Quick repairing structure for leakage point of boiler air pre-heater

Abstract

The utility model relates to the technical field of the industrial boiler industry, and discloses a boiler air pre-heater leakage point rapid repairing structure which is characterized in that a built-in sleeve is coaxially sleeved inside a position, close to an opening end, of a leakage point pipe of an air pre-heater, and the built-in sleeve comprises an interference section and a sealing section; wherein the outer peripheral wall of the interference section is in interference connection with the inner peripheral wall of the air pre-heater leakage point pipe, and the outer peripheral wall of the sealing section is in sealing connection with the inner peripheral wall of the air pre-heater leakage point pipe through a sealing structure. According to the structure, a leakage point is blocked through the pipe wall of the interference section to achieve primary sealing of the built-in sleeve and the leakage point pipe, meanwhile, secondary sealing is achieved through sealing connection of the sealing structure between the sealing section and the leakage point pipe, and finally third-time sealing is achieved through welding sealing of the annular welding ring, so that air leakage is well eliminated; meanwhile, the structure can ensure that the flue gas can continuously flow in the newly added built-in sleeve, and normal output of the air pre-heater is ensured, so that safe and economical operation of the boiler is ensured; and the structure is rapid and convenient to install and repair and beneficial to popularization.

Description

TECHNICAL FIELD

[0001] The utility model relates to industrial boiler industry technical field especially relates to a boiler air preheater leak point quick repair structure. BACKGROUND

[0002] Air preheater (abbreviation air preheater) is the heat that carries in the flue gas that boiler tail discharged, through the fin conduction to the air before entering the boiler, and will air preheat to certain temperature equipment. The use of air preheater can guarantee the stable combustion in the boiler, improve the combustion efficiency, can strengthen the radiation heat transfer in the furnace, and can reduce the loss in the furnace, reduce the exhaust gas temperature, and then improve the boiler thermal efficiency.

[0003] The main heat transfer component of tubular air preheater is thin-walled steel pipe, thin-walled steel pipe is perpendicular to each other and staggered arrangement, both ends are welded on the upper and lower tube plate, the flue gas carrying heat passes through the preheater along the inside of the steel pipe, and the air passes through the preheater transversely, so as to complete heat transfer.

[0004] The tubular air preheater is used for a long time, and the corrosive components in the flue gas composition can cause corrosion to the thin-walled steel pipe, and the fluid flow in the steel pipe can also cause abrasion to the steel pipe, so that the thin-walled steel pipe near the two end openings is damaged and air leakage occurs. The air leakage phenomenon can cause the power consumption of the air supply fan and the induced draft fan to increase, the boiler thermal efficiency to decrease, the heating surface to corrode, the pipe to be blocked by ash, the boiler load to decrease and other situations, thereby causing the economic performance to decrease. In order to prevent the air leakage from continuing to deteriorate, the damaged air preheater pipe is generally treated as a blind hole in the prior art, that is, the pipe ends where air leakage occurs are plugged with plugs. However, in this way, the flue gas cannot pass through the blind hole pipe plugged by the plug, which can cause the heat exchange efficiency of the air preheater to be worse than before, the exhaust gas temperature to be increased, the flue gas resistance to be increased, the induced draft fan output to be increased, and the heat loss to be increased due to the fact that the blind hole pipe cannot exchange heat, thereby reducing the efficiency of the boiler. UTILITY MODEL CONTENTS

[0005] In order to make up for the above shortcomings, the utility model provides a boiler air preheater leak point quick repair structure, which aims to improve the boiler efficiency reduction caused by air preheater air leakage and the low heat efficiency after air preheater blind hole treatment.

[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0007] A boiler air preheater leak point quick repair structure, comprising an air preheater leak point pipe, an inner sleeve is coaxially sleeved on the inside of the opening end of the air preheater leak point pipe, the inner sleeve comprises an interference section and a sealing section, wherein the outer peripheral wall of the interference section is interference connected with the inner peripheral wall of the air preheater leak point pipe, and the outer peripheral wall of the sealing section is sealed connected with the inner peripheral wall of the air preheater leak point pipe through a sealing structure.

[0008] Further, the sealing section of the inner sleeve is a necked structure extending from the radial end face of the interference section and gradually necked inward, and the slope of the peripheral surface of the necked structure is not greater than 2°.

