Fuel distribution system and method
The fuel distribution system uses a pressurization chamber and controllable valve to address the inefficiencies of mechanical pumps, ensuring efficient and cost-effective fuel delivery from cryogenic tanks to aircraft engines.
Patent Information
- Application Number
- FR2022002237
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-03-15
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2042-03-15
AI Technical Summary
Existing fuel distribution systems for cryogenic tanks in aircraft face issues with mechanical pumps, including sealing, lubrication, efficiency, energy consumption, and increased mass and cost due to redundancy, as well as complex heat exchanger systems that affect engine performance.
A fuel distribution system that eliminates mechanical pumps by using a pressurization chamber to store fuel in a gaseous state at high pressure, connected to a cryogenic tank, and a controllable valve to manage fuel flow, allowing distribution without mechanical pumps.
Enables reliable and efficient fuel distribution from cryogenic tanks to engines, reducing system mass and cost while maintaining pressure requirements, and simplifying the distribution process.
Smart Images
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Abstract
Description
Title of the invention: Fuel distribution system and method. Technical field
[0001] The present invention relates to the field of fuel distribution systems and more specifically to fuel distribution systems for fuel stored in a cryogenic tank. The invention is particularly applicable to a fuel distribution system in an aircraft.
[0002] It is known to store fuel, particularly hydrogen, in liquid form in a cryogenic tank. Liquid storage reduces the size and mass of tanks in an aircraft, for example. As an example, fuel is stored at a temperature of approximately 20 to 22 Kelvin (-253 to -251°C) in the aircraft's cryogenic tanks.
[0003] In a known manner, with reference to [Fig. 1], a distribution system 101 comprises a cryogenic tank 102, in which liquid fuel Q1 is stored, and a mechanical pump P for delivering the fuel from the cryogenic tank 102 to an engine, for example, an aircraft turbomachine T. Such a mechanical pump P, known as a "fuel pump" or "feed pump," is configured both to pressurize the fuel and to deliver it to the injectors mounted in the turbomachine T.
[0004] In practice, the mechanical pump P, of the positive displacement or centrifugal type, is also called a high-pressure pump and operates at pressures of 50 bar. Such a mechanical pump has many drawbacks in terms of sealing, lubrication, and efficiency. In particular, a mechanical pump requires significant energy to perform compression. Furthermore, such a mechanical pump includes an electronic control system with a limited lifespan. Also, it is known to use redundancy for mechanical pumps to compensate for the failure of one of them, which presents a significant disadvantage because the increased number of mechanical pumps raises the mass and cost of the distribution system.
[0005] A fuel distribution system comprising a heat source for raising the pressure and temperature in the cryogenic tank to propel the fuel is also known in the prior art. However, such a distribution system is complex to implement and requires the addition of piping and several heat exchangers to enable the heat source from the engine to provide sufficient energy to allow fuel distribution. outside the cryogenic tank. Such a distribution system can also affect engine performance, which is undesirable.
[0006] The invention thus aims to eliminate at least some of these disadvantages by proposing a simple fuel distribution system free of mechanical pumps while allowing fuel distribution in a reliable and practical manner. PRESENTATION OF THE INVENTION
[0007] The invention relates to a fuel distribution system configured to supply an aircraft turbomachine, the distribution system comprising: • at least one cryogenic tank containing liquid fuel in a lower section and gaseous fuel in an upper section, the cryogenic tank having a fuel dispensing outlet in the lower section, and • a fuel propulsion device comprising: • at least one pressurization chamber in which fuel is stored in a gaseous state at a pressure greater than a predetermined storage pressure, hereinafter referred to as "pressurized fuel", the pressurization chamber being fluidly connected to the cryogenic tank by a connecting pipeline, • at least one controllable valve configured to control the flow of pressurized fuel in the connecting line so as to permit the distribution of fuel in liquid form via the distribution outlet.
