Air distribution device for circulating fluidized bed boiler and circulating fluidized bed boiler

Abstract

The application discloses a wind distribution device for a circulating fluidized bed boiler, which comprises a wind chamber, a wind distribution part, an adjustable baffle and a driving device. The wind chamber comprises a wind distribution area and a wind guide area, the wind distribution area is arranged above the wind guide area, and the wind distribution area is in communication with the wind guide area. The wind distribution part is arranged on the top of the wind distribution area. The adjustable baffle is rotatably connected to the top of the wind guide area. The driving device is connected to the adjustable baffle and drives the adjustable baffle to rotate so as to adjust the wind volume entering the wind distribution area. The air inlet is arranged on at least one side of the wind guide area. Thus, the wind volume entering each area of the furnace of the circulating fluidized bed boiler can be quantitatively controlled by arranging the adjustable baffle on the device, and the fluidization state of the bed material in each area can be differentially adjusted, so that the operation problems, such as poor fluidization of the bed material, high local bed temperature, coking and partial bed, are solved. Meanwhile, the device has the advantages of simple operation and low installation and maintenance cost.

Description

Technical Field

[0001] This invention belongs to the technical field of circulating fluidized bed boilers, specifically relating to a circulating fluidized bed boiler air distribution device and a circulating fluidized bed boiler. Background Technology

[0002] Circulating fluidized bed boilers typically employ air distribution plates with air caps to achieve uniform air distribution. As circulating fluidized bed boilers continue to increase in size, the cross-sectional area of ​​the furnace also expands, making it increasingly challenging to ensure good fluidization of the bed material during actual operation. In practice, many companies first operate the circulating fluidized bed boiler for a period of time, and then, based on operational feedback data, differentiate the resistance of the air caps in different areas of the air distribution plate to achieve better bed material fluidization. However, when there are significant variations in coal type, the abrasive properties of the coal after ash formation differ considerably. This may cause the current distribution of air cap resistance to become unsuitable for the circulating fluidized bed boiler, thus failing to achieve optimal bed material fluidization.

[0003] To date, a number of devices for adjusting the distribution of air volume in the air chamber have emerged in the market, but they may have at least one of the following problems: (1) The device structure is relatively complex, the on-site layout is difficult, and the installation cost is also high; (2) The device can only macroscopically adjust the airflow distribution in the air chamber and cannot effectively cope with the local poor fluidization conditions in actual operation; (3) Some devices require the addition of adjustment components between each air cap and the air duct to adjust the air volume at the outlet of each air cap, which greatly increases the difficulty of operation and maintenance costs. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, one objective of this invention is to provide an air distribution device for a circulating fluidized bed boiler. Thus, by incorporating adjustable baffles into the device, the airflow entering each zone of the circulating fluidized bed boiler furnace can be quantitatively controlled, thereby differentially adjusting the fluidization state of the bed material in each zone. This solves operational problems such as poor bed material fluidization, localized high bed temperature, coking, and bed imbalance. Simultaneously, the device also has the advantages of simple operation and low installation and maintenance costs.

[0005] In a first aspect, the present invention provides an air distribution device for a circulating fluidized bed boiler. In an embodiment of the present invention, the circulating fluidized bed boiler air distribution device includes:

[0006] The air chamber includes an air distribution area and an air guiding area. The air distribution area is located above the air guiding area and is connected to the air guiding area.

[0007] A ventilation element, wherein the ventilation element is disposed at the top of the ventilation area;

[0008] An adjustable baffle is rotatably connected to the top of the air guide zone;

[0009] A driving device is connected to the adjustable baffle, and the driving device drives the adjustable baffle to rotate so as to adjust the air volume entering the air distribution area;

[0010] An air inlet is provided on at least one side of the air guide zone.

