Gas-fired boiler superheater hoisting method

Abstract

The invention discloses a gas boiler superheater hoisting method, and relates to the field of electric power construction project equipment hoisting. According to the method, aiming at the problems of high aloft work quantity, low efficiency and high safety risk in a traditional hoisting method, a superheater system is divided into a front part, a middle part and a rear part, and the front part (a ceiling superheater inlet header, an inlet pipe row and a platen superheater) and the rear part (a ceiling superheater outlet pipe row and an outlet header) are integrally hoisted after being assembled on the ground respectively. Wherein when the front part is assembled, the operation of the platen superheater is changed from high altitude to ground by utilizing an assembling platform, and the whole hoisting of the front part and the platen superheater is realized when the front part is hoisted; the rear part and the furnace rear top plate are integrally hoisted; and the low-temperature superheater tube bundle is pre-stored in the tail flue, so that the efficiency is saved. According to the invention, a large amount of high-altitude assembling and penetrating operations are converted into ground operations, so that the high-altitude cross operations are reduced, the hoisting efficiency is obviously improved, the construction safety risk is reduced, and the investment cost is saved.

Description

Technical Field

[0001] This invention relates to the field of equipment hoisting in power construction projects, and in particular to a method for hoisting a gas-fired boiler superheater. Background Technology

[0002] The superheater system of a gas-fired boiler includes a roof superheater, a screen superheater, a low-temperature superheater, and a high-temperature superheater. The screen superheater, high-temperature superheater, and low-temperature superheater pass sequentially through the roof superheater and are suspended inside the furnace. The entire superheater system is suspended below the large rear beam of the furnace by a hanging device. Due to its unique structure, the inlet tube bank of the roof superheater is divided into several modules because the screen superheater passes through it. A section of the tube bank in the middle is further divided into several loose tubes because the high- and low-temperature superheater tube banks pass through it, requiring on-site assembly welding. Only the outlet tube bank is a single, integral structure. Traditional hoisting methods first require hoisting the large rear beam and hoisting device, then hoisting the inlet header of the roof superheater, followed by welding the inlet tube bank modules one by one to the inlet header assembly. After welding one module, one screen-type superheater is installed until all inlet tube banks are welded. Next, the high-temperature superheater tube banks and low-temperature superheaters are hoisted one by one, and then the loose tubes are welded one by one. Finally, the roof superheater outlet tube banks are welded to the loose tube assembly, and the roof superheater outlet header is hoisted and welded together. This hoisting method is not only inefficient, but also poses significant safety risks due to high-altitude cross-operations and has high construction costs. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for hoisting superheaters of gas-fired boilers, so as to solve the problems of low hoisting efficiency, high safety risks of high-altitude cross-operations, and high construction costs in traditional hoisting methods.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a method for hoisting a superheater in a gas-fired boiler, wherein the superheater system is suspended below the large plate beam behind the boiler by a hoisting device, comprising the following steps: Step 1: Superheater module division; The superheater system is divided into the front, middle and rear sections according to its structural characteristics. Step 2: Assembly and hoisting of the front section and the rear large plate beam; On the ground assembly platform, the assembly of the inlet headers and tube banks of the screen superheater and the roof superheater is completed to form the front assembly. The front assembly is then lifted and temporarily fixed using a temporary hoisting device. After the large plate beam behind the furnace is hoisted, the front assembly is transferred to the formal hoisting device. Step 3: Hoisting of the high-temperature superheater and pre-storage of the low-temperature superheater; Hoist the inlet and outlet headers of the high-temperature superheater and pre-store all the tube banks of the low-temperature superheater in the rear outlet flue area of ​​the boiler. Step 4: Rear assembly and hoisting; After the ground assembly forms the pipe bank and header of the superheater outlet of the roof into a partial assembly, it is hoisted together with the rear roof plate to the design position. Step 5: Installation of intermediate tubes and low-temperature superheater; After the front and rear sections are in place, install the diffuser tubes in the middle of the roof superheater, and hoist the inlet and outlet headers of the low-temperature superheater and the pre-stored tube bank to complete the assembly and welding. Step 6: Fine-tuning and sealing of the header; The elevation of each level of container is finely adjusted, and a sealing weld is performed. Step 7: Superheater installation complete; A thorough inspection and removal of temporary measures were conducted.

[0005] Furthermore, in step 1, the first part includes the tube bank and header of the inlet of the roof superheater and the screen-type superheater to be installed; the middle part includes the diffused tubes in the middle of the roof superheater and the high-temperature superheater and the low-temperature superheater; and the rear part includes the tube bank and header of the outlet of the roof superheater.

[0006] Furthermore, in step 2, a dedicated assembly platform is erected on the ground to complete the first part of the assembly; the assembly platform is a double-layered stepped steel structure, with a clear cavity excavated directly below it to accommodate the screen-type superheater.

