DEVICE AND METHOD FOR SUPPLYING NON-PROPULSIVE POWER TO AN AIRCRAFT
Patent Information
- Application Number
- FR2012058682
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2012-09-17
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2032-09-17
Smart Images
Figure 00000013_0000 
Figure 00000013_0001 
Figure 00000013_0002
Abstract
Description
GENERAL TECHNICAL FIELD AND PRIOR ART The present invention relates to the field of providing non-propulsive power for an aircraft, including the production of electrical and pneumatic power, enabling the pressurization and air conditioning of a passenger cabin of an aircraft. The temperature and pressure regulation of a passenger cabin is conventionally carried out by a system known to those skilled in the art under its English designation ECS for "Environmental Control System". When the main engines of the aircraft are stopped, the supply of pneumatic and / or electrical power is ensured by an auxiliary power unit known to those skilled in the art under the English designation APU for "Auxiliary Power Unit". In simplified terms, with reference to Figure 1A, an ECS system 1 is adapted to take a flow of ambient air Aamb from the aircraft with external pressure PO and external temperature T0 in order to cool it or heat it before distributing it into a passenger cabin 2. In practice, with reference to Figure 1A, an ECS system 1 comprises a load compressor 11 and a turbine 12 connected by a connecting shaft 13, a heat exchanger 14 and a condenser 15. In operation, the ECS system 1 draws air AM from the aircraft's main engines to rotate the load compressor 11. The load compressor 11 draws ambient air Aamb via a supply valve 17 and compresses it in the heat exchanger 14 to regulate its temperature and then in the condenser 15 to dehumidify it. The cooled air flow then expands in the cold turbine 12 before being conveyed into the passenger cabin 2 as illustrated in FIG. 1A. Optionally, after circulation in the passenger cabin 2, the air from the passenger cabin 2 can be introduced into a mixer 16 with ambient air Aamb, the mixture then being sucked in by the load compressor 11 in order to improve the efficiency of the ECS system 1 by limiting the quantity of air AM taken from the main engines. The power draw of the ECS 1 system from the main engines penalizes, on the one hand, the aircraft's fuel consumption and, on the other hand, the configuration of the main engines which must be adapted to cooperate with the ECS 1 system. In practice, for reliability reasons, the ECS 1 system is redundant in an aircraft which increases the constraints relating to the main engines. With reference to Figure 1B, it has been proposed to drive the ECS system 1 by means of an electric motor 3 in order to avoid taking power from the main engines of the aircraft. However, such an electric drive has a low energy efficiency, which is a disadvantage. GENERAL PRESENTATION OF THE INVENTION To eliminate at least some of these drawbacks, the invention relates to a device for supplying non-propulsive power for an aircraft, the device comprising: an auxiliary power unit comprising a power compressor, a combustion chamber and a power turbine connected to said power compressor by a power shaft; and an environmental control system which includes a regulated air distribution turbine for an aircraft cabin and a charge compressor connected to the distribution turbine by a connecting shaft. The device according to the invention is autonomous and integrates the functions of an auxiliary power unit APU, but also of an ECS environment control system, which is advantageous. The invention is remarkable in that the environmental control system comprises a free drive turbine integral with the connecting shaft and in that the environmental control system and the auxiliary power unit are configured so that the power turbine provides an air flow to the free drive turbine so as to drive the load compressor integral with the connecting shaft. Typically, an aircraft has an auxiliary power unit, known by its English abbreviation APU, to provide pneumatic or electrical power to the aircraft's equipment when the aircraft is on the ground and its turbojet engines are not running. During aircraft flight, the APU is not used and is considered "dead weight". Advantageously, the power unit and the environmental control system are coupled in order, on the one hand, to limit the draws on the aircraft's main engines and, on the other hand, to fully utilize the capabilities of the APU power unit, which was traditionally only used at start-up. In addition, the APU power unit can supplement the power supply of the ECS system, which no longer necessarily has to be redundant. The aircraft's efficiency is thus improved. In the prior art, the APU power unit and the ECS system are traditionally considered as separate functional modules, i.e., devoid of interactions. This technical prejudice translates concretely into a clear differentiation in the specificities of the aircraft manufacturers who consider the APU power unit and the ECS system as belonging to different and distant functional classes. The APU power unit and the ECS system belong respectively to the ATA 49 and ATA 21 functional classes well