Material recirculation regulating device for a circulating fluidized bed boiler

Abstract

The utility model provides a kind of material back sending adjusting device for circulating fluidized bed boiler, it is related to circulating fluidized bed boiler technical field, and it includes: cyclone separator, the cyclone separator lower end is connected with back material riser by unloading valve, first air supply pipe is connected with the back material riser feed falling section pipe face, the left pipe face of the back material riser bottom section is connected with second air supply pipe, the lower pipe face of the back material riser ascending section is connected with third air supply pipe, the left pipe face of the back material riser discharge section is connected with fourth air supply pipe, and first air supply pipe, second air supply pipe, third air supply pipe and fourth air supply pipe are connected with feeding fan by five-way pipe joint, and the pipe face of first air supply pipe, second air supply pipe, third air supply pipe and fourth air supply pipe is all equipped with control valve. The utility model solves the problem that the regulation accuracy of back material ash quantity is low by single valve and air pipe in prior art, and the material back sending efficiency is not good.

Description

Technical Field

[0001] This utility model relates to the field of circulating fluidized bed boiler technology, and specifically to a material return and adjustment device for a circulating fluidized bed boiler. Background Technology

[0002] The circulating fluidized bed boiler uses the most advanced clean coal combustion technology in industrial applications. Circulating fluidized bed boilers employ fluidized bed combustion. Their main structure comprises two parts: a combustion chamber (including dense and dilute phase zones) and a circulating return system (including a high-temperature gas-solid separator and a return material system). In the circulating return section, the high-temperature solid material captured by the boiler separator needs to be returned to the bottom of the furnace to maintain a stable material concentration and temperature field. A search revealed an existing technology (publication number: CN202222504178.2) for a separator used in circulating fluidized bed boilers. The paper describes that "this invention connects a hot air disturbance interface installed at the lower part of the separator cone to the primary air hot air duct. The disturbance airflow is controlled by a valve to regulate the total ash amount and particle size of the circulating ash captured by the fluidized bed boiler separator entering the return material system. This facilitates control of the return ash amount when the fuel ash content is high and the separation efficiency is fixed, resulting in more stable boiler operation and reducing the likelihood of blockage in the return material system due to excessive circulating ash." However, the existing technology suffers from low precision in adjusting the return ash amount through a single valve and duct, leading to poor material return efficiency. Utility Model Content

[0003] To overcome the shortcomings of existing technologies, a material return regulating device for circulating fluidized bed boilers is provided to solve the problem that the adjustment accuracy of the ash amount of the returned material is low due to the use of a single valve and air duct in existing technologies, which affects the material return efficiency.

[0004] To achieve the above objectives, a material return and regulation device for a circulating fluidized bed boiler is provided, comprising: a cyclone separator, wherein the cyclone separator is connected to a boiler flue gas duct via an air inlet. The lower end of the cyclone separator is connected to a return riser via a discharge valve. The feed and falling section of the return riser is connected to a first air supply pipe. The left side of the bottom section of the return riser is connected to a second air supply pipe. The lower side of the rising section of the return riser is connected to a third air supply pipe. The left side of the discharge section of the return riser is connected to a fourth air supply pipe. The first, second, third, and fourth air supply pipes are connected to a feeding fan via a five-way pipe joint. Control valves are installed on the surfaces of the first, second, third, and fourth air supply pipes.

[0005] Furthermore, a discharge valve is installed at the lower end of the cone section of the cyclone separator, and the discharge port of the discharge valve is connected to the feed drop section of the return riser.

[0006] Furthermore, an air inlet is provided on the cross-section of the left side of the cyclone separator, and an air outlet is provided on the upper end face of the cyclone separator.

[0007] Furthermore, a material level sensor is embedded in the cone of the cyclone separator, and a return controller is provided on the side of the lower support of the cyclone separator.

[0008] Furthermore, three sets of pressure sensors are embedded in the surface of the return riser, and the return riser is connected to the furnace of the circulating fluidized bed boiler through the outlet section.

[0009] Furthermore, air supply outlets are provided on the walls of the feed drop section, bottom section, rising section and discharge section of the return material riser.

