Anti-stall system with a fuel cell
An anti-stall system for an aircraft may be provided, where the aircraft includes a propulsion system including a fuel cell assembly and a combustion engine, the combustion engine including a compressor section having a compressor. The anti-stall system may include at least one sensor configured to sense data indicative of at least one operating parameter indicative of a compressor stall condition of the compressor; and a controller including a processor and a memory storing instructions that when executed by the processor cause the controller to determine that the at least one operating parameter has achieved a compressor stall condition threshold and execute an anti-stall action responsive to determining that the at least one operating parameter has achieved the compression stall condition threshold. The anti-stall action may be configured to adjust at least one fuel cell parameter.
1 . An anti-stall system for an aircraft, the anti-stall system comprising:
a propulsion system including, in serial flow relationship, a low-pressure compressor, a high-pressure compressor, and a combustion section, wherein the propulsion system further comprises a secondary compressor, a fuel cell assembly, an electric bus, an electric machine, and at least one shaft, and wherein the combustion section comprises a combustor including an inner liner, an outer liner, and a combustion chamber defined therebetween, wherein the secondary compressor is fluidly coupled to the low-pressure compressor via a first bleed flow path to receive a first bleed flow from the low-pressure compressor, wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second bleed flow path to receive a second bleed flow from the high-pressure compressor, wherein the second compressor is in airflow communication with the fuel cell assembly to provide at least one of the first bleed flow or the second bleed flow to the fuel cell assembly, wherein the fuel cell assembly is integrated with the inner liner or the outer liner and is in fluid communication with the combustion chamber, and wherein the electric bus is electrically coupled to the fuel cell assembly and the electric machine;
a sensor configured to sense data indicative of an operating parameter indicative of a compressor stall condition of at least one of the low-pressure compressor or the high-pressure compressor; and
a controller electronically coupled to the sensor, wherein the controller is configured to:
receive the data indicative of the operating parameter indicative of the compressor stall condition, wherein receiving the data indicative of the operating parameter comprises receiving data indicative of one or more of a flame in the combustor, rotational speed of the at least one shaft, or a combustion engine load; and
execute an anti-stall action responsive to the data indicative of the operating parameter indicative of the compressor stall condition if the operating parameter has achieved a compression stall condition threshold, wherein executing the anti-stall action includes increasing or decreasing at least one fuel cell parameter of the fuel cell assembly.
2 . The anti-stall system of claim 1 , wherein the at least one fuel cell parameter includes:
a current output of the fuel cell assembly;
a fuel utilization of the fuel cell assembly;
an air to fuel ratio of a fuel cell stack of the fuel cell assembly; or
any combination thereof.
3 . The anti-stall system of claim 1 , wherein the fuel cell assembly comprises a fuel cell defining an outlet positioned to remove output products from the fuel cell and provide the output products to the combustor, wherein a combustor output power of the combustor is controlled by adjusting the at least one fuel cell operating parameter.
4 . The anti-stall system of claim 3 , wherein the electric machine is rotatable with the at least one shaft, wherein adjusting the at least one fuel cell parameter comprises adjusting a fuel cell power output to the electric machine.
5 . The anti-stall system of claim 1 , wherein receiving the data indicative of the operating parameter comprises receiving sensor data of a change in rotational speed of the at least one shaft, wherein adjusting the at least one fuel cell parameter includes adjusting the electric machine based on an acceleration of the at least one shaft.
6 . The anti-stall system of claim 1 , wherein adjusting the at least one fuel cell parameter includes increasing a pressure, a flow rate, or both of at least one of the first bleed flow or the second bleed flow from the secondary compressor to the fuel cell assembly.
7 . The anti-stall system of claim 6 , wherein adjusting the at least one fuel cell parameter includes increasing the pressure of at least one of the first bleed flow or the second bleed flow to be greater than a combustion chamber pressure.
8 . The anti-stall system of claim 6 , wherein the secondary compressor is configured to:
receive at least one of the first bleed flow or the second bleed flow at a secondary compressor inlet of the secondary compressor;
increase the pressure of at least one of the first bleed flow or the second bleed flow; and
communicate at least one of the first bleed flow or the second bleed flow to the fuel cell assembly with a secondary compressor outlet of the secondary compressor.
9 . The anti-stall system of claim 8 , wherein the secondary compressor is further configured to receive a motive force from the propulsion system.
10 . The anti-stall system of claim 8 , wherein the secondary compressor is configured to receive power from the fuel cell assembly.
11 . The anti-stall system of claim 8 , further comprising a recirculation flow, the recirculation flow configured to divert at least a portion of at least one of the first bleed flow or the second bleed flow downstream of the secondary compressor outlet to upstream of the secondary compressor inlet.
12 . The anti-stall system of claim 11 , further comprising a recirculation control device, the recirculation control device configured to control a proportion of the recirculation flow diverted to upstream of the secondary compressor inlet.
13 . The anti-stall system of claim 12 , further comprising a mixing assembly, the mixing assembly configured to entrain at least one of the first bleed flow or the second bleed flow upstream of the secondary compressor inlet with at least a portion of the recirculation flow.
14 . The anti-stall system of claim 8 , wherein the secondary compressor comprises a mixing assembly, the mixing assembly configured to:
receive the first bleed flow at a first pressure;
receive the second bleed flow at a second pressure, wherein the second pressure is greater than the first pressure;
entrain the first bleed flow with the second bleed flow; and
communicate a combined bleed flow from the secondary compressor outlet, the combined bleed flow having a third pressure, wherein the third pressure is greater than the first pressure and less than the second pressure.
15 . A method of operating an anti-stall system for an aircraft, the aircraft comprising a propulsion system including, in serial flow relationship, a low-pressure compressor, a high-pressure compressor, and a combustor, the propulsion system further comprising a secondary compressor and a fuel cell assembly, wherein the secondary compressor is fluidly coupled to the low-pressure compressor via a first bleed flow path to receive a first bleed flow from the low-pressure compressor, wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second bleed flow path to receive a second bleed flow from the high-pressure compressor, wherein the second compressor is in airflow communication with the fuel cell assembly to provide at least one of the first bleed flow or the second bleed flow to the fuel cell assembly, the combustor including an inner liner and an outer liner defining a combustion chamber therebetween, the method comprising:
detecting, with at least one sensor, an operating parameter indicative of a compressor stall condition; and
executing, with at least one controller, an anti-stall action responsive to the operating parameter having achieved a compressor stall condition threshold, wherein the anti-stall action comprises increasing or decreasing at least one fuel cell parameter, wherein the fuel cell assembly is integrated with the inner liner or the outer liner and is in fluid communication with the combustion chamber, wherein receiving the data indicative of the compressor stall condition comprises receiving data indicative of rotational speed of at least one shaft of the propulsion system, and receiving sensor data of a change in rotational speed of the at least one shaft of the propulsion system.
16 . The method of claim 15 , wherein adjusting the at least one fuel cell parameter comprises controlling at least one of the first bleed flow or the second bleed flow into the fuel cell assembly.
17 . The method of claim 15 , wherein adjusting the at least one fuel cell parameter comprises controlling a fuel cell fuel supply.
18 . The method of claim 15 , further comprising transmitting a stall condition message to a pilot responsive to the operating parameter having achieved the compressor stall condition threshold.
19 . The method of claim 15 , wherein the anti-stall action further comprises increasing or decreasing at least one combustion engine parameter.
20 . The method of claim 15 , further comprising:
ceasing execution, of the anti-stall action if the operating parameter falls below the compressor stall condition threshold.