A high efficiency burner for coal-fired unit and method thereof

Abstract

The present invention relates to the technical field of burners, and in particular to a high-efficiency burner and method for a coal-fired unit, which includes a pipeline unit and a diversion unit arranged inside the pipeline unit; the diversion unit diverts and disperses the coal powder inside the pipeline unit, and the coal powder airflow enters from the inlet elbow. During the rapid turning process in the elbow, the coal powder particles are acted upon by centrifugal force and flow along the inner wall near the large diameter end of the inlet elbow, and the first stage of coal powder concentration occurs. Then, the high-concentration coal powder airflow turns rapidly after meeting the concentrator, and the coal powder particles are inertially separated, and the second stage of coal powder concentration occurs, thereby improving the burner's stable combustion capability, so as to achieve the purpose of reducing the minimum stable combustion load to 20% THA, and strengthening the coal powder concentration-grading combustion and stable combustion can be achieved by changing the burner operation nozzle, further enhancing the coal powder ignition stability and reducing the NOx generation effect, and meeting the stable combustion of low-load boilers.

Description

Technical Field

[0001] The invention relates to the technical field of burners, in particular to a high-efficiency burner for a coal-fired unit and a method thereof. Background Art

[0002] In recent years, with the reform of the electricity market and the continuous increase in the proportion of volatile renewable energy generation, a highly coupled "multi-energy complementary" energy structure of fire, heat, wind, light, etc. has gradually formed. Coal-fired power is used as the basic regulating energy and plays a key role in load regulation. However, at this stage, the overall peak-shaving capacity of coal-fired units is far from the target of the minimum technical output (20% to 25%) when stable combustion is achieved without oil injection, and it is difficult to take into account the environmental protection needs of low NOx generation.

[0003] At present, various types of direct current pulverized coal burners still have room for optimization in practical applications: ① The diversity of coal types and the blending of coal need to be further improved. Usually, when burning bituminous coal, it shows good stable combustion characteristics and low NOx emission performance, but when burning difficult-to-burn coal, it is difficult to ensure stable combustion and low NOx emissions at the same time; ② The optimization of the pulverized coal airflow nozzle structure is manifested in paying attention to the role of the pulverized coal concentration separation device, while insufficient consideration is given to the synergistic effect of the pulverized coal airflow nozzle and its downstream reflux zone; ③ It is difficult to meet the requirements of stable combustion and low NOx capabilities for low-load operation. Under low-load operation, on the one hand, the pulverized coal concentration is reduced, which increases the ignition heat, resulting in delayed ignition and poor combustion stability. At the same time, due to the weakening of the reducing high-temperature reflux zone and the increase in the wind-coal ratio under low load, the ability to suppress NOx generation is weakened, resulting in a high NOx generation. Summary of the invention

[0004] In view of the above problems or problems existing in the prior art, the present invention is proposed.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides the following technical solutions: a high-efficiency burner for a coal-fired unit and a method thereof, comprising a pipeline unit and a flow diversion unit disposed inside the pipeline unit;

[0007] The diversion unit diverts and disperses the coal powder inside the pipeline unit.

[0008] As a preferred solution of the high-efficiency burner and method for coal-fired units of the present invention, it further comprises a nozzle unit fixedly connected to the pipeline unit;

[0009] The nozzle unit is used to spray the coal powder inside the pipeline unit.

[0010] As a preferred solution of the high-efficiency burner and method for coal-fired units of the present invention, the pipeline unit includes a coal conveying pipe assembly and a cooling pipe assembly arranged outside the coal conveying pipe assembly;

[0011] The cooling pipe assembly cools down the coal powder inside the coal conveying pipe assembly.

[0012] As a preferred solution of the high-efficiency burner and method for coal-fired units of the present invention, the flow diversion unit includes a group of flow diversion pipe assemblies and a baffle door arranged inside the flow diversion pipe assemblies.

[0013] As a preferred solution of the high-efficiency burner and method for coal-fired units of the present invention, the nozzle unit includes a combustion nozzle assembly arranged at one end of the shunt pipe assembly, and a tuyere assembly arranged at one end of the combustion nozzle assembly;

[0014] The combustion nozzle assembly is used to spray out the coal powder in the diverter pipe assembly.

