A small radiation temperature measurement probe for an aeroengine turbine blade

Abstract

The present invention discloses a small radiation temperature measurement probe for an aeroengine turbine blade, which includes a mirror, a probe housing, an optical tube, a mounting seat, a photodetector, a fixing plate, a rear cover, etc. The mirror, the probe housing, the optical tube, the mounting seat, the fixing plate, and the rear cover are all made of GH3044 superalloy, having good high-temperature and high-pressure resistance characteristics. The photodetector uses a cooled mercury cadmium telluride infrared photodetector. This device uses a mercury cadmium telluride (HgCdTe) photoconductive chip as the photosensitive element, and uses a micro thermoelectric cooler to adjust the temperature difference between the inside of the detector and the environment, so that the photosensitive material works stably. The lens part of the mirror is polished and its surface has an infrared fused silica antireflection film with a thickness of 1.5 - 2.3 um, and it is connected to the probe housing by threads. The dimensions of its various components can be customized according to different usage environments, and it can meet the requirements for radiation temperature measurement in different situations.

Description

Technical Field

[0001] The present invention relates to the field of radiation temperature measurement of aero-engines, and designs a small optical probe suitable for collecting radiation information on the surface of turbine blades. Background Technique

[0002] As the core component of an aircraft, aero-engines have long been a research hotspot for scholars at home and abroad. Moreover, due to their high precision and complexity, they are known as "the pearl on the crown of modern industry". As a hot-end component inside an aero-engine, the turbine blade is the rotating component with the highest temperature in the aero-engine. Its high-temperature resistance can directly determine the maximum operating temperature of the aero-engine. In addition, when the temperature of the aero-engine turbine blade is too high, it will directly lead to the risk of fracture, resulting in irreparable losses. Therefore, real-time monitoring of the surface temperature of turbine blades is very important for the entire aviation industry.

[0003] Currently, the methods for measuring the temperature of aero-engine turbine blades can be mainly divided into two types: contact temperature measurement methods and non-contact temperature measurement methods. The main principle of the contact temperature measurement method is: fix the temperature sensor on the surface of the object to be measured. After sufficient contact for a certain period of time, the temperature sensor and the object to be measured reach a thermal equilibrium state. At this time, the temperature sensor can reflect the true temperature of the object to be measured. Thermal resistors and thermocouples are the two most commonly used temperature sensors in contact temperature measurement. The main advantages of the contact temperature measurement method are small temperature measurement error, relatively simple equipment, and easy to implement in applications. However, the contact temperature measurement method will directly affect the surface state of the object to be measured and destroy the temperature field distribution of the object to be measured. The basic principle of the non-contact temperature measurement method is: since the thermal radiation of an object changes with temperature, the temperature of the object to be measured can be solved based on the thermal radiation of the object. Non-contact temperature measurement can not directly contact the object to be measured, but collect the surface thermal radiation of the object to be measured and infer the temperature of the object to be measured according to the thermal radiation law. Non-contact temperature measurement methods are mainly divided into acoustic temperature measurement method, radiation temperature measurement method, spectral temperature measurement method, laser interference temperature measurement, etc. according to different principles.

[0004] Radiation thermometry is a non-contact temperature measurement method based on the radiation law. It converts optical signals into electrical signals through sensors such as photoelectric detectors, and then calculates the temperature of the object to be measured. Radiation thermometry does not disrupt the surface temperature field distribution of the object to be measured, has a fast response speed, and a wide temperature measurement range, making it very suitable for temperature measurement under complex conditions such as high temperature and high pressure. Since it does not directly contact the object to be measured, it will not affect the physical properties of the object to be measured. In summary, radiation thermometry is very suitable for temperature measurement of devices such as turbine blades that are in a high temperature and high pressure environment for a long time. Based on this, the present invention proposes a small radiation temperature measurement probe for an aeroengine turbine blade, and the designed structure can withstand the high temperature and high pressure environment of the engine, and can accurately collect the radiation information on the surface of the turbine blade and convert it into an electrical signal.

