A through type sealing mounting structure of a fiber grating sensor on a boiler header

Abstract

The utility model discloses a kind of through type sealing installation structures of fiber grating sensor on boiler header, including through seat, two sealing gland and sealing assembly, the through seat is installed on the boiler header box wall mounting hole in through type, and the sealing assembly is installed in the through seat, the sealing compression of the sealing gland of the through seat both ends opening is carried out by screwing;The first sealing layer is arranged at the intermediate gap of sleeve and the through seat, for the primary sealing of the through seat. By filling first sealing layer at the intermediate gap of through seat and sleeve on sealing installation structure, and setting the second sealing layer and third sealing layer of the difference of thermal expansion value on the outside of fiber in sleeve, so that multiple sealing layers carry out multistage sealing to the fiber grating sensor fiber of through installation, improve the through type sealing installation sealing efficiency of fiber grating sensor on boiler header.

Description

Technical Field

[0001] This utility model relates to the field of boiler header sensor installation technology, specifically to a through-type sealed installation structure for a fiber optic grating sensor on a boiler header. Background Technology

[0002] Boiler headers are an important component of boilers, consisting of upper and lower headers. They collect, mix, and distribute the working fluid: the headers gather the working fluid and then redistribute it to other pipes. During boiler operation, different parts of the pipes absorb different amounts of heat. The redistribution of the working fluid within the headers reduces thermal deviation and optimizes heat absorption, flow, boiler cooling, and thermal efficiency. The upper header, located in the upper part of the furnace, collects the water-steam mixture and separates the water and steam through the steam collection chamber. The collected steam is discharged under control by the steam outlet valve. The lower header, located in the lower part of the furnace, collects the mixture and discharges moisture-free steam. The water pan serves as the outlet for wastewater treatment, ensuring even water distribution within the furnace and preventing localized overheating or uneven heat transfer. The lower header, also known as the anti-coking box, is located on both sides of the grate, directly contacting the burning coal bed. It absorbs some heat, regulates the fuel bed temperature, prevents coking, and cools the coked slag to prevent it from adhering to the side walls.

[0003] Existing through-sealed sensor mounting structures (such as the sealing structure and method for mounting sensors through two pressure boundaries, application number 202010190824.5) employ a self-tightening sealing method with a gasket and sealing threads in the same direction of rotation to improve the sensor's sealing performance under high temperature and high pressure conditions. However, this sealing structure cannot position the optical fiber that needs to be installed horizontally and linearly on the inner side. Furthermore, a single gasket and sealing threads cannot effectively seal the through-seat where temperature differences exist. The integrated sealing filler also affects the replacement and maintenance of the optical fiber, thus impacting the ease of installation and sealing stability of the fiber optic grating sensor in the boiler header. Utility Model Content

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a through-type sealed installation structure for fiber optic grating sensors on boiler headers. This structure addresses the technical problems of existing through-type sealed installation structures for fiber optic grating sensors on boiler headers, which cannot position the optical fibers that need to be installed horizontally and in a straight line on the inside. Furthermore, the single sealing gasket and sealing thread cannot effectively seal the through-type seat where there is a temperature difference, and the integrated sealing filler affects the replacement and maintenance of the optical fibers. Consequently, these structures affect the ease of installation and sealing stability of the through-type sealed installation of fiber optic grating sensors on boiler headers.

[0005] According to the technical solution provided in the embodiments of this application, a through-type sealed mounting structure for a fiber Bragg grating sensor on a boiler header includes a through-type seat, two sealing caps, and a sealing assembly. The through-type seat is installed through a mounting hole in the boiler header wall, and the sealing assembly is installed inside the through-type seat. The openings at both ends of the through-type seat are sealed and tightened by the screw-connected sealing caps. The sealing assembly includes a first sealing layer, a sleeve, a second sealing layer, a third sealing layer, and a positioning mechanism; The first sealing layer is disposed at the gap between the sleeve and the through seat, and is used for the primary sealing of the through seat; The sleeve has an internal cylindrical cavity filled with a second sealing layer and a third sealing layer. The coefficient of thermal expansion of the second sealing layer is greater than that of the third sealing layer, with a difference of 0.5 × 10⁻⁶. -6 / ℃ to 5×10 -6 / ℃; The positioning mechanism includes multiple positioning plates, which are arranged in a ring around the outside of the sleeve and engaged in corresponding positioning grooves on the through seat for positioning and fixing the sleeve.

