Boiler reheater header stress detector

Abstract

The invention relates to the technical field of stress detectors, and discloses a boiler reheater header stress detector, which comprises a fiber grating sensor, a ventilation plate and a U-shaped cover, one end of the fiber bragg grating sensor is integrally connected with a probe, a notch is formed in the edge of the fiber bragg grating sensor, the ventilation plate is installed in the notch, an air channel is formed in the ventilation plate, a pressure sensing piece is installed on the inner wall of one end of the ventilation plate, and one end of the fiber bragg grating sensor is sleeved with the U-shaped cover. The U-shaped cover is provided with an elastic piston piece which is inserted into the ventilation plate and abuts against the pressure sensing piece. And an air blowing assembly is mounted at the top in the U-shaped cover. One end of the fiber bragg grating sensor is sleeved with the U-shaped cover, all-directional protection is achieved, a probe is prevented from being damaged, during installation, the scraping piece of the U-shaped cover can clean the surface of the collecting box, feed back the unevenness condition and pre-position the adhering piece, the blowing assembly removes floating dust, the locking piece locks the sensor, the installation stability is improved, and it is guaranteed that the stress detection work of the collecting box is conducted smoothly.

Description

Technical Field

[0001] This invention relates to the field of stress detector technology, and more particularly to a stress detector for a boiler reheater header. Background Technology

[0002] With the increasing demand for energy and the ever-improving environmental protection requirements, energy-saving boilers, as a highly efficient and environmentally friendly thermal energy equipment, have gradually become an important part of industrial production. Energy-saving boilers achieve efficient energy utilization and sustainable environmental development through technologies such as optimizing the combustion process, improving thermal efficiency, reducing energy consumption, and lowering pollutant emissions. Among the many components of an energy-saving boiler, the reheater is one of its key components. The main function of the reheater is to reheat the steam discharged from the high-pressure cylinder of the steam turbine, thereby increasing the temperature and enthalpy of the steam, and thus improving the thermal efficiency of the steam turbine and reducing steam consumption. The reheater header is the core component of the reheater. It collects the steam discharged from the high-pressure cylinder of the turbine and distributes it evenly to the various tube panels of the reheater for heating. The reheater header is usually located in the high-temperature zone. During operation, the header is subjected to various loads, such as internal pressure, external load, and temperature changes, which can easily lead to stress concentration areas. These areas are high-risk parts for equipment damage. Therefore, it is necessary to detect the stress on the header in time to identify potential safety hazards and avoid accidents such as equipment cracking and leakage caused by excessive stress, so as to ensure the safe operation of the boiler. Stress detection of headers typically employs fiber Bragg grating stress sensors. The sensor's probe head is usually mounted flush against the header surface. When the header is subjected to stress, the shape and refractive index of the fiber Bragg grating within the stress sensor change, causing a change in the wavelength of the reflected light. By measuring this change in wavelength, the stress on the header can be calculated. The stress sensor converts the reflected light signal into an electrical signal, which is then transmitted to a data acquisition system. The data acquisition system processes and analyzes the signal, calculates the stress value, and displays the results in real time. In the boiler reheater header area, due to its complex environment, workers often carelessly drop or even accidentally fall the stress sensors during installation, causing damage to the sensor probes. However, existing stress sensors lack corresponding self-protection structures, making it impossible to effectively prevent such damage. Furthermore, stress sensors are usually installed by directly attaching them to the header surface without checking the flatness of the header surface. The sensors themselves are also not equipped with structures to detect the flatness of the header surface. This means that the sensors may not be able to fit tightly against the header surface after installation, thus affecting the accurate monitoring and assessment of the header stress state.

[0003] To address the aforementioned issues, this application proposes a boiler reheater header stress detector. Summary of the Invention

[0004] This invention proposes a stress detector for boiler reheater headers, which solves the problems in related technologies where the boiler reheater header area is complex, stress sensors are easily dropped or fallen, leading to probe damage, and there is no self-protection structure. Furthermore, the flatness of the header surface is not checked during installation, and the stress sensor does not have this function, affecting the accuracy of stress monitoring.

