TURBOMACHINE FOR AN AIRCRAFT AND ITS COOLING METHOD

Abstract

Turbomachine (2) for an aircraft, this turbomachine (2) comprising: - an annular flow duct (V) of a gas flow (F3), - an engine (M), - at least one piece of equipment (E), - a first heat exchanger (210) of the ACOC type, which is capable of being swept by said gas flow (F3) and which includes a first oil circuit (C1) connected to an engine cooling system (S1), - a second heat exchanger (220) of the ACOC type, which is capable of being swept by said gas flow (F3) and which includes a second oil circuit (C2) connected to a cooling system (S2) of said at least one piece of equipment (E), and - at least one third heat exchanger (230, 230') of the ACOC type, which is capable of being swept by said gas flow (F3) and which includes at least one third oil circuit (C3, C3'). Figure for the summary: Figure 4

Description

Title of the invention: TURBOMACHINE FOR AN AIRCRAFT AND ITS COOLING METHOD Technical field of the invention

[0001] The present invention relates to a turbomachine for an aircraft, and a method for cooling this turbomachine. Technical Downstream Plan

[0002] A turbomachine for an aircraft comprises various components and / or equipment requiring lubrication and / or cooling, such as bearings, gears, etc. Furthermore, new-generation turbomachines include onboard electric machines for hybridization, these machines requiring lubrication and cooling by oil. The heat generated by these components is carried by the oil and dissipated to available onboard cooling sources.

[0003] Among the cold sources available on board are air and fuel. The oil can be cooled first by the fuel in a fuel / oil heat exchanger (generally known by the acronym FCOC, for "Fuel Cooled Oil Cooler"), which also has the function of preheating the fuel before it enters the combustion chamber. FCOC heat exchangers are not sufficient to absorb all heat loss because the fuel temperature is limited due to safety constraints. Additional cooling can be provided by an air / oil heat exchanger (generally known by the acronym ACOC for "Air Cooled Oil Cooler").

[0004] Air constitutes a cold source of oil cooling and can come, for example, from the secondary flow in the case of a twin-flow turbomachine, or from the tertiary flow in the case of a triple-flow turbomachine as illustrated in [Fig.1] and described in document WO-A1-2023 / 099533.

[0005] ACOC heat exchangers are increasingly required in the next generation of engines due to the significant increase in heat dissipation, mainly due to:

[0006] - Future engines are larger, which increases the need for lubrication and oil cooling;

[0007] - the presence of a speed reducer in new motor architectures, this The gearbox transmits very high mechanical power and needs to be lubricated and cooled by oil.

[0008] - the addition of electric machines on board an engine for hybridization, these machines need to be lubricated and cooled with oil.

[0009] An engine may have several oil circuits, each with a defined function, for example a first circuit for cooling the oil dedicated to the lubrication and cooling of the engine, a second for the lubrication and cooling of electrical machines, etc.

[0010] The oil temperature and flow rate must be controlled according to the corresponding circuit. For example, the oil used to lubricate and cool electrical machines has a different temperature range than that used for engine cooling. Thus, the ACOC heat exchanger is preferably divided into several exchangers, each exchanger dedicated to a specific oil circuit. These different exchangers are installed in parallel in one of the turbomachine's oil channels and occupy a portion of that channel.

[0011] In [Fig. 2], the ACOC 1 heat exchanger can be used to cool the engine cooling oil. The ACOC 2 heat exchanger can be used to cool the oil of the electric machines for the turbomachine hybridization.

[0012] Each of the ACOCs 1 and 2 occupies a given angular sector of the vein. The vein V is delimited by coaxial annular walls 101, 102 which are connected to each other by structural arms 100 to ensure mechanical strength. The angular sectors denoted by "A" are sectors where air flows without any obstruction (no ACOC exchanger).

[0013] Each of the two heat exchangers must be sized for the most critical case in order to dissipate the thermal power over all other phases of flight.

[0014] The ACOC 1 heat exchanger is divided in [Fig.3] into two parts:

[0015] - la: part of the ACOC 1 heat exchanger used to ensure oil cooling engine on all phases of flight except the most critical phases.

[0016] - 1b: part of the ACOC 1 heat exchanger which is added to part 1a in order to ensure the additional cooling on the most critical phases (for example, an aircraft on the ground on an extremely hot day).

[0017] The ACOC 2 heat exchanger is divided in [Fig.3] into two parts:

[0018] - 2a: part of the ACOC 2 heat exchanger used to cool the machine oil electrical systems are used on all phases of flight except the most critical phases, and

[0019] - 2b: part of the ACOC 2 heat exchanger which is added to part aa in order to ensure the additional cooling on the most critical phases.

[0020] The two ACOC heat exchangers (ACOC 1 and ACOC 2) perform different cooling functions. This results in different design phases for each of the two heat exchangers and leads to oversized heat exchangers during other phases and flight conditions, which has a direct impact on the pressure drop on the air side (aerothermal performance) and on the mass of the heat exchangers. This has the effect of increasing the specific fuel consumption (SFC) of the turbomachine and consequently fuel consumption (FB for Fuel Burn).

[0021] There is therefore a need to optimize the aerothermal performance of these exchangers.

