Aircraft soft oil tank supercharged by turbojet engine
By designing the internal and external fuel tank structures and constant pressure valves, the problem of unstable engine fuel supply caused by fuel consumption in soft fuel tanks was solved, achieving stable fuel output and stable flight of the aircraft.
Patent Information
- Application Number
- CN202520544098.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-03-26
AI Technical Summary
When existing aircraft are in flight, the consumption of fuel in the soft fuel tank causes a change in the center of gravity, which leads to unstable fuel supply to the engine and may cause abnormal engine speed. Existing control methods have problems with unstable pressure or booster pump failure.
It adopts an internal and external fuel tank structure. The internal fuel tank is made of soft material and forms a stable positive pressure environment through the positive pressure chamber provided by the engine. Combined with sloshing suppression components and constant pressure valve, it ensures stable fuel output.
It achieves continuous and stable fuel output, ensures stable engine speed, improves the flight stability of the aircraft, reduces the risk of fuel leakage, and extends the service life of the fuel tank.
Smart Images
Figure CN223835809U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of aircraft soft fuel tanks, and particularly relates to an aircraft soft fuel tank that utilizes a turbojet engine for pressurization. Background Technology
[0002] When an aircraft is in flight, the engine's oil pump needs to continuously supply fuel to the engine, and the fuel supply must be stable. When the fuel supply is unstable, abnormal engine speed will occur, leading to loss of aircraft control.
[0003] Currently, during flight, as fuel in the flexible fuel tank is consumed, the aircraft's center of gravity shifts, causing fluctuations in the fuel pressure supplied to the engine. This can easily lead to inaccurate fuel pumping and abnormal engine speed. Existing control methods for these issues mainly fall into two categories: 1. Using external air pressurization to supply pressure to the aircraft's fuel tank. Fuel lines within the tank connect to the engine's fuel pump. When the aircraft starts, the pump draws fuel from the flexible fuel tank and supplies it to the engine. 2. Installing a booster pump to supply pressure to the aircraft's fuel tank. Fuel lines within the tank connect to the engine's fuel pump inlet. When the aircraft starts, the pump draws fuel from the tank and supplies it to the engine. However, the first solution suffers from unstable pressure when external pressure is unstable. In the second solution, if the booster pump malfunctions, it could lead to abnormal fuel output from the tank, causing abnormal engine speed and reduced stability. Utility Model Content
[0004] The purpose of this invention is to provide a soft fuel tank for aircraft that utilizes a turbojet engine for pressurization, in order to solve the above-mentioned problems and achieve the goal of enabling the fuel tank to stably supply fuel to the engine.
[0005] To achieve the above objectives, this utility model provides the following solution: a soft fuel tank for aircraft pressurized by a turbojet engine, comprising:
[0006] External fuel tank, which is fixedly connected inside the aircraft fuselage;
[0007] The inner fuel tank is made of a soft material and is located inside the outer fuel tank. A positive pressure chamber is formed between the inner fuel tank and the outer fuel tank. A sway-suppressing component is provided between the inner fuel tank and the outer fuel tank. The inner fuel tank is used to store fuel, and the positive pressure chamber is provided with positive pressure by the engine.
[0008] Preferably, the outer fuel tank is made of a soft material.
[0009] Preferably, the inner oil tank and the outer oil tank are made of soft PE material.
[0010] Preferably, the sway suppression component includes a plurality of elastic restraint bands evenly distributed in the positive pressure cavity, and the two ends of the elastic restraint bands are fixedly connected to the inner wall of the outer oil tank and the outer wall of the inner oil tank, respectively.
[0011] Preferably, one end of the inner fuel tank is connected to a fuel pipe, and the other end of the fuel pipe is correspondingly connected to the engine. A fuel pump is connected to the fuel pipe, and the fuel pump supplies fuel to the engine through the fuel pipe.
[0012] Preferably, one end of the external oil tank is connected to an air pipe, the air pipe is connected to the positive pressure chamber, the other end of the air pipe is connected to the compressor of the engine, and a constant pressure component is connected to the air pipe.
[0013] Preferably, the constant pressure component includes a constant pressure valve, which is connected to the air pipe and has a vent port that is connected to the engine's air intake passage.
[0014] Preferably, the trachea is connected to a venting nozzle.
[0015] Preferably, the fuel line is connected to a fuel inlet and a valve, and the valve is located between the fuel inlet and the fuel pump.