[0015] As a preferred solution of the high-efficiency burner and method for coal-fired units of the present invention, the coal delivery pipe assembly includes a coal delivery pipe, a diverter box disposed at one end of the coal delivery pipe, and a group of baffles disposed inside the diverter box;

[0016] The cooling pipe assembly includes a first cooling air pipe and a second cooling air pipe, and air doors are arranged inside the first cooling air pipe and the second cooling air pipe.

[0017] As a preferred embodiment of the high-efficiency burner and method for coal-fired units of the present invention, the diverter pipe assembly includes a first diverter pipe and a second diverter pipe, the first cooling air duct is fixedly connected to the first diverter pipe, the second cooling air duct is fixedly connected to the second diverter pipe, and one end of the first diverter pipe and the second diverter pipe are fixedly connected to the diverter box.

[0018] As a preferred solution of the high-efficiency burner and method for coal-fired units of the present invention, baffle doors are arranged inside the first shunt pipe and the second shunt pipe, and the baffle doors are hinged to the first shunt pipe and the second shunt pipe.

[0019] As a preferred solution of the high-efficiency burner and method for coal-fired units of the present invention, the combustion nozzle assembly includes a connecting pipe fixedly arranged at one end of the first shunt pipe and the second shunt pipe, an arc plate is arranged inside the connecting pipe, a flat plate is arranged inside the connecting pipe, and an arc-shaped protrusion is arranged inside the connecting pipe;

[0020] The tuyere assembly includes an outlet panel, a secondary tuyere arranged on one side of the outlet panel, a peripheral tuyere arranged on one side of the outlet panel, a light phase zone outlet arranged on one side of the outlet panel, and a dense phase zone outlet arranged on one side of the outlet panel.

[0021] In a second aspect, the present invention provides the following technical solutions: a high-efficiency burner for a coal-fired unit and a method of using the same, which comprises diverting pulverized coal transported by a pipeline unit through a diverting unit;

[0022] The tuyere assembly can discharge the pulverized coal after diversion by the diversion unit, and burn the pulverized coal through the burner.

[0023] The beneficial effects of the present invention are as follows: the coal powder airflow enters from the inlet elbow, and during the rapid turning process in the elbow, the coal powder particles are acted upon by centrifugal force and flow along the inner wall near the large diameter end of the inlet elbow, and the first stage of coal powder concentration occurs. Then, the high-concentration coal powder airflow rapidly turns after meeting the concentrator, and the coal powder particles are inertially separated, and the second stage of coal powder concentration occurs, thereby improving the burner's stable combustion capability, so as to achieve the purpose of reducing the minimum stable combustion load to 20% THA. Strengthening the graded combustion and stable combustion of coal powder can be achieved by changing the burner's operating nozzle, further enhancing the coal powder ignition stability and reducing the NOx generation effect, and meeting the stable combustion of low-load boilers. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0025] Figure 1 The overall structure of the high-efficiency burner and method for coal-fired units is shown in FIG. Figure 1 .

[0026] Figure 2 The overall structure of the high-efficiency burner and method for coal-fired units is shown in FIG. Figure 2 .

[0027] Figure 3 It is a schematic diagram of some structures.

[0028] Figure 4 This is a schematic diagram of the explosion of part of the structure. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0032] Example 1

[0033] Reference Figure 1 , which is the first embodiment of the present invention, and provides a high-efficiency burner for a coal-fired unit and a method thereof, which includes a pipeline unit 100 and a flow distribution unit 200 disposed inside the pipeline unit 100;

[0034] The flow diversion unit 200 diverts and disperses the pulverized coal inside the pipeline unit 100 .

[0035] It should be noted that the diversion unit 200 can divert the coal powder inside the pipeline unit 100 by being installed at one end of the pipeline unit 100. It can not only divert the coal powder, but also allow it to flow along the inner wall near the large diameter end of the inlet elbow, thereby causing the first stage of coal powder concentration.

[0036] In summary, the beneficial effects of the high-efficiency burner and method for coal-fired units of the present invention are that the coal powder inside the pipeline unit can be diverted through the setting of the diversion unit, and the first stage of concentration can be performed when the coal powder enters the diversion unit and passes through the bend area, thereby increasing the concentration of the coal powder and improving the combustion effect of the coal powder.

