Engine plume fault diagnosis device and method

Abstract

The invention discloses an engine plume fault diagnosis device and method, and relates to the field of engine detection, and the device comprises a light path unit which comprises a first pinhole end cap, a first lens, a dichroscope, a second lens and a second pinhole end cap which are sequentially arranged in the plume collection direction; the laser unit is used for emitting laser beams to the dichroscope of the light path unit; the laser beam is reflected by the dichroscope and then is transmitted to the first pinhole end cap along the reverse direction of the plume acquisition direction; the acquisition unit is used for receiving the laser beam transmitted by the first pinhole end cap and focusing the laser beam to the tail flame of the engine so as to generate breakdown sparks on the tail flame of the engine; a spark optical signal generated by the breakdown spark is acquired, and the spark optical signal is transmitted to the second pinhole end cap along the plume acquisition direction; and the control unit is used for receiving the spark optical signal transmitted by the second pinhole end cap and determining the plume fault of the engine based on the spark optical signal.

Description

Technical Field

[0001] This invention relates to the field of engine testing, and more particularly to an engine plume fault diagnosis device and method. Background Technology

[0002] Developing high-thrust hydrocarbon fuel engines requires reliable engine health monitoring during ground testing. During hot-fire testing, internal engine components may experience wear, ablation, or other malfunctions. Some metallic impurities will rapidly enter the engine plume along with combustion products through the thrust chamber. The high temperature of the plume atomizes the metal elements, and the outer electron transitions of these metal atoms emit characteristic spectra. Therefore, spectroscopic analysis of the engine plume is a crucial method for detecting internal engine wear, ablation, and other malfunctions.

[0003] Traditional plume spectroscopy detection methods utilize atomic emission spectra. However, in scenarios such as turbopump joint testing or semi-system commissioning, the low temperature of the plume prevents the outer electrons of metal atoms from reaching an excited state, making it difficult for interstage electron transitions to occur, thus resulting in the inability to detect emission lines. Summary of the Invention

[0004] In view of the above-mentioned technical status, the present invention provides an engine plume fault diagnosis device and method to solve the problem that in turbopump joint testing or semi-system testing scenarios, due to the low temperature of the exhaust plume, the outer electrons of metal atoms cannot reach the excited state, making it difficult for interstage electron transitions to occur, resulting in the inability to detect emission spectral lines.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An engine plume fault diagnosis device includes: a control unit, a laser unit, an optical path unit, and a data acquisition unit; the optical path unit includes a first pinhole cap, a first lens, a dichroic mirror, a second lens, and a second pinhole cap arranged sequentially along the plume acquisition direction; the laser unit is used to emit a laser beam into the dichroic mirror of the optical path unit; the laser beam is reflected by the dichroic mirror and transmitted to the first pinhole cap in the opposite direction of the plume acquisition direction; the data acquisition unit is used to receive the laser beam transmitted from the first pinhole cap and focus the laser beam onto the engine exhaust flame to generate a breakdown spark in the engine exhaust flame; and to acquire the spark light signal generated by the breakdown spark and transmit the spark light signal along the plume acquisition direction to the second pinhole cap; the control unit is used to receive the spark light signal transmitted from the second pinhole cap and determine the engine plume fault based on the spark light signal.

[0006] In one optional embodiment of this application, the laser unit includes: a laser and a harmonic separator and a beam collector arranged sequentially along the laser emission direction of the laser; the harmonic separator is used to remove the fundamental infrared component from the laser beam emitted by the laser and reflect the laser beam after removing the fundamental infrared component to the dichroic mirror; the beam collector is used to collect stray and residual beams in the laser emission direction.

[0007] In one optional embodiment of this application, the acquisition unit includes an optical fiber probe and a lens group arranged along the laser beam emission direction of the optical fiber probe; the optical fiber probe is connected to the first pinhole end cap via an optical fiber and is used to receive the laser beam emitted by the first pinhole end cap; the lens group is used to focus the laser beam onto the engine exhaust flame to generate a breakdown spark; and to transmit the spark light signal generated by the breakdown spark to the optical fiber probe, so that the optical fiber probe sends the spark light signal to the first pinhole end cap.

