Low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology

Abstract

The invention discloses a low-temperature economizer leakage monitoring device based on a distributed optical fiber sensing technology, and relates to the technical field of economizer leakage monitoring devices. A plurality of groups of heat exchange tubes are sequentially arranged in an economizer at intervals in the flue gas conveying direction; comprising a plurality of groups of temperature measuring optical fibers, the temperature measuring optical fibers are arranged on the sides, close to or away from the adjacent heat exchange tubes, of each group of heat exchange tubes, each group of temperature measuring optical fibers are arranged in an S shape in the direction perpendicular to the flue gas conveying direction to form a net-shaped temperature measuring face, and then a temperature zone monitoring net group is formed in the economizer in the flue gas conveying direction; and the temperature measurement host is connected with the plurality of groups of temperature measurement optical fibers so as to carry out temperature monitoring. According to the invention, the low-temperature economizer can be monitored in real time, the leakage point can be accurately positioned, the leakage monitoring precision and reliability are improved, and the safety and reliability of the operation of a coal-fired power plant unit are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of economizer leakage monitoring devices, and in particular to a low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology. Background Art

[0002] With the development of science and technology in my country, the concept of energy conservation and environmental protection has become deeply rooted in people's minds. The country has established strict standards for pollutant emissions and energy conservation in coal-fired power plants. Low-temperature economizers are now widely used in coal-fired power plants due to their significant energy-saving effects and their significant auxiliary effect on improving the efficiency of electrostatic precipitators. However, due to the harsh flue gas environment in which they operate, flue gas erosion, wear, and low-temperature corrosion are common. After long-term operation, low-temperature economizers are prone to leakage. Leakage can exacerbate corrosion of the low-pressure economizer and flue, causing internal blockage of the low-pressure economizer. In severe cases, it can even cause the electrostatic precipitator to clog and harden, seriously affecting the safe operation of coal-fired power plant units. Therefore, accurate and effective monitoring of low-temperature economizer leakage has become an urgent problem that needs to be solved in the industry.

[0003] Traditional low-temperature economizer leakage monitoring methods mainly include the following: furnace tube leakage detection and alarm device, heat exchanger flue gas humidity detection, flow difference or inlet and outlet pressure difference detection, high-temperature camera monitoring, etc. However, various leakage monitoring methods generally have shortcomings such as poor resistance to environmental interference, inability to accurately locate the leakage point, poor sensitivity to initial small flow leakage monitoring, and prone to false alarms.

[0004] Distributed fiber optic sensing technology is based on the spontaneous Raman scattering effect. The optical fiber is the sensor, and the transmission and sensing are integrated to realize distributed measurement. It can realize real-time collection of strain, temperature, vibration and other data. The positioning accuracy can reach centimeter level (such as 0.05 meters) and the temperature measurement accuracy can reach 0.005℃. It has the advantages of long measurement distance, simple installation, precise positioning, and anti-electromagnetic interference. It is suitable for industrial fields such as cable temperature monitoring, fire warning, and pipeline temperature anomaly detection.

[0005] To this end, how to provide a low-temperature economizer leakage monitoring device based on distributed fiber optic sensing technology that can realize real-time monitoring of the low-temperature economizer and accurately locate the leakage point, so as to improve the leakage monitoring accuracy and reliability, and thereby improve the safety and reliability of the operation of coal-fired power plant units is a problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0006] In view of this, the present invention proposes a low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology, aiming to solve the technical problems of low leakage monitoring accuracy and poor reliability of the above-mentioned traditional economizer leakage monitoring device.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology. Multiple groups of heat exchange tubes are sequentially arranged along the flue gas transmission direction inside the economizer; the device comprises:

[0009] Multiple groups of temperature measuring optical fibers, each group of heat exchange tubes is provided with a temperature measuring optical fiber on one side close to or away from an adjacent heat exchange tube, and each group of temperature measuring optical fibers is arranged in an S-shape perpendicular to the flue gas conveying direction to form a mesh temperature measuring surface, thereby forming a temperature zone monitoring network group inside the economizer along the flue gas conveying direction;

[0010] A temperature measuring host is connected to multiple groups of temperature measuring optical fibers to perform temperature monitoring.

