Nitrogen-rich gas flow distribution device for inerting aircraft fuel tank

Abstract

The invention belongs to the technical field of aircraft fuel oil systems, and particularly relates to a nitrogen-rich gas flow distribution device for aircraft fuel oil tank inerting. The air separation device is used for generating nitrogen-rich gas; a flute-shaped pipe, an oil tank pressure sensor and an oil tank oil quantity sensor are arranged in the oil tank; one end of the inerting pipeline is connected with the air separation device, the other end of the inerting pipeline penetrates through the oil tank to be connected with the flute-shaped pipe, and the inerting pipeline is sequentially provided with a one-way valve, a flow adjusting ball valve, an oxygen concentration sensor and a flow sensor from upstream to downstream. The upper computer is used for collecting a wheel load signal; the controller is used for judging the current flight stage of the aircraft according to the pressure of the fuel tank and the wheel load signal, and controlling the opening degree of the flow adjusting ball valve according to the current flight stage of the aircraft, the pressure of the fuel tank and the fuel quantity of the fuel tank, so that the fuel tank is filled with the nitrogen-rich gas with the corresponding flow. According to the invention, monitoring of various parameters can be realized, and the flow of nitrogen-rich gas entering the oil tank can be timely adjusted.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft fuel systems, and in particular relates to a nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks. Background Art

[0002] Fire or explosion in aircraft fuel system is one of the main causes of aircraft crashes. The fire and explosion prevention capabilities of aircraft fuel system are directly related to aircraft survivability and vulnerability, as well as aircraft utilization, cost and personnel safety. Aircraft fuel tank inerting technology can effectively solve the fire and explosion prevention problems of aircraft fuel system.

[0003] The nitrogen-rich gas flow distribution device used in the inerting of existing aircraft fuel tanks is generally divided into several fixed flow modes. Under the condition of constant bleed air pressure at the inlet of the air separation device, the flow rates of different flow modes are constant. The flow rates corresponding to different flow modes are determined according to the most stringent conditions, that is, the flow rates corresponding to different flow modes are determined according to the maximum values. If the flight process is not the most stringent, the flow rate corresponding to the flow mode is too large, and there is a problem of wasting engine bleed air. In addition, if the flow rate is too large, the corresponding oxygen concentration of the nitrogen-rich gas will also be too large, reducing the inerting effect of the inerting system on the fuel tank.

[0004] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned defects of the prior art. Summary of the invention

[0005] The purpose of the present application is to provide a nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks to solve at least one problem existing in the prior art.

[0006] The technical solution of this application is: The present application provides a nitrogen-rich gas flow distribution device for inerting an aircraft fuel tank, comprising: an air separation unit for generating nitrogen-rich gas; A fuel tank, wherein a flute, a fuel tank pressure sensor, and a fuel tank oil level sensor are arranged in the fuel tank; an inerting pipeline, one end of which is connected to the air separation device, and the other end of which passes through the oil tank and is connected to the flute pipe, wherein the inerting pipeline is provided with a one-way valve, a flow regulating ball valve, an oxygen concentration sensor, and a flow sensor in sequence from upstream to downstream; A host computer, the host computer is used to obtain wheel load signals; A controller, wherein the controller is respectively connected to the flow regulating ball valve, the oxygen concentration sensor, the flow sensor, the fuel tank pressure sensor, the fuel tank oil quantity sensor, and the host computer, and the controller is used to determine the current flight stage of the aircraft according to the fuel tank pressure fed back by the fuel tank pressure sensor and the wheel load signal fed back by the host computer, and control the opening of the flow regulating ball valve according to the current flight stage of the aircraft, the fuel tank pressure fed back by the fuel tank pressure sensor, and the fuel tank oil quantity fed back by the fuel tank oil quantity sensor, so that the corresponding flow of nitrogen-rich gas is filled into the fuel tank.

[0007] In at least one embodiment of the present application, an oil drain valve is provided at the lowest point of the inerting pipeline between the one-way valve and the flow regulating ball valve.

[0008] In at least one embodiment of the present application, the flow regulating ball valve is in a closed position when the nitrogen-rich gas flow distribution device for inerting an aircraft fuel tank is not working.

[0009] In at least one embodiment of the present application, the flow regulating ball valve is in a closed position in the event of an electrical power failure.

[0010] In at least one embodiment of the present application, the flute is provided with a plurality of openings in different directions.