[0037] Example 2

[0038] Reference Figure 2-3 , which is the second embodiment of the present invention, and provides a high-efficiency burner for a coal-fired unit and a method thereof, which includes a pipeline unit 100 and a flow distribution unit 200 disposed inside the pipeline unit 100;

[0039] The flow diversion unit 200 diverts and disperses the pulverized coal inside the pipeline unit 100 .

[0040] Preferably, the diversion unit 200 can divert the coal powder inside the pipeline unit 100 by being installed at one end of the pipeline unit 100. It can not only divert the coal powder, but also allow it to flow along the inner wall near the large diameter end of the inlet elbow to achieve the first stage of coal powder concentration.

[0041] Further, a nozzle unit 300 fixedly connected to the pipeline unit 100;

[0042] The nozzle unit 300 is used to spray the pulverized coal inside the pipeline unit 100 .

[0043] Furthermore, the pipeline unit 100 includes a coal conveying pipe assembly 101 and a cooling pipe assembly 102 disposed outside the coal conveying pipe assembly 101.

[0044] The cooling pipe assembly 102 cools the coal powder inside the coal conveying pipe assembly 101 .

[0045] It should be noted that the pipeline unit 100 is arranged at one end of the diversion unit 200. The pipeline unit 100 transports coal powder to the inside of the diversion unit 200 through the coal conveying pipe assembly 101. At the same time, the cooling pipe assembly 102 can cool down the inside of the diversion unit 200 and clean the inside of the diversion unit 200 to prevent the pulverized coal pipe from backfired without coal powder medium and reduce the burning of the inside of the diversion unit 200 by high-temperature flue gas.

[0046] Furthermore, the flow dividing unit 200 includes a group of flow dividing pipe assemblies 201 and a baffle door 202 disposed inside the flow dividing pipe assembly 201 .

[0047] Further, the nozzle unit 300 includes a combustion nozzle assembly 301 disposed at one end of the shunt pipe assembly 201, and a tuyere assembly 302 disposed at one end of the combustion nozzle assembly 301;

[0048] The combustion nozzle assembly 301 is used to spray out the coal powder in the diverter pipe assembly 201 .

[0049] It should be noted that the diverter assembly 201 diverts the pulverized coal transported by the coal conveying pipe assembly 101, so that the pulverized coal airflow enters the corresponding burner for ignition and combustion.

[0050] Preferably, the deep concentrated pulverized coal airflow flows out from the concentrated pulverized coal airflow channel located in the middle, and the formed low-concentration pulverized coal airflow flows out from the channel of the combustion nozzle assembly 301.

[0051] Furthermore, the coal delivery pipe assembly 101 includes a coal delivery pipe 101a, a diverter box 101b disposed at one end of the coal delivery pipe 101a, and a group of baffles 101c disposed inside the diverter box 101b;

[0052] It should be noted that the setting of the diverter box 101b can divert the coal powder transported by the coal delivery pipe 101a. Two baffles 101c are arranged inside the diverter box 101b. The baffles 101c are movably installed and can be opened and closed according to actual conditions during use. The first diverter pipe 201a can be operated alone or the second diverter pipe 201b can be operated alone, or the first diverter pipe 201a and the second diverter pipe 201b can be operated simultaneously according to the load of the unit.

[0053] The cooling pipe assembly 102 includes a first cooling air pipe 102a and a second cooling air pipe 102b. Air doors 102c are disposed inside the first cooling air pipe 102a and the second cooling air pipe 102b.

[0054] It should be noted that the first cooling air duct 102a and the second cooling air duct 102b are both provided with dampers 102c, and the dampers 102c are both hinged inside the first cooling air duct 102a and the second cooling air duct 102b.

[0055] Preferably, the coal conveying pipe assembly 101 can convey the coal powder to the inside of the diversion unit 200, and the cooling pipe assembly 102 can cool the inside of the diversion unit 200 to prevent the coal powder pipe from flashing back without coal powder medium and reduce the burning of the inside of the diversion unit 200 by high-temperature flue gas, thereby extending the service life of the diversion unit 200.

[0056] Furthermore, the diverter pipe assembly 201 includes a first diverter pipe 201a and a second diverter pipe 201b, the first cooling air duct 102a is fixedly connected to the first diverter pipe 201a, the second cooling air duct 102b is fixedly connected to the second diverter pipe 201b, and one end of the first diverter pipe 201a and the second diverter pipe 201b are fixedly connected to the diverter box 101b.

