Self-contained hybrid turbine engine
By installing mechanical power feeding devices and capacitor components in the turbine engine, the problem of large electrical loss during assisted propulsion in the prior art is solved, and self-supporting hybrid operation and efficient power storage and recovery are achieved.
Patent Information
- Application Number
- CN202380048589.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-05
- Filing Date
- 2023-06-28
- Publication Date
- 2025-02-07
AI Technical Summary
Existing turbine engines require a large amount of high-capacity electrical energy when assisting propulsion, resulting in significant large and high electrical losses.
Using a self-sufficient hybrid turbine engine, by installing a mechanical power feeding device on the rotating shaft and a capacitor assembly is arranged on the turbine engine or its support structure, the capacitor assembly is adapted to supply electrical energy to the turbine engine through the mechanical power feeding device.
Self-supporting hybrid operation is achieved, reducing electrical losses, limiting the volume and mass of the connectors, and allowing efficient storage and recovery of electrical energy on the aircraft.
Smart Images
Figure CN119404001A_ABST
Abstract
Description
Technical Field
[0001] The field of the invention is that of aviation turbine engines and, in particular, that of aircraft engines produced in the form of twin-shaft turbofans. More particularly, the invention relates to a self-contained hybrid turbine engine of this type for aircraft. Background Art
[0002] Thermal / electric hybridization of aircraft turbine engines offers new paths to improve the behavior and performance of these turbine engines.
[0003] This mixing consists of feeding or extracting mechanical power at a certain time and at a certain level through an electric motor mounted on the rotating shaft of the turbine engine.
[0004] A key requirement of conventional turbine engines for aircraft propulsion is to ensure that the maximum ascent time is not exceeded between the idle speed at which the engine produces only low thrust and the maximum speed at which the engine thrust is at its maximum.
[0005] Figure 1 A conventional twin-shaft turbofan type turbine engine is schematically shown in FIG.
[0006] It generally comprises, from upstream to downstream in the air flow direction, a fan S, a low-pressure compressor 1 , a high-pressure compressor 2 , a combustion chamber 3 receiving 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 via a high-pressure shaft 9 and together with the combustion chamber form a high-pressure body.
[0009] A fan S driven directly or via a reduction gearbox by a low-pressure shaft 10 compresses the air coming from the air inlet. Downstream of the fan S, this air is divided into 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 turbine engine, and a so-called primary flow, which enters a gas generator consisting of a low-pressure body and a high-pressure body and is then ejected into the primary nozzle 6.
[0010] Generally, it is known to install generators in turbine engines in order to power the onboard electrical systems. These generators are driven by the high-voltage shaft 9 via the accessory gearbox in order to convert mechanical energy into electrical energy intended for secondary systems on board the aircraft.
[0011] One variant may consist of replacing at least one of the generators with at least one starter to start the turbine engine using electrical energy. The start-up is achieved by controlling the electric starter via a converter, located in the engine area or in the cockpit area, powered by a source external to the turbine engine for starting. This source may be a ground-based power unit or another onboard power source previously activated (auxiliary power generator, generator of another turbine engine). Once the turbine engine is started, the electric starter changes mode to operate exclusively as a generator.
[0012] However, the use of such systems to assist turbine engines by supplying large amounts of electrical energy is not always satisfactory, since it requires the use of high-capacity electrical energy sources located in the aircraft area and associated electrical connections, which generate significant and high electrical losses. Summary of the invention
[0013] The present invention aims to overcome these drawbacks by providing a self-sufficient hybrid turbine engine. For this purpose, the present invention relates to a two-shaft turbofan type turbine engine for an aircraft, the turbine engine comprising a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine and a low-pressure turbine, the low-pressure turbine being connected to the low-pressure compressor by a rotating low-pressure shaft and the high-pressure turbine being connected to the high-pressure compressor by a rotating high-pressure shaft, the turbine engine also comprising a mechanical power feed device located on at least one of the rotating shafts,
[0014] Characterized in that the turbine engine comprises a capacitor assembly, which is adapted to supply electrical energy to the turbine engine through the mechanical power feeding device, and the capacitor assembly is arranged on the turbine engine or on a supporting structure of the turbine engine and is arranged to form at least one pair of concentric circles, the paired circles being centered on the main axis of the turbine engine, and the circles in the same pair of circles of the capacitor assembly are close to each other in the radial direction.
