A vertical boiler with a water-cooled premixed combustion annular header

Abstract

This utility model discloses a vertical boiler with a water-cooled premixed combustion annular header, mainly composed of an upper annular header, a lower annular header, an inner ring of finned tubes, an outer ring of folded spiral finned tubes, a water-cooled premixed burner, a flue gas chamber shell, and a main body flue gas outlet. The upper and lower annular headers adopt an annular structure, which helps to prevent problems such as thermal stress deformation and cracking of the boiler tube sheet. The cavity formed by the inner ring of finned tubes and the water-cooled wall of the burner is the combustion chamber, and a flue gas isobaric chamber is formed between the flue gas chamber shell and the outer ring of folded spiral finned tubes. The key feature is that the flame emitted by the water-cooled premixed burner burns in the combustion chamber, and the high-temperature flue gas diffuses evenly outward. A narrow gap channel is formed between the fins of the inner ring of finned tubes and the water pipes. The flue gas undergoes intense laminar heat transfer through this gap, which can reduce the flue gas temperature to below 650℃. The flue gas then enters the flue gas isobaric chamber through the outer ring of folded spiral finned tubes with a high finning ratio, further reducing the flue gas temperature to below 280℃.

Description

Technical Field

[0001] This utility model relates to the field of boiler technology, specifically a vertical boiler with a water-cooled premixed combustion annular header, which is particularly suitable for steam generators or industrial boilers. Background Technology

[0002] Traditional water-cooled premixed burner boilers typically employ circular flat tube sheets, hemispherical heads, or butterfly heads for their upper and lower headers. These headers are connected by multiple drain pipes forming a tube bundle. This design presents several problems: the tube sheet is in direct contact with the high-temperature flue gas, making it prone to deformation or cracking due to significant temperature differences, thus affecting boiler lifespan; and the tube bundle connecting the upper and lower headers in traditional boilers is difficult to maintain, often requiring tube plugging, which impacts boiler thermal efficiency. This invention addresses these issues by integrating a ring-shaped header with double-ring reinforced heat exchange tubes, optimizing the flue gas flow path and thermal stress distribution to achieve efficient premixed combustion and stepped heat exchange. Utility Model Content

[0003] Therefore, this utility model provides a vertical boiler with a water-cooled premixed combustion annular header, which aims to solve the problem of deformation or cracking caused by a large temperature difference between the front and back of the tube plate of existing boilers, thus affecting the boiler's lifespan.

[0004] To achieve the above objectives, this utility model provides the following technical solution: A vertical boiler with a water-cooled premixed combustion annular header, mainly composed of an upper annular header, a lower annular header, an inner ring finned tube, an outer ring folded spiral finned tube, a water-cooled premixed burner, a flue gas chamber shell, and a main body flue gas outlet, etc. The upper and lower annular headers adopt an annular structure to form an annular header. The cavity formed by the inner ring finned tube and the water-cooled wall of the burner is the combustion chamber. A flue gas isobaric chamber is formed between the flue gas chamber shell and the outer ring folded spiral finned tube. The flame ejected by the water-cooled premixed burner burns in the combustion chamber, and the high-temperature flue gas diffuses outward evenly. A narrow gap channel is formed between the fins of the inner ring finned tube and the water pipe. The channel gap is 0.1-4mm. The flue gas undergoes intense laminar heat transfer through this gap and enters the outer ring folded spiral finned tube with a high finning rate and flows into the flue gas isobaric chamber.

[0005] Preferably, the upper annular header and the lower annular header are coaxially arranged, and the inner ring finned tube, the outer ring folded spiral finned tube and the burner water-cooled wall are arranged vertically between them.

[0006] Preferably, the inner fin tube adopts a curved fin structure, the inner diameter of the fin is larger than the outer diameter of the water pipe, the fins and adjacent water pipes are arranged concentrically, and the width of the gap between them is uniform, maintained between 0.1 and 4 mm, preferably 0.5 to 3 mm.

[0007] Preferably, a burner water-cooled wall is provided on one side of the annular header, and burner nozzle fins are provided between the water pipes of the water-cooled wall.

[0008] Preferably, the burner water-cooled wall is arranged in a straight line.

[0009] Preferably, the burner water-cooled wall is arranged in a curved pattern.

[0010] Preferably, the outer ring folded spiral fin tube is processed by folding the fins, and the cross-section is trapezoidal. The gap between the two outer ring folded spiral fin tubes should be maintained at 0.2 to 5 mm.

[0011] Preferably, the water-cooled premixed burner is provided with observation holes on both sides.

[0012] Preferably, flue gas channels are provided between the inner ring finned tubes and between the outer ring folded spiral finned tubes, so that the flue gas can flow out evenly between each water pipe.