[0011] The circulating fluidized bed boiler air distribution device according to an embodiment of the present invention uses a drive device to control the opening of adjustable baffles, thereby controlling the air volume entering each air guide zone and differentially regulating the fluidization state of the bed material in each zone of the boiler, thus optimizing the fluidization effect of the bed material in each zone of the boiler. Therefore, by setting adjustable baffles in the above device, the air volume entering each zone of the circulating fluidized bed boiler furnace can be quantitatively controlled, thereby differentially regulating the fluidization state of the bed material in each zone, solving operational problems such as poor bed material fluidization, localized high bed temperature, coking, and bed imbalance. At the same time, the above device also has the advantages of simple operation and low installation and maintenance costs.

[0012] In addition, the circulating fluidized bed boiler air distribution device according to the above embodiments of the present invention may also have the following additional technical features:

[0013] In some embodiments of the present invention, a support member is disposed at the top of the air guiding zone, and at least one end of the adjustable baffle is connected to the support member so that the adjustable baffle is rotatably connected to the top of the air guiding zone.

[0014] In some embodiments of the present invention, one end of the adjustable baffle is connected to the support member, and the other end of the adjustable baffle is connected to the side wall of the air guide zone;

[0015] Alternatively, one end of the adjustable baffle is connected to one of the support members, and the other end of the adjustable baffle is connected to another support member.

[0016] In some embodiments of the present invention, one end of the adjustable baffle is connected to the side wall of the air guide zone, and the other end of the adjustable baffle is connected to the side wall opposite to the side wall.

[0017] In some embodiments of the present invention, a plurality of the adjustable baffles are evenly distributed along the length direction of the device.

[0018] In some embodiments of the present invention, the number of adjustable baffles is 4-12.

[0019] In some embodiments of the present invention, the adjustable baffle is rotated at an angle of -90° to 90° with the side of the adjustable baffle closest to the air distribution area as the axis.

[0020] In some embodiments of the invention, the adjustable baffles are stacked and rotatably connected to the top of the air guide zone.

[0021] In some embodiments of the present invention, the adjustable baffle is connected to the support member via a rotating shaft.

[0022] In some embodiments of the present invention, a plurality of the support members are uniformly distributed along the width direction of the device.

[0023] In some embodiments of the present invention, the height of the adjustable baffle is set to x;

[0024] Let the dimension of the support member along the height direction of the device be y, where y ≤ x.

[0025] In some embodiments of the present invention, the height of the adjustable baffle is set to x;

[0026] Let P be the dimension of the air guiding zone along the length of the device;

[0027] Let n be the number of adjustable baffles along the length of the device, and x < P / 2(n+1).

[0028] In some embodiments of the present invention, the adjustable baffle divides the air guide into multiple air guide zones, and the initial state is that the height direction of the adjustable baffle is perpendicular to the air distribution zone.

[0029] Let the difference between the air inlet area S2 of the adjusted air guide zone and the air inlet area S1 of the initial air guide zone be ΔS.

[0030] Let α be the angle between the adjusted adjustable baffle and the initial adjustable baffle;

[0031] Let the air intake volume of the adjusted air guide zone be Q2, and the air intake volume of the initial air guide zone be Q1, satisfying the following calculation formula:

[0032]

[0033] Where K is the correction factor.

[0034] In a second aspect, the present invention provides a circulating fluidized bed boiler, which, according to an embodiment of the invention, includes the circulating fluidized bed boiler air distribution device described in the above embodiments. Thus, the circulating fluidized bed boiler incorporates all the advantages of the circulating fluidized bed boiler air distribution device described in the above embodiments. Specifically, this circulating fluidized bed boiler can quantitatively control the air volume entering each zone of the circulating fluidized bed boiler furnace, thereby differentially adjusting the fluidization state of the bed material in each zone and solving operational problems such as poor bed material fluidization, localized high bed temperature, coking, and bed imbalance.

[0035] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0036] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0037] Figure 1 This is a schematic diagram of an air distribution device for a circulating fluidized bed boiler according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the air guide zone of the circulating fluidized bed boiler air distribution device according to an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the partitioning of the air distribution zone of a circulating fluidized bed boiler air distribution device according to an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the air guide zone of the circulating fluidized bed boiler air distribution device according to another embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the air guide zone of the circulating fluidized bed boiler air distribution device according to another embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the air guide zone of the circulating fluidized bed boiler air distribution device according to another embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of the air distribution zone of a circulating fluidized bed boiler air distribution device according to another embodiment of the present invention.

