CN105606275B - The core plate on-line monitoring system and method for a kind of membrane filter plate - Google Patents

Abstract

The invention discloses an on-line monitoring system and method for a core plate of a diaphragm filter plate. The system includes a fiber grating demodulator, a fiber coupler, a processor and a fiber grating sensor component, wherein the fiber grating sensor component is arranged in the core plate, The light source sends out a light signal, which is transmitted to the FBG sensor component through the fiber coupler. After the light signal interacts with the FBG, the reflected light enters the FBG demodulator through the fiber coupler, and the FBG demodulator is connected to the processor for processing. The controller calls the core board damage database, analyzes the damage degree, builds a three-dimensional model, and outputs the damage distribution of the core board. The invention can evaluate the health of the core board and issue early warnings in time, which is helpful to accurately and quickly eliminate core board failures and potential safety hazards. Avoid safety accidents and production losses, and ensure the interests of both equipment manufacturers and users.

Description

A core plate online monitoring system and method of a diaphragm filter plate

technical field

The invention relates to an on-line monitoring system and method for a core plate of a diaphragm filter plate.

Background technique

Chamber diaphragm filter press has the advantages of high pressing pressure, good corrosion resistance, convenient maintenance, safety and reliability, etc. It is the first choice for industries such as metallurgy, papermaking, pharmaceuticals, food, brewing, and sludge.

Chamber filter press is a pressurized filtration equipment that operates intermittently and requires constant loading and unloading. And in the actual working environment, the pressure on both sides of the filter plate may be severely unbalanced under special conditions such as pipeline blockage, or the filter plate is directly impacted by the slurry due to damage to the filter cloth. In this way, the filter plate is in a state of periodically and frequently subjected to uneven out-of-plane dynamic loads, which further deteriorates its bearing environment. During use, the filter plate will have fatigue cracking to varying degrees.

The working principle of the box-type diaphragm filter press is that a certain number of ordinary box-type filter plates and diaphragm filter plates are closely alternately arranged to form a filter chamber under the action of strong mechanical force, and the filter slurry is input into the filter chamber under the pressure of the feeding pump. The chamber separates the solid and liquid in the filter slurry through the filter medium filter cloth. After the normal filtration is completed, the compressed medium (such as air, water) enters the tympanic membrane of the squeeze chamber of the diaphragm filter plate to reduce the volume of the filter chamber, and squeezes the filter cake to both sides to further compact the filter cake. The diaphragm filter plate of the box-type diaphragm filter press includes a main core plate and two layers of diaphragms on the upper and lower core plates. The main core plate mainly plays the role of rigid support.

However, it is time-consuming and labor-intensive to troubleshoot damaged filter plates on the production site, relying on the accumulated experience of skilled workers for a long time, and troubleshooting can only be carried out after irreparable losses have occurred. If the damaged filter plate continues to work without knowing it, it may cause serious damage to the entire equipment. In this way, the health monitoring technology of the filter plate service is particularly important for the filter plate of the filter press. The health monitoring under the service state is carried out to ensure safe production, real-time early warning of the filter plate with problems, and troubleshooting in advance. To a certain extent It prolongs the safe service life of the filter plate. At the same time, it can also analyze the service state data of the filter plate collected and saved from the field to determine whether the user has violated the regulations during the operation process, effectively avoiding product quality disputes between equipment manufacturers and customers. In addition, it is helpful for the technical upgrade of the filter press from automation to intelligence.

Conventional health monitoring methods are mainly based on some non-destructive testing methods, including ray, ultrasonic, infrared, eddy current, microwave, laser holography, visual inspection, etc. The characteristics of these traditional nondestructive testing methods are offline, static and passive. So far, due to the constraints of various technologies and sensor conditions, there has not been a technology to monitor the service state of the filter plate of the filter press in my country.

Contents of the invention

In order to solve the above problems, the present invention proposes an on-line monitoring system and method for a core plate of a diaphragm filter plate. The present invention can realize dynamic real-time non-destructive detection of the use state of the filter plate of the filter press, calculate the remaining strength of the filter plate, and check the filter plate. The safety and remaining service life of the plate can be estimated, the use efficiency and safe operation performance of the filter press can be improved, the maintenance cost can be reduced, and the filter press can be upgraded from automation to intelligence.

In order to achieve the above object, the present invention adopts the following technical solutions:

A core plate on-line monitoring system of a diaphragm filter plate, including a fiber grating demodulator, a fiber coupler, a processor and a fiber grating sensor assembly, wherein the fiber grating sensor assembly is arranged in the core plate, the light source sends out an optical signal, and the optical signal After the optical signal interacts with the fiber grating, the reflected light enters the fiber grating demodulator through the fiber coupler, and the fiber grating demodulator is connected to the processor.

The processor calls the core plate damage database of the diaphragm filter plate, analyzes the damage degree, builds a three-dimensional model, outputs the damage distribution of the core plate, and evaluates the health of the core plate.

