CN215447561U

CN215447561U - Finned tube heating surface structure and economizer

Info

Publication number: CN215447561U
Application number: CN202120651606.7U
Authority: CN
Inventors: 康德林
Original assignee: Datang Qinling Power Generation Co ltd
Current assignee: Datang Qinling Power Generation Co ltd
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2022-01-07
Anticipated expiration: 2031-03-30

Abstract

The utility model discloses a finned tube heating surface structure and an economizer, which comprise a heating tube, and a fin and an anti-wear plate which are connected with the heating tube; the plurality of fins are arranged in parallel and arranged along the radial direction of the heated tube, the wear-resistant plates penetrate through the fins and are arranged along the axial direction of the heated tube, and the plurality of wear-resistant plates are arranged along the circumference of the heated tube and are distributed in a radial shape. The anti-abrasion sheet is arranged on the heated tube opposite to the windward side, so that the problem that the finned tube on the heated surface of the existing low-temperature economizer is not anti-abrasion and causes leakage is thoroughly solved, and the anti-abrasion sheet and the fin are combined on the heated tube, so that the effects of preventing the leakage of the heated tube and ensuring the heat transfer area of the heated tube are achieved; the anti-abrasion sheet is directly welded on the heated tube, the absorbed smoke heat is directly transferred to the heated surface tube, the heated tube area is increased, the temperature of the medium in the tube is increased, the anti-abrasion effect is achieved, the heat utilization rate is also improved, and the anti-abrasion pipe has high use value and popularization value.

Description

Finned tube heating surface structure and economizer

Technical Field

The utility model relates to the technical field of low-temperature economizers, in particular to a finned tube heating surface structure and an economizer.

Background

In order to improve the efficiency of a power plant boiler and utilize the waste heat of boiler flue gas, a low-temperature economizer is generally arranged in a tail flue of a domestic thermal power plant at present, and the low-temperature economizer is arranged behind a preheater and in front of electric dust remover equipment and belongs to high smoke dust arrangement. The low-temperature economizer module structure is formed by arranging front and rear groups of 60 pipes from top to bottom, 12 groups of finned pipes from front to rear along the air flow direction, and 2 pipes in each group, wherein the total number of the finned pipes is 24 heated pipes, and the specification of the cabinet is phi 38 multiplied by 4.5mm, which is shown in figure 1.

The anti-abrasion measure of the low-temperature economizer module design is that a dummy pipe is anti-abrasion, namely a pipe (shown in figure 2) which has the same specification and no medium circulation inside is additionally arranged at the front part of the windward side of the heated surface pipe to be protected by 90-150 mm, when the dust-containing smoke washes the heating surface pipe, firstly the anti-abrasion dummy pipe is washed to protect the heating surface pipe from being abraded by fly ash, in the actual installation, because a certain distance is arranged between the anti-abrasion dummy pipe and the protected heating surface pipe, the distance is summarized according to a dynamic field simulation test, when the distance is too small, the flue gas passes through the dummy pipe, the heating surface of the adjacent pipe bank is easy to be washed, when the distance is too large, the protection effect can not be achieved, the flue gas is converged behind the dummy pipe to continuously wash the heating surface pipe, the leakage of the heating surface caused by the abrasion of fly ash frequently occurs during the operation of the heating pipe of the low-temperature economizer working in a high-dust environment, so that the equipment can not normally operate.

SUMMERY OF THE UTILITY MODEL

Aiming at the problems in the prior art, the utility model provides a finned tube heating surface structure and an economizer, wherein a fly ash abrasion prevention structure is arranged on a heating tube, and a heat exchange fin is arranged on the outer part of the heating tube, so that the problem of fly ash abrasion on the heating surface of a low-temperature economizer working in a high-dust environment is solved under the condition of ensuring that the heat transfer area of the heating tube is not reduced.

The utility model is realized by the following technical scheme:

a finned tube heating surface structure comprises a heating tube, and fins and an anti-wear plate which are connected with the heating tube;

the plurality of fins are arranged in parallel and arranged along the radial direction of the heated tube, the wear-resistant plates penetrate through the fins and are arranged along the axial direction of the heated tube, and the plurality of wear-resistant plates are arranged along the circumference of the heated tube and are distributed in a radial shape.

Preferably, the plurality of wear plates are distributed in a fan shape and are positioned on the windward side of the heated pipe.

Preferably, the distance between the top ends of the wear plates at the two extreme sides is equal to the diameter of the heated tube.

Preferably, the central angle alpha formed by the wear-resistant plates at the two extreme sides and the center of the heated tube is 30-50 degrees.

Preferably, the fins are provided with avoiding holes, and the wear-resistant plate penetrates through the avoiding holes of each fin to be fixedly connected with the heated tube.

