阅读说明：本技术 用于飞行器的燃油转输与燃油箱惰化的交联系统及其方法 (Cross-linking system and method for fuel transfer and fuel tank inerting of aircraft ) 是由 熊晋 安凤林 卞刚 刘德刚 银未宏 王鹏 于 2019-10-16 设计创作，主要内容包括：本发明涉及一种用于飞行器的燃油转输与燃油箱惰化的交联系统,所述飞行器的燃油箱包括中央翼油箱、外翼油箱和通气油箱,所述交联系统包括：气源,来自气源的惰性气体进入中央翼油箱并使其惰化；连通中央翼油箱和外翼油箱的转输管路,转输管路在飞行器飞行时借助惰性气体的压力将中央翼油箱中的燃油转输至外翼油箱；以及连通中央翼油箱与通气油箱的通气管路,通气管路在飞行器加油时使中央翼油箱与外界大气连通。该系统以惰性气体的压力为动力进行燃油转输,在简化燃油转输系统设计的同时,实现了燃油箱惰化。这样,提高了系统可靠性,减轻了飞行器重量并节约了飞行成本。(The invention relates to a cross-linking system for fuel transfer and fuel tank inerting of an aircraft, the fuel tank of the aircraft comprising a centre wing tank, an outer wing tank and a ventilation tank, the cross-linking system comprising: the gas source, the inert gas from gas source enters the central wing fuel tank and makes it inerted; the transfer pipeline is communicated with the central wing oil tank and the outer wing oil tank and transfers fuel oil in the central wing oil tank to the outer wing oil tank by means of the pressure of inert gas when the aircraft flies; and the ventilation pipeline is used for communicating the central wing oil tank with the ventilation oil tank, and the ventilation pipeline enables the central wing oil tank to be communicated with the outside atmosphere when the aircraft refuels. The system uses the pressure of inert gas as power to transfer fuel, simplifies the design of the fuel transfer system and simultaneously realizes the inerting of the fuel tank. In this way, system reliability is improved, aircraft weight is reduced and flight costs are saved.)

1. A crosslinking system for fuel transfer and tank inerting of an aircraft, the fuel tank of the aircraft comprising centre-wing tanks (10), outer-wing tanks (20) and vented tanks (30), the crosslinking system comprising:

a source of inert gas (G) from said source of gas into said centre wing tank (10) and inerting it;

a transfer line (13) communicating the centre-wing tanks (10) and the outer-wing tanks (20), the transfer line (13) transferring fuel in the centre-wing tanks (10) to the outer-wing tanks (20) by means of the pressure of the inert gas (G) while the aircraft is flying; and

-a ventilation line (12) communicating the centre-wing tank (10) with the ventilation tank (30), the ventilation line (12) putting the centre-wing tank (10) into communication with the outside atmosphere when the aircraft is refueled.

2. A fuel transfer and fuel tank inerting cross-linking system as set forth in claim 1, wherein said gas source communicates with said center wing tank (10) via a gas supply line (11).

3. A fuel transfer and fuel tank inerting cross-linking system as set forth in claim 1, characterized in that said transfer line (13) is provided with a check valve (131) preventing the reverse flow of fuel.

4. A fuel transfer and fuel tank inerting cross-link system as set forth in claim 3, wherein said transfer line (13) is further provided with a transfer shut-off valve (132) for establishing fuel transfer during flight of said aircraft and shutting off fuel transfer during refueling of said aircraft.

5. A fuel transfer and fuel tank inerting cross-linking system as set forth in claim 1, characterized in that said vent line (12) is provided with a vent shut-off valve (121) which shuts off the vent when the aircraft is flying and establishes the vent when the aircraft is refuelling.

6. A fuel transfer and fuel tank inerting cross-linking system as set forth in claim 5, wherein said vent line (12) is further provided with a two-way pressure relief valve (122) connected in parallel with said vent cutoff valve (121) or two one-way pressure relief valves connected in parallel with said vent cutoff valve (121) in opposite directions to each other.

7. Cross-linking system for fuel transfer and tank inerting according to claim 1, characterized in that the openings of said transfer line (13) in said central wing tank (10) and in said outer wing tank (20) are close to the lowest point of the tanks.