Further, there are two fiber optic couplers, and the optical signal is divided into two paths, which are respectively transmitted to both ends of the fiber grating sensor assembly through one fiber optic coupler, forming two ports.

Further, the optical signal is transmitted to one end of the fiber grating sensor component through a fiber coupler, forming a port with both light incident and reflection.

Preferably, the light source is a built-in light source of the fiber grating demodulator, which generates continuous frequency-modulated laser, and the laser signal enters the fiber grating through the lead wire to form a stable reflection signal.

The fiber grating sensor assembly includes several rows of fiber grating sensor inserts, the fiber grating sensor inserts include temperature fiber gratings and strain fiber gratings, temperature fiber gratings are used to measure temperature, and strain fiber gratings are used to measure temperature Strain, temperature fiber gratings and strain fiber gratings are arranged in parallel and adjacent to each other, and each temperature grating unit in the temperature fiber grating corresponds to each strain grating unit of the strain fiber grating, so that the temperature fiber and the adjacent strain fiber are composed of A fiber grating pair.

The temperature fiber grating and the strain fiber grating should be separated by a certain distance when they are arranged in parallel and adjacent to each other, so as to avoid the local strengthening phenomenon produced by the hard capillary outside the temperature fiber grating in the filter plate and affect the material of the strain fiber grating test area. out of shape. The normal distance between two parallel optical fibers is 5-12mm, preferably 10mm.

The fiber grating pair sensor insert is fixed in the inner cavity of the core plate mold of the filter plate, and is integrally formed with the core plate during molding or injection molding. During the molding process, the end of the insert can extend to the side wall of the inner cavity of the mold to ensure that the fiber grating sensor in the insert can be easily drawn out from the core plate and reliably protected.

An optical fiber connector is provided at the end of the fiber grating-to-sensor insert, and several rod-shaped supports are distributed on the fiber-optic grating-to-sensor insert to realize positioning and fixing of the insert in the mold during molding and injection molding.

The optical fiber grating sensor is packaged in thermoplastic, preferably the same thermoplastic as the core plate material, and the embedded joint of the dual-core optical fiber connector embedded in the core plate structure is pre-installed on one or both ends of the packaging mold, and the optical fiber grating The opposite is placed in the package mold, the thermoplastic melt is poured into the mold, and after cooling, the mold is opened to obtain the fiber grating pair sensor insert with the dual-core optical fiber connector at the end of the thermoplastic package.

Further, the rod-shaped support cooperates with the preset installation hole on the core plate mold, and the end of the rod-shaped support can also be bonded and fixed on the mold to realize the positioning and fixing of the insert in the mold.

The fiber grating pair sensor insert can be a unidirectional lead wire or a bidirectional lead wire, both of which can include a plurality of grating units engraved with different central wavelengths, and each grating unit is an independent sensor unit. Only the gate area can be encapsulated, and the embedded part of the entire fiber grating pair can also be encapsulated. In this way, the packaged fiber grating pair can be a bulk fiber grating sensor insert with a single gate pair of unidirectional leads, a rod shape with multiple gate regions with a unidirectional lead, a block shape with a bidirectional lead, and a rod fiber grating sensor insert with a bidirectional lead. pieces.

The optical fiber connector includes three parts: an embedded connector embedded in the frame of the core plate of the diaphragm filter plate, a plugging head and an external connector. The plugging head is matched. After the core plate has undergone subsequent mechanical processing after forming, the sealing head is removed, and the fiber grating pair sensor in the embedded joint is connected to the optical fiber of the external joint to realize the fiber grating pair sensor buried in the core board. Connect with demodulator.

The processor includes a fiber grating signal analysis module, a core board damage database module, a CAD modeling module, a CAE finite element analysis module, a core board health overall assessment module and a display output module, wherein the fiber grating signal analysis module uses It is used to analyze the signal collected by the fiber grating demodulator; the core plate damage database module is used to store the core plate damage data; the CAD modeling module is used to establish a three-dimensional geometric model of the core plate; the CAE finite element analysis A module for simulating and calculating the damage degree of the core board; the overall evaluation module for the health of the core board is used for evaluating the health of the core board according to the damage distribution of the core board; the display output module is used for displaying the three-dimensional geometry of the core board model and health.

The fiber coupler is a fiber grating signal coupler, which has excellent wavelength selection capability and multi-port characteristics, and is a fiber coupler with compact structure, small loss and polarization irrelevance.

The fiber grating demodulator is a medium-speed or high-speed fiber grating wavelength demodulator, which has a multi-channel parallel demodulation scheme, realizes fast signal demodulation, meets the needs of health monitoring, and can quickly demodulate the filter plate in the working environment raster signal.

