A method for installing a drum of an angle tube type steam boiler

Abstract

The application discloses a kind of angle tube type steam boiler drum installation method, comprising the following steps: S1, construction n boiler foundation;S2, install each lower header on corresponding support;S3, calculate the weld gap between each lower header and the downcomer and connecting pipe of butt joint;S4, hoist each downcomer and connecting pipe, and each downcomer, connecting pipe and each lower header butt joint welding;S5, install each water wall lower header;S6, erect support;S7, hoist drum to installation position, then hoist part water wall upper header, and the hoisted part water wall upper header is butt jointed with corresponding part downcomer and connecting pipe and welded;Again, drum is butt jointed with corresponding downcomer, water wall upper header and connecting pipe and welded;S8, hoist the rest water wall upper header and upper header, and each water wall upper header and upper header, downcomer and connecting pipe are all butt jointed and welded to completion.The application can effectively improve the efficiency of drum construction and the utilization rate of hoisting equipment.

Description

Technical Field

[0001] This invention relates to the field of boiler drums. More specifically, this invention relates to a method for installing a steam drum in a corner-tube steam boiler. Background Technology

[0002] Angle-tube steam boilers have a pressure-bearing structure consisting of downcomers, connecting pipes, and upper and lower headers forming a cage frame. Because the components of angle-tube steam boilers are primarily supplied modularly, while this significantly reduces on-site operation and assembly difficulties and improves installation efficiency, it also presents several weaknesses in overall boiler installation. These include limited installation space, small operating area, high operational difficulty, high installation precision, and challenging welding. To overcome these weaknesses, existing technologies typically involve erecting a full-span scaffold and temporary upper header supports within the boiler installation area to assemble the downcomers, connecting pipes, and upper and lower headers into a unified frame before hoisting the steam drum. However, this method involves a large workload for scaffold erection, consumes significant manpower, has low mechanical construction efficiency, and is cumbersome with significant welding errors. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] To achieve these objectives and other advantages according to the present invention, a method for installing a steam drum in a corner-tube steam boiler is provided, comprising the following steps: S1. Construct n boiler foundations, with embedded steel plates on the boiler foundations and supports on the embedded steel plates; S2. Install each lower header on the corresponding support, and confirm that the upward-facing pipe openings of each lower header are in a vertical position. S3. Calculate the weld gap between each lower header and the downcomer and connecting pipe; S4. Hoist each downcomer pipe and connecting pipe according to the weld gap calculated in step S2, and weld each downcomer pipe, connecting pipe and each lower header together. S5. Install the lower headers of each water-cooled wall; S6. Erect a support frame, which is set from the ground to below the steam drum installation position and to the side of the steam drum; S7. Hoist the steam drum to the installation position, then hoist part of the water-cooled wall upper header, while adjusting the weld gap between each pipe opening of the steam drum and the pipe openings of the downcomer and connecting pipe. Butt weld the hoisted part of the water-cooled wall upper header to the corresponding part of the downcomer and connecting pipe; then butt weld the steam drum to the corresponding downcomer, water-cooled wall upper header and connecting pipe. S8. Hoist the remaining water-cooled wall upper headers and upper headers, and weld all the water-cooled wall upper headers, upper headers, downcomers and connecting pipes together.

[0005] Preferably, in step S1, the elevation error range of the boiler foundation is 0-10mm, and the strength of the boiler foundation must be able to bear the weight of the boiler body and meet the seismic requirements.

[0006] Preferably, in step S1, the n supports include one fixed support and multiple movable supports. The movable support includes a positioning plate slidably disposed on the embedded steel plate and four limiting plates. The four limiting plates are symmetrically disposed around the positioning plate about the center of the embedded steel plate. The four limiting plates are spaced a certain distance from the outer perimeter of the positioning plate. A first rib is fixedly disposed on the side of the four limiting plates away from the center of the embedded steel plate. The embedded steel plate of the fixed support and the positioning plate of each movable support are all fixedly disposed with column feet. The top of the column feet is fixedly connected to an arc-shaped support plate that cooperates with the lower header.

[0007] Preferably, each of the limiting plates on the sliding support is fixedly connected to a horizontal pressure plate on the side facing the center of the embedded steel plate, and the bottom surface of the horizontal pressure plate is in contact with the top surface of the positioning plate.

