Partial exhaust bottoming cycle

Patent metadata

Field	Value
Publication number	US-2025154900-A1
Application number	US-202519020050-A
Country	US
Kind code	A1
Filing date	Jan 14, 2025
Priority date	Aug 29, 2023
Publication date	May 15, 2025
Grant date	—

Abstract

An aircraft propulsion system includes a compressor section where an inlet airflow is compressed, a combustor section where the compressed inlet airflow is mixed with fuel and ignited to generate an exhaust gas flow that is communicated through a core flow path, a turbine section through which the exhaust gas flow expands to generate a mechanical power output, the exhaust gas flow is split into at least a first exhaust gas flow and a second exhaust gas flow, and a condenser where water is extracted from the second exhaust gas flow, and a bottoming cycle where extracted water is transformed into a steam flow and injected into the core flow path.

First claim

What is claimed is:

1 . An aircraft propulsion system comprising:
a compressor section where an inlet airflow is compressed; a combustor section where the compressed inlet airflow is mixed with fuel and ignited to generate an exhaust gas flow that is communicated through a core flow path; a turbine section through which the exhaust gas flow expands to generate a mechanical power output, wherein the exhaust gas flow is split into at least a first exhaust gas flow and a second exhaust gas flow, the first exhaust gas flow continues through the turbine section and out through an aft turbine exit and the second exhaust gas flow is drawn from a location within the turbine section that is upstream of the aft exit of the turbine section; a condenser configured to extract water from the second exhaust gas flow; and a bottoming cycle comprising a thermal transfer medium circulating within a closed circuit, an evaporator configured to heat the thermal transfer medium and a heat exchange configured to cool the thermal transfer medium, wherein a portion of the second exhaust gas flow is cooled in the evaporator before being communicated to the condenser.

2 . The aircraft propulsion system as recited in claim 1 , wherein the evaporator is configured to communicate heat from the second exhaust gas flow into a water flow generated from water extracted from the exhaust gas flow in the condenser to generate a steam flow for injection into the core flow path.

3 . The aircraft propulsion system as recited in claim 2 , wherein the evaporator is configured to precool the second exhaust gas flow prior to communication to the condenser.

4 . The aircraft propulsion system as recited in claim 1 , wherein the bottoming cycle further comprises a turboexpander in communication with the thermal transfer medium, wherein the heated thermal transfer medium is expanded through the turboexpander.

5 . The aircraft propulsion system as recited in claim 4 , wherein the bottoming cycle further includes a pump for pressurizing the thermal transfer medium communicated through the evaporator.

6 . The aircraft propulsion system as recited in claim 4 , wherein the heat exchanger is in thermal communication with a cold sink flow for cooling the thermal transfer medium.

7 . The aircraft propulsion system as recited in claim 6 , wherein the cold sink flow comprises at least one of a cooling airflow, a cryogenic fuel flow or a water flow.

8 . The aircraft propulsion system as recited in claim 1 , further including a steam turbine where power is extracted from the steam flow prior to injection into the core flow path.

9 . The aircraft propulsion system as recited in claim 1 , including an intercooling system and a portion of water extracted by the condenser is communicated to the compressor section for cooling a portion of the core flow.

10 . The aircraft propulsion system as recited in claim 1 , including a propulsive fan driven by the turbine section.

11 . A turbine engine assembly comprising:
a core engine defining a core flow path and configured to generate an exhaust gas flow; a fuel system configured to provides a flow of cryogenic fuel to the core engine; a condenser configured to receive a partial portion of the exhaust gas flow and to extract water from the partial portion of the total exhaust gas flow to generate a water flow; and a bottoming cycle comprising an evaporator configured to communicate thermal energy between the partial portion of the exhaust gas flow, a thermal transfer medium, and the water flow generated in the condenser, the evaporator is further configured to generate a steam flow from the water flow for injection into the core flow path.

12 . The turbine engine assembly as recited in claim 11 , wherein the bottoming cycle further comprises a closed circuit for circulation of the thermal transfer medium, a turboexpander, and a pump for pressurizing the thermal medium and a heat exchanger for cooling the thermal medium, wherein the partial portion of the exhaust gas flow is cooled in the evaporator by the thermal medium and the water flow before communication to the condenser.

13 . The turbine engine assembly as recited in claim 12 , wherein the heat exchanger is in thermal communication with at least one of a cooling airflow or a water flow for cooling the thermal transfer medium.

14 . The turbine engine assembly as recited in claim 11 , wherein the heat exchanger is configured provides thermal communication between the cryogenic fuel flow and the thermal transfer medium.

15 . The turbine engine assembly as recited in claim 11 , further including a steam turbine where power is extracted from the steam flow prior to injection into the core flow path.

16 . The turbine engine assembly as recited in claim 11 , wherein the evaporator is configured to transfer thermal energy between the thermal transfer medium, the partial portion of the exhaust as flow and the water flow.

17 . The turbine engine assembly as recited in claim 11 , including an intercooling system and a portion of water extracted by the condenser is communicated to the core engine for cooling a portion of the core flow.

18 . The turbine engine assembly as recited in claim 11 , wherein the core engine further comprises a turbine section with an aft exit for the exhaust gas flow, wherein the partial portion of the exhaust gas flow is drawn from a location within the turbine section that is upstream of an aft exit of the turbine section.

19 . A method of operating a turbine engine comprising:
generating an exhaust gas flow with a core engine including a compressor where inlet airflow is compressed, a combustor where the compressed inlet airflow is mixed with fuel and ignited to generate the exhaust gas flow that is expanded through a turbine section and exhausted through an aft turbine exit; cooling a partial portion of the exhaust gas flow drawn from a location upstream of the aft turbine exit with a thermal transfer medium circulating with a closed circuit of a bottoming cycle; extracting water from the partial portion of the total exhaust gas flow in a condenser; and generating a steam flow from the extracted water with thermal energy from the exhaust gas flow.

20 . The method as recited in claim 19 , further comprising cooling the thermal transfer medium within the closed circuit with at least one of a cooling airflow, a cryogenic fuel flow or a water flow for cooling the thermal transfer medium.

Assignees

• Rtx Corp

Inventors

• Terwilliger Neil J
• Smith Lance L

Classifications

• F05D2260/609

  Deoiling or demisting · CPC title

• F05D2260/212

  by water injection · CPC title

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title

• F02C7/16

  characterised by cooling medium · CPC title

• F02C3/305 Primary

  Increasing the power, speed, torque or efficiency of a gas turbine or the thrust of a turbojet engine by injecting or adding water, steam or other fluids (F01K21/04 takes precedence) · CPC title