[0005] The present invention proposes a boiler reheater header stress detector, which includes a fiber optic grating sensor, a vent plate, and a U-shaped cover; One end of the fiber optic grating sensor is integrally connected to a probe. The edge of the fiber optic grating sensor has a slot. A vent plate is installed in the slot. An air passage is opened in the vent plate. A pressure sensor is installed on the inner wall of one end of the vent plate. The U-shaped cover is fitted onto one end of the fiber optic grating sensor. An elastic piston is installed on the U-shaped cover, which is inserted into the vent plate and abuts against the pressure sensor. An air blowing assembly is installed at the top inside the U-shaped cover to blow gas into the U-shaped cover, and the ventilation plate is connected to the air blowing assembly via a hose. The end of the U-shaped cover away from the fiber optic grating sensor is connected to a scraper via an adhesive attachment. The fiber optic grating sensor has a socket on its side, and a locking device corresponding to the socket is installed on the side of the U-shaped cover.

[0006] As a further optimization of the present invention, the pressure sensing element includes a pressure sensor and a loading plate. The pressure sensor located in the air passage is installed on the inner wall of one end of the vent plate through the loading plate, and the elastic piston element abuts against the pressure sensor.

[0007] As a further optimization of the present invention, the elastic piston component includes a piston head and a rod-type elastic part. The piston head is slidably disposed in the air passage within the vent plate and abuts against the pressure sensor. A slider that slides in cooperation with the slot is installed on the top wall inside the U-shaped cover. The rod-type elastic part is connected between the slider and the piston head. One end of the vent plate is provided with an air hole that communicates with the air passage and allows the piston head to move smoothly.

[0008] As a further optimization of the present invention, the rod-type elastic part includes a shaft and a first spring. One end of the shaft that slides through the vent plate is connected to the piston head, and the other end of the shaft away from the piston head is connected to the slider. The first spring is sleeved on the shaft, and both ends of the first spring are connected to the vent plate and the slider, respectively.

[0009] As a further optimization of the present invention, the air blowing assembly includes a flow divider and an air blowing section. The top wall inside the U-shaped cover has an installation port, the flow divider is fixed in the installation port, and a cavity is formed inside the flow divider. The two ends of the hose are respectively connected to the other end of the ventilation plate and the flow divider. The bottom of the flow divider is connected to two sets of air blowing sections communicating with the cavity, one set facing the probe and the other set facing the outside of the U-shaped cover.

[0010] As a further optimization of the present invention, the air blowing part includes an air blowing nozzle, which is fixed to the bottom of the diverter plate and communicates with the cavity, and a filter screen is connected to the bottom of the air blowing nozzle.

[0011] As a further optimization of the present invention, the adhesive attachment includes an adhesive plate, which is fixed to the end of the U-shaped cover away from the fiber optic sensor. The surface of the adhesive plate is provided with an adhesive layer, and the squeegee is adhered to the adhesive layer.

[0012] As a further optimization of the present invention, the wiping component includes a U-shaped piece and a wiping protrusion. The U-shaped piece is adhered to the adhesive layer, and a wiping protrusion adapted to it is fixed on the side of the U-shaped piece away from the adhesive plate.

[0013] As a further optimization of the present invention, the locking member includes a plug rod, an end head, and a second spring. The plug rod, which is adapted to the plug hole, is slidably connected to the outer side of the U-shaped cover. One end of the plug rod is fixed with an end head. The second spring is sleeved on the plug rod, and the two ends of the second spring are respectively connected to the U-shaped cover and the end head.

[0014] As a further optimization of the present invention, a cable is fixed at the end of the fiber Bragg grating sensor away from the probe, and a protective sleeve is covered at the connection between the cable and the fiber Bragg grating sensor.

