Inerting system for aircraft fuel tank

Abstract

An aircraft fuel tank inerting system comprises: an inerting gas separation device (100), the inerting gas separation device (100) comprising a to-be-separated gas inlet (110) and an inerting gas outlet (120); the aircraft fuel tank inerting system comprises an inerting gas separation device (100), an inerting gas outlet (120) and an inerting gas conveying pipeline (200), the inerting gas conveying pipeline (200) is in fluid connection with the inerting gas outlet (120) and used for introducing the inerting gas produced by the inerting gas separation device (100) into an aircraft fuel tank (300), and the aircraft fuel tank inerting system further comprises an injection device and a control device, and the injection device is configured to inject the cabin bleed air (420) by taking the engine bleed air (410) as an active flow and then convey the obtained air to the to-be-separated air inlet (110). According to the aircraft fuel tank inerting system, two strands of gas are introduced from the passenger cabin and the engine, and the jet pump is arranged on the upstream of the system, so that the temperature / pressure adjustment of engine bleed gas and passenger cabin bleed gas is realized at lower cost.

Description

Technical Field

[0001] The present invention relates to the field of aircraft design and manufacturing, more specifically to the field of explosion-proof technology of aircraft fuel tanks, and in particular to an aircraft fuel tank inerting system. Background Art

[0002] In aircraft design and manufacturing, it is generally necessary to provide inert gas to the aircraft fuel tank to provide a relatively stable environment for the fuel tank and the entire aircraft fuel system.

[0003] In order to ensure the supply of inert gas, airborne equipment is generally used to produce and supply inert gas. In the prior art, in order to obtain inert gas with the desired temperature and pressure, the following two technical routes can generally be used:

[0004] 1) Use engine bleed air alone as the inert gas source.

[0005] In this method, a conventional heat exchanger is generally used to adjust the bleed air temperature, and the outside air is generally used as the cold side of the heat exchanger. In order to introduce the outside air into the cold side channel of the heat exchanger, it is often necessary to open a hole in the fuselage skin and install a ram air intake and exhaust device.

[0006] This technical approach has the problems of heavy weight of the heat dissipation device, increased flight resistance due to holes in the fuselage, and large amounts of engine bleed air reducing engine performance.

[0007] 2) Use cabin bleed air alone as the source of inert gas.

[0008] In this method, an electric compressor is generally used to pressurize and heat the normal temperature bleed air.

[0009] This technical route has the problem of introducing high-power electric compressors, greatly increasing the power consumption of the inerting system, increasing the number of power-consuming equipment, and increasing the complexity of the control system.

[0010] On the other hand, in recent years, the application of high-temperature resistant air separators has significantly reduced the heat dissipation demand of the inerting system, while improving the nitrogen production capacity. Therefore, it is necessary to further explore and develop technical solutions to significantly reduce the weight of the inerting system and improve the operating efficiency of the aircraft by reducing the number or size of air separators and reducing or even eliminating heat dissipation devices.

[0011] An inerting system solution is disclosed in EP2915750A1, which adopts a cabin bleed air configuration and uses a single-stage booster of an electric compressor to increase the temperature and pressure of the air separator inlet. It is suitable for air separators with higher operating temperatures, wherein the operating temperature of the air separator is about 150°C and the optimal pressure ratio of the compressor is 2.5. This configuration can significantly reduce the number of boosting stages and heat dissipation requirements, reduce the complexity of the inerting system, and reduce the weight of the system. A heat exchanger is set on the outlet side of the air separator as needed to reduce the temperature of the nitrogen-rich gas and ensure the safety of the fuel tank. The cold source can be fuel or cabin bleed air. This document adopts a design based on an electric compressor for bleed air regulation and pure cabin bleed air.

[0012] EP3636552A1 discloses an inerting system solution, which uses a high-temperature configuration air separator. By increasing the working temperature of the air separator to 121°C-177°C, the separation performance of the air separator is significantly improved, the size of the air separator is reduced, and the size and weight of the corresponding temperature regulation subsystem are reduced. The nitrogen-rich gas temperature needs to be adjusted to below 93°C before entering the fuel tank to ensure the safety of the fuel tank. This configuration can significantly reduce the complexity of the inerting system and reduce the weight of the system. Some embodiments install a booster device upstream of the air separator to increase the inlet pressure of the air separator, some embodiments add a heater between the air separator and the heat exchanger to increase the gas temperature, and some embodiments set a bypass valve on the hot side of the heat exchanger to increase the gas temperature as needed. This document uses a traditional heat exchanger to adjust the engine bleed air temperature and the nitrogen-rich gas temperature, and it is necessary to introduce external environment ram air as a cold source.

