JPH09242611A - Fuel tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of fire by dividing high temperature pressure air supplied from a pressure source into low and high winds by a vortex tube while a part thereof is passed a branch pipe, and reducing the temperature of the other high temperature pressure air to a proper temperature by low temperature wind from the vortex tube in a heat exchanger. SOLUTION: Bladders A7, B8, C9 for storing fuel respectively are arranged in the fuel tank 2 of an air craft 1. Pressure air supplied to an air pipe 30 is supplied 4 to a vortex tube 24 while partly passing a branch pipe 31 branched from an air pipe 30. A flow rate is regulated by a throttle valve 22. Pressure air 21 is divided into low temperature wind 24b and high temperature wind 24a by the vortex tube 24 utilizing vortex. The other high temperature pressure air 21 is supplied to a heat exchanger 23, the temperature thereof is reduced to a proper temperature by low temperature wind 24b supplied from the vortex tube so as to form pressurized air 21a of the bladders A7, B8, C9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel tank for an air vehicle, and more particularly to a pressurized supply type liquid fuel tank equipped with a bladder.

[0002]

2. Description of the Related Art A pressure-supply type fuel tank for delivering liquid fuel from a tank to an engine by using pressure air as a power source is of a type in which pressure air pressurizes fuel through a bladder which is an elastic bag. There is a method in which pressurized air directly contacts the fuel to pressurize it.

Further, in a system of pressurizing fuel through a bladder, a system provided with a plurality of bladders, one in which the fuel delivery sequence from the bladders is left to the end, or a weighing sensor is provided in each bladder, and a weighing sensor is provided. It is common to control the fuel delivery from the bladder in a predetermined order by actuating the switching valve based on the signal.

[0004]

However, the pressurized supply type liquid fuel tank provided with the bladder has the following problems. (B) High-pressure air that exceeds the self-ignition temperature of the fuel cannot be used for pressurization because of the risk of ignition and explosion. For example, the ignition temperature of jet fuel is about 220 ° C, but if pressurized air having a temperature higher than this temperature is used for pressurization, even if a small amount of fuel leaks, an ignition explosion will occur immediately. Even if there is no leakage, when the fuel in the bladder becomes small, heat is conducted to the inside through the bladder film, and this heat may cause the internal fuel to ignite and explode. It also has a large effect on the rubber that is the material of the bladder film. Therefore, the risk of accident is very high.

(B) Since the position of the bladder easily shifts with respect to the outer shell of the tank during abrupt movement, the connecting portion of the fuel pipe is forced and the bladder is damaged. Some baskets have a basket-like object in contact with the fuel to prevent displacement, but the effect is small and the fuel may leak from the fixed part of the basket. (C) It is difficult to control the center of gravity associated with fuel consumption in an aircraft that has a large amount of fuel and has a slender fuel container. Due to the reasons (a) to (c) above, the speed and movement of the air vehicle are significantly limited.

(D) In addition, in order to control the center of gravity associated with fuel consumption, a plurality of bladders are used and fuel is fed from the bladders in a predetermined order. It requires a complicated tank switching circuit including means and an electric control circuit, which increases the cost. (E) The size of the outer shell must be increased so that the outer shell does not burst even if the pressure in the outer shell rises due to thermal expansion of the fuel during storage. Becomes larger.

According to the present invention, the hot compressed air can be used as a power source, the displacement of the bladder with respect to the outer shell of the tank can be prevented even during a sudden movement, and the fuel can be delivered from a plurality of bladders in a predetermined order. It is therefore an object of the present invention to provide a fuel tank capable of preventing the pressure in the outer shell from rising even if the fuel thermally expands during storage without requiring any measuring means or a complicated tank switching circuit for controlling To do.

