Novel arrangement of flue gas recirculation and method of hanging seal thereof

Abstract

Novel arrangement of flue gas recirculation and its hanging sealing method. The existing flue gas recirculation and water cooled wall need to be sealed separately, and the water cooled wall ash bucket is arranged with an independent sealing structure, which increases the production cost. The composition of the method comprises: the water cooled wall (1), the flue gas recirculation device (2), the flue sealing plate is installed between the bottom water cooled wall ash bucket of the water cooled wall and the flue gas recirculation device, the front and rear flue sealing plates (5) of the flue sealing plate are connected with the front and rear water cooled wall tube screens respectively, the two side flue sealing plates (6) of the flue sealing plate are connected with the side water cooled wall header (8), the flue gas recirculation device is connected with the front water cooled wall header (10) and the rear water cooled wall header (7) through the recirculation flue hanger (3) respectively, the guide device (4) is installed between the bottom of the flue gas recirculation device and the ground, and the water cooled wall sealing box (9) is installed above the side water cooled wall header. The present application is used for the novel arrangement of flue gas recirculation.

Description

Technical fields: This invention relates to the field of power plant boiler technology, specifically to a novel arrangement for flue gas recirculation and its hanging and sealing method. Background technology: In existing power plant boilers, the flue gas recirculation structure is arranged on both sides of the water-cooled wall, requiring a separate sealing device for the water-cooled wall, as well as a separate hanging device to cooperate with it. An independent sealing structure is also required at the ash hopper of the water-cooled wall. Within the effective space inside the furnace, the arrangement of the above sealing structures requires a separate design of the water-cooled wall tubes. The traditional arrangement method greatly increases the production cost. At the same time, due to the arrangement of multiple sealing and hanging structures in a narrow space, the structure is complex, the sealing effect is poor, and it is not conducive to energy conservation and emission reduction. Summary of the Invention: The purpose of this invention is to provide a novel arrangement of flue gas recirculation and its hanging and sealing method. In this method, the interface between the flue gas recirculation and the water-cooled wall is arranged at the bottom of the furnace. The recirculation is suspended by the water-cooled wall tube panel and the header. The sealing is integrated with the sealing of the bottom of the water-cooled furnace. By utilizing the bottom throat, the water-cooled wall tube can be eliminated, which greatly simplifies the hanging and sealing of the flue gas recirculation and also eliminates the need for the water-cooled wall tube.

[0004] The above objectives are achieved through the following technical solutions: A novel arrangement and hanging sealing method for flue gas recirculation are disclosed. The method comprises: a water-cooled wall and a flue gas recirculation device. A flue gas sealing plate is installed between the bottom water-cooled wall ash hopper of the water-cooled wall and the flue gas recirculation device. The front and rear sealing plates of the flue gas sealing plate are respectively connected to the front and rear water-cooled wall tube panels. The sealing plates on both sides of the flue gas sealing plate are connected to the side water-cooled wall headers. The flue gas recirculation device is suspended and connected to the front water-cooled wall header and the rear water-cooled wall header respectively via a recirculation flue. A guide device is installed between the bottom of the flue gas recirculation device and the ground. A water-cooled wall sealing box is installed above the side water-cooled wall header. The novel arrangement of flue gas recirculation and its hanging sealing method include the following steps: First, a flue sealing plate is installed between the flue gas recirculation device and the water-cooled wall ash hopper. The front and rear sealing plates of the flue are fixed to the front and rear water-cooled wall tube panels, and the sealing plates on both sides of the flue are fixed to the side water-cooled wall headers. This can connect the water-cooled wall ash hopper and the flue gas recirculation device, while also providing a sealing function and bearing part of the flue load. A water-cooled wall sealing box is installed above the side water-cooled wall header. Several suspension points are designed below the front and rear water-cooled wall headers. The flue gas recirculation device is suspended through the recirculation flue. The flue gas recirculation device is directly suspended in the rear recirculation flue. The flue gas recirculation device is suspended through the suspension beam in the front recirculation flue. In the end, part of the load before and after the flue is transferred to the front and rear water-cooled wall headers through the recirculation flue suspension, which avoids excessive load at the flue sealing plate and deformation of the water-cooled wall. A guide device is arranged between the bottom of the flue gas recirculation device and the ground. The guide device can make the flue gas recirculation device and the water-cooled wall expansion direction consistent during boiler operation, so as to avoid the water-cooled wall being affected by the unrestrained expansion of the flue.

[0005] Beneficial effects: 1. This invention relates to a novel arrangement of flue gas recirculation and its hanging and sealing method. The method arranges the interface between the flue gas recirculation device and the water-cooled wall at the furnace bottom. Its hanging relies on the water-cooled wall tube panel and water-cooled wall header. Its sealing is integrated with the water-cooled wall furnace bottom seal. Utilizing the furnace bottom throat eliminates the need for water-cooled wall tubes, greatly simplifying the hanging and sealing of flue gas recirculation. Simultaneously, eliminating the need for water-cooled wall tubes significantly reduces production costs and effectively improves boiler efficiency.

[0006] 2. The present invention arranges the flue gas recirculation device at the bottom of the water-cooled wall ash hopper. The flue gas recirculation device is suspended by the water-cooled wall ash hopper, and the flue gas recirculation device is sealed by the water-cooled wall ash hopper. This achieves the dual functions of suspension and sealing by utilizing the system's own structure, saving costs, conserving energy, reducing energy consumption, and reducing pollutant emissions. Attached image description: Appendix Figure 1 This is a schematic diagram of the structure of the present invention.

