JP2003054499A - Pressurized fuel tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressurized fuel tank provided on a flying body capable of eliminating trouble that it is difficult to employ an engine requiring supply of super high pressure fuel to the flying body because fuel is pressurized and supplied by a pump in a usual engine and the pump rising fuel pressure to super high pressure tends to be excessively bulky and heavy to be mounted on the flying body. SOLUTION: This tank is comprised of a low pressure supply fuel tank and a high pressure fuel tank and each tank is compressed and deformed by inert gas from a pressurizing source to compress inside liquid fuel and to regulate pressure thereof at a necessary pressure for each flight and to supply the same to a propulsion engine. Consequently, liquid fuel can be pressurized to super high pressure without using a fuel pump and an engine using super high pressure fuel can be employed to greatly improve flight performances. Division of the fuel tank to the low pressure one and the high pressure one makes capacity of a fuel tank used for flying body of short high speed flight time small to miniaturize and lighten the flying body.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressurized fuel tank of a direct pressurizing type which pressurizes fuel in a tank mounted on an air vehicle by directly pressurizing the fuel. In particular, it withstands the differential pressure generated by the high discharge pressure, and the tank shape is deformed stably in response to the fuel discharge from the tank, and the fuel in the tank is supplied to the thrust engine at the pressure required during flight. The present invention relates to a pressurized fuel tank that can be used. [0002] A ramjet engine comprising a combination of an air intake (air intake), a combustor, and a nozzle,
A structure without rotating elements such as compressors and turbines can be removed.
In the field of flying objects such as aircraft and flying objects, design and development for practical use are underway in order to achieve a simple structure. However, such a ramjet engine has to operate at a vehicle speed at which the ram pressure becomes effective as the speed increases, and specifically at a vehicle speed at which the Mach number upstream of the intake is about 3.0. Since it cannot be a propulsion engine in low-speed flight, a separate propulsion engine for low-speed flight must be provided, and a high-pressure liquid fuel used during high-speed flight is required. [0003] For this reason, in the case of a small conventional flying object requiring high speed and high turning performance, the initial acceleration is performed by the propulsive force generated by burning the solid propellant, and the aircraft speed at which the ram pressure becomes effective At this point, the development of a flying object has been promoted in which liquid fuel is introduced into the compressed air taken in from the air intake at a high pressure and blown by ramjet propulsion. [0004] FIG. 2 is a view showing the entire flying object of such a flying object. In FIG.
2 is a pressurized fuel tank section, 3 is an air intake which forms a part of a thrust engine that takes in air from the outside during ramjet propulsion and compresses, and 4 is a combustion chamber to generate propulsion during initial acceleration. A filled solid propellant. The conventional pressurized fuel tank section 2 is provided with a fuel tank 5 filled with a liquid fuel such as a low-pressure liquid jet fuel, as shown in FIG. When the fuel burns and the speed of the flying object 1 increases and reaches the speed at which the ram pressure is effective, the liquid fuel filled in the fuel tank 5 is supplied to the pressurizing pump 6 installed behind the fuel tank 5. The fuel is pressurized to about 100 atm, and liquid fuel is injected from the inner side walls of the air intake 3 already provided on both sides of the flying object 1 toward the compressed high-pressure air flowing through the air intake 3. The fuel is supplied to the fuel supply ports 7a and 7b provided so as to perform the above operations. At the time of the initial acceleration by the solid propellant, the air intake 3 is closed by a cover or the like so that the air intake 3 is not operated. Is approached, the cover is removed and external air is allowed to flow in to be ready for operation. In addition, solid propellant 4
Since the solid propellant is exhausted by the initial acceleration and reaches the speed of the flying object 1 at which the ram pressure is effective, the combustion chamber filled with is in a hollow state. The gas mixture of the high-pressure air pressurized by the shock wave generated inside when flowing through the inside 3 and the liquid fuel injected into the high-pressure air from the fuel supply ports 7a and 7b flows into the hollow combustion chamber. I do. An ignition device is provided at the entrance to the combustion chamber into which the mixed gas flows from the air intake 3, and the mixed gas flowing into the combustion chamber is ignited here, burns in the combustion chamber, and the combustion gas Is ejected rearward from a nozzle 8 provided at the rear end of the flying object 1 to generate a propulsive force. Note that, depending on the flying object 1, instead of the above-described initial acceleration by the solid propellant 4, only the liquid fuel in the fuel tank 5 shown in FIG. You can also do so. In other words, the pressurizing pump 6 can be supplied from the low pressure supply required in the early stages of flying to the high pressure supply after acceleration,
By installing a ramjet engine on the fuselage and using it as an auxiliary booster, or by adopting a composite ramjet propulsion system, etc.
