Systems and methods for filling a fuel manifold of a gas turbine engine
In response to exiting from a non-full non-filling state of a secondary manifold of a gas turbine engine, the method of filling the secondary fuel manifold of the engine includes: setting at least one engine schedule limit based on a measured value of a scheduling parameter that is within a first range that corresponds to a non-full state of the secondary fuel manifold. The method includes determining whether the filling of the secondary fuel manifold is completed. The method includes adjusting the at least one engine schedule limit to control at least one operational parameter of the engine, in response to a determination that the filling of the secondary fuel manifold is completed.
1 . A method comprising:
in response to exiting a non-full non-filling state of a gas turbine engine in which a secondary fuel manifold of the engine is at least partially empty and is not receiving fuel at a fuel flow that exceeds a threshold filling fuel flow, initiating filling the secondary fuel manifold of the engine, including:
setting at least one engine schedule limit based on a measured value of scheduling parameters that is within a first range that corresponds to a non-full state of the secondary fuel manifold;
determining whether the filling of the secondary fuel manifold is completed; and
adjusting the at least one engine schedule limit to control at least one operational parameter of the engine, in response to a determination that the filling of the secondary fuel manifold is completed, by setting the at least one engine schedule limit based on a measured value of the scheduling parameters that is within a second range that corresponds to a full state of the secondary fuel manifold the at least one engine schedule limit based on the measured value within the second range is less than the at least one engine schedule limit based on the measured value within the first range, wherein the at least one engine schedule limit includes an engine core acceleration (ECA) limit.
2 . The method of claim 1 , wherein the at least one engine schedule limit includes a first engine schedule limit and a second engine schedule limit.
3 . The method of claim 2 , wherein the scheduling parameters include a first scheduling parameter and a second scheduling parameter different from the first scheduling parameter; setting the at least one engine schedule limit based on the measured value of the scheduling parameters that corresponds to the non-full state of the secondary fuel manifold comprises: setting a first engine schedule limit based on a measured value of the first scheduling parameter; and
setting a second engine schedule limit based on a measured value of the second scheduling parameter.
4 . The method of claim 1 , wherein exiting the non-full non-filling state of the engine includes at least one of:
starting the engine;
relighting the engine;
exiting an Asymmetric Operating Regine (AOR) standby mode of the engine of a multi-engine system;
exiting a low-fuel mode of the engine; or
recovering from the fuel flow of the engine below a flow divider valve cracking point.
5 . The method of claim 1 , wherein determining that the filling of the secondary fuel manifold is completed comprises: determining a first duration of time elapsed from the initiating the filling of the secondary fuel manifold.
6 . The method of claim 5 , further comprising:
in response to determining that the filling of the secondary fuel manifold is completed, maintaining the at least one engine schedule limit based on the measured value of the scheduling parameters that is within the first range for a second duration of time that follows the first duration of time; and
adjusting the at least one engine schedule limit after the second duration of time elapses.
7 . The method of claim 1 , wherein: determining that the filling of the secondary fuel manifold is completed further comprises: determining the measured value of the scheduling parameters is no longer within the first range.
8 . The method of claim 1 , wherein: the at least one engine schedule limit includes the ECA limit and an engine max fuel flow rate (Wfdot ma ) limit;
the measured value of the scheduling parameters comprises an ECA measurement;
setting the at least one engine schedule limit based on the measured value of the scheduling parameters that is within the first range comprises:
setting the ECA limit to a first ECA value; and
setting the Wfdot m limit to a first value; and
adjusting the at least one engine schedule limit comprises:
setting the ECA limit to a second ECA value that is less than the first ECA value, thereby controlling the at least one operational parameter of the engine to target the second ECA value; and
setting the Wfdot m limit to a second value that is less than the first value.
9 . An electronic device comprising: a processor configured to:
in response to exiting a non-full non-filling state of a gas turbine engine in which a secondary fuel manifold of the engine is at least partially empty and is not receiving fuel at a fuel flow that exceeds a threshold filling fuel flow, initiate filling the secondary fuel manifold of the engine, including:
set at least one engine schedule limit based on a measured value of scheduling parameters that is within a first range that corresponds to a non-full state of the secondary fuel manifold;
determine whether the filling of the secondary fuel manifold is completed; and
adjust the at least one engine schedule limit to control at least one operational parameter of the engine, in response to a determination that the filling of the secondary fuel manifold is completed, by setting the at least one engine schedule limit based on the measured value of the scheduling parameters that is within a second range that corresponds to a full state of the secondary fuel manifold the at least one engine schedule limit based on the measured value within the second range is less than the at least one engine schedule limit based on the measured value within the first range, wherein the at least one engine schedule limit includes an engine core acceleration (ECA) limit.
