FR3077861A1 - PRESSURE LIMITATION DEVICE FOR AIRCRAFT, SYSTEM AND ASSOCIATED AIRCRAFT - Google Patents

Abstract

The invention relates to a device for limiting the pressure, in particular for an environmental control system (ECS), in particular an aircraft, comprising - at least one valve (3) that is substantially rigid, and - a seat (4) of said valve (3), said valve (3) being movably configured between - an open position in which it allows a passage of fluid through the pressure limiting device, and - a closed position in which it opposes the passage of fluid through the device of pressure limitation, the pressure limiting device further comprising a return means (5) configured to move said valve (3) to the closed position, characterized in that said valve (3) and said seat (4) comprise each at least one magnetic closure means (8, 9) configured to magnetically hold said valve (3) in the closed position. The invention further relates to an environmental control system (ECS) and a corresponding aircraft.

Description

PRESSURE LIMITING DEVICE FOR AIRCRAFT, ASSOCIATED SYSTEM AND AIRCRAFT

The present invention relates to a pressure limiting device, in particular for an environmental control system (ECS), more particularly for an aircraft. The invention further relates to an environmental control system (ECS) and a corresponding aircraft,

This type of valve device is generally used in air distribution circuits to protect the pipes from overpressures generated by the environmental control systems (SCS) relating to air conditioning and pressurization, in particular for aircraft.

In general, the air supplied to the distribution air network of an aircraft such as an airplane is taken from the engines. The pressure and the temperature of this air are then regulated by a conditioning group, and then distributed to 1a. cabin by a set of pipes which can be made of composite.

These lines are calibrated to resist a certain pressure which is sometimes exceeded during sudden changes in engine speed. In general, the air conditioning unit does not react quickly enough to peak pressure peaks. The object of a pressure limiting device is to open to evacuate to the outside the excess air which generates this excess pressure.

More generally, this type of device can be used in all similar systems where there is a need for pressure limitation in tanks or pipes, when the requirements for pressure drop, size, mass are very demanding.

A safety valve has two separate chambers, the. the first with an inlet pressure and the second with an outlet pressure, separated by a high resistance valve resting on one. seat. A spring is present downstream and a threaded rod allows the compression or decompression of the spring in particular to adjust the calibration, When the valve separating the two chambers undergoes significant pressure, the spring compresses to create an opening between the two chambers and thus allow the fluid to escape from the first chamber to the second chamber and therefore to decompress the network.

Are known in particular in the prior art, pressure relief valves, using valves kept closed by means of a cylindrical spring arranged in the direction of movement of the valve in translation and whose opening pressure generally applies on a circular section. When the force delivered by the pressure of the fluid which is applied to this circular section is greater than the force developed by the spring, the valve of the valve opens, thus allowing the fluid to escape. When the valve begins to open, said circular spring compresses and the pressure required to keep it open increases.

To overcome this effect, a piloting section is produced on the valve so that the pressure is applied over a larger surface when the valve is open than when it is closed. A pressure lower than or equal to the opening pressure thus generates a force on the valve greater than the force of the spring and keeps the valve open.

However, when it is desired to integrate this valve into pipes, the passage of the fluid is sinuous, which results in a significant pressure drop. The creation of the pipe which completely encompasses the valve generates a large bulk, which causes a significant mass for the valve as well as for the surrounding piping. In addition, the increase in pressure to keep the valve in the open position causes an oscillation between the open and closed positions of the valve, which can generate additional pressure inside the first chamber and noise produced by the impacts of the valve. against the seat.

Also known in the field of pressure limiting valves, two-way check valves, conventionally integrated between two fixing flanges. The flaps of these valves have an angular displacement, by means of torsion springs, and allow an integral passage of the fluid in large opening and in an almost rectilinear manner, which generates little pressure drop. When the pressure of the fluid inside the first chamber is greater than the force developed by the torsion spring allowing the flaps to be kept in the closed position, the two flaps of the non-return valve open to allow the fluid to pass through. the second chamber, thereby reducing the pressure of the first.

However, in the open position, the flaps are not very stable due to their aerodynamic floating which generates frequent impacts against the seat, then causing noises due to shocks and rapid degradation of the components.

Membrane valves are also known in the field of pressure limiting valves. The membrane is made of an elastic material and rests on a stop located between the first and the second chamber allowing a separation between the two spaces. In the case of an overpressure in the first chamber, the elastic membrane deforms and thus lets the fluid pass into the second chamber, thus limiting the -pressure in the system.

This principle is not related to the invention 'which relates to rigid check valves.

An object of the invention is to provide a valve device with a low load share in use, including the size and the. mass are reduced compared to the prior art, limiting the noise produced by the impacts of the valve on the seat.