[0022] The solution presented in EP-A1-2 472 067 proposes an ACOC heat exchanger buried in a compartment of the turbomachine. The heat exchanger is integrated into a cavity opening into a radially internal wall of the secondary flow. A portion of the secondary airflow, drawn from the secondary flow, passes through the buried heat exchanger, where it is heated and then reinjected into the secondary flow. A controlled scoop, formed, for example, by a pivoting and / or translationally movable flap, is positioned at the cavity inlet so as to extend into the secondary flow and provide an adjustable airflow to the buried heat exchanger. The movable flap of the scoop can generate pressure losses in the secondary flow when it is open. The movable flap is controlled to close when the heat exchange requirement in the buried heat exchanger becomes zero.

[0023] Patent WO-A1-2022 / 123168A1 proposes a solution for optimizing the aerothermal performance of the heat exchanger in a cavity and reducing pressure losses through coupling between a movable flap and a movable element that allows adaptation to the different flight phases of the turbomachine and the aircraft. It relates to a heat exchange system for a turbomachine, comprising a cavity including an air inlet, a heat exchanger disposed in the cavity and comprising a first circuit in which a first fluid can circulate, a movable flap mounted at the air inlet and moving between two positions allowing or preventing, respectively, the circulation of an airflow in the cavity, and a control device comprising a movable element for driving the movement of the movable flap.The control device is arranged in the heat exchanger supply circuit and is configured to allow or prevent the flow of the first fluid to the heat exchanger and simultaneously act on one of the two positions of the movable flap.

[0024] The present invention offers a solution to the problems and needs of the prior art, which is simple, effective and economical. Summary of the invention

[0025] The invention relates to a turbomachine for an aircraft, this turbomachine comprising:

[0026] - an annular flow vein of a gas stream,

[0027] - an engine,

[0028] - at least one piece of equipment,

[0029] - a first ACOC-type heat exchanger, which is capable of being swept by said gas flow and which includes a first oil circuit connected to an engine cooling system,

[0030] - a second heat exchanger of the ACOC type, which is capable of being swept by said gas flow and which includes a second oil circuit connected to a cooling system of said at least one piece of equipment,

[0031] characterized in that it further comprises:

[0032] - at least one third ACOC-type heat exchanger, which is suitable for being swept by said gas flow and comprising at least one third oil circuit, and

[0033] - connecting valves of the first, second and third circuits, which are suitable for adopt three configurations:

[0034] - a first configuration in which said at least one third circuit is isolated from the first and second circuits,

[0035] - a second configuration in which the first circuit is connected in series with said at least a third circuit, the first and third circuits being isolated from the second circuit, and

[0036] - a third configuration in which the second circuit is connected in series with said at least a third circuit, the second and third circuits being isolated from the first circuit.

[0037] In this application, ACOC exchanger means an air / oil exchanger, ACOC being the acronym for "Air Cooled OU Cooler".

[0038] The invention proposes sizing each of the first and second heat exchangers to ensure oil cooling during all flight phases except the critical phases, and adding a third heat exchanger in the stream that is common to the first and second exchangers and will serve to provide supplementary oil cooling during the critical phases. Since the critical phases for the first and second exchangers are not necessarily identical, the third exchanger can be used as a common exchanger to provide supplementary cooling during the critical flight phases of each of the two oil circuits. Because the third exchanger is common to the other two exchangers, this makes it possible to reduce the cross-section of the stream occupied by the exchangers, and consequently to reduce the pressure losses related to the exchangers.

[0039] Since the oil circuit of the third heat exchanger is likely to be connected to the circuits of the first and second heat exchangers, it is preferable that the oils circulating in the circuits of the first and second heat exchangers be identical. Otherwise, the oil circulating in the third heat exchanger, which might originate, for example, from the first heat exchanger, could be contaminated by oil from the second heat exchanger that had previously circulated in the third heat exchanger, and vice versa.

[0040] The turbomachine according to the invention may comprise one or more of the following features, taken individually or in combination with each other:

[0041] - the connecting valves are three-way valves and there are two of them, one first three-way valve comprising a first port connected to an outlet of the first circuit, a second port connected to an outlet of the second circuit and a third port connected to an inlet of said at least one third circuit, and a second three-way valve comprising a first port connected to the outlet of the first circuit, a second port connected to the outlet of the second circuit and a third port connected to an outlet of said at least one third circuit;

[0042] - the first circuit includes a first outlet valve connected to an outlet of the first circuit, and the second circuit includes a second outlet valve connected to an outlet of the second circuit;

[0043] - the first outlet valve is located downstream of a connection point of the outlet of the first circuit at the first port of the first three-way valve, and upstream of a connection point from the outlet of the first circuit to the first port of the second three-way valve, and the second outlet valve is located downstream of a connection point from the outlet of the second circuit to the second port of the first three-way valve, and upstream of a connection point from the outlet of the second circuit to the second port of the second three-way valve;

[0044] - said at least a third heat exchanger is interposed circumferentially between the first and second heat exchangers in said vein;

[0045] - said at least one third heat exchanger is of the number two or more, said second configuration being of two types:

[0046] - type I, in which the first circuit is connected in series with the third circuit of a only one of the third exchangers, these first and third circuits being isolated from the second circuit, and

