EP3198143A1

EP3198143A1 - Method and system for the circulation of fuel in an aircraft

Info

Publication number: EP3198143A1
Application number: EP15778374.7A
Authority: EP
Inventors: Florian DUMAS; Nicolas Travers
Original assignee: Zodiac Aerotechnics SAS
Current assignee: Safran Aerotechnics SAS
Priority date: 2014-09-24
Filing date: 2015-09-22
Publication date: 2017-08-02
Also published as: FR3026091B1; WO2016046485A1; FR3026091A1; BR112017005962A2; US20170320587A1; RU2683050C2; RU2017109887A3; CA2962011A1; RU2017109887A; JP2017530049A

Abstract

The invention relates to a method for the circulation of fuel in an aircraft, characterised in that it consists in using at least one diaphragm pump (1) having an undulating diaphragm that can undulate between two flanges, under the action of actuating means, for circulating said fuel between an admission line (4) of the pump (1) and an exhaust line (5) of the pump (1).

Description

METHOD AND SYSTEM FOR FUEL CIRCULATION IN

AN AIRCRAFT

TECHNICAL AREA

The present invention relates to a method and a fuel circulation system in an aircraft, such as an airplane for example.

PRIOR ART

In the field of aeronautics, it is well known to circulate fuel in an aircraft, either from external equipment for refueling, or from inside equipment to distribute the fuel between the different tanks (transfer), and / or to provide the engines, such as aircraft engines or at least one Auxiliary Power Unit (APU) auxiliary power unit, with the fuel required for their operation (power supply).

The refueling of an aircraft is an operation performed to set up the quantity of fuel required for a next flight from a pressure line from a truck (+/- 100 m ³ / h to 2, 5 bars). This operation is also called "Pressure refuel".

Fuel transfer is a necessary operation in aircraft if they have more than one tank. The quantity of tanks varies according to the aircraft manufacturer and the configuration of the model in question, and a dump sequence is imposed. In particular, the transfer of fuel can occur when filling the collector, also called "Scavenge", which is fed continuously and with a higher flow rate than the consumption of the engines. The objective is to maintain this 100% full collector and with an overflow in another tank to ensure good power of the engines, whatever the flight conditions of the aircraft in roll and / or pitch. The transfer of fuel can also occur either during the transfer of fuel between two tanks located on each side of the aircraft to restore the center of gravity in case of overconsumption of one of the engines, and / or stopping the one of the engines, and / or non-homogeneous filling of the aircraft's tanks, which would result in an imbalance of the aircraft from one side or the other, either during the eventual transfer of fuel from a rear tank, also called "AFT Tank", and / or from a front tank, also called "FWD Tank", and / or from a central tank, also called "CTR Tank", to optimize the position of the center of gravity of the aircraft which influences the aerodynamic characteristics of the flight and therefore on the fuel consumption induced.

The fuel supply of the engines is carried out by a feed pump which sucks the fuel from the collector to send it to the engine. There is usually one motor pump, and one backup pump per side, which are located in the bottom of the tank and / or tank (s). They can be installed in a disassembly bell to allow their maintenance without having to empty the tanks.

Thus, the circulation of fuel in an aircraft is done by means of rotary-type pumps, such as turbopumps and / or volumetric pumps, for example, powered by electric or hydraulic energy, or in effect pumps. Venturi (ejectors) powered by a driving pressure.

The most commonly used roto-dynamic pumps in aircraft power systems are the turbopumps, also known as centrifugal pumps, which include a pump body consisting mainly of a suction manifold, a volute, and a discharge pipe. The volute receives the moving part or rotor which is formed of the impeller, said impeller being in the form of a paddle wheel, mounted on a shaft. The rotor is driven by a driving machine which can be an electric or hydraulic or thermal motor or a turbine.

