Combination structure of flue gas recirculation and combustion optimization for low calorific value pulverized coal boiler

Abstract

The utility model discloses a low heat value coal powder furnace flue gas recirculation and combustion optimization combined structure, the utility model relates to energy -conserving and environment -friendly technical field. The combined structure, including the combustion furnace, one side of the combustion furnace is provided with the circulating box, and the outside of combustion furnace is provided with circulating assembly, the inside of circulating box is provided with filter assembly, the filter assembly includes first delivery pipe, one end of first delivery pipe is connected with second delivery pipe, and the bottom of second delivery pipe is penetrated to the inside of circulating box, and the high temperature flue gas is extracted from the top end of combustion furnace through first delivery pipe, and the flue gas after purification is sent into from the bottom of combustion furnace in combination with third, fourth delivery pipe, forms the complete flue gas circulation path, and the circulating flue gas sent into the bottom is fully mixed with the new coal powder and air convection, breaks the temperature stratification in the furnace, makes the heat distribution more uniform, improves the combustion fullness of low heat value coal powder, reduces the waste of unburnt coal powder, and improves fuel utilization.

Description

Technical Field

[0001] This utility model relates to the field of energy conservation and environmental protection technology, specifically to an optimized combination structure for flue gas recirculation and combustion in low-calorific-value pulverized coal boilers. Background Technology

[0002] In the energy structure, coal, as an important primary energy source, has always been a key focus in the energy sector for its efficient and clean utilization. Low-calorific-value pulverized coal, due to its low calorific value and poor combustion performance, often faces numerous problems during combustion, becoming a key factor restricting its efficient utilization.

[0003] To improve the combustion efficiency of low-calorific-value pulverized coal, some technologies have attempted to use flue gas recirculation technology, which reintroduces some flue gas into the combustion furnace to regulate the furnace temperature and oxygen concentration and promote the combustion reaction. However, existing flue gas recirculation systems have shortcomings in their structural design, such as unreasonable flue gas extraction and transportation paths, resulting in low flue gas recirculation efficiency and making it difficult to fully exert their optimization effect on combustion. Utility Model Content

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this utility model provides an optimized combination structure for flue gas recirculation and combustion in low-calorific-value pulverized coal boilers. This solves the problem of low flue gas recirculation efficiency caused by unreasonable flue gas extraction and transportation paths, which makes it difficult to fully utilize the optimization effect on combustion.

[0005] (II) Technical Solution To achieve the above objectives, this utility model is implemented through the following technical solution: a combined structure for flue gas recirculation and combustion optimization of a low-calorific-value pulverized coal boiler, including a combustion furnace, a circulation box provided on one side of the combustion furnace, a circulation component provided outside the combustion furnace, and a filter component provided inside the circulation box; The circulation assembly includes a first conveying pipe, one end of which is connected to a second conveying pipe. The bottom of the second conveying pipe extends into the interior of the circulation box for secondary circulation of the flue gas generated inside the combustion furnace. The top of the circulation box is connected to an air inlet pipe, the interior of which is equipped with a filter plate to prevent external gas from bringing in impurities when entering the circulation box. The bottom of the circulation box is connected to a third conveying pipe, one end of which is connected to a blower. One end of the blower is connected to a fourth conveying pipe, which extends into the interior of the combustion furnace for conveying the filtered gas into the combustion furnace.

[0006] Preferably, the first conveying pipe is located at the top of the combustion furnace, and the second conveying pipe is located at the top of the circulation box.

[0007] Preferably, the third conveying pipe is located at the bottom of the circulation box, and the fourth conveying pipe is located at the bottom of the combustion furnace.

[0008] Preferably, the filter assembly includes a slide rod disposed inside the circulation box, a slide box slidably disposed outside the slide rod, the slide box being disposed at the bottom of the support plate, a connecting rod disposed outside the support plate, a handle disposed outside the connecting rod, a squeezing rod disposed inside the door of the circulation box for fixing and limiting the installed filter assembly, a filter barrel disposed inside the support plate, a fixing handle disposed on the top of the filter barrel, and filter cotton disposed inside the filter barrel for filtering the gas in the combustion furnace.