[0013] US9327243B2 discloses an inerting system solution, which is suitable for air separators with higher operating temperatures (operating temperatures above 100°C). Through two sets of heat exchanger temperature control devices upstream and downstream of the air separator, both the operating temperature requirements of the air separator and the temperature limit of the nitrogen-rich gas entering the fuel tank are met. The air separator has better permeability under high-temperature operation. Under the same nitrogen-rich gas demand, the air separator has a small weight and volume, and the heat dissipation demand of the cooperating heat exchanger is small, which can also reduce weight. The document uses a heat exchanger to adjust the engine bleed air temperature and the nitrogen-rich gas temperature, and it is necessary to introduce external environment ram air as a cold source.

[0014] US20140053726A1 discloses an aircraft fuel tank flame retardant system, which is implemented through a variety of inerting system architectures based on high-temperature carbon-based air separators. The operating temperature range of the air separator is 120℃-195℃. A heat exchanger is set between the pressure source and the air separator as needed to adjust the air bleed temperature at the air separator inlet, and a heat exchanger is set between the air separator outlet and the fuel tank to adjust the nitrogen-rich gas temperature to ensure the safety of the fuel tank. The document uses a heat exchanger to adjust the engine bleed air temperature and the nitrogen-rich gas temperature.

[0015] US20180290761A1 discloses an inerting system, which uses an electric compressor to increase the inlet temperature of the air separator and directly supplies nitrogen to the air separator. It does not need to draw air from the external atmospheric environment to participate in heat dissipation, cancels the environmental ram pressure intake and exhaust device, and simplifies the system architecture. At the same time, a turbine coaxial with the electric compressor is set on the outlet side of the air separator to recover the energy of the nitrogen-rich gas, reduce the overall power consumption, reduce the temperature of the nitrogen-rich gas, and ensure the safety of the fuel tank. The operating temperature range of the air separator used in this document is 100℃-140℃. This comparative document adopts a design based on an electric compressor for bleed air regulation and uses pure cabin bleed air.

[0016] CN112960126B discloses a low-temperature fuel tank inerting system and its working method, which uses a turbocharger to expand the downstream nitrogen-rich gas through the turbine to reduce the temperature of the nitrogen-rich gas, while driving a coaxial compressor to increase the inlet gas pressure of the upstream air separator, and at the same time drives a fan located at the outlet side of the cold side of the heat exchanger to strengthen the heat dissipation of the cold side of the heat exchanger. This reference document uses a traditional heat exchanger to adjust the engine bleed air temperature, and needs to introduce external environment ram air as a cold source.

[0017] From the above analysis, it can be seen that the existing technology generally adopts a bleed air temperature regulation design based on a heat exchanger, in which the hot side air source is the high-temperature bleed air of the engine, and the cold side needs to introduce external environment ram air as a cold source, or use an electric compressor to boost the pressure and temperature of the normal temperature bleed air from the cabin.

[0018] Specifically, one design can adopt a bleed air regulation system based on a heat exchanger, while the other design does not involve a heat exchanger but requires the introduction of an electric supercharger, which increases the system's power consumption and control difficulty, and the bleed air is only a single-path bleed air to the cabin. Summary of the invention

[0019] Based on the deficiencies of the current technical solutions, the present invention provides an aircraft fuel tank inerting system, which introduces two streams of gas from the cabin and the engine and arranges an ejection device upstream of the system, thereby achieving temperature / pressure regulation of the engine bleed air and the cabin bleed air at a lower cost.

[0020] To this end, the present invention provides an aircraft fuel tank inerting system.

[0021] include:

[0022] an inert gas separation device, the inert gas separation device comprising an inlet for a gas to be separated and an inert gas outlet; and

[0023] an inert gas delivery pipeline, the inert gas delivery pipeline being fluidly connected to the inert gas outlet and used for passing the inert gas produced by the inert gas separation device into the aircraft fuel tank,

[0024] The aircraft fuel tank inerting system also includes:

[0025] The ejector device is configured to use the engine bleed air as an active flow to eject the cabin bleed air, and then deliver the resulting gas to the inlet of the gas to be separated.

