A nitrogen-enriched gas flow distribution device for aircraft fuel tank inerting

Abstract

The application belongs to the technical field of aircraft fuel system, and particularly relates to a nitrogen-rich gas flow distribution device for aircraft fuel tank inerting. The device comprises: an air separation device for generating nitrogen-rich gas; a flute-shaped pipe, a fuel tank pressure sensor and a fuel tank oil quantity sensor arranged in the fuel tank; one end of an inerting pipeline is connected with the air separation device, and the other end is connected with the flute-shaped pipe through the fuel tank; a one-way valve, a flow regulating ball valve, an oxygen concentration sensor and a flow sensor are sequentially arranged in the inerting pipeline from upstream to downstream; an upper computer is used for collecting wheel load signals; a controller is used for judging the current flight phase of the aircraft according to the fuel tank pressure and the wheel load signals, and controlling the opening degree of the flow regulating ball valve according to the current flight phase of the aircraft, the fuel tank pressure and the fuel tank oil quantity, so that the nitrogen-rich gas corresponding to the flow is filled into the fuel tank. The application can realize the monitoring of multiple parameters and timely adjust the flow of the nitrogen-rich gas entering the fuel tank.

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] Aircraft fuel system fires or explosions are one of the leading causes of aircraft accidents. The fire and explosion resistance of aircraft fuel systems is directly related to aircraft survivability and vulnerability, as well as aircraft utilization, costs, and crew safety. Aircraft fuel tank inerting technology can effectively address these fire and explosion issues.

[0003] The nitrogen-rich gas flow distribution devices used in existing aircraft fuel tank inerting are generally divided into several fixed flow modes. Under the condition of constant bleed air pressure at the inlet of the air separation unit, the flow rate of each flow mode is constant. The flow rate corresponding to each flow mode is determined according to the most stringent conditions, that is, the flow rate corresponding to each flow mode is determined according to the maximum value. Under non-strict flight conditions, the flow rate corresponding to the flow mode is too large, resulting in the problem of wasting engine bleed air. In addition, a large flow rate will also increase the corresponding oxygen concentration of the nitrogen-rich gas, 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 deficiencies 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:

[0007] The present application provides a nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks, comprising:

[0008] an air separation unit for generating nitrogen-rich gas;

[0009] A fuel tank, wherein a flute, a fuel tank pressure sensor, and a fuel tank oil level sensor are provided in the fuel tank;

[0010] an inerting pipeline, one end of which is connected to the air separation device, and the other end of which passes through the fuel 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;

[0011] A host computer, the host computer is used to obtain wheel load signals;

[0012] A 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 level sensor, and the host computer. The controller is used to determine the current flight phase of the aircraft based on 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 based on the current flight phase of the aircraft, the fuel tank pressure fed back by the fuel tank pressure sensor, and the fuel tank oil level fed back by the fuel tank oil level sensor, so that a corresponding flow of nitrogen-rich gas is filled into the fuel tank.

[0013] 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.

[0014] 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 aircraft fuel tanks is not working.

[0015] 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.

[0016] In at least one embodiment of the present application, the flute is provided with a plurality of openings in different directions.

[0017] 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 level 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.

[0018] 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 aircraft's current climb inerting stage, the fuel tank pressure, and the fuel level in the 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.

[0019] In at least one embodiment of the present application, when the fuel tank pressure is between [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 aircraft's current cruise inerting stage, the fuel tank pressure, and the fuel level in the 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.

[0020] 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 level 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.

[0021] In at least one embodiment of the present application, when the fuel tank pressure is greater than 4 kPa and the wheel-borne signal indicates that the aircraft has landed from the air, the controller determines that the aircraft is currently in the landing inerting stage, and controls the opening of the flow regulating ball valve based on the aircraft's current landing inerting stage, 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 fifth flow value, and the fifth flow value is a fixed value.

[0022] In at least one embodiment of the present application, during the initial ground inerting stage, the oxygen concentration fed back by the oxygen concentration sensor is no greater than 7%.

[0023] 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%.

[0024] 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%.

[0025] In at least one embodiment of the present application, during the descent inerting phase, the oxygen concentration fed back by the oxygen concentration sensor is no greater than 15%.

[0026] 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%.

