Airborne nitrogen generating device with adaptive regulation of nitrogen-rich gas flow

Abstract

An airborne nitrogen generator with adaptive flow rate regulation of nitrogen-enriched gas is disclosed. The bleed air and treatment subsystem receives engine bleed air from the engine and ram air from outside the engine. After processing by the bleed air and treatment subsystem, the engine bleed air and ram air are sent to an air separator. A temperature sensor is installed at the inlet of the air separator, and a pressure-sensitive flow control valve is installed at the nitrogen-enriched gas outlet of the air separator. The nitrogen-enriched gas flows through the pressure-sensitive flow control valve and into the fuel tank through a nitrogen-enriched gas distribution pipeline. After gas exchange with the gas phase space inside the fuel tank, the nitrogen-enriched gas is discharged from the fuel tank through an active exhaust valve. The temperature sensor and the active exhaust valve are connected to a host computer. This invention enables adaptive flow rate regulation of nitrogen-enriched gas, maintaining both low oxygen concentration and fuel tank pressure, effectively simplifying the control logic of the equipment, and ensuring safety and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of aviation mechanical control equipment technology, and in particular to an airborne nitrogen generator with adaptive adjustment of nitrogen-rich gas flow rate. Background Technology

[0002] The airborne nitrogen generation system uses an air separation device containing an air separation membrane to separate oxygen and nitrogen in the air into oxygen-rich gas and nitrogen-rich gas. The oxygen-rich gas is discharged outside the engine, and the nitrogen-rich gas is introduced into the fuel tank. Through gas replacement, the oxygen concentration in the gas phase space inside the fuel tank and the flammability of the fuel tank are reduced, thus promoting the "inertization" of the fuel tank.

[0003] Due to the special physical properties of the air separation membrane, the airborne nitrogen generation system has the following operating performance: under the same conditions, the higher the nitrogen-enriched gas flow rate, the higher the nitrogen generation efficiency, but the lower the nitrogen-enriched gas concentration; the lower the nitrogen-enriched gas flow rate, the lower the nitrogen generation efficiency, but the higher the nitrogen-enriched gas concentration. Existing airborne nitrogen generation systems usually use electrically controlled flow distribution valves to divide the nitrogen-enriched gas flow rate into 2 to 5 levels to meet the nitrogen-enriched gas requirements of different flight phases.

[0004] Because the electrically controlled flow distribution valve allocates nitrogen-enriched gas flow at fixed levels, the flow rate and concentration of nitrogen-enriched gas entering the fuel tank are both fixed values. This makes precise, real-time adjustment impossible based on the aircraft's flight status, negatively impacting the fuel tank's inerting effect. For combat aircraft, during repeated climbs and dives, the pressure inside and outside the fuel tank fluctuates significantly. Therefore, precise adjustment of the nitrogen-enriched gas flow rate is crucial to maintaining both low oxygen concentration and sufficient pressure to meet system requirements. Summary of the Invention

[0005] The technical problem solved by this invention is to provide an airborne nitrogen generator with adaptive flow rate adjustment for nitrogen-rich gas, so as to solve the problems in the background art mentioned above.

[0006] The technical problem solved by this invention is achieved by the following technical solution:

[0007] An airborne nitrogen generator with adaptive flow regulation of nitrogen-enriched gas includes a bleed air and treatment subsystem, a host computer connected to the bleed air and treatment subsystem, a temperature sensor, an air separator, a pressure-sensitive flow control valve, a nitrogen-enriched gas distribution pipeline, an active exhaust valve, and a fuel tank. The bleed air and treatment subsystem receives engine bleed air from the engine and ram air from outside the engine. After processing, the engine bleed air and ram air are sent to the air separator. The temperature sensor is located at the inlet of the air separator, and the pressure-sensitive flow control valve is installed at the nitrogen-enriched gas outlet of the air separator. The nitrogen-enriched gas flows through the pressure-sensitive flow control valve and into the fuel tank via the nitrogen-enriched gas distribution pipeline. After gas exchange with the gas in the gas phase space of the fuel tank, the nitrogen-enriched gas is discharged from the fuel tank through the active exhaust valve, thereby reducing the oxygen concentration in the gas phase space of the fuel tank compartment and inerting the fuel tank. The temperature sensor and the active exhaust valve are connected to the host computer.