[0016] Compared with existing technologies, this invention has the following advantages and technical effects: the main function of making the inner fuel tank from a soft material is to facilitate air pressure compression of the inner fuel tank, maintaining stable fuel output; the main function of the positive pressure chamber is to accommodate the airflow provided by the engine compressor and create positive pressure to compress the inner fuel tank; the main function of the sway suppression component is to prevent excessive swaying of the inner fuel tank within the outer fuel tank when its volume is compressed, thereby reducing the change in the aircraft's center of gravity. Overall, this invention creates a positive pressure environment for the inner fuel tank by the positive pressure generated during engine operation. As fuel is consumed, the inner fuel tank can be compressed, ensuring that it is always full of fuel. The positive pressure environment assists in fuel extrusion, ensuring continuous fuel output, thereby guaranteeing stable engine speed and improving the stability of the aircraft during flight. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the arrangement of the flexible oil tank of this utility model;
[0019] Figure 2This is a schematic diagram showing the connection between the flexible fuel tank and the engine of this utility model;
[0020] Figure 3 This is a schematic diagram of the flexible oil tank of this utility model;
[0021] The components include: 1. Aircraft fuselage; 2. Engine; 3. Internal fuel tank; 4. External fuel tank; 5. Fuel line; 6. Fuel pump; 7. Constant pressure valve; 8. Air line; 9. Indicator; 10. Connecting air nozzle; 11. Elastic restraint strap; 12. Fuel inlet; 13. Vent nozzle; 14. Positive pressure chamber; and 15. Valve. Detailed Implementation
[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0023] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0024] Reference Figures 1-3 This utility model provides a soft fuel tank for aircraft pressurized by a turbojet engine, comprising:
[0025] External fuel tank 4 is fixedly connected inside the aircraft fuselage 1;
[0026] The inner fuel tank 3 is made of soft material and is located inside the outer fuel tank 4. A positive pressure chamber 14 is formed between the inner fuel tank 3 and the outer fuel tank 4. A sway suppression component is provided between the inner fuel tank 3 and the outer fuel tank 4. The inner fuel tank 3 is used to store fuel, and the positive pressure chamber 14 is provided with positive pressure by the engine 2.
[0027] The main function of the inner fuel tank 3 being made of soft material is to facilitate air pressure compression of the inner fuel tank 3, maintaining stable fuel output. The main function of the positive pressure chamber 14 is to accommodate the airflow provided by the engine compressor and create positive pressure to compress the inner fuel tank 3. The main function of the sway suppression component is to prevent excessive swaying of the inner fuel tank 3 within the outer fuel tank 4 when its volume is compressed, thereby reducing the change in the aircraft's center of gravity. Overall, this invention creates a positive pressure environment for the inner fuel tank by the positive pressure generated during engine operation. As fuel is consumed, the inner fuel tank can be compressed, ensuring that it is always full of fuel. The positive pressure environment assists in the extrusion of fuel, ensuring continuous fuel output, thereby guaranteeing stable engine speed and improving the stability of the aircraft during flight.
[0028] The design was further optimized, and the outer fuel tank 4 was made of soft material.
[0029] The design was further optimized by using soft PE material to make the inner fuel tank 3 and the outer fuel tank 4.
[0030] Soft PE materials (such as LDPE and LLDPE) possess excellent flexibility, allowing them to adapt to a certain degree of deformation without cracking. This effectively reduces the risk of fuel leakage when the fuel tank of this invention is subjected to external impacts or bumps. Furthermore, soft PE materials exhibit excellent chemical corrosion resistance, resisting the erosion of various chemicals in fuel and ensuring the service life of the fuel tank. Simultaneously, PE material is a thermoplastic with good processing properties, allowing it to be molded into complex shapes through processes such as blow molding to meet the needs of different installation spaces.
[0031] Further optimization of the scheme: the sway suppression component includes several elastic restraint bands 11 evenly distributed in the positive pressure chamber 14, with the two ends of the elastic restraint bands 11 fixedly connected to the inner wall of the outer oil tank 4 and the outer wall of the inner oil tank 3, respectively.
[0032] like Figure 3 As shown, several elastic restraint bands 11 are evenly distributed within the positive pressure chamber 14, allowing the inner fuel tank 3 to be connected to the outer fuel tank 4 from all sides via the elastic restraint bands 11. During flight, the outer fuel tank 4 expands under positive pressure, maintaining a relatively stable shape. As fuel is consumed, the inner fuel tank 3 is compressed by air pressure, reducing its volume and causing significant swaying between the inner and outer fuel tanks 4. However, the elastic restraint bands 11 are simultaneously stretched, restricting the inner fuel tank 3 with elastic force in all directions, thus reducing the degree of swaying within the outer fuel tank 4 and decreasing the change in the aircraft's center of gravity, which is beneficial for stable flight.
[0033] The design is further optimized so that one end of the fuel pipe 5 is connected to the inner fuel tank 3, and the other end of the fuel pipe 5 is correspondingly set to the engine 2. The fuel pump 6 is connected to the fuel pipe 5, and the fuel pump 6 supplies fuel to the engine 2 through the fuel pipe 5.
[0034] Further optimization of the scheme: one end of the air pipe 8 is connected to the outer oil tank 4, the air pipe 8 is connected to the positive pressure chamber 14, the other end of the air pipe 8 is connected to the compressor of the engine 2, and a constant pressure component is connected to the air pipe 8.
[0035] like Figure 1 and Figure 2 As shown, a connecting nozzle 10 is connected to the compressor section of engine 2. When engine 2 is running, the positive pressure generated by the compressor can be transmitted to the positive pressure chamber 14 through the air pipe 8, so that the positive pressure chamber 14 is always in a positive pressure state, so as to compress the inner oil tank 3.