The laser light source, the fiber coupler, and the fiber grating sensor are all connected through optical fibers, the fiber grating demodulator and the fiber coupler are connected through optical fibers, the transmission signal is an optical signal, the fiber grating demodulator and the processor are connected through a data line, The transmission signal is a digital signal.

A method based on the above monitoring system, comprising the following steps:

(1) According to the structure of the core plate of the diaphragm filter plate and the monitoring needs, the grating unit is engraved, and each grating unit is numbered, and two fiber gratings are selected to form a fiber grating pair;

(2) Encapsulate the fiber grating-to-sensor and the embedded joint of the dual-core optical fiber connector in a packaging mold by thermoplastic melt casting, so as to obtain the fiber-optic grating-to-sensor insert;

(3) The core plate of the diaphragm filter plate is prepared by molding or injection molding process, and the integral molding of the core plate of the diaphragm filter plate and the fiber grating to the sensor insert is realized;

(4) Connect the embedded joints of the dual-core fiber optic connectors at one or both ends of each fiber grating sensor insert to the corresponding ports of the fiber coupler, and the fiber coupler is connected to the fiber grating demodulator through the fiber, and the fiber grating The demodulator is connected to the signal processor through the data line, and the signal processor analyzes the signal collected by the fiber grating demodulator to solve the core plate temperature, strain and stress of the diaphragm filter plate;

(5) Establish the three-dimensional geometric model of the core plate of the diaphragm filter plate, use the finite element analysis method to calculate the damage degree of the core plate of the diaphragm filter plate, judge whether there is damage to the core plate, if there is damage, judge the damage position and the damage degree, and output the damage, Then evaluate the health of the core board.

In the step (3), before the core plate of the diaphragm filter plate is molded or injection-molded, the mounting holes are preset in the cavity of the mold according to the number of rod-shaped supports of the packaged fiber grating to the sensor insert, and the fiber grating is inserted into the sensor insert. The rod-shaped support of the part is matched with the preset installation hole in the inner cavity of the mold, or the end of the rod-shaped support is glued to fix the insert in the mold; the embedded joint of the optical fiber connector at the end of the insert and the sealing Plug fit; After the core plate of the diaphragm filter plate is molded or injected, the excess fiber grating remaining on the outside of the core plate is removed from the rod-shaped support of the sensor insert, and the surface of the core plate is polished flat.

In described step (5), concrete steps include:

(5-1) Use CAD modeling software to establish a three-dimensional geometric model of the core plate, and import CAE finite element analysis software to divide the grid and establish a finite element model;

(5-2) According to the spatial position correspondence, establish the correspondence between the unit e _xkj and the grating unit xkj in the finite element model: Map the temperature, strain and stress measured by the grating into the finite element model, and carry out the finite element simulation of the temperature field and stress and strain field of the core plate;

(5-3) The processor receives the signal transmitted by the fiber grating demodulator, and counts the dead grating number;

(5-4) Compare the received grating xkj signal with the corresponding damage data model in the core board damage database, diagnose whether the core board at the position of the grating unit is damaged and the degree of damage, and establish the damage degree of the grating unit and the core board The relationship between: xkj→d _(xkj) ;

(5-5) Combining steps (5-2) and (5-4), the change relationship of the damage degree of the grating unit group in the finite element model during the health monitoring process is obtained: e _(xkj) → d _(xkj) , compare Analyze the finite element simulation results of the damage degree and the diagnosis results obtained in step (5-4), enrich and optimize the damage database of the core board, and then output the distribution state of the damage degree of the core board through the cloud image;

(5-6) Estimate the safety and service life of the core board according to the degree of damage, and issue an alarm in time to improve the service safety of the core board.

In the step (5), the processing of the double-lead grating signal is selective: when the optical fiber is intact, the two lead signals of the same grating received by the processor are the same, and only one end of the lead is processed to transmit the signal; if the optical fiber is broken, the two ends of the lead are transmitted The signals are different, and the processor needs to process the signals at both ends at the same time.

The beneficial effects of the present invention are:

(1) The present invention provides a core plate online health monitoring system and method of a diaphragm filter plate, which realizes real-time online non-destructive monitoring of the core plate of a diaphragm filter plate under complex working conditions. The monitoring system and method are based on mature pressure The filter plate production technology of the filter machine has strong implementability and is easy to realize in large-scale production.

(2) The present invention provides an online health monitoring system and a signal processing method for visually outputting the core plate damage position and damage degree of the diaphragm filter plate, and timely releases early warnings, which helps to accurately and quickly eliminate filter plate failures and potential safety hazards, and avoid Safety accidents and production losses, to ensure the interests of both equipment manufacturers and users.

Description of drawings

Figure 1 Schematic diagram of the structure of the thin rod-shaped bidirectional lead fiber Bragg grating pair sensor insert;

Fig. 2 Schematic diagram of the structure of the thin rod-shaped unidirectional lead fiber Bragg grating pair sensor insert;

Fig. 3 is a kind of schematic diagram of the online health monitoring system of the core plate of feeding diaphragm filter plate;

Figure 4 is a schematic diagram of an online health monitoring system for the core plate of a middle-feed membrane filter plate.