[0009] Preferably, four connecting rods are provided, and both ends of the four connecting rods are fixedly connected to the support plate.

[0010] Preferably, the filter barrel has filter holes inside, and the filter cotton is distributed in a circular array around the central axis of the filter barrel.

[0011] (III) Beneficial Effects This invention provides an optimized combination structure for flue gas recirculation and combustion in a low-calorific-value pulverized coal boiler. It offers the following advantages: (i) The optimized combination structure of flue gas recirculation and combustion in this low-calorific-value pulverized coal boiler draws high-temperature flue gas from the top of the combustion furnace through the first conveying pipe, and sends the purified flue gas from the bottom of the combustion furnace through the third and fourth conveying pipes, forming a complete flue gas circulation path. The circulating flue gas sent from the bottom is fully convected and mixed with the newly added pulverized coal and air, breaking the temperature stratification in the furnace, making the heat distribution more uniform, improving the combustion completeness of low-calorific-value pulverized coal, reducing the waste of unburned pulverized coal, and improving fuel utilization.

[0012] (II) The optimized combination structure of flue gas recirculation and combustion in this low-calorific-value pulverized coal boiler can filter impurities of different particle sizes in stages through the gradually changing pore size of the filter barrel. The circular array of filter cotton can fully adsorb fine particulate matter, achieving deep purification of the circulating flue gas. At the same time, the filter plate of the air inlet pipe filters impurities in the external air, preventing impurities from entering the system and causing secondary pollution. The flue gas that has undergone dual filtration re-enters the combustion furnace, reducing the emission concentration of pollutants, mitigating the impact on the environment, and meeting environmental protection requirements. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the cross-sectional structure of the circulation box of this utility model; Figure 3 This is a schematic diagram of the structure of the circulation component of this utility model; Figure 4This is a schematic diagram of the structure of the filter assembly of this utility model; Figure 5 This is a schematic diagram of the structure of the bearing plate of this utility model; Figure 6 This is a schematic diagram of the structure of the filter barrel of this utility model.

[0014] In the diagram: 1. Combustion furnace; 2. Circulation box; 3. Circulation assembly; 4. Filter assembly; 311. First conveying pipe; 312. Second conveying pipe; 313. Air inlet pipe; 314. Filter plate; 321. Third conveying pipe; 322. Blower; 323. Fourth conveying pipe; 411. Slide rod; 412. Slide box; 413. Support plate; 414. Connecting rod; 415. Handle; 421. Extrusion rod; 422. Filter barrel; 423. Fixing handle; 424. Filter cotton. Detailed Implementation

[0015] 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.

[0016] Please see Figure 1-6 This utility model provides a technical solution: a combined structure for flue gas recirculation and combustion optimization of low calorific value pulverized coal boiler, including a combustion furnace 1, a circulation box 2 on one side of the combustion furnace 1, a circulation component 3 on the outside of the combustion furnace 1, and a filter component 4 inside the circulation box 2. The circulation assembly 3 includes a first conveying pipe 311, one end of which is connected to a second conveying pipe 312. The bottom of the second conveying pipe 312 extends into the interior of the circulation box 2 for secondary circulation of the flue gas generated inside the combustion furnace 1. The top of the circulation box 2 is connected to an air inlet pipe 313, and a filter plate 314 is installed inside the air inlet pipe 313 to prevent external gas from bringing in impurities when entering the circulation box 2. The bottom of the circulation box 2 is connected to a third conveying pipe 321, one end of which is connected to a blower 322. One end of the blower 322 is connected to a fourth conveying pipe 323, which extends into the interior of the combustion furnace 1 for conveying the filtered gas into the combustion furnace 1.

[0017] The first conveying pipe 311 is located at the top of the combustion furnace 1, and the second conveying pipe 312 is located at the top of the circulation box 2. Since hot flue gas has a natural tendency to rise, placing the first conveying pipe 311 at the top can capture high-temperature flue gas more efficiently, reduce the retention loss of flue gas in the furnace, and improve the initial collection efficiency of flue gas recirculation. The second conveying pipe 312 is located at the top of the circulation box 2, which allows the flue gas introduced from the first conveying pipe 311 to sink naturally by gravity and form more sufficient contact with the filter components 4 in the circulation box 2, avoiding filtration dead zones caused by airflow turbulence, and reducing energy loss during flue gas conveying.

