Electrical power generation system for a hybrid power source aircraft

Abstract

An electrical power generation system for a hybrid-powered aircraft includes a combustion engine (23) arranged to provide mechanical power. The system further includes power electronics (21) arranged to convert the mechanical power supplied by the engine (23) into electrical power for aircraft propulsion. The system further includes a heat exchanger (33) connected to the power electronics (21). The system further includes a gas inlet (11) and a gas outlet (13). The system also includes a gas circuit fluidly connecting the gas inlet (11) to the gas outlet (13). The gas circuit terminates at least at the gas outlet (13) via a discharge line (41). This discharge line (41) has an end portion (42) opposite the gas outlet (13).The gas circuit comprises a first circuit, arranged to supply the engine (23) with air from the gas inlet (11) and to discharge exhaust gases from the engine (23) to the end portion (42) of the discharge pipe (41). The gas circuit further comprises a second circuit, fluidly connecting the gas inlet (11) to the end portion (42) of the discharge pipe (41). The second circuit is arranged to receive an airflow from the gas inlet (11) to cool the heat exchanger (33). This airflow is generated by a jet pump effect as the exhaust gases pass through the end portion (42) of the discharge pipe (41). [Fig. 1]

Description

Title of the invention: Electrical power generation system for a hybrid power source aircraft

[0001] The invention relates to the field of hybrid-powered aircraft. More particularly, the invention relates to electrical power generation systems for such aircraft.

[0002] An aircraft generally comprises a main engine group, which provides the power necessary for its propulsion and lift. This main engine group is typically integrated into the aircraft's fuselage.

[0003] Nowadays, for most aircraft, the main propulsion unit is of the thermal type, that is to say, this unit generates mechanical power from a thermal energy source. Typically, this unit may include a combustion engine connected to a propeller, or a turbojet engine.

[0004] In addition, an aircraft often includes one or more auxiliary power units, also called APUs in the technical field. An APU generally consists of a turbogenerator, arranged to generate electrical power from a thermal energy source. Typically, this electrical power is on the order of a few tens of kilowatts. The turbogenerator includes electronic components, which generally operate at voltages on the order of one hundred volts.

[0005] An APU is designed to provide electrical power to the aircraft on a transient basis. For example, this power is intended to supply onboard systems of the aircraft when it is on the ground and its main engine is shut down. This power may also be intended to assist the (re)start of the aircraft's main engine, whether the aircraft is on the ground or in flight.

[0006] An aircraft is said to be "hybrid power-source" when its main propulsion system is of the hybrid type, that is, when this system includes an electrical power generation system capable of generating electrical power from a thermal energy source. Typically, such an electrical power generation system includes a fuel cell or an internal combustion engine, arranged to produce mechanical power from the combustion of a fuel, and an electrical generation component, arranged to convert the mechanical power supplied by the internal combustion engine into electrical power. This electrical power is then generally stored in one or more batteries for later use in propulsion or lift of the aircraft.

[0007] The electrical power generation system of a hybrid main power unit must generate significantly more electrical power than that generated by the turbogenerator of an APU. Furthermore, unlike an APU, the electrical power generation system of a hybrid main power unit is designed to operate continuously while the aircraft is in flight.

[0008] Thus, unlike an APU, an electrical power generation system for a hybrid main power unit generally includes a power electronics component. This power electronics is capable of generating, from the mechanical power supplied by the combustion engine, sufficient electrical power to provide propulsion and lift for the aircraft. Typically, the power electronics handles power levels between 100 kW and 1 MW. The power electronics may include several types of devices, such as electrical generators and inverters. Typically, these devices operate at voltages between 500 V and 800 V.

[0009] The operation of the power electronics in the electrical power generation system generates significantly more heat than that generated during the operation of the electrical power generation section of an APU. To prevent the formation of hot spots within the system, a cooling circuit is necessary to dissipate this heat. Typically, the operation of the power electronics generates heat with a thermal power that can reach several tens of kilowatts.

[0010] Preferably, the cooling circuit involves the circulation of a heat transfer fluid or coolant. This coolant heats up in the vicinity of the power electronics and cools down in the vicinity of circulating air. In this way, the heat generated by the power electronics dissipates rapidly, without creating hot spots. The cooling circuit includes a heat exchanger, arranged to ensure heat transfer between the coolant and the circulating air. The coolant is, for example, a mixture of water and glycol.

