Device for supplying cryogenic fuel to the combustion chamber of a turbine engine

Abstract

The invention relates to a device (2) for supplying a combustion chamber (16) of a turbine engine (1) of an aircraft with cryogenic fuel. The device is characterized in that it comprises: a mixing chamber (21) receiving different flows of cryogenic fuel in a supercritical or gaseous state and connected to the combustion chamber (16), at least one heat exchanger (27A, 27B) between the cryogenic fuel and the air of the aircraft's air conditioning circuit, the at least one heat exchanger being installed in the line (201, 203, 204, 205, 206, 207) connecting the cryogenic fuel tank (20) to the mixing chamber (21).

Description

Technical Field

[0001] The field of the invention is that of aircraft turbine engines.

[0002] More specifically, the present invention relates to a device for supplying cryogenic fuel to a combustion chamber of a turbine engine of an aircraft and to a turbine engine of the aircraft, the turbine engine comprising a main flow passage which is sequentially provided with at least one air compressor, a combustion chamber supplied with cryogenic fuel and at least one turbine, the turbine engine being equipped with the device for supplying cryogenic fuel. Background Art

[0003] Cryogenic fuels are commonly used in space propulsion because they produce better thermodynamic yields. However, the transition of cryogenic fuels to the aviation sector and the industrialization of large-scale use require solving a number of technical problems.

[0004] Therefore, the use of liquid hydrogen has been proposed, as it would be able to reduce CO2 emissions to zero.

[0005] Another cryogenic fuel that can be used is liquefied natural gas (known by its abbreviation LNG), which has the additional advantage of being able to be used at much higher temperatures than liquid hydrogen, since LNG has a low relative humidity at 1 bar (10 5 The liquefaction temperature of liquefied natural gas is -161°C at 370 Pa, while that of liquid hydrogen is -252°C, which simplifies the use of liquefied natural gas.

[0006] It may also be desirable to use cryogenic fuels in the combustion chamber, no longer in a gaseous state but in a supercritical fluid state, which is not proposed in the cited prior art. It is worth reminding that when a fuel is at a temperature greater than its critical temperature and at a pressure greater than its critical pressure, the fuel reaches a supercritical fluid state.

[0007] However, in both cases, these cryogenic fuels still need to be transported in liquid form so that the volume of cryogenic fuel carried in the aircraft is acceptable, and then the cryogenic fuel is evaporated and / or heated so that it can be used in the combustion chamber. Summary of the invention

[0008] One object of the present invention is therefore to provide a device for supplying a combustion chamber of a turbine engine of an aircraft with cryogenic fuel, which device is able to evaporate this liquid cryogenic fuel or bring it to a supercritical state in an ecologically and energetically advantageous manner.

[0009] To this end, the invention relates to a device for supplying cryogenic fuel to a combustion chamber of a turbine engine of an aircraft comprising an air conditioning circuit.

[0010] According to the present invention, the system comprises:

[0011] - tanks for cryogenic fuels in liquid form,

[0012] a mixing chamber receiving different flows of cryogenic fuel in a supercritical state or in a gaseous state, the mixing chamber being configured to be connected to the combustion chamber in order to supply the combustion chamber with the cryogenic fuel in a supercritical state or in a gaseous state,

[0013] - at least one heat exchanger between the cryogenic fuel and the air of the aircraft's air conditioning circuit, at least one heat exchanger being installed in the line connecting the cryogenic fuel tank to the mixing chamber and in the line configured to be connected to the air conditioning circuit, in which heat exchange takes place in order to cool the air of the aircraft's air conditioning circuit and to increase the temperature of the cryogenic fuel coming from the tank.

[0014] By means of these features of the invention, it is possible to recover heat from the equipment present in the turbine engine in order to heat the cryogenic fuel and bring it into the gaseous or supercritical phase.

[0015] More precisely, having a heat exchanger between the cryogenic fuel and the air of the air conditioning circuit of the aircraft makes it possible to heat this fuel while reducing the size of the exchanger used in the air conditioning circuit and / or reducing the complexity of the system.

[0016] Other advantageous and non-limiting features according to the invention, taken individually or in combination:

[0017] - the device comprises at least one heat exchanger between the cryogenic fuel and the air circulating in the air compressor of the turbine engine, at least one heat exchanger being installed in the line connecting the cryogenic fuel tank to the mixing chamber, heat exchange taking place in the at least one heat exchanger in order to heat the cryogenic fuel and cool the air circulating in the air compressor of the turbine engine,

[0018] - the device comprises at least one cryogenic fuel / lubricating oil heat exchanger, at least one cryogenic fuel / lubricating oil heat exchanger being installed in the line connecting the cryogenic fuel tank to the mixing chamber, in which heat exchange takes place in order to heat the cryogenic fuel and cool the lubricating oil,

[0019] - the device comprises at least one heat exchanger between the cryogenic fuel and the cooling air for the turbine blades of the turbine engine, the at least one heat exchanger being installed in the line connecting the cryogenic fuel tank to the mixing chamber, in series with the cryogenic fuel / lubricating oil heat exchanger and downstream of the cryogenic fuel / lubricating oil heat exchanger, in which heat exchange takes place in order to heat the cryogenic fuel coming from the cryogenic fuel / lubricating oil heat exchanger and cool the cooling air for the turbine blades of the turbine engine,

[0020] - at least one of the heat exchangers between the cryogenic fuel and the air of the aircraft's air conditioning circuit, between the cryogenic fuel and the air circulating in the air compressor of the turbine engine, the cryogenic fuel / lubricating oil heat exchanger and between the cryogenic fuel and the cooling air for the turbine blades of the turbine engine is a supercritical exchanger capable of bringing the cryogenic fuel to a temperature above its critical temperature.

