Fuel control system

Abstract

The present invention relates to a fuel control system (4) comprising: a fuel source; a supply conduit; a main circuit comprising: a first centrifugal pump; a connecting conduit; a second centrifugal pump; a discharge conduit; and a secondary circuit.

Description

[0001] FUEL CONTROL SYSTEM

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the aeronautical field. More specifically, the present invention relates to fuel regulation within an aircraft engine.

[0004] STATE OF THE ART

[0005] Fuel regulation in an aircraft engine is typically achieved by a system comprising a positive displacement pump driven by a rotating body of the engine. Replacing the positive displacement pump with a centrifugal pump could provide some advantages; in particular, it would make the fuel regulation system more robust. However, a centrifugal pump has some disadvantages; in particular, its efficiency depends on the fuel flow rate it delivers.

[0006] STATEMENT OF THE INVENTION

[0007] An aim of the invention is to improve a fuel regulation system for an aircraft engine comprising at least one centrifugal pump.

[0008] To this end, according to one aspect of the invention, a fuel control system for an aircraft engine is proposed, the system comprising: a fuel source; a supply duct connected to the fuel source; a main circuit comprising: a first centrifugal pump comprising an inlet port and a discharge port, the inlet port being connected to the supply duct; a connecting duct connected to the discharge port of the first centrifugal pump; a second centrifugal pump comprising an inlet port and a discharge port, the inlet port of the second centrifugal pump being connected to the connecting duct; a discharge duct connected to the discharge port of the second centrifugal pump, the discharge duct being further configured to be connected to an injector of a combustion chamber of the engine;and a secondary circuit comprising at least one member configured to be actuated by fuel pressure circulating within the secondary circuit, the secondary circuit comprising an inlet duct connected to the delivery duct and an outlet duct connected to the connecting duct. Advantageously, but optionally, the system according to the invention may comprise at least one of the following characteristics, taken alone or in combination:;

[0009] - the first centrifugal pump and the second centrifugal pump are configured such that, in operation, the first centrifugal pump provides a first pressure and the second centrifugal pump provides a second pressure, the first pressure being lower than the second pressure;

[0010] - the first centrifugal pump and the second centrifugal pump are configured so that, in operation, the first centrifugal pump delivers a first flow rate of fluid solely dedicated to supplying the combustion chamber and the second centrifugal pump delivers a second flow rate of fluid dedicated both to supplying the combustion chamber and to actuating the at least one member, the first flow rate being lower than the second flow rate;

[0011] - the main circuit further comprises a restriction arranged at the level of the delivery duct and configured to control the flow of fuel delivered by the second centrifugal pump;

[0012] - at least one organ is equipment with variable geometries;

[0013] - each of the first centrifugal pump and the second centrifugal pump comprises a rotor part and a stator part, the rotor part of the first centrifugal pump being rotationally fixed to the rotor part of the second centrifugal pump; and

[0014] - each of the first centrifugal pump and the second centrifugal pump comprises a rotor part and a stator part, the stator part of the first centrifugal pump being fixedly mounted on the stator part of the second centrifugal pump.

[0015] According to another aspect, the invention relates to an aircraft engine comprising: a system as previously described; an electric motor comprising a rotating element connected to at least one of the rotor part of the first centrifugal pump and the rotor part of the second centrifugal pump to drive it in rotation relative to the stator part; an electrical power source connected to the electric motor to transmit electrical power thereto in order to drive the rotating element in rotation; and a combustion chamber comprising an injector connected to the delivery conduit to receive fuel from the second centrifugal pump.

[0016] According to another aspect, the invention relates to an aircraft engine comprising: a system as previously described; an accessory housing comprising a rotating element connected to at least one of the rotor portion of the first centrifugal pump and the rotor portion of the second centrifugal pump to drive it in rotation relative to the stator portion; a rotating body connected to the accessory housing to drive the rotating element in rotation; and a combustion chamber comprising an injector connected to the discharge conduit to receive fuel from the second centrifugal pump.

[0017] According to another aspect, the invention relates to an aircraft comprising an aircraft engine as previously described.

[0018] DESCRIPTION OF FIGURES

[0019] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0020] Figure 1 illustrates an aircraft schematically.