[0015] The capacitive assembly may in particular form two pairs of circles which are axially spaced apart from one another.
[0016] The support structure may be a nacelle housing a turbine engine.
[0017] Such a turbine engine allows self-sufficient hybrid operation, is able to store energy in electrical and / or electrochemical form and to recover it to the propulsion system, is arranged close to the nacelle so as to limit the volume and mass of the connections and the electrical losses.
[0018] The power feeding device may advantageously also act as a generator.
[0019] The capacitive component may be a supercapacitor, in particular a carbon nanotube supercapacitor.
[0020] Such a capacitive assembly has a low internal resistance, making it possible to deliver high power for a short period of time and thus assist propulsion during critical phases such as take-off of an aircraft.
[0021] The power supplied may be, for example, approximately 500 kW, delivered for a duration of approximately one second.
[0022] Alternatively, the supercapacitor may be an electrochemical double layer supercapacitor (also known as EDLC), or a hybrid supercapacitor (also known as LIC for lithium ion capacitors).
[0023] The capacitor components may be connected in series, and each capacitor component may have an equivalent resistance less than or equal to 100 μOhm.
[0024] This feature makes it possible to maintain the voltage at which the power is restored at 400 V or higher for the required time.
[0025] For each pair of circles of capacitor components, the radially inner circle of capacitor components may be arranged to be circumferentially offset relative to the radially outer circle of capacitor components by half of the circumferential width of the capacitor components.
[0026] This arrangement makes it possible to reduce the length of the connection between the capacitor assemblies by arranging the connectors of the two circular capacitor assemblies so that they are radially in line with each other.
[0027] Each capacitor assembly may include an input connector and an output connector arranged on a same axial connection face of the capacitor assembly, the connection faces of the same pair of assemblies being oriented in the same axial direction.
[0028] This arrangement allows the length of the connections between the capacitor components to be further reduced.
[0029] For each pair of concentric circles of capacitive components, except for the first and last components of the pair of circles, the input connector and output connector of each capacitive component of each of the circles are connected to the output connector and input connector of the components of the other circle, respectively.
[0030] This arrangement allows all capacitive components of both circles to be connected in series with connections having a short overall length.
[0031] The turbine engine may comprise two pairs of circles of capacitor assemblies, the connection faces of the capacitor assemblies of each pair of circles being arranged facing the connection faces of the capacitor assemblies of the other pair of circles.
[0032] This arrangement allows a simple series connection of the two pairs of circular assemblies and also allows the effects of magnetic fields generated by the flow of current in the interconnect to be reduced.
[0033] The turbine engine may comprise two pairs of concentric circles of capacitor assemblies, the assemblies of the two pairs of circles being connected together in series.
[0034] The interconnect between the two pairs of circles may be adapted to be electrically connected to the aircraft body to create an electrical potential reference, and / or to the aircraft electrical system to act as a ground reference.
[0035] Pairs of circles of the capacitor assembly may be connected in parallel with each other.
[0036] This feature makes it possible for the system to be compatible with 540V (+ / -270V) systems or with 230 / 400VAC systems with fixed or variable frequency.
[0037] In this case, the pairs of circles may be continuously offset in order to continue to ensure that the effects of the magnetic fields between the various interconnections of the capacitive assembly are cancelled.
[0038] The invention also relates to a propulsion assembly comprising a turbine engine as above and at least one nacelle housing the turbine engine, the capacitor assembly being arranged in a space radially delimited between an inner casing and an outer casing of the nacelle.