Preferably, the fins comprise two sub-fins with the same structure, the edge of each sub-fin is provided with a groove for assembling the heated tube and the anti-wear sheet, and the two fins are symmetrically arranged on two sides of the heated tube.

Preferably, the number of the heated pipes is two, the two heated pipes are arranged in parallel, and the anti-abrasion piece is arranged on the heated pipe close to the windward side.

Preferably, the number of the wear-proof sheets is sheets.

The economizer comprises the finned tube heating surface structure.

Compared with the prior art, the utility model has the following beneficial technical effects:

according to the finned tube heating surface structure provided by the utility model, the anti-abrasion sheet is arranged on the heating tube opposite to the windward surface, the anti-abrasion plates are arranged in a fan-shaped radial manner, fly ash particles in boiler flue gas directly impact the anti-abrasion plates and are reflected between two adjacent anti-abrasion plates, so that the impact force of the fly ash particles is greatly reduced, the abrasion of the heating tube is reduced, the heating tube is protected from failure caused by scouring and thinning, the problem that finned tubes on the heating surface of the existing low-temperature economizer are not anti-abrasion and cause failure is thoroughly solved, the anti-abrasion sheet and fins are combined on the heating tube, and the effects of preventing the leakage of the heating tube and ensuring the heat transfer area of the heating tube are achieved; the anti-abrasion sheet is directly welded on the heated tube, and the absorbed smoke heat is directly transferred to the heated tube, thereby increasing the area of the heated tube, improving the temperature of the medium in the tube, playing the role of anti-abrasion and improving the heat utilization rate.

Drawings

FIG. 1 is a three-view illustration of an economizer, including a front view, a top view, and a side view;

FIG. 2 is a schematic diagram of a conventional wear tube and heated tube;

FIG. 3 is a cross-sectional view of a heated tube of the present invention;

FIG. 4 is a view showing a positional relationship between a heated tube and a fin according to the present invention;

FIG. 5 is a cross-sectional view of a heated tube of the present invention;

FIG. 6 is a schematic diagram of the wear prevention of the fin of the present invention;

FIG. 7 is a structural view of a fin of the present invention.

In the figure: 1. a heated tube; 2. a fin; 3. a wear plate.

Detailed Description

The present invention will now be described in further detail with reference to the attached drawings, which are illustrative, but not limiting, of the present invention.

Referring to fig. 2-5, a heating surface structure of a finned tube comprises a heated tube 1, and a fin 2 and a wear-resistant plate 3 connected with the heated tube.

The plurality of wear-resistant plates are arranged along the circumference of the heated tube and are distributed in a radial mode, the length direction of the wear-resistant plates is arranged along the axial direction of the heated tube, the plurality of fins 2 are arranged in parallel, and the fins are arranged along the radial direction of the heated tube.

The wear-resistant plates are arranged in a fan-shaped radial mode, the fan-shaped cambered surfaces are opposite to the direction of flue gas, and the wear-resistant plates are arranged at a certain inclination, so that fly ash particles in the flue gas of the boiler directly impact the wear-resistant plates and are reflected between every two adjacent wear-resistant plates, the impact force of the fly ash particles is greatly reduced, the abrasion of the heated pipe is reduced, and the heated pipe is protected from being invalid due to scouring and thinning.

The number of the wear-resistant plates is 3, the width of each wear-resistant plate is 6mm, the height of each wear-resistant plate is 12mm, and a central angle alpha formed by the wear-resistant plates at two ends and the circle center of the heated tube is 30-50 degrees.

The central angle alpha and the length of the center line of the tops of the flat steels at two sides are the diameter of the heated surface pipe, that is, the distance between the tops of the two anti-wear sheets at the two sides is the diameter of the heated pipe, so that the heated pipe can be completely shielded, for example, the distance between the tops of the two anti-wear sheets at the two sides is smaller than the diameter of the heated pipe, so that the heated pipe cannot be completely shielded, the fly ash in the flue gas can wear the heated pipe, and similarly, when the distance between the tops of the two anti-wear sheets at the two sides is larger than the diameter of the heated pipe, the flow cross-section area of the flue gas between the pipe rows can be reduced, the flow velocity of the flue gas is increased, and the heated pipe at the rear row is easily worn.

Under the condition that the heights of the anti-wear pieces are fixed, the central angle of each anti-wear piece controls the distance between the tops of the two anti-wear pieces at the two extreme sides, and the relationship between the central angle alpha and the radius of the heated surface pipe is as follows, namely the calculation method of the central angle alpha is expressed as follows:

for example, the heated pipe diameter Φ 38 of the low-temperature economizer is calculated according to the formula: α is 62 °.