[0011] In at least one embodiment of the present application, when the fuel tank pressure is [-2, 2] kPa and the wheel-load signal indicates that the aircraft is always on the ground, the controller determines that the aircraft is currently in the initial ground inerting stage, and controls the opening of the flow regulating ball valve according to the current initial ground inerting stage of the aircraft, the fuel tank pressure, and the fuel amount in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor is a first flow value, and the first flow value is a fixed value.

[0012] In at least one embodiment of the present application, when the fuel tank pressure continues to increase and the wheel-borne signal indicates that the aircraft is in the air, the controller determines that the aircraft is currently in a climb inerting stage, and controls the opening of the flow regulating ball valve according to the current climb inerting stage of the aircraft, the fuel tank pressure, and the fuel level in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor is a second flow value, and the second flow value is a fixed value.

[0013] In at least one embodiment of the present application, when the fuel tank pressure is [24, 28] kPa and the wheel-borne signal indicates that the aircraft is in the air, the controller determines that the aircraft is currently in the cruise inerting stage, and controls the opening of the flow regulating ball valve according to the current cruise inerting stage of the aircraft, the fuel tank pressure, and the fuel level in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor is a third flow value, and the third flow value is a fixed value that is the same as the second flow value.

[0014] In at least one embodiment of the present application, when the fuel tank pressure is less than or equal to 4 kPa, the fuel tank pressure continues to decrease, and the wheel-borne signal indicates that the aircraft is in the air, the controller determines that the aircraft is currently in a descent inerting stage, and controls the opening of the flow regulating ball valve according to the current descent inerting stage of the aircraft, the fuel tank pressure, and the fuel amount in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor is a fourth flow value, and the fourth flow value is a variable value.

[0015] In at least one embodiment of the present application, when the fuel tank pressure is greater than 4 kPa and the wheel-loaded signal indicates that the aircraft changes from the air to the ground, the controller determines that the aircraft is currently in the landing inerting stage, and controls the opening of the flow regulating ball valve according to the current landing inerting stage of the aircraft, the fuel tank pressure, and the fuel amount in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor is the fifth flow value, and the fifth flow value is a fixed value.

[0016] In at least one embodiment of the present application, during the initial inerting stage on the ground, the oxygen concentration fed back by the oxygen concentration sensor is no greater than 7%.

[0017] In at least one embodiment of the present application, during the climb inerting phase, the oxygen concentration fed back by the oxygen concentration sensor is no greater than 3%.

[0018] In at least one embodiment of the present application, during the cruise inerting phase, the oxygen concentration fed back by the oxygen concentration sensor is no greater than 3%.

[0019] In at least one embodiment of the present application, during the descent inerting stage, the oxygen concentration fed back by the oxygen concentration sensor is no greater than 15%.

[0020] In at least one embodiment of the present application, during the landing inerting phase, the oxygen concentration fed back by the oxygen concentration sensor is no greater than 9%.

[0021] The invention has at least the following beneficial technical effects: The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks of the present application can monitor parameters such as oxygen concentration, nitrogen-rich gas flow, fuel tank pressure, and fuel tank oil level, and identify different flight phases according to the fuel tank pressure and wheel load signals. In the corresponding flight phase, the nitrogen-rich gas flow entering the fuel tank is adjusted in a timely manner according to the fuel tank pressure and the fuel tank oil level. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to one embodiment of the present application.

[0023] in: 1-air separation device; 2-check valve; 3-drain valve; 4-flow regulating ball valve; 5-oxygen concentration sensor; 6-flow sensor; 7-flute; 8-fuel tank; 9-fuel tank pressure sensor; 10-fuel tank oil level sensor; 11-controller. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0025] The following is combined with Figure 1 This application is described in further detail.

[0026] The present application provides a nitrogen-rich gas flow distribution device for inerting an aircraft fuel tank, comprising: an air separation device 1, a fuel tank 8, an inerting pipeline and a controller 11.

[0027] like Figure 1 As shown, the air separation device 1 can separate nitrogen and oxygen from air to generate nitrogen-rich gas; a flute 7, a tank pressure sensor 9, and a tank oil level sensor 10 are provided in the fuel tank 8, and the tank pressure sensor 9 is arranged on the wall plate of the fuel tank 8. One end of the inerting pipeline is connected to the air separation device 1, and the other end passes through the fuel tank 8 and is connected to the flute 7. The inerting pipeline is provided with a one-way valve 2, a flow regulating ball valve 4, an oxygen concentration sensor 5, and a flow sensor 6 in sequence from upstream to downstream. The controller 11 is respectively connected to the flow regulating ball valve 4, the oxygen concentration sensor 5, the flow sensor 6, the tank pressure sensor 9, the tank oil level sensor 10, and the upper computer for obtaining wheel load signals. The controller 11 can collect data fed back by the oxygen concentration sensor 5, the flow sensor 6, the tank pressure sensor 9, the tank oil level sensor 10, and the upper computer, and control the opening of the flow regulating ball valve 4.

