Turbomachine hybrid autonomous

Abstract

Autonomous hybrid turbomachine Double-spool turbomachine, comprising a low-pressure turbine (5) connected to a low-pressure compressor (1) by a low-pressure rotation shaft (10) and a high-pressure turbine (4) connected to a high-pressure compressor (2) by a high-pressure rotation shaft (9), the turbomachine (11) also comprising a mechanical power injection device (13) on at least one of the rotation shafts (9, 10).The turbomachine (11) comprises capacitive components (15) adapted to supply the turbomachine (11) with electrical energy through said mechanical power injection device (13), said capacitive components (15) being arranged on the turbomachine (11) or on a support structure of the turbomachine (11) and arranged to form at least one pair of concentric circles (17) centered on a main axis (A) of the turbomachine (11), the circles of capacitive components (15) being radially in the vicinity of each other. Figure to be published with the abstract: 2.

Description

Title of the invention: Autonomous hybrid turbomachine Technical field of the invention

[0001] The field of the invention is that of aeronautical turbomachines, and in particular that of aircraft engines produced in the form of twin-spool, twin-flow turbojets. More particularly, the invention relates to a turbomachine of this type, hybrid and autonomous, for aircraft. State of the prior art

[0002] Thermal / electric hybridization of an aircraft turbomachine is a new way of improving the behavior and performance of these turbomachines.

[0003] This hybridization consists, through electrical machines installed on the rotating shafts of the turbomachine, of injecting or taking mechanical power at certain times and at a certain level.

[0004] A key requirement of conventional aircraft propulsion turbomachines is to guarantee a maximum rise time not to be exceeded between an idle speed, in which the engine exerts only low thrust, and a maximum speed, in which the engine thrust is maximum.

[0005] A conventional double-spool, double-flow, fan turbomachine is shown schematically in [Fig.l].

[0006] It conventionally comprises, from upstream to downstream in the direction of gas flow, a fan S, a low pressure compressor 1, a high pressure compressor 2, a combustion chamber 3 which receives a fuel flow Qc, a high pressure turbine 4, a low pressure turbine 5 and a primary exhaust nozzle 6.

[0007] The low pressure compressor 1 and the low pressure turbine 5 are connected by a low pressure shaft 10 and together form a low pressure body.

[0008] The high-pressure compressor 2 and the high-pressure turbine 4 are connected by a high-pressure shaft 9 and together with the combustion chamber form a high-pressure body.

[0009] The fan S, which is driven by the low-pressure shaft 10, either directly or via a reducer, compresses the air coming from the air inlet. This air is divided downstream of the fan S between a secondary air flow which is directed directly towards a secondary nozzle (not shown) through which it is ejected to contribute to the thrust provided by the turbomachine, and a so-called primary flow which enters the gas generator, consisting of the low- and high-pressure bodies, and which is then ejected into the primary nozzle 6.

[0010] Conventionally, it is known to install electrical generators in the turbomachine to power the on-board electrical network. These generators are driven by the high-pressure shaft 9 through an accessory box in order to convert mechanical energy into electrical energy intended for the secondary systems on board the aircraft.

[0011] A variant may consist of replacing at least one of the electric generators with at least one starter in order to ensure the starting of the turbomachine from electrical energy. The starting is done by controlling the electric starter via a converter located either in the engine zone or in the cabin zone, powered by a source external to the turbomachine to be started. This source may be either a ground-based ground generator or another on-board electrical source which has been previously put into service (auxiliary power generator, electric generator of the other turbomachines). Once the turbomachine has started, the electric starter changes mode to operate exclusively as an electric generator.

[0012] However, the use of such a system to assist the turbomachine by providing a significant quantity of electrical energy is not always satisfactory because it requires the use of a high-capacity electrical energy source located in the aircraft area and associated electrical connections, which generates significant bulk and high electrical losses. Presentation of the invention

[0013] The invention aims to overcome these drawbacks by providing an autonomous hybrid turbomachine. To this end, the subject of the invention is a dual-flow twin-spool turbomachine for aircraft, comprising a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine and a low-pressure turbine, said low-pressure turbine being connected to said low-pressure compressor by a low-pressure rotation shaft and said high-pressure turbine being connected to said high-pressure compressor by a high-pressure rotation shaft, the turbomachine also comprising a device for injecting mechanical power onto at least one of said rotation shafts,

[0014] characterized in that the turbomachine comprises capacitive components adapted to supply the turbomachine with electrical energy through said mechanical power injection device, said capacitive components being arranged on the turbomachine or on a support structure of the turbomachine and arranged to form at least one pair of concentric circles, said pairs of circles being centered on a main axis of the turbomachine, the circles of capacitive components of the same pair of circles being radially in the vicinity of each other.