[0039] Arrangement of the capacitive assembly in the nacelle makes it possible to benefit from a favourable thermal environment with a short distance between the assembly and the power feeding device. BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Figure 1 is a schematic representation of a twin-shaft turbofan type turbine engine according to the state of the art,
[0041] Figure 2 is a schematic representation of a turbine engine according to the invention,
[0042] Figure 3 for Figure 2 Electrical diagram of the energy storage assembly of a turbine engine,
[0043] Figure 4 Including the cabin and Figure 2 A schematic axial cross-sectional view of a propulsion assembly of a turbine engine of
[0044] Figure 5 for Figure 3 A schematic radial cross-sectional view of an energy storage assembly of
[0045] Figure 6 for Figure 5 A schematic top view of an energy storage assembly of
[0046] Figure 7 is an electrical diagram of an energy storage assembly according to another embodiment of the present invention, and
[0047] Figure 8 FIG. 4 is a schematic top view of an energy storage assembly according to another embodiment of the present invention. DETAILED DESCRIPTION
[0048] Figure 2 A turbine engine 11 according to the invention is shown mounted on an aircraft. The turbine engine 11 (similar to Figure 1 The turbine engine in the embodiment of the present invention comprises, from upstream to downstream in the air flow direction, a fan S, a low-pressure compressor 1, a high-pressure compressor 2, a combustion chamber 3 receiving 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 via a high-pressure shaft 9 and together with the combustion chamber 3 form a high-pressure body.
[0051] A fan S driven directly or via a reduction gearbox by a low-pressure shaft 10 compresses the air coming from the air inlet. Downstream of the fan S, this air is divided into 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 turbine engine, and a so-called primary flow, which enters a gas generator consisting of a low-pressure body and a high-pressure body and is then ejected into the primary nozzle 6.
[0052] The turbine engine 11 also comprises a mechanical power feed 13 combined with the high-voltage shaft 9. The mechanical power feed 13 is capable of converting electrical power into mechanical power causing the rotation of the high-voltage shaft 9 and, conversely, of taking mechanical power from the high-voltage shaft 9 to convert it into electrical power for storage and / or to supply loads 12 of the aircraft.
[0053] The feed device 13 can in particular be operated alternately as a motor and as a generator, depending on the flight phase of the aircraft, and takes mechanical power from the high-voltage shaft 9 to convert it into electrical power.
[0054] The feed device 13 is connected to the low-pressure shaft, for example via an accessory gearbox (not shown) which meshes with the high-pressure shaft 9 .
[0055] The turbine engine 11 also comprises an electrical energy storage assembly comprising a power converter 14 and a plurality of capacitive energy storage elements 15 .
[0056] The energy storage element 15 is in particular a supercapacitor, for example a carbon nanotube supercapacitor.
[0057] A typical order of magnitude for starting assistance of a turbine engine is to supply about 500 kW of power for a duration of about 1 s, so the total energy supplied is about 500 kJ. In this case, the capacity design of a storage assembly based on supercapacitors is defined by both the power density of the capacitive component and the energy density of its storage.
[0058] In this regard, supercapacitors made with carbon nanotubes and graphene make it possible to increase the conductivity and therefore divide the resistivity of the component by 10 (or more), which allows the storage system to be suitable for operating cycles of about one second (rather than 10 to 20 seconds for conventional supercapacitors).
[0059] The storage assembly comprises, for example, 296 carbon nanotube supercapacitors of 900 F capacitance connected in series, which makes it possible to obtain an equivalent series resistance (ESR) of less than 100 μOhm per assembly.
[0060] Energy storage components Figure 3 , which shows the electrical architecture of the assembly. The feeding device 13 typically comprises a motor 13a and an inverter 16, the latter being connected in parallel to a power converter 14, here a DC / DC converter.
[0061] The converter 14 , being a chopper type converter, is configured to control the power taken from or fed to the high voltage shaft 9 or delivered to the load 12 .
[0062] The energy storage assembly is also connected in parallel to a load 12 of the aircraft.
[0063] like Figure 4 , the energy storage assembly is completely integrated outside the aircraft area and in particular is completely enclosed in the nacelle 20 which carries the turbine engine 11 and forms with it a self-sufficient hybrid propulsion assembly.