[0021] - at least one of the heat exchangers between the cryogenic fuel and the air of the aircraft's air conditioning circuit, between the cryogenic fuel and the air circulating in the air compressor of the turbine engine, the cryogenic fuel / lubricating oil heat exchanger and between the cryogenic fuel and the cooling air for the turbine blades of the turbine engine is a heat exchanger capable of bringing the cryogenic fuel into a gaseous state.

[0022] The heat exchanger between the cryogenic fuel and the air of the aircraft's air conditioning circuit is a heat exchanger between the evaporated cryogenic fuel and the air of the aircraft's air conditioning circuit, which performs a heat exchange between the air of the aircraft's air conditioning circuit and the cryogenic fuel evaporated in the cryogenic fuel tank.

[0023] - A heat exchanger between cryogenic fuel and the air of the aircraft's air conditioning circuit is a heat exchanger between cryogenic fuel and the air of the aircraft's air conditioning circuit, which performs a heat exchange between the air of the aircraft's air conditioning circuit and the cryogenic fuel stored in said cryogenic fuel tank.

[0024] -The device includes a high-pressure compressor for vaporized cryogenic fuel and a buffer tank for storing the cryogenic fuel in a gaseous state, the high-pressure compressor compresses the cryogenic fuel vaporized in the cryogenic fuel tank, the high-pressure compressor and the buffer tank are installed in series in a line connecting the upper part of the cryogenic fuel tank to the mixing chamber, and the buffer tank is installed downstream of the high-pressure compressor for vaporized cryogenic fuel.

[0025] - A heat exchanger between the boiled-off cryogenic fuel and the air of the aircraft's air conditioning circuit is installed in the line connecting the upper part of the cryogenic fuel tank to the mixing chamber, between the high-pressure compressor of the boiled-off cryogenic fuel and the buffer tank for storing the cryogenic fuel in the gaseous state.

[0026] The device comprises: a first heat exchanger between the cryogenic fuel and the air of the aircraft's air conditioning circuit, and a second heat exchanger between the cryogenic fuel and the air of the aircraft's air conditioning circuit, the first heat exchanger and the second heat exchanger being mounted in series between the cryogenic fuel tank and the mixing chamber.

[0027] The device comprises a first high-pressure pump which is arranged between the mixing chamber and the combustion chamber and which brings the low-temperature fuel from the mixing chamber to a high pressure before being introduced into the combustion chamber.

[0028] -The device comprises at least one heat exchanger between the cryogenic fuel and the air circulating in the air compressor of the turbine engine, installed in the line connecting the cryogenic fuel tank to the mixing chamber, in which heat exchange occurs in order to heat the cryogenic fuel and cool the air circulating in the air compressor of the turbine engine, the device also comprises at least one cryogenic fuel / lubricating oil heat exchanger, the at least one cryogenic fuel / lubricating oil heat exchanger is installed in the line connecting the cryogenic fuel tank to the mixing chamber, in which heat exchange occurs in order to heat the cryogenic fuel and cool the lubricating oil, and the heat exchanger between the cryogenic fuel and the air circulating in the air compressor of the turbine engine and the cryogenic fuel / lubricating oil heat exchanger are installed in parallel between the cryogenic fuel tank and the mixing chamber.

[0029] -The device comprises at least one heat exchanger between the cryogenic fuel and the air circulating in the air compressor of the turbine engine, installed in the line connecting the cryogenic fuel tank to the mixing chamber, in which heat exchange occurs in order to heat the cryogenic fuel and cool the air circulating in the air compressor of the turbine engine, the device also comprises at least one cryogenic fuel / lubricating oil heat exchanger, the at least one cryogenic fuel / lubricating oil heat exchanger is installed in the line connecting the cryogenic fuel tank to the mixing chamber, in which heat exchange occurs in order to heat the cryogenic fuel and cool the lubricating oil, and the device comprises a second high-pressure pump, which is arranged downstream of the cryogenic fuel tank, upstream of the heat exchanger between the cryogenic fuel and the air circulating in the air compressor of the turbine engine, and upstream of the cryogenic fuel / lubricating oil heat exchanger.

[0030] The second high-pressure pump is capable of bringing the cryogenic fuel to a pressure greater than its critical pressure.

[0031] The device comprises at least one valve upstream of each heat exchanger, and the opening and closing of these various valves are controlled by a central control unit.

[0032] - The cryogenic fuel is selected from liquid hydrogen and liquefied natural gas.

[0033] The invention also relates to a turbine engine for an aircraft, comprising a main air flow duct provided in sequence with at least one air compressor, a combustion chamber supplied with cryogenic fuel and at least one turbine.

[0034] According to the invention, the turbine engine comprises a device as described above for supplying cryogenic fuel to a combustion chamber of a turbine engine of an aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other characteristics, objectives and advantages of the invention will emerge from the following description, given in a purely illustrative and non-limiting manner and to be read with reference to the accompanying drawings, in which:

[0036] [ Figure 1 ] shows an overview of a turbine engine according to the invention, which can be equipped with a device for supplying cryogenic fuel to its combustion chamber.