[0011] As is known, a gas circuit is provided to receive this airflow, fluidly connecting a gas inlet and a gas outlet. This gas inlet and gas outlet are, for example, formed by openings in a portion of the fuselage fairing. The gas circuit draws fresh air from the external environment through the gas inlet. The gas circuit then circulates this air near the heat exchanger to ensure the dissipation of the heat carried by the coolant. Finally, the gas circuit expels this air through the gas outlet.

[0012] The air circulation in the gaseous circuit must have a minimum flow rate so that The heat exchanger efficiently dissipates the heat generated by the power electronics. In particular, this minimum flow rate must be achievable even when the aircraft is stationary.

[0013] To guarantee this flow rate, a prior art solution consists of installing an electric fan near the heat exchanger. This fan, through its rotation, ensures air circulation at the necessary flow rate, even when the aircraft is stationary. However, this solution is not satisfactory, as the presence of the fan adds mass and bulk to the system. Furthermore, the fan's operation consumes electricity.

[0014] The invention improves the situation.

[0015] To this end, the Applicant proposes an electrical power generation system for a hybrid-powered aircraft. The system comprises a combustion engine arranged to provide mechanical power. The system further comprises power electronics arranged to convert the mechanical power supplied by the engine into electrical power for aircraft propulsion. The system further comprises a heat exchanger connected to the power electronics. The system further comprises a gas inlet and a gas outlet. The system also comprises a gas circuit fluidly connecting the gas inlet to the gas outlet. The gas circuit opens onto the gas outlet at least via a discharge pipe. This discharge pipe has an end portion opposite the gas outlet.The gas circuit comprises a first circuit, arranged to supply the engine with air from the gas inlet and to exhaust the engine to the end of the exhaust pipe. The gas circuit further comprises a second circuit, fluidly connecting the gas inlet to the end of the exhaust pipe. The second circuit is arranged to receive airflow from the gas inlet, which is used to cool the heat exchanger. This airflow is generated by a jet pump effect as the exhaust gases pass through the end of the exhaust pipe.

[0016] This system allows for efficient cooling of the power electronics, even when the aircraft is stationary. The jet pump effect utilizes the exhaust gases from the combustion engine to create airflow sufficient to dissipate the heat generated by the power electronics. This eliminates the need for an electric fan, or at least reduces its size and power consumption. The result is a lighter, more compact, and more energy-efficient electrical power generation system.

[0017] Optional features of the invention, complementary or alternative, are stated below:

[0018]

[0019]

[0020]

[0021]

[0022] - power electronics is capable of providing electrical power between 100 kW and 1 MW; - Power electronics is designed to operate at voltages between 500 V and 800 V; - the engine and power electronics are designed to operate continuously while the aircraft is in flight; - the system further includes an engine block, housing the engine, the power electronics and the heat exchanger, the engine block delimiting, at least in part, a conduit for the second circuit, and the air circulation intended to cool the heat exchanger also being intended to ensure air renewal inside the engine block; - the first circuit includes an exhaust pipe, arranged to evacuate exhaust gases from the engine towards the end portion of the exhaust pipe; - a ratio between a section at the outlet of the exhaust pipe and a section at the inlet of the end portion is on the order of 1:2; - the distance between an outlet of the exhaust pipe and an inlet of the end portion is substantially zero; - the heat exchanger is located near the gas inlet, away from the end portion of the exhaust pipe; - the end portion of the exhaust pipe has a clearance, the heat exchanger being positioned near this clearance. The invention also relates to a hybrid power source aircraft comprising this system. Other features and advantages of the invention are described in detail below, with reference to the accompanying drawings, in which: - [Fig.1] is a schematic representation of an electrical power generation system, according to a first embodiment of the invention; - [Fig.2] is a schematic representation of an electrical power generation system, according to a second embodiment of the invention; - [Fig.3] is a schematic representation of another electrical power generation system. The drawings and description below contain, for the most part, elements of a definite nature. They can therefore not only serve to better explain the present invention, but also contribute to its definition, if necessary. We are referring to [Fig.1]. This figure represents an electrical power generation system, according to a first embodiment of the invention. This system is designated by the reference digital 10 on the drawings and in the rest of the description.