[0008] In one optional embodiment of this application, the lens group includes a collimating lens and a focusing lens arranged sequentially along the laser beam emission direction of the fiber optic probe.

[0009] In one optional embodiment of this application, the control unit includes: a spectrometer and a computer; wherein the spectrometer is connected to the second pinhole cap via an optical fiber, the spectrometer is used to receive the spark light signal transmitted by the second pinhole cap, and to split the spark light signal to obtain spark spectral data; the computer is used to receive the spark spectral data sent by the spectrometer, and to perform combustion component analysis based on the spark spectral data to determine the metal composition of the combustion of the engine plume, and to determine the engine plume fault based on the metal composition.

[0010] In one optional embodiment of this application, the control unit further includes: a pulse generator, an enhanced charge-coupled device (CCD), and a controller; the controller is used to synchronize the pulse generator and the spectrometer according to preset parameters; the pulse generator is used to send a laser control signal to the laser unit to control the opening and closing of the laser unit; the enhanced charge-coupled device serves as a detector of the spectrometer and controls the delay time and gate width of the spectrometer through a built-in gate controller.

[0011] Compared with existing technologies, the engine plume fault diagnosis device provided by this invention addresses the problem that the outer electrons of metal atoms cannot reach an excited state due to the low exhaust temperature in scenarios such as turbopump joint testing or semi-system testing. It uses a laser unit in conjunction with an optical path unit to generate a breakdown spark in the engine exhaust, thus making it unaffected by the engine exhaust temperature. At the same time, the structure of the optical path unit, which consists of a first pinhole cap, a first lens, a dichroic mirror, a second lens, and a second pinhole cap arranged sequentially along the plume collection direction, ensures that the emission path of the laser beam in the optical path unit and the plume collection direction are in the same optical path, which helps to improve the effectiveness of the collected spectral data.

[0012] The present invention also provides a method for diagnosing engine plume faults, which uses the engine plume fault diagnosis device described in any one of claims 1-7 to determine engine plume faults.

[0013] Compared with the prior art, the beneficial effects of the engine plume fault diagnosis method provided by the present invention are the same as those of the engine plume fault diagnosis device described in the above technical solution, and will not be repeated here. Attached Figure Description

[0014] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a structural diagram of the engine plume fault diagnosis device provided in the embodiments of this application; Figure 2 This is a flowchart of engine plume fault detection provided in an embodiment of this application; Figure 3 This application provides a spark spectrum data for an embodiment of the present application. Detailed Implementation

[0015] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0017] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0018] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] This application provides an engine plume fault diagnosis device and method, which will be described in detail in the following embodiments.

[0021] This application first provides an engine plume fault diagnosis device, please refer to... Figure 1 , Figure 1 This is a structural diagram of the engine plume fault diagnosis device provided in an embodiment of this application.

[0022] like Figure 1 As shown, the engine plume fault diagnosis device includes: control unit 1, laser unit 2, optical path unit 3, and acquisition unit 4.

[0023] The optical path unit 3 includes a first pinhole cap 301, a first lens 302, a dichroic mirror 303, a second lens 304, and a second pinhole cap 305 arranged sequentially along the plume collection direction.

[0024] Laser unit 2 is used to emit a laser beam to the dichroic mirror 303 of the optical path unit. After being reflected by the dichroic mirror 303, the laser beam is transmitted to the first pinhole cap 301 in the opposite direction of the plume collection direction.

[0025] In this embodiment, the laser unit 2 includes: a laser 201, a harmonic separator 202 and a beam collector 203 arranged sequentially along the laser emission direction of the laser 201.

[0026] Among them, the harmonic separator 202 is used to remove the fundamental infrared component in the laser beam, and the beam collector 203 is used to collect stray and residual beams in the beam exit direction to protect the device.

