FUEL SUPPLY SYSTEM OF A TURBOMACHINE

Abstract

The invention relates to a fuel supply system (200) for a turbomachine (100), the system (200) comprising at least: a centrifugal pump (300) having at least one impeller (302) with vanes driven in rotation by a shaft (310) so as to provide a fuel flow; a supply line (340) for the centrifugal pump connected to the centrifugal pump (300) and to a fuel tank (202); the system (200) further comprising: at least one jet nozzle (320) disposed in the line (340); and a stability control device (360) comprising a conduit (362) connecting the jet nozzle (324) to a branch (306b) of the centrifugal pump (300), this branch being supplied with fuel driven by the impeller. Figure for the abstract: Fig. 6

Description

Title of the invention: FUEL SUPPLY SYSTEM FOR A TURBOMACHINE Technical field of the invention

[0001] The present invention relates to the field of turbomachines. It relates more particularly to a fuel supply system, a fuel supply circuit comprising the supply system, a turbomachine comprising the supply circuit and a method for controlling stability in the supply circuit of the turbomachine. Technological background

[0002] Turbomachines installed on an aircraft are equipped with a fuel supply circuit, delivering the fuel to the combustion chamber, which must be regulated as needed according to the flight conditions. The fuel supply circuit generally comprises a main pump which sends the fuel to a hydromechanical unit before injection into the combustion chamber. The assembly is arranged to ensure, at the outlet to the combustion chamber, a fuel flow adapted to the need.

[0003] The fuel regulation system is generally composed of a main regulator, controlling the injection flow rate into the combustion chamber and the activation flow rate of variable geometries of the turbomachine, supplied by the main fuel pump.

[0004] Conventional fuel supply circuits generally incorporate a positive displacement pump as the main pump. The use of these pumps requires the installation of a recirculation loop through which the hydromechanical unit must return excess fuel to the pump, in order to be able to regulate the injected flow rate. This recirculation reduces the overall efficiency of the circuit and, in fact, causes the fuel to heat up, thus limiting the cooling capacity of the oil circuits.

[0005] To improve the efficiency of the fuel supply circuit, one approach is to regulate the rotational speed of the volumetric pump.

[0006] However, implementing this approach requires an increase in pump size, which may lead to very low rotational speed operation that is not suitable for the technology.

[0007] Another approach consists of using a centrifugal pump comprising an impeller whose speed is regulated to adapt the pressure delivered to the needs of a circuit downstream of the hydromechanical group.

[0008] However, to achieve sufficient efficiency to limit heating, the impeller of the centrifugal pump must be driven at a high rotation speed.

[0009] Furthermore, the needs of the turbomachine imply a wide range of injected flow rates. However, the usual use of centrifugal pumps is limited around the point of.

[0010] For example, and in a non-limiting manner, an industrial centrifugal pump operates at a flow rate of the order of + / -30% of a nominal flow rate, whereas the needs of the turbomachine can cover a range of 5 to 100%.

[0011] Furthermore, operation at very low flow rate can lead to the appearance of hydrodynamic operating instabilities at the pump inlet which have the consequence of degrading the hooking capacity of the pump defined by a parameter NPSH (Net Positive Suction Height) which makes it possible to determine the correct operation of the pump in the fuel supply circuit.

[0012] Furthermore, the increase in rotation speed, and therefore in flow rate, also contributes to degrading this attachment capacity and the need to cover a case of loss of the pump.

[0013] [Fig. 1] illustrates for example, and in a non-limiting manner, the hooking capacity of a fast centrifugal pump at the nominal flow rate used in a low pressure stage of an aircraft turbomachine.

[0014] A so-called “stall” zone can be observed in which the hooking capacity of the pump does not allow proper operation of the aircraft turbomachine.

[0015] For example, and in a non-limiting manner, in the event of a failure of the pump used to supply a fuel flow to a fuel supply circuit of the turbomachine, the system must be able to operate correctly with a pressure which may be in the stall zone of the centrifugal pump or even further to the left of said zone, which cannot in this case meet the need and therefore the correct operation of the aircraft.

