Sealing structure of boiler membrane type water cooling wall

Abstract

A sealing structure of a boiler membrane type water cooling wall comprises a middle water collecting tank, a plurality of vertical pipes and a plurality of spiral pipes arranged below the vertical pipes, first bent pipes are in butt joint with the vertical pipes through first elbows, and second bent pipes are in butt joint with the spiral pipes through second elbows. Rectangular windows are formed in the portions, between the first elbows and the second elbows and between every two adjacent second elbows, of the sealing fins, sealing boxes are connected into the rectangular windows in a matched and sealed mode, and the sealing boxes are filled with refractory castable. The heating area of the sealing fins with the large elbow portion area is reduced, the phenomenon that the sealing fins crack due to long-term high-temperature operation, and consequently the water cooling wall leaks is avoided, and normal operation of a unit is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of boiler equipment, specifically to a sealing structure for a boiler membrane water-cooled wall. Background Technology

[0002] To ensure sufficient cooling capacity for boilers under various loads and effectively compensate for thermal deviations along the furnace perimeter, current supercritical boiler units generally employ spiral tube coils for the lower membrane water-cooled wall and a single-rise vertical tube screen for the upper membrane water-cooled wall. The two are connected via an intermediate water collection tank. The membrane water-cooled wall is composed of an airtight tube screen welded from flat steel fins and tubes. The intermediate water collection tank, as a key node in the membrane water-cooled wall, evenly distributes water or steam-water mixtures into the vertical tubes, ensuring flow rates in all areas of the heating surface. To balance the cooling system and prevent localized overheating, the vertical and spiral pipes are connected to the intermediate water tank via bends. The bends require specific angles to prevent plastic deformation, inevitably creating large gaps that necessitate sealing with large-area fins. These fins, being large and far from the cooling medium, are not adequately cooled, leading to prolonged high-temperature operation and cracking. In severe cases, the cracks extend to the water-cooled wall tubes, causing leaks and ultimately unit shutdown. Utility Model Content

[0003] To address the shortcomings of existing technologies that cause cracking of sealing fins and leakage in bends, this invention provides a sealing structure for a boiler membrane water-cooled wall.

[0004] The technical solution of this utility model is: a sealing structure for a boiler membrane water-cooled wall, the membrane water-cooled wall including an intermediate water collection tank, several vertical pipes and several spiral pipes arranged below the vertical pipes, each of the vertical pipes being connected to the intermediate water collection tank through a first bend, each of the spiral pipes being connected to the intermediate water collection tank through a second bend, and adjacent vertical pipes and adjacent spiral pipes being connected by sealing fins, and adjacent vertical pipes and spiral pipes being connected by sealing fins; the first bend is connected to the vertical pipe through a first elbow, and the second bend is connected to the spiral pipe through a second elbow; rectangular windows are opened on the sealing fins between the first elbow and the second elbow and between two adjacent second elbows, and sealing boxes are adapted to be sealed and connected in the rectangular windows, and refractory castable is filled inside the sealing boxes.

[0005] Preferably, the end of the sealed box facing the inside of the boiler is provided as an opening, and the refractory castable is injected from the opening.

[0006] Preferably, the sealing box between the first bend and the second bend is arranged vertically along the length direction, and the sealing box between two adjacent second bends is arranged horizontally along the length direction.

[0007] Preferably, an expansion joint is provided at the middle of both side walls along the length of the sealing box.

[0008] Preferably, the sidewalls of the sealing box that fit into the first elbow and the second elbow are both set as slopes.

[0009] Preferably, all four side walls of the sealed box are sloped.

[0010] The beneficial effects of this utility model are as follows: by setting a sealing box filled with refractory castable, the heat-receiving area of ​​the large sealing fins at the elbow is reduced, preventing the sealing fins from cracking due to long-term high-temperature operation, which could lead to leakage in the water-cooled wall and ensure the normal operation of the unit. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model;

[0012] Figure 2 This is a side sectional view of the present invention;

[0013] Figure 3 This is a front view structural diagram of the sealed box;

[0014] Figure 4 This is a rear view structural diagram of the sealed box. Detailed Implementation

[0015] To better understand the concept of this utility model, the technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0016] The technical solution of this utility model is as follows: A sealing structure for a boiler membrane water-cooled wall is as follows. Figure 1 As shown, the membrane water-cooled wall includes an intermediate water collection tank 1, several vertical pipes 2, and several spiral pipes 3 arranged below the vertical pipes 2. Each vertical pipe 2 is connected to the intermediate water collection tank 1 through a first bend 4, and each spiral pipe 3 is connected to the intermediate water collection tank 1 through a second bend 5. Adjacent vertical pipes 2 and adjacent spiral pipes 3 are connected by sealing fins 6, and adjacent vertical pipes 2 and spiral pipes 3 are also connected by sealing fins 6, thereby isolating the high temperature inside the boiler. The first bend 4 is connected to the vertical pipe 2 through a first bend 7, and the second bend 5 is connected to the spiral pipe 3 through a second bend 8. Rectangular windows 6-1 are opened on the sealing fins 6 between the first bend 7 and the second bend 8 and between two adjacent second bends 8. A sealing box 9 is adapted and sealed in the rectangular window 6-1, and refractory castable 10 is filled inside the sealing box 9.

