Distributed glass-lined reactor internal porcelain explosion prevention and monitoring method and device

Abstract

This invention relates to a method and device for preventing and monitoring porcelain cracking inside a distributed glass-lined reactor. The glass-lined reactor is equipped with sensing optical fibers that simultaneously monitor temperature and stress changes at the sensing fibers, obtaining the spatial location of environmental changes in real time. It detects shifts in the Brillouin gain spectrum, calibrating the time-domain information of the detected signal and the positional relationship of the sensing fibers. Differential pulse processing and Brillouin frequency shift fitting calculations are performed on the 3D Brillouin gain spectrum obtained by real-time acquisition and frequency sweeping to obtain the Brillouin frequency shift occurring at different sensing fiber positions. By detecting the Brillouin frequency shift change trend at the same location at different times, the temperature, stress, and environmental changes occurring at the corresponding sensing fiber positions within the reactor are obtained, thereby preventing and monitoring porcelain cracking events in the glass-lined reactor. This invention can monitor porcelain cracking phenomena in multiple glass-lined reactors in real time, simultaneously locate abnormal phenomena, and the monitoring process is simple, fast, and highly reliable.

Description

Technical Field

[0001] The present invention relates to the field of distributed optical fiber sensing, and in particular to a distributed glass-lined reactor internal porcelain explosion (glass-lined layer detachment) prevention and monitoring method based on the Brillouin optical time domain analysis technology principle of differential pulse pairs. Background Art

[0002] Ceramic glass (also called glass ceramic) is a material that combines the properties of glass and ceramic, with excellent thermal stability, mechanical strength and chemical corrosion resistance. Glass-lined reactors are high-pressure sealed containers with ceramic glass inner walls, which are usually used to store or process substances with special requirements, which may be highly corrosive, have high purity requirements, or need to be stored under extreme conditions. The porcelain explosion phenomenon of high-pressure sealed containers with ceramic glass inner walls refers to the situation where the ceramic glass inner wall of the container breaks or peels off under high pressure conditions. After the porcelain explosion phenomenon occurs, the corrosive liquid directly contacts the substrate, which may cause the container to lose its sealing function, resulting in material loss, and may also cause significant harm to the environment and human safety. Therefore, timely monitoring of the occurrence of porcelain explosion phenomenon and early prevention and location of its occurrence are of great significance for safe and efficient industrial production.

[0003] In order to ensure the normal use of the glass-lined reactor, the glass-lined layer must be monitored during the regular inspection process. The main detection methods currently include regular macroscopic manual inspections to observe whether the surface of the glass-lined layer is uniform and smooth, whether there is wear and tear, and whether there is any falling off. The internal situation can be checked through hand holes, observation holes or endoscopes. This method uses manual inspections, lacks accuracy and is inefficient, and the inspection steps are cumbersome. There is a DC high-voltage detection method, which adds 10KV DC high voltage to the glass-lined reactor. If it is not conductive, it is judged to be qualified. However, this solution must ensure that the reactor is under harsh conditions of dryness and cleanliness. The cleaning process of the reactor is relatively complicated, and this method cannot locate the fault location, making it difficult to support subsequent repair work. There is a method of taking samples through a probe. Through the inherent material extraction pipe of the reactor, the probe is used to extract liquid samples in the reactor at regular intervals, and then it is sent to a special device for iron ion concentration analysis. This solution is slow, lacks real-time performance, has no porcelain explosion point positioning function, and can only be detected after the porcelain explosion phenomenon has completely occurred, and has no prevention capability.

[0004] As a new sensing technology, the distributed fiber optic sensing system can sense the environment along the line directly by detecting the changes in the optical signal in the optical fiber without the need for introducing any special structure. It is often used for various types of long-distance and large-scale building health detection and various security needs. The Brillouin optical time domain analysis technology based on differential pulse pairs is sensitive to environmental changes such as temperature and strain at various locations of the sensing optical fiber, and is an absolute measurement without the need for reference. The differential pulse pair technology can achieve centimeter-level spatial resolution. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention relates to a distributed method and device for preventing and monitoring porcelain explosion inside a glass-lined reactor, which utilizes the sensitive characteristics of temperature and strain and the positioning capability of distributed optical fiber sensing to achieve high spatial resolution prevention detection and positioning of porcelain explosion inside a glass-lined reactor.