[0064] The supercapacitors 15 are arranged circumferentially around the main axis A of the turbine engine 11. This makes it possible to reduce the length of the connection and therefore the total mass of the system, and to reduce energy losses in said connection.
[0065] The supercapacitors 15 are in particular prismatic in shape and are distributed so as to form two pairs of concentric circles 17 in the nacelle 20. The circles of supercapacitors 15 are in particular radially comprised between an outer casing 21 and an inner casing 22 of said nacelle 20 and are centered on the main axis A.
[0066] This flat shape of the capacitor 15 makes it possible to obtain a thickness of a few centimetres (about 5 cm in the above example), which is compatible with the aerodynamic dimensions of the nacelle 20 .
[0067] Placing the ultracapacitor 15 in the nacelle 20 is advantageous because it benefits from a favorable thermal environment (unlike temperatures in an engine which can reach hundreds of degrees) that is compatible with ultracapacitors.
[0068] The power electronics may be located in a compartment in the nacelle 20. The power feed 13 is typically located on an accessory gearbox (AGB), and the converter 14 may advantageously be located at various locations between the supercapacitor 15 and the power feed 13.
[0069] exist Figure 5 In FIG. 1 , one of the paired circles 17 is shown in detail in a cross-sectional view in a plane orthogonal to the main axis A. FIG.
[0070] The radially outer supercapacitor 15 is circumferentially offset relative to the radially outer supercapacitor by half the circumferential width of the supercapacitor 15 .
[0071] Each supercapacitor 15 has a substantially parallelepiped shape, the axial connection face 18 of which comprises a first connector 19a, called input connector, and a second connector 19b, called output connector.
[0072] Thus, for each pair of circles 17, the input connectors 19a of the supercapacitors 15 of each circle are positioned radially in line with the output connectors 19b of the capacitors 15 of the other circle.
[0073] The input connector 19a and the output connector 19b of each capacitive component 15 of each of the circles, except the first component 15a and the last component 15b of the pair of circles 17, are connected to the output connector 19b and the input connector 19a of the capacitive component 15 of the other circle, respectively.
[0074] The first component 15 a and the last component 15 b of each pair of circles 17 are capacitive components 15 , through which the capacitive half-unit formed by the components 15 of the pair of circles is connected to the other half-unit or converter 14 .
[0075] This allows all the capacitors 15 of the pair of circles 17 to be connected in series with an interconnection of minimum length. The interconnection connecting the input connector 19a to the output connector 19b is in particular of busbar type and extends radially. This allows the inductance and the total resistance of the interconnection to be reduced.
[0076] In addition, if Figure 6 , the offset arrangement of the concentric circles allows the interconnects of the supercapacitors 15 of each pair of circles 17 to be placed axially facing each other. A simple interconnect 23 between two pairs of circles 17 facing each other allows the two "half cells" of the capacitor 15 to be connected at their midpoints.
[0077] With this arrangement, the axially facing interconnects have opposite current flow directions, one direction radially "upwards" while the other direction is radially "downwards" (the terms up and down are relative to the direction of flow of the current, away from the main axis A and towards the main axis A, respectively). This has the effect that the magnetic fields generated by these facing interconnects are opposite and tend to cancel each other, resulting in a significant reduction in wiring inductance.
[0078] according to Figure 7 In the variant shown in , the interconnection 23 between the two pairs of concentric circles 17 can be electrically connected to the body of the aircraft in order to create a potential reference, and / or to the electrical network of the aircraft (DC_Réseau) in order to act as a ground reference.
[0079] according to Figure 8 In another variation shown in , the two half-units formed 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) system or a 230 / 400VAC system with fixed or variable frequency. In this case, the second half-unit must be offset in order to continue to ensure that the effects of the magnetic fields between the various interconnections of the capacitors 15 are cancelled.
