) regulating flow through the bypass passage (76) and a controller (80) programmed to operate the valve (78) to route the first heated flow (58) around the first steam turbine (68) at a takeoff engine operating condition.
  3. The turbine engine assembly (20) as recited in claim 1, including a valve (78) regulating flow through the bypass passage (76) and a controller (80) programmed to operate the valve (78) to route the first heated flow (58) around the first steam turbine (68) in response to a steam quality being below a predefined amount, wherein, optionally, the controller (80) is programed to operate the valve (78) based on a predicted steam quality of steam at an exit of the steam turbine (68).
  4. The turbine engine assembly (20) as recited in claim 1, 2 or 3, including a second steam turbine (72) where a steam flow (60) from the superheater (66) is expanded to generate shaft power, wherein, optionally, at least one of the first steam turbine (68) and the second steam turbine (72) is mechanically coupled to an engine spool (96).
  5. The turbine engine assembly (20) as recited in any preceding claim, wherein the core engine (22) includes a core flow path (C) and at least one of the first steam flow (58) and the second steam flow (60) is injected into the core flow path (C).
  6. The turbine engine assembly (20) as recited in any preceding claim, including a pump (52) where water extracted from the condenser (48) is pressurized before being communicated to the first evaporator (64).
  7. The turbine engine assembly (20) as recited in any preceding claim, wherein the first evaporator (64) and the superheater (66) are disposed within a flow path for the exhaust gas flow (38), and, optionally, the first evaporator (64) receives the exhaust gas flow (38) after the superheater (66).
  8. The turbine engine assembly (20) as recited in any preceding claim, including a fuel system (40) where a hydrogen based fuel flow (46) is communicated to a combustor (26) of the core engine (22).
  9. A turbine engine assembly (20) of any preceding claim, wherein: the core engine (22) includes a compressor (24) where an inlet airflow is compressed and communicated to a combustor (26) where a compressed core flow (36) is mixed with fuel and ignited to generate the exhaust gas flow (38) that is expanded through a turbine section (28) to generate shaft power, and the bypass passage (76) defines a path for first steam flow (58) around the first steam turbine (68) to the superheater (66); and the turbine engine assembly (20) further comprises: a hydrogen based fuel system (40) for supplying a hydrogen based fuel to the combustor (26); a second steam turbine (72) where the second steam flow (60) from the superheater (66) is expanded and cooled; a valve (78) regulating flow through the bypass passage (76); and a controller (80) programmed to operate the valve (78) to route the first steam flow (58) around the first steam turbine (68) in response to a predefined engine operation condition.
  10. The turbine engine assembly (20) as recited in claim 9, wherein the core engine (22) includes a core flow path (C) and the second steam flow (60) is injected into the core flow path (C).
  11. The turbine engine assembly (20) as recited in claim 9 or 10, wherein the predefined engine operating condition comprises: a takeoff engine operating condition; or a steam quality below predefined value.
  12. A method of operating a steam injected turbine engine comprising: transforming a water flow (56) into a first steam flow (58) with a first heat input (Q1); determining a condition of the first steam flow (58); bypassing the first steam flow (58) around a first steam turbine (68) to a second heat input (Q2) in response to the determined condition of the first steam flow (58) being indicative of condensation greater than a predefined amount; generating a second steam flow (60) with the second heat input (Q2); and injecting the second steam flow (60) into a core flow path (C) of a core engine (22), wherein the method further comprises expanding the first steam flow (58) through a first steam turbine (68) to cool the first steam flow (58) in response to the determined condition of the first steam flow (58) being indicative of a condensation below the predefined amount followed by reheating with the second heat input (Q2) to generate the second steam flow (60).
  13. The method as recited in claim 12, including operating a valve (78) to route the first steam flow (58) through a bypass (76) in response to the determined condition of the first steam flow (58).