[0016] We generally distinguish two types of NPSH parameters: an NPSHreq parameter called required and an NPSHdisp parameter called available.

[0017] The required NPSHreq parameter is set by the intrinsic (factory) characteristics of the pump and varies depending on the engine speed and flow rate. It indicates the suction capacity of the pump at a given moment of its operation. The lower the NPSHreq value, the higher the suction capacity of the pump.

[0018] As for the available parameter NPSHdisp, it depends on the type of installation and measures, at a point in the fuel supply circuit, the difference between the absolute pressure of the fuel at this point and its saturated vapor pressure at a given temperature.

[0019] When the absolute pressure of the fuel is lower than its saturated vapor pressure, which is equivalent to NPSHdisp lower than NPSHreq, and at partial flow rates, there is the appearance of hydrodynamic instabilities such as a rotating reflux at the inlet of the centrifugal pump and the appearance of a depression zone with the creation of a cavitation "torch" extending far upstream of the pump. Cavitation is manifested by the appearance of bubbles that move with the fuel in the supply circuit to the place where there is more pressure and end up recondensing. It is also possible for the bubbles to burst (explode or impose) which causes erosion of the pump, vibrations, noise, ..., which contribute to reducing the performance and life of the centrifugal pump.

[0020] Backflow can occur for flow rates less than approximately 50% of the nominal flow rate, and cavitation "flare" can become significant when the flow rate drops below 20% of the nominal flow rate.

[0021] There are solutions in the prior art implemented so that this reflux no longer modifies the behavior of the fuel at the pump inlet.

[0022] For example, [Fig. 2] illustrates a prior art centrifugal pump 600, comprising an axial inlet 602, a radial outlet 604 and a stability control device 700 disposed at the axial inlet of the centrifugal pump 600 in order to reduce the backflow phenomenon at the inlet of the pump.

[0023] The control device comprises an inlet 702 arranged in the vicinity of the radial outlet 604 of the centrifugal pump 600, an outlet 706 arranged in the vicinity of the axial inlet 602 of the centrifugal pump 600 and a conduit 704 connecting the inlet and outlet of the control device 700.

[0024] In operation, a portion F1 of the fuel flow F0 entering the pump is diverted and passes through the inlet 702 of the device. This diverted flow F1 circulates in the opposite direction to the incoming flow F0 and is injected into the pump via the outlet 706 in the vicinity of the pump inlet. This recirculation of the fuel, which results in an increase in the flow rate at the pump inlet, makes it possible to reduce the reflux at the pump inlet and to gain in hooking capacity (NPSH) at low flow rates.

[0025] At high flow rate, there is no or very little backflow and the pump is close to its nominal operating point. However, this solution does not meet the pressure requirement over the entire operating range of an aircraft turbomachine as described above.

[0026] [Fig. 3] illustrates a similar system with a 600' axial pump and which makes it possible to increase the flow rate entering the pump (to approach the design flow rate), without impacting the output flow rate, and therefore on the overall characteristic of the 600' axial pump.

[0027] The axial pump 600' comprises an axial inlet 602, an axial outlet 604, an impeller 608 with blades or propellers and a 606 bypass arranged at the height of the pump impeller blades.

[0028] The power supply system also comprises a stability control device 700 which comprises an inlet 702 arranged at the bypass 606 of the axial pump 600', an outlet 706 arranged in the vicinity of the axial inlet 602 of the pump and a conduit 704 connecting the inlet and outlet of the control device 700.

[0029] In operation, the control device 700 collects fuel (flow rate FJ in the first step of the pump, via the bypass 606 to recirculate it by injection upstream at the inlet of the pump 602. The collected fuel is mixed with the fuel entering the pump (flow rate Fo).

[0030] At low flow rate, the pressure generated by the impeller increases, which creates greater upstream circulation.

[0031] By increasing the flow rate on the leading edge of the blading, there is a better distribution of the fluid along the blading, reducing or even eliminating the reflux zone.