[0047] — type II, in which the first circuit is connected in series with the third circuits of all the third exchangers, these first and third circuits being isolated from the second circuit;

[0048] and said third configuration being of two types:

[0049] - type I, in which the second circuit is connected in series with the third circuit of a only one of the third exchangers, these second and third circuits being isolated from the first circuit;

[0050] — type II, in which the second circuit is connected in series with the third circuit of all third exchangers, these second and third circuits being isolated from the first circuit;

[0051] - said vein is a secondary flow vein of a secondary gas flow, the turbomachine further comprising a primary flow channel of a primary gas flow inside said engine;

[0052] - said vein is a tertiary flow vein of a tertiary gas flow, the tur bomachine further comprising two annular veins, respectively primary and secondary, for the flow of primary and secondary gas streams;

[0053] - the tertiary vein is radially intercalated between the primary and secondary veins;

[0054] - said at least a third heat exchanger has a cooling capacity lower than that of the first heat exchanger, and lower than that of the second heat exchanger;

[0055] - said at least one piece of equipment includes electrical machines;

[0056] — said engine is a gas generator.

[0057] The invention further relates to a cooling method in a turbomachine as described above, in which it comprises three stages corresponding to the three aforementioned configurations:

[0058] - a first step corresponding to the first configuration, in which the The engine cooling system is supplied with oil exiting the first heat exchanger, and the cooling system of said at least one piece of equipment is supplied with oil exiting the second heat exchanger.

[0059] - a second step corresponding to the second configuration, in which the the engine cooling system is supplied with oil exiting the first heat exchanger and passing through said at least one third heat exchanger, and the cooling system of said at least one piece of equipment is supplied with oil exiting the second heat exchanger, and

[0060] - a third step corresponding to the third configuration, in which the The engine cooling system is supplied with oil exiting the first heat exchanger, and the cooling system of said at least one piece of equipment is supplied with oil exiting the second heat exchanger and passing through said at least one third heat exchanger.

[0061] The method according to the invention may comprise one or more of the following features or steps, taken individually or in combination with each other:

[0062] - the second stage occurs when the aircraft is on the ground and the temperature ex ambient temperature is above a predetermined threshold,

[0063] - the third step occurs when the aircraft is in descent phase and the The ambient outdoor temperature is above a predetermined threshold, and

[0064] - the first step occurs by default in other cases;

[0065] - the first heat exchanger is supplied with oil at a maximum temperature of 160°C, and the second heat exchanger is supplied with oil at a temperature maximum of 90°C. Brief description of the figures

[0066] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0067] [Fig-1] [Fig.1] is a schematic axial cross-sectional view of a turbomachine for an aircraft;

[0068] [Fig.2] [Fig.2] is a very schematic cross-sectional view of a vein of a gas flow, in which heat exchangers are located,

[0069] [Fig.3] [Fig.3] is a view similar to that of [Fig.2] and shows a breakdown of the heat exchangers,

[0070] [Fig.4] [Fig.4] is a schematic cross-sectional view of a vein of a gas flow system, in which three heat exchangers are located, and illustrates one embodiment of the invention,

[0071] [Fig. 5] [Fig. 5] is a very schematic view of the three heat exchangers of the [Fig.4] and shows a first configuration of connecting valves for the heat exchangers,

[0072] [Fig.6] [Fig.6] is a view similar to that of [Fig.4] and shows the first valve configuration,

[0073] [Fig.7] [Fig.7] is a view similar to that of [Fig.5] and shows a second configuration of the interconnecting valves of the heat exchangers,

[0074] [Fig.8] [Fig.8] is a view similar to that of [Fig.6] and shows the second valve configuration,

[0075] [Fig.9] [Fig.9] is a view similar to that of [Fig.5] and shows a third configuration of the interconnecting valves of the heat exchangers,

[0076] [Fig. 10] [Fig. 10] is a view similar to that of [Fig. 6] and shows the third valve configuration,

[0077] [Fig. 11] [Fig. 11] is a view similar to that of [Fig. 4] and illustrates a variant of the realization of the invention,

[0078] [Fig. 12] [Fig. 12] is a very schematic view of the heat exchangers of the [Fig. 1 1] and shows a first configuration of the connecting valves of the exchangers,

[0079] [Fig. 13] [Fig. 13] is a very schematic view of the heat exchangers of the [Fig. 1 1] and shows one type of each of the second and third configurations of the interconnecting valves of the exchangers,

[0080] [Fig. 14] [Fig. 14] is a very schematic view of the heat exchangers of the [Fig. 1 1] and shows another type of the second configuration of the heat exchanger connecting valves, and

[0081] [Fig. 15] [Fig. 15] is a very schematic view of the heat exchangers of the [Fig.11] and shows another type of the third configuration of the interconnecting valves of the exchangers. Detailed description of the invention

[0082] [Fig. 1] shows a turbomachine 2 for an aircraft. This turbomachine 2 illustrates the prior art as described in document WO-A1-2023 / 099533, but can be used to describe an installation environment of the invention.

[0083] The turbomachine 2 evolves in an airflow F whose movement relative to the turbomachine 2 is generated by the rotation of the propeller 4 and the forward movement of the aircraft on which the turbomachine 2 is mounted.