[0009] Further, the axial length of the sealing section of the inner sleeve is 1 / 6-1 / 7 of the axial length of the inner sleeve.

[0010] Further, the transition region of the outer peripheral surfaces of the interference section and the sealing section of the inner sleeve is an arc-shaped smooth curved surface.

[0011] Further, the sealing structure comprises an annular groove formed on the outer peripheral wall of the sealing section, and a flat sealing ring is fixedly embedded in the annular groove, and the outer surface of the flat sealing ring is tightly fitted on the inner peripheral wall of the air preheater leak point pipe.

[0012] Further, the inner side surface of the flat sealing ring is formed with at least one embedding part extending in the axial direction, the annular groove of the inner sleeve is formed with an embedding groove corresponding to the embedding part, and the embedding part is clamped in the corresponding embedding groove.

[0013] Further, the embedding part comprises a connecting part extending in the axial direction from the inner side surface of the flat sealing ring and a protruding part formed at the end of the connecting part, and the protruding part is in the form of an inverted hook structure.

[0014] Further, the embedding part is provided with two embedding parts respectively located at the upper part and the lower part of the inner side surface of the flat sealing ring.

[0015] Further, the port of the interference section of the inner sleeve or the outer peripheral surface and the port of the air preheater leak point pipe are formed with an annular welding ring.

[0016] The utility model has the advantages of:

[0017] This invention adds an internal sleeve to the leaking pipe of the air preheater. The interference fit section of the internal sleeve is connected to the leaking pipe, allowing the leak to be plugged using the wall of the interference fit section. Simultaneously, the sealing section of the internal sleeve is connected to the leaking pipe, achieving a secondary seal between the internal sleeve and the inner wall of the leaking pipe, preventing flue gas leakage. Furthermore, the welding seal using a ring provides a tertiary sealing effect. These three functions effectively eliminate air leakage. Moreover, the use of this internal sleeve does not simply block the leaking pipe; the flue gas can continue to flow within the newly added internal sleeve. That is, when the air in the air preheater passes through the steel pipe with this repair structure, it can still exchange heat with the flue gas flowing inside, thus ensuring normal air preheater output and safe and economical boiler operation. Finally, the repair structure is easy to use. After the sealing ring is nested, the sealing section can be directly aligned with the leaking end of the thin-walled steel pipe. The angle of the sealing section is used to guide it into the thin-walled steel pipe, and then external force is used to hammer the entire built-in sleeve into the leaking pipe. It is quick and convenient. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a half-sectional view of the overall structure of this utility model;

[0020] Figure 3 for Figure 2 Enlarged diagram of part A in the middle;

[0021] Figure 4 for Figure 2 Enlarged diagram of section B;

[0022] Legend:

[0023] 1-Air preheater leak pipe; 2-Built-in sleeve; 21-Interference fitting section; 22-Sealing section; 23-Outer circumferential transition area; 3-Annular groove; 31-Matching groove; 4-Flat sealing ring; 41-Matching part; 41a-Connecting part; 41b-Protrusion; 5-Annular welding ring. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] The boiler air preheater leak point quick repairing structure disclosed in the utility model is applied to the air preheater thin-wall steel pipe. In actual use, the damaged and air leakage prone position of the air preheater thin-wall steel pipe is usually close to the opening of the two ends of the thin-wall steel pipe due to flue gas scouring and flue gas corrosion. The thin-wall steel pipe with the damaged and air leakage prone position is referred to as the air preheater leak point pipe 1 in the application, and the air leakage of one end of the air preheater leak point pipe is taken as an example for description.

[0026] The inner sleeve 2 is coaxially sleeved at the inside of the air preheater leak point pipe 1 close to the opening end. The inner sleeve 2 comprises an interference section 21 and a sealing section 22. The interference section 21 is a hollow tubular structure, the radial cross-sectional shape of the tubular structure is consistent with the radial cross-sectional shape of the air preheater leak point pipe, and the matching relationship between the outer diameter size of the interference section and the inner diameter size of the air preheater leak point pipe is just capable of interference connecting the outer peripheral wall of the interference section with the inner peripheral wall of the air preheater leak point pipe, and the pipe wall of the interference section in the interference connecting relationship can plug the leak point of the air preheater leak point pipe.

