Four-engine aircraft fueling and fuel transfer system and method

Abstract

The present application belongs to the field of aircraft fuel system, and relates to a four-engine aircraft fuel supply and fuel transfer system and method. The scheme combines the pressure fueling system and the fuel supply system without increasing the system development cost too much, can use the cross-feed fuel supply mode to eliminate the imbalance through the consumption of the engine, and can also use the transfer mode to transfer the fuel to other fuel tanks to quickly eliminate the imbalance. The fuel transfer / cross-feed can be automatically controlled by the fuel computer software, or manually controlled by the crew. The system can meet the fuel transfer demand and the cross-feed fuel supply demand, reduces the development and inspection and maintenance cost of the aircraft, and has outstanding economy and practicability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aircraft fuel system, and relates to a four-engine aircraft fuel supply and fuel transfer system and method. BACKGROUND

[0002] In the actual operation process of an aircraft, fuel imbalance between the left and right sides is a phenomenon that needs to be closely monitored. This imbalance is often related to a variety of factors. For example, when there are slight differences in the performance of the left and right engines, and when they are in the same working state for a long time, the differences accumulate over time, and the fuel consumption may be inconsistent. When this imbalance continues to increase, the center of gravity balance of the aircraft in the lateral direction will be broken, and the handling performance of the aircraft will be significantly affected, which may increase the difficulty of driving or even cause safety hazards.

[0003] In the face of fuel imbalance between the left and right sides, the industry generally uses two methods, transfer fuel supply or transfer, to eliminate it.

[0004] The first transfer method is to guide the fuel in the tank with high fuel quantity to the tank with low fuel quantity through a special transfer system. This method has obvious advantages, with high transfer efficiency, and can quickly eliminate fuel imbalance in a short time, allowing the aircraft to quickly restore a stable center of gravity state. This is particularly important in emergency situations where the aircraft attitude needs to be quickly adjusted. However, it also has a shortcoming that cannot be ignored. In order to achieve fuel transfer, a complete fuel transfer system needs to be designed, including a special pump body, pipeline, control valve, and corresponding monitoring and control system. These additional designs not only increase the cost of aircraft development, but also make the fuel system structure more complex, making maintenance and repair work more difficult.

[0005] The second method of transfer fuel supply is relatively simple in system structure. The operation process is to open the transfer valve between the tank with high fuel quantity and the tank with low fuel quantity, and at the same time, close the fuel supply pump of the tank with low fuel quantity, so that the tank with high fuel quantity supplies fuel to both engines at the same time. By consuming the fuel in the tank with high fuel quantity, the purpose of balancing the fuel quantity between the left and right sides is achieved. However, this method also has obvious disadvantages. After closing the fuel supply pump of the tank with low fuel quantity, one fuel supply channel is reduced, and if the working fuel supply pump fails, it may affect the normal fuel supply of the engine, reducing the safety margin of the aircraft. Moreover, the entire operation process requires crew members to manually calculate the fuel quantity in the left and right wing tanks, determine when to open the transfer valve and when to close the fuel supply pump, etc., which undoubtedly increases the workload of the crew members, and may distract their attention during busy flight tasks, potentially affecting flight safety. SUMMARY

[0006] Technical problems solved by the present application: The technical problems solved by the present application are to provide a four-engine aircraft fuel supply and fuel transfer system and method, which combines the pressure fuel supply system with the fuel supply system without increasing the system development cost too much, can use the transfer fuel supply method to eliminate the imbalance through the consumption of the engine, and can also use the transfer method to quickly eliminate the imbalance by transferring the fuel to other fuel tanks. The fuel transfer / transfer can be automatically controlled by the fuel computer software, or manually controlled by the crew.