[0006] In this solution, the sealing assembly further includes multiple first metal washers and multiple second metal washers. Each first metal washer is fitted onto the through seat for sealing the outside of the through seat, while each second metal washer is installed in the sealing groove of the sealing cover for sealing the connection between the sealing cover and the inside of the through seat.

[0007] In this design, the sleeve has a screw-on sealing cap located on its outer end.

[0008] In this design, the sleeve and the sealing cap are provided with optical fiber through holes.

[0009] In this solution, the materials of the first sealing layer and the second sealing layer are compatible, and metal fiber sealant is used.

[0010] In this solution, the third sealing layer material is ceramic sealant.

[0011] In this design, the inner side of the sealing cap is provided with a protruding abutment block for pressing against the first sealing layer.

[0012] In this design, the through seat and the sealing cap are made of high-temperature resistant stainless steel.

[0013] In this solution, the sleeve is made of ceramic material.

[0014] In this solution, the installation structure is suitable for boiler header environments with an operating temperature range of 200℃ to 600℃.

[0015] In summary, the beneficial effects of this application are as follows: 1. By filling the gap between the through seat and the sleeve in the sealed installation structure with a first sealing layer, and setting a second sealing layer and a third sealing layer with different thermal expansion values ​​on the outside of the optical fiber inside the sleeve, multiple sealing layers can perform multi-level sealing on the optical fiber of the through-mounted fiber Bragg grating sensor, thereby improving the sealing efficiency of the through-mounted sealed installation of the fiber Bragg grating sensor on the boiler header. 2. By setting a positioning plate in a ring array on the outside of the sleeve, the other end of each positioning plate is engaged in the positioning groove on the through seat, so that the sleeve is positioned and installed in the through seat, preventing the optical fiber from bending during the installation and sealing process, which would affect the installation quality of the fiber optic grating sensor through-sealed installation on the boiler header. Third, a screw-on sealing gland and a sealing cap are installed at the front end of the through seat and the sleeve to facilitate timely maintenance and replacement of the installed optical fiber, thereby improving the ease of use of the through-sealed installation of the fiber optic grating sensor on the boiler header. Attached Figure Description

[0016] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the installation structure of this utility model; Figure 2 This is a cross-sectional three-dimensional structural diagram of the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the sealing gland of this utility model; Figure 4 This is a side view sectional structural diagram of the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of this utility model.

[0017] The following are the labels in the diagram: through seat 100, positioning slide 110, sealing cover 200, abutment block 210, sealing assembly 300, first sealing layer 310, sleeve 320, sealing cover 321, second sealing layer 330, third sealing layer 340, positioning mechanism 350, positioning plate 351, first metal washer 360, and second metal washer 370. Detailed Implementation

[0018] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the relevant utility model and not intended to limit the scope of the utility model. Furthermore, it should be noted that, for ease of description, only the parts relevant to the utility model are shown in the accompanying drawings.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] A through-type sealed mounting structure for a fiber Bragg grating sensor on a boiler header, the structure of which is as follows: Figure 1 and Figure 2 As shown, the system includes a through seat 100, two sealing caps 200, and a sealing assembly 300. The through seat 100 is installed through the mounting hole in the wall of the boiler header, while the sealing assembly 300 is installed inside the through seat 100. Stainless steel sealing caps 200 are screwed to the openings at both ends of the through seat 100. The inner side of the sealing cap 200 also has a protruding abutment block 210, so that when the sealing cap 200 is screwed to the opening of the through seat 100, the abutment block 210 presses and seals the openings at both ends of the through seat 100.

[0021] like Figure 2 and Figure 3 As shown, the sealing assembly 300 includes a first sealing layer 310, a sleeve 320, a second sealing layer 330, a third sealing layer 340, and a positioning mechanism 350. The first sealing layer 310 fills the gap between the sleeve 320 and the through seat 100, providing a primary seal for the through seat 100. The sleeve 320 is installed at the center of the through seat 100 via the positioning mechanism 350, and a cylindrical cavity is provided inside the sleeve 320. The cavity is filled with the second sealing layer 330 and the third sealing layer 340, with the second sealing layer 330 located outside the third sealing layer 340. The second sealing layer 330 and the third sealing layer 340 are made of sealing materials with different thermal expansion values, so that the second sealing layer 330 and the third sealing layer 340 provide a secondary seal for the through seat 100.