[0026] By providing the ejector device, the different characteristics of the engine bleed air and the cabin bleed air can be fully utilized to obtain the gas to be inerted with the desired pressure and temperature at a relatively low cost.

[0027] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, the ejection device includes an ejection pump, which transports the gas obtained by mixing the engine bleed air and the cabin bleed air in the diffuser chamber to the gas inlet to be separated.

[0028] As an ejection device with practical advantages, the ejection pump can further contribute to the manufacturing and maintenance costs of the aircraft fuel tank inerting system of the present invention, and its mixing functional characteristics are more suitable for the ejection object required by the present invention.

[0029] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, the ejector pump is configured such that the pressure of the gas obtained after blending is in a range of 25 psia to 45 psia.

[0030] The gas in this pressure range can meet the actual needs of the inerting system under the actual operating conditions of the aircraft and conform to the physical properties of the ejection object itself.

[0031] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, the inerting gas separation device is a hollow fiber membrane air separator capable of producing nitrogen-rich gas as the inerting gas.

[0032] This particular type of inerting gas separation device makes it possible to better utilize the gas obtained by upstream blending for the desired inerting.

[0033] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, the operating temperature range of the inerting gas separation device is 100°C to 140°C.

[0034] This high-temperature inert gas separation device can better adapt to the working environment of the aircraft fuel tank inerting system, and is conducive to improving the stability and reliability of the system.

[0035] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, a first one-way valve is provided on the cabin bleed air passage for introducing the cabin bleed air into the ejector device to prevent the gas on one side of the ejector device from flowing back into the cabin.

[0036] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, a second one-way valve is provided on the inerting gas delivery pipeline to prevent the gas on one side of the fuel tank from flowing back to the inerting gas separation device.

[0037] The provision of the above two types of one-way valves is helpful in avoiding interference and adverse effects of the downstream inerting system gas diversion on the fuel tank and the cabin.

[0038] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, a controllable isolation valve is provided on a cabin bleed air passage for introducing the cabin bleed air into the ejection device and / or an engine bleed air passage for introducing the engine bleed air into the ejection device.

[0039] The provision of the above-mentioned isolation valve is further helpful in avoiding interference and adverse effects of the downstream inerting system gas diversion on the fuel tank and the cabin.

[0040] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, a heat exchanger is provided on the inerting gas delivery pipeline, and the heat exchanger is configured to use the cabin bleed air as a cold side and the inerting gas as a hot side.

[0041] The heat exchanger can better utilize the heat source in the system, thereby helping to reduce the aircraft's heat exchange energy consumption.

[0042] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, a turbofan mechanism driven by the inerting gas is provided on the inerting gas delivery pipeline.

[0043] By arranging a turbofan mechanism on the inert gas delivery pipeline, the kinetic energy of the inert gas can be better utilized, which is beneficial to reducing the driving energy consumption of the onboard components of the aircraft.

[0044] According to a preferred embodiment of the aircraft fuel tank inerting system of the present invention, the ejection device includes a primary ejection pump and a secondary ejection pump, the primary ejection pump is configured to eject and pressurize the cabin bleed air using the engine bleed air as an active flow to obtain primary ejection gas, and the secondary ejection pump is configured to eject and pressurize the primary ejection gas using the engine bleed air as an active flow to obtain secondary ejection gas, and then deliver the obtained gas to the gas inlet to be separated.

[0045] The two-stage arrangement of the ejector helps to better utilize the characteristics of the ejector gas and the ejected gas

[0046] In summary, the technical advantages of various preferred embodiments of the aircraft fuel tank inerting system according to the present invention are at least:

[0047] 1) Eliminate the traditional heat dissipation device, reduce the system weight, and reduce the openings in the fuselage skin, reduce the aircraft's flight resistance, and improve the aircraft's overall efficiency;

[0048] 2) Using the internal energy differences of different gas sources to complete temperature and pressure regulation, without consuming electrical energy, avoiding the introduction of high-power electrical equipment, reducing the number of electrical equipment, and reducing the complexity of the inerting system; and

[0049] 3) Nitrogen-rich gas heat dissipation does not require ram air, but can utilize its own or the aircraft’s own secondary energy to reduce the overall energy consumption of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] This document includes the accompanying drawings to provide a further understanding of the various embodiments, and the accompanying drawings are incorporated in and constitute a part of this specification.