[0044] Figure label:

[0045] 1-Air distribution zone; 2-Air guide zone; 3-Air distribution component; 4-Adjustable baffle; 5-Air inlet; 6-Support component; 7-Rotating shaft; W-1: External view of the air distribution device for a circulating fluidized bed boiler; W-2: Cross-sectional view of the air distribution device for a circulating fluidized bed boiler; W-3: Air guide zone in its initial state; W-4: Air guide zone after adjustment. Detailed Implementation

[0046] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0047] In one aspect of the invention, an air distribution device for a circulating fluidized bed boiler is provided, as shown in the attached drawing. Figure 1 and 2 The device includes: an air chamber, which includes an air distribution zone 1 and an air guide zone 2. The air distribution zone 1 is located above the air guide zone 2 and is connected to the air guide zone 2; an air distribution component 3 (e.g., an air distribution plate), which is located at the top of the air distribution zone 1. The air distribution component can support the stationary bed material layer in the furnace and can evenly distribute the air entering the furnace through the air guide zone 2. It should be explained that the area above the air distribution component 3 is the furnace area of ​​the circulating fluidized bed boiler; an adjustable baffle 4, which is rotatably connected to the top of the air guide zone 2; a driving device, which is connected to the adjustable baffle 4. The driving device drives the adjustable baffle 4 to rotate so as to regulate the air volume entering each air guide zone, thereby differentially regulating the fluidization state of the bed material in each area of ​​the boiler and improving the fluidization effect of the bed material in each area of ​​the boiler; and an air inlet 5, which is located on at least one side of the air guide zone 2, through which outside air enters the air guide zone 2.

[0048] It should be explained that the criteria for judging the fluidization effect of the bed material in each zone of the boiler are parameters such as the circulating fluidized bed temperature, circulating fluidized bed pressure, coal feed rate, and the concentration of each gas component.

[0049] In an embodiment of the present invention, an adjustable baffle divides the air guide area into multiple independently adjustable air guide areas, and the air volume of each air guide area is controlled by adjusting the opening of the adjustable baffle.

[0050] According to some specific embodiments of the present invention, refer to the appendix Figure 3 Eight adjustable baffles (a1, a2, b1, b2, c1, c2, d1, d2) divide the airflow zone into ten airflow zones (A1, A2, B1, B2, C1, C2, D1, D2, E1, E2). A drive device controls the opening of the adjustable baffles, thereby regulating the airflow in different airflow zones.

[0051] Furthermore, if poor fluidization is found in certain areas during boiler operation, the adjustable baffles can be rotated using a drive device to increase the air intake in those areas. For example, if the fluidization in areas A1 and A2 is poor, the adjustable baffles a1 and a2 can be rotated counterclockwise using the drive device to increase the air intake area of ​​A1 and A2, thereby increasing the corresponding air intake volume. It is important to note that when the positions of other adjustable baffles remain unchanged, increasing the air intake area of ​​A1 and A2 by controlling the rotation of the adjustable baffles is equivalent to decreasing the air intake area of ​​B1 and B2. Therefore, if there are special requirements for the air intake in other areas, other adjustable baffles need to be adjusted according to specific needs to meet actual production requirements.

[0052] According to further specific embodiments of the present invention, see attached drawing. Figure 2 and attached Figure 5-6 The circulating fluidized bed boiler air distribution device also includes: a support member 6, which is disposed at the top of the air guide zone 2, and at least one end of the adjustable baffle 4 is connected to the support member 6 so that the adjustable baffle is rotatably connected to the top of the air guide zone.

[0053] According to some specific embodiments of the present invention, see attached drawing. Figure 5 and 6 One end of the adjustable baffle 4 is connected to the support member 6, and the other end of the adjustable baffle 4 is connected to the side wall (a point on the side wall) of the air guide zone 2. Thus, the support member and the side wall of the air guide zone can support the adjustable baffle.