[0023] The system 10 is intended to generate electrical power for a hybrid-powered aircraft. In particular, the system 10 is arranged to generate electrical power for the propulsion and lift of the aircraft. Typically, the system 10 is integrated within the aircraft fuselage. The system 10 may, as shown here, be integrated near a fairing portion 15 belonging to the fuselage.

[0024] System 10 comprises a hybrid power unit capable of generating electrical power from a thermal energy source. System 10 is designed to operate continuously while the aircraft is in flight.

[0025] The hybrid power unit comprises a thermal engine unit, arranged to provide mechanical power from the thermal energy source. Here, the thermal energy source is a fuel, in particular a fuel. This fuel is, for example, stored in a tank of the aircraft (not shown in the figures). The thermal engine unit is arranged to provide mechanical power from the combustion of the fuel. The thermal engine unit is supplied with air, in a manner that will be detailed later. The operation of the thermal engine unit results in exhaust emissions, which are discharged in a manner that will be detailed later.

[0026] The thermal propulsion unit may comprise one or more examples of combustion engines. Here, the thermal propulsion unit comprises one example of a combustion engine, or engine 23. The engine 23 may, for example, be a piston engine or a turboshaft engine.

[0027] The hybrid power unit further comprises a power electronics component 21, arranged to generate, from the mechanical power supplied by the internal combustion engine unit, electrical power intended to provide propulsion and lift to the aircraft. Typically, the power electronics component 21 handles power levels between 100 kW and 1 MW.

[0028] The power electronics 21 includes an electricity generation section, mechanically connected to the thermal engine unit. The electricity generation section is arranged to generate electrical power from the mechanical power supplied by the thermal engine unit.

[0029] The electricity generation part may include one or more examples of electric generators. Here, the power electronics 21 includes one example of an electric generator, or generator 25, mechanically connected to the motor 23.

[0030] The power electronics 21 may further include, as shown here, other power electronic devices. These devices are electrically connected to the power generation section. These devices are arranged to use or transform the electrical power generated by the power generation unit, particularly for storage in a battery (not shown in the figures). This electrical power is then used for the propulsion and lift of the aircraft.

[0031] Here, the power electronics 21 includes an inverter 27, electrically connected to the generator 25.

[0032] Typically, electric generators and other power electronic devices 21 operate at voltages between 500 V and 800 V.

[0033] The system 10 further includes a cooling circuit 31, arranged to remove at least part of the heat released by the operation of the power electronics 21. Here, the cooling circuit 31 is arranged to cool the generator 25 and the inverter 27.

[0034] The cooling circuit 31 includes a heat exchanger 33. This heat exchanger 33 is arranged to dissipate the heat released by the operation of the power electronics 21, as detailed later.

[0035] Here, the cooling circuit 31 further comprises a pipe configured as a cooling loop 35. This cooling loop is arranged to receive the circulation of a heat transfer fluid or coolant. The cooling loop 35 is connected, on the one hand, to the power electronics 21, and, on the other hand, to the heat exchanger 33. The cooling loop 35 is arranged to capture the heat released by the operation of the power electronics 21 and to transfer this heat to the heat exchanger 33. Here, the coolant is a mixture of water and glycol.

[0036] Here, the system 10 further comprises an engine block 17, housing the hybrid power unit. The engine block 17 is arranged to provide protection for the hybrid power unit in the event of a fire. Here, the engine block 17 houses the motor 23, the generator 25, and the inverter 27. Here, the engine block 17 also houses the cooling circuit 31. In particular, the engine block 17 houses the heat exchanger 33 and the cooling loop 35.

[0037] The system 10 further includes a gas inlet 11 and a gas outlet 13. Here, the gas inlet 11 is formed into a first opening, provided on the fairing portion 15. Here, the gas outlet 13 is formed into a second opening, provided on the fairing portion 15.