[0008] In this invention, the bleed air and treatment subsystem is equipped with a mixing chamber and a water separator. Engine bleed air enters the mixing chamber of the bleed air and treatment subsystem through the hot circuit control valve and ram air enters through the cold circuit control valve. After water is removed by the water separator, the mixture is sent to the air separation device.

[0009] In this invention, a temperature sensor is installed at the inlet of the air separation device to feed back the temperature signal to the host computer in real time. The host computer adjusts the opening of the hot circuit control valve and the cold circuit control valve in real time based on the temperature signal so that the temperature of the gas entering the air separation device is within its operating temperature range.

[0010] In this invention, the air separation device separates oxygen and nitrogen in the air into oxygen-rich gas and nitrogen-rich gas, with the oxygen-rich gas being discharged outside the machine.

[0011] In this invention, the pressure-sensitive flow regulating valve includes an upper diaphragm cavity for sensing tank pressure, a diaphragm assembly for moving a valve assembly, a lower diaphragm cavity for sensing ambient pressure, a valve body, a valve assembly, and a spring. The valve body has an inlet at one end and an outlet at the other end. A valve assembly is located in the middle of the valve body, with its upper end connected to the diaphragm assembly. A spring is installed at the lower end of the diaphragm assembly, and the other end of the spring is fixed to the valve body. The diaphragm assembly has an upper diaphragm cavity at its upper part and a lower diaphragm cavity at its lower part. The diaphragm assembly pushes the valve assembly downwards to achieve real-time flow regulation.

[0012] In this invention, a small flow orifice is provided at the valve body inlet of the pressure-sensitive flow regulating valve so that when the valve assembly is in the closed position, the airborne nitrogen generator continuously supplies gas to the oil tank at a minimum nitrogen-rich gas flow rate, ensuring that the oil tank maintains a preset boost value and a low oxygen concentration.

[0013] In this invention, a one-way valve is provided at the outlet of the pressure-sensitive flow regulating valve to prevent fuel in the fuel tank from flowing back into the airborne nitrogen generator through the nitrogen-rich gas distribution pipeline.

[0014] In this invention, both the active vent valve and the overpressure vent valve can automatically open when the tank pressure exceeds a certain limit. The opening pressure of the active vent valve is equivalent to the preset boost pressure value. When the tank pressure reaches the opening pressure of the active vent valve, the active vent valve opens to release air, ensuring that the tank pressure remains within the preset boost pressure range. The opening pressure of the overpressure vent valve is higher than that of the active vent valve, and it is used to release air when the tank is overpressured, protecting the tank structure from excessive air pressure load. At the same time, a negative pressure prevention valve is provided on the tank. This valve is used to open the intake air when negative pressure occurs in the tank, protecting the tank structure from damage due to excessive negative pressure. Beneficial effects

[0015] 1) In this invention, the temperature signal of the air separation device inlet fed back by the temperature sensor is jointly controlled by the host computer to control the temperature of the gas output from the induced draft and processing subsystem, so as to ensure that the temperature of the gas entering the air separation device is within its operating temperature range.

[0016] 2) In this invention, the pressure-sensitive flow regulating valve dynamically adjusts the valve opening by sensing the oil tank pressure and the external environmental pressure to achieve adaptive adjustment of the nitrogen-rich gas flow. This can maintain both the low oxygen concentration and the oil tank pressure required for operation, effectively reducing the number of downstream sensors monitoring the aircraft and oil tank status, simplifying the control logic of the equipment, and ensuring safety and efficiency.

[0017] 3) In this invention, the host computer controls the opening / closing of the active exhaust valve through the operation signals of the pilot or ground crew to achieve functions such as initial inertization of the equipment and refueling and exhaust.

[0018] 4) In this invention, the active exhaust valve opens to exhaust when the oil tank pressure reaches the preset boost value, the overpressure exhaust valve opens to exhaust when the oil tank is overpressured, and the anti-negative pressure valve opens to allow air in when the oil tank is under negative pressure, so as to ensure that the oil tank pressure is within the set range. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the composition of a preferred embodiment of the present invention.

[0020] Figure 2 This is a functional diagram of a preferred embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the air intake and processing subsystem in a preferred embodiment of the present invention.