  14. The method as recited in claim 12 or 13, wherein the first heat input (Q1) is from an exhaust gas flow (38) in a first evaporator (64) and the second heat input (Q2) is from the exhaust gas flow (38) in a superheater (66).
  15. The method as recited in any of claims 12 to 14, including pressurizing the water flow (56) before transformation into the first steam flow (58).

Description

TECHNICAL FIELD The present invention relates generally to a steam injected turbine engine and more particularly to a steam injection system that increases a heat absorption capacity of an extracted water flow and a bypass passage for controlling condensation accumulation. BACKGROUND Reduction and/or elimination of carbon emissions generated by aircraft operation is a stated goal of aircraft manufacturers and airline operators. Turbine engines compress incoming core airflow, mix the compressed airflow with fuel that is ignited in a combustor to generate a high energy exhaust gas flow. Some energy in the high energy exhaust flow is recovered as it is expanded through a turbine section. Water can be extracted from the exhaust gas flow and transformed into a steam flow and injected into the core flow to enhance engine efficiency. Additionally, the recovered water flow can be utilized to absorb and recover heat from the exhaust gas flow. The recovered heat can be used to generate mechanical power in a steam turbine. The amount of heat available may not always be sufficient to generate a steam flow to drive the steam turbine. Moreover, condensation accumulation may reduce gains in efficiency provided by recovered heat. Turbine engine manufacturers continue to seek further improvements to engine performance including improvements to reduce environmental impact while improving thermal and propulsive efficiencies. US 5896740 A1 discloses a prior art turbine engine. SUMMARY A turbine engine assembly according to an aspect is provided according to claim 1. In a further embodiment of the foregoing, the turbine engine includes a valve that regulates flow through the bypass passage and a controller that is programmed to operate the valve to route the first heated flow around the first steam turbine at a takeoff engine operating condition. In a further embodiment of any of the foregoing, the turbine engine includes a valve that regulates flow through the bypass passage and a controller that is programmed to operate the valve to route the first heated flow around the first steam turbine in response to a steam quality that begins to fall below a predefined amount. In a further embodiment of any of the foregoing, the turbine engine includes a second steam turbine where a steam flow from the superheater is expanded to generate shaft power. In a further embodiment of any of the foregoing, at least one of the first steam turbine and the second steam turbine is mechanically coupled to an engine spool. In a further embodiment of any of the foregoing, the core engine includes a core flow path and at least one of the first steam flow and the second steam flow is injected into the core flow path. In a further embodiment of any of the foregoing, the turbine engine assembly includes a pump where water extracted from the condenser is pressurized before being communicated to the first evaporator. In a further embodiment of any of the foregoing, a pressure of water at the first evaporator is greater than a pressure of water at the superheater. In a further embodiment of any of the foregoing, the first evaporator and the superheater are disposed within a flow path for the exhaust gas flow. In a further embodiment of any of the foregoing, the first evaporator receives the exhaust gas flow after the superheater. In a further embodiment of any of the foregoing, the turbine engine assembly includes a fuel system where a hydrogen based fuel flow is communicated to a combustor of the core engine. There is further provided a turbine engine assembly according to claim 9. In a further embodiment of the foregoing, the predefined engine operating condition includes a takeoff engine operating condition. In a further embodiment of any of the foregoing, the predefined engine operating condition includes a steam quality below predefined value. In a further embodiment of any of the foregoing, the core engine includes a core flow path and the second steam flow is injected into the core flow path. A method of operating a steam injected turbine engine according to another aspect is provided according to claim 12. In a further embodiment of any of the foregoing, the method includes operating a valve to route the first steam flow through a bypass in response to the determined condition of the first steam flow. In a further embodiment of any of the foregoing, the first heat input is from an exhaust gas flow in a first evaporator and the second heat input is from the exhaust gas flow in a superheater. In a further embodiment of any of the foregoing, the method includes pressurizing the water flow before transformation into the first steam flow. Although the different examples have the specific components shown in the illustrations, embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the exa