JP2001348000A - Nitrogen supply device for fuel tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost nitrogen separator preventing deterioration of airframe performance caused by increase in engine bleed air quantity and improving a mounting property from reduction of size and weight by improving a nitrogen separation efficiency without increasing engine bleed air quantity, for a device supplying nitrogen to a fuel tank provided with a nitrogen separator supplying engine bleed air of an aircraft or the like to the fuel tank after separating nitrogen. SOLUTION: In an air conditioner adjusting temperature of air bled from an engine to a designated temperature and sending it to a coordinated air user in a cabin or the like, and a device supplying nitrogen to a fuel tank provided with a nitrogen separator separating nitrogen from the air and then supplying the air to a space in the fuel tank. A compressed air supply pipe is provided which supplies compressed air from a compressor outlet of the air conditioner or an outlet of a compressor separately provided to the nitrogen separator, and the nitrogen separator separates nitrogen from the compressed air and supplies the same to the fuel tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for adjusting the temperature of air extracted from an engine of an aircraft or the like and sending the air to a destination of conditioned air, and separating nitrogen from the air and supplying it to a space in a fuel tank. The present invention relates to an apparatus for supplying nitrogen to a fuel tank provided with a nitrogen separator.

[0002]

2. Description of the Related Art In an aircraft, a fuel tank (vapor) is filled in an upper space in a fuel tank, and when the fuel tank in such a state encounters a lightning strike, a short circuit of an electric wire, an accidental landing of an aircraft, or the like, See the explosion of the fuel tank and the occurrence on the flame. As means for preventing the occurrence of such an accident, steam or air filling the space in the fuel tank is released, and instead, nitrogen gas (N ₂ ), which is an inert gas having low ignitability, is discharged. Means are provided for supplying to the space and maintaining a safe low level of oxygen concentration in the space.

FIG. 3 shows an example of a conventional apparatus for supplying nitrogen to a fuel tank in such an aircraft. In FIG. 1, reference numeral 1 denotes an engine, which sends air compressed by a compressor to a combustor, and supplies and burns fuel in the combustor;
The combustion gas drives the turbine.
Reference numeral 7 denotes a cabin to be air-conditioned, and 02 denotes an air conditioner for supplying conditioned air to the cabin 7.
In 2, air (engine bleed) extracted from an intermediate stage (last stage at idling) of the compressor of the engine 1 is introduced through a bleed pipe 11, adjusted to a required temperature, and adjusted through a conditioned air pipe 14. It is supplied to the cabin 7.

On the other hand, 012 is a pressurized air pipe branched from the middle of the bleed pipe 11 and connected to the nitrogen separator 5, and 3 and 4 are a pressure regulator and a precooler provided in the pressurized air pipe 012, respectively. The air (engine bleed air) diverted from the trachea 11 to the pressurized air pipe 012 is adjusted to a required pressure by the pressure regulator 3, cooled to a required temperature by the precooler 4, and introduced into the nitrogen separator 5. . In the nitrogen separator 5, nitrogen in the pressurized air is separated. As such a nitrogen separation method, an adsorption method in which oxygen (O ₂ ) in air is adsorbed to extract nitrogen (N ₂ ), or a separation membrane method in which nitrogen and oxygen in air are continuously separated by a separation membrane is used. Used. The nitrogen separated from the air in the nitrogen separator 5 is sent to the fuel tank 6 and filled in the space inside the fuel tank 6.
Thus, the oxygen concentration in the fuel tank 6 is maintained at a safe low level. The air from which nitrogen has been separated in the nitrogen separator 5 is discharged through a discharge pipe 19 to the outside of the system.

[0005]

As the nitrogen separator 5, a separation membrane system capable of continuously separating nitrogen is used in many cases. However, in such a separation membrane type nitrogen separator 5, a high nitrogen separation is required. In order to obtain efficiency, it is necessary to increase the pressure of the air introduced into the nitrogen separator 5. However, in the apparatus for supplying nitrogen to the fuel tank shown in FIG.
The air extracted from the compressor of the engine 1 is introduced into the nitrogen separator 5 to separate nitrogen in the air. However, since the air is still extracted from the compressor of the engine 1, the air in the fuel tank 6 is particularly high. When the aircraft descends and requires a large amount of nitrogen gas, the thrust of the engine is reduced, so that the pressure level of the air (engine bleed air) to the nitrogen separator 5 decreases.

