Optical fiber total temperature probe

Abstract

The invention belongs to the technical field of optical fiber total temperature probe design, and particularly relates to an optical fiber total temperature probe, which collects optical signals under a high-temperature condition and within a limited volume by using a high-temperature-resistant sapphire optical fiber, can effectively collect blackbody radiation energy, and transmits the blackbody radiation energy to a low-temperature area for detection in a low-loss manner. According to the optical fiber total temperature probe structure, the inner wall of the probe protection tube radiates optical signals, the sapphire optical fiber for receiving the optical signals is designed to be located at the position, with the relatively low temperature, of the rear end of the probe, blackbody radiation signals of the probe protection tube are received in a non-contact mode, the sapphire optical fiber can be prevented from making direct contact with the highest-temperature area, and the temperature measurement upper limit can be improved; the radiation optical signal has a fixed radiation source and is propagated in the closed cavity, so that measurement errors caused by environmental interference and emissivity deviation of the object to be measured in radiation temperature measurement can be effectively avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of optical fiber total temperature probe design, and specifically relates to an optical fiber total temperature probe. Background Art

[0002] The most mainstream measurement method for aircraft engine temperature parameters is to use thermocouples in combination with stagnation structures to form a total temperature sensor. With the development of technology, the gas temperature at the outlet of the combustion chamber of current aircraft engines has reached over 1800°C. In such a harsh environment, the difficulty of measuring the total temperature has greatly increased.

[0003] A metal thermocouple is used as the total temperature measurement probe of the temperature sensing element, which directly contacts the gas to measure the total temperature of the gas. The thermocouple wire is easily oxidized and fails under high temperature conditions, resulting in reduced measurement accuracy and poor reliability. At the same time, since the thermocouple generates a weak potential signal when measuring temperature, its anti-electromagnetic interference ability is poor, and it is difficult to meet the test requirements of the total temperature of high-temperature gas at the outlet of the aircraft engine combustion chamber.

[0004] Special fiber optic sensors based on sapphire optical fiber are widely regarded as ultra-high temperature working condition sensor solutions because they do not involve electrical characteristics, the optical properties of the material are stable under high temperature working conditions, they have good long-term temperature resistance, and they have high stability.

[0005] At present, the high-temperature sapphire fiber optic sensor is generally in the form of a platinum coating sputtered on the end of a bare fiber optic rod to form a cylindrical blackbody cavity to sense the gas temperature. The end of the fiber optic sensor is exposed to the high-temperature gas, and the blackbody radiation light reflecting the gas temperature is repeatedly totally reflected on the inner surface of the sapphire rod, and is transmitted through the optical cable to the back-end detector to be converted into a temperature indication.

[0006] The current sapphire blackbody cavity fiber optic sensor is used to measure the total temperature at the outlet of an aircraft engine combustion chamber. Due to the sapphire rod melting point of 2045°C, the upper temperature measurement limit is not high. At the same time, since the temperature sensing end is directly exposed to the high-temperature gas environment of the combustion chamber components, the radiation environment interference is large, and it is easily contaminated by carbon soot in the gas environment, which causes the blackbody cavity emissivity to change, resulting in a large total temperature measurement error.

[0007] At present, sapphire blackbody cavity optical fiber sensors are mostly measured by direct contact perpendicular to the high-temperature gas flow. The sapphire rod is directly exposed to the high-temperature gas environment. When the gas flow rate is high, its temperature measurement coefficient is low, resulting in a large temperature measurement speed error. In addition, due to the thermal radiation heat exchange between the low-temperature wall of the surrounding environment and the sensor probe, the radiation error introduced is large. Due to the uneven temperature field at the outlet of the combustion chamber components and the cooling effect of the root of the optical fiber sensor support structure, the temperature sensing end of the sensor will also produce a large thermal conductivity error.