The wear-resistant plate is flat steel, one end of the wear-resistant plate is fixedly connected with the heated pipe, the other end of the wear-resistant plate is a free end, in a fly ash wear mechanism of the heated surface, the impact of fly ash particles on the surface of the pipe is divided into a vertical mode and an oblique mode, the wear is generally found to be mainly generated between the impact angle alpha of ash particles in a range of 30-50 degrees through field inspection, three wear-resistant flat steels are arranged on the left side, the middle side and the right side of the heated surface pipe in a targeted mode, the vertical impact of the ash particles can be prevented through the middle arrangement, and the included angle formed by the left flat steel and the right flat steel is 30-50 degrees, so that the oblique impact of the ash particles can be effectively prevented. And secondly, the anti-abrasion sheet is made of 6 multiplied by 12mm flat steel which is a common welding material in a power plant or a manufacturing plant, is convenient to repair and maintain, has stronger rigidity and strength and is not easy to deform and damage when being used as the anti-abrasion flat steel.

Each fin 2 is provided with an avoiding hole, and the wear-resistant plate penetrates through the avoiding hole of each fin and is fixedly connected with the heated tube.

The fin 2 comprises two sub-fins with the same structure, the edge of each sub-fin is provided with a groove for assembling the heated tube and the anti-abrasion sheet, the two fins are symmetrically arranged on two sides of the heated tube, and the sub-fins and the heated tube are integrated through welding.

The two heated tubes are arranged in parallel, and the anti-abrasion sheet is arranged on the heated tube close to the windward side.

An economizer comprises the fin heating surface structure.

The utility model also provides a fin heating surface tube structure, wherein the anti-abrasion sheet is arranged on the heating tube opposite to the windward surface, so that the problem of leakage caused by no abrasion of the fin tube on the heating surface of the existing low-temperature economizer is thoroughly solved, and the anti-abrasion sheet and the fin are combined on the heating tube, thereby playing the roles of preventing the leakage of the heating tube and ensuring the heat transfer area of the heating tube; the anti-abrasion sheet is directly welded on the heated tube, and the absorbed smoke heat is directly transferred to the heated tube, thereby increasing the area of the heated tube, improving the temperature of the medium in the tube, playing the role of anti-abrasion and improving the heat utilization rate.

Secondly, because the heating area of the anti-abrasion sheet is larger than the reduced fin area, the pitch between the fins can be widened by 30-50% under the condition that the total heat transfer area is not changed, the current 20mm is increased to 25-30 mm, the smoke flow area is increased, the flow resistance of high-dust smoke is reduced, and the problem of large-area dust accumulation existing in the actual operation of the heating surface of the low-temperature economizer is solved.

In addition, the fin heating surface with the anti-abrasion piece is adopted to replace the heating surface false pipe anti-abrasion technology of the existing low-temperature economizer, the anti-abrasion false pipe can be removed, the geometric size of the low-temperature economizer module is reduced, and the structure of the optimized low-temperature economizer is more reasonable.

Finally, in the design of the low-temperature economizer in China at present, the wear prevention adopts a fake tube wear prevention technology, the heated tube adopts a fin tube technology, leakage is frequent after about 2 years of operation, the low-temperature economizer is disconnected or dismantled in the operation of a plurality of power plants at present, serious economic loss is caused, and the problem of fly ash wear leakage existing in the low-temperature economizer at present can be thoroughly solved by adopting the fin tube technology.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A heating surface structure of a fin tube is characterized by comprising a heating tube (1), and a fin (2) and a wear-resistant plate (3) which are connected with the heating tube;

the fins (2) are arranged in parallel and are arranged along the radial direction of the heated tube, the wear-resistant plates penetrate through the fins and are arranged along the axial direction of the heated tube, and the wear-resistant plates are distributed along the circumference of the heated tube in a radial mode.

2. The fin tube heating surface structure of claim 1, wherein the plurality of wear plates are arranged in a fan shape on a windward side of the heated tube.

3. A fin tube heating surface structure according to claim 1, wherein the distance between the top ends of the wear plates at the two extreme sides is equal to the diameter of the heated tube (1).

4. The heated surface structure of a finned tube as claimed in claim 1, wherein the central angle α formed by the outermost wear plate and the center of the heated tube is 30 ° to 50 °.

5. The heating surface structure of the fin tube as claimed in claim 1, wherein the fin (2) is provided with an avoiding hole, and the wear-resistant plate passes through the avoiding hole of each fin and is fixedly connected with the heating tube.

6. A fin tube heating surface structure as claimed in claim 5, wherein the fin (2) comprises two sub-fins of the same structure, the edge of each sub-fin is provided with a groove for assembling a heating tube and an anti-wear sheet, and the two fins are symmetrically arranged on two sides of the heating tube.

7. The fin tube heating surface structure of claim 5, wherein the number of the heating tubes is two, the two heating tubes are arranged in parallel, and the wear prevention sheet is arranged on the heating tube near the windward side.

8. The fin tube heating surface structure of claim 7, wherein the number of the wear prevention sheets is 3.

9. An economizer comprising the finned tube heating surface structure of any one of claims 1 to 8.