[0027] In one alternative embodiment, the laser is an Nd:YAG laser with a pulse energy of 300mJ, a pulse width of 3~5ns, a repetition frequency of 10Hz, a fundamental wavelength of 1064nm, and a second harmonic of 532nm.

[0028] The laser beam emitted from the laser 201 is reflected by the harmonic separator 202 and enters the dichroic mirror 303 of the optical path unit 3. After being reflected by the dichroic mirror 303, it propagates in the opposite direction of the plume collection direction to the first lens 302 and converges to the first pinhole cap 301.

[0029] The first pinhole cap 301 is connected to the acquisition unit 4 via an optical fiber to transmit the laser beam to the acquisition unit 4.

[0030] The acquisition unit 4 is used to receive the laser beam transmitted by the first pinhole cap 301 and focus the laser beam onto the engine exhaust flame to generate a breakdown spark in the engine exhaust flame.

[0031] Specifically, the acquisition unit 4 includes: an optical fiber probe 401, and a lens group arranged along the laser beam emission direction of the optical fiber probe 401.

[0032] The fiber optic probe 401 is connected to the first pinhole cap 301 via an optical fiber and is used to receive the laser beam emitted by the first pinhole cap; the lens group is used to focus the laser beam onto the engine exhaust flame to generate a breakdown spark.

[0033] Specifically, the lens group includes a collimating lens 402 and a focusing lens 403 arranged sequentially along the laser beam emission direction of the fiber optic probe 401. The collimating lens 402 can be collimated using a lens with a focal length of 20cm, and the focusing lens 403 can be focused using an ultraviolet-grade quartz lens with a focal length of 20cm to generate a penetration spark in the engine exhaust flame.

[0034] Furthermore, the acquisition unit 4 is also used to transmit the spark light signal generated by the breakdown spark to the fiber optic probe 401 through the lens group, so that the fiber optic probe 401 sends the spark light signal to the first pinhole cap 301.

[0035] After receiving the spark light signal, the first pinhole cap 301 couples with the signal and then, in the form of a laser beam, passes sequentially through the first lens 302, the dichroic mirror 303, and the second lens 304 along the plume collection direction until it enters the second pinhole cap 305.

[0036] The second pinhole cap 305 is connected to the control unit 1 via an optical fiber.

[0037] In practical applications, laser 201 can be an Nd:YAG laser with a pulse energy of 300 mJ, a pulse width of 3-5 ns, a repetition frequency of approximately 10 Hz, a fundamental wavelength of 1064 nm, and a second harmonic of 532 nm. After the fundamental infrared component is removed by a harmonic separator, the 532 nm second harmonic beam propagates to the optical path unit. The dichroic mirror 303, through a special coating, reflects the 532 nm wavelength, causing it to propagate in the opposite direction to the plume acquisition direction to the second lens 304. Simultaneously, wavelengths of 200-510 nm and 550-900 nm are transmitted along the plume direction to the spectrometer, completing the acquisition of the spark spectral signal. This ensures that the output direction of the laser beam in the optical path unit is on the same optical path as the plume acquisition direction, which helps improve data validity.

[0038] The control unit 1 includes a spectrometer 101 and a computer 102.

[0039] The spectrometer 101 is connected to the second pinhole cap 305 via optical fiber. The spectrometer 101 is used to receive the spark light signal transmitted by the second pinhole cap 305 and to split the spark light signal to obtain spark spectral data. The spectrometer 101 is equipped with a diffraction grating with 2400 lines / mm for recording the spectrum, with a resolution of approximately 0.07nm.

[0040] Computer 102 is used to receive spark spectrum data sent by spectrometer 101, perform combustion component analysis based on spark spectrum data, determine the metal composition of engine plume combustion, and determine engine plume faults based on metal composition.

[0041] For details, please refer to Figure 2 , Figure 2 A flowchart for engine plume fault detection provided in an embodiment of this application.