[0015] The above-described technical solution of the present invention has the following beneficial technical effects: 1. This invention features a U-shaped cover fitted over one end of a fiber Bragg grating sensor, providing all-around protection for the sensor's probe. When the fiber Bragg grating sensor is not installed, the U-shaped cover effectively prevents the probe from being damaged by collisions with other objects. If the fiber Bragg grating sensor is accidentally dropped, the U-shaped cover can collide with the ground. When the U-shaped cover is subjected to impact force, the elastic piston connected to the U-shaped cover undergoes elastic deformation and moves within the vent plate, acting as a buffer. This design reduces the risk of the probe being damaged by a fall, thereby effectively avoiding stress detection failure or inaccuracy caused by probe damage, and ensuring the smooth progress of the header stress detection work. 2. When installing the fiber Bragg grating sensor, the operator holds the sensor and places the scraper at the end of the U-shaped cover against the installation area on the header surface, moving it from top to bottom. The scraper removes dust from the header surface, keeping the installation area clean. If the header surface is uneven, the U-shaped cover is pushed by a reaction force to move the elastic piston within the vent plate. The elastic piston contacts the pressure sensor. When it deforms and separates from the pressure sensor, the pressure sensor in the pressure sensor experiences a change in force, providing timely feedback on the unevenness of the header surface. The operator can then reselect the installation area. This design effectively removes dust from the header surface, providing a good foundation for the installation of the fiber Bragg grating sensor, and provides timely feedback on unevenness, ensuring a tight fit between the fiber Bragg grating sensor and the header surface. This improves the accuracy of monitoring and evaluating the stress state of the header and avoids stress detection errors caused by unsuitable installation positions. 3. After cleaning the installation area of ​​the header surface and ensuring it meets installation requirements, the scraper can be removed directly from the adhesive. Then, the fiber Bragg grating sensor can be held by hand, allowing the adhesive at the end of the U-shaped cover to adhere to the header surface installation area. The adhesive layer in the adhesive provides pre-positioning, effectively preventing displacement during subsequent installation. The fiber Bragg grating sensor can then be pushed repeatedly in small amplitudes, causing the vent plate to reciprocate along the elastic piston. The piston head in the elastic piston changes position within the vent plate's air passage, allowing gas to be delivered through the hose to the blowing assembly at the top of the U-shaped cover. The blowing assembly then blows the gas towards the probe at the fiber Bragg grating sensor end and the header surface, further removing any adhering dust. During this process, the reciprocating motion of the elastic piston utilizes efficient mechanical energy conversion, transforming the manual pushing mechanical energy into the kinetic energy of the gas. This dust-blowing operation requires no additional energy input, achieving high efficiency and energy saving. This further ensures the accuracy of subsequent header stress detection, providing more accurate monitoring data support for the safe operation of the header. 4. After blowing dust off the header and probe surfaces, the fiber Bragg grating sensor can be pushed through the U-shaped cover and fitted into the header. During this process, the vent plate moves along the elastic piston. When the insertion hole on the outside of the fiber Bragg grating sensor aligns with the locking piece on the side of the U-shaped cover, the locking piece inserts into the insertion hole, locking the fiber Bragg grating sensor and effectively limiting the possible rebound phenomenon that may occur under the action of the elastic piston, ensuring the stability of the sensor after installation. Subsequently, the U-shaped cover can be fixed to the header surface with screws or other fasteners to complete the installation of the fiber Bragg grating sensor. After installation, the U-shaped cover can protect the connection between the fiber Bragg grating sensor and the header, resisting the erosion and damage of the connection between the fiber Bragg grating sensor and the header by external environmental factors, further improving the stability and reliability of the fiber Bragg grating sensor after installation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a boiler reheater header stress detector proposed in this invention. Figure 2 For the present invention Figure 1 Overall front view; Figure 3 This is a schematic diagram of the fiber optic grating sensor of the present invention; Figure 4 This is a schematic diagram of the mating structure of the vent plate, U-shaped cover and elastic piston component of the present invention; Figure 5 For the present invention Figure 4 Overall bottom view; Figure 6 This is an internal cross-sectional view of the vent plate of the present invention; Figure 7 This is a schematic diagram of the mating structure of the pressure sensing element and the elastic piston element of the present invention; Figure 8 This is a schematic diagram of the air blowing assembly of the present invention; Figure 9 For the present invention Figure 8 Enlarged view of A in the middle; Figure 10 This is a schematic diagram of the separation structure of the adhesive attachment and the scraping component of the present invention; Figure 11 This is a schematic diagram of the locking component of the present invention.