[0038] The system 10 further comprises a gas circuit, which fluidly connects the gas inlet 11 to the gas outlet 13. The gas flow from the gas inlet 11 to the gas outlet 13 is represented by arrows 81, 83, 85, 87 and 89. These arrows illustrate one direction for the gas flow in the gas circuit.

[0039] The gas circuit is arranged to supply the engine 23 with air from the inlet of gas 11. The airflow from the gas inlet 11 and supplying the engine 23 is represented by arrow 81. The gas circuit is further arranged to evacuate exhaust gases from the engine 23 through the gas outlet 13. The exhaust gas flow from the engine 23 and evacuated through the gas circuit towards the gas outlet 13 is represented by arrows 83 and 85.

[0040] The gas circuit is further arranged to receive an airflow, which cools the cooling circuit 31. In particular, the gas circuit is arranged so that the heat exchanger 33 ensures heat transfer between the coolant and this airflow. The airflow dissipates the heat released by the operation of the power electronics 21 and transported to the heat exchanger 33 by the coolant circulating in the cooling loop 35.

[0041] The air circulation cooling the cooling circuit 31 includes an airflow represented by arrows 89, 87 and 85. This airflow is discharged through the gas outlet 13. Here, this airflow originates from the gas inlet 11.

[0042] The gas circuit includes a discharge line 41, leading to the gas outlet 13. The gas circuit is arranged to discharge exhaust gases from the engine 23 via the discharge line 4L. The gas circuit is further arranged to discharge the airflow cooling the cooling circuit 31 via the discharge line 4L.

[0043] The discharge pipe 41 has an end portion 42, disposed on one end of the discharge pipe 41 opposite the gas outlet 13. Here, the discharge pipe 41 is fluidly connected to the engine block 17 via this end portion 42.

[0044] The gas circuit has a first circuit, or engine circuit 46, arranged to serve the engine 23. The engine circuit 46 forms a first pathway for the passage of gas flows between the gas inlet 11 and the end portion 42. The engine circuit 46 is arranged to supply the engine 23 with air and to exhaust the exhaust gases emitted by the engine 23. The engine circuit 46 connects to the end portion 42 of the exhaust line 4L

[0045] Here, the engine circuit 46 includes a supply line 45, which fluidly connects the gas inlet 11 to the engine 23, and an exhaust line 47, which fluidly connects the engine 23 to the end portion 42. The supply line 45 is arranged to supply the engine 23 with air. The exhaust line 47 is arranged to discharge the exhaust gases emitted by the engine 23 to the end portion 42. Here, the exhaust line 47 opens into the end portion 42. The supply line 45 receives the airflow represented by arrow 81. The exhaust line 47 receives the exhaust gas flow. presented by arrow 83.

[0046] The gas circuit further includes a second circuit, or air circuit, arranged to cool the cooling circuit 31. The air circuit forms a second pathway for the passage of gas flows between the gas inlet 11 and the end portion 42. In particular, the air circuit is arranged to receive the air circulation cooling the heat exchanger 33. The air circuit fluidly connects the gas inlet 11 to the end portion 42 of the discharge line 4L

[0047] The air circuit includes a first duct, arranged to conduct the air cooling the cooling circuit 31 to the end portion 42. Here, this first duct is formed by a chamber 49, delimited in part by the engine block 17. The chamber 49 receives the airflow represented by the arrows 87.

[0048] The air circuit further includes a second duct or inlet duct 51, which fluidly connects the gas inlet 11 to its first duct, here the enclosure 49. The inlet duct 51 receives the airflow represented by the arrow 89.

[0049] The first air circuit duct fluidly connects the inlet duct 51 and the end portion 42. The first air circuit duct is arranged to conduct the air cooling the cooling circuit 31, from one end of the inlet duct 51 to the end portion 42 of the discharge duct 4L

[0050] Here, the engine circuit 46 and the air circuit are separate from each other along their entire length. The engine circuit 46 and the air circuit join at the end portion 42 of the exhaust pipe 4L. The supply pipe 45 of the engine circuit 46 is separate from the inlet pipe 51 of the air circuit. Furthermore, the supply pipe 45 and the exhaust pipe 47 of the engine circuit 46, together with the engine block 17, define one of the pipes of the air circuit, namely the enclosure 49.