You can also fly fast. However, as shown in FIG. 3, in the case where the liquid fuel in the fuel tank 5 is pressurized by the pressurizing pump 6 to fly at a high speed, the scale can be increased by about 20 to 30 atm. The space for mounting the pressurizing pump 6 can be secured even with a small flying object 1 that requires high speed and high turning performance. When the pressure pump 6 capable of pressurizing the liquid fuel to about 100 atm required for jet propulsion is provided, the pressure pump 6 becomes large, for example, becomes the same size as the cross section of the flying object 1 and becomes very bulky. In terms of space and weight, it cannot be mounted on the small flying vehicle 1 at all, and the ramjet propulsion uses a simpler and more lightweight flying structure. There is a problem that can not be realized of You body 1. [0010] The present invention relates to a flying object capable of performing high-speed flight by ramjet propulsion or the like.
In particular, the pressure required for ramjet propulsion during high-speed flight of liquid fuel or ramjet propulsion is used in order to eliminate problems that are particularly noticeable in small and lightweight flying objects with limited space and weight. Without using a pressurizing pump to pressurize to the pressure required during low-speed flight until it becomes possible, use an inert gas or the like to change the outer shape of the fuel tank filled with liquid fuel. An object of the present invention is to provide a pressurized fuel tank capable of increasing the pressure of liquid fuel to a pressure required during flight by deforming the fuel tank. Therefore, the pressurized fuel tank according to the present invention has the following means. The fuel tank is filled with liquid fuel that is supplied to the thrust engine to generate propulsion, and the fuel tank mounted on the flying object has at least a low-pressure supply fuel tank that supplies low-pressure liquid fuel during low-speed flight and a high-pressure liquid tank during high-speed flight. It consists of a high-pressure supply fuel tank that supplies fuel, and each tank is compressed by an inert gas supplied from a pressurized source provided inside the flying object, and its external shape is deformed and filled by this deformation. The compressed liquid fuel is compressed to the required pressure for each flight and can be supplied to the thrust engine. Thus, the liquid fuel supplied to the thrust engine can be made extremely high in pressure required for high-speed flight without using a fuel pump, and the structure is simple and the weight can be easily reduced. For example, a ramjet engine that can be used only during high-speed flight, such as a ramjet engine, can be adopted as a thrust engine, and the performance of the flying object can be greatly improved. Further, by dividing the fuel tank into at least a low-pressure supply and a high-pressure supply, when a high-speed flight time is adopted for a short flying body, a high-pressure supply fuel tank that requires a pressure-resistant strength member and has a large weight and volume is used. The flying object can be reduced in size, and the performance can be further improved. An embodiment of a pressurized fuel tank according to the present invention will be described below with reference to the drawings. FIG. 1 is a structural view of a pressurized fuel tank showing a first embodiment of a pressurized fuel tank according to the present invention and corresponding to FIG. As shown in FIG. 2, a high-pressure fuel tank 11 and a low-pressure fuel tank 11 are provided in a pressurized fuel tank section 2 defined in the center of the fuselage of the flying object, as shown in FIG. A tank 12 is arranged adjacent to the body axis direction, and each of the tanks 11 and 12 is filled with liquid jet fuel. Among them, the high-pressure supply fuel tank 11 is formed by a rearmost partition wall 17 having a central portion that is deeply hollowed toward the right side on the right side of the figure, which is a rear end side, and an aluminum foil of about 0.5 mm on the left side of the figure. It comprises a container section formed of a flexible metal bladder 18 which is a membrane and filled with liquid jet fuel, and a high pressure supply section 19 formed between the rear partition 16 and the metal bladder 18. The low-pressure supply fuel tank 12 is filled with a structure made of an aluminum alloy having a thickness of about 3 to 5 mm including the outer plate of the flying object 1, the foremost partition wall 15, and the front partition wall 24, and liquid jet fuel. As fuel tanks for aircraft
It consists of a commonly used rubber inner bag having a thickness of about 5 mm, and a low-pressure supply section 25 formed between the aluminum alloy structure and the rubber inner bag. A high-pressure supply pressurizing source 13 is provided in front of the high-pressure supply fuel tank 11, and a low-pressure supply pressurization source 14 is provided in front of the low-pressure supply fuel tank 12.