[0032] Just like the system described in [Fig.2], at high flow rate, when the pressure generated by the impeller is low, there is little flow entering the control device. Backflow is almost non-existent and the pump is close to the nominal operating point.

[0033] It may thus be desirable to provide a power supply system which makes it possible to overcome at least some of the aforementioned problems and constraints. Summary of the invention

[0034] A fuel supply system for a turbomachine is therefore proposed, the system comprising at least: - a centrifugal pump comprising at least: • a paddle wheel, • a shaft carrying said impeller and configured to rotate said impeller so as to provide a fuel flow; • an axial fuel inlet for supplying fuel to the impeller, and a radial fuel outlet for delivering fuel driven by the impeller; - a supply pipe for the centrifugal pump, one end of which is connected to the axial inlet of the centrifugal pump and one opposite end of which is intended to be connected to a fuel tank; characterized in that the system further comprises: - at least one jet pump arranged in the pipeline and comprising at least one outlet oriented towards the axial inlet of the centrifugal pump, said at least one jet pump further comprising at least one inlet; and - a stability control device comprising a pipe connecting said to the

[0035]

[0036]

[0037]

[0038]

[0039] at least one inlet of said at least one jet pump to a bypass of the centrifugal pump, this bypass being supplied with fuel driven by the impeller. To ensure proper operation of the turbomachine over the entire flow range, and in particular to avoid the appearance of instability phenomena at low flow rates, it will be necessary to: - collect fuel via the stability control device manifold at the centrifugal pump bypass; - injecting the fuel collected in the jet pump via the stability control device injector to mix it with the fuel flow from the tank; and - to increase the pressure at the inlet of the impeller of the centrifugal pump by means of the jet pump; The installation of a bypass of the centrifugal pump and / or the coupling to a jet pump makes it possible to increase the flow rate at the pump inlet and to reduce or eliminate hydrodynamic instability phenomena, without impacting the flow rate at the impeller outlet. Thus, the solution as described makes it possible to ensure a sufficient pressure level for proper operation of the turbomachine over the entire flow range while reducing the hydrodynamic instability phenomena present at low flow rates. The invention also allows for savings in energy and material resources by adapting to the pressure requirement while avoiding oversizing the pump components. The invention may further comprise one or more of the following optional features, in any technically possible combination: - the bypass is arranged upstream of the impeller in the direction of fuel entry into the pump, between the axial inlet of the impeller and its radial outlet; - the bypass is located at the height of the blades of the impeller of the centrifugal pump; - the bypass is arranged at the exit of the wheel; - the pipe comprises at a first end, arranged at the bypass, a fuel collector and at a second end, opposite the first end, a fuel injector arranged at the inlet of the jet pump; - the centrifugal pump has an open or semi-open impeller; - the jet nozzle comprises an intermediate portion having a flow section smaller than that of the portions located at the ends of said nozzle; - the system comprises coupling means arranged at the interface between the centrifugal pump and the jet pump; - the coupling means comprise at least one seal; - the system includes a speed control device configured to control the rotation speed of the centrifugal pump impeller.

[0040] The invention also relates to a supply circuit for a turbomachine comprising at least: - a hydromechanical group configured to control at least the fuel outlet to a combustion chamber of the turbomachine; - the power supply system according to one of the preceding claims, for providing a fuel flow to the hydromechanical group; - a fuel tank supplying fuel to the supply system.

[0041] The invention also relates to a turbomachine comprising at least one supply circuit according to the invention.

[0042] The invention also relates to a method for controlling stability in a fuel supply circuit of a turbomachine according to the invention, the method comprising: - fuel collection via the stability control device collector; - injection of fuel into the jet horn via the injector of the device stability control; - increasing the pressure at the inlet of the impeller of the centrifugal pump by means of the jet pump. Brief description of the figures