[0084] The airflow F is separated by a first separation nozzle 10 into a radially internal airflow F' and a radially external airflow F2, called the secondary flow F2. The propeller 4 can be arranged upstream of the first separation nozzle 10 or downstream.

[0085] The radially internal airflow F' passes through a movable wheel 12 which directs it towards a second separation nozzle 14 suitable for separating the radially internal airflow F' into a primary flow Fl and a tertiary flow F3, the latter being distinct from the secondary flow F2.

[0086] The first separation nozzle 10 includes an internal wall forming a first external guide wall 11 of the radially internal airflow F', said first external guide wall 11 forming a convex profile seen from said radially internal airflow F'.

[0087] The second separation nozzle 14 includes an external wall forming a second external guide wall 13 of the radially internal airflow F' having passed through the moving wheel 12, said second external guide wall 13 forming a convex profile seen from the tertiary flow F3.

[0088] The tertiary flow F3 enters a tertiary flow vein 16 radially external to said primary flow FL. The tertiary flow F3 passes through a heat exchanger 18 disposed in the tertiary flow vein 16.

[0089] The turbomachine 2 is illustrated symmetrically with respect to the longitudinal axis 8. Indeed, the tertiary flow vein 16 is annular and circumferentially continuous over 360° around the longitudinal axis 8. For this purpose, the tertiary flow F3 is a flow which crosses annularially the tertiary flow vein 16.

[0090] In this configuration, the tertiary flow F3 extends essentially along the axial direction and in a position radially included between the primary flow Fl and the secondary flow F2.

[0091] The tertiary flow F3 extends in the tertiary flow vein 16 from the internal radial airflow F' downstream of the moving wheel 12 and to the secondary flow F2 after passing through the heat exchanger 18.

[0092] The turbomachine 2 further includes a stator (not shown) arranged upstream of the heat exchanger 18 at the level of the tertiary flow vein 16. Advantageously, the stator allows the tertiary flow F3 to be straightened before it passes through the heat exchanger 18 in order to minimize the aerodynamic disturbances of the tertiary flow F3 which can be caused by the moving wheel 12, this allows the heat exchange between the air and the oil to be optimized.

[0093] The stator corresponds to a row of stator blades arranged in the tertiary flow vein downstream of the separation nozzle 14. Alternatively, the stator can be arranged upstream of the separation nozzle 14 and downstream of the moving wheel 12.

[0094] The heat exchanger 18 extends radially and axially in an upstream section 20 of the tertiary flow vein 16, presenting a longitudinal section diverging in the direction of the flow of the tertiary flow F3.

[0095] The heat exchanger 18 is arranged axially between the low pressure compressor 17 and the high pressure compressor 15 in the example shown. A VBV type discharge channel 19 (Variabe Bleed Valve) having an outlet through an internal wall of the tertiary flow vein 16 and arranged axially downstream of the heat exchanger 18, the VBV channel provides a discharge function by returning part of the primary flow Fl to the tertiary flow F3, this allows for the evacuation of any ice particles from the primary flow Fl to avoid clogging of the high pressure compressor 15, particularly when the flow rate of the primary flow Fl becomes too low.

[0096] Advantageously, the arrangement of the outlet of the channel “VBV” 19 downstream of the heat exchanger 18 makes it possible to protect the latter from a possible risk of clogging.

[0097] The heat exchanger 18 can extend continuously over 360° in the upstream section 20 of the vein 16 around the longitudinal axis 8 of the turbomachine 2. Preferably, the heat exchanger 18 extends discontinuously over 360° around the longitudinal axis 8 by subdividing into several angular segments and each can ensure a heat exchange function between the air and the oil which can be different from one segment to another.

[0098] The heat exchanger 18 is of the "ACOC" type, an acronym for the English expression "Air Cooled OR Cooler", comprising oil passages which extend in the tertiary flow vein, said oil passages extend particularly in a radial and axial direction between an upper wall and a lower wall of said heat exchanger 18. Advantageously, the "ACOC" 18 heat exchanger allows heat exchange between air and oil, preferably with air cooling of the oil. Indeed, the oil temperature can reach an operating temperature of up to 180°C and a flow rate reaching 30000 l / h. In this regard, the exchanger 18 can provide cooling for the oil used in several aircraft components, including an engine, a gearbox, a generator engine and any electronic component requiring cooling.

[0099] A single heat exchanger 18 can combine the cooling of several functions or oil circuits of the turbomachine, depending on various parameters related to the oil cooling requirements, i.e., inlet temperatures, flow rates, required outlet temperature, or air conditions. The different circuits can be in thermal contact or isolated. The heat exchanger 18, and in particular its oil passages, can withstand a low oil temperature of -54°C.

[0100] Figures 2 and 3 have been described above.

[0101] Figure 4 illustrates one embodiment of the invention and shows in a very clear way schematic of an annular flow vein V of a gas flow in a turbomachine.

[0102] This turbomachine can be of the triple-flow type as described above and illustrated in [Fig. 1]. It is then understood that the V channel is a tertiary 16 channel of flow of a tertiary flow F3.

[0103] Alternatively, the turbomachine could be of the dual-flow type, and the V-flow could be a secondary flow-flow from a secondary flow.