[0027] The sealing section 22 is a tubular structure formed by extending from the radial end face of the interference section 21 along the axial direction. The tubular structure of the sealing section is a necking structure formed by gradually shrinking from the starting end, that is, the radial cross section of the sealing section is an isosceles trapezoid. The slope of the peripheral surface of the necking structure is not greater than 2°, that is, the slope of the oblique side of the isosceles trapezoid is not greater than 2°, and in addition, the axial length of the sealing section 22 is 1 / 6-1 / 7 of the axial length of the inner sleeve. Generally, the length of the inner sleeve is usually set to 35-40 cm, and the length of the sealing section is usually 5-7 cm, and the length of the interference section on the inner sleeve is usually between 28-33, that is, about 30 cm, which can usually cover the leak point at one end of the air preheater leak point pipe. The sealing section forms a necking structure because the interference section of the inner sleeve and the air preheater leak point pipe need to be interference connected, and the interference section outer diameter and the leak point pipe inner diameter size have high matching requirements. It is very difficult to align and sleeve when directly sleeving the inner sleeve into the leak point pipe, so the necking structure is designed to play a certain guiding role and facilitate the insertion of the inner sleeve into the leak point pipe from the sealing section. The design of the length of the sealing section and the necking slope mainly aims to ensure that the air volume of the inner sleeve is as small as possible compared with the air volume of the original thin-wall steel pipe, so as to reduce the reduction of heat exchange efficiency caused by the repairing structure. At the same time, the gap between the necking peripheral surface and the inner peripheral wall of the air preheater leak point pipe can also be used to accommodate the sealing structure for secondary sealing described later.

[0028] The outer circumferential surface of the transition region 23 is formed by the junction of the interference section 21 and the sealing section 22, and is an arc-shaped smooth surface that smoothly transitions from the interference section 21 to the sealing section 22. The arc-shaped smooth surface makes the insertion of the built-in sleeve more smooth.

[0029] The outer circumferential wall of the sealing section 22 is sealingly connected to the inner circumferential wall of the air preheater leak point pipe 1 by a sealing structure. The sealing structure includes an annular groove 3 formed on the outer circumferential wall of the sealing section 22, and a flat sealing ring 4 fixedly embedded in the annular groove 3. The flat sealing ring 4 can be made of a corrosion-resistant and high-temperature-resistant alloy material with a certain elasticity, and the outer surface of the flat sealing ring 4 tightly fits the inner circumferential wall of the air preheater leak point pipe 1. The sealing connection between the sealing section of the built-in sleeve and the leak point pipe can achieve secondary sealing between the two, which can further prevent the leakage of flue gas.

[0030] The specific embedding structure can be provided as follows: at least one embedding part 41 is formed on the inner side of the flat sealing ring 4 along the axial direction, the embedding part 41 includes a connecting part 41a extending along the axial direction from the inner side of the flat sealing ring and a protruding part 41b formed at the end of the connecting part, and the protruding part is in the form of a barb structure; an embedding groove 31 corresponding to the embedding part 41 is formed in the annular groove 3 of the built-in sleeve 2, and the shape of the embedding groove matches the shape of the embedding part; and the embedding part is clamped in the corresponding embedding groove. In this specific embodiment, in order to firmly embed the flat sealing ring in the annular groove 3, two embedding parts 41 are provided, one on the upper part and the other on the lower part of the inner side of the flat sealing ring. When the flat sealing ring is installed in the built-in sleeve, the protruding part 41b on the upper part or the lower part of the flat sealing ring can be clamped into the embedding groove at a certain inclination angle, and then the protruding part of the other part is clamped into the corresponding embedding groove by deforming the elastic flat sealing ring, thereby achieving the embedding of the flat sealing ring on the built-in sleeve.

[0031] In addition, an annular welding ring 5 is formed between the port of the interference section 21 of the built-in sleeve 2 or the outer circumferential surface and the port of the air preheater leak point pipe 1. The welding sealing of the annular welding ring can achieve the third sealing of the air leakage point.