[0022] like Figure 2 and Figure 4 As shown, the first sealing layer 310 and the second sealing layer 330 are made of the same material, both filled with metal fiber sealant. The third sealing layer 340 is made of ceramic sealant. The metal fiber sealant and the ceramic sealant have different thermal expansion values, so that the ceramic sealant can wrap and seal the optical fiber that is installed through the wire after thermal expansion.

[0023] like Figure 3 and Figure 5As shown, the positioning mechanism 350 includes multiple positioning plates 351, which are arranged in a ring array on the outside of the sleeve 320. Each positioning plate 351 is engaged with the corresponding positioning groove 110 on the through seat 100. The positioning mechanism 350 is designed to position the sleeve 320 in the middle of the through seat 100, preventing the optical fiber installed in the sleeve 320 from bending and affecting the through-sealing installation quality of the fiber optic sensor on the boiler header.

[0024] like Figure 2 and Figure 3 As shown, the sealing assembly 300 also includes a plurality of first metal washers 360 and a plurality of second metal washers 370. Each first metal washer 360 is sleeved on the through seat 100. When the sealing cover 200 is screwed onto the through seat 100, the first metal washers 360 move to seal the outside of the through seat 100. At the same time, each second metal washer 370 is installed in the annular sealing groove of the sealing cover 200. When the sealing cover 200 is screwed on, the second metal washers 370 seal the connection between the sealing cover 200 and the inside of the through seat 100.

[0025] like Figure 2 and Figure 3 As shown, the sleeve 320 and the sealing cover 200 are provided with optical fiber through holes. The outer end of the sleeve 320 is provided with a screw-on sealing cover 321, so that the optical fiber inside the sleeve 320 can be installed, repaired and replaced by opening the sealing cover 321, thereby improving the ease of use of the through-sealed installation of the fiber optic grating sensor on the boiler header.

[0026] like Figure 1 and Figure 2 As shown, the sealing gland 200 and the through seat 100 are made of stainless steel, preferably 310S, which can withstand temperatures above 800℃, while the sleeve 320 is made of ceramic. This installation structure is used in boiler headers, and the header's operating temperature range is 200℃~600℃. The first sealing layer 310 and the second sealing layer 330 use high-temperature resistant metal fiber sealant with a thermal expansion coefficient of 12×10⁻⁶. -6 / ℃, the third sealing layer 340 uses ceramic sealant with a thermal expansion coefficient of 5×10. -6 / ℃. ; Subsequently, the sealing material was filled in layers, and after testing, the structure did not leak after 100 temperature cycles.