[0007] The technical solutions of the present application are as follows:

[0008] A four-engine aircraft fuel supply and fuel transfer system, comprising a fuel supply pump, a transfer valve, a transfer valve, a fuel control valve and a fuel tank; the fuel tank comprises a No. 1 fuel tank, a No. 2 fuel tank, a No. 3 fuel tank and a No. 4 fuel tank, each fuel tank has an independent fuel supply system to supply fuel to the engine, the No. 1 fuel tank is provided with a fuel supply pump, the fuel supply pump provides fuel for the No. 1 engine, the No. 1 engine and the fuel supply pump are provided with a fuel tank transfer fuel supply pipeline, and the fuel tank transfer fuel supply pipeline is provided with a transfer valve; the fuel control valve is arranged on the pressure fuel supply pipeline, and the fuel control valve is used for providing on-off for the fuel supply of the No. 1 fuel tank; four fuel tank transfer fuel supply pipelines are collected and connected with four collected pressure fuel supply pipelines through a transfer pipeline, and the on-off is realized through a transfer valve;

[0009] Further, the fuel supply pump is provided with two for each fuel tank, which is designed for redundancy;

[0010] Further, the fuel control valve is provided with a fuel diffuser for reducing the flow rate of fuel entering the fuel tank to avoid static electricity accumulation;

[0011] Further, the No. 1 fuel tank and the No. 2 fuel tank are located on one side of the aircraft, and the No. 3 fuel tank and the No. 4 fuel tank are located on the other side of the aircraft.

[0012] Further, it further comprises a flow limiting hole 8, which is arranged in the transfer pipeline and is used for limiting the transfer fuel flow in the transfer process to avoid the situation that the fuel supply flow to the engine is insufficient during the transfer.

[0013] Further, the control of the fuel supply pump, the transfer valve, the transfer valve and the fuel control valve can be realized by computer automatic control or crew manual control.

[0014] Further, the logic of the manual control is consistent with the logic of the automatic control.

[0015] A four-engine aircraft fuel supply and fuel transfer method, comprising a transfer fuel supply method and a transfer fuel supply method.

[0016] Further, the transfer fuel supply method comprises the following steps:

[0017] When the fuel quantity of one tank on one side wing is high and the fuel quantity of one tank on the other side wing is low, the cross-feeding valve of the tank with high fuel quantity is opened, the transfer valve is opened, and the fuel control valve in the tank with low fuel quantity is opened, at this time, the fuel in the tank with high fuel quantity directly enters the tank with low fuel quantity through the cross-feeding oil supply pipeline and the pressure fuel supply pipeline; when the fuel on the left and right wings is balanced, the fuel control valve in the tank with low fuel quantity is closed, the transfer valve is closed, and the cross-feeding valve in the tank with high fuel quantity is closed. The fuel flow in the transfer process is limited by the flow limiting hole diameter size on the transfer pipeline, so as to avoid the insufficient fuel supply.

[0018] Further, the cross-feeding fuel supply method comprises the following steps:

[0019] When the fuel quantity of one tank on one side wing is high and the fuel quantity of one tank on the other side wing is low, if it is needed or the transfer valve and the fuel control valve cannot be opened due to failure, the cross-feeding valves in the two tanks are opened, and the fuel pump in the tank with low fuel quantity is closed, at this time, the engine corresponding to the tank with low fuel quantity is supplied with fuel by the fuel pump in the tank with high fuel quantity; when the fuel on the left and right wings is balanced, the fuel pump in the tank with low fuel quantity is opened, and the cross-feeding valves in the two tanks are closed. The fuel quantity balance on the two sides of the wing is realized.

[0020] Technical effects:

[0021] The cross-feeding fuel supply method combines the fuel supply pipeline and the pressure fuel supply pipeline which are possessed by conventional multi-engine aircraft, controls the communication between the two by the transfer valve, controls the fuel transfer between specific tanks by the opening and closing of the transfer valve and the fuel control valve, and balances the fuel quantity on the left and right wings by cross-feeding fuel supply when the transfer valve or the fuel control valve fails, thereby effectively avoiding the risk of functional failure caused by the failure of a single device.