[0017] Furthermore, the end of the sealing box 9 facing the inside of the boiler is set as an opening 11, through which the refractory castable 10 is injected. Before construction, the refractory castable is injected into the sealing box through the opening. After the refractory castable has solidified and hardened, the sealing box is installed in the designated position to replace the sealing fins 6 removed by opening the rectangular window 6-1, ensuring that the airtightness of the membrane water-cooled wall is not compromised.

[0018] When the water-cooled wall is in operation, the spiral tubes serve as the water inlet pipes, and the vertical tubes serve as the water outlet pipes. The inlet and outlet pipes are configured in a 1:3 ratio to ensure sufficient water outlet capacity in the vertical tubes when water is being fed into the spiral tubes, preventing overflow from the intermediate water collection tank. Figure 1 and Figure 2 The structure shown has three second bends connected to the middle water collection tank, with three corresponding second bends 8, and nine first bends connected to the middle water collection tank, with nine corresponding first bends 7. Specifically, three first upper bends 7-1 are set at the top and six first lower bends 7-2 are set at the bottom.

[0019] The specific installation positions of the sealing boxes are as follows: a sealing box 9 is installed between the first upper bend 7-1 and the second bend 8, which are arranged vertically between every two adjacent vertical pipes, and the sealing box 9 is arranged vertically along the length direction; a sealing box 9 is installed between every two adjacent second bends 8, and the sealing box 9 is arranged horizontally along the length direction below the first lower bend 7-2. This arrangement can minimize the heat-receiving area of ​​the large sealing fins and prevent the sealing fins from cracking due to long-term high-temperature operation.

[0020] Furthermore, since the two side walls of the sealing box 9 along its length are close to the first bend 7 and the second bend 8, in order to prevent the sealing box from cracking due to thermal expansion and affecting its service life, such as... Figure 3 As shown, expansion joints 12 are provided in the middle of the two side walls along the length of the sealing box 9. When the sealing box is heated, the thermal expansion energy is released through the expansion joints to prevent the sealing box from cracking and being damaged.

[0021] To further reduce the heat-exposed area of ​​the sealing fins, increase the protection range of the sealing fins within the sealing box, and ensure sufficient refractory castable filling within the sealing box, such as... Figure 4 As shown, the side walls of the sealing box 9 that fit into the first elbow 7 and the second elbow 8 are both set as slopes.

[0022] To facilitate mass production and easy installation of the sealing boxes, the boxes should have a uniform shape, such as... Figure 4 As shown, all four side walls of the sealing box 9 are set as inclined surfaces, or all four side walls of the sealing box 9 are set as curved surfaces that fit against the outer periphery of the spiral tube and the vertical tube, which can increase the capacity of the refractory castable.

[0023] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.

Claims

1. A sealing structure for a boiler membrane water-cooled wall, the membrane water-cooled wall comprising an intermediate water collection tank (1), a plurality of vertical pipes (2), and a plurality of spiral pipes (3) disposed below the vertical pipes (2), each of the vertical pipes (2) being connected to the intermediate water collection tank (1) via a first bend (4), each of the spiral pipes (3) being connected to the intermediate water collection tank (1) via a second bend (5), and adjacent vertical pipes (2) and adjacent spiral pipes (3) being connected via sealing fins (6), and adjacent vertical pipes (2) and spiral pipes (3) being connected via sealing fins (6); the first bend (4) is connected to the vertical pipe (2) via a first bend (7), and the second bend (5) is connected to the spiral pipe (3) via a second bend (8); characterized in that: A rectangular window (6-1) is provided on the sealing fin (6) between the first elbow (7) and the second elbow (8) and between two adjacent second elbows (8). A sealing box (9) is adapted to be sealed in the rectangular window (6-1), and refractory castable (10) is filled inside the sealing box (9).

2. The seal structure of a boiler membrane water wall according to claim 1, characterized in that: The sealed box (9) is provided with an opening (11) at one end facing the inside of the boiler, and the refractory castable (10) is injected from the opening (11).

3. The seal structure of a boiler membrane wall water cooling wall according to claim 2, characterized in that: The sealing box (9) between the first bend (7) and the second bend (8) is arranged vertically along the length direction, and the sealing box (9) between two adjacent second bends (8) is arranged horizontally along the length direction.

4. The seal structure of a boiler membrane wall water cooling wall according to claim 3, characterized in that: Expansion joints (12) are provided in the middle of the two side walls along the length of the sealing box (9).

5. The seal structure of a boiler membrane wall water cooling panel according to claim 4, characterized in that: The side walls of the sealing box (9) that fit the first elbow (7) and the second elbow (8) are both set as slopes.

6. The seal structure of a boiler membrane wall water cooling wall according to claim 4, characterized in that: The four side walls of the sealed box (9) are all set as slopes.

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