DTS-based temperature monitoring device for small steel pipe in boiler top

Abstract

The utility model discloses a DTS-based temperature monitoring device for small steel tubes in a boiler top, and relates to the technical field of boiler temperature monitoring, multimode optical fibers of polyimide coating layers are arranged on each group of tube rows in an S-shaped structure, and the same multimode optical fiber crosses one steel tube every time the multimode optical fiber is bent; the four multimode optical fibers of each group of pipe rows are gathered into one pipeline and are fixed in the pipeline through the fixing buckles II so as to guide the multimode optical fibers to the outside of the furnace; the multimode optical fiber is connected with a multichannel Raman temperature measurement demodulator through a communication optical cable to form a distributed optical fiber temperature measurement system; through the steps of laser pulse emission, scattered light signal receiving and processing, data acquisition, analysis, alarm and the like, distributed, real-time and high-precision monitoring of the temperature of the small steel pipe in the boiler top large ladle is realized by using a multi-channel Raman temperature measurement demodulator, so that the safety and efficiency of boiler operation are improved.

Description

Technical Field

[0001] This utility model relates to the field of boiler temperature monitoring technology, specifically a temperature monitoring device for a small steel pipe inside the boiler furnace top based on DTS. Background Technology

[0002] The boiler furnace top ladle is a critical component of the boiler system, and the temperature distribution of its internal fine steel tubes directly affects the boiler's operating efficiency and safety. Traditional temperature monitoring methods (such as thermocouples, ultrasound, X-ray, magnetic particle, and infrared thermometry) suffer from limitations such as limited measurement points, large-area missed detections, complex on-site deployment, electromagnetic crosstalk, and poor anti-interference capabilities, making it difficult to meet the comprehensive temperature monitoring needs of the fine steel tubes inside the boiler furnace top ladle. Therefore, this invention proposes a temperature monitoring device for the fine steel tubes inside the boiler furnace top based on DTS (Digital Temperature Detection System). Utility Model Content

[0003] To address the problems existing in the prior art, this utility model provides a temperature monitoring device for small steel pipes inside the boiler furnace top based on DTS. It utilizes a multi-channel distributed Raman temperature measurement system to perform real-time distributed measurement of the temperature of small steel pipes inside the boiler furnace top ladle. This device not only has high measurement sensitivity but also enables multi-point temperature measurement.

[0004] To achieve the above objectives, this utility model provides a temperature monitoring device for a small steel pipe inside the boiler furnace top based on DTS, comprising:

[0005] Multiple flexible temperature sensors are wound around the pipe bank in an "S" shape at intervals, so that each flexible temperature sensor crosses a steel pipe each time it bends.

[0006] The first fixing buckle is fastened to the steel pipe and then fitted onto the flexible temperature sensor;

[0007] The second fixing clip is fastened to the pipe and fitted onto multiple flexible temperature sensors;

[0008] The flexible temperature sensor is connected to the demodulator via a communication optical cable.

[0009] Preferably, the flexible temperature sensor is a multimode optical fiber with a polyimide coating.

[0010] Multimode optical fiber consists of, from the inside out, the core, cladding, polyimide coating, and fiber sheath.

[0011] Preferably, both the first and second fixing buckles include a first retaining sleeve, a second retaining sleeve, and a locking component. One end of the first retaining sleeve is hinged to one end of the second retaining sleeve, and the other end of the first retaining sleeve is connected to the second retaining sleeve via the locking component. A slot is provided on the first or second retaining sleeve of the first fixing buckle; a slot is provided on the first and second retaining sleeves of the second fixing buckle.

[0012] The locking assembly includes a locking screw and a locking nut. The first and second ferrules are respectively provided with a first "U" shaped groove and a second "U" shaped groove at their ends. One end of the locking screw is rotatably disposed in the first "U" shaped groove. The locking screw engages with the second "U" shaped groove by rotation. The locking nut is threaded onto the locking screw.