[0010] Furthermore, the wall of the feed drop section of the return material riser is connected to the first air supply pipe through the air supply mesh and the air guide cavity.

[0011] The beneficial effects of this utility model are as follows: The material return regulating device for circulating fluidized bed boilers utilizes a feeding fan, a first air supply pipe, a second air supply pipe, a third air supply pipe, a fourth air supply pipe, and a control valve to form a segmented air supply mechanism. By changing the proportion of air volume delivered by the four sets of air supply pipes to the feed drop section, bottom section, rising section, and discharge section of the return material riser, the multi-segment air force can coordinately regulate the material return flow rate, facilitating more efficient regulation of the material return volume, enhancing the flexibility of material return in circulating fluidized bed boilers, avoiding easy blockage and backflow during material return, fully utilizing the fan power, optimizing energy consumption, and improving the return efficiency of the material return regulating device. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the material return and regulating device for a circulating fluidized bed boiler according to an embodiment of the present invention.

[0013] Figure 2 This is a schematic diagram of the material return and adjustment device for a circulating fluidized bed boiler according to an embodiment of the present invention.

[0014] Figure 3 This is a schematic diagram of the fan adjustment mechanism according to an embodiment of the present invention.

[0015] Figure 4 This is a partial cross-sectional structural diagram of the return riser according to an embodiment of the present utility model.

[0016] In the diagram: 1. Cyclone separator; 11. Air inlet; 12. Air outlet; 13. Material level sensor; 2. Boiler flue gas duct; 3. Unloading valve; 4. Return riser; 41. Pressure sensor; 42. Air guide chamber; 43. Air supply network outlet; 5. Return controller; 6. Feeding fan; 61. First air supply pipe; 62. Second air supply pipe; 63. Third air supply pipe; 64. Fourth air supply pipe; 65. Control valve; 66. Five-way pipe joint. Detailed Implementation

[0017] Reference Figures 1 to 4 As shown, this utility model provides a material return and regulating device for a circulating fluidized bed boiler, including: a cyclone separator 1, which is connected to a boiler flue gas duct 2 through an air inlet 11. The lower end of the cyclone separator 1 is connected to a return riser 4 via a discharge valve 3. The feed section of the return riser 4 is connected to a first air supply pipe 61. The bottom left side of the return riser 4 is connected to a second air supply pipe 62. The rising section of the return riser 4 is connected to a third air supply pipe 63. The discharge section of the return riser 4 is connected to a fourth air supply pipe 64. The first air supply pipe 61, the second air supply pipe 62, the third air supply pipe 63, and the fourth air supply pipe 64 are connected to a feeding fan 6 via a five-way pipe joint 66. Control valves 65 are installed on the pipe surfaces of the first air supply pipe 61, the second air supply pipe 62, the third air supply pipe 63, and the fourth air supply pipe 64.

[0018] First, when the flue gas from the circulating fluidized bed boiler is delivered to the cyclone separator 1, it undergoes centrifugal motion within the separator, causing solid materials in the flue gas to fall to the cone section of the cyclone separator 1. The discharge valve 3 discharges the solid materials to the return riser 4. The feed fan 6 is pre-started, and the air volume of each set of air supply pipes is adjusted by the control valve 65. When the solid materials are at the feed falling section, the first air supply pipe 61 assists in feeding the solid materials in this section, allowing them to flow to the bottom section. Then, the second air supply pipe 62 transports the solid materials to the right to the lower end of the rising section. After that, the third air supply pipe 63 blows the solid materials upward, causing them to turn and move upward. Finally, the solid materials flow to the outlet of the fourth air supply pipe 64, guiding them into the furnace of the circulating fluidized bed boiler.

[0019] In this embodiment, a discharge valve 3 is installed at the lower end of the cone of the cyclone separator 1, and the discharge port of the discharge valve 3 is connected to the feed drop section of the return riser 4. An air inlet 11 is provided at the cross-section of the left side of the cylinder of the cyclone separator 1, and an air outlet 12 is provided on the upper end face of the cyclone separator 1. A material level sensor 13 is embedded in the cone of the cyclone separator 1, and a return controller 5 is provided on the side of the lower support of the cyclone separator 1.