[0027] The invention has at least the following beneficial technical effects:

[0028] The nitrogen-rich gas flow distribution device for aircraft fuel tank inerting 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 based on 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 fuel tank oil level. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of a nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks according to one embodiment of the present application.

[0030] in:

[0031] 1-Air separation unit; 2-One-way valve; 3-Oil drain valve; 4-Flow regulating ball valve; 5-Oxygen concentration sensor; 6-Flow sensor; 7-Flute pipe; 8-Fuel tank; 9-Fuel tank pressure sensor; 10-Fuel tank oil level sensor; 11-Controller. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments 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 the embodiments. 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 understood 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.

[0033] The following is combined with Figure 1 This application is described in further detail.

[0034] The present application provides a nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks, comprising: an air separation device 1, a fuel tank 8, an inerting pipeline, and a controller 11.

[0035] like Figure 1 As shown, the air separation unit 1 can separate nitrogen and oxygen from air to produce nitrogen-rich gas. A flute 7, a tank pressure sensor 9, and a fuel level sensor 10 are installed within the fuel tank 8. The tank pressure sensor 9 is mounted on the wall of the fuel tank 8. One end of the inerting line is connected to the air separation unit 1, and the other end passes through the fuel tank 8 and connects to the flute 7. The inerting line 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 order from upstream to downstream. A controller 11 is connected to the flow regulating ball valve 4, the oxygen concentration sensor 5, the flow sensor 6, the tank pressure sensor 9, the fuel level sensor 10, and a host computer for acquiring wheel load signals. The controller 11 collects data from the oxygen concentration sensor 5, the flow sensor 6, the tank pressure sensor 9, the fuel level sensor 10, and the host computer, and controls the opening of the flow regulating ball valve 4.

[0036] The nitrogen-rich gas flow distribution device for aircraft fuel tank inerting disclosed herein operates as follows: an air separation unit 1 generates nitrogen-rich gas, which then passes through a one-way valve 2 and a flow regulating ball valve 4 and is then charged into the fuel tank 8 via a flute 7 within the fuel tank 8 for inerting. A controller 11 determines the aircraft's current flight phase based on the tank pressure reported by the tank pressure sensor 9 and a wheel load signal reported by a host computer. Data corresponding to the required nitrogen-rich gas flow rate for different flight phases, tank fuel levels, and tank pressures is pre-programmed into the controller 11 software. During operation, the controller 11 controls the opening of the flow regulating ball valve 4 based on the aircraft's current flight phase, the tank pressure reported by the tank pressure sensor 9, and the tank fuel level reported by the tank fuel level sensor 10, thereby allowing the corresponding flow rate of nitrogen-rich gas to be charged into the fuel tank 8.

[0037] The nitrogen-rich gas flow distribution device for aircraft fuel tank inerting disclosed herein generates nitrogen-rich gas through an air separation unit 1. A one-way valve 2 prevents fuel and fuel vapor from flowing back into the air separation unit 1. A flow regulating ball valve 4 regulates the flow of nitrogen-rich gas entering a fuel tank 8. An oxygen concentration sensor 5 monitors the oxygen concentration of the nitrogen-rich gas and the performance of the air separation unit 1. Air separation unit 1 performance degrades under conditions such as inlet bleed air overheating and fuel immersion. Therefore, monitoring the oxygen concentration of the nitrogen-rich gas can be used to determine whether the performance of the air separation unit 1 meets requirements. A flow sensor 6 monitors the flow of nitrogen-rich gas entering the fuel tank 8. A flute 7 evenly distributes the nitrogen-rich gas into the fuel tank 8. The fuel tank 8 stores fuel. A fuel tank pressure sensor 9 monitors the relative pressure of the fuel tank 8. A fuel tank level sensor 10 measures the fuel level. A controller 11 collects data fed back by various signal acquisition components and controls the opening of the flow regulating ball valve 4.