[0013] The demodulator is a distributed temperature demodulator, preferably a multi-channel distributed fiber optic Raman thermometer.

[0014] Compared with existing technologies, it has the following beneficial effects:

[0015] This invention employs an "S"-shaped arrangement of multimode optical fibers on the pipe array. To meet the bending radius limitations of the optical fibers, each multimode fiber crosses one steel pipe with each bend. Each pipe array uses four multimode optical fibers fixed to the steel pipe using fasteners. Utilizing this fiber optic deployment technology, the distributed optical fiber sensing system can monitor temperature changes in the small steel pipes inside the large ladle at the top of the boiler in real time and with high accuracy. This technology not only enables independent monitoring of each boiler steel pipe but also significantly improves measurement accuracy while reducing overall costs. Furthermore, this device possesses strong anti-interference capabilities and excellent stability, making it suitable for long-term stable operation in complex industrial environments. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only preferred embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the layout of the temperature monitoring device of this utility model;

[0018] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0019] Figure 3 This is a schematic diagram of the multi-channel distributed Raman temperature measurement system of this utility model;

[0020] Figure 4This is a schematic diagram of the layout of the temperature monitoring device of this utility model;

[0021] Figure 5 This is a schematic diagram of the fixing buckle of this utility model;

[0022] Figure 6 This is a schematic diagram of the fixing buckle 2 of this utility model;

[0023] Figure 7 This is an exponential response graph of the ratio of the intensity of anti-Stokes light to that of Stokes light with temperature.

[0024] Reference numerals in the attached diagram: 1-Multimode optical fiber; 2-Fixing clip one; 3-Fixing clip two; 4-Demodulator; 5-Boiler; 101-First ferrule; 102-Second ferrule; 103-Locking assembly; 104-Slot; 105-First "U"-shaped slot; 106-Second "U"-shaped slot; 1031-Locking screw; 1032-Locking nut. Detailed Implementation

[0025] To better understand the structure, functional features, and advantages of this utility model, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings:

[0026] Example:

[0027] like Figures 1 to 6 As shown, this utility model provides a temperature monitoring device for a small steel pipe inside the boiler furnace top based on DTS, comprising:

[0028] Multiple flexible temperature sensors are wound around the pipe bank in an "S" shape at intervals, so that each flexible temperature sensor crosses a steel pipe each time it bends. This arrangement method achieves highly stable distributed temperature measurement.

[0029] Fixed buckle 12 is fastened to the steel pipe and then fitted onto the flexible temperature sensor;

[0030] Fixed buckle 2 3, snaps onto the pipe and is fitted onto multiple flexible temperature sensors;

[0031] The flexible temperature sensor is connected to demodulator 4 via a communication optical cable.

[0032] See Figure 4 The flexible temperature sensor is a multimode optical fiber with a polyimide coating 1.

[0033] See Figure 1 The multimode fiber 1 consists of, from the inside out, a core, a cladding, a polyimide coating, and an optical fiber sheath.

[0034] See Figure 2 , Figure 5 and Figure 6 The fixing buckle 1 2 and fixing buckle 2 3 of this utility model both include a first retaining sleeve 101, a second retaining sleeve 102 and a locking component 103. One end of the first retaining sleeve 101 is hinged to one end of the second retaining sleeve 102, and the other end of the first retaining sleeve 101 is connected to the second retaining sleeve 102 through the locking component 103. The first retaining sleeve 101 and / or the second retaining sleeve 102 are provided with a slot 104 to fix the multimode optical fiber 1 through the slot 104, so that the multimode optical fiber 1 can be wound around the tube in an "S" shaped structure at intervals.

[0035] See Figure 5 and Figure 6 The card slot 104 of this utility model is formed on the first card sleeve 101 or the second card sleeve 102 on the first fixed buckle 2; the card slot 104 is formed on the first card sleeve 101 and the second card sleeve 102 on the second fixed buckle 3. Specifically, there is one card slot 104 on the first fixed buckle 2 and four card slots 104 on the second fixed buckle 3.