[0018] The third conveying pipe 321 is located at the bottom of the circulation box 2, and the fourth conveying pipe 323 is located at the bottom of the combustion furnace 1. Because the filtered flue gas will gather at the bottom of the circulation box 2 under the action of gravity, the conveying pipes arranged at the bottom can reduce the amount of residual flue gas and improve the flue gas recycling rate. The fourth conveying pipe 323 is located at the bottom of the combustion furnace 1, which is in line with the airflow circulation pattern in the combustion furnace 1. The circulating flue gas sent from the bottom can form a strong convection mixing with the newly entered coal powder and air, promoting the full combustion reaction.

[0019] The filter assembly 4 includes a slide rod 411 disposed inside the circulation box 2, a slide box 412 slidably disposed outside the slide rod 411, the slide box 412 being disposed at the bottom of the support plate 413, a connecting rod 414 disposed outside the support plate 413, a handle 415 disposed outside the connecting rod 414, a squeezing rod 421 disposed inside the door of the circulation box 2 for fixing and limiting the installed filter assembly 4, a filter bucket 422 disposed inside the support plate 413, a fixing handle 423 disposed on the top of the filter bucket 422, and filter cotton 424 disposed inside the filter bucket 422 for filtering the gas in the combustion furnace 1.

[0020] Four connecting rods 414 are provided, and both ends of the four connecting rods 414 are fixedly connected to the support plate 413. The four-rod connection can evenly distribute the weight of the support plate 413 and the filter box 422, avoid structural deformation caused by excessive force at a single point, and enhance the stability of the filter assembly 4 during the sliding process. At the same time, the symmetrically distributed connecting rods 414 can ensure the force balance of the support plate 413 when sliding on the slide rod 411, reduce frictional resistance, make the cleaning and replacement operation of the filter box 422 smoother and less labor-intensive, and extend the service life of the equipment.

[0021] The filter barrel 422 has filter holes inside, and the filter cotton 424 is distributed in a circular array around the central axis of the filter barrel 422. These filter holes adopt a gradually decreasing aperture design, with the aperture gradually decreasing from the flue gas inlet end to the outlet end, which can realize the graded filtration of impurities of different particle sizes and improve the filtration efficiency. The circular array distribution of the filter cotton 424 around the central axis of the filter barrel 422 allows the flue gas to form a symmetrical airflow field within the filter barrel 422, ensuring that the filter cotton 424 in each area can play its full role and avoiding the overall filtration effect being affected by excessive load on local filter cotton 424. The circular array structure also facilitates the installation and replacement of filter cotton 424, reducing maintenance costs.

[0022] In use, the hot flue gas generated by the combustion of pulverized coal in the combustion furnace 1 gathers upward due to its natural rising characteristics. The first conveying pipe 311 located at the top of the combustion furnace 1 efficiently captures this high-temperature flue gas and introduces it into the second conveying pipe 312. Since the second conveying pipe 312 is located at the top of the circulation box 2, the flue gas can naturally sink into the interior of the circulation box 2 by gravity, and in this process, it fully contacts the filter components 4 in the circulation box 2. Meanwhile, the air inlet pipe 313 at the top of the circulation box 2 introduces external air. The air is first filtered through the filter holes of the filter plate 314 to remove impurities, preventing impurities from entering the system and affecting the operation of the equipment. After the flue gas entering the circulation box 2 mixes with the air, it flows through the filter barrel 422 in the filter assembly 4. The filter holes inside the filter barrel 422 adopt a gradient pore size design, which can filter impurities of different particle sizes in stages. The filter cotton 424 distributed in a circular array along the central axis further adsorbs fine particulate matter in the flue gas, ensuring that the flue gas is fully purified.