[0008] The distribution system according to the invention makes it possible to increase the volume of fuel in the gaseous state in the upper part of the cryogenic tank, so as to push the fuel in the liquid state out of the cryogenic tank by reducing the volume of fuel in the liquid state in the lower part.
[0009] The distribution system advantageously allows fuel in liquid form to be conveyed from a cryogenic tank to a conditioning system and an engine, without requiring the use of a mechanical pump.
[0010] The controllable valve allows the circulation of pressurized fuel in the connecting pipeline to be authorized or blocked in a simple and efficient manner.
[0011] In one embodiment, the distribution system comprising a plurality of cryogenic tanks, the pressurization chamber is connected to each of the cryogenic tanks, so as to distribute the pressurized fuel into each of the cryogenic tanks.
[0012] In one embodiment, the propulsion device includes a controllable distributor for distributing pressurized fuel into each tank cryogenic. The distributor thus allows the pressurized fuel to be distributed into each cryogenic tank. The distributor allows the transfer of pressurized fuel to the cryogenic tanks to be controlled independently, for example, sequentially.
[0013] In a first embodiment, the predetermined storage pressure is greater than or equal to 350 bar. Such a pressure ensures the propulsion of the fuel in the circuit, while maintaining pressure equipment at a known pressure value generally used in industry.
[0014] In a second embodiment, the predetermined storage pressure is greater than or equal to 700 bar. Such a pressure allows for greater autonomy of the distribution system.
[0015] In one embodiment, the cryogenic tank and the propulsion device are carried in a vehicle, preferably in an aircraft.
[0016] In an alternative embodiment, the cryogenic tank and the propulsion device are fixed to the ground.
[0017] The invention also relates to an aircraft comprising a turbomachine and a fuel distribution system as described above, configured to supply the turbomachine.
[0018] The invention further relates to a method of fuel distribution, by means of a distribution system as described above, the fuel in the cryogenic tank being in a liquid state in the lower part and in a gaseous state in the upper part, the pressurization chamber comprising pressurized fuel in a gaseous state stored at a pressure greater than a predetermined storage pressure, the method comprising: • a controllable valve opening step, so as to allow the flow of pressurized fuel in the connecting pipeline, • a step of distributing fuel in liquid state from the cryogenic tank via the fuel distribution outlet.
[0019] The invention also relates to a method of fuel distribution, by means of a distribution system as described above, the fuel in the cryogenic tank being in a liquid state in the lower part and in a gaseous state in the upper part, the pressurization chamber comprising pressurized fuel in a gaseous state stored at a pressure greater than a predetermined storage pressure, the method comprising: • a refueling step in the pressurization chamber of the propulsion system, with the refueling step being carried out on the ground using at least one refueling device external to the aircraft, • a controllable valve opening step, so as to allow the flow of pressurized fuel in the connecting pipeline, • a step of distributing fuel in liquid state from the cryogenic tank via the fuel distribution outlet. PRESENTATION OF THE FIGURES
[0020] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.
[0021] Fig. 1 is a schematic representation of a fuel distribution system according to the prior art.
[0022] Fig. 2 is a schematic representation of a fuel distribution system according to a first embodiment of the invention.
[0023] Fig. 3 is a schematic representation of a fuel distribution system according to a second embodiment of the invention.
[0024] Fig. 4 is a diagram of the steps of a fuel distribution process according to one embodiment of the invention.
[0025] It should be noted that the figures set out the invention in detail to implement the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION
[0026] With reference to [Fig.2], a fuel distribution system 1 is shown configured to deliver fuel from the outlet of a cryogenic tank 2, according to a first embodiment of the invention.
[0027] The distribution system 1 according to the invention comprises a cryogenic tank 2, in which fuel is stored, and a propulsion device 3, configured to allow the distribution of fuel from the cryogenic tank 2.
[0028] In this example, the cryogenic tank 2 and the propulsion device 3 are configured to be carried on board a vehicle. For example, in an aircraft comprising a turbomachine T (shown in [Fig. 2]), the onboard fuel distribution system 1 is configured to supply the turbomachine T.