known to those skilled in the art. Preferably, the non-propulsive power device is mounted in the same housing of an aircraft. Thus, the cooperation between the APU power unit and the ECS system is not only functional but also physical in order to be able to reduce the size of the control device while allowing high-efficiency coupling. Preferably, the power turbine and the free turbine are separated by a distance of less than 30 cm so as to allow efficient pneumatic coupling. Preferably, the auxiliary power unit comprises a starter / power generator adapted to rotate the power shaft. More preferably, the starter / power generator is adapted to generate electrical energy when the power turbine is rotated. The starter / generator thus makes it possible to start the APU power unit and to provide additional electrical power to the ECS system in case of additional compressed air requirement. In addition, the starter / generator advantageously makes it possible to store electrical energy during autonomous operation of the APU power unit, which improves the energy efficiency of the control device. Advantageously, the environmental control system comprises an accessory starter / generator adapted to rotate the connecting shaft. Preferably, the accessory starter / generator of the environmental control system is electrically connected to the auxiliary power unit, preferably to the power starter / generator. Thus, the accessory starter / generator makes it possible to provide surplus energy to the ECS system depending on the compressed air requirements. According to a preferred aspect of the invention, the regulation device comprises means for venting the free drive turbine so as to allow rotation of the free drive turbine when the ECS system is powered by auxiliary energy sources other than the auxiliary power unit. Preferably, the free drive turbine is mounted directly near the load compressor on the connecting shaft, which makes it possible to limit the size and complexity of the ECS system. Preferably, the regulating device comprises compressed air supply means and / or electricity supply means arranged to rotate the free drive turbine of the environmental control system. The invention further relates to a method for regulating an aircraft passenger cabin, the aircraft comprising an environmental control system which comprises a turbine for distributing regulated air intended for an aircraft cabin and a load compressor connected to the distribution turbine by a connecting shaft and an auxiliary power unit comprising a power compressor, a combustion chamber and a power turbine connected to said power compressor and to a free drive turbine by a power shaft, in which method the power turbine of the auxiliary power unit provides an air flow to the free drive turbine so as to drive the load compressor secured to the connecting shaft. PRESENTATION OF FIGURES The invention will be better understood on reading the following description, given solely by way of example, and referring to the appended drawings in which: Figure 1A is a simplified schematic representation of a prior art ECS system driven by AM air from the aircraft's main engines (already discussed); Figure 1B is a simplified schematic representation of a prior art ECS system driven by a dedicated electric motor (already commented on); Figure 2 is a schematic representation of a non-propulsive power supply device for an aircraft according to the invention comprising an ECS system coupled to an auxiliary power unit; Figure 3 is a schematic representation of the non-propulsive power supply device according to the invention according to a first mode of implementation (MODE-A) in which the operation of the device is autonomous; Figure 4 is a schematic representation of the non-propulsive power supply device according to the invention according to a second embodiment (MODE-T) in which the auxiliary power group supplies pneumatic energy and electrical energy to drive the ECS system; Figure 5 is a schematic representation of the non-propulsive power supply device according to the invention according to a third embodiment (MODE-E) in which the device is powered by an auxiliary electrical source, the auxiliary power group not being active; and Figure 6 is a schematic representation of the non-propulsive power supply device according to the invention according to a fourth mode of implementation (MODE-P) in which the device is powered by an auxiliary pneumatic source, the auxiliary power group not being active. It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate. DESCRIPTION OF ONE OR MORE METHODS OF EMBODIMENT AND IMPLEMENTATION The invention will be presented for an aircraft comprising one or more main engines in order to enable the aircraft to move. The aircraft further comprises a passenger cabin which must be regulated in pressure and / or temperature. With reference to FIG. 2, a non-propulsive power supply device 10 will be presented. The non-propulsive power supply device 10 comprises an environmental control system 1, known to those skilled in the art as the ECS system, and an auxiliary power unit 4, known to those skilled in the art as the APU unit. According to the invention, the ECS system 1 and the APU unit 4 are coupled