[0028] The nitrogen-rich gas flow distribution device for inerting an aircraft fuel tank of the present application has the following working principle: an air separation device 1 generates nitrogen-rich gas, and the nitrogen-rich gas passes through a one-way valve 2 and a flow regulating ball valve 4 and then is filled into the fuel tank 8 through a flute 7 in the fuel tank 8 for inerting; a controller 11 determines the current flight stage of the aircraft according to the fuel tank pressure fed back by the fuel tank pressure sensor 9 and the wheel load signal fed back by the host computer, and the corresponding data of the required nitrogen-rich gas flow rate under different flight stages, different fuel tank oil levels and fuel tank pressure conditions are written into the software of the controller 11 in advance. When the nitrogen-rich gas flow distribution device for inerting an aircraft fuel tank is working, the controller 11 controls the opening of the flow regulating ball valve 4 according to the current flight stage of the aircraft, the fuel tank pressure fed back by the fuel tank pressure sensor 9, and the fuel tank oil level fed back by the fuel tank oil level sensor 10, so that the corresponding flow of nitrogen-rich gas is filled into the fuel tank 8.

[0029] The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks of the present application generates nitrogen-rich gas through an air separation device 1; a one-way valve 2 can prevent fuel and fuel vapor from flowing back into the air separation device 1. A flow regulating ball valve 4 is used to regulate the flow of nitrogen-rich gas entering the fuel tank 8; an oxygen concentration sensor 5 is used to monitor the oxygen concentration of the nitrogen-rich gas and the performance of the air separation device 1. The performance of the air separation device 1 will be reduced under conditions such as inlet bleed air overheating and being soaked in fuel, so monitoring the oxygen concentration of the nitrogen-rich gas can be used to determine whether the performance of the air separation device 1 meets the requirements; a flow sensor 6 is used to monitor the flow of nitrogen-rich gas entering the fuel tank 8; a flute 7 is used to uniformly fill the nitrogen-rich gas into the fuel tank 8; the fuel tank 8 is used to store fuel; a fuel tank pressure sensor 9 is used to monitor the pressure of the fuel tank 8 relative to the atmosphere; a fuel tank oil level sensor 10 is used to measure the fuel level in the fuel tank; and a controller 11 is used to collect data fed back by various signal collection components and control the opening of the flow regulating ball valve 4.

[0030] In the preferred embodiment of the present application, an oil drain valve 3 is provided on the inerting pipeline between the one-way valve 2 and the flow regulating ball valve 4. The oil drain valve 3 is used to discharge the fuel and fuel vapor that flow back from the fuel tank 8 into the inerting pipeline. The oil drain valve 3 can be set at the lowest point of the inerting pipeline between the one-way valve 2 and the flow regulating ball valve 4. When the nitrogen-rich gas flow distribution device for inerting the aircraft fuel tank is working, the oil drain valve 3 is closed. After the nitrogen-rich gas flow distribution device for inerting the aircraft fuel tank stops working, the pressure in the inerting pipeline is reduced to a certain value, and the oil drain valve 3 is opened to discharge the fuel and fuel vapor. In addition, according to the oil discharge amount of the oil drain valve 3, it is possible to monitor whether the reverse air tightness of the flow regulating ball valve 4 meets the design requirements. Under normal circumstances, the oil drain valve 3 discharges fuel in drops. When the flow regulating ball valve 4 is not airtight in the reverse direction, the oil drain valve 3 will discharge fuel in streams.

[0031] In a preferred embodiment of the present application, the flow regulating ball valve 4 is in a closed position when the nitrogen-rich gas flow distribution device for inerting the aircraft fuel tank is not working, and the flow regulating ball valve 4 is also in a closed position by default in the event of an electrical power failure, which can prevent the fuel tank 8 from having too much oil, and the fuel in the fuel tank 8 from flowing back into the air separation device 1 from the flute 7 through the inerting pipeline.

