Patent Application
20240166356
The embodiments disclosed herein relate generally to multifunctional air systems that are especially useful in fuel cell powered electrical power trains for the aeronautics and aerospace industries.
With the exception of relatively small aircraft, the vast majority of airplanes in service today operate with thermal engines which combust fossil fuels. However, electric solutions to power aircraft combining an electrical motor to either battery energy or fuel cells are extensively being studied generating a number of scientific publications and the creation of demonstrator aircraft.
Aircraft are conventionally equipped with air systems to provide cabin pressurization and temperature control as well as ice protection for the aircraft's aerodynamic surfaces. Since thermal engines that combust fossil fuels typically include a compressor to provide compressed air to feed the combustion chamber (e.g., as is found in conventional turbine aircraft engines), an aircraft normally make use of a small amount of such a compressed air (colloquially known as “bleed air”) to feed the aircraft's air systems.
To date, however, it is believed that no consolidated and detailed solutions have been proposed for aircraft air systems in the situation where the aircraft is powered by a fuel cell power train rather than a thermal engine which combusts fossil fuels. It is therefore providing such solutions that the embodiments disclosed herein are directed.
Broadly, the embodiments disclosed herein are directed toward air systems for fuel cell powered aircraft. According to some embodiments, the air systems will include at least one compressor for supplying heated compressed air, at least one heat exchange system for receiving the heated compressed air and from the at least one compressor and discharging cooled compressed air and at least one turbine for receiving the cooled compressed air from the heat exchange system and directing the cooled compressed air to on-board aircraft cabin pressurization and temperature control systems. At least one shaft operatively interconnects the at least one compressor and the at least one turbine. An electric motor is provided and adapted to being powered by electrical power supplied by an on-board fuel cell of the aircraft, the electric motor being operatively connected to the shaft interconnecting the at least one compressor and the at least one turbine so as to operatively cause the shaft to drive the at least one compressor and the at least one turbine.
According to certain embodiments, the heat exchange system(s) will include respective heat exchangers which exchange heat from the heated compressed air with a hydrogen (H2) flow to the fuel cell, a coolant supplied to the fuel cell and/or external ram air impinging on a wing of the aircraft. A selector/mixing valve may be provided to selectively direct the heated compressed air to one of the heat exchangers in dependence upon the flight conditions of the aircraft. The heat exchanger which exchanges heat from the heated compressed air with external ram air impinging on a wing of the aircraft may include a thermal anti-icing system associated with a leading edge of a wing of the aircraft, the heated compressed air being directed to the anti-icing system so as to heat the leading edge of the wing whereby cooled compressed air is discharged from the anti-icing system.
The air systems according to some embodiments may include first and second compressors and first and second turbines. The first compressor and the first turbine may be interconnected by a first shaft, while the second compressor and the second compressor may be connected together by a second shaft. The at least one heat exchange system may thus include port and starboard side heat exchange systems, whereby the first and second compressors respectively supply heated compressed air to the port and starboard side heat exchange systems, while the port and starboard side heat exchange systems respectively supply cooled compressed air to the first and second turbines. The electric motor may thus be adapted to being operatively coupled to a propeller gearbox associated with a propeller of the aircraft, while the first shaft may be connected to the propeller gearbox. In such embodiments, the first and second shafts are interconnected by a shaft gearbox. According to some embodiments, the electric motor is adapted to being operatively coupled to a propeller gearbox associated with a propeller of the aircraft and the at least one shaft is connected to the propeller gearbox.
The air system according to other embodiments may further include first and second compressors and first and second turbines. The at least one heat exchange system may thereby comprise port and starboard side heat exchange systems, whereby the first compressor is adapted to being operatively connected by a first subshaft to propeller gear box associated with a propeller of the aircraft so as to supply heated compressed air to the port side heat exchanger. The first turbine will therefore receive cooled compressed air from the port side heat exchanger. The first turbine will include a second subshaft and a generator connected to the second subshaft. The second compressor and the second turbine are connected together by a second shaft, whereby the second compressor supplies heated compressed air to the starboard side heat exchanger while the second turbine receives cooled compressed air from the starboard side heat exchanger.