[0006] The present invention is achieved through the following technical solutions:

[0007] A distributed method for preventing and monitoring porcelain explosion inside a glass-lined reactor. A sensing optical fiber is arranged inside the glass-lined reactor. The temperature and stress changes at the sensing optical fiber inside the glass-lined reactor are monitored simultaneously, and the spatial position of the environmental change is obtained in real time. When a Brillouin gain spectrum shift is detected, the time domain information of the detected signal and the position relationship of the sensing optical fiber are calibrated. The 3D Brillouin gain spectrum obtained by real-time acquisition and recording of the frequency sweep is subjected to differential pulse processing and Brillouin frequency shift fitting calculation to obtain the Brillouin frequency shift occurring in the sensing optical fiber at different positions. By detecting the change trend of the Brillouin frequency shift at the same position at different times, the temperature, stress and environmental changes occurring at the corresponding sensing optical fiber position in the reactor are obtained, thereby preventing and monitoring porcelain explosion events in the glass-lined reactor.

[0008] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method analyzes the Brillouin frequency shift information of any position of the sensing optical fiber over time, and uses machine learning to build a model to identify and distinguish the state of a specific position in the glass-lined reactor.

[0009] The status of a specific position in the glass-lined reactor is divided into multiple levels according to the severity.

[0010] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method adopts differential pulse to Brillouin light time domain analysis, takes narrowband laser as light source, and divides into two paths through 1-to-2 coupler, one of which is controlled by upper computer to control semiconductor optical amplifier to generate two optical pulses with different pulse widths τ1 and τ2, τ1 is greater than τ2, and then the pulse is power amplified by erbium-doped fiber amplifier, and enters sensing optical fiber from circulator port 1 through polarization scrambler as pump light, and the other path is used as detection light, and is passed into circulator port 2 through sensing optical fiber after frequency shift and filtering by electro-optic modulator, wherein port 3 of circulator is connected to photoelectric detector and data acquisition card.

[0011] The electro-optic modulator is controlled by a frequency source, and the frequency source sweeps to control the detection light frequency shift. A three-dimensional Brillouin gain spectrum is synthesized through each frequency differential pulse signal; and the Brillouin frequency shift at different optical fiber positions is determined by the Lorentz fitting method.

[0012] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method adopts a polarizer to disturb the polarization state in order to suppress the interference of the polarization weakening effect.

[0013] The glass-lined metal tank body in the glass-lined reactor is engraved with grooves for fixing the sensing optical fiber. The sensing optical fiber is laid in the glass-lined reactor in a cylindrical manner by reciprocatingly winding around the tank body to ensure that its sensing area fully covers the entire reactor tank body.

[0014] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method uses heat-resistant and corrosion-resistant glue to tightly attach the sensing optical fiber to the groove; the depth of the groove is twice the outer diameter of the sensing optical fiber, and the width is the outer diameter of the sensing optical fiber.

[0015] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method measures multiple glass-lined reactors, adopts the optical switch parallel connection method, and selects the reactor to be measured through the optical path. At this time, both ends of the overall sensing optical fiber can be connected in parallel using the optical switch method; or a parallel connection method using an optical switch at one end and an optical power splitter at the other end; or a cascade method is adopted, that is, the optical fiber input and output ports of multiple reactors are connected in series.

[0016] A distributed glass-lined reactor internal porcelain explosion prevention and monitoring device, comprising a Brillouin optical time domain analysis device and a glass-lined reactor part;