[0008] In addition, when current aircraft engine total temperature probes measure the total temperature at the combustion chamber outlet, they mostly use ceramic-based materials as the probe's support rod load-bearing parts. During the test, they are constantly subjected to the erosion of high-temperature and high-speed combustion gas flow in the engine flow path. At the same time, the nearby rotating blades also impose alternating loads on them. The ceramic-based material has poor toughness and thermal vibration resistance, and the ceramic-based support rod is not reliable. During processing and use, the root is prone to fracture and failure, threatening the safety of aircraft engine testing.

[0009] Currently, the internal sensors of total temperature measurement probes are mostly fixed packaging structures. High-temperature glue or cement is poured inside to fix the temperature sensing element to the supporting structure, which also plays a sealing role to prevent the high-temperature gas in the flow channel from leaking to the rear-end lead packaging part and causing ablation damage. However, this kind of fixing and sealing structure will make it difficult to disassemble and replace the temperature sensing element, which is not conducive to the repair and maintenance of the temperature probe. At the same time, the high-temperature glue and cement will age after long-term use, and the sealing effect will be reduced or even fail, resulting in damage to the rear-end lead packaging part of the probe.

[0010] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0011] The purpose of the present application is to provide a fiber optic total temperature probe to overcome or alleviate at least one of the known technical deficiencies.

[0012] The technical solution of this application is:

[0013] An optical fiber total temperature probe comprises an optical fiber total temperature probe, a compression nut, a mounting seat, a ceramic outer support, and a ceramic inner support;

[0014] The mounting seat has a penetrating mounting hole;

[0015] The ceramic outer support is hollow inside, with an opening at the top of the root and a blocked front end of the tail;

[0016] The front end of the tail of the ceramic outer support passes through the mounting hole on the mounting seat, and the top end of the root is in the mounting hole, and is in contact with the 45° conical surface between the mounting holes;

[0017] The front end side wall of the tail of the ceramic outer support has an air inlet hole and an exhaust hole, wherein the air inlet hole is closer to the front end of the tail than the exhaust hole; the diameter of the air inlet hole is larger than the diameter of the exhaust hole;

[0018] The ceramic inner support has a through inner hole, is arranged in the ceramic outer support, and the top end is matched with the ceramic outer support through a step structure, a second high-temperature ceramic fiber sealing pad is arranged at the matching position of the step structure, and the front end extends to the front of the exhaust hole on the side wall of the rear end of the ceramic outer support;

[0019] The optical fiber total temperature probe includes an optical fiber connector, a quartz optical fiber, an adapter, an inner tube, a sapphire optical fiber and a probe protection tube;

[0020] The probe protection tube is sealed at the front end, passes through the inner hole of the ceramic inner support, and extends into the front end of the tail of the ceramic outer support;

[0021] The front end of the sapphire optical fiber extends into the protective tube of the probe;

[0022] The inner tube is fixed between the probe protection tube and the sapphire optical fiber by high temperature adhesive bonding;

[0023] The adapter is connected to the top of the probe protection tube;

[0024] The adapter seat has an adapter hole inside and an annular boss on the outer wall. The front end extends into the inner hole of the ceramic inner support and is matched with the inner hole of the ceramic inner support through a step structure. A first high-temperature ceramic fiber sealing pad is provided at the matching position of the step structure.

[0025] The rear end of the sapphire optical fiber extends into the transfer hole;

[0026] The front end of the quartz optical fiber extends into the adapter hole and is connected to the rear end of the sapphire optical fiber;

[0027] The optical fiber connector is connected to the rear end of the quartz optical fiber;

[0028] The compression nut is sleeved on the outer periphery of the adapter seat, threadedly connected in the mounting hole of the mounting seat, compressed on the annular boss, and matched with the annular boss through a step structure, and a sealing gasket is arranged at the matching position of the step structure.

[0029] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, a threaded hole is opened on the side wall of the mounting seat for installing a locking screw;

[0030] A locking opening is arranged on the top side wall of the root of the ceramic outer support, and a locking screw is inserted into the locking opening.