[0029] According to one variant, the cryogenic tank 2 and the propulsion device 3 are configured to be fixed to the ground, so as for example to fill a cryogenic tank of a vehicle engine, in particular, an aircraft.
[0030] With reference to [Fig. 2], the cryogenic tank 2 comprises a lower part 21 and an upper part 22. The cryogenic tank 2 contains fuel at liquid state Q1 in the lower part 21 and fuel in gaseous state Qg in the upper part 22.
[0031] The lower part 21 of the cryogenic tank 2 has a distribution outlet 23, fluidly connected to a fuel circuit CQ which allows the fuel in liquid state Q1 to be conveyed from the cryogenic tank 2 for example to a conditioning system SC in which the fuel Q1 is heated and pressurized, the conditioning system SC being, in this example, itself connected to the turbomachine T.
[0032] Preferably, the upper part 22 of the cryogenic tank 2 has a fuel inlet 24, fluidly connected to the propulsion device 3. For this purpose, the distribution system 1 also includes a connecting pipe 4 fluidly connecting the cryogenic tank 2, and more particularly the fuel inlet 24 of the upper part 22 of the cryogenic tank 2, to the propulsion device 3.
[0033] Still with reference to [Fig.2], the propulsion device 3 according to the invention comprises a pressurization chamber 31, in which fuel in gaseous state Qg is stored, in particular, of the same type as that stored in the cryogenic tank 2. The pressurization chamber 31 is fluidically connected to the upper part 22 of the cryogenic tank 2 by the connecting pipe 4.
[0034] According to the invention, the fuel in its gaseous state Qg is stored in the pressurization chamber 31 at a pressure P31 that is higher than a predetermined storage pressure Ps. The fuel in its gaseous state Qg stored in the pressurization chamber 31 will hereafter be referred to as "pressurized fuel" Qp. Preferably, the predetermined storage pressure Ps is between 40 and 60 bar (abs) and is determined based on the pressure losses in the circuit and the requirements of the engine pumps. In a first embodiment, the pressure P31 in the pressurization chamber 31 is greater than or equal to 350 bar. In a second embodiment, the pressure P31 in the pressurization chamber 31 is greater than or equal to 700 bar. Such pressure values are known, which allows the simple manufacture of pressurization chambers 31 whose behavior with respect to high pressures can be anticipated.
[0035] With further reference to [Fig. 2], the propulsion device 3 includes a controllable valve 32, configured to control the flow of pressurized fuel Qp in the connecting line 4, so as to allow the distribution of fuel in the liquid state Q1 via the distribution outlet 23, as will be described in more detail later. The controllable valve 32 is preferably mounted on the connecting line 4 between the pressurization chamber 31 and the fuel inlet 24 of the upper part 22 of the cryogenic tank 2. Thus, when the controllable valve 32 is opened, the pressure P31 of the fuel in the gaseous state Qg allows the tank to be filled The cryogenic tank 2 contains fuel in a gaseous state Qg. The increase in the gaseous phase in the cryogenic tank 2 allows the fuel in a liquid state Q1 to be pushed out of the cryogenic tank 2 via the distribution outlet 23.
[0036] Such a controllable valve 32 allows the circulation of pressurized fuel Qp in the connecting pipe 4 to be authorized or not. Preferably, depending on the degree of opening of the controllable valve 32, the pressure of the gaseous phase is controlled and therefore, consequently, the distribution pressure of the cryogenic tank 2. The controllable valve 32 is configured to be controlled to open when it is necessary to convey fuel to the turbomachine T.
[0037] The pressurization chamber 31 is preferably configured to be supplied with gaseous fuel Qg by means of one or more refueling devices. For example, in the case of a distribution system 1 installed in an aircraft, the pressurization chamber 31 of the propulsion device 3 is configured to be refueled with gaseous fuel Qg when the aircraft is on the ground, by means of one or more external refueling devices. Preferably, the refueling is carried out by means of compressors external to the aircraft.