[0042] like Figure 2As shown, after obtaining spark spectral data through the aforementioned engine plume fault detection device, the engine plume fault detection includes the following S1 to S3: S1, performing peak identification processing on the spark spectral data to determine the characteristic radiation intensity peak of the spark spectral data; S2, comparing the characteristic radiation intensity peak with the standard emission characteristic wavelength of the metal material to determine the metal composition of the engine plume combustion; S3, determining the engine plume fault based on the metal composition of the engine plume combustion.

[0043] In this field, peaks typically correspond to specific energy states such as molecular vibrations and electronic transitions, used for substance identification. Peak identification refers to the process of automatically or semi-automatically identifying local maxima from spectral data to determine the peak position, height, width, and other characteristics in the spectral data.

[0044] The standard characteristic emission wavelengths of metallic materials can be determined based on existing databases, such as the NIST database. For example, in the spectral analysis of metallic elements, the standard characteristic wavelengths of common metallic elements such as copper (Cu), iron (Fe), and nickel (Ni) are shown below: Cu element: 301.08 / 303.61 / 306.34 / 310.86 / 324.75 / 327.40 / 330.80 / 353.04 / 406.26...

[0045] Fe element: 344.06 / 358.12 / 371.99 / 373.49 / 373.71 / 374.56 / 374.83 / 374.95 / 385.99...

[0046] Ni element: 341.48 / 344.63 / 345.85 / 346.17 / 349.30 / 351.51 / 352.45 / 356.64 / 361.94...

[0047] For further details, please refer to... Figure 3 , Figure 3 This application provides a spark spectrum data for an embodiment of the present application.

[0048] like Figure 3 As shown, the characteristic wavelengths of the characteristic radiation intensity peaks in the spark spectral data are 324.72 nm and 327.36 nm.

[0049] By such Figure 3By comparing the spark spectrum data shown with the standard characteristic emission wavelengths of metallic materials, it can be determined that the two characteristic wavelengths of copper, 324.75 nm and 327.40 nm, are closest to 324.72 nm and 327.36 nm in the spark spectrum data. The difference is within the wavelength calibration error range. Therefore, it is determined that the metallic component of the engine plume combustion is copper.

[0050] Furthermore, based on the main components inside the engine combustion chamber, it can be further inferred that the engine plume failure is caused by the ablation of the copper inner wall of the engine combustion chamber.

[0051] In one alternative embodiment of this application, the control unit 1 further includes a pulse generator 103, an enhanced charge-coupled device 104, and a controller 105.

[0052] An enhanced charge-coupled device (CCD) 104 is mounted on the entrance slit of the spectrometer 101. The CCD 104 acts as the detector of the spectrometer and controls the delay time and gate width of the spectrometer 101 via a built-in gate controller. The delay time refers to the time interval between the generation of plasma after the laser strikes the plume and the start of spectral acquisition by the CCD 104. Selecting an appropriate delay time can avoid strong continuous radiation background. The gate width refers to the duration of the spectral acquisition window, i.e., the length of time the detector of the spectrometer 101 acquires the spectrum. In an optional embodiment of this application, the delay time and gate width of the CCD 104 can be set and adjusted according to actual needs; for example, the delay time can be set to 20 μs and the gate width can be set to 10 μs.

[0053] The pulse generator 103 is electrically connected to the laser unit and is used to send laser control signals to the laser 201 to control the laser 201 to turn on and off. The controller 105 is electrically connected to the pulse generator 103, the spectrometer 101, and the computer 102, and is used to synchronize the pulse generator 103 and the spectrometer 101 according to preset parameters, and to control the laser 201 to turn on and off via the pulse generator 103.