[0043] The invention will be better understood with the aid of the following description, given solely by way of example and with reference to the appended drawings in which: - [Fig. 1] shows a curve representative of the hooking capacity of a fast centrifugal pump at the nominal flow rate and supplying a fuel circuit of a low pressure stage of a turbomachine of an aircraft, - [Fig. 2] shows very schematically a half-section of a supply system comprising a centrifugal pump and a stability control device according to the prior art; - [Fig.3] shows very schematically a supply system comprising an axial pump and a stability control device according to the prior art; - [Fig.4] shows very schematically a half-section of a turbomachine capable of using the invention, - [Fig.5] shows very schematically a power supply circuit which can use the invention; - [Fig.6] shows very schematically a fuel supply system according to a first variant of the invention; - [Fig.7] shows very schematically a fuel supply system according to a second variant of the invention; - [Fig.8] schematically shows a stability control method according to the invention. Detailed description of the invention

[0044] By convention, in the description below, the term “axial” (or longitudinal) qualifies the orientation of structural elements extending in the direction of a longitudinal axis. This longitudinal axis corresponds substantially to an axis of rotation or revolution. The term “radial” (or vertical) qualifies an orientation of structural elements extending in a direction perpendicular to the longitudinal axis.

[0045] With reference to [Fig.4], an example of a turbomachine capable of using the invention will be described.

[0046] In this example, the turbomachine 100 is a dual-flow turbomachine. Those skilled in the art will understand that this example is non-limiting, and that the invention can be applied to any type of turbomachine equipped with a fuel supply circuit.

[0047] The turbomachine 100 comprises at least one fan 110, low pressure 114 and high pressure 118 compressors, a combustion chamber 108 (mark incorrectly positioned), high pressure 120 and low pressure 122 turbines.

[0048] The turbomachine further comprises a motor shaft (not shown). Generally, the assembly of high-pressure compressors 118 and high-pressure turbines 120 rotates as a unit on the motor shaft and forms the motor part of the turbomachine 100 with the combustion chamber 108.

[0049] The turbomachine may further comprise an accessory relay housing (not shown) and a fuel supply circuit 102. The accessory relay housing may comprise several gear trains connected to output shafts to drive various equipment.

[0050] Generally, the accessory relay box provides the link between the motor shaft and a starter / generator, not shown in [Fig.4], which can be used to drive the turbomachine 100 during the start-up phases or generate an electric current when the turbomachine is switched on.

[0051] The turbomachine may further comprise variable geometries 206 (not shown in [Fig.4]), previously mentioned, which can be activated under certain conditions of use. These variable geometries 206 are, for example and in a non-limiting manner, variable pitch blades at the inlet of a low pressure compressor.

[0052] Still with reference to [Fig.4], the air flow leaving the fan 110 is divided into a primary flow Q entering the engine and a secondary flow S surrounding the latter. The primary flow then passes through low pressure 114 and high pressure 118 compressors, the combustion chamber 108 supplied by the supply circuit 102 fuel supply circuit previously mentioned, then the high pressure 120 and low pressure 122 turbines.

[0053] With reference to [Fig.5], a fuel supply circuit 102 according to the invention will be described.

[0054] The circuit 102 may comprise a hydroelectric group 204 configured to control at least one fuel outlet to the combustion chamber 108 of the turbomachine. The hydromechanical group 204 may, furthermore, be configured to receive a flow rate instruction issued by a computer of the turbomachine 100, not shown, in order to meet a need. For example, and in a non-limiting manner, a takeoff.

[0055] The circuit 102 may further comprise a fuel supply system 200 and a tank 202 supplying fuel to the fuel supply system 200.

[0056] The fuel system 200 is connected to the hydromechanical group 204 in order to provide a fuel flow.

[0057] The circuit 102 may further comprise a variable geometry supply loop 206 of the turbomachine 100 connecting the pump 200 and the variable geometries 206.

[0058] [Fig.6] illustrates a first variant of the supply system 200 of the fuel supply circuit 102 according to the invention.

[0059] The feed system 200 comprises at least one centrifugal pump 300.

[0060] The centrifugal pump 300 comprises at least one impeller 302 and a shaft 310 extending along a longitudinal axis X and carrying the impeller 302. The shaft 310 is configured to drive the impeller 302 in rotation so as to provide a flow of fuel in the fuel supply circuit 102 of said turbomachine 100.