[0038] A propulsion device 3 is presented comprising a single pressurization chamber 31, however it is understood that the propulsion device 3 could just as well comprise several pressurization chambers 31.
[0039] In a second embodiment shown in [Fig.3], the distribution system 1 comprises two cryogenic tanks 2A, 2B, in which fuel Q is stored. It is understood that the distribution system 1 can comprise a different number of cryogenic tanks 2, in particular, a number greater than two cryogenic tanks 2.
[0040] In this embodiment, the propulsion device 3 also includes a controllable distributor 33, allowing the pressurization chamber 31 to be connected to the various cryogenic tanks 2A, 2B. The controllable distributor 33 allows the transfer of pressurized fuel Qp to be permitted only in one of the cryogenic tanks 2, for example, to favor one cryogenic tank 2 over another. In an alternative embodiment, the controllable distributor 33 is configured to distribute the pressurized fuel Qp uniformly into each cryogenic tank 2.
[0041] Such a controllable distributor 33 is presented for example in the form of a three-way valve.
[0042] In this example, still with reference to [Fig. 3], the controllable distributor 33 is mounted on the connecting pipe 4 between the pressurization chamber 31 and each cryogenic tank 2. More precisely, the distributor 33 is preferably mounted between the controllable valve 32 and the cryogenic tanks 2A, 2B. In In this example, the connecting pipeline 4 then comprises a single conduit 4C between the pressurization chamber 31 and the distributor 33 and two separate conduits 4A, 4B between the distributor 33 and the cryogenic tanks 2A, 2B, a first conduit 4A between the controllable distributor 33 and a first cryogenic tank 2A and a second conduit 4B between the controllable distributor 33 and a second cryogenic tank 2B.
[0043] In this example, the pressure in the controllable distributor 33 is also controlled by the controllable valve 32.
[0044] The distribution system 1 according to the invention is configured to convey the pressurized fuel Qp, via the controllable valve 32, through the controllable distributor 33 and via the connecting pipe 4, from the pressurization chamber 31 to each cryogenic tank 2, so as to increase the volume of fuel in the gaseous state Qg in the upper part 22 of each cryogenic tank 2 and thus allow the fuel in the liquid state Q1 to be expelled from the cryogenic tank 2, via each distribution outlet 23, as will be described in more detail. The use of several tanks advantageously allows the gaseous phase of one tank to be recharged while another is being supplied with fuel to the turbomachine T.
[0045] A fuel distribution method using the distribution system 3 as described above, with reference to [Fig.4], will now be described according to an embodiment of the invention.
[0046] In this example, the distribution system 1 comprises two cryogenic tanks 2A, 2B. In each cryogenic tank 2A, 2B, the fuel is initially in liquid form Q1 in the lower part 21 and in gaseous form Qg in the upper part 22. In addition, the pressurization chamber 31 contains pressurized fuel Qp, i.e., fuel in gaseous form Qg stored, in this example, at a pressure P31 of at least 350 MPa. In this example, the pressure of the fuel in gaseous form Qg in the cryogenic tank 2A is insufficient to ensure adequate distribution pressure.
[0047] The process includes a first step E1 of opening the controllable valve 32, so as to allow the circulation of the pressurized fuel Qp in the connecting pipe 4. The pressurized fuel Qp then flows, in a step E2, from the pressurization chamber 31 of the propulsion device 3 to the controllable distributor 33, which distributes it, in this example, into the conduit 4A of the connecting pipe 4 so as to be distributed into the cryogenic tank 2A.
[0048] The fuel in its gaseous state Qg then enters the cryogenic tank 2A, via the fuel inlet 24, resulting, in a third step E3, in an increase in the volume of fuel in its gaseous state Qg in the upper part 22 of the tank cryogenic 2A, which increases the distribution pressure in the cryogenic tank 2A. The liquid fuel Q1 stored in the lower part 21 of the cryogenic tank 2A can then be distributed via the fuel distribution outlet 23, out of the cryogenic tank 2A.