[0038] In a 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. Oil drain valve 3 is used to drain fuel and fuel vapor that flows backward from the fuel tank 8 into the inerting pipeline. Oil drain valve 3 can be positioned at the lowest point in the inerting pipeline between the one-way valve 2 and the flow regulating ball valve 4. During operation of the nitrogen-enriched gas flow distribution device for inerting aircraft fuel tanks, oil drain valve 3 closes. After the nitrogen-enriched gas flow distribution device for inerting aircraft fuel tanks stops operating, the pressure in the inerting pipeline drops to a certain value, and oil drain valve 3 opens to discharge fuel and fuel vapor. Furthermore, the oil discharge volume of oil drain valve 3 can be used to monitor whether the reverse flow tightness of the flow regulating ball valve 4 meets design requirements. Under normal circumstances, oil drain valve 3 discharges fuel in drops. If the flow regulating ball valve 4 is not airtight in the reverse flow, oil drain valve 3 discharges fuel in streams.

[0039] In a preferred embodiment of the present application, the flow regulating ball valve 4 is in the closed position when the nitrogen-rich gas flow distribution device for inerting the aircraft fuel tank is not working. The flow regulating ball valve 4 is also in the closed position by default in the event of an electrical power failure, thereby preventing the fuel tank 8 from having an excessive amount of fuel, and preventing the fuel in the fuel tank 8 from flowing back into the air separation device 1 from the flute 7 through the inerting pipeline.

[0040] In a preferred embodiment of the present application, 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 .

[0041] The specific process of the nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks of the present application, which realizes flight phase determination and control of the opening of the flow regulating ball valve 4 through the controller 11, is as follows:

[0042] After the nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks is started on the ground, the fuel tank pressure is 0 and the wheel load signal indicates that the aircraft is on the ground.

[0043] 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 rate value, and the first flow rate value is a fixed value.

[0044] After the aircraft lifts off and climbs, when the fuel tank pressure continues to increase and the wheel-load 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 based on the aircraft's current climb inerting stage, the fuel tank pressure, and the fuel level in the tank, so that the nitrogen-rich gas flow rate fed back by the flow sensor 6 is a second flow rate value, which is a fixed value.

[0045] When the fuel tank pressure is stabilized at [24, 28] kPa and the wheel-borne 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 aircraft's current cruise inerting stage, 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, which is a fixed value that is the same as the second flow rate value.

[0046] 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 rate value, and the fourth flow rate value is a variable value.

[0047] Specifically, during the descent inerting stage, the required flow rate of nitrogen-rich gas is constantly changing. When the fuel tank amount is less than or equal to 30% of the total fuel volume of the entire aircraft, and the fuel tank pressure change rate is less than or equal to -0.0666 Pa / s, the flow rate of nitrogen-rich gas is the maximum flow rate value of the system design capacity; when the fuel tank amount is less than or equal to 30% of the total fuel volume of the entire aircraft, and the fuel tank pressure change rate is between -0.0666 Pa / s and -0.0533 Pa / s, the flow rate of nitrogen-rich gas is the second largest flow rate value of the system design capacity; when the fuel tank amount is less than or equal to 30% of the total fuel volume of the entire aircraft, and the fuel tank pressure change rate is between -0.0666 Pa / s and -0.0533 Pa / s, the flow rate of nitrogen-rich gas is the second largest flow rate value of the system design capacity; When the tank pressure change rate is greater than or equal to -0.0533 Pa / s and less than or equal to -0.04 Pa / s, the flow rate of nitrogen-enriched gas is the third 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 entire aircraft, and the tank pressure change rate is between -0.04 Pa / s and -0.032 Pa / s, the flow rate of nitrogen-enriched gas is the fourth 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 entire aircraft, and the tank pressure change rate is greater than or equal to -0.032 Pa / s, the flow rate of nitrogen-enriched gas is the fifth maximum flow value of the system design capacity;

[0048] When the fuel tank volume is greater than 30% of the total fuel volume of the whole aircraft, and the rate of change of the fuel tank pressure is less than or equal to -0.0666Pa / s, the flow rate of nitrogen-enriched gas is the second largest flow rate value of the system design capacity; when the fuel tank volume is greater than 30% of the total fuel volume of the whole aircraft, and the rate of change of the fuel tank pressure is between -0.0666Pa / s and -0.0533Pa / s, the flow rate of nitrogen-enriched gas is the third largest flow rate value of the system design capacity; when the fuel tank volume is greater than 30% of the total fuel volume of the whole aircraft, and the rate of change of the fuel tank pressure is greater than or equal to -0.05 When the fuel tank oil volume is greater than 30% of the total fuel volume of the whole aircraft and the fuel tank pressure change rate is between -0.04 Pa / s and -0.032 Pa / s, the flow rate of nitrogen-rich gas is the fifth maximum flow rate of the system design capacity; when the fuel tank oil volume is greater than 30% of the total fuel volume of the whole aircraft and the fuel tank pressure change rate is greater than or equal to -0.032 Pa / s, the flow rate of nitrogen-rich gas is the sixth maximum flow rate of the system design capacity.