1 Fiber Bragg grating temperature sensor; 2 Fiber Bragg grating strain sensor; 3 Double-core joint embedded in fiber optic connector; 4 Fiber Bragg grating pair sensor insert rod support; 5 Core board feeding hole; Inserts; 7 squeezed air and water inlet holes; 8 horizontal holes; 9 feed holes in the core board; 10 unidirectional lead thin rod-shaped fiber grating pair sensor inserts.

Detailed ways:

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

An on-line health monitoring system for the core plate of a diaphragm filter plate, including a fiber grating demodulator, a fiber coupler, a processor, and a fiber grating pair sensor insert suitable for core plate molding and injection molding processes packaged in polypropylene thin rods And a dual-core optical fiber connector embedded in the core board structure. The process is that a single light source or the built-in light source of the fiber grating demodulator sends out optical signals, and the optical signals are divided into two paths through the optical fiber and transmitted to both ends of the fiber grating pair sensor through two fiber couplers on the left and right sides or a fiber coupler on one side Or one end, forming two or one port with both light incident and reflection, pre-fixed in the inner cavity of the core plate mold, the fiber grating packaged in the shape of a polypropylene thin rod is integrally formed with the core plate during the molding or injection molding process , after the optical signal interacts with the fiber grating pair, the reflected light enters the fiber grating demodulator through the fiber coupler. Damage distribution of the core board to assess the health of the core board.

The fiber grating pair sensor insert contains two fiber gratings, namely a temperature fiber grating and a strain fiber grating. The temperature fiber grating is used to measure temperature, and the strain fiber grating is used to measure strain. The temperature fiber grating and the strain fiber grating are parallel and adjacent Each temperature grating unit in the temperature fiber grating corresponds to each strain grating unit of the strain fiber grating, so that the temperature fiber and the adjacent strain fiber form a fiber grating pair.

The temperature fiber grating and the strain fiber grating should be separated by a certain distance when they are parallel and adjacently arranged, preferably 10mm, so as to avoid the local strengthening phenomenon produced by the hard capillary outside the temperature fiber grating in the core plate and affect the strain fiber grating test area of material deformation. The fiber grating-to-sensor insert adopts the fiber grating-to-sensor polypropylene packaging technology, and a sensor insert with a rod-shaped support for the package grid area pair or the entire embedded part is made to ensure that the fiber grating-to-sensor is in the core. The board can be effectively fixed during the molding and injection molding process without being damaged by the molding or injection molding pressure.

The fixing of the fiber grating to the sensor insert in the molding and injection molding process of the core plate is realized by the rod support of the insert and the preset installation holes in the mold of the molding and injection molding core plate. The end of the rod-shaped support is glued and fixed on the mold to realize the positioning and fixing of the insert in the mold.

The fiber grating-to-sensor polypropylene packaging technology is to pre-install the embedded joint of the dual-core optical fiber connector embedded in the core board structure at one or both ends of the packaging mold, and the fiber grating is placed in the packaging mold and poured into the mold. Polypropylene melt, mold opening after cooling to obtain fiber grating pair sensor inserts with dual-core optical fiber connectors at the end of polypropylene package. Encapsulation molds can be made to form rod inserts with rod supports.

The optical fiber can be a unidirectional lead or a bidirectional lead, both of which can include multiple grating units engraved with different central wavelengths, and each grating unit is an independent sensor unit. It can only encapsulate the gate area, or encapsulate the embedded part of the entire fiber grating. In this way, the packaged fiber grating pair can be a bulk fiber grating sensor insert with a single gate pair of unidirectional leads, a rod shape with multiple gate regions with a unidirectional lead, a block shape with a bidirectional lead, and a rod fiber grating sensor insert with a bidirectional lead. pieces.

The dual-core optical fiber connector for embedded in the core board structure includes three parts: the embedded connector embedded in the frame of the core board, the plugging head and the external connector. During the forming process of the core plate, one end of the embedded joint is connected to the embedded fiber grating pair sensor, and the other end is matched with the sealing head. After the formed core plate undergoes subsequent mechanical processing, the sealing head is removed, and the embedded joint The fiber grating pair sensor is connected to the optical fiber of the external joint, and the fiber grating pair sensor embedded in the core board is connected to the fiber coupler.

The light source can be an independent light source or built in the fiber grating demodulator to generate continuous frequency-modulated laser. The laser signal enters the fiber grating through the lead wire to form a stable reflection signal.

