Air preheater of fluidized bed boiler

Abstract

The utility model relates to the technical field of air preheating equipment, in particular to an air preheater of a fluidized bed boiler, which comprises an upper tube box, a middle tube box and a lower tube box, the upper tube box, the middle tube box and the lower tube box are sequentially connected from top to bottom, one side of the upper tube box is provided with an air outlet, and one side of the lower tube box is provided with an air inlet. The lower tube box is connected with the middle tube box through a first communication cover, the middle tube box is connected with the upper tube box through a second communication cover, a plurality of heat exchange tubes are installed on the inner walls of the upper tube box, the middle tube box and the lower tube box, and horizontal air channels are formed in the upper tube box, the middle tube box and the lower tube box. According to the air preheater of the fluidized bed boiler, the design that the upper tube box, the middle tube box and the lower tube box are sequentially connected from top to bottom is adopted, and the first communicating cover and the second communicating cover are arranged to form the S-shaped air channel, so that the flowing path of air in the preheater is effectively improved, and the heat exchange effect is enhanced. And a plurality of heat exchange tubes are mounted in each tube box, so that a plurality of heat exchange spaces are formed, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of air preheating equipment, and more specifically, to an air preheater for a fluidized bed boiler. Background Technology

[0002] In fluidized bed boiler systems, the air preheater is a crucial component. Its main function is to preheat the incoming air before combustion in the boiler, thereby improving the boiler's thermal efficiency and combustion stability.

[0003] Traditional air preheater designs often employ a single heat exchange chamber and a simple duct structure. While this design can achieve air preheating to some extent, it often suffers from low heat exchange efficiency, high duct resistance, and inconvenient cleaning and maintenance. Especially in fluidized bed boilers, which require efficient and stable operation, traditional air preheater designs struggle to meet higher performance requirements. Therefore, developing an air preheater with higher heat exchange efficiency, lower duct resistance, and easier cleaning and maintenance has become a pressing technical challenge in the field of fluidized bed boiler technology. Utility Model Content

[0004] The purpose of this utility model is to provide an air preheater for a fluidized bed boiler, in order to solve the problems mentioned in the background art. Traditional air preheater designs often use a single heat exchange chamber and a simple air duct structure. Although such designs can achieve the purpose of air preheating to a certain extent, they often have problems such as low heat exchange efficiency, high air duct resistance, and inconvenient cleaning and maintenance.

[0005] To achieve the above objectives, this utility model provides an air preheater for a fluidized bed boiler, comprising an upper tube box, a middle tube box, and a lower tube box, which are connected sequentially. An air outlet is provided on one side of the upper tube box, and an air inlet is provided on one side of the lower tube box. The lower tube box is connected to the middle tube box via a first connecting cover, and the middle tube box is connected to the upper tube box via a second connecting cover. A plurality of heat exchange tubes are installed on the inner walls of each of the upper, middle, and lower tube boxes, and horizontal air ducts are formed inside each of the upper, middle, and lower tube boxes.

[0006] Preferably, the middle tube box is provided with intermediate smoke boxes at both the upper and lower ends, and a cleaning port is provided on one side of the intermediate smoke box.

[0007] Preferably, the top of the upper pipe box is connected to an inlet smoke box, the top of the inlet smoke box is provided with a flue gas inlet, and the bottom of the lower pipe box is provided with a flue gas outlet.

[0008] Preferably, the upper tube box, middle tube box, and lower tube box are each divided into two chambers, forming two heat exchange spaces.

[0009] Preferably, the inlet smoke box, heat exchange tube, and intermediate smoke box are connected from top to bottom to form a flue gas channel.

[0010] Preferably, tube sheets are installed on the inner walls of the upper and lower ends of the upper tube box, middle tube box and lower tube box, and the upper and lower ends of the heat exchange tubes pass through the tube sheets and are fixed vertically.

[0011] Preferably, the upper pipe box, middle pipe box and lower pipe box are all supported by shelves, and brackets are installed on the outer side of the shelves.

[0012] Preferably, the upper pipe box, middle pipe box and lower pipe box are connected by a first connecting cover and a second connecting cover to form an S-shaped air duct.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] In the air preheater of this fluidized bed boiler, the design of connecting the upper tube box, middle tube box and lower tube box in sequence, and setting the first connecting hood and the second connecting hood to form an S-shaped air duct, effectively improves the air flow path in the preheater, thereby enhancing the heat exchange effect.

[0015] Meanwhile, each tube box is equipped with several heat exchange tubes, forming multiple heat exchange spaces and further improving heat exchange efficiency. In addition, the design of intermediate smoke boxes at the top and bottom of the central tube box, as well as the design of the inlet smoke box and flue gas outlet, allows the flue gas to pass smoothly through the preheater, reducing duct resistance.

[0016] The inclusion of a cleaning port facilitates regular cleaning and maintenance of the preheater, ensuring its long-term stable operation. In summary, the air preheater of this invention offers advantages such as higher heat exchange efficiency, lower duct resistance, and ease of cleaning and maintenance. It meets the high-performance requirements of fluidized bed boilers for air preheaters, improving the boiler's thermal efficiency and combustion stability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal structure of the present invention from the front.