[0027] The working principle of the through-sealed mounting structure of the fiber optic grating sensor on the boiler header of this utility model is as follows: During the installation of the fiber Bragg grating sensor in the through-sealed mounting structure on the boiler header, the installer welds the through-mount 100 into the mounting hole in the boiler header wall. During installation, the positioning plate 351 of the sleeve 320 is aligned with the positioning groove 110 of the through-mount 100 and pushed in to secure it, ensuring the optical fiber is horizontal and straight. A first sealing layer 310 of metal fiber material is filled between the through-mount 100 and the sleeve 320 in the sealed mounting structure. A second sealing layer 330 and a third sealing layer 340 with different thermal expansion values ​​are set inside the sleeve 320 on the outside of the optical fiber, so that multiple sealing layers provide multi-level sealing for the through-mounted fiber Bragg grating sensor optical fiber, improving the sealing efficiency of the through-sealed mounting of the fiber Bragg grating sensor on the boiler header. During the installation of the sealing assembly 300 inside the through-mount 100, the sleeve 320 is installed on the through-mount 100 via the positioning mechanism 350. The sleeve 320 is positioned in the middle, and multiple positioning plates 351 on the positioning mechanism 350 are arranged in a ring array on the outside of the sleeve 320, so that the other end of each positioning plate 351 is engaged in the positioning groove 110 on the through seat 100, thereby positioning the sleeve 320 in the through seat 100. This prevents the optical fiber from bending during the installation and sealing process, which would affect the installation quality of the fiber optic grating sensor in the through-sealed installation on the boiler header. At the same time, screw-connected sealing caps 200 and sealing covers 321 are provided at both ends of the through seat 100 and the front end of the sleeve 320, so that the sealing structure can be opened in time by screwing on the sealing caps 200 and sealing covers 321. This facilitates timely maintenance and replacement of the installed optical fiber, thereby improving the ease of use of the fiber optic grating sensor in the through-sealed installation on the boiler header. The above description is merely a preferred embodiment of this application and an explanation of the technical principles and solutions employed. Furthermore, the scope of the utility model involved in this application is not limited to the specific combination of the above-described technical features, but should also cover other technical solutions formed by any combination of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A through-type sealed mounting structure for a fiber Bragg grating sensor on a boiler header, comprising a through seat (100), two sealing caps (200), and a sealing assembly (300), wherein the through seat (100) is through-mounted in a mounting hole in the boiler header wall, and the sealing assembly (300) is installed inside the through seat (100), and the openings at both ends of the through seat (100) are sealed and pressed together by the screw-on sealing caps (200), characterized in that: The sealing assembly (300) includes a first sealing layer (310), a sleeve (320), a second sealing layer (330), a third sealing layer (340), and a positioning mechanism (350). The first sealing layer (310) is disposed in the gap between the sleeve (320) and the through seat (100) for the first-level sealing of the through seat (100); The sleeve (320) has a cylindrical cavity inside, and the cavity is filled with a second sealing layer (330) and a third sealing layer (340). The coefficient of thermal expansion of the second sealing layer (330) is greater than that of the third sealing layer (340), and the difference is 0.5 × 10⁻⁶. -6 / ℃ to 5×10 -6 / ℃; The positioning mechanism (350) includes multiple positioning plates (351), and the multiple positioning plates (351) are arranged in a ring on the outside of the sleeve (320) and are engaged in the corresponding positioning grooves (110) on the through seat (100) for positioning and fixing the sleeve (320).

2. The through-type sealed mounting structure for a fiber optic grating sensor on a boiler header according to claim 1, characterized in that: The sealing assembly (300) further includes a plurality of first metal washers (360) and a plurality of second metal washers (370), wherein each of the first metal washers (360) is sleeved on the through seat (100) for sealing the outside of the through seat (100), and each of the second metal washers (370) is installed in the sealing groove of the sealing cover (200) for sealing the connection between the sealing cover (200) and the inside of the through seat (100).

3. The through-type sealed mounting structure for a fiber optic grating sensor on a boiler header according to claim 1, characterized in that: The sleeve (320) has a screw-on sealing cap (321) at its outer end.

4. The through-type sealed mounting structure for a fiber optic grating sensor on a boiler header according to claim 1, characterized in that: The sleeve (320) and the sealing cap (200) are provided with optical fiber through holes.

5. The through-type sealed mounting structure for a fiber optic grating sensor on a boiler header according to claim 1, characterized in that: The first sealing layer (310) and the second sealing layer (330) are made of the same material, namely metal fiber sealant.

6. The through-type sealed mounting structure for a fiber optic grating sensor on a boiler header according to claim 1, characterized in that: The material of the third sealing layer (340) is ceramic sealant.

7. The through-type sealed mounting structure for a fiber optic grating sensor on a boiler header according to claim 1, characterized in that: The inner side of the sealing cap (200) is provided with a protruding abutment block (210) for abutting and pressing against the first sealing layer (310).

8. The through-type sealed mounting structure for a fiber Bragg grating sensor on a boiler header according to claim 1, characterized in that: The through seat (100) and the sealing cap (200) are made of high-temperature resistant stainless steel.

9. The through-type sealed mounting structure for a fiber optic grating sensor on a boiler header according to claim 1, characterized in that: The sleeve (320) is made of ceramic.

10. The through-type sealed mounting structure for a fiber optic grating sensor on a boiler header according to claim 1, characterized in that: The installation structure is suitable for boiler header environments with an operating temperature range of 200℃ to 600℃.

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