[0008] Preferably, step S3 further includes calculating the weld gap between the headers on each of the water-cooled walls and the downcomer and connecting pipes.

[0009] Preferably, in step S7, two truck cranes are used to hoist the steam drum and part of the water-cooled wall headers respectively, and the number of the water-cooled wall headers hoisted for the first time is 3 to 4.

[0010] Preferably, in step S7, the hoisted portion of the water-cooled wall upper header is butt-welded to the corresponding 3-4 downcomers and connecting pipes; Preferably, in step S7, the steam drum is leveled before it is butt-welded to the corresponding downcomer, the water-cooled wall header, and the connecting pipe.

[0011] The present invention has at least the following beneficial effects: The steam drum installation method for a corner tube steam boiler provided by this invention only requires hoisting and welding a portion of the water-cooled wall upper headers to ensure the current tube cage frame is sufficient to support the steam drum 5. Therefore, only supports need to be erected from the ground to below the steam drum installation position and on one side of the steam drum to ensure sufficient space for steam drum hoisting construction and personnel operation. Compared with traditional steam drum installation methods, this method effectively reduces the workload of support erection and improves construction efficiency. After the steam drum is hoisted and welded, the relevant hoisting equipment can be removed to improve the utilization rate of large hoisting equipment. Furthermore, during the steam drum hoisting process, only the weld gap between the steam drum and a portion of the water-cooled wall upper headers needs to be adjusted, which effectively improves the hoisting efficiency of the steam drum and facilitates the subsequent hoisting and welding of the water-cooled wall upper headers and upper headers 6.

[0012] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0013] Figure 1 This is a side view of the steam drum of the present invention; Figure 2 for Figure 1 The left view; Figure 3 This is a top view of the boiler foundation described in this invention; Figure 4 This is a side view of the movable support described in this invention. Detailed Implementation

[0014] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0015] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0016] like Figure 1 and Figure 4 As shown, the present invention provides a method for installing the steam drum of a corner tube steam boiler, including the following steps: S1. Construct n boiler foundations 1, wherein a pre-embedded steel plate 9 is installed on the boiler foundation 1, and a support 2 is installed on the pre-embedded steel plate 9; S2. Install each lower header 3 on the corresponding support 2, and confirm that the upward opening of each lower header 3 is in a vertical state. S3. Calculate the weld gap between each lower header 3 and the connected downcomer 4 and connecting pipe; S4. Hoist each downcomer pipe 4 and connecting pipe according to the weld gap calculated in step S2, and weld each downcomer pipe 4, connecting pipe and each lower header 3 together. S5. Install the lower headers of each water-cooled wall; S6. Erect a support frame, which is set from the ground to below the installation position of the steam drum 5 and on the side of the steam drum 5; S7. Hoist the steam drum 5 to the installation position, then hoist part of the water-cooled wall upper header 8, while adjusting the weld gap between each pipe opening of the steam drum 5 and the downcomer 4 and connecting pipe, and weld the hoisted part of the water-cooled wall upper header 8 to the corresponding part of the downcomer 4 and connecting pipe; then weld the steam drum 5 to the corresponding downcomer 4, water-cooled wall upper header 8 and connecting pipe. S8. Hoist the remaining water-cooled wall upper headers 8 and upper headers 6, and weld all the water-cooled wall upper headers 8 and upper headers 6, downcomers 4 and connecting pipes together.

[0017] In this technical solution, since only the upper header 8 of the water-cooled wall needs to be hoisted and welded first to ensure that the current tube cage frame is sufficient to support the steam drum 5, only a support structure needs to be erected from the ground to below the installation position of the steam drum 5 and on one side of the steam drum 5 to ensure space for steam drum hoisting construction and personnel operation. Compared with traditional steam drum installation methods, this effectively reduces the workload of support erection and improves construction efficiency. After the steam drum 5 is hoisted and welded, the relevant hoisting equipment can be removed to improve the utilization rate of large hoisting equipment. Furthermore, during the hoisting process of the steam drum 5, only the weld gap between it and part of the upper header 8 of the water-cooled wall needs to be adjusted, which can effectively improve the hoisting efficiency of the steam drum 5 and facilitate the subsequent hoisting and welding of the upper header 8 of the water-cooled wall and the upper header 6.