[0017] The Brillouin optical time domain analysis device comprises a laser, an electro-optic modulator, an optical filter, a microwave frequency source, an optical coupler optical circulator, an optical beam splitter, a data acquisition card, an erbium-doped fiber amplifier, and a semiconductor optical amplifier; the laser emitted by the laser is divided into two paths through the optical beam splitter, one of which passes through the semiconductor optical amplifier to generate pulses and is amplified by the erbium-doped fiber amplifier, and is connected to port 1 of the optical circulator, and then the 2-port optical fiber jumper of the circulator is connected to the external device of the device as a pump pulse output end, and the other light passes through the electro-optic modulator and is modulated by the microwave frequency source, and then is filtered by the optical filter and connected to the external device of the device by the jumper as an interface, and the 3-port of the optical circulator is connected to the photoelectric detector, and then connected to the data acquisition card to collect data and upload it to the host computer for analysis; the external device of the Brillouin optical time domain analysis device is provided with two optical fiber interfaces, namely a pump pulse light emission end and a detection light emission end, and the detection light emission end is connected to the input end of the sensing optical fiber; the pump pulse light emission end is connected to the output end of the sensing optical fiber;

[0018] The glass-lined reactor part includes an explosion-proof motor, an inlet with a sight glass, a tube clamp, a sandwich body, a glass-lined metal tank body, a glass-lined layer, a discharge port of the reactor, a transmission shaft, a sleeve fixing device, a sensing optical fiber, an impeller-type mixer, a sensing optical fiber output end, and a sensing optical fiber input end; the sensing optical fiber takes the incident end of the sensing optical fiber as a starting point, enters the groove engraved on the glass-lined metal tank body through the inlet with a sight glass, and the glass-lined metal tank body is attached with a glass-lined layer. After the sensing optical fiber is distributed and arranged in the groove, the output end of the sensing optical fiber is also led out through the inlet with a sight glass; the sandwich body is the outermost protective layer of the glass-lined reactor, and the tube clamp ensures the tight connection between the upper and lower parts of the reactor, wherein the discharge port of the reactor, the transmission shaft, the sleeve fixing device, the impeller-type mixer and the explosion-proof motor are used as the transmission and stirring devices of the reactor, and do not contact the laid sensing optical fiber.

[0019] The beneficial effects of the present invention are:

[0020] It can monitor the occurrence of porcelain explosion in one or more glass-lined reactors in real time, and locate the position in the reactor where the abnormal phenomenon occurs. The monitoring process is simple and fast with high reliability. It can prevent and rectify abnormal safety hazards such as porcelain explosion in glass-lined reactors more quickly, improve industrial production safety and production efficiency, and is of great value to improving the efficiency of modern industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the reactor structure and sensor optical fiber laying in the distributed glass-lined reactor internal porcelain explosion (glass-lined layer detachment) prevention and monitoring method based on differential pulse Brillouin optical time domain analysis technology (DPP-BOTDA).

[0022] Figure 2 It is a cross-sectional view of the concave groove of the glass-lined tank and the laying method of the sensing optical fiber.

[0023] Figure 3 It is a spatial distribution diagram of the laying method of the sensing optical fiber on the inner surface of the glass-lined tank.

[0024] Figure 4 It is a structural schematic diagram of the internal components of the Brillouin optical time domain distribution technology detection equipment based on differential pulse pairs.

[0025] Figure 5 It is a schematic diagram of the construction of a series scheme for the prevention and monitoring of internal porcelain explosion in a distributed glass-lined reactor using Brillouin optical time-domain distribution technology based on differential pulse pairs.

[0026] Figure 6 It is a schematic diagram of a parallel scheme for implementing the Brillouin optical time domain distribution technology based on differential pulse pairs in the prevention and monitoring of porcelain explosion inside the distributed glass-lined reactor.

[0027] Figure 7 It is another schematic diagram of the construction of a parallel scheme for the prevention and monitoring of internal porcelain explosion in a distributed glass-lined reactor using Brillouin optical time-domain distribution technology based on differential pulse pairs.