[0032] In a preferred embodiment of the present application, the nitrogen-rich gas is distributed in the fuel tank 8 through a flute 7 , and a plurality of openings in different directions are evenly provided on the flute 7 to accelerate the mixing of the nitrogen-rich gas with the gas in the fuel tank 8 .

[0033] The specific process of the nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks of the present application to realize flight phase judgment and control of the opening of the flow regulating ball valve 4 through the controller 11 is as follows: After the nitrogen-rich gas flow distribution device for aircraft fuel tank inerting is started on the ground, the fuel tank pressure is 0 and the wheel load signal indicates that the aircraft is on the ground.

[0034] When the fuel tank pressure is stabilized at [-2, 2] kPa and the wheel load signal indicates that the aircraft is always on the ground, the controller 11 determines that the aircraft is currently in the initial ground inerting stage, and controls the opening of the flow regulating ball valve 4 according to the current initial ground inerting stage of the aircraft, the fuel tank pressure, and the fuel amount in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor 6 is a first flow value, and the first flow value is a fixed value.

[0035] After the aircraft takes off and climbs, when the fuel tank pressure continues to increase and the wheel-loaded signal indicates that the aircraft is in the air, the controller 11 determines that the aircraft is currently in the climb inerting stage, and controls the opening of the flow regulating ball valve 4 according to the current climb inerting stage of the aircraft, the fuel tank pressure, and the fuel amount in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor 6 is the second flow value, and the second flow value is a fixed value.

[0036] When the fuel tank pressure is stabilized at [24, 28] kPa and the wheel-loaded signal indicates that the aircraft is in the air, the controller 11 determines that the aircraft is currently in the cruise inerting stage, and controls the opening of the flow regulating ball valve 4 according to the current cruise inerting stage of the aircraft, the fuel tank pressure, and the fuel amount in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor 6 is a third flow value, and the third flow value is a fixed value that is the same as the second flow value.

[0037] When the fuel tank pressure is less than or equal to 4 kPa, the fuel tank pressure continues to decrease, and the wheel-loaded signal indicates that the aircraft is in the air, the controller 11 determines that the aircraft is currently in the descent inerting stage, and controls the opening of the flow regulating ball valve 4 according to the current descent inerting stage of the aircraft, the fuel tank pressure, and the fuel amount in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor 6 is the fourth flow value, and the fourth flow value is a variable value.

[0038] Specifically, during the descent inerting stage, the required flow rate of nitrogen-rich gas is constantly changing. When the fuel tank oil volume is less than or equal to 30% of the total fuel volume of the whole aircraft, and the fuel tank pressure change rate is less than or equal to -0.0666Pa / s, the flow rate of nitrogen-rich gas is the maximum flow value of the system design capacity; when the fuel tank oil volume is less than or equal to 30% of the total fuel volume of the whole aircraft, and the fuel tank pressure change rate is between -0.0666Pa / s and -0.0533Pa / s, the flow rate of nitrogen-rich gas is the second largest flow value of the system design capacity; when the fuel tank oil volume is less than or equal to 30% of the total fuel volume of the whole aircraft, and the fuel tank pressure change rate is between -0.0666Pa / s and -0.0533Pa / s, the flow rate of nitrogen-rich gas is the second largest flow value of the system design capacity; When the tank pressure change rate is greater than or equal to -0.0533Pa / s and less than or equal to -0.04Pa / s, the flow rate of nitrogen-rich gas is the third largest flow value of the system design capacity; when the oil volume in the tank is less than or equal to 30% of the total oil volume of the whole machine, and the tank pressure change rate is between -0.04Pa / s and -0.032Pa / s, the flow rate of nitrogen-rich gas is the fourth largest flow value of the system design capacity; when the oil volume in the tank is less than or equal to 30% of the total oil volume of the whole machine, and the tank pressure change rate is greater than or equal to -0.032Pa / s, the flow rate of nitrogen-rich gas is the fifth largest flow value of the system design capacity; When the fuel tank oil volume is greater than 30% of the total fuel volume of the whole machine, and the fuel tank pressure change rate is less than or equal to -0.0666Pa / s, the flow rate of nitrogen-enriched gas is the second largest flow value of the system design capacity; when the fuel tank oil volume is greater than 30% of the total fuel volume of the whole machine, and the fuel tank pressure change rate is between -0.0666Pa / s and -0.0533Pa / s, the flow rate of nitrogen-enriched gas is the third largest flow value of the system design capacity; when the fuel tank oil volume is greater than 30% of the total fuel volume of the whole machine, and the fuel tank pressure change rate is greater than or equal to -0.05 33Pa / s is less than or equal to -0.04Pa / s, the flow rate of nitrogen-rich gas is the fourth largest flow value of the system design capacity; when the oil amount in the fuel tank is greater than 30% of the total oil amount of the whole machine and the fuel tank pressure change rate is between -0.04Pa / s and -0.032Pa / s, the flow rate of nitrogen-rich gas is the fifth largest flow value of the system design capacity; when the oil amount in the fuel tank is greater than 30% of the total oil amount of the whole machine and the fuel tank pressure change rate is greater than or equal to -0.032Pa / s, the flow rate of nitrogen-rich gas is the sixth largest flow value of the system design capacity.