[0005] Patent CN201710413059.7 proposed a temperature monitoring device for an aeroengine turbine blade, but it relies heavily on post-data processing, and the overall size of the temperature measurement device is relatively large. Patent CN201710524151.0 proposed an optical path device for turbine blade temperature monitoring, but this patent only verified the theoretical feasibility from the design of the optical system and did not design a mature product. Patent CN201910588599.8 proposed an infrared radiation thermometer for reducing the background radiation of the meter, mainly overcoming the influence of the background measurement of the pyrometer. Patent CN202010806727.4 proposed a four-axis multi-functional temperature measurement device, which can realize the function of detecting different surface radiations. The above patents have carried out research on the field of aeroengine radiation temperature measurement from different aspects, but no one has designed a small radiation pyrometer with a light volume. Summary of the Invention

[0006] In view of the field of aeroengine radiation temperature measurement, the present invention proposes a small radiation pyrometer for an aeroengine turbine blade, which overcomes various disadvantages of the original pyrometers such as large volume, heavy weight, and difficulty in disassembly, and can be flexibly used in the temperature measurement scenarios of turbine blades of various different models of aeroengines.

[0007] The technical solution of the present invention is: a small radiation temperature measurement probe for an aeroengine turbine blade, the probe includes: a reflecting mirror, a probe housing, an optical tube, a mounting seat, a photoelectric detector, a fixing plate, and a rear cover; the reflecting mirror, the probe housing, the optical tube, the mounting seat, the fixing plate, and the rear cover are all made of GH3044 high-temperature alloy; the photoelectric detector uses a cooled mercury cadmium telluride infrared photodetector, and this device uses a mercury cadmium telluride (HgCdTe) photoconductive chip as the photosensitive element, and uses a micro thermoelectric cooler to adjust the temperature difference between the inside of the detector and the environment, so that the photosensitive material works stably;

[0008] The probe housing includes a base and a rod. The base is a disc structure with a circular groove at its center, and a through hole is opened at the center of the groove. The rod is a hollow structure, and the head section is welded to the midline of the base. The central hole of the rod is aligned with the through hole at the center of the base groove. A window is provided on the side surface of the end of the rod. The mirror is a cylindrical structure with an inclined plane. The mirror consists of two parts. One part is a cylinder with the same outer diameter as the rod of the probe housing. The other part is a cylindrical structure with an inclined plane and the same inner diameter as the rod of the probe housing. The inclined plane is polished to serve as a mirror surface. The inclined plane of the mirror is inserted from the end of the rod of the probe housing, and the inclined plane is aligned with the window on the side surface of the end of the rod of the probe housing.

[0009] The light pipe includes a mounting head and a body. The mounting head is disc-shaped and has the same size as the central groove of the probe housing base. The mounting head is fixedly connected to the central groove of the housing base by screws. A central hole is opened in the mounting head. The body is a tubular structure, and the inner diameter of the tubular structure is the same as the diameter of the central hole in the mounting head. The head end of the body is fixed at the central position of the mounting head, and the inner diameter of the tubular structure is aligned with the central hole of the mounting head. The tail end is fixed inside the rod of the probe housing. An optical component is installed inside the body to receive and process the light reflected from the mirror. The outer diameter of the body is smaller than the inner diameter of the rod of the probe housing.

[0010] The mounting seat is a cylindrical cup-shaped structure, including a cup bottom and a side wall. The cup bottom is disc-shaped with a central hole. The outer diameter of the cup bottom is the same as the outer diameter of the probe housing base and is fixedly connected by screws. The central hole of the cup bottom is the same as the outer diameter of the mounting head of the light pipe. The outer diameter of the side wall is smaller than the diameter of the cup bottom. External threads are provided on the outer side surface of the cup mouth of the side wall of the mounting seat.

[0011] The detection head of the photodetector is located in the central hole of the cup bottom of the mounting seat and is aligned with the light pipe. The fixing plate is disc-shaped, and a plurality of through holes for the detector data line to pass through are opened at the central part. The photodetector is located between the fixing plate and the bottom of the cup-shaped structure of the mounting seat. The fixing plate is connected to the bottom of the mounting seat by screws to clamp the photodetector.

[0012] The rear cover has internal threads that match the external threads provided on the outer side surface of the cup mouth of the side wall of the mounting seat. There is an opening at the center of the rear cover for the detector data line to pass through the plurality of through holes.