[0049] The process then includes a fourth step E4 of distributing the fuel in liquid state Q1 via the fuel distribution outlet 23 to the conditioning system SC. Advantageously, during the recharging of the gaseous phase of the cryogenic tank 2A, the cryogenic tank 2B can supply fuel to the turbomachine T.
Claims
Demands
1. A fuel distribution system (1) configured to supply an aircraft turbomachine, the distribution system (1) comprising: • at least one cryogenic tank (2) containing fuel in liquid form (Ql) in a lower portion (21) and fuel in gaseous form (Qg) in an upper portion (22), the cryogenic tank (2) having in the lower portion (21) a fuel distribution outlet (23), and • a fuel propulsion device (3) comprising: • at least one pressurization chamber (31) in which fuel in gaseous form (Qg) is stored having a pressure (P31) greater than a predetermined storage pressure (Ps), hereinafter referred to as "pressurized fuel" (Qp), the pressurization chamber (31) being fluidly connected only to said at least one cryogenic tank (2) by a connecting pipe (4),• at least one controllable valve (32) configured to control the flow of pressurized fuel (Qp) in the connecting line (4) so as to permit the distribution of fuel in liquid state (Ql) via the distribution outlet (23), • the distribution system (1) being free of a mechanical pump.
2. Distribution system (1) according to claim 1 comprising a plurality of cryogenic tanks (2), the pressurization chamber (31) is connected to each of the cryogenic tanks (2).
3. Distribution system (1) according to claim 2, wherein the propulsion device (3) includes an controllable distributor (33) for distributing pressurized fuel (Qp) into each cryogenic tank (2).
4. Dispensing system (1) according to any one of claims 1 to 3, wherein the predetermined storage pressure (Ps) is greater than or equal to 350 bar.
5. Dispensing system (1) according to any one of claims 1 to 4, wherein the predetermined storage pressure (Ps) is greater than or equal to 700 bar.
6. Fuel distribution system (1) according to any one of claims 1 to 5, wherein the cryogenic tank (2) and the propulsion device (3) are carried on board a vehicle, preferably an aircraft.
7. Fuel distribution system (1) according to any one of claims 1 to 5, wherein the cryogenic tank (2) and the propulsion device (3) are fixed to the ground.
8. Aircraft comprising a turbomachine (T) and a fuel distribution system (1) according to any one of claims 1 to 5, configured to supply the turbomachine (T).
9. A method of dispensing fuel, by means of a dispensing system (1) according to any one of claims 1 to 7, the fuel in the cryogenic tank (2) being in liquid state (Ql) in the lower part (21) and in gaseous state (Qg) in the upper part (22), the pressurization chamber (31) comprising pressurized fuel (Qp) in gaseous state stored at a pressure (P31) greater than a predetermined storage pressure (Ps), the method comprising: • a step of opening the controllable valve (32), so as to allow the circulation of the pressurized fuel (Qp) in the connecting pipe (4), • a step of dispensing fuel in liquid state (Ql) from the cryogenic tank (2) via the fuel dispensing outlet (23).
10. A method for dispensing fuel, by means of a dispensing system (1) according to any one of claims 1 to 7, the fuel in the cryogenic tank (2) being in liquid form (Ql) in the lower part (21) and in gaseous form (Qg) in the upper part (22), the pressurization chamber (31) comprising pressurized fuel (Qp) in gaseous form stored at a pressure (P31) greater than a predetermined storage pressure (Ps), the method comprising: a refueling step in the gaseous state (Qg) of the pressurization chamber (31) of the propulsion device (3), the refueling step being carried out on the ground by means of at least one refueling device external to the aircraft, a step of opening the controllable valve (32), so as to allow the circulation of pressurized fuel (Qp) in the connecting pipe (4), a step of distributing fuel in liquid state (Ql) from the cryogenic tank (2) via the fuel distribution outlet (23).