[0022] Compared with conventional aircraft, the cross-feeding fuel supply method only adds a set of transfer valve and transfer pipeline, and on the basis of not excessively increasing the design complexity, the system can meet the needs of fuel transfer and cross-feeding fuel supply, reduces the development and inspection and maintenance cost of the aircraft, and has outstanding economic efficiency and practicality.

[0023] The control logic of the system is simple and clear, supports automatic control to complete the transfer operation and reduces the burden of the crew, and retains the function of manual control of the crew, so that the operation mode can be flexibly switched in special circumstances. The dual-mode design of "automatic + manual" and the dual functions of transfer and cross-feeding fuel supply make the whole fuel supply and fuel transfer system have high safety margin, and fully guarantee the safety of the aircraft. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 : A four-engine aircraft fuel supply and fuel transfer system principle diagram

[0025] In the figure: 1 - No. 1 oil tank; 2 - No. 2 oil tank; 3 - No. 3 oil tank; 4 - No. 4 oil tank; 5 - oil supply pump; 6 - transfer valve; 7 - transfer valve; 8 - flow limiting hole; 9 - oil filling control valve; 10 - transfer pipe; A - No. 1 engine; B - No. 2 engine; C - No. 3 engine; D - No. 4 engine. DETAILED DESCRIPTION

[0026] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0027] The features and illustrative embodiments of various aspects of the present application will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one of ordinary skill in the art that the present application can be practiced without some of these specific details. The description of the embodiments below is merely intended to provide a better understanding of the present application by showing examples of the present application. The present application is in no way limited to any specific settings and methods presented below, but covers any improvements, replacements and modifications of structures, methods and devices without departing from the spirit of the present application. In the following description, well-known structures and techniques are not shown in order to avoid unnecessary obscuring of the present application.

[0028] In the description of the present application, it should be noted that the directions or positional relationships belonging to "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are based on the described directions or positional relationships, and are only for the convenience of describing the present application and simplifying the description, and cannot be understood as limiting the present application. In addition, the ordinal numbers (for example, "first and second", etc.) are used to distinguish objects, and are not limited to the order, and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, "mounting", "connection" and "connection" should be understood in a broad sense, which can be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0030] It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other, and each embodiment can be mutually referred to and quoted. The present application will be described in detail below with reference to and in conjunction with the embodiments.

[0031] The application will be further described in conjunction with the accompanying drawings:

[0032] Each of the No. 1 oil tank, No. 2 oil tank, No. 3 oil tank and No. 4 oil tank has an independent oil supply system for supplying oil to the engine; a transfer valve is arranged on each oil tank transfer oil supply pipeline; the four transfer oil supply pipelines are connected with the oil supply pipeline; each oil tank is provided with a transfer valve; the oil filling control valve is arranged on the pressure oil filling pipeline of each oil tank; each oil tank is provided with an oil filling control valve; the transfer valve is arranged on the transfer pipeline between the pressure oil filling pipeline and the transfer oil supply pipeline; the connection and disconnection of the transfer valve can control the connection and disconnection between the pressure oil filling pipeline and the transfer oil supply pipeline; the flow limiting hole is arranged on the transfer pipeline; the fuel flow during the transfer is limited by the size of the flow limiting hole; the control of the oil supply pump, the transfer valve, the transfer valve and the oil filling control valve can be automatic control by the computer or manual control by the crew, and the manual control logic is consistent with the automatic control logic.

[0033] According to the above structure, the fuel transfer method of the application is as follows: when the oil quantity of the oil tank on one side wing is high and the oil quantity of the oil tank on the other side wing is low, the transfer valve of the oil tank with high oil quantity is opened, the transfer valve is opened, and the oil filling control valve in the oil tank with low oil quantity is opened; at this time, the fuel in the oil tank with high oil quantity directly enters the oil tank with low oil quantity through the transfer oil supply pipeline and the pressure oil filling pipeline; when the fuel on the left and right wings is balanced, the oil filling control valve in the oil tank with low oil quantity is closed, the transfer valve is closed, and the transfer valve in the oil tank with high oil quantity is closed. The connection and disconnection of the pump and the valve in this process can be automatically controlled by the computer or manually controlled by the crew; the fuel flow during the transfer process is limited by the size of the flow limiting hole located on the pipeline between the main pressure oil filling pipeline and the main transfer oil supply pipeline.

