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CN-121977619-A - Optical fiber sensor probe for high-temperature high-pressure endoscopic of engine combustion chamber

CN121977619ACN 121977619 ACN121977619 ACN 121977619ACN-121977619-A

Abstract

The invention provides a high-temperature high-pressure endoscopic optical fiber sensor probe of an engine combustion chamber, which comprises a sensor ceramic matrix, a sapphire lens component, a metal sealing ring, a metal transition layer and a high-temperature quartz optical fiber, wherein the sensor ceramic matrix is provided with a light path channel in a penetrating way, the outer wall of the front end of the sensor ceramic matrix is provided with a section of fine thread, the rear part of the fine thread is provided with an annular thick end face, the annular thick end face is embedded with the metal sealing ring, the sapphire lens component is embedded in one end of the light path channel, the outer wall of the sapphire lens component is welded and fixed with the light path channel through the metal transition layer, and the high-temperature quartz optical fiber comprises an optical fiber input end and two output optical fibers welded with the optical fiber input end through an arc welding technology. The invention has compact overall structure design and strong environmental resistance, and is suitable for real-time multi-parameter optical diagnosis and state monitoring of high-temperature high-pressure combustion systems of aeroengines, gas turbines and the like.

Inventors

  • LI XINYANG
  • GUO DONGNI
  • LIAN HUAN

Assignees

  • 中国科学院力学研究所

Dates

Publication Date
20260505
Application Date
20260108

Claims (10)

  1. 1. The high-temperature high-pressure endoscopic optical fiber sensor probe for the engine combustion chamber is characterized by comprising a sensor ceramic matrix (1), a sapphire lens assembly (2), a metal sealing ring (3), a metal transition layer (4) and a high-temperature quartz optical fiber (5); The sensor ceramic matrix (1) is internally provided with a light path channel in a penetrating way along the length direction, the outer wall of the front end is provided with a section of fine thread (11), the outer diameter of the front end is enlarged and then an annular thick end face (12) is formed, the annular thick end face (12) is tightly abutted against the wall of a combustion chamber when the optical fiber sensor probe is installed, the annular thick end face (12) is provided with a deep annular groove, a metal sealing ring (3) is embedded in the deep annular groove in a matching way, the sensor ceramic matrix (1) is connected with a tested piece through the fine thread (11) and then forms a first high-temperature high-pressure seal together with the metal sealing ring (3), when the optical fiber sensor probe is screwed down, the annular thick end face (12) is pressed against the wall of the combustion chamber, and the metal sealing ring (3) is extruded to generate plastic deformation to fill all microscopic uneven parts so as to form an absolute airtight barrier, namely a second seal; The sapphire lens component (2) is used as an optical acquisition window, is embedded into one end of the optical path channel, and is welded and fixed with the optical path channel by adopting a metal transition layer (4); The high-temperature quartz optical fiber (5) is used for realizing low-loss transmission and multiplexing output of optical signals and comprises an optical fiber input end (51) and two output optical fibers (52), one end of the optical fiber input end (51) is inserted into the other end of the optical path channel, the end face of the optical fiber input end is tightly attached to the inner plane of the sapphire lens assembly (2) in parallel, and the other end of the optical fiber input end (51) is positioned on the outer side of the sensor ceramic matrix (1) and is welded with the two output optical fibers (52) through an arc welding technology.
  2. 2. The high-temperature and high-pressure endoscopic fiber sensor probe of an engine combustion chamber according to claim 1, wherein a ceramic protective sleeve is sleeved outside a fusion joint of the fiber input end (51) and the output fiber (52) and coated with high-temperature silicone rubber.
  3. 3. The high-temperature high-pressure endoscopic fiber sensor probe according to claim 1, wherein the outer wall of the sapphire lens assembly (2) and the metal transition layer (4) are welded in a manner that a plurality of layers of metallized films are firstly deposited on the edge of the sapphire lens assembly (2), then the metal transition ring is welded with each lens in the sapphire lens assembly (2) through metal brazing, and then the metal transition ring is welded with each lens in the sapphire lens assembly (2) to form a component which is welded in the same brazing process into a light path channel at the front end of the sensor ceramic matrix (1).
  4. 4. The high-temperature high-pressure endoscopic optical fiber sensor probe of the engine combustion chamber according to claim 1, wherein one end face of the optical fiber input end (51) inserted into the optical path channel is tightly attached to the inner plane of the sapphire lens assembly (2) in a parallel manner with a micron-sized interval under the precise adjustment of an installation clamp.
  5. 5. The high-temperature high-pressure endoscopic fiber optic sensor probe of an engine combustion chamber according to claim 1, wherein the ratio of the length and the diameter of the high-temperature quartz fiber (5) inserted into the optical path channel, namely the depth-to-diameter ratio, is more than 30:1.
  6. 6. The high-temperature high-pressure endoscopic fiber sensor probe of claim 1, wherein said optical path channel has a coaxial stepped hole structure, and a front end channel hole diameter is larger than a rear end channel hole diameter, wherein said front end channel is used for accommodating said sapphire lens assembly (2), and said rear end channel is used as said fiber input end insertion channel.
  7. 7. The high-temperature high-pressure endoscopic fiber sensor probe of the engine combustion chamber according to claim 1, wherein the metal sealing ring (3) is a superalloy metal O-shaped ring.
  8. 8. The high-temperature high-pressure endoscopic fiber optic sensor probe for an engine combustion chamber according to claim 1, wherein the sensor ceramic substrate (1) is made of zirconia or alumina ceramic material.
  9. 9. The high-temperature high-pressure endoscopic fiber optic sensor probe for engine combustion chamber according to claim 1, wherein said metal transition layer (4) is made of, but not limited to, 4J42 as an intermediate layer material, and has a thermal expansion coefficient between that of sapphire and ceramic matrix.
  10. 10. The high-temperature high-pressure endoscopic fiber optic sensor probe for an engine combustion chamber according to claim 1, wherein the compactness of said sensor ceramic matrix (1) is >99%.