[0036] See Figure 5 and Figure 6 The locking assembly 103 of this utility model includes a locking screw 1031 and a locking nut 1032. The first sleeve 101 and the second sleeve 102 are respectively provided with a first "U" shaped groove 105 and a second "U" shaped groove 106 at their ends. One end of the locking screw 1031 is rotatably disposed in the first "U" shaped groove 105. The locking screw 1031 is engaged with the second "U" shaped groove 106 by rotation. The locking nut 1032 is threadedly connected to the locking screw 1031.

[0037] The locking assembly 103 is used to lock the closed fixing buckles 1 and 2 to fix the multimode fiber 1 to the steel pipe and pipeline.

[0038] See Figure 3 The demodulator 4 of this utility model is a distributed temperature demodulator, preferably a multi-channel distributed fiber Raman thermometer.

[0039] like Figure 1 and Figure 3 As shown, this utility model also proposes a method for temperature monitoring of small steel pipes inside the boiler furnace top based on DTS, including the following steps:

[0040] S1: Multimode optical fiber 1 coated with polyimide is arranged in an "S" shape on each group of tubes, and the same multimode optical fiber 1 crosses a steel pipe each time it bends. Four multimode optical fibers 1 are arranged on each group of tubes to monitor the real-time temperature of each steel pipe.

[0041] S2: Fix the four multimode optical fibers 1 of each group of pipes to the steel pipe with fixing clip one 2. The four multimode optical fibers 1 are gathered into one pipe and fixed in the pipe with fixing clip two 3 to guide them to the outside of the furnace.

[0042] S3: Then connect the multimode optical fiber 1 after it comes out of the furnace to the communication optical cable outside the furnace. The connected communication optical cable is then connected to the distributed temperature demodulator to form a distributed optical fiber temperature measurement system.

[0043] S4: A distributed fiber optic temperature measurement system is used to monitor the temperature of the small steel pipes inside the large ladle at the top of boiler 5, and an alarm signal is issued when the temperature is abnormal.

[0044] The distributed temperature demodulator displays and records the temperature change curve of each channel in real time, as well as the temperature curve of any location on multimode fiber 1 as a function of time.

[0045] The temperature measurement principle of this utility model based on the DTS-based temperature monitoring device for small steel pipes inside the boiler furnace top is as follows:

[0046] A typical DTS (Digital Temperature Detection System) consists of a pulsed laser, sensing fiber, wavelength division multiplexer (WDM), avalanche diode, amplifier, and signal processing and analysis units. The temperature measurement principle of this sensing system is as follows: Light emitted from the pulsed laser travels along the sensing fiber into the temperature region to be measured. As the laser propagates through the fiber, it continuously generates backscattered Raman light. After being filtered by the WDM, only Stokes and anti-Stokes beams remain. The anti-Stokes beam is highly sensitive to changes in the ambient temperature of the sensing fiber, while the Stokes beam is independent of temperature changes and can be used as a reference beam. By monitoring the intensity ratio of the anti-Stokes beam to the Stokes beam, the temperature change information of the region to be measured can be obtained. Based on the speed of light propagation in the fiber and the return time of the backscattered light, the temperature information can be located.

[0047] According to Raman scattering theory, the ratio of the anti-Stokes intensity Ias to the Stokes intensity Is is:

[0048] (1)

[0049] In the formula, λ and ν are the wavelengths of Stokes light and anti-Stokes light, respectively, and h is Planck's constant. Let be the Raman frequency shift, K be the Boltzmann constant, and T be the absolute temperature.

[0050] The temperature T can be determined by using the relationship described in equation (1):

[0051] (2)

[0052] Based on the speed of light in the sensing fiber and the return time of backscattered light, the location of the temperature anomaly can be determined as follows:

[0053] (3)

[0054] In the formula, L is the distance from the incident end of the short-pulse laser to the temperature anomaly point; t is the round-trip time of the light; and n is the refractive index of the optical fiber.