This type of pump has many disadvantages. In fact, in general, this type of pump has a poor energy efficiency, of the order of 30 to 70%, a bulk and a significant weight, a significant wear of rotating parts inducing frequent maintenance and sensitivity. to the phenomenon of cavitation. Cavitation is a noisy phenomenon that can destroy a machine in minutes. When pumping, the liquid inside a centrifugal pump does not have a uniform pressure. In particular, there are areas with depressions more or less accentuated. When the pumped liquid is sufficiently close to its boiling point, that is to say from the point of passage from the liquid state to the gaseous state, it can happen that the pressure at these points falls below its vapor pressure, so that vapor bubbles are formed in the pump. When these bubbles arrive in areas where the pressure rises, they implode suddenly. Implosion is accompanied by noise and, when it occurs in the vicinity of a wall, it is likely to cause mechanical damage by causing micro-perforations of the metal (erosion). The other pumps used in the power systems of an aircraft are the Venturi effect pumps; however, these venturi effect pumps require the use of another type of pump to generate the driving pressure, which strike the weight of the assembly. In addition, these pumps have a very low energy efficiency, of the order of 10 to 25%, and are sensitive to the cavitation phenomenon.

In the application under consideration, cavitation phenomena are very disadvantageous for so-called "sensitive" equipment because they generate mechanical degradation of equipment, degradation of efficiency, noise and in some cases introduction of gas bubbles. which may be problematic for jet engines. In aeronautics, the conditions that lead to cavitation are the type of fuel with a density specific to each fuel, a low atmospheric pressure, that is to say when the aircraft is at high altitude, a high temperature of the fluid which facilitates the transition from the liquid state to the gaseous state and a high fluid velocity. There is therefore a real need for a fuel supply system for an aircraft having a good energy efficiency, a small footprint and a low weight, requiring reduced maintenance and not being sensitive to the phenomenon of cavitation likely to appear depending on flight conditions in particular.

SUMMARY OF THE INVENTION

One of the aims of the invention is therefore to remedy these drawbacks by proposing a method and a fuel circulation system in an aircraft having a good performance, requiring reduced maintenance, and not being sensitive to the phenomenon of cavitation.

For this purpose, and in accordance with the invention, there is provided a remarkable process in that it consists in using at least one undulating diaphragm pump capable of waving, under the action of actuating means, between two flanges for circulating said fuel between an intake pipe of the pump to an exhaust pipe of the pump. Compared to the fuel circulation methods of the prior art, reduced maintenance is obtained due to the absence of rotating parts in the diaphragm pump and a high tolerance to cavitation and pollution phenomena. In addition, the implementation of the fuel circulation method is facilitated since the diaphragm pump allows self-priming of the pump.

The method according to the invention can be declined according to several particular embodiments. Indeed, a first embodiment consists in using the at least one diaphragm pump with its intake pipe connected to an external fuel supply source, and with its exhaust pipe connected to a tank of the aircraft for refueling.

A second embodiment consists in using the at least one diaphragm pump with its intake pipe connected to a tank, and with its exhaust pipe connected to another tank of the aircraft for the transfer of fuel between said tanks.

A third embodiment consists in using the at least one diaphragm pump with its intake pipe connected to a tank, and with its exhaust pipe connected to an engine of the aircraft for its fuel supply.

A fourth embodiment consists in using the at least one diaphragm pump with its intake pipe connected to a tank, and with its pipe exhaust connected to an auxiliary power unit of the aircraft for its fuel supply.

Finally, a fifth embodiment consists in using the at least one diaphragm pump with its intake pipe connected to a tank, and with its exhaust pipe connected to an external fuel receiving source for emptying the tank. .

It has also been developed a fuel circulation system in a remarkable aircraft in that it comprises at least one undulating diaphragm pump capable of waving, under the action of actuating means, between two flanges to circulate said fuel enters an intake pipe of the pump to an exhaust pipe of the pump. Compared to the fuel circulation systems of the prior art, reduced maintenance is obtained due to the absence of rotating parts in the diaphragm pump and a high tolerance to cavitation and pollution phenomena. In addition, the implementation of the fuel circulation system is facilitated since the diaphragm pump allows self-priming of the pump.

According to a first embodiment, the intake pipe of the diaphragm pump is connected to an external fuel supply source, and the exhaust pipe is connected to a tank of the aircraft for filling it with fuel.