[0039] When the fuel tank pressure is greater than 4 kPa and the wheel-loaded signal indicates that the aircraft has changed from the air to the ground, the controller 11 determines that the aircraft is currently in the landing inerting stage, and controls the opening of the flow regulating ball valve 4 according to the current landing inerting stage of the aircraft, the fuel tank pressure, and the fuel amount in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor 6 is the fifth flow value, and the fifth flow value is a fixed value.

[0040] After completion, the nitrogen-rich gas flow distribution device for inerting the aircraft fuel tank is closed, the flow regulating ball valve 4 is closed, and the controller 11 is powered off.

[0041] Advantageously, in a preferred embodiment of the present application, the oxygen concentration of the nitrogen-rich gas is monitored by the controller 11 in each flight phase, thereby ensuring that: in the initial ground inerting phase, the oxygen concentration fed back by the oxygen concentration sensor 5 is not greater than 7%, wherein, since the membrane assembly of the air separation device 1 is a life-limited component, there will be performance degradation during the life cycle, and the oxygen concentration has taken into account the degradation, which is an indicator that should be met during the entire life cycle; in the climbing inerting phase, the oxygen concentration fed back by the oxygen concentration sensor 5 is not greater than 3%; in the cruising inerting phase, the oxygen concentration fed back by the oxygen concentration sensor 5 is not greater than 3%; in the descending inerting phase, the oxygen concentration fed back by the oxygen concentration sensor 5 is not greater than 15%, specifically, the oxygen concentration corresponding to the maximum flow value should be no greater than 15%, the oxygen concentration corresponding to the second largest flow value should be no greater than 14%, the oxygen concentration corresponding to the third largest flow value should be no greater than 13%, the oxygen concentration corresponding to the fourth largest flow value should be no greater than 12%, the oxygen concentration corresponding to the fifth largest flow value should be no greater than 11%, and the oxygen concentration corresponding to the sixth largest flow value should be no greater than 10%; in the landing inerting phase, the oxygen concentration fed back by the oxygen concentration sensor 5 is no greater than 9%.

[0042] The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks of the present application, the controller 11 can identify different flight stages according to the tank pressure and wheel load signal, and in different flight stages, according to the tank pressure and the tank oil quantity data, according to the corresponding relationship between the tank oil quantity, the tank pressure and the nitrogen-rich gas flow rate written in advance into the controller 11 software, the opening of the flow regulating ball valve 4 is controlled, so that the corresponding flow of nitrogen-rich gas is filled into the tank 8 for inerting. The present application realizes flow distribution through the flow regulating ball valve 4, the principle is simple, the number of finished products is small, the layout on the aircraft is simple, and the flow of nitrogen-rich gas filled into the tank 8 can be adjusted in time according to the tank pressure and the tank oil quantity for different flight states of the aircraft, saving engine bleed air.

[0043] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks, characterized in that: include: An air separation device (1), wherein the air separation device (1) is used to generate nitrogen-rich gas; An oil tank (8), wherein a flute (7), an oil tank pressure sensor (9), and an oil tank oil level sensor (10) are arranged in the oil tank (8); an inerting pipeline, one end of the inerting pipeline being connected to the air separation device (1), and the other end of the inerting pipeline passing through the oil tank (8) and connected to the flute (7), the inerting pipeline being provided with a one-way valve (2), a flow regulating ball valve (4), an oxygen concentration sensor (5), and a flow sensor (6) in sequence from upstream to downstream; A host computer, the host computer is used to obtain wheel load signals; A controller (11), the controller (11) being connected to the flow regulating ball valve (4), the oxygen concentration sensor (5), the flow sensor (6), the fuel tank pressure sensor (9), the fuel tank oil quantity sensor (10), and the host computer respectively. The controller (11) is used to determine the current flight phase of the aircraft according to the fuel tank pressure fed back by the fuel tank pressure sensor (9) and the wheel load signal fed back by the host computer, and to control the opening of the flow regulating ball valve (4) according to the current flight phase of the aircraft, the fuel tank pressure fed back by the fuel tank pressure sensor (9), and the fuel tank oil quantity fed back by the fuel tank oil quantity sensor (10), so that a corresponding flow of nitrogen-rich gas is filled into the fuel tank (8).

2. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 1, characterized in that: An oil drain valve (3) is provided at the lowest point of the inerting pipeline between the one-way valve (2) and the flow regulating ball valve (4).

3. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 2, characterized in that: The flow regulating ball valve (4) is in a closed position when the nitrogen-rich gas flow distribution device for inerting an aircraft fuel tank is not working.

4. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 3, characterized in that: The flow regulating ball valve (4) is in the closed position in the event of an electrical power failure.

5. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 4, characterized in that: The flute-shaped tube (7) is provided with a plurality of openings facing in different directions.

6. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 1, characterized in that: When the fuel tank pressure is at [-2, 2] kPa and the wheel load signal indicates that the aircraft is always on the ground, the controller (11) determines that the aircraft is currently in the initial ground inerting stage, and controls the opening of the flow regulating ball valve (4) according to the initial ground inerting stage, the fuel tank pressure, and the fuel tank oil level of the aircraft, so that the nitrogen-rich gas flow rate fed back by the flow sensor (6) is a first flow rate value, and the first flow rate value is a fixed value.

7. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 6, characterized in that: When the fuel tank pressure continues to increase and the wheel-loaded signal indicates that the aircraft is in the air, the controller (11) determines that the aircraft is currently in a climbing inerting stage, and controls the opening of the flow regulating ball valve (4) according to the current climbing inerting stage of the aircraft, the fuel tank pressure, and the fuel volume in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor (6) is a second flow rate value, and the second flow rate value is a fixed value.

8. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 7, characterized in that: When the fuel tank pressure is at [24, 28] kPa and the wheel-loaded signal indicates that the aircraft is in the air, the controller (11) determines that the aircraft is currently in the cruise inerting stage, and controls the opening of the flow regulating ball valve (4) according to the current cruise inerting stage of the aircraft, the fuel tank pressure, and the fuel level in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor (6) is a third flow rate value, and the third flow rate value is a fixed value that is the same as the second flow rate value.

9. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 8, characterized in that: When the fuel tank pressure is less than or equal to 4 kPa, the fuel tank pressure continues to decrease, and the wheel-loaded signal indicates that the aircraft is in the air, the controller (11) determines that the aircraft is currently in a descent inerting stage, and controls the opening of the flow regulating ball valve (4) according to the current descent inerting stage of the aircraft, the fuel tank pressure, and the fuel volume in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor (6) is a fourth flow rate value, and the fourth flow rate value is a variable value.

10. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 9, characterized in that: When the fuel tank pressure is greater than 4 kPa and the wheel load signal indicates that the aircraft has changed from the air to the ground, the controller (11) determines that the aircraft is currently in the landing inerting stage, and controls the opening of the flow regulating ball valve (4) according to the current landing inerting stage of the aircraft, the fuel tank pressure, and the fuel volume in the fuel tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor (6) is a fifth flow rate value, and the fifth flow rate value is a fixed value.

11. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 10, characterized in that: During the initial inerting stage on the ground, the oxygen concentration fed back by the oxygen concentration sensor (5) is no greater than 7%.

12. The nitrogen-rich gas flow distribution device for aircraft fuel tank inerting according to claim 11, characterized in that: During the climbing inerting stage, the oxygen concentration fed back by the oxygen concentration sensor (5) is no greater than 3%.

13. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 12, characterized in that: During the cruise inerting phase, the oxygen concentration fed back by the oxygen concentration sensor (5) is no greater than 3%.

14. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to claim 13, characterized in that: During the descent inerting stage, the oxygen concentration fed back by the oxygen concentration sensor (5) is no greater than 15%.

15. The nitrogen-rich gas flow distribution device for aircraft fuel tank inerting according to claim 14, characterized in that: During the landing inerting phase, the oxygen concentration fed back by the oxygen concentration sensor (5) is no greater than 9%.

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