For this reason, in the prior art, as described above, since the nitrogen gas is separated in the nitrogen separator 5 at a relatively low pressure level, the nitrogen separation efficiency is low. In order to obtain the required amount of nitrogen gas for preventing the occurrence of the above-mentioned disaster, a large amount of engine bleed air is required. Therefore, the amount of bleed air from the compressor of the engine increases, and the performance of the airframe deteriorates in accordance with the degree of the bleed air. Requires a nitrogen separator, which deteriorates the mountability on an aircraft.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, the present invention provides an apparatus for supplying nitrogen to a fuel tank provided with a nitrogen separator for separating nitrogen from engine bleed air of an aircraft or the like and supplying the separated nitrogen into the fuel tank. By increasing the nitrogen separation efficiency in the nitrogen separator without increasing, to prevent the deterioration of the body performance due to the increase in the amount of engine bleed,
It is an object of the present invention to obtain a nitrogen separator having a small size, light weight, and improved mountability.

[0008]

According to the present invention, in order to solve the above-mentioned problems, the present invention as described in claim 1 regulates air extracted from an engine to a predetermined temperature and sends it to a conditioned air destination such as a cabin. An apparatus for supplying nitrogen to a fuel tank, comprising: an air conditioner; and a nitrogen separator for separating nitrogen from air and supplying the separated nitrogen into a space in a fuel tank. A nitrogen supply device for a fuel tank, comprising a pressurized air supply pipe for sending to the vessel, wherein the nitrogen separator separates nitrogen from the pressurized air and supplies the separated nitrogen to the fuel tank. suggest.

The invention according to claim 3 relates to a specific configuration of the air conditioner.
A pre-cooling heat exchanger for pre-cooling the air from the engine and a compressor for pressurizing the pre-cooled air, a heat exchanger for cooling the compressed air at the compressor outlet, and expanding the pressurized air passing through the heat exchanger. And a turbine for lowering the temperature, and diverts the pressurized air at the compressor outlet to the heat exchanger and the nitrogen separator, and cools the cooled air at the turbine outlet to air from which a portion of nitrogen has been separated by the nitrogen separator. It is characterized by being merged and sent to a conditioned air destination such as the cabin.

According to the invention, when nitrogen is separated by the nitrogen separator, the air introduced into the nitrogen separator is compressed air which is compressed by the compressor of the air conditioner and is pressurized to a high pressure. Therefore, in the nitrogen separator, nitrogen in the pressurized air can be separated with high nitrogen separation efficiency. Therefore, in an aircraft, when descending the aircraft that needs the most nitrogen gas in the fuel tank,
Even if the pressure level of the engine bleed is reduced, as described above, the engine bleed is increased in pressure by the compressor and supplied to the nitrogen separator. Occurrence is avoided. This eliminates the need to increase the amount of engine bleed air in order to prevent a decrease in nitrogen separation efficiency, thereby preventing a decrease in body performance due to bleeding and consumption of a large amount of air from the engine, Oxygen concentration at a safe low level. In addition, the increase in the nitrogen separation efficiency of the nitrogen separator as described above eliminates the need to equip a large and heavy nitrogen separator to obtain a required amount of nitrogen, so that the nitrogen separator can be reduced in size and weight. , Mountability is improved.

According to a second aspect of the present invention, in addition to the first aspect, a combined air pipe is provided for connecting the air after the nitrogen is separated by the nitrogen separator to a conditioned air pipe from an outlet of the air conditioner. It is characterized by having. According to this invention, the air after separating the nitrogen in the nitrogen separator joins the low-temperature conditioned air flowing through the conditioned air pipe at the outlet of the air conditioner through the combined air pipe. Then, the conditioned air is sent to a place to be air-conditioned such as a cabin and is provided for cooling or heating. Therefore, according to the invention, the air after separating nitrogen from the engine bleed air in the nitrogen separator is not discharged to the outside of the system, but is combined with the conditioned air through the combined air pipe and reused as air conditioning air. Therefore, the bleed loss of the engine is reduced, and the engine efficiency is increased.