[0023] The purified flue gas gathers at the bottom of the circulation box 2 under the action of gravity. At this time, the third conveying pipe 321 at the bottom of the circulation box 2 draws out the clean flue gas, which is then pressurized by the blower 322 and sent into the bottom of the combustion furnace 1 through the fourth conveying pipe 323. The circulating flue gas sent from the bottom forms a strong convective mixture with the newly entered pulverized coal and air, breaking the temperature stratification in the combustion furnace 1, making the heat distribution more uniform, promoting the combustion reaction to proceed fully, and thus achieving combustion optimization.

[0024] When the filter cartridge 422 needs to be cleaned or replaced, the door on one side of the circulation box 2 can be opened, and the support plate 413 can be pulled by the handle 415 on the outside of the connecting rod 414. The sliding box 412 at the bottom of the support plate 413 slides along the sliding rod 411, which moves the filter cartridge 422 out of the circulation box 2. When the door is closed, the squeezing rod 421 inside the door can form a stable limit on the support plate 413, ensuring the structural stability of the filter assembly 4 during operation. The four symmetrically distributed connecting rods 414 ensure the force balance of the support plate 413 during the sliding process, making the operation smoother.

[0025] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0026] 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 combined structure for flue gas recirculation and combustion optimization of a low-calorific-value pulverized coal boiler, comprising a combustion furnace (1), wherein a circulation box (2) is provided on one side of the combustion furnace (1), characterized in that: The combustion furnace (1) is provided with a circulation component (3) on the outside, and the circulation box (2) is provided with a filter component (4) inside. The circulation assembly (3) includes a first conveying pipe (311), one end of which is connected to a second conveying pipe (312). The bottom of the second conveying pipe (312) extends into the interior of the circulation box (2) for secondary circulation of the flue gas generated inside the combustion furnace (1). The top of the circulation box (2) is connected to an air inlet pipe (313), and a filter plate (314) is installed inside the air inlet pipe (313) to prevent external gas from bringing in impurities when it enters the circulation box (2). The bottom of the circulation box (2) is connected to a third conveying pipe (321), one end of which is connected to a blower (322), and one end of the blower (322) is connected to a fourth conveying pipe (323). The fourth conveying pipe (323) extends into the interior of the combustion furnace (1) for conveying the filtered gas into the combustion furnace (1).

2. The optimized combination structure of low-calorific-value pulverized coal boiler flue gas recirculation and combustion according to claim 1, characterized in that: The first conveying pipe (311) is located at the top of the combustion furnace (1), and the second conveying pipe (312) is located at the top of the circulation box (2).

3. The optimized combination structure of low-calorific-value pulverized coal boiler flue gas recirculation and combustion according to claim 1, characterized in that: The third conveying pipe (321) is located at the bottom of the circulation box (2), and the fourth conveying pipe (323) is located at the bottom of the combustion furnace (1).

4. The optimized combination structure of low-calorific-value pulverized coal boiler flue gas recirculation and combustion according to claim 1, characterized in that: The filter assembly (4) includes a slide rod (411) disposed inside the circulation box (2), a slide box (412) slidably disposed outside the slide rod (411), the slide box (412) being disposed at the bottom of the support plate (413), a connecting rod (414) being disposed outside the support plate (413), a handle (415) being disposed outside the connecting rod (414), a squeezing rod (421) being disposed inside the door of the circulation box (2) for fixing and limiting the installed filter assembly (4), a filter bucket (422) being disposed inside the support plate (413), a fixing handle (423) being disposed on the top of the filter bucket (422), and filter cotton (424) being disposed inside the filter bucket (422) for filtering the gas in the combustion furnace (1).

5. The optimized combination structure of flue gas recirculation and combustion in a low-calorific-value pulverized coal boiler according to claim 4, characterized in that: Four connecting rods (414) are provided, and both ends of the four connecting rods (414) are fixedly connected to the support plate (413).

6. The optimized combination structure of flue gas recirculation and combustion in a low-calorific-value pulverized coal boiler according to claim 4, characterized in that: The filter barrel (422) has filter holes inside, and the filter cotton (424) is distributed in a circular array around the central axis of the filter barrel (422).

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