[0008]

A fuel tank according to the present invention is a pressurization for pressurizing a bladder housed in an outer shell to deliver fuel in the bladder by using hot compressed air supplied from a pressure source as a power source. In a supply-type fuel tank, a branch pipe is provided branching from the air pipe that supplies pressurized air for pressurization, and this branch pipe is connected to a vortex tube that divides hot air into low-temperature air and high-temperature air. A heat exchanger is provided on the way to lower the temperature of the pressure air to an appropriate temperature by exchanging heat with the low temperature air supplied from the vortex tube.

The hot pressurized air supplied from the pressure source is
A part is supplied to the vortex tube through a branch pipe branched from the air pipe, and divided into low temperature air and high temperature air by the vortex tube. Other hot compressed air
It is used to pressurize the bladder by exchanging heat with the low-temperature air supplied from the vortex tube in the heat exchanger to lower the temperature to an appropriate temperature.

In this way, even if high-temperature pressure air exceeding the self-ignition temperature of fuel is supplied from the pressure source for power, the temperature of the pressure air is lowered to an appropriate temperature without requiring any other power. The bladder can be pressurized as low temperature pressurized air.

Also, a semi-cylindrical cage is fixed so as to be integrated along the outer shell over the lower half of the bladder housed in the outer shell, and an inner liner that shuts off the fuel from the inner surface of the basket is bladdered. The bladder is prevented from being damaged because the bladder is prevented from being displaced with respect to the outer shell even if the flying body makes a sudden motion by providing the inside of the bladder. Since the fuel is not in contact with the basket, there is no risk of fuel leaking from the fixed part of the basket.

Further, by accommodating a plurality of bladders in the outer shell and providing a priority valve for regulating the order of fuel supply from the bladders at the confluence of the fuel pipes for delivering the fuel from the bladders, the weighing sensor is provided. Without using a complicated tank switching circuit including measuring means such as etc. and an electric control circuit,
Fuel can be delivered from multiple bladders in a predetermined order.

While the fuel tank is being stored, a desiccant-filled drying attachment is attached to the outer shell so that the outer shell and the outer shell communicate with each other so that a pressure difference does not occur. It is possible to prevent the pressure inside the outer shell from rising and to prevent moisture from entering the outer shell.

[0014]

1 is a vertical cross-sectional view showing the overall construction of a fuel tank according to an embodiment of the present invention, FIG. 2 is a perspective view of an aircraft equipped with this fuel tank, and FIG. 3 is a fuel. FIG. 4 is an explanatory view of the structure of the tank, FIG. 4 is a sectional view taken along the line II-II of FIG. 1, FIG. 5 is a perspective view of the basket, and FIG. 6 is a partially enlarged sectional view of a mounting portion of the basket.
FIG. 7 is a cross-sectional view showing the configuration of the A priority valve, and FIG. 8 is an explanatory view of the operation of the A priority valve.

An elongated flying body 1 is provided with a fuel tank 2 in the center and an engine 3 behind it (on the right side in the figure). The flying body 1 flies at supersonic speed, and due to aerodynamic heating, both the ambient air and the pressure air 21 for power supplied from the engine 3 are in a state of exceeding the self-ignition temperature of the fuel 14.

The fuel tank 2 of the aircraft 1 has a cylindrical shape, which satisfies pressure resistance and strength and has a heat insulating outer shell 4 whose front portion is divided into three parts, each of which stores a bladder A.
7, a bladder B8, and a bladder C9 are provided. Here, for the convenience of the flight pattern, the fuel 14 in the front bladder A7 is consumed first, and then the fuel 14 in the rear bladder C9 is consumed.
Is consumed, and finally, the fuel 14 in the central bladder B8 is consumed in the preferred sequence for moving the center of gravity of the air vehicle 1.