[0018] Figure 2 This is a schematic diagram of the internal structure of the side of this utility model;

[0019] Figure 3 This is a top view of the internal structure of this utility model;

[0020] The meanings of the labels in the diagram are as follows:

[0021] 1. Upper tube box; 12. Air outlet; 2. Middle tube box; 3. Lower tube box; 31. Flue gas outlet; 32. Air inlet; 4. Heat exchange tube; 5. First connecting hood; 6. Second connecting hood; 7. Inlet smoke box; 71. Flue gas inlet; 8. Intermediate smoke box; 9. Support; 91. Shelf. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] This utility model provides an air preheater for a fluidized bed boiler, such as... Figures 1-3 As shown, the system includes an upper tube box 1, a middle tube box 2, and a lower tube box 3, which are connected vertically. An air outlet 12 is located on one side of the upper tube box 1, and an air inlet 32 ​​is located on one side of the lower tube box 3. The lower tube box 3 is connected to the middle tube box 2 via a first connecting cover 5, and the middle tube box 2 is connected to the upper tube box 1 via a second connecting cover 6. Several heat exchange tubes 4 are installed on the inner walls of each of the three tube boxes, forming horizontal air ducts. By cleverly connecting the upper tube box 1, middle tube box 2, and lower tube box 3 vertically and using the first and second connecting covers 5 and 6 to tightly connect them, a compact and efficient air duct system is formed. The air outlet 12 on one side of the upper tube box 1 and the air inlet 32 ​​on one side of the lower tube box 3 work together to ensure smooth airflow throughout the entire preheater. Meanwhile, several heat exchange tubes 4 are installed on the inner walls of the upper tube box 1, middle tube box 2, and lower tube box 3. These heat exchange tubes not only increase the contact area between air and flue gas but also greatly improve the heat exchange efficiency. Since horizontal air ducts are formed inside the upper tube box 1, middle tube box 2, and lower tube box 3, the air can more fully exchange heat with the heat exchange tubes 4 during flow, thus achieving uniform preheating of the air. In summary, the air preheater of this invention has the technical advantages of compact structure, high heat exchange efficiency, and uniform air preheating, providing a strong guarantee for the efficient operation of fluidized bed boilers.

[0024] In this embodiment, intermediate smoke boxes 8 are provided at both the upper and lower ends of the central tube box 2, and a cleaning port is provided on one side of the intermediate smoke box 8. The intermediate smoke box 8 helps to distribute the flue gas evenly within the preheater and provides additional heat exchange area, thereby enhancing the heat exchange effect. The cleaning port greatly facilitates the regular maintenance and cleaning of the preheater, ensuring high efficiency and stability during long-term operation.

[0025] Specifically, the top of the upper tube box 1 is connected to an inlet smoke box 7, and the top of the inlet smoke box 7 is equipped with a flue gas inlet 71. The bottom of the lower tube box 3 is equipped with a flue gas outlet 31. The design of the inlet smoke box 7 and the flue gas inlet 71 allows the flue gas to smoothly enter the preheater, while the flue gas outlet 31 at the bottom of the lower tube box 3 ensures that the flue gas can be smoothly discharged after heat exchange. This design not only optimizes the flow path of the flue gas but also reduces the duct resistance and improves the overall performance of the preheater.

[0026] Furthermore, the upper tube box 1, the middle tube box 2, and the lower tube box 3 are each divided into two chambers, forming two heat exchange spaces. This design not only improves heat exchange efficiency but also enhances the structural strength and stability of the preheater. Simultaneously, the two heat exchange spaces can each carry out different heat exchange processes, achieving more flexible heat exchange control.

[0027] Furthermore, the imported smoke box 7, heat exchange tube 4, and intermediate smoke box 8 are connected from top to bottom to form a flue gas channel. This ensures smooth flow of flue gas within the preheater. This design not only optimizes the flow path of the flue gas but also improves heat exchange efficiency, enabling the preheater to utilize the heat in the flue gas more efficiently to preheat the air.

[0028] Furthermore, tube sheets are installed on the inner walls of the upper and lower ends of the upper tube box 1, middle tube box 2, and lower tube box 3, and the upper and lower ends of the heat exchange tubes 4 penetrate the tube sheets and are vertically fixed. The tube sheets provide fixed support for the heat exchange tubes 4, ensuring stable installation of the heat exchange tubes within the preheater. At the same time, the vertical fixing of the upper and lower ends of the heat exchange tubes 4 through the tube sheets enhances the structural strength and stability of the preheater, improving its ability to withstand high temperatures and high pressures.

[0029] Furthermore, the upper tube box 1, middle tube box 2, and lower tube box 3 are all supported by shelves 91, with brackets 9 installed on the outer side of the shelves 91. The shelves 91 and brackets 9 provide stable support for the preheater, ensuring its stability and safety during operation. At the same time, this design facilitates the installation and disassembly of the preheater, providing convenience for subsequent maintenance and replacement.