[0017] Reference numerals: 1. Fiber optic grating sensor; 101. Probe; 102. Groove; 103. Cable; 104. Socket; 2. Vent plate; 21. Hose; 22. Air hole; 3. U-shaped cover; 31. Slider; 4. Pressure sensing element; 41. Pressure sensor; 42. Loading plate; 5. Elastic piston element; 51. Piston head; 52. Rod-type elastic part; 521. Shaft; 522. First spring; 6. Air blowing assembly; 61. Diverter plate; 62. Air blowing part; 621. Air blowing nozzle; 622. Filter screen; 7. Adhesive attachment; 71. Adhesive plate; 72. Adhesive layer; 8. Scraper; 81. U-shaped piece; 82. Scraper protrusion; 9. Locking element; 91. Insert rod; 92. End; 93. Second spring. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0019] like Figure 1-11As shown, the present invention proposes a boiler reheater header stress detector, which includes a fiber optic grating sensor 1, a vent plate 2, and a U-shaped cover 3. One end of the fiber optic grating sensor 1 is integrally connected to a probe 101. The edge of the fiber optic grating sensor 1 has a slot 102. A vent plate 2 is installed in the slot 102. An air passage is opened in the vent plate 2. A pressure sensor 4 is installed on the inner wall of one end of the vent plate 2. A U-shaped cover 3 is fitted on one end of the fiber optic grating sensor 1. An elastic piston 5 is installed on the U-shaped cover 3, which is inserted into the vent plate 2 and abuts against the pressure sensor 4. An air blowing assembly 6 is installed at the top inside the U-shaped cover 3 to blow gas into the U-shaped cover 3. The ventilation plate 2 and the air blowing assembly 6 are connected by a hose 21. The end of the U-shaped cover 3 away from the fiber optic sensor 1 is connected to a scraper 8 via an adhesive attachment 7; The fiber optic grating sensor 1 has a socket 104 on its side, and the U-shaped cover 3 has a locking element 9 corresponding to the socket 104 on its side.

[0020] The present invention provides a U-shaped cover 3 on one end of the fiber Bragg grating sensor 1, which provides all-round protection for the probe 101 of the fiber Bragg grating sensor 1. When the fiber Bragg grating sensor 1 is accidentally dropped to the ground, it can be protected by the collision with the ground through the U-shaped cover 3. At the same time, the elastic piston 5 connected to the U-shaped cover 3 undergoes elastic deformation to buffer the impact.