[0020] In a preferred embodiment, the discharge valve 3 facilitates the discharge of solid material accumulated in the cone section of the cyclone separator 1 into the return riser 4. Flue gas enters the inner side of the cyclone separator 1 tangentially through the inlet 11 and undergoes centrifugal motion, separating the solid material from the flue gas. The separated flue gas is discharged from the outlet 12, while the solid material accumulates at the cone section of the cyclone separator 1. The level sensor 13 detects the level of solid material in the cone section of the cyclone separator 1. The return controller 5 controls the electrical equipment involved in the material return adjustment process and receives and processes signals transmitted by the sensors.

[0021] In this embodiment, three sets of pressure sensors 41 are embedded in the surface of the return riser 4. The return riser 4 is connected to the furnace of the circulating fluidized bed boiler through the outlet section. Air supply ports 43 are correspondingly provided on the walls of the feed drop section, bottom section, rising section, and outlet section of the return riser 4. The wall of the feed drop section of the return riser 4 is connected to the first air supply pipe 61 through the air supply ports 43 and the air guide cavity 42.

[0022] In a preferred embodiment, pressure sensor 41 monitors the pressure values ​​of each section of the return riser 4 to reflect the flow of solid material within the return riser 4. Multiple air vents at the feed drop section, bottom section, rising section, and discharge section of the return riser 4 are used to discharge air from the air supply pipe, thereby conveying the solid material in the segmented pipes, providing the required airflow to each pipe segment, and promoting the return of solid material to the circulating fluidized bed boiler.

[0023] This utility model provides a material return regulating device for circulating fluidized bed boilers. It effectively solves the problem in the prior art where the adjustment accuracy of the ash amount of returned material is low due to the use of a single valve and air duct, which affects the material return efficiency. It facilitates more efficient adjustment of the material return amount, enhances the flexibility of material return in circulating fluidized bed boilers, avoids easy blockage and backflow during material return, makes full use of the fan power, optimizes energy consumption, and improves the return efficiency of the material return regulating device. It is suitable for material return regulating devices in circulating fluidized bed boilers.

Claims

1. A material return regulating device for a circulating fluidized bed boiler, comprising: Cyclone separator (1), wherein the cyclone separator (1) is connected to a boiler flue gas duct (2) through an air inlet (11), characterized in that: The cyclone separator (1) is connected to a return pipe (4) at its lower end via a discharge valve (3). The return pipe (4) is connected to a first air supply pipe (61) on the feed and falling section. The return pipe (4) is connected to a second air supply pipe (62) on the left side of the bottom section. The return pipe (4) is connected to a third air supply pipe (63) on the lower side of the rising section. The return pipe (4) is connected to a fourth air supply pipe (64) on the left side of the discharge section. The first air supply pipe (61), the second air supply pipe (62), the third air supply pipe (63), and the fourth air supply pipe (64) are connected to a feeding fan (6) via a five-way pipe joint (66). Control valves (65) are installed on the pipe surfaces of the first air supply pipe (61), the second air supply pipe (62), the third air supply pipe (63), and the fourth air supply pipe (64).

2. The material return and regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that, The cyclone separator (1) has a discharge valve (3) installed at the lower end of the cone section. The discharge port of the discharge valve (3) is connected to the feed drop section of the return riser (4).

3. The material return and regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that, The cyclone separator (1) has an air inlet (11) on the left side of the cylinder cross-section and an air outlet (12) on the upper end face of the cyclone separator (1).

4. A material return and regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that, A material level sensor (13) is embedded in the cone of the cyclone separator (1), and a return controller (5) is provided on the side of the lower support of the cyclone separator (1).

5. A material return and regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that, The return riser (4) is equipped with three sets of pressure sensors (41) embedded in its surface. The return riser (4) is connected to the furnace of the circulating fluidized bed boiler through the outlet section.

6. A material return regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that, The return riser (4) is equipped with air supply outlets (43) at the pipe walls of the feeding and falling section, bottom section, rising section and discharge section.

7. A material return and regulating device for a circulating fluidized bed boiler according to claim 1, characterized in that, The feed drop section of the return riser (4) is connected to the first air supply pipe (61) through the air supply mesh (43) and the air guide cavity (42).

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