Tubular air pre-heater and circulating fluidized bed boiler system

Abstract

The utility model relates to a tubular air pre-heater and a circulating fluidized bed boiler system. The tubular air pre-heater comprises a plurality of air pre-heater tubes, an upper tube plate, an anti-abrasion tube and castable. The air pre-heater pipes extend in the vertical direction, each air pre-heater pipe comprises a body and a protruding pipe which are connected with each other, the bodies are located below the upper pipe plate, the protruding pipes are located above the upper pipe plate and used for allowing boiler flue gas to enter, and the air pre-heater pipes are connected with the upper pipe plate in a sealed mode; the anti-abrasion pipes are connected with the protruding pipes of the corresponding air pre-heater pipes, and the anti-abrasion pipes are arranged in the vertical direction in an extending mode. The pouring material is used for being filled among the multiple protruding pipes and used for being filled among the multiple anti-abrasion pipes. The anti-abrasion pipe is arranged at the upper end of the protruding pipe, and the anti-abrasion pipe is communicated with the protruding pipe, so that normal entering of smoke can be guaranteed, normal use of the air pre-heater pipe and the upper pipe plate is not affected even if the anti-abrasion pipe and castable are abraded, and the air leakage rate of the air pre-heater pipe and the air leakage rate of the upper pipe plate are reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of boiler power generation, and in particular to a tubular air preheater and a circulating fluidized bed boiler system. Background Art

[0002] In the related technology, the boiler air preheater adopts a tubular air preheater with a horizontal structure, three strokes and in-line arrangement. The flue gas flows longitudinally between the tubes, and the air flows inside the tubes. The cold air of the primary and secondary air is introduced from the back of the furnace, and the hot air duct is led out from the front of the furnace. Due to the large difference in the pressure of the primary and secondary air, the air preheater tube box is divided into three independent channels. The primary air is arranged in the center, and the secondary air duct boxes are arranged on both sides. The tube box is divided into three layers. The specifications of the air preheater tube are Φ60*2, L=7.6m, and the low temperature section adopts Φ57*2.5NS1-3 corrosion-resistant steel. The entire load of the air preheater is distributed on the crossbeam of the boiler frame on the lower layer of the air preheater. There are 12,840 primary air ducts and 14,400 secondary air ducts. All air preheater tubes are fixedly arranged by four groups of tube sheets. The pipe openings on both sides are fully welded with the flower plates and metal compensators are provided at the ends to absorb the heat expansion of the tubes.

[0003] During the upgrade and renovation, the original horizontal three-stage air preheater and related ancillary facilities were dismantled and transformed into a vertical three-dimensional finned tube air preheater. A flue gas dry burning system was added and transformed into a vertical air preheater. The flue gas runs inside the tube and the air runs outside the tube for heat exchange. The primary and secondary air temperatures are heated by preheating to improve the boiler efficiency. The flue gas in the tube has dust at the flue gas inlet. There is a pressure difference of 800pa between the inlet and outlet of the air preheater, so there is wear at the inlet. If the air preheater inlet tube sheet is worn, there will inevitably be air leakage at the air preheater tube mouth. As the running time goes by, the air leakage will become larger and larger, thereby affecting the air preheater leakage rate and further reducing the boiler efficiency. It is urgent to solve the anti-wear problem of the flue gas inlet of the air preheater. Utility Model Content

[0004] The purpose of the present disclosure is to provide a tubular air preheater and a circulating fluidized bed boiler system to solve the technical problems existing in the related art.

[0005] In order to achieve the above object, the present disclosure provides a tubular air preheater, which comprises a plurality of air preheater tubes, an upper tube plate, an anti-wear tube and a castable;

[0006] The air preheater tubes are arranged extending in the up-down direction, and a plurality of the air preheater tubes are arranged in pairs, and each of the air preheater tubes comprises a body and a protruding tube connected to each other, the body is located below the upper tube plate, the protruding tube is located above the upper tube plate for the boiler flue gas to enter, and the air preheater tubes are sealedly connected to the upper tube plate;

[0007] The plurality of anti-wear pipes are arranged correspondingly to the plurality of air preheater pipes, the anti-wear pipes are connected to the protruding pipes of the corresponding air preheater pipes, and the anti-wear pipes are extended and arranged in the up-down direction;

[0008] The casting material is used to be filled between the plurality of protruding tubes and between the plurality of anti-wear tubes.

