An in-situ real-time non-invasive acetylene content monitoring gas relay and device

Abstract

The present application discloses an in-situ, real-time, non-invasive acetylene content monitoring gas relay and device in the technical field of transformers for power transmission and transformation equipment. The gas relay has two inspection windows symmetrically arranged along the oil flow direction. Each of the inspection windows adopts a circular three-layer composite structure. The middle layer is a light-transmitting magnetic fluid cavity filled with magnetic fluid. A Halbach permanent magnet array ring is bonded to the outside of the inspection window, and an electromagnetic coil is arranged on the outside of the ring. The device includes a light source unit, a photoacoustic detection unit, and a magnetic fluid control device. The addition of a light beam analyzer and a dirt sensor solves the problem that the existing technology cannot detect acetylene gas in real time in situ, thereby achieving the beneficial effects of improving monitoring accuracy, real-time performance, and enhancing fault warning capabilities.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers for power transmission and transformation equipment, and in particular to an in-situ real-time non-invasive acetylene content monitoring gas relay and device. Background Art

[0002] Oil-immersed transformers use transformer oil as both an insulating and cooling medium. When internal faults occur in the transformer, such as overheating, insulation damage, or partial discharge, the transformer oil decomposes and produces a series of characteristic gases. The composition and concentration of these gases are closely related to the type and severity of the internal fault. Therefore, real-time monitoring of the composition and concentration of these characteristic gases is crucial for ensuring the safe operation of oil-immersed transformers. Gas relays are a crucial component of non-electrical protection for oil-immersed transformers. Their light gas protection features the ability to rapidly detect and respond to internal discharges in the early stages. However, when the transformer is poorly sealed or the oil level drops, non-fault gases such as air can enter the gas relay, causing false alarms. Currently, gas chromatography is commonly used to analyze characteristic gases to verify the accuracy of early fault warnings. This method has a detection cycle of hours, while the time interval between the generation of fault characteristic gases and a transformer explosion can be as short as minutes, making it difficult to meet the real-time requirements for explosion warnings. Furthermore, gas chromatography relies on manual on-site sampling, which not only increases response delays but also poses significant safety risks. There are also solutions that use photoacoustic spectroscopy gas detection to detect gas, but this requires additional gas extraction through a photoacoustic cell, etc., and cannot achieve in-situ real-time detection. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the present invention provides an in-situ real-time non-invasive acetylene content monitoring gas relay and device to solve the problem that the above-mentioned existing technology cannot detect acetylene gas in-situ and in real time.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0005] An in-situ, real-time, non-invasive acetylene content monitoring gas relay includes a gas signal contact, an oil flow rate signal contact, and an inspection window. There are two inspection windows, which are symmetrically arranged along the oil flow direction. Each inspection window adopts a circular three-layer composite structure. The inner and outer layers of the three-layer composite structure are both made of solid transparent materials, and the middle layer is a light-transmitting magnetic fluid cavity. A Halbach permanent magnet array ring is coaxially bonded to the outside of each inspection window. An electromagnetic coil is arranged on the outside of the permanent magnet array ring. Magnetic fluid is sealed in the magnetic fluid cavity, and the electromagnetic coil has a reserved interface for external connection.

[0006] Preferably, the solid transparent material is quartz glass, the magnetic fluid is silicone oil filled with 20 vol% carboxylated Fe3O4 nanoparticles, and the nanoparticles are surface-treated with sodium laurate.

[0007] Based on the same inventive concept, the present application also discloses an in-situ real-time non-invasive acetylene content monitoring device for in-situ real-time non-invasive acetylene content monitoring of a gas relay, comprising a light source unit, a photoacoustic detection unit, and a magnetofluid control device. The light source unit is configured to emit an infrared light beam through the permanent magnet array ring of the aforementioned in-situ real-time non-invasive acetylene content monitoring gas relay and through an inspection window to the acetylene gas accumulated above the oil level in the gas relay. The photoacoustic detection unit is configured to capture the acoustic signal generated by the acetylene gas through a sensor close to the inspection window and calculate the concentration of the acetylene gas in the gas relay in real time. The magnetofluid control device includes a controller, the controller being connected to an external connection interface of the electromagnetic coil of the aforementioned in-situ real-time non-invasive acetylene content monitoring gas relay. The controller is configured to stabilize the light spot of the light beam emitted by the light source unit and peel off the contaminated oil film on the inside of the inspection window by controlling the current output to the coil.