[0015] The capacitive components can in particular form two pairs of circles spaced apart axially from each other.

[0016] Said support structure may be a nacelle receiving the turbomachine.

[0017] Such a turbomachine allows autonomous hybrid operation, with a capacity for storing energy in electrical and / or electrochemical form, and for restoring energy to the propulsion system, arranged in the vicinity of the nacelle in order to limit the size and mass of the connections as well as electrical losses.

[0018] The power injection device can advantageously also operate as an electric generator.

[0019] The capacitive components may be supercapacitors, in particular carbon nanotube supercapacitors.

[0020] Such capacitive components have low internal resistance, making it possible to deliver high power over a short time, and thus to assist propulsion during critical phases such as during takeoff of the aircraft.

[0021] The power supplied may for example be of the order of 500 kW, delivered for a time of the order of one second.

[0022] Alternatively, the supercapacitors can be electrochemical double layer supercapacitors (also called EDLC, for electrochemical double layer capacitor in English), or hybrid supercapacitors (also called LIC, for Lithium Ion Capacitor in English).

[0023] The capacitive components may be connected in series and have an equivalent resistance less than or equal to 100 qOhm per capacitive component.

[0024] Such a characteristic makes it possible to maintain the voltage under which the electrical energy is restored greater than or equal to 400 V for the required time.

[0025] For each pair of capacitive component circles, the capacitive components of a radially inner circle may be arranged circumferentially offset by half the circumferential width of the capacitive components relative to the capacitive components of a radially outer circle.

[0026] Such an arrangement makes it possible to reduce the length of the connections between the capacitive components, by arranging the connectors of the capacitive components of the two circles radially in line with each other.

[0027] Each capacitive component may comprise an input connector and an output connector arranged on the same axial connection face of the capacitive component, the connection faces of the components of the same pair of circles being oriented in the same axial direction.

[0028] Such an arrangement makes it possible to further reduce the lengths of the connections between the capacitive components.

[0029] For each pair of concentric circles of capacitive components, the input and output connectors of each component of each of the circles are connected to output and input connectors, respectively, of components of the other circle, except for a first component and a last component of the pair of circles.

[0030] Such an arrangement makes it possible to connect in series all the capacitive components of the two circles with connections of short total length.

[0031] The turbomachine may comprise two pairs of circles of capacitive components, the connection faces of the capacitive components of each pair of circles being arranged opposite the connection faces of the capacitive components of the other pair of circles.

[0032] Such an arrangement makes it possible to simply connect in series the components of the two pairs of circles, and also to reduce the magnetic field effects generated by the circulation of electric current in the interconnections.

[0033] The turbomachine may comprise two pairs of concentric circles of capacitive components, the components of the two pairs of circles being connected in series together.

[0034] The interconnection between the two pairs of circles may be adapted to be electrically connected to an aircraft chassis to create a potential reference, and / or to be connected to an aircraft electrical network to serve as a ground reference.

[0035] The pairs of capacitive component circles can be connected in parallel to each other.

[0036] Such a feature makes it possible to make the system compatible with a 540V (+ / -270V) network or a 230 / 400 VAC network with fixed or variable frequency.

[0037] In this case, the pairs of circles can be successively offset to continue to guarantee the cancellation effect of the magnetic fields between the different interconnections of the capacitive components.

[0038] The invention also relates to a propulsion assembly comprising a turbomachine as above and at least one nacelle receiving the turbomachine, the capacitive components being arranged in a space delimited radially between an internal casing and an external casing of the nacelle.