[0011] The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology of the present invention constructs a temperature zone monitoring network group in the flue gas flow channel inside the economizer; since the temperature of the flue gas will decrease each time it passes through a group of heat exchange tubes, different temperature zones with gradually decreasing temperatures are formed in the flow channel inside the economizer along the direction of flue gas transportation; the temperature zone monitoring network group can realize the temperature monitoring function of different temperature zones, and the mesh temperature measuring surface constructed by the temperature measuring optical fiber arranged in an S shape can sense the temperature changes of each point along the optical fiber in real time and transmit the signal to the temperature measuring host; the temperature measuring host is used to measure the temperature distribution along the optical fiber, can realize long-distance, high-precision temperature measurement, and can quickly locate the leakage point according to the change of temperature data. The present invention can realize real-time monitoring of the low-temperature economizer and accurately locate the leakage point, so as to improve the accuracy and reliability of leakage monitoring, thereby improving the safety and reliability of the operation of the coal-fired power plant unit.

[0012] As a further improvement of the above technical solution, it also includes an industrial computer, which is connected to the temperature measurement host and is equipped with a display.

[0013] The beneficial effect of the above technical solution is that the temperature distribution curve can be displayed in real time on the display of the industrial computer to facilitate monitoring of abnormal temperature changes.

[0014] As a further improvement of the above technical solution, it also includes an optical fiber fixing and cleaning component, and each group of the temperature measuring optical fibers is installed inside the economizer through the optical fiber fixing and cleaning component.

[0015] The beneficial effect of the above technical solution is that the optical fiber fixing and cleaning assembly provides support for the S-shaped arrangement and stability of the temperature measuring optical fiber.

[0016] As a further improvement of the above technical solution, the optical fiber fixing and cleaning assembly includes a fixed tube, which is arranged in an S shape along the direction perpendicular to the flue gas conveying direction to form a fixed mesh surface; the temperature measuring optical fiber is fixed to the fixed tube and extends along the length direction of the fixed tube to form an S shape to form a mesh temperature measuring surface;

[0017] A cleaning spray hole is provided on the outer peripheral wall of the fixed tube corresponding to the temperature measuring optical fiber, so as to clean the temperature measuring optical fiber by spraying air or liquid.

[0018] The beneficial effects of the above technical solution are: the fixed tube can not only install and support the temperature measuring optical fiber, but also transport the gas or liquid used to clean the temperature measuring optical fiber; the cleaning gas or liquid is sprayed out from the self-cleaning nozzle to clean or wash the silt or dirt attached to the periphery of the temperature measuring optical fiber, thereby ensuring the temperature sensing accuracy of the temperature measuring optical fiber, and thereby improving the sensitivity and reliability of temperature monitoring.

[0019] As a further improvement of the above technical solution, the optical fiber fixing and cleaning assembly also includes a wiping mechanism, which is slidably connected to the fixed tube and can move along the length direction of the fixed tube; the wiping head of the wiping mechanism corresponds to abutting against the temperature measuring optical fiber for sliding wiping.

[0020] The beneficial effects of the above technical solution are: by arranging a wiping mechanism that can move along the length direction of the fixed tube, the wiping mechanism can be started according to cleaning needs, so that the wiping head moves and wipes along the length direction of the temperature measuring optical fiber; the moving wiping head and the cleaning nozzle spray air or liquid synchronously, which can achieve better and more efficient cleaning effects, ensuring the accuracy and reliability of leakage monitoring.

[0021] As a further improvement of the above technical solution, the wiping mechanism includes a walking frame, which is slidably connected to the fixed tube and can move along the length direction of the fixed tube; the wiping head is installed on the walking frame and movably presses and covers the outer periphery of the temperature measuring optical fiber.

[0022] The beneficial effect of the above technical solution is that the traveling frame is used to install and support the wiping head, and by pressing the wiping head against the outer periphery of the temperature measuring optical fiber, the temperature measuring optical fiber can be better and more comprehensively cleaned.

[0023] As a further improvement of the above technical solution, the walking frame includes a slide, an elastic arc plate, a driving wheel and a driving motor;

[0024] The temperature measuring optical fiber is arranged on the side wall 1 of the fixed tube; the slide is slidably provided on both side walls of the fixed tube corresponding to the side wall 1, the elastic arc plate is arranged corresponding to the side wall 1 and surrounds the outer periphery of the temperature measuring optical fiber, and the two ends of the elastic arc plate are fixedly connected to the two slides in a one-to-one correspondence;

[0025] The driving wheel is mounted on the carriage and its outer circumference abuts against the outer wall of the fixed tube. The driving motor is connected to the driving wheel to drive the rotation, thereby causing the driving wheel to roll along the length direction of the fixed tube.