[0055] Based on equation (2), the Raman temperature demodulator can obtain the temperature information of the area to be measured by the ratio of the anti-Stokes light intensity to the Stokes light intensity, and then achieve spatial positioning of the temperature according to equation (3).

[0056] See Figure 7 The figure shows the exponential response characteristics of the ratio of the intensity of anti-Stokes light to that of Stokes light to temperature. Based on these exponential response characteristics, the temperature of steel pipes can be measured.

[0057] The technical solution of this invention utilizes multimode optical fiber to monitor the temperature changes of each tiny steel pipe inside the boiler's top ladle in real time and with high accuracy. This solution not only meets the needs of multi-point monitoring but also significantly improves monitoring accuracy while effectively reducing costs. Furthermore, the monitoring device possesses strong anti-interference capabilities and excellent stability, fully meeting the application requirements of DTS technology in the field of high-precision, multi-point high-temperature monitoring.

[0058] The above description is merely a preferred embodiment of this utility model and does not constitute any limitation on this utility model. Any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model, or modify it into equivalent embodiments, without departing from the scope of the technical solution of this utility model. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technology of this utility model without departing from the scope of the technical solution of this utility model shall fall within the protection scope of this technical solution.

Claims

1. A temperature monitoring device for a small steel pipe inside the boiler furnace top based on DTS, characterized in that, include: Multiple flexible temperature sensors are wound around the pipe bank at intervals in an "S" shape, so that each flexible temperature sensor crosses a steel pipe each time it bends. Fixed buckle 1 (2) is snapped onto the steel pipe and fitted onto the flexible temperature sensor; Fixed buckle two (3) is snapped onto the pipe and fitted onto multiple flexible temperature sensors; The flexible temperature sensor is connected to the demodulator (4) via a communication optical cable.

2. The temperature monitoring device for the small steel pipe inside the boiler furnace top based on DTS according to claim 1, characterized in that, The flexible temperature sensor is a multimode optical fiber with a polyimide coating (1).

3. The temperature monitoring device for the small steel pipe inside the boiler furnace top based on DTS according to claim 2, characterized in that, The multimode optical fiber (1) includes, from the inside out, a core, a cladding, a polyimide coating, and an optical fiber sheath.

4. The temperature monitoring device for the small steel pipe inside the boiler furnace top based on DTS according to claim 3, characterized in that, Both the first fixing buckle (2) and the second fixing buckle (3) include a first retaining sleeve (101), a second retaining sleeve (102), and a locking component (103). One end of the first retaining sleeve (101) is hinged to one end of the second retaining sleeve (102), and the other end of the first retaining sleeve (101) is connected to the second retaining sleeve (102) through the locking component (103). The first retaining sleeve (101) and / or the second retaining sleeve (102) are provided with a slot (104).

5. The temperature monitoring device for the small steel pipe inside the boiler furnace top based on DTS according to claim 4, characterized in that, The card slot (104) is formed on the first card sleeve (101) or the second card sleeve (102) on the first fixed buckle (2); the card slot (104) is formed on the first card sleeve (101) and the second card sleeve (102) on the second fixed buckle (3).

6. The temperature monitoring device for the small steel pipe inside the boiler furnace top based on DTS according to claim 5, characterized in that, The locking assembly (103) includes a locking screw (1031) and a locking nut (1032). The ends of the first sleeve (101) and the second sleeve (102) are respectively provided with a first "U" groove (105) and a second "U" groove (106). One end of the locking screw (1031) is rotatably disposed in the first "U" groove (105). The locking screw (1031) is engaged with the second "U" groove (106) by rotation. The locking nut (1032) is threadedly connected to the locking screw (1031).

7. The temperature monitoring device for the small steel pipe inside the boiler furnace top based on DTS according to claim 6, characterized in that, The demodulator (4) is a distributed temperature demodulator.

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