[0061] The centrifugal pump further comprises an axial fuel inlet 304 and at least one radial fuel outlet 306a intended to supply fuel to the hydromechanical group 204 and / or the variable geometries 206 or even a secondary circuit (not shown).

[0062] The centrifugal pump further comprises a bypass 306b arranged upstream of the impeller in the direction of entry of the fuel into the pump, between its axial inlet 304 and its radial outlet 306a.

[0063] Preferably, the bypass 306b is located at the height of the blades 314 of the impeller. 302 of the centrifugal pump 300 and preferably in the first steps of the blades 314.

[0064] Preferably, the centrifugal pump may have an open or semi-open impeller.

[0065] The power system 200 may further comprise a speed control device 312 configured to control a rotational speed of the impeller 302 of the centrifugal pump 300.

[0066] The supply system further comprises a supply pipe 340 of the centrifugal pump 200, one end 342 of which is connected to the axial inlet 304 and one opposite end 344 of which is intended to be connected to the fuel tank 202 of the fuel supply circuit 102.

[0067] The feed system further comprises a jet pump 320 arranged in the feed pipe 340, such that the jet pump 320 and the centrifugal pump 300 are arranged coaxially.

[0068] The jet pump 320 comprises at least one outlet 326 oriented towards the axial inlet 304 of the centrifugal pump and an inlet 324 connected to the reservoir 202.

[0069] The jet pump comprises an intermediate portion 322 having a flow section smaller than that of the portions located at the ends of the pump.

[0070] The supply system may further comprise coupling means 380 arranged at the interface between the centrifugal pump 300 and the jet pump 320.

[0071] The coupling means 380 comprise at least one seal.

[0072] The power supply system 200 further comprises a stability control device 360 ​​such as, for example, and in a non-limiting manner, the cavitation phenomenon.

[0073] The stability control device 360 ​​connects the inlet 324 of the horn to the bypass 306b of the centrifugal pump 300.

[0074] The stability control device 360 ​​comprises at a first end, disposed at the bypass, a fuel manifold 364b and at a second end, opposite the first end, a fuel injector 364a disposed at the inlet 324 of the jet pump 360.

[0075] The stability control device 360 ​​further comprises at least one elongated section 362 connecting the manifold 364b and the injector 364a.

[0076] The stability control device 360 ​​is configured to recover fuel at the bypass 306b of the centrifugal pump 300 by means of the manifold 364b and to inject it at the inlet 324 of the pump 320 by means of the injector 364a.

[0077] The fuel flow passing through the stability control device 360, called the active flow, is then mixed with the flow coming from the tank. The intermediate portion 322 of the jet pump 320, having a reduced section compared to the sections of the ends of the jet pump 320, makes it possible to transform the pressure into speed by the venturi effect. Thus, depending on the need for a hydraulic circuit downstream of the hydromechanical group of the fuel supply circuit (a high or low flow requirement), the mixture of momentum (of the active flow and the flow from the tank) associated with a divergent can allow an increase in pressure at the outlet of the jet pump connected to the axial inlet 304 of the centrifugal pump 300.

[0078] For example, when the need for a hydraulic circuit downstream of the fuel supply circuit corresponds to a high flow rate, the pressure generated by the impeller 302 is low and there is little flow rate passing through the stability control device 360 ​​via the bypass 306b of the centrifugal pump 300. When the need corresponds to a low flow rate, the pressure generated by the impeller increases and the flow rate passing through the stability control device 360 ​​is greater. It is thus possible to recover approximately more than 50% of the total pressure generated by the impeller of the centrifugal pump, without degrading the characteristic of the centrifugal pump.

[0079] Advantageously, those skilled in the art will understand that, when the need corresponds to a low flow rate, increasing the flow rate on the leading edge of the impeller 302, i.e. at the level of the axial inlet 304, by means of the stability control device 360, allows a better distribution of the fluid along the impeller. This has the effect of reducing or eliminating the backflow.