[0026] The wiping head is installed on the inner side of the elastic arc plate and is adapted to press and cover the outer periphery of the temperature measuring optical fiber.

[0027] The beneficial effects of the above technical solution are: the driving motor is used to drive the driving wheel to roll and move, thereby driving the wiping head connected to the slide to move and wipe; the two ends of the elastic arc plate are straddled on the fixed tube through the slide, and since the elastic arc plate has bending deformation characteristics, the slide can move smoothly through the S-bend part of the fixed tube without getting stuck; in addition, the elastic arc plate has the function of making the wiping head more elastic and pressed against the outer periphery of the temperature measuring optical fiber, so as to avoid the situation where the wiping head is not wiped clean due to the decrease in pressure after wear, thereby improving its service life.

[0028] As a further improvement of the above technical solution, the optical fiber fixing and cleaning assembly further includes a heat insulating pad, which is arranged between the temperature measuring optical fiber and the fixing tube.

[0029] The beneficial effect of the above technical solution is that the thermal insulation pad plays the role of thermal insulation and protection of the temperature measuring optical fiber, thereby ensuring its measurement accuracy.

[0030] As a further improvement of the above technical solution, the optical fiber fixing and cleaning assembly further includes a clamp, and the clamp adapter hoop is sleeved on the outer periphery of the temperature measuring optical fiber and fixed on the thermal insulation pad.

[0031] The beneficial effect of the above technical solution is that the clamp fits tightly to the outer periphery of the temperature measuring optical fiber in the clamp sleeve, which can improve the fixing firmness of the temperature measuring optical fiber to avoid displacement or vibration caused by the influence of flue gas flow, which may affect the measurement.

[0032] As a further improvement of the above technical solution, it also includes a fluid supply part, the output port of the fluid supply part is connected to the fixed tube to transport gas or liquid for cleaning the temperature measuring optical fiber.

[0033] The beneficial effect of the above technical solution is that the fluid supply part can deliver gas or liquid with a certain pressure to the fixed pipe as needed, so that the gas or liquid can be ejected from the cleaning nozzle, thereby improving the cleaning flushing force and effect.

[0034] As can be seen from the above technical solutions, compared with the prior art, the present invention discloses a low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology, which has the following advantages and beneficial effects:

[0035] 1. The present invention uses optical fiber as a detection carrier, which can realize the temperature and alarm positioning of each point along the optical cable. It has the characteristics of flexible layout, precise positioning, and strong anti-interference ability, which improves the reliability and stability of the monitoring system. It can also monitor the temperature distribution in the monitored equipment in real time, find leakage points in time, and reduce energy loss.

[0036] 2. The present invention utilizes a fixed tube as a supporting structure for the installation and arrangement of the temperature measuring optical fiber. By opening a cleaning nozzle on the fixed tube, the spray cleaning of the temperature measuring optical fiber is realized. In addition, by arranging a wiping mechanism on the fixed tube, all-round wiping and cleaning of the temperature measuring optical fiber is realized. The cleaning nozzle sprays liquid in conjunction with the wiping head of the wiping mechanism for wiping, which can achieve effective cleaning of the temperature measuring optical fiber and avoid the temperature measuring optical fiber arranged inside the economizer from being affected by too thick scaling and siltation, thereby providing a guarantee for improving the safety and reliability of the operation of coal-fired power plant units. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0038] Figure 1 A three-dimensional schematic diagram of a temperature zone monitoring network constructed with multiple groups of temperature measuring optical fibers of a low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to the present invention;

[0039] Figure 2 Schematic diagram of the S-shaped arrangement of the temperature measuring optical fibers of the low-temperature economizer leakage monitoring device based on the distributed optical fiber sensing technology of the present invention;

[0040] Figure 3 Schematic diagram of the distribution of temperature measuring points and temperature measuring areas of the temperature measuring optical fiber of the low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology of the present invention;

[0041] Figure 4 Schematic diagram of the overall structural layout of the low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology of the present invention;

[0042] Figure 5 Schematic diagram of the structure of the optical fiber fixing and cleaning components of the low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology of the present invention;

[0043] Figure 6 Schematic diagram of the wiping mechanism structure of the low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology of the present invention;

[0044] Figure 7 Schematic diagram of the state in which the temperature measuring optical fiber of the low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology of the present invention is bonded to the thermal insulation pad;

[0045] Figure 8Schematic diagram of the state in which the temperature measuring optical fiber of the low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology of the present invention is fastened to the thermal insulation pad by screws;

[0046] Figure 9 Schematic diagram of the internal structure of the temperature measuring optical fiber of the low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology of the present invention.