8. A method of cross-linking fuel transfer and fuel tank inerting for use in flight of an aircraft using the cross-linking system of claim 1, the method comprising:

-an inert gas (G) from the gas source enters the centre wing tank (10) via a gas supply line (11) and inerts it;

opening a transfer cut valve (132) provided in a transfer line (13) communicating the center-wing tank (10) and the outer-wing tank (20), and closing a vent cut valve (121) provided in a vent line (12) communicating the center-wing tank (10) and the vent tank (30), transferring fuel in the center-wing tank (10) to the outer-wing tank (20) by means of the pressure of the inert gas (G).

9. A method of cross-linking fuel transfer and fuel tank inerting for use in aircraft refueling using the cross-linking system of claim 1, the method comprising:

closing a transfer shut-off valve (132) provided in a transfer line (13) that communicates the center-wing tank (10) and the outer-wing tank (20), and opening a vent shut-off valve (121) provided in a vent line (12) that communicates the center-wing tank (10) and the vent tank (30) to communicate the center-wing tank (10) with the outside atmosphere.

10. A method of cross-linking fuel transfer and fuel tank inerting in the event of inerting failure using the cross-linking system of claim 1, the method comprising:

opening a transfer cut valve (132) provided in a transfer line (13) that communicates the center-wing tank (10) and the outer-wing tank (20), and opening a vent cut valve (121) provided in a vent line (12) that communicates the center-wing tank (10) and the vent tank (30), thereby enabling fuel transfer by gravity.

Technical Field

The invention relates to a cross-linking system for fuel transfer and fuel tank inerting of aircraft, particularly for civil aircraft. The invention further relates to a method for cross-linking fuel transfer and fuel tank inerting.

Background

In civil aircraft that store fuel using a plurality of fuel tanks, the function of the fuel transfer system is mainly to ensure that the fuel is consumed from the individual fuel tanks in a predetermined sequence. For example, with a conventional three tank arrangement aircraft, fuel is consumed in the center wing fuel tanks first, followed by two more tanks.

There are three main methods and/or architectures for civil aircraft fuel transfer: gravity, override transfer and sequential oil transfer.

Override retransmission architectures are commonly used on most boeing aircraft. For a conventional three tank configuration aircraft, center wing tanks may be used to override the transfer pump. The override transfer pump generates a much higher supply line pressure than the main supply boost pump can generate, thereby consuming fuel from the center wing tank first.

The sequential transfer architecture relies on a selector valve. When the oil supply oil tank is full of oil, the selection valve is closed to stop transferring; when the fuel supply to the fuel tank drops to a predetermined fuel amount, the selector valve is opened to resume delivery.

In addition, military aircraft can also adopt fuel tank pressure difference to realize fuel oil transfer. The method can be used only by pressurizing the fuel tank, so that the method is very reliable, light in weight and low in cost.

During fuel transfer, controlled inerting of the oil-free space in the fuel tank by means of a fuel tank inerting system is also required in order to provide a safe transfer environment for the aircraft fuel tank. Typically, fuel for civil aircraft is stored in integral fuel tanks on the wings. Metal winged fuel tanks are considered less hazardous because the volume of oil-free space at the beginning of the transfer is small and the air flow quickly cools the tank to very low temperatures. Therefore, in the conventional three-tank layout of metal wings, the fuel tank inerting system of civil aircraft is mainly considered to be the central wing tank.

Early military aircraft fuel tank inerting systems employed stored inert gas to effect inerting of the fuel tanks. Later, on-board nitrogen generation systems replaced earlier inerting systems. The system uses air separation technology to remove oxygen molecules from the engine/cabin bleed air, leaving nitrogen-enriched air to replace the air in the fuel tank ullage. In addition, military aircraft have also used "molecular sieve" based air separation technology.

At present, the fuel tank inerting system of the civil aircraft mainly adopts an onboard nitrogen production system based on a permeable membrane air separation technology. This technique separates the air passing through the air separation module into molecular components, primarily oxygen and nitrogen. During this process, the oxygen molecules are encouraged to move toward the vent (along with any entrained carbon dioxide and water vapor molecules) while leaving the nitrogen molecules as nitrogen-enriched air through the axial outlet to inertize the fuel tank.