An invention according to a fourth aspect is an invention corresponding to the second embodiment, comprising: an air conditioner for adjusting the air extracted from the engine to a predetermined temperature and sending the air to a conditioned air use destination such as a cabin; A nitrogen separator for supplying nitrogen into the space inside the fuel tank by separating nitrogen from the fuel tank, wherein the nitrogen separator is branched from an air pipe between the engine and the air conditioner. A compressor that pressurizes air from the engine and supplies it to the nitrogen separator in a branch air pipe connected to the fuel cell, and separates nitrogen from the pressurized air by the nitrogen separator and supplies the nitrogen to the fuel tank The air from which a part of nitrogen is separated by the nitrogen separator is combined with the air at the outlet of the air conditioner.

According to this invention, it is not necessary to use the compressor of the air conditioner for pressurizing the engine bleed air.
Without being limited by the air conditioner, the type and capacity of the compressor for engine bleed pressure can be freely selected,
A compressor that can obtain a pressurized air pressure that maximizes the nitrogen separation efficiency of the nitrogen separator can be selected, and the nitrogen separation efficiency of the nitrogen separator can be further increased.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just

FIG. 1 is a system diagram of an apparatus for supplying nitrogen to a fuel tank in an aircraft according to a first embodiment of the present invention, and FIG. 2 is a view corresponding to FIG. 1 showing a second embodiment.

FIG. 1 shows a first embodiment of the present invention.
Reference numeral 1 denotes an engine, which comprises a gas turbine engine configured to send air compressed by a compressor to a combustor, supply fuel in the combustor and burn the fuel, and drive the turbine with the combustion gas. Reference numeral 7 denotes a cabin to be air-conditioned, and reference numeral 2 denotes an air conditioner for supplying conditioned air to the cabin 7. The air conditioner 2 is provided with an air bleed from an intermediate stage of the compressor of the engine 1 (the last stage when idling). The extracted air (engine bleed) is introduced through a bleed pipe 11.

The air conditioner 2 is configured as follows. That is, 21 is a heat exchanger A for cooling the air (engine bleed air) from the engine 1, and 22 is a compressor for pressurizing the air passing through the heat exchanger A. A pressurized air supply pipe 12 is connected to a discharge port of the compressor 22. The pressurized air supply pipe 12 is connected to a heat exchanger B24 for cooling the pressurized air and a nitrogen separator 5 described later. . 2
3 is provided coaxially with the compressor and has the heat exchanger B
This is a turbine that expands the pressurized air that has passed through 24. The conditioned air sent from the turbine 23 is supplied to the cabin 7 via a conditioned air pipe 14.

The pressurized air pipe 12 is connected to the heat exchanger B2.
A pressure regulator 3 for adjusting the pressurized air to a required pressure, and a pressurized air which is branched into a pipe to a nitrogen pipe 4 and a pipe to a nitrogen separator 5 described later. A pre-cooler 4 is provided for cooling to a required temperature. 5
Is a nitrogen separator. The nitrogen separator 5 has the same configuration as that of the prior art, and separates nitrogen in the pressurized air. As such a nitrogen separation method, oxygen in the air (O
₂ ) An adsorption method of adsorbing nitrogen to remove nitrogen (N ₂ ) or a separation membrane method of continuously separating nitrogen and oxygen in air by a separation membrane is used. In this embodiment, pressurized air is used. A separation membrane system capable of continuously separating nitrogen from nitrogen is used. Reference numeral 6 denotes a fuel tank, the upper space of which is connected to a nitrogen outlet of the nitrogen separator 5 by a nitrogen supply pipe 16. Reference numeral 17 denotes a merging air pipe that connects the air (air after separating nitrogen) outlet of the nitrogen separator 5 and the middle of the conditioned air pipe 14.

