Intelligent sleeve system and method for aircraft high temperature bleed air lines

Abstract

The application discloses an intelligent sleeve system for an aircraft high-temperature bleed air pipeline, which comprises a first fiber grating temperature sensor for monitoring the temperature at corresponding positions of an aircraft bleed air duct body through respective gratings to obtain distributed temperature data of the aircraft bleed air duct body, and a second fiber grating temperature sensor for monitoring the temperature at corresponding positions of a joint of the aircraft bleed air duct through respective gratings to obtain distributed temperature data of the joint of the aircraft bleed air duct; a bleed air duct temperature field construction module adopts an interpolation-based temperature field restoration algorithm to construct a bleed air duct temperature field model according to the distributed temperature data of the aircraft bleed air duct body and the distributed temperature data of the joint, utilizes the bleed air duct temperature field model to obtain temperature data of each point of the aircraft bleed air duct, and utilizes the temperature data of each point of the aircraft bleed air duct to determine a bleed air leakage condition. The application realizes rapid monitoring and positioning of aircraft bleed air pipeline leakage, and improves the reliability of leakage alarm.

Description

Technical Field

[0001] This invention relates to the field of aircraft high-temperature piping technology, specifically to an intelligent sleeve system and method for aircraft high-temperature bleed air piping. Background Technology

[0002] The aircraft air duct system is a crucial component of the aircraft air management system, and leaks can occur in the bleed air ducts during aircraft operation. If a high-temperature bleed air leak occurs due to a duct rupture or damage, it can expose control fan mounts, pressure floors, pressure beams, fuel vent boxes, or fuel lines to extremely high temperatures. This could lead to loss of rudder control and compromise the structural integrity of major structures or fuel ignition systems. Therefore, monitoring for high-pressure duct leaks is essential to protect aircraft systems, equipment, and structures around the leaking duct.

[0003] Aircraft bleed air ducts consist of an inner and outer tube, with an air layer sandwiched between them for insulation. High-temperature, high-pressure bleed air is transported within the inner tube. The outer tube, besides its protective insulation function, has a guide hole at regular intervals. When a bleed air leak occurs, the leaking hot air flows out through these guide holes, heating the surrounding air to an alarm threshold. This is then detected by a temperature-sensing component located above the guide hole, triggering a leak alarm. However, investigations show that the aircraft bleed air leak detection system may fail to detect leaks. Firstly, the gas flowing from the guide hole may not heat the temperature-sensing component above it to the alarm threshold. Secondly, since the temperature-sensing component is currently only installed above the bleed air duct, it may not detect leaks at the bottom of the duct or in other directions. For example, bleed air at the bleed air duct joint may leak in any direction.

[0004] With the increasing demands for aircraft safety in civil aviation standards, reducing the occurrence of leaks in aircraft bleed air duct monitoring and alarms, achieving rapid monitoring and location of leaks in aircraft bleed air ducts, and improving the reliability of leak alarms have become key technical challenges that urgently need to be addressed. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent sleeve system and method for aircraft high-temperature bleed air pipelines. This invention reduces the probability of leakage alarms and false alarms in aircraft bleed air pipeline leakage monitoring, realizes rapid monitoring and location of aircraft bleed air pipeline leaks, and improves the reliability of leakage alarms.

[0006] To achieve this objective, the present invention provides an intelligent sleeve system for high-temperature bleed air ducts in aircraft, comprising a bleed air duct temperature field construction module, an insulating sleeve fitted over the aircraft bleed air duct, a first fiber optic grating temperature sensor attached to the inner wall of the insulating sleeve, a temperature monitoring ring fitted over the aircraft bleed air duct connector, and a second fiber optic grating temperature sensor attached to the inner wall of the temperature monitoring ring, wherein the first fiber optic grating temperature sensor and the second fiber optic grating temperature sensor are connected. The first fiber optic temperature sensor monitors the temperature at corresponding locations on the aircraft bleed air duct body through each grating, thereby obtaining distributed temperature data of the aircraft bleed air duct body. The second fiber optic temperature sensor monitors the temperature at corresponding locations on the aircraft bleed air duct connector through each grating, thereby obtaining distributed temperature data of the aircraft bleed air duct connector. The air duct temperature field construction module is used to construct an air duct temperature field model based on the distributed temperature data of the aircraft air duct body and the distributed temperature data of the aircraft air duct joints using an interpolation-based temperature field restoration algorithm. The air duct temperature field model is used to obtain the temperature data of each point of the aircraft air duct, and the temperature data of each point of the aircraft air duct is used to determine the air leakage situation.

