A coarse powder separator and boiler system for flexible operation of coal-fired power plants

Abstract

The application provides a coarse powder separator and a boiler system for flexible operation of a coal-fired power plant. The coarse powder separator comprises a shell cylinder, a powder inlet pipe, a cyclone component, a moving vane, a powder outlet pipe and a powder return pipe. The shell cylinder comprises a first end, a main body and a second end distributed along an axial direction of the shell cylinder. The main body has a separation cavity comprising adjacent first and second separation regions. The first separation region is close to the first end, and the second separation region is close to the second end. The powder inlet pipe is arranged at the first end and communicates with the separation cavity. The cyclone component is arranged in the powder inlet pipe. The moving vane is arranged in the second separation region and comprises first blades and a first inner cavity formed by the first blades. The first inner cavity communicates with the separation cavity through the first blades. The powder outlet pipe is arranged at the second end and communicates with the first inner cavity. The powder return pipe is arranged at the first end, communicates with the separation cavity and is independent of the powder inlet pipe. According to the embodiment, the separation effect of the pulverized coal can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of thermal power generation technology, and in particular to a coarse powder separator and boiler system for flexible operation of coal-fired power plants. Background Technology

[0002] The pulverizing system is an important auxiliary system in thermal power plants, and its operation directly affects the safe and economical operation of the boiler. The function of the coarse powder separator is to separate out unqualified coal particles and send them back to the coal mill for further grinding, thereby ensuring the fineness of the coal burned in the boiler.

[0003] Currently, coarse powder separators are mainly classified into radial baffle type, axial baffle type, and dynamically adjustable type based on their separation principle. However, all three types of coarse powder separators have significant drawbacks. For example, radial baffle type coarse powder separators have few separation stages and poor efficiency; the built-in return airlock is prone to detachment and jamming; the separator has high resistance and insufficient pulverizing output; axial baffle type coarse powder separators have insufficient coal powder fineness; the coal powder uniformity from impact separation is poor; and they are not suitable for wide loads and wide coal types; dynamically adjustable type coarse powder separators have low separation efficiency and the rotor is prone to shaking. Therefore, there is an urgent need to improve coarse powder separators. Summary of the Invention

[0004] In view of the above problems, this application provides a coarse coal separator and boiler system for flexible operation of coal-fired power plants, which can effectively improve the separation effect of pulverized coal.

[0005] In a first aspect, embodiments of this application provide a coarse powder separator for flexible operation in a coal-fired power plant. The coarse powder separator includes an outer shell, an inlet pipe, a swirling component, a moving impeller, an outlet pipe, and a return pipe. The outer shell includes a first end, a main body, and a second end distributed axially. The main body has a separation chamber, which includes adjacent first and second separation regions. The first separation region is closer to the first end, and the second separation region is closer to the second end. The inlet pipe is located at the first end and communicates with the separation chamber. The swirling component is located inside the inlet pipe. The moving impeller is located in the second separation region and includes a first blade and a first inner cavity formed by the first blade. The first inner cavity communicates with the separation chamber through the first blade. The outlet pipe is located at the second end and communicates with the first inner cavity. The return pipe is located at the first end, communicates with the separation chamber, and is independent of the inlet pipe.

[0006] In some embodiments of the first aspect, the coarse powder separator further includes a circulation component located in the first separation zone. The circulation component includes a recovery cylinder and a spiral pipe. One end of the recovery cylinder along its own axial direction is provided with an opening toward the second separation zone, and the other end is connected to the inlet of the spiral pipe. The outlet of the spiral pipe is located in the first separation zone.

[0007] In some embodiments of the first aspect, the coarse powder separator further includes a baffle plate corresponding to the spiral pipe, the baffle plate being connected to the inner wall of the outer casing and located on the side of the spiral pipe outlet near the second separation zone.

[0008] In some embodiments of the first aspect, the number of spiral pipes is at least two, and the at least two spiral pipes are distributed circumferentially at intervals along the outer shell.

[0009] In some embodiments of the first aspect, the internal diameter of the recovery cylinder tends to increase along the direction from the first end to the second end.

[0010] In some embodiments of the first aspect, the coarse powder separator further includes a stationary impeller disposed in the second separation region. The stationary impeller includes a second blade and a second inner cavity formed by the second blade. A moving impeller is located in the second inner cavity. The second inner cavity is connected to the separation cavity through the second blade, and the second inner cavity is connected to the first inner cavity through the first blade.

[0011] In some embodiments of the first aspect, the swirling component includes swirling guide vanes, the angle between the swirling guide vanes and the axis of the powder inlet pipe being adjustable.