[0021] Figure 2 is a schematic sectional view of an aircraft propulsion assembly.

[0022] Figure 3 schematically illustrates a fuel control system according to one embodiment of the invention.

[0023] Figure 4 illustrates the pressure / flow characteristic, for two distinct regimes, of each of the two centrifugal pumps of a fuel control system according to one embodiment of the invention.

[0024] Figure 5 illustrates the efficiency / flow rate characteristic for each of the two speeds of each of the two centrifugal pumps whose pressure / flow rate characteristic is illustrated in Figure 4.

[0025] Throughout the figures, similar elements have identical references.

[0026] DETAILED DESCRIPTION OF THE INVENTION

[0027] Aircraft

[0028] Figure 1 illustrates an aircraft 100 comprising at least one propulsion unit 1, in this case two propulsion units 1. The aircraft 100 shown is an airplane, civil or military, but could be any other type of aircraft 100, such as a helicopter. The propulsion units 1 are attached and fixed to the airplane 100, each under a wing of the airplane 100, as visible in Figure 1. This is not, however, limiting, since at least one propulsion unit 1 can also be mounted on the wing of the airplane or at the rear of its fuselage.

[0029] Figure 2 illustrates a propulsion unit 1 having a longitudinal axis XX, and comprising an engine 2 (or turbomachine) and a nacelle 3 surrounding the engine 2.

[0030] The propulsion assembly 1 is intended to be mounted on an aircraft 100, for example in the manner illustrated in FIG. 1. In this regard, the propulsion assembly 1 may comprise a mast (not shown) intended to connect the propulsion assembly 1 to a part of the aircraft 100.

[0031] The engine 2 illustrated in Figure 2 is a twin-spool, twin-flow, direct-drive turbojet engine. This is not, however, limiting since the engine 2 may have a different number of spools and / or flows, and / or be another type of turbojet engine, such as a geared turbojet engine or a turboprop engine.

[0032] Unless otherwise specified, the terms “upstream” and “downstream” are used with reference to the overall direction of airflow through the propulsion unit 1 in operation. Similarly, an axial direction corresponds to the direction of the longitudinal axis XX and a radial direction is a direction perpendicular to the longitudinal axis XX and intersecting the longitudinal axis XX. Furthermore, an axial plane is a plane containing the longitudinal axis XX and a radial plane is a plane perpendicular to the longitudinal axis XX. A circumference is understood to be a circle belonging to a radial plane and whose center belongs to the longitudinal axis XX. A tangential or circumferential direction is a direction tangent to a circumference: it is perpendicular to the longitudinal axis XX but does not pass through the longitudinal axis XX.Finally, the adjectives "inner" (or "internal") and "outer" (or "external") are used in reference to a radial direction so that the inner part of an element is, in a radial direction, closer to the longitudinal axis XX than the outer part of the same element.

[0033] As seen in Figure 2, the engine 2 comprises, from upstream to downstream, a fan 20, a compression section 22 comprising a low-pressure compressor 220 and a high-pressure compressor 222, a combustion chamber 24 and an expansion section 26 comprising a high-pressure turbine 262 and a low-pressure turbine 260. The combustion chamber 24 comprises a fuel injection rail (not shown) and a plurality of ignition injectors (not shown). The injection rail and / or the ignition injectors constitute the main fuel-consuming components of the engine 2.The fan 20, the rotor part of the low-pressure compressor 220, and the rotor part of the low-pressure turbine 260 are connected to each other by a low-pressure shaft 280 extending along the longitudinal axis XX, the fan 20, the low-pressure compressor 220 and the low-pressure turbine 260 then forming a low-pressure body 20, 220, 260, 280, which is a first rotating body. The rotor part of the high-pressure compressor 222 and the rotor part of the high-pressure turbine 262 are connected to each other by a high-pressure shaft 282 extending along the longitudinal axis XX, the high-pressure compressor 222 and the high-pressure turbine 262 then forming a high-pressure body 222, 262, 282, which is a second rotating body. As seen in Figure 2, the compression section 22, the combustion chamber 24 and the expansion section 26 are surrounded by a crankcase 23, while the fan 20 is surrounded by a fan casing 25.The engine casing 23 and the fan casing 25 are connected to each other by profiled structural arms 27 forming rectifiers (or OGV for "Outlet Guide Vanes" in English terminology) distributed circumferentially all around the longitudinal axis XX. The longitudinal axis XX forms an axis of rotation for the fan 20, the rotor part of the compression section 22 and the rotor part of the expansion section 26, in other words for the low-pressure body 20, 220, 260, 280 and the high-pressure body 222, 262, 282, which are capable of being driven in rotation around the longitudinal axis XX relative to the engine casing 23 and the fan casing 25.

