Fuel storage and distribution system

Abstract

The fuel storage and distribution system based on multiple variable-volume fuel tanks can simply measure the fuel quantity and quickly disassemble and maintain, can eliminate the unusable fuel in the fuel tank, reduce the flight weight of the aircraft, and greatly reduce the use of the inerting system, and improve the economy of the aircraft. The fuel storage and distribution system has multiple variable-volume fuel tanks, and can realize fuel storage and fuel distribution functions based on multiple fuel tanks. The outer peripheral wall of each fuel tank is a fixed-volume rigid body, and the inside of each fuel tank is divided into a fuel storage part for storing fuel and a pressure regulating fluid storage part for storing pressure regulating fluid. A one-way oil inlet valve and a one-way oil outlet valve connected to both ends of a two-way cross transfer valve are provided at the fuel storage part, and a pressure regulating valve connected to a pressure control pump and used to control the pressure of the pressure regulating fluid is provided at the pressure regulating fluid storage part.

Description

Technical Field

[0001] This invention relates to the layout and architecture of a fuel system for a civil aircraft, and more specifically to a fuel storage and distribution system based on multiple variable-volume fuel tanks. Background Technology

[0002] Traditional civil aircraft fuel tank layout (also known as "fuel storage and distribution system")

[0003] The "fuel system" typically consists of multiple fixed-volume integral fuel tanks and supporting components such as fuel pumps, ejector pumps, fuel filling and emptying lines, vent lines, and one-way valves. The fuel level in each fuel tank is detected and calculated by a sensor array, which includes multiple sensors such as a fuel level sensor, a fuel level compensation sensor, a low fuel level sensor, a high fuel level sensor, and a temperature sensor.

[0004] In addition, traditional civil aircraft fuel systems use dewatering systems to reduce unusable fuel remaining in the fuel tanks. These systems primarily consist of a flow check valve, an ejector pump, and a transfer control float valve. However, even with these measures, it's impossible to completely eliminate unusable fuel remaining in the tanks. Unusable fuel increases aircraft weight and reduces fuel economy. Furthermore, to prevent combustion explosions, traditional civil aircraft fuel systems typically also require an inerting system to supply inert gas to the fuel tanks.

[0005] With continuous technological innovation, various improvements have been made to the layout and architecture of fuel systems in existing technologies.

[0006] For example, US Patent 8002142B2 describes an airbag-type variable volume fuel tank design and its application in unmanned aerial vehicles. In addition, US Patent 9919807B2 provides an airbag outside the fuel tank of an aircraft. This external airbag allows the fuel in the fuel tank to expand and contract without taking up additional space inside the aircraft, thereby allowing more fuel mass to be maintained and a smaller shape, and making the aircraft shape more aerodynamically efficient.

[0007] For example, Chinese patent application CN 112849419A provides a completely oxygen-isolated fuel tank for aircraft. An airbag is installed in the fuel tank, allowing outside air to enter and exit the airbag through a pressure regulating valve, rather than directly entering the fuel tank. This effectively prevents oxygen in the outside air from contacting the fuel, thus ensuring that the fuel will not ignite or explode and that the fuel tank remains in an oxygen-isolated state at all times. Furthermore, the adaptive contraction and expansion of multiple airbags, working in combination, can achieve automatic pressure balance between the inside and outside of the fuel tank, solving the technical problem in existing technologies where aircraft fuel tanks cannot be completely isolated from outside air (oxygen).

[0008] For example, Chinese patent application CN 113353272A provides a foldable fuel tank for drones. The volume of the fuel tank can be changed during refueling and use, which can prevent fuel surging inside the tank to maintain the center of gravity and effectively avoid the generation of air bubbles inside the tank, thereby enabling timely and uninterrupted fuel supply for drones.

[0009] Nevertheless, in the layout and architecture of fuel systems in various existing technical documents,

[0010] Many technical challenges remain to be solved.

[0011] For example, the technology described in US Patent 8002142B2 is only applicable to small unmanned aerial vehicles with a single fuel tank, and its applicability to large commercial aircraft (civil aircraft) is limited. While the technology described in US Patent 9919807B2 can solve the problem of additional space occupation inside the aircraft by placing the airbag on the outside of the rest of the aircraft, it fails to solve the problems of simple fuel quantity measurement and quick disassembly and maintenance.