[0047] In the figure: 1. Economizer; 11. Flue gas inlet; 12. Flue gas outlet; 2. Heat exchange tube; 3. Temperature measuring optical fiber; 31. Optical fiber; 311. Temperature measuring point; 312. Temperature measuring area; 32. Stainless steel welded pipe; 33. Steel wire stranded layer; 4. Temperature measuring host; 5. Optical fiber fixing and cleaning assembly; 51. Fixing tube; 511. Cleaning nozzle; 512. Side wall 1; 52. Wiping mechanism; 521. Traveling frame; 5211. Slide; 5212. Elastic arc plate; 5213. Driving wheel; 5214. Driving motor; 5215. Guide wheel; 522. Wiping head; 53. Thermal insulation pad; 54. Clamp; 55. Battery; 56. Screw; 6. Industrial computer; 61. Display; 7. Control cabinet. DETAILED DESCRIPTION

[0048] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0049] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0051] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0052] According to an embodiment of the present invention, Figures 1 to 9 As shown, the present invention provides a low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology. Multiple groups of heat exchange tubes 2 are arranged in sequence along the flue gas transmission direction inside the economizer 1; it includes: multiple groups of temperature measuring optical fibers 3 and a temperature measuring host 4.

[0053] A temperature measuring optical fiber 3 is arranged on one side of each group of heat exchange tubes 2 close to or away from the adjacent heat exchange tube 2. Each group of temperature measuring optical fibers 3 is arranged in an S shape along the direction perpendicular to the flue gas transportation to form a mesh temperature measurement surface, thereby forming a temperature zone monitoring network group inside the economizer 1 along the flue gas transportation direction.

[0054] The temperature measuring host 4 is connected to multiple groups of temperature measuring optical fibers 3 for temperature monitoring.

[0055] The low-temperature economizer leakage monitoring device of this embodiment based on distributed optical fiber sensing technology constructs a temperature zone monitoring network group in the flue gas flow channel inside the economizer 1; since the temperature of the flue gas will decrease each time it passes through a group of heat exchange tubes 2, different temperature zones with gradually decreasing temperatures are formed in the flow channel inside the economizer 1 along the flue gas transportation direction; the temperature zone monitoring network group can realize the temperature monitoring function of different temperature zones, and the mesh temperature measuring surface constructed by the temperature measuring optical fiber 3 arranged in an S shape can sense the temperature changes of each point along the optical fiber in real time and transmit the signal to the temperature measuring host 4; the temperature measuring host 4 is used to measure the temperature distribution along the optical fiber, which can realize long-distance, high-precision temperature measurement and can quickly locate the leakage point according to the change of temperature data. The present invention can realize real-time monitoring of the low-temperature economizer and accurately locate the leakage point, so as to improve the accuracy and reliability of leakage monitoring, thereby improving the safety and reliability of the operation of the coal-fired power plant unit.

[0056] In some embodiments, an industrial computer 6 is further included. The industrial computer 6 is connected to the temperature measurement host 4 and is equipped with a display 61 .

[0057] The temperature distribution curve can be displayed in real time on the display 61 of the industrial computer 6 to facilitate monitoring of abnormal temperature changes.

[0058] Specifically, the temperature-measuring optical fiber 3, installed as a sensor around the low-temperature economizer tube bundle, can sense temperature changes in real time. It can measure temperature, strain, and vibration at every point along the optical cable, locate alarms, and transmit these signals to the temperature-measuring host 4. An industrial computer 6, equipped with monitoring software and connected to the temperature-measuring host 4, receives and processes the temperature signals transmitted by the temperature-measuring optical fiber 3, displays the temperature distribution curve and alarm information in real time, and can exchange data with the monitoring center for remote monitoring and management.

[0059] The temperature measuring host 4, industrial computer 6 and display 61 and other equipment are all installed in the control cabinet 7, and the control cabinet 7 provides centralized management and protection of the equipment.