[0039] The arrangement of the capacitive components in the nacelle makes it possible to benefit from an advantageous thermal environment and to have a short distance between the components and the power injection device. Brief description of the figures

[0040] [Fig-1] [Fig.l] is a schematic representation of a double turbomachine dual-flow body according to the state of the art,

[0041] [Fig.2] [Fig.2] is a schematic representation of a turbomachine according to the invention,

[0042] [Fig.3] [Fig.3] is an electrical diagram of an energy storage assembly of the turbomachine of [Fig.2],

[0043] [Fig.4] [Fig.4] is a schematic axial sectional view of a propulsion unit comprising a nacelle and the turbomachine of [Fig.2],

[0044] [Fig.5] [Fig.5] is a schematic radial sectional view of the energy storage assembly of [Fig.3],

[0045] [Fig.6] [Fig.6] is a schematic top view of the energy storage assembly of [Fig.5],

[0046] [Fig.7] [Fig.7] is an electrical diagram of an energy storage assembly according to another embodiment of the invention, and

[0047] [Fig.8] [Fig.8] is a schematic top view of an energy storage assembly according to another embodiment of the invention. Detailed description of the invention

[0048] [Fig. 2] represents a turbomachine 11 according to the invention, installed on an aircraft. The turbomachine 11, in a manner similar to that of [Fig. 1], comprises from upstream to downstream in the direction of gas flow, a fan S, a low pressure compressor 1, a high pressure compressor 2, a combustion chamber 3 which receives a fuel flow Qc, a high pressure turbine 4, a low pressure turbine 5 and a primary exhaust nozzle 6.

[0049] The low pressure compressor 1 and the low pressure turbine 5 are connected by a low pressure shaft 10 and together form a low pressure body.

[0050] The high-pressure compressor 2 and the high-pressure turbine 4 are connected by a high-pressure shaft 9 and together form, with the combustion chamber 3, a high-pressure body.

[0051] The fan S, which is driven by the low-pressure shaft 10, either directly or via a reducer, compresses the air coming from the air inlet. This air is divided downstream of the fan S between a secondary air flow which is directed directly towards a secondary nozzle (not shown) through which it is ejected to contribute to the thrust provided by the turbomachine, and a so-called primary flow which enters the gas generator, consisting of the low- and high-pressure bodies, and which is then ejected into the primary nozzle 6.

[0052] The turbomachine 11 also comprises a mechanical power injection device 13 combined with the high-pressure shaft 9. Said mechanical power injection device 13 is capable of converting electrical power into mechanical power contributing to the rotation of the high-pressure shaft 9, and conversely capable of taking mechanical power from the high-pressure shaft 9 to convert it into electrical power for storage and / or for supplying loads 12 of the aircraft.

[0053] The injection device 13 is in particular capable of operating alternately as an electric motor and as a generator, depending on the flight phases of the aircraft, and of taking mechanical power from the high pressure shaft 9 to convert it into electrical power.

[0054] The injection device 13 is for example connected to the low pressure shaft by an accessory box (not shown) engaged on the high pressure shaft 9.

[0055] The turbomachine 11 also comprises an electrical energy storage assembly, said assembly comprising a power converter 14 and a plurality of capacitive type storage elements 15.

[0056] The energy storage elements 15 are in particular supercapacitors, for example carbon nanotube supercapacitors.

[0057] A typical order of magnitude for starting assistance for a turbomachine is the supply of power of the order of 500 kW for a duration of the order of 1 s, the total energy supplied is therefore of the order of 500 kJ. In this case, the sizing of the supercapacitor storage assembly is defined both by the power density of the capacitive components and by the energy density that they store.

[0058] In this respect, supercapacitors made with carbon nanotubes and graphene make it possible to increase electrical conductivity and thus divide by 10 (or more) the resistivity of the components, which allows the storage system to be adapted to operating cycles of the order of a second (instead of 10 to 20 seconds for conventional supercapacitors).

[0059] The storage assembly comprises, for example, 296 900F carbon nanotube supercapacitors connected in series, which makes it possible to obtain an equivalent series resistance (ESR) of less than 100 pOhms per component.

[0060] The energy storage assembly is shown schematically in [Fig. 3], which shows the electrical architecture of said assembly. The injection device 13 conventionally comprises an electrical machine 13a and an inverter 16, the latter being connected in parallel to the power converter 14, here a DC / DC type converter.