On one hand, a special transfer system needs to be designed for the traditional civil aircraft, and sometimes, the transfer system is very complex, so that the complexity and cost of system design are increased, and the reliability is reduced; on the other hand, the gas generated by the fuel tank inerting system may be discharged to the atmosphere through the ventilation system at times (such as during climbing, when the external atmospheric pressure drops), and the external atmosphere may enter the fuel tank through the ventilation system at times (such as during descending of the aircraft, when the aircraft is parked on the ground, and the like), so that the fuel tank inerting effect is reduced.

Therefore, there is a need to develop a cross-linking system for fuel transfer and tank inerting of aircraft that can reduce the weight of the aircraft and save the flight costs as much as possible while ensuring reliability.

Disclosure of Invention

The aim of the invention is to provide a cross-linking system for fuel transfer and fuel tank inerting of aircraft, which cross-linking system ensures reliability, at the same time as it reduces the weight of the aircraft as much as possible and saves flight costs.

According to a first aspect, the present invention relates to a cross-linking system for fuel transfer and fuel tank inerting of an aircraft, the fuel tank of the aircraft comprising a centre-wing tank, an outer-wing tank and a ventilation tank, the cross-linking system comprising:

the gas source, the inert gas from gas source enters the central wing fuel tank and makes it inerted;

the transfer pipeline is communicated with the central wing oil tank and the outer wing oil tank and transfers fuel oil in the central wing oil tank to the outer wing oil tank by means of the pressure of inert gas when the aircraft flies; and

and the ventilation pipeline is used for communicating the central wing oil tank with the ventilation oil tank, and the ventilation pipeline enables the central wing oil tank to be communicated with the outside atmosphere when the aircraft refuels.

In a preferred embodiment, the gas supply may be connected to the center wing tank via a gas supply line in the fuel transfer and fuel tank inerting cross-linking system described above.

In another preferred embodiment, in the above-described fuel transfer and fuel tank inerting cross-linking system, the transfer line may be provided with a check valve preventing reverse flow of fuel.

More preferably, in the above-mentioned cross-linking system for fuel transfer and fuel tank inerting, the transfer line may also be provided with a transfer shut-off valve which establishes fuel transfer during flight of the aircraft and shuts off fuel transfer during refueling of the aircraft.

In a further preferred embodiment, in the above described cross-linking system for fuel transfer and fuel tank inerting, the vent line may be provided with a vent shut-off valve which shuts off venting during flight of the aircraft and establishes venting during refueling of the aircraft.

More preferably, in the cross-linking system for fuel transfer and fuel tank inerting, the vent pipeline may be further provided with a bidirectional pressure relief valve connected in parallel with the vent shut-off valve.

Alternatively, in the above-described fuel transfer and fuel tank inerting cross-linking system, two one-way pressure release valves in opposite directions may be provided on the vent line in parallel with the vent cut-off valve.

In a further preferred embodiment, in the above described cross-linking system for fuel transfer and fuel tank inerting, the transfer line may have openings in the centre wing tank and the outer wing tank near the lowest point of the tanks.

According to a second aspect, the present invention relates to a method for cross-linking fuel transfer and fuel tank inerting in flight of an aircraft using the cross-linking system according to the first aspect of the invention, the method comprising:

inert gas from a gas source enters the center wing oil tank through a gas supply pipeline and is inerted;

the transfer shutoff valve provided in the transfer line that communicates the center-wing tank and the outer-wing tank is opened, and the vent shutoff valve provided in the vent line that communicates the center-wing tank and the vent tank is closed, and the fuel in the center-wing tank is transferred to the outer-wing tank by the pressure of the inert gas.

According to a third aspect, the present invention relates to a method for cross-linking fuel transfer and fuel tank inerting for use in the refuelling of an aircraft using a cross-linking system according to the first aspect of the invention, the method comprising:

the transfer shut-off valve provided in the transfer line communicating the center-wing tank and the outer-wing tank is closed, and the vent shut-off valve provided in the vent line communicating the center-wing tank and the vent tank is opened to communicate the center-wing tank with the outside atmosphere.

According to a fourth aspect of the invention, there is provided a method of cross-linking fuel transfer and fuel tank inerting in the event of inerting failure using the cross-linking system of the first aspect of the invention, the method comprising:

and opening a transfer stop valve arranged in a transfer pipeline for communicating the central wing oil tank and the outer wing oil tank, and opening a ventilation stop valve arranged in a ventilation pipeline for communicating the central wing oil tank and the ventilation oil tank, so that fuel transfer is realized by using gravity.