[0060] In some embodiments, an alarm system is also included. When an abnormal temperature change is detected, the alarm system can intelligently analyze the signal, monitor and determine whether the equipment has leaked, and locate the leak. At the same time, it can issue an alarm signal in a timely manner and transmit the alarm information to the monitoring center.

[0061] Specifically, temperature measuring optical fibers are laid along the heating surface of the tube bundle in the low-temperature economizer, and the optical fibers are arranged in an S-shape along the heating surface to ensure that the heating surface area can be fully covered; if there are two groups of heat exchange tubes 2 along the flue gas flow direction, arranging three mesh temperature measuring surfaces can enable more comprehensive measurement. The temperature monitoring resolution accuracy is less than or equal to 0.25m 2 / point, the temperature measuring optical fiber adopts high temperature resistant polyester coated optical fiber or polyimide coated optical fiber, which has high temperature resistance and wear resistance and is equipped with a protective structure, and the maximum temperature is ≤200℃.

[0062] The two ends of the temperature-measuring optical fiber 3 are connected to a temperature-measuring host 4. This host 4 monitors the backscattered signal of the pulses in the optical fiber to detect subtle temperature parameters at various locations. Since there is a time lag between the pulse entering the optical fiber and the scattered signal returning to the optical fiber port, and the transmission speed of the light pulse in the optical fiber is known, information about each location along the optical fiber can be calculated, thereby obtaining real-time temperature distribution information along the optical fiber. The temperature signal is then transmitted to the monitoring software's data processing system. This system processes the received temperature signal and displays the temperature distribution curve in real time through a human-machine interface. The data refresh rate is ≤1s. When an abnormal temperature change is detected, the system intelligently determines whether a leak has occurred and issues an alarm through the alarm system.

[0063] The device of the present invention has an intelligent decision-making function, which can automatically determine whether the equipment has leaked and automatically alarm, and can quickly respond to leaks. When the temperature at a certain location (temperature measurement point 311) is lower than the average temperature alarm threshold of the area (temperature measurement area 312), or the average temperature of the area is lower than the average temperature alarm threshold of the plane, the system automatically determines that a leak has occurred at that point or area and sends a switch alarm signal to the distributed control system (DCS). For example: when the temperature of a certain detection point is lower than the difference between the average temperature of the area and the set temperature alarm threshold, the alarm signal is output with a delay of 5 minutes; when the temperature of a certain area is lower than the difference between the average temperature of the surface (mesh temperature measurement surface) and the set temperature alarm threshold, the alarm signal is output with a delay of 5 minutes; and the leak point is located, improving monitoring efficiency and accuracy.

[0064] The device of the present invention has a leakage locating function. It realizes the subtle temperature sensing parameters of each position of the optical fiber through the backscattered signal of the pulse in the optical fiber. According to the time difference between the pulse entering the optical fiber and the scattered signal being transmitted back to the optical fiber port and the transmission speed of the light pulse in the optical fiber, the temperature change information of each position of the optical fiber is calculated. The corresponding layout information of the optical fiber in the flue can quickly locate the leakage point, improve maintenance efficiency and reduce maintenance costs.

[0065] The monitoring software of the device of the present invention has a good human-machine interface, which can quickly query the temperature distribution curve and alarm information, making it convenient for operators to monitor and manage.

[0066] The device of the present invention is easy to install and requires minimal maintenance due to the inherent flexibility of the optical fiber and its adaptability to various environments. The temperature measuring host 4 can accurately locate and display the location of the leak with an accuracy of ≤ 0.5 meters, providing maintenance personnel with accurate leak location information.

[0067] In some embodiments, an optical fiber fixing and cleaning assembly 5 is further included, and each set of temperature measuring optical fibers 3 is installed inside the economizer 1 through the optical fiber fixing and cleaning assembly 5 .

[0068] The optical fiber fixing and cleaning assembly 5 provides support for the S-shaped arrangement and stability of the temperature measuring optical fiber 3 .

[0069] In some embodiments, the optical fiber fixing and cleaning assembly 5 includes a fixing tube 51, which is arranged in an S-shape along the direction perpendicular to the flue gas transmission to form a fixed mesh surface; the temperature measuring optical fiber 3 is fixed to the fixing tube 51 and extends along the length direction of the fixing tube 51 to form an S-shaped arrangement to form a mesh temperature measuring surface;

[0070] A cleaning spray hole 511 is provided on the outer wall of the fixing tube 51 corresponding to the temperature measuring optical fiber 3 to clean the temperature measuring optical fiber 3 by spraying air or liquid.