[0061] This converter 14, of the chopper type, is configured to control the power taken from or injected on the high pressure shaft 9 or delivered to the loads 12.

[0062] The energy storage assembly is also connected in parallel to the loads 12 of the aircraft.

[0063] As shown in [Fig.4], the energy storage assembly is entirely integrated away from the aircraft zone, and in particular entirely included in a nacelle 20 carrying the turbomachine 11 and forming with the turbomachine 11 an autonomous hybrid propulsion assembly.

[0064] The supercapacitors 15 are arranged circumferentially around a main axis A of the turbomachine 11. This makes it possible to reduce the length of the connections and therefore the total mass of the system, as well as the energy losses in said connections.

[0065] The supercapacitors 15 are in particular prismatic in shape and are distributed to form two pairs 17 of concentric circles in the nacelle 20. Said circles of supercapacitors 15 are in particular radially between an external casing 21 and an internal casing 22 of said nacelle 20, and are centered on the main axis A.

[0066] Such a flattened shape of the capacitors 15 makes it possible to obtain a thickness of a few centimeters (of the order of 5 cm in the example above) compatible with the aerodynamic dimensioning of the nacelle 20.

[0067] The location of the supercapacitors 15 in the nacelle 20 is advantageous since they benefit from a favorable thermal environment (unlike the temperatures in the engine which can reach several hundred degrees) and compatible with the supercapacitors.

[0068] The power electronics can be positioned in the compartment in the nacelle 20. The power injection device 13 is conventionally positioned on a power transmission box (AGB “Accessories Gear Box”) and the converter 14 can be advantageously positioned in the various locations situated between the super capacitors 15 and the power injection device 13.

[0069] One of the pairs 17 of circles is shown in detail in [Fig.5], in section in a plane orthogonal to the main axis A.

[0070] The supercapacitors 15 of the radially outer circle are circumferentially offset relative to the supercapacitors of the radially outer circle by half the circumferential width of the supercapacitors 15.

[0071] Each supercapacitor 15 has a substantially parallelepiped shape with an axial connection face 18 comprising a first connector 19a called the input connector and a second connector 19b called the output connector.

[0072] Thus, for each pair of circles 17, the input connectors 19a of the supercapacitors 15 of each circle are located radially in line with the output connectors 19b of the capacitors 15 of the other circle.

[0073] The input connectors 19a and output 19b of each capacitive component 15 of each of the circles are connected to output connectors 19b and input 19a, respectively, of capacitive components 15 of the other circle, with the exception of a first component 15a and a last component 15b of the pair of circles 17.

[0074] The first and last components 15a, 15b of each pair of circles 17 are the capacitive components 15 by which the capacitive half-block formed by the components 15 of the pair of circles is connected to the other half-block or to the converter 14.

[0075] This makes it possible to connect all the capacitors 15 of the pair of circles 17 in series with interconnections of minimal length. The interconnections connecting the input connectors 19a to the output connectors 19b are notably of the busbar type, and extend radially. This makes it possible to reduce the inductance and the total resistance of the interconnections.

[0076] Furthermore, as shown in [Fig.6], the offset arrangement of the concentric circles makes it possible to place the interconnections of the supercapacitors 15 of each pair 17 of circles axially opposite each other. A simple interconnection 23 between the 2 pairs of circles 17 facing each other makes it possible to connect the two “half-blocks” of capacitors 15 at their midpoint.

[0077] Thanks to this arrangement, the axially facing interconnections have opposite directions of current flow, one being "rising" radially while the other is "descending" radially (the terms rising and falling relating to the direction of current flow respectively away from the main axis A and towards the main axis A). This has the effect that the magnetic fields created by these facing interconnections are in opposition and tend to cancel each other out, which results in a strong reduction in the wiring inductance.

[0078] According to a variant shown in [Fig.7], the interconnection 23 between the two pairs of concentric circles 17 can be electrically connected to the chassis of the aircraft to create a potential reference, and / or be connected to the electrical network of the aircraft to serve as a ground reference.

[0079] According to another variant shown in [Fig.8], the two half-blocks constituted by the capacitors 15 of each of the two pairs of circles 17 can be connected in parallel, to make the system compatible with a 540V (+ / -270V) network or a 230 / 400 VAC network with fixed or variable frequency. In this case, the second half-block must be offset to continue to guarantee the effect of cancellation of the magnetic fields between the different interconnections of the capacitors 15.