[0057] It should be noted that the first diversion pipe 201a and the second diversion pipe 201b can perform secondary diversion on the pulverized coal diverted from the diversion box 101b.

[0058] Furthermore, a baffle door 202 is provided inside the first diverter pipe 201a and the second diverter pipe 201b, and the baffle door 202 is hinged to the first diverter pipe 201a and the second diverter pipe 201b.

[0059] It should be noted that both the first branch pipe 201a and the second branch pipe 201b are provided with an arc bend, and the setting of the arc bend allows the coal powder to flow on the inner wall close to the large diameter end of the inlet bend pipe, resulting in the first stage of coal powder concentration.

[0060] Preferably, the first diversion pipe 201a and the second diversion pipe 201b are each provided with an arc bend, and the coal powder airflow enters from the inlet arc bend. During the rapid turning process in the arc bend, the coal powder particles are acted upon by centrifugal force and flow along the inner wall near the large diameter end of the inlet arc bend, resulting in the first stage of coal powder concentration.

[0061] Furthermore, the combustion nozzle assembly 301 includes a connecting pipe 301a fixedly arranged at one end of the first shunt pipe 201a and the second shunt pipe 201b, an arc plate 301b is arranged inside the connecting pipe 301a, a flat plate 301c is arranged inside the connecting pipe 301a, and an arc-shaped protrusion 301d is arranged inside the connecting pipe 301a;

[0062] The tuyere assembly 302 includes an outlet panel 302a, a secondary tuyere 302b disposed on one side of the outlet panel 302a, a peripheral tuyere 302c disposed on one side of the outlet panel 302a, a light phase zone outlet 302d disposed on one side of the outlet panel 302a, and a dense phase zone outlet 302e disposed on one side of the outlet panel 302a.

[0063] When in use, coal powder is transported to the diverter pipe assembly 201 through the coal delivery pipe 101a arranged in the coal delivery pipe assembly 101, and is respectively diverted into the first diverter pipe 201a and the second diverter pipe 201b after passing through the diverter box 101b. When passing through the bends arranged in the first diverter pipe 201a and the second diverter pipe 201b, the coal powder particles are subjected to centrifugal force during the rapid turning process in the arc bend, and flow along the inner wall of the large diameter end of the arc bend near the inlet, resulting in the first stage of coal powder concentration. The coal powder is further transported to the combustion nozzle assembly 301 through the first diverter pipe 201a and the second diverter pipe 201b, and is further ejected through the light phase zone outlet 302d and the dense phase zone outlet 302e arranged on the outlet panel 302a.

[0064] In summary, the present invention provides a high-efficiency burner for a coal-fired unit and a method thereof with beneficial effects: the pulverized coal enters the diversion box 101b through the coal delivery pipe 101a and then diverts to the first diversion pipe 201a and the second diversion pipe 201b. During the rapid turning process at the bends set by the first diversion pipe 201a and the second diversion pipe 201b, the pulverized coal particles are acted upon by centrifugal force and flow along the inner wall near the large diameter end of the inlet bend, and the first stage of pulverized coal concentration occurs. Then, the high-concentration pulverized coal airflow turns rapidly after meeting the concentrator, and the pulverized coal particles are denatured and separated, and the second stage of pulverized coal concentration occurs, thereby improving the burner's stable combustion capability to achieve the purpose of reducing the minimum stable combustion load to 20% THA. The pulverized coal concentration-gradient combustion and stable combustion can be enhanced by changing the burner's operating nozzle, further enhancing the pulverized coal ignition stability and reducing the NOx generation effect, thereby meeting the stable combustion of low-load boilers.

[0065] Example 3

[0066] Reference Figure 4 , which is the third embodiment of the present invention, provides a high-efficiency burner for a coal-fired unit and a method of using the same, which includes diverting the pulverized coal transported by the pipeline unit 100 through the diverting unit 200;

[0067] The tuyere assembly 302 can discharge the coal powder diverted by the diversion unit 200 and burn the coal powder through the burner.

[0068] It should be noted that the tuyere assembly 302 is provided with a light phase zone outlet 302d and a dense phase zone outlet 302e, which can increase the combustibility of the coal powder and improve the combustion effect of the coal powder.