[0031] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, the mounting seat is entirely made of high-temperature alloy material;

[0032] The outer wall of the mounting seat has a mounting edge and can be mounted on the receiver by bolts;

[0033] A mounting gasket is provided on the mounting seat. The mounting gasket is made of relatively soft metal material and is located between the mounting edge and the receiver.

[0034] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, the ceramic outer support member and the ceramic inner support member are tightly connected by high temperature resistant ceramic fibers;

[0035] The air inlet and exhaust holes on the ceramic outer support are circular, and the air inlet openings are 45° Chamfer.

[0036] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, the ceramic outer support is reinforced near the root of the mounting seat and transitions to the exhaust hole position on the front end side wall of the tail at a certain cone angle.

[0037] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, the probe protection tube is made of metal iridium;

[0038] The ratio of the length of the portion of the probe protection tube extending into the front end of the tail of the ceramic outer support to the diameter is greater than 10.

[0039] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, the inner tube is a ceramic tube.

[0040] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, the adapter is connected to the top end of the probe protection tube by bonding or welding.

[0041] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, the front end of the quartz optical fiber and the rear end of the sapphire optical fiber are fused in the transfer hole, and the fusion joint is sealed and protected.

[0042] According to at least one embodiment of the present application, in the above-mentioned optical fiber total temperature probe, a high-temperature spring washer is provided on the outer periphery of the adapter;

[0043] The high temperature spring washer is located between the annular boss and the top end of the ceramic outer support member.

[0044] This application has at least the following beneficial technical effects:

[0045] Provided is an optical fiber total temperature probe, which uses a high-temperature resistant sapphire optical fiber to collect optical signals under high temperature conditions and in a limited volume, can effectively collect blackbody radiation energy and transmit it to a low-temperature area with low loss for detection. The inner wall of the probe protection tube can radiate optical signals, and the sapphire optical fiber that receives the optical signal is designed to be located at a relatively low temperature position at the rear end of the probe, so as to receive the blackbody radiation signal of the probe protection tube in a non-contact manner, thereby preventing the sapphire optical fiber from directly contacting the highest temperature area and improving the upper limit of temperature measurement. In addition, in the optical fiber total temperature probe structure, the radiated optical signal has a fixed radiation source and is propagated in a closed cavity, which can effectively avoid measurement errors caused by environmental interference and emissivity offset of the object to be measured in radiation temperature measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic diagram of an optical fiber total temperature probe provided in an embodiment of the present application;

[0047] Figure 2 is a schematic diagram of a mounting base provided in an embodiment of the present application;

[0048] Figure 3 is a schematic diagram of a ceramic outer support provided in an embodiment of the present application;

[0049] Figure 4 is a schematic diagram of an optical fiber total temperature probe provided in an embodiment of the present application;

[0050] Figure 5 is a schematic diagram of the variation of the blackbody radiation spectrum with temperature provided in the embodiment of the present application;

[0051] in:

[0052] 1-optical fiber total temperature probe; 2-compression nut; 3-sealing gasket; 4-high temperature spring washer; 5-locking screw; 6-mounting seat; 7-mounting gasket; 8-first high temperature ceramic fiber sealing gasket; 9-ceramic outer support; 10-second high temperature ceramic fiber sealing gasket; 11-ceramic inner support;

[0053] 1-1-fiber optic connector; 1-2-quartz optical fiber; 1-3-adapter; 1-4-inner tube; 1-5-sapphire optical fiber; 1-6-probe protection tube.

[0054] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0055] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0056] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0057] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0058] A fiber optic total temperature probe, such as Figure 1 As shown, it includes an optical fiber total temperature probe 1, a compression nut 2, a sealing gasket 3, a high-temperature spring washer 4, a locking screw 5, a mounting seat 6, a mounting gasket 7, a first high-temperature ceramic fiber sealing gasket 8, a ceramic outer support 9, a second high-temperature ceramic fiber sealing gasket 10, and a ceramic inner support 11.