[0080] Furthermore, the increase in pressure between the jet pump and the centrifugal impeller has the effect of limiting cavitation at the axial inlet 304. This makes it possible to reach a pressure value necessary for the proper operation of the centrifugal pump, even for operation at maximum flow rate.

[0081] Advantageously, those skilled in the art will also understand that an arrangement of the bypass 306b of the centrifugal pump 300 upstream of the impeller makes it possible to increase the flow rate at the inlet of the pump and to reduce or eliminate hydrodynamic instability phenomena, without impacting the flow rate at the outlet of the impeller 302.

[0082] Thus, thanks to the stability control device 360 ​​and the jet pump 320, the pressure at the inlet of the impeller 302 of the centrifugal pump is increased, thus ensuring the attachment of the pump over the entire flow range (high and low flow) necessary for the proper operation of the turbomachine.

[0083] [Fig.7] illustrates a second variant of the power supply system 200.

[0084] In a similar manner to the supply system described above, and with reference to [Fig.7], the supply system 200 comprises a centrifugal pump 300 comprising at least one impeller 302 with blades 314 and a shaft 310 extending along a longitudinal axis X and carrying the impeller 302.

[0085] The centrifugal pump further comprises an axial fuel inlet 304 and at least one radial fuel outlet 306a intended to supply fuel to the hydromechanical group 204 and / or the variable geometries 206 or even a secondary circuit (not shown).

[0086] The centrifugal pump 300 also comprises a bypass 306b. In this second variant, the bypass 306b is arranged at the outlet of the impeller, that is to say downstream of the impeller in the direction of entry of the fuel into the pump.

[0087] Still with reference to [Fig.7], the supply system 200 further comprises a supply pipe 340 of the centrifugal pump 300, one end 342 of which is connected to the axial inlet 304 and one opposite end 344 of which is intended to be connected to the fuel tank 202 (not shown) of the fuel supply circuit 102. The supply system 200 may further comprise a speed regulating device 312 (not shown) controlling a rotation speed of the impeller 302 of the centrifugal pump 300.

[0088] The feed system may further comprise a jet pump 320 arranged in the feed pipe 340, such that the jet pump 320 and the centrifugal pump 300 are arranged coaxially.

[0089] The jet pump 320 comprises at least one outlet 326 oriented towards the axial inlet 304 of the centrifugal pump and an inlet 324 connected to the reservoir 202.

[0090] The jet pump comprises an intermediate portion 322 having a flow section smaller than that of the portions located at the ends of the pump.

[0091] The supply system may further comprise coupling means 380, for example and in a non-limiting manner sealing joints, arranged at the interface between the centrifugal pump 300 and the jet pump 320.

[0092] The power supply system 200 further comprises a stability control device 360 ​​stability control device such as, for example, and in a non-limiting manner, the cavitation phenomenon.

[0093] The stability control device 360 ​​connects the inlet 324 of the horn to the bypass 306b of the centrifugal pump 300.

[0094] The stability control device 360 ​​comprises at a first end, disposed at the bypass, a fuel manifold 364b and at a second end, opposite the first end, a fuel injector 364a disposed at the inlet 324 of the jet pump 360.

[0095] The stability control device is configured to recover fuel at the bypass 306b of the centrifugal pump 300 by means of the manifold 364b and to inject it at the inlet 324 of the pump 320 by means of the injector 364a.

[0096] Still with reference to [Fig.7], the fuel system may further comprise a drain 316 to reduce the fuel pressure in the pump and improve the stability of the system.

[0097] The invention also relates to a stability control method 400 in a fuel supply circuit of an aircraft turbomachine comprising the supply system described above.