The cross-linking system for fuel transfer and fuel tank inerting according to the invention has the following advantages:

the system uses the pressure of inert gas as power to transfer fuel, simplifies the design of the fuel transfer system and simultaneously realizes the inerting of the fuel tank. In this way, system reliability is improved, aircraft weight is reduced and flight costs are saved. The system and the method thereof can be widely applied to civil aircrafts, in particular to civil aircrafts with three oil tanks distributed on the traditional metal wings.

Drawings

To further illustrate the structure of the cross-linking system for fuel transfer and fuel tank inerting of aircraft and the method thereof, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments, in which:

FIG. 1 is a schematic diagram of the operating principle of a cross-linking system for fuel transfer and fuel tank inerting according to the present invention; and

fig. 2 shows in an enlarged manner a vent shut-off valve and a two-way pressure relief valve connected in parallel provided on a vent line.

Reference numerals

10 center wing fuel tank

11 air supply pipeline

12 air vent pipeline

121 ventilation cut-off valve

122 bidirectional pressure relief valve

13 transfer pipeline

131 check valve

132 transfer cut-off valve

20 outer wing oil tank

30 ventilating oil tank

G inert gas

Detailed Description

The cross-linking system for fuel transfer and tank inerting of aircraft and the method thereof according to the present invention will be described with reference to the accompanying drawings, in which like elements are designated by like reference numerals.

FIG. 1 is a schematic diagram of the operating principle of a fuel transfer and fuel tank inerting crosslinking system according to the present invention. The figure shows in a schematic way the centre-wing tanks 10, the outer-wing tanks 20 and the vented tanks 30 which constitute the fuel tanks of the aircraft, with the outer-wing tanks 20 being located between the centre-wing tanks 10 and the vented tanks 30.

It should be noted that since the tank arrangement of the aircraft is symmetrical, only half of the tanks are shown in fig. 1. For the sake of illustration, the respective pipes are only partially shown, and some of the pipes not related to the present invention, such as the vent pipe of the outer wing tank and the like, are omitted.

Although the center-wing tank 10, the outer-wing tank 20 and the ventilation tank 30 are illustrated in the drawings as being simply connected together, it is easily understood by those skilled in the art that fuel tanks constructed in various ways should be included within the scope of the present invention as long as they include at least the center-wing tank, the outer-wing tank and the ventilation tank.

The cross-linking system for fuel transfer and tank inerting of aircraft according to the invention is composed of a gas and air supply line 11, a transfer line 13 and a ventilation line 12.

As indicated by the arrows in fig. 1, inert gas G from a gas source (not shown) enters the center wing tank 10 via a gas supply line 11. In other words, the air supply is communicated with the center wing tank 10 via the air supply line 11. As the inert gas G enters the centre wing tank 10 and fills it, the centre wing tank 10 is inerted.

The transfer line 13 communicates the center wing tank 10 and the outer wing tank 20. The transfer line 13 transfers the fuel in the center wing tanks 10 to the outer wing tanks 20 by the pressure exerted by the inert gas G filled in the center wing tanks 10 while the aircraft is flying.

A check valve 131 is provided in the transfer line 13 to prevent fuel from flowing in the reverse direction, i.e., from the outer wing tanks 20 to the center wing tank 10. Of course, those skilled in the art may substitute the check valve 131 with other devices for preventing the reverse flow of fuel, and such modifications are within the scope of the present invention.

The transfer line 13 is also provided with a transfer shut-off valve 132 downstream of or near the check valve 131. The transfer shut-off valve 132 is opened during flight of the aircraft to establish fuel transfer between the centre wing tanks 10 and the outer wing tanks 20; the transfer shut-off valve 132 is closed when the aircraft is refueled to shut off the transfer of fuel between the centre wing tanks 10 and the outer wing tanks 20.

The ventilation line 12 communicates the center-wing tank 10 with the ventilation tank 30. The vent line 12 communicates air in the centre wing tank 10 with air in the vented tank 30 when the aircraft is refuelling. Since the ventilation tank 30 is in direct communication with the outside atmosphere, it can also be considered that, during the refuelling of the aircraft, the ventilation line 12 connects the air inside the centre wing tank 10 to the outside atmosphere.