The processor includes a fiber grating signal analysis module, a core board damage database module, a CAD modeling module, a CAE finite element analysis module, a core board health overall assessment module and a display output module, wherein the fiber grating signal analysis module is used for analyzing The signal collected by the fiber grating demodulator; the core plate damage database module is used to store core plate damage data; the CAD modeling module is used to establish a three-dimensional geometric model of the core plate; the CAE finite element analysis module, It is used to calculate the damage degree of the core plate; the core plate health overall assessment module is used to evaluate the health of the filter plate according to the damage distribution of the core plate; the display output module is used to display the three-dimensional geometric model and the health condition of the core plate .

The fiber coupler is a fiber grating signal coupler with excellent wavelength selection capability and multi-port characteristics. It is a fiber coupler with compact structure, low loss and polarization independent.

The fiber grating demodulator is a medium-speed or high-speed fiber grating wavelength demodulator. It has a multi-channel parallel demodulation scheme to realize fast signal demodulation and meet the needs of health monitoring. It can quickly demodulate the grating signal of the filter plate in the working environment. .

The laser light source, fiber coupler, and fiber grating sensor are all connected through optical fibers. The fiber grating demodulator and fiber coupler are connected through optical fibers, and the transmission signal is an optical signal. The fiber grating demodulator and processor are connected through a data line to transmit signals. for digital signals.

A method for on-line health monitoring of a core plate of a diaphragm filter plate, comprising the following steps:

(1) Select the optical fiber, engrave the grating according to the structure of the core plate of the diaphragm filter plate and the monitoring needs, each optical fiber can be engraved with multiple grating units, and each grating unit is numbered, and the lead wires can be drawn from one or both ends of the sensor , form a single-lead or double-lead fiber grating string, and calibrate the temperature coefficient of the grating;

(2) Select two fiber gratings to form a fiber grating pair, one fiber grating is used to measure temperature, marked as T, and the other fiber grating is used to measure strain, marked as S, the grating marked T is covered with a casing, and the nozzle is sealed with glue;

(3) Encapsulate the fiber grating-to-sensor and the embedded joint of the dual-core optical fiber connector by polypropylene melt casting to obtain the fiber-optic grating-to-sensor insert;

(4) Before the core plate of the diaphragm filter plate is molded or injected, the mounting holes are preset in the cavity of the mold according to the number of rod-shaped supports of the fiber grating to the sensor insert after packaging, and the rod-shaped support of the fiber grating to the sensor insert is Cooperate with the preset mounting holes in the inner cavity of the mold, the end of the rod-shaped support can also be bonded in the mold to realize the positioning and fixing of the insert in the mold; the embedded joint of the optical fiber connector at the end of the insert and the sealing plug fit;

(5) The core plate is prepared by molding or injection molding process to realize the integral molding of the core plate and the fiber grating to the sensor insert; Remove the rod support and polish the surface of the core board;

(6) After the formed core board undergoes subsequent mechanical processing, the plugging head is removed, and the embedded joints of the dual-core optical fiber connectors at one or both ends of each fiber grating pair sensor insert are respectively connected to the corresponding fiber couplers. Port, the fiber coupler is connected to the fiber grating demodulator through the optical fiber, the fiber grating demodulator is connected to the signal processor through the data line, the signal processor analyzes the signal collected by the fiber grating demodulator, and solves the temperature, strain and stress of the core board;

(7) Establish a three-dimensional geometric model of the core board, use the finite element analysis method to calculate the damage degree of the core board, judge whether there is damage to the core board, if there is damage, judge the damage location and damage degree, output the damage, and then evaluate the health of the core board .

(7-1) Use CAD modeling software to establish a three-dimensional geometric model of the core plate, and import CAE finite element analysis software to divide the grid and establish a finite element model;

(7-2) According to the spatial position correspondence, establish the correspondence between the unit e _xkj and the grating unit xkj in the finite element model: Map the temperature, strain and stress measured by the grating into the finite element model, and carry out the finite element simulation of the temperature field and stress and strain field of the core plate;

(7-3) The processor receives the signal transmitted by the fiber grating demodulator, and counts the dead grating number;

(7-4) Compare the received grating xkj signal with the corresponding damage data model in the core board damage database, diagnose whether the core board at the position of the grating unit is damaged and the degree of damage, and establish the damage degree of the grating unit and the core board The relationship between: xkj→d _(xkj) ;

(7-5) Combining steps (7-2) and (7-4), the change relationship of the damage degree of the grating unit in the finite element model during the health monitoring process is obtained: e(xkj)→d(xkj), comparative analysis The finite element simulation results of the damage degree and the diagnosis results obtained in step (7-4) enrich and optimize the damage database of the core board, and then output the distribution state of the damage degree of the core board through the cloud map;

(7-6) Estimate the safety and service life of the core board according to the degree of damage, and issue an alarm in time to improve the service safety of the core board.