[0059] The mounting seat 6 is made of high temperature alloy material as a whole. Figure 2 As shown, there is a through mounting hole. The side wall of the mounting seat 6 is provided with a threaded hole for mounting the locking screw 5.

[0060] The outer wall of the mounting seat 6 has a mounting edge, and can be mounted on the receiver by bolts.

[0061] The mounting gasket 7 is made of relatively soft metal material, is sleeved on the outer periphery of the mounting seat 6, and is located between the mounting edge and the casing, and can play a role in vibration reduction and sealing.

[0062] The ceramic outer support 9 and the ceramic inner support 11 are combined into a double-layer load-bearing support rod, which can withstand the scouring of high-temperature combustion gas in the flow channel in the casing, and the ceramic outer support 9 and the ceramic inner support 11 are designed to be tightly connected by high-temperature resistant ceramic fibers.

[0063] Ceramic outer support 9 such as Figure 3 As shown, the whole adopts a conical structure, which is hollow inside, with an open top at the root and a blocked front end at the tail. The front end of the tail of the ceramic outer support 9 passes through the mounting hole on the mounting seat 6 and extends into the casing to contact with the high-temperature combustion gas. The top of the root is in the mounting hole and contacts with the 45° cone surface between the mounting holes.

[0064] The ceramic outer support 9 has an air inlet and an air outlet on its rear front end side wall, wherein the air inlet is closer to the rear front end than the air outlet. This ensures that the high-temperature gas flow rate from the air inlet hole into the ceramic outer support 9 is reduced to less than M0.2. The air inlet hole is chamfered at 45°, which can expand the insensitive angle range of the temperature test and improve the accuracy of temperature measurement.

[0065] The ceramic outer support 9 is reinforced near the root of the mounting seat 6, and transitions to the exhaust hole position on the front end side wall of the tail at a certain cone angle, close to the center of the flow channel in the casing.

[0066] A locking hole is provided on the top side wall of the root of the ceramic outer support 9, and the locking screw 5 is inserted into the locking hole to lock and limit the ceramic outer support 9 to prevent the ceramic outer support 9 from circumferential rotation and axial movement during use.

[0067] The ceramic inner support 11 has a penetrating inner hole and is arranged in the ceramic outer support 9. The top end is matched with the ceramic outer support 9 through a step structure. A second high-temperature ceramic fiber sealing pad 10 is arranged at the matching position of the step structure, and the front end extends to the front of the exhaust hole on the front end side wall of the rear end of the ceramic outer support 9.

[0068] Fiber optic total temperature probe 1 Figure 4 As shown, it is mainly composed of an optical fiber connector 1-1, a quartz optical fiber 1-2, an adapter seat 1-3, an inner tube 1-4, a sapphire optical fiber 1-5 and a probe protection tube 1-6.

[0069] The probe protection tube 1-6 is blocked at the front end, passes through the inner hole of the ceramic inner support 11, and extends into the front end of the tail of the ceramic outer support 9. The ratio of the length of the portion of the probe protection tube 1-6 extending into the front end of the tail of the ceramic outer support 9 to the diameter is greater than 10.

[0070] The probe protection tube 1-6 is made of metal iridium and will be in direct contact with the high-temperature gas. The high-temperature gas entering the front end of the rear end of the ceramic outer support 9 is stagnant at the front end of the probe protection tube 1-6. At this time, the temperature of the front end of the probe protection tube 1-6 is the stagnant total temperature of the high-temperature gas. The front end of the probe protection tube 1-6 can emit a blackbody radiation signal at the corresponding temperature, which is not interfered by the external high-temperature gas environment.

[0071] The front end of the sapphire optical fiber 1-5 extends into the probe protection tube 1-6 and can receive black body radiation signals.