According to a second embodiment, the intake pipe of the diaphragm pump is connected to a tank, and the exhaust pipe is connected to another tank of the aircraft for the transfer of fuel between said tanks. According to a third embodiment, the intake pipe of the diaphragm pump is connected to a tank, and the exhaust pipe is connected to a motor of the aircraft for its fuel supply. According to a fourth embodiment, the intake pipe of the diaphragm pump is connected to a tank, and the exhaust pipe is connected to an auxiliary power unit of the aircraft for its fuel supply. Finally, according to a fifth embodiment, the inlet pipe of the diaphragm pump is connected to a tank, and whose exhaust pipe is connected to an external fuel receiving source for emptying the tank.

SUMMARY DESCRIPTION OF THE FIGURES

Other advantages and features will become more apparent from the following description, of several alternative embodiments, given as non-limiting examples, of the pump and the fuel supply system of an aircraft according to the invention. from the attached drawings in which:

FIG. 1 is a schematic representation of the method and the fuel circulation system according to the invention for filling the tanks of an aircraft,

FIG. 2 is a schematic representation of the method and the fuel circulation system according to the invention for the transfer of fuel from a first tank to a second tank of an aircraft,

FIG. 3 is a schematic representation of the method and the fuel circulation system according to the invention for supplying fuel to the reactors of an aircraft,

FIG. 4 is a schematic representation of the method and the fuel circulation system according to the invention for supplying an auxiliary power unit (APU) of an aircraft,

FIG. 5 is a schematic representation of the method and the fuel circulation system according to the invention for emptying the tanks of an aircraft,

FIG. 6 is a side view of a first alternative embodiment of the pump used in the method according to the invention,

FIG. 7 is a side view of a second alternative embodiment of the pump implemented in the method according to the invention,

- Figure 8 is a side view of a third alternative embodiment of the pump implemented in the method according to the invention. DETAILED DESCRIPTION OF THE INVENTION

In the following description of the method and the fuel circulation system in an aircraft according to the invention, the same reference numerals designate the same elements. In addition, the different views are not necessarily drawn to scale.

With reference to Figures 1 to 5, the invention relates to a method and a fuel circulation system in an aircraft. According to the invention, the method consists in using at least one undulating diaphragm pump (1) capable of waving, under the action of actuating means, between two flanges for circulating said fuel between an intake pipe of the pump (1) to an exhaust pipe of the pump.

For this purpose, and with reference to Figures 1 to 8, the fuel circulation system comprises at least one diaphragm pump (1). According to a particular embodiment, the diaphragm pump comprises a cylindrical pump body (2) delimiting a cylindrical chamber into which an intake pipe (4) and an exhaust pipe (5) coaxial with the pump body ( 2), an undulating membrane having a central opening and extending into the cylindrical chamber between a fixed lower flange and a fixed upper flange, said flanges extending into said cylindrical chamber. The undulating membrane has the shape of a disk having a circular central opening. The undulating membrane is obtained in a deformable material such as a silicone elastomer for example or the like. The thickness of the undulating membrane is increasing from its central portion to its peripheral edge, and the circular central opening has a diameter substantially equal to the internal diameter of the exhaust pipe (5).

The lower flange is secured to the bottom wall of the body (2) of the pump (1) and the upper flange is able to be moved vertically to vary the displacement of the pump as it will be detailed later. Moreover, the walls of the lower and upper flanges forming the right side of the membrane are convex.

In addition, the pump (1) comprises rigid support means of the membrane between the lower and upper flanges. Said support means cooperate in particular with the peripheral edge of the membrane. These support means consist, for example, in an annular ring bearing the peripheral edge of the membrane.

Furthermore, the pump (1) comprises means for actuating the undulating membrane cooperating with the support means of the latter. Said actuating means consist, for example, in an electromagnetic linear actuator and damping means which delimit the travel of the electromagnetic actuator.

The electromagnetic actuator consists, in turn, in a movable cylindrical ring extending coaxially with the exhaust pipe (5) above the upper flange and to the right of an excitation motor. The excitation motor is constituted by an internal so-called fixed cylindrical armature and a so-called external fixed cylindrical armature carrying an annular coil and two annular permanent magnets extending above and respectively below the annular coil, said coil ring is connected to a power supply circuit. The supply circuit comprises, for example, at least one power amplifier and a signal generator.

The lower end of the movable cylindrical ring is integral with an annular ring provided with a shoulder, and engaged with a connecting piece secured to the support ring of the undulating membrane. Thus, the connecting piece maintains the undulating membrane when the actuator is at rest in particular.

