US-12618335-B2 - In-flight hybrid electric engine shutdown

US12618335B2US 12618335 B2US12618335 B2US 12618335B2US-12618335-B2

Abstract

A method for operating a hybrid-electric propulsion system of an aircraft is provided. The hybrid-electric propulsion system includes a gas turbine engine having a high pressure system, a low pressure system, and an electric machine coupled to one of the high pressure system or low pressure system. The method includes receiving data indicative of an actual or anticipated in-flight shutdown of the gas turbine engine; and adding power to the gas turbine engine through the electric machine in response to receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine.

Inventors

David Alexander Hiett
Stefan Joseph Cafaro
David Marion Ostdiek
Robert Jon MCQUISTON
Paul Robert Gemin
Jeffrey Douglas Rambo

Assignees

GENERAL ELECTRIC COMPANY

Dates

Publication Date: 20260505
Application Date: 20210205

Claims (15)

1 . A method for operating a hybrid-electric propulsion system of an aircraft, the hybrid-electric propulsion system comprising a gas turbine engine having a starter system, a high pressure system, a low pressure system, a first electric machine coupled to the low pressure system, and a second electric machine coupled to the high pressure system, the first electric machine and the second electric machine separate from the starter system, the method comprising: during a flight, receiving data indicative of an actual or anticipated in-flight shutdown of the gas turbine engine; and during the flight, adding power to the gas turbine engine within five seconds after receiving data of the actual in-flight shutdown through the first electric machine and the second electric machine in response to receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine; wherein adding power to the gas turbine engine comprises adding power using the first electric machine and the second electric machine to maintain a rotation speed of the low pressure system and the high pressure system of at least 25% of a pre-shutdown rotation speed of the low pressure system and the high pressure system throughout the actual in-flight shutdown and a subsequent restart of the gas turbine engine, wherein adding power to the gas turbine engine comprises adding at least 10 horsepower and up to 1000 horsepower, wherein adding power to the gas turbine engine comprises adding power to the high pressure system to reduce an exhaust gas temperature of the gas turbine engine by at least 10° Celsius and up to 100° Celsius, and wherein adding power to the gas turbine engine includes adding power to the low pressure system of the gas turbine engine using the first electric machine embedded within the gas turbine engine at a location aft of a turbine section of the gas turbine engine and inward of a core airflow path through the gas turbine engine to reduce a rate of deceleration of components of the gas turbine engine following the actual in-flight shutdown, decrease a first amount of time required for the gas turbine engine to get back to the pre-shutdown rotational speed following the actual in-flight shutdown, and reduce altitude loss during the subsequent restart of the gas turbine engine; and adding power to the high pressure system of the gas turbine engine using the second electric machine in electrical communication with an electric power bus and inward of the core airflow path through the gas turbine engine to reduce the rate of deceleration of the components of the gas turbine engine following the actual in-flight shutdown, decrease the first amount of time required for the gas turbine engine to get back to the pre- shutdown rotational speed following the actual in-flight shutdown, and reduce altitude loss during the subsequent restart of the gas turbine engine.
2 . The method of claim 1 , wherein receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine comprises receiving data indicative of the actual in-flight shutdown of the gas turbine engine.
3 . The method of claim 2 , further including initiating a re-start of the engine after a second amount of time after receiving data indicative of the actual in-flight shutdown of a gas turbine engine, wherein adding power to the gas turbine engine includes adding power to the gas turbine engine substantially continuously until the re-start process is initiated and adding power to the gas turbine engine substantially continuously until the engine is re-ignited.
4 . The method of claim 3 , wherein the second amount of time is at least 10 seconds.
5 . The method of claim 1 , wherein receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine comprises determining an anticipated in-flight shutdown of the gas turbine engine.
6 . The method of claim 1 , wherein adding power to the gas turbine engine includes adding power to the low pressure system of the gas turbine engine using the first electric machine to maintain a rotation speed of the low pressure system within 75% of the pre-shutdown rotational speed.
7 . The method of claim 1 , wherein adding power to the gas turbine engine includes adding power to the low pressure system of the gas turbine engine using the first electric machine to maintain the rotation speed of the low pressure system above 25% of a maximum corrected speed of the low pressure system.
8 . The method of claim 1 , wherein adding power to the gas turbine engine includes providing electrical power to the first electric machine and the second electric machine from an external source.
9 . The method of claim 8 , wherein adding power to the gas turbine engine includes providing electrical power to the first electric machine from electric energy storage units and an auxiliary power unit.
10 . The method of claim 1 , wherein adding power to the gas turbine engine includes adding at least 10 horsepower.
11 . The method of claim 1 , wherein adding power to the gas turbine engine includes adding at least 50 horsepower.
12 . The method of claim 1 , wherein adding power to the gas turbine engine comprises adding at least 100 horsepower and up to 1000 horsepower.
13 . The method of claim 1 , wherein adding power to the gas turbine engine comprises adding power to the high pressure system to reduce the exhaust gas temperature of the gas turbine engine by at most 100° Celsius.