[0012] In some embodiments of the first aspect, the swirling component and the powder inlet pipe are integrally formed.

[0013] In some embodiments of the first aspect, the impeller further includes a connecting shaft and a reinforcing member, the connecting shaft being fixedly connected to the first blade and rotatably connected to the outer casing, and the reinforcing member being connected between the connecting shaft and the first blade.

[0014] Secondly, embodiments of this application provide a boiler system, which includes the coarse powder separator provided in any embodiment of the first aspect.

[0015] The coarse powder separator and boiler system provided in this application include a coarse powder separator comprising an outer shell, an inlet pipe, a swirling component, a moving impeller, an outlet pipe, and a return pipe. The outer shell includes a first end, a main body, and a second end distributed axially. The main body has a separation chamber, which includes adjacent first and second separation regions. The first separation region is located near the first end, and the second separation region is located near the second end. The inlet pipe is located at the first end and communicates with the separation chamber. The swirling component is located inside the inlet pipe. The moving impeller is located in the second separation region and includes first blades and a first inner cavity formed by the first blades. The first inner cavity communicates with the separation chamber through the first blades. The outlet pipe is located at the second end and communicates with the first inner cavity. The return pipe is located at the first end, communicates with the separation chamber, and is independent of the inlet pipe. By installing a swirling component inside the powder inlet pipe, the air-powder mixture entering from the inlet pipe undergoes primary separation via centrifugal motion in the first separation zone. Under high-speed centrifugal motion, the air-powder mixture efficiently separates larger (non-fine) coal particles, significantly improving the separation efficiency of the primary separation and reducing the circulation rate, allowing more coal powder to enter the second separation zone for secondary separation. By installing a moving impeller in the second separation zone, the air-powder mixture after primary separation undergoes secondary separation, further separating larger (non-fine) coal particles from the air-powder mixture after primary separation. This further improves the fineness of the coal powder in the air-powder mixture and enhances the separation effect. Thus, the overall separation effect of the coarse powder separator is effectively improved.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0018] Figure 1 This is a schematic diagram illustrating the connection relationship between a coarse powder separator, a coal mill, a coal feeder, an induced draft fan, and a boiler, provided in some embodiments of this application.

[0019] Figure 2 This is a schematic diagram of the structure of a coarse powder separator provided in some embodiments of this application;

[0020] Figure 3 for Figure 2 A schematic diagram showing the flow direction of the air-powder mixture in the coarse powder separator;

[0021] Figure 4 This is a schematic diagram of the structure of another coarse powder separator provided in some embodiments of this application;

[0022] Figure 5 for Figure 4 A schematic diagram showing the flow direction of the air-powder mixture gas flow during a single cycle of separation in the coarse powder separator.

[0023] Figure 6 for Figure 4 A schematic diagram showing the flow direction of the secondary circulation separation of the air-powder mixture in the coarse powder separator;

[0024] Figure 7 This is a schematic diagram of the structure of yet another coarse powder separator provided in some embodiments of this application;

[0025] Figure 8 for Figure 7 A schematic diagram showing the flow direction of the air-powder mixture in the coarse powder separator;

[0026] Figure 9 This is a schematic diagram of the structure of another coarse powder separator provided in some embodiments of this application;

[0027] Figure 10 for Figure 9 A schematic diagram showing the flow direction of the air-powder mixture gas flow during a single cycle of separation in the coarse powder separator.

[0028] Figure 11 for Figure 9 The diagram shows the flow direction of the secondary circulation separation of the air-powder mixture in the coarse powder separator.

[0029] The reference numerals in the detailed embodiments are as follows:

[0030] 100. Coarse powder separator; 200. Coal mill; 300. Coal feeder; 400. Exhaust fan; 500. Boiler;

[0031] 10. Outer shell; 11. First end; 12. Main body; 121. Separation chamber; 121a. First separation area; 121b. Second separation area; 13. Second end; 20. Powder inlet pipe; 30. Swirl component; 31. Swirl guide vane; 40. Moving impeller; 41. First blade; 42. First inner cavity; 43. Connecting shaft; 44. Reinforcing component; 50. Powder outlet pipe; 60. Powder return pipe; 70. Circulation component; 71. Recovery cylinder; 72. Spiral pipe; 80. Baffle; 90. Stationary impeller; 91. Second blade; 92. Second inner cavity. Detailed Implementation

[0032] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0033] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0034] In the description of the embodiments in this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", and "bottom" are used.