From the lower ends of the front bladder A7, the central bladder B8, and the rear bladder C9, dedicated fuel pipes 5a, 5b, 5c are respectively piped to the rear valve chamber 6. The bladders A7, bladders B8, and bladders C9 are each made of rubber and have a cylindrical bag shape, and basically have the same structure although different in length and the like. As shown in FIGS. 4, 5 and 6,
A bladder A7, a bladder B8, and a bladder C9 housed in the outer shell 4 are provided with a basket 10 over the lower half so as to be integrated with the outer shell 4. The cage 10 has a semi-cylindrical shape along the lower half of the outer shell 4, and is provided with slightly thick bones on both edges in order to smoothly deform the bladders 7, 8 and 9 as shown by phantom lines in FIG. A nut 13 is provided as a connecting tool at a predetermined node.

The basket 10 is completely joined to the outside of the inner liner 11 of the bladders 7, 8 and 9, and the reinforcing liner 12 is also provided.
Has been fixed by. In addition, the basket 10 has a mounting portion 1
It is fixed to the outer shell 4 by a screw 15 screwed to the nut 13 at 0a. The screw holes are filled with botching 16.

The inner liner 11 is composed of fuel tubes 5a, 5b, 5
Except for the outlet portion connected to c, it has a completely continuous bag shape, so that the fuel 14 does not touch the basket 10 or the outer shell 4 unless it is damaged.

As shown in FIG. 4, a slight fuel expansion margin V is provided between the outer shell 4 and the upper portion of the bladder A7. The expansion margin V and the outside of the outer shell 4 communicate with each other. A drying attachment 26 is attached by a quick coupler. The dry attachment 26 is filled with silica gel as a desiccant, and this silica gel absorbs moisture during storage of the fuel tank 2 and prevents moisture from entering the outer shell 4.

As shown in FIG. 3, the valve chamber 6 receives the fuel 14 metered and sent from the ground material 19 for fuel filling, and passes through the fuel pipes 5a, 5b, 5c, and the bladders 7, 8, Refueling valve 20 for refueling 9 with fuel 14, refueling pipe 32, and relief valve 25 for preventing rupture of outer shell 4.
And A priority valve 17 and C priority valve 18 which will be described later.
The heat exchanger 23 and the vortex tube 24 are arranged.

A branch pipe 31 is branched from an air pipe 30 for supplying pressure air 21 for power for pressurizing the bladders 7, 8 and 9, and this branch pipe 31 is connected to a vortex tube 24 via a throttle valve 22. It is connected. The vortex tube 24 is a device developed by Vortex, Inc. of the United States and capable of separating the pressure air 21 into a high temperature air 24a and a low temperature air 24b by utilizing a vortex, and has a simple structure and no moving parts. It is small and lightweight.

The vortex tube 24 is composed of pressure air 2
When the temperature of 1 is high, there is an advantage that low-temperature air with a larger temperature difference can be obtained. Vortex tube 24
Hot air 24a generated in the
Is supplied to the heat exchanger 23 provided in the middle of the air pipe 30,
It is used for heat exchange with the hot pressurized air 21.

The hot compressed air 21 is cooled by the heat exchanger 23 to an appropriate temperature, and then the bladder 7, 8 or 9 is pressurized with the compressed air 2.
Supplied as 1a. Since the vortex tube 24 having no moving parts is used, the pressurized air 21a at a safe temperature can be stably obtained even after long-term storage.

A fuel pipe 5a extending from the front bladder A7,
The fuel pipe 5c exiting from the rear bladder C9 is A at the confluence.
The fuel pipe 5A that is connected to the priority valve 17 and that exits from the A priority valve 17 and the fuel pipe 5b that exits from the central bladder B8 are connected to the C priority valve 18 at the confluence point, and the C priority valve 18 The exiting fuel pipe 5 is connected to the engine 3.

As shown in FIG. 7, the A priority valve 17 is
A shuttle 27 and an accumulator 29 are provided inside. The shuttle 27 is biased by a spring 28, and is normally in a position where the fuel pipe 5a and the fuel pipe 5A communicate with each other and the fuel pipe 5c is shut off. Therefore, if equal fuel pressures are applied from the bladder A7 and the bladder C9, the bladder A
The fuel 14 from 7 flows into the downstream fuel pipe 5A and simultaneously fills the accumulator 29.