[0051] Here, the heat exchanger 33 is disposed near the gas inlet 11. In particular, the heat exchanger 33 is disposed in the enclosure 49, near the end of the inlet pipe 51.

[0052] The fairing portion 15 may, as here, have, on the gas inlet 11, a projecting part forming a first deflector 16. This first deflector 16 is arranged to guide airflows towards the gas inlet 11, in particular towards the supply line 45 and towards the inlet line 51.

[0053] The gas circuit is arranged to generate, by jet pump effect, the circulation of air cooling the cooling circuit 31, when the exhaust gases of the engine 23 pass through the end portion 42. In particular, the gas circuit is arranged to cause, by jet pump effect, a suction of the airflow cooling the heat exchanger 33, when the exhaust gases of the engine 23 pass through the end portion 42.

[0054] The jet pump effect is also known in the art by its English equivalent, "jet pump effect". This effect refers to the fact that a fluid flow creates a low-pressure zone, which tends to draw other fluids into this flow.

[0055] When the engine 23 is running, it emits exhaust gases. These exhaust gases are received in the exhaust pipe 47 of the engine circuit 46. This exhaust pipe 47 guides the exhaust gases towards the end portion 42 of the outlet pipe 41, as shown by arrow 83. When the exhaust gases pass through the end portion 42, this creates a jet pump effect, which generates a suction of air at the gas inlet 11. This effect results in both the suction of air into the supply pipe 45 of the engine circuit 46, as shown by arrow 81, and the suction of air into the inlet pipe 51 of the air circuit, as shown by arrow 89. The air drawn into the inlet pipe 51 then enters the enclosure 49, where this air cools the cooling circuit 31, during a heat transfer carried out by the heat exchanger 33.This air then circulates in enclosure 49, as represented by arrows 87, until it reaches the end portion 42. This air is then evacuated through the discharge pipe 41, as are the exhaust gases from the engine 23.

[0056] Here, the discharge pipe 41 has a variable cross-section. In particular, the end portion 42 has a cross-section that gradually decreases in the direction of gas flow in the gas circuit. This configuration of the end portion 42 helps to limit pressure losses in the flow at the inlet of the discharge pipe 4L. Here, the discharge pipe 41 also has a constant cross-section portion 43, which fluidly connects the end portion 42 to the gas outlet 13.

[0057] Thanks to the invention, efficient dissipation of the heat emitted by the power electronics 21 is ensured, even when the aircraft is stationary. The airflow generated by the jet pump effect creates an air circulation with a flow rate sufficient to cool the cooling circuit 31. In particular, this air flow rate is sufficient to dissipate heat with a thermal power on the order of several tens of kilowatts.

[0058] The air circulation flow rate depends on structural arrangements of system 10.

[0059] This flow rate depends on the arrangement of the exhaust pipe 47 and the portion end 42 of the exhaust pipe 4L For example, the flow rate depends on the ratio between the cross-section at the outlet of the exhaust pipe 47 and the cross-section at the inlet of the end portion 42. Preferably, as here, this ratio is on the order of 1:2.

[0060] Furthermore, the flow rate depends on the relative position of the exhaust pipe 47 and the end portion 42. Here, the distance between the outlet of the pipe The exhaust pipe 47 and the inlet of the end portion 42 are zero. Alternatively, the exhaust pipe 47 may be disposed, at least partially, through the end portion 42, over a length substantially equal to the diameter of the section at the inlet of the end portion 42. Alternatively again, the outlet of the exhaust pipe 47 may be disposed at a distance from the inlet of the end portion 42 substantially equal to the diameter of the section at the inlet of the end portion 42. Alternatively still, the exhaust pipe 47 and the end portion 42 may be in a relative position intermediate between those described above.

[0061] The airflow rate also depends on the sizing of the gas inlet pipes 11. For example, the flow rate depends on the ratio between the cross-sectional area of ​​the supply pipe 45 of the engine circuit 46 and the cross-sectional area of ​​the inlet pipe 51 of the air circuit. Preferably, as in this case, the supply pipe 45 of the engine circuit 46 has a smaller cross-sectional area than the inlet pipe 51 of the air circuit.

[0062] These structural arrangements contribute to generating, by jet pump effect, an air circulation with a flow rate sufficient to cool the cooling circuit 31.

