New heat exchange element and anti-blocking mechanism of air preheater of coal-fired boiler

Abstract

The utility model relates to a new heat exchange element and anti -blocking mechanism of coal -fired boiler air preheater, it includes preheating box, preheating box top is provided with flue gas import, preheating box lower part is provided with flue gas export, preheating box both sides are provided with air duct, preheating box inside is provided with heat exchange storehouse, flue gas import, flue gas export with heat exchange storehouse intercommunication, heat exchange storehouse both sides are provided with air storehouse, air duct with air storehouse intercommunication, the fixed setting of baffle between air storehouse and heat exchange storehouse, the arrangement of heat exchange element is provided with between baffle, through heat exchange element will two air storehouse intercommunication, heat exchange storehouse middle part is provided with anti -blocking mechanism, this device can increase the heat exchange area, strengthen the fluid heat exchange in pipe, make the heat exchange between air and flue gas more fully, promote preheating effect, reduce energy consumption, avoid the occurrence jam.

Description

Technical Field

[0001] This utility model belongs to the technical field of boiler air preheaters, specifically relating to a novel heat exchange element and anti-clogging mechanism for air preheaters in coal-fired boilers. Background Technology

[0002] The air preheater (Air Preheater) of a coal-fired boiler is a crucial heat exchange device in the boiler's tail flue. Its core function is to utilize the waste heat from the flue gas discharged from the boiler to heat the combustion air that is about to enter the furnace, thereby significantly improving boiler thermal efficiency and reducing fuel consumption. Existing traditional tubular air preheaters mainly use bare tube or ordinary finned tube heat exchange elements, coupled with a fixed gap sealing structure. Once the heat transfer of the air preheater is obstructed, it will have a very adverse effect on the boiler's efficiency.

[0003] Traditional heat exchange elements, such as ordinary bare tubes or conventional finned tubes, cannot achieve efficient heat exchange simultaneously on a single heat transfer surface to enhance heat transfer. Furthermore, coal-fired flue gas contains a large amount of fly ash and acidic gases. When the flue gas temperature drops below the dew point in the air preheater, sulfuric acid mist forms, adhering to the fly ash and forming hard, low-temperature, adhesive ash deposits on the surface of the heat exchange elements. This ash accumulation not only significantly reduces heat exchange efficiency but also blocks flue gas passages. Summary of the Invention

[0004] The purpose of this utility model is to provide a new type of heat exchange element and anti-clogging mechanism for air preheaters of coal-fired boilers, so as to solve the problems mentioned in the background art.

[0005] The purpose of this utility model is achieved as follows: a novel heat exchange element and anti-clogging mechanism for an air preheater of a coal-fired boiler, comprising a preheating box, a flue gas inlet at the top of the preheating box, a flue gas outlet at the bottom of the preheating box, air pipes on both the front and rear sides of the preheating box, a heat exchange chamber inside the preheating box, the flue gas inlet and outlet connected to the heat exchange chamber, air chambers on both the left and right sides of the heat exchange chamber, air pipes connected to the air chambers, a partition fixedly installed between the air chambers and the heat exchange chamber, heat exchange elements arranged between the partitions, the two air chambers connected by the heat exchange elements, and an anti-clogging mechanism in the middle of the heat exchange chamber.

[0006] The heat exchange element includes a heat exchange tube, on the outer surface of which three-dimensional fins are fixedly arranged, and on the inner surface of which longitudinal micro-protrusions are fixedly arranged. The three-dimensional fins and longitudinal micro-protrusions can effectively increase the heat exchange area.

[0007] The three-dimensional rib has a baffle hole inside, and the baffle hole is rhomboid in shape.

[0008] The anti-clogging mechanism includes a panel and a cleaning pipe. A limit frame is fixedly installed on the side of the panel. A connecting head is provided in the middle of the panel. An air guide pipe is provided on the outside of the connecting head. A straight pipe is connected to the bottom of the cleaning pipe. The outer end of the straight pipe is connected to the connecting head. A reinforcing plate is provided between the straight pipe and the limit frame. A steering component is provided between the straight pipe and the cleaning pipe. Nozzles are provided on both the upper and lower sides of the cleaning pipe.

[0009] The steering assembly includes a steering gear and a drive motor. The steering gear is fixed to the lower part of the sweeping pipe, and the drive motor is fixed to the straight pipe. The drive motor and the steering gear cooperate with each other. The drive motor can drive the steering gear to rotate, thereby driving the sweeping pipe to rotate.