When the fuel 14 in the bladder A7 becomes empty, the fuel pressure on the fuel pipe 5a side (spring 28 side) becomes zero. Therefore, as shown in FIG.
The fuel pressure from the side causes the fuel pipe 5c and the fuel pipe 5A to communicate with each other, and moves to the position where the fuel pipe 5a is blocked against the spring 28, so that the fuel 14 from the bladder C9 flows to the downstream fuel pipe 5A. It comes to flow.

When the shuttle 27 is switched, the outflow of the fuel 14 from the bladder A7 and the bladder C9 is interrupted for a very short time. During this period, the fuel is discharged from the accumulator 29 to make up for it, so the fuel 14 is supplied from the fuel pipe 5A. Are sent continuously.

The C-priority valve 18 has the same structure as the A-priority valve 17. First, the fuel 14 from the fuel pipe 5A is supplied.
Bladder C9 is empty and bladder B is empty.
The fuel 14 from 8 is switched to flow into the fuel line 5.

The operation will be described below with reference to FIG. Numerical values such as temperature, pressure, and flow rate written in parentheses in FIG. 3 indicate an example of the operation. Here, 25 supplied to the air pipe 30
The pressure air 21 at 0 ° C. and 0.55 MPa is supplied to the vortex tube 24 through a branch pipe 31 partly branched from the air pipe 30. The flow rate is adjusted by the throttle valve 22. In the vortex tube 24, the pressure air 21 becomes a low temperature air 24b at 150 ° C and a high temperature air 24a at 310 ° C.

The other hot compressed air 21 enters the heat exchanger 23. Here, the low temperature air 24b supplied from the vortex tube 24 changes the temperature of the pressure air 21 to 200 ° C.
The pressure is reduced to a certain level to obtain the pressurized air 21a for the bladders 7, 8 and 9. If the temperature of the pressurized air 21a is about 200 ° C,
Since the fuel does not ignite and the bladder membrane does not deteriorate much, it does not cause an accident.

The bladders 7, 8 and 9 are provided with pressurized air 2 in the outer shell 4.
It is pressurized at about 0.53 MPa by 1a. Fuel 14
Is 0.5M due to the pressure loss in the fuel pipes 5a, 5b, 5c, 5A, 5 and the A priority valve 17 and the C priority valve 18.
It is supplied to the engine 3 at about Pa. The flow rate is here 2.5 LPS.

The pressure of the pressurized air 21a is equal to that of all the bladders 7,
However, due to the action of the priority valves 17 and 18, fuel is continuously supplied to the engine 3 in the order of the bladder A7, the bladder C9, and finally the bladder B8.

The flying body 1 makes a vigorous exercise, and the bladder 7,
Even if a large acceleration is applied to the upper and lower sides of the bladder 7, 8 and 9, the lower halves of the bladders 7, 8 and 9 are fixed along the outer shell 4, Therefore, there is no possibility of damage due to relative displacement between the fuel pipes 5a, 5b and 5c and the joints, etc.

When the air vehicle 1 is stored while being fully loaded with the fuel 14, if the dry attachment 26 is attached and stored, even if the fuel 14 expands due to changes in temperature, the pressure inside the outer shell 4 will be reduced. It does not rise, and there is no risk of moisture entering the outer shell 4.

[0036]

As described above, in the fuel tank of the present invention, the pressurized air is kept at a low temperature even when the pressure air supplied as power for driving the fuel around the flying body is high. Because it is possible, there is no danger of fire and other accidents and it is safe. Since the heat exchange system uses a vortex tube with no moving parts, it can stably obtain pressurized air at a safe temperature after long-term storage.

In the bladder housed in the outer shell, the lower half of the bladder is fixed along the outer shell so that even if the flying body makes an abrupt movement, the bladder will not be displaced relative to the outer shell and the bladder will not move. Since relative displacement does not occur between the joint and the like, damage can be prevented.