[0007] The beneficial effects of this invention are: This invention utilizes fiber optic temperature sensors installed inside the high-temperature bleed air duct of an aircraft to comprehensively and sensitively monitor for leaks in the bleed air system. This allows for the timely detection of even minute leaks, preventing safety hazards and performance degradation caused by leaks. The design of the insulating sleeve, which separates the air insulation layer from the external environment, effectively isolates the bleed air duct from the external environment, preventing the high-temperature bleed air duct from heating the surrounding air. The intelligent system enables real-time monitoring and location of bleed air duct temperature and leaks, reducing manual intervention and improving the timeliness and accuracy of monitoring. Timely detection and repair of leaks enhances the reliability of leak alarms, avoiding greater losses and maintenance costs caused by leaks. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the insulation sleeve structure of the present invention; Figure 3 This is a schematic diagram of the three-dimensional structure of the thermal insulation sleeve of the present invention; Figure 4 This is a diagram showing the unfolded inner wall of the insulation sleeve; Figure 5 This is a side view of the temperature monitoring ring; Figure 6 This is a diagram of the internal structure of the temperature monitoring loop; Figure 7 Diagram showing the connection between the temperature monitoring loop and the insulation sleeve; Figure 8 This is a flowchart of the present invention; Figure 9 This is a schematic diagram of the current aircraft bleed air duct structure; Figure 10 This is a temperature field diagram of the insulation sleeve; Among them, 1-insulating sleeve, 1.1-hinged ring, 1.2-rectangular insulation layer, 1.3-first buckle, 2-aircraft air duct, 3-first fiber Bragg grating temperature sensor, 4-temperature monitoring ring, 4.1-second buckle, 5-second fiber Bragg grating temperature sensor, 6-air insulation layer, 7-fiber optic connector. Detailed Implementation

[0009] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1 A smart sleeve system for high-temperature bleed air ducts in aircraft, such as Figure 1 , 2 As shown in Figures 3, 4, 5, 6, and 7, it includes a temperature field construction module for the air duct, an insulating sleeve 1 that is fitted over the aircraft air duct 2, a first fiber grating temperature sensor 3 that is attached to the inner wall of the insulating sleeve 1, a temperature monitoring ring 4 that is fitted over the joint of the aircraft air duct 2, and a second fiber grating temperature sensor 5 that is attached to the inner wall of the temperature monitoring ring 4. The first fiber grating temperature sensor 3 and the second fiber grating temperature sensor 5 are connected. The first fiber optic temperature sensor 3 monitors the temperature at corresponding positions on the body of the aircraft air duct 2 through each grating, thereby obtaining distributed temperature data of the body of the aircraft air duct 2. The second fiber optic temperature sensor 5 monitors the temperature at corresponding positions on the connector of the aircraft air duct 2 through each grating, thereby obtaining distributed temperature data of the connector of the aircraft air duct 2. The air duct temperature field construction module is used to construct an air duct temperature field model based on the distributed temperature data of the aircraft air duct 2 body and the distributed temperature data of the aircraft air duct 2 connector, using an interpolation-based temperature field restoration algorithm. The air duct temperature field model is used to obtain the temperature data of each point of the aircraft air duct 2, and the temperature data of each point of the aircraft air duct 2 is used to determine the air leakage situation. This design uses an interpolation-based temperature field restoration algorithm, which can use a limited number of distributed temperature data points to calculate the distribution of the entire duct temperature field, thus improving the accuracy and comprehensiveness of temperature monitoring.