[0037] [ Figure 2 ] is a schematic diagram of a first embodiment of an apparatus for supplying cryogenic fuel according to the present invention.

[0038] [ Figure 3 ] is a schematic diagram of a second embodiment of the device for supplying cryogenic fuel according to the present invention.

[0039] [ Figure 4 ] is a schematic diagram of a third embodiment of the device for supplying cryogenic fuel according to the present invention.

[0040] [ Figure 5 ] is a schematic diagram of a fourth embodiment of the device for supplying cryogenic fuel according to the present invention.

[0041] In all the drawings, the same elements are given the same reference numerals. DETAILED DESCRIPTION

[0042] The invention relates to a device for supplying cryogenic fuel to a combustion chamber of a turbine engine of an aircraft, such as an airplane.

[0043] Figure 1 An example of such a turbine engine 1 is shown. In the present case, this is a twin-spool, two-path turbine engine.

[0044] The turbine engine 1 is arranged along the direction of air flow (in other words, from upstream ( Figure 1in the left side) to the downstream ( Figure 1 The air inlet 10 is provided with a fan 11, which delivers air to a primary channel 12 on the one hand and to a secondary channel 13 on the other hand. The term "stream" shall refer to a space (in the form of an annular channel in this text) through which an air flow circulates.

[0045] The air flow flowing through the main flow passage 12 passes through a low-pressure air compressor 14 , a high-pressure air compressor 15 , a combustion chamber 16 , a high-pressure turbine 17 , and a low-pressure turbine 18 in sequence, and is then discharged through a main flow nozzle 19 .

[0046] Without exceeding the scope of the present invention, other types of turbine engines (e.g. single-rotor turbine engines) may be equipped with a cryogenic fuel supply device according to the present invention, whereby the single-rotor turbine engine comprises only one air compressor and only one turbine connected together by an axis, with the combustion chamber being arranged between the air compressor and the turbine.

[0047] Now, combine Figure 2 A device 2 according to the invention for supplying cryogenic fuel is described.

[0048] The device 2 comprises a tank 20 for storing a cryogenic fuel in liquid state. This cryogenic fuel is intended to be supplied to the combustion chamber 16 through various circuits to be described below.

[0049] Such cryogenic fuels are, for example, liquefied natural gas or liquid hydrogen.

[0050] It should be noted that although the cryogenic fuel is stored in liquid form in the tank 20, and although the tank 20 is preferably insulated, a portion of the fuel may vaporize within the tank and accumulate in the upper portion of the tank.

[0051] The device 2 comprises a mixing chamber 21 which receives different flows of cryogenic fuel in supercritical or gaseous state. The mixing chamber 21 is connected to the combustion chamber 16 via a line 200 so that the combustion chamber can be supplied with cryogenic fuel in supercritical or gaseous state.

[0052] Although not shown, injectors inject fuel into the combustion chamber 16 .

[0053] Advantageously, a first high-pressure pump 22 is arranged in line 200 between the mixing chamber 21 and the combustion chamber 16 in order to bring the cryogenic fuel in a gaseous or supercritical state from the mixing chamber 21 to a high pressure before introducing the cryogenic fuel into the combustion chamber 16. One or more air compressors compress the air upstream of the combustion chamber 16 so that a relatively high pressure (e.g. at least 50 bar, i.e. 50·10 5Pa). Therefore, in order for the fuel to be injected into the chamber 16, the pressure of the introduced fuel must be greater than the pressure of the chamber 16. Therefore, the efficiency of the thermodynamic cycle of the turbine engine is improved.

[0054] Preferably, the device 2 also comprises at least one heat exchanger 23 between the liquid cryogenic fuel and the air circulating in the compressor of the turbine engine.

[0055] The heat exchanger 23 is installed in the line 201 connecting the cryogenic fuel tank 20 (preferably, a point located in the lower part of the cryogenic fuel tank 20) ​​to the mixing chamber 21. In the lower part of the tank 20, the cryogenic fuel is liquid. The exchanger 23 is capable of performing heat exchange so as to heat the cryogenic fuel from the tank 20 on the one hand and to cool the air (schematically represented by flow F1 in the figure) circulating in the compressor on the other hand. The heat exchanger reduces the temperature of the entire flow of the compressor to reduce the work required for compression. This is called "intercooling". Heat exchange can be performed while compression is being performed, so the exchanger 23 is, for example, arranged in the casing of the compressor. The exchanger 23 can also be arranged between the low-pressure compressor 14 and the high-pressure compressor 15.

[0056] According to a first alternative embodiment, the exchanger 23 is a two-phase exchanger and is capable of passing the cryogenic fuel in the liquid state into the gaseous state. Thus, this exchanger 23 is, for example, a tube-and-shell exchanger.

[0057] According to a second alternative embodiment, the exchanger 23 is capable of bringing the cryogenic fuel to a temperature above its critical temperature. The exchanger 23 is then called a "supercritical" exchanger.

[0058] Preferably, a second high-pressure pump 24 is arranged in line 201 downstream of the tank 20 and upstream of the heat exchanger 23 .

[0059] Preferably, in the case where the exchanger 23 is a supercritical exchanger, the pump 24 is chosen so as to enable the cryogenic fuel to reach a pressure greater than its critical pressure.

[0060] Preferably, the device 2 further comprises a low temperature fuel / lubricating oil heat exchanger 25 .

[0061] The heat exchanger 25 is installed in the line 202 connecting the cryogenic fuel tank 20 to the mixing chamber 21. Preferably, the line 202 is connected to the second high-pressure pump 24 when the second high-pressure pump 24 is present.