[0012] For example, although the technology described in Chinese patent application CN 112849419A can effectively prevent oxygen in the outside air from coming into contact with the fuel by allowing air from outside the aircraft to enter and exit the airbags set in the fuel tank through a pressure regulating valve instead of directly entering the fuel tank, it also fails to solve the problems of simple measurement of fuel quantity and quick disassembly and maintenance.

[0013] For example, although the technology described in Chinese patent application CN 113353272A has the technical effects of preventing fuel surge in the fuel tank to maintain the center of gravity, effectively avoiding the generation of air bubbles in the fuel tank, and providing timely and uninterrupted fuel supply for drones, it also fails to solve the problems of simple measurement of fuel quantity and quick disassembly and maintenance.

[0014] Therefore, it is desirable to design a new type of fuel storage and distribution system to solve the many technical problems left by the fuel systems of civil aircraft and existing technical documents mentioned above. Summary of the Invention

[0015] This invention is made to solve the above-mentioned technical problems. Its purpose is to provide a fuel storage and distribution system based on multiple variable-volume fuel tanks, which can easily measure the fuel quantity and can be quickly disassembled and maintained. It can eliminate unusable fuel in the fuel tanks, reduce the flight weight of the aircraft, and at the same time greatly reduce the use of inerting systems, thereby improving the aircraft's economy.

[0016] To achieve the above-mentioned objectives, the fuel storage and distribution system of the present invention has multiple variable-volume fuel tanks and can realize fuel storage and fuel distribution functions based on the multiple fuel tanks. The outer peripheral wall of each fuel tank is a rigid body with a fixed volume. The interior of each fuel tank is divided into a fuel storage section for storing fuel and a pressure regulating fluid storage section for storing pressure regulating fluid. The fuel storage section is equipped with a one-way inlet valve and a one-way outlet valve respectively connected to both ends of a bidirectional cross-flow valve. The pressure regulating fluid storage section is equipped with a pressure regulating valve connected to a pressure control pump for controlling the pressure of the pressure regulating fluid.

[0017] Preferably, the one-way inlet valves of the plurality of fuel tanks are connected to each other through a refueling line and to one end of the bidirectional cross-flow valve, and the one-way outlet valves of the plurality of fuel tanks are connected to each other through a fuel supply line and to the other end of the bidirectional cross-flow valve.

[0018] More preferably, the pressure regulating valve of each of the plurality of fuel tanks is connected to a pressure control pump via a vent line.

[0019] More preferably, when fuel needs to be distributed from one or more designated fuel tanks to another designated fuel tank, the one-way outlet valve of the designated one or more fuel tanks that need to discharge fuel is opened while the one-way inlet valve is closed, and the one-way outlet valve of the designated fuel tank that needs to receive fuel is closed while the one-way inlet valve is opened. The pressure of the pressure regulating fluid in the pressure regulating fluid storage section is controlled by the pressure control pump and the pressure regulating valve, thereby controlling the inflow and outflow of fuel relative to the fuel storage section and the fuel flow rate.

[0020] More preferably, a temperature sensor and a pressure sensor are respectively provided in the fuel storage section and the pressure regulating fluid storage section of each of the fuel tanks.

[0021] More preferably, the plurality of fuel tanks are fuel tanks of different sizes disposed on the wings of the aircraft.

[0022] In addition, the fuel tanks mentioned above are airbag-type fuel tanks, piston-type fuel tanks, or flexible fuel tanks.

[0023] In addition, the pressure regulating fluid is a liquid other than air, inert gas, or fuel.

[0024] According to the above-described configuration, the fuel storage and distribution system based on multiple variable-volume fuel tanks of the present invention has the following technical advantages:

[0025] (1) The fuel storage and distribution system has multiple fuel tanks that are interconnected by refueling lines and fuel supply lines connected to both ends of the bidirectional cross-flow valve. Therefore, a certain degree of aircraft weight distribution can be achieved by distributing fuel in multiple fuel tanks.