[0035] The orientations or positional relationships indicated by terms such as "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the purpose of facilitating the description of the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0036] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0038] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0039] The pulverizing system is an important auxiliary system in thermal power plants, and its operation directly affects the safe and economical operation of the boiler. The function of the coarse powder separator is to separate out unqualified coal particles and send them back to the coal mill for further grinding, thereby ensuring the fineness of the coal burned in the boiler.

[0040] Currently, coarse powder separators are mainly classified into radial baffle type, axial baffle type, and dynamically adjustable type based on their separation principle. However, all three types of coarse powder separators have significant drawbacks. For example, radial baffle type coarse powder separators have fewer separation stages and poorer performance; the built-in return airlock is prone to detachment and jamming; the separator has high resistance and insufficient pulverizing output. Axial baffle type coarse powder separators have insufficient coal powder fineness, poor uniformity of coal powder separated by impact, and are not suitable for wide loads and wide coal types. Dynamically adjustable type coarse powder separators have low separation efficiency and the rotor is prone to shaking.

[0041] To address the aforementioned problems in the prior art, this application provides a coarse pulverizer separator and boiler system for flexible operation of coal-fired power plants, which can effectively improve the separation efficiency of pulverized coal. The coarse pulverizer provided in this application is described below.

[0042] Figure 1 This is a schematic diagram illustrating the connection relationship between a coarse powder separator, a coal mill, a coal feeder, an induced draft fan, and a boiler, provided in some embodiments of this application. Figure 2 This is a schematic diagram of the structure of a coarse powder separator provided in some embodiments of this application. Figure 3 for Figure 2 The diagram shows the flow direction of the air-powder mixture in the coarse powder separator.

[0043] like Figure 1 and Figure 3As shown in the figure, this application provides a coarse powder separator 100. The coarse powder separator 100 includes an outer shell cylinder 10, a powder inlet pipe 20, a swirling component 30, a moving impeller 40, a powder outlet pipe 50, and a powder return pipe 60. The outer shell cylinder 10 includes a first end 11, a main body 12, and a second end 13 distributed along its own axial direction. The main body 12 has a separation chamber 121, which includes an adjacent first separation region 121a and a second separation region 121b. The first separation region 121a is close to the first end 11, and the second separation region 121b is close to the second end 13. The powder inlet pipe 20 is disposed at the first end 11 and communicates with the separation chamber 121. The swirling component 30 is disposed inside the powder inlet pipe 20. The moving impeller 40 is disposed in the second separation region 121b. The moving impeller 40 includes a first blade 41 and a first inner cavity 42 formed by the first blade 41. The first inner cavity 42 communicates with the separation chamber 121 through the first blade 41. The powder outlet pipe 50 is located at the second end 13 and communicates with the first inner cavity 42. The powder return pipe 60 is located at the first end 11, communicates with the separation cavity 121, and is independent of the powder inlet pipe 20.

[0044] In this embodiment, the coarse powder separator 100 separates coal powder particles that are not fine enough and sends them back to the coal mill 200 for re-grinding, thereby ensuring the fineness of the coal burned in the boiler 500. Coal powder particles that are fine enough are output to the boiler 500 for combustion.

[0045] The inlet pipe 20 of the coarse powder separator 100 is connected to the coal mill 200. One end of the coal mill 200 is connected to the induced draft fan 400 and the coal feeder 300. The coal feeder 300 conveys raw coal into the coal mill 200, and the coal mill 200 grinds the raw coal into coal powder. The induced draft fan 400 introduces air into the coal mill 200, which then forms an air-powder mixture airflow with the ground coal powder in the coal mill 200. The air-powder mixture airflow passes through the inlet pipe 20 of the coarse powder separator 100 for coarse powder separation. After separation, qualified coal powder is output to the boiler 500 for combustion through the outlet pipe 50, and unqualified coal powder is recycled back to the coal mill 200 for re-grinding through the return pipe 60.

[0046] The main body 12 of the coarse powder separator 100 is the part that separates coal powder. The main body 12 has a separation chamber 121. The first separation area 121a of the separation chamber 121 is used for primary separation of coal powder, and the second separation area 121b of the separation chamber 121 is used for secondary separation of coal powder.

[0047] For example, the air-powder mixture airflow in the coal mill 200 enters the first separation zone 121a of the separation chamber 121 through the powder inlet pipe 20. Since the powder inlet pipe 20 is equipped with a swirl component 30, the air-powder mixture airflow undergoes centrifugal motion in the first separation zone 121a under the action of the swirl component 30. The coal powder with larger particles (unqualified fineness) in the air-powder mixture will fall into the return powder pipe 60 under the action of centrifugal force and gravity, and then be recycled back to the coal mill 200 for re-grinding.