[0069] In summary, the beneficial effect of the high-efficiency burner and method for coal-fired units of the present invention is that different coal powders can be discharged through different light phase zone outlets 302d and dense phase zone outlets 302e to increase the combustion effect of the coal powder and improve the combustion stability.

[0070] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A high efficiency burner for a coal-fired unit, characterized in that: include, A pipeline unit (100) and a flow distribution unit (200) arranged inside the pipeline unit (100); The flow diversion unit (200) diverts and disperses the coal powder inside the pipeline unit (100).

2. The high-efficiency burner for a coal-fired unit and the method thereof according to claim 1, characterized in that: It also includes a nozzle unit (300) fixedly connected to the pipeline unit (100); The nozzle unit (300) is used to spray out the coal powder inside the pipeline unit (100).

3. The high-efficiency burner for a coal-fired unit and the method thereof as claimed in claim 2, characterized in that: The pipeline unit (100) comprises a coal conveying pipe assembly (101) and a cooling pipe assembly (102) arranged outside the coal conveying pipe assembly (101). The cooling pipe assembly (102) cools the coal powder inside the coal conveying pipe assembly (101).

4. The high-efficiency burner for a coal-fired unit and the method thereof as claimed in claim 3, characterized in that: The flow distribution unit (200) comprises a group of flow distribution pipe assemblies (201) and a baffle door (202) arranged inside the flow distribution pipe assembly (201).

5. The high-efficiency burner for a coal-fired unit and the method thereof as claimed in claim 4, characterized in that: The nozzle unit (300) comprises a combustion nozzle assembly (301) arranged at one end of the diverter pipe assembly (201), and a tuyere assembly (302) arranged at one end of the combustion nozzle assembly (301); The combustion nozzle assembly (301) is used to spray out the coal powder in the diverter pipe assembly (201).

6. The high-efficiency burner for a coal-fired unit and the method thereof as claimed in claim 5, characterized in that: The coal delivery pipe assembly (101) comprises a coal delivery pipe (101a), a diverter box (101b) arranged at one end of the coal delivery pipe (101a), and a group of blocking plates (101c) arranged inside the diverter box (101b); The cooling pipe assembly (102) comprises a first cooling air pipe (102a) and a second cooling air pipe (102b). Air doors (102c) are arranged inside the first cooling air pipe (102a) and the second cooling air pipe (102b).

7. The high-efficiency burner for a coal-fired unit and the method thereof as claimed in claim 6, characterized in that: The shunt pipe assembly (201) comprises a first shunt pipe (201a) and a second shunt pipe (201b); the first cooling air pipe (102a) is fixedly connected to the first shunt pipe (201a); the second cooling air pipe (102b) is fixedly connected to the second shunt pipe (201b); and one end of each of the first shunt pipe (201a) and the second shunt pipe (201b) is fixedly connected to the shunt box (101b).

8. The high-efficiency burner for a coal-fired unit and the method thereof according to claim 7, characterized in that: The first flow diversion pipe (201a) and the second flow diversion pipe (201b) are both provided with baffle doors (202) inside, and the baffle doors (202) are hingedly connected to the first flow diversion pipe (201a) and the second flow diversion pipe (201b).

9. The high-efficiency burner for a coal-fired unit and the method thereof as claimed in claim 8, characterized in that: The combustion nozzle assembly (301) comprises a connecting pipe (301a) fixedly arranged at one end of the first shunt pipe (201a) and the second shunt pipe (201b), an arc-shaped plate (301b) arranged inside the connecting pipe (301a), a flat plate (301c) arranged inside the connecting pipe (301a), and an arc-shaped protrusion (301d) arranged inside the connecting pipe (301a); The tuyere assembly (302) comprises an outlet panel (302a), a secondary tuyere (302b) arranged on one side of the outlet panel (302a), a peripheral tuyere (302c) arranged on one side of the outlet panel (302a), a light phase zone outlet (302d) arranged on one side of the outlet panel (302a), and a dense phase zone outlet (302e) arranged on one side of the outlet panel (302a).

10. A method of using the high-efficiency burner for a coal-fired unit and the method thereof according to any one of claims 7 to 9, characterized in that: The coal powder transported by the pipeline unit (100) is diverted by the diverting unit (200); The tuyere assembly (302) can discharge the coal powder diverted by the diversion unit (200) and burn the coal powder through the burner.

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