[0010] A flip cover is hinged to the outside of the nozzle, and a torsion spring is provided between the flip cover and the nozzle. The flip cover prevents impurities from clogging the nozzle.

[0011] A positioning seat is fixedly provided on the side of the panel, and a positioning screw is screwed into the positioning seat.

[0012] The preheating box has a slot on the side near the anti-blocking mechanism, the panel has an insert plate on the inside, and the slot has a sealing strip inside.

[0013] The beneficial effects of this utility model are: A dual-enhanced heat transfer structure, combining internal and external features, is created using three-dimensional fins with diamond-shaped perforations and longitudinal micro-protrusions. The perforations disrupt the boundary layer, increasing flue gas turbulence and improving heat transfer efficiency; the longitudinal micro-protrusions increase the roughness of the inner surface, enhancing heat transfer within the tube. This design increases the heat transfer area, strengthens internal fluid heat transfer, and allows for more thorough heat exchange between air and flue gas, improving preheating and reducing energy consumption.

[0014] Nozzles are installed on both the upper and lower sides of the cleaning pipe to spray cleaning media onto the heat exchange elements, promptly removing accumulated dust, dirt, and other impurities from the surface of the heat exchange elements, preventing blockages, and ensuring smooth air and flue gas circulation. The cleaning pipe can be rotated by the steering component, thereby changing the spray direction of the nozzles, achieving comprehensive cleaning of heat exchange elements in different locations, expanding the cleaning range, and improving the cleaning effect. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the preheating box for the novel heat exchange element and anti-clogging mechanism of the air preheater for a coal-fired boiler according to this utility model.

[0016] Figure 2 This is a structural diagram of the heat exchange chamber and air chamber of the novel heat exchange element and anti-clogging mechanism of the air preheater for a coal-fired boiler according to this utility model.

[0017] Figure 3This is a structural diagram of the heat exchange element of the novel heat exchange element and anti-clogging mechanism for the air preheater of a coal-fired boiler according to this utility model.

[0018] Figure 4 This is a three-dimensional rib structure diagram of the novel heat exchange element and anti-clogging mechanism of the air preheater for a coal-fired boiler according to this utility model.

[0019] Figure 5 This is a longitudinal micro-convex structure diagram of the novel heat exchange element and anti-clogging mechanism of the air preheater for a coal-fired boiler according to this utility model.

[0020] Figure 6 This is a structural diagram of the anti-blocking mechanism of the novel heat exchange element and anti-blocking mechanism for the air preheater of a coal-fired boiler according to this utility model.

[0021] Figure 7 This is a diagram showing the nozzle structure of the novel heat exchange element and anti-clogging mechanism for the air preheater of a coal-fired boiler according to this utility model.

[0022] Figure 8 This is a structural diagram of the slot and insert plate of the novel heat exchange element and anti-clogging mechanism for the air preheater of a coal-fired boiler according to this utility model.

[0023] In the diagram: 1. Preheating box; 2. Flue gas inlet; 3. Flue gas outlet; 4. Air duct; 5. Heat exchange chamber; 6. Air chamber; 7. Baffle; 8. Heat exchange element; 9. Anti-clogging mechanism; 10. Heat exchange tube; 11. Three-dimensional fins; 12. Longitudinal micro-protrusion; 13. Baffle hole; 14. Panel; 15. Limiting bracket; 16. Straight pipe; 17. Connecting head; 18. Air guide pipe; 19. Cleaning pipe; 20. Nozzle; 21. Reinforcing plate; 22. Positioning seat; 23. Positioning screw; 24. Flip cover; 25. Slot; 26. Insert plate; 27. Steering assembly. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings. Example 1

[0025] like Figure 1-5 As shown, a novel heat exchange element and anti-clogging mechanism for an air preheater of a coal-fired boiler includes a preheating box 1, a flue gas inlet 2 at the top of the preheating box 1, a flue gas outlet 3 at the bottom of the preheating box 1, air ducts 4 on both the front and rear sides of the preheating box 1, a heat exchange chamber 5 inside the preheating box 1, the flue gas inlet 2 and the flue gas outlet 3 connected to the heat exchange chamber 5, air chambers 6 on both the left and right sides of the heat exchange chamber 5, the air ducts 4 connected to the air chambers 6, a partition 7 fixedly installed between the air chambers 6 and the heat exchange chamber 5, heat exchange elements 8 arranged between the partitions 7, connecting the two air chambers 6 through the heat exchange elements 8, and an anti-clogging mechanism 9 in the middle of the heat exchange chamber 5.