[0034] The engine 2 may also comprise at least one accessory box (not shown), called ÀGB (for “Accessory gear box” in English terminology), for example housed in a cavity provided within the nacelle 3. The accessory box comprises a set of rotating elements, such as gears, making it possible to drive a plurality of shafts in rotation around their own axis, accessories being mounted on these shafts to derive useful mechanical power from their rotation. The gear assembly is itself driven using a power take-off shaft connecting, possibly via a transfer case (not shown), the accessory case to at least one of the high pressure body 222, 262, 282 and the low pressure body 20, 220, 260, 280, typically by being meshed with at least one of the high pressure shaft 282 and the low pressure shaft 280.In this regard, the power take-off shaft may extend within a longitudinal cavity provided within one of the structural arms 27. In this manner, mechanical power may be taken from at least one of the high pressure body 222, 262, 282 and the low pressure body 20, 220, 260, 280 to be delivered to the at least one of the accessories via the accessory housing.

[0035] The engine 2 comprises a number of components (or equipment) configured to be actuated by means of fuel. More precisely, these components are hydraulically actuated and it is intended to use pressurized fuel to ensure their operation. These components are usually referred to as “variable geometry equipment (or accessories) 4200” or, more simply, “variable geometries 4200”. Examples of variable geometries 4200 are: variable-pitch vanes (e.g., stator vanes of the high-pressure compressor 222), discharge valves of the primary stream A or of the secondary stream B. These variable geometries 4200 therefore need the pneumatic energy linked to the fuel pressure to operate. However, unlike an injector (ignition or injection rail) of the combustion chamber, the variable geometries 4200 do not consume fuel, because they do not degrade it by combustion.

[0036] The nacelle 3 extends radially outside the engine 2, all around the longitudinal axis XX, so as to surround both the fan casing 25 and the engine casing 23, and to define, with a downstream portion of the engine casing 23, a downstream portion of a secondary duct B, the upstream portion of the secondary duct B being defined by the fan casing 25 and an upstream portion of the engine casing 23. The upstream portion of the nacelle 3 further defines an air inlet 29 through which the fan 20 sucks in the air flow circulating through the propulsion unit 1. The nacelle 3 is integral with the fan casing 25 and attached and fixed to the aircraft 100 by means of the mast.

[0037] In operation, the fan 20 draws in an air flow, a portion of which, circulating within a primary vein A passing through the engine casing 23 from one side to the other, is successively compressed within the compression section 22, ignited within the combustion chamber 24 by combustion of fuel, and expanded within the expansion section 26 before being ejected from the engine 2. Another portion of the air flow circulates within the secondary vein B which takes an elongated annular shape surrounding the engine casing 23, the air drawn in by the fan 20 being straightened by the straighteners 27 and then ejected from the propulsion unit 1. In this way, the propulsion unit 1 generates thrust. This thrust can, for example, be used for the benefit of the aircraft 100 on which the propulsion unit 1 is attached and fixed.

[0038] In order to supply both the fuel-consuming organs, such as the injectors (ignition or injection rail) of the combustion chamber 24, and the variable geometries 4200, the engine 2 comprises a fuel regulation system 4, illustrated in FIG. 3.

[0039] The fuel control system 4 comprises a fuel source 40, such as a tank, containing the fuel intended for the operation of the variable geometries 4200 and for combustion within the combustion chamber 24. Furthermore, a supply conduit 400 is connected to the fuel source 40. As illustrated in FIG. 3, the fuel control system 4 comprises a main circuit 41 and a secondary circuit 42, the secondary circuit 42 being connected to the main circuit 41, which is connected to the fuel source 40 via the supply conduit 400.