In the apparatus for supplying nitrogen to the fuel tank of the aircraft having the above construction, the air (engine bleed) extracted from the intermediate stage (the last stage at the time of idling) of the compressor of the engine 1 is air-conditioned through the bleed pipe 11. It is introduced into the heat exchanger A21 of the device 2, where it is cooled to a predetermined temperature and then sent to the compressor 22. The compressor 22 is rotationally driven by a coaxial turbine 23 and compresses air from the heat exchanger A21 to increase the pressure. The pressurized air whose temperature has been raised along with the pressurization enters the pressurized air supply pipe 12, and one of the two, ie, the turbine 2
The diverted air to the third side passes through the air pipe 13 to the heat exchanger B.
The air diverted to the other side, that is, to the nitrogen separator 5 side, is guided to the pressure regulator 3. The heat exchanger B2
The pressurized air guided to 4 is cooled here, cooled, and sent to the turbine 23. The pressurized air is reduced in pressure and temperature by performing expansion work in the turbine 23 to become low-pressure, low-temperature conditioned air, and the conditioned air pipe 1 is cooled.
Enter 4.

On the other hand, the pressurized air guided to the pressure regulator 3 is adjusted to a required pressure here, cooled to a required temperature by the precooler 4 and introduced into the nitrogen separator 5. In the nitrogen separator 5, nitrogen in the pressurized air supplied from the precooler 4 is separated. As described above, in this embodiment, a separation membrane system in which nitrogen and oxygen are continuously separated by the separation membrane is used. At the time of separating nitrogen in the nitrogen separator 5, the pressurized air introduced into the nitrogen separator 5 is compressed by the compressor 22 of the air conditioner 2 and is pressurized to a high pressure. In the separator 5, nitrogen in the pressurized air can be separated with high nitrogen separation efficiency.
Therefore, even if the pressure level of the engine bleed air drops during the descent flight of the airframe that requires the most nitrogen gas in the fuel tank 6, as described above, the engine bleed air is pressurized by the compressor 22 and the nitrogen separation is performed. Since it is supplied to the separator 5, the pressure level in the nitrogen separator 5 does not decrease as in the prior art.

The nitrogen separated from the air in the nitrogen separator 5 is sent to a fuel tank 6 and filled in the space inside the fuel tank 6. Thus, the oxygen concentration in the fuel tank 6 is maintained at a safe low level. The air from which nitrogen has been separated in the nitrogen separator 5 passes through the combined air pipe 17 and joins with the low-temperature conditioned air flowing through the conditioned air pipe 14. This conditioned air is sent to the cabin 7 and is used for cooling or heating the cabin 7. Therefore, the air after the nitrogen is separated from the engine bleed air in the nitrogen separator 5 is not discharged to the outside of the system, but is combined with the conditioned air through the merged air pipe 17 and reused as air for air conditioning. 1, the bleeding loss is reduced, and the engine efficiency is increased.

In the second embodiment shown in FIG. 2, air (engine bleed) extracted from an intermediate stage (last stage at idling) of the compressor of the engine 1 passes through a branch air pipe 120 and passes through a pressure regulator 3. Then, it is guided to the compressor 8 installed in the branch air pipe 120, pressurized to a high pressure by the compressor 8, supplied to the nitrogen separator 5 via the precooler 4, and a part of nitrogen is separated by the nitrogen separator 5. The air thus joined is combined with the conditioned air pipe 14 at the outlet of the air conditioner 2 via the combined air pipe 17.
According to this embodiment, unlike the first embodiment, since the compressor 22 of the air conditioner 2 is not used for pressurizing the engine bleed air, the compressor for pressurizing the engine bleed air is not limited by the air conditioner. The type and capacity of the compressor 8 can be freely selected, and a compressor 8 that can obtain a pressurized air pressure that maximizes the nitrogen separation efficiency of the nitrogen separator 5 can be selected.

[0023]

As described above, according to the present invention, since the air introduced into the nitrogen separator is high-pressure pressurized air compressed by the compressor, the nitrogen separator has a high nitrogen separation. The nitrogen in the air can be separated with efficiency. Therefore, in an aircraft, even when the pressure level of the engine bleed air drops during the descent flight of the airframe that requires the most nitrogen gas in the fuel tank, the engine bleed air can be pressurized by the compressor and supplied to the nitrogen separator. The occurrence of reduced pressure levels in the nitrogen separator as in the prior art is avoided.