[0009] Optionally, the anti-wear pipe comprises an anti-wear pipe body and a connecting pipe head, the anti-wear pipe body is extended in the up-down direction, and the connecting pipe head is connected to the lower end of the anti-wear pipe body and connected to the corresponding protruding pipe;

[0010] Among them, the inner diameter of the connecting pipe head is the same as the outer diameter of the protruding pipe, the connecting pipe head is compressed and sleeved on the protruding pipe, and the inner diameter of the protruding pipe is the same as the inner diameter of the anti-wear pipe body.

[0011] Optionally, the upper ends of the plurality of protruding tubes of the plurality of air preheater tubes are arranged flush with each other, and the upper ends of the plurality of anti-wear tube bodies of the plurality of anti-wear tubes are arranged flush with each other.

[0012] Optionally, the dimension of the connecting pipe head along the up-down direction is a first dimension, the dimension of the protruding pipe along the up-down direction is a second dimension, and the first dimension is equal to the second dimension.

[0013] Optionally, the anti-wear pipe body and the connecting pipe head are constructed as an integrally formed structure;

[0014] Among them, the outer diameter of the protruding tube is φ57mm, and the inner diameter of the connecting pipe head is expanded to φ57mm by a mouth expansion machine.

[0015] Optionally, the plurality of air preheater tubes include a plurality of air preheater tube groups, the plurality of air preheater tube groups are arranged in pairs along the first direction, and the air preheater tubes in each of the air preheater tube groups are arranged in pairs along the second direction;

[0016] The plurality of anti-wear tubes include a plurality of anti-wear tube groups, the plurality of anti-wear tube groups are arranged in pairs along the first direction, and the anti-wear tubes in each anti-wear tube group are arranged in pairs along the second direction;

[0017] The first direction and the second direction are perpendicular to each other.

[0018] Optionally, the upper tube sheet is formed with tube sheet holes for the plurality of air preheater tubes to pass through in a one-to-one correspondence, and the outer circumferential wall of the air preheater tube is sealingly welded to the inner circumferential wall of the tube sheet hole.

[0019] Optionally, the out-of-roundness of the wear-resistant tube is ≤2 mm.

[0020] Optionally, the anti-wear tube is formed by cutting, and the inclination of the cutting surface of the anti-wear tube is ≤0.5 mm.

[0021] The present disclosure further provides a circulating fluidized bed boiler system, wherein the circulating fluidized bed boiler system includes the tubular air preheater.

[0022] In the above technical scheme, firstly, the protruding tube is arranged on the upper tube plate in an upward protruding manner. Since the flue gas carries dust and there is a differential pressure of 800pa at the inlet and outlet of the air preheater, the protruding tube is prone to wear. If the upper tube plate is worn, there will inevitably be air leakage at the air preheater tube mouth. As the running time goes by, the air leakage will become larger and larger, thereby affecting the air preheater leakage rate. By arranging an anti-wear tube at the upper end of the protruding tube, and the anti-wear tube is connected to the protruding tube, the normal entry of flue gas can be guaranteed. In addition, by arranging a castable, and the castable is used to fill between multiple protruding tubes and to fill between multiple anti-wear tubes, on the one hand, the anti-wear tube can be firmly arranged on the protruding tube, and the stability of the installation is improved. On the other hand, the gaps of the protruding tube and the gaps of the anti-wear tube can be filled. Even if the anti-wear tube and the castable are worn, it does not affect the normal use of the air preheater tube and the upper tube plate, and reduces the air leakage rate of the air preheater tube and the upper tube plate. In addition, during the pouring process of the above-mentioned castable, in order to prevent the castable from entering the anti-wear pipe, a blocking structure such as a plugging cover may be provided on the anti-wear pipe before pouring.