[0040] Advantageously, a centrifugal booster pump 4000 is interposed between the fuel source 40 and the main circuit 41, on the supply pipe 400, for pressurizing the main circuit 41 and the secondary circuit 42.

[0041] The main circuit 41 comprises a number of members connected in series, including a first centrifugal pump 411 and a second centrifugal pump 412. Each of the first centrifugal pump 411 and the second centrifugal pump 412 comprises an inlet port 4110, 4120 and a discharge port 4112, 4122. In addition, a connecting conduit 413 connects the discharge port 4112 of the first centrifugal pump 411 to the inlet port 4120 of the second centrifugal pump 412, so that the fluid discharged by the first centrifugal pump 411 is fully admitted by the second centrifugal pump 412.

[0042] The first centrifugal pump 411 is arranged so that its inlet port 4110 is connected to the supply conduit 400 to admit fuel from the fuel source 40, possibly previously pressurized by the centrifugal booster pump 4000.

[0043] As visible in Figure 3, the main circuit 41 further comprises a delivery conduit 414 connected to the delivery port 4122 of the second centrifugal pump 412 and to a fuel-consuming member, such as an injector of the combustion chamber 24 so that the latter receives fuel from the second centrifugal pump 412. Thus, at least a portion of the fuel delivered by the second centrifugal pump 412 can be admitted into the combustion chamber 24 to be mixed with the air from the compression section 22 in order to be ignited.

[0044] Advantageously, the main circuit 41 comprises a heat exchanger 415 and / or a filter 416, positioned on the connecting duct 413, between the discharge port 4112 of the first centrifugal pump 411 and the inlet port 4120 of the second centrifugal pump 412. The filter 416 makes it possible to treat the fuel circulating within the fuel regulation system 4 in order to optimize its operation. In addition, the heat exchanger 415 makes it possible to cool the oil circuit of the enclosures of the engine 1 in contact with which the fuel circulates, the fuel regulation system then being considered as a cold source capable of absorbing calories. Advantageously, the main circuit 41 further comprises a restriction 417 arranged at the discharge duct 414 and configured to control the flow rate of fuel delivered by the second centrifugal pump 412.More specifically, the restriction 417 is configured to generate line losses (or pressure losses), of a thermal nature, within the delivery duct 414, which makes it possible to adjust the fuel flow rate within the duct connecting the delivery duct 414 to the injectors of the combustion chamber 24. The restriction 417 may be a variable-section valve controlled by a servovalve.

[0045] The secondary circuit 42 is arranged in parallel with the main circuit 41, more precisely in parallel with the second centrifugal pump 412, advantageously also in parallel with the heat exchanger 415 and the filter 416. In this respect, the secondary circuit 42 comprises an inlet duct 420 connected to the discharge duct 414 and an outlet duct 421 connected to the connecting duct 413.

[0046] Furthermore, the secondary circuit 42 comprises at least one variable geometry 4200, which is thus supplied with at least a portion of the fuel delivered by the second centrifugal pump 412. After passing through the variable geometry 4200, the fuel is then discharged into the connecting conduit 413 so that a portion of the fuel admitted by the second centrifugal pump 412 has, in fact, circulated through the variable geometries 4200. In other words, the fuel admitted by the second centrifugal pump 412 is partly delivered by the first centrifugal pump 411, and for the remainder has circulated within the secondary circuit 42. Furthermore, the fuel delivered by the second centrifugal pump 412 is partly circulated within the secondary circuit 42, and for the remainder is burned within the combustion chamber 24.