In addition, advantageously, the upper flange is secured to a carriage slidable vertically relative to the inner fixed armature to vary the displacement of said pump (1). Said carriage consists, for example, in a circular part having a central recess for the passage of the exhaust pipe (5) and holes in which extend guides integral with the internal fixed armature. In order to vary the position of said carriage, the latter comprises a cooperating tapping with a screw extending into a hole made in the internal fixed armature. The screw consists of a tubular piece of circular cross section having a thread on its outer wall, in its lower part. The upper flange is integral with the underside of said carriage so that, by varying the position of said carriage along the vertical axis of revolution of the pump (1), it is possible to vary the displacement of the pump by according to the need of the intended application. Incidentally, the intake pipe (4) and / or the exhaust pipe (5) may comprise at least one filter.

In addition, the pump according to the invention may advantageously comprise at least one sensor such as a pressure sensor and / or a temperature sensor and / or a fuel presence sensor. The information measured by these sensors may be transmitted to the power supply circuit which may include management means for regulating the flow rate as a function of said information by modifying the supply characteristics of the electromagnetic linear actuator in particular. Thus, when the electromagnetic linear actuator is activated, the movable cylindrical ring is moved alternately downwards and upwards, driving the undulating membrane downwards and upwards respectively to the frequency supplying the electromagnetic linear actuator. In this way, the membrane propagates a wavefront which provides the displacement of the fuel present in the cylindrical chamber to the exhaust pipe (5).

In other words, the fuel circulation system incorporates a positive displacement diaphragm pump (1) that uses the reciprocating membrane, in which the fuel is displaced by trapping a fixed amount of fuel, and forcing the unloading of the trapped volume by the exhaust pipe (5). The diaphragm pump (1) therefore has good suction properties. The only moving part with which the fuel is in contact in the pump is the elastomeric membrane. All mechanical and electrical components are isolated from fuel exposure. This makes it possible to minimize the risk of trapping foreign bodies and to maximize the reliability of the method and fuel circulation system according to the invention. System maintenance is reduced.

Several alternative embodiments are possible for the arrangement of the intake pipe (4) with respect to the body of account (2). Indeed, and according to a first variant illustrated in Figure 6, the inlet pipe (4) of the diaphragm pump (1) extends radially relative to the pump body (1).

According to a second variant illustrated in Figure 7, the intake pipe (4) extends on the opposite side to the exhaust pipe (5), and coaxially with the latter. Finally, according to a third variant illustrated in FIG. 8, the admission duct

(4) of the diaphragm pump (1) is in the form of a plurality of vents (29) in the cylindrical pump body (2) for communicating the cylindrical chamber with the outside pump (1). In this particular embodiment, said vents (29) consist of longitudinal slots uniformly distributed over the circumference of the cylindrical pump body (2) and extend over the entire height of the cylindrical chamber.

It goes without saying that the shape of the pump does not limit the invention, said pump body (2), the chamber and the membrane may have any shape, such as a parallelepiped shape for the pump body (2) and the chamber, and a rectangular shape for the membrane without departing from the scope of the invention. The bottom line lies in the advantageous use of a diaphragm pump in a fuel circulation process in an aircraft. Finally, it is obvious that the examples which have just been given are only particular illustrations and in no way limiting as to the field of application of the invention. From the foregoing, the method according to the invention makes it possible to carry out several fuel circulation operations in an aircraft by means of the diaphragm pump (1). With reference to FIG. 1, the method according to the invention allows the fueling of at least one of the tanks (30) of an aircraft. For this purpose, the intake pipe (4) of the circulation pump diaphragm pump (1) is connected to an external fuel supply source, and the exhaust pipe (5) is connected to a reservoir (30) of the aircraft for refueling.

With reference to FIG. 2, the method makes it possible to transfer fuel between at least two tanks (30 of the aircraft) For this purpose, the intake pipe (4) of the circulating pump (1) of the circulation system is connected to a tank (30), and the exhaust pipe (5) is connected to another tank (30) of the aircraft for the transfer of fuel between said tanks (30).