[0062] This heat exchanger 25 is capable of exchanging heat in order to heat, on the one hand, the cryogenic fuel coming from the tank 20 and, on the other hand, cool the lubricating oil used to lubricate the various mechanical elements of the turbine engine 1. Arrows F2 in the figure indicate this flow of lubricating oil.

[0063] Inside the turbine engine, a certain number of mechanical elements must indeed be cooled by the lubricating oil in order to maintain the mechanical integrity of these mechanical elements. These mechanical elements are, for example, reduction gears of an accessory gearbox or bearings supporting a rotating shaft. Therefore, the oil heated by contact with these mechanical elements is cooled by the exchanger 25, leaves the exchanger 25 and can then be sent back to contact the various mechanical elements mentioned above.

[0064] According to a first alternative embodiment, the exchanger 25 is a two-phase exchanger, preferably a plate-fin exchanger. This exchanger is capable of passing the cryogenic fuel in the liquid state into the gaseous state.

[0065] According to a second alternative embodiment, the exchanger 25 is capable of bringing the cryogenic fuel to a temperature above its critical temperature. The exchanger 25 is then called a "supercritical" exchanger.

[0066] Preferably, the device 2 also includes a heat exchanger 26 between the cryogenic fuel and the cooling air of the turbine blades of the turbine engine 1. The heat exchanger 26 is installed in the line 202, in series with the heat exchanger 25 and located downstream of the heat exchanger 25 (relative to the flow direction of the cryogenic fuel in the line 202). The exchanger 26 is also located upstream of the mixing chamber 21.

[0067] On the one hand, this exchanger 26 can heat the cryogenic fuel in the gaseous state (if below the critical pressure and temperature) or in the supercritical state (if above the critical pressure and temperature) coming from the exchanger 25, and on the other hand, it can cool the air used to cool the blades of a single turbine or, in the case of a twin-spool turbine engine, the air used to cool the blades of the high-pressure turbine 17 and the low-pressure turbine 18. Arrows F3 in the figure indicate this flow of cooling air.

[0068] The air used to cool the turbine blades comes from the outlet of the compressor. At the outlet of the compressor, this air is hot. Using cryogenic fuel as a cold source, it is also possible to further cool the air used to cool the blades, so that less air is used compared to the technology of the prior art, so that less air can be extracted at the outlet of the compressor (especially the high-pressure compressor). Therefore, a larger amount of compressed air from the compressor can be directed into the combustion chamber 16, and the overall efficiency of the turbine engine is thus improved.

[0069] Injecting cold fuel into the combustion chamber 16 reduces combustion efficiency. It is therefore preferred to heat the cryogenic fuel again even after it has undergone a phase change or entered a supercritical state in the exchanger 25.

[0070] The exchanger 26 may be a two-phase exchanger, such as a plate-fin exchanger or a shell-and-tube exchanger, or may be a supercritical exchanger.

[0071] The second high-pressure pump 24 enables the pressure of the liquid cryogenic fuel to be increased before it enters the exchangers 23 and 25. Preferably, in the case where the exchangers 25 and / or 26 are supercritical exchangers, the pump 24 is selected to bring the cryogenic fuel to a pressure greater than its critical pressure.

[0072] In each exchanger 23 , 25 and 26 , the flows F1 , F2 and F3 circulate in opposite directions relative to the cryogenic fuel.

[0073] It should be noted that, as shown, exchanger 23 is mounted in parallel with exchangers 25 and 26 .

[0074] The device 2 also comprises at least one heat exchanger between the cryogenic fuel and the air of the air conditioning circuit of the aircraft, which at least one heat exchanger therefore interacts with an air conditioning circuit belonging to the aircraft.

[0075] exist Figure 2 In the exemplary embodiment of the device 2 shown, this type of heat exchanger is a heat exchanger between vaporized cryogenic fuel and air of the aircraft's air conditioning circuit and is denoted by reference numeral 27 .

[0076] The heat exchanger 27 is installed in a line 203 connecting the tank 20 to the mixing chamber 21. More specifically, the line 203 is connected to an upper portion of the tank 20, and the vaporized low-temperature fuel is accumulated in the upper portion of the tank 20.

[0077] This exchanger 27 thus makes it possible to further heat the evaporated cryogenic fuel in the gaseous state and to cool the air circulated in the air conditioning circuit of the aircraft, as will be described in greater detail below.

[0078] Preferably, the exchanger 27 is a two-phase exchanger, preferably a plate-fin exchanger.

[0079] Advantageously, a third high-pressure pump (or compressor) 28 is provided in line 203 downstream of tank 20 and upstream of heat exchanger 27. Such a pump makes it possible to increase the pressure of the cryogenic fuel before it is introduced into exchanger 27.

[0080] Advantageously, a buffer tank 29 of cryogenic fuel in the gaseous state is installed in the line 203 downstream of the exchanger 27 and upstream of the mixing chamber 21. Thus, during the ground movement of the aircraft, the cryogenic fuel in the gaseous state coming from the exchanger 27 is stored in this buffer tank 29. During a flight phase of the aircraft, this additional reserve of cryogenic fuel in the gaseous state can then be released from the tank 29 in order to be supplied to the combustion chamber 16 after entering the mixing chamber 21.