[0072] The inner tube 1-4 is a ceramic tube, which is fixed between the probe protection tube 1-6 and the sapphire optical fiber 1-5 by high-temperature adhesive bonding, and plays a supporting and limiting role for the sapphire optical fiber 1-5, ensuring the stability of the sapphire optical fiber 1-5 when receiving the black body radiation signal.

[0073] The adapter seat 1-3 is connected to the top of the probe protection tube 1-6 by bonding or welding, and is used for the installation and fixation of the optical fiber total temperature probe 1. The adapter seat 1-3 has an adapter hole inside, and an annular boss on the outer wall. The front end extends into the inner hole of the ceramic inner support 11, and is matched with the inner hole of the ceramic inner support 11 through a step structure. A first high-temperature ceramic fiber sealing pad 8 is provided at the matching position of the step structure. The rear end of the sapphire optical fiber 1-5 extends into the adapter hole.

[0074] The front end of the quartz optical fiber 1-2 extends into the transfer hole and is fused with the rear end of the sapphire optical fiber 1-5. The fusion joint is sealed for protection. The black body radiation signal received by the front end of the sapphire optical fiber 1-5 can be transmitted to the quartz optical fiber 1-2 in the low temperature area at the rear end. The two optical fibers are coupled by fusion or the like.

[0075] The optical fiber connector 1-1 is connected to the rear end of the quartz optical fiber 1-2.

[0076] The clamping nut 2 is sleeved on the outer periphery of the adapter 1-3, threadedly connected in the mounting hole of the mounting seat 6, pressed on the annular boss, and matched with the annular boss through a step structure, and a sealing gasket 3 is arranged at the matching position of the step structure.

[0077] The high-temperature spring washer 4 is sleeved on the outer periphery of the adapter 1-3, and is located between the annular boss and the top of the ceramic outer support 9. It can play a buffering and vibration reduction role when the clamping nut 2 clamps the optical fiber total temperature probe 1. At the same time, it can also adjust the thread preload force of the clamping nut 2 to prevent the clamping nut 2 from loosening due to vibration during use.

[0078] In the optical fiber total temperature probe disclosed in the above embodiment, four movable sealing structures are designed, which are respectively a 45° conical surface seal between the ceramic outer support 9 and the mounting seat 6, a first high-temperature ceramic fiber sealing pad 8 is added to the ceramic inner support 11 and the optical fiber total temperature probe 1 to seal, a second high-temperature ceramic fiber sealing pad 10 is added to seal between the ceramic inner support 11 and the ceramic outer support 9, and a sealing gasket 3 is added to seal between the optical fiber total temperature probe 1 and the clamping nut 2. After the clamping nut 2 is tightened, the four movable sealing structures can be pressed by force to ensure that the high-temperature fuel gas will not leak. At the same time, the arrangement of the four movable sealing structures facilitates the replacement of the optical fiber total temperature probe 1.

[0079] The optical fiber total temperature probe 1 is a key temperature sensing component of the optical fiber total temperature probe, and it must be reliably fixed when in use. When the compression nut is tightened 2, a compression force is applied to the optical fiber total temperature probe 1, and the optical fiber total temperature probe 1 then transmits the compression force to the ceramic inner support 11 and the ceramic outer support 9, so that all components inside the optical fiber total temperature probe form a reliable connection with the mounting seat 6, and the optical fiber total temperature probe 1 is reliably fixed. This fixing structure can support the flexible replacement of the optical fiber total temperature probe 1, and has higher reliability and economy.

[0080] When the total temperature at the outlet of an aircraft engine combustion chamber is measured using the optical fiber total temperature probe disclosed in the above-mentioned embodiment, the mounting edge on the mounting seat 6 can be connected to the casing by bolts for fixation. The mounting seat 6 and the front end of its ceramic outer support 9 extend into the flow channel through the measuring hole provided on the casing. The high-temperature combustion gas can enter from the windward side from the air inlet hole on the ceramic outer support 9, stop at the front end of the optical fiber total temperature probe 1, and be discharged from the exhaust hole on the leeward side of the ceramic outer support 9. The front end temperature of the optical fiber total temperature probe 1 is the stagnation temperature of the high-temperature combustion gas, that is, the total temperature of the high-temperature combustion gas at the outlet of the aircraft engine combustion chamber.