[0034] In addition, according to the above structure, the transfer oil supply method of the application is as follows: when the oil quantity of the oil tank on one side wing is high and the oil quantity of the oil tank on the other side wing is low, if it is needed or the transfer valve and the oil filling control valve cannot be opened due to failure, the transfer valves in the two oil tanks are opened, and the oil supply pump in the oil tank with low oil quantity is closed; at this time, the engine corresponding to the oil tank with low oil quantity is supplied with oil by the oil supply pump in the oil tank with high oil quantity; when the fuel on the left and right wings is balanced, the oil supply pump in the oil tank with low oil quantity is opened, and the transfer valves in the two oil tanks are closed. The connection and disconnection of the pump and the valve in this process can be automatically controlled by the computer or manually controlled by the crew.

[0035] Embodiment

[0036] When the system normally supplies oil to the engine, the oil tank transfer valve 6, the oil filling control valve 9 and the transfer valve 7 are all in the closed state, and the No. 1, No. 2, No. 3 and No. 4 oil tanks supply oil to the corresponding engines by the oil supply pumps 5;

[0037] In addition, when the imbalance is eliminated by the transfer mode: when the fuel quantity of the fuel tank on one side of the wing is high, and the fuel quantity of the fuel tank on the other side of the wing is low, resulting in the imbalance of the fuel quantity of the left and right wings, the transfer valve 6 of the fuel tank with high fuel quantity is opened, the transfer valve 7 is opened, and the fuel control valve 9 in the fuel tank with low fuel quantity is opened, at this time, the fuel in the fuel tank with high fuel quantity flows into the fuel tank with low fuel quantity through the transfer valve 6 of the fuel tank with high fuel quantity, the transfer oil supply pipeline, the flow limiting hole 8, the transfer valve 7 and the pressure oil supply pipeline in sequence; when the fuel quantity of the left and right wings is balanced, the fuel control valve 9 in the fuel tank with low fuel quantity is closed, the transfer valve 7 is closed, and the transfer valve 6 of the fuel tank with high fuel quantity is closed;

[0038] When the imbalance is eliminated by the transfer mode: when the fuel quantity of the fuel tank on one side of the wing is high, and the fuel quantity of the fuel tank on the other side of the wing is low, resulting in the imbalance of the fuel quantity of the left and right wings, the transfer valve 6 of the fuel tank with high fuel quantity is opened, the transfer valve 7 is opened, and the fuel control valve 9 in the fuel tank with low fuel quantity is opened, at this time, the fuel in the fuel tank with high fuel quantity flows into the fuel tank with low fuel quantity through the transfer valve 6 of the fuel tank with high fuel quantity, the transfer oil supply pipeline, the flow limiting hole 8, the transfer valve 7 and the pressure oil supply pipeline in sequence; when the fuel quantity of the left and right wings is balanced, the fuel control valve 9 in the fuel tank with low fuel quantity is closed, the transfer valve 7 is closed, and the transfer valve 6 of the fuel tank with high fuel quantity is closed;

[0039] The connection and disconnection of the pump and the valve in the transfer and the transfer process can be controlled automatically by the computer or manually by the crew. Under the automatic control logic, when the imbalance of the fuel quantity of the left and right wings occurs and the system devices are working normally, the transfer mode is used to eliminate the imbalance, and when the transfer valve 7 or the fuel control valve 9 cannot be opened due to failure, the system automatically switches to the control logic of the transfer mode to eliminate the imbalance.

[0040] The fuel flow in the transfer process is limited by the size of the flow limiting hole 8 on the transfer pipeline 10.

[0041] The scheme has clear principles, simple system architecture, high work reliability, can meet the automatic control and manual control requirements of the crew, and has high safety margin.