[0104] It is therefore understood that the type of turbomachine is not limiting within the scope of the present invention.

[0105] The turbomachine according to the invention comprises, in addition to the V-shaped section, an engine M and at least one piece of equipment E.

[0106] The engine M is preferably the gas generator of the turbomachine and therefore comprises at least one compressor, one annular combustion chamber, and at least one turbine.

[0107] Said at least one piece of equipment E is for example an electrical machine or several electrical machines.

[0108] The V-shaped channel has an annular shape around an axis 8 which is generally the longitudinal axis of the turbomachine. The channel comprises two coaxial annular walls, respectively internal 101 and external 102, which are connected to each other by radial arms 100, four in number in the example shown.

[0109] The arms 100 divide the V vein into angular sectors, some of which are empty to allow the gas flow to pass without obstruction, and others are occupied by exchangers 210, 220, 230.

[0110] The turbomachine is equipped with three ACOC type heat exchangers 210, 220, 230.

[0111] The first exchanger 210 is suitable for being swept by the gas flow flowing into the vein V and includes a first oil circuit Cl connected to an SI system for cooling the M engine.

[0112] The second exchanger 220 is capable of being swept by the gas flow and includes a second oil circuit C2 connected to a cooling system S2 for the equipment E.

[0113] The third exchanger 230 is also suitable for being swept by the gas flow and includes a third oil circuit C3.

[0114] In the example shown, each exchanger is located in the vein V and occupies a portion of the cross-section of this vein V. For example, the first exchanger 210 may occupy the entire radial extent or dimension of the vein, or only a portion of this radial extent, and extend circumferentially over a portion, for example 2 / 3, of an angular sector of the vein V between two arms 100. The second exchanger 220 may occupy the entire radial extent or dimension of the vein, or only a portion of this radial extent, and extend circumferentially over a portion, for example 2 / 3, of another angular sector of the vein V between two arms 100. The third exchanger 230 may occupy the entire radial extent or dimension of the vein, or only a portion of this radial extent, and extend circumferentially between the two exchangers 210, 220.The third interchange 230 can, for example, occupy the remainder of the circumferential space of the angular sector in which the second interchange 220 is located.

[0115] Preferably, the third exchanger 230 has a cooling capacity less than that of the first heat exchanger 210, and less than that of the second heat exchanger 220. In practice, this may mean that the third exchanger 230 occupies a portion of the gas flow passage cross-section in the vein V, which is less than that of the first heat exchanger 210, and less than that of the second heat exchanger 220.

[0116] Figures 5 and following show the fluidic links between the exchangers 210, 220, 230 and in particular between the circuits Cl, C2, C3 of these exchangers.

[0117] The turbomachine according to the invention comprises valves 310, 320 connecting the first, second and third circuits Cl, C2, C3, which are capable of adopting three distinct configurations illustrated in figures 5 and following.

[0118] According to a first configuration illustrated in [Fig.5] and 6, the third circuit C3 is isolated from the first and second circuits Cl, C2.

[0119] According to a second configuration illustrated in [Fig.7] and 8, the first and third circuits Cl, C3 are connected in series and are isolated from the second circuit C2.

[0120] According to a third configuration illustrated in [Fig. 9] and [Fig. 10], the second and third circuits C2, C3 are connected in series and are isolated from the first circuit CL

[0121] Advantageously, the connecting valves 310, 320 are three-way valves.

[0122] These valves 310, 320 can be two in number:

[0123] - a first three-way valve 310 comprises a first port 310a connected to an outlet Cls of the first circuit Cl, a second port 310b connected to an output C2s of the second circuit C2 and a third port 310c connected to an input C3e of the third circuit C3, and

[0124] - a second three-way valve 320 has a first port 320a connected to the output Cs of the first circuit, a second 320b port connected to the C2s output of the second circuit C2 and a third 320c port connected to a C3s output of the third circuit C3.

[0125] The first circuit Cl may include a first outlet valve 410 connected to the outlet Cls of the first circuit Cl. The first circuit Cl could also include a first inlet valve (not shown) connected to the inlet Cle of the first circuit CL

[0126] The second circuit C2 may include a second outlet valve 420 connected to the outlet C2s of the second circuit C2. The second circuit C2 could also include a second inlet valve (not shown) connected to the inlet C2e of the second circuit C2.

[0127] In the example shown, the first outlet valve 410 is located downstream of a connection point PI of the outlet Cls of the first circuit Cl to the first port 310a of the first three-way valve 310, and upstream of a connection point P2 of the outlet Cls of the first circuit Cl to the first port 320a of the second three-way valve 320. Similarly, the second outlet valve 420 is located downstream of a connection point P3 of the outlet C2s of the second circuit C2 to the second port 310b of the first three-way valve 310, and upstream of a connection point P4 of the outlet C2s of the second circuit C2 to the second port 320b of the second three-way valve 320.

[0128] The present invention also relates to a cooling method in the tur-bomachine according to the invention, this method comprising three steps corresponding to the three aforementioned configurations.