[0051] The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.

[0052] With reference to the above objects, the technical features of the present invention are clearly described hereinafter, and advantages thereof are apparent from the following detailed description with reference to the accompanying drawings, which illustrate preferred embodiments of the present invention by way of example without limiting the scope of the present invention.

[0053] In the attached figure:

[0054] Figure 1 Detailed description of the invention is given in Figure 1. It is a schematic structural block diagram of a first preferred embodiment of an aircraft fuel tank inerting system according to the present invention.

[0055] Figure 2 4 is a schematic structural block diagram of a second preferred embodiment of an aircraft fuel tank inerting system according to the present invention.

[0056] Figure 3 4 is a schematic structural block diagram of a third preferred embodiment of an aircraft fuel tank inerting system according to the present invention.

[0057] Figure 4 4 is a schematic structural block diagram of a fourth preferred embodiment of an aircraft fuel tank inerting system according to the present invention.

[0058] Reference numerals list

[0059] 100 Inert gas separation device

[0060] 110 Inlet for gas to be separated

[0061] 120 Inert gas outlet

[0062] 200 Inert gas delivery pipeline

[0063] 210 Second check valve

[0064] 220 Heat exchanger

[0065] 230 Turbofan Mechanism

[0066] 240 Nitrogen-rich gas flow control valve

[0067] 300 Aircraft fuel tank

[0068] 410 Engine Bleed Air

[0069] 420 Cabin bleed air

[0070] 430 Ejector Pump

[0071] 430A One-stage ejector pump

[0072] 430B Two-stage ejector pump

[0073] 500 Cabin bleed air duct

[0074] 510 First check valve

[0075] 600 Engine bleed air passage

[0076] 700 Controllable Isolation Valve DETAILED DESCRIPTION

[0077] Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below.

[0078] Although the present invention will be described in conjunction with exemplary embodiments, it should be appreciated that this specification is not intended to limit the present invention to those exemplified embodiments. On the contrary, the present invention is intended to cover not only these exemplary embodiments, but also various alternative forms, modifications, equivalent forms and other embodiments that may be included within the spirit and scope of the present invention.

[0079] To facilitate explanation and accurately define the technical solutions of the present invention, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments shown in the drawings with reference to their positions.

[0080] Various preferred but non-limiting embodiments of the aircraft fuel tank inerting system of the present invention will be described in detail below with reference to the accompanying drawings.

[0081] First reference Figure 1, an aircraft fuel tank inerting system according to a first preferred embodiment of the present invention is described. The aircraft fuel tank inerting system comprises: an inerting gas separation device 100, an inerting gas delivery pipeline 200 and an ejector device.

[0082] The inert gas separation device 100 includes a gas inlet 110 for introducing the gas to be separated and an inert gas outlet 120 for conducting the inert gas. Figure 1 In the preferred embodiment shown in FIG. 1 , the inert gas separation device 100 is a hollow fiber membrane air separator capable of producing nitrogen-rich gas as the inert gas. In a more preferred embodiment, the air separator is a high temperature resistant type, and the operating temperature range of the high temperature resistant air separator may be, for example, 100° C. to 140° C. However, it should be noted that those skilled in the art can understand that other air separators may also be used here to only realize the separation function of the inert gas itself.

[0083] The inert gas delivery pipeline 200 is fluidically connected to the inert gas outlet 120 for passing the inert gas produced by the inert gas separation device 100 into the aircraft fuel tank 300 .

[0084] The ejector device is configured to eject the cabin bleed air 420 using the engine bleed air 410 as an active flow, and then deliver the resulting gas to the gas inlet 110 to be separated. Figure 1 As shown in , preferably, the ejector device may include an ejector pump 430, and the ejector pump 430 delivers the gas obtained by mixing the engine bleed air 410 and the cabin bleed air 420 in the diffuser chamber to the gas inlet 110 to be separated. More specifically, in a preferred embodiment, the ejector pump 430 is configured so that the pressure of the gas obtained after mixing can range from 25psia to 45psia.