[0007] Furthermore, in step 2, a temporary lifting device is used to lift the front assembly; the temporary lifting device is provided with multiple lifting lugs at the bottom for suspending the screen-type superheater, and with lifting lugs at the top for connecting to a crane.

[0008] Furthermore, in step 5, the installation sequence of the low-temperature superheater is as follows: first, hoist its inlet and outlet headers into place, and then install the pre-existing pipe bank in the outlet flue in sequence and weld it to the header assembly.

[0009] Furthermore, in step 6, the header fine-tuning is achieved by adjusting the extension length of the boom and using a laser level or spirit level to precisely adjust the elevation of each header to the designed installation elevation.

[0010] Furthermore, in step 6, the sealing welding is performed symmetrically from the middle of the roof superheater to both sides, followed by sealing welding at the connection between the surrounding water-cooled walls and the furnace walls.

[0011] Furthermore, in step 7, temporary measures include temporary lugs, temporary supports, and auxiliary platforms.

[0012] This invention divides the superheater into three parts: front, middle, and rear. The front and rear parts are assembled and hoisted separately on the ground. This transforms the installation of the screen-type superheater and the operation of the inlet and outlet headers of the roof superheater into ground operations, reducing a large amount of welding work, improving hoisting efficiency, reducing safety hazards, and saving construction costs. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the invention and form part of this application. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0014] Figure 1 This is a schematic diagram of the module division of the present invention; Figure 2 This is a schematic diagram of the first part of the assembly platform of the present invention; Figure 3 This is an isometric drawing of the temporary suspension device of the present invention; Figure 4 This is a schematic diagram of the hoisting of the front part of the present invention; Figure 5 This is a schematic diagram of the hoisting of the latter part of the present invention; In the diagram, 1-roof superheater, 101-roof superheater inlet, 102-roof superheater outlet, 2-screen superheater, 3-high temperature superheater, 4-low temperature superheater, 5-platform assembly, 501-first-layer platform assembly, 502-second-layer platform assembly, 6-temporary hoisting device, 601-screen superheater lifting lug, 602-hoisting sling lifting lug, 7-crane, 8-front section, 9-boiler, 10-rear section, 11-rear roof plate. Detailed Implementation

[0015] To enable those skilled in the art to better understand the present invention, the present invention will be further described clearly and completely below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0016] This embodiment involves the installation of superheaters for two 110t / h gas-fired boilers. The superheater system to be installed includes a roof superheater 1, a screen superheater 2, a high-temperature superheater 3, and a low-temperature superheater 4. The screen superheater 2, high-temperature superheater 3, and low-temperature superheater 4 pass through the roof superheater 1 and are suspended inside the furnace by a hanging device. In this boiler structure, the tube bank at the roof superheater inlet 101 is divided into six independent modules due to the passage of the screen superheater 2. A section of the tube bank in the middle, through which the high-temperature superheater 3 and low-temperature superheater 4 tube banks pass, is a loose tube structure and requires on-site welding of each group. Only the tube bank at the roof superheater outlet 102 is a single, integral structure.

[0017] The overall concept of this invention is to divide the entire superheater system into three modules—front, middle, and rear—for assembly and hoisting. The front section 8 (including the header of the roof superheater inlet 101, the tube bank of the roof superheater inlet 101, and the screen-type superheater 2) and the rear section 10 (including the tube bank of the roof superheater outlet 102 and the header of the roof superheater outlet 102) are assembled on the ground, transforming a large amount of high-altitude work into ground-based work. The middle section (roof superheater 1 tubes, high-temperature superheater 3, and low-temperature superheater 4) is installed interleaved after the front section 8 and the rear section 10 are in place.

[0018] Based on the above concept, a typical embodiment of the present invention provides a method for hoisting a superheater in a gas-fired boiler, which mainly includes the following steps: Step 1: Superheater Module Division like Figure 1 As shown, based on the structural characteristics and hoisting sequence of the superheater system, the superheater system is divided into three parts: The first part 8 includes the tube bank and header of the roof superheater inlet 101 and the 6 screen-type superheaters 2 to be installed; The middle section includes the diffused tubes in the middle of the roof superheater 1, the high-temperature superheater 3, and the low-temperature superheater 4; Rear section 10: includes the pipe bank and header of the roof superheater outlet 102.