[0049] When the fuel tank pressure is greater than 4 kPa and the wheel-load signal indicates that the aircraft has landed from the air, 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 aircraft's current landing inerting stage, 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 the fifth flow rate value, which is a fixed value.

[0050] 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.

[0051] Advantageously, in a preferred embodiment of the present application, the oxygen concentration of the nitrogen-rich gas is monitored by the controller 11 during each flight phase, thereby ensuring that: during the initial ground inerting phase, the oxygen concentration reported by the oxygen concentration sensor 5 is no greater than 7%. Since the membrane assembly of the air separation unit 1 is a life-limited component and will experience performance degradation during its life cycle, this oxygen concentration has already taken into account the degradation and is an indicator that should be met throughout the entire life cycle; during the climb inerting phase, the oxygen concentration reported by the oxygen concentration sensor 5 is no greater than 3%; during the cruise inerting phase, the oxygen concentration reported by the oxygen concentration sensor 5 is no greater than 3%; during the descent inerting phase, the oxygen concentration reported by the oxygen concentration sensor 5 is no greater than 15%. Specifically, the oxygen concentration corresponding to the maximum flow rate value should be no greater than 15%, the oxygen concentration corresponding to the second maximum flow rate value should be no greater than 14%, the oxygen concentration corresponding to the third maximum flow rate value should be no greater than 13%, the oxygen concentration corresponding to the fourth maximum flow rate value should be no greater than 12%, the oxygen concentration corresponding to the fifth maximum flow rate value should be no greater than 11%, and the oxygen concentration corresponding to the sixth maximum flow rate value should be no greater than 10%; and during the landing inerting phase, the oxygen concentration reported by the oxygen concentration sensor 5 is no greater than 9%.

[0052] The nitrogen-enriched gas flow distribution device for aircraft fuel tank inerting disclosed herein features a controller 11 capable of identifying different flight phases based on tank pressure and wheel load signals. During each flight phase, the controller 11 controls the opening of the flow regulating ball valve 4 based on tank pressure and fuel level data, and in accordance with the correspondence between tank level, tank pressure, and nitrogen-enriched gas flow rate pre-programmed into the controller 11 software. This allows a corresponding flow rate of nitrogen-enriched gas to be introduced into the fuel tank 8 for inerting. This device achieves flow distribution through the flow regulating ball valve 4, resulting in a simple principle, a small number of finished products, and simple onboard deployment. The device can adjust the flow rate of nitrogen-enriched gas entering the fuel tank 8 in a timely manner based on the tank pressure and fuel level, saving engine bleed air, according to different aircraft flight states.

[0053] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks, characterized in that: include: An air separation unit (1), the air separation unit (1) being used to generate nitrogen-rich gas; A fuel tank (8), wherein a flute tube (7), a fuel tank pressure sensor (9), and a fuel tank oil level sensor (10) are provided in the fuel 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 being connected to the flute (7) through the oil tank (8), 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) is 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 based on 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) based on 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 the 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 in operation.

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 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 aircraft's current initial ground inerting stage, the fuel tank pressure, and the fuel tank oil level, 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-borne 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 aircraft's current climb inerting stage, the fuel tank pressure, and the fuel tank oil level, 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 [24, 28] kPa and the wheel-borne 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 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-borne 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 aircraft's current descent inerting stage, 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-loaded signal indicates that the aircraft has landed from the air, 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 aircraft's current landing inerting stage, 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 the fifth flow rate value, which 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 more than 7%.

12. The nitrogen-rich gas flow distribution device for inerting aircraft fuel tanks 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 more 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 more 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 inerting aircraft fuel tanks 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 more than 9%.

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