[0013] Preferably, a flue gas isobaric chamber is formed between the smoke chamber shell and the outer ring of folded spiral fin tubes.

[0014] Compared with existing technologies, the vertical boiler with a water-cooled premixed combustion annular header of this utility model realizes a combination of narrow-gap enhanced laminar flow heat transfer and high-finned spiral finned tube heat transfer. The gap between the inner ring water tube fins and the water tubes is 0.1 to 4 mm, forming a laminar flow enhanced heat transfer structure. The high-finned spiral finned tube adopts a folded fin process to reduce the flue gas passage between the spiral fins, increase the flue gas velocity, improve the convective heat transfer efficiency, and enable the boiler exhaust temperature to drop rapidly to below 280℃.

[0015] The inner finned tubes and the water-cooled wall of the burner form a cavity to form a combustion chamber, which increases the radiative heat transfer area of ​​the combustion chamber. The fuel burns in the combustion chamber and the flame radiates to all sides, which improves the radiative heat transfer of the boiler and can significantly reduce the furnace temperature.

[0016] The upper and lower annular headers adopt an annular structure, which effectively avoids the rigid constraint of the tube bundle group and helps to prevent problems such as thermal stress deformation and cracking of the boiler tube sheet.

[0017] The upper and lower annular header tube sheets of the boiler are only arranged with two rings of water pipes. Due to the combustion chamber naturally formed by the inner ring of water pipes, it is possible to repair or replace damaged boiler water pipes and also to repair the water-cooled premixed burner. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of an annular header water-cooled premixed boiler according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the flue gas flow of a water-cooled premixed boiler according to an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of a burner water-cooled wall arranged in a curved manner according to an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the inner ring finned tube structure according to an embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of the outer ring folded spiral fin tube structure according to an embodiment of the present invention.

[0024] In the attached diagram, 1-upper annular header, 2-lower annular header, 3-inner ring finned tube, 31-fin, 32-water pipe, 4-outer ring folded spiral finned tube, 5-water-cooled premixed burner, 6-smoke chamber shell, 7-body smoke outlet, 8-burner water-cooled wall, 81-water-cooled wall water pipe, 9-burner nozzle fin, 10-combustion chamber, 11-isobaric chamber, 12-natural gas inlet, 13-steam outlet, 14-air inlet, 15-observation hole, 16-drain outlet. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] like Figure 1-5 As shown, this utility model provides a vertical boiler with a water-cooled premixed combustion annular header. The overall structure of the boiler is as follows: The vertical boiler with a water-cooled premixed combustion annular header of this invention mainly consists of an upper annular header 1, a lower annular header 2, an inner ring finned tube 3, an outer ring folded spiral finned tube 4, a water-cooled premixed burner 5, a flue gas chamber shell 6, and a main body flue gas outlet 7. Both the upper annular header 1 and the lower annular header 2 adopt an annular structure. This structural design can effectively avoid the rigid constraint of the tube bundle group, fundamentally helping to prevent the boiler tube plate from deforming and cracking due to thermal stress, and greatly improving the structural stability and service life of the boiler.

[0031] Combustion chamber structure: The cavity formed by the inner finned tube 3 and the burner water-cooled wall 8 constitutes the combustion chamber 10. This structure increases the radiative heat transfer area of ​​the combustion chamber. When the fuel burns in the combustion chamber, the flame radiates to all sides, which can significantly improve the radiative heat transfer of the boiler, while effectively reducing the furnace temperature and improving combustion efficiency and safety.

[0032] Flue gas passage and heat exchange structure:

[0033] Inner finned tube heat exchange: A narrow gap channel is formed between the fins 31 of the inner finned tube 3 and the water pipe 32, and this gap is precisely controlled between 0.1 and 4 mm. When high-temperature flue gas passes through this gap, a violently enhanced laminar heat transfer phenomenon occurs, which can rapidly reduce the temperature of the flue gas after combustion to below 650°C. In some preferred embodiments, the narrow gap between the fins 31 of the inner finned tube 3 and the water pipe 32 is further optimized to 0.8–3 mm, which can more significantly enhance the laminar heat transfer effect and improve the heat transfer efficiency.

[0034] Heat exchange via outer ring folded spiral finned tubes: After heat exchange via the inner ring finned tubes, the flue gas enters the outer ring folded spiral finned tubes 4 with a high finning ratio, and then flows into the flue gas isobaric chamber 11. The outer ring folded spiral finned tubes 4 are manufactured using a folding process, and their cross-section has a trapezoidal structure. The folding amount can be flexibly set according to actual layout requirements. The gap between the two outer ring folded spiral finned tubes 4 is maintained at 0.2–5 mm. This structural design enhances convective heat transfer, further reducing the flue gas temperature to below 280°C, and finally, it is discharged from the main body's flue gas outlet 7.