[0081] Preferably, valves 211, 212, 213 are provided upstream of each heat exchanger 27, 23 and 25 in the corresponding lines 203, 201 and 202, respectively, in order to regulate the flows circulating in these different exchangers. Preferably, valve 214 is also provided in line 203 downstream of a buffer tank 29 in which gaseous fuel is accumulated as required, or on the contrary, in order to allow the gaseous fuel in reserve to reach the mixing chamber 21. The opening and closing of these different valves are controlled by a central control unit 3, for example a computer or a programmable logic controller.

[0082] Now, combine Figure 2 An exemplary embodiment of an air conditioning circuit 4 of an aircraft is described.

[0083] This circuit 4 comprises a compressor 40 for conditioned air and a turbine 41 for conditioned air, which are connected together via a drive shaft 42. An additional motor 43 arranged on the shaft 42 provides mechanical energy supplementation so that the turbine 41 can drive the compressor 40 in rotation.

[0084] The inflowing air from the outlet of the air compressor 14 or 15 or the dedicated compressor of the aircraft is indicated by the arrow F4 in the figure. This inflowing hot air enters the compressor 40, where it is compressed and becomes hotter, and then circulates in the line 401, which connects the compressor 40 to the heat exchanger 27 between the vaporized cryogenic fuel and the air of the air conditioning circuit of the aircraft. The air provides heat to the vaporized cryogenic fuel that also circulates here. The slightly cooled compressed air then circulates in the line 402 that connects the exchanger 27 to the turbine 41. The air expands and cools again in the turbine 41, where it flows out through the line 403 so as to be directed into the circuit 5 of the conditioned air of the aircraft. The air thus flows out at a temperature suitable for the passengers in the cabin and is mixed with the recirculation flow in the mixing chamber 56 described below.

[0085] Now, an exemplary embodiment of a distribution circuit 5 of conditioned air of an aircraft will be described. Other embodiments of this circuit 5 are possible without exceeding the scope of the invention.

[0086] Inside the aircraft, the conditioned air is intended to be delivered into the cabin space 50, but also to the avionics and electrical components 51, to the toilet and galley space 52, and in the cargo hold to the cargo storage space 53. Finally, part of this conditioned air also escapes into the aircraft in the form of leaks (see reference numeral 54). All these air flows are then discharged to the outside of the aircraft through outlets 55.

[0087] Preferably, the line 403 is connected to the air conditioning mixing chamber 56. The air leaving this chamber 56 is directed towards the cabin space 50 via the line 560. The air leaving the cabin space 50 is directed towards the avionics and electrical components 51, the lavatory and galley space 52 and the cargo 53 via the lines referenced 510, 520 and 530, respectively, and flows out towards the outlet 55 via the lines referenced 511, 521 and 531, respectively. Finally, a part of the air can be recirculated from the cabin space 50 towards the air conditioning mixing chamber 56 via the line 500.

[0088] Now, combine Figure 3 A second embodiment of an air conditioning circuit for an aircraft is described. This circuit is denoted by reference numeral 4 '.

[0089] This circuit differs from the previous one in that it also comprises a condenser-type heat exchanger 44 .

[0090] Furthermore, in the device 2, there is no longer a heat exchanger 27 between the vaporized cryogenic fuel and the air of the aircraft's air conditioning circuit, but in its place there is at least one heat exchanger between the cryogenic fuel and the air of the aircraft's air conditioning circuit, preferably two of this type, respectively denoted by 27A for the first exchanger and 27B for the second exchanger. These two exchangers are installed in series in the line connecting the storage tank 20 (more precisely, the second high-pressure pump 24) to the mixing chamber 21.

[0091] The line connecting the second high-pressure pump 24 to the first exchanger 27A is denoted by 204 , the line connecting the two exchangers 27A to 27B together is denoted by 205 , and the lines connecting the second exchanger 27B to the mixing chamber 21 are denoted by 206 and 207 .

[0092] Preferably, a valve 215 is arranged in the line 204 upstream of the second high-pressure pump 24 and downstream of the first exchanger 27A. The valve 215 is controlled by the central control unit 3.

[0093] Furthermore, advantageously, a three-way valve 208 may be provided, the inlet of which is connected to the line 206 , and the two outlets of which are respectively connected to the line 207 and the line 209 , which connects the three-way valve 208 to the storage tank 20 .

[0094] A portion of the cryogenic fuel stored in the tank 20 may be directed to the first exchanger 27A via line 204, where this very cold fuel is heated. Once heated, the cryogenic fuel enters the second exchanger 27B, where it is further heated.

[0095] The exchangers 27A, 27B can be two-phase exchangers (fuel passes through the exchanger in gaseous state, or changes phase to enter gaseous state), or supercritical exchangers (fuel passes through the exchanger at a temperature above its critical temperature). The fuel flows out to be directed towards the three-way valve 208 .

[0096] Depending on the flight phase of the aircraft, the valve 208 may have a first position, in which all the gaseous or supercritical cryogenic fuel is directed toward the mixing chamber 21, a second position, in which all the gaseous or supercritical cryogenic fuel is directed toward the tank 20, and a plurality of intermediate positions, in which a certain proportion of the gaseous or supercritical cryogenic fuel is directed toward the tank 20 and the remaining cryogenic fuel is directed toward the mixing chamber 21. At takeoff, preferably, the fuel is directed to the chamber 21, during the descent phase or on the ground, the fuel is directed to the tank 20, and at cruise, the valve 208 is in an intermediate position.