[0080] Alternatively, supercapacitors can be adapted for longer engine cycles, up to 5 s, with power limited to 200 kW. This type of cycle is typically compatible with electrochemical double layer supercapacitors (also called EDLC, for electrochemical double layer capacitor in English). Capacitors of this type make it possible to increase the cycle time up to 10 s, provided that an increase in the storage volume is accepted.

[0081] It would also be possible to further increase the cycle time to 20 s or 30 s by using hybrid supercapacitors (also called LIC, for Lithium Ion Capacitor in English) subject to adding a preheating system, or bringing the capacitors closer to the turbomachine, in order to guarantee a temperature above -10°C.

Claims

Claims

1. Double-spool dual-flow turbomachine for aircraft, comprising a low-pressure compressor (1), a high-pressure compressor (2), a combustion chamber (3), a high-pressure turbine (4) and a low-pressure turbine (5), said low-pressure turbine (5) being connected to said low-pressure compressor (1) by a low-pressure rotation shaft (10) and said high-pressure turbine (4) being connected to said high-pressure compressor (2) by a high-pressure rotation shaft (9), the turbomachine (11) also comprising a mechanical power injection device (13) on at least one of the rotation shafts (9, 10), characterized in that the turbomachine (11) comprises capacitive components (15) adapted to supply the turbomachine (11) with electrical energy through said mechanical power injection device (13),said capacitive components (15) being arranged on the turbomachine (11) or on a support structure of the turbomachine (11) and arranged to form at least one pair of concentric circles (17), said pairs of circles (17) being centered on a main axis (A) of the turbomachine (11), the circles of capacitive components (15) of the same pair of circles (17) being radially in the vicinity of one another, in which, for each pair of circles (17) of capacitive components (15), the capacitive components (15) of a radially inner circle are arranged circumferentially offset by half the circumferential width of the capacitive components (15) relative to the capacitive components (15) of a radially outer circle.,

2. Turbomachine (11) according to the preceding claim, in which the capacitive components (15) are supercapacitors, in particular carbon nanotube supercapacitors.

3. Turbomachine (11) according to one of the preceding claims, in which the capacitive components (15) are connected in series and have an equivalent resistance less than or equal to 100 qOhm per capacitive component (15).

4. Turbomachine (11) according to one of the preceding claims, in which each capacitive component (15) comprises an input connector (19a) and an output connector (19b) arranged on the same axial connection face (18) of the capacitive component (15), the connection faces (18) of the components of the same pair of circles (17) being oriented in the same axial direction.

5. Turbomachine (11) according to the preceding claim, in which, for each pair of concentric circles (17) of capacitive components (15), the input (19a) and output (19b) connectors of each capacitive component (15) of each of the circles are connected to output (19b) and input (19a) connectors, respectively, of capacitive components (15) of the other circle, with the exception of a first component (15a) and a last component (15b) of the pair of circles (17).

6. Turbomachine (11) according to claim 4 or 5, wherein the turbomachine (11) comprises two pairs of circles (17) of capacitive components (15), the connection faces (18) of the capacitive components (15) of each pair of circles (17) being arranged opposite the connection faces (18) of the capacitive components (15) of the other pair of circles (17).

7. A turbomachine (11) according to any preceding claim, wherein the turbomachine (11) comprises two pairs of circles (17) of capacitive components (15), the capacitive components (15) of the two pairs of circles (17) being connected in series together, the two pairs of circles (17) being electrically connected by an interconnection (23).

8. Turbomachine (11) according to the preceding claim, in which the interconnection (23) between the two pairs of circles (17) is adapted to be electrically connected to an aircraft chassis to create a potential reference, and / or to be connected to an aircraft electrical network to serve as a ground reference.

9. Turbomachine according to one of claims 1 to 6, in which the pairs of circles (17) of capacitive components (15) are connected in parallel to each other.

10. Propulsion assembly for aircraft comprising a turbomachine (11) according to one of the preceding claims and at least one nacelle (20) receiving the turbomachine (11), the capacitive components (15) being arranged in a space delimited radially between an internal casing (22) and an external casing (21) of the nacelle (20).

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