With reference to FIG. 3, the method also makes it possible to supply fuel to at least one of the engines (31) from at least one of the tanks (30). For this purpose, the inlet pipe (4) of the circulation pump diaphragm pump (1) is connected to a tank (30), and the exhaust pipe (5) is connected to a motor (31). of the aircraft for fuel supply.

With reference to FIG. 4, the method makes it possible to supply fuel to at least one auxiliary power unit (APU) from at least one of the tanks (30). For this purpose, the inlet pipe (4) of the circulation pump diaphragm pump (1) is connected to a tank (30), and the exhaust pipe (5) is connected to an auxiliary power unit (32) of the aircraft for fuel supply.

Finally, the method according to the invention also makes it possible, with reference to FIG. 5, to empty at least one of the tanks (30). For this purpose, the inlet pipe (4) of the circulation pump diaphragm pump (1) is connected to a tank (30) and the exhaust pipe (5) is connected to a receiving source external fuel for draining the tank (30). It is obvious that the system may include as many diaphragm pumps (1) as different fuel flow operations to achieve.

Claims

A method for circulating fuel in an aircraft, characterized in that it consists in using at least one undulating diaphragm pump (1) capable of waving, under the action of actuating means, between two flanges to circulate said fuel between an intake pipe (4) of the pump (1) to an exhaust pipe (5) of the pump (1). 2 fuel circulation method according to claim 1, characterized in that it consists in using the at least one diaphragm pump (1) with its intake pipe (4) connected to an external fuel supply source , and with its exhaust pipe (5) connected to a tank (30) of the aircraft for filling it with fuel.

3 fuel circulation method according to any one of claims 1 to 2, characterized in that it consists in using the at least one diaphragm pump (1) with its intake pipe (4) connected to a reservoir (30), and with its exhaust pipe (5) connected to another tank (30) of the aircraft for the transfer of fuel between said tanks (30).

4 A fuel circulation method according to any one of claims 1 to 3, characterized in that it consists in using the at least one diaphragm pump (1) with its intake pipe (4) connected to a reservoir (30), and with its exhaust pipe (5) connected to a motor (31) of the aircraft for its fuel supply.

5 fuel circulation method according to any one of claims 1 to 4, characterized in that it consists in using the at least one diaphragm pump (1) with its intake pipe (4) connected to a reservoir (30), and with its exhaust pipe (5) connected to an auxiliary power unit (32) of the aircraft for its fuel supply. 6 fuel circulation method according to any one of claims 1 to 5, characterized in that it consists in using the at least one diaphragm pump (1) with its intake pipe (4) connected to a reservoir (30), and with its exhaust line (5) connected to an external fuel receiving source for emptying the tank (30).

7 fuel circulation system in an aircraft, characterized in that it comprises at least one undulating diaphragm pump (1) capable of waving, under the action of actuating means, between two flanges to circulate said fuel between an intake pipe (4) of the pump (1) to an exhaust pipe (5) of the pump (1).

Fuel circulation system according to claim 7, characterized in that the intake pipe (4) of the at least one diaphragm pump (1) is connected to an external fuel supply source, and the pipe exhaust system (5) is connected to a tank (30) of the aircraft for filling it with fuel.

Fuel circulation system according to one of Claims 7 to 8, characterized in that the inlet pipe (4) of the at least one diaphragm pump (1) is connected to a reservoir (30). and the exhaust pipe (5) is connected to another tank (30) of the aircraft for the transfer of fuel between said tanks (30).

Fuel circulation system according to one of Claims 7 to 9, characterized in that the inlet pipe (4) of the at least one diaphragm pump (1) is connected to a reservoir (30). and the exhaust pipe (5) is connected to a motor (31) of the aircraft for its fuel supply.

Fuel circulation system according to one of Claims 7 to 10, characterized in that the inlet pipe (4) of the at least one diaphragm pump (1) is connected to a reservoir (30). and the exhaust pipe (5) is connected to an auxiliary power unit (32) of the aircraft for its fuel supply. Fuel circulation system according to one of Claims 7 to 11, characterized in that the inlet pipe (4) of the at least one diaphragm pump (1) is connected to a reservoir (30). and the exhaust pipe (5) is connected to an external fuel receiving source for emptying the tank (30).