[0008] Preferably, the light source unit includes a driving circuit, a broadband light source and a filtering device. The driving circuit is electrically connected to the broadband light source and controls the broadband power supply to emit light. The filtering device is arranged and fixed on the light path between the light-emitting port of the broadband light source and the solid transparent material on the outer layer of the gas relay inspection window.

[0009] Preferably, the photoacoustic detection unit includes an acoustic wave sensor and a signal processing unit. The acoustic wave sensor is attached to the solid transparent material on the outer layer of the inspection window and is used to capture the acoustic signal generated by acetylene gas and convert it into an electrical signal. The signal processing unit is used to process the electrical signal generated by the sensor unit to obtain the target gas concentration. The signal processing unit includes a phase-locked amplifier and a host computer. The phase-locked amplifier is electrically connected to the acoustic wave sensor and the host computer respectively. The phase-locked amplifier is used to perform phase-locked amplification processing on the electrical signal generated by the acoustic wave sensor. The host computer is used to analyze the electrical signal amplified by the phase-locked amplifier to obtain the concentration of acetylene gas in the gas relay.

[0010] Preferably, the acoustic wave sensor uses a silver film optical fiber FP acoustic wave sensor, which includes a housing, a silver film, a ceramic ferrule, and a single-mode optical fiber. The ceramic ferrule is bonded to the single-mode optical fiber in the middle and is arranged in the cavity of the housing. The rear end face of the ceramic ferrule is flat, and the front end face is set with a symmetrical inclination angle that decreases forward, and a silver film is provided at the front of the cavity.

[0011] Preferably, the tilt angle is 8°, the diameter of the silver film is 6 mm, the thickness is 0.6 μm, and the length of the Fabry-Perot cavity is 1500 μm.

[0012] Preferably, it also includes a beam analyzer, the light inlet of the beam analyzer is arranged on the opposite side of the gas relay relative to the light source unit and is aligned with the light beam emitted by the light source unit, the data output end of the beam analyzer is electrically connected to the controller, and the beam analyzer is used to detect the spot diameter.

[0013] Preferably, a dirt sensor is further included, which is arranged in the incident point area of the light source unit incident inspection window above the oil, and the data output end of the dirt sensor is electrically connected to the controller. The dirt sensor is used to detect the oil contamination status of the inner surface of the solid transparent material inside the inspection window.

[0014] Preferably, the dirt sensor uses a transmittance sensor.

[0015] Compared with the prior art, the present solution has the following beneficial effects: by improving the inspection window of the gas relay, the gas relay has the ability to realize in-situ real-time non-invasive acetylene content monitoring in conjunction with a suitable device, without the need for an additional photoacoustic cell. The in-situ real-time non-invasive acetylene content monitoring device for use with the gas relay disclosed in this application adopts a combination of a light source unit and a photoacoustic detection unit, and all detection components are located outside the gas relay. Compared with traditional gas chromatography, the response delay is greatly reduced, real-time monitoring is achieved, and the accuracy and safety of monitoring are further improved, thereby enabling accurate monitoring of the acetylene gas concentration in the gas relay. By determining the central wavelength of the filter device, the photoacoustic signal intensity is increased and cross-interference from other gases is reduced. By using an optical fiber acoustic wave sensor instead of an ordinary acoustic-to-electric conversion device, the device size is reduced, the sound receiving sensitivity is improved, and it is not affected by electromagnetic interference. By adding additional components such as a magnetofluid control device, a beam analyzer, and a dirt sensor, the light spot is stabilized and the transparency of the inspection window is maintained, achieving the beneficial effects of improving monitoring accuracy, real-time performance, and enhancing fault warning capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the connection arrangement of a gas relay and a monitoring device in accordance with an embodiment of the present invention, perpendicular to the direction of oil flow;

[0017] Figure 2 Schematic diagram of the central cross section of an embodiment of a silver film optical fiber FP acoustic wave sensor;

[0018] Figure 3 A schematic diagram of parameters of a filter in an embodiment of a filter device;

[0019] Figure 4 The absorption spectrum of the acetylene absorption spectrum in the transformer oil is the absorption spectrum of other gases and the acetylene gas to be monitored in the vicinity of the wave number to be selected;