[0080] Alternatively, supercapacitors may be suitable for longer engine cycles of up to 5 s, where power is limited to 200 kW. This type of cycle is generally compatible with electrochemical double layer supercapacitors (also known as EDCs). This type of capacitor can increase cycle time up to 10 s, provided that the increase in storage capacity is acceptable.
[0081] It is also possible to increase the cycle time further to 20s or 30s by using hybrid supercapacitors (also known as LICs for lithium-ion capacitors), provided a preheating system is added, or the capacitors are moved closer to the turbine engine to ensure the temperature is above -10°C.
Claims
1. A twin-shaft turbofan type turbine engine for an aircraft, the turbine engine 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), the low-pressure turbine (5) being connected to the low-pressure compressor (1) by a rotating low-pressure shaft (10), and the high-pressure turbine (4) being connected to the high-pressure compressor (2) by a rotating high-pressure shaft (9), The turbine engine (11) further comprises a mechanical power feed device (13) located on at least one of the rotating shafts (9, 10), It is characterized in that The turbine engine (11) comprises a capacitor assembly (15) adapted to supply electrical energy to the turbine engine (11) via the mechanical power feed device (13), the capacitor assembly (15) being arranged on the turbine engine (11) or on a supporting structure of the turbine engine (11) and arranged to form at least one pair of concentric circles (17), the paired circles (17) being centered on the main axis (A) of the turbine engine (11), the circles in the same pair of circles (17) of the capacitor assembly (15) being close to each other in radial direction, For each pair of circles (17) of the capacitor assembly (15), the capacitor assembly (15) of the radial inner circle is arranged to be circumferentially offset by half of the circumferential width of the capacitor assembly (15) relative to the capacitor assembly (15) of the radial outer circle.
2. Turbine engine (11) according to the preceding claim, characterized in that The capacitor component (15) is a supercapacitor, in particular a carbon nanotube supercapacitor.
3. A turbine engine (11) according to any one of the preceding claims, characterised in that The capacitor components (15) are connected in series, and each capacitor component (15) has an equivalent resistance less than or equal to 100 μOhm.
4. A turbine engine (11) according to any one of the preceding claims, characterised in that Each capacitor assembly (15) comprises an input connector (19a) and an output connector (19b) arranged on the same axial connection surface (18) of the capacitor assembly (15), the connection surfaces (18) of the assemblies of the same pair of circles (17) being oriented in the same axial direction.
5. Turbine engine (11) according to the preceding claim, characterized in that For each pair of concentric circles (17) of capacitor components (15), except for the first component (15a) and the last component (15b) of the pair of circles (17), the input connector (19a) and the output connector (19b) of each capacitor component (15) of each of the circles are respectively connected to the output (19b) and input (19a) connectors of the capacitor component (15) of the other circle.
6. The turbine engine (11) according to claim 4 or 5, characterized in that The turbine engine (11) comprises two pairs of circles (17) of capacitor assemblies (15), the connection surfaces (18) of the capacitor assemblies (15) of each pair of circles (17) being arranged to face the connection surfaces (18) of the capacitor assemblies (15) of the other pair of circles (17).
7. A turbine engine (11) according to any one of the preceding claims, characterised in that The turbine engine (11) comprises two pairs of circles (17) of capacitor assemblies (15), the capacitor assemblies (15) of the two pairs of circles (17) being connected together in series, and the two pairs of circles (17) being electrically connected via an interconnector (23).
8. Turbine engine (11) according to the preceding claim, characterized in that The interconnection (23) between the two pairs of circles (17) is adapted to be electrically connected to the aircraft body to create a potential reference, and / or to the aircraft electrical system to act as a ground reference.
9. The turbine engine according to any one of claims 1 to 6, characterized in that The paired circles (17) of the capacitor assembly (15) are connected in parallel to each other.
10. A propulsion assembly for an aircraft, comprising a turbine engine (11) according to any one of the preceding claims, and at least one nacelle (20) for housing the turbine engine (11), the capacitor assembly (15) being arranged in a space radially delimited between an inner casing (22) and an outer casing (21) of the nacelle (20).