[0071] The fixed tube 51 is welded and fixed to the inner wall of the economizer 1 shell, which not only plays the role of installing and supporting the temperature measuring optical fiber 3, but also has the function of transporting gas or liquid for cleaning the temperature measuring optical fiber 3; the cleaning gas or liquid is sprayed out from the self-cleaning nozzle 511 to clean or wash the silt or dirt attached to the periphery of the temperature measuring optical fiber 3, thereby ensuring the temperature sensing accuracy of the temperature measuring optical fiber 3, thereby improving the sensitivity and reliability of temperature monitoring.

[0072] In some embodiments, the optical fiber fixing and cleaning assembly 5 also includes a wiping mechanism 52, which is slidably connected to the fixing tube 51 and can move along the length direction of the fixing tube 51; the wiping head 522 of the wiping mechanism 52 corresponds to abutting against the temperature measuring optical fiber 3 for sliding wiping.

[0073] By arranging a wiping mechanism 52 that can move along the length direction of the fixed tube 51, the wiping mechanism 52 can be started according to cleaning needs, so that the wiping head 522 moves and wipes along the length direction of the temperature measuring optical fiber 3; the moving wiping head 522 and the cleaning nozzle 511 spray air or liquid synchronously, which can achieve better and more efficient cleaning effects, ensuring the accuracy and reliability of leakage monitoring.

[0074] In some embodiments, the wiping mechanism 52 includes a traveling frame 521, which is slidably connected to the fixed tube 51 and can move along the length direction of the fixed tube 51; the wiping head 522 is installed on the traveling frame 521 and is movable to press and cover the outer periphery of the temperature measuring optical fiber 3.

[0075] The traveling frame 521 is used to install and support the wiping head 522. By pressing the wiping head 522 against the outer periphery of the temperature measuring optical fiber 3, the temperature measuring optical fiber 3 can be cleaned and wiped more comprehensively.

[0076] In some embodiments, the traveling frame 521 includes a slide 5211 , an elastic arc plate 5212 , a driving wheel 5213 and a driving motor 5214 ;

[0077] The temperature measuring optical fiber 3 is arranged on the side wall 1 512 of the fixed tube 51; slides 5211 are slidably provided on both side walls of the fixed tube 51 corresponding to the side wall 1 512. Elastic arc plates 5212 correspond to the side wall 1 512 and are arranged around the outer periphery of the temperature measuring optical fiber 3. The two ends of the elastic arc plates 5212 are fixedly connected to the two slides 5211 in a one-to-one correspondence.

[0078] The driving wheel 5213 is mounted on the carriage 5211 and its outer circumference abuts against the outer wall of the fixed tube 51. The driving motor 5214 is connected to the driving wheel 5213 to drive the rotation, thereby causing the driving wheel 5213 to roll along the length of the fixed tube 51.

[0079] The wiping head 522 is installed on the inner side of the elastic arc plate 5212 and is adapted to press and cover the outer periphery of the temperature measuring optical fiber 3 .

[0080] The driving motor 5214 is used to drive the driving wheel 5213 to roll and move, thereby driving the wiping head 522 connected to the slide 5211 to move and wipe; the two ends of the elastic arc plate 5212 are straddled on the fixed tube 51 through the slide 5211. Since the elastic arc plate 5212 has a bending deformation characteristic, the slide 5211 can move smoothly through the S-bend part of the fixed tube 51 without getting stuck; in addition, the elastic arc plate 5212 has the function of making the wiping head 522 more elastically pressed against the outer periphery of the temperature measuring optical fiber 3, so as to avoid the situation where the wiping head 522 is not wiped clean due to the decrease in the pressing force after wear, thereby improving its service life.

[0081] Specifically, both ends of the slide 5211 are rotatably connected to guide wheels 5215 , and the guide wheels 5215 at both ends of the slide 5211 are symmetrically rollingly connected to the opposite side walls of the fixed tube 51 .

[0082] Specifically, the fixed end of the drive motor 5214 is fixed to one side of the slide 5211, while the other side of the slide 5211 is fixed to a battery 55. The battery 55 is electrically connected to the drive motor 5214 to provide power. To prevent the internal temperature of the economizer 1 from affecting the performance of the drive motor 5214 and the battery 55, a heat shield made of polytetrafluoroethylene is installed outside the drive motor 5214 and the battery 55.