[0097] Furthermore, in the aircraft's air conditioning circuit 4', the incoming hot air flow indicated by the arrow F4 passes in turn through the condenser 44 and then through the line 404, passing through the second heat exchanger 27B between the liquid cryogenic fuel and the air of the aircraft's air conditioning circuit. The air flows out via the line 405 in order to return to the condenser 44 and to exchange heat there (in other words, the air that circulates in the line 405 and has been cooled is used to condense the water present in the incoming air flow F4 and remove moisture). The air flows out from the condenser 44 through the line 406 and enters the compressor 40 for the air to be conditioned, where it is compressed and heated. The air flows out from the compressor 40 via the line 407, passing through the first heat exchanger 27A between the cryogenic fuel and the air of the aircraft's air conditioning circuit. The cooled air flows out from the first exchanger 27A via the line 408, enters the air conditioning turbine 41, and finally, as before, the air flows out via the line 403 to be directed to the air conditioning mixing chamber 56.

[0098] Now, combine Figure 4 A third alternative embodiment of an air conditioning circuit for an aircraft is described. This circuit is denoted by reference numeral 4 ″.

[0099] Elements identical to those of the circuit 4 ′ have the same reference numerals.

[0100] This circuit 4 ″ differs from the circuit 4 ′ in that this circuit 4 ″ comprises a heater 45 . The inflowing air flow F4 enters the circuit 4 ″ via this heater 45 . The heater 45 is connected to the condenser 44 via a line 409 . Furthermore, for return, the condenser 44 is connected to the heater 45 via a line 410 . Finally, the heater 45 is connected to the compressor 40 via a line 411 .

[0101] The operation of the heat exchanger in loop 4″ differs from that in loop 4′ in that the inflowing air flow F4 is cooled in the heater 45 and then passes through the condenser 44, where the air flow is further cooled, the air flow leaving the condenser 44 and after having passed through the second heat exchanger 27B is hotter than at the outlet of the condenser 44, and when the air flow passes through the heater 45, the air flow recovers heat from the inflowing air flow F4 and is then directed to the compressor 40.

[0102] Now, combine Figure 5 A fourth alternative embodiment of an air conditioning circuit for an aircraft is described. This circuit is denoted by reference numeral 4'". This circuit comprises the same elements as circuit 4". However, the flow from one element to another is different. The same lines as circuits 4, 4' and 4" have the same reference numerals.

[0103] The condenser 44 is connected to the heater 45 via line 412, and the heater 45 is connected to the second heat exchanger 27B via line 413. The second heat exchanger 27B is connected to the compressor 40 via line 414. The turbine 41 is connected to the condenser 44 via line 415. Finally, the condenser 44 is connected to the air conditioning mixing chamber 56 via line 416.

[0104] The heat exchange in loop 4'" differs from that in loop 4" in that the air leaving the condenser 44 is used to cool the incoming air F4 circulating in the heater 45. The air that has passed through the condenser 44 and left the heater 45 (via line 413) is directed to the second exchanger 27B in order to make the heated low-temperature fuel leaving the first exchanger 27A even hotter. The cooled air leaving the second exchanger 27B is sent to the compressor 40 where it is compressed and heated. The air leaves the compressor 40 to pass through the first exchanger 27A and provide heat to the very cold low-temperature fuel leaving the tank 20. The cooled air is sent to the turbine 41 to expand there and be further cooled. At the outlet of the turbine 41, the air is sent back to the condenser 44 where it is heated by heat exchange with the air flow leaving the heater 45 and is finally directed to the air conditioning mixing chamber 56.

[0105] Preferably, when the exchangers 27A and 27B are supercritical exchangers, the pump 24 is also a supercritical pump.

[0106] Despite Figures 2 to 5 Not shown in the embodiment of FIG. 2 , a heat exchanger 27 may be provided in line 203 in addition to exchangers 27A and 27B.

[0107] The distribution of the different flows of liquid cryogenic fuel among the lines 204 , 201 and 202 is achieved, depending on the flight phase, by opening or closing valves 215 , 212 and 213 , respectively.

[0108] exist Figures 3 to 5 Tank 29 , valve 214 and high pressure pump 28 are shown, but they are optional and are only used to manage “boil-off” of the fuel due to imperfect insulation of the fuel tank 20 .

[0109] It is worth reminding that, remembering the critical temperature, hydrogen has a critical point at 32K (minus 241.15°C) and a critical pressure of 12.8 bar (12.8·10 5 Pa), natural gas has a critical point at 190K (minus 83.15°C) and a critical pressure of 46.8 bar (46.8·10 5 Pa).

Claims

1. A device (2) for supplying a combustion chamber (16) of a turbine engine (1) of an aircraft, the aircraft comprising a distribution circuit (5) for conditioned air, characterized in that: The device comprises: - a tank (20) for the cryogenic fuel in liquid state, a mixing chamber (21) receiving different flows of cryogenic fuel in a supercritical state or in a gaseous state, said mixing chamber (21) being configured to be connected to said combustion chamber (16) in order to supply said combustion chamber with the cryogenic fuel in a supercritical state or in a gaseous state, - an air heat exchanger (27, 27A, 27B) of at least one cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'"), installed in a first line (203, 204, 205, 206, 207) connecting the cryogenic fuel tank (20) to the mixing chamber (21) and in a line (401, 402, 403, 404, 405, 406, 407, 408) of the air conditioning circuit (4, 4', 4", 4'") configured to be connected to the distribution circuit (5) of conditioned air, in which heat exchange takes place in the air heat exchanger of the at least one cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'") in order to cool the air of the aircraft air conditioning circuit (4, 4', 4", 4'") and to increase the temperature of the cryogenic fuel coming from the tank (20).