[0013] Compared with the prior art, the advantages of the present invention are:

[0014] (1) Compared with traditional large probes, the overall size of the probe is smaller and the weight is lighter, and it can effectively maintain stability in the high-vibration environment of aeroengines.

[0015] (2) The probe has a simple structure and is easy to assemble. It can be stored in the form of independent components and assembled on-site during use.

[0016] (3) The internal card of the probe can flexibly adjust its structure according to different models of photodetectors, and can effectively support a variety of photodetectors for acquisition. This probe has the advantages of high temperature and high pressure resistance, high stability and small size. Description of the Drawings

[0017] Figure 1 is the external view of the small radiation temperature measurement probe for the turbine blade of the aero-engine of the present invention;

[0018] Figure 2 is the exploded view of the small radiation temperature measurement probe for the aero-engine of the present invention;

[0019] Figure 3 is the cross-sectional view of the small radiation temperature measurement probe of the present invention;

[0020] Figure 4 is the overall structure dimension diagram of the present invention;

[0021] Figure 5 is the probe assembly diagram in the actual aero-engine of the present invention;

[0022] Figure 6 is the diagram of the reflector of the present invention;

[0023] Figure 7 is the diagram of the probe housing of the present invention;

[0024] Figure 8 is the diagram of the mounting base of the present invention;

[0025] Figure 9 is the diagram of the fixing plate of the present invention;

[0026] Figure 10 is the diagram of the rear cover of the present invention.

[0027] In the figure, 1 is the reflector; 2 is the probe housing; 3 is the mounting base; 4 is the rear cover; 5 is the photodetector; 6 is the fixing plate; 7 is the light pipe; 8 is the turbine blade, 9 is the data line. Detailed Embodiments

[0028] When performing real-time optical signal acquisition, the probe is inserted into the aero-engine, and the position of the probe is adjusted so that the reflector faces the surface of the turbine blade. After the adjustment is completed, the small probe is connected to the flange outside the aero-engine through screws and nuts, and flat gaskets of appropriate size are added to the screws to reduce the risk of falling off.

[0029] The radiation light information on the surface of the turbine blade is received by the mirror through the small hole outside the light pipe housing. The mirror is at a 45° angle, reflecting as much of the radiation light as possible into the probe. The light pipe inside the probe receives the radiation light and uses its internal optical system to process the original light information, filtering out the radiation light in the unwanted wavelength bands and focusing the radiation light in the desired wavelength bands for output. The photodetector on the mounting base is coaxial with the light pipe, receives the light information output by the light pipe onto its chip, converts the radiation light signal into an electrical signal using the internal circuit, and outputs it through a cable.

[0030] The small radiation temperature measurement probe generally needs to be connected to the chassis. The output electrical signal is processed by the chassis and then output as specific temperature data.

[0031] The present invention will be further described below in conjunction with the accompanying drawings:

[0032] The inner diameter of the mirror structure is 8.5 mm, the outer diameter is 10.5 mm, and there is a 45° inclined plane inside, and this inclined plane has been polished; a protective film with a thickness of 1.5 - 2.3 um is plated on the polished surface of the mirror to protect the polished surface from wear caused by the external environment;

[0033] The total length of the probe housing is 290 mm. A two - stage structure is used to improve its overall rigidity. The first stage is 181 mm long with an outer diameter of 10.5 mm, and the second stage is 100 mm long with an outer diameter of 14.5 mm; the inner diameter of the probe housing is 10 mm, and the light pipe can be directly installed inside it. After installation, the axial distance between the light pipe and the mirror surface is about 14 mm; a through - hole with a diameter of 5.0 mm is opened at the very front end of the probe housing, and after the mirror is installed, the light enters through this opening.

[0034] The total length of the light pipe is 272 mm, the outer diameter is 8 mm, and there are three solder joints with a diameter of about 1 mm at the very front end to ensure stability inside the probe housing after being inserted; the light pipe contains optical components such as sapphire window panes, collimating mirrors, focusing mirrors, filter plates, field diaphragms, and aperture diaphragms inside, which can perform basic filtering and focusing processing on the collected optical signals.