10 . The electronic device of claim 9 , wherein the at least one engine schedule limit includes a first engine schedule limit and a second engine schedule limit.
11 . The electronic device of claim 10 , wherein:
the scheduling parameters include a first scheduling parameter and a second scheduling parameter different from the first scheduling parameter; to set the at least one engine schedule limit based on the measured value of the scheduling parameters that corresponds to the non-full state of the secondary fuel manifold, the processor is configured to:
set a first engine schedule limit based on a measured value of the first scheduling parameter; and
set a second engine schedule limit based on a measured value of the second scheduling parameter.
12 . The electronic device of claim 9 , wherein exiting from the non-full non-filling state of the engine includes at least one of:
starting the engine;
relighting the engine;
exiting an Asymmetric Operating Regine (AOR) standby of the engine of a multi-engine system;
exiting a low-fuel mode of the engine; or
recovering from the fuel flow of the engine below a flow divider valve cracking point.
13 . The electronic device of claim 9 , wherein to determine that the filling of the secondary fuel manifold is completed, the processor is configured to:
determine a first duration of time elapsed from the initiation of the filling the secondary fuel manifold.
14 . The electronic device of claim 13 , the processor is further configured to:
in response to determine that the filling of the secondary fuel manifold is completed, maintain the at least one engine schedule limit based on the measured value of the scheduling parameters that is within the first range for a second duration of time that follows the first duration of time; and
adjust the at least one engine schedule limit after the second duration of time elapses.
15 . The electronic device of claim 9 , wherein: to determine that the filling of the secondary fuel manifold is completed, the processor is configured to determine the measured value of the scheduling parameters is no longer within the first range.
16 . The electronic device of claim 9 , wherein: the at least one engine schedule limit includes the ECA limit and an engine max fuel flow (Wfdot) limit;
the measured value of the scheduling parameters comprises an ECA measurement;
to set the at least one engine schedule limit based on the measured value of the scheduling parameters that is within the first range, the processor is configured to: set the ECA limit to a first ECA value; and
set the Wfdot ma limit to a first value; and
to adjust the at least one engine schedule limit, the processor is configured to: set the ECA limit to a second ECA value that is less than the first ECA value, thereby controlling the at least one operational parameter of the engine to target the second ECA value; and
set the Wfdot ma limit to a second value that is less than the first value.
17 . A non-transitory computer readable medium embodying a computer program, the computer program comprising computer readable program code that when executed causes at least one processor to: in response to exiting from a non-full non-filling state of a gas turbine engine in which a secondary fuel manifold of the engine is at least partially empty and is not receiving fuel at a fuel flow that exceeds a threshold filling fuel flow, initiate filling the secondary fuel manifold of the engine, including:
set at least one engine schedule limit based on a measured value of scheduling parameters that is within a first range that corresponds to a non-full state of the secondary fuel manifold;
determine whether the filling of the secondary fuel manifold is completed; and
adjust the at least one engine schedule limit to control at least one operational parameter of the engine, in response to a determination that the filling of the secondary fuel manifold is completed, by setting the at least one engine schedule limit based on a measured value of the scheduling parameter that is within a second range that corresponds to a full state of the secondary fuel manifold the at least one engine schedule limit based on the measured value within the second range is less than the at least one engine schedule limit based on the measured value within the first range, wherein the at least one engine schedule limit includes an engine core acceleration (ECA) limit.
18 . The non-transitory computer readable medium of claim 17 , wherein:
the at least one engine schedule limit includes a first engine schedule limit and a second engine schedule limit;
the scheduling parameters include a first scheduling parameter and a second scheduling parameter different from the first scheduling parameter;
the program code that when executed causes the at least one processor to set the at least one engine schedule limit based on the measured value of the scheduling parameter that corresponds to the non-full state of the secondary fuel manifold, further comprise program code that when executed causes the at least one processor to:
set the first engine schedule limit based on a measured value of the first scheduling parameter; and
set the second engine schedule limit based on a measured value of the second scheduling parameter.
19 . The non-transitory computer readable medium of claim 17 , wherein the program code that when executed causes the at least one processor to determine that the filling of the secondary fuel manifold is completed, further comprise program code that when executed causes the at least one processor to:
determine a first duration of time elapsed from the initiation of the filling the secondary fuel manifold.
20 . The non-transitory computer readable medium of claim 17 , wherein: the program code that when executed causes the at least one processor to determine that the filling of the secondary fuel manifold is completed, further comprise program code that when executed causes the at least one processor to determine the measured value of the scheduling parameters is no longer within the first range.