In step (7), the processing of the double-lead grating signal is selective: when the optical fiber is intact, the two lead signals of the same grating received by the processor are the same, and only one end of the lead transmission signal is processed; if the optical fiber is broken, the two ends of the lead transmission signal are different , the processor needs to process signals at both ends at the same time.

Fiber Bragg Grating (Fiber Bragg Grating, FBG) is a sensor element sensitive to stress, strain and temperature, which can realize the measurement of dozens of strain nodes by a single optical fiber. Long, high reliability, corrosion resistance, long transmission distance and other advantages, can realize the measurement of various parameters such as strain, stress, temperature, etc., in the following examples choose fiber Bragg grating.

Embodiment 1: An on-line health monitoring device and method for a core plate of an upper-feed box-type diaphragm filter plate.

As shown in Figure 3, the system includes: a thin rod-shaped bidirectional lead fiber Bragg grating pair sensor insert 6, a fiber coupler, a fiber grating digital demodulator, a computer system, and the like.

The structure of the thin rod-shaped two-way lead fiber Bragg grating pair sensor insert 6 is shown in Figure 1. There are leads at both ends of each fiber Bragg grating, forming two signal channels. After being broken by external force, a double-lead grating sensor can become 2 single-lead grating sensors, the grating can work normally, ensuring the stability of online monitoring process monitoring.

(1) According to the size of the core plate of the upper-feed box-type diaphragm filter plate, 26 optical fibers with a cladding diameter of 40 μm are engraved to engrave gratings. Each optical fiber is engraved with 10 grating units with different central wavelengths, numbered 1-10.

(2) Take two engraved optical fibers to form a fiber grating pair, and number them 1-13. The temperature measurement grating is covered with stainless steel steel pipes, and the nozzle is sealed with glue. It is marked as T, and the strain grating is marked as S.

(3) To package the fiber grating pair, first pre-install the embedded joint 3 of the double-core fiber optic connector on both ends of the packaging mold, fix the two optical fibers in the rod-shaped packaging mold, and keep the positions of the grating units of the two optical fibers corresponding to each other. , the distance between the two optical fibers is 10mm, and the lead wires at both ends of the fiber grating sensor are connected to the embedded joint 3 of the dual-core optical fiber connector fixed at both ends of the cavity of the mold. The polypropylene melt is poured into the mold, and after cooling, the mold is opened to obtain a rod-shaped optical fiber grating pair sensor insert 6 with a dual-core optical fiber connector at the end.

(4) Presetting mounting holes on the surface of the inner cavity of the core plate molding or injection mold according to the number of rod-shaped supports 4 to which the rod-shaped packaged fiber gratings are mounted. Match the rod-shaped support 4 of the rod-shaped fiber grating to the sensor insert with the preset installation hole on the mould. Mate the embedded joint of the fiber optic connector at the end of the insert with the blanking head.

(5) The core plate of the box-type diaphragm filter plate is prepared by the molding process, and the integral molding of the core plate of the diaphragm filter plate and the rod-shaped fiber grating to the sensor insert is realized.

(6) After the core plate of the box-type diaphragm filter plate is molded, remove the excess fiber grating rod-shaped support 4 for the sensor insert that remains on the outside of the core plate and polish it smooth.

(7) After the formed core board undergoes subsequent mechanical processing, the plugging head is removed, and the embedded joints of each dual-core optical fiber connector at both ends are respectively connected to the corresponding ports of the optical fiber coupler, and the optical fiber coupler is connected to the optical fiber through the optical fiber. The grating demodulator, the fiber grating demodulator is connected to the computer through a network cable, and the computer has health monitoring system software for processing fiber grating data, geometric three-dimensional modeling, and the output shows the damage distribution.

Embodiment 2 An on-line health monitoring device and method for a core plate of a middle-feed box-type membrane filter plate

As shown in Figure 4, the system includes: thin rod-shaped unidirectional lead fiber Bragg grating sensor insert, thin rod-shaped bidirectional lead fiber Bragg grating sensor insert, fiber coupler, fiber grating digital demodulator, computer system, etc. .

The structure of the thin rod-shaped unidirectional lead fiber Bragg grating pair package insert 10 is shown in Figure 2. Each fiber Bragg grating has only one lead wire, and the fiber Bragg grating with unidirectional lead wire is convenient for the distribution around the feeding hole in the center of the core plate of the diaphragm filter plate. Row.

(1) According to the shape, structure, and size of the core plate of the middle-feed box-type diaphragm filter plate, 22 optical fiber gratings with a cladding diameter of 40 μm of bidirectional leads were engraved. Each optical fiber is engraved with 10 grating units with different central wavelengths, numbered 1-10. Take two engraved optical fibers to form a fiber grating pair, and number them 1-11. The temperature measurement grating is covered with stainless steel steel pipes, and the nozzle is sealed with glue. It is marked as T, and the strain grating is marked as S.