[0054] Alternatively, refer to the appendix. Figure 5 and 6 One end of the adjustable baffle 4 is connected to a support member 6, and the other end of the adjustable baffle 4 is connected to another support member 6. Thus, the two support members can support the adjustable baffle.

[0055] According to some specific embodiments of the present invention, see attached drawing. Figure 4 The two ends of the adjustable baffle are respectively connected to two opposite side walls (a point on the side wall) of the air guide zone, so that the two opposite side walls of the air guide zone can support the adjustable baffle.

[0056] According to some specific embodiments of the present invention, see attached drawing. Figure 1The dimension of the air distribution zone 1 along the height direction of the device is H, and the value of H ranges from 8 to 15 cm. This ensures that the impact on the fluidization of the bed material in the area above the support is small, and also avoids that if H is too large, the air direction of the air distribution zone corresponding to the air guide zone will move around (to the air distribution zone corresponding to other air guide zones), which in turn affects the accuracy of the adjustable baffle in quantitatively controlling the air volume of each area entering the furnace of the circulating fluidized bed boiler.

[0057] According to some specific embodiments of the present invention, see attached drawing. Figure 1-7 Multiple adjustable baffles 4 are evenly distributed along the length of the device, which further facilitates the control of the air volume in each zone of the air guide zone 2.

[0058] According to some specific embodiments of the present invention, see attached drawing. Figure 1-7 The number of adjustable baffles 4 is 4-12. This controls the number of adjustable baffles within a certain range, ensuring that the number of air guide zones is appropriate. This is beneficial for regulating the air volume of each air guide zone, while avoiding an excessive number of air guide zones, which would lead to an all-round increase in the workload of equipment modification, equipment maintenance, and time and labor costs.

[0059] According to some specific embodiments of the present invention, see attached drawing. Figure 1-7 With the adjustable baffle 4 on the side closest to the air distribution area 1 as the pivot 7, the rotation angle of the adjustable baffle is -90° to 90°.

[0060] It should be explained that: In this application, the adjustable baffle is defined as being perpendicular to the air distribution plate in the initial state. The adjustable baffle rotates clockwise as a negative angle and counterclockwise as a positive angle. Therefore, the rotation angle of the adjustable baffle in the initial state is 0°, the angle range of the adjustable baffle rotating clockwise is -90° to 0°, and the angle range of the adjustable baffle rotating counterclockwise is 0° to 90°.

[0061] According to some specific embodiments of the present invention, see attached drawing. Figure 6 Adjustable baffles 4 are stacked and rotatably connected to the top of the air guide zone 2, preferably in two layers. If a single layer of adjustable baffles is rotatably connected to the top of the air guide zone while the positions of other adjustable baffles remain unchanged, increasing the air intake area of ​​A1 and A2 by rotating the adjustable baffles is equivalent to reducing the air intake area of ​​B1 and B2, which is not conducive to precise control of the air volume of each air guide zone. The stacked adjustable baffles can solve this technical problem.

[0062] Specifically, taking the example of two adjustable baffles stacked and rotatably connected at the top of the air guide zone, refer to the attached document. Figure 6When one adjustable baffle rotates clockwise, the air intake of the corresponding wind-guiding zone decreases. If the other adjustable baffle remains unchanged in its initial state, the air intake of adjacent wind-guiding zones remains unchanged. If the other adjustable baffle rotates counterclockwise, the air intake of adjacent wind-guiding zones decreases. Thus, the solution has the characteristic of adjusting the air intake area of ​​a single wind-guiding zone without affecting the air intake area of ​​other wind-guiding zones. At the same time, it can reduce the overall air intake area of ​​the wind-guiding zone, thereby increasing the resistance of the entire air distribution device and having the function of adjusting the air chamber resistance of the air distribution device over a wide range.