Among these, the high-pressure supply pressurizing source 13 is installed between the front partition 24 and the rear partition 16, has a cross section substantially equivalent to the trunk section, and has an axial direction substantially equivalent to the high-pressure supply fuel tank 11. It has a large volume with a length, and is filled with an inert gas such as nitrogen or argon at an ultra-high pressure of about 400 atm. The low-pressure supply pressurizing source 14 is
It consists of an accumulator or a small-capacity high-pressure tank that is arranged in a donut-shaped space in the forefront partition 15 and is filled with an inert gas such as nitrogen or argon at a high pressure of 10 atm or less. ing. The rear bulkhead 16 is provided with a supply passage penetrating through the axial center portion and communicating the high-pressure supply pressurizing source 13 with the high-pressure supply section 19.
0 is interposed, the flow rate of ultra-high pressure nitrogen or the like supplied from the high-pressure supply pressurizing source 13 to the high-pressure supply section 19 is controlled, and the pressure in the high-pressure supply section 19 is controlled so that the metal bladder 18 is controlled. The fuel tank 1 for high pressure supply is pushed toward the rear partition 17 side.
The outer shape of 1 is deformed to pressurize the liquid filled therein. In addition, as shown in FIG. 2, on both sides between the high-pressure supply pressurizing source 13 and the rear bulkhead 16, as shown in FIG. High pressure supply fuel tank 11 or low pressure supply fuel tank 12
Supply ports 21a, 21 for injecting liquid fuel from
1b is provided. One end of each of the fuel supply ports 21a and 21b is connected to a hole formed in the rearmost partition, and the other ends of high-pressure fuel pipes 22a and 22b connected to the high-pressure supply fuel tank 11 are connected. An opening formed in the outer plate of the flying object 1 with which an opening through which high-pressure liquid fuel of about 100 atm is supplied from the high-pressure supply fuel tank 11 at the time of high-speed flight and a side portion of the low-pressure supply fuel tank 12 abuts. Low-pressure fuel pipe 23 connected at one end to the low-pressure supply fuel tank 12
The other ends of the fuel tank 11 and the high pressure supply tank 11 are connected to the opening through which the low pressure liquid fuel is supplied from the low pressure supply fuel tank 12 and the flow of the compressed air in the air intake 3 when flying at low speed. Openings for injecting liquid fuel from the low-pressure supply fuel tank 12 are provided, and a check valve is attached to each opening to prevent backflow. In the example of the flying object 1 described above, the supply of the high-pressure liquid fuel is not required during the initial flight, and the supply of the high-pressure liquid fuel is performed only for a limited time during the terminal flight. Therefore, the conventional fuel tank 5 as shown in FIG. 3 is divided into a high-pressure supply fuel tank 11 and a low-pressure supply fuel tank 12 at a volume ratio of approximately 1: 3. Since the pressurized fuel tank of this embodiment is constructed as described above, the fuel supply to the propulsion engine is performed by closing the solenoid valve 20 at the time of the initial flight so that the fuel is supplied to the low pressure supply fuel tank 12. From the low-pressure supply pressurizing source 14, the low-pressure supply fuel tank 12 and the outer plate of the flying object 1, the foremost partition 15, and the front partition 2
The low-pressure supply fuel tank 12 is compressed from the outside and uniformly deformed by blowing an inert gas such as a low-pressure nitrogen gas into the low-pressure supply section 25 formed between the fuel tank 4 and the low-pressure supply section 25. Liquid fuel having a pressure of
Via a and 21b, it is supplied to a propulsion engine (not shown) provided for accelerating the aircraft at the time of initial flight. Further, when the ram pressure starts to increase due to the increase of the airframe speed and the ram jet engine flies, the high pressure supply pressurizing source 14 opens and closes the solenoid valve 20 to supply the high pressure supply section 19 to the high pressure supply section 19 through the supply passage. By blowing high-pressure nitrogen gas or the like close to the cylinder, the metal bladder 18 is compressed from the outside and moves to the right to be deformed. The liquid fuel in the fuel supply port 21