[0098]

[0099]

[0100] The method 400, illustrated in [Fig.8], comprises at least: - 500 fuel collection via the stability control device manifold at the centrifugal pump bypass; - injecting 502 the fuel into the jet pump via the injector of the stability control device, the flow of fuel from the stability control device is then mixed with the flow of fuel from the tank; and - the increase 504 of the pressure at the inlet of the impeller of the centrifugal pump by means of the jet pump. This increase in pressure is achieved via the intermediate portion of the jet pump by the venturi effect. It is clear from the above description that the invention makes it possible to reduce or eliminate hydrodynamic instabilities upstream of the impeller of the centrifugal pump while increasing the pressure at the inlet of the centrifugal pump over the entire flow range in order to ensure proper operation of the turbomachine. The invention also allows for a gain in energy and material resources by adapting to the pressure requirement while avoiding oversizing the pump components. Indeed, the supply system allows the use of a fast centrifugal pump instead of a positive displacement pump and which is more easily controlled to adapt to the needs of the turbomachine. This allows the elimination of a recirculation loop from the hydromechanical group to the pump and therefore limits additional heating of the fuel. The elimination of the recirculation loop allows a gain in power consumption, which can be used to increase the cooling capacity of the fuel.

Claims

Claims

1. Fuel supply system (200) for a turbomachine (100), the system (200) comprising at least: - a centrifugal pump (300) comprising at least: • a bladed impeller (302); • a shaft (310) carrying said impeller (302) and configured to rotate said impeller (302) so as to provide a fuel flow; • an axial fuel inlet (304) for supplying fuel to the impeller, and a radial fuel outlet (306a) for delivering fuel driven by the impeller; - a supply pipe (340) of the centrifugal pump, one end (342) of which is connected to the axial inlet (304) of the centrifugal pump (300) and an opposite end (344) of which is intended to be connected to a fuel tank (202);characterized in that the system (200) further comprises: - at least one jet pump (320) arranged in the pipe (340) and comprising at least one outlet (326) oriented towards the axial inlet (304) of the centrifugal pump (300), said at least one jet pump further comprising at least one inlet; and - a stability control device (360) comprising a pipe (362) connecting said at least one inlet of said at least one jet pump (324) to a bypass (306b) of the centrifugal pump (300), this bypass being supplied with fuel driven by the impeller.;

2. System according to claim 1, in which the bypass (306b) is arranged upstream of the impeller in the direction of entry of the fuel into the pump, between the axial inlet (304) of the impeller and its radial outlet (306a).

3. System according to claim 2, in which the bypass (306b) is located at the height of the blades (314) of the impeller (302) of the centrifugal pump (300).

4. The system of claim 1, wherein the bypass (306b) is arranged at the exit of the spinning wheel (302).

5. System according to one of claims 1 to 4, in which the conduit (362) comprises at a first end, arranged at the bypass (306b), a fuel collector (364b) and at a second end, opposite the first end, a fuel injector (364a) arranged at the inlet (324) of the jet pump (320).

6. System according to one of claims 1 to 5, in which the centrifugal pump (300) has an open or semi-open impeller.

7. System according to one of claims 1 to 6, in which the jet nozzle (320) comprises an intermediate portion (322) having a flow section smaller than that of the portions located at the ends of said nozzle (320).

8. System (200) according to one of claims 1 to 7, comprising coupling means arranged at the interface between the centrifugal pump (300) and the jet pump (320).

9. System (200) according to the preceding claim, wherein the coupling means comprise at least one seal (380).

10. System according to one of claims 1 to 9, comprising a speed control device (312) configured to control a rotational speed of the impeller (302) of the centrifugal pump (300).

11. Fuel supply circuit (102) of a turbomachine (100) comprising at least: - a hydromechanical group (204) configured to control at least the fuel outlet to a combustion chamber (108) of the turbomachine (100); - the supply system (200) according to one of the preceding claims, to provide a fuel flow to the hydromechanical group (204); - a fuel tank (202) providing fuel to the supply system (200).

12. Turbomachine (100) comprising at least one circuit (102) according to the preceding claim.

13. Method (400) for stability control in a fuel supply circuit (102) of a turbomachine (100) according to the preceding claim in an aircraft, characterized in that it comprises: - the collection (500) of fuel via the collector of the device stability control; injecting (502) the fuel into the jet nozzle via the stability control device injector; increasing (504) the pressure at the inlet of the impeller of the centrifugal pump by means of the jet pump.

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