[0081] The internal flow temperature measurement of aircraft engines usually refers specifically to the internal flow total temperature measurement. The total temperature T* of the airflow consists of two parts: static temperature T and dynamic temperature Tv. The static temperature T is the kinetic energy of the free movement of gas molecules, and the dynamic temperature Tv is the kinetic energy of the directional movement of gas molecules. In order to make the surface temperature of the sensor closer to the total temperature of the airflow, a stagnation structure is designed for the total temperature probe. The airflow will be subject to the dual stagnation effect of the stagnation cavity and the end face of the sensor, and the flow velocity will drop significantly. The kinetic energy of the airflow will be converted into thermal energy, which will increase the temperature of the airflow inside the total temperature probe. When heat dissipation is ignored, the temperature at the top of the sensor is the total temperature of the airflow.

[0082] According to the radiation principle, all objects with temperature will continuously emit thermal radiation to the outside world, and it will be manifested in the form of electromagnetic waves. According to Planck's formula, the radiation energy per unit wavelength interval of a specific wavelength emitted by a black body per unit area in all directions of the hemispherical space per unit time is Where λ is the radiation wavelength of the object, T is the absolute temperature of the object, C1 = 3.7418 × 10 －16 Wm 2 , C 2 =1.4388×10 －2 mk are the first and second radiation constants respectively.

[0083] The variation of blackbody radiation spectrum with temperature is as follows: Figure 5 As shown. It can be seen that the blackbody radiation energy characteristics within a certain band are modulated by temperature. For actual objects, the above characteristics are also applicable. Based on this characteristic, the corresponding temperature information can be demodulated by measuring the characteristic signal of the target object's radiation energy.

[0084] The optical fiber total temperature probe disclosed in the above embodiment uses a high temperature resistant sapphire optical fiber 1-5 to collect optical signals under high temperature conditions and in a limited volume, and can effectively collect black body radiation energy and transmit it to the low temperature area with low loss for detection. The inner wall of the probe protection tube 1-6 will radiate optical signals. The sapphire optical fiber 1-5 that receives the optical signal is designed to be located at a relatively low temperature position at the rear end of the probe, and the black body radiation signal of the probe protection tube 1-6 is received non-contactly, so that the sapphire optical fiber 1-5 can avoid direct contact with the highest temperature area, thereby increasing the upper limit of temperature measurement. In addition, in the optical fiber total temperature probe structure disclosed in the above embodiment, the radiated optical signal has a fixed radiation source and propagates in a closed cavity, which can effectively avoid measurement errors caused by environmental interference and emissivity offset of the object to be measured in radiation temperature measurement.

[0085] In the optical fiber total temperature probe disclosed in the above embodiment, the ceramic outer support member 9 is designed to have a rear end and a front end side wall. The flow rate of the high-temperature combustion gas entering the front end of the tail of the ceramic outer support 9 can be reduced to below M0.2, which can effectively reduce the speed error of the temperature measurement of the optical fiber total temperature probe 1, and the front end of the tail of the ceramic outer support 9 can effectively shield the radiation interference of the low-temperature wall of the surrounding environment on the optical fiber total temperature probe 1 therein, reduce the temperature difference between the optical fiber total temperature probe 1 and the wall "seen" by it, and reduce the temperature measurement error caused by radiation heat exchange. In addition, the optical fiber total temperature probe 1 is parallel to the gas flow direction in the shielding cavity formed at the front end of the tail of the ceramic outer support 9. According to the principle of infinite length pivot heat conduction, the ratio of the length to the diameter of the optical fiber total temperature probe 1 in the shielding cavity is designed to be greater than 10, and the convective heat transfer area and thermal conductivity resistance of the optical fiber total temperature probe 1 are increased. The optical fiber total temperature probe 1 in the shielding cavity will be uniformly heated by the high-temperature combustion gas, and the temperature at the internal support base will be closer to the temperature of the temperature sensing area at the front end of the probe, so as to reduce the thermal conduction error.