[0048] The smaller (fineness qualified) coal particles in the air-coal mixture enter the second separation zone 121b with the airflow for secondary separation. The second separation zone 121b is equipped with a moving impeller 40, which includes a first blade 41 and a first inner cavity 42 formed by the first blade 41. The first inner cavity 42 is connected to the separation chamber 121 through the first blade 41. The rotation of the moving impeller 40 creates a rotational separation zone at the position of the first blade 41. In this zone, the coal particles are subjected to centrifugal force from the moving impeller 40 and are also subjected to the traction force of the airflow. When the centrifugal force on the coal particles is greater than the traction force, the coal particles are separated to the outside of the first blade 41; when the centrifugal force is less than the traction force, the coal particles are separated to the inside of the first blade 41, i.e., into the first inner cavity 42. Understandably, the larger the coal powder particles, the greater the centrifugal force exerted by the impeller 40 in the rotating separation zone. Therefore, larger coal powder particles (those with unacceptable fineness) in the air-coal mixture will be passively separated by the impeller 40 to the outside of the first blade 41. Coal powder with unacceptable fineness will fall into the return pipe 60 under the influence of gravity and be recycled to the coal mill 200 for regrinding. Meanwhile, smaller coal powder particles (those with acceptable fineness) in the air-coal mixture will be passively separated by the impeller 40 into the first inner cavity 42. Finally, coal powder with acceptable fineness will be output through the outlet pipe 50 to the outside of the coarse powder separator 100 and enter the boiler for combustion.

[0049] Optionally, the connection between the powder inlet pipe 20, the powder outlet pipe 50, and the powder return pipe 60 and the outer shell cylinder 10 can be welding, bolting, or snap-fitting. This application does not limit the specific connection method between the powder inlet pipe 20, the powder outlet pipe 50, and the powder return pipe 60 and the outer shell cylinder 10, and can be selected according to the actual situation.

[0050] Optionally, the powder inlet pipe 20 and the outer shell 10 can be integrally formed. The outer shell 10 is integrally formed with the powder inlet pipe 20 through stamping or casting, making the powder inlet pipe 20 and the outer shell 10 a single unit. On the one hand, this eliminates the need for additional connecting processes to connect the powder inlet pipe 20 and the outer shell 10, simplifying the manufacturing process of the powder inlet pipe 20. At the same time, compared to connecting the powder inlet pipe 20 and the outer shell 10 through additional connecting processes, the integral structure of the powder inlet pipe 20 and the outer shell 10 provides a higher connection strength, thereby further improving the overall structural strength of the coarse powder separator 100. It should be noted that the powder outlet pipe 50 and the outer shell 10 can also be integrally formed, and the powder return pipe 60 and the outer shell 10 can also be integrally formed; these will not be elaborated further here.

[0051] In the above technical solution, by setting a swirling component 30 inside the powder inlet pipe 20, the swirling component 30 enables the air-powder mixture airflow entering from the powder inlet pipe 20 to undergo primary separation in the first separation zone 121a through centrifugal motion. Under high-speed centrifugal motion, the air-powder mixture airflow can efficiently separate out larger (unqualified) coal powder particles, greatly improving the separation efficiency of the primary separation, reducing the circulation ratio of the primary separation, and allowing more coal powder to enter the second separation zone 121b for secondary separation. By setting a moving impeller 40 in the second separation zone 121b, the air-powder mixture airflow after primary separation undergoes secondary separation in the second separation zone 121b, further separating out larger (unqualified) coal powder particles in the air-powder mixture airflow after primary separation, which can further improve the fineness of the coal powder in the air-powder mixture airflow and further improve the separation effect. In this way, the overall separation effect of the coarse powder separator 100 can be effectively improved.

[0052] Figure 4 This is a schematic diagram of the structure of another coarse powder separator 100 provided in some embodiments of this application. Figure 5 for Figure 4 The diagram shows the flow direction of the air-powder mixture gas flow in a single cycle of separation in the coarse powder separator 100. Figure 6 for Figure 4 The diagram shows the flow direction of the air-powder mixture gas flow in the coarse powder separator 100 during secondary circulation separation.

[0053] Continue to refer to Figures 4 to 6 In some embodiments, the coarse powder separator 100 further includes a circulation component 70 located in the first separation region 121a. The circulation component 70 includes a recovery cylinder 71 and a spiral pipe 72. One end of the recovery cylinder 71 along its own axial direction is provided with an opening facing the second separation region 121b, and the other end is connected to the inlet of the spiral pipe 72. The outlet of the spiral pipe 72 is located in the first separation region 121a.