[0085] like Figure 1 As shown in , in a preferred embodiment, a first one-way valve 510 may be provided on the cabin bleed air passage 500 that introduces the cabin bleed air 420 into the ejector device to prevent the gas on one side of the ejector device from flowing back into the cabin.

[0086] See also Figure 1 In a preferred embodiment, a second one-way valve 210 may be provided on the inert gas delivery pipeline 200 to prevent the gas on one side of the fuel tank 300 from flowing back to the inert gas separation device 100 .

[0087] In addition, if Figure 1 As shown in FIG. 2 , a nitrogen-rich gas flow control valve 240 may be provided upstream of the second one-way valve 210 to allow the output flow of the nitrogen-rich gas to be adjusted as desired.

[0088] A controllable isolation valve 700 is provided on the cabin bleed air passage 500 for introducing the cabin bleed air 420 into the ejection device and / or the engine bleed air passage 600 for introducing the engine bleed air 410 into the ejection device.

[0089] The following reference Figure 1 The first preferred embodiment briefly describes its working process:

[0090] First, the cabin bleed air 420 enters the ejector pump 430 through the controllable isolation valve 700 and the first non-return valve 510 at its downstream.

[0091] Furthermore, the engine bleed air 410 enters the ejector pump 430 as an active flow through the controllable isolation valve 700 downstream thereof.

[0092] Next, the gas from the ejector pump 430 enters the inert gas separation device 100. The inert gas separation device 100 generates oxygen-rich gas and nitrogen-rich gas.

[0093] After that, the oxygen-rich gas is discharged from the oxygen-rich gas exhaust pipe ( Figure 1 The nitrogen-rich gas enters the second check valve 210 through the nitrogen-rich gas flow control valve 240 and finally enters the fuel tank 300.

[0094] The following references Figure 2 , an aircraft fuel tank inerting system according to a first preferred embodiment of the present invention is described. The aircraft fuel tank inerting system comprises: an inerting gas separation device 100, an inerting gas delivery pipeline 200 and an ejector device.

[0095] The inert gas separation device 100 includes a gas inlet 110 for introducing the gas to be separated and an inert gas outlet 120 for conducting the inert gas. Figure 2 In the preferred embodiment shown in FIG. 1 , the inert gas separation device 100 is a hollow fiber membrane air separator capable of producing nitrogen-rich gas as the inert gas. In a more preferred embodiment, the air separator is a high temperature resistant type, and the operating temperature range of the high temperature resistant air separator may be, for example, 100° C. to 140° C. However, it should be noted that those skilled in the art can understand that other air separators may also be used here to only realize the separation function of the inert gas itself.

[0096] The inert gas delivery pipeline 200 is fluidically connected to the inert gas outlet 120 for passing the inert gas produced by the inert gas separation device 100 into the aircraft fuel tank 300 .

[0097] The ejector device is configured to eject the cabin bleed air 420 using the engine bleed air 410 as an active flow, and then deliver the resulting gas to the gas inlet 110 to be separated. Figure 2As shown in , preferably, the ejector device may include an ejector pump 430, and the ejector pump 430 delivers the gas obtained by mixing the engine bleed air 410 and the cabin bleed air 420 in the diffuser chamber to the gas inlet 110 to be separated. More specifically, in a preferred embodiment, the ejector pump 430 is configured so that the pressure of the gas obtained after mixing can range from 25psia to 45psia.

[0098] like Figure 2 As shown in , in a preferred embodiment, a first one-way valve 510 may be provided on the cabin bleed air passage 500 that introduces the cabin bleed air 420 into the ejector device to prevent the gas on one side of the ejector device from flowing back into the cabin.

[0099] See also Figure 2 In a preferred embodiment, a second one-way valve 210 may be provided on the inert gas delivery pipeline 200 to prevent the gas on one side of the fuel tank 300 from flowing back to the inert gas separation device 100 .

[0100] In addition, if Figure 2 As shown in FIG. 2 , a nitrogen-rich gas flow control valve 240 may be provided upstream of the second one-way valve 210 to allow the output flow of the nitrogen-rich gas to be adjusted as desired.

[0101] A controllable isolation valve 700 is provided on the cabin bleed air passage 500 for introducing the cabin bleed air 420 into the ejection device and / or the engine bleed air passage 600 for introducing the engine bleed air 410 into the ejection device.