[0019] Step 2: The first part consists of 8 ground groups. The traditional high-altitude pipe-threading and assembly work is transferred to the ground, such as... Figure 2As shown, a dedicated assembly platform 5 is erected on the ground at the boiler installation site. This platform is a double-layered stepped steel structure. The first assembly platform 501 (bottom layer) measures 5.6m long, 4.2m wide, and 1.4m high; the second assembly platform 502 (top layer) is stacked on top of the first platform 501, measuring 5m long, 3.5m wide, and 1m high. The horizontal projected area of ​​the first platform 501 is larger than that of the second platform 502, thus forming an outer edge area around the top surface of the first platform 501, serving as an operating and standing space for construction personnel. To meet the installation requirements of the screen-type superheater 2, a clear cavity is excavated directly below the assembly platform 5. This cavity is 5m long, 2m wide, and 2.5m deep, used to accommodate the screen-type superheater 2, allowing it to be inserted from the bottom and assembled with the header and tube bank of the superheater inlet 101 on the ceiling. During construction, firstly, the header (5.04m long, 3.6m wide) of the roof superheater inlet 101 is hoisted onto the second-level assembly platform 502 of the assembly platform 5, and temporarily fixed and aligned. Secondly, the six screen-type superheaters 2 (6.1m high, 0.8m spaced) are hoisted sequentially to the vicinity of the platform. Utilizing the clear cavity below the platform, the screen-type superheaters 2 are inserted into the cavity, with the upper part passing through a pre-set opening on the second-level assembly platform 502. After all six screen-type superheaters 2 are installed and initially fixed, the tube bank module of the roof superheater inlet 101 is assembled and welded to the header to form the complete front part of the 8-assembly assembly.

[0020] Step 2-2: Lifting of the front section 8 like Figure 3 A temporary sling device 6, 5.3m long, is constructed. Six lifting lugs 601 are installed at the bottom of the temporary sling device 6 for temporarily suspending the screen-type superheater 2 during hoisting. Two lifting lugs 602 are installed at the top of the temporary sling device 6 for securing the rigging during hoisting. Simultaneously, four auxiliary lifting points are installed on the ceiling superheater 1, connected to the temporary sling device 6 via hand-operated hoists, for adjusting the hoisting balance and component posture. A crane 7 is used, secured to the lifting lugs 602 above the temporary sling device 6 with wire ropes, to smoothly lift the entire front section 8 assembly. After hoisting to the installation elevation, it is temporarily secured, awaiting conversion to the permanent sling device.

[0021] Steps 2-3: Hoisting of the large plate beam behind the furnace Crane 7 was used to lift the large plate girder behind the furnace. When it was about 2 meters above the ground, the lifting was paused, and the construction workers installed the lifting rods and other hanging devices one by one on the large plate girder. After checking that everything was in order, the lifting continued, and the large plate girder with the lifting rods was hoisted as a whole to the top of the furnace and placed in place.

[0022] Steps 2-4: The first part (8 sections) is officially in place. After the large rear girder and formal hoisting device are installed, the hoisting points of the front section 8 are changed. Using a combination of a hand-operated hoist and a chain hoist, the front section 8 is transferred one by one from the temporary hoisting device 6 to the formal hoisting device. After confirming that all the screen-type superheaters 2 are hung on the formal hoisting rods, the temporary hoisting device 6 and all auxiliary rigging are removed.

[0023] Step 3: Hoisting of the high-temperature superheater 3 First, the inlet and outlet headers of the high-temperature superheater 3 are hoisted to their designed positions. Then, the tube banks of the high-temperature superheater 3 are hoisted into the furnace piece by piece, taking care to protect them from collisions during the hoisting process. After the tube banks are in place, the assembly and welding of the tube banks with the inlet and outlet headers is carried out.

[0024] Step 3-1: Pre-store the low-temperature superheater 4 Considering the sequence and space constraints of the subsequent intermediate tube installation, all the tubes of the low-temperature superheater 4 were first hoisted to the outlet flue area at the rear of the boiler and temporarily stored in sequence for later installation and use.

[0025] Step 4: The last 10 pairs The pipe bank and header of the roof superheater outlet 102 are assembled and welded to form an integral rear part 10 assembly.

[0026] Step 4-1: Rear section 10 hoisting like Figure 5 As shown, the rear part 10 assembly, which is assembled on the ground, and the rear top plate 11 are hoisted together by crane 7 and hoisted to the design position.

[0027] Step 5: Installation of intermediate pipe After the front section 8 and the rear section 10 are in place and fixed, the intermediate pipes are installed. The intermediate pipes in the middle of the ceiling superheater 1 are hoisted one by one and then matched and welded to the installed front section 8 pipes and rear section 10 pipes one by one.

[0028] Step 5-1: Lifting of Low-Temperature Superheater 4 First, hoist the inlet and outlet headers of the low-temperature superheater 4 into place. Then, install the pre-existing tube bank of the low-temperature superheater 4 into its designed position. Complete the assembly and welding of the tube bank of the low-temperature superheater 4 with its inlet and outlet headers.