[0021] When installing the fiber Bragg grating sensor 1, the operator can hold the sensor and attach the scraper 8 at the end of the U-shaped cover 3 to the mounting area on the header surface. Moving it from top to bottom, the scraper 8 can be used to wipe away dust from the header surface, maintaining cleanliness for subsequent installation. If the header surface is uneven, the U-shaped cover 3 will experience a reaction force, causing the elastic piston 5 to deform and move within the vent plate 2. When the elastic piston 5 deforms and detaches from the pressure sensor 4, the pressure on the pressure sensor 4 will change, allowing the operator to promptly identify any unevenness on the header surface and reselect the installation area. After cleaning the header surface and ensuring it meets installation requirements, the scraper 8 can be directly removed from the adhesive attachment 7. Then, the operator can hold the fiber Bragg grating sensor 1 and attach the adhesive attachment 7 at the end of the U-shaped cover 3 to the header surface mounting area for adhesion and pre-positioning, effectively preventing displacement during subsequent installation. The fiber Bragg grating sensor 1 can then be repeatedly pushed to allow ventilation. The plate 2 reciprocates along the elastic piston 5, and the position of the elastic piston 5 within the air passage of the vent plate 2 changes back and forth, allowing the gas in the vent plate 2 to be delivered along the hose 21 to the air blowing assembly 6 at the top of the U-shaped cover 3. The air blowing assembly 6 blows the gas toward the probe 101 at the end of the fiber Bragg grating sensor 1 and the surface of the header, thereby further removing any dust that may adhere to the surfaces of the two. After the dust is blown off the surfaces of the header and the probe 101, the fiber Bragg grating sensor 1 can be pushed through the U-shaped cover 3 and fit against the header. During this process, the vent plate 2 moves along the elastic piston 5. When the insertion hole 104 on the outside of the fiber Bragg grating sensor 1 corresponds to the locking member 9 on the side of the U-shaped cover 3, the locking member 9 is inserted into the insertion hole 104, locking the fiber Bragg grating sensor 1. This effectively limits the possible rebound phenomenon of the fiber Bragg grating sensor 1 under the action of the elastic piston 5, ensuring the stability of the sensor after installation. Subsequently, the U-shaped cover 3 can be fixed to the surface of the header by screws or other fasteners to complete the installation of the fiber Bragg grating sensor 1.

[0022] In this embodiment, the pressure sensing element 4 includes a pressure sensor 41 and a loading plate 42. The pressure sensor 41, located in the air passage, is installed on the inner wall of one end of the vent plate 2 through the loading plate 42. The elastic piston 5 abuts against the pressure sensor 41, and the pressure sensor 41 is connected to an external data acquisition system. When the U-shaped cover 3 is subjected to the reaction force of uneven surface of the header or the impact force of falling, the elastic piston 5 will squeeze or detach from the pressure sensor 41, causing the pressure in the air passage to change. The pressure sensor 41 converts the pressure change into an electrical signal and transmits it to the data acquisition system. The above-mentioned cooperation between the elastic piston 5 and the pressure sensor 41 realizes the rapid perception of external force changes, providing reliable signal support for flatness detection and anti-fall buffering.

[0023] In this embodiment, the elastic piston 5 includes a piston head 51 and a rod-type elastic part 52. The piston head 51 is slidably disposed in the air passage within the vent plate 2 and abuts against the pressure sensor 41. A slider 31 that slides and engages with the slot 102 is installed on the top wall inside the U-shaped cover 3. The rod-type elastic part 52 is connected between the slider 31 and the piston head 51. One end of the vent plate 2 is provided with an air hole 22 that communicates with the air passage and allows the piston head 51 to move smoothly. When the U-shaped cover 3 is subjected to external force, the slider 31 drives the rod-type elastic part 52 to extend and retract, thereby pushing the piston head 51 to slide in the air passage, changing the pressure on the pressure sensor 41. The air hole 22 communicates with the air passage, ensuring normal gas flow in the air passage when the piston head 51 moves, and avoiding gas pressure accumulation that affects detection accuracy.

[0024] In this embodiment, the rod-type elastic part 52 includes a shaft 521 and a first spring 522. One end of the shaft 521, which slides through the vent plate 2, is connected to the piston head 51, and the other end of the shaft 521, away from the piston head 51, is connected to the slider 31. The first spring 522 is sleeved on the shaft 521, and both ends of the first spring 522 are connected to the vent plate 2 and the slider 31, respectively. When the U-shaped cover 3 is subjected to force and drives the slider 31 to move, the first spring 522 will undergo elastic deformation, generating a reverse elastic force to buffer the external force. After the external force disappears, the elastic force of the first spring 522 drives the slider 31 and the piston head 51 to reset, so that the pressure sensor 41 returns to the initial detection state. The above effectively reduces the damage to the probe 101 caused by the drop impact, and at the same time ensures that the components quickly return to their original positions after the flatness detection.