To do this, the invention proposes a valve device in particular for an environmental control system (ECS), in particular for an aircraft, comprising - at least one substantially rigid valve, and - a seat of said valve, said valve being configured to be movable between - an 'open position in which it allows one. passage of fluid through the valve device, and - a closed position in which it opposes the passage of fluid through the valve device, the valve device further comprising return means configured to move said valve towards the position, closed. characterized in that said valve and said seat each comprise at least one magnetic closure means configured to hold said valve by magnetic force in the closed position®.

According to a particularly interesting aspect, said valve, and said seat each comprise at least one magnetic closure means configured to hold said valve by magnetic force in the closed position.

Advantageously, the arrangement of the valve device makes it possible to limit the pressure drop in use, as well as the space requirement, in particular by making it possible to provide an internal diameter of the device that is substantially constant. In addition, a magnetic closure of the valve allows the opening of the valve with an opening pressure that can counteract the magnetic force, the restoring force, and the inertia of the valve; and holding open in order to counteract only the restoring force and the inertia of the valve, which implies better control of the pressures and less impact of the valve on the seat.

According to other aspects taken in isolation or combined according to all the technically feasible combinations: the magnetic closure means preferably comprises a magnet on the seat, and a magnetic piece preferably on the valve; and / or - the valve device has a substantially constant internal diameter; and / or - said valve and / or said seat comprises at least one means of absorbing shocks from said valve on said seat; and / or - said shock absorbing means comprises a seal; and / or - said valve comprises at least one narrow sealing lip; and / or - the sealing lip cooperates with said absorption means; and / or - the valve device comprises two rotary valves; and / or - the return means comprises a cylindrical spring whose axis is arranged parallel to the axis of rotation of the valves. The invention further relates to an environmental control system (ECS), in particular for aircraft, comprising a valve device according to the invention.

Another object of the invention relates to an aircraft comprising a valve device according to the invention or an environmental control system (ECS) according to the invention. The invention will be further detailed by the description of nonlimiting embodiments, and on the basis of the appended figures in which: - Figure 1 is a sectional view of a pressure limiting device, according to a preferred variant of the invention. invention, where the valves are in the open position; - Figure 2 is a view similar to that of Figure 1, where the valves are in the closed position; - Figure 3 is a close-up view of part of the device of Figure 1 illustrating the cooperation of the valve and the valve seat. The invention relates to a pressure limiting device device 1 having an application in particular in environmental control systems (ECS) such as those of aircraft.

This type of device for limiting the pressure device 1 is generally used to protect a pipe 2 from the overpressures generated by the environmental control systems (ECS) relating in particular to air conditioning and pressurization, in particular of aircraft. Line 2 can be made of composite. Generally, the pipes 2 can form a fixing flange forming the valve device 1.

This type of system generally comprises, upstream of the valve device 1, a motor, a conditioning group and distribution pipes; and downstream, distribution pipes and the exterior. The invention can of course be applied to other fields where there is a need for pressure limitation in tanks or pipes, when the requirements for pressure drop, bulk, mass are very demanding.

The valve device 1 comprises at least one, in particular two substantially rigid valves 3. Said valve 3, in particular the valves 3, cooperate with a valve seat 4. the assembly is associated with a return means 5 which is in particular a cylindrical spring, for example a torsion spring.

Said valve 3, in particular the valves 3 are mounted to rotate about an axis, preferably common, substantially perpendicular to an axis of revolution of the valve device 1. The valves 3 are here arranged symmetrically with respect to their axis of rotation. The axis of rotation of said valve 3 is preferably secured to the seat 4. The spring 5 has an axis arranged parallel to, in particular coincident with the axis of rotation of said valve 3. In other words, the flaps of these valves have an angular displacement, and are returned to position by means of the torsion spring 5.

Thus, said valve 3 is mounted movable with respect to the seat 4 between an open position and a closed position. In the open position, the valve 3 comprises a working section 6 remote from the seat 4 so that the valve 3 allows a passage of fluid through the pressure limiting device 1, In the closed position, said working section 6 is close to, in particular at least partially in contact with, the seat 4 so that the valve 3 is opposed to the passage of fluid through the valve device 1.

In particular, the working section 6 is a circular section of the valve cooperating with a corresponding circular section 7 of the seat 4.

The return means 5, in particular the cylindrical spring, is configured to move said valve 3 towards the closed position. Thus, in normal operation, an overpressure downstream of the valve 3 causes the valve 3 to close.

According to a particularly interesting aspect, said valve 3 and said seat 4 each comprise at least one magnetic closure means 8, 9 configured to hold said valve 3 by magnetic force in the closed position. Said magnetic means is preferably arranged near a lateral end of the valve 3. This arrangement makes it possible to improve the efficiency of the magnetic force.

Advantageously, a magnetic closure of the valve 3 allows the opening of the valve 3 with an opening pressure which can counteract the magnetic force, the restoring force, and the inertia of the valve 3; and keeping it open in order to counteract only the restoring force and the inertia of the valve 3 e · which implies better control of the pressures and less impact of the valve 3 on the seat 4.