[0032] In the installation of the structure, the deformed sealing ring is first embedded in the annular groove of the built-in sleeve, then the necked structure of the sealing section is aligned with the port of the leak point pipe, the built-in sleeve is hammered into the leak point pipe by external force until the port is flush or the axial length of the built-in sleeve is exposed at the end of the air preheater leak point pipe, and then an annular welding ring is welded between the port of the interference section of the built-in sleeve or the outer circumferential surface and the port of the air preheater leak point pipe by a welding process.

[0033] The quick repair structure can block the leakage point by the interference section of the built-in sleeve and the interference connection of the leakage point pipe, and can prevent the flue gas from leaking by the secondary sealing between the built-in sleeve and the inner wall of the leakage point pipe through the sealing structure. Furthermore, the welding sealing of the annular welding ring can achieve the effect of three times sealing. The above three effects can well eliminate the air leakage. In addition, the use of the built-in sleeve is not simply to block the leakage pipe, but the flue gas can continue to flow in the added built-in sleeve, that is, the air in the air preheater can still exchange heat with the flue gas flowing in the built-in sleeve when the air passes through the steel pipe with the repair structure, so as to ensure the normal output of the air preheater and the safe and economic operation of the boiler. Furthermore, the repair structure is convenient to use. After the sealing ring is nested, the sealing section can be directly aligned with one end of the thin-walled steel pipe where the air leakage occurs, and then the built-in sleeve is hammered into the leakage point pipe by using the slope of the sealing section and external force, which is quick and convenient.

[0034] Finally, it should be pointed out that: the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some technical features, as long as they are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. shall be included in the protection scope of the present application.

Claims

1. A boiler air preheater leak point quick repair structure comprising an air preheater leak point pipe (1), characterized by: The inner coaxial sleeve (2) of the air preheater leakage tube (1) near the opening end comprises an interference section (21) and a sealing section (22), wherein the outer peripheral wall of the interference section (21) is connected with the inner peripheral wall of the air preheater leakage tube (1) in interference, and the outer peripheral wall of the sealing section (22) is connected with the inner peripheral wall of the air preheater leakage tube (1) in sealing structure.

2. The quick fix structure for boiler air preheater leakage point according to claim 1, characterized in that: The sealing section (22) of the inner coaxial sleeve (2) is a necked structure extending from the radial end face of the interference section (21) and gradually shrinking inward, and the slope of the peripheral surface of the necked structure is not greater than 2°.

3. The quick fix structure for boiler air preheater leakage point according to claim 2, characterized in that: The axial length of the sealing section (22) of the inner coaxial sleeve (2) is 1 / 6-1 / 7 of the axial length of the inner coaxial sleeve (2).

4. The quick fix structure for boiler air preheater leakage point according to claim 1, characterized in that: The transition zone (23) of the outer peripheral surface of the interference section (21) and the sealing section (22) of the inner coaxial sleeve (2) is an arc-shaped smooth curved surface.

5. The quick fix structure for boiler air preheater leakage point according to claim 1, characterized in that: The sealing structure comprises an annular groove (3) formed on the outer peripheral wall of the sealing section (22), and a flat sealing ring (4) is fixedly embedded in the annular groove (3), and the outer surface of the flat sealing ring is tightly fitted on the inner peripheral wall of the air preheater leakage tube (1).

6. The quick fix structure for boiler air preheater leakage point according to claim 5, characterized in that: At least one embedding part (41) is formed on the inner side surface of the flat sealing ring (4) along the axial direction, and an embedding groove (31) is formed in the annular groove (3) of the inner coaxial sleeve (2) corresponding to the embedding part (41), and the embedding part is clamped in the corresponding embedding groove.

7. The quick fix structure for boiler air preheater leakage point according to claim 6, characterized in that: The embedding part (41) comprises a connecting part (41a) extending from the inner side surface of the flat sealing ring along the axial direction and a protruding part (41b) formed at the end of the connecting part, and the protruding part is in the form of an inverted hook structure.

8. The quick fix structure for boiler air preheater leakage point according to claim 6, characterized in that: The embedding part (41) is provided with two embedding parts, which are respectively located on the upper and lower parts of the inner side surface of the flat sealing ring.

9. The quick fix structure for boiler air preheater leakage point according to claim 1, characterized in that: An annular welding ring (5) is formed between the port of the interference section (21) of the inner coaxial sleeve (2) and the port of the air preheater leakage tube (1).

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