[0025] In this embodiment, the air blowing assembly 6 includes a flow divider 61 and air blowing sections 62. An installation port is provided on the top wall of the U-shaped cover 3, and the flow divider 61 is fixed within the installation port. A cavity is provided within the flow divider 61. Both ends of the hose 21 are connected to the other end of the vent plate 2 and the flow divider 61, respectively. Two sets of air blowing sections 62, communicating with the cavity, are connected to the bottom of the flow divider 61. One set faces the probe 101, and the other set faces the outside of the U-shaped cover 3. When the vent plate 2 reciprocates along the elastic piston 5, the gas in the airway enters the cavity of the flow divider 61 through the hose 21. The two sets of air blowing sections 62 communicate with the cavity, with one set blowing towards the probe 101 to clear the probe 101. The surface dust is removed to prevent dust from affecting the accuracy of stress detection. Another set of air blowers blows air outwards towards the U-shaped cover 3 to clean residual dust in the header installation area. The directional blowing of the two sets of air blowers 62 ensures the cleanliness of the probe 101 and the installation area, providing a clean environment for the detection of the fiber optic grating sensor 1. In this process, the design of the air blowing assembly 6 makes full use of the airflow generated by the reciprocating motion of the ventilation plate 2. Through the reasonable layout of the diverter plate 61 and the directional blowing of the air blowing assembly 62, the cleaning operation is carried out by efficiently utilizing mechanical energy. No additional energy input is required to complete the air blowing cleaning, which improves energy utilization efficiency and achieves the effect of high efficiency and energy saving.

[0026] In this embodiment, the air blowing section 62 includes an air blowing nozzle 621, which is fixed to the bottom of the diverter plate 61 and communicates with the cavity. A filter screen 622 is connected to the bottom of the air blowing nozzle 621. The air blowing nozzle 621 is used to spray the diverted gas in a directional manner. The filter screen 622 at the bottom of the air blowing nozzle 621 can filter impurities and large dust particles in the gas, preventing impurities from being blown towards the probe 101 or the surface of the header with the gas.

[0027] It should be noted that when cleaning the dust adhering to the filter screen 622, the dust adhering to the filter screen 622 can be effectively shaken off by tapping the U-shaped cover 3 under the elastic action of the elastic piston 5.

[0028] In this embodiment, the adhesive attachment 7 includes an adhesive plate 71, which is fixed to the end of the U-shaped cover 3 away from the fiber optic grating sensor 1. The surface of the adhesive plate 71 is provided with an adhesive layer 72, and the scraper 8 is adhered to the adhesive layer 72. Before installation, the surface of the header can be scraped with the scraper 8 to clean the dust. When the surface of the header meets the installation requirements, the scraper 8 can be directly peeled off from the adhesive layer 72. At this time, the adhesive plate 71 can be attached to the surface of the header through the adhesive layer 72, which plays a pre-positioning role and prevents the sensor from shifting during subsequent installation.

[0029] In this embodiment, the scraping component 8 includes a U-shaped piece 81 and a scraping protrusion 82. The U-shaped piece 81 is adhered to the adhesive layer 72, and a scraping protrusion 82 adapted to it is fixed on the side of the U-shaped piece 81 away from the adhesive plate 71. The scraping protrusion 82 on one side of the U-shaped piece 81 is made of elastic material, which can conform to the slight unevenness of the header surface during the scraping process. While removing dust, if it encounters an obvious uneven area, it will generate a reaction force to push the U-shaped cover 3, thereby driving the elastic piston 5 to squeeze the pressure sensor 4 and trigger a change in pressure signal.