Further, by accommodating a plurality of bladders in the outer shell and providing a priority valve for regulating the order of fuel supply from the bladders at the confluence of the fuel pipes for delivering the fuel from the bladders, the metering sensor Without using a complicated tank switching circuit including measuring means such as etc. and an electric control circuit,
Since fuel can be delivered and consumed from a plurality of bladders in a predetermined order, it is possible to move the center of gravity so as to help the flight balance of the aircraft.

Cooling of the high temperature pressurized air for pressurizing the bladder, delivery of fuel to the engine, and switching of the bladder consuming fuel are performed only by the pressurized air supplied as power, and other power such as a power source is used. Since it is not necessary, the cost is low and the reliability can be easily improved.

A dry attachment filled with a desiccant is attached to the outer shell of the fuel tank so that the inner and outer shells communicate with each other during storage so that a pressure difference does not occur, so that the fuel thermally expands during storage. Also, since the pressure inside the outer shell can be prevented from rising, there is no need for extra space required to mitigate the pressure rise, the outer shell volume can be designed small, and the aircraft can be made compact and lightweight. become.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the overall configuration of a fuel tank that is an embodiment of the present invention.

FIG. 2 is a perspective view of an aircraft equipped with a fuel tank.

FIG. 3 is an explanatory diagram of a configuration of a fuel tank.

FIG. 4 is a sectional view taken along line II-II of FIG.

FIG. 5 is a perspective view of a basket.

FIG. 6 is an enlarged cross-sectional view of a mounting portion of the basket.

FIG. 7 is a cross-sectional view showing the configuration of an A priority valve.

FIG. 8 is an explanatory diagram of the operation of the A priority valve.

[Explanation of symbols]

 1 Aircraft 2 Fuel Tank 3 Engine 4 Outer Shell 5 Fuel Tube 5A Fuel Tube 5a Fuel Tube 5b Fuel Tube 5c Fuel Tube 6 Valve Chamber 7 Bladder A 8 Bladder B 9 Bladder C 10 Basket 11 Inner Liner 12 Reinforcing Liner 13 Nut 14 Screw 16 Botching 17 A Priority Valve 18 C Priority Valve 19 Fuel Filling Ground Equipment 20 Refueling Valve 21 Pressure Air 21a Pressurized Air 22 Throttle Valve 23 Heat Exchanger 24 Vortex Tube 24a High Temperature Air 24b Low Temperature Air 25 Relief Valve 26 Dry Attachment 27 Shuttle 28 Spring 29 Accumulator 30 Air Pipe 31 Branch Pipe 32 Oil Supply Pipe

Claims (4)

[Claims] 1. A pressure-supply type fuel tank for pressurizing a bladder housed in an outer shell to deliver fuel in the bladder by using high temperature pressurized air supplied from a pressure source as a power source,
A branch pipe is provided by branching from an air pipe that supplies pressurized air for pressurization, and the branch pipe is connected to a vortex tube that divides hot air into low-temperature air and high-temperature air. A fuel tank characterized by comprising a heat exchanger for exchanging heat between the low temperature air supplied from the vortex tube and the temperature of the pressure air to an appropriate temperature. 2. A bladder having an inner liner for isolating an inner surface of the basket and fuel from the lower half of the bladder accommodated in the outer shell, fixing a semi-cylindrical cage integrally with the outer shell. The fuel tank according to claim 1, wherein the fuel tank is provided inside the fuel tank. 3. A plurality of bladders are accommodated in the outer shell, and a priority valve for restricting the order of fuel supply from each bladder is provided at the confluence of the fuel pipes for delivering the fuel from each bladder. The fuel tank according to claim 1 or 2. 4. The outer shell is fitted with a desiccant-filled drying attachment for communicating the inner and outer shells so that a pressure difference does not occur during storage. Item 3. The fuel tank according to item 3.