[0042] The above specific embodiments are detailed descriptions of the present application, and cannot be considered as limiting the specific embodiments of the present application to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, some simple deductions and substitutions can be made without departing from the concept of the present application, and all of them should be considered as belonging to the protection scope of the present application.

Claims

1. A method of fuelling and fuel transfer for a four-engined aircraft, characterised in that, It is realized based on a transfer system, the transfer system comprises an oil supply pump, a transfer valve, a transfer valve, a refueling control valve and an oil tank; the oil tank comprises a No. 1 oil tank, a No. 2 oil tank, a No. 3 oil tank and a No. 4 oil tank, each of which has an independent oil supply system to supply oil to the engine, the No. 1 oil tank is provided with an oil supply pump, which provides fuel for the No. 1 engine, and the oil supply pump is provided with an oil tank transfer oil supply pipeline between the No. 1 engine and the oil supply pump, and the oil tank transfer oil supply pipeline is provided with a transfer valve; the refueling control valve is arranged on the pressure refueling pipeline, and the refueling control valve is used for providing on-off for the refueling of the No. 1 oil tank; four oil tank transfer oil supply pipelines are collected and connected with four collected pressure refueling pipelines through a transfer pipeline, and on-off is realized through a transfer valve; the method comprises a transfer oil supply method and a transfer oil supply method; the transfer oil supply method comprises the following steps: When the oil quantity of an oil tank on one side of the wing is high and the oil quantity of an oil tank on the other side of the wing is low, open the transfer valve of the oil tank with high oil quantity, open the transfer valve, and open the refueling control valve in the oil tank with low oil quantity, at this time, the fuel in the oil tank with high oil quantity directly enters the oil tank with low oil quantity through the transfer oil supply pipeline and the pressure refueling pipeline; when the fuel on the left and right wings is balanced, close the refueling control valve in the oil tank with low oil quantity, close the transfer valve, and close the transfer valve in the oil tank with high oil quantity; the fuel flow in the transfer process is limited by the size of the flow limiting hole diameter on the transfer pipeline, so as to avoid the occurrence of insufficient oil supply flow; The transfer oil supply method comprises the following steps: When the oil quantity of an oil tank on one side of the wing is high and the oil quantity of an oil tank on the other side of the wing is low, if it is needed or the transfer valve and the refueling control valve cannot be opened due to failure, open the transfer valves in the two oil tanks, and close the oil supply pump in the oil tank with low oil quantity, at this time, the engine corresponding to the oil tank with low oil quantity is supplied by the oil supply pump of the oil tank with high oil quantity; when the fuel on the left and right wings is balanced, open the oil supply pump in the oil tank with low oil quantity, close the transfer valves in the two oil tanks, and realize the balance of the oil quantity on the left and right wings.

2. The method of oil supply and fuel transfer according to claim 1, wherein The oil supply pump is provided with two in each oil tank, which is a redundancy design.

3. The method of claim 1, wherein the fuel oil is a fuel oil having a viscosity of 1000 cSt or more at 40°C. The refueling control valve is provided with a fuel diffuser.

4. The method of claim 1, wherein the fuel oil is a fuel oil having a viscosity of 1000 cSt or more at 40°C. The No. 1 oil tank and the No. 2 oil tank are located on one side of the aircraft, and the No. 3 oil tank and the No. 4 oil tank are located on the other side of the aircraft.

5. The method of claim 1, wherein the fuel oil is a fuel oil having a viscosity of 1000 cSt or more at 40°C. It also comprises a flow limiting hole, which is arranged on the transfer pipeline and is used to limit the transfer fuel flow in the transfer process.

6. The method of oil supply and fuel transfer of claim 1, wherein, The control of the oil supply pump, the transfer valve, the transfer valve and the refueling control valve is realized through computer automatic control or crew manual control.

7. The method of oil supply and fuel transfer of claim 6, wherein, The logic of the crew manual control is consistent with that of the automatic control.

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