[0102] exist Figure 2 In the preferred embodiment shown in , a heat exchanger 220 may be provided on the inert gas delivery pipeline 200 , and the heat exchanger 220 is configured to use the cabin bleed air 420 as a cold side and the inert gas as a hot side.

[0103] The following reference Figure 2 The second preferred embodiment in briefly describes its working process:

[0104] First, the cabin bleed air 420 enters the ejector pump 430 through the controllable isolation valve 700 and the first non-return valve 510 at its downstream.

[0105] Furthermore, the engine bleed air 410 enters the ejector pump 430 as an active flow through the controllable isolation valve 700 downstream thereof.

[0106] Next, the gas from the ejector pump 430 enters the inert gas separation device 100. The inert gas separation device 100 generates oxygen-rich gas and nitrogen-rich gas.

[0107] Furthermore, the outlet of the nitrogen-rich gas flow control valve 240 is connected to the heat exchanger 220 , and the airflow on the cold side of the heat exchanger 220 may originate from the cabin exhaust gas.

[0108] After that, the oxygen-rich gas is discharged from the oxygen-rich gas exhaust pipe ( Figure 2 The nitrogen-rich gas cools down and enters the second one-way valve 210, and finally enters the fuel tank 300.

[0109] The following references Figure 3 , an aircraft fuel tank inerting system according to a third preferred embodiment of the present invention is described. The aircraft fuel tank inerting system comprises: an inerting gas separation device 100, an inerting gas delivery pipeline 200 and an ejector device.

[0110] The inert gas separation device 100 includes a gas inlet 110 for introducing the gas to be separated and an inert gas outlet 120 for conducting the inert gas. Figure 3 In the preferred embodiment shown in FIG. 1 , the inert gas separation device 100 is a hollow fiber membrane air separator capable of producing nitrogen-rich gas as the inert gas. In a more preferred embodiment, the air separator is a high temperature resistant type, and the operating temperature range of the high temperature resistant air separator may be, for example, 100° C. to 140° C. However, it should be noted that those skilled in the art can understand that other air separators may also be used here to only realize the separation function of the inert gas itself.

[0111] The inert gas delivery pipeline 200 is fluidically connected to the inert gas outlet 120 for passing the inert gas produced by the inert gas separation device 100 into the aircraft fuel tank 300 .

[0112] The ejector device is configured to eject the cabin bleed air 420 using the engine bleed air 410 as an active flow, and then deliver the resulting gas to the gas inlet 110 to be separated. Figure 3 As shown in , preferably, the ejector device may include an ejector pump 430, and the ejector pump 430 delivers the gas obtained by mixing the engine bleed air 410 and the cabin bleed air 420 in the diffuser chamber to the gas inlet 110 to be separated. More specifically, in a preferred embodiment, the ejector pump 430 is configured so that the pressure of the gas obtained after mixing can range from 25psia to 45psia.

[0113] like Figure 3 As shown in , in a preferred embodiment, a first one-way valve 510 may be provided on the cabin bleed air passage 500 that introduces the cabin bleed air 420 into the ejector device to prevent the gas on one side of the ejector device from flowing back into the cabin.

[0114] See also Figure 3 In a preferred embodiment, a second one-way valve 210 may be provided on the inert gas delivery pipeline 200 to prevent the gas on one side of the fuel tank 300 from flowing back to the inert gas separation device 100 .

[0115] In addition, if Figure 3 As shown in FIG. 2 , a nitrogen-rich gas flow control valve 240 may be provided upstream of the second one-way valve 210 to allow the output flow of the nitrogen-rich gas to be adjusted as desired.

[0116] A controllable isolation valve 700 is provided on the cabin bleed air passage 500 for introducing the cabin bleed air 420 into the ejection device and / or the engine bleed air passage 600 for introducing the engine bleed air 410 into the ejection device.

[0117] exist Figure 3 In the third preferred embodiment shown in , a heat exchanger 220 may be provided on the inert gas delivery pipeline 200 , and a turbofan mechanism 230 driven by the inert gas may be provided on the inert gas delivery pipeline 200 .

[0118] The following reference Figure 3 The third preferred embodiment briefly describes its working process:

[0119] First, the cabin bleed air 420 enters the ejector pump 430 through the controllable isolation valve 700 and the first non-return valve 510 at its downstream.