(2) Engraving 8 optical fiber engraving gratings with a cladding diameter of 40 μm for unidirectional leads. Five grating units with different central wavelengths are engraved on each fiber, numbered 1-5. Take two engraved optical fibers to form a fiber grating pair, and number them 12-15. The temperature measurement grating is covered with stainless steel steel pipes, and the nozzle is sealed with glue. It is marked as T, and the strain grating is marked as S.

(3) Encapsulate the bidirectional lead fiber grating pair, pre-install the embedded joints of the dual-core optical fiber connector at both ends of the packaging mold, fix the two optical fibers numbered 1-11 in the thin rod-shaped packaging mold, and keep the two The position of the grating unit of the optical fiber is corresponding, the distance between the two optical fibers is 10mm, and the lead wires at both ends of the optical fiber grating to the sensor are connected to the embedded joints of the dual-core optical fiber connectors fixed at both ends of the mold cavity. The polypropylene melt is poured into the mold, and after cooling, the mold is opened to obtain the fiber grating pair sensor insert 6 with a double-core optical fiber connector at the end of the thin rod-shaped bidirectional lead wire.

(4) Encapsulate the unidirectional lead fiber grating pair, pre-install the embedded joint of the double-core optical fiber connector at one end of the packaging mold, fix the two optical fibers numbered 12-15 in the thin rod-shaped packaging mold, and keep The positions of the grating units of the two optical fibers are corresponding, and the distance between the two optical fibers is 10mm. The lead wire of the fiber grating to the sensor end is connected to the embedded joint of the dual-core optical fiber connector fixed at the end of the mold cavity. The polypropylene melt is poured into the mold, and after cooling, the mold is opened to obtain the fiber grating pair sensor insert 10 with a double-core optical fiber connector at the end of a thin rod-shaped unidirectional lead wire.

(5) Bonding the end of the rod-shaped packaged fiber grating to the rod-shaped support 4 on the mold to fix it in the mold. The one-way lead fiber grating pair sensor insert 10 is arranged around the feeding hole at the center of the core plate. Mate the embedded joint of the fiber optic connector at the end of the insert with the blanking head.

(6) The core plate of the box-type diaphragm filter plate is prepared by molding technology, and the integral molding of the core plate of the diaphragm filter plate and the rod-shaped fiber grating to the sensor insert is realized.

(7) After the core plate of the box-type diaphragm filter plate is molded, the excess fiber grating remaining on the outside of the core plate for the rod-shaped support of the sensor insert is removed and polished to make it smooth.

(8) After the formed core board undergoes subsequent mechanical processing, the plugging head is removed, and the embedded joints of each double-core optical fiber connector are respectively connected to the corresponding ports of the fiber coupler. The fiber coupler is connected to the fiber grating through the optical fiber The fiber grating demodulator is connected to the computer through a network cable, and the computer has health monitoring system software to process the fiber grating data, three-dimensional modeling, and the output shows the damage distribution.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (8)

1. a kind of core plate on-line monitoring system of membrane filter plate, it is characterized in that：Including fiber Bragg grating (FBG) demodulator, fiber coupler, Processor and fiber-optic grating sensor component, wherein, fiber-optic grating sensor component is arranged in core plate, and light source sends light letter Number, optical signal is transferred to fiber-optic grating sensor component by fiber coupler, after optical signal interacts with fiber grating, instead Penetrate light and enter fiber Bragg grating (FBG) demodulator, fiber Bragg grating (FBG) demodulator connection processor by fiber coupler；

The fiber-optic grating sensor component, includes the fiber grating pair sensor insert of several columns, and the fiber grating pair passes Sensor inserts, including optical fiber temperature grating and strain fiber grating, optical fiber temperature grating are used for measurement temperature, strain fiber grating For measuring strain, optical fiber temperature grating is parallel with strain fiber grating, arranged adjacent, each temperature in optical fiber temperature grating Raster unit and each strain raster unit of strain fiber grating correspond；

The end of the fiber grating pair sensor insert is provided with the interior of the joints of optical fibre and buries joint, and fiber grating pair sensor is embedding Several rod shaped supports are distributed with part, to realize the positioning and fixation of inserts in a mold in molding, injection molding process, The rod shaped support is engaged with default mounting hole on core plate mould or the end of rod shaped support is adhesively fixed on mould.

2. a kind of core plate on-line monitoring system of membrane filter plate as claimed in claim 1, it is characterized in that：The optical signal passes through One fiber coupler is transferred to one end of fiber-optic grating sensor component, forms one and has the incident end with light reflection of light concurrently Mouthful；The fiber coupler has one or two, and optical signal is divided into all the way or two-way, passes through one or two respectively Fiber coupler is transferred to one end or both ends of fiber-optic grating sensor component, forms one or two ports.

3. a kind of core plate on-line monitoring system of membrane filter plate as claimed in claim 1, it is characterized in that：The fiber grating pair Sensor insert is fixed on the dies cavity of core plate, is integrally formed in molding or injection moulding process with core plate.