Description

Optical fiber sensor probe for high-temperature high-pressure endoscopic of engine combustion chamber Technical Field The invention relates to the technical field of combustion diagnosis of a sensor of an aerospace engine, in particular to an optical fiber sensor probe for high-temperature and high-pressure endoscopic of an engine combustion chamber. Background During operation of high-temperature combustion systems such as space engines and gas turbines, the interior of the combustion chamber is in extremely high-temperature, high-pressure and high-turbulence states. In order to realize real-time monitoring, performance evaluation and fault diagnosis of the combustion process, the combustion diagnosis technology based on optical sensing is attracting attention because of non-invasive, high space-time resolution and multi-parameter synchronous measurement capability. In particular, the high-fidelity acquisition of spectrum signals of the transient combustion process in a combustion chamber is performed in high-temperature and high-pressure environments such as a scramjet engine, a gas turbine and the like, so that the method has become a key technical means for combustion optimization and safety control. Currently, fiber optic sensors for combustion diagnostics face mainly the following technical challenges: (1) The traditional optical fiber probe mostly adopts a metal or common ceramic shell, has lower temperature resistance limit, and is easy to generate structural failure or signal drift under a long-time high-temperature environment. Meanwhile, the conventional threaded connection and sealing mode is easy to leak in a high-temperature and high-pressure environment, so that flame can enter or an optical window is polluted, and the measurement reliability is affected. (2) The heat resistance and the light transmittance of the optical window contradict that common optical window materials such as quartz glass are easy to be mismatched or softened by thermal expansion at a continuous high temperature, and the connection between high temperature resistant materials such as sapphire and the metal or ceramic matrix is mostly glued or mechanically pressed, so that cracks or falling off are easy to be generated in thermal circulation, and the stability and the transmittance of optical signals are influenced. (3) The signal transmission quality is affected by the environment, namely, the optical fiber connection part is easy to attenuate, reflect and strengthen or fluctuate due to thermal expansion, mechanical looseness or pollution under the high-temperature, high-pressure and strong vibration environment, and the measurement accuracy is affected. Conventional fiber optic connection (e.g., mechanical connectors, cold junctions) are difficult to maintain long-term stable signal transmission performance under extreme conditions. (4) The prior probe has limited multi-channel synchronous measurement capability, which is difficult to realize synchronous acquisition of multi-band spectrum signals at the same measuring point by adopting single-channel optical fiber transmission, and limits real-time correlation analysis of multi-parameter optical signals such as OH, CH and the like in the combustion process. Therefore, there is a need to develop an optical fiber sensor probe structure which can stably work in a high-temperature and high-pressure environment of an engine combustion chamber, has excellent sealing performance, high optical transmittance and low signal loss, and supports multichannel synchronous acquisition, and a preparation method thereof, so as to meet the requirements of high-precision optical diagnosis of a modern aeroengine and a combustion system of a gas turbine. Disclosure of Invention Aiming at the technical problems in the background art, the invention provides an optical fiber sensor probe for high-temperature high-pressure endoscopic of an engine combustion chamber, which adopts a double serial sealing structure of screw thread sealing and end face extrusion sealing to solve the sealing and high-temperature protection problems of an optical probe in extreme environments, adopts a sapphire lens and metal transition layer welding process to improve the heat resistance and the mechanical strength of an optical window, adopts an integrated fusion type optical fiber beam splitting structure, realizes single-point multi-signal synchronous acquisition, ensures the transmission quality and long-term stability of signals in high-temperature and vibration environments, has compact integral structure and strong environmental resistance, and is suitable for real-time multi-parameter optical diagnosis and state monitoring of high-temperature high-pressure combustion systems such as aeroengines, gas turbines and the like. In order to solve the technical problems, the invention provides a high-temperature high-pressure endoscopic optical fiber sensor probe of an engine combustion chamber, which comprises a s