Other embodiments are provided with an air system for a fuel cell powered aircraft which includes at least one compressor for supplying heated compressed air, at least one heat exchange system for receiving the heated compressed air and from the at least one compressor and discharging cooled compressed air and a vapor cycle machine which receives the cooled compressed air from the at least one heat exchanger. The VCM is adapted to supply pressurization and environmental air to an aircraft cabin. As in other embodiments, an electric motor is adapted to being powered by electrical power supplied by an on-board fuel cell of the aircraft, the electric motor being operatively connected to the at least one compressor. At least one turbine and at least one shaft interconnecting the at least one turbine with the at least one compressor and the electric motor may also be provided.
These and other aspects and advantages of the present invention will become clearer after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.
The disclosed embodiments of the present invention will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative embodiments in conjunction with the drawings of which:
A fuel cell powered aircraft AC is schematically depicted in
The air system AS includes an air flow subsystem AFS which comprises two shafts S1, S2 linked by a gear box GB2, each shaft S1, S2 bearing a compressor C1, C2 and a turbine T1, T2, respectively. The shaft S2 is also operatively coupled with an electric motor 11 that serves as motive power for the shaft S2, and hence the shaft S1 via the gearbox GB2, from electrical power the motor 11 receives from the fuel cell 12. The compressors C1, C2 provide air flow to the fuel cell 12 and the airplane air systems such as the anti-icing system and the cabin pressurization systems. A selector/mixer valve 1 selects which of the compressors C1 or C2 the air flow for cabin control is supplied from. Selection or mixing is defined by a controller (not shown) adjusted to choose the best source for each flight condition.
The compressed air discharged from the selector/mixing valve 1 is directed to a port side heat exchange system 9 which reduces the temperature of the air. The air flow within the portside heat exchange system 9 may exchange heat with the hydrogen (H2) flow to the fuel cell 12, the coolant supplied to the fuel cell 12 and/or external ram air impinging on the portside wing PW. The controller (not shown) operates a selector/mixing valve 2 so as to direct the compressed air from the compressor C1 to the heat exchange mechanism, i.e., the portside H2 heat exchanger PHX_H2 or the portside fuel cell coolant heat exchanger PHX_Coolant in dependence on which is best for the flight conditions encountered by the aircraft AC. The cooled air flow supplied to the turbine T1 expands within the turbine T1 thereby donating energy to the air flow subsystem AFS and decreasing the air temperature and pressure to appropriate levels for cabin pressurization and temperature control.
A portion of the air flow from compressor C1 may be directed by the selector/mixing valve 1 to a starboard side heat exchange system 10 in which the air flow temperature is modulated to the temperature required by the fuel cell exchanging heat with H2 via the starboard side H2 heat exchanger SHX_H2 or the starboard side fuel cell coolant heat exchanger SHX_Coolant. The starboard side heat exchange system 10, like the portside heat exchange system 9, will include a selector/mixing valve 4 chooses which heat exchange mechanism is best for the flight conditions encountered by the aircraft AC.
The compressed air flow from compressor C2 is bifurcated at a T-junction 8, such that part of the compressed air flow is directed to the starboard side heat exchange system 10 so as to ultimately feed the fuel cell 12 which thereafter joins via the selector/mixing valve 7 with the previously diverted air to expand in the turbine T2. The diversion allows the compressor C2 to operate at high pressure even at low fuel cell air flow demand and allows that the air that expands in turbine T2 is preheated which avoids icing formation issues after expansion.
A principal advantage provided by the embodiment of the present invention as shown in
While reference is made to particular embodiments of the invention, various modifications within the skill of those in the art may be envisioned. Therefore, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope thereof.
This application is based on and claims domestic priority benefits from U.S. Provisional Application Ser. No. 63/427,274 filed on Nov. 22, 2022, the entire content of which is expressly incorporated hereinto by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63427274 | Nov 2022 | US |