[0054] It is understandable that the coal powder entering from the coal inlet pipe 20, after passing through the secondary separation and before being output from the coal outlet pipe 50, is likely to contain some smaller (fineness qualified) coal powder particles. If these smaller (fineness qualified) coal powder particles directly enter the coal mill 200 through the return pipe 60 for re-grinding, it will inevitably waste energy.

[0055] The circulation component 70 is used to collect the coal powder that has passed through the secondary separation of the air-coal mixture airflow input from the coal inlet pipe 20 and has not been output from the coal outlet pipe 50, and to transport it to the first separation zone 121a for secondary circulation separation, so as to improve the pulverizing efficiency of the coarse powder separator 100, enhance the overall pulverizing system output of the boiler system, and reduce the overall energy waste of the pulverizing system of the boiler system.

[0056] For example, after the air-powder mixture airflow completes secondary separation in the second separation zone 121b, the larger coal particles (those with unacceptable fineness) in the air-powder mixture are passively separated by the impeller 40 to the outside of the first blade 41. Due to the presence of the circulation component 70, the coal particles with unacceptable fineness fall into the recovery cylinder 71 of the circulation component 70 under the action of gravity, and then enter the spiral pipe 72 from the recovery cylinder 71, and finally enter the first separation zone 121a from the outlet of the spiral pipe 72 for secondary circulation separation. It can be understood that when the coal particles undergoing secondary circulation separation enter the first separation zone 121a from the outlet of the spiral pipe 72, the air-powder mixture airflow in the powder inlet pipe 20 is simultaneously input into the first separation zone 121a. At this time, the coal particles undergoing secondary circulation separation will mix with the air-powder mixture airflow input from the powder inlet pipe 20 and undergo primary separation together.

[0057] After primary separation in the first separation zone 121a, the pulverized coal undergoing secondary circulation separation enters the second separation zone 121b for secondary separation. It should be noted that the primary separation in the first separation zone 121a and the secondary separation in the second separation zone 121b are based on the same principle as the primary and secondary separation of the air-powder mixture gas flow input from the pulverized coal inlet pipe 20, and will not be elaborated further here.

[0058] Optionally, the connection between the spiral pipe 72 and the recovery cylinder 71 can be welding, bolting, or snap-fitting. This application does not limit the specific connection method between the spiral pipe 72 and the recovery cylinder 71, and the choice can be made according to the actual situation.

[0059] Optionally, the spiral pipe 72 and the recovery cylinder 71 can be a single-piece structure. The circulation component 70 is integrally formed by stamping or casting the spiral pipe 72 and the recovery cylinder 71, resulting in a one-piece structure. On the one hand, this eliminates the need for additional connecting processes to connect the spiral pipe 72 and the recovery cylinder 71, simplifying the manufacturing process of the circulation component 70. On the other hand, compared to connecting the spiral pipe 72 and the recovery cylinder 71 through additional connecting processes, the one-piece structure of the spiral pipe 72 and the recovery cylinder 71 provides a higher connection strength, thereby further improving the overall structural strength of the circulation component 70.

[0060] In the above technical solution, by setting a circulation component 70 in the first separation zone 121a, the circulation component 70 can collect the coal powder that has passed through the secondary separation after the air-coal mixture airflow input from the coal inlet pipe 20 has passed through the coal outlet pipe 50, and transport it to the first separation zone 121a for secondary circulation separation. This can effectively improve the pulverizing efficiency of the coarse powder separator 100, enhance the overall pulverizing system output of the boiler system, and reduce the overall energy consumption waste of the pulverizing system of the boiler system.

[0061] In some embodiments, the coarse powder separator 100 further includes a baffle 80, which is correspondingly disposed with the spiral pipe 72. The baffle 80 is connected to the inner wall of the outer casing cylinder 10 and is located on the side of the spiral pipe 72 outlet near the second separation region 121b.

[0062] The baffle 80 can block the coal powder that is being separated in the secondary circulation from the outlet of the spiral pipe 72, thereby preventing larger coal powder particles (those that are not fine enough) from entering the second separation zone 121b for secondary separation. Instead, the coal powder particles directly enter the coal mill 200 through the return pipe 60 for re-grinding, further improving the separation efficiency of the coarse powder separator 100.

[0063] Optionally, the connection between the baffle 80 and the inner wall of the outer casing 10 can be welding, bolting, or snap-fitting. This application does not limit the specific connection method between the baffle 80 and the inner wall of the outer casing 10, and the method can be selected according to the actual situation.