[0028] In the figure: 1. Explosion-proof motor, 2. Inlet with sight glass, 3. Pipe clamp, 4. Interlayer, 5. Glass-lined tank, 6. Glass-lined layer, 7. Reactor discharge port, 8. Transmission shaft, 9. Casing fixture, 10. Sensing fiber, 11. Impeller mixer, 12. Sensing fiber output end, 13. Sensing fiber input end, 14. Pump pulse light emission end, 15. Detection light emission end, 16. Brillouin optical time domain technology analysis and detection equipment, 17. Rectangular groove, 18. Heat-resistant and corrosion-resistant glue, 19. Narrow-band laser, 20. RF frequency source, 21. Electro-optic modulator, 22. Narrow-band optical filter, 23. Semiconductor optical amplifier, 24. Erbium-doped fiber amplifier, 25. Polarization scrambler, 26. Isolator, 27. Circulator, 28. Photodetector, 29. Data acquisition card, 30. Host computer, 31. Glass-lined reactor, 32. Optical switch, 33. Optical power splitter. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0030] A distributed method for preventing and monitoring porcelain explosion (glass lining layer detachment) inside a glass-lined reactor based on the principle of Brillouin optical time domain analysis technology of differential pulse pairs includes a laying method of a sensing optical fiber in a glass-lined reactor, a connection method between the sensing optical fiber in the reactor and a demodulation device, and the construction of the demodulation device.

[0031] A distributed method for preventing and monitoring porcelain explosion inside a glass-lined reactor. A sensing optical fiber is arranged inside the glass-lined reactor. The temperature and stress changes at the sensing optical fiber inside the glass-lined reactor are monitored simultaneously, and the spatial position of the environmental change is obtained in real time. When a Brillouin gain spectrum shift is detected, the time domain information of the detected signal and the position relationship of the sensing optical fiber are calibrated. The 3D Brillouin gain spectrum obtained by real-time acquisition and recording of the frequency sweep is subjected to differential pulse processing and Brillouin frequency shift fitting calculation to obtain the Brillouin frequency shift occurring in the sensing optical fiber at different positions. By detecting the change trend of the Brillouin frequency shift at the same position at different times, the temperature, stress and environmental changes occurring at the corresponding sensing optical fiber position in the reactor are obtained, thereby preventing and monitoring porcelain explosion events in the glass-lined reactor.

[0032] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method analyzes the Brillouin frequency shift information of any position of the sensing optical fiber over time, and uses machine learning to build a model to identify and distinguish the state of a specific position in the glass-lined reactor.

[0033] The status of a specific position in the glass-lined reactor is divided into multiple levels according to the severity.

[0034] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method adopts differential pulse to Brillouin light time domain analysis, takes narrowband laser as light source, and divides into two paths through 1-to-2 coupler, one of which is controlled by upper computer to control semiconductor optical amplifier to generate two optical pulses with different pulse widths τ1 and τ2, τ1 is greater than τ2, and then the pulse is power amplified by erbium-doped fiber amplifier, and enters sensing optical fiber from circulator port 1 through polarization scrambler as pump light, and the other path is used as detection light, and is passed into circulator port 2 through sensing optical fiber after frequency shift and filtering by electro-optic modulator, wherein port 3 of circulator is connected to photoelectric detector and data acquisition card.

[0035] The electro-optic modulator is controlled by a frequency source, and the frequency source sweeps to control the detection light frequency shift. A three-dimensional Brillouin gain spectrum is synthesized through each frequency differential pulse signal; and the Brillouin frequency shift at different optical fiber positions is determined by the Lorentz fitting method.

[0036] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method adopts a polarizer to disturb the polarization state in order to suppress the interference of the polarization weakening effect.

[0037] The glass-lined metal tank body in the glass-lined reactor is engraved with grooves for fixing the sensing optical fiber. The sensing optical fiber is laid in the glass-lined reactor in a cylindrical manner by reciprocatingly winding around the tank body to ensure that its sensing area fully covers the entire reactor tank body.

[0038] The distributed glass-lined reactor internal porcelain explosion prevention and monitoring method uses heat-resistant and corrosion-resistant glue to tightly attach the sensing optical fiber to the groove; the depth of the groove is twice the outer diameter of the sensing optical fiber, and the width is the outer diameter of the sensing optical fiber.