2. The device (2) according to claim 1, characterized in that The device comprises a heat exchanger (23) for air (F1) circulating in at least one cryogenic fuel / turbine engine's air compressor (14, 15), the heat exchanger being installed in a second line (201) connecting the cryogenic fuel tank (20) to the mixing chamber (21), wherein heat exchange takes place in the heat exchanger for air (F1) circulating in the at least one cryogenic fuel / turbine engine's air compressor (14, 15) so as to heat the cryogenic fuel and cool the air (F1) circulating in the turbine engine's air compressor (14, 15).

3. The device (2) according to claim 1 or 2, characterized in that The device comprises at least one cryogenic fuel / lubricating oil heat exchanger (25), which is installed in a third line (202) connecting the cryogenic fuel tank (20) to the mixing chamber (21), and in which heat exchange occurs in order to heat the cryogenic fuel and cool the lubricating oil (F2).

4. The device (2) according to claim 3, characterized in that The device comprises at least one cryogenic fuel / cooling air (F3) heat exchanger (26) for turbine blades of a turbine engine (1), wherein the at least one cryogenic fuel / cooling air (F3) heat exchanger (26) for turbine blades of a turbine engine (1) is installed in the third line (202) connecting the cryogenic fuel tank (20) to the mixing chamber (21), is connected in series with the cryogenic fuel / lubricating oil heat exchanger (25) and is located downstream of the cryogenic fuel / lubricating oil heat exchanger, and heat exchange occurs in the at least one cryogenic fuel / cooling air (F3) heat exchanger (26) for turbine blades of a turbine engine (1) so as to heat the cryogenic fuel from the cryogenic fuel / lubricating oil heat exchanger (25) and cool the cooling air (F3) for the turbine blades of the turbine engine (1).

5. The device (2) according to claim 1 or 2, characterized in that At least one of the air heat exchangers (27A, 27B) of the cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'"), the air (F1) heat exchanger (23) circulating in the cryogenic fuel / turbine engine air compressor (14, 15), and the cooling air (F3) heat exchanger (26) for the turbine blades of the cryogenic fuel / turbine engine (1) is a supercritical exchanger capable of bringing the cryogenic fuel to a temperature above its critical temperature.

6. The device (2) according to claim 1 or 2, characterized in that At least one of the air heat exchangers (27, 27A, 27B) of the cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'"), the air (F1) heat exchanger (23) circulating in the cryogenic fuel / turbine engine air compressor (14, 15), and the cooling air (F3) heat exchanger (26) for the turbine blades of the cryogenic fuel / turbine engine (1) is a heat exchanger capable of putting the cryogenic fuel into a gaseous state.

7. The device (2) according to claim 1 or 2, characterized in that The air heat exchanger (27) of the cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'") is a heat exchanger between the cryogenic fuel in a vaporized state and the air of the aircraft's air conditioning circuit, and performs heat exchange between the air of the aircraft's air conditioning circuit (4, 4', 4", 4'") and the cryogenic fuel vaporized in the cryogenic fuel tank (20).

8. The device (2) according to claim 1 or 2, characterized in that The air heat exchanger (27A, 27B) of the cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'") is a heat exchanger that performs heat exchange between the air of the aircraft air conditioning circuit (4, 4', 4", 4'") and the cryogenic fuel stored in the cryogenic fuel tank (20).

9. The device (2) according to claim 1 or 2, characterized in that The device comprises a high-pressure compressor (28) for vaporized cryogenic fuel and a buffer tank (29), wherein the high-pressure compressor compresses the cryogenic fuel vaporized in the cryogenic fuel tank (20), and the buffer tank is used to store the cryogenic fuel in a gaseous state, wherein the high-pressure compressor and the buffer tank are installed in series in a first line (203) connecting the upper part of the cryogenic fuel tank (20) to the mixing chamber (21), and the buffer tank (29) is installed downstream of the high-pressure compressor (28) for vaporized cryogenic fuel.

10. The device (2) according to claim 7, characterized in that The device comprises a high-pressure compressor (28) for vaporized cryogenic fuel and a buffer tank (29), wherein the high-pressure compressor compresses the cryogenic fuel vaporized in the cryogenic fuel tank (20), and the buffer tank is used to store the cryogenic fuel in a gaseous state, wherein the high-pressure compressor and the buffer tank are installed in series in a first line (203) connecting the upper part of the cryogenic fuel tank (20) to the mixing chamber (21), and the buffer tank (29) is installed downstream of the high-pressure compressor (28) for vaporized cryogenic fuel, and a heat exchanger between the vaporized cryogenic fuel and the air of the air conditioning circuit (4, 4', 4", 4'") of the aircraft is installed in the first line (203) connecting the upper part of the cryogenic fuel tank (20) to the mixing chamber (21), and is located between the high-pressure compressor (28) for vaporized cryogenic fuel and the buffer tank (29) for storing the cryogenic fuel in a gaseous state.

11. The device (2) according to claim 8, characterized in that The device comprises: an air heat exchanger (27A) of a first cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4"'), and an air heat exchanger (27B) of a second cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4"'). The air heat exchanger (27A) of the first cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4"') and the air heat exchanger (27B) of the second cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4"') are installed in series between the cryogenic fuel tank (20) and the mixing chamber (21).