[0064] Optionally, the baffle 80 and the outer shell 10 can be integrally formed. The outer shell 10 integrally forms the baffle 80 through stamping or casting, making the baffle 80 and the outer shell 10 a single unit. On the one hand, this eliminates the need for additional connecting processes to connect the baffle 80 and the outer shell 10, simplifying the manufacturing process of the baffle 80. On the other hand, compared to connecting the baffle 80 and the outer shell 10 through additional connecting processes, the integral structure of the baffle 80 and the outer shell 10 provides a higher degree of connection strength, thereby further improving the overall reliability of the coarse powder separator 100.

[0065] Optionally, the angle between the plane containing the baffle 80 and the axis of the main body 12 is adjustable. By adjusting the angle between the plane containing the baffle 80 and the axis of the main body 12, the blocking angle of the baffle 80 on the coal powder that undergoes secondary circulation separation output from the spiral pipe 72 outlet can be adjusted, thereby adapting to the pulverizing efficiency requirements of the coarse powder separator 100 in different application environments and effectively improving the flexibility and applicability of the coarse powder separator 100.

[0066] In some embodiments, the number of spiral pipes 72 is at least two, and the at least two spiral pipes 72 are distributed at circumferential intervals along the outer shell cylinder 10.

[0067] For example, the number of spiral pipes 72 can be, but is not limited to, two, three, or four, etc.

[0068] In the above technical solution, by setting the number of spiral pipes 72 to at least two, the conveying rate of coal powder from the recovery cylinder 71 to the spiral pipes 72 can be effectively improved, that is, the efficiency of the secondary circulation of coal powder, which can further improve the overall separation efficiency of the coarse powder separator 100.

[0069] In some embodiments, the internal diameter of the recovery cylinder 71 increases along the direction from the first end 11 to the second end 13, making the recovery cylinder 71 a conical cylinder structure. On the one hand, the internal diameter of the opening on the side of the recovery cylinder 71 near the second end 13 is larger, which makes it easier for the coal powder that has passed through the secondary separation and has not been discharged from the powder outlet pipe 50 after the air-coal mixture airflow input from the powder inlet pipe 20 to enter the recovery cylinder 71. On the other hand, the receiving cavity on the side of the recovery cylinder 71 near the first end 11 has a smaller internal diameter, which makes it easier for the coal powder entering the recovery cylinder 71 to accumulate and enter the spiral pipe 72. In this way, the recovery effect of the recovery cylinder 71 can be effectively improved.

[0070] Figure 7 This is a schematic diagram of the structure of another coarse powder separator 100 provided in some embodiments of this application. Figure 8 for Figure 7 A schematic diagram showing the flow direction of the air-powder mixture airflow in the coarse powder separator 100.

[0071] Continue to refer to Figures 7 to 8 In some embodiments, the coarse powder separator 100 further includes a stationary impeller 90 disposed in the second separation region 121b. The stationary impeller 90 includes a second blade 91 and a second inner cavity 92 formed by the second blade 91. The moving impeller 40 is located in the second inner cavity 92. The second inner cavity 92 is connected to the separation chamber 121 through the second blade 91, and the second inner cavity 92 is connected to the first inner cavity 42 through the first blade 41.

[0072] As described above, after the air-powder mixture airflow input from the powder inlet pipe 20 completes primary separation in the first separation zone 121a, a portion of the air-powder mixture airflow will enter the second separation zone 121b for secondary separation.

[0073] For example, the air-powder mixture airflow undergoing secondary separation in the second separation zone 121b will still maintain centrifugal motion. The second blade 91 of the stationary impeller 90 will block some of the larger (non-fine) coal powder particles in the air-powder mixture airflow from the outside of the second blade 91. Another part of the coal powder particles in the air-powder mixture airflow will enter the second inner cavity 92 through the second blade 91. Since the second inner cavity 92 is provided with a moving impeller 40, the moving impeller 40 will continue to separate this part of the air-powder mixture airflow located in the second inner cavity 92.

[0074] In the above technical solution, the stationary impeller 90 performs a primary separation of the air-powder mixture airflow undergoing secondary separation in the second separation zone 121b. The air-powder mixture airflow after separation by the stationary impeller 90 enters the second inner cavity 92, where the moving impeller 40 further separates this portion of the air-powder mixture airflow. In other words, by setting the stationary impeller 90 in the second separation zone 121b, the secondary separation of the coarse powder separator 100 has two separation processes, further improving the separation effect of the secondary separation in the coarse powder separator 100.

[0075] Optionally, the connection between the stationary impeller 90 and the inner wall of the outer casing 10 can be welding, bolting, or snap-fitting. This application does not limit the specific connection method between the stationary impeller 90 and the inner wall of the outer casing 10, and the method can be selected according to the actual situation.