[0120] Furthermore, the engine bleed air 410 enters the ejector pump 430 as an active flow through the controllable isolation valve 700 downstream thereof.

[0121] Next, the gas from the ejector pump 430 enters the inert gas separation device 100. The inert gas separation device 100 generates oxygen-rich gas and nitrogen-rich gas.

[0122] Furthermore, the outlet of the nitrogen-rich gas flow control valve 240 is connected to the heat exchanger 220 , and the airflow at the cold side of the heat exchanger 220 may come from a turbofan driven by the nitrogen-rich gas.

[0123] After that, the oxygen-rich gas is discharged from the oxygen-rich gas exhaust pipe ( Figure 3 The nitrogen-rich gas cools down and enters the second one-way valve 210, and finally enters the fuel tank 300.

[0124] The following references Figure 4 , an aircraft fuel tank inerting system according to a fourth preferred embodiment of the present invention is described. The aircraft fuel tank inerting system comprises: an inerting gas separation device 100, an inerting gas delivery pipeline 200 and an ejector device.

[0125] The inert gas separation device 100 includes a gas inlet 110 for introducing the gas to be separated and an inert gas outlet 120 for conducting the inert gas. Figure 4In the preferred embodiment shown in FIG. 1 , the inert gas separation device 100 is a hollow fiber membrane air separator capable of producing nitrogen-rich gas as the inert gas. In a more preferred embodiment, the air separator is a high temperature resistant type, and the operating temperature range of the high temperature resistant air separator may be, for example, 100° C. to 140° C. However, it should be noted that those skilled in the art can understand that other air separators may also be used here to only realize the separation function of the inert gas itself.

[0126] The inert gas delivery pipeline 200 is fluidically connected to the inert gas outlet 120 for passing the inert gas produced by the inert gas separation device 100 into the aircraft fuel tank 300 .

[0127] The ejector device is configured to eject the cabin bleed air 420 using the engine bleed air 410 as an active flow, and then deliver the resulting gas to the gas inlet 110 to be separated. Figure 4 As shown in , preferably, the ejector device may include an ejector pump 430, and the ejector pump 430 delivers the gas obtained by mixing the engine bleed air 410 and the cabin bleed air 420 in the diffuser chamber to the gas inlet 110 to be separated. More specifically, in a preferred embodiment, the ejector pump 430 is configured so that the pressure of the gas obtained after mixing can range from 25psia to 45psia.

[0128] like Figure 4 As shown in , in a preferred embodiment, a first one-way valve 510 may be provided on the cabin bleed air passage 500 that introduces the cabin bleed air 420 into the ejector device to prevent the gas on one side of the ejector device from flowing back into the cabin.

[0129] See also Figure 4 In a preferred embodiment, a second one-way valve 210 may be provided on the inert gas delivery pipeline 200 to prevent the gas on one side of the fuel tank 300 from flowing back to the inert gas separation device 100 .

[0130] In addition, if Figure 4 As shown in FIG. 2 , a nitrogen-rich gas flow control valve 240 may be provided upstream of the second one-way valve 210 to allow the output flow of the nitrogen-rich gas to be adjusted as desired.

[0131] A controllable isolation valve 700 is provided on the cabin bleed air passage 500 for introducing the cabin bleed air 420 into the ejection device and / or the engine bleed air passage 600 for introducing the engine bleed air 410 into the ejection device.

[0132] exist Figure 4In the preferred embodiment shown in , the ejection device may include a primary ejection pump 430A and a secondary ejection pump 430B. The primary ejection pump 430A is configured to eject and pressurize the cabin bleed air 420 using the engine bleed air 410 as an active flow to obtain primary ejection gas, and the secondary ejection pump 430B is configured to eject and pressurize the primary ejection gas using the engine bleed air 410 as an active flow to deliver the obtained gas to the gas inlet 110 to be separated.

[0133] The following reference Figure 4 The fourth preferred embodiment briefly describes its working process:

[0134] First, the cabin bleed air 420 enters the ejector pump 430 through the controllable isolation valve 700 and the first non-return valve 510 at its downstream.

[0135] The controllable isolation valve 700 downstream of the engine bleed air 410 is divided into two branches, one of which is connected to the primary ejector pump 430A and the other is connected to the secondary ejector pump 430B. This structure allows the outlet airflow of the primary ejector pump 430A to enter the secondary ejector pump 430B for continued pressurization.