[0035] The mounting base and the fixing plate are used to fix the photodetector. The outer diameter of the contact end of the mounting base with the probe housing is 70 mm, the thickness is 10 mm, and there are 8 through - holes with a diameter of 5.1 mm, which are connected to the probe housing by M5 bolts. The outer diameter of the contact end with the photodetector is 50 mm and the inner diameter is 46 mm, and there is a 10 - mm - long thread for connecting to the rear cover. There are two M4 threaded holes inside the mounting base for connecting the photodetector and the fixing plate. The outer diameter of the fixing plate is 45 mm, and the positions of the holes inside can be adjusted according to the size of the photodetector to firmly fix the photodetector at the designated position on the mounting base. At the same time, the fixing plate conducts the heat of the photodetector cooler to protect the internal temperature of the photodetector from being constant.

[0036] The outer diameter of the rear cover is 50 mm, and the inner part is an M50 threaded hole with a depth of 10 mm. It is connected to the mounting base through this structure. There is a wire bundling base with an outer diameter of 12 mm, an inner diameter of 9 mm, and a length of 20 mm at the rear end, and there is a groove, through which the cable led out by the photodetector can be fixed.

[0037] Figure 1 It is the external view of the small radiation temperature measurement probe for the turbine blade of the aero-engine of the present invention. The materials of the mirror 1, the probe housing 2, the mounting base 3, the rear cover 4, and the fixing plate 6 are all GH3044 high-temperature resistant hard alloy, which has high plasticity and medium thermal strength, and has excellent oxidation resistance and good stamping and welding process performance.

[0038] Figure 2 It is the exploded view of the structure of the small radiation temperature measurement probe for the turbine blade of the aero-engine of the present invention. Combining Figure 1 and Figure 2 , the steps for assembling the probe are as follows:

[0039] Step ①, install the mirror 1 to the probe housing 2. The size of the mirror is customized according to the size of the probe housing, and the internal thread method is used for connection.

[0040] Step ②, install the light pipe 7 to the probe housing 2. The inner diameter of the probe housing can be customized according to the outer diameter of the light pipe, and two m3 screws are used to pass through the through holes at the rear end of the light pipe and connect to the threaded holes in the inner ring of the flange of the probe housing.

[0041] Step ③, install the photodetector 5 to the mounting base 3. The size of the through hole inside the mounting base and the pitch of the threaded holes in the cavity can be customized according to the different models of the photodetector.

[0042] Step ④, install the fixing plate 6 to the mounting base 3. The fixing plate passes through the pins at the rear end of the photodetector and is connected to the mounting base with m3 screws. The central hole of the fixing plate can be changed according to the different models of the photodetector, and it can be adapted to a variety of different photodetectors.

[0043] Step ⑤, install the cable of the photodetector to the fixed photodetector, and the front-end interface of the cable is connected to the rear-end pins of the photodetector by insertion.

[0044] Step ⑥, pass the rear cover 4 through the cable of the photodetector and connect it to the mounting base 3 through its external M50 thread.

[0045] Step ⑦, use a cable tie to fix the cable led out by the photodetector to the wire bundling base at the rear end of the rear cover 4.

[0046] Step ⑧: Connect the probe housing 2 and the mounting base 3 with all components installed through their respective flanges, using 4 m5 screws for the connection, and adding flat gaskets at both ends for anti-slip treatment.

[0047] Figure 3 The figure shows a cross-sectional view of the small radiation temperature measurement probe. As shown in the figure, from left to right near the hot end of the probe are the mirror 1, the probe housing 2, the light pipe 7, the mounting base 3, the photoelectric detector 5, the fixing plate 6, and the rear cover 4. The processing of the original signal by this probe can be divided into three parts: initial light, optical system processing, and photoelectric conversion. The mirror reflects the initial light to the light pipe, the light pipe performs optical system processing, and the photoelectric detector converts the processed optical signal into an electrical signal. The functions of the remaining components are to carry these three main components.