The air can be supplied to the flow of the compressed air in the air intake 3 via a and 21b. The metal bladder 18 finally deforms into a convex shape on the right side, and is deformed so as to be attached to the surface of the rearmost partition wall 17 whose central portion is deeply hollowed toward the right side, and the outer shape of the fuel tank 11 for high-pressure supply is changed. In this case, the liquid fuel is uniformly deformed in accordance with the discharge of the liquid fuel. In the pressurized fuel tank of the present embodiment, the pressure and pressure of the liquid fuel sucked from the conventional fuel tank by the above-described structure and operation are increased by only 20 to 30 atm. What could not be done is that the high pressure supply pressure source 13
A high-pressure nitrogen gas or the like close to 400 atm is blown into the tank, and the high-pressure supply fuel tank 11 is uniformly deformed to compress the internal liquid fuel, so that the capacity can be improved to about 70 atm. The pressure can be increased to about 100 atm, which is required for the operation of. Therefore, in order to increase the pressure of the liquid fuel to about 100 atm, a large and heavy fuel pump is required. A ramjet engine with a simple structure and the advantage of light weight, which was difficult to adopt in such applications, can be adopted as a propulsion engine for high-speed flight, greatly improving the performance of the flying object 1. Can be. Further, the volume of the high-pressure supply fuel tank 11 that is required only for a limited short time at the time of the terminal flight,
By setting the volume of the low-pressure supply fuel tank 12 to about 1/3, the volumes of the high-pressure supply fuel tank 11, the high-pressure supply pressurization source 13, and the like, which need to increase the pressure resistance, can be reduced. The weight of the flying object 1 can be further reduced, and the performance can be further improved. As described above, in the pressurized fuel tank according to the present invention, the fuel tank comprises at least a low-pressure supply fuel tank for supplying low-pressure liquid fuel during low-speed flight and a high-pressure liquid fuel during high-speed flight. It consists of a high-pressure supply fuel tank to be supplied. Each tank is compressed by an inert gas supplied from a pressurized source, compresses the liquid fuel filled by deformation of the external shape, and the pressure required for each flight And supplied to the thrust engine. As a result, the liquid fuel supplied to the thrust engine can be set to an extremely high pressure without using a fuel pump, and a thrust engine that can be used only during high-speed flight can be employed, greatly improving the performance of the flying object. The fuel tank has been divided into a low-pressure supply and a high-pressure supply, so that for a flying object with a short high-speed flight time, the high-pressure supply fuel tank can be made smaller and smaller, lighter, and more efficient. Can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural view showing a first embodiment of a pressurized fuel tank according to the present invention; FIG. 2 is a general view showing a flying object as a flying body employing a pressurized fuel tank; FIG. 3 is a structural view showing a conventional pressurized fuel tank. [Description of Signs] 1 Flying object 2 Pressurized fuel tank section 3 Air intake 4 Solid propellant 5 Fuel tank 6 Pressurized pumps 7a, 7b Fuel supply port 8 Nozzle 11 High pressure supply fuel tank 12 Low pressure supply fuel tank 13 High-pressure supply pressurization source 14 Low-pressure supply pressurization source 15 Frontmost partition 16 Rear partition 17 Last partition 18 Metal bladder 19 High-pressure supply section 20 Solenoid valves 21a, 21b Fuel supply ports 22a, 22b High-pressure fuel supply pipes 23a, 23b Low pressure fuel supply pipe 24 Front partition 25 Low pressure supply section

Claims (1)

Claims: 1. A liquid fuel for generating a propulsion force is charged,
In the fuel tank mounted on the flying object, the fuel tank includes at least a low-pressure supply fuel tank that supplies low-pressure liquid fuel during low-speed flight and a high-pressure supply fuel tank that supplies high-pressure liquid fuel during high-speed flight. Each tank is compressed and deformed by the inert gas supplied from the pressurized source, and the filled liquid fuel is supplied to the thrust engine at a pressure required for each flight. A pressurized fuel tank characterized by the following.