Anti-corrosion evaporation heating surface structure

Abstract

The utility model belongs to the field of circulating fluidized bed boilers, and particularly relates to an anti-corrosion evaporation heating surface structure, which can effectively avoid corrosion of a supporting piece of the evaporation heating surface structure and improve safety and continuous operation economy of a boiler, and comprises a flue, the flue is formed by a water-cooling enclosure wall, an evaporation heating surface is arranged in the flue, and the water-cooling enclosure wall is arranged in the flue. The evaporation heating surface consists of a plurality of groups of heating surface pipes which are arranged at intervals, and is characterized in that connecting plates are arranged between the adjacent heating surface pipes at intervals to connect all the heating surface pipes into a whole, and vertical sections of the heating surface pipes close to the water-cooling enclosure wall are fixedly connected with the water-cooling enclosure wall.

Description

Technical Field

[0001] The utility model belongs to the field of circulating fluidized bed boilers, and in particular relates to an anti-corrosion evaporation heating surface structure. Background Art

[0002] Circulating fluidized bed boilers burning solid waste typically use a higher concentration of chlorine in their fuel than conventional coal, often found in waste plastics, chemical fiber products, and other solid waste. During the combustion of this solid waste, chlorine transforms into a highly corrosive acid mist. This acid mist becomes increasingly corrosive when the metal wall temperature rises above 450°C, significantly damaging the boiler's heating surfaces and hindering its long-term stable operation.

[0003] In order to protect high-wall temperature heating surfaces such as superheaters, it is generally necessary to rapidly cool the flue gas during the design of a solid waste furnace. Therefore, the first-stage convection heating surface through which the high-temperature flue gas passes is often the evaporation heating surface. Since the evaporation heating surface contains a mixture of saturated water and saturated steam, its temperature is generally relatively constant, with a medium temperature of around 300°C. The metal wall temperature of the heating surface tubes is usually also below 400°C, which is not within the corrosion temperature range of acid mist.

[0004] However, the support structure used to secure the evaporating heating surface is typically not properly cooled and cannot reach the same temperature as the heating surface tubes. Its wall temperature is generally above 450°C. While the evaporating heating surface structure is less susceptible to tube corrosion and bursting, corrosion damage to the support structure can lead to damage to the heating surface tubes due to the loss of support.

[0005] The following are two common ways to fix the evaporation heating surface: Figure 1 It is the ventilation beam supporting structure. Figure 2 It is a pipe clamp type support structure. Figure 1 The most susceptible areas of corrosion in the structure are the ventilation beams and the pipe clamps that secure them to the ventilation beams. Figure 2 The most susceptible areas to corrosion are the clamps at the return path of each serpentine tube. Because these locations are farther from the tubes, their cooling effect is poor, resulting in higher wall temperatures and a greater tendency to corrosion. Summary of the Invention

[0006] In order to solve the above technical problems, the utility model provides a corrosion-resistant evaporation heating surface structure, which can effectively avoid the corrosion of the evaporation heating surface structure support parts, and improve the safety and continuous operation economy of the boiler.

[0007] The technical solution is as follows: a corrosion-resistant evaporation heating surface structure, which includes a flue, which is composed of a water-cooled wall, an evaporation heating surface is arranged in the flue, and the evaporation heating surface is composed of multiple groups of heating surface tubes arranged at intervals. It is characterized in that connecting plates are arranged at intervals between adjacent heating surface tubes to connect all the heating surface tubes into a whole, and the vertical section of the heating surface tube close to the water-cooled wall is fixedly connected to the water-cooled wall.

[0008] Its further feature is that a reserved groove is provided on the water-cooling wall, a fixing plate is welded on the vertical section of the heating surface tube, and the fixing plate passes through the reserved groove and is welded to the flat steel on the water-cooling wall.

[0009] After adopting the utility model, the structure used for supporting and fixing is directly welded to the heated surface tube, which can effectively cool and reduce the wall temperature to prevent it from being in the high corrosion temperature range. Compared with the original structure, it is simpler, easier to implement, and reduces material costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the existing evaporation heating surface ventilation beam support structure;

[0011] Figure 2 This is a schematic diagram of the existing evaporation heating surface tube clamp support structure;

[0012] Figure 3 This is a schematic diagram of the ventilation beam support structure of the evaporation heating surface of the utility model;

[0013] Figure 4 This is a schematic diagram of the tube clamp support structure of the evaporating heating surface of the utility model. DETAILED DESCRIPTION

[0014] A corrosion-resistant evaporation heating surface structure includes a flue 1, which is composed of a water-cooled wall. An evaporation heating surface 2 is provided in the flue 1. The evaporation heating surface 2 is composed of multiple groups of heating surface tubes arranged at intervals. Connecting plates 3 are provided between adjacent heating surface tubes to connect all heating surface tubes into a whole. The heating surface tubes are serpentine tubes, including inclined sections and vertical sections, forming a W shape or multiple V shapes. They are divided into two different joints, respectively as follows: Figure 3 and Figure 4 As shown, the vertical section of the heated surface tube close to the water-cooling wall is fixedly connected to the water-cooling wall. The specific connection method is: a reserved groove is provided on the water-cooling wall, and a fixing plate 4 is welded on the vertical section of the heated surface tube. The fixing plate 4 passes through the reserved groove and is welded to the flat steel on the water-cooling wall.

[0015] In this application, the fixing method between the serpentine tubes is optimized to reduce the wall temperature of the fixing device, thereby avoiding high-temperature corrosion. By using connecting plates to fix each serpentine tube, cooling is provided for the fixing device, thereby avoiding the original design of the pipe clamp structure to be at a higher temperature in the high-temperature flue gas. Compared with the pipe clamp form, the structure is simpler, the implementation and operation are convenient, and materials are saved.

Claims

1. A corrosion-resistant evaporative heating surface structure, comprising a flue, the flue being composed of a water-cooled wall, an evaporative heating surface being arranged in the flue, the evaporative heating surface being composed of a plurality of groups of spaced-apart heating surface tubes, characterized in that: Connecting plates are arranged at intervals between adjacent heating surface tubes to connect all the heating surface tubes into a whole, and the vertical sections of the heating surface tubes close to the water-cooling wall are fixedly connected to the water-cooling wall.

2. The anti-corrosion evaporation heating surface structure according to claim 1, characterized in that: The water-cooling wall is provided with a reserved groove, and a fixing plate is welded to the vertical section of the heating surface tube. The fixing plate passes through the reserved groove and is welded to the flat steel on the water-cooling wall.

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