[0129] According to a first step corresponding to the first configuration, the SI cooling system of the engine M is supplied with oil exiting the first heat exchanger 210, and the S2 cooling system of the equipment E is supplied with oil exiting the second heat exchanger 220. This step and this configuration are illustrated in Figures 5 and 6, in which the solid arrows show the circulation of oil in each of the heat exchangers 210, 220. The heat exchanger 230 is isolated and is not used in this step / configuration.

[0130] This first step / configuration can be adopted by default in most phases of turbomachine operation and aircraft flight.

[0131] According to a second step corresponding to the second configuration, the SI engine cooling system M is supplied with oil exiting the first heat exchanger 210 and passing through the third heat exchanger 230, and the S2 cooling system of the or Equipment E is supplied with oil exiting the second exchanger 220. This step and configuration are illustrated in figures 7 and 8 in which the solid arrows show the circulation of the oil in each of the exchangers 210, 220, 230. The outlet Cls of the first exchanger 210 is connected to the inlet C3e of the third exchanger 230, so the oil exiting the first exchanger 210 circulates in the third exchanger 230 in order to be further cooled.

[0132] This second step / configuration can be adopted when the aircraft is on the ground and the ambient outside temperature is above a predetermined threshold.

[0133] According to a third step corresponding to the third configuration, the engine cooling system S3 of the M is supplied with oil exiting the first heat exchanger 210, and the cooling system S2 of the equipment E is supplied with oil exiting the second heat exchanger 220 and passing through the third heat exchanger 230. This step and this configuration are illustrated in Figures 9 and 10, in which the solid arrows show the circulation of the oil in each of the heat exchangers 210, 220, 230. The outlet C2s of the second heat exchanger 220 is connected to the inlet C3e of the third heat exchanger 230, so the oil exiting the second heat exchanger 220 circulates in the third heat exchanger 230 in order to be further cooled.

[0134] This third step / configuration can be adopted when the aircraft is in descent phase and the ambient outside temperature is above a predetermined threshold.

[0135] Figures 11 to 15 illustrate an alternative embodiment in which there are at least two or more third interchanges 230, 230'.

[0136] The first and second interchanges 210, 220 are similar to those described above.

[0137] The two third exchangers 230, 230' are both capable of being swept by the gas flow and each include a third oil circuit C3, C3'.

[0138] The third exchanger 230 can occupy the entire radial extent or dimension of the vein, or only a part of this radial extent, and extend circumferentially over one half of the remaining circumferential space of the angular sector in which the second exchanger 220 is located. The third exchanger 230' can occupy the entire radial extent or dimension of the vein, or only a part of this radial extent, and extend circumferentially over the other half of the remaining circumferential space of the angular sector in which the second exchanger 220 is located.

[0139] The third heat exchangers 230, 230' may have identical or different cooling capacities. In practice, this may mean that the third heat exchangers 230 occupy portions of the flow passage cross-section of gases in vein V, which are identical or different.

[0140] Figures 12 and following show the fluidic links between the exchangers 210, 220, 230, 230' and in particular between the circuits Cl, C2, C3, C3' of these exchangers.

[0141] The turbomachine according to the invention comprises valves 310, 320, 330, 340 connecting the first, second and third circuits Cl, C2, C3, C3'.

[0142] Advantageously, the connecting valves 310, 320, 330, 340 are three-way valves.

[0143] These valves 310, 320, 330, 340 can be four in number:

[0144] - a first three-way valve 310 comprises a first port 310a connected to an outlet Cls of the first circuit Cl, a second port 310b connected to an output C3's of the third circuit C3', and a third port 310c connected to an input C3e of the third circuit C3,

[0145] - a second three-way valve 320 has a first port 320a connected to the output C1s of the first circuit, a second 320b port connected to the C2s output of the second circuit C2, and a third 320c port connected to a C3s output of the third circuit C3,

[0146] - a third three-way valve 330 has a first port 33a connected to the outlet C3s of the third circuit C3, a second port 330b connected to the output C2s of the second circuit C2, and a third port 330c connected to an input C3'e of the third circuit C3', and

[0147] - a fourth three-way valve 340 has a first port 340a connected to the output Cs of the first circuit, a second 340b port connected to the C2s output of the second circuit C2, and a third 340c port connected to a C3's output of the third circuit C3'.

[0148] The first circuit Cl may include a first outlet valve 410 connected to the outlet Cls of the first circuit CL. The first circuit Cl could also include a first inlet valve (not shown) connected to the inlet Cle of the first circuit CL.

[0149] The second circuit C2 may include a second outlet valve 420 connected to the outlet C2s of the second circuit C2. The second circuit C2 could also include a second inlet valve (not shown) connected to the inlet C2e of the second circuit C2.

[0150] In the example shown, the first outlet valve 410 is located downstream of a connection point P5 of the outlet Cls of the first circuit Cl to the first port 310a of the first three-way valve 310, and upstream of connection points P6, P7 of the outlet Cls of the first circuit Cl to the first port 320a of the second three-way valve 320, and to the first port 340a of the fourth three-way valve 340. Similarly, the second outlet valve 420 is located downstream of a connection point P8 of the outlet C2s of the second circuit C2 to the second port 330b of the third three-way valve 310, and upstream of connection points P9, P10 of the outlet C2s of the second circuit C2 to the second port 320b of the second three-way valve 320, and to the second port 340b of the fourth three-way valve 340.