[0063] The airflow rate also depends on the engine speed 23. In particular, when the engine 23 is running at a high speed, there is a concomitant increase in the heat released by the power electronics 21 and in the airflow rate in the gaseous circuit.

[0064] The operation of the hybrid power unit in the engine block 17 causes the air present in this engine block 17 to heat up.

[0065] In this embodiment, the heat exchanger 33 is located near the gas inlet 11. This arrangement allows the heat exchanger 33 to be exposed to an outside temperature airflow, in particular before this air is heated by its passage through the engine block 17.

[0066] In addition, the use of the engine block 17 to delimit one of the air circuit ducts allows the air circulation cooling the cooling circuit 31 to also ensure air renewal inside the engine block 17. This provides ventilation of the enclosure 49.

[0067] Reference is made to [Fig.2].

[0068] This figure represents a second embodiment of the electrical power generation system according to the invention. This second embodiment differs from the first embodiment essentially in the arrangement of its cooling circuit, in particular the arrangement of its heat exchanger. The elements analogous to those described in relation to [Fig. 1] bear the same numerical references.

[0069] In this second embodiment, the heat exchanger 33 is located near the end portion 42 of the discharge pipe 41. The cooling loop 35 is longer than that of the first embodiment.

[0070] The arrangement of the end portion 42 is further modified to form a clearance 44 near the heat exchanger 33. This clearance 44 makes it easier to integrate the heat exchanger 33. This clearance 44 also makes it possible to increase the air circulation around the heat exchanger 33, and therefore to cool it more efficiently.

[0071] Reference is made to [Fig.3].

[0072] This figure represents a third embodiment of a jet pump-effect electrical power generation system. The elements analogous to those described in relation to [Fig. 1] bear the same numerical references.

[0073] This third embodiment differs from the first embodiment by the arrangement of its cooling circuit 31, in particular the arrangement of its heat exchanger 33, and by the arrangement of its gaseous circuit.

[0074] In this third embodiment, the heat exchanger 33 and part of the cooling loop 35 are located outside the engine block 17. The heat exchanger 33 and this part of the cooling loop 35 are located between the engine block 17 and the fairing portion 15. The heat exchanger 33 is located near the gas inlet 11. The engine block 17 has, for example, bores arranged to allow the passage of the cooling loop 35. The cooling loop 35 connects the power electronics 21, housed inside the engine block 17, and the heat exchanger 33, located outside the engine block.

[0075] In this third embodiment, the gaseous circuit comprises a main circuit and a secondary circuit, distinct from each other.

[0076] The main circuit is arranged to serve the engine 23 and provide ventilation for the engine block 17. The main circuit fluidly connects the gas inlet 11 to the gas outlet 13. The main circuit includes the exhaust pipe 41, in particular its end portion 42. The main circuit further includes the engine circuit 46 as described in relation to [Fig. 1].

[0077] The main circuit further includes an inlet duct 151, structurally analogous to the inlet duct described in relation to [Fig. 1]. The main circuit further includes an enclosure 149, structurally analogous to the enclosure described in relation to [Fig. 1]. The inlet duct 151 and the enclosure 149 of the third embodiment have different functions from those described for the inlet duct and the enclosure of the first embodiment. Unlike what was described in relation to [Fig. 1], the airflow entering through the inlet duct 151, as represented by arrow 99, then which circulates in enclosure 149, as represented by arrows 97, is solely intended for the ventilation of the engine block 17. This airflow does not ensure the cooling of the cooling circuit 31. In particular, this airflow does not ensure the cooling of the heat exchanger 33, which is located outside enclosure 149.

[0078] The secondary circuit is arranged to ensure the cooling of the cooling circuit 31. In particular, the secondary circuit is arranged to receive the air circulation cooling the heat exchanger 33. The secondary circuit fluidly connects the gas inlet 11 to the gas outlet 13. The secondary circuit includes an air duct 53, which fluidly connects the gas inlet 11 to the gas outlet 13. Here, the air duct 53 is delimited, in part, by the fairing portion 15, the engine block 17, the exhaust duct 41, the inlet duct 151 and the supply duct 45.