[0039] like Figure 1 As shown, a distributed glass-lined reactor internal porcelain explosion prevention and monitoring device includes a Brillouin optical time domain analysis device and a glass-lined reactor part; the Brillouin optical time domain analysis device 16 is internally connected as shown in FIG. Figure 4As shown, it includes a laser, an electro-optic modulator, an optical filter, a microwave frequency source, an optical coupler, an optical circulator, an optical beam splitter, a data acquisition card, an erbium-doped fiber amplifier, and a semiconductor optical amplifier; the laser emitted by the laser is divided into two paths through the optical beam splitter, one of which passes through the semiconductor optical amplifier to generate pulses and is amplified by the erbium-doped fiber amplifier, connected to port 1 of the optical circulator, and then the 2-port optical fiber jumper of the circulator is connected to the external device of the device as a pump pulse output end, and the other light passes through the electro-optic modulator and is modulated by the microwave frequency source, and then filtered by the optical filter and connected to the external device of the device by the jumper as an interface, and after the 3-port of the optical circulator is connected to the photoelectric detector, it is connected to the data acquisition card to collect data and upload it to the host computer for analysis; the Brillouin optical time domain analysis device 16 is provided with two optical fiber interfaces at the external device, namely, a pump pulse light emitting end 14 and a detection light emitting end 15, and the detection light emitting end 15 is connected to the sensing fiber input end 13; the pump pulse light emitting end 14 is connected to the sensing fiber output end 12.

[0040] Glass-lined reactor parts such as Figure 1 As shown, it includes an explosion-proof motor 1, an inlet with a sight glass 2, a pipe clamp 3, a sandwich body 4, a glass-lined metal tank body 5, a glass-lined layer 6, a discharge port of a reactor 7, a transmission shaft 8, a sleeve fixing device 9, a sensing optical fiber 10, an impeller mixer 11, a sensing optical fiber output end 12, and a sensing optical fiber input end 13; the sensing optical fiber 10 takes the sensing optical fiber input end 13 as a starting point, enters the groove engraved on the glass-lined metal tank body 5 through the inlet with a sight glass 2, and the glass-lined metal tank body 5 is provided with a glass-lined layer, and after the sensing optical fiber 10 is distributed and arranged in the groove, the output end 12 of the sensing optical fiber is also led out through the inlet 2 with a sight glass; the sandwich body 4 is the outermost protective layer of the glass-lined reactor, and the tube clamp 3 ensures the tight connection between the upper and lower parts of the reactor, wherein the reactor discharge port 7, the transmission shaft 8, the sleeve fixing device 9, the impeller mixer 11 and the explosion-proof motor 1 are used as the material adding and transmission stirring devices of the reactor, and have no contact with the laid sensing optical fiber 10.

[0041] The sensing optical fiber is a single-mode optical fiber.

[0042] like Figure 1 As shown, the sandwich body 4 in the glass-lined reactor is the outermost protective layer of the glass-lined reactor. The pipe clamp 3 ensures the tight connection between the upper and lower parts of the reactor to prevent material leakage. The inner wall of the glass-lined tank body 5 of the glass-lined reactor is Figure 3 The distribution is engraved as Figure 2 The rectangular groove 17 shown in the figure ensures that the minimum spacing between the mutually parallel concave grooves is less than or equal to 20 cm (corresponding to the spatial resolution of the sensing system). The head and the tail of the groove are led to the outside of the reactor through the pipe opening with the sight glass inlet 2, serving as the passage for the sensing optical fiber input end 13 and the sensing optical fiber output end 12.

[0043] The sensing optical fiber laid in the glass-lined reactor should be taut during laying to ensure that the optical fiber has prestress. The sensing optical fiber is laid between the glass-lined layer and the glass-lined tank body in the glass-lined reactor in the rectangular groove 17 engraved on the glass tank body. Figure 2 As shown, it is ensured that the local environmental changes when porcelain explosion or porcelain explosion pre-abnormality occurs can be quickly sensed by the sensing optical fiber. The sensing optical fiber is wound in a cyclical manner, such as Figure 3 As shown, starting from the fiber optic inlet in the reactor, the sensing fiber optic reciprocates along the groove on the inner wall of the glass-lined tank and reciprocates back and forth in the vertical direction. It is necessary to ensure that the path of the fiber optic winding in the same direction is different each time and there is an equal parallel interval of 20 cm, and ensure that the fiber optic input end and the fiber optic output port lead to the same position of the external conduit of the reactor to facilitate the connection of external equipment.