[0022] Figure 4 This is a functional diagram of the air intake and processing subsystem in a preferred embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of the pressure-sensitive flow regulating valve structure in a preferred embodiment of the present invention. Implementation

[0024] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0025] See Figures 1-5 An airborne nitrogen generator with adaptive flow regulation of nitrogen-enriched gas includes a bleed air and treatment subsystem, a host computer connected to the bleed air and treatment subsystem, a temperature sensor, an air separator, a pressure-sensitive flow control valve, a one-way valve, a nitrogen-enriched gas distribution pipeline, an active exhaust valve, and an overpressure exhaust valve. The pilot or ground crew sends an operation signal to the host computer, which then activates the bleed air and treatment subsystem to receive engine bleed air from the engine and ram air from outside the aircraft. After being processed in the bleed air and treatment subsystem, the engine bleed air and ram air are sent to the air separator. The device includes a temperature sensor at the inlet of the air separator and a pressure-sensitive flow control valve at the nitrogen-rich gas outlet. The nitrogen-rich gas flows sequentially through the pressure-sensitive flow control valve, a one-way valve, and a nitrogen-rich gas distribution pipeline before finally entering each compartment of the fuel tank. After the nitrogen-rich gas entering the fuel tank compartment undergoes gas exchange with the gas in the gas phase space of the fuel tank, it is discharged from the fuel tank through an active exhaust valve or an overpressure exhaust valve installed on the fuel tank, thereby reducing the oxygen concentration in the gas phase space of the fuel tank compartment and inertizing the fuel tank. The temperature sensor and the active exhaust valve are respectively connected to the host computer.

[0026] In this embodiment, engine bleed air enters the mixing chamber of the bleed air and treatment subsystem through the hot circuit control valve, and ram air enters through the cold circuit control valve. After water removal by the water separator, it is sent to the air separation device, such as... Figure 4 As shown.

[0027] In this embodiment, a temperature sensor is installed at the inlet of the air separator to feed back the temperature signal to the host computer in real time. Based on this temperature signal, the host computer adjusts the opening of the hot circuit control valve and the cold circuit control valve in real time to ensure that the temperature of the gas entering the air separator is within its operating temperature range. Figure 2 As shown.

[0028] In this embodiment, the air separation device separates oxygen and nitrogen in the air into oxygen-rich gas and nitrogen-rich gas, with the oxygen-rich gas being discharged outside the machine.

[0029] In this embodiment, the pressure-sensitive flow control valve is installed at the nitrogen-rich gas outlet of the air separator, such as... Figure 5As shown, the black arrows indicate the gas flow direction. The system includes an upper diaphragm cavity 1, a diaphragm assembly 2, a lower diaphragm cavity 3, a valve body 4, a valve assembly 5, and a spring 6. One end of the valve body 4 has an inlet, and the other end has an outlet. The valve assembly 5 is located in the middle of the valve body 4, with its upper end connected to the diaphragm assembly 2. A spring 6 is installed at the lower end of the diaphragm assembly 2, and its other end is fixed to the valve body 4. The upper diaphragm cavity 1 is located at the top of the diaphragm assembly 2, and the lower diaphragm cavity 3 is located at the bottom of the diaphragm assembly 2. The lower diaphragm chamber 1 senses the oil tank pressure, and the lower diaphragm chamber 3 senses the ambient pressure. Under the pressure difference between the two, the diaphragm assembly 2 pushes the valve assembly 5 downward to achieve the function of real-time flow regulation. A spring 6 is installed at the lower end of the valve assembly 5. When the ambient pressure is equal to the oil tank pressure, that is, when the oil tank pressure is 0, the valve assembly 5 is in the initial position under the action of the spring 6. At this time, the valve assembly 5 has the largest opening. When the oil tank pressure reaches the preset pressure value, the diaphragm assembly 2 pushes the valve assembly 5 downward to the closed position.

[0030] A small flow orifice 7 is provided at the inlet of the valve body 4 of the pressure-sensitive flow regulating valve so that when the valve assembly 5 is in the closed position, the airborne nitrogen generator continuously supplies gas to the oil tank at a minimum nitrogen-rich gas flow rate, ensuring that the oil tank maintains the preset boost value and a low oxygen concentration.

[0031] In this embodiment, a one-way valve is installed at the outlet of the pressure-sensitive flow regulating valve to prevent fuel in the fuel tank from overflowing through the nitrogen-rich gas distribution pipeline.

