Water cooling wall of once-through boiler

Abstract

The utility model discloses a once-through boiler water-cooled wall, which comprises a water-cooled wall main body and a plurality of protective plates, and is characterized in that the water-cooled wall main body comprises a plurality of pipe bodies arranged in a once-through boiler hearth in parallel, and every two adjacent pipe bodies are connected with each other through two parallel connecting plates; and the protective plate is attached to the outer part of the pipe body and is fixedly mounted with the connecting plate. According to the water cooling wall of the once-through boiler, the pipe body is protected through the protection plate, and the pipe body is prevented from being abraded and corroded at high temperature. Meanwhile, bolts penetrate through the penetrating grooves to be fixedly connected with the threaded grooves in the connecting plate, the pipe body can be protected through the protection plate and prevented from being abraded and corroded, the elastic element is made of a rubber strip of an arch structure, and the two ends of the elastic element abut against the disc spring. And impact force can be dispersed and buffered through self deformation and recovery under the action of external force, so that the stability of connection between the protection plate and the water-cooled wall main body is improved.

Description

Technical Field

[0001] This utility model relates to the field of boiler technology, and in particular to a water-cooled wall for a once-through boiler. Background Technology

[0002] A once-through boiler refers to a boiler that relies on feedwater pump pressure to sequentially pass feedwater through the economizer, evaporative heating surface (water-cooled wall), and superheater, transforming it all into superheated steam. The water-cooled wall is the main heating component of a once-through boiler. It consists of several rows of steel tubes distributed around the boiler furnace. Its interior contains flowing water or steam, receiving heat from the flames in the furnace and primarily absorbing radiant heat from the high-temperature combustion products. The working fluid rises within it, evaporating upon heating. Because the water-cooled wall is directly exposed inside the furnace, it is constantly subjected to the scouring of coal dust particles after combustion and the erosion of corrosive gases within the boiler. This causes varying degrees of wear and corrosion to the water-cooled wall tubes, affecting not only the normal operation of the once-through boiler but also posing safety hazards. Generally, to address the wear and corrosion issues, boiler manufacturers primarily adopt measures such as selecting better water-cooled wall materials, for example, changing the conventional 20G carbon steel material to 15CrMoG alloy steel. However, since the water-cooled wall inside the furnace is a large, monolithic structure, dissimilar steels cannot be welded together. Therefore, it's not feasible to simply replace the water-cooled wall in the high-temperature area with a better material while retaining conventional materials in other areas. This would require replacing the entire water-cooled wall and its headers in the furnace with 15CrMoG alloy steel, which would increase the overall cost of the boiler. While the solution is good, it is not economically viable and has poor feasibility. For example, invention application CN112548381A discloses a welding fusion anti-corrosion device for the water-cooled wall in the high-temperature area of ​​the furnace. The water-cooled wall is made of metal sheets and metal pipes welded alternately, effectively solving the problem of achieving corrosion protection in the high-temperature area of ​​the water-cooled wall without using expensive materials, and also solving the problem of high-temperature damage to the water-cooled wall during welding fusion anti-corrosion, greatly reducing the cost of corrosion protection in the high-temperature area of ​​the water-cooled wall. However, the welding method is relatively difficult to operate, and because the welding fixes the water-cooled wall into a whole, it is not conducive to replacing the water-cooled pipes during local repairs or maintenance, increasing the difficulty of maintenance.

[0003] Therefore, this utility model provides a water-cooled wall for a DC boiler to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a water-cooled wall for a DC boiler to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a water-cooled wall for a DC boiler, comprising a water-cooled wall body and multiple protective plates, characterized in that the water-cooled wall body comprises multiple tubes arranged in parallel inside the furnace of the DC boiler, two adjacent tubes are connected to each other by two parallel connecting plates, and the protective plates are attached to the outside of the tubes and fixedly installed with the connecting plates.

[0006] The protective plate includes a single protective cover and a connecting piece. The protective cover is generally arc-shaped and is attached to the outside of the tube body. The connecting piece is fixedly installed to the connecting plate through a connector.

[0007] The connecting piece is provided with a through groove, the connecting plate is provided with a threaded groove, the connecting component includes a bolt, a nut, an elastic element and a disc spring, the disc spring is located at the opening of the through groove, the elastic element is located between the nut and the disc spring, and the bolt passes through the nut, the elastic element, the disc spring and the through groove and is screwed into the threaded groove.

[0008] Preferably, the inner wall of the pipe is coated with an anti-scaling coating.

[0009] Preferably, the anti-scaling coating is a nano-composite double-layer anti-scaling coating.

[0010] Preferably, the inner wall of the tube is provided with a plurality of triangular fins, which are evenly arranged on the inner wall of the tube along the circumference of the tube, and adjacent triangular fins are not in contact.