[0044] The external demodulation device is based on the differential pulse Brillouin optical time domain analysis technology. The internal device connection diagram of the whole device is as follows: Figure 4 As shown, a narrow-band laser 19 is used as a light source and is divided into two paths through a 1-to-2 coupler. One path is controlled by a host computer to control a semiconductor optical amplifier 23 to generate optical pulses with two pulse widths of 36ns and 34ns, and the pulse rise and fall edges are less than 2ns. The pulses are then power-amplified by an erbium-doped fiber amplifier 24, and enter the sensing optical fiber 10 from a circulator (27) port 1 through a polarization scrambler 25 as pump light, so that a circulator (27) port 2 is connected to an optical fiber jumper and fixed to an external device as an interface for a pump pulse light transmitting end 14. The other path is used as a detection light and is frequency-shifted by an electro-optical modulator 21. After the optical narrowband filter 22 retains the low-frequency sideband, the fiber jumper interface is fixed to the external device and connected to the sensing fiber 10 through the sensing fiber input end 13, and is passed through the sensing fiber output end 12 to the circulator (27) 2 port, that is, the pump pulse light emission end 14 port, wherein the circulator (27) 3 port is connected to the photodetector 28 and the subsequent 500MHz data acquisition card 29, and the data is transmitted to the host computer through the data transmission protocol and processed. The system can achieve a spatial resolution of 20cm, and the strain and temperature sensitivities are approximately 0.05MHz per microstrain and 1MHz per °C, respectively.

[0045] The sensing principle of the differential pulse to Brillouin optical time domain analysis technology is: the pump pulse and the detection light are respectively injected into the two ends of the sensing optical fiber 10. When the frequency difference between the two beams of light is a Brillouin frequency shift, stimulated Brillouin scattering will be generated. According to the linear relationship between temperature and strain and Brillouin frequency shift, the temperature and strain distribution of the sensing optical fiber can be obtained by measuring the Brillouin frequency shift. Two pump pulse lights with pulse widths of t1 and t3 are successively incident on an optical fiber with a length of L, with an interval of t2 (>2nL / c). After interacting with the continuous detection light, it is received by the detector, and the Brillouin signals corresponding to the two pulses are collected and differentiated. The Brillouin gain spectrum of each point in the optical fiber is obtained by frequency scanning, and the Brillouin frequency shift at each point of the optical fiber is obtained by curve fitting. The temperature and strain of each point in the optical fiber are demodulated according to the frequency shift. At this time, the spatial resolution of the system can reach c(t1-t3) / 2n, where c is the speed of light in vacuum and n is the equivalent refractive index of fundamental mode transmission in single-mode optical fiber.

[0046] exist Figure 5 In the process, the pump pulse light emitting end 14 of the Brillouin optical time domain technology analysis detection device 16 of the external differential pulse pair method is connected to the sensing fiber input end 13 of the first reactor in the reactor pair, and its sensing fiber output end 12 is connected to the sensing fiber input end 13 of the second reactor, and so on, and the sensing fiber input end 13 of the last reactor is connected to the detection light emitting end 15 of the external device.

[0047] The connection between the sensing optical fiber in the glass-lined reactor and the external demodulation device can be divided into two forms, namely, cascade mode and parallel mode: 1. Cascade mode, such as Figure 5 As shown, the sensing fiber inlets and outlets of multiple glass-lined reactors are connected to each other, and the arrangement order is recorded. The sensing fiber input end 13 of the first reactor is connected to the external pump pulse light emission end 14, and the fiber output end 12 of the last reactor is connected to the external device detection light emission end 15. 2 Parallel mode, such as Figure 6 As shown, a connection mode of two 1-to-N optical switches 33 is adopted, N is the number of glass-lined reactors to be tested, the pump pulse light emitting end 14 of the external demodulation device is connected to the single-side port of the optical switch 32, and each port on the N side of the optical switch 32 is respectively connected to the optical fiber output end 12 of the N reactor sensing optical fiber, and the detection light emitting end 15 of the external demodulation device is connected to the single-side port of another optical switch 32, and each port on the N side of the optical switch 32 is respectively connected to the sensing optical fiber input end 13 of the N reactors. When the designated reactor needs to be detected, the two optical switches can be adjusted to the corresponding ports, or as shown in FIG. Figure 7 As shown, Figure 6 One of the 1×N optical switches shown is replaced with a 1-to-N optical power splitter 33 , in which the connection of the single port and the N ports completely corresponds to the connection mode of the optical switch 32 .