[0079] The fairing portion 15 may, as here, have, on the gas inlet 11, another projecting part forming a second deflector 20. The fairing portion 15 may, as here, have, on the gas outlet 13, a projecting part forming a third deflector 18. The second deflector 20 and the third deflector 18 are arranged to partially delimit the air duct 53.

[0080] When the exhaust gases from the engine 23 pass through the end portion 42 of the discharge pipe 41, a first jet pump effect, similar to that described in relation to [Fig. 1], causes both an air intake in the supply pipe 45, as represented by arrow 81 and an air intake in the inlet pipe 151, as represented by arrow 99. To a lesser extent, this first jet pump effect also causes an air intake in the air pipe 53, as represented by arrow 189.

[0081] Furthermore, when the exhaust gases exit the exhaust pipe 41, this results in a second jet pump effect at the gas outlet 13. This second jet pump effect contributes to drawing air into the air pipe 53 at the gas inlet 11.

[0082] The air drawn into the air duct 53, represented by arrow 189, cools the heat exchanger 33, then flows along the air duct 53, as represented by arrows 187. This air is then discharged through the gas outlet 13.

[0083] The arrangement of the heat exchanger 33 between the engine block 17 and the fairing portion 15 makes it possible to reduce the size of the system 10.

[0084] The invention is not limited to the embodiments described above, but encompasses all variants conceivable by a person skilled in the art.

Claims

Demands

1. An electrical power generation system for a hybrid-powered aircraft, the system comprising: - a combustion engine (23) arranged to provide mechanical power, - power electronics (21) arranged to convert the mechanical power supplied by the engine (23) into electrical power for aircraft propulsion, - a heat exchanger (33) connected to the power electronics (21), - a gas inlet (11) and a gas outlet (13), - a gas circuit fluidly connecting the gas inlet (11) to the gas outlet (13), the gas circuit opening onto the gas outlet (13) at least by means of a discharge line (41), this discharge line (41) having an end portion (42) opposite the gas outlet (13), the gas circuit comprising a first circuit,arranged to supply the engine (23) with air from the gas inlet (11) and to discharge exhaust gases from the engine (23) to the end portion (42) of the discharge pipe (41), the gas circuit further comprising a second circuit, fluidly connecting the gas inlet (11) to the end portion (42) of the discharge pipe (41), the second circuit being arranged to receive an airflow from the gas inlet (11) suitable for cooling the heat exchanger (33), this airflow being generated by jet pump effect when the exhaust gases pass through the end portion (42) of the discharge pipe (41).

2. System according to claim 1, wherein the power electronics (21) is suitable for supplying electrical power between 100 kW and 1 MW.

3. System according to any one of claims 1 and 2, wherein the power electronics (21) is suitable for operating at voltages between 500 V and 800 V.

4. System according to any one of claims 1 to 3, wherein the motor (23) and the power electronics (21) are designed to operate continuously while the aircraft is in flight.

5. System according to any one of claims 1 to 4, further comprising an engine block (17), housing the engine (23), the power electronics (21) and the heat exchanger (33), the engine block (17) delimiting, at least in part, a conduit for the second circuit, and the air circulation suitable for cooling the heat exchanger (33) being further suitable for ensuring air renewal inside the engine block (17).

6. System according to any one of claims 1 to 5, wherein the first circuit comprises an exhaust pipe (47), arranged to evacuate exhaust gases from the engine (23) to the end portion (42) of the discharge pipe (41).

7. System according to claim 6, wherein a ratio between an outlet section of the exhaust pipe (47) and an inlet section of the end portion (42) is of the order of 1:

2.

8. System according to any one of claims 6 and 7, wherein the distance between an outlet of the exhaust pipe (47) and an inlet of the end portion (42) is substantially zero.

9. System according to any one of claims 1 to 8, wherein the heat exchanger (33) is disposed near the gas inlet (11), at a distance from the end portion (42) of the discharge pipe (41).

10. System according to any one of claims 1 to 8, wherein the end portion (42) of the discharge pipe (41) has a clearance (44), the heat exchanger (33) being disposed near this clearance (44).

11. Hybrid power source aircraft, comprising the system of any one of claims 1 to 10.

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