14 . A hybrid-electric system comprising: a gas turbine engine having a starter system, a high pressure system, a low pressure system, an electric machine coupled to one of the high pressure system or low pressure system, the electric machine separate from the starter system, and a controller, the controller including memory and one or more processors, the memory storing instructions that when executed by the one or more processors cause the system to perform one or more functions, the functions including: during a flight, receiving data indicative of an actual or anticipated in-flight shutdown of the gas turbine engine; during the flight, adding power within five seconds after receiving data of the actual in-flight shutdown to the gas turbine engine through the electric machine in response to receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine; and maintaining, with the electric machine, a rotation speed of the low pressure system and the high pressure system of at least 25% of a pre-shutdown rotation speed of the low pressure system and the high pressure system throughout the actual in-flight shutdown and subsequent restart of the gas turbine engine, wherein adding power to the gas turbine engine comprises adding at least 10 horsepower and up to 1000 horsepower, wherein adding power to the gas turbine engine comprises adding power to the high pressure system to reduce an exhaust gas temperature of the gas turbine engine by at least 10° Celsius and up to 100° Celsius, and wherein the electric machine comprises a low pressure electric machine embedded within the gas turbine engine at a location aft of a turbine section of the gas turbine engine and inward of a core airflow path through the gas turbine engine and a high pressure electric machine in electrical communication with an electric power bus and inward of the core airflow path through the gas turbine engine, wherein adding power to the gas turbine engine includes adding power to the low pressure system of the gas turbine engine using the low pressure electric machine to reduce a rate of deceleration of components of the gas turbine engine following the actual in-flight shutdown, decrease a first amount of time required for the gas turbine engine to get back to the pre-shutdown rotational speed following the actual in-flight shutdown, and reduce altitude loss during the subsequent restart of the gas turbine engine; and adding power to the high pressure system of the gas turbine engine using the high pressure electric machine to reduce the rate of deceleration of the components of the gas turbine engine following the actual in-flight shutdown, decrease the first amount of time required for the gas turbine engine to get back to the pre-shutdown rotational speed following the actual in-flight shutdown, and reduce altitude loss during the subsequent restart of the gas turbine engine.
15 . The hybrid-electric system of claim 14 , wherein receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine comprises receiving data indicative of the actual in-flight shutdown of the gas turbine engine.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a non-provisional application claiming the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/072,573, filed Aug. 31, 2020, which is hereby incorporated by reference in its entirety. FIELD The present subject matter relates generally to a hybrid-electric aircraft propulsion system, and more particularly to in-flight engine shutdown operations for a hybrid electric engine. BACKGROUND A conventional commercial aircraft generally includes a fuselage, a pair of wings, and a propulsion system that provides thrust. The propulsion system typically includes at least two aircraft engines, such as turbofan jet engines. Each turbofan jet engine is typically mounted to a respective one of the wings of the aircraft, such as in a suspended position beneath the wing, separated from the wing and fuselage. Hybrid electric propulsion systems are being developed to improve an efficiency of the conventional commercial aircraft. Various hybrid electric propulsion systems include an electric machine driven by one of the aircraft engines. The inventors of the present disclosure have come up with various configurations and/or methods to improve the currently-known hybrid electric propulsion systems. BRIEF DESCRIPTION Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. In one exemplary aspect of the present disclosure, a method for operating a hybrid-electric propulsion system of an aircraft is provided. The hybrid-electric propulsion system includes a gas turbine engine having a high pressure system, a low pressure system, and an electric machine coupled to one of the high pressure system or low pressure system. The method includes receiving data indicative of an actual or anticipated in-flight shutdown of the gas turbine engine; and adding power to the gas turbine engine through the electric machine in response to receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine. These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: FIG. 1 is a schematic, cross-sectional view of a gas turbine engine in accordance with an exemplary embodiment of the present disclosure. FIG. 2 is a schematic, cross-sectional view of a gas turbine engine in accordance with another exemplary embodiment of the present disclosure. FIG. 3 is a schematic view of a propulsion system in accordance with another exemplary embodiment of the present disclosure. FIG. 4 is a flow diagram of a method for operating a gas turbine engine in accordance with an exemplary aspect of the present disclosure. FIG. 5 is a graph depicting engine conditions following a shutdown of an engine according to exemplary aspects of the present disclosure. FIG. 6 is a graph depicting additional engine conditions following a shutdown of an engine according to exemplary aspects of the present disclosure. FIG. 7 is a graph depicting additional engine conditions following a shutdown of an engine according to exemplary aspects of the present disclosure. FIG. 8 is a graph depicting engine conditions between a shutdown and restart of an engine according to exemplary aspects of the present disclosure. FIG. 9 is a graph depicting additional engine conditions between a shutdown and restart of an engine according to exemplary aspects of the present disclosure. FIG. 10 is a graph depicting engine conditions following a shutdown of an engine according to exemplary aspects of the present disclosure. DETAILED DESCRIPTION Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations. Additionally, unless specifically identified otherwise, all embodiments described herein should be considered exemplary.