[0026] (2) Multiple variable volume fuel tanks can be designed to include a variety of variable volume fuel tanks of different sizes to form a series of standardized products, thereby facilitating parts management;

[0027] (3) The fuel tank is connected to the aircraft via refueling lines, fuel supply lines and venting lines. Compared with the traditional fuel layout where the entire wing is the fuel tank, it can be quickly disassembled and assembled, which greatly facilitates the cleaning and maintenance of the fuel tank.

[0028] (4) Variable volume fuel tanks greatly reduce the amount of unusable fuel remaining in the aircraft and greatly reduce the use of inert gas, thereby reducing the aircraft's flight weight and improving flight economy. Attached Figure Description

[0029] Figure 1 This is a schematic diagram showing the structure of a single fuel tank in the fuel storage and distribution system (hereinafter sometimes referred to as the "fuel system") based on multiple variable-volume fuel tanks of the present invention.

[0030] Figure 2 This is a schematic diagram illustrating the combined arrangement of multiple fuel tanks in the fuel system of the present invention and the transfer between them.

[0031] Figure 3 This is a schematic diagram illustrating the specific layout and architecture of the fuel system of the present invention.

[0032] Figure 4 This is a flowchart illustrating the distribution of fuel in multiple fuel tanks in the fuel system of the present invention.

[0033] (Symbol Explanation)

[0034] 100 fuel system;

[0035] 110 fuel tank;

[0036] 111 Fuel Storage Department;

[0037] 112 Pressure regulating fluid storage section;

[0038] 113 One-way oil inlet valve;

[0039] 114 One-way oil outlet valve;

[0040] 115 pressure regulating valve;

[0041] 120 refueling pipeline;

[0042] 130 fuel supply line;

[0043] 140 bidirectional transfer valve;

[0044] 150 ventilation line;

[0045] 160 pressure control pump. Detailed Implementation

[0046] Below, in conjunction with Figures 1 to 4 The present invention will be described in detail with respect to the fuel system 100 based on multiple variable volume fuel tanks. Figure 1 This is a schematic diagram showing the structure of a single fuel tank 110 in the fuel system 100 having multiple variable-volume fuel tanks 110 according to the present invention. Figure 2 This is a schematic diagram illustrating the combined arrangement of multiple fuel tanks 110 in the fuel system 100 of the present invention and the transfer between them. Figure 3 This is a schematic diagram showing the specific layout and architecture of the fuel system 100 of the present invention. Figure 4 This is a flowchart illustrating the distribution of fuel in multiple fuel tanks 110 in the fuel system 100 of the present invention.

[0047] The fuel system (fuel storage and distribution system) 100 of the present invention is a system that realizes fuel storage and fuel distribution functions based on multiple variable volume fuel tanks 110.

[0048] The fuel system 100 of the present invention has a plurality of fuel tanks 110 of different sizes and having variable volumes.

[0049] Here, as Figure 1 As shown, the variable-volume fuel tank 110 is, for example, an airbag-type fuel tank, which has the following characteristics: the outer peripheral wall of the fuel tank 110 is a rigid body with a fixed volume; and the interior of the fuel tank 110 is divided into two parts, one part being a fuel storage section 111 for storing fuel, and the other part being a pressure-regulating fluid storage section 112 for storing pressure-regulating fluids such as air. Furthermore, for this airbag-type fuel tank, as... Figure 1 As shown, a one-way inlet valve 113 and a one-way outlet valve 114 are provided at the fuel storage section 111, and a pressure regulating valve 115 is provided at the pressure regulating fluid storage section 112 (see...). Figure 3 ).

[0050] Each of the multiple fuel tanks 110 has a one-way inlet valve 113 that merges with each other through a refueling line 120 and is connected to one end of a two-way transfer valve 140. Each of the multiple fuel tanks 110 has a one-way outlet valve 114 that merges with each other through a fuel supply line 130 and is connected to the other end of a two-way transfer valve 140. When fuel needs to be distributed from one or more fuel tanks 110 to another one or more fuel tanks 110, the one-way outlet valve 114 of the fuel tank 110 that needs to discharge fuel is opened and the one-way inlet valve 113 is closed, and the one-way outlet valve 114 of the fuel tank 110 that needs to receive fuel is closed and the one-way inlet valve 113 is opened. Each of the multiple fuel tanks 110 has a pressure regulating valve 115 connected to a pressure control pump 160 via a vent pipe 150. This valve controls the pressure of a pressure regulating fluid, such as air. By controlling the pressure of the pressure regulating fluid, such as air, in the pressure regulating fluid reservoir 112, the inflow and outflow of fuel relative to the fuel reservoir 111 and the fuel flow rate can be controlled. Furthermore, although not shown in the figures, each fuel tank 110 is equipped with a temperature sensor and a pressure sensor at both the fuel reservoir 111 and the pressure regulating fluid reservoir 112.