[0035] Combustion system structure: Air enters the water-cooled premixed burner 5 through air inlet 14, while natural gas enters through natural gas inlet 12. Inside the water-cooled premixed burner 5, air and natural gas are fully premixed, and the resulting mixture is then evenly sprayed out through small holes on the burner nozzle fins 9, where it burns stably in the combustion chamber 10. Simultaneously, an observation port 15 is provided on the boiler, allowing operators to observe the combustion process in the combustion chamber in real time and adjust combustion parameters promptly to ensure stable and efficient combustion.

[0036] Steam and blowdown system structure: The steam generated by the boiler is transported out through steam outlet 13 to meet the steam needs of production and daily life. The water concentrated in the lower annular header 2 can be discharged through the bottom blowdown port 16 to ensure the stability of the water quality in the boiler and prevent water quality problems from affecting the normal operation and heat exchange efficiency of the boiler.

[0037] Selectable Arrangement of Burner Water-Cooled Walls: This application provides two embodiments, the main difference being the distribution of the burner water-cooled walls 8, while the rest of the structure remains the same. In one embodiment, the burner water-cooled walls can be arranged according to the actual boiler structure requirements, such as... Figure 2The diagram shows a linear arrangement; in another embodiment, as shown... Figure 3 The burner water-cooled walls shown are arranged in a curved pattern. This diverse arrangement can better adapt to different boiler design requirements and improve the versatility and applicability of the boiler.

[0038] Structural optimization of the inner finned tube: such as Figure 4 As shown, the inner finned tube 3 adopts a curved fin structure. The inner diameter of the fin 31 is larger than the outer diameter of the water pipe 32, and the fins 31 and the adjacent water pipes 32 are arranged concentrically. The width of the gap channel between them is uniform, maintained between 0.1 and 4 mm. In some more preferred embodiments, this gap width can be further optimized to 0.5 to 3 mm. Through this structural design, the laminar flow heat transfer effect of the flue gas can be further enhanced, and the overall heat transfer performance of the boiler can be improved.

[0039] Structural details of the outer ring folded spiral finned tube: such as Figure 5 As shown, the outer ring of folded spiral finned tubes 4 has a trapezoidal cross-section after folding. The amount of folding is precisely set according to the actual layout requirements, and the gap between the two outer rings of folded spiral finned tubes 4 is strictly maintained at 0.2-5mm. This structural design can effectively improve the flue gas velocity, enhance the convective heat transfer efficiency, and ensure that the boiler's exhaust gas temperature can be rapidly reduced to below 280℃, meeting the requirements of high efficiency, energy saving, and environmental protection.

[0040] This invention discloses a vertical boiler with a water-cooled premixed combustion annular header, achieving a combination of narrow-gap enhanced laminar flow heat transfer and high-finned spiral finned tube heat transfer. A gap of 0.1–4 mm is formed between the inner ring water tube fins and the water tubes, creating a laminar flow enhanced heat transfer structure. The high-finned spiral finned tubes employ a folded-fin process to reduce the flue gas passage between the spiral fins, increasing the flue gas velocity and improving convective heat transfer efficiency, allowing the boiler exhaust temperature to rapidly drop below 280℃. The cavity formed by the inner ring finned tubes and the burner water-cooled wall constitutes a combustion chamber, increasing the radiative heat transfer area of ​​the combustion chamber. Fuel burns within the combustion chamber, and the flame radiates outwards, increasing the boiler's radiative heat transfer and significantly reducing the furnace temperature. The upper and lower annular headers adopt an annular structure, effectively avoiding the rigid constraint of the tube bundle group and helping to prevent problems such as thermal stress deformation and cracking of the boiler tube sheet. The upper and lower annular header tube sheets of the boiler are only arranged with two rings of water pipes. Due to the combustion chamber naturally formed by the inner ring of water pipes, it is possible to repair or replace damaged boiler water pipes and also to repair the water-cooled premixed burner.

[0041] Working principle:

[0042] According to the design requirements, the upper annular header 1 and the lower annular header 2 are installed and fixed in an annular structure to ensure their stability. Then, the inner ring finned tubes 3 are installed in sequence. The narrow gap between the fins 31 and the water pipes 32 of the inner ring finned tubes 3 is set to 0.8mm, and a curved fin structure is adopted. The fins 31 and the adjacent water pipes 32 are arranged concentrically, and the gap channel width is uniform. Next, the burner water-cooled wall 8 is installed. In this embodiment, the burner water-cooled wall 8 is arranged in a straight line, forming a combustion chamber 10 with the inner ring finned tubes 3. Then, the outer ring folded spiral finned tubes 4 are installed. The gap between the two outer ring folded spiral finned tubes 4 is set to 0.3mm, and the folding amount is reasonably set according to the actual heat exchange requirements. Finally, the water-cooled premixed burner 5, the flue shell 6, and other components are installed to complete the overall assembly of the boiler.