[0029] Step 6: Fine-tune the superheater header to the installation elevation. After the main components of the entire superheater system are installed, the headers at each stage are fine-tuned. By adjusting the extension length of the hanger rods and using a laser level or spirit level to measure, the elevation of the inlet and outlet headers of the roof superheater 1, high-temperature superheater 3, and low-temperature superheater 4 are precisely adjusted to the design installation elevation, with the deviation controlled within the allowable range.

[0030] Step 6-1: First sealing weld After the header elevation is adjusted to be within acceptable limits, the first sealing weld of the roof superheater 1 is carried out. The welding sequence is symmetrical from the middle of the roof superheater 1 outwards to both sides to reduce welding stress. After the sealing weld of the roof superheater 1 is completed, the sealing weld at the connection between the surrounding water-cooled walls and the furnace walls is carried out to ensure the airtightness of the furnace.

[0031] Step 7: Superheater installation complete After a comprehensive inspection of the entire superheater system to confirm that all welding and installation work has been completed and meets quality standards, all temporary measures such as temporary lifting lugs, temporary supports, and auxiliary platforms set up during construction were removed, and the site was cleaned up. At this point, the superheater installation work was completed.

[0032] The scope of protection claimed by this invention is not limited to the specific embodiments described above. For those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for hoisting a superheater in a gas-fired boiler, wherein the superheater system is suspended from the rear beam of the boiler by a hoisting device, characterized in that, Includes the following steps: Step 1, superheater module division; The superheater system is divided into the front part (8), the middle part and the rear part (10) according to its structural characteristics. Step 2, assembly and hoisting of the front part (8) and the large plate beam behind the furnace; On the ground assembly platform (5), the assembly of the screen superheater (2) and the header and tube bank of the roof superheater inlet (101) is completed to form the front part (8) assembly. The temporary hoisting device (6) is used to lift and temporarily fix it. After the large plate beam behind the furnace is hoisted, the front part (8) is transferred to the formal hoisting device. Step 3: Hoisting of the high-temperature superheater (3) and pre-storage of the low-temperature superheater (4); Hoist the inlet and outlet headers of the high-temperature superheater (3) and store all the tubes of the low-temperature superheater (4) in the rear outlet flue area of ​​the boiler. Step 4, the latter part (10) is assembled and hoisted; The pipe bank and header of the superheater outlet (102) on the ground are assembled to form the rear part (10) assembly, and the assembly is hoisted together with the rear top plate (11) to the design position. Step 5, hoisting of intermediate diffuser tubes and low-temperature superheater (4); After the front and rear parts are in place, install the diffuser tubes in the middle of the roof superheater (1), and hoist the inlet and outlet headers of the low temperature superheater (4) and the pre-stored pipe bank to complete the assembly welding. Step 6: Fine-tuning and sealing of the header; The elevation of each level of container is finely adjusted, and a sealing weld is performed. Step 7: Superheater installation complete; A thorough inspection and removal of temporary measures were conducted.

2. The method according to claim 1, characterized in that, In step 1, the front part (8) includes the pipe bank and header of the inlet (101) of the roof superheater and the screen-type superheater (2) to be installed; the middle part includes the diffuser pipes in the middle of the roof superheater (1) and the high-temperature superheater (3) and the low-temperature superheater (4); the rear part (10) includes the pipe bank and header of the outlet (102) of the roof superheater.

3. The method according to claim 2, characterized in that, In step 2, an assembly platform (5) is built on the ground to complete the assembly of each part of the front part (8) and form the front part (8) assembly. The assembly platform (5) is a double-layer stepped steel structure with a clear cavity excavated directly below it to accommodate the screen-type superheater (2).

4. The method according to claim 3, characterized in that, In step 2, a temporary hoisting device (6) is used to lift the front part (8) assembly. The temporary hoisting device (6) has multiple lifting lugs (601) for suspending the screen-type superheater (2) below and lifting lugs (602) for connecting the crane (7) above.

5. The method according to claim 1, characterized in that, In step 5, the installation sequence of the low-temperature superheater (4) is as follows: first, hoist its inlet and outlet headers into place, and then install the pre-existing pipe bank in the outlet flue in sequence and weld it to the header assembly.

6. The method according to claim 1, characterized in that, In step 6, the header fine-tuning is achieved by adjusting the extension length of the boom and using a laser level or a spirit level to precisely adjust the elevation of each header to the designed installation elevation.

7. The method according to claim 1, characterized in that, In step 6, the sealing welding is performed symmetrically from the middle of the roof superheater (1) to both sides, and then the sealing welding at the connection between the surrounding water-cooled walls and the furnace walls is completed.

8. The method according to claim 1, characterized in that, In step 7, temporary measures include temporary lifting lugs, temporary supports, and auxiliary platforms.

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