[0010] In the above technical solution, the outer wall of the heat insulation sleeve 1 is fixed to the fuselage positioning plate outside the aircraft air duct 2, so that the heat insulation sleeve 1 is suspended outside the aircraft air duct 2. There is an air insulation layer 6 between the heat insulation sleeve 1 and the aircraft air duct 2 (the air insulation layer 6 is set because the temperature of the aircraft air duct 2 is too high, so it is easy to isolate it from the external environment and not affect the aircraft cabin environment, thus playing a protective and heat-insulating role). The joint of the heat insulation sleeve 1 is located outside the joint of the aircraft air duct 2. The temperature monitoring ring 4 is coaxially fixed at the joint of the heat insulation sleeve 1. There is an air insulation layer 6 between the temperature monitoring ring 4 and the aircraft air duct 2. The above design forms an effective heat insulation barrier through the air insulation layer 6 between the heat insulation sleeve 1 and the aircraft air duct 2, which can isolate the high temperature of the air duct and prevent it from being directly conducted to the fuselage or cabin interior, thereby protecting the cabin environment from the influence of high temperature.

[0011] In the above technical solution, the heat insulation sleeve 1 includes hinge rings 1.1 at both ends and a rectangular heat insulation layer 1.2 disposed between the hinge rings at both ends. After the hinge rings 1.1 at both ends are fastened by the first buckle 1.3, the rectangular heat insulation layer 1.2 is rolled into a sleeve shape. The first fiber optic temperature sensor 3 is attached to the inner wall of the rectangular heat insulation layer 1.2 in a triangular reciprocating manner, so that the rectangular heat insulation layer 1.2 can obtain the distributed temperature data of the aircraft air duct 2 after being rolled into a sleeve shape. (The first fiber optic temperature sensor 3 is attached to the inner wall of the heat insulation sleeve 1 and fixed by the mounting bracket; the inner wall of the heat insulation sleeve 1 is a spatial closed curved surface with a diameter d. When the inner wall of the heat insulation sleeve is unfolded, the unfolded two-dimensional shape is a two-dimensional shape with a length of L and a width of d.) A rectangle, To identify the effective distance for bleed air leakage; when When, that is, the number of wrapping turns is greater than or equal to When the first fiber optic temperature sensor is used, it can realize comprehensive monitoring of air leakage in the aircraft air duct 2. The above design is to facilitate the opening, closing, disassembly and assembly of the insulation sleeve 1.

[0012] In the above technical solution, the temperature monitoring ring 4 is provided with fiber optic connectors at both ends, and the first fiber optic temperature sensor 3 and the second fiber optic temperature sensor 5 are connected through fiber optic connector 7. The temperature monitoring ring 4 is a hinged monitoring ring. The second fiber optic temperature sensor 5 is reciprocated and attached to the inner wall of the hinged monitoring ring. The temperature monitoring ring 4 is secured by the second buckle 4.1. The second fiber optic temperature sensor 5 monitors the temperature at the corresponding position of the aircraft air duct 2 connector through each grating, thereby obtaining distributed temperature data at the aircraft air duct 2 connector. The above design, through the hinged design and the use of fiber optic connectors, makes the installation and maintenance of the temperature monitoring ring simpler and faster. When it is necessary to replace or repair the sensor, it is only necessary to perform plugging and unplugging operations through the fiber optic connectors, without disassembling the entire monitoring ring.