[0023] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0025] Figure 1 It is a cross-sectional view of a partial structure of a tubular air preheater according to an embodiment of the present invention.

[0026] Figure 2 It is a top view of a partial structure of a tubular air preheater according to an embodiment of the present invention.

[0027] Description of Reference Numerals

[0028] 1. Air preheater tube; 11. Main body; 12. Protruding tube;

[0029] 2. Upper tube plate;

[0030] 3. Anti-wear pipe; 30. Anti-wear pipe assembly; 31. Anti-wear pipe body; 32. Connecting pipe head;

[0031] 4. Casting material. DETAILED DESCRIPTION

[0032] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0033] In the present disclosure, unless otherwise stated, the directional words such as "upper" and "lower" used generally refer to the upper and lower parts of the tubular air preheater of the present disclosure under normal use conditions. Figure 1 As shown, the first direction and the second direction used in addition can be specifically referred to Figure 2 Positional words such as "inside" and "outside" refer to the inside and outside of a specific structural outline, and terms such as "first" and "second" are used only to distinguish one element from another, and do not have order or importance.

[0034] Reference Figure 1 and Figure 2 As shown, the present disclosure provides a tubular air preheater, which includes a plurality of air preheater tubes 1, an upper tube sheet 2, an anti-wear tube 3 and a castable 4. The air preheater tube 1 is extended and arranged in the up-down direction, and the plurality of air preheater tubes 1 are arranged in pairs, and each air preheater tube 1 includes a body 11 and a protruding tube 12 connected to each other, the body 11 is located below the upper tube sheet 2, the protruding tube 12 is located above the upper tube sheet 2 for boiler flue gas to enter, and the air preheater tube 1 is sealedly connected to the upper tube sheet 2; the plurality of anti-wear tubes 3 are arranged in one-to-one correspondence with the plurality of air preheater tubes 1, the anti-wear tubes 3 are connected to the protruding tubes 12 of the corresponding air preheater tubes 1, and the anti-wear tubes 3 are extended and arranged in the up-down direction; the castable 4 is used to fill between the plurality of protruding tubes 12 and to fill between the plurality of anti-wear tubes 3.

[0035] In the above technical solution, firstly, the protruding tube 12 is protruding upwardly on the upper tube sheet 2. Since the flue gas carries dust and there is a pressure difference of 800pa between the inlet and outlet of the air preheater, the protruding tube 12 is prone to wear. If the upper tube sheet 2 is worn, there will inevitably be air leakage at the air preheater tube mouth. As the running time goes by, the air leakage will become larger and larger, thereby affecting the air preheater leakage rate. By setting an anti-wear tube 3 at the upper end of the protruding tube 12, and the anti-wear tube 3 is connected to the protruding tube 12, the normal entry of flue gas can be guaranteed. In addition, by setting a castable 4, and the castable 4 is used to fill between multiple protruding tubes 12 and between multiple anti-wear tubes 3, on the one hand, the anti-wear tube 3 can be firmly set on the protruding tube 12 to improve the stability of the installation. On the other hand, the gaps in the protruding tube 12 and the gaps in the anti-wear tube 3 can be filled. Even if the anti-wear pipe 3 and the castable 4 are worn, it does not affect the normal use of the air preheater pipe 1 and the upper tube sheet 2, and reduces the air leakage rate of the air preheater pipe 1 and the upper tube sheet 2. In addition, during the pouring process of the castable 4, in order to prevent the castable 4 from entering the anti-wear pipe 3, a blocking structure such as a plugging cover can be set on the anti-wear pipe 3 before pouring.