[0136] Next, the gas from the secondary ejector pump 430B enters the inert gas separation device 100. The inert gas separation device 100 generates oxygen-rich gas and nitrogen-rich gas.

[0137] After that, the oxygen-rich gas is discharged from the oxygen-rich gas exhaust pipe ( Figure 4 The nitrogen-rich gas enters the second check valve 210 through the nitrogen-rich gas flow control valve 240 and finally enters the fuel tank 300.

[0138] Finally, those skilled in the art can combine the independent technical features of the four preferred embodiments described above according to actual needs, and the obtained results are still included in the protection scope of the present invention.

[0139] Preferred embodiments of the present invention have been described above in detail, but it should be understood that aspects of the embodiments can be modified, if necessary, to employ aspects, features and concepts of the various patents, applications and publications to provide further embodiments.

[0140] Various changes can be readily appreciated in light of the above detailed description, and can be made to the embodiments described herein.

[0141] In general, in the claims, the terms used should not be considered limited to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which the claims are entitled.

Claims

1. An aircraft fuel tank inerting system, include: An inert gas separation device (100), the inert gas separation device (100) comprising an inlet (110) for a gas to be separated and an inert gas outlet (120); and an inert gas delivery pipeline (200), the inert gas delivery pipeline (200) being fluidically connected to the inert gas outlet (120) and used for passing the inert gas produced by the inert gas separation device (100) into the aircraft fuel tank (300), It is characterized in that The aircraft fuel tank inerting system also includes: An ejector device is configured to eject the cabin bleed air (420) using the engine bleed air (410) as an active flow, and then deliver the resulting gas to the inlet (110) for the gas to be separated.

2. The aircraft fuel tank inerting system according to claim 1, It is characterized in that The ejector device comprises an ejector pump (430), and the ejector pump (430) transports the gas obtained by mixing the engine bleed air (410) and the cabin bleed air (420) in the diffuser chamber to the gas inlet (110) to be separated.

3. The aircraft fuel tank inerting system according to claim 2, It is characterized in that The ejector pump (430) is configured such that the pressure of the gas obtained after blending is in the range of 25 psia to 45 psia.

4. The aircraft fuel tank inerting system according to claim 1, It is characterized in that The inert gas separation device (100) is a hollow fiber membrane air separator capable of producing nitrogen-rich gas as inert gas.

5. The aircraft fuel tank inerting system according to claim 1, It is characterized in that The operating temperature range of the inert gas separation device (100) is 100°C to 140°C.

6. The aircraft fuel tank inerting system according to claim 1, It is characterized in that A first non-return valve (510) is provided on a cabin bleed air passage (500) for introducing the cabin bleed air (420) into the ejector device, so as to prevent the gas on one side of the ejector device from flowing back into the cabin. and / or A second one-way valve (210) is provided on the inert gas delivery pipeline (200) to prevent the gas on one side of the fuel tank (300) from flowing back to the inert gas separation device (100).

7. The aircraft fuel tank inerting system according to claim 1, It is characterized in that A controllable isolation valve (700) is provided on a cabin bleed air passage (500) for introducing the cabin bleed air (420) into the ejector device and / or an engine bleed air passage (600) for introducing the engine bleed air (410) into the ejector device.

8. The aircraft fuel tank inerting system according to claim 1, It is characterized in that A heat exchanger (220) is arranged on the inert gas delivery pipeline (200), and the heat exchanger (220) is configured to use the cabin bleed air (420) as a cold side and the inert gas as a hot side.

9. The aircraft fuel tank inerting system according to claim 8, It is characterized in that A turbofan mechanism (230) driven by the inert gas is arranged on the inert gas delivery pipeline (200).

10. The aircraft fuel tank inerting system according to claim 1, It is characterized in that The ejection device comprises a primary ejection pump (430A) and a secondary ejection pump (430B), wherein the primary ejection pump (430A) is configured to eject and pressurize the cabin bleed air (420) using the engine bleed air (410) as an active flow to obtain primary ejection gas, and the secondary ejection pump (430B) is configured to eject and pressurize the primary ejection gas using the engine bleed air (410) as an active flow to deliver the obtained gas to the inlet (110) for the gas to be separated.

Images