[0013] In the above technical solution, the specific method for constructing the bleed air duct temperature field model using the distributed temperature data of the aircraft bleed air duct 2 body and the distributed temperature data of the aircraft bleed air duct 2 connector, employing an interpolation-based temperature field restoration algorithm, is as follows: Let the temperature at any point on the inner wall of the insulation sleeve 1 and the temperature monitoring ring 4 be... , , Let n be the set of all points on the inner wall of the insulation sleeve 1 and the temperature monitoring ring 4. Assume the total number of gratings in the first fiber Bragg grating temperature sensor 3 and the second fiber Bragg grating temperature sensor 5 is n. At time t, acquire temperature data from n points on the inner wall of the insulation sleeve 1 and the temperature monitoring ring 4. , , Using these n points as sample functions, define the interpolation function. : in, This indicates the midpoint between insulation sleeve 1 and temperature monitoring ring 4. With point European distance, Weighting coefficients ( The weighting coefficients are calculated by inputting the temperature values ​​of the points acquired by the sensors into the difference model. For radial basis functions, , where α is the shape parameter of the radial basis function and e is the natural constant; function Interpolation conditions are met: Substituting the n sample points into the above equation, we get: make The above equation can be simplified to obtain the temperature field model of the expiratory duct as follows: ; The above design infers the temperature of unknown points by detecting the temperature of the points. From points to areas, the interpolation algorithm can use the temperature information of a finite number of known measuring points to mathematically calculate the temperature values ​​of other unknown points in the temperature field. This method does not rely on complete temperature field data and only requires a small number of known points. The interpolation algorithm is based on spatial relationships, assuming that the closer the points are in space, the more similar their temperature values ​​are. It is especially suitable for areas where the temperature field distribution is relatively uniform or changes relatively gently.

[0014] In the above technical solution, the linear combination coefficients are obtained by solving a system of linear equations. ,Will Substitute The interpolation model is obtained, which is the temperature field model of the air duct. The above design is used to obtain the temperature field model of the air duct.

[0015] In the above technical solution, the region where the temperature gradient in the bleed air duct temperature field model is greater than the threshold is the bleed air leakage region (under normal circumstances, the temperature gradient is two orders of magnitude smaller than the leakage). The temperature at the point where the temperature gradient is greater than the threshold is taken as the isotherm, and its isotherm profile is used to characterize the size and shape of the bleed air leakage. The above design achieves accurate positioning and quantitative characterization of the bleed air leakage region through temperature gradient analysis and isotherm profile analysis, providing strong support for subsequent maintenance work and helping to improve the overall performance and safety of the aircraft bleed air duct system.

[0016] Example 2 A smart sleeve method for high-temperature bleed air ducts in aircraft, such as Figure 8 As shown.

[0017] The specific method for using a smart sleeve in aircraft high-temperature bleed air ducts includes the following steps: The first fiber optic temperature sensor 3 monitors the temperature at corresponding positions on the body of the aircraft air duct 2 through each grating, thereby obtaining distributed temperature data of the body of the aircraft air duct 2. The second fiber optic temperature sensor 5 monitors the temperature at corresponding positions on the connector of the aircraft air duct 2 through each grating, thereby obtaining distributed temperature data of the connector of the aircraft air duct 2. Based on the distributed temperature data of the aircraft bleed air duct 2 body and the distributed temperature data of the aircraft bleed air duct 2 connector, a temperature field model of the bleed air duct is constructed using an interpolation-based temperature field restoration algorithm. The temperature data of each point of the aircraft bleed air duct 2 is obtained using the temperature field model of the bleed air duct 2, and the bleed air leakage situation is determined using the temperature data of each point of the aircraft bleed air duct 2.

[0018] Example 3 A smart sleeve system for high-temperature bleed air ducts in aircraft, such as Figure 2 , 3 As shown in Figure 9, it includes: Figure 9 This is a schematic diagram of the current aircraft bleed air duct structure, which mainly consists of the bleed air duct, a solid insulation layer, and flow guide holes. The function of the solid insulation layer is to isolate the high-temperature bleed air duct from the surrounding cabin environment. Flow guide holes are opened on the insulation layer. When the duct leaks, the leaked gas flows out from the flow guide holes and is eventually detected by the eutectic salt sensor. Figure 2 , Figure 3This is a schematic diagram of the structure of the insulating sleeve 1 designed based on the characteristics of fiber optic sensors in this invention: The insulating sleeve 1 has no flow guide holes, which simplifies the original duct structure; The insulating sleeve 1 uses air as the insulating layer material and uses thin-walled aerospace metal as the outer wall to isolate the air insulating layer from the external environment, which further simplifies the duct structure and reduces costs; The insulating sleeve 1 can be opened and closed vertically, and the first fiber optic grating temperature sensor 3 is attached to the inner wall of the insulating sleeve 1 in a triangular reciprocating pattern by installing a bracket on the inner wall of the insulating sleeve 1. The insulating sleeve 1 can be directly sleeved on the air duct 2, which greatly reduces the cabin space occupied by the air duct 2 and the leakage monitoring device.