[0036] Further optimization of the scheme: the constant pressure component includes a constant pressure valve 7, which is connected to the air pipe 8. The constant pressure valve 7 is provided with a vent, which is connected to the air intake passage of the engine 2.
[0037] The scheme is further optimized by adding an indicator 9, which is connected to the constant pressure valve 7 to display the air pressure value at the outlet of the constant pressure valve 7.
[0038] like Figure 2 As shown, when the speed of engine 2 increases, the pressure of the extracted gas will increase. By using the constant pressure valve 7 to release the excess gas, the pressure extracted by engine 2 can be kept within 0.03 MPa to 0.09 MPa. The released gas can be connected to the engine intake passage through a dedicated pipeline (not shown in the figure) to allow the gas to re-enter the engine and participate in combustion.
[0039] The design has been further optimized so that the trachea 8 is connected to a venting nozzle 13.
[0040] like Figure 3 As shown, the main function of the vent nozzle 13 is to release the gas in the positive pressure chamber 14.
[0041] The design is further optimized by connecting a fuel inlet 12 and a valve 15 to the fuel line 5, with the valve 15 positioned between the fuel inlet 12 and the fuel pump 6.
[0042] like Figure 3 As shown, when it is necessary to inject oil into the inner oil tank 3, valve 15 can be closed and oil injection can be opened through oil injection port 12. At the same time, venting nozzle 13 can be opened so that as the inner oil tank 3 expands, the gas in the positive pressure chamber 14 can be quickly released, so that the oil injection process can proceed smoothly.
[0043] During the non-oil filling stage, valve 15 is in the open state and venting nozzle 13 is in the closed state.
[0044] The working process of this embodiment is as follows: The compressor of engine 2 is used to guide pressurized gas through air pipe 8 into positive pressure chamber 14. During flight, when the speed of engine 2 increases, the pressure of the extracted gas increases. At this time, constant pressure valve 7 releases excess gas, so that the pressure in positive pressure chamber 14 is always controlled within 0.03Mpa to 0.09Mpa.
[0045] When engine 2 consumes fuel, the volume of inner fuel tank 3 decreases. At this time, pressure is continuously applied to inner fuel tank 3 so that it obtains constant external pressure and is always full of fuel. This also helps to squeeze out the oil from inner fuel tank 3, and helps the amount of fuel pump 6 to draw from inner fuel tank 3 to remain stable, thereby ensuring stable engine speed.
[0046] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0047] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.
Claims
1. A flexible fuel tank for aircraft pressurized by a turbojet engine, characterized in that, include: External fuel tank (4), which is fixedly connected inside the aircraft fuselage (1); The inner fuel tank (3) is made of soft material and is located inside the outer fuel tank (4). A positive pressure chamber (14) is formed between the inner fuel tank (3) and the outer fuel tank (4). A sway suppression component is provided between the inner fuel tank (3) and the outer fuel tank (4). The inner fuel tank (3) is used to store fuel. The positive pressure chamber (14) is provided with positive pressure by the engine (2).
2. The aircraft soft fuel tank pressurized by a turbojet engine according to claim 1, characterized in that: The outer fuel tank (4) is made of soft material.
3. The aircraft soft fuel tank pressurized by a turbojet engine according to claim 2, characterized in that: The inner oil tank (3) and the outer oil tank (4) are made of soft PE material.
4. The aircraft soft fuel tank pressurized by a turbojet engine according to claim 1, characterized in that: The sway suppression component includes several elastic restraint bands (11) evenly distributed in the positive pressure chamber (14), and the two ends of the elastic restraint bands (11) are fixedly connected to the inner wall of the outer oil tank (4) and the outer wall of the inner oil tank (3), respectively.
5. The aircraft soft fuel tank pressurized by a turbojet engine according to claim 1, characterized in that: One end of the fuel pipe (5) is connected to the inner fuel tank (3), and the other end of the fuel pipe (5) is correspondingly set to the engine (2). The fuel pump (6) is connected to the fuel pipe (5), and the fuel pump (6) supplies fuel to the engine (2) through the fuel pipe (5).
6. The aircraft soft fuel tank pressurized by a turbojet engine according to claim 1, characterized in that: One end of the air pipe (8) is connected to the outer oil tank (4), the air pipe (8) is connected to the positive pressure chamber (14), the other end of the air pipe (8) is connected to the compressor of the engine (2), and a constant pressure component is connected to the air pipe (8).
7. The aircraft soft fuel tank pressurized by a turbojet engine according to claim 6, characterized in that: The constant pressure component includes a constant pressure valve (7), which is connected to the air pipe (8). The constant pressure valve (7) is provided with a vent, which is connected to the air intake passage of the engine (2).
8. The aircraft soft fuel tank pressurized by a turbojet engine according to claim 6, characterized in that: The trachea (8) is connected to a venting nozzle (13).
9. A turbojet engine-pressurized aircraft fuel tank according to claim 5, characterized in that: The fuel line (5) is connected to an oil inlet (12) and a valve (15), and the valve (15) is located between the oil inlet (12) and the oil pump (6).