[0026] For better performance, the heat exchange element 8 includes a heat exchange tube 10, with three-dimensional fins 11 fixedly arranged on the outer surface of the heat exchange tube 10 and longitudinal micro-protrusions 12 fixedly arranged on the inner surface of the heat exchange tube 10.

[0027] For better results, the three-dimensional rib 11 is provided with a baffle hole 13 inside, and the baffle hole 13 is rhomboid in shape.

[0028] In use, the flue gas generated by the coal-fired boiler enters the heat exchange chamber 5 through the flue gas inlet 2 above the preheating box 1. After exchanging heat with the heat exchange element 8 inside the heat exchange chamber 5, it is discharged from the flue gas outlet 3 below the preheating box 1. Air enters the air chamber 6 through the air pipes 4 on both sides of the preheating box 1. When passing through the heat exchange element 8, it exchanges heat with the flue gas in the heat exchange chamber 5. The preheated air is then output from another air chamber 6 through the air pipe 4 and supplied to the boiler for combustion.

[0029] Furthermore, the three-dimensional fins 11 on the outer surface of the heat exchange tube 10 enhance the heat exchange between the flue gas and the outer wall of the heat exchange tube 10 by increasing the heat exchange area and creating turbulence; the longitudinal micro-protrusions 12 on the inner surface enhance the heat exchange between the air and the inner wall of the heat exchange tube 10, enabling efficient and continuous heat exchange between the air and the flue gas. The design of fixing the three-dimensional fins 11 to the outer surface of the heat exchange tube 10 and the longitudinal micro-protrusions 12 to the inner surface of the heat exchange tube 10 ensures the stability of the structure, allowing it to continuously perform good heat exchange during long-term operation and extending the service life of the equipment. Example 2

[0030] like Figure 1-8 As shown, a novel heat exchange element and anti-clogging mechanism for an air preheater of a coal-fired boiler includes a preheating box 1, a flue gas inlet 2 at the top of the preheating box 1, a flue gas outlet 3 at the bottom of the preheating box 1, air ducts 4 on both the front and rear sides of the preheating box 1, a heat exchange chamber 5 inside the preheating box 1, the flue gas inlet 2 and the flue gas outlet 3 connected to the heat exchange chamber 5, air chambers 6 on both the left and right sides of the heat exchange chamber 5, the air ducts 4 connected to the air chambers 6, a partition 7 fixedly installed between the air chambers 6 and the heat exchange chamber 5, heat exchange elements 8 arranged between the partitions 7, connecting the two air chambers 6 through the heat exchange elements 8, and an anti-clogging mechanism 9 in the middle of the heat exchange chamber 5.

[0031] For better performance, the heat exchange element 8 includes a heat exchange tube 10, with three-dimensional fins 11 fixedly arranged on the outer surface of the heat exchange tube 10 and longitudinal micro-protrusions 12 fixedly arranged on the inner surface of the heat exchange tube 10.

[0032] For better results, the three-dimensional rib 11 is provided with a baffle hole 13 inside, and the baffle hole 13 is rhomboid in shape.

[0033] For better results, the anti-clogging mechanism 9 includes a panel 14 and a cleaning pipe 19. A limit frame 15 is fixedly installed on the side of the panel 14. A connecting head 17 is provided in the middle of the panel 14. An air guide pipe 18 is provided on the outside of the connecting head 17. A straight pipe 16 is connected to the bottom of the cleaning pipe 19. The outer end of the straight pipe 16 is connected to the connecting head 17. A reinforcing plate 21 is provided between the straight pipe 16 and the limit frame 15. A steering assembly 27 is provided between the straight pipe 16 and the cleaning pipe 19. Nozzles 20 are provided on both the upper and lower sides of the cleaning pipe 19.

[0034] For better performance, the steering assembly 27 includes a steering gear and a drive motor. The steering gear is fixed to the lower part of the cleaning pipe 19, and the drive motor is fixed to the straight pipe 16. The drive motor and the steering gear cooperate with each other.

[0035] For better results, a hinged cover 24 is provided on the outer side of the nozzle 20, and a torsion spring is provided between the hinged cover 24 and the nozzle 20. When cleaning is not required, the hinged cover 24 closes the nozzle 20 under the action of the torsion spring to prevent impurities from entering the nozzle 20 and causing blockage.