[0020] Among them, 1-gas relay, 111-quartz glass, 112-magnetic fluid cavity, 21-permanent magnet array ring, 22-coil, 23-sealing ring, 31-driving circuit, 32-broadband light source, 33-filtering device, 41-acoustic wave sensor, 411-housing, 412-silver film, 413-ceramic ferrule, 414-single-mode optical fiber, 42-lock-in amplifier, 43-host computer, 5-beam analyzer, 6-controller, 7-transmittance sensor. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] An embodiment of a gas relay 1 for in-situ, real-time, non-invasive acetylene content monitoring includes two gas signal contacts, an oil flow rate signal contact, and inspection windows. The two inspection windows are symmetrically arranged along the oil flow direction. Each inspection window utilizes a circular three-layer composite structure, with both the inner and outer layers made of solid, transparent materials. The middle layer comprises a light-transmitting magnetic fluid cavity 112. A Halbach permanent magnet array ring 21 is coaxially bonded to the exterior of each inspection window. An electromagnetic coil 22 is positioned outside the permanent magnet array ring 21. The magnetic fluid cavity 112 is sealed with magnetic fluid, and the electromagnetic coil 22 has a reserved interface for external connection. This three-layer composite structure facilitates the synergistic effects of light, magnetism, and force.

[0023] The magnetic fluid described in this example uses a chemical precipitation method to prepare Fe₃O₄ nanoparticles. The particles are then surface-treated with sodium laurate to impart a charge to the surface and prevent precipitation in the base fluid. Silicone oil with a viscosity of 5000 cP and a refractive index of 1.40 is used as the dispersion medium, and the magnetic fluid concentration is 20 vol%. The solid transparent material used in this example is quartz glass 111. The outer layer is 5 mm thick, highly transparent quartz glass 111 with a transmittance greater than 99.7%, and the inner layer is also 5 mm thick. A 0.5 mm thick magnetic fluid cavity 112 is left between the two layers of quartz glass 111. The edge of the magnetic fluid cavity 112 is sealed with a PDMS seal 23 that meets the oil corrosion resistance standard of ASTM D471 and has a 72-hour expansion rate of less than 3%. This seal 23 forms a molecular bond with the glass interface through a vacuum hot pressing process. The silicone oil-based magnetic fluid containing carboxylated Fe₃O₄ nanoparticles has a particle size distribution of 10 to 20 nm. The quartz glass 111 and magnetic fluid in the embodiment can be replaced by other suitable materials, such as high-transmittance PMMA, other magnetic fluids with nanoparticles such as Fe2O3, Ni and Co, etc.

[0024] In this embodiment, the Halbach permanent magnet array ring 21 and electromagnetic coil 22 are arranged concentrically outside the outer quartz glass layer 111. The inner edge of the permanent magnet array ring 21 is 10 mm from the outer edge of the outer quartz glass layer 111, forming a circular control zone. The Halbach permanent magnet array ring 21 uses N52-grade neodymium iron boron with a remanence of 1.45 T to provide the base magnetic field. The copper flat coil 22 superimposed on the outer surface of the permanent magnet array ring 21 uses 0.5 mm copper wire with 200 turns per unit. Current regulation generates a superimposed magnetic field, ultimately forming an adjustable magnetic field gradient of 0.2-1 T / m. Under 15 MPa oil pressure and a temperature range of -40 to 120°C, this design achieves a magnetic field uniformity deviation of less than ±5% and a transmittance fluctuation of less than 1.5%. By using the controller 6 of the in-situ, real-time, non-invasive acetylene content monitoring device, the spot diameter can be maintained stable by adjusting the current in the coil 22, thereby obtaining a stable signal.

[0025] Based on the same inventive concept, the present application discloses an in-situ real-time non-invasive acetylene content monitoring device for use with an in-situ real-time non-invasive acetylene content monitoring gas relay 1, comprising a light source unit, a photoacoustic detection unit, and a magnetic fluid control device. The light source unit is configured to emit an infrared light beam through the permanent magnet array ring 21 of the aforementioned in-situ real-time non-invasive acetylene content monitoring gas relay and through the inspection window to the acetylene gas accumulated above the oil level in the gas relay. In this embodiment, the light source unit comprises a drive circuit 31, a broadband light source 32, and a filter device 33. The driving circuit 31 is electrically connected to the broadband light source 32 and controls the broadband power supply to emit light. The driving circuit 31 outputs a square wave current signal with a frequency of 50Hz, a high level of 2.4V, a low level of 0V, and a duty cycle of 50%. The broadband light source 32 adopts a blackbody radiation infrared broad spectrum light source with a wavelength range of 4000nm to 11000nm. The filtering device 33 is fixed on the optical path between the light-emitting port of the broadband light source 32 and the solid transparent material of the outer layer of the inspection window of the gas relay 1. In this embodiment, the filtering device 33 adopts a filter. The parameters of the filter are shown as follows: Figure 3 , CWL is the center wavelength of the filter, T peak is the maximum transmittance of the filter, and HW is the half-height width. The selection of the filter parameters is to maximize the photoacoustic signal generated by acetylene and minimize the interference of other gases, such as Figure 4A represents the infrared absorption spectrum peak of acetylene near 3050 nm, and B represents the infrared absorption peaks of other gas components that can cause cross-interference in acetylene detection. In this embodiment, the filter's center wavelength is preferably 3050 nm, and its half-peak bandwidth is preferably 100 nm, significantly reducing interference from other characteristic gases. The driver circuit 31 modulates the intensity of the incident light, which then passes through the filter and, through an inspection window on the side of the gas relay 1, impinges upon the gas accumulated above the oil level. The filter's spectral passband covers the characteristic absorption peak of acetylene gas in the mid-infrared band. Light of a specific wavelength is selectively absorbed by acetylene gas, causing the gas to periodically expand, thereby generating an acoustic signal.