[0076] In some embodiments, the swirling component 30 includes a swirling guide vane 31, and the angle between the swirling guide vane 31 and the axis of the powder inlet pipe 20 is adjustable.

[0077] Understandably, the greater the swirling speed or the larger the cutting angle, the smaller the particle size of the coal powder that can be separated, and the finer the coal powder output through the powder outlet pipe 50. Conversely, the smaller the swirling speed or the smaller the cutting angle, the larger the particle size of the coal powder that can be separated, and the finer the coal powder output through the powder outlet pipe 50.

[0078] In this way, the swirling speed and cutting angle of the airflow of the air-powder mixture in the first separation zone can be adjusted by adjusting the angle between the axis of the swirling guide vane 31 and the powder inlet pipe 20. Different swirling speeds and cutting angles can affect the fineness of the coal powder separation, so that the fineness of the coal powder output from the powder outlet pipe 50 of the coarse powder separator 100 can be adjusted within a certain range, thereby adapting to the requirements of different application environments on the fineness of the powder making of the coarse powder separator 100, and effectively improving the flexibility and applicability of the coarse powder separator 100.

[0079] In some embodiments, the swirling component 30 and the powder inlet pipe 20 are integrally formed.

[0080] The powder inlet pipe 20 is integrally formed with the swirling component 30 through stamping or casting, resulting in a one-piece structure between the swirling component 30 and the powder inlet pipe 20. This eliminates the need for additional connection processes, simplifying the manufacturing process of the baffle 80. Furthermore, compared to connecting the swirling component 30 and the powder inlet pipe 20 through additional processes, the one-piece structure provides a stronger connection, further improving the overall reliability of the coarse powder separator 100.

[0081] In some embodiments, the impeller 40 further includes a connecting shaft 43 and a reinforcing member 44. The connecting shaft 43 is fixedly connected to the first blade 41 and rotatably connected to the outer casing 10, and the reinforcing member 44 is connected between the connecting shaft 43 and the first blade 41.

[0082] For example, the reinforcing member 44 is connected between the connecting shaft 43 and the first blade 41, which can strengthen the firmness of the first blade 41, thereby reducing the shaking phenomenon during the rotation of the first blade 41, effectively improving the stability of the moving impeller 40, and further improving the separation effect of the powder separator.

[0083] Optionally, the reinforcing component 44 may be, but is not limited to, a reinforcing rib, a reinforcing fin, or a reinforcing plate.

[0084] According to some embodiments of this application, this application also provides a boiler system including a coarse powder separator 100 of any of the above embodiments.

[0085] It is understood that the boiler system includes the coarse powder separator 100 provided in the embodiments of this application. For specific details of the coarse powder separator 100, please refer to the description of the corresponding part of the coarse powder separator 100 described in the embodiments of this application above. For the sake of brevity, it will not be repeated here.

[0086] To better understand the coarse powder separator 100 provided in the embodiments of this application, based on the same inventive concept, embodiments of the coarse powder separator 100 in practical applications are described herein.

[0087] Figure 9 This is a schematic diagram of the structure of another coarse powder separator 100 provided in some embodiments of this application. Figure 10 for Figure 9 The diagram shows the flow direction of the air-powder mixture gas flow in a single cycle of separation in the coarse powder separator 100. Figure 11 for Figure 9 The diagram shows the flow direction of the air-powder mixture gas flow in the coarse powder separator 100 during secondary circulation separation.