[0151] The valves 310, 320, 330, 340 are capable of adopting three distinct configurations illustrated in Figures 12 and following, as well as two types for each of the second and third configurations.

[0152] According to a first configuration illustrated in [Fig.12], the third circuits C3, C3' are isolated from the first and second circuits Cl, C2.

[0153] The SI cooling system of the M engine is supplied with oil exiting the first heat exchanger 210, and the S2 cooling system of the equipment E is supplied with oil exiting the second heat exchanger 220. This first stage / configuration can be adopted by default in most phases of operation of the turbomachine and flight of the aircraft.

[0154] According to a second configuration illustrated in [Fig. 13], the first and third circuits Cl, C3 are connected in series, on the one hand, and the second and third circuits C2, C3' are connected in series on the other hand.

[0155] This [Fig. 13] illustrates a first type of the second configuration with regard to the first exchanger 210 and also a first type of the third configuration with regard to the second exchanger 220.

[0156] The SI system for cooling the M engine is supplied with oil exiting the first heat exchanger 210 and then passing through the third heat exchanger 230, and the S2 system for cooling the equipment E is supplied with oil exiting the second heat exchanger 220 and then passing through the third heat exchanger 230'.

[0157] The outlet Cls of the first heat exchanger 210 is connected to the inlet C3e of the third heat exchanger 230, so the oil exiting the first heat exchanger 210 flows through the third heat exchanger 230 to be further cooled. The outlet C2s of the second heat exchanger 220 is connected to the inlet C3'e of the third heat exchanger 230', so the oil exiting the second heat exchanger 220 flows through the third heat exchanger 230' to be further cooled.

[0158] This first type of each of the second and third configurations can be adopted when the aircraft is on the ground and the ambient outside temperature is above a predetermined threshold, or when the aircraft is in descent phase and the ambient outside temperature is above a predetermined threshold.

[0159] According to a second type of the second configuration illustrated in [Fig.14], the first and third circuits Cl, C3, C3' are all connected in series and are isolated from the second circuit C2.

[0160] The SI system for cooling the M engine is supplied with oil exiting the first heat exchanger 210 and then passing through the third heat exchangers 230, 230', and the S2 system for cooling the equipment E is supplied with oil exiting the second heat exchanger 220.

[0161] The Cls output of the first interchange 210 is connected to the C3e input of the third exchanger 230, and the outlet C3s of the third exchanger 230 is connected to the inlet C3'e of the other third exchanger 230', so the oil that comes out of the first exchanger 210 circulates in the third exchangers 230, 230' in order to be further cooled.

[0162] This second type of the second configuration can be adopted when the aircraft is on the ground and the ambient outside temperature is above a predetermined threshold.

[0163] According to a second type of the third configuration illustrated in [Fig. 15], the second and third circuits C2, C3, C3' are all connected in series and are isolated from the first circuit Cl.

[0164] The S2 cooling system for the equipment E is supplied with oil exiting the second heat exchanger 220 and then passing through the third heat exchangers 230, 230', and the SI cooling system for the engine M is supplied with oil exiting the first heat exchanger 210.

[0165] The outlet C2s of the second exchanger 220 is connected to the inlet C3”e of the third exchanger 230', and the outlet C3s of the third exchanger 230' is connected to the inlet C3e of the other third exchanger 230, so the oil which comes out of the first exchanger 210 circulates in the third exchangers 230', 230 in order to be further cooled.

[0166] This second type of the third configuration can be adopted when the aircraft is in descent phase and the ambient outside temperature is above a predetermined threshold.

[0167] The present invention also relates to a cooling method in the tur-bomachine according to the invention, this method comprising three steps corresponding to the three aforementioned configurations and to the types mentioned above for each of the second and third configurations.

[0168] The first heat exchanger 210 can be supplied with oil at a maximum temperature of 160°C.

[0169] The second exchanger 220 can be supplied with oil at a maximum temperature of 90°C.

Claims

Demands

1. Turbomachine (2) for an aircraft, this turbomachine (2) comprising: - an annular flow duct (V) of a gas flow (F3), - an engine (M), - at least one piece of equipment (E), - a first heat exchanger (210) of the ACOC type, which is capable of being swept by said gas flow (F3) and which includes a first oil circuit (C1) connected to an engine cooling system (S1), - a second heat exchanger (220) of the ACOC type, which is capable of being swept by said gas flow (F3) and which includes a second oil circuit (C2) connected to a cooling system (S2) of said at least one piece of equipment (E), characterized in that it further comprises: - at least one third heat exchanger (230, 230') of the ACOC type, which is capable of being swept by said gas flow (F3) and which includes at least one third oil circuit (C3, C3'), and - valves (310, 320, 330, 340) connecting the first, second and third circuits (C3, C3'), which are capable of adopting three configurations: - a first configuration in which said at least one third circuit (C3, C3') is isolated from the first and second circuits (C1, C2), - a second configuration in which the first circuit (C1) is connected in series with said at least one third circuit (C3, C3'), the first and third circuits (C1, C3, C3') being isolated from the second circuit (C2), and - a third configuration in which the second circuit (C2) is connected in series with said at least one third circuit (C3, C3'), the second and third circuits (C2, C3, C3') being isolated from the first circuit (Cl).