[0083] Specifically, the side wall of the economizer 1 is provided with a through-hole for the temperature-measuring optical fiber 3 to pass through, and the wiping mechanism 52 can enter and exit the economizer 1 through the through-hole. When not cleaning, the wiping mechanism 52 is located outside the economizer 1 in standby mode. The wiping head 522 can be replaced manually. The wiping head 522 can be a sponge block, which is clamped to the elastic arc plate 5212. When spraying and wiping, the wiping head 522 (sponge block) can absorb some of the liquid sprayed from the cleaning nozzle 511, thereby improving the wiping and cleaning effect. The industrial computer 6 is electrically connected to the drive motor 5214 of the wiping mechanism 52 and can control the wiping mechanism 52 to perform cleaning operations at regular intervals.

[0084] Specifically, the fixed tube 51 is a rectangular stainless steel tube. Laser-perforated sidewall 512 forms cleaning nozzles 511. Multiple cleaning nozzles 511 are evenly spaced along the length of the fixed tube 51. The spray direction of the cleaning nozzles 511 corresponds to the outer circumference of the temperature measurement optical fiber 3. The sidewall of the fixed tube 51 opposite sidewall 512 serves as a connecting wall. The fixed tube 51 is welded to the inner wall of the economizer 1 housing via a connecting rod. One end of the connecting rod is welded to the inner wall of the economizer 1 housing, while the other end is welded to the connecting wall of the fixed tube 51, providing stable support for the fixed tube 51.

[0085] In some embodiments, the optical fiber fixing and cleaning assembly 5 further includes a heat insulation pad 53 , which is arranged between the temperature measuring optical fiber 3 and the fixing tube 51 .

[0086] The thermal insulation pad 53 plays the role of thermal insulation and protection of the temperature measuring optical fiber 3, ensuring its measurement accuracy.

[0087] Specifically, the thermal insulation pad 53 can be a polytetrafluoroethylene pad, and the thermal insulation pad 53 is bonded and fixed to the side wall 512 of the fixed tube 51.

[0088] In some embodiments, the optical fiber fixing and cleaning assembly 5 further includes a clamp 54 , which is adapted to be sleeved around the outer periphery of the temperature measuring optical fiber 3 and fixed on the thermal insulation pad 53 .

[0089] The clamp 54 fits tightly against the outer periphery of the temperature measuring optical fiber 3 , which can improve the fixing firmness of the temperature measuring optical fiber 3 to avoid displacement or vibration due to the influence of flue gas flow, which may affect the measurement.

[0090] Specifically, both ends of the clamp 54 are fastened to the thermal insulation pad 53 by screws 56; the thermal insulation pad 53 can be fixed to the side wall 512 of the fixed tube 51 by bonding or screwing.

[0091] In some embodiments, a fluid supply unit is further included, and an output port of the fluid supply unit is connected to the fixed tube 51 to transport gas or liquid for cleaning the temperature measuring optical fiber 3 .

[0092] The fluid supply unit can deliver gas or liquid with a certain pressure to the fixed pipe 51 as needed, so that the gas or liquid can be ejected from the cleaning spray hole 511 to improve the cleaning flushing force and effect.

[0093] Specifically, the fluid supply unit includes an air pump and / or a water pump; the injected fluid can be air, water, or a mixture of water and a detergent; the detergent can be a calcium sulfate scale cleaner, a boiler decoking agent, and an alkaline detergent (sodium hydroxide, potassium hydroxide), etc.; the air source is the external atmosphere, and the fluid source is a liquid storage tank; the liquid inlet of the water pump is connected to the liquid storage tank through a pipeline, and the liquid outlet of the water pump is connected to one end of the fixed pipe 51 through a pipeline, and the other end of the fixed pipe 51 is closed.

[0094] In some embodiments, the temperature-sensing optical fiber 3 is an armored temperature-sensing optical cable. Armored temperature-sensing optical cables have strong environmental adaptability. Because the flue gas velocity in the flue is approximately 9 meters per second, the armored temperature-sensing optical cable can withstand flue gas erosion, corrosion, and abrasion. The armored temperature-sensing optical cable has a certain tensile strength and comprises an optical fiber 31, a stainless steel welded tube 32, and a stranded steel wire layer 33. The optical fiber is freely threaded within the stainless steel welded tube, while the stranded steel wire layer is sheathed outside the stainless steel welded tube. The outer protection of the steel tube and wire ensures rapid heat transfer and enhances temperature sensing sensitivity.