Thus, it is possible to prevent a decrease in nitrogen separation efficiency without increasing the amount of engine bleed air, to prevent a decrease in body performance due to consumption of the engine bleed air, and to reduce the oxygen concentration in the fuel tank. Can be kept at a safe low level at all times. In addition, the increase in the nitrogen separation efficiency of the nitrogen separator makes it unnecessary to equip a large and heavy nitrogen separator to obtain the required amount of nitrogen. An improved and low-cost nitrogen separator can be obtained.

According to a second aspect of the present invention, the air after the separation of nitrogen from the engine bleed air in the nitrogen separator is not discharged to the outside of the system, but is joined to the conditioned air via the merged air pipe for air conditioning. Since it is reused as working air, the bleeding loss of the engine is reduced and the engine efficiency is increased.

Further, according to the present invention, the type and capacity of the compressor for pressurizing the engine bleed air can be freely selected, and the compressed air pressure which maximizes the nitrogen separation efficiency of the nitrogen separator can be obtained. And a further increase in the nitrogen separation efficiency of the nitrogen separator can be obtained.

[Brief description of the drawings]

FIG. 1 is a system diagram of an apparatus for supplying nitrogen to a fuel tank in an aircraft according to a first embodiment of the present invention.

FIG. 2 is a view corresponding to FIG. 1 showing a second embodiment.

FIG. 3 is a diagram corresponding to FIG. 1 showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Air conditioner 3 Pressure regulator 4 Precooler 5 Nitrogen separator 6 Fuel tank 7 Cabin 8 Compressor 11 Extraction pipe 12 Compressed air supply pipe 14 Conditioned air pipe 16 Nitrogen supply pipe 17 Combined air pipe 21 Heat exchanger A 22 Compressor 23 Turbine 24 Heat exchanger B 120 Branch air pipe

Claims (4)

[Claims] 1. An air conditioner that adjusts air extracted from an engine to a predetermined temperature and sends it to a conditioned air destination such as a cabin, and a nitrogen separator that separates nitrogen from air and supplies it to a space in a fuel tank. And a pressurized air supply pipe for sending pressurized air at a compressor outlet of the air conditioner to the nitrogen separator, wherein the pressurized air is supplied from the pressurized air at the nitrogen separator. An apparatus for supplying nitrogen to a fuel tank, wherein nitrogen is separated and supplied to the fuel tank. 2. The fuel tank according to claim 1, further comprising a merging air pipe for connecting the air from which nitrogen has been separated by the nitrogen separator to a conditioned air pipe from an outlet of the air conditioner. Nitrogen supply device to the plant. 3. The air conditioner includes a pre-cooling heat exchanger for pre-cooling air from the engine, a compressor for pressurizing the pre-cooled air, a heat exchanger for cooling pressurized air at an outlet of the compressor, A turbine that expands the pressurized air that has passed through the heat exchanger to lower the temperature by causing the pressurized air to flow through the heat exchanger and the nitrogen separator. The nitrogen supply device for a fuel tank according to claim 1, wherein a part of the nitrogen is combined with the air separated by a nitrogen separator and sent to a conditioned air destination such as the cabin. 4. An air conditioner that adjusts air extracted from the engine to a predetermined temperature and sends it to a conditioned air destination such as a cabin, and a nitrogen separator that separates nitrogen from the air and supplies the separated nitrogen to a space in a fuel tank. In a nitrogen supply device for a fuel tank having a device, the air from the engine is pressurized to a branch air tube branched from an air pipe between the engine and the air conditioner and connected to the nitrogen separator. A compressor for supplying to the nitrogen separator is provided, the nitrogen is separated from the pressurized air by the nitrogen separator and supplied to the fuel tank, and the air from which a part of nitrogen is separated by the nitrogen separator is air-conditioned. An apparatus for supplying nitrogen to a fuel tank, wherein the apparatus is configured to be combined with air at an outlet of the apparatus.