[0047] Each of the first centrifugal pump 411 and the second centrifugal pump 412 comprises a rotor portion and a stator portion, the rotor portion being movable relative to the stator portion, typically by rotation of an input shaft of the centrifugal pump 411, 412 about its own axis. Generally, each of the first centrifugal pump 411 and the second centrifugal pump 412 is a rotating machine that pumps fuel by forcing it through an impeller, or propeller, generally called an "impeller," which is integral with the shaft and forms, with the shaft, the rotor portion. The impeller is housed within a casing of the centrifugal pump 411, 412, which forms the stator portion.By the effect of the rotation of the impeller, the pumped fuel is sucked axially into the centrifugal pump 411, 412, i.e. in a direction parallel to the axis of the shaft, then accelerated radially, i.e. in a direction perpendicular to the axis of the shaft, and finally discharged tangentially, i.e. in a direction tangential to the axis of the shaft. The centrifugal booster pump 4000 advantageously has the same structure as that of each of the first centrifugal pump 411 and the second centrifugal pump 412. In any event, it should be noted that, unlike a positive displacement pump which is a source of flow, a centrifugal pump 411, 412, 4000 is a source of pressure.Indeed, a centrifugal pump 411, 412, 4000 is configured so that, in operation, it can deliver a fuel flow rate which is variable, since it depends on the rotation speed of its rotor part relative to its stator part, but with an increase in pressure between the intake port 4110, 4120 and the discharge port 4112, 4122 which remains constant, or almost constant, and this whatever the flow rate, as can be seen in particular in FIG. 4.

[0048] Advantageously, the rotor part of the first centrifugal pump 411 is integral in rotation with the rotor part of the second centrifugal pump 412. Typically, the input shaft of the first centrifugal pump 411 is common to the input shaft of the second centrifugal pump 412.

[0049] Also advantageously, the stator part of the first centrifugal pump 411 is fixedly mounted on the stator part of the second centrifugal pump 412. Typically, the casing of the first centrifugal pump 411 is fixedly mounted on the casing of the second centrifugal pump 412.

[0050] The rotational drive of the rotor portion, relative to the stator portion, of each of the first centrifugal pump 411 and the second centrifugal pump 412, can be implemented in different ways.

[0051] In a variant, the aircraft engine 2 100 comprises an electric motor (not shown), which may be synchronous or asynchronous, and which comprises a rotating element, typically an output shaft, connected to at least one of the rotor portion of the first centrifugal pump 411 and the rotor portion of the second centrifugal pump 412 to drive it in rotation relative to the stator portion. In addition, the aircraft engine 2 100 comprises an electrical power source, typically a battery or a generator driven by at least one of the high-pressure body 222, 262, 282 and the low-pressure body 20, 220, 260, 280, the electrical power source being connected to the electric motor to transmit electrical power thereto in order to drive the rotating element of the electric motor in rotation.The use of an electric motor allows each of the first centrifugal pump 411 and the second centrifugal pump 412 to deliver the necessary fuel flow rate, in particular for the variable geometries 4200, even at low drive speeds of the rotating bodies 20, 22, 26. Indeed, an electric motor can drive each of the first centrifugal pump 411 and the second centrifugal pump 412 at high rotation speeds, even at low drive speeds of the rotating bodies 20, 22, 26, since the drive speed of the electric motor 2 is not linked to the rotation speed of the rotating bodies 20, 22, 26. In doing so, it is not necessary to oversize the centrifugal pumps 411, 412 to be able to meet the fuel flow rate requirements at low drive speeds of the rotating bodies 20, 22, 26, in particular from the variable geometries 4200.Furthermore, the user of the electric motor also makes it possible to optimize the power taken from the rotating bodies 20, 22, 26, if applicable.

[0052] In another variant, a gear of the accessory housing is connected to at least one of the rotor part of the first centrifugal pump 411 and the rotor part of the second centrifugal pump 412 to drive it in rotation relative to the stator part. In this other variant, it may be useful to provide an auxiliary member connected to the main circuit 41 to provide sufficient fuel pressure, both in the secondary circuit 42 and in the delivery duct 414, at low operating speeds of the rotating bodies 20, 22, 26.

[0053] Figure 4 and Figure 5 illustrate characteristics of the centrifugal pumps 411, 412 for two distinct operating regimes, one illustrated by a solid line, the other by a dotted line.

[0054] Figure 4 represents, for each of the first centrifugal pump 411 and the second centrifugal pump 412, the evolution of the differential pressure (i.e., the difference between the fuel pressure at the discharge port 4112, 4122 and the fuel pressure at the intake port 4110, 4120) as a function of the fuel flow rate delivered by the centrifugal pump 411, 412. As visible in Figure 4, this evolution is different depending on the operating speed of the centrifugal pump 411, 412, that is to say depending on the drive speed of the rotor part of the pump relative to its stator part.