[0030] Furthermore, the upper tube box 1, middle tube box 2, and lower tube box 3 are connected by a first connecting cover 5 and a second connecting cover 6 to form an S-shaped air duct. This not only extends the airflow path but also increases the contact area and time between the air and the heat exchange tubes 4, thereby improving heat exchange efficiency. At the same time, the S-shaped air duct design also helps to reduce airflow resistance, allowing air to flow more smoothly through the preheater.

[0031] In operation, the air preheater of this fluidized bed boiler first introduces flue gas into the preheater through the flue gas inlet 71 at the top of the inlet smoke box 7. Subsequently, the flue gas flows smoothly along the flue gas channel formed by the inlet smoke box 7, heat exchange tubes 4, and intermediate smoke box 8 connected from top to bottom. This design not only optimizes the flow path of the flue gas but also ensures that the flue gas is evenly distributed throughout the preheater, thereby improving heat exchange efficiency.

[0032] Simultaneously, air enters the preheater through the air inlet 32 ​​on one side of the lower tube box 3. Air begins to flow within the horizontal air duct formed inside the upper tube box 1, middle tube box 2, and lower tube box 3. Since several heat exchange tubes 4 are installed on the inner walls of the upper tube box 1, middle tube box 2, and lower tube box 3, these heat exchange tubes increase the contact area between the air and the flue gas, allowing the air to exchange heat more fully with the heat exchange tubes 4 during its flow.

[0033] Furthermore, the upper tube box 1, the middle tube box 2, and the lower tube box 3 are connected by a first connecting cover 5 and a second connecting cover 6, forming an S-shaped air duct. This design not only extends the airflow path but also further increases the contact area and time between the air and the heat exchange tubes 4, thereby improving heat exchange efficiency. At the same time, the S-shaped air duct design also helps to reduce air duct resistance, allowing air to flow more smoothly through the preheater.

[0034] During the heat exchange process, the heat in the flue gas is transferred to the air through the heat exchange tubes 4, thus preheating the air. The preheated air is discharged from the preheater through the air outlet 12 on one side of the upper tube box 1, and then enters the fluidized bed boiler for combustion. The flue gas that has completed the heat exchange is discharged from the preheater through the flue gas outlet 31 at the bottom of the lower tube box 3.

[0035] Furthermore, the intermediate smoke boxes 8 located at both ends of the central tube box 2 not only facilitate the uniform distribution of flue gas within the preheater but also provide additional heat exchange area, further enhancing the heat exchange effect. Simultaneously, the cleaning port on one side of the intermediate smoke box 8 greatly facilitates regular maintenance and cleaning of the preheater, ensuring high efficiency and stability during long-term operation.

[0036] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An air preheater for a fluidized bed boiler, comprising an upper tube box (1), a middle tube box (2), and a lower tube box (3), characterized in that: The upper tube box (1), middle tube box (2) and lower tube box (3) are connected vertically. An air outlet (12) is provided on one side of the upper tube box (1), and an air inlet (32) is provided on one side of the lower tube box (3). The lower tube box (3) and the middle tube box (2) are connected by a first connecting cover (5), and the middle tube box (2) and the upper tube box (1) are connected by a second connecting cover (6). Several heat exchange tubes (4) are installed on the inner walls of the upper tube box (1), the middle tube box (2) and the lower tube box (3). Horizontal air ducts are formed inside the upper tube box (1), the middle tube box (2) and the lower tube box (3).

2. The air preheater for a fluidized bed boiler according to claim 1, characterized in that: The middle tube box (2) is provided with intermediate smoke boxes (8) at both the upper and lower ends, and a cleaning port is provided on one side of the intermediate smoke box (8).

3. The air preheater for a fluidized bed boiler according to claim 2, characterized in that: The top of the upper pipe box (1) is connected to the inlet smoke box (7), the top of the inlet smoke box (7) is provided with a flue gas inlet (71), and the bottom of the lower pipe box (3) is provided with a flue gas outlet (31).

4. The air preheater for a fluidized bed boiler according to claim 1, characterized in that: The upper tube box (1), middle tube box (2) and lower tube box (3) are each divided into two chambers, forming two heat exchange spaces.

5. The air preheater for a fluidized bed boiler according to claim 3, characterized in that: The inlet smoke box (7), heat exchange tube (4), and intermediate smoke box (8) are connected from top to bottom to form a flue gas channel.

6. The air preheater for a fluidized bed boiler according to claim 1, characterized in that: The upper and lower ends of the upper tube box (1), middle tube box (2) and lower tube box (3) are all equipped with tube sheets, and the upper and lower ends of the heat exchange tube (4) pass through the tube sheet and are fixed vertically.

7. The air preheater for a fluidized bed boiler according to claim 1, characterized in that: The upper pipe box (1), the middle pipe box (2) and the lower pipe box (3) are all supported by a shelf (91), and a bracket (9) is installed on the outside of the shelf (91).

8. The air preheater for a fluidized bed boiler according to claim 1, characterized in that: The upper tube box (1), the middle tube box (2) and the lower tube box (3) are connected by a first connecting cover (5) and a second connecting cover (6) to form an S-shaped air duct.

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