[0063] According to some specific embodiments of the present invention, the adjustable baffle 4 is connected to the support member 6 via a rotating shaft 7, thereby the rotation angle of the rotating shaft can be adjusted by a driving device, and thus the rotation angle of the adjustable baffle can be controlled.

[0064] According to some specific embodiments of the present invention, multiple support members 6 are evenly distributed along the width direction of the device, thereby making it easier to control the air volume entering each zone of the air distribution area, and thus differentiate the fluidization state of the bed material in each zone of the boiler.

[0065] According to some specific embodiments of the present invention, the number of support members 6 is 0-2. Thus, the number of support members 6 is controlled within a certain range, which not only ensures that the number of adjustable baffles is appropriate, which is conducive to regulating the air volume of each zone of the air guide zone, but also avoids that too many adjustable baffles will lead to an all-round increase in the workload of device modification, device maintenance, and time and labor costs.

[0066] According to some specific embodiments of the present invention, let the height of the adjustable baffle be x, and let the dimension of the support member along the height direction of the device be y, where y≤x. Thus, it is ensured that the adjustable baffle and the support member divide the air guide into different zones, thereby allowing for the control of each air guide zone, while also avoiding the waste of support member material due to excessively large dimensions of the support member along the height direction of the device.

[0067] According to some specific embodiments of the present invention, see attached drawing. Figure 1 and 2 Let the height of the adjustable baffle be x; let the dimension of the air guide zone along the length of the device be P; let the number of adjustable baffles along the length of the device be n, x < P / 2(n+1). Thus, collisions between adjacent adjustable baffles can be avoided, thereby affecting the air volume of each zone of the air guide zone controlled by the adjustable baffle.

[0068] According to some specific embodiments of the present invention, see attached drawing. Figure 1 and 7The aforementioned adjustable baffle divides the aforementioned air distribution area into multiple air distribution zones. The initial state is that the height direction of the aforementioned adjustable baffle is perpendicular to the air distribution area.

[0069] Let the difference between the air inlet area S2 of the adjusted air guide zone and the air inlet area S1 of the initial air guide zone be ΔS (ΔS=S2-S1).

[0070] Let α be the angle between the adjusted adjustable baffle and the initial adjustable baffle.

[0071] Let the air intake volume of the adjusted air guide zone be Q2, and the air intake volume of the initial air guide zone be Q1, satisfying the following calculation formula:

[0072]

[0073] Where K is a correction factor, the value of which is related to the air distribution method, the drag characteristics of the wind caps on the air distribution components, and the height of the support components. (Appendix) Figure 7 W-3 and W-4 in the text represent the different times when the air guides with the same adjustable baffles are divided.

[0074] Specifically, the initial inlet area S1 of the air guide zone remains unchanged (correspondingly, Q1 remains unchanged). The adjusted inlet area S2 of the air guide zone changes with the rotation angle of the adjustable baffle (correspondingly, Q2 changes). ΔS>0 indicates that the adjusted inlet area S2 of the air guide zone increases (i.e., the corresponding Q2 increases), and ΔS<0 indicates that the adjusted inlet area S2 of the air guide zone decreases (i.e., the corresponding Q2 decreases). Furthermore, with the spacing between the adjustable baffles in the above device remaining constant, the values ​​of K, P, and n all remain unchanged. Therefore, the ratio of Q2 / Q1 can be obtained based on the value of α, and thus the specific value of Q2 can be determined. Therefore, the airflow entering the air guide zone can be quantitatively controlled according to the rotation angle of the adjustable baffle, thereby better differentiating the fluidization state of the bed material in each area and improving the fluidization effect of the bed material in each area of ​​the boiler.

[0075] The circulating fluidized bed boiler air distribution device according to an embodiment of the present invention uses a drive device to control the opening of adjustable baffles, thereby controlling the air volume entering each air guide zone and thus differentially regulating the fluidization state of the bed material in each zone of the boiler, improving the fluidization effect of the bed material in each zone of the boiler. Therefore, by setting adjustable baffles in the above device, the air volume entering each zone of the circulating fluidized bed boiler furnace can be quantitatively controlled, thereby differentially regulating the fluidization state of the bed material in each zone, solving operational problems such as poor bed material fluidization, localized high bed temperature, coking, and bed imbalance. At the same time, the above device also has the advantages of simple operation and low installation and maintenance costs.