[0054] In summary, the engine plume fault diagnosis device provided in this application addresses the problem that the outer electrons of metal atoms cannot reach an excited state due to the low plume temperature in scenarios such as turbopump joint testing or semi-system testing. It uses a laser unit in conjunction with an optical path unit to generate a breakdown spark in the engine plume, thus eliminating the limitation imposed by the engine plume temperature. Furthermore, the optical path unit structure, consisting of a first pinhole cap, a first lens, a dichroic mirror, a second lens, and a second pinhole cap arranged sequentially along the plume collection direction, ensures that the laser beam's emission path and the plume collection direction are in the same optical path, thereby improving the effectiveness of the acquired spectral data.

[0055] This application also provides an engine plume fault diagnosis method, which is used to determine engine plume faults through the above-mentioned engine plume fault diagnosis device.

[0056] It should be noted that the above-mentioned engine plume fault diagnosis method is basically the same as the process by which the computer 102 in the above-mentioned engine plume diagnosis device determines the engine plume fault. For relevant details, please refer to the relevant instructions of the engine plume fault diagnosis device. It will not be repeated here.

[0057] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. An engine plume fault diagnosis device, characterized in that, include: Control unit, laser unit, optical path unit, and acquisition unit; The optical path unit includes a first pinhole end cap, a first lens, a dichroic mirror, a second lens, and a second pinhole end cap arranged sequentially along the plume collection direction. The laser unit is used to emit a laser beam into the dichroic mirror of the optical path unit; The laser beam is reflected by the dichroic mirror and transmitted in the opposite direction of the plume collection direction to the first pinhole cap. The acquisition unit is used to receive the laser beam transmitted by the first pinhole cap and focus the laser beam onto the engine exhaust flame to generate a breakdown spark in the engine exhaust flame; and to acquire the spark light signal generated by the breakdown spark and transmit the spark light signal along the plume acquisition direction to the second pinhole cap. The control unit is used to receive the spark light signal transmitted by the second pinhole cap, and determine the engine plume fault based on the spark light signal.

2. The apparatus according to claim 1, characterized in that, The laser unit includes: a laser and a harmonic separator and a beam collector arranged sequentially along the laser emission direction of the laser; The harmonic separator is used to remove the fundamental infrared component from the laser beam emitted by the laser and reflect the laser beam after removing the fundamental infrared component to the dichroic mirror. The beam collector is used to collect stray and residual beams in the direction of laser emission.

3. The apparatus according to claim 1, characterized in that, The acquisition unit includes an optical fiber probe and a lens group arranged along the laser beam emission direction of the optical fiber probe; The fiber optic probe is connected to the first pinhole cap via an optical fiber and is used to receive the laser beam emitted by the first pinhole cap. The lens group is used to focus the laser beam onto the engine exhaust flame to generate a breakdown spark; and to transmit the spark light signal generated by the breakdown spark to the fiber optic probe, so that the fiber optic probe sends the spark light signal to the first pinhole cap.

4. The apparatus according to claim 3, characterized in that, The lens group includes a collimating lens and a focusing lens arranged sequentially along the laser beam emission direction of the fiber optic probe.

5. The apparatus according to claim 1, characterized in that, The control unit includes: a spectrometer and a computer; The spectrometer is connected to the second pinhole cap via an optical fiber. The spectrometer is used to receive the spark light signal transmitted by the second pinhole cap and to split the spark light signal to obtain spark spectral data. The computer is used to receive spark spectral data sent by the spectrometer, perform combustion component analysis based on the spark spectral data, determine the metallic composition of the combustion in the engine plume, and determine the engine plume fault based on the metallic composition.

6. The apparatus according to claim 5, characterized in that, The control unit further includes: a pulse generator, an enhanced charge-coupled device, and a controller; The controller is used to synchronize the pulse generator and the spectrometer according to preset parameters; The pulse generator is used to send laser control signals to the laser unit to control the laser unit to turn on and off; The enhanced charge-coupled device serves as the detector of the spectrometer, and through a built-in gate controller, it controls the delay time and gate width of the spectrometer.

7. A method for diagnosing engine plume faults, characterized in that, The engine plume fault diagnosis device according to any one of claims 1-6 is used to determine the engine plume fault.

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