[0018] In step S1, the construction of each boiler foundation 1 determines the final installation accuracy. During the civil construction process, the elevation error of each boiler foundation must be controlled within 0-10mm according to the design requirements of the drawings to ensure accurate installation of equipment and pipelines. The overall elevation, axis, and levelness of each boiler foundation 1 must be completed according to the design requirements. The embedded steel plates 9 on each boiler foundation 1 must be precisely positioned in terms of elevation, axis, and levelness according to the pre-embedded requirements of the drawings.

[0019] Furthermore, the strength of the boiler foundation 1 must meet certain design requirements to bear the weight of the boiler body and meet seismic resistance requirements.

[0020] Specifically, in step S1, the n supports 2 include one fixed support 21 and multiple movable supports 22. The movable support 22 includes a positioning plate 221 slidably disposed on the embedded steel plate 9 and four limiting plates 223 fixedly disposed on the embedded steel plate 9. The four limiting plates 223 are symmetrically disposed around the positioning plate 221 about the center of the embedded steel plate 9. The four limiting plates 223 are spaced a certain distance from the outer periphery of the positioning plate 221. A first rib 222 is fixedly disposed on the side of the four limiting plates 222 away from the center of the embedded steel plate 9. A column foot 10 is fixedly disposed on the embedded steel plate 9 of the fixed support 21 and the positioning plate 221 of each movable support 22. An arc-shaped support plate that cooperates with the lower header 3 is fixedly connected to the top of the column foot 10.

[0021] The support 2 is used to transfer the load it bears to each of the boiler foundations 1. (Refer to...) Figure 3 and Figure 4 In the movable support 22, the positioning plate 221 is limited in four directions (front, back, left, and right) by four limiting plates 223, and the strength of the corresponding limiting plate 223 is increased by each first rib 222. The movable support 22 allows free expansion in the horizontal plane. Specifically, the sliding between the positioning plate 221 and the embedded steel plate 9 is achieved by fixing a composite plate 226 at the bottom of the positioning plate 221. The composite plate 226 includes an upper steel plate and a PTFE plate bonded together. The upper steel plate is fixedly connected to the positioning plate 22. A lower steel plate 227 is fixedly installed on the top surface of the embedded steel plate 9. The PTFE plate and the upper steel plate are in direct contact. The area of ​​the lower steel plate 227 is larger than the area of ​​the PTFE plate.

[0022] Furthermore, each of the limiting plates 223 on the sliding support 22 is fixedly connected to a horizontal pressure plate 224 on the side facing the center of the embedded steel plate 9, and the bottom surface of the horizontal pressure plate 224 is in contact with the top surface of the positioning plate 221. The horizontal pressure plate 224 restricts vertical expansion, so that the positioning plate 221 can only move in the horizontal plane.

[0023] In step S2, it is confirmed that the upward openings of each lower header 3 are in a vertical position to ensure the verticality of the downcomer 4 and the connecting pipe, thereby ensuring that the pipe opening direction of the steam drum 5 during hoisting can be accurately aligned with the downcomer 4 and the connected pipe, and then assembled and welded.

[0024] Step S3 also includes calculating the weld gap between the headers 8 on each water-cooled wall and the connected downcomer 4 and connecting pipe. By accurately calculating each weld gap, it is ensured that the welds of the headers 8 on each water-cooled wall and the steam drum 5 are within the welding requirements and that there is no stress during the assembly process.

[0025] In step S5, the stability and strength of each of the lower headers 3, the downcomer 4, and the connecting pipe are ensured by installing the lower header 7 of the condenser wall, and the upper header 8 of the water-cooled wall can be accurately hoisted and connected.

[0026] In step S6, a scaffold, typically full-span, is erected from the ground to directly below and to the side of the steam drum 5 to serve as a platform for hoisting the steam drum 5 and for personnel operations, ensuring the safety of the construction process.

[0027] In step S7, two truck cranes are used to lift the 5 steam drums and part of the water-cooled wall headers 8 respectively. The number of water-cooled wall headers lifted in the first lifting is 3 to 4.