[0095] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0096] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology, wherein a plurality of heat exchange tubes (2) are sequentially arranged in the direction of flue gas transport inside the economizer (1); characterized in that: include: Multiple groups of temperature measuring optical fibers (3), each group of heat exchange tubes (2) is provided with the temperature measuring optical fibers (3) on one side close to or away from the adjacent heat exchange tube (2), and each group of temperature measuring optical fibers (3) is arranged in an S-shape along a direction perpendicular to the flue gas conveying direction to form a mesh temperature measuring surface, thereby forming a temperature zone monitoring network group inside the economizer (1) along the flue gas conveying direction; A temperature measuring host (4) is connected to a plurality of temperature measuring optical fibers (3) to perform temperature monitoring.

2. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 1 is characterized in that: It also includes an industrial control computer (6), the industrial control computer (6) is connected to the temperature measurement host (4), and the industrial control computer (6) is equipped with a display (61).

3. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 1 is characterized in that: It also includes an optical fiber fixing and cleaning component (5), and each group of the temperature measuring optical fibers (3) is installed inside the economizer (1) through the optical fiber fixing and cleaning component (5).

4. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 3 is characterized in that: The optical fiber fixing and cleaning assembly (5) comprises a fixing tube (51), wherein the fixing tube (51) is arranged in an S-shape along a direction perpendicular to the smoke conveying direction to form a fixed mesh surface; the temperature measuring optical fiber (3) is fixed on the fixing tube (51) and extends along the length direction of the fixing tube (51) to form an S-shaped arrangement to form a mesh temperature measuring surface; A cleaning spray hole (511) is provided on the outer peripheral wall of the fixed tube (51) corresponding to the temperature measuring optical fiber (3) to clean the temperature measuring optical fiber (3) by spraying air or liquid.

5. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 4 is characterized in that: The optical fiber fixing and cleaning assembly (5) further comprises a wiping mechanism (52), wherein the wiping mechanism (52) is slidably connected to the fixing tube (51) and is movable along the length direction of the fixing tube (51); a wiping head (522) of the wiping mechanism (52) correspondingly abuts against the temperature measuring optical fiber (3) for sliding wiping.

6. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 5 is characterized in that: The wiping mechanism (52) comprises a traveling frame (521), the traveling frame (521) being slidably connected to the fixed tube (51) and capable of traveling and moving along the length direction of the fixed tube (51); the wiping head (522) being mounted on the traveling frame (521) and movably pressing and covering the outer periphery of the temperature measuring optical fiber (3).

7. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 6 is characterized in that: The walking frame (521) includes a slide (5211), an elastic arc plate (5212), a driving wheel (5213) and a driving motor (5214); The temperature measuring optical fiber (3) is arranged on the side wall one (512) of the fixed tube (51); the slides (5211) are slidably provided on the two side walls of the fixed tube (51) corresponding to the side wall one (512); the elastic arc plate (5212) corresponds to the side wall one (512) and is arranged around the outer periphery of the temperature measuring optical fiber (3); the two ends of the elastic arc plate (5212) are fixedly connected to the two slides (5211) in a one-to-one correspondence; The driving wheel (5213) is mounted on the carriage (5211) and its outer circumference abuts against the outer wall of the fixed tube (51); the driving motor (5214) is connected to the driving wheel (5213) to drive the rotation, thereby causing the driving wheel (5213) to roll along the length direction of the fixed tube (51); The wiping head (522) is installed on the inner side of the elastic arc plate (5212) and is adapted to press and cover the outer periphery of the temperature measuring optical fiber (3).

8. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 4 is characterized in that: The optical fiber fixing and cleaning assembly (5) further comprises a heat insulating pad (53), and the heat insulating pad (53) is arranged between the temperature measuring optical fiber (3) and the fixing tube (51).

9. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 8, characterized in that: The optical fiber fixing and cleaning assembly (5) further comprises a clamp (54), wherein the clamp (54) is adapted to be sleeved on the outer periphery of the temperature measuring optical fiber (3) and fixed on the thermal insulation pad (53).

10. The low-temperature economizer leakage monitoring device based on distributed optical fiber sensing technology according to claim 4, characterized in that: It also includes a fluid supply part, the output port of which is connected to the fixed tube (51) to transport gas or liquid for cleaning the temperature measuring optical fiber (3).

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