[0030] In this embodiment, the locking component 9 includes a rod 91, an end 92, and a second spring 93. The rod 91, which is adapted to the socket 104, is slidably connected to the outer side of the U-shaped cover 3. One end of the rod 91 is fixed with the end 92. The second spring 93 is sleeved on the rod 91, and both ends of the second spring 93 are connected to the U-shaped cover 3 and the end 92, respectively. In the initial state, the second spring 93 is in a naturally extended state, and one end of the rod 91 is not inserted into the socket 104. When the fiber optic grating sensor 1 is pushed to fit against the housing and the socket 104 is aligned with the rod 91, the elastic force of the second spring 93 pushes the rod 91 into the socket 104, thereby locking the fiber optic grating sensor 1 and the U-shaped cover 3. When disassembling, pulling the end 92 can drive the rod 91 out of the socket 104, making unlocking convenient.

[0031] In this embodiment, a cable 103 is fixed to the end of the fiber Bragg grating sensor 1 away from the probe 101, and a protective sleeve is covered at the connection between the cable 103 and the fiber Bragg grating sensor 1; the cable 103 is used to transmit the stress signal collected by the fiber Bragg grating sensor 1 to the data acquisition system to realize real-time transmission and analysis of the signal.

[0032] The specific working principle of this invention is as follows: The staff holds the fiber optic grating sensor 1 and places the scraper 8 at the end of the U-shaped cover 3 against the header installation area. Moving it from top to bottom, the scraper 82 removes surface dust. If the header surface is uneven, it will generate a reaction force on the U-shaped cover 3, pushing the slider 31 to move. This causes the shaft 521 and piston head 51 to slide in the air passage and disengage from the pressure sensor 41. The pressure sensor 41 transmits the pressure change signal to the system, reminding the staff to change the installation area. After confirming that the header surface is flat, peel off the scraper 8, and attach the adhesive plate 71 to the header surface in a pre-positioned manner through the adhesive layer 72. Then, push the fiber optic grating sensor 1 back and forth to make the ventilation plate 2 move back and forth along the elastic piston 5. The gas in the air passage enters the cavity of the diverter plate 61 through the hose 21 and is sprayed out through the air nozzle 621. The filter screen 622 filters impurities. One set of air nozzles 621 discharges the gas to clean the probe 101, and another set of air nozzles 621 cleans the header surface. Push the fiber Bragg grating sensor 1 through the U-shaped cover 3 so that the probe 101 fits tightly against the surface of the header. When the insertion hole 104 of the fiber Bragg grating sensor 1 is aligned with the insertion rod 91 of the U-shaped cover 3, the second spring 93 pushes the insertion rod 91 into the insertion hole 104 to lock the fiber Bragg grating sensor 1 and prevent it from springing back. Then, fix the U-shaped cover 3 to the surface of the header with screws and other fasteners to complete the installation. The U-shaped cover 3 provides protection for the connection of the fiber Bragg grating sensor 1. When the container is in operation, it can be detected by the probe 101 on the fiber Bragg grating sensor 1. When the stress generated by the container causes the shape and refractive index of the fiber Bragg grating in the fiber Bragg grating sensor 1 to change, the wavelength of the reflected light changes. The fiber Bragg grating sensor 1 converts this into an electrical signal and transmits it to the data acquisition system through the cable 103 to realize real-time stress monitoring.

[0033] The embodiments of the present invention have been described above, but the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the embodiments described above, all of which are within the protection scope of the embodiments described above.

Claims

1. A stress detector for a boiler reheater header, characterized in that, Includes fiber optic grating sensor (1), ventilation plate (2) and U-shaped cover (3); One end of the fiber optic grating sensor (1) is integrally connected to a probe (101). A slot (102) is opened on the edge of the fiber optic grating sensor (1). A vent plate (2) is installed in the slot (102). An air passage is opened in the vent plate (2). A pressure sensor (4) is installed on the inner wall of one end of the vent plate (2). The U-shaped cover (3) is sleeved on one end of the fiber optic grating sensor (1). An elastic piston (5) is installed on the U-shaped cover (3) and inserted into the vent plate (2) and in contact with the pressure sensor (4). An air blowing assembly (6) is installed at the top inside the U-shaped cover (3) to blow gas into the U-shaped cover (3). The ventilation plate (2) and the air blowing assembly (6) are connected by a hose (21). The end of the U-shaped cover (3) away from the fiber optic grating sensor (1) is connected to a scraper (8) via an adhesive attachment (7); The fiber optic grating sensor (1) has a socket (104) on its side, and the U-shaped cover (3) has a locking element (9) corresponding to the socket (104) on its side.