[0086] The optical fiber total temperature probe disclosed in the above embodiment is applied to the total temperature measurement of the combustion chamber outlet of an aircraft engine, which can effectively suppress the velocity error, radiation error and thermal conductivity error, and reduce the influence of these three errors on the accuracy of the total temperature measurement.

[0087] In the optical fiber total temperature probe disclosed in the above embodiment, the thermal radiation energy of the part of the optical fiber total temperature probe 1 that contacts the high-temperature fuel gas is received by the sapphire optical fiber 1-5 inside the probe, and the fuel gas stagnation temperature is then demodulated. The total temperature of the high-temperature and high-speed fuel gas at the outlet of the aircraft engine combustion chamber can be measured in a contact manner. This can solve the problems of the existing temperature measurement methods that are susceptible to environmental interference, poor reliability and low accuracy, and can effectively avoid the measurement errors caused by the emissivity offset of the object to be measured in traditional radiation temperature measurement.

[0088] In the optical fiber total temperature probe disclosed in the above embodiment, the shielding cavity formed at the front end of the tail of the ceramic outer support 9 can shield the radiation interference of the low-temperature wall of the surrounding environment, reduce the temperature measurement error caused by the radiation heat exchange, and reduce the high-temperature gas flow rate at the temperature sensing end of the optical fiber total temperature probe 1 by designing the area of ​​the air inlet and outlet holes. The optical fiber total temperature probe 1 is parallel to the flow direction of the high-temperature gas in the shielding cavity. The optical fiber total temperature probe 1 will be uniformly heated by the gas in the shielding cavity, and the surface temperature is close to the same, which can reduce the cooling effect of the root of the supporting structure of the optical fiber total temperature probe 1 and reduce the thermal conductivity error.

[0089] In the optical fiber total temperature probe disclosed in the above embodiment, a ceramic outer support member 9 and a ceramic inner support member 11 are combined into a double-layer load-bearing support rod to form a double-layer composite ceramic support structure. The inner and outer layer support rods are compressed and connected by high-temperature resistant ceramic fibers, which can reduce the impact load of the high-temperature gas flow and the alternating load applied by the rotating blades, improve the rigidity and vibration resistance of the support structure, and the inner and outer layer support rods and seals under this structure can be replaced separately if damaged, which is economical.

[0090] In the optical fiber total temperature probe disclosed in the above embodiment, a reliable internal sealing and fixing structure is designed to prevent leakage of high-temperature fuel gas and avoid ablation of the probe tail packaging part. At the same time, this structure can also ensure that the optical fiber total temperature probe 1 inside the probe can be reliably fixed and flexibly replaced, with high reliability and economy.