[0036] For better performance, a positioning seat 22 is fixedly provided on the side of the panel 14, and a positioning screw 23 is screwed into the positioning seat 22. The positioning seat 22 and the positioning screw 23 facilitate the installation, disassembly and positioning of the anti-blocking mechanism 9, and make daily maintenance and repair easier.

[0037] For better performance, a slot 25 is provided on the side of the preheating box 1 near the anti-blocking mechanism 9, and an insert plate 26 is provided on the inner side of the panel 14. A sealing strip is provided inside the slot 25. The sealing strip can prevent flue gas leakage and ensure the sealing and safety of the equipment operation.

[0038] In another embodiment, the anti-clogging mechanism 9 is activated periodically for cleaning based on the boiler's operating conditions and ash accumulation. The valve is opened, and cleaning gas enters the connecting head 17 through the gas guide pipe 18, then through the straight pipe 16 into the cleaning pipe 19, and finally is ejected at high speed from the nozzles 20 on both sides of the cleaning pipe 19. During the spraying process, the flip-top 24 on the outside of the nozzle 20 opens under the pressure of the gas, overcoming the spring force of the torsion spring. The cleaning gas is sprayed onto the surface of the heat exchange element 8, blowing off accumulated ash, scale, and other impurities, preventing blockage of the heat exchange element 8. Cleaning particles can also be added to the cleaning gas to further enhance the cleaning effect. Additionally, the drive motor is started, causing the steering gear to rotate, which in turn rotates the cleaning pipe 19, adjusting the spray direction of the nozzles 20 in the cleaning pipe 19 to ensure comprehensive coverage of all parts of the heat exchange element 8.

Claims

1. A novel heat exchange element and anti-clogging mechanism for an air preheater in a coal-fired boiler, comprising a preheating box, characterized in that: A flue gas inlet is located above the preheating box, and a flue gas outlet is located below the preheating box. Air ducts are provided on both the front and rear sides of the preheating box. A heat exchange chamber is provided inside the preheating box. The flue gas inlet and outlet are connected to the heat exchange chamber. Air chambers are provided on both the left and right sides of the heat exchange chamber, and air ducts are connected to the air chambers. A partition is fixedly installed between the air chambers and the heat exchange chamber. Heat exchange elements are arranged between the partitions to connect the two air chambers. An anti-blocking mechanism is provided in the middle of the heat exchange chamber.

2. The novel heat exchange element and anti-clogging mechanism for a coal-fired boiler air preheater according to claim 1, characterized in that: The heat exchange element includes a heat exchange tube, on the outer surface of which three-dimensional fins are fixedly provided, and on the inner surface of which longitudinal micro-protrusions are fixedly provided.

3. The novel heat exchange element and anti-clogging mechanism for a coal-fired boiler air preheater according to claim 2, characterized in that: The three-dimensional rib has a baffle hole inside, and the baffle hole is rhomboid in shape.

4. The novel heat exchange element and anti-clogging mechanism for a coal-fired boiler air preheater according to claim 1, characterized in that: The anti-clogging mechanism includes a panel and a cleaning pipe. A limit frame is fixedly installed on the side of the panel. A connecting head is provided in the middle of the panel. An air guide pipe is provided on the outside of the connecting head. A straight pipe is connected to the bottom of the cleaning pipe. The outer end of the straight pipe is connected to the connecting head. A reinforcing plate is provided between the straight pipe and the limit frame. A steering component is provided between the straight pipe and the cleaning pipe. Nozzles are provided on both the upper and lower sides of the cleaning pipe.

5. The novel heat exchange element and anti-clogging mechanism for a coal-fired boiler air preheater according to claim 4, characterized in that: The steering assembly includes a steering gear and a drive motor. The steering gear is fixed to the lower part of the sweeping pipe, and the drive motor is fixed to the straight pipe. The drive motor and the steering gear cooperate with each other.

6. The novel heat exchange element and anti-clogging mechanism for a coal-fired boiler air preheater according to claim 5, characterized in that: A flip cover is hinged to the outside of the nozzle, and a torsion spring is provided between the flip cover and the nozzle.

7. The novel heat exchange element and anti-clogging mechanism for a coal-fired boiler air preheater according to claim 6, characterized in that: A positioning seat is fixedly provided on the side of the panel, and a positioning screw is screwed into the positioning seat.

8. The novel heat exchange element and anti-clogging mechanism for a coal-fired boiler air preheater according to claim 7, characterized in that: The preheating box has a slot on the side near the anti-blocking mechanism, the panel has an insert plate on the inside, and the slot has a sealing strip inside.

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