[0026] The photoacoustic detection unit is used to calculate the concentration of acetylene gas in the gas relay in real time by capturing the acoustic signal generated by acetylene gas through a sensor close to the inspection window from the outside. In this embodiment, the photoacoustic detection unit includes an acoustic wave sensor 41 and a signal processing unit. The acoustic wave sensor 41 is close to the solid transparent material of the outer layer of the inspection window and is used to capture the acoustic signal generated by acetylene gas and convert it into an electrical signal. The signal processing unit is used to process the electrical signal generated by the sensor unit to obtain the target gas concentration. The signal processing unit includes a phase-locked amplifier 42 and a host computer 43. The phase-locked amplifier 42 is electrically connected to the acoustic wave sensor 41 and the host computer 43 respectively. The phase-locked amplifier 42 is used to The electrical signal generated by the acoustic wave sensor 41 is amplified, filtered, phase-locked, and other processes are performed to convert the captured weak acoustic signal into a DC signal reflecting the amplitude of the acoustic signal frequency component corresponding to the modulation frequency. The signal amplitude is the photoacoustic signal intensity. The host computer 43 is used to analyze the electrical signal amplified by the phase-locked amplifier 42 to obtain the concentration of acetylene gas in the gas relay. The concentration is calculated based on the clear linear relationship between the photoacoustic signal intensity and the acetylene gas concentration. The clear linear relationship between the photoacoustic signal intensity and the acetylene gas concentration can be calibrated through a pre-calibration process. The photoacoustic signal intensity of this band can be calibrated using commercially available standard concentration acetylene gas to establish a correlation between the measured value and the gas concentration.

[0027] To achieve better sound collection, the acoustic wave sensor 41 utilizes a silver-film fiber FP acoustic wave sensor. The sensor comprises a housing 411, a silver film 412, a ceramic ferrule 413, and a single-mode optical fiber 414. The ceramic ferrule 413 is bonded to the single-mode optical fiber 414 and disposed within the cavity of the housing 411. The rear end of the ceramic ferrule 413 is flat, while the front end is configured with a symmetrical tapered angle that tapers forward. The silver film 412 is disposed at the front of the cavity. In this embodiment, the tapered angle is 8°. The silver film 412 has a diameter of 6 mm and a thickness of 0.6 μm. The front cone vertex of the ceramic ferrule 413 is 1500 μm from the silver film 412. Using an optical fiber acoustic wave sensor instead of a traditional capacitive microphone offers advantages such as small size, high sensitivity, and immunity to electromagnetic interference. The metallic silver film has excellent density and is easy to form. Furthermore, silver has a low Young's modulus. Using metallic silver as the sensitive diaphragm of the optical fiber FP acoustic wave sensor can achieve higher sensitivity. The acoustic wave sensor 41 is as close as possible to the gas gathering area, that is, close to the incident light axis. In order not to affect the operation of other components, in this embodiment, the vertical position of the acoustic wave sensor and the incident light axis are greater than or equal to 3 mm.

[0028] The magnetic fluid control device includes a controller 6 connected to the external interface of the electromagnetic coil 22 of the aforementioned in-situ, real-time, non-invasive acetylene content monitoring gas relay 1. The controller 6 includes a current controller for stabilizing the spot of the light beam emitted by the light source unit by controlling the current output to the coil 22, thereby stripping the oil film contaminated inside the inspection window. The stabilized spot is achieved by controlling the magnetic field to drive the Fe3O4 nanoparticles to form a density gradient, dynamically adjusting the refractive index of the magnetic fluid and compensating for the laser beam divergence angle. The oil film stripping process can be timed or initiated upon detection of contamination inside the inspection window. The controller 6 activates the rotating magnetic field mode by initiating a magnetic field eddy current flushing program: the coil array is sequentially activated, generating a rotating magnetic field at 50 rpm. Driven by the Lorentz force, the magnetic fluid nanoparticles form micro-scale turbulence with a Reynolds number of Re ≈ 200, thereby stripping over 90% of the oil film.