A vent shut-off valve 121 is provided in the vent line 12. The vent shut-off valve 121 shuts off gas communication between the centre wing tank 10 and the vent tank 30 when the aircraft is flying and establishes gas communication between the centre wing tank 10 and the vent tank 30 when the aircraft is refuelling.

In view of the possibility of failure of the vent shut-off valve 121, a two-way pressure relief valve 122 is also provided in the vent line 12 in order to ensure that the air inside the center-wing tank 10 can communicate with the outside atmosphere when necessary, and to ensure that the pressure difference between the air inside the center-wing tank 10 and the outside atmosphere is within the limits that the center-wing tank 10 can withstand.

Referring to fig. 2, a bi-directional pressure relief valve 122 is shown in an enlarged manner disposed on the vent line 12. It can be seen that the vent shut-off valve 121 and the bi-directional pressure relief valve 122 are arranged in parallel connection. When the pressure difference between the air in the center-wing tank 10 and the outside air reaches a certain value (which is smaller than the limit of the pressure difference that the center-wing tank 10 can withstand), the two-way pressure release valve 122 opens to eliminate the pressure difference between the air in the center-wing tank 10 and the outside air, thereby ensuring that the pressure difference between the air in the center-wing tank 10 and the outside air is still within the limit that the center-wing tank 10 can withstand in the event of failure of the vent cut-off valve 121.

Of course, those skilled in the art may substitute the above-mentioned two-way pressure relief valve 122 with other equivalent devices, for example, two one-way pressure relief valves connected in parallel with the vent cut-off valve 121 may be provided on the vent line 12, and such modifications are within the scope of the present invention.

In a preferred embodiment, the transfer lines 13 may be provided in the openings in the center wing tank 10 and the outer wing tank 20 near the lowest point of the tanks. In this way, if the inerting system fails, the transfer cut valve 132 provided in the transfer line 13 that communicates the center-wing tank 10 and the outer-wing tank 20 can be opened, and the vent cut valve 121 provided in the vent line 12 that communicates the center-wing tank 10 and the vent tank 30 can be opened, thereby achieving fuel transfer using gravity.

The cross-linking method for fuel transfer and fuel tank inerting using the cross-linking system described above will now be described.

In the case of aircraft flight, the cross-linking method for fuel transfer and fuel tank inerting is as follows:

the transfer shut-off valve 132 provided in the transfer line 13 that communicates the center-wing tank 10 and the outer-wing tank 20 is opened, and the vent shut-off valve 121 provided in the vent line 12 that communicates the center-wing tank 10 with the vent tank 30 is closed. At this time, the transfer line 13 is connected and the vent line 12 is disconnected. Thereby, the fuel in the center-wing tank 10 can be transferred to the outer-wing tank 20 by the pressure of the inert gas G.

In the case of aircraft refueling, the cross-linking method for fuel transfer and fuel tank inerting is as follows:

first, an inert gas G from a gas source is introduced into the center wing tank 10 via the gas supply line 11 and inerted.

Next, after the fuel transfer is stopped, the transfer cut valve 132 provided in the transfer line 13 that communicates the center-wing tank 10 and the outer-wing tank 20 is closed, and the vent cut valve 121 provided in the vent line 12 that communicates the center-wing tank 10 and the vent tank 30 is opened. At this time, the transfer line 13 is disconnected and the vent line 12 is connected. Thus, the air in the center-wing tank (10) is communicated with the outside atmosphere.

The cross-linking method of fuel transfer and fuel tank inerting on the occasion of inerting system failure is as follows:

the transfer shut-off valve 132 provided in the transfer line 13 that communicates the center-wing tank 10 and the outer-wing tank 20 is opened, and the vent shut-off valve 121 provided in the vent line 12 that communicates the center-wing tank 10 with the vent tank 30 is opened. At this time, the transfer line 13 and the vent line 12 are both communicated. Therefore, the fuel oil is transferred by utilizing gravity.

After the aircraft lands, the inerting system is shut down.

While the cross-linking system and method for fuel transfer and tank inerting of aircraft of the present invention has been described above in connection with a preferred embodiment, those of ordinary skill in the art will recognize that the foregoing examples are illustrative only and are not to be construed as limiting the invention. Therefore, modifications and variations of the present invention may be made within the true spirit and scope of the claims, and these modifications and variations are intended to fall within the scope of the claims of the present invention.