[0028] Furthermore, the hoisted portion of the water-cooled wall upper header 8 is butt-welded to the corresponding 3-4 downcomer pipes 4 and the connecting pipes; The hoisting process requires the cooperation of two cranes (25-ton and 80-ton). First, the 80-ton crane is used to hoist the steam drum 5 to the installation elevation and position. Then, 3-4 of the water-cooled wall upper headers are hoisted. Simultaneously, the positions of the downcomer pipes 4 and connecting pipes are adjusted to the weld gaps of the pipe openings of the steam drum 5. This ensures that the pipe openings of the water-cooled wall upper headers 8 and the downcomer pipes 4 and connecting pipes can be welded according to welding specifications. The 3-4 water-cooled wall upper headers and the 3-4 downcomer pipes 4 and connecting pipes are butt-welded to ensure the stability of the steam drum 5 and prevent it from tilting or collapsing. After the above welds are completed, the 80-ton crane is removed to ensure the utilization rate of the large crane. Then, the 25-ton crane is used to weld and assemble the remaining water-cooled wall upper headers 8, upper headers 6, and downcomer pipes 4 and connecting pipes, completing the hoisting of the steam drum 5 in one go.

[0029] In the above process, before the steam drum 5 is welded to the corresponding downcomer 4, the water-cooled wall header 8 and the connecting pipe, it is first leveled to ensure that the load distribution of each downcomer 4 is uniform.

[0030] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for installing the steam drum of a corner tube steam boiler, characterized in that, Includes the following steps: S1. Construct n boiler foundations, each with an embedded steel plate and supports. The n supports include one fixed support and multiple movable supports. Each movable support includes a positioning plate slidably mounted on the embedded steel plate and four limiting plates. The four limiting plates are symmetrically arranged around the positioning plate about the center of the embedded steel plate, with a certain distance between each limiting plate and the outer perimeter of the positioning plate. A first rib is fixedly mounted on the side of each limiting plate away from the center of the embedded steel plate. Column feet are fixedly mounted on the embedded steel plate of the fixed support and the positioning plate of each movable support. An arc-shaped support plate that mates with the lower header is fixedly connected to the top of each column foot. S2. Install each lower header on the corresponding support, and confirm that the upward-facing pipe openings of each lower header are in a vertical position. S3. Calculate the weld gap between each lower header and the downcomer and connecting pipe; S4. Hoist each downcomer pipe and connecting pipe according to the weld gap calculated in step S3, and weld each downcomer pipe, connecting pipe and each lower header together. S5. Install the lower headers of each water-cooled wall; S6. Erect a support frame, which is set from the ground to below the steam drum installation position and to the side of the steam drum; S7. Hoist the steam drum to the installation position, then hoist part of the water-cooled wall upper header, while adjusting the weld gap between each pipe opening of the steam drum and the pipe openings of the downcomer and connecting pipe. Butt weld the hoisted part of the water-cooled wall upper header to the corresponding part of the downcomer and connecting pipe; then butt weld the steam drum to the corresponding downcomer, water-cooled wall upper header and connecting pipe. S8. Hoist the remaining water-cooled wall upper headers and upper headers, and weld all the water-cooled wall upper headers, upper headers, downcomers and connecting pipes together.

2. The steam drum installation method for a corner tube steam boiler as described in claim 1, characterized in that, In step S1, the elevation error range of the boiler foundation is 0-10mm, and the strength of the boiler foundation must be able to support the weight of the boiler body and meet seismic requirements.

3. The steam drum installation method for a corner tube steam boiler as described in claim 1, characterized in that, Each of the limiting plates on the movable support is fixedly connected to a horizontal pressure plate on the side facing the center of the embedded steel plate, and the bottom surface of the horizontal pressure plate is in contact with the top surface of the positioning plate.

4. The steam drum installation method for a corner tube steam boiler as described in claim 1, characterized in that, Step S3 also includes calculating the weld gap between the headers on each of the water-cooled walls and the downcomer and connecting pipes that are connected to them.

5. The steam drum installation method for a corner tube steam boiler as described in claim 1, characterized in that, In step S7, two truck cranes are used to lift the steam drum and part of the water-cooled wall headers respectively. The number of water-cooled wall headers lifted in the first operation is 3 to 4.

6. The steam drum installation method for a corner tube steam boiler as described in claim 5, characterized in that, In step S7, the hoisted portion of the water-cooled wall upper header is welded to the corresponding 3-4 downcomers and connecting pipes.

7. The steam drum installation method for a corner tube steam boiler as described in claim 1, characterized in that, In step S7, the steam drum is leveled before it is welded to the corresponding downcomer, the water-cooled wall header and the connecting pipe.

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