so that the APU unit 4 supplies power to the ECS unit 1 and thus reduces its power draws from the main engines of the aircraft. ECS System 1 As illustrated in Figure 2, the ECS system 1 comprises a turbine 12 for distributing regulated air Areg intended for the aircraft cabin 2 and a load compressor 11 connected to the distribution turbine 12 by a connecting shaft 13. Preferably, the ECS system 1 comprises a heat exchanger 14 and a condenser 15 so that the ambient air Aamb taken by the load compressor 11 via supply means 17 can be regulated in temperature by the heat exchanger 14 and dehumidified by the condenser 15 in order to obtain a flow of regulated air Areg capable of being introduced into the passenger cabin 2. Preferably, the ECS system 1 comprises an accessory starter / generator 18 mounted on the connecting shaft 13 of the ECS system 1 so as to be able, on the one hand, to drive the connecting shaft 13 in rotation during a “starter” operation from its electrical energy reserves, and, on the other hand, to accumulate electrical energy during the rotation of the connecting shaft 13 (“generator” operation). Advantageously, in starter operation, the accessory starter / generator 18 makes it possible to precisely regulate the pressurized air supply to the passenger cabin 2. The supply means 17 are in this example in the form of a supply valve 17 but it goes without saying that other means could be suitable. More preferably, the ECS system 1 comprises a mixer 16 adapted to mix the ambient air flow Aamb coming from the supply valve 17 with an air flow coming from the passenger cabin 2. Such a recirculation of the air flow from the passenger cabin 2 advantageously improves the efficiency of the ECS system 1. APU Group 4 Still with reference to Figure 2, the APU group 4 of the non-propulsive power supply device 10 comprises a power compressor 41, a combustion chamber 44 and a power turbine 42 connected to said power compressor 41 by a power shaft 43. In other words, the APU group 4 forms a gas generator and allows the electrical and / or pneumatic supply of equipment of the aircraft. Preferably, the APU group 4 comprises a starter / power generator 46 mounted on the power shaft 43 of the APU group 4 so as to be able, on the one hand, to drive the power shaft 43 in rotation during “starter” operation from its electrical energy reserves, and, on the other hand, to accumulate electrical energy during the rotation of the power shaft 43. Preferably, the starter / power generator 46 is mounted on the power shaft 43 via a relay box 45, i.e., a multiplier, so as to adapt the rotational speed of the power shaft 43 to that of the starter / power generator 46. Thus, the starter / power generator 46 can be driven by the power shaft 43 to generate electrical energy or drive the power shaft 43, i.e., generate mechanical energy from electrical energy. According to one aspect of the invention, the accessory starter / generator 18 of the ECS system 1 is electrically connected to the APU group 4, preferably to its power starter / generator 46 so as to allow electrical drive of the connecting shaft 13 of the ECS system 1 as will be detailed later. Furthermore, the accessory starter / generator 18 of the ECS system 1 can also be electrically connected to electrical services of an airport as will be detailed later. Since the APU and ECS system each have a starter / generator 18, 46, the speed of each shaft can be freely regulated to reactively adapt to the needs of the non-propulsive power supply device 10. Conventionally, such an APU 4 group is only used during ground phases, that is to say, before the actual ignition of the main engines of the aircraft, as well as after their shutdown. The APU 4 group and the ECS 1 system are conventionally separate devices which do not interact with each other when the aircraft is in flight. According to the invention, the APU 4 group and the ECS 1 system cooperate during a flight of the aircraft in order to limit the power draws on the engines main components of the aircraft and thus increase the aircraft's energy efficiency. In addition, this makes it possible to form a device with limited size and mass. According to the invention, the ECS system 1 comprises a free drive turbine 5 secured to the connecting shaft 13 as illustrated in FIG. 2. The ECS system 1 and the APU group 4 are configured so that the power turbine 42 provides an air flow AApu to the free drive turbine 5 so as to drive the load compressor 11 secured to the connecting shaft 13. The air expelled from the combustion chamber 44 of the APU group 4 expands in the power turbine 42 then in the free turbine 5 as illustrated in Figure 2. Thus, the energy from the combustion chamber 44 participates, on the one hand, in driving the power compressor 41 of the APU group 4 and, on the other hand, in driving the load compressor 11 of the ECS system 1. Preferably, the non-propulsive power supply device 10 comprises means 63 for supplying auxiliary air Aaux to the free turbine 5. Auxiliary air Aaux is understood to mean an air flow originating, for example, from the main engines of the aircraft or supplied by airport services. In this example, the means 63 for supplying auxiliary air Aaux are in the form