[0008] The components are: 1. Water-cooled wall, 2. Flue gas recirculation device, 3. Recirculation flue hanging, 4. Guide device, 5. Front and rear sealing plates of flue, 6. Side sealing plates of flue, 7. Rear water-cooled wall header, 8. Side water-cooled wall header, 9. Water-cooled wall sealing box, 10. Front water-cooled wall header. Detailed implementation method: Example 1: A novel arrangement and hanging sealing method for flue gas recirculation are disclosed. The method comprises: a water-cooled wall 1 and a flue gas recirculation device 2. A flue gas sealing plate is installed between the bottom water-cooled wall ash hopper of the water-cooled wall and the flue gas recirculation device. The front and rear sealing plates 5 of the flue gas sealing plate are respectively connected to the front and rear water-cooled wall tube panels. The side sealing plates 6 of the flue gas sealing plate are connected to the side water-cooled wall headers 8. The flue gas recirculation device is connected to the front water-cooled wall headers 10 and the rear water-cooled wall headers 7 respectively through a recirculation flue suspension 3. A guide device 4 is installed between the bottom of the flue gas recirculation device and the ground. A water-cooled wall sealing box 9 is installed above the side water-cooled wall headers. The novel arrangement of flue gas recirculation and its hanging sealing method include the following steps: First, a flue gas sealing plate is installed between the flue gas recirculation device and the water-cooled wall ash hopper. The front and rear sealing plates of the flue gas are fixed to the front and rear water-cooled wall tube panels, and the sealing plates on both sides of the flue gas are fixed to the side water-cooled wall headers. This not only connects the water-cooled wall ash hopper and the flue gas recirculation device, but also provides a sealing function and can bear part of the flue gas load. However, because the load-bearing capacity of the ash hopper water-cooled wall tube panels is relatively weak, the loads on both sides can be transferred to the side water-cooled wall headers, while the front and rear loads need to be transferred to the front and rear water-cooled wall headers through a separately designed hanging device. The structure of the pipe-feeding area near the two side water-cooled walls is complex, and the unsealed areas are sealed by a separately designed water-cooled wall sealing box. A water-cooled wall sealing box is installed above the side water-cooled wall header. Several suspension points are designed below the front and rear water-cooled wall headers. The flue gas recirculation device is suspended through the recirculation flue. The flue gas recirculation device is directly suspended in the rear recirculation flue. The flue gas recirculation device is suspended through the suspension beam in the front recirculation flue. In the end, part of the load before and after the flue is transferred to the front and rear water-cooled wall headers through the recirculation flue suspension, which avoids excessive load at the flue sealing plate and deformation of the water-cooled wall. A guide device is arranged between the bottom of the flue gas recirculation device and the ground. The guide device can make the flue gas recirculation device and the water-cooled wall expansion direction consistent during boiler operation, so as to avoid the water-cooled wall being affected by the unrestrained expansion of the flue. This application arranges the flue gas recirculation device at the bottom of the water-cooled wall ash hopper, relying on the water-cooled wall ash hopper to suspend the flue gas recirculation device and relying on the flue gas recirculation device to seal the water-cooled wall ash hopper, thereby achieving the function of suspending and sealing by utilizing the system's own structure. It is suitable for ashless boilers such as gas-fired boilers and oil-fired boilers.

Claims

1. A hanging and sealing method for a flue gas recirculation device, the method comprising: A water-cooled wall and flue gas recirculation device are characterized in that: a flue sealing plate is installed between the bottom water-cooled wall ash hopper of the water-cooled wall and the flue gas recirculation device; the front and rear sealing plates of the flue sealing plate are respectively connected to the front and rear water-cooled wall tube panels; the sealing plates on both sides of the flue sealing plate are connected to the side water-cooled wall headers; the flue gas recirculation device is connected to the front water-cooled wall headers and the rear water-cooled wall headers respectively via recirculation flue suspension; a guide device is installed between the bottom of the flue gas recirculation device and the ground; and a water-cooled wall sealing box is installed above the side water-cooled wall headers. The method includes the following steps: First, a flue gas sealing plate is installed between the flue gas recirculation device and the water-cooled wall ash hopper. The front and rear sealing plates of the flue gas are fixed to the front and rear water-cooled wall tube panels, while the side sealing plates of the flue gas are fixed to the side water-cooled wall headers. This connects the water-cooled wall ash hopper and the flue gas recirculation device, provides a seal, and can also bear part of the flue gas load. A water-cooled wall sealing box is installed above the side water-cooled wall headers. Several lifting points are designed below the front and rear water-cooled wall headers. The flue gas recirculation device is suspended via the recirculation flue gas. The flue gas recirculation device is directly suspended from the recirculation flue behind the boiler, while the flue gas recirculation device is suspended from the recirculation flue in front of the boiler via a suspension beam. Ultimately, part of the load before and after the flue is transferred to the front and rear water-cooled wall headers through the recirculation flue suspension, avoiding excessive load at the flue sealing plate that could cause deformation of the water-cooled wall. A guide device is arranged between the bottom of the flue gas recirculation device and the ground. The guide device ensures that the expansion direction of the flue gas recirculation device is consistent with that of the water-cooled wall during boiler operation, avoiding the impact of unrestrained expansion of the flue on the water-cooled wall.

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