[0036] In one embodiment, reference Figure 1 As shown, the anti-wear pipe 3 includes an anti-wear pipe body 31 and a connecting pipe head 32. The anti-wear pipe body 31 is extended in the up and down directions. The connecting pipe head 32 is connected to the lower end of the anti-wear pipe body 31 and is connected to the corresponding protruding pipe 12; wherein, the inner diameter of the connecting pipe head 32 is the same as the outer diameter of the protruding pipe 12, the connecting pipe head 32 is pressed and sleeved on the protruding pipe 12, and the inner diameter of the protruding pipe 12 is the same as the inner diameter of the anti-wear pipe body 31.

[0037] In this embodiment, firstly, the inner diameter of the connecting pipe head 32 is the same as the outer diameter of the protruding pipe 12, so the operator can install it by hammering with a hand hammer, without setting up extra installation parts, which is convenient for installation and arrangement; secondly, if the installation of the protruding pipe 12 is tilted, it is also convenient to align it before pouring the castable 4. In addition, the use of the compression sleeve method is also convenient for the later operator to disassemble and replace the anti-wear pipe 3. In addition, the inner diameter of the protruding pipe 12 is the same as the inner diameter of the anti-wear pipe body 31, which does not affect the normal circulation of dust carried by smoke, and does not increase the smoke circulation resistance and air pressure difference. However, the present disclosure does not limit the specific structure of the anti-wear pipe 3, nor does it limit the installation and connection method of the anti-wear pipe 3 and the protruding pipe 12. For example, the anti-wear pipe 3 can also be connected to the protruding pipe 12 by welding.

[0038] In addition, refer to Figure 1As shown, the upper ends of the multiple protruding tubes 12 of the multiple air preheater tubes 1 are arranged flush, and the upper ends of the multiple anti-wear tube bodies 31 of the multiple anti-wear tubes 3 are arranged flush, ensuring the flatness of the upper end surface after the anti-wear tubes 3 and the castable 4 are arranged.

[0039] Optionally, the size of the connecting pipe head 32 in the vertical direction is a first size, the size of the protruding pipe 12 in the vertical direction is a second size, and the first size is equal to the second size. It is ensured that the connecting pipe head 32 can completely cover the protruding pipe 12, and the connection is firm while effectively protecting the protruding pipe 12. For example, the first size and the second size can be 10 mm, but the present disclosure does not limit the specific size.

[0040] In addition, the anti-wear pipe body 31 and the connecting pipe head 32 can be constructed as an integrally formed structure; wherein the outer diameter of the protruding pipe 12 is φ57 mm, the inner diameter of the connecting pipe head 32 is expanded to φ57 mm by a mouth-opening machine, and then the connecting pipe head 32 is knocked onto the protruding pipe 12 by a hand hammer.

[0041] Optionally, refer to Figure 2 As shown, the multiple air preheater tubes 1 include multiple air preheater tube groups, the multiple air preheater tube groups are arranged in pairs along the first direction A, and the air preheater tubes 1 in each air preheater tube group are arranged in pairs along the second direction B; the multiple anti-wear tubes 3 include multiple anti-wear tube groups 30, the multiple anti-wear tube groups 30 are arranged in pairs along the first direction A, and the anti-wear tubes 3 in each anti-wear tube group 30 are arranged in pairs along the second direction B; wherein the first direction A is perpendicular to the second direction B. However, the present disclosure does not limit the specific arrangement of the multiple air preheater tubes 1 and the multiple anti-wear tubes 3, nor does it limit the number of the air preheater tubes 1 and the anti-wear tubes 3.

[0042] In other embodiments, the upper tube sheet 2 is formed with tube sheet holes for a plurality of air preheater tubes 1 to pass through in a one-to-one correspondence, and the outer peripheral wall of the air preheater tube 1 is sealedly welded to the inner peripheral wall of the tube sheet hole. On the one hand, the stability of the connection between the air preheater tube 1 and the upper tube sheet 2 can be ensured, and on the other hand, the sealing performance can be improved.