[0043] Combustion Operation: Upon boiler startup, air enters the water-cooled premixed burner 5 through air inlet 14, and natural gas enters through natural gas inlet 12. Inside the water-cooled premixed burner 5, the air and natural gas are fully premixed and then ejected through small holes on the burner nozzle fins 9, where combustion takes place in the combustion chamber 10. Operators observe the combustion through the observation port 15 and adjust parameters such as the air and natural gas intake rates appropriately based on the actual combustion effect to ensure stable and efficient combustion.

[0044] Heat exchange and steam generation: High-temperature flue gas undergoes heat exchange sequentially through the inner ring finned tubes 3 and the outer ring folded spiral finned tubes 4. At the inner ring finned tubes 3, laminar heat transfer is enhanced through narrow gaps, reducing the flue gas temperature to below 650℃. At the outer ring folded spiral finned tubes 4, convective heat transfer is enhanced using a high-finning-ratio folding process, lowering the flue gas temperature to below 280℃ before it is discharged from the main body outlet 7. During this process, water absorbs heat and converts into steam, which is output through the steam outlet 13. Concentrated water in the lower annular header 2 is discharged through the bottom drain outlet 16, maintaining the normal operation and efficient heat exchange of the boiler. Real-time monitoring of steam quality ensures that the steam meets the requirements for production and daily life, such as controlling the steam dryness and impurity content within specified ranges.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vertical boiler of water-cooled premix combustion ring header, mainly composed of an upper ring header (1), a lower ring header (2), an inner circle finned tube (3), an outer circle folded fin spiral finned tube (4), a water-cooled premix burner (5), a smoke chamber shell (6), a body smoke outlet (7) and the like, characterized in that: The upper annular header (1) and the lower annular header (2) adopt an annular structure to form an annular header. The cavity formed by the inner ring finned tube (3) and the burner water-cooled wall (8) is the combustion chamber (10). A flue gas isobaric chamber (11) is formed between the flue gas shell (6) and the outer ring folded spiral finned tube (4). The water-cooled premixed burner (5) sprays flames that burn in the combustion chamber (10). The high-temperature flue gas diffuses outward evenly. A narrow gap channel is formed between the fins (31) of the inner ring finned tube (3) and the water pipe (32). The channel gap is 0.1 to 4 mm. The flue gas undergoes intense laminar heat transfer through this gap. The flue gas enters the outer ring folded spiral finned tube (4) with a high finning rate and flows into the flue gas isobaric chamber (11).

2. A water-tube boiler of the type defined in claim 1, characterised in that The upper annular header (1) and the lower annular header (2) are coaxially arranged, and the inner ring finned tube (3), the outer ring folded spiral finned tube (4) and the burner water-cooled wall (8) are vertically arranged between them.

3. A water-tube boiler of the once-through type with a water-cooled premix annular header according to claim 1, characterised in that, The inner fin tube (3) adopts a curved fin (31) structure. The inner diameter of the fin (31) is larger than the outer diameter of the water pipe (32). The fin (31) and the adjacent water pipe (32) are arranged concentrically. The width of the gap between them is uniform and maintained between 0.1 and 4 mm, preferably 0.5 to 3 mm.

4. A water-tube boiler of the type defined in claim 1, characterised in that A burner water-cooled wall (8) is provided on one side of the annular header, and burner nozzle fins (9) are provided between the water-cooled wall water pipes (81).

5. The vertical boiler with a water-cooled premixed combustion annular header according to claim 4, characterized in that, The burner water-cooled wall (8) is arranged in a straight line.

6. The vertical boiler with a water-cooled premixed combustion annular header according to claim 4, characterized in that, The burner water-cooled wall (8) is arranged in a curved pattern.

7. The vertical boiler with a water-cooled premixed combustion annular header according to claim 1, characterized in that, The outer ring folded spiral fin tube (4) is processed by folding its wings, and its cross-section is trapezoidal. The gap between the two outer ring folded spiral fin tubes (4) should be maintained at 0.2 to 5 mm.

8. The vertical boiler with a water-cooled premixed combustion annular header according to claim 1, characterized in that, The water-cooled premixed burner (5) is provided with observation holes (15) on both sides.

9. The vertical boiler with a water-cooled premixed combustion annular header according to claim 1, characterized in that, There are flue gas channels between the inner ring finned tubes (3) and between the outer ring folded spiral finned tubes (4), so that the flue gas can flow out evenly between each water pipe.

10. The vertical boiler with a water-cooled premixed combustion annular header according to claim 1, characterized in that, A flue gas isobaric chamber (11) is formed between the smoke chamber shell (6) and the outer ring folded spiral fin tube (4).

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