[0048] If the actual operation is Figure 5 As shown, in the data processing process, the different reactors 31 to be tested and the corresponding positions in the reactors are spatially distinguished by time domain decomposition. Figure 6 or Figure 7 As shown, the reactor to be sensed is selected by adjusting the channel of the optical switch 32, and the selected reactor to be sensed and the corresponding position in the reactor are spatially characterized by the difference in the time domain of the signal.

[0049] In the subsequent data processing, wavelet denoising and other methods can be used to improve the signal-to-noise ratio, and then the Brillouin frequency shift at each optical fiber position can be obtained by Lorentz fitting, and then the position of the above optical fiber is converted to the corresponding position in the reactor. By real-time monitoring of the Brillouin frequency shift at each position, the temperature strain of the glass-lined layer 6 can be obtained over time. The machine learning CNN model can be used to determine the state of the glass-lined layer 6. If it is displayed as "normal", continue to use it normally. If it is displayed as "mild pre-explosion", reduce the number of times the reactor is used, and wait for regular maintenance of the abnormal position where it is located. If it is displayed as "moderate pre-explosion" or "complete explosion", stop using the reactor immediately, wait for regular maintenance to completely melt the Tang glass layer in the reactor and then re-coat and fire the glass-lined layer 6.

[0050] The technical features of the above-described embodiments can be further combined. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-described embodiments only express several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, several variations and improvements can be made, all of which belong to the protection scope of the present invention. The protection scope of the present invention is given by the attached claims and any equivalent technical solutions thereof.

Claims

1. A distributed glass-lined reactor internal porcelain explosion prevention and monitoring method, characterized in that: A sensing optical fiber is arranged inside the glass-lined reactor, and the temperature and stress changes at the sensing optical fiber inside the glass-lined reactor are monitored at the same time, and the spatial position of the environmental changes is obtained in real time; the Brillouin gain spectrum is detected to shift, and the time domain information of the detected signal and the position relationship of the sensing optical fiber are calibrated; The 3D Brillouin gain spectrum acquired and recorded in real time by frequency sweep is subjected to differential pulse processing and Brillouin frequency shift fitting calculation to obtain the Brillouin frequency shift of the sensing optical fiber at different positions. By detecting the change trend of the Brillouin frequency shift at the same position at different times, the temperature, stress and environmental changes at the corresponding sensing optical fiber position in the reactor are obtained, thereby preventing and monitoring porcelain explosion events in glass-lined reactors. Differential pulses are used for Brillouin light time domain analysis. A narrowband laser is used as the light source. The light is divided into two paths through a 1-to-2 coupler. One path is controlled by a host computer to control a semiconductor optical amplifier to generate two optical pulses with different pulse widths, τ1 and τ2. τ1 is greater than τ2. The pulses are then power-amplified by an erbium-doped fiber amplifier and enter the sensing fiber from port 1 of the circulator through a polarization scrambler as pump light. The other path is used as detection light. After frequency shifting and filtering by an electro-optical modulator, it enters port 2 of the circulator through the sensing fiber. Port 3 of the circulator is connected to a photoelectric detector and a data acquisition card. The glass-lined metal tank body in the glass-lined reactor is engraved with grooves for fixing the sensing optical fiber. The sensing optical fiber is laid in the glass-lined reactor in a cylindrical manner by reciprocatingly winding around the tank body to ensure that its sensing area fully covers the entire reactor tank body.

2. The method for preventing and monitoring internal porcelain explosion of a distributed glass-lined reactor according to claim 1 is characterized in that: By analyzing the Brillouin frequency shift information of any position of the sensing optical fiber over time, a model is constructed using machine learning to identify and distinguish the state of a specific position in the glass-lined reactor.

3. The method for preventing and monitoring internal porcelain explosion of a distributed glass-lined reactor according to claim 1 is characterized in that: The status of a specific position in the glass-lined reactor is divided into multiple levels according to the severity.