2. A boiler reheater header stress detector according to claim 1, characterized in that, The pressure sensing element (4) includes a pressure sensor (41) and a loading plate (42). The pressure sensor (41) located in the air passage is installed on the inner wall of one end of the vent plate (2) through the loading plate (42), and the elastic piston element (5) abuts against the pressure sensor (41).

3. A boiler reheater header stress detector according to claim 2, characterized in that, The elastic piston component (5) includes a piston head (51) and a rod-type elastic part (52). The piston head (51) is slidably disposed in the air passage in the vent plate (2) and abuts against the pressure sensor (41). The top wall inside the U-shaped cover (3) is equipped with a slider (31) that slides in cooperation with the slot (102). The rod-type elastic part (52) is connected between the slider (31) and the piston head (51). One end of the vent plate (2) is provided with an air hole (22) that communicates with the air passage and allows the piston head (51) to move smoothly.

4. A boiler reheater header stress detector according to claim 3, characterized in that, The rod-type elastic part (52) includes a shaft (521) and a first spring (522). One end of the shaft (521) slides through the vent plate (2) and is connected to the piston head (51), and the other end of the shaft (521) away from the piston head (51) is connected to the slider (31). The first spring (522) is sleeved on the shaft (521), and both ends of the first spring (522) are connected to the vent plate (2) and the slider (31) respectively.

5. A boiler reheater header stress detector according to claim 1, characterized in that, The air blowing assembly (6) includes a flow divider (61) and an air blowing part (62). The top wall inside the U-shaped cover (3) has an installation port. The flow divider (61) is fixed inside the installation port. A cavity is opened inside the flow divider (61). The two ends of the hose (21) are respectively connected to the other end of the ventilation plate (2) and the flow divider (61). The bottom of the flow divider (61) is connected to two sets of air blowing parts (62) that communicate with the cavity. One set is set towards the probe (101), and the other set is set towards the outside of the U-shaped cover (3).

6. A boiler reheater header stress detector according to claim 5, characterized in that, The air blowing part (62) includes an air blowing nozzle (621), which is fixed to the bottom of the diverter plate (61) and communicates with the cavity. A filter screen (622) is connected to the bottom of the air blowing nozzle (621).

7. A boiler reheater header stress detector according to claim 1, characterized in that, The adhesive attachment (7) includes an adhesive plate (71), which is fixed to one end of the U-shaped cover (3) away from the fiber optic sensor (1). The surface of the adhesive plate (71) is provided with an adhesive layer (72), and the scraper (8) is adhered to the adhesive layer (72).

8. A boiler reheater header stress detector according to claim 8, characterized in that, The scraping component (8) includes a U-shaped piece (81) and a scraping protrusion (82). The U-shaped piece (81) is adhered to the adhesive layer (72), and a scraping protrusion (82) adapted to it is fixed on the side of the U-shaped piece (81) away from the adhesive plate (71).

9. A boiler reheater header stress detector according to claim 1, characterized in that, The locking member (9) includes a plug rod (91), an end (92) and a second spring (93). The plug rod (91) adapted to the insertion hole (104) is slidably connected to the outside of the U-shaped cover (3). One end of the plug rod (91) is fixed with an end (92). The second spring (93) is sleeved on the plug rod (91), and the two ends of the second spring (93) are respectively connected to the U-shaped cover (3) and the end (92).

10. A boiler reheater header stress detector according to claim 1, characterized in that, The fiber Bragg grating sensor (1) has a cable (103) fixed at one end away from the probe (101), and the connection between the cable (103) and the fiber Bragg grating sensor (1) is covered with a protective sleeve.

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