[0055] Figure 5 represents, for each of the first centrifugal pump 411 and the second centrifugal pump 412, the evolution of the efficiency of the centrifugal pump 411, 412 as a function of the fuel flow rate delivered by the centrifugal pump 411, 412, for the same operating speeds as those illustrated in Figure 4. Here again, Figure 5 illustrates that this evolution is different depending on the operating speed of the centrifugal pump 411, 412.

[0056] To optimize the efficiency of the fuel control system 4, it should be operated so as to unbalance the first centrifugal pump 411 relative to the second centrifugal pump 412. More precisely, each of the first centrifugal pump 411 and the second centrifugal pump 412 should be configured, then operated, so that, whatever their speed, the first centrifugal pump 411 delivers a flow rate lower than the flow rate delivered by the second centrifugal pump 412 and introduces an increase in fuel pressure into the main circuit 41 which is lower than the increase in pressure introduced by the second centrifugal pump 412 into the main circuit 41.In this configuration, the fluid flow delivered by the first centrifugal pump 411 is, in fact, solely dedicated to supplying the combustion chamber 24, while the fluid flow delivered by the second centrifugal pump 412 is, for its part, dedicated both to supplying the combustion chamber 24 and to actuating the variable geometries 4200.

[0057] This is particularly visible in Figure 4 and Figure 5, in which the triangle marks the operating point of each of the first centrifugal pump 411 and the second centrifugal pump 412 when the aircraft 100 is cruising, while the star marks the operating point of each of the first centrifugal pump 411 and the second centrifugal pump 412 when the aircraft 100 is taking off. Each of these operating points corresponds to different speeds of the first centrifugal pump 411 and the second centrifugal pump 412, the operating speed associated with takeoff being illustrated by the solid line curve, while the operating speed associated with cruising is illustrated by dotted lines.

[0058] Benefits obtained

[0059] Generally, centrifugal pumps are more robust and more compact than positive displacement pumps.

[0060] On the other hand, the efficiency of centrifugal pumps depends on their operating point and can become very low if they operate far from the operating point where the efficiency is maximum, as seen in Figure 5.

[0061] Thanks to the fuel control system, in which the centrifugal pumps can be unbalanced, i.e. operate at different pressures and flow rates, with each of the centrifugal pumps operating close to its maximum efficiency, the entire operating range of the engine can be covered without it being necessary to size one and / or the other of the centrifugal pumps at the engine performance level imposing the greatest constraints on the fuel control system. In fact, regardless of the engine speed considered, the centrifugal pumps will always operate at their maximum efficiency. Furthermore, thanks to centrifugal pumps, it is not necessary to provide a reduction gear between an electric motor and the pump supplying a fuel control system of an aircraft engine, which allows the engine mass to be reduced.In fact, unlike positive displacement pumps, centrifugal pumps can be driven at higher speeds, which minimizes the size of the electric motor.

[0062] Furthermore, thanks to the configuration and operating mode of each of the first pump and the second pump, but also to the arrangement of the secondary circuit in relation to the main circuit, it is the second centrifugal pump which delivers the surplus fuel flow useful to the variable geometries, while the fuel flow transferred to the injectors of the combustion chamber is, in fact, delivered by the first centrifugal pump. Furthermore, it is the second centrifugal pump which provides the pressure necessary for the actuation of the variable geometries, the pressure required by the injectors being linked to the accumulation of the pressure provided by the first centrifugal pump and the pressure provided by the second centrifugal pump.

[0063] The benefits of this configuration and this mode of operation of each of the first pump and the second pump are also visible in Figure 5. Indeed, as visible in this figure, for each operating regime described with reference to Figure 4, the operating point of the first pump and the second pump, always illustrated, respectively by the triangle for cruising, and by the star for takeoff, is close to the maximum efficiency of the centrifugal pump corresponding to this operating regime, and are identical, or almost identical, for the two centrifugal pumps. More precisely, the efficiency of the fuel regulation system, taken as a whole, remains constant, or almost constant, whatever the operating regime of the aircraft. Ultimately, this configuration makes it possible to achieve optimal efficiency with a system equipped with a double centrifugal pump.