[0048] Figure 4 This is the external dimension diagram of the small radiation temperature measurement probe of the present invention. As shown in the figure, the total length of the probe inserted into the turbine is 183 mm + 100 mm + 2 mm (welding length) = 285 mm. The total length of the probe outside the turbine is 7 mm + 5.5 mm + 37 mm + 25 mm = 74.5 mm, and the maximum outer diameter is 70 mm. The total length of the probe (excluding the lead cable) is 285 mm + 74.5 mm = 359.5 mm.

[0049] Figure 5 This is the installation schematic diagram of the radiation temperature measurement probe of the present invention on the turbine. When installing the probe, insert the radiation temperature measurement probe into the turbine, adjust the position of the probe until the mirror is facing the turbine blade, use screws to connect the probe flange to the turbine external flange, and add flat gaskets for anti-slip treatment.

[0050] According to the above embodiments, the dimensions of each part of the small radiation temperature measurement probe for turbine blades do not limit the present invention. For those skilled in the art to implement the small radiation temperature measurement probe for turbine blades, the type of photoelectric detector and the dimensions of other components can be changed according to the actual working environment of different aeroengine turbine blades, and the material of the heat-resistant alloy can be changed according to the actual situation.

Claims

1. A small radiation temperature measurement probe for an aeroengine turbine blade, the probe comprising: Mirror, probe housing, light tube, mounting base, photodetector, fixing plate, rear cover; The mirror, probe housing, light tube, mounting base, fixing plate, and rear cover are all made of GH3044 superalloy; the photodetector uses a cooled mercury cadmium telluride infrared photodetector. This device uses a mercury cadmium telluride (HgCdTe) photoconductive chip as the photosensitive element and uses a micro thermoelectric cooler to adjust the temperature difference between the inside of the detector and the environment, enabling the photosensitive material to work stably; The probe housing includes a base and a rod portion. The base is a disc structure with a circular groove in the center. There is a through hole in the center of the groove. The rod portion is a hollow structure. The head section is welded to the midline of the base. The central hole of the rod portion is aligned with the through hole in the center of the base groove. There is a window on the side of the end of the rod portion; the mirror is a cylindrical structure with an inclined cut surface. The mirror consists of two parts. One part is a cylinder with the same outer diameter as the rod portion of the probe housing; the other part is a cylindrical structure with an inclined cut surface and the same inner diameter as the rod portion of the probe housing. The inclined cut surface is polished to serve as a mirror surface; the inclined cut surface of the mirror is inserted from the end of the rod portion of the probe housing, and the inclined cut surface is aligned with the window on the side of the end of the rod portion of the probe housing; The light tube includes a mounting head and a body. The mounting head is disc-shaped with the same size as the central groove of the probe housing base. The mounting head is fixedly connected to the central groove of the housing base by screws; there is a central hole in the mounting head. The body is a tubular structure with an inner diameter the same as the diameter of the central hole in the mounting head. The head end of the tubular structure is fixed at the central position of the mounting head. The inner diameter of the tubular structure is aligned with the central hole in the mounting head, and the tail end is fixed inside the rod portion of the probe housing; an optical component is installed inside the body to receive and process the light reflected from the mirror; the outer diameter of the body is smaller than the inner diameter of the rod portion of the probe housing; The mounting base is a cylindrical cup-shaped structure, including a cup bottom and a side wall. The cup bottom is disc-shaped with a central hole. The outer diameter of the cup bottom is the same as the outer diameter of the probe housing base and is fixedly connected by screws. The central hole in the cup bottom is the same as the outer diameter of the mounting head of the light tube; the outer diameter of the side wall is smaller than the diameter of the cup bottom; there is an external thread on the outer side of the cup mouth of the side wall of the mounting base; The detection head of the photodetector is located in the central hole of the cup bottom of the mounting base and is aligned with the light tube; the fixing plate is disc-shaped, and there are multiple through holes in the central part for the detector data line to pass through. The photodetector is located between the fixing plate and the bottom of the cup-shaped structure of the mounting base. The fixing plate is connected to the bottom of the mounting base by screws to clamp the photodetector; The rear cover has an internal thread that matches the external thread provided on the outer side of the cup mouth of the side wall of the mounting base. There is a central hole in the rear cover for the detector data line to pass through multiple through holes.

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