[0076] In a second aspect, the present invention provides a circulating fluidized bed boiler. According to an embodiment of the invention, the circulating fluidized bed boiler includes the air distribution device of the circulating fluidized bed boiler described above. Thus, the circulating fluidized bed boiler incorporates all the advantages of the air distribution device of the circulating fluidized bed boiler described above. Specifically, this circulating fluidized bed boiler can quantitatively control the air volume entering each zone of the furnace, thereby differentially adjusting the fluidization state of the bed material in each zone and solving operational problems such as poor bed material fluidization, localized high bed temperature, coking, and bed imbalance.

[0077] The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0078] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An air distribution device for a circulating fluidized bed boiler, characterized in that, include: The air chamber includes an air distribution area and an air guiding area. The air distribution area is located above the air guiding area and is connected to the air guiding area. A ventilation element, wherein the ventilation element is disposed at the top of the ventilation area; An adjustable baffle is rotatably connected to the top of the air guide zone; multiple adjustable baffles are evenly distributed along the length of the device; the adjustable baffles are double-layered and rotatably connected to the top of the air guide zone; the adjustable baffles are perpendicular to the air distribution component in the initial state. A driving device is connected to the adjustable baffle, and the driving device drives the adjustable baffle to rotate so as to adjust the air volume entering the air distribution area; An air inlet, wherein the air inlet is disposed on at least one side of the air guiding zone; The height of the adjustable baffle is x; The dimension of the air guiding zone along the length of the device is P; The number of adjustable baffles along the length of the device is n, x < P / 2(n+1); The adjustable baffle divides the air distribution area into multiple air distribution zones, and the height direction of the adjustable baffle is perpendicular to the air distribution area in the initial state. The difference between the air inlet area S2 of the adjusted air guide zone and the air inlet area S1 of the initial air guide zone is ΔS. The angle between the adjusted adjustable baffle and the initial adjustable baffle is α; The adjusted air intake volume of the air guide zone is Q2, and the initial air intake volume of the air guide zone is Q1, satisfying the following calculation formula: Where K is the correction factor.

2. The circulating fluidized bed boiler air distribution device according to claim 1, characterized in that, Also includes: A support member is disposed at the top of the air guide zone, and at least one end of the adjustable baffle is connected to the support member so that the adjustable baffle is rotatably connected to the top of the air guide zone.

3. The circulating fluidized bed boiler air distribution device according to claim 2, characterized in that, One end of the adjustable baffle is connected to the support member, and the other end of the adjustable baffle is connected to the side wall of the air guide zone; Alternatively, one end of the adjustable baffle is connected to one of the support members, and the other end of the adjustable baffle is connected to another support member.

4. The air distribution device for a circulating fluidized bed boiler according to claim 1, characterized in that, The two ends of the adjustable baffle are respectively connected to the two opposite side walls of the air guide zone.

5. The circulating fluidized bed boiler air distribution device according to any one of claims 1-4, characterized in that, The number of adjustable baffles is 4-12; And / or, with the side of the adjustable baffle closest to the air distribution area as the axis, the rotation angle of the adjustable baffle is -90° to 90°.

6. The air distribution device for a circulating fluidized bed boiler according to claim 2 or 3, characterized in that, The adjustable baffle is connected to the support member via a rotating shaft; And / or, a plurality of the support members are evenly distributed along the width direction of the device.

7. The air distribution device for a circulating fluidized bed boiler according to claim 2 or 3, characterized in that, The height of the adjustable baffle is x; The dimension of the support member along the height direction of the device is y, where y ≤ x.

8. A circulating fluidized bed boiler, characterized in that, Includes the circulating fluidized bed boiler air distribution device as described in any one of claims 1-7.

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