[0029] In order to better stabilize the light spot, the device also includes a beam analyzer 5. The light inlet of the beam analyzer 5 is arranged on the opposite side of the gas relay 1 relative to the light source unit and is aligned with the light beam emitted by the light source unit. The data output end of the beam analyzer 5 is electrically connected to the controller 6. During the acetylene gas content monitoring process of the gas relay 1, the light spot diameter in the light beam geometric parameters is obtained through the beam analyzer 5. After detecting the fluctuation of the light spot diameter, the controller 6 adjusts the coil current to keep the light spot diameter stable, thereby obtaining a stable signal.

[0030] When dirt is detected on the inside of the inspection window and the oil is removed, the device further includes a dirt sensor. The dirt sensor is arranged in the incident point area of the inspection window where the light source unit above the oil enters, as close as possible to the incident point, so as to judge the dirt condition of the incident point area on the inside of the inspection window as accurately as possible. The data output end of the dirt sensor is electrically connected to the controller 6. The dirt sensor is used to detect the oil contamination state of the inner surface of the solid transparent material on the inside of the inspection window. In this embodiment, the dirt sensor uses a transmittance sensor 7. The transmittance sensor 7 is placed on the incident light side of the gas relay 1 and the split part is placed on the other side of the gas relay 1. It simultaneously detects the dirt condition of the inside of the two quartz glasses 111. When the transmittance is less than a set threshold value, such as 70%, the magnetic field eddy current flushing program is started to remove the oil.

[0031] In addition to the transmittance sensor 7 , the dirt sensor may also use other devices such as a camera to determine the dirt condition of the inner side of the inner quartz glass 111 by taking pictures.

[0032] The measurement percentage error of the acetylene gas concentration in the solution of the present application does not exceed 10%. This solution can not only be used for acetylene gas detection, but can also be used for other gas detection when using different filtering devices 33 and corresponding photoacoustic signal intensity correlation tables.

[0033] In the description of this specification, the schematic diagrams in the accompanying drawings highlight the main features and key parts of the figures, and appropriately simplify or omit details, and therefore do not represent the proportions and dimensional relationships in reality. The descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in an appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0034] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An in-situ, real-time, non-invasive acetylene content monitoring gas relay, comprising a gas signal contact, an oil flow rate signal contact, and an inspection window, characterized in that: There are two inspection windows, which are symmetrically arranged along the oil flow direction. Each inspection window adopts a circular three-layer composite structure. The inner and outer layers of the three-layer composite structure are both made of solid transparent materials, and the middle layer is a light-transmitting magnetic fluid cavity (112). A Halbach permanent magnet array ring (21) is coaxially bonded to the inspection window outside each inspection window. An electromagnetic coil (22) is arranged on the outside of the permanent magnet array ring (21). A magnetic fluid is sealed in the magnetic fluid cavity (112). The electromagnetic coil (22) is reserved with an interface for external connection. The solid transparent material is quartz glass (111). The magnetic fluid is filled with 20 vol% carboxylated Fe3O4 nanoparticles containing silicone oil, wherein the nanoparticles are surface-treated with sodium laurate, and the Halbach permanent magnet array ring (21) and the electromagnetic coil (22) are arranged in the form of concentric rings outside the outer quartz glass (111), and the inner edge of the permanent magnet array ring (21) is 10 mm away from the outer edge of the outer quartz glass (111), forming an annular control area.

2. The in-situ real-time non-invasive acetylene content monitoring gas relay according to claim 1, characterized in that: The viscosity of the silicone oil is 5000 cP and the refractive index is 1.

40. The edge of the magnetic fluid cavity (112) is sealed with a PDMS sealing ring (23) with an oil corrosion resistance grade of ASTMD471 and a 72-hour expansion rate of less than 3%. The sealing ring (23) forms a molecular-level bond with the glass interface through a vacuum hot pressing process. The particle size distribution of the silicone oil-based magnetic fluid of carboxylated Fe3O4 nanoparticles is 10 to 20 nm. The Halbach permanent magnet array ring (21) uses N52 grade neodymium iron boron with a remanence of 1.45 T. The copper flat coil (22) superimposed on the outside of the permanent magnet array ring (21) uses a copper wire with a wire diameter of 0.5 mm and 200 turns / unit. The superimposed magnetic field is generated by current regulation, and finally an adjustable magnetic field gradient of 0.2-1 T / m is formed.