[0019] Example 4 A smart sleeve system for high-temperature bleed air ducts in aircraft, such as Figure 10 As shown, it includes: The temperature field of the insulation sleeve is reconstructed in real time using an interpolation model. The temperature field of the insulation sleeve 10 seconds after conduit leakage is shown below. Figure 10 As shown, in the temperature field model of the bleed air duct, the region where the temperature gradient is greater than the threshold is the bleed air leakage region, and the region where the isotherm profile is greater than the quantization error is used to characterize the size and shape of the bleed air leakage. This method can realize leak monitoring of the bleed air duct without leak points and can achieve accurate leak location. At the same time, this method does not require waiting for the temperature to be heated to the threshold temperature before issuing an alarm, which greatly shortens the alarm response time.

[0020] Example 5 A computer program product includes a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the method described in Embodiment 2.

[0021] Example 6 A computer-readable storage medium storing a computer program, characterized in that: when the computer program is executed by a processor, it implements the steps of the method described in Embodiment 2.

[0022] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A smart sleeve system for high-temperature bleed air ducts in aircraft, characterized in that, It includes a temperature field construction module for the air duct, an insulating sleeve (1) fitted outside the aircraft air duct (2), a first fiber grating temperature sensor (3) attached to the inner wall of the insulating sleeve (1), a temperature monitoring ring (4) fitted at the joint of the aircraft air duct (2), and a second fiber grating temperature sensor (5) attached to the inner wall of the temperature monitoring ring (4). The first fiber grating temperature sensor (3) and the second fiber grating temperature sensor (5) are connected. The first fiber grating temperature sensor (3) monitors the temperature at the corresponding position of the aircraft bleed air duct (2) through each grating, thereby obtaining distributed temperature data of the aircraft bleed air duct (2) and the second fiber grating temperature sensor (5) monitors the temperature at the corresponding position of the aircraft bleed air duct (2) connector through each grating, thereby obtaining distributed temperature data of the aircraft bleed air duct (2) connector. The air duct temperature field construction module is used to construct the air duct temperature field model based on the distributed temperature data of the aircraft air duct (2) body and the distributed temperature data of the aircraft air duct (2) joint using an interpolation-based temperature field restoration algorithm. The air duct temperature field model is used to obtain the temperature data of each point of the aircraft air duct (2) and to use the temperature data of each point of the aircraft air duct (2) to determine the air leakage situation. The heat insulation sleeve (1) includes hinge rings (1.1) at both ends and a rectangular heat insulation layer (1.2) disposed between the hinge rings at both ends. After the hinge rings (1.1) at both ends are fastened by the first buckle (1.3), the rectangular heat insulation layer (1.2) is rolled into a sleeve shape. The first fiber optic temperature sensor (3) is attached to the inner wall of the rectangular heat insulation layer (1.2) in a triangular reciprocating manner, so that the rectangular heat insulation layer (1.2) can obtain the distributed temperature data of the body of the aircraft air duct (2) after being rolled into a sleeve shape.

2. The intelligent sleeve system for high-temperature bleed air ducts in aircraft according to claim 1, characterized in that: The outer wall of the heat insulation sleeve (1) is fixed to the fuselage positioning plate outside the aircraft air duct (2), so that the heat insulation sleeve (1) is suspended outside the aircraft air duct (2). There is an air insulation layer (6) between the heat insulation sleeve (1) and the aircraft air duct (2). The joint of the heat insulation sleeve (1) is located outside the joint of the aircraft air duct (2). The temperature monitoring ring (4) is coaxially fixed at the joint of the heat insulation sleeve (1). There is an air insulation layer (6) between the temperature monitoring ring (4) and the aircraft air duct (2).