4. The method for preventing and monitoring internal porcelain explosion of a distributed glass-lined reactor according to claim 1 is characterized in that: The electro-optic modulator is controlled by a frequency source, and the frequency source sweeps to control the detection light frequency shift. A three-dimensional Brillouin gain spectrum is synthesized through each frequency differential pulse signal; and the Brillouin frequency shift at different optical fiber positions is determined by the Lorentz fitting method.

5. The method for preventing and monitoring internal porcelain explosion of a distributed glass-lined reactor according to claim 1 is characterized in that: In order to suppress the interference of polarization attenuation effect, a polarization bypass filter is used to disturb the polarization state.

6. The method for preventing and monitoring internal porcelain explosion of a distributed glass-lined reactor according to claim 1 is characterized in that: The sensing optical fiber is tightly attached to the groove by using heat-resistant and corrosion-resistant glue; the depth of the groove is twice the outer diameter of the sensing optical fiber, and the width is the outer diameter of the sensing optical fiber.

7. The method for preventing and monitoring internal porcelain explosion of a distributed glass-lined reactor according to claim 1 is characterized in that: To measure multiple glass-lined reactors, optical switches are used in parallel. The reactor to be measured is selected through the optical path. At this time, both ends of the overall sensing optical fiber can be connected in parallel using optical switches; or a parallel connection method using an optical switch at one end and an optical power splitter at the other end; or a cascade method is adopted, that is, the optical fiber input and output ports of multiple reactors are connected in series.

8. A distributed glass-lined reactor internal porcelain explosion prevention and monitoring device, characterized in that: Including Brillouin optical time domain analysis equipment and glass-lined reactor; The Brillouin optical time domain analysis device (16) comprises a laser, an electro-optic modulator, an optical filter, a microwave frequency source, an optical coupler, an optical circulator, an optical beam splitter, a data acquisition card, an erbium-doped fiber amplifier, and a semiconductor optical amplifier; the laser light emitted by the laser is divided into two paths through the optical beam splitter, one of which passes through the semiconductor optical amplifier to generate pulses and is amplified by the erbium-doped fiber amplifier and connected to port 1 of the optical circulator, and then the 2-port optical fiber jumper of the circulator is connected to the external device of the device as the pump pulse output end, and the other light passes through the electro-optic modulator and is modulated by the microwave frequency source. The optical pulses are then filtered by an optical filter and connected to an external device via a jumper as an interface, serving as a detection light output end. The three ports of the optical circulator are connected to a photodetector, and then connected to a data acquisition card to collect data and upload it to a host computer for analysis. The Brillouin optical time domain analysis device (16) is provided with two optical fiber interfaces at the external device, namely a pump pulse light emission end (14) and a detection light emission end (15). The detection light emission end (15) is connected to a sensing optical fiber input end (13); and the pump pulse light emission end (14) is connected to a sensing optical fiber output end (12). The glass-lined reactor part comprises an explosion-proof motor (1), an inlet with a sight glass (2), a pipe clamp (3), a sandwich body (4), a glass-lined metal tank body (5), a glass-lined layer (6), a reactor discharge port (7), a transmission shaft (8), a casing fixing device (9), a sensing optical fiber (10), an impeller mixer (11), a sensing optical fiber output end (12), and a sensing optical fiber input end (13); the sensing optical fiber (10) takes the sensing optical fiber input end (13) as a starting point, passes through the inlet with a sight glass (2), and enters the groove engraved on the glass-lined metal tank body (5). Inside, a glass-lined layer is attached to the glass-lined metal tank body (5), and after the sensing optical fiber (10) is distributed and arranged in the groove, the output end (12) of the sensing optical fiber is also led out through the inlet with a sight glass (2); the sandwich body (4) is the outermost protective layer of the glass-lined reactor, and the pipe clamp (3) ensures the tight connection between the upper and lower parts of the reactor, wherein the reactor discharge port (7), the transmission shaft (8), the sleeve fixing device (9), the impeller stirrer (11) and the explosion-proof motor (1) serve as the transmission stirring device of the reactor and do not contact the laid sensing optical fiber (10).

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