[0011] The beneficial effects of this utility model are:

[0012] The water-cooled wall of the DC boiler provided by this utility model protects the tube body with a protective plate to prevent wear and high-temperature corrosion. Simultaneously, this utility model uses bolts passing through the through-slot and threaded groove on the connecting plate for fixed connection. The protective plate further protects the tube body from wear and corrosion. The elastic element is made of an arched rubber strip, with both ends resting on disc springs. When subjected to external force, it can disperse and buffer the impact force through its own deformation and recovery, improving the stability of the connection between the protective plate and the water-cooled wall body. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0015] Figure 2 This is a structural schematic diagram of the connector of this utility model.

[0016] In the diagram: 1. Water-cooled wall main body; 2. Tube body; 3. Connecting plate; 4. Protective plate; 5. Anti-scaling coating; 6. Triangular fin; 7. Once-through boiler furnace; 8. Threaded groove; 9. Through groove; 10. Bolt; 11. Nut; 12. Elastic element; 13. Disc spring. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Therefore, the following detailed description of the embodiments of this utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but merely to illustrate selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0018] Please see Figure 1-2 This utility model provides a technical solution: a water-cooled wall for a DC boiler, comprising a water-cooled wall body 1 and multiple protective plates 4. The water-cooled wall body 1 includes multiple tubes 2 arranged in parallel inside the furnace 7 of the DC boiler. Two adjacent tubes 2 are connected to each other by two parallel connecting plates 3. The protective plates 4 are attached to the outside of the tubes 2 and fixedly installed with the connecting plates 3.

[0019] Furthermore, the protective plate 4 includes a single protective cover and a connecting piece. The protective cover is arc-shaped and is attached to the outside of the pipe body 2. The connecting piece is fixedly installed to the connecting plate 3 through a connector.

[0020] Furthermore, the connecting piece is provided with a through groove 9, and the connecting plate 3 is provided with a threaded groove 8. The connecting parts include a bolt 10, a nut 11, an elastic element 12, and a disc spring 13. The disc spring 13 is located at the opening of the through groove 9, and the elastic element 12 is located between the nut 11 and the disc spring 13. The bolt 10 passes through the nut 11, the elastic element 12, the disc spring 13, and the through groove 9 and is screwed into the threaded groove 8. The elastic element 12 is made of an arched rubber strip, and both ends of the elastic element 12 abut against the disc spring 13. When subjected to external force, it can disperse and buffer the impact force through its own deformation and recovery, thereby improving the stability of the connection between the protective plate 4 and the water-cooled wall body 1.

[0021] Furthermore, the inner wall of the pipe body 2 is coated with an anti-scaling coating 5.

[0022] Furthermore, the anti-scaling coating 5 is a nano-composite double-layer anti-scaling coating, which makes it less likely for scale to form on the inner wall of the pipe body 2.

[0023] Furthermore, the inner wall of the tube body 2 is provided with multiple triangular fins 6, which are evenly arranged along the circumference of the inner wall of the tube body 2, with adjacent triangular fins 6 not in contact. The triangular fins 6 increase the inner surface area of ​​the tube body 2, reduce laminar flow during liquid flow, increase turbulence, increase the heat transfer coefficient, and greatly improve the heat transfer capacity, thus enabling the tube body to achieve optimal heat transfer performance.

[0024] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A water-cooled wall for a DC boiler, comprising a water-cooled wall body (1) and a plurality of protective plates (4), characterized in that, The water-cooled wall body (1) includes multiple tubes (2) arranged in parallel inside the furnace (7) of the DC boiler. Two adjacent tubes (2) are connected to each other by two parallel connecting plates (3). The protective plate (4) is attached to the outside of the tube (2) and fixedly installed with the connecting plate (3). The protective plate (4) includes a single protective cover and a connecting piece. The protective cover is arc-shaped and is attached to the outside of the tube body (2). The connecting piece is fixedly installed to the connecting plate (3) through a connector. The connecting piece is provided with a through groove (9), and the connecting plate (3) is provided with a threaded groove (8). The connecting component includes a bolt (10), a nut (11), an elastic element (12), and a disc spring (13). The disc spring (13) is located at the opening of the through groove (9), and the elastic element (12) is located between the nut (11) and the disc spring (13). The bolt (10) passes through the nut (11), the elastic element (12), the disc spring (13), and the through groove (9) and is screwed into the threaded groove (8).

2. The water-cooled wall of a once-through boiler according to claim 1, characterized in that: The inner wall of the tube (2) is coated with an anti-scaling coating (5).

3. The water-cooled wall of a once-through boiler according to claim 2, characterized in that: The anti-scaling coating (5) is a nano-composite double-layer anti-scaling coating.

4. The water-cooled wall of a once-through boiler according to claim 3, characterized in that: The inner wall of the tube (2) is provided with a plurality of triangular fins (6). The triangular fins (6) are evenly arranged on the inner wall of the tube (2) along the circumference of the tube (2), and two adjacent triangular fins (6) are not in contact.

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