[0043] Optionally, the out-of-roundness of the wear-resistant tube 3 is ≤2 mm, the wear-resistant tube 3 is formed by cutting, and the inclination of the cutting surface of the wear-resistant tube 3 is ≤0.5 mm. In addition, the above-mentioned castable 4 can be concrete, which is not limited in the present disclosure.

[0044] The present disclosure further provides a circulating fluidized bed boiler system, which includes the above-mentioned tubular air preheater.

[0045] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0046] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0047] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A tubular air preheater, characterized in that: The tubular air preheater comprises a plurality of air preheater tubes, an upper tube plate, an anti-wear tube and a castable; The air preheater tubes are arranged extending in the up-down direction, and a plurality of the air preheater tubes are arranged in pairs, and each of the air preheater tubes comprises a body and a protruding tube connected to each other, the body is located below the upper tube plate, the protruding tube is located above the upper tube plate for the boiler flue gas to enter, and the air preheater tubes are sealedly connected to the upper tube plate; The plurality of anti-wear pipes are arranged correspondingly to the plurality of air preheater pipes, the anti-wear pipes are connected to the protruding pipes of the corresponding air preheater pipes, and the anti-wear pipes are extended and arranged in the up-down direction; The casting material is used to be filled between the plurality of protruding tubes and between the plurality of anti-wear tubes.

2. The tubular air preheater according to claim 1, characterized in that: The anti-wear pipe comprises an anti-wear pipe body and a connecting pipe head, wherein the anti-wear pipe body is extended in the up-down direction, and the connecting pipe head is connected to the lower end of the anti-wear pipe body and connected to the corresponding protruding pipe; Among them, the inner diameter of the connecting pipe head is the same as the outer diameter of the protruding pipe, the connecting pipe head is compressed and sleeved on the protruding pipe, and the inner diameter of the protruding pipe is the same as the inner diameter of the anti-wear pipe body.

3. The tubular air preheater according to claim 2, characterized in that: The upper ends of the plurality of protruding tubes of the plurality of air preheater tubes are arranged flush with each other, and the upper ends of the plurality of anti-wear tube bodies of the plurality of anti-wear tubes are arranged flush with each other.

4. The tubular air preheater according to claim 2, characterized in that: The dimension of the connecting pipe head along the up-down direction is a first dimension, the dimension of the protruding pipe along the up-down direction is a second dimension, and the first dimension is equal to the second dimension.

5. The tubular air preheater according to claim 2, characterized in that: The anti-wear pipe body and the connecting pipe head are constructed as an integrally formed structure; Among them, the outer diameter of the protruding tube is φ57mm, and the inner diameter of the connecting pipe head is expanded to φ57mm by a mouth expansion machine.

6. The tubular air preheater according to any one of claims 1 to 5, characterized in that: The plurality of air preheater tubes include a plurality of air preheater tube groups, the plurality of air preheater tube groups are arranged in pairs along the first direction, and the air preheater tubes in each of the air preheater tube groups are arranged in pairs along the second direction; The plurality of anti-wear tubes include a plurality of anti-wear tube groups, the plurality of anti-wear tube groups are arranged in pairs along the first direction, and the anti-wear tubes in each anti-wear tube group are arranged in pairs along the second direction; The first direction and the second direction are perpendicular to each other.

7. The tubular air preheater according to any one of claims 1 to 5, characterized in that: The upper tube sheet is formed with tube sheet holes for a plurality of the air preheater tubes to pass through in a one-to-one correspondence, and the outer peripheral walls of the air preheater tubes are sealingly welded to the inner peripheral walls of the tube sheet holes.

8. The tubular air preheater according to any one of claims 1 to 5, characterized in that: The out-of-roundness of the anti-wear pipe is ≤2mm.

9. The tubular air preheater according to any one of claims 1 to 5, characterized in that: The anti-wear tube is formed by cutting, and the inclination of the cutting surface of the anti-wear tube is ≤0.5mm.

10. A circulating fluidized bed boiler system, characterized in that: The circulating fluidized bed boiler system comprises the tubular air preheater according to any one of claims 1-9.

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