[0051] In addition, the pressure regulating fluid is preferably air, but it can also be any other gas besides air.

[0052] Examples of inert gases include nitrogen and helium. Furthermore, the pressure regulating fluid is not limited to gases; although not the preferred choice, other liquids such as water can be used to regulate pressure and weight, as long as it is not fuel oil.

[0053] In actual use, depending on the specific internal structure of the aircraft fuselage and wings and the available space, such as Figure 2 The diagram shows a plan with multiple fuel tanks 110 of different sizes. The fuel tanks 110 are connected to each other by a refueling line 120 and a fuel supply line 130. This allows for the maximization of space utilization and the creation of a product standard library by planning various commonly used fuel tank sizes 110.

[0054] In addition, such as Figure 2 and Figure 3 As shown, since the fuel tank 110 is connected to the aircraft via a refueling line 120, a fuel supply line 130, and a venting line 150, compared with the traditional integrated fuel layout where the entire wing is a fuel tank, it enables quick disassembly and assembly of the fuel system 100 and greatly facilitates the cleaning and maintenance of the fuel tank 110.

[0055] The fuel system (fuel storage and distribution system) 100 of the present invention has multiple variable-volume fuel tanks 110, thus enabling fuel distribution according to the aircraft's weight requirements.

[0056] More specifically, fuel distribution and transmission are mainly controlled by a pressure control pump 160, a two-way transfer valve 140, and one-way inlet valves 113 and one-way outlet valves 114 of the fuel storage compartments 111 of each of the multiple fuel tanks 110. After acquiring the fuel distribution requirements of the entire aircraft (step S100), the fuel system (fuel storage and distribution system) 100 calculates the target fuel weight of each fuel tank 110 (step S200) and converts it into the target liquid level of fuel in the fuel storage compartments 111 of each fuel tank 110 (step S300). The rise and fall of the liquid level of fuel in the fuel storage compartments 111 of each fuel tank 110 is regulated by the pressure control of pressure-regulating fluids such as air (step S400). At this time, the sensor acquires the liquid level of fuel in the fuel storage compartments 111 of each fuel tank 110 in real time and simultaneously judges whether the fuel level has reached the target liquid level (step S500). If the judgment is "no", the process returns to step S400 for further adjustment. In other words, if the fuel level in one or more fuel tanks 110 is higher than the calculated target level for that fuel tank 110, the one-way outlet valve 114 of the corresponding fuel tank 110 is opened and the one-way inlet valve 113 is closed. At the same time, the pressure (volume) of the pressure regulating fluid, such as air, in the pressure regulating fluid storage section 112 of the fuel tank 110 is appropriately increased by the pressure control pump 160. Conversely, if the fuel level in one or more fuel tanks 110 is lower than the calculated target level for that fuel tank 110, the one-way inlet valve 113 of the corresponding fuel tank 110 is opened and the one-way outlet valve is closed. Valve 114, and at the same time, through pressure control pump 160, appropriately reduce the pressure (volume) of the pressure regulating fluid such as air in the pressure regulating fluid storage section 112 of the corresponding fuel tank 110 until the fuel level of the corresponding fuel tank 110 reaches the calculated target level of the fuel tank 110 (i.e., the judgment in step S500 is "yes"). At this time, the one-way inlet valve 113 and the one-way outlet valve 114 of the corresponding fuel tank 110 are closed (step S600), and the pressure of the pressure regulating fluid such as air in the pressure regulating fluid storage section 112 is adjusted to prevent the internal and external pressure difference from being too large (step S700).