3. An in-situ real-time non-invasive acetylene content monitoring device for in-situ real-time non-invasive acetylene content monitoring of a gas relay (1), characterized in that: The invention comprises a light source unit, a photoacoustic detection unit, and a magnetofluid control device, wherein the light source unit is used to emit an infrared light beam through the permanent magnet array ring (21) of the in-situ real-time non-invasive acetylene content monitoring gas relay of one of claims 1 to 2 and through the inspection window to the acetylene gas accumulated above the oil level in the gas relay, the photoacoustic detection unit is used to capture the acoustic signal generated by the acetylene gas through a sensor close to the inspection window and then calculate the concentration of the acetylene gas in the gas relay in real time, the magnetofluid control device comprises a controller (6), the controller (6) is connected to the interface of the electromagnetic coil (22) of the in-situ real-time non-invasive acetylene content monitoring gas relay of one of claims 1 to 2 to the outside, the controller (6) is used to stabilize the light spot of the light beam emitted by the light source unit by controlling the current output to the coil (22) and to peel off the oil film contaminated on the inside of the inspection window, the photoacoustic detection unit comprises an acoustic wave sensor (41) and a signal processing unit, the acoustic wave sensor (41) is close to the solid transparent material of the outer layer of the inspection window, and is used to capture the acoustic signal generated by the acetylene gas and convert it into The signal processing unit is used to process the electric signal generated by the sensor unit to obtain the target gas concentration. The signal processing unit includes a phase-locked amplifier (42) and a host computer (43). The phase-locked amplifier (42) is electrically connected to the acoustic wave sensor (41) and the host computer (43), respectively. The phase-locked amplifier (42) is used to perform phase-locked amplification processing on the electric signal generated by the acoustic wave sensor (41). The host computer (43) is used to analyze the electric signal phase-locked amplified by the phase-locked amplifier (42) to obtain the gas relay concentration. The concentration of acetylene gas in the device is measured. The acoustic wave sensor (41) uses a silver film optical fiber FP acoustic wave sensor. The silver film optical fiber FP acoustic wave sensor includes a housing (411), a silver film (412), a ceramic ferrule (413), and a single-mode optical fiber (414). The ceramic ferrule (413) and the single-mode optical fiber (414) in the middle are bonded and arranged in the cavity of the housing (411). The rear end face of the ceramic ferrule (413) is flat, and the front end face is provided with a symmetrical cone angle that decreases forward. The front part of the cavity is provided with a silver film (412).

4. The in-situ real-time non-invasive acetylene content monitoring device according to claim 3, characterized in that: The light source unit comprises a driving circuit (31), a broadband light source (32) and a filter device (33). The driving circuit (31) is electrically connected to the broadband light source (32) and controls the broadband power source to emit light. The filter device (33) is fixed on the light path between the light-emitting port of the broadband light source (32) and the solid transparent material on the outer layer of the inspection window of the gas relay (1).

5. The in-situ real-time non-invasive acetylene content monitoring device according to claim 3, characterized in that: The cone angle is 8°, the silver film (412) has a diameter of 6 mm and a thickness of 0.6 μm, and the front cone vertex of the ceramic ferrule (413) is 1500 μm away from the silver film (412).

6. The in-situ real-time non-invasive acetylene content monitoring device according to claim 3, characterized in that: It also includes a beam analyzer (5), wherein a light inlet of the beam analyzer (5) is arranged on the opposite side of the gas relay (1) relative to the light source unit and is aligned with the light beam emitted by the light source unit, a data output end of the beam analyzer (5) is electrically connected to the controller (6), and the beam analyzer (5) is used to detect the diameter of the light spot.

7. The in-situ real-time non-invasive acetylene content monitoring device according to claim 3, characterized in that: It also includes a dirt sensor, which is arranged in the incident point area of the light source unit incident inspection window above the oil, and the data output end of the dirt sensor is electrically connected to the controller (6). The dirt sensor is used to detect the oil contamination state of the inner surface of the solid transparent material inside the inspection window.

8. The in-situ real-time non-invasive acetylene content monitoring device according to claim 7, characterized in that: The dirt sensor uses a transmittance sensor (7).

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