[0088] Continue to refer to Figures 9 to 11This application provides a coarse powder separator 100, which includes an outer shell cylinder 10, a powder inlet pipe 20, a swirling component 30, a moving impeller 40, a powder outlet pipe 50, and a powder return pipe 60. The outer shell cylinder 10 includes a first end 11, a main body 12, and a second end 13 distributed along its own axial direction. The main body 12 has a separation chamber 121, which includes adjacent first separation regions 121a and second separation regions 121b. The first separation region 121a is close to the first end 11, and the second separation region 121b is close to the second end 13. The powder inlet pipe 20 is disposed at the first end 11 and communicates with the separation chamber 121. The swirling component 30 is disposed inside the powder inlet pipe 20. The moving impeller 40 is disposed in the second separation region 121b and includes a first blade 41 and a first inner cavity 42 formed by the first blade 41. The first inner cavity 42 communicates with the separation chamber 121 through the first blade 41. The powder outlet pipe 50 is located at the second end 13 and communicates with the first inner cavity 42. The powder return pipe 60 is located at the first end 11, communicates with the separation chamber 121, and is independent of the powder inlet pipe 20. Further, the coarse powder separator 100 also includes a circulation component 70 located in the first separation region 121a. The circulation component 70 includes a recovery cylinder 71 and a spiral pipe 72. One end of the recovery cylinder 71 along its axial direction has an opening facing the second separation region 121b, and the other end communicates with the inlet of the spiral pipe 72. The outlet of the spiral pipe 72 is located in the first separation region 121a. Further, the coarse powder separator 100 also includes a baffle 80, which is correspondingly arranged with the spiral pipe 72. The baffle 80 is connected to the inner wall of the outer shell cylinder 10 and is located on the side of the spiral pipe 72 near the outlet of the spiral pipe 72, close to the second separation region 121b. Further, the number of spiral pipes 72 is at least two, and the at least two spiral pipes 72 are distributed at intervals along the circumference of the outer shell cylinder 10. Furthermore, the internal diameter of the recovery cylinder 71 increases along the direction from the first end 11 to the second end 13. Furthermore, the coarse powder separator 100 also includes a stationary impeller 90 disposed in the second separation region 121b. The stationary impeller 90 includes a second blade 91 and a second inner cavity 92 formed by the second blade 91. A moving impeller 40 is located in the second inner cavity 92. The second inner cavity 92 communicates with the separation chamber 121 through the second blade 91, and the second inner cavity 92 communicates with the first inner cavity 42 through the first blade 41. Furthermore, the swirling component 30 includes a swirling guide vane 31, the angle between the swirling guide vane 31 and the axis of the powder inlet pipe 20 being adjustable. Furthermore, the moving impeller 40 also includes a connecting shaft 43 and a reinforcing component 44. The connecting shaft 43 is fixedly connected to the first blade 41 and rotatably connected to the outer casing cylinder 10, and the reinforcing component 44 is connected between the connecting shaft 43 and the first blade 41.

[0089] It should be noted that the specific details of the embodiment of the coarse powder separator 100 in practical application can be found in the description of the corresponding part of the coarse powder separator 100 described in the above embodiment of the present application. For the sake of brevity, it will not be repeated here.

[0090] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A coarse powder separator for flexible operation in coal-fired power plants, characterized in that, The coarse powder separator includes: The outer shell includes a first end, a main body, and a second end distributed along its own axial direction. The main body has a separation cavity, which includes an adjacent first separation region and a second separation region. The first separation region is close to the first end, and the second separation region is close to the second end. A powder inlet pipe is disposed at the first end and communicates with the separation chamber; A swirl component is disposed inside the powder inlet pipe; A moving impeller is disposed in the second separation region. The moving impeller includes a first blade and a first inner cavity formed by the first blade. The first inner cavity is connected to the separation cavity through the first blade. A powder outlet pipe is located at the second end and communicates with the first inner cavity; A powder return pipe is located at the first end, communicates with the separation chamber, and is independent of the powder inlet pipe; The coarse powder separator further includes a circulation component located in the first separation zone. The circulation component includes a recovery cylinder and a spiral pipe. One end of the recovery cylinder along its own axial direction is provided with an opening facing the second separation zone, and the other end is connected to the inlet of the spiral pipe. The outlet of the spiral pipe is located in the first separation zone, and the outlet of the spiral pipe faces away from the swirling component. The coarse powder separator also includes a baffle plate, which is correspondingly arranged with the spiral pipe. The baffle plate is connected to the inner wall of the outer shell cylinder and is located on the side of the spiral pipe outlet near the second separation area.

2. The coarse powder separator according to claim 1, characterized in that, The number of spiral pipes is at least two, and the at least two spiral pipes are distributed at intervals along the circumference of the outer shell.

3. The coarse powder separator according to claim 1, characterized in that, The internal diameter of the recovery cylinder increases from the first end to the second end.

4. The coarse powder separator according to claim 1, characterized in that, It also includes a stationary impeller disposed in the second separation area. The stationary impeller includes a second blade and a second inner cavity formed by the second blade. The moving impeller is located in the second inner cavity. The second inner cavity is connected to the separation cavity through the second blade, and the second inner cavity is connected to the first inner cavity through the first blade.

5. The coarse powder separator according to claim 1, characterized in that, The swirling component includes swirling guide vanes, and the angle between the swirling guide vanes and the axis of the powder inlet pipe is adjustable.

6. The coarse powder separator according to claim 1, characterized in that, The swirl component and the powder inlet pipe are integrally formed.

7. The coarse powder separator according to claim 1, characterized in that, The impeller also includes a connecting shaft and a reinforcing component. The connecting shaft is fixedly connected to the first blade and rotatably connected to the outer casing. The reinforcing component is connected between the connecting shaft and the first blade.

8. A boiler system, characterized in that, Includes the coarse powder separator as described in any one of claims 1-7.

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