[0057] Furthermore, by utilizing the fuel system (fuel storage and distribution system) 100 of the present invention, the distribution of fuel in multiple fuel tanks 110 can assist in aircraft weight balancing to a certain extent. Simultaneously, when the fuel level in the fuel storage section 111 of a certain fuel tank 110 is higher than the target level, the pressure control pump 160 appropriately increases the pressure (volume) of the regulating fluid, such as air, in the corresponding pressure regulating fluid storage section 112 of the fuel tank 110 to discharge the fuel from the fuel storage section 111. Conversely, when the fuel level in the fuel storage section 111 of a certain fuel tank 110 is lower than the target level, the pressure control pump 160 appropriately decreases the pressure (volume) of the regulating fluid, such as air, in the corresponding pressure regulating fluid storage section 112 of the fuel tank 110 to allow fuel to enter the fuel storage section 111. Therefore, the remaining unusable fuel in the aircraft is greatly reduced, the use of inerting gas is significantly reduced, the aircraft's flight weight is lowered, and flight economy is improved.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0059] In the embodiments of the present invention, a variable volume fuel tank 110, such as an airbag-type fuel tank, has been described as an example. However, the present invention is not limited to this and may also be other types of fuel tanks, such as piston-type fuel tanks or flexible fuel tanks, which have the same characteristics as airbag-type fuel tanks.

Claims

1. A fuel storage and distribution system, characterized in that, The fuel storage and distribution system has multiple fuel tanks (110) and is capable of performing fuel storage and fuel distribution functions based on the multiple fuel tanks (110). The outer peripheral wall of each of the fuel tanks (110) is a rigid body with a fixed volume. Each of the fuel tanks (110) is divided into a fuel storage section (111) for storing fuel and a pressure regulating fluid storage section (112) for storing pressure regulating fluid. The fuel storage section (111) is equipped with a one-way inlet valve (113) and a one-way outlet valve (114) respectively connected to both ends of a two-way transfer valve (140). The pressure regulating fluid storage section (112) is equipped with a pressure regulating valve (115) connected to a pressure control pump (160) for controlling the pressure of the pressure regulating fluid. The pressure regulating valves (115) of each of the plurality of fuel tanks (110) can control the inflow and outflow of fuel relative to the fuel storage section (111) and the fuel flow rate by controlling the pressure of the pressure regulating fluid in the pressure regulating fluid storage section (112). The one-way inlet valves (113) of each of the plurality of fuel tanks (110) converge with each other through the refueling line (120) and are connected to one end of the two-way transfer valve (140). The one-way outlet valves (114) of each of the multiple fuel tanks (110) converge with each other through the fuel supply line (130) and are connected to the other end of the two-way transfer valve (140).

2. The fuel storage and distribution system as described in claim 1, characterized in that, Each of the fuel tanks (110) has a pressure regulating valve (115) connected to a pressure control pump (160) via a vent line (150).

3. The fuel storage and distribution system as described in claim 2, characterized in that, When fuel needs to be distributed from one or more designated fuel tanks (110) to another designated fuel tank (110) in the plurality of fuel tanks (110), the one-way outlet valve (114) of the designated one or more designated fuel tanks (110) that needs to discharge fuel is opened and the one-way inlet valve (113) is closed, and the one-way outlet valve (114) of the designated other designated fuel tanks (110) that needs to receive fuel is closed and the one-way inlet valve (113) is opened. The pressure of the pressure regulating fluid in the pressure regulating fluid storage section (112) is controlled by the pressure control pump (160) and the pressure regulating valve (115), thereby controlling the inflow and outflow of fuel relative to the fuel storage section (111) and the fuel flow rate.

4. The fuel storage and distribution system as described in claim 3, characterized in that, Temperature sensors and pressure sensors are respectively provided in the fuel storage section (111) and the pressure regulating fluid storage section (112) of each of the fuel tanks (110).

5. The fuel storage and distribution system as described in claim 1, characterized in that, The multiple fuel tanks (110) are fuel tanks of different sizes located on the wings of the aircraft.

6. The fuel storage and distribution system as described in any one of claims 1 to 5, characterized in that, The plurality of said fuel tanks (110) are airbag-type fuel tanks, piston-type fuel tanks or flexible fuel tanks.

7. The fuel storage and distribution system as described in any one of claims 1 to 5, characterized in that, The pressure regulating fluid is a liquid other than air, inert gas, or fuel.

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