[0032] In this embodiment, both the active vent valve and the overpressure vent valve can automatically open when the tank pressure exceeds a certain limit. The opening pressure of the active vent valve is equivalent to the preset boost pressure value. When the tank pressure reaches the opening pressure of the active vent valve, the active vent valve opens to release air, ensuring that the tank pressure remains within the preset boost pressure range. The opening pressure of the overpressure vent valve is higher than that of the active vent valve, and it is used to release air when the tank is overpressured, protecting the tank structure from excessive air pressure load. At the same time, an anti-negative pressure valve is provided on the tank. The anti-negative pressure valve is used to open the intake air when negative pressure occurs in the tank, protecting the tank structure from damage due to excessive negative pressure.

[0033] In this embodiment, the pilot sends an inerting signal to the host computer via the inerting switch in the cockpit. The host computer then controls the active exhaust valve to open, allowing the fuel tank's vapor space to communicate with the outside atmosphere through the venting pipe. At this time, the pressure-sensitive flow control valve introduces nitrogen-rich gas into the fuel tank at maximum flow rate to reduce the oxygen concentration in the fuel tank as quickly as possible. This stage is usually carried out on the ground and lasts for a period of time, known as the initial inerting stage. After the initial inerting stage ends, the host computer controls the active exhaust valve to close. Similarly, ground crew sends a refueling signal to the host computer via the fuselage refueling switch. The host computer also controls the active exhaust valve to open, allowing the fuel tank's vapor space to communicate with the outside atmosphere through the venting pipe, thus preventing excessive back pressure in the fuel tank from prolonging the refueling time.

[0034] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An airborne nitrogen-generating device with adaptive flow regulation of nitrogen-rich gas, comprising an air induction and processing subsystem, a host computer connected to the air induction and processing subsystem, a temperature sensor, an air separation device, a pressure-sensing flow regulating valve, a nitrogen-rich gas distribution pipeline, a positive air exhaust valve, and an oil tank, characterized in that, The bleed air and treatment subsystem receives engine bleed air from the engine and ram air from outside the engine block. After processing by the bleed air and treatment subsystem, the engine bleed air and ram air are sent to the air separator. A temperature sensor is installed at the inlet of the air separator, and a pressure-sensitive flow control valve is installed at the nitrogen-rich gas outlet of the air separator. The nitrogen-rich gas flows through the pressure-sensitive flow control valve and into the fuel tank through the nitrogen-rich gas distribution pipeline. After the nitrogen-rich gas entering the fuel tank undergoes gas exchange with the gas phase space inside the fuel tank, it is discharged from the fuel tank through the active exhaust valve installed on the fuel tank. The temperature sensor and the active exhaust valve are respectively connected to the host computer. The pressure-sensing flow control valve includes an upper diaphragm chamber for sensing tank pressure, a diaphragm assembly for moving a valve assembly, a lower diaphragm chamber for sensing ambient pressure, a valve body, a valve assembly, and a spring. The valve body has an inlet at one end and an outlet at the other. A valve assembly is located in the middle of the valve body, with its upper end connected to the diaphragm assembly. A spring is installed at the lower end of the diaphragm assembly, and the other end of the spring is fixed to the valve body. The diaphragm assembly has an upper diaphragm chamber at its upper part and a lower diaphragm chamber at its lower part.

2. The airborne nitrogen generator with adaptive flow rate adjustment for nitrogen-rich gas according to claim 1, characterized in that, The bleed air and treatment subsystem is equipped with a mixing chamber and a water separator. Engine bleed air enters the mixing chamber of the bleed air and treatment subsystem through the hot circuit control valve and ram air through the cold circuit control valve. After water is removed by the water separator, the air is sent to the air separation device.

3. The airborne nitrogen generator with adaptive flow rate adjustment for nitrogen-rich gas according to claim 1, characterized in that, A small flow orifice is provided at the inlet of the pressure-sensitive flow regulating valve body.

4. The airborne nitrogen generator with adaptive flow rate adjustment for nitrogen-rich gas according to claim 1, characterized in that, A one-way valve is installed at the outlet of the pressure-sensitive flow regulating valve.

5. An airborne nitrogen generator with adaptive flow rate adjustment for nitrogen-rich gas according to claim 1, characterized in that, The fuel tank is equipped with a negative pressure prevention valve.

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