2. Turbomachine (2) according to claim 1, wherein the connecting valves (310, 320) are three-way valves and are two in number, a first three-way valve (310) having a first port (310a) connected to an outlet (Cls) of the first circuit (Cl), a second port (310b) connected to an outlet (C2s) of the second circuit (C2) and a third port (310c) connected to an inlet (C3e) of said at least one third circuit (C3), and a second three-way valve (320) having a first port (320a) connected to the outlet (Cls) of the first circuit (Cl), a second port (320b) connected to the output (C2s) of the second circuit (C2) and a third port (320c) connected to an output (C3s) of said at least one third circuit (C3).

3. Turbomachine (2) according to claim 1 or 2, wherein the first circuit (Cl) comprises a first outlet valve (410) connected to an outlet (Cls) of the first circuit (Cl), and the second circuit (C2) comprises a second outlet valve (420) connected to an outlet (C2s) of the second circuit (C2).

4. Turbomachine (2) according to claims 2 and 3, wherein the first outlet valve (410) is located downstream of a connection point (PI) of the outlet (Cls) of the first circuit (Cl) to the first port (310a) of the first three-way valve (310), and upstream of a connection point (P2) of the outlet (Cls) of the first circuit (Cl) to the first port (320a) of the second three-way valve (320), and the second outlet valve (420) is located downstream of a connection point (P3) of the outlet (C2s) of the second circuit (C2) to the second port (310b) of the first three-way valve (310), and upstream of a connection point (P4) of the outlet (C2s) of the second circuit (C2) to the second port (320b) of the second three-way valve (320).

5. Turbomachine (2) according to any one of the preceding claims, wherein said at least one third heat exchanger (230, 230') is circumferentially intercalated between the first and second heat exchangers (210, 220) in said vein (V).

6. Turbomachine (2) according to any one of the preceding claims, wherein said at least one third heat exchanger (230, 230') is of two or more numbers, said second configuration being of two types: - type I, wherein the first circuit (C1) is connected in series with the third circuit (C3) of only one of the third heat exchangers (330), these first and third circuits (C1, C3, C3') being isolated from the second circuit (C2), and - type II, wherein the first circuit (C1) is connected in series with the third circuits (C3, C3') of all the third heat exchangers (230, 230'), these first and third circuits (C1, C3, C3') being isolated from the second circuit (C2), and said third configuration being of two types: - type I, wherein the second circuit (C2) is connected in series with the third circuit (C3') of only one of the third heat exchangers (230'), these second and third circuits (C2, C3, C3') being isolated from the first circuit (Cl). — type II, in which the second circuit (C2) is connected in series with the third circuits (C3, C3') of all the third exchangers (230, 230'), these second and third circuits (C2, C3, C3') being isolated from the first circuit (Cl).

7. Turbomachine (2) according to any one of the preceding claims, wherein said flow (V) is a secondary flow of a secondary gas stream, the turbomachine (2) further comprising a primary flow of a primary gas stream (Fl) within said engine.

8. Turbomachine (2) according to any one of claims 1 to 6, wherein said flow (V) is a tertiary flow of a tertiary gas stream (F3), the turbomachine further comprising two annular flow of primary and secondary gas streams respectively (F1, F2).

9. Turbomachine (2) according to the preceding claim, wherein the tertiary vein is radially intercalated between the primary and secondary veins.

10. Turbomachine (2) according to any one of the preceding claims, wherein said at least a third heat exchanger (230, 230') has a cooling capacity lower than that of the first heat exchanger (210), and lower than that of the second heat exchanger (220).

11. Turbomachine (2) according to any one of the preceding claims, wherein said at least one piece of equipment (E) comprises electrical machines.

12. A cooling method in a turbomachine (2) according to any one of the preceding claims, wherein it comprises three stages corresponding to the three aforementioned configurations: - a first stage corresponding to the first configuration, in which the engine (M) cooling system (SI) is supplied with oil exiting the first heat exchanger (210), and the cooling system (S2) for said at least one piece of equipment (E) is supplied with oil exiting the second heat exchanger (220), - a second stage corresponding to the second configuration, in which the engine (M) cooling system (SI) is supplied with oil exiting the first heat exchanger (310) and passing through said at least one third heat exchanger (230, 230'), and the cooling system (S2) dissement of said at least one piece of equipment (E) is supplied with oil exiting the second heat exchanger (220), and - a third stage corresponding to the third configuration, in which the engine cooling system (SI) (M) is supplied with oil exiting the first heat exchanger (210), and the cooling system (S2) of said at least one piece of equipment (E) is supplied with oil exiting the second heat exchanger (220) and passing through said at least one third heat exchanger (230, 230').

13. A method according to claim 12, wherein: - the second step occurs when the aircraft is on the ground and the ambient outside temperature is above a predetermined threshold, - the third step occurs when the aircraft is in descent phase and the ambient outside temperature is above a predetermined threshold, and - the first step occurs by default in other cases.

14. A method according to claim 12 or 13, wherein the first heat exchanger (210) is supplied with oil at a maximum temperature of 160°C, and the second heat exchanger (220) is supplied with oil at a maximum temperature of 90°C.

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