12. The device (2) according to claim 1 or 2, characterized in that The device comprises a first high-pressure pump (22), which is arranged between the mixing chamber (21) and the combustion chamber (16), and the first high-pressure pump makes the low-temperature fuel from the mixing chamber (21) reach high pressure before being introduced into the combustion chamber (16).

13. The device (2) according to claim 1, characterized in that The device comprises at least one heat exchanger (23) for air (F1) circulating in a cryogenic fuel / turbine engine air compressor (14, 15), the at least one heat exchanger (23) for air (F1) circulating in a cryogenic fuel / turbine engine air compressor (14, 15) being installed in a second line (201) connecting the cryogenic fuel tank (20) to the mixing chamber (21), heat exchange taking place in the heat exchanger (23) for air (F1) circulating in the at least one cryogenic fuel / turbine engine air compressor (14, 15) in order to heat the cryogenic fuel and cool the air (F1) circulating in the turbine engine air compressor (14, 15), Furthermore, the device comprises at least one cryogenic fuel / lubricating oil heat exchanger (25), which is installed in a third line (202) connecting the cryogenic fuel tank (20) to the mixing chamber (21), and in which heat exchange occurs in order to heat the cryogenic fuel and cool the lubricating oil (F2), Furthermore, a heat exchanger (23) for air (F1) flowing through the air compressor (14, 15) of the cryogenic fuel / turbine engine and the cryogenic fuel / lubricating oil heat exchanger (25) are installed in parallel between the cryogenic fuel tank (20) and the mixing chamber (21).

14. The device (2) according to claim 1, characterized in that The device comprises at least one heat exchanger (23) for air (F1) circulating in a cryogenic fuel / air compressor (14, 15) of a turbine engine, the at least one heat exchanger (23) for air (F1) circulating in a cryogenic fuel / air compressor (14, 15) of a turbine engine being installed in a second line (201) connecting the cryogenic fuel tank (20) to the mixing chamber (21), heat exchange taking place in the at least one second heat exchanger in order to heat the cryogenic fuel and cool the air (F1) circulating in the air compressor (14, 15) of the turbine engine, Furthermore, the device comprises at least one cryogenic fuel / lubricating oil heat exchanger (25), which is installed in a third line (202) connecting the cryogenic fuel tank (20) to the mixing chamber (21), and in which heat exchange occurs in order to heat the cryogenic fuel and cool the lubricating oil (F2), Furthermore, the device includes a second high-pressure pump (24), which is arranged downstream of the cryogenic fuel tank (20), upstream of the air (F1) heat exchanger (23) flowing through the cryogenic fuel / turbine engine's air compressor (14, 15), and upstream of the cryogenic fuel / lubricating oil heat exchanger (25).

15. The device (2) according to claim 14, characterized in that The second high-pressure pump (24) is capable of bringing the low-temperature fuel to a pressure greater than its critical pressure.

16. The device (2) according to claim 4, characterized in that The device comprises at least one valve (211, 212, 213, 215) upstream of each heat exchanger, and the opening and closing of these various valves are controlled by a central control unit (3).

17. The device (2) according to claim 1 or 2, characterized in that The cryogenic fuel is selected from liquid hydrogen and liquefied natural gas.

18. The device (2) according to claim 3, characterized in that At least one of the air heat exchangers (27A, 27B) of the cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'"), the air (F1) heat exchanger (23) circulating in the cryogenic fuel / turbine engine air compressor (14, 15), and the cooling air (F3) heat exchanger (26) for the turbine blades of the cryogenic fuel / turbine engine (1) is a supercritical exchanger capable of bringing the cryogenic fuel to a temperature above its critical temperature.

19. The device (2) according to claim 4, characterized in that At least one of the air heat exchangers (27A, 27B) of the cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'"), the air (F1) heat exchanger (23) circulating in the cryogenic fuel / turbine engine air compressor (14, 15), and the cooling air (F3) heat exchanger (26) for the turbine blades of the cryogenic fuel / turbine engine (1) is a supercritical exchanger capable of bringing the cryogenic fuel to a temperature above its critical temperature.

20. The device (2) according to claim 3, characterized in that At least one of the air heat exchangers (27, 27A, 27B) of the cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'"), the air (F1) heat exchanger (23) circulating in the cryogenic fuel / turbine engine air compressor (14, 15), and the cooling air (F3) heat exchanger (26) for the turbine blades of the cryogenic fuel / turbine engine (1) is a heat exchanger capable of putting the cryogenic fuel into a gaseous state.

21. The device (2) according to claim 4, characterized in that At least one of the air heat exchangers (27, 27A, 27B) of the cryogenic fuel / aircraft air conditioning circuit (4, 4', 4", 4'"), the air (F1) heat exchanger (23) circulating in the cryogenic fuel / turbine engine air compressor (14, 15), and the cooling air (F3) heat exchanger (26) for the turbine blades of the cryogenic fuel / turbine engine (1) is a heat exchanger capable of putting the cryogenic fuel into a gaseous state.

22. A turbine engine for an aircraft, comprising a main air flow passage (12), wherein the main air flow passage (12) is provided with at least one air compressor (14, 15), a combustion chamber (16) supplied with cryogenic fuel and at least one turbine (17, 18) in sequence, characterized in that: The turbine engine comprises a device (2) for supplying a combustion chamber (16) of a turbine engine of an aircraft with cryogenic fuel according to any one of claims 1 to 21.

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