[0091] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. An optical fiber total temperature probe, characterized in that: It comprises an optical fiber total temperature probe (1), a compression nut (2), a mounting seat (6), a ceramic outer support (9), and a ceramic inner support (11); The mounting seat (6) has a through mounting hole; The ceramic outer support member (9) is hollow inside, with an opening at the top of the root and a blocked front end of the tail; The front end of the tail of the ceramic outer support member (9) passes through the mounting hole on the mounting seat (6), and the top end of the root is located in the mounting hole and is in contact with the 45° conical surface between the mounting holes; The ceramic outer support member (9) has an air inlet hole and an air outlet hole on its rear front end side wall, wherein the air inlet hole is closer to the rear front end than the air outlet hole; the diameter of the air inlet hole is larger than the diameter of the air outlet hole; The ceramic inner support (11) has a through inner hole, is arranged in the ceramic outer support (9), and the top end is matched with the ceramic outer support (9) through a step structure. A second high-temperature ceramic fiber sealing pad (10) is arranged at the matching position of the step structure, and the front end extends to the front of the exhaust hole on the side wall of the rear end of the ceramic outer support (9); The optical fiber total temperature probe (1) comprises an optical fiber connector (1-1), a quartz optical fiber (1-2), an adapter seat (1-3), an inner tube (1-4), a sapphire optical fiber (1-5) and a probe protection tube (1-6); The probe protection tube (1-6) is sealed at the front end, passes through the inner hole of the ceramic inner support (11), and extends into the front end of the tail of the ceramic outer support (9); The front end of the sapphire optical fiber (1-5) extends into the probe protection tube (1-6); The inner tube (1-4) is fixed between the probe protection tube (1-6) and the sapphire optical fiber (1-5) by means of high-temperature adhesive bonding; The adapter (1-3) is connected to the top of the probe protection tube (1-6); The adapter seat (1-3) has an adapter hole inside and an annular boss on its outer wall. The front end extends into the inner hole of the ceramic inner support (11) and is matched with the inner hole of the ceramic inner support (11) via a step structure. A first high-temperature ceramic fiber sealing pad (8) is provided at the matching position of the step structure. The rear end of the sapphire optical fiber (1-5) extends into the transfer hole; The front end of the quartz optical fiber (1-2) extends into the transfer hole and is connected to the rear end of the sapphire optical fiber (1-5); The optical fiber connector (1-1) is connected to the rear end of the quartz optical fiber (1-2); The clamping nut (2) is sleeved on the outer circumference of the adapter seat (1-3), threadedly connected in the mounting hole of the mounting seat (6), and clamped on the annular boss. The clamping nut and the annular boss are matched via a step structure, and a sealing gasket (3) is provided at the matching position of the step structure.

2. The optical fiber total temperature probe according to claim 1, characterized in that: The side wall of the mounting seat (6) is provided with a threaded hole for mounting a locking screw (5); A locking opening is provided on the top side wall of the root of the ceramic outer support member (9), and a locking screw (5) is inserted into the locking opening.

3. The optical fiber total temperature probe according to claim 2, characterized in that: The mounting seat (6) is entirely made of high-temperature alloy material; The outer wall of the mounting seat (6) has a mounting edge and can be mounted on the receiver by bolts; The mounting seat (6) is sleeved with a mounting gasket (7), which is made of relatively soft metal material and is located between the mounting edge and the casing.

4. The optical fiber total temperature probe according to claim 3, characterized in that: The ceramic outer support member (9) and the ceramic inner support member (11) are tightly connected by using high temperature resistant ceramic fibers; The air inlet and the air outlet on the ceramic outer support (9) are circular, and the opening of the air inlet is chamfered at 45°.

5. The optical fiber total temperature probe according to claim 4, characterized in that: The ceramic outer support member (9) is reinforced near the root of the mounting seat (6) and transitions to the exhaust hole position on the front end side wall of the tail at a certain cone angle.

6. The optical fiber total temperature probe according to claim 5, characterized in that: The probe protection tube (1-6) is made of metal iridium; The ratio of the length of the portion of the probe protection tube (1-6) extending into the front end of the tail of the ceramic outer support (9) to the diameter is greater than 10.

7. The optical fiber total temperature probe according to claim 6, characterized in that: The inner pipe (1-4) is a ceramic pipe.

8. The optical fiber total temperature probe according to claim 7, characterized in that: The adapter seat (1-3) is connected to the top of the probe protection tube (1-6) by bonding or welding.

9. The optical fiber total temperature probe according to claim 8, characterized in that: The front end of the quartz optical fiber (1-2) and the rear end of the sapphire optical fiber (1-5) are fused in the transfer hole, and the fusion joint is sealed for protection.

10. The optical fiber total temperature probe according to claim 9, characterized in that: A high-temperature spring washer (4) is provided on the outer periphery of the adapter seat (1-3); The high-temperature spring washer (4) is located between the annular boss and the top end of the ceramic outer support member (9).

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