of a supply valve. Preferably, the regulating device 10 comprises means 64 for venting the free turbine 5 when the APU group 4 is not activated. In this example, the venting means 64 are in the form of a venting valve. More preferably, the non-propulsive power supply device 10 comprises a mixer 62 arranged to mix an air flow from the auxiliary air supply means 63 Aaux, an air flow from the venting means 64 and an air flow AApu from the power turbine 42. Preferably, the non-propulsive power supply device 10 comprises means 61 for regulating the air flow Aapu supplied by the power turbine 42 to the mixer 62, preferably a regulating valve. Whereas, in the prior art, the APU power unit 4 and the ECS system 1 were several meters apart from each other in the aircraft, the invention proposes to bring them together in order to form a non-propulsive power supply device 10 of low mass and limited size. According to one aspect of the invention, the APU power unit 4 and the ECS system 1 belong to the same housing of the aircraft, the housing being able to be unitary or compartmentalized. Preferably, the power turbine 42 of the APU unit 4 and the free turbine 5 of the ECS system 1 are separated by a distance of less than 30 cm, preferably of the order of 5 cm. The proximity of the power turbine 42 of the APU group 4 with the free turbine 5 of the ECS system 1 makes it possible to take advantage effectively of the expansion of the gases coming from the combustion chamber 44 of the APU group. Preferably, the free drive turbine 5 is mounted directly near the load compressor 11 on the connecting shaft 13, that is to say without intermediary, so as to limit the size and complexity of the non-propulsive power supply device 10. The invention will be better understood with reference to Figures 3 to 6 which show different modes of implementation of the invention. Autonomous operation (MODE-A) With reference to Figure 3, in autonomous operation, the APU group 4 is active. The power compressor 41 draws in ambient air Aamb which is conducted and compressed in the combustion chamber 44. The gases from the combustion chamber 44 are expanded in the power turbine 42. Downstream of the power turbine 42, an air flow AApu is received by the free drive turbine 5 in order to drive the load compressor 11 of the ECS system 1 via the connecting shaft 13. In other words, the energy of the air flow Aapu is taken advantage of to supply energy to the ECS system 1 and thus avoid taking energy from the main engines of the aircraft. The load compressor 11 draws in outside air Aamb via the supply means 17 which is conducted and compressed in the exchanger 14 and cooled by an outside air flow Aext. Once cooled, the air flow is dried by the condenser 15 before being expanded in the distribution turbine 12 to then be conducted into the passenger cabin 2. Recirculated air from the passenger cabin 2 can also be taken by the load compressor 11. The mixer 16 can also adapt the proportion of ambient air Aamb in the air drawn in by the load compressor 11. Advantageously, during MODE-A, the starter / power generator 46 of the APU group 4, after having been used to start the assembly, can supply electrical energy via the relay box 45. Preferably, the starter / power generator 18 of the ECS system 1 can also supply electrical energy. In this example, the auxiliary air supply means 63 and the venting means 64 are closed. In MODE-A autonomous operation, the ECS 1 system is pneumatically powered by the APU 4 group. This pneumatic energy is transformed by the free turbine drive 5 in one rotation of the connecting shaft 13. The APU group is thus used when starting the aircraft but also during flight. Operation with electrical energy transfer (MODE-T) With reference to Figure 4, in electrical energy transfer operation, the APU group 4 is active and the gases from the combustion chamber 44 are expanded in the power turbine 42. In a similar manner to MODE-A, downstream of the power turbine 42, an air flow AApu is received by the free drive turbine 5 in order to drive the load compressor 11 via the connecting shaft 13. Advantageously, during MODE-T, the power starter / generator 46 electrically powers the accessory starter / generator 18 of the ECS system 1 so as to accelerate the drive speed of the connecting shaft 13. In other words, if the ECS system 1 requires, for particular conditions, a significant amount of energy, the power starter / generator 46 can provide electrical energy which supplements the pneumatic energy supplied by the power turbine 42, which is very advantageous. The connecting shaft 13 thus receives a temporary power “boost”, which is advantageous in the flight phases of the aircraft where the need for pressurized air is significant (so-called “pull-up” or “pull-down” phases). In this example, the auxiliary air supply means 63 and the venting means 64 are closed. In MODE-A autonomous operation, the ECS system 1 is powered pneumatically and electrically by the APU group 4. Advantageously, it is not necessary to oversize the non-propulsive power supply device 10 to respond to transient forces, the surplus electrical energy supplied by the APU group 4 making it possible to absorb the transient forces. Electric operation (MODE-E) Referring to Figure 5, in electrical operation, the APU 4 group is inactive. The ECS 1 system is driven by the accessory starter / generator 18 which is electrically powered by an auxiliary electrical source, for example, from the electrical services of an airport. Thus, when operating in electric mode, the connecting shaft 13 is driven by the auxiliary electrical source Water. Since the free drive turbine 5 is integral with the connecting shaft 13, it is important to vent the free drive turbine 5 in order to avoid any malfunction in the absence of air supply to the APU group 4. For this purpose, the valve vent 64 is open in electrical operation while the auxiliary air supply means 63 remain closed. In MODE-E electric operation, the ECS 1 system is electrically powered by an auxiliary electrical source, which is advantageous and does not draw on any resources specific to the aircraft. Pneumatic operation (MODE-P) Referring to Figure 6, in pneumatic operation, the APU group 4 is inactive. The ECS system 1 is driven by the free drive turbine 5 via an auxiliary pneumatic source Aaux, for example, compressed air supply services of an airport. Thus, during operation in pneumatic mode, the free drive turbine 5 is driven by the auxiliary pneumatic source Aaux. For this purpose, the auxiliary air supply means 63 are open in pneumatic operation while the venting means 64 remain closed. In MODE-P pneumatic operation, the ECS 1 system is pneumatically powered by an auxiliary pneumatic source Aaux. This pneumatic power source can be either external to the aircraft (e.g. airport services) or come from a compressed air source integrated into the aircraft (main engines, cabin pressurization recovery, etc.).
Claims
CLAIMS 1. Method for providing non-propulsive power to an aircraft, comprising driving a shaft (13) of an environmental control system (1) of the aircraft by a combination of energy sources chosen from: an auxiliary power unit (4), said auxiliary power unit (4) generating an air flow for driving a free turbine (5) secured to the shaft (13) of the environmental control system (1) a starter / generator (18), in starter operation, and auxiliary air supply means (63), said auxiliary air supply means (63) driving the free turbine (5) secured to the shaft (13) of the environmental control system (1).
2. Method according to claim 1, in which the starter / generator (18) is, in starter operation, supplied with electricity by electrical supply means, such as electrical services of an airport, or the electrical network of the aircraft.
3. Method according to one of claims 1 or 2, in which the starter / generator (18) is, in starter operation, supplied with electricity by a generator / starter (46) of the auxiliary power group (4).
4. Method according to one of claims 1 to 3, in which the auxiliary air supply means (63) are formed by the main engines of the aircraft or by air supply services of an airport.
5. Device for supplying non-propulsive power to an aircraft, the device comprising: an auxiliary power unit (4) comprising a power compressor (41), a combustion chamber (44) and a power turbine (42) connected to said power compressor (41) by a power shaft (43); an environmental control system (1) which comprises a turbine (12) for distributing regulated air (Areg) intended for an aircraft cabin (2) and a load compressor (11) connected to the distribution turbine (12) by a connecting shaft (13); the environmental control system (1) comprising a free drive turbine (5) secured to the connecting shaft (13), and the environmental control system (1) and the auxiliary power unit (4) being configured so that the power turbine (42) provides an air flow (Aapu) to the free drive turbine (5) so as to drive the load compressor (11) secured to the connecting shaft (13), device characterized by the fact that it further comprises at least any one of the following energy sources: - an accessory starter / generator (18) adapted to drive the connecting shaft (13) in rotation, and - auxiliary air supply means (63) arranged to rotate the free drive turbine (5) of the environmental control system so as to drive the load compressor (11) secured to the connecting shaft (13).
6. Device according to claim 5, wherein the environmental control system (1) comprises an accessory starter / generator (18) adapted to rotate the connecting shaft (13).
7. Device according to claim 6, wherein the accessory starter / generator (18) of the environmental control system (1) is electrically connected to the auxiliary power group (4).
8. A method of providing non-propulsive power to an aircraft by means of a device according to one of claims 5 to 7, wherein the connecting shaft is driven by at least one of the following power sources: - the auxiliary power unit (4), the power turbine (42) of which supplies an air flow (Aapu) to the free drive turbine (5) so as to drive the load compressor (11) secured to the connecting shaft (13), or - the accessory starter / generator (18) of the environmental control system (1), and - the supply means (63) which provide an auxiliary air flow to the free drive turbine (5) of the environmental control system (1) so as to drive the load compressor (11) secured to the connecting shaft (13).