4. a kind of core plate on-line monitoring system of membrane filter plate as claimed in claim 1, it is characterized in that：Described fiber grating Sensor insert is prepared by thermoplastic encapsulation technology, will be buried in core plate structure with double-core optical fiber connector The one or both ends that joint is pre-installed on encapsulating mould are inside buried, fiber grating is opposite in encapsulating mould, and heat injection is poured into mould Thermoplastic plastic melt, die sinking is to obtain fiber grating of the end with double-core optical fiber connector of thermoplastic encapsulation after cooling To sensor insert.

5. a kind of core plate on-line monitoring system of membrane filter plate as claimed in claim 1, it is characterized in that：The processor includes Fiber grating signal resolution module, core plate damage data library module, CAD modeling modules, CAE finite element analysis modules, core plate are good for Health total evaluation module and display output module, wherein, the fiber grating signal resolution module, for parsing fiber grating solution Adjust the signal of instrument collection；The core plate damage data library module, for storing core plate damage data；The CAD modeling modules, use In the 3-D geometric model for establishing core plate；The CAE finite element analysis modules, for simulation calculation core plate degree of injury；It is described Core plate health total evaluation module, the health condition for the damage profile condition evaluation filter plate according to core plate；The display is defeated Go out module, for showing the 3-D geometric model and health condition of core plate.

6. a kind of method of the monitoring system based on as any one of claim 1-5, it is characterized in that：Including following step Suddenly：

(1) raster unit is scribed according to the structure of the core plate of membrane filter plate and monitoring needs, and each raster unit is numbered, Two fiber gratings of selection set up fiber grating pair；

(2) to burying joint in fiber grating pair sensor and double-core optical fiber connector using thermoplastic melt cast Mode is packaged in encapsulating mould, obtains fiber grating pair sensor insert；

(3) membrane filter plate core plate is prepared using molding or Shooting Technique, realizes membrane filter plate core plate and fiber grating pair sensing Device inserts is integrally formed；

(4) joint is buried in the double-core optical fiber connector the one or both ends of each fiber grating pair sensor insert respectively to connect The corresponding ports of fiber coupler are connect, fiber coupler is led to by intelligent acess fiber Bragg grating (FBG) demodulator, fiber Bragg grating (FBG) demodulator Data wire connection signal processor is crossed, the signal of signal processor parsing fiber Bragg grating (FBG) demodulator collection, core plate temperature is solved, answers Change and stress；

(5) 3-D geometric model of the core plate of membrane filter plate is established, the degree of injury of core plate is calculated using finite element method, Judge whether core plate damages, if damaging, judge damage position and degree of injury, output damage, and then evaluate core Plate health degree.

7. method as claimed in claim 6, it is characterized in that：In the step (3), it is molded or is molded in membrane filter plate core plate Before shaping, mounting hole is preset according to the rod shaped support quantity of the fiber grating pair sensor insert after encapsulation in dies cavity, Default mounting hole in the rod shaped support and dies cavity of fiber grating pair sensor insert is coordinated, or by rod shaped support end Viscose glue connects fixation and realizes the fixation of inserts in a mold；Joint will be buried in the joints of optical fibre of inserts end with block head to match somebody with somebody Close；After core plate molding or injection molding, by the bar-shaped branch of fiber grating pair sensor insert of the excessive residual outside core plate Support is removed, and core plate surface is polished flat.

8. method as claimed in claim 6, it is characterized in that：In the step (5), specific steps include：

(5-1) establishes the 3-D geometric model of membrane filter plate core plate using CAD modeling softwares, and it is soft to import CAE finite element analyses Part, grid division, establish FEM model；

(5-2) establishes unit e in FEM model according to locus corresponding relation_xkjWith raster unit xkj corresponding relation：The temperature of grating measuring, strain and stress are mapped in FEM model, carry out temperature field and the stress of core plate The finite element modelling of strain field；

The signal that the transmission of (5-3) processor reception optical fiber grating demodulation instrument comes, and count dead grating numbering；

Corresponding damage data model after (5-4) is handled the grating xkj signals received and in core plate damage data storehouse Whether contrast, the core plate of diagnosis grating cell position occur damage and degree of injury, establish raster unit and core plate damage journey Relation between degree：xkj→d_(xkj)；

(5-5) combines step (5-2), (5-4), and the raster unit group obtained in FEM model damages during health monitoring Hinder the variation relation of degree：e_(xkj)→d_(xkj), institute in the finite element modelling result and step (5-4) of comparative analysis degree of injury The diagnostic result obtained, enrich, the damage data storehouse of optimization core plate, then pass through the distribution shape that cloud atlas exports core plate degree of injury State；

(5-6) estimates the security and service life of core plate, sends alarm in time, improve membrane filter plate core according to degree of injury The usage security of plate.