[0064] Finally, even in embodiments where a restriction is necessary, it dissipates less energy in the form of heat than when a positive displacement pump is used. The unbalancing of the first centrifugal pump relative to the second centrifugal pump is all the more relevant since the pressure required by the variable geometries is not too great.

[0065] In fact, the pressure provided by the second centrifugal pump is set to the value required by the variable geometries, without being oversized, regardless of the operating speed. Thus, an optimization of the size and mass of the centrifugal pumps, the overall efficiency of the system and, where applicable, the size and mass of the electric motor, are advantageously obtained.

Claims

DEMANDS 1. Fuel regulation system (4) for an aircraft engine (2) (100), the system (4) comprising: a fuel source (40); a supply line (400) connected to the fuel source (40); a main circuit (41) comprising: a first centrifugal pump (411) comprising an inlet port (4110) and a discharge port (4112), the inlet port (4110) being connected to the supply line (400); a connecting line (413) connected to the discharge port (4112) of the first centrifugal pump (411); a second centrifugal pump (412) comprising an inlet port (4120) and a discharge port (4122), the inlet port (4120) of the second centrifugal pump (412) being connected to the connecting line (413); a discharge conduit (414) connected to the discharge port (4122) of the second centrifugal pump (412), the discharge conduit (414) being further configured to be connected to an injector of a combustion chamber (24) of the engine;and a secondary circuit (412) comprising at least one component (4200) configured to be actuated by fuel pressure circulating within the secondary circuit (412), the secondary circuit (412) comprising an inlet conduit (420) connected to the discharge conduit (414) and an outlet conduit (421) connected to the connecting conduit (413).

2. System (4) according to claim 1, wherein the first centrifugal pump (411) and the second centrifugal pump (412) are configured such that, in operation, the first centrifugal pump (411) provides a first pressure and the second centrifugal pump (412) provides a second pressure, the first pressure being lower than the second pressure.

3. System (4) according to any one of claims 1 and 2, wherein the first centrifugal pump (411) and the second centrifugal pump (412) are configured such that, in operation, the first centrifugal pump (411) delivers a first flow of fluid solely dedicated to supplying the combustion chamber (24) and the second centrifugal pump (412) delivers a second flow of fluid dedicated both to supplying the combustion chamber (24) and to actuation of at least one component (4200), the first flow being less than the second flow.

4. System (4) according to any one of claims 1 to 3, wherein the main circuit (41) further comprises a restriction (417) arranged at the discharge conduit (414) and configured to control the fuel flow delivered by the second centrifugal pump (412).

5. System (4) according to any one of claims 1 to 4, wherein at least one component (4200) is a variable geometry device.

6. System (4) according to any one of claims 1 to 5, wherein each of the first centrifugal pump (411) and the second centrifugal pump (412) comprises a rotor part and a stator part, the rotor part of the first centrifugal pump (411) being rotationally fixed to the rotor part of the second centrifugal pump (412).

7. System (4) according to any one of claims 1 to 6, wherein each of the first centrifugal pump (411) and the second centrifugal pump (412) comprises a rotor part and a stator part, the stator part of the first centrifugal pump (411) being fixedly mounted on the stator part of the second centrifugal pump (412).

8. Aircraft engine (2) (100) comprising: a system (4) according to any one of claims 6 and 7; an electric motor (2) comprising a rotating element connected to at least one of the rotor part of the first centrifugal pump (411) and the rotor part of the second centrifugal pump (412) to drive it in rotation relative to the stator part; an electrical power supply connected to the electric motor (2) to transmit electrical power to it in order to drive the rotating element in rotation; and a combustion chamber (24) comprising an injector connected to the discharge conduit (414) to receive fuel from the second centrifugal pump (412).

9. Aircraft engine (2) (100) comprising: a system (4) according to any one of claims 6 and 7; an accessory housing comprising a rotating element connected to at least one of the rotor part of the first centrifugal pump (411) and the rotor part of the second centrifugal pump (412) to drive it in rotation relative to the stator part; a rotating body connected to the accessory housing to drive the rotating element; and a combustion chamber (24) comprising an injector connected to the delivery conduit (414) to receive fuel from the second centrifugal pump (412).

10. Aircraft (100) comprising an aircraft engine (2) (100) according to one of claims 8 and 9.

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