3. The intelligent sleeve system for high-temperature bleed air ducts in aircraft according to claim 1, characterized in that: The temperature monitoring ring (4) is provided with fiber optic connectors at both ends, and the first fiber optic temperature sensor (3) and the second fiber optic temperature sensor (5) are connected through fiber optic connector (7). The temperature monitoring ring (4) is a hinged monitoring ring. The second fiber optic temperature sensor (5) is reciprocally attached to the inner wall of the hinged monitoring ring. The temperature monitoring ring (4) is secured by the second buckle (4.1). The second fiber optic temperature sensor (5) monitors the temperature at the corresponding position of the aircraft air duct (2) connector through each grating, thereby obtaining the distributed temperature data at the aircraft air duct (2) connector.

4. The intelligent sleeve system for high-temperature bleed air ducts in aircraft according to claim 1, characterized in that: The specific method for constructing the temperature field model of the bleed air duct (2) based on the distributed temperature data of the duct body and the distributed temperature data of the joint of the bleed air duct (2) using the interpolation-based temperature field restoration algorithm is as follows: Let the temperature at any point on the inner wall of the insulating sleeve (1) and the temperature monitoring ring (4) be . , , Let n be the set of all points on the inner wall of the insulation sleeve (1) and the temperature monitoring ring (4). Let the total number of gratings of the first fiber optic temperature sensor (3) and the second fiber optic temperature sensor (5) be n. Let the temperature data of n points on the inner wall of the insulation sleeve (1) and the temperature monitoring ring (4) be acquired at time t. , , Using these n points as sample functions, define the interpolation function. : in, This indicates the midpoint between the insulation sleeve (1) and the temperature monitoring ring (4). With point European distance, Weighting coefficients For radial basis functions, , where α is the shape parameter of the radial basis function and e is the natural constant; function Interpolation conditions are met: Substituting the n sample points into the above equation, we get: make The above equation can be simplified to obtain the temperature field model of the expiratory duct as follows: 。 5. The intelligent sleeve system for high-temperature bleed air ducts in aircraft according to claim 4, characterized in that: The coefficients of the linear combination are obtained by solving the system of linear equations. ,Will Substitute The interpolation model is obtained, which is the temperature field model of the air intake duct.

6. The intelligent sleeve system for high-temperature bleed air ducts in aircraft according to claim 4, characterized in that: In the temperature field model of the bleed air duct, the region where the temperature gradient is greater than the threshold is the bleed air leakage region. The temperature at the point where the temperature gradient is greater than the threshold is taken as the isotherm, and its isotherm profile is used to characterize the size and shape of the bleed air leakage.

7. A method for monitoring bleed air leakage in an aircraft high-temperature bleed air pipeline based on the system described in claim 1, characterized in that, It includes the following steps: The first fiber grating temperature sensor (3) monitors the temperature at the corresponding position of the aircraft bleed air duct (2) through each grating, thereby obtaining distributed temperature data of the aircraft bleed air duct (2) and the second fiber grating temperature sensor (5) monitors the temperature at the corresponding position of the aircraft bleed air duct (2) connector through each grating, thereby obtaining distributed temperature data of the aircraft bleed air duct (2) connector. Based on the distributed temperature data of the aircraft bleed air duct (2) body and the distributed temperature data of the aircraft bleed air duct (2) joint, a temperature field model of the bleed air duct is constructed using an interpolation-based temperature field restoration algorithm. The temperature data of each point of the aircraft bleed air duct (2) is obtained using the temperature field model of the bleed air duct, and the bleed air leakage situation is judged using the temperature data of each point of the aircraft bleed air duct (2).

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 7.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it implements the steps of the method as described in claim 7.

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