This is all the more important since the purpose of the valve, in particular in the context of aircraft SCS systems, is to prevent the pressure in the upstream piping from exceeding the admissible limit value by the piping. it is therefore important that it opens at a pressure value below the admissible limit. It must also not open at too low a value since all the air exhausted to the outside is a loss which increases the fuel consumption of the aircraft. Once the valve begins to open, the pressure in the piping must not increase under pain of exceeding the admissible limit by the piping. Thus, it is important that the pressure does not increase when the valve is open. This aspect is better controlled by implementing the magnetic force.

According to a variant, the magnetic closure means comprises a magnet 8 preferably on the seat 4, and a magnetic part 9 preferably on the valve 3. The magnetic part 9 comprises an element sensitive to magnetic fields, for example a metal part capable of include iron or steel. This arrangement makes it possible to limit the weight of the movable valve 3 because the magnetic part 9 generally has a weight less than that of the magnet 8.

The pressure limiting device 1 preferably has a substantially constant internal diameter. According to a variant, said valve 3 and / or said seat 4 comprises at least one shock absorption means 10 of said valve on said seat. Surprisingly, the Applicant has noticed that this arrangement makes it possible, on the one hand, to limit the inconvenience in terms of noise linked to the impacts of said valve 3 on the seat 4. On the other hand, this also makes it possible to limit the valve wear 3.

Preferably, said shock absorption means 10 comprises a seal made of elastic material, for example of elastomer.

According to a particularly advantageous variant, said valve 3 comprises at least one narrow sealing lip. The narrow sealing lip in particular forms the working section of the valve 6. This configuration makes it possible to provide a working section 6 having a reduced surface, the sealing lip has a thick section having for example a triangular shape. Another shape, for example square or rounded, can be provided, but a triangular shape is preferred to provide a working portion at a vertex of the triangle.

Said narrow sealing lip is preferably disposed near a lateral end of the valve 3, more preferably laterally to said magnetic closure means (8).

Preferably, the sealing lip cooperates with said absorption means 10. In particular, said absorption means 10 extends over a small distance along the top of the triangle. Surprisingly, the applicant has noticed that this arrangement makes it possible to limit both the surface of the working section 6, but also that of the shock absorption means 10. Thus, a smaller joint can be used and disposed at the contact area with the narrow sealing lip. In particular, a housing is provided on the seat for arranging, and in particular fixing therein, the shock absorption means 10. The housing of the absorption means 10 may have a square section.

Preferably, housings which may be square, are further provided for the mechanical part and the magnet. The invention further relates to an environmental control system (ECS), in particular for aircraft, comprising at least one pressure limiting device 1 as described above.

In a preferred variant, the system generally comprises, upstream of the valve device 1, a motor, a conditioning group and distribution pipes; and downstream, distribution pipes and the exterior.

Another object of the invention relates to an aircraft comprising a pressure limiting device or an environmental control system (ECS) as described above.

Claims (10)

1. Pressure limiting device in particular for an environmental control system (ECS), in particular for an aircraft, comprising - at least one substantially rigid valve (3), and - a seat (4) of said valve (3), said valve ( 3) being configured to move between - an open position in which it allows the passage of fluid through the pressure limiting device, and - a closed position in which it opposes the passage of fluid through the pressure limiting device , the pressure limiting device further comprising “n return means (5) configured to move said valve (3) to the closed position, characterized in that said valve (3) and said seat (4) each comprise at least magnetic closing means (8, 9) configured to hold said valve (3) in the magnetic force. closed position. 2. Pressure limiting device according to one of the preceding claims, characterized in that the magnetic closure means comprises a magnet (8) preferably on the seat (4), and a magnetic piece (9) preferably on the valve (3). 3. Pressure limiting device according to one of the preceding claims having a substantially constant internal diameter, characterized in that said valve (3) and / or said seat (4) comprises at least one shock absorption means (10 } of said valve (3) on said seat (4). 4. Pressure limiting device according to the preceding claim, characterized in. that said shock absorbing means (10) comprises a seal. 5. Pressure limiting device according to one of the preceding claims, characterized in that said valve (3) comprises at least one narrow sealing lip (6). 6. Pressure limiting device according to preceding claims, at least of which claims 3 and 5, characterized in that the sealing lip (6) cooperates with said absorption means (10), 7. Pressure limiting device according to one of the preceding claims, characterized in that it comprises two rotary valves (3). 8. Pressure limiting device according to the preceding claim, characterized in that the return means (5) comprises a cylindrical spring whose axis is arranged parallel to the axis of rotation of the valves (3). 9. Environmental control system (ECS), in particular for aircraft, comprising a pressure limiting device according to one of the preceding claims. 